117 results on '"Carter AM"'
Search Results
2. P2X4 Purinergic Receptors as a Therapeutic Target in Aggressive Prostate Cancer
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Janielle P. Maynard, Igor Vidal, Kempski R, Sosa R, Carter Am, Luke Mummert, Jiayun Lu, Karen S. Sfanos, De Marzo Am, Tamara L. Lotan, Jessica L. Hicks, Corinne E. Joshu, Lauren B. Peiffer, and Ali T
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biology ,business.industry ,Purinergic receptor ,Cancer ,Cell migration ,urologic and male genital diseases ,medicine.disease ,Metastasis ,Prostate cancer ,DU145 ,LNCaP ,biology.protein ,Cancer research ,Medicine ,PTEN ,business - Abstract
Prostate cancer (PCa) remains a leading cause of cancer-related deaths in American men and treatment options for metastatic PCa are limited. There is a critical need to identify new mechanisms that contribute to PCa progression, that distinguish benign from lethal disease, and that have potential for therapeutic targeting. P2X4 belongs to the P2 purinergic receptor family that is commonly upregulated in cancer and is associated with poorer outcomes. Herein, we report that the P2X4 purinergic receptor is overexpressed in PCa, associated with PCa metastasis, and a driver of tumor development in vivo. We observed P2X4 protein expression primarily in epithelial cells of the prostate, a subset of CD66+ neutrophils, and most CD68+ macrophages. Our analysis of tissue microarrays representing 491 PCa cases demonstrated significantly elevated P2X4 expression in cancer compared to benign tissue spots, in prostatic intraepithelial neoplasia, in cancer from White compared to Black men, and in PCa with ERG positivity or with PTEN loss. High P2X4 expression in benign tissues was likewise associated with the development of metastasis after radical prostatectomy. Treatment with P2X4-specific agonist CTP increased transwell migration and invasion of PC3, DU145, and CWR22Rv1 PCa cells. P2X4 antagonist 5-BDBD treatment resulted in a dose-dependent decrease in viability of PC3, DU145, LNCaP, CWR22Rv1, TRAMP-C2, Myc-CaP, BMPC1, and BMPC2 cells and decreased DU145 cell migration and invasion. Knockdown of P2X4 attenuated growth, migration, and invasion of PCa cells. Finally, knockdown of P2X4 in Myc-CaP cells resulted in significantly attenuated subcutaneous allograft growth in FVB/NJ mice. Collectively, these data strongly support a role for the P2X4 purinergic receptor in PCa aggressiveness and identifies P2X4 as a candidate for therapeutic targeting.
- Published
- 2021
3. Causal effect of plasminogen activator inhibitor type 1 on coronary heart disease
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Song, C, Burgess, S, Eicher, JD, O'Donnell, CJ, Johnson, AD, Huang, J, Sabater-Lleal, M, Asselbergs, FW, Tregouet, D, Shin, SY, Ding, J, Baumert, J, Oudot-Mellakh, T, Folkersen, L, Smith, NL, Williams, SM, Ikram, MA, Kleber, ME, Becker, DM, Truong, V, Mychaleckyj, JC, Tang, W, Yang, Q, Sennblad, B, Moore, JH, Williams, FMK, Dehghan, A, Silbernagel, G, Schrijvers, EMC, Smith, S, Karakas, M, Tofler, GH, Silveira, A, Navis, GJ, Lohman, K, Chen, MH, Peters, A, Goel, A, Hopewell, JC, Chambers, JC, Saleheen, D, Lundmark, P, Psaty, BM, Strawbridge, RJ, Boehm, BO, Carter, AM, Meisinger, C, Peden, JF, Bis, JC, McKnight, B, Öhrvik, J, Taylor, K, Franzosi, MG, Seedorf, U, Collins, R, Franco-Cereceda, A, Syvänen, AC, Goodall, AH, Yanek, LR, Cushman, M, Müller-Nurasyid, M, Folsom, AR, Basu, S, Matijevic, N, Van Gilst, WH, Kooner, JS, Danesh, J, Clarke, R, Meigs, JB, Kathiresan, S, Reilly, MP, Klopp, N, Harris, TB, Winkelmann, BR, Grant, PJ, Hillege, HL, Watkins, H, Spector, TD, Becker, LC, Tracy, RP, März, W, Uitterlinden, AG, Eriksson, P, Cambien, F, Morange, PE, Koenig, W, Soranzo, N, Van der Harst, P, Liu, Y, Hamsten, A, Ehret, GB, Munroe, PB, Rice, KM, Bochud, M, Chasman, DI, Smith, AV, Epidemiology, Internal Medicine, Radiology & Nuclear Medicine, Virology, Clinical Genetics, Obstetrics & Gynecology, and Gastroenterology & Hepatology
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0301 basic medicine ,Blood Glucose ,Aging ,Cardiac & Cardiovascular Systems ,Epidemiology ,medicine.medical_treatment ,Genome-wide association study ,Coronary Disease ,Review ,Coronary Artery Disease ,030204 cardiovascular system & hematology ,Cardiorespiratory Medicine and Haematology ,Cardiovascular ,chemistry.chemical_compound ,0302 clinical medicine ,Risk Factors ,single nucleotide polymorphism ,GENETIC-VARIANTS ,Odds Ratio ,ARTERY-DISEASE ,METABOLIC SYNDROME ,genome‐wide association study ,INSULIN-RESISTANCE ,education.field_of_study ,Systematic Review and Meta‐Analysis ,Fibrinolysis ,Incidence ,Mendelian Randomization Analysis ,Single Nucleotide ,C-REACTIVE PROTEIN ,3. Good health ,Observational Studies as Topic ,plasminogen activator inhibitor type 1 ,Heart Disease ,CARDIOVASCULAR-DISEASE ,Plasminogen activator inhibitor-1 ,Cardiology ,Cardiology and Cardiovascular Medicine ,Risk assessment ,Lipoproteins, HDL ,Life Sciences & Biomedicine ,medicine.medical_specialty ,HDL ,Lipoproteins ,Population ,Polymorphism, Single Nucleotide ,Risk Assessment ,03 medical and health sciences ,Genetic, Association Studies ,Clinical Research ,Internal medicine ,Mendelian randomization ,Plasminogen Activator Inhibitor 1 ,Journal Article ,medicine ,Humans ,Genetic Predisposition to Disease ,GENOME-WIDE ASSOCIATION ,Polymorphism ,coronary heart disease ,education ,Heart Disease - Coronary Heart Disease ,Science & Technology ,genome-wide association study ,business.industry ,coronary heart disease ■ genome‐wide association study ■ Mendelian randomization ■ plasminogen activator inhibitor type 1 ■ single nucleotide polymorphism ,Odds ratio ,SUMMARIZED DATA ,030104 developmental biology ,Endocrinology ,MYOCARDIAL-INFARCTION ,chemistry ,Multivariate Analysis ,Cardiovascular System & Cardiology ,business ,Biomarkers ,Genome-Wide Association Study - Abstract
Background Plasminogen activator inhibitor type 1 ( PAI ‐1) plays an essential role in the fibrinolysis system and thrombosis. Population studies have reported that blood PAI ‐1 levels are associated with increased risk of coronary heart disease ( CHD ). However, it is unclear whether the association reflects a causal influence of PAI ‐1 on CHD risk. Methods and Results To evaluate the association between PAI ‐1 and CHD , we applied a 3‐step strategy. First, we investigated the observational association between PAI ‐1 and CHD incidence using a systematic review based on a literature search for PAI ‐1 and CHD studies. Second, we explored the causal association between PAI ‐1 and CHD using a Mendelian randomization approach using summary statistics from large genome‐wide association studies. Finally, we explored the causal effect of PAI ‐1 on cardiovascular risk factors including metabolic and subclinical atherosclerosis measures. In the systematic meta‐analysis, the highest quantile of blood PAI ‐1 level was associated with higher CHD risk comparing with the lowest quantile (odds ratio=2.17; 95% CI: 1.53, 3.07) in an age‐ and sex‐adjusted model. The effect size was reduced in studies using a multivariable‐adjusted model (odds ratio=1.46; 95% CI : 1.13, 1.88). The Mendelian randomization analyses suggested a causal effect of increased PAI ‐1 level on CHD risk (odds ratio=1.22 per unit increase of log‐transformed PAI ‐1; 95% CI : 1.01, 1.47). In addition, we also detected a causal effect of PAI ‐1 on elevating blood glucose and high‐density lipoprotein cholesterol. Conclusions Our study indicates a causal effect of elevated PAI ‐1 level on CHD risk, which may be mediated by glucose dysfunction.
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- 2017
4. Genetic predictors of fibrin D-dimer levels in healthy adults.
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Smith NL, Huffman JE, Strachan DP, Huang J, Dehghan A, Trompet S, Lopez LM, Shin SY, Baumert J, Vitart V, Bis JC, Wild SH, Rumley A, Yang Q, Uitterlinden AG, Stott DJ, Davies G, Carter AM, Thorand B, and Polasek O
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- 2011
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5. Reevaluation of the interaction between HLA-DRB1 shared epitope alleles, PTPN22, and smoking in determining susceptibility to autoantibody-positive and autoantibody-negative rheumatoid arthritis in a large UK Caucasian population.
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Morgan AW, Thomson W, Martin SG, Carter AM, Erlich HA, Barton A, Hocking L, Reid DM, Harrison P, Wordsworth P, Steer S, Worthington J, Emery P, Wilson AG, Barrett JH, and Yorkshire Early Arthritis Register ConsortiumMembers of the YEAR Consortium and the UK Rheumatoid Arthritis Genetics Consortium are listed in Appendices A and B, respectively
- Abstract
OBJECTIVE: To define interactions between the HLA-DRB1 shared epitope (SE), PTPN22, and smoking in cyclic citrullinated peptide (CCP) antibody- and rheumatoid factor (RF)-positive and -negative rheumatoid arthritis (RA). METHODS: Data on approximately 5,000 RA patients and approximately 3,700 healthy controls recruited from 6 centers in the UK were analyzed; not all centers had both genotype data and smoking data available for study. The magnitude of association was assessed in autoantibody-positive and -negative subgroups. The effect of smoking on antibody status among cases was assessed following adjustment for year of birth and center, using Mantel-Haenszel analysis. Analyses of the combined effects of PTPN22, HLA-DRB1 SE, and smoking were performed using additive and multiplicative models of interaction within a logistic regression framework. RESULTS: The combined effects of PTPN22, HLA-DRB1 SE, and smoking were defined, with no evidence of departure from a multiplicative model. Within the case population, all 3 factors were independently associated with the generation of CCP antibodies (odds ratio [OR] 11.1, P < 0.0001), whereas only HLA-DRB1 SE and smoking were independently associated with RF production (OR 4.4, P < 0.0001). There was some evidence of increasing likelihood of antibody positivity with heavier smoking. Finally, we demonstrated that smoking was associated with the generation of both CCP and RF antibodies (OR 1.7, P = 0.0001). CONCLUSION: PTPN22 appears to be primarily associated with anticitrulline autoimmunity, whereas HLA-DRB1 SE is independently associated with RF. This study has confirmed associations of specific gene-environment combinations with a substantially increased risk of developing RA. Further work is needed to determine how these data can be used to inform clinical practice. [ABSTRACT FROM AUTHOR]
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- 2009
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6. Complement C3 and C-reactive protein are elevated in South Asians independent of a family history of stroke.
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Somani R, Grant PJ, Kain K, Catto AJ, Carter AM, Somani, Riyaz, Grant, Peter J, Kain, Kirti, Catto, Andrew J, and Carter, Angela M
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- 2006
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7. Elevated C-reactive protein and long-term mortality after ischaemic stroke: relationship with markers of endothelial cell and platelet activation.
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Shantikumar S, Grant PJ, Catto AJ, Bamford JM, Carter AM, Shantikumar, Saran, Grant, Peter J, Catto, Andrew J, Bamford, John M, and Carter, Angela M
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- 2009
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8. Reply to Hu: Postdoctoral consortia remove barriers to retention and effectively prepare participants for career advancement.
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Lowman HE, DeSiervo M, Hall RO Jr, Jahner JP, Jimoh SO, Laughlin DC, Patterson AC, Weiss-Lehman C, Barbosa CC, Bell KL, Blaszczak JR, Buerkle CA, Carter AM, Collins SM, DeLeo V, Dunkle M, Gannon D, Grames EM, Harrison JG, McFarlane SE, Oleksy I, Powers BF, Ray C, Stears A, Summers B, Torrens CL, Trentman M, Werner CM, and Shoemaker LG
- Abstract
Competing Interests: Competing interests statement:The authors declare no competing interest.
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- 2024
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9. Collaborative consortia can boost postdoctoral workforce development.
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Lowman HE, DeSiervo M, Hall RO Jr, Jahner JP, Jimoh SO, Laughlin DC, Patterson AC, Weiss-Lehman C, Barbosa CC, Bell KL, Blaszczak JR, Buerkle CA, Carter AM, Collins SM, DeLeo V, Dunkle M, Gannon D, Grames EM, Harrison JG, McFarlane SE, Oleksy I, Powers BF, Ray C, Stears A, Summers B, Torrens CL, Trentman M, Werner CM, and Shoemaker LG
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- Humans, Research Personnel, Education, Graduate, Workforce, Cooperative Behavior
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Competing Interests: Competing interests statement:The authors declare no existing or potential competing interest.
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- 2024
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10. Surveillance for Coccidioidomycosis, Histoplasmosis, and Blastomycosis During the COVID-19 Pandemic - United States, 2019-2021.
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Williams SL, Smith DJ, Benedict K, Ahlers JR, Austin C, Birn R, Carter AM, Christophe NN, Cibulskas K, Cieslak PR, Gibbons-Burgener SN, Gosciminski M, Ireland MJ, Lazenby KV, Loftus T, Lunquest K, Mathewson AA, Nguyen AD, Oltean HN, Osborn B, Petro EM, Power DJ, Reik RR, Schlosser L, Sedivy J, Smelser CB, Chiller T, and Toda M
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- Humans, United States epidemiology, Pandemics, Blastomycosis epidemiology, Histoplasmosis diagnosis, Histoplasmosis epidemiology, Histoplasmosis microbiology, Coccidioidomycosis diagnosis, Coccidioidomycosis epidemiology, COVID-19 epidemiology, Respiratory Tract Infections epidemiology
- Abstract
Coccidioidomycosis, histoplasmosis, and blastomycosis are lower respiratory tract fungal infections whose signs and symptoms can resemble those of other respiratory illnesses, including pneumonia caused by bacterial or viral etiologies; this overlap in clinical presentation might lead to missed or delayed diagnoses. The causative fungi live in the environment, often in soil or plant matter. To describe the epidemiologic characteristics of cases of coccidioidomycosis, histoplasmosis, and blastomycosis during the COVID-19 pandemic, CDC analyzed case surveillance data for 2019-2021. During this period, a total of 59,655 coccidioidomycosis cases, 3,595 histoplasmosis cases, and 719 blastomycosis cases were reported to CDC. In 2020, fewer cases of each disease occurred in spring compared with other seasons, and most cases occurred in fall; national seasonality is not typically observed, and cases were seasonally distributed more evenly in 2019 and 2021. Fewer cases coinciding with the start of the COVID-19 pandemic, along with an unusually high blastomycosis case fatality rate in 2021 (17% compared with more typical rates of 8%-10%), suggest that the pandemic might have affected patients' health care-seeking behavior, public health reporting practices, or clinical management of these diseases. Increased awareness and education are needed to encourage health care providers to consider fungal diseases and to identify pneumonia of fungal etiology. Standardized diagnostic guidance and informational resources for fungal testing could be incorporated into broader respiratory disease awareness and preparedness efforts to improve early diagnosis of coccidioidomycosis, histoplasmosis, and blastomycosis., Competing Interests: All authors have completed and submitted the International Committee of Medical Journal Editors form for disclosure of potential conflicts of interest. No potential conflicts of interest were disclosed.
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- 2024
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11. Daily SARS-CoV-2 Nasal Antigen Tests Miss Infected and Presumably Infectious People Due to Viral Load Differences among Specimen Types.
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Viloria Winnett A, Akana R, Shelby N, Davich H, Caldera S, Yamada T, Reyna JRB, Romano AE, Carter AM, Kim MK, Thomson M, Tognazzini C, Feaster M, Goh YY, Chew YC, and Ismagilov RF
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- Humans, Cross-Sectional Studies, Longitudinal Studies, Viral Load, SARS-CoV-2, COVID-19 diagnosis
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In a recent household transmission study of SARS-CoV-2, we found extreme differences in SARS-CoV-2 viral loads among paired saliva, anterior nares swab (ANS), and oropharyngeal swab specimens collected from the same time point. We hypothesized these differences may hinder low-analytical-sensitivity assays (including antigen rapid diagnostic tests [Ag-RDTs]) by using a single specimen type (e.g., ANS) from reliably detecting infected and infectious individuals. We evaluated daily at-home ANS Ag-RDTs (Quidel QuickVue) in a cross-sectional analysis of 228 individuals and a longitudinal analysis (throughout infection) of 17 individuals enrolled early in the course of infection. Ag-RDT results were compared to reverse transcription-quantitative PCR (RT-qPCR) results and high, presumably infectious viral loads (in each, or any, specimen type). The ANS Ag-RDT correctly detected only 44% of time points from infected individuals on cross-sectional analysis, and this population had an inferred limit of detection of 7.6 × 10
6 copies/mL. From the longitudinal cohort, daily Ag-RDT clinical sensitivity was very low (<3%) during the early, preinfectious period of the infection. Further, the Ag-RDT detected ≤63% of presumably infectious time points. The poor observed clinical sensitivity of the Ag-RDT was similar to what was predicted based on quantitative ANS viral loads and the inferred limit of detection of the ANS Ag-RDT being evaluated, indicating high-quality self-sampling. Nasal Ag-RDTs, even when used daily, can miss individuals infected with the Omicron variant and even those presumably infectious. Evaluations of Ag-RDTs for detection of infected or infectious individuals should be compared with a composite (multispecimen) infection status to correctly assess performance. IMPORTANCE We reveal three findings from a longitudinal study of daily nasal antigen rapid diagnostic test (Ag-RDT) evaluated against SARS-CoV-2 viral load quantification in three specimen types (saliva, nasal swab, and throat swab) in participants enrolled at the incidence of infection. First, the evaluated Ag-RDT showed low (44%) clinical sensitivity for detecting infected persons at all infection stages. Second, the Ag-RDT poorly detected (≤63%) time points that participants had high and presumably infectious viral loads in at least one specimen type. This poor clinical sensitivity to detect infectious individuals is inconsistent with the commonly held view that daily Ag-RDTs have near-perfect detection of infectious individuals. Third, use of a combination nasal-throat specimen type was inferred by viral loads to significantly improve Ag-RDT performance to detect infectious individuals., Competing Interests: The authors declare a conflict of interest. R.F.I. is a co-founder, consultant, and a director and has stock ownership of Talis Biomedical Corp. All other authors declare that they have no competing interests.- Published
- 2023
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12. Bile acids modulate reinstatement of cocaine conditioned place preference and accumbal dopamine dynamics without compromising appetitive learning.
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Zanella D, Smith NK, Hardaway JA, Buchanan AM, Mullins CH, Galli A, and Carter AM
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- Animals, Mice, Bile Acids and Salts, Dopamine, Learning, Conditioning, Classical, Cocaine pharmacology, Central Nervous System Stimulants
- Abstract
Psychostimulants target the dopamine transporter (DAT) to elicit their psychomotor actions. Bile acids (BAs) can also bind to DAT and reduce behavioral responses to cocaine, suggesting a potential therapeutic application of BAs in psychostimulant use disorder. Here, we investigate the potential of BAs to decrease drug-primed reinstatement when administered during an abstinence phase. To do this, after successful development of cocaine-associated contextual place preference (cocaine CPP), cocaine administration was terminated, and animals treated with vehicle or obeticholic acid (OCA). When preference for the cocaine-associated context was extinguished, mice were challenged with a single priming dose of cocaine, and reinstatement of cocaine-associated contextual preference was measured. Animals treated with OCA demonstrate a significantly lower reinstatement for cocaine CPP. OCA also impairs the ability of cocaine to reduce the clearance rate of electrically stimulated dopamine release and diminishes the area under the curve (AUC) observed with amperometry. Furthermore, the AUC of the amperometric signal positively correlates with the reinstatement index. Using operant feeding devices, we demonstrate that OCA has no effect on contextual learning or motivation for natural rewards. These data highlight OCA as a potential therapeutic for cocaine use disorder., (© 2023. Springer Nature Limited.)
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- 2023
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13. I W Rowlands, Barbara J Weir and the biology of the hystricomorph rodents.
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Carter AM, Acuña F, and Barbeito CG
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- Male, Pregnancy, Guinea Pigs, Female, Animals, Corpus Luteum, Fetus, Biology, Rodentia, Placenta
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In Brief: Current research on the genomics, ecology and reproductive biology of hystricomorph rodents relies on the pioneering studies of B J Weir and I W Rowlands. We show the enduring influence of a symposium on hystricomorph biology held 50 years ago., Abstract: The rodent suborder Hystricomorpha comprises seven families from Africa and Asia and ten from South America, where they have undergone an extensive radiation and occupy a variety of biomes. Although the guinea pig was a common laboratory rodent, little was known about reproductive biology in the other species until the ambitious research programme of Barbara Weir and her mentor I W Rowlands. Much of their work and of others then in the field was summarized at a symposium held 50 years ago at The Zoological Society of London. Currently, there is a resurgence of interest in the reproductive biology of the South American species. Compared to other rodents, unique features include a long gestation, a long oestrous cycle, a tendency to form accessory corpora lutea and a vaginal closure membrane. There is a distinctive placental structure, the subplacenta. Most give birth to precocial young. Individual species exhibit peculiarities such as polyovulation, systematic fetal loss and an active female prostate. Here, we highlight the achievements of Barbara Weir and show how her legacy has been sustained in the twenty-first century by South American scientists.
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- 2023
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14. Extreme differences in SARS-CoV-2 viral loads among respiratory specimen types during presumed pre-infectious and infectious periods.
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Viloria Winnett A, Akana R, Shelby N, Davich H, Caldera S, Yamada T, Reyna JRB, Romano AE, Carter AM, Kim MK, Thomson M, Tognazzini C, Feaster M, Goh YY, Chew YC, and Ismagilov RF
- Abstract
SARS-CoV-2 viral-load measurements from a single-specimen type are used to establish diagnostic strategies, interpret clinical-trial results for vaccines and therapeutics, model viral transmission, and understand virus-host interactions. However, measurements from a single-specimen type are implicitly assumed to be representative of other specimen types. We quantified viral-load timecourses from individuals who began daily self-sampling of saliva, anterior-nares (nasal), and oropharyngeal (throat) swabs before or at the incidence of infection with the Omicron variant. Viral loads in different specimen types from the same person at the same timepoint exhibited extreme differences, up to 10
9 copies/mL. These differences were not due to variation in sample self-collection, which was consistent. For most individuals, longitudinal viral-load timecourses in different specimen types did not correlate. Throat-swab and saliva viral loads began to rise as many as 7 days earlier than nasal-swab viral loads in most individuals, leading to very low clinical sensitivity of nasal swabs during the first days of infection. Individuals frequently exhibited presumably infectious viral loads in one specimen type while viral loads were low or undetectable in other specimen types. Therefore, defining an individual as infectious based on assessment of a single-specimen type underestimates the infectious period, and overestimates the ability of that specimen type to detect infectious individuals. For diagnostic COVID-19 testing, these three single-specimen types have low clinical sensitivity, whereas a combined throat-nasal swab, and assays with high analytical sensitivity, was inferred to have significantly better clinical sensitivity to detect presumed pre-infectious and infectious individuals., (© The Author(s) 2023. Published by Oxford University Press on behalf of National Academy of Sciences.)- Published
- 2023
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15. The trophoblast giant cells of cricetid rodents.
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Favaron PO and Carter AM
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Giant cells are a prominent feature of placentation in cricetid rodents. Once thought to be maternal in origin, they are now known to be trophoblast giant cells (TGCs). The large size of cricetid TGCs and their nuclei reflects a high degree of polyploidy. While some TGCs are found at fixed locations, others migrate throughout the placenta and deep into the uterus where they sometimes survive postpartum . Herein, we review the distribution of TGCs in the placenta of cricetids, including our own data from the New World subfamily Sigmodontinae, and attempt a comparison between the TGCs of cricetid and murid rodents. In both families, parietal TGCs are found in the parietal yolk sac and as a layer between the junctional zone and decidua. In cricetids alone, large numbers of TGCs, likely from the same lineage, accumulate at the edge of the placental disk. Common to murids and cricetids is a haemotrichorial placental barrier where the maternal-facing layer consists of cytotrophoblasts characterized as sinusoidal TGCs. The maternal channels of the labyrinth are supplied by trophoblast-lined canals. Whereas in the mouse these are lined largely by canal TGCs, in cricetids canal TGCs are interspersed with syncytiotrophoblast. Transformation of the uterine spiral arteries occurs in both murids and cricetids and spiral artery TGCs line segments of the arteries that have lost their endothelium and smooth muscle. Since polyploidization of TGCs can amplify selective genomic regions required for specific functions, we argue that the TGCs of cricetids deserve further study and suggest avenues for future research., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Favaron and Carter.)
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- 2023
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16. Syntaxin 1 Ser 14 phosphorylation is required for nonvesicular dopamine release.
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Shekar A, Mabry SJ, Cheng MH, Aguilar JI, Patel S, Zanella D, Saleeby DP, Zhu Y, Romanazzi T, Ulery-Reynolds P, Bahar I, Carter AM, Matthies HJG, and Galli A
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- Animals, Amphetamine pharmacology, Dopamine Plasma Membrane Transport Proteins metabolism, Drosophila melanogaster metabolism, Phosphorylation, Dopamine metabolism, Syntaxin 1 genetics, Syntaxin 1 metabolism
- Abstract
Amphetamine (AMPH) is a psychostimulant that is commonly abused. The stimulant properties of AMPH are associated with its ability to increase dopamine (DA) neurotransmission. This increase is promoted by nonvesicular DA release mediated by reversal of DA transporter (DAT) function. Syntaxin 1 (Stx1) is a SNARE protein that is phosphorylated at Ser
14 by casein kinase II. We show that Stx1 phosphorylation is critical for AMPH-induced nonvesicular DA release and, in Drosophila melanogaster , regulates the expression of AMPH-induced preference and sexual motivation. Our molecular dynamics simulations of the DAT/Stx1 complex demonstrate that phosphorylation of these proteins is pivotal for DAT to dwell in a DA releasing state. This state is characterized by the breakdown of two key salt bridges within the DAT intracellular gate, causing the opening and hydration of the DAT intracellular vestibule, allowing DA to bind from the cytosol, a mechanism that we hypothesize underlies nonvesicular DA release.- Published
- 2023
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17. Laboratory Evaluation Links Some False-Positive COVID-19 Antigen Test Results Observed in a Field Study to a Specific Lot of Test Strips.
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Carter AM, Viloria Winnett A, Romano AE, Akana R, Shelby N, and Ismagilov RF
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During a household-transmission field study using COVID-19 antigen rapid diagnostic tests (Ag-RDT), a common test strip lot was identified among 3 participants with false-positive results. In blinded laboratory evaluation, this lot exhibited a significantly higher false-positive rate than other lots. Because a positive Ag-RDT result often prompts action, reducing lot-specific false positives can maintain confidence and actionability of true-positive Ag-RDT results., Competing Interests: Potential conflicts of interest. R. F. I. is a co-founder, consultant, and director for and has stock ownership in Talis Biomedical Corporation. All other authors report no potential conflicts., (© The Author(s) 2023. Published by Oxford University Press on behalf of Infectious Diseases Society of America.)
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- 2023
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18. Morning SARS-CoV-2 Testing Yields Better Detection of Infection Due to Higher Viral Loads in Saliva and Nasal Swabs upon Waking.
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Viloria Winnett A, Porter MK, Romano AE, Savela ES, Akana R, Shelby N, Reyes JA, Schlenker NW, Cooper MM, Carter AM, Ji J, Barlow JT, Tognazzini C, Feaster M, Goh YY, and Ismagilov RF
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- Humans, COVID-19 Testing, Saliva, Clinical Laboratory Techniques methods, Viral Load, Specimen Handling methods, SARS-CoV-2, COVID-19 diagnosis
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Optimizing specimen collection methods to achieve the most reliable SARS-CoV-2 detection for a given diagnostic sensitivity would improve testing and minimize COVID-19 outbreaks. From September 2020 to April 2021, we performed a household-transmission study in which participants self-collected specimens every morning and evening throughout acute SARS-CoV-2 infection. Seventy mildly symptomatic participants collected saliva, and of those, 29 also collected nasal swab specimens. Viral load was quantified in 1,194 saliva and 661 nasal swab specimens using a high-analytical-sensitivity reverse transcription-quantitative PCR (RT-qPCR) assay. Viral loads in both saliva and nasal swab specimens were significantly higher in morning-collected specimens than in evening-collected specimens after symptom onset. This aspect of the biology of SARS-CoV-2 infection has implications for diagnostic testing. We infer that morning collection would have resulted in significantly improved detection and that this advantage would be most pronounced for tests with low to moderate analytical sensitivity. Collecting specimens for COVID-19 testing in the morning offers a simple and low-cost improvement to clinical diagnostic sensitivity of low- to moderate-analytical-sensitivity tests. IMPORTANCE Our findings suggest that collecting saliva and nasal swab specimens in the morning immediately after waking yields higher SARS-CoV-2 viral loads than collection later in the day. The higher viral loads from morning specimen collection are predicted to significantly improve detection of SARS-CoV-2 in symptomatic individuals, particularly when using moderate- to low-analytical-sensitivity COVID-19 diagnostic tests, such as rapid antigen tests.
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- 2022
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19. Embryonic specializations for vertebrate placentation.
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Whittington CM, Buddle AL, Griffith OW, and Carter AM
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- Animals, Biological Evolution, Female, Gases, Hormones, Mammals, Pregnancy, Vertebrates, Lizards physiology, Placentation physiology
- Abstract
The vertebrate placenta, a close association of fetal and parental tissue for physiological exchange, has evolved independently in sharks, teleost fishes, coelacanths, amphibians, squamate reptiles and mammals. This transient organ forms during pregnancy and is an important contributor to embryonic development in both viviparous and oviparous, brooding species. Placentae may be involved in transport of respiratory gases, wastes, immune molecules, hormones and nutrients. Depending on the taxon, the embryonic portion of the placenta is comprised of either extraembryonic membranes (yolk sac or chorioallantois) or temporary embryonic tissues derived via hypertrophy of pericardium, gill epithelium, gut, tails or fins. These membranes and tissues have been recruited convergently into placentae in several lineages. Here, we highlight the diversity and common features of embryonic tissues involved in vertebrate placentation and suggest future studies that will provide new knowledge about the evolution of pregnancy. This article is part of the theme issue 'Extraembryonic tissues: exploring concepts, definitions and functions across the animal kingdom'.
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- 2022
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20. Genetic impairment of succinate metabolism disrupts bioenergetic sensing in adrenal neuroendocrine cancer.
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Gupta P, Strange K, Telange R, Guo A, Hatch H, Sobh A, Elie J, Carter AM, Totenhagen J, Tan C, Sonawane YA, Neuzil J, Natarajan A, Ovens AJ, Oakhill JS, Wiederhold T, Pacak K, Ghayee HK, Meijer L, Reddy S, and Bibb JA
- Subjects
- Animals, Cyclin-Dependent Kinase 5 metabolism, Energy Metabolism, Glycogen Synthase Kinase 3 metabolism, Mice, Phosphorylation, Succinates, Adenylate Kinase metabolism, Carcinoma, Neuroendocrine
- Abstract
Metabolic dysfunction mutations can impair energy sensing and cause cancer. Loss of function of the mitochondrial tricarboxylic acid (TCA) cycle enzyme subunit succinate dehydrogenase B (SDHB) results in various forms of cancer typified by pheochromocytoma (PC). Here we delineate a signaling cascade where the loss of SDHB induces the Warburg effect, triggers dysregulation of [Ca
2+ ]i , and aberrantly activates calpain and protein kinase Cdk5, through conversion of its cofactor from p35 to p25. Consequently, aberrant Cdk5 initiates a phospho-signaling cascade where GSK3 inhibition inactivates energy sensing by AMP kinase through dephosphorylation of the AMP kinase γ subunit, PRKAG2. Overexpression of p25-GFP in mouse adrenal chromaffin cells also elicits this phosphorylation signaling and causes PC. A potent Cdk5 inhibitor, MRT3-007, reverses this phospho-cascade, invoking a senescence-like phenotype. This therapeutic approach halted tumor progression in vivo. Thus, we reveal an important mechanistic feature of metabolic sensing and demonstrate that its dysregulation underlies tumor progression in PC and likely other cancers., Competing Interests: Declaration of interests The authors declare no competing interests., (Copyright © 2022 The Author(s). Published by Elsevier Inc. All rights reserved.)- Published
- 2022
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21. Evolution of Placental Hormones: Implications for Animal Models.
- Author
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Carter AM
- Subjects
- Animals, Female, Glycoproteins metabolism, Horses, Humans, Models, Animal, Placentation, Pregnancy, Rodentia, Placenta metabolism, Placental Hormones genetics, Placental Hormones metabolism
- Abstract
Human placenta secretes a variety of hormones, some of them in large amounts. Their effects on maternal physiology, including the immune system, are poorly understood. Not one of the protein hormones specific to human placenta occurs outside primates. Instead, laboratory and domesticated species have their own sets of placental hormones. There are nonetheless several examples of convergent evolution. Thus, horse and human have chorionic gonadotrophins with similar functions whilst pregnancy-specific glycoproteins have evolved in primates, rodents, horses, and some bats, perhaps to support invasive placentation. Placental lactogens occur in rodents and ruminants as well as primates though evolved through duplication of different genes and with functions that only partially overlap. There are also placental hormones, such as the pregnancy-associated glycoproteins of ruminants, that have no equivalent in human gestation. This review focusses on the evolution of placental hormones involved in recognition and maintenance of pregnancy, in maternal adaptations to pregnancy and lactation, and in facilitating immune tolerance of the fetal semiallograft. The contention is that knowledge gained from laboratory and domesticated mammals can translate to a better understanding of human placental endocrinology, but only if viewed in an evolutionary context., Competing Interests: The author declares that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Carter.)
- Published
- 2022
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22. Light and flow regimes regulate the metabolism of rivers.
- Author
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Bernhardt ES, Savoy P, Vlah MJ, Appling AP, Koenig LE, Hall RO Jr, Arroita M, Blaszczak JR, Carter AM, Cohen M, Harvey JW, Heffernan JB, Helton AM, Hosen JD, Kirk L, McDowell WH, Stanley EH, Yackulic CB, and Grimm NB
- Subjects
- Carbon metabolism, Light, Seasons, Temperature, Weather, Ecosystem, Rivers
- Abstract
Mean annual temperature and mean annual precipitation drive much of the variation in productivity across Earth's terrestrial ecosystems but do not explain variation in gross primary productivity (GPP) or ecosystem respiration (ER) in flowing waters. We document substantial variation in the magnitude and seasonality of GPP and ER across 222 US rivers. In contrast to their terrestrial counterparts, most river ecosystems respire far more carbon than they fix and have less pronounced and consistent seasonality in their metabolic rates. We find that variation in annual solar energy inputs and stability of flows are the primary drivers of GPP and ER across rivers. A classification schema based on these drivers advances river science and informs management., Competing Interests: The authors declare no competing interest., (Copyright © 2022 the Author(s). Published by PNAS.)
- Published
- 2022
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23. Quantitative SARS-CoV-2 Viral-Load Curves in Paired Saliva Samples and Nasal Swabs Inform Appropriate Respiratory Sampling Site and Analytical Test Sensitivity Required for Earliest Viral Detection.
- Author
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Savela ES, Viloria Winnett A, Romano AE, Porter MK, Shelby N, Akana R, Ji J, Cooper MM, Schlenker NW, Reyes JA, Carter AM, Barlow JT, Tognazzini C, Feaster M, Goh YY, and Ismagilov RF
- Subjects
- Humans, Nasopharynx, Pandemics, Saliva, Specimen Handling, COVID-19, SARS-CoV-2
- Abstract
Early detection of SARS-CoV-2 infection is critical to reduce asymptomatic and presymptomatic transmission, curb the spread of variants, and maximize treatment efficacy. Low-analytical-sensitivity nasal-swab testing is commonly used for surveillance and symptomatic testing, but the ability of these tests to detect the earliest stages of infection has not been established. In this study, conducted between September 2020 and June 2021 in the greater Los Angeles County, California, area, initially SARS-CoV-2-negative household contacts of individuals diagnosed with COVID-19 prospectively self-collected paired anterior-nares nasal-swab and saliva samples twice daily for viral-load quantification by high-sensitivity reverse-transcription quantitative PCR (RT-qPCR) and digital-RT-PCR assays. We captured viral-load profiles from the incidence of infection for seven individuals and compared diagnostic sensitivities between respiratory sites. Among unvaccinated persons, testing saliva with a high-analytical-sensitivity assay detected infection up to 4.5 days before viral loads in nasal swabs reached concentrations detectable by low-analytical-sensitivity nasal-swab tests. For most participants, nasal swabs reached higher peak viral loads than saliva but were undetectable or at lower loads during the first few days of infection. High-analytical-sensitivity saliva testing was most reliable for earliest detection. Our study illustrates the value of acquiring early (within hours after a negative high-sensitivity test) viral-load profiles to guide the appropriate analytical sensitivity and respiratory site for detecting earliest infections. Such data are challenging to acquire but critical to designing optimal testing strategies with emerging variants in the current pandemic and to respond to future viral pandemics.
- Published
- 2022
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24. Bile Acids Gate Dopamine Transporter Mediated Currents.
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Romanazzi T, Zanella D, Cheng MH, Smith B, Carter AM, Galli A, Bahar I, and Bossi E
- Abstract
Bile acids (BAs) are molecules derived from cholesterol that are involved in dietary fat absorption. New evidence supports an additional role for BAs as regulators of brain function. Sterols such as cholesterol interact with monoamine transporters, including the dopamine (DA) transporter (DAT) which plays a key role in DA neurotransmission and reward. This study explores the interactions of the BA, obeticholic acid (OCA), with DAT and characterizes the regulation of DAT activity via both electrophysiology and molecular modeling. We expressed murine DAT (mDAT) in Xenopus laevis oocytes and confirmed its functionality. Next, we showed that OCA promotes a DAT-mediated inward current that is Na
+ -dependent and not regulated by intracellular calcium. The current induced by OCA was transient in nature, returning to baseline in the continued presence of the BA. OCA also transiently blocked the DAT-mediated Li+ -leak current, a feature that parallels DA action and indicates direct binding to the transporter in the absence of Na+ . Interestingly, OCA did not alter DA affinity nor the ability of DA to promote a DAT-mediated inward current, suggesting that the interaction of OCA with the transporter is non-competitive, regarding DA. Docking simulations performed for investigating the molecular mechanism of OCA action on DAT activity revealed two potential binding sites. First, in the absence of DA, OCA binds DAT through interactions with D421, a residue normally involved in coordinating the binding of the Na+ ion to the Na2 binding site (Borre et al., J. Biol. Chem., 2014, 289, 25764-25773; Cheng and Bahar, Structure, 2015, 23, 2171-2181). Furthermore, we uncover a separate binding site for OCA on DAT, of equal potential functional impact, that is coordinated by the DAT residues R445 and D436. Binding to that site may stabilize the inward-facing (IF) open state by preventing the re-formation of the IF-gating salt bridges, R60-D436 and R445-E428, that are required for DA transport. This study suggests that BAs may represent novel pharmacological tools to regulate DAT function, and possibly, associated behaviors., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The reviewer (PH) declared a past co-authorship with the authors (DZ, MC) to the handling Editor., (Copyright © 2021 Romanazzi, Zanella, Cheng, Smith, Carter, Galli, Bahar and Bossi.)- Published
- 2021
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25. Cdk5 drives formation of heterogeneous pancreatic neuroendocrine tumors.
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Carter AM, Kumar N, Herring B, Tan C, Guenter R, Telange R, Howse W, Viol F, McCaw TR, Bickerton HH, Gupta P, Gillardon F, Woltering EA, Dhall D, Totenhagen J, Banerjee RR, Kurian EM, Reddy S, Chen H, Schrader J, Bart Rose J, Mukhtar MS, and Bibb JA
- Abstract
Pancreatic neuroendocrine tumors (PanNETs) are a heterogeneous population of neoplasms that arise from hormone-secreting islet cells of the pancreas and have increased markedly in incidence over the past four decades. Non-functional PanNETs, which occur more frequently than hormone-secreting tumors, are often not diagnosed until later stages of tumor development and have poorer prognoses. Development of successful therapeutics for PanNETs has been slow, partially due to a lack of diverse animal models for pre-clinical testing. Here, we report development of an inducible, conditional mouse model of PanNETs by using a bi-transgenic system for regulated expression of the aberrant activator of Cdk5, p25, specifically in β-islet cells. This model produces a heterogeneous population of PanNETs that includes a subgroup of well-differentiated, non-functional tumors. Production of these tumors demonstrates the causative potential of aberrantly active Cdk5 for generation of PanNETs. Further, we show that human PanNETs express Cdk5 pathway components, are dependent on Cdk5 for growth, and share genetic and transcriptional overlap with the INS-p25OE model. The utility of this model is enhanced by the ability to form tumor-derived allografts. This new model of PanNETs will facilitate molecular delineation of Cdk5-dependent PanNETs and the development of new targeted therapeutics., (© 2021. The Author(s).)
- Published
- 2021
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26. Routine management, healthcare resource use and patient and carer-reported outcomes of patients with transfusion-dependent β-thalassaemia in the United Kingdom: A mixed methods observational study.
- Author
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Shah F, Telfer P, Velangi M, Pancham S, Wynn R, Pollard S, Chalmers E, Kell J, Carter AM, Hickey J, Paramore C, Jobanputra M, and Ryan K
- Abstract
Objectives: We evaluated routine healthcare management, clinical status and patient- and carer-reported outcomes in UK paediatric and adult patients with transfusion-dependent β-thalassaemia (TDT)., Methods: A multi-centre, observational mixed-methodology study evaluated 165 patients (50% male; median age 24.1 [interquartile range (IQR)] 11.8-37.2] years) from nine UK centres., Results: Patients had a mean of 13.7 (standard deviation [SD] ±3.2) transfusion episodes/year (mean retrospective observation period 4.7 [±0.7] years). The median (IQR) for iron overload parameters at the last assessment during the observation period were: serum ferritin ( n = 165) 1961.0 (1090.0-3003.0) μg/L (38% > 2500 μg/L); R2 liver iron ( n = 119) 5.4 (2.9-11.6) mg/g (16% ≥15 mg/g); T2* cardiac iron ( n = 132) 30.3 (22.0-37.1) ms (10% < 10 ms). All patients received ≥1 iron chelator during the observation period; 21% received combination therapy. Patients had a mean of 7.8 (±8.1) non-transfusion-related hospital attendances or admissions/year. Adult patients' mean EQ-5D utility score was 0.69 (±0.33; n = 94 [≥16 years]) and mean Transfusion-dependent quality of life score was 58.6 (±18.4; n = 94 [≥18 years]). For Work Productivity and Activity impairment, mean activity impairment for patients ≥18 years ( n = 88) was 48% (±32%) and for carers ( n = 29) was 28% (±23%)., Conclusions: TDT presents significant burden on patients, carers and healthcare resources., Competing Interests: FS declares advisory board (silence therapeutics, Roche, Novartis, bluebird bio, Celgene), clinical safety committee (Abfero pharmaceuticals) and steering committee for trial (Celgene) involvement; PT declares advisory committee (Global Blood Therapeutics, Novartis, bluebird bio), data monitoring committee (Pfizer), clinical trial activity (Apopharma, Celgene, Global Blood Therapeutics, Novartis, Napp Pharma), investigator led funding (Kyowa Kirin Limited, bluebird bio) and speaker activity (Apopharma, Terumo plc); MV states advisory board activity for bluebird bio; SPancham declares advisory board (Celegene and Novartis) and sponsorship to attend educational meeting (Celegene); RW states nothing to declare; SPollard declares Novartis support to attend educational meetings, advisory board activity for bluebird bio; EC declares consultancy fees from Novartis; JK declares advisory boards with Celgene, Jazz and Novartis; AMC and JH are employees of pH Associates Ltd, doing business as OPEN Health; CP and MJ are employees of bluebird bio and own stock in the company; KR declares advisory boards for bluebird bio and Pfizer, Educational grant from Novartis. The study was funded by bluebird bio, Inc. bluebird bio, Inc. has a gene therapy for β thalassaemia currently licensed in the EU., (© 2021 The Authors. eJHaem published by British Society for Haematology and John Wiley & Sons Ltd.)
- Published
- 2021
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27. Unique Aspects of Human Placentation.
- Author
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Carter AM
- Subjects
- Animals, Female, Humans, Placental Hormones metabolism, Pregnancy, Primates, Uterine Artery, Biological Evolution, Placenta, Placentation
- Abstract
Human placentation differs from that of other mammals. A suite of characteristics is shared with haplorrhine primates, including early development of the embryonic membranes and placental hormones such as chorionic gonadotrophin and placental lactogen. A comparable architecture of the intervillous space is found only in Old World monkeys and apes. The routes of trophoblast invasion and the precise role of extravillous trophoblast in uterine artery transformation is similar in chimpanzee and gorilla. Extended parental care is shared with the great apes, and though human babies are rather helpless at birth, they are well developed (precocial) in other respects. Primates and rodents last shared a common ancestor in the Cretaceous period, and their placentation has evolved independently for some 80 million years. This is reflected in many aspects of their placentation. Some apparent resemblances such as interstitial implantation and placental lactogens are the result of convergent evolution. For rodent models such as the mouse, the differences are compounded by short gestations leading to the delivery of poorly developed (altricial) young.
- Published
- 2021
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28. Early amphibians evolved distinct vertebrae for habitat invasions.
- Author
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Carter AM, Hsieh ST, Dodson P, and Sallan L
- Subjects
- Amphibians physiology, Animals, Biodiversity, Ecosystem, Locomotion physiology, Spine physiology, Amphibians anatomy & histology, Biological Evolution, Spine anatomy & histology
- Abstract
Living tetrapods owe their existence to a critical moment 360-340 million years ago when their ancestors walked on land. Vertebrae are central to locomotion, yet systematic testing of correlations between vertebral form and terrestriality and subsequent reinvasions of aquatic habitats is lacking, obscuring our understanding of movement capabilities in early tetrapods. Here, we quantified vertebral shape across a diverse group of Paleozoic amphibians (Temnospondyli) encompassing different habitats and nearly the full range of early tetrapod vertebral shapes. We demonstrate that temnospondyls were likely ancestrally terrestrial and had several early reinvasions of aquatic habitats. We find a greater diversity in temnospondyl vertebrae than previously known. We also overturn long-held hypotheses centered on weight-bearing, showing that neural arch features, including muscle attachment, were plastic across the water-land divide and do not provide a clear signal of habitat preferences. In contrast, intercentra traits were critical, with temnospondyls repeatedly converging on distinct forms in terrestrial and aquatic taxa, with little overlap between. Through our geometric morphometric study, we have been able to document associations between vertebral shape and environmental preferences in Paleozoic tetrapods and to reveal morphological constraints imposed by vertebrae to locomotion, independent of ancestry., Competing Interests: The authors have declared that no competing interests exist.
- Published
- 2021
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29. Psychomotor impairments and therapeutic implications revealed by a mutation associated with infantile Parkinsonism-Dystonia.
- Author
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Aguilar JI, Cheng MH, Font J, Schwartz AC, Ledwitch K, Duran A, Mabry SJ, Belovich AN, Zhu Y, Carter AM, Shi L, Kurian MA, Fenollar-Ferrer C, Meiler J, Ryan RM, Mchaourab HS, Bahar I, Matthies HJ, and Galli A
- Subjects
- Animals, Chloroquine pharmacology, Disease Models, Animal, Dopamine metabolism, Dopamine Plasma Membrane Transport Proteins deficiency, Dopamine Plasma Membrane Transport Proteins drug effects, Dystonic Disorders drug therapy, Flight, Animal drug effects, HEK293 Cells, Humans, Molecular Structure, Mutation, Missense, Parkinson Disease drug therapy, Psychomotor Disorders drug therapy, Dopamine Plasma Membrane Transport Proteins genetics, Drosophila melanogaster, Dystonic Disorders genetics, Parkinson Disease genetics, Psychomotor Disorders genetics
- Abstract
Parkinson disease (PD) is a progressive, neurodegenerative disorder affecting over 6.1 million people worldwide. Although the cause of PD remains unclear, studies of highly penetrant mutations identified in early-onset familial parkinsonism have contributed to our understanding of the molecular mechanisms underlying disease pathology. Dopamine (DA) transporter (DAT) deficiency syndrome (DTDS) is a distinct type of infantile parkinsonism-dystonia that shares key clinical features with PD, including motor deficits (progressive bradykinesia, tremor, hypomimia) and altered DA neurotransmission. Here, we define structural, functional, and behavioral consequences of a Cys substitution at R445 in human DAT (hDAT R445C), identified in a patient with DTDS. We found that this R445 substitution disrupts a phylogenetically conserved intracellular (IC) network of interactions that compromise the hDAT IC gate. This is demonstrated by both Rosetta molecular modeling and fine-grained simulations using hDAT R445C, as well as EPR analysis and X-ray crystallography of the bacterial homolog leucine transporter. Notably, the disruption of this IC network of interactions supported a channel-like intermediate of hDAT and compromised hDAT function. We demonstrate that Drosophila melanogaster expressing hDAT R445C show impaired hDAT activity, which is associated with DA dysfunction in isolated brains and with abnormal behaviors monitored at high-speed time resolution. We show that hDAT R445C Drosophila exhibit motor deficits, lack of motor coordination (i.e. flight coordination) and phenotypic heterogeneity in these behaviors that is typically associated with DTDS and PD. These behaviors are linked with altered dopaminergic signaling stemming from loss of DA neurons and decreased DA availability. We rescued flight coordination with chloroquine, a lysosomal inhibitor that enhanced DAT expression in a heterologous expression system. Together, these studies shed some light on how a DTDS-linked DAT mutation underlies DA dysfunction and, possibly, clinical phenotypes shared by DTDS and PD., Competing Interests: JA, MC, JF, AS, KL, SM, AB, YZ, AC, LS, MK, CF, JM, RR, HM, IB, HM, AG No competing interests declared, AD is now employed at Cyrus Biotechnology with granted stock options. However, all contributions to the present work were made during AD's graduate education at Vanderbilt University
- Published
- 2021
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30. Animal models of human pregnancy and placentation: alternatives to the mouse.
- Author
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Carter AM
- Subjects
- Animals, Female, Humans, Placenta cytology, Pregnancy, Models, Animal, Placenta physiology, Placentation
- Abstract
The mouse is often criticized as a model for pregnancy research as gestation is short, with much of organ development completed postnatally. There are also differences in the structure and physiology of the placenta between mouse and human. This review considers eight alternative models that recently have been proposed and two established ones that seem underutilized. A promising newcomer among rodents is the spiny mouse, which has a longer gestation than the mouse with organogenesis complete at birth. The guinea pig is also recommended both because it has well-developed neonates and because there is a wealth of information on pregnancy and placentation in the literature. Several smaller primates are considered. The mouse lemur has its advocates yet is less suited as a model for human pregnancy as its young are altricial, placentation very different from that of humans, and husbandry requirements not fully assessed. In contrast, the common marmoset, a New World monkey, has well-developed neonates and is kept at many primate centres. Marmoset placenta has some features that closely resemble human placentation, such as the interhaemal barrier, although it is uncertain if invasion of the uterine arteries occurs in this species. In conclusion, pregnancy research would benefit greatly from increased use of alternative models such as the spiny mouse and common marmoset.
- Published
- 2020
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31. Phosphoprotein-based biomarkers as predictors for cancer therapy.
- Author
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Carter AM, Tan C, Pozo K, Telange R, Molinaro R, Guo A, De Rosa E, Martinez JO, Zhang S, Kumar N, Takahashi M, Wiederhold T, Ghayee HK, Oltmann SC, Pacak K, Woltering EA, Hatanpaa KJ, Nwariaku FE, Grubbs EG, Gill AJ, Robinson B, Gillardon F, Reddy S, Jaskula-Sztul R, Mobley JA, Mukhtar MS, Tasciotti E, Chen H, and Bibb JA
- Subjects
- Animals, Biomarkers analysis, Biomarkers metabolism, Cyclin-Dependent Kinase 5 antagonists & inhibitors, Cyclin-Dependent Kinase 5 genetics, Cyclin-Dependent Kinase 5 metabolism, Heterografts, Humans, Mice, Neoplasms genetics, Neuroectodermal Tumors genetics, Neuroectodermal Tumors metabolism, Phosphoproteins analysis, Phosphoproteins genetics, Phosphorylation, Neoplasms drug therapy, Neoplasms metabolism, Neuroectodermal Tumors drug therapy, Phosphoproteins metabolism, Protein Kinase Inhibitors administration & dosage
- Abstract
Disparities in cancer patient responses have prompted widespread searches to identify differences in sensitive vs. nonsensitive populations and form the basis of personalized medicine. This customized approach is dependent upon the development of pathway-specific therapeutics in conjunction with biomarkers that predict patient responses. Here, we show that Cdk5 drives growth in subgroups of patients with multiple types of neuroendocrine neoplasms. Phosphoproteomics and high throughput screening identified phosphorylation sites downstream of Cdk5. These phosphorylation events serve as biomarkers and effectively pinpoint Cdk5-driven tumors. Toward achieving targeted therapy, we demonstrate that mouse models of neuroendocrine cancer are responsive to selective Cdk5 inhibitors and biomimetic nanoparticles are effective vehicles for enhanced tumor targeting and reduction of drug toxicity. Finally, we show that biomarkers of Cdk5-dependent tumors effectively predict response to anti-Cdk5 therapy in patient-derived xenografts. Thus, a phosphoprotein-based diagnostic assay combined with Cdk5-targeted therapy is a rational treatment approach for neuroendocrine malignancies., Competing Interests: The authors declare no competing interest.
- Published
- 2020
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32. Role of ureides in source-to-sink transport of photoassimilates in non-fixing soybean.
- Author
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Thu SW, Lu MZ, Carter AM, Collier R, Gandin A, Sitton CC, and Tegeder M
- Subjects
- Nitrogen, Phloem, Seeds, Fabaceae, Glycine max genetics
- Abstract
Nitrogen (N)-fixing soybean plants use the ureides allantoin and allantoic acid as major long-distance transport forms of N, but in non-fixing, non-nodulated plants amino acids mainly serve in source-to-sink N allocation. However, some ureides are still synthesized in roots of non-fixing soybean, and our study addresses the role of ureide transport processes in those plants. In previous work, legume ureide permeases (UPSs) were identified that are involved in cellular import of allantoin and allantoic acid. Here, UPS1 from common bean was expressed in the soybean phloem, which resulted in enhanced source-to-sink transport of ureides in the transgenic plants. This was accompanied by increased ureide synthesis and elevated allantoin and allantoic acid root-to-sink transport. Interestingly, amino acid assimilation, xylem transport, and phloem partitioning to sinks were also strongly up-regulated. In addition, photosynthesis and sucrose phloem transport were improved in the transgenic plants. These combined changes in source physiology and assimilate partitioning resulted in increased vegetative growth and improved seed numbers. Overall, the results support that ureide transport processes in non-fixing plants affect source N and carbon acquisition and assimilation as well as source-to-sink translocation of N and carbon assimilates with consequences for plant growth and seed development., (© The Author(s) 2020. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)
- Published
- 2020
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33. Evolution of placentation in cattle and antelopes.
- Author
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Carter AM
- Abstract
Bovids have enjoyed great evolutionary success as evidenced by the large number of extant species. Several important domestic animals are from this family. They derive from both subfamilies: cattle and their kin belong to Bovinae and sheep and goats to Antilopinae. The premise of this review, therefore, is that evolution of reproduction and placentation is best understood in a context that includes antelope-like bovines and antelopes. Many key features of placentation, including hormone secretion, had evolved before bovids emerged as a distinct group. Variation nevertheless occurs. Most striking is the difference in fusion of the binucleate trophoblast cell with uterine epithelium that yields a transient trinucleate cell in bovines and many antelopes, but a more persistent syncytium in wildebeest, sheep and goat. There is considerable variation in placentome number and villus branching within the placentome. Many antelopes have right-sided implantation in a bicornuate uterus whilst others have a uterus duplex. Finally, there has been continued evolution of placental hormones with tandem duplication of PAG genes in cattle, differences in glycosylation of placental lactogen and the emergence of placental growth hormone in sheep and goats. The selection pressures driving this evolution are unknown though maternal-fetal competition for nutrients is an attractive hypothesis., Competing Interests: Conflict of interest statement: The author declares that he has no conflicting interest., (Copyright © The Author(s). Published by CBRA.)
- Published
- 2020
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34. Review of metastatic colorectal cancer treatment pathways and early clinical experience of trifluridine/tipiracil in the UK named patient programme.
- Author
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Iveson T, Carter AM, Shiu KK, Spooner C, Stevens D, and Mullamitha S
- Subjects
- Aged, Antineoplastic Combined Chemotherapy Protocols therapeutic use, Camptothecin analogs & derivatives, Camptothecin therapeutic use, Disease Progression, Drug Combinations, Female, Fluorouracil therapeutic use, Humans, Leucovorin therapeutic use, Male, Middle Aged, Neoplasm Metastasis, Organoplatinum Compounds therapeutic use, Pyrrolidines therapeutic use, Thymine, Treatment Outcome, Trifluridine therapeutic use, United Kingdom, Uracil administration & dosage, Uracil therapeutic use, Colorectal Neoplasms drug therapy, Pyrrolidines administration & dosage, Trifluridine administration & dosage, Uracil analogs & derivatives
- Abstract
Background: The standard first- and second- line chemotherapy backbone regimens for metastatic colorectal cancer (mCRC) are 5-fluorouracil (5-FU)/capecitabine-based with addition of irinotecan or oxaliplatin. Until recently, evidence for optimal sequencing post second-line was sparse. Trifluridine/tipiracil (indicated for mCRC and gastric cancer after standard chemotherapies) was made available to UK patients via a named patient programme (NPP) before receiving marketing authorisation in Europe in 2016, allowing characterisation of UK treatment pathways, and evaluation of trifluridine/tipiracil in a UK non-trial population., Methods: Data collected routinely for the NPP were analysed to describe the patient demographics, clinical characteristics and treatment pathways. Patients eligible for the programme were adults (≥18 years) with histologically or cytologically confirmed mCRC who had previously received chemotherapy treatment(s)., Results: Of the 250 eligible patients enrolled in the NPP, 194 patients received ≥1 dose of trifluridine/tipiracil and 56 patients did not receive trifluridine/tipiracil. The following results are reported first for patients who received trifluridine/tipiracil and second for those who did not receive trifluridine/tipiracil: median (IQR) age was 63.0 (54.0-69.0) and 62.0 (54.8-69.0) years; Eastern Cooperative Oncology Group performance status score was 0 for 28 and 14%, 1 for 65 and 70%, 2 for 7 and 16%. In terms of previous systemic treatments 47 and 43% had 2 prior lines of therapy. FOLFOX-, FOLFIRI- and CAPOX-based therapies were the most common first-line regimens in patients receiving trifluridine/tipiracil (37, 35 and 21%, respectively), and in patients not receiving trifluridine/tipiracil (41, 30 and 20%, respectively). Second-line treatment regimens in patients receiving and not receiving trifluridine/tipiracil were most commonly FOLFIRI-based (48 and 41%, respectively) and FOLFOX-based (19 and 21%, respectively). Patients received a median of 2 cycles of trifluridine/tipiracil with a median treatment duration of 1.8 (95% CI: 1.8-2.4) months. In patients who discontinued treatment due to disease progression, the median progression-free duration was 2.8 (95% CI: 2.4-2.9) months., Conclusions: The results highlight the number of treatment pathways used to treat mCRC in routine UK clinical practice prior to the marketing authorisation and National Institute for Health and Care Excellence approval of trifluridine/tipiracil and highlight the lack of clinical guidelines for mCRC.
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- 2020
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35. Repeat Episodes of Symptomatic Urethritis Due to a Uropathogenic Meningococcal Clade.
- Author
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Bazan JA, Tzeng YL, Stephens DS, Carter AM, Brown MA, Snyder B, Prince DJ, and Turner AN
- Subjects
- Adult, Electronic Health Records, Female, Genome, Bacterial, Humans, Male, Neisseria gonorrhoeae genetics, Neisseria meningitidis classification, Recurrence, Whole Genome Sequencing, Young Adult, Neisseria meningitidis genetics, Neisseria meningitidis pathogenicity, Urethritis microbiology
- Abstract
In 2015, we identified a non-groupable clade of Neisseria meningitidis that causes urethritis in men (the US_NmUC). Because repeat infection is common with Neisseria gonorrhoeae, we examined whether reinfection also occurs with the US_NmUC. We provide evidence that men are susceptible to repeat episodes of urethritis from the US_NmUC.
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- 2020
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36. DSS-induced colitis produces inflammation-induced bone loss while irisin treatment mitigates the inflammatory state in both gut and bone.
- Author
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Metzger CE, Narayanan SA, Elizondo JP, Carter AM, Zawieja DC, Hogan HA, and Bloomfield SA
- Subjects
- Animals, Biomechanical Phenomena, Body Weight, Bone Density drug effects, Bone Morphogenetic Proteins metabolism, Bone Resorption physiopathology, Bone and Bones diagnostic imaging, Bone and Bones drug effects, Bone and Bones physiopathology, Cancellous Bone drug effects, Cancellous Bone pathology, Cancellous Bone physiopathology, Colitis pathology, Colitis physiopathology, Colon drug effects, Colon pathology, Dextran Sulfate, Femur Neck diagnostic imaging, Femur Neck drug effects, Femur Neck pathology, Fibronectins pharmacology, Gastrointestinal Tract drug effects, Genetic Markers, Inflammation drug therapy, Intestinal Mucosa drug effects, Intestinal Mucosa pathology, Lymphatic Vessels drug effects, Lymphatic Vessels pathology, Male, Osteocytes metabolism, Osteogenesis drug effects, Osteoprotegerin metabolism, RANK Ligand metabolism, Rats, Sprague-Dawley, Tibia diagnostic imaging, Tibia drug effects, Tibia pathology, Tomography, X-Ray Computed, Tumor Necrosis Factor-alpha metabolism, Weight-Bearing, Bone Resorption etiology, Bone and Bones pathology, Colitis chemically induced, Colitis drug therapy, Fibronectins therapeutic use, Gastrointestinal Tract pathology, Inflammation complications
- Abstract
Chronic pediatric inflammatory bowel disease (IBD) leads to lack of bone accrual, bone loss, and increased fractures. Presently there is no cure, and many IBD treatments incur negative side effects. We previously discovered treatment with exogenous irisin resolved inflammatory changes in the colon, gut lymphatics, and bone in a mild IBD rodent model. Here we assess irisin treatment in severe IBD induced via dextran sodium sulfate (DSS). Male Sprague Dawley rats (2-mo-old) were untreated (Con) or given 2% DSS in drinking water. In week two, half of each group (Con + Ir and DSS + Ir) received injections of recombinant irisin (i.p., 2x/wk). After 4 weeks, gut inflammation was associated with declines in bone mineral density and cancellous bone volume. Furthermore, elevated osteocyte TNF-α, interleukin-6, RANKL, OPG, and sclerostin corresponded with higher osteoclast surfaces and lower bone formation rate in DSS animals as well as lower ultimate load. While irisin treatment improved colon inflammation, there were no improvements in bone density or bone mechanical properties; however, irisin elevated bone formation rate, decreased osteoclast surfaces, and reduced osteocyte pro-inflammatory factors. These data highlight the negative impact of chronic gut inflammation on bone as well as the therapeutic potential of irisin as an anti-inflammatory treatment.
- Published
- 2019
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37. Preclinical characterization of tyrosine kinase inhibitor-based targeted therapies for neuroendocrine thyroid cancer.
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Pozo K, Zahler S, Ishimatsu K, Carter AM, Telange R, Tan C, Wang S, Pfragner R, Fujimoto J, Grubbs EG, Takahashi M, Oltmann SC, and Bibb JA
- Abstract
Medullary thyroid carcinoma (MTC) is a slow growing neuroendocrine (NE) tumor for which few treatment options are available. Its incidence is rising and mortality rates have remained unchanged for decades. Increasing the repertoire of available treatments is thus crucial to manage MTC progression. Scarcity of patient samples and of relevant animal models are two challenges that have limited the development of effective non-surgical treatments. Here we use a clinically accurate mouse model of MTC to assess the effects and mode of action of the tyrosine kinase inhibitor (TKI) Vandetanib, one of only two drugs currently available to treat MTC. Effects on tumor progression, histopathology, and tumorigenic signaling were evaluated. Vandetanib blocked MTC growth through an anti-angiogenic mechanism. Furthermore, Vandetanib had an apparent anti-angiogenic effect in a patient MTC sample. Vandetanib displayed minimal anti-proliferative effects in vivo and in human and mouse MTC tumor-derived cells. Based on these results, we evaluated the second-generation TKI, Nintedanib, alone and in combination with the histone deacetylase (HDAC) inhibitor, Romidepsin, as potential alternative treatments to Vandetanib. Nintedanib showed an anti-angiogenic effect while Romidepsin decreased proliferation. Mechanistically, TKIs attenuated RET-, VEGFR2- and PI3K/AKT/FOXO signaling cascades. Nintedanib alone or in combination with Romidepsin, but not Vandetanib, inhibited mTOR signaling suggesting Nintedanib may have broader anti-cancer applicability. These findings validate the MTC mouse model as a clinically relevant platform for preclinical drug testing and reveal the modes of action and limitations of TKI therapies., Competing Interests: CONFLICTS OF INTEREST The authors declare that they have no conflicts of interest with the contents of this article.
- Published
- 2018
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38. Recent advances in understanding evolution of the placenta: insights from transcriptomics.
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Carter AM
- Abstract
The mammalian placenta shows an extraordinary degree of variation in gross and fine structure, but this has been difficult to interpret in physiological terms. Transcriptomics offers a path to understanding how structure relates to function. This essay examines how studies of gene transcription can inform us about placental evolution in eutherian and marsupial mammals and more broadly about convergent evolution of viviparity and placentation in vertebrates. Thus far, the focus has been on the chorioallantoic placenta of eutherians at term, the reproductive strategies of eutherians and marsupials, and the decidual response of the uterus at implantation. Future work should address gene expression during early stages of placental development and endeavor to cover all major groups of mammals. Comparative studies across oviparous and viviparous vertebrates have centered on the chorioallantoic membrane and yolk sac. They point to the possibility of defining a set of genes that can be recruited to support commonalities in reproductive strategies. Further advances can be anticipated from single-cell transcriptomics if those techniques are applied to a range of placental structures and in species other than humans and mice., Competing Interests: No competing interests were disclosed.No competing interests were disclosed.No competing interests were disclosed.No competing interests were disclosed.No competing interests were disclosed.
- Published
- 2018
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39. Biomimetic nanoparticles with enhanced affinity towards activated endothelium as versatile tools for theranostic drug delivery.
- Author
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Martinez JO, Molinaro R, Hartman KA, Boada C, Sukhovershin R, De Rosa E, Kirui D, Zhang S, Evangelopoulos M, Carter AM, Bibb JA, Cooke JP, and Tasciotti E
- Subjects
- Animals, Fluorescent Dyes pharmacokinetics, Gadolinium pharmacokinetics, Leukocytes chemistry, Leukocytes metabolism, Membrane Proteins isolation & purification, Membrane Proteins metabolism, Mice, Neoplasms diagnosis, Neoplasms drug therapy, Phospholipids isolation & purification, Phospholipids metabolism, Protein Binding, Rhodamines pharmacokinetics, Staining and Labeling methods, Theranostic Nanomedicine methods, Vascular Diseases diagnosis, Vascular Diseases drug therapy, Biomimetic Materials chemistry, Biomimetic Materials pharmacokinetics, Drug Carriers chemistry, Drug Carriers pharmacokinetics, Endothelium, Vascular metabolism, Nanoparticles chemistry, Nanoparticles metabolism
- Abstract
Activation of the vascular endothelium is characterized by increased expression of vascular adhesion molecules and chemokines. This activation occurs early in the progression of several diseases and triggers the recruitment of leukocytes. Inspired by the tropism of leukocytes, we investigated leukocyte-based biomimetic nanoparticles (i.e., leukosomes) as a novel theranostic platform for inflammatory diseases. Methods : Leukosomes were assembled by combining phospholipids and membrane proteins from leukocytes. For imaging applications, phospholipids modified with rhodamine and gadolinium were used. Leukosomes incubated with antibodies blocking lymphocyte function-associated antigen 1 (LFA-1) and CD45 were administered to explore their roles in targeting inflammation. In addition, relaxometric assessment of NPs was evaluated. Results : Liposomes and leukosomes were both spherical in shape with sizes ranging from 140-170 nm. Both NPs successfully integrated 8 and 13 µg of rhodamine and gadolinium, respectively, and demonstrated less than 4% variation in physicochemical features. Leukosomes demonstrated a 16-fold increase in breast tumor accumulation relative to liposomes. Furthermore, quantification of leukosomes in tumor vessels demonstrated a 4.5-fold increase in vessel lumens and a 14-fold increase in vessel walls. Investigating the targeting mechanism of action revealed that blockage of LFA-1 on leukosomes resulted in a 95% decrease in tumor accumulation. Whereas blockage of CD45 yielded a 60% decrease in targeting and significant increases in liver and spleen accumulation. In addition, when administered in mice with atherosclerotic plaques, leukosomes exhibited a 4-fold increase in the targeting of inflammatory vascular lesions. Lastly, relaxometric assessment of NPs demonstrated that the incorporation of membrane proteins into leukosomes did not impact the r
1 and r2 relaxivities of the NPs, demonstrating 6 and 30 mM-1 s-1 , respectively. Conclusion : Our study demonstrates the ability of leukosomes to target activated vasculature and exhibit superior accumulation in tumors and vascular lesions. The versatility of the phospholipid backbone within leukosomes permits the incorporation of various contrast agents. Furthermore, leukosomes can potentially be loaded with therapeutics possessing diverse physical properties and thus warrant further investigation toward the development of powerful theranostic agents., Competing Interests: Competing Interests: The authors have declared that no competing interest exists.- Published
- 2018
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40. Anterior Cingulate Cortex Input to the Claustrum Is Required for Top-Down Action Control.
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White MG, Panicker M, Mu C, Carter AM, Roberts BM, Dharmasri PA, and Mathur BN
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- Animals, Mice, Mice, Transgenic, Basal Ganglia cytology, Basal Ganglia physiology, Gyrus Cinguli cytology, Gyrus Cinguli physiology, Interneurons cytology, Interneurons physiology
- Abstract
Cognitive abilities, such as volitional attention, operate under top-down, executive frontal cortical control of hierarchically lower structures. The circuit mechanisms underlying this process are unresolved. The claustrum possesses interconnectivity with many cortical areas and, thus, is hypothesized to orchestrate the cortical mantle for top-down control. Whether the claustrum receives top-down input and how this input may be processed by the claustrum have yet to be formally tested, however. We reveal that a rich anterior cingulate cortex (ACC) input to the claustrum encodes a preparatory top-down information signal on a five-choice response assay that is necessary for optimal task performance. We further show that ACC input monosynaptically targets claustrum inhibitory interneurons and spiny glutamatergic projection neurons, the latter of which amplify ACC input in a manner that is powerfully constrained by claustrum inhibitory microcircuitry. These results demonstrate ACC input to the claustrum is critical for top-down control guiding action., (Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.)
- Published
- 2018
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41. Increasing Nitrogen Fixation and Seed Development in Soybean Requires Complex Adjustments of Nodule Nitrogen Metabolism and Partitioning Processes.
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Carter AM and Tegeder M
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- Nitrogen Fixation, Seeds metabolism, Glycine max metabolism, Nitrogen metabolism, Root Nodules, Plant metabolism, Seeds growth & development, Glycine max growth & development
- Abstract
Legumes are able to access atmospheric di-nitrogen (N2) through a symbiotic relationship with rhizobia that reside within root nodules. In soybean, following N2 fixation by the bacteroids, ammonia is finally reduced in uninfected cells to allantoin and allantoic acid [1]. These ureides present the primary long-distance transport forms of nitrogen (N), and are exported from nodules via the xylem for shoot N supply. Transport of allantoin and allantoic acid out of nodules requires the function of ureide permeases (UPS1) located in cells adjacent to the vasculature [2, 3]. We expressed a common bean UPS1 transporter in cortex and endodermis cells of soybean nodules and found that delivery of N from nodules to shoot, as well as seed set, was significantly increased. In addition, the number of transgenic nodules was increased and symbiotic N2 fixation per nodule was elevated, indicating that transporter function in nodule N export is a limiting step in bacterial N acquisition. Further, the transgenic nodules showed considerable increases in nodule N assimilation, ureide synthesis, and metabolite levels. This suggests complex adjustments of nodule N metabolism and partitioning processes in support of symbiotic N2 fixation. We propose that the transgenic UPS1 plants display metabolic and allocation plasticity to overcome N2 fixation and seed yield limitations. Overall, it is demonstrated that transporter function in N export from nodules is a key step for enhancing atmospheric N2 fixation and nodule function and for improving shoot N nutrition and seed development in legumes., (Copyright © 2016 Elsevier Ltd. All rights reserved.)
- Published
- 2016
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42. The role of invasive trophoblast in implantation and placentation of primates.
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Carter AM, Enders AC, and Pijnenborg R
- Subjects
- Animals, Female, Humans, Pregnancy, Species Specificity, Biological Evolution, Embryo Implantation physiology, Placentation physiology, Primates physiology, Trophoblasts physiology
- Abstract
We here review the evolution of invasive placentation in primates towards the deep penetration of the endometrium and its arteries in hominoids. The strepsirrhine primates (lemurs and lorises) have non-invasive, epitheliochorial placentation, although this is thought to be derived from a more invasive type. In haplorhine primates, there is differentiation of trophoblast at the blastocyst stage into syncytial and cellular trophoblast. Implantation involves syncytiotrophoblast that first removes the uterine epithelium then consolidates at the basal lamina before continuing into the stroma. In later stages of pregnancy, especially in Old World monkeys and apes, cytotrophoblast plays a greater role in the invasive process. Columns of trophoblast cells advance to the base of the implantation site where they spread out to form a cytotrophoblastic shell. In addition, cytotrophoblasts advance into the lumen of the spiral arteries. They are responsible for remodelling these vessels to form wide, low-resistance conduits. In human and great apes, there is additional invasion of the endometrium and its vessels by trophoblasts originating from the base of the anchoring villi. Deep trophoblast invasion that extends remodelling of the spiral arteries to segments in the inner myometrium evolved in the common ancestor of gorilla, chimp and human., (© 2015 The Author(s) Published by the Royal Society. All rights reserved.)
- Published
- 2015
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43. A gigantic, exceptionally complete titanosaurian sauropod dinosaur from southern Patagonia, Argentina.
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Lacovara KJ, Lamanna MC, Ibiricu LM, Poole JC, Schroeter ER, Ullmann PV, Voegele KK, Boles ZM, Carter AM, Fowler EK, Egerton VM, Moyer AE, Coughenour CL, Schein JP, Harris JD, Martínez RD, and Novas FE
- Subjects
- Animals, Argentina, Biological Evolution, Bone and Bones anatomy & histology, Dinosaurs classification, Phylogeny, Fossils
- Abstract
Titanosaurian sauropod dinosaurs were the most diverse and abundant large-bodied herbivores in the southern continents during the final 30 million years of the Mesozoic Era. Several titanosaur species are regarded as the most massive land-living animals yet discovered; nevertheless, nearly all of these giant titanosaurs are known only from very incomplete fossils, hindering a detailed understanding of their anatomy. Here we describe a new and gigantic titanosaur, Dreadnoughtus schrani, from Upper Cretaceous sediments in southern Patagonia, Argentina. Represented by approximately 70% of the postcranial skeleton, plus craniodental remains, Dreadnoughtus is the most complete giant titanosaur yet discovered, and provides new insight into the morphology and evolutionary history of these colossal animals. Furthermore, despite its estimated mass of about 59.3 metric tons, the bone histology of the Dreadnoughtus type specimen reveals that this individual was still growing at the time of death.
- Published
- 2014
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44. Regulated localization is sufficient for hormonal control of regulator of G protein signaling homology Rho guanine nucleotide exchange factors (RH-RhoGEFs).
- Author
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Carter AM, Gutowski S, and Sternweis PC
- Subjects
- Catalysis, GTP-Binding Protein alpha Subunits, G12-G13 chemistry, GTP-Binding Protein alpha Subunits, G12-G13 genetics, GTP-Binding Protein alpha Subunits, G12-G13 metabolism, HeLa Cells, Humans, rhoA GTP-Binding Protein chemistry, rhoA GTP-Binding Protein genetics, rhoA GTP-Binding Protein metabolism, Cell Membrane chemistry, Cell Membrane enzymology, Cell Membrane genetics, Hormones chemistry, Hormones genetics, Hormones metabolism, Protein Multimerization physiology, Rho Guanine Nucleotide Exchange Factors chemistry, Rho Guanine Nucleotide Exchange Factors genetics, Rho Guanine Nucleotide Exchange Factors metabolism
- Abstract
The regulator of G protein signaling homology (RH) Rho guanine nucleotide exchange factors (RhoGEFs) (p115RhoGEF, leukemia-associated RhoGEF, and PDZ-RhoGEF) contain an RH domain and are specific GEFs for the monomeric GTPase RhoA. The RH domains interact specifically with the α subunits of G12 heterotrimeric GTPases. Activated Gα13 modestly stimulates the exchange activity of both p115RhoGEF and leukemia-associated RhoGEF but not PDZ-RhoGEF. Because all three RH-RhoGEFs can localize to the plasma membrane upon expression of activated Gα13, cellular localization of these RhoGEFs has been proposed as a mechanism for controlling their activity. We use a small molecule-regulated heterodimerization system to rapidly control the localization of RH-RhoGEFs. Acute localization of the proteins to the plasma membrane activates RhoA within minutes and to levels that are comparable with activation of RhoA by hormonal stimulation of G protein-coupled receptors. The catalytic activity of membrane-localized RhoGEFs is not dependent on activated Gα13. We further show that the conserved RH domains can rewire two different RacGEFs to activate Rac1 in response to a traditional activator of RhoA. Thus, RH domains act as independent detectors for activated Gα13 and are sufficient to modulate the activity of RhoGEFs by hormones via mediating their localization to substrate, membrane-associated RhoA., (© 2014 by The American Society for Biochemistry and Molecular Biology, Inc.)
- Published
- 2014
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45. Genome-wide association study for circulating tissue plasminogen activator levels and functional follow-up implicates endothelial STXBP5 and STX2.
- Author
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Huang J, Huffman JE, Yamakuchi M, Trompet S, Asselbergs FW, Sabater-Lleal M, Trégouët DA, Chen WM, Smith NL, Kleber ME, Shin SY, Becker DM, Tang W, Dehghan A, Johnson AD, Truong V, Folkersen L, Yang Q, Oudot-Mellkah T, Buckley BM, Moore JH, Williams FM, Campbell H, Silbernagel G, Vitart V, Rudan I, Tofler GH, Navis GJ, Destefano A, Wright AF, Chen MH, de Craen AJ, Worrall BB, Rudnicka AR, Rumley A, Bookman EB, Psaty BM, Chen F, Keene KL, Franco OH, Böhm BO, Uitterlinden AG, Carter AM, Jukema JW, Sattar N, Bis JC, Ikram MA, Sale MM, McKnight B, Fornage M, Ford I, Taylor K, Slagboom PE, McArdle WL, Hsu FC, Franco-Cereceda A, Goodall AH, Yanek LR, Furie KL, Cushman M, Hofman A, Witteman JC, Folsom AR, Basu S, Matijevic N, van Gilst WH, Wilson JF, Westendorp RG, Kathiresan S, Reilly MP, Tracy RP, Polasek O, Winkelmann BR, Grant PJ, Hillege HL, Cambien F, Stott DJ, Lowe GD, Spector TD, Meigs JB, Marz W, Eriksson P, Becker LC, Morange PE, Soranzo N, Williams SM, Hayward C, van der Harst P, Hamsten A, Lowenstein CJ, Strachan DP, and O'Donnell CJ
- Subjects
- Aged, Cells, Cultured, Coronary Artery Disease blood, Coronary Artery Disease enzymology, Coronary Artery Disease genetics, Europe, Female, Gene Expression Regulation, Gene Silencing, Genetic Loci, Genetic Predisposition to Disease, Genome-Wide Association Study, Humans, Male, Middle Aged, Nerve Tissue Proteins genetics, Phenotype, Polymorphism, Single Nucleotide, R-SNARE Proteins genetics, Risk Factors, Stroke blood, Stroke enzymology, Stroke genetics, Syntaxin 1 genetics, Tissue Plasminogen Activator genetics, Transfection, United States, Up-Regulation, Endothelial Cells enzymology, Nerve Tissue Proteins metabolism, R-SNARE Proteins metabolism, Syntaxin 1 metabolism, Tissue Plasminogen Activator blood
- Abstract
Objective: Tissue plasminogen activator (tPA), a serine protease, catalyzes the conversion of plasminogen to plasmin, the major enzyme responsible for endogenous fibrinolysis. In some populations, elevated plasma levels of tPA have been associated with myocardial infarction and other cardiovascular diseases. We conducted a meta-analysis of genome-wide association studies to identify novel correlates of circulating levels of tPA., Approach and Results: Fourteen cohort studies with tPA measures (N=26 929) contributed to the meta-analysis. Three loci were significantly associated with circulating tPA levels (P<5.0×10(-8)). The first locus is on 6q24.3, with the lead single nucleotide polymorphism (SNP; rs9399599; P=2.9×10(-14)) within STXBP5. The second locus is on 8p11.21. The lead SNP (rs3136739; P=1.3×10(-9)) is intronic to POLB and <200 kb away from the tPA encoding the gene PLAT. We identified a nonsynonymous SNP (rs2020921) in modest linkage disequilibrium with rs3136739 (r(2)=0.50) within exon 5 of PLAT (P=2.0×10(-8)). The third locus is on 12q24.33, with the lead SNP (rs7301826; P=1.0×10(-9)) within intron 7 of STX2. We further found evidence for the association of lead SNPs in STXBP5 and STX2 with expression levels of the respective transcripts. In in vitro cell studies, silencing STXBP5 decreased the release of tPA from vascular endothelial cells, whereas silencing STX2 increased the tPA release. Through an in silico lookup, we found no associations of the 3 lead SNPs with coronary artery disease or stroke., Conclusions: We identified 3 loci associated with circulating tPA levels, the PLAT region, STXBP5, and STX2. Our functional studies implicate a novel role for STXBP5 and STX2 in regulating tPA release.
- Published
- 2014
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46. A randomized controlled trial evaluating the erythropoiesis stimulating agent sparing potential of a vitamin E-bonded polysulfone dialysis membrane.
- Author
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Lines SW, Carter AM, Dunn EJ, Lindley EJ, Tattersall JE, and Wright MJ
- Subjects
- Aged, C-Reactive Protein metabolism, Darbepoetin alfa, Drug Resistance, Erythropoietin therapeutic use, Female, Humans, Male, Membranes, Artificial, Middle Aged, Prospective Studies, Vitamin E chemistry, Erythropoietin analogs & derivatives, Hematinics therapeutic use, Kidney Failure, Chronic therapy, Polymers chemistry, Renal Dialysis, Sulfones chemistry
- Abstract
Background: Vitamin E (VE) bonded polysulfone dialysis membranes have putative erythropoiesis stimulating agent (ESA)-sparing and anti-inflammatory properties based on data from a small number of studies. We sought to investigate this in a large, prospective 12-month randomized controlled trial., Methods: Two-hundred and sixty prevalent haemodialysis (HD) patients were randomized to dialysis with VE-bonded polysulfone membranes or non-VE-bonded equivalents. All ESA-dosing was performed by means of a computer-based anaemia management decision support system. Monthly data were used to calculate the ESA resistance index (ERI) and blood tests were performed at baseline, 6 and 12 months for measurement of C-reactive protein (CRP) levels., Results: Of the 260 patients, 123 were randomized to dialysis with the VE-membrane and 12-month data was available for 220 patients. At the study population level, no beneficial effect of the VE membranes on the ERI or CRP levels was observed. Post hoc analyses indicated that there was a significant fall in ERI for patients with the highest baseline ESA resistance dialysed with the VE (9.28 [7.70-12.5] versus 7.70 [5.34-12.7] IU/week/kg/g/dL Hb, P = 0.01) but not the control membranes (9.45 [7.62-12.3] versus 8.14 [4.44-15.6] IU/week/kg/g/dL Hb, P = 0.41); this was not attributable to changes in CRP levels., Conclusions: Wholesale switching of all chronic HD patients to dialysis with VE-bonded polysulfone membranes appears not to be associated with improvements in ESA-responsiveness or CRP. These membranes may have utility in patients with heightened ESA resistance.
- Published
- 2014
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47. Homoarginine levels are regulated by L-arginine:glycine amidinotransferase and affect stroke outcome: results from human and murine studies.
- Author
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Choe CU, Atzler D, Wild PS, Carter AM, Böger RH, Ojeda F, Simova O, Stockebrand M, Lackner K, Nabuurs C, Marescau B, Streichert T, Müller C, Lüneburg N, De Deyn PP, Benndorf RA, Baldus S, Gerloff C, Blankenberg S, Heerschap A, Grant PJ, Magnus T, Zeller T, Isbrandt D, and Schwedhelm E
- Subjects
- Adult, Aged, Animals, Cohort Studies, Disease Models, Animal, Female, Genome-Wide Association Study, HEK293 Cells, Humans, Male, Mice, Mice, Inbred C57BL, Middle Aged, Polymorphism, Single Nucleotide genetics, Prospective Studies, Stroke diagnosis, Treatment Outcome, Amidinotransferases genetics, Arginine genetics, Homoarginine genetics, Stroke genetics
- Abstract
Background: Endogenous arginine homologues, including homoarginine, have been identified as novel biomarkers for cardiovascular disease and outcomes. Our studies of human cohorts and a confirmatory murine model associated the arginine homologue homoarginine and its metabolism with stroke pathology and outcome., Methods and Results: Increasing homoarginine levels were independently associated with a reduction in all-cause mortality in patients with ischemic stroke (7.4 years of follow-up; hazard ratio for 1-SD homoarginine, 0.79 [95% confidence interval, 0.64-0.96]; P=0.019; n=389). Homoarginine was also independently associated with the National Institutes of Health Stroke Scale+age score and 30-day mortality after ischemic stroke (P<0.05; n=137). A genome-wide association study revealed that plasma homoarginine was strongly associated with single nucleotide polymorphisms in the L-arginine:glycine amidinotransferase (AGAT) gene (P<2.1 × 10(-8); n=2806), and increased AGAT expression in a cell model was associated with increased homoarginine. Next, we used 2 genetic murine models to investigate the link between plasma homoarginine and outcome after experimental ischemic stroke: (1) an AGAT deletion (AGAT(-/-)) and (2) a guanidinoacetate N-methyltransferase deletion (GAMT(-/-)) causing AGAT upregulation. As suggested by the genome-wide association study, homoarginine was absent in AGAT(-/-) mice and increased in GAMT(-/-) mice. Cerebral damage and neurological deficits in experimental stroke were increased in AGAT(-/-) mice and attenuated by homoarginine supplementation, whereas infarct size in GAMT(-/-) mice was decreased compared with controls., Conclusions: Low homoarginine appears to be related to poor outcome after ischemic stroke. Further validation in future trials may lead to therapeutic adjustments of homoarginine metabolism that alleviate stroke and other vascular disorders.
- Published
- 2013
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48. Activated RhoA is a positive feedback regulator of the Lbc family of Rho guanine nucleotide exchange factor proteins.
- Author
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Medina F, Carter AM, Dada O, Gutowski S, Hadas J, Chen Z, and Sternweis PC
- Subjects
- A Kinase Anchor Proteins genetics, Animals, Guanine Nucleotide Exchange Factors genetics, HeLa Cells, Humans, Mice, Minor Histocompatibility Antigens, Mutation, Phospholipids genetics, Phospholipids metabolism, Protein Structure, Tertiary, Proto-Oncogene Proteins genetics, Rho Guanine Nucleotide Exchange Factors, rhoA GTP-Binding Protein genetics, A Kinase Anchor Proteins metabolism, Guanine Nucleotide Exchange Factors metabolism, Proto-Oncogene Proteins metabolism, Signal Transduction physiology, rhoA GTP-Binding Protein metabolism
- Abstract
The monomeric Rho GTPases are essential for cellular regulation including cell architecture and movement. A direct mechanism for hormonal regulation of the RhoA-type GTPases is their modulation by the G12 and G13 proteins via RH (RGS homology) containing RhoGEFs. In addition to the interaction of the G protein α subunits with the RH domain, activated RhoA also binds to the pleckstrin homology (PH) domain of PDZRhoGEF. The latter interaction is now extended to all seven members of the homologous Lbc family of RhoGEFs which includes the RH-RhoGEFs. This is evinced by direct measurements of binding or through effects on selected signaling pathways in cells. Overexpression of these PH domains alone can block RhoA-dependent signaling in cells to various extents. Whereas activated RhoA does not modulate the intrinsic activity of the RhoGEFs, activated RhoA associated with phospholipid vesicles can facilitate increased activity of soluble RhoGEFs on vesicle-delimited substrate (RhoA-GDP). This demonstrates feasibility of the hypothesis that binding of activated RhoA to the PH domains acts as a positive feedback mechanism. This is supported by cellular studies in which mutation of this binding site on PH strongly attenuates the stimulation of RhoA observed by overexpression of five of the RhoGEF DH-PH domains. This mutation is even more dramatic in the context of full-length p115RhoGEF. The utilization of this mechanism by multiple RhoGEFs suggests that this regulatory paradigm may be a common feature in the broader family of RhoGEFs.
- Published
- 2013
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49. Genome-wide association study for circulating levels of PAI-1 provides novel insights into its regulation.
- Author
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Huang J, Sabater-Lleal M, Asselbergs FW, Tregouet D, Shin SY, Ding J, Baumert J, Oudot-Mellakh T, Folkersen L, Johnson AD, Smith NL, Williams SM, Ikram MA, Kleber ME, Becker DM, Truong V, Mychaleckyj JC, Tang W, Yang Q, Sennblad B, Moore JH, Williams FM, Dehghan A, Silbernagel G, Schrijvers EM, Smith S, Karakas M, Tofler GH, Silveira A, Navis GJ, Lohman K, Chen MH, Peters A, Goel A, Hopewell JC, Chambers JC, Saleheen D, Lundmark P, Psaty BM, Strawbridge RJ, Boehm BO, Carter AM, Meisinger C, Peden JF, Bis JC, McKnight B, Öhrvik J, Taylor K, Franzosi MG, Seedorf U, Collins R, Franco-Cereceda A, Syvänen AC, Goodall AH, Yanek LR, Cushman M, Müller-Nurasyid M, Folsom AR, Basu S, Matijevic N, van Gilst WH, Kooner JS, Hofman A, Danesh J, Clarke R, Meigs JB, Kathiresan S, Reilly MP, Klopp N, Harris TB, Winkelmann BR, Grant PJ, Hillege HL, Watkins H, Spector TD, Becker LC, Tracy RP, März W, Uitterlinden AG, Eriksson P, Cambien F, Morange PE, Koenig W, Soranzo N, van der Harst P, Liu Y, O'Donnell CJ, and Hamsten A
- Subjects
- ARNTL Transcription Factors genetics, ATPases Associated with Diverse Cellular Activities, Adaptor Proteins, Signal Transducing genetics, Cell Line, Cell Line, Tumor, Cohort Studies, Coronary Artery Disease blood, Coronary Artery Disease genetics, Diabetes Mellitus, Type 2 blood, Diabetes Mellitus, Type 2 genetics, Gene Expression Profiling, Gene Expression Regulation, Gene Frequency, Genotype, Humans, LIM Domain Proteins genetics, Meta-Analysis as Topic, Monocytes metabolism, Mucin-3 genetics, PPAR gamma genetics, Proteasome Endopeptidase Complex, RNA Interference, Transcription Factors genetics, Genome-Wide Association Study methods, Plasminogen Activator Inhibitor 1 blood, Plasminogen Activator Inhibitor 1 genetics, Polymorphism, Single Nucleotide
- Abstract
We conducted a genome-wide association study to identify novel associations between genetic variants and circulating plasminogen activator inhibitor-1 (PAI-1) concentration, and examined functional implications of variants and genes that were discovered. A discovery meta-analysis was performed in 19 599 subjects, followed by replication analysis of genome-wide significant (P < 5 × 10(-8)) single nucleotide polymorphisms (SNPs) in 10 796 independent samples. We further examined associations with type 2 diabetes and coronary artery disease, assessed the functional significance of the SNPs for gene expression in human tissues, and conducted RNA-silencing experiments for one novel association. We confirmed the association of the 4G/5G proxy SNP rs2227631 in the promoter region of SERPINE1 (7q22.1) and discovered genome-wide significant associations at 3 additional loci: chromosome 7q22.1 close to SERPINE1 (rs6976053, discovery P = 3.4 × 10(-10)); chromosome 11p15.2 within ARNTL (rs6486122, discovery P = 3.0 × 10(-8)); and chromosome 3p25.2 within PPARG (rs11128603, discovery P = 2.9 × 10(-8)). Replication was achieved for the 7q22.1 and 11p15.2 loci. There was nominal association with type 2 diabetes and coronary artery disease at ARNTL (P < .05). Functional studies identified MUC3 as a candidate gene for the second association signal on 7q22.1. In summary, SNPs in SERPINE1 and ARNTL and an SNP associated with the expression of MUC3 were robustly associated with circulating levels of PAI-1.
- Published
- 2012
- Full Text
- View/download PDF
50. Evolution of placental function in mammals: the molecular basis of gas and nutrient transfer, hormone secretion, and immune responses.
- Author
-
Carter AM
- Subjects
- Animals, Female, Humans, Placental Hormones genetics, Placental Hormones metabolism, Pregnancy, Maternal-Fetal Exchange physiology, Placenta physiology, Placentation physiology
- Abstract
Placenta has a wide range of functions. Some are supported by novel genes that have evolved following gene duplication events while others require acquisition of gene expression by the trophoblast. Although not expressed in the placenta, high-affinity fetal hemoglobins play a key role in placental gas exchange. They evolved following duplications within the beta-globin gene family with convergent evolution occurring in ruminants and primates. In primates there was also an interesting rearrangement of a cassette of genes in relation to an upstream locus control region. Substrate transfer from mother to fetus is maintained by expression of classic sugar and amino acid transporters at the trophoblast microvillous and basal membranes. In contrast, placental peptide hormones have arisen largely by gene duplication, yielding for example chorionic gonadotropins from the luteinizing hormone gene and placental lactogens from the growth hormone and prolactin genes. There has been a remarkable degree of convergent evolution with placental lactogens emerging separately in the ruminant, rodent, and primate lineages and chorionic gonadotropins evolving separately in equids and higher primates. Finally, coevolution in the primate lineage of killer immunoglobulin-like receptors and human leukocyte antigens can be linked to the deep invasion of the uterus by trophoblast that is a characteristic feature of human placentation.
- Published
- 2012
- Full Text
- View/download PDF
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