225 results on '"Bennett DC"'
Search Results
2. Expression of NM23 in human melanoma progression and metastasis.
- Author
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Easty, DJ, Maung, K, Lascu, I, Véron, M, Fallowfield, ME, Hart, IR, Bennett, DC, Easty, D J, Véron, M, Fallowfield, M E, Hart, I R, and Bennett, D C
- Published
- 1996
- Full Text
- View/download PDF
3. Suppression of properties associated with malignancy in murine melanoma-melanocyte hybrid cells.
- Author
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Wakeling, WF, Greetham, J, Devlin, LM, and Bennett, DC
- Published
- 1992
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4. NALP1 in vitiligo-associated multiple autoimmune disease.
- Author
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Jin Y, Mailloux CM, Gowan K, Riccardi SL, LaBerge G, Bennett DC, Fain PR, and Spritz RA
- Published
- 2007
5. Cell Senescence and the Genetics of Melanoma Development.
- Author
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Constantinou SM and Bennett DC
- Subjects
- Humans, Telomerase genetics, Genetic Predisposition to Disease, Cyclin-Dependent Kinase Inhibitor p16 genetics, Ubiquitin-Protein Ligases, Retinoblastoma Binding Proteins, Melanoma genetics, Melanoma pathology, Cellular Senescence genetics, Skin Neoplasms genetics, Skin Neoplasms pathology, Mutation
- Abstract
Cutaneous malignant melanoma is an aggressive skin cancer with an approximate lifetime risk of 1 in 38 in the UK. While exposure to ultraviolet radiation is a key environmental risk factor for melanoma, up to ~10% of patients report a family history of melanoma, and ~1% have a strong family history. The understanding of causal mutations in melanoma has been critical to the development of novel targeted therapies that have contributed to improved outcomes for late-stage patients. Here, we review current knowledge of the genes affected by familial melanoma mutations and their partial overlap with driver genes commonly mutated in sporadic melanoma development. One theme linking a set of susceptibility loci/genes is the regulation of skin pigmentation and suntanning. The largest functional set of susceptibility variants, typically with high penetrance, includes CDKN2A, RB1, and telomerase reverse transcriptase (TERT) mutations, associated with attenuation of cell senescence. We discuss the mechanisms of action of these gene sets in the biology and progression of nevi and melanoma., (© 2024 The Author(s). Genes, Chromosomes and Cancer published by Wiley Periodicals LLC.)
- Published
- 2024
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6. The Caenorhabditis elegans protein SOC-3 permits an alternative mode of signal transduction by the EGL-15 FGF receptor.
- Author
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Rodriguez Torres CS, Wicker NB, Puccini de Castro V, Stefinko M, Bennett DC, Bernhardt B, Garcia Montes de Oca M, Jallow S, Flitcroft K, Palalay JS, Payán Parra OA, Stern YE, Koelle MR, Voisine C, Woods IG, Lo TW, Stern MJ, and de la Cova CC
- Subjects
- Animals, Mutation genetics, Mitogen-Activated Protein Kinase 1, Caenorhabditis elegans metabolism, Caenorhabditis elegans genetics, Caenorhabditis elegans Proteins metabolism, Caenorhabditis elegans Proteins genetics, Signal Transduction genetics, Receptors, Fibroblast Growth Factor metabolism, Receptors, Fibroblast Growth Factor genetics
- Abstract
Fibroblast Growth Factors and their receptors (FGFRs) comprise a cell signaling module that can stimulate signaling by Ras and the kinases Raf, MEK, and ERK to regulate animal development and homeostatic functions. In Caenorhabditis elegans, the sole FGFR ortholog EGL-15 acts with the GRB2 ortholog SEM-5 to promote chemoattraction and migration by the sex myoblasts (SMs) and fluid homeostasis by the hypodermis (Hyp7). Cell-specific differences in EGL-15 signaling were suggested by the phenotypes caused by egl-15(n1457), an allele that removes a region of its C-terminal domain (CTD) known to bind SEM-5. To determine how mutations altered EGL-15 activity in the SMs and Hyp7, we used the kinase reporter ERK-KTR to measure activation of the ERK ortholog MPK-1. Consequences of egl-15(n1457) were cell-specific, resulting in loss of MPK-1 activity in the SMs and elevated activity in Hyp7. Previous studies of Hyp7 showed that loss of the CLR-1 phosphatase causes a fluid homeostasis defect termed "Clear" that is suppressed by reduction of EGL-15 signaling, a phenotype termed "Suppressor of Clear" (Soc). To identify mechanisms that permit EGL-15 signaling in Hyp7, we conducted a genetic screen for Soc mutants in the clr-1; egl-15(n1457) genotype. We report the identification of SOC-3, a protein with putative SEM-5-binding motifs and PH and PTB domains similar to DOK and IRS proteins. In combination with the egl-15(n1457) mutation, loss of either soc-3, the GAB1 ortholog soc-1, or the SHP2 ortholog ptp-2, reduced MPK-1 activation. We generated alleles of soc-3 to test the requirement for the SEM-5-binding motifs, finding that residue Tyr
356 is required for function. We propose that EGL-15-mediated SM chemoattraction relies solely on the direct interaction between SEM-5 and the EGL-15 CTD. In Hyp7, EGL-15 signaling uses two mechanisms: the direct SEM-5 binding mechanism; and an alternative, CTD-independent mechanism involving SOC-3, SOC-1, and PTP-2. This work demonstrates that FGF signaling uses distinct, tissue-specific mechanisms in development, and identifies SOC-3 as a potential adaptor that facilitates Ras pathway activation by FGFR., (Copyright © 2024 Elsevier Inc. All rights reserved.)- Published
- 2024
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7. The effects of Religiosity, Spirituality, and sense of purpose on posttraumatic stress disorder treatment outcomes among Veterans.
- Author
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Fry KM, Bennett DC, Roberge EM, McClain CM, Rugo-Cook K, Brewczynski J, and Pryor C
- Subjects
- Humans, Male, Female, Middle Aged, Adult, Treatment Outcome, Implosive Therapy, Religion, Psychiatric Status Rating Scales, Aged, Veterans, Stress Disorders, Post-Traumatic therapy, Spirituality, Cognitive Behavioral Therapy methods
- Abstract
Background: Religion/spirituality (R/S) is an important and commonly used resource for coping with difficult experiences and has been shown to reduce the development of posttraumatic stress disorder (PTSD) symptoms following a trauma. However, it is not clear how R/S affects response to treatment of PTSD., Objective: The aim of this paper was to understand how Veterans' R/S and sense of purpose were related to clinical outcomes when engaging in Cognitive Processing Therapy (CPT) or Prolonged Exposure (PE). It was predicted that Veterans identifying as R/S would have a higher sense of purpose, be more likely to complete treatment, and have greater symptom change during treatment., Method: The study included 91 military Veterans from a VA Medical Center outpatient PTSD Clinical Team who initiated CPT or PE and responded to a question about the importance of R/S in their lives at intake., Results: Forty nine percent of the Veterans in this sample reported R/S were important to them and had mixed feelings about whether their life had a clear sense of purpose. Neither R/S nor sense of purpose were associated with treatment completion or response to PTSD treatment., Conclusion: These findings suggest that once PTSD has developed, R/S or sense of purpose may not play a significant role in completion of or response to evidence-based psychotherapies (EBPs) for PTSD. EBPs for PTSD are equally effective for Veterans identifying as R/S and those who do not, which may be reflective of administering EBPs in a culturally responsive manner., Competing Interests: Declaration of competing interest The views expressed are those of the authors and do not necessarily reflect the official policy or position of the Department of Veterans Affairs or U.S. Government. The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Published by Elsevier Ltd.)
- Published
- 2024
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8. RNA Therapy for Oncogenic NRAS-Driven Nevi Induces Apoptosis.
- Author
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Bryant D, Barberan-Martin S, Maeshima R, Del Valle Torres I, Rabii M, Baird W, Sauvadet A, Demetriou C, Jones P, Knöpfel N, Michailidis F, Riachi M, Bennett DC, Zecchin D, Pittman A, Polubothu S, Hart S, and Kinsler VA
- Abstract
RAS proteins regulate cell division, differentiation, and apoptosis through multiple downstream effector pathways. Oncogenic RAS variants are the commonest drivers in cancers; however, they also drive many benign lesions predisposing to malignancy, such as melanocytic nevi, thyroid nodules, and colonic polyps. Reversal of these benign lesions could reduce cancer incidence; however, the effects of oncogenic RAS have been notoriously difficult to target with downstream pathway inhibitors. In this study, we show effective suppression of oncogenic and currently undruggable NRAS
Q61K in primary cells from melanocytic nevi using small interfering RNA targeted to the recurrent causal variant. This results in striking reduction in expression of ARL6IP1, a known inhibitor of endoplasmic reticulum stress-induced apoptosis not previously linked to NRAS. We go on to show that a single dose of small interfering RNA in primary cells triggers an apoptotic cascade, in contrast to treatment with a MAPK/extracellular signal-regulated kinase kinase inhibitor. Protective packaging of the targeted small interfering RNA into lipid nanoparticles permits successful delivery into a humanized mouse model of melanocytic nevi and results in variant NRAS knockdown in vivo. These data show that RAS-induced protection from apoptosis is involved in persistence of NRAS-driven melanocytic nevi and anticipate that targeted small interfering RNA could form the basis of clinical trials for RAS-driven benign tumors., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)- Published
- 2024
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9. Review: Are moles senescent?
- Author
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Bennett DC
- Subjects
- Humans, Animals, Nevus, Pigmented pathology, Nevus, Pigmented genetics, Mice, Telomere metabolism, Telomere genetics, Cellular Senescence genetics, Skin Neoplasms pathology, Skin Neoplasms genetics, Skin Neoplasms metabolism
- Abstract
Melanocytic nevi (skin moles) have been regarded as a valuable example of cell senescence occurring in vivo. However, a study of induced nevi in a mouse model reported that the nevi were arrested by cell interactions rather than a cell-autonomous process like senescence, and that size distributions of cell nests within nevi could not be accounted for by a stochastic model of oncogene-induced senescence. Moreover, others reported that some molecular markers used to identify cell senescence in human nevi are also found in melanoma cells-not senescent. It has thus been questioned whether nevi really are senescent, with potential implications for melanoma diagnosis and therapy. Here I review these areas, along with the genetic, biological, and molecular evidence supporting senescence in nevi. In conclusion, there is strong evidence that cells of acquired human benign (banal) nevi are very largely senescent, though some must contain a minor non-senescent cell subpopulation. There is also persuasive evidence that this senescence is primarily induced by dysfunctional telomeres rather than directly oncogene-induced., (© 2024 The Authors. Pigment Cell & Melanoma Research published by John Wiley & Sons Ltd.)
- Published
- 2024
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10. Contrasting ecological contexts among treatment-seeking military sexual assault survivors: Consideration of relationships with sexual and gender minority identification.
- Author
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Paulson JL, Florimbio AR, Rogers TA, Hartl Majcher J, Bennett DC, and Sexton MB
- Subjects
- Humans, Survivors, Military Personnel psychology, Sex Offenses psychology, Veterans psychology, Sexual and Gender Minorities
- Abstract
Survivors of military sexual trauma (MST) seeking mental health services may present with concerns extending beyond symptom relief. Attention to social, economic, and coping resource contexts is salient for care consideration. Although those identifying as sexual and gender minorities (SGM) are overrepresented among service members exposed to assaultive MST, research contrasting ecological resource variability among treatment seekers is limited. The present study delineates modifiable risk and protective factors that might be used to inform MST-related health care for Veterans, broadly, and SGM-identifying Veterans, specifically. Veterans ( N = 493, 12.8% identifying as SGM) presenting for treatment secondary to military sexual assault completed a semistructured clinical interview and intake survey including demographic characteristics, diversity-related factors, and access to psychosocial resources. SGM/non-SGM-identifying groups were contrasted on individual-, interpersonal-, and community-level ecological characteristics. SGM-identifying Veterans were less likely to report access to sufficient financial resources and had double the prevalence rate of housing instability in contrast to non-SGM-identifying Veterans. No significant differences emerged in terms of past-year interpersonal violence exposure, endorsement of helpful spiritual beliefs, or availability of social support based on SGM identification. Findings underscore the importance of attending to the intersection of SGM identity and ecological factors that can influence Veterans' clinical presentation and treatment engagement. Recommendations for provision of MST services are made. (PsycInfo Database Record (c) 2024 APA, all rights reserved).
- Published
- 2024
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11. Preferential killing of melanoma cells by a p16-related peptide.
- Author
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Soo JK, Castle JT, and Bennett DC
- Subjects
- Humans, HeLa Cells, Cellular Senescence, Melanocytes metabolism, Retinoblastoma Protein metabolism, Cyclin-Dependent Kinase Inhibitor p16 genetics, Cyclin-Dependent Kinase Inhibitor p16 metabolism, Melanoma
- Abstract
We report the identification of a synthetic, cell-penetrating peptide able to kill human melanoma cells efficiently and selectively, while being less toxic to normal human melanocytes and nontoxic to human fibroblasts. The peptide is based on the target-binding site of the melanoma suppressor and senescence effector p16 (also known as INK4A or CDKN2A), coupled to a cell-penetrating moiety. The killing is by apoptosis and appears to act by a route other than the canonical downstream target of p16 and CDK4, the retinoblastoma (RB) protein family, as it is also effective in HeLa cells and a melanocyte line expressing HPV E7 oncogenes, which both lack any active RB. There was varying toxicity to other types of cancer cell lines, such as glioblastoma. Melanoma cell killing by a p16-derived peptide was reported once before but only at a higher concentration, while selectivity and generality were not previously tested., Competing Interests: Competing interests The authors declare no competing or financial interests., (© 2023. Published by The Company of Biologists Ltd.)
- Published
- 2023
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12. Coordination of canonical and noncanonical Hedgehog signalling pathways mediated by WDR11 during primordial germ cell development.
- Author
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Lee J, Kim Y, Ataliotis P, Kim HG, Kim DW, Bennett DC, Brown NA, Layman LC, and Kim SH
- Subjects
- Cell Differentiation, Biological Transport, Germ Cells, Hedgehog Proteins genetics, Signal Transduction
- Abstract
WDR11, a gene associated with Kallmann syndrome, is important in reproductive system development but molecular understanding of its action remains incomplete. We previously reported that Wdr11-deficient embryos exhibit defective ciliogenesis and developmental defects associated with Hedgehog (HH) signalling. Here we demonstrate that WDR11 is required for primordial germ cell (PGC) development, regulating canonical and noncanonical HH signalling in parallel. Loss of WDR11 disrupts PGC motility and proliferation driven by the cilia-independent, PTCH2/GAS1-dependent noncanonical HH pathway. WDR11 modulates the growth of somatic cells surrounding PGCs by regulating the cilia-dependent, PTCH1/BOC-dependent canonical HH pathway. We reveal that PTCH1/BOC or PTCH2/GAS1 receptor context dictates SMO localisation inside or outside of cilia, respectively, and loss of WDR11 affects the signalling responses of SMO in both situations. We show that GAS1 is induced by PTCH2-specific HH signalling, which is lost in the absence of WDR11. We also provide evidence supporting a role for WDR11 in ciliogenesis through regulation of anterograde intraflagellar transport potentially via its interaction with IFT20. Since WDR11 is a target of noncanonical SMO signalling, WDR11 represents a novel mechanism by which noncanonical and canonical HH signals communicate and cooperate., (© 2023. The Author(s).)
- Published
- 2023
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13. Isolation, Culture, and Transfection of Melanocytes.
- Author
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Goff PS, Castle JT, Kohli JS, Sviderskaya EV, and Bennett DC
- Subjects
- Humans, Animals, Mice, Melanins, Ultraviolet Rays, Melanocytes, Transfection, Melanoma genetics, Nevus, Pigmented, Skin Neoplasms
- Abstract
Located in the basal epidermis and hair follicles, melanocytes of the integument are responsible for its coloration through production of melanin pigments. Melanin is produced in a type of lysosome-related-organelle (LRO) called the melanosome. In humans, this skin pigmentation acts as an ultraviolet radiation filter. Abnormalities in the division of melanocytes are quite common, with potentially oncogenic growth usually followed by cell senescence producing benign naevi (moles), or occasionally, melanoma. Therefore, melanocytes are a useful model for studying both cellular senescence and melanoma, as well as many other aspects of biology such as pigmentation, organelle biogenesis and transport, and the diseases affecting these mechanisms. Melanocytes for use in basic research can be obtained from a range of sources, including surplus postoperative skin or from congenic murine skin. Here we describe methods to isolate and culture melanocytes from both human and murine skin (including the preparation of mitotically inactive keratinocytes for use as feeder cells). We also describe a high-throughput transfection protocol for human melanocytes and melanoma cells. © 2023 The Authors. Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: Primary explantation of human melanocytic cells Basic Protocol 2: Preparation of keratinocyte feeder cells for use in the primary culture of mouse melanocytes Basic Protocol 3: Primary culture of melanocytes from mouse skin Basic Protocol 4: Transfection of human melanocytes and melanoma cells., (© 2023 The Authors. Current Protocols published by Wiley Periodicals LLC.)
- Published
- 2023
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14. Microbial diversity and metabolic function in duodenum, jejunum and ileum of emu (Dromaius novaehollandiae).
- Author
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Kim JE, Tun HM, Bennett DC, Leung FC, and Cheng KM
- Subjects
- Animals, Male, Female, RNA, Ribosomal, 16S genetics, Duodenum, Ileum, Bacteria genetics, Jejunum microbiology, Dromaiidae
- Abstract
Emus (Dromaius novaehollandiae), a large flightless omnivorous ratite, are farmed for their fat and meat. Emu fat can be rendered into oil for therapeutic and cosmetic use. They are capable of gaining a significant portion of its daily energy requirement from the digestion of plant fibre. Despite of its large body size and low metabolic rate, emus have a relatively simple gastroinstetinal (GI) tract with a short mean digesta retention time. However, little is known about the GI microbial diversity of emus. The objective of this study was to characterize the intraluminal intestinal bacterial community in the different segments of small intestine (duodenum, jejunum, and ileum) using pyrotag sequencing and compare that with the ceca. Gut content samples were collected from each of four adult emus (2 males, 2 females; 5-6 years old) that were free ranged but supplemented with a barley-alfalfa-canola based diet. We amplified the V3-V5 region of 16S rRNA gene to identify the bacterial community using Roche 454 Junior system. After quality trimming, a total of 165,585 sequence reads were obtained from different segments of the small intestine (SI). A total of 701 operational taxonomic units (OTUs) were identified in the different segments of small intestine. Firmicutes (14-99%) and Proteobacteria (0.5-76%) were the most predominant bacterial phyla in the small intestine. Based on species richness estimation (Chao1 index), the average number of estimated OTUs in the small intestinal compartments were 148 in Duodenum, 167 in Jejunum, and 85 in Ileum, respectively. Low number of core OTUs identified in each compartment of small intestine across individual birds (Duodenum: 13 OTUs, Jejunum: 2 OTUs, Ileum: 14 OTUs) indicated unique bacterial community in each bird. Moreover, only 2 OTUs (Escherichia and Sinobacteraceae) were identified as core bacteria along the whole small intestine. PICRUSt analysis has indicated that the detoxification of plant material and environmental chemicals seem to be performed by SI microbiota, especially those in the jejunum. The emu cecal microbiome has more genes than SI segments involving in protective or immune response to enteric pathogens. Microbial digestion and fermentation is mostly in the jejunum and ceca. This is the first study to characterize the microbiota of different compartments of the emu intestines via gut samples and not fecal samples. Results from this study allow us to further investigate the influence of the seasonal and physiological changes of intestinal microbiota on the nutrition of emus and indirectly influence the fatty acid composition of emu fat., (© 2023. The Author(s).)
- Published
- 2023
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15. Characteristics associated with non-suicidal self-injury among veterans seeking military sexual trauma-related mental healthcare.
- Author
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Cawood CD, Bennett DC, Lusk RK, Lass ANS, Christ NM, Sholander LE, and Sexton MB
- Subjects
- Humans, Mental Health Services, Retrospective Studies, Stress Disorders, Post-Traumatic epidemiology, Stress Disorders, Post-Traumatic psychology, Military Sexual Trauma therapy, Self-Injurious Behavior epidemiology, Self-Injurious Behavior psychology, Veterans psychology, Patient Acceptance of Health Care
- Abstract
Military sexual trauma (MST) is a serious issue among Veterans; it is associated with increased rates of posttraumatic stress disorder (PTSD) and nonsuicidal self-injury (NSSI), both of which are correlated with poorer mental health outcomes, including increased suicide risk. Additional insight into the characteristics associated with NSSI among Veterans with MST can help identify individuals at increased risk for suicide and other negative outcomes and improve care for Veterans with a history of MST. The current study was comprised of 327 Veterans referred for MST-related mental health services at a VHA hospital. Participants completed a semi-structured interview for clinical symptoms, including NSSI behaviors. Results of a retrospective chart review revealed a high endorsement of lifetime NSSI (26.9%) with cutting behaviors identified as the most frequently endorsed method. Logistic regression showed personality features, history of cumulative sexual trauma, and younger age were uniquely related to lifetime NSSI. These results corroborate previous findings that show elevated rates of NSSI among Veterans with exposure to trauma. This study expands upon previous findings by examining risk factors specific to treatment-seeking Veterans with a history of MST, which can aid clinical care and risk management procedures in Veteran healthcare., Competing Interests: Declaration of competing interest None., (Copyright © 2022. Published by Elsevier Ltd.)
- Published
- 2023
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16. Seasonal and sexual variation in mRNA expression of selected adipokine genes affecting fat deposition and metabolism of the emu (Dromaius novaehollandiae).
- Author
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Kim JE, Bennett DC, Wright K, and Cheng KM
- Subjects
- Adipokines genetics, Animals, Phylogeny, RNA, Messenger genetics, Seasons, Dromaiidae
- Abstract
Emus are farmed for fat production. Oil rendered from their back and abdominal fat pads has good anti-oxidant and anti-inflammatory properties and has ingredients that promote cell growth. Our objective is to examine the mRNA expression of 7 emu adipokine genes (eFABP4, eSCD1, eAdipoQ, eAdipoR1, eAdipoR2, eLEP and eLepR) to identify gene markers that may help improve emu fat production. Back and abdominal fat tissues from 11 adult emus were biopsied at four time points (April, June, August and November). Total RNA was isolated and cDNA was synthesized. Gene specific primers were designed for partial cloning fragments to amplify the open reading frame of the 7 genes. eLEP was not expressed in emu fat tissue. Nucleotides and amino acids sequences of the 6 expressed gene were compared with homologs from other species and phylogenetic relationships established. Seasonal mRNA expression of each gene was assessed by quantitative RT-PCR and differential expression analysed by the 2
-ΔΔC T method. The 6 expressed genes showed seasonal variation in expression and showed association of expression level with back fat adiposity. More whole-genome scanning studies are needed to develop novel molecular markers that can be applied to improve fat production in emus., (© 2022. The Author(s).)- Published
- 2022
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17. Mahogunin Ring Finger 1 regulates pigmentation by controlling the pH of melanosomes in melanocytes and melanoma cells.
- Author
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Sirés-Campos J, Lambertos A, Delevoye C, Raposo G, Bennett DC, Sviderskaya E, Jiménez-Cervantes C, Olivares C, and García-Borrón JC
- Subjects
- Animals, Humans, Hydrogen-Ion Concentration, Melanocytes, Melanoma, Experimental, Melanosomes, Mice, Skin cytology, Skin pathology, Pigmentation, Skin metabolism, Transient Receptor Potential Channels metabolism, Ubiquitin-Protein Ligases physiology
- Abstract
Mahogunin Ring Finger 1 (MGRN1) is an E3-ubiquitin ligase absent in dark-furred mahoganoid mice. We investigated the mechanisms of hyperpigmentation in Mgrn1-null melan-md1 melanocytes, Mgrn1-KO cells obtained by CRISPR-Cas9-mediated knockdown of Mgrn1 in melan-a6 melanocytes, and melan-a6 cells depleted of MGRN1 by siRNA treatment. Mgrn1-deficient melanocytes showed higher melanin content associated with increased melanosome abundance and higher fraction of melanosomes in highly melanized maturation stages III-IV. Expression, post-translational processing and enzymatic activity of the rate-limiting melanogenic enzyme tyrosinase measured in cell-free extracts were comparable in control and MGRN1-depleted cells. However, tyrosinase activity measured in situ in live cells and expression of genes associated with regulation of pH increased upon MGRN1 repression. Using pH-sensitive fluorescent probes, we found that downregulation of MGRN1 expression in melanocytes and melanoma cells increased the pH of acidic organelles, including melanosomes, strongly suggesting a previously unknown role of MGRN1 in the regulation of melanosomal pH. Among the pH regulatory genes upregulated by Mgrn1 knockdown, we identified those encoding several subunits of the vacuolar adenosine triphosphatase V-ATPase (mostly Atp6v0d2) and a calcium channel of the transient receptor potential channel family, Mucolipin 3 (Mcoln3). Manipulation of expression of the Mcoln3 gene showed that overexpression of Mcoln3 played a significant role in neutralization of the pH of acidic organelles and activation of tyrosinase in MGRN1-depleted cells. Therefore, lack of MGRN1 led to cell-autonomous stimulation of pigment production in melanocytes mostly by increasing tyrosinase specific activity through neutralization of the melanosomal pH in a MCOLN3-dependent manner., (© 2021. The Author(s).)
- Published
- 2021
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18. A BLOC-1-AP-3 super-complex sorts a cis-SNARE complex into endosome-derived tubular transport carriers.
- Author
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Bowman SL, Le L, Zhu Y, Harper DC, Sitaram A, Theos AC, Sviderskaya EV, Bennett DC, Raposo-Benedetti G, Owen DJ, Dennis MK, and Marks MS
- Subjects
- Endosomes genetics, Humans, Melanocytes metabolism, Melanosomes genetics, Protein Transport genetics, Adaptor Protein Complex 3 genetics, Adaptor Protein Complex delta Subunits genetics, Nerve Tissue Proteins genetics, Qa-SNARE Proteins genetics, R-SNARE Proteins genetics
- Abstract
Membrane transport carriers fuse with target membranes through engagement of cognate vSNAREs and tSNAREs on each membrane. How vSNAREs are sorted into transport carriers is incompletely understood. Here we show that VAMP7, the vSNARE for fusing endosome-derived tubular transport carriers with maturing melanosomes in melanocytes, is sorted into transport carriers in complex with the tSNARE component STX13. Sorting requires either recognition of VAMP7 by the AP-3δ subunit of AP-3 or of STX13 by the pallidin subunit of BLOC-1, but not both. Consequently, melanocytes expressing both AP-3δ and pallidin variants that cannot bind their respective SNARE proteins are hypopigmented and fail to sort BLOC-1-dependent cargo, STX13, or VAMP7 into transport carriers. However, SNARE binding does not influence BLOC-1 function in generating tubular transport carriers. These data reveal a novel mechanism of vSNARE sorting by recognition of redundant sorting determinants on a SNARE complex by an AP-3-BLOC-1 super-complex., (© 2021 Bowman et al.)
- Published
- 2021
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19. SLC45A2 protein stability and regulation of melanosome pH determine melanocyte pigmentation.
- Author
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Le L, Escobar IE, Ho T, Lefkovith AJ, Latteri E, Haltaufderhyde KD, Dennis MK, Plowright L, Sviderskaya EV, Bennett DC, Oancea E, and Marks MS
- Subjects
- Animals, Antigens, Neoplasm physiology, Carrier Proteins metabolism, Cell Line, Chloride Channels metabolism, HeLa Cells, Humans, Lysosomes metabolism, Male, Melanosomes metabolism, Membrane Transport Proteins physiology, Mice, Pigmentation physiology, Protein Stability, Skin metabolism, Antigens, Neoplasm metabolism, Melanocytes metabolism, Membrane Transport Proteins metabolism, Skin Pigmentation physiology
- Abstract
SLC45A2 encodes a putative transporter expressed primarily in pigment cells. SLC45A2 mutations cause oculocutaneous albinism type 4 (OCA4) and polymorphisms are associated with pigmentation variation, but the localization, function, and regulation of SLC45A2 and its variants remain unknown. We show that SLC45A2 localizes to a cohort of mature melanosomes that only partially overlaps with the cohort expressing the chloride channel OCA2. SLC45A2 expressed ectopically in HeLa cells localizes to lysosomes and raises lysosomal pH, suggesting that in melanocytes SLC45A2 expression, like OCA2 expression, results in the deacidification of maturing melanosomes to support melanin synthesis. Interestingly, OCA2 overexpression compensates for loss of SLC45A2 expression in pigmentation. Analyses of SLC45A2- and OCA2-deficient mouse melanocytes show that SLC45A2 likely functions later during melanosome maturation than OCA2. Moreover, the light skin-associated SLC45A2 allelic F374 variant restores only moderate pigmentation to SLC45A2-deficient melanocytes due to rapid proteasome-dependent degradation resulting in lower protein expression levels in melanosomes than the dark skin-associated allelic L374 variant. Our data suggest that SLC45A2 maintains melanosome neutralization that is initially orchestrated by transient OCA2 activity to support melanization at late stages of melanosome maturation, and that a common allelic variant imparts reduced activity due to protein instability.
- Published
- 2020
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20. Mahogunin Ring Finger 1 Is Required for Genomic Stability and Modulates the Malignant Phenotype of Melanoma Cells.
- Author
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Martínez-Vicente I, Abrisqueta M, Herraiz C, Sirés-Campos J, Castejón-Griñán M, Bennett DC, Olivares C, García-Borrón JC, and Jiménez-Cervantes C
- Abstract
The mouse mahoganoid mutation abrogating Mahogunin Ring Finger-1 (MGRN1) E3 ubiquitin ligase expression causes hyperpigmentation, congenital heart defects and neurodegeneration. To study the pathophysiology of MGRN1 loss, we compared Mgrn1 -knockout melanocytes with genetically matched controls and melan-md1 ( mahoganoid ) melanocytes. MGRN1 knockout induced a more differentiated and adherent phenotype, decreased motility, increased the percentage of cells in the S phase of the cell cycle and promoted genomic instability, as shown by stronger γH2AX labelling, increased burden of DNA breaks and higher abundance of aneuploid cells. Lack of MGRN1 expression decreased the ability of melanocytes to cope with DNA breaks generated by oxidizing agents or hydroxyurea-induced replicative stress, suggesting a contribution of genomic instability to the mahoganoid phenotype. MGRN1 knockout in B16-F10 melanoma cells also augmented pigmentation, increased cell adhesion to collagen, impaired 2D and 3D motility and caused genomic instability. Tumors formed by Mgrn1 -KO B16-F10 cells had lower mitotic indices, fewer Ki67-positive cells and showed a trend towards smaller size. In short-term lung colonization assays Mgrn1-KO cells showed impaired colonization potential. Moreover, lower expression of MGRN1 is significantly associated with better survival of human melanoma patients. Therefore, MGRN1 might be an important phenotypic determinant of melanoma cells.
- Published
- 2020
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21. Effects of subzero saline chilling on broiler chilling efficiency, meat quality, and microbial safety.
- Author
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Lee HC, Metheny MM, Viliani S, Bennett DC, Hurley S, and Kang I
- Subjects
- Animals, Colony Count, Microbial veterinary, Saline Waters pharmacology, Bacteria drug effects, Chickens, Cold Temperature, Food Handling methods, Food Microbiology methods, Meat microbiology, Meat standards
- Abstract
The poultry industry has attempted to improve carcass chilling efficiency, meat quality, and product safety. The purpose of this research was to investigate the effects of subzero saline chilling on carcass chilling, breast fillet tenderness, and microbial safety. After evisceration, broiler carcasses were chilled using ice slurry control (0% NaCl/0.5°C) or subzero saline solutions (3% NaCl/-1.8°C and 4% NaCl/-2.41°C). Broiler carcasses in the subzero saline solutions were chilled efficiently and reduced the chilling time by 11% in 3% NaCl/-1.8°C and 37% in 4% NaCl/-2.41°C over the ice slurry chilling. The breast fillets of broiler carcasses in 4% NaCl/-2.41°C were significantly tenderized than those in water control (P < 0.05), with an intermediate value observed in 3% NaCl/-1.8°C. Before chilling, broiler carcasses possessed mesophilic aerobic bacteria, Escherichia coli, and total coliforms for 3.81, 0.78, and 1.86 log cfu/g, respectively, which were significantly reduced after chilling in 3% NaCl/-1.8°C or 4% NaCl/-2.41°C solution over the water control (P < 0.05), except the mesophilic aerobic bacteria. Based on these results, chilling of boiler carcass in 4% NaCl/-1.8°C solution appears to improve carcass chilling efficiency, meat tenderness, and bacterial reduction for E. coli and total coliforms., (Copyright © 2020. Published by Elsevier Inc.)
- Published
- 2020
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22. Pullet Rearing Affects Collisions and Perch Use in Enriched Colony Cage Layer Housing.
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Pullin AN, Temple SM, Bennett DC, Rufener CB, Blatchford RA, and Makagon MM
- Abstract
Hens reared in aviaries (AVI) as pullets have improved spatial abilities compared to hens reared in non-enriched cages (CON). However, this effect on behavior has been shown only to 23 weeks of age. Lohmann LSL-Lite hens were reared in either CON or AVI until 19 weeks of age and then moved into enriched colony cages (ECC) containing two elevated perches of different heights ( n = 6 ECC/treatment). Focal hens (3 per ECC) were fitted with tri-axial accelerometers to record acceleration events at 21, 35, and 49 weeks of age. Video recordings from each age were used to identify behaviors associated with acceleration events as well as the proportion of hens utilizing perches. CON hens experienced more acceleration events ( p = 0.008) and more collisions ( p = 0.04) than AVI hens during the day at 21 and 35 weeks of age. The total proportion of hens perching at night was similar between treatments across most time points, but fewer CON hens used the high perch compared to AVI hens throughout the study ( p = < 0.001). Rearing in aviaries influences hen behavior out to peak lay for collisions and out to mid-lay for perch height preference in ECC.
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- 2020
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23. Evaluation of potential human health risk associated with consumption of edible products from livestock fed ration supplemented with Red Lake Diatomaceous Earth.
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Wikoff DS, Bennett DC, Brorby GP, and Franke KS
- Subjects
- Animals, Chickens, Food Safety, Humans, Risk Assessment, Diatomaceous Earth chemistry, Dioxins analysis, Environmental Monitoring, Food Analysis, Food Contamination analysis, Ovum chemistry
- Abstract
Red Lake Diatomaceous Earth (DE) is a naturally occurring blend of diatomaceous earth and calcium bentonite that can be used as an anti-caking agent in animal feed and contains naturally occurring dioxins. A quantitative risk assessment was conducted to assess potential human health risk associated with consumption of edible tissues from livestock exposed to dioxins via feed containing Red Lake DE. Empirical data characterising the transfer of dioxins to eggs and other tissues in chickens demonstrate that resulting concentrations in eggs are lower than those found in the general food supply. These data also provided product-specific input for a risk assessment conducted both with default parameters and with media-specific input from the feed study. Results demonstrate that exposure to dioxins in edible tissue from livestock that consumed Red Lake DE in feed would not be associated with an increased risk to humans. Findings from this assessment highlight the utility and importance of accounting for bioavailability as part of health-based risk assessment and provide information critical to risk managers in determining the safe use of Red Lake DE as an anticaking agent in livestock and pet feed.
- Published
- 2020
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24. Military Sexual Trauma Survivor Preferences for Provider Gender and Associations With Mental Health Evaluation Attendance.
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Sexton MB, Anderson RE, Bennett DC, Thomas EJ, Broman RB, and Richards SKH
- Abstract
Competing Interests: The authors have no conflicts of interest to report.
- Published
- 2020
25. The Reliability and Accuracy of Palpation, Radiography, and Sonography for the Detection of Keel Bone Damage.
- Author
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Tracy LM, Temple SM, Bennett DC, Sprayberry KA, Makagon MM, and Blatchford RA
- Abstract
Palpation is the most popular method of measuring keel bone damage on live birds, although it has been criticized for being subjective and inaccurate. The goals of this study were to examine intra- and inter-rater reliability when trained with feedback of accuracy, as well as determine the accuracy of portable radiography and sonography. Four evaluators palpated 50 103-week old Lohmann LSL-lite hens immediately following euthanasia. Of those birds, 34 were then radiographed, sonographed, and all 50 were re-palpated. Lastly, the keels were dissected and scored. The presence of deviations (DEV), fractures (FR), and tip fractures (TFR) was scored for each method. Reliability of palpation was analyzed using Cronbach's Alpha (intra) and Fleiss' Kappa (inter) tests. Radiography and Sonography scores were further compared with dissection scores to determine sensitivity and specificity. Initial inter-observer reliability was 0.39 DEV, 0.53 FR, and 0.12 TFR, with similar scores for the second round of palpation. Scores for intra-observer reliability ranged from 0.58-0.79 DEV, 0.66-0.90 FR, and 0.37-0.87 TFR. A high prevalence of TFR, but low assessor agreement, warrants the development of specialized training for the palpation of this area. Both radiography and sonography showed relatively high sensitivity for FR and TFR, but low for DEV. On the other hand, specificity was generally high across all damage types. Even with feedback, palpation reliability was poor. However, portable radiography and sonography show promise for detecting keel fractures.
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- 2019
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26. Cell Senescence and Cerebral Small Vessel Disease in the Brains of People Aged 80 Years and Older.
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Norton EJ, Bridges LR, Kenyon LC, Esiri MM, Bennett DC, and Hainsworth AH
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- Aged, 80 and over, Aging pathology, Aging physiology, Cerebral Arteries pathology, Cerebral Arteries physiopathology, Female, Humans, Male, White Matter pathology, White Matter physiopathology, Brain physiology, Brain physiopathology, Cellular Senescence, Cerebral Small Vessel Diseases pathology, Cerebral Small Vessel Diseases physiopathology
- Abstract
Cerebral small vessel disease (cSVD) in penetrating arteries is a major cause of age-related morbidity. Cellular senescence is a molecular process targeted by novel senolytic drugs. We quantified senescence in penetrating arteries and tested whether myocyte senescence was associated with cSVD. We immunolabeled subcortical white matter of older persons (age 80-96 years, n = 60) with minimal AD, using antibodies to 2 established senescence markers (H3K9me3, γH2AX) and a myocyte marker (hSMM). Within the walls of penetrating arteries (20-300 µm), we quantified senescence-associated heterochromatic foci (SAHF)-positive nuclei, cell density (nuclei/µm2), and sclerotic index (SI). Senescent-appearing mural cells were present in small arteries of all cases. cSVD cases exhibited a lower proportion of senescent-appearing cells and lower area fraction (AF%) of SAHF-positive nuclei compared to controls (p = 0.014, 0.016, respectively). cSVD severity and SI both correlated negatively with AF% (p = 0.013, 0.002, respectively). Mural cell density was lower (p < 0.001) and SI higher (p < 0.001) in cSVD, relative to controls. In conclusion, senescent myocyte-like cells were universal in penetrating arteries of an AD-free cohort aged 80 years and older. Senescent-appearing nuclei were more common in persons aged 80 years and older without cSVD compared to cSVD cases, indicating caution in senolytic drug prescribing. Myocyte senescence and cSVD may represent alternative vessel fates in the aging human brain., (© 2019 American Association of Neuropathologists, Inc. All rights reserved.)
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- 2019
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27. Cellular Senescence: Defining a Path Forward.
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Gorgoulis V, Adams PD, Alimonti A, Bennett DC, Bischof O, Bishop C, Campisi J, Collado M, Evangelou K, Ferbeyre G, Gil J, Hara E, Krizhanovsky V, Jurk D, Maier AB, Narita M, Niedernhofer L, Passos JF, Robbins PD, Schmitt CA, Sedivy J, Vougas K, von Zglinicki T, Zhou D, Serrano M, and Demaria M
- Subjects
- Cell Cycle Checkpoints genetics, Chromatin genetics, Gene Expression Regulation genetics, Genetic Diseases, Inborn therapy, Humans, Aging genetics, Biomarkers, Cellular Senescence genetics, Genetic Diseases, Inborn genetics
- Abstract
Cellular senescence is a cell state implicated in various physiological processes and a wide spectrum of age-related diseases. Recently, interest in therapeutically targeting senescence to improve healthy aging and age-related disease, otherwise known as senotherapy, has been growing rapidly. Thus, the accurate detection of senescent cells, especially in vivo, is essential. Here, we present a consensus from the International Cell Senescence Association (ICSA), defining and discussing key cellular and molecular features of senescence and offering recommendations on how to use them as biomarkers. We also present a resource tool to facilitate the identification of genes linked with senescence, SeneQuest (available at http://Senequest.net). Lastly, we propose an algorithm to accurately assess and quantify senescence, both in cultured cells and in vivo., (Copyright © 2019 Elsevier Inc. All rights reserved.)
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- 2019
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28. Improvement of chilling efficiency and meat tenderness of broiler carcasses using subzero saline solutions.
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Metheny MM, Lee HC, Viliani S, Bennett DC, Hurley S, and Kang I
- Subjects
- Animals, Chickens, Pectoralis Muscles physiology, Salinity, Sodium Chloride analysis, Cold Temperature, Crystalloid Solutions analysis, Food Preservation methods, Food Quality, Meat analysis
- Abstract
Carcass chilling in subzero saline solutions has the potential to improve chilling efficiency and meat quality. The purpose of this research was to investigate the effects of subzero saline chilling on broiler carcass for chilling efficiency and breast tenderness. Broiler carcasses were chilled using 2 high saline solutions (4% NaCl/-2.41°C and 8% NaCl/-5.08°C) without (Experiment I) and with (Experiment II) a pre-chilling step, and 3 low saline solutions (1% NaCl/-0.6°C, 2% NaCl/-1.2°C, and 3% NaCl/-1.8°C) in Experiment III. Ice water slurry (0% NaCl/0.5°C) was used as a control. In Experiments I and II, the breast fillets of broilers in subzero saline solutions showed significantly lower shear forces than those in water control, regardless of salt content and temperature level (P < 0.05). In Experiment III, 3% NaCl/-1.8°C solution reduced the broiler chilling time by 22% over the water control, with an intermediated reduction (13 to 17%) observed for 1% NaCl/-0.6°C and 2% NaCl/-1.2°C solutions. Shear force was stepwise reduced as the salt concentration increased from 0 to 3% and the solution temperature decreased from 0.5 to -1.8°C. No significant difference was observed for carcass chilling yield, breast pH/R-value, and breast cooking yield/salt content, regardless of chilling method. Based on these results, chilling of boiler carcass in 3% NaCl/-1.8°C or higher NaCl and lower temperature solutions appears to improve carcass chilling efficiency and meat tenderness over the traditional water immersion chilling., (© 2019 Poultry Science Association Inc.)
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- 2019
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29. In vitro behavior and UV response of melanocytes derived from carriers of CDKN2A mutations and MC1R variants.
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Hernando B, Swope VB, Guard S, Starner RJ, Choi K, Anwar A, Cassidy P, Leachman S, Kadekaro AL, Bennett DC, and Abdel-Malek ZA
- Subjects
- Adolescent, Adult, Animals, Cells, Cultured, Cellular Senescence genetics, Cyclin-Dependent Kinase Inhibitor p15 genetics, Cyclin-Dependent Kinase Inhibitor p15 metabolism, DNA Damage, Female, Heterozygote, Humans, Male, Neoplasm Proteins genetics, Neoplasm Proteins metabolism, Phosphorylation radiation effects, Receptor, Melanocortin, Type 1 metabolism, Retinoblastoma Protein genetics, Retinoblastoma Protein metabolism, Young Adult, beta-Galactosidase metabolism, Genetic Predisposition to Disease, Melanocytes metabolism, Melanocytes radiation effects, Mutation genetics, Receptor, Melanocortin, Type 1 genetics, Ultraviolet Rays
- Abstract
Coinheritance of germline mutation in cyclin-dependent kinase inhibitor 2A (CDKN2A) and loss-of-function (LOF) melanocortin 1 receptor (MC1R) variants is clinically associated with exaggerated risk for melanoma. To understand the combined impact of these mutations, we established and tested primary human melanocyte cultures from different CDKN2A mutation carriers, expressing either wild-type MC1R or MC1RLOF variant(s). These cultures expressed the CDKN2A product p16 (INK4A) and functional MC1R. Except for 32ins24 mutant melanocytes, the remaining cultures showed no detectable aberrations in proliferation or capacity for replicative senescence. Additionally, the latter cultures responded normally to ultraviolet radiation (UV) by cell cycle arrest, JNK, p38, and p53 activation, hydrogen peroxide generation, and repair of DNA photoproducts. We propose that malignant transformation of melanocytes expressing CDKN2A mutation and MC1RLOF allele(s) requires acquisition of somatic mutations facilitated by MC1R genotype or aberrant microenvironment due to CDKN2A mutation in keratinocytes and fibroblasts., (© 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)
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- 2019
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30. Context Matters: Posttraumatic Stress Disorder Symptom Associations With Military Sexual Trauma Event Characteristics and Dual Histories of Interpersonal Trauma.
- Author
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Bennett DC, Thomas EJ, Porter KE, Broman RB, Rauch SAM, and Sexton MB
- Subjects
- Adult, Cluster Analysis, Female, Humans, Intimate Partner Violence statistics & numerical data, Male, Middle Aged, Midwestern United States, Psychiatric Status Rating Scales, Sex Offenses statistics & numerical data, United States, United States Department of Veterans Affairs, Intimate Partner Violence psychology, Military Personnel psychology, Sex Offenses psychology, Stress Disorders, Post-Traumatic psychology, Veterans psychology
- Abstract
Despite the high rates of military sexual trauma (MST) experienced by service members and veterans, little is known about how contextual features of the MST event or concurrent histories of other interpersonal traumas are associated with diverse clinical presentations. This study examined contextual factors of MST events (number of perpetrators, location of MST, relationship to perpetrator, location of MST) and dual history of interpersonal traumas (including sexual abuse or assault throughout the lifespan, repeated MST, and intimate partner violence) in relation to total symptoms and symptom clusters of Posttraumatic Stress Disorder (PTSD). MST involving multiple perpetrators was related to higher avoidance and hyperarousal. MST while combat-deployed was associated with higher hyperarousal. Veterans endorsing a history of partner violence presented with higher reexperiencing and avoidance. Recognition of phenotypic differences may assist providers in treatment planning and optimizing outcomes., (© Copyright 2019 Springer Publishing Company, LLC.)
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- 2019
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31. Relation between sexual and gender minority status and suicide attempts among veterans seeking treatment for military sexual trauma.
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Sexton MB, Davis MT, Anderson RE, Bennett DC, Sparapani E, and Porter KE
- Subjects
- Female, Humans, Male, Military Personnel psychology, Risk Factors, Sex Factors, Suicidal Ideation, Crime Victims psychology, Culturally Competent Care, Sex Offenses psychology, Sexual and Gender Minorities psychology, Stress Disorders, Post-Traumatic psychology, Suicide, Attempted psychology, Veterans psychology
- Abstract
There is limited study of suicidal behaviors among veterans identifying as sexual and gender minorities (SGMs), despite previous research indicating rates of suicide attempts are high within civilian SGM populations. Further, some research incorporating military service members suggests those identifying as SGMs are disproportionately exposed to military sexual trauma (MST), an additional risk factor for negative psychiatric sequelae. To address health care research disparities among minority veterans (i.e., women, those endorsing MST, SGMs), we examined presentations of veterans (N = 277) who attended initial consultation appointments for MST-related treatment and completed a semistructured clinical interview including demographic characteristics, history of suicide attempts (HSA), and a diagnostic evaluation. Twenty-eight (10.1%) veterans identified as SGMs. SGM/non-SGM groups were contrasted on suicidal and psychiatric morbidity outcomes. Overall, endorsement of HSA was high (30.7%). Despite similar clinical profiles, 53.6% of veterans who identified as SGM endorsed HSA in contrast with 28.1% of peers identifying as heterosexual and nontransgender, a significant effect of small-to-moderate size. Findings suggest assessment and clinical management of suicidality is of critical importance for clinicians providing services to veterans pursuing recovery from MST, generally, and may be especially so when delivering care to SGM. Further, results underscore the need for culturally competent delivery of trauma-focused interventions. (PsycINFO Database Record, ((c) 2018 APA, all rights reserved).)
- Published
- 2018
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32. MPDU1 regulates CEACAM1 and cell adhesion in vitro and in vivo.
- Author
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Bennett DC, Cazet A, Charest J, and Contessa JN
- Subjects
- Antigens, CD genetics, Cell Adhesion genetics, Cell Adhesion Molecules genetics, Cell Line, Tumor, Glycolipids genetics, Glycosylation, Humans, Antigens, CD biosynthesis, Cell Adhesion Molecules biosynthesis, Gene Expression Regulation, Glycolipids biosynthesis
- Abstract
N-linked glycosylation (NLG) is a co-translational modification that is essential for the folding, stability, and trafficking of transmembrane (TM) and secretory glycoproteins. Efficient NLG requires the stepwise synthesis and en bloc transfer of a 14-sugar carbohydrate known as a lipid-linked oligosaccharide (LLO). The genetics of LLO biosynthesis have been established in yeast and Chinese hamster systems, but human models of LLO biosynthesis are lacking. In this study we report that Kato III human gastric cancer cells represent a model of deficient LLO synthesis, possessing a homozygous deletion of the LLO biosynthesis factor, MPDU1. Kato III cells lacking MPDU1 have all the hallmarks of a glycosylation-deficient cell line, including altered sensitivity to lectins and the formation of truncated LLOs. Analysis of transcription using an expression microarray and protein levels using a proteome antibody array reveal changes in the expression of several membrane proteins, including the metalloprotease ADAM-15 and the cell adhesion molecule CEACAM1. Surprisingly, the restoration of MPDU1 expression in Kato III cells demonstrated a clear phenotype of increased cell-cell adhesion, a finding that was confirmed in vivo through analysis of tumor xenografts. These experiments also confirmed that protein levels of CEACAM-1, which functions in cell adhesion, is dependent on LLO biosynthesis in vivo. Kato III cells and the MPDU1-rescued Kato IIIM cells therefore provide a novel model to examine the consequences of defective LLO biosynthesis both in vitro and in vivo.
- Published
- 2018
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33. Associations between posttraumatic stress and legal charges among substance using veterans.
- Author
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Bennett DC, Morris DH, Sexton MB, Bonar EE, and Chermack ST
- Subjects
- Adult, Aged, Female, Humans, Male, Middle Aged, United States epidemiology, Young Adult, Crime legislation & jurisprudence, Stress Disorders, Post-Traumatic epidemiology, Substance-Related Disorders epidemiology, Veterans statistics & numerical data
- Abstract
Substance misuse is prevalent among veterans entering the criminal justice system, and is related to recidivism. Research demonstrates that trauma exposure and posttraumatic stress (PTS) symptoms, which commonly co-occur with substance misuse, also increase the risk of legal involvement and recidivism. However, it is unclear whether the associations between trauma, PTS symptoms and violent and nonviolent crime may be conflated by substance use. The aim of the present study was to understand the association between PTS symptoms and criminal justice involvement (both violent and nonviolent crime) among substance-using veterans seeking Veterans Affairs (VA) specialty mental health care after accounting for substance use frequency and demographics including age, gender, and ethnicity. Further, this study examined whether specific clusters of PTS were associated with violent and nonviolent veteran offending. Participants included 697 veterans (52 women) aged 21 to 75 (M = 47.49, SD = 13.51) with a history of trauma exposure. Veterans self-reported past-month PTS symptoms, substance use, and lifetime legal charges. Logistic regression results indicated total PTS symptoms were associated with violent, but not nonviolent charges, above and beyond age, sex, race, cocaine use, and heavy alcohol use. Intrusion symptoms, in particular, were associated with violent charges. Results highlight the utility of examining PTS as a multifaceted construct and have implications for the assessment and treatment needs of justice-involved veterans. For example, the findings suggest that treatment needs appear to differ for those reporting violent or nonviolent offending, with a greater need for assessing and treating PTS for those involved with violent crime. (PsycINFO Database Record, ((c) 2018 APA, all rights reserved).)
- Published
- 2018
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34. Interaction of genotype and diet on small intestine microbiota of Japanese quail fed a cholesterol enriched diet.
- Author
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Liu S, Tun HM, Leung FC, Bennett DC, Zhang H, and Cheng KM
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- Animal Feed, Animals, Cholesterol, HDL blood, Cholesterol, LDL blood, Plasma chemistry, Cholesterol administration & dosage, Coturnix, Diet, High-Fat, Duodenum microbiology, Gastrointestinal Microbiome, Genetic Background, Ileum microbiology
- Abstract
Our previous study has shown that genetic selection for susceptibility/resistance to diet-induced atherosclerosis has affected the Japanese quail's cecal environment to accommodate distinctly different cecal microbiota. In this study, we fed the Atherosclerosis-resistant (RES) and -susceptable (SUS) quail a regular and a cholesterol enriched diet to examine the interaction of host genotype and diet on the diversity, composition, and metabolic functions of the duodenal and ileal microbiota with relations to atherosclerosis development. In the duodenal content, 9 OTUs (operational taxonomic units) were identified whose abundance had significant positive correlations with plasma total cholesterol, LDL level and/or LDL/HDL ratio. In the ileal content, 7 OTUs have significant correlation with plasma HDL. Cholesterol fed RES hosted significantly less Escherichia and unclassified Enterobacteriaceae (possibly pathogenic) in their duodenum than SUS fed the same diet. Dietary cholesterol significantly decreased the duodenal microbiome of SUS's biosynthesis of Ubiquinone and other terpenoid-quinone. Cholesterol fed RES had significantly more microbiome genes for Vitamin B6, selenocompound, taurine and hypotaurine, and Linoleic acid metabolism; Bisphenol degradation; primary bile acid, and butirosin and neomycin biosynthesis than SUS on the same diet. Microbiome in the ileum and ceca of RES contributed significantly towards the resistance to diet induced atherosclerosis.
- Published
- 2018
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35. A psychometric evaluation of the Posttraumatic Cognitions Inventory with Veterans seeking treatment following military trauma exposure.
- Author
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Sexton MB, Davis MT, Bennett DC, Morris DH, and Rauch SAM
- Subjects
- Adult, Diagnostic and Statistical Manual of Mental Disorders, Female, Humans, Male, Middle Aged, Military Personnel, Psychiatric Status Rating Scales, Reproducibility of Results, Stress Disorders, Post-Traumatic psychology, Stress Disorders, Post-Traumatic therapy, Surveys and Questionnaires, Veterans psychology, Cognition, Personality Inventory statistics & numerical data, Psychometrics statistics & numerical data, Stress Disorders, Post-Traumatic diagnosis, Veterans statistics & numerical data
- Abstract
Trauma-related beliefs have salient relationships to the development and maintenance of Posttraumatic Stress Disorder (PTSD) following stress exposure. The Posttraumatic Cognitions Inventory (PTCI) has the potential to be a standard assessment of this critical construct. However, some critical aspects of validity and reliability appear to vary by population. To date, the PTCI has not been psychometrically evaluated for use with military-specific traumas such as combat and military sexual trauma (MST). Based on exploratory and confirmatory analyses with 949 Veterans seeking trauma-focused treatment for military traumas, we found a four factor model (negative view of the self, negative view of the world, self-blame, and negative beliefs about coping competence) provided the best fit. In contrast, the original three factor model was not confirmed. Both models demonstrated convergent and discriminative validity. Although gender was associated with PTCI total and factor scores, differences did not persist after controlling for trauma type. MST was associated with higher PTCI scores even when controlling for gender, though the clinical magnitude of these differences is likely negligible. Internal reliability validity was demonstrated with PTCI total and subscale scores., (Published by Elsevier B.V.)
- Published
- 2018
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36. ETS1, nucleolar and non-nucleolar TERT expression in nevus to melanoma progression.
- Author
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Kohli JS, Mir H, Wasif A, Chong H, Akhras V, Kumar R, Nagore E, and Bennett DC
- Abstract
TERT (telomerase reverse transcriptase) is the catalytic component of telomerase. TERT shows little expression in normal somatic cells but is commonly re-expressed in cancers, facilitating immortalization. Recently-discovered TERT promoter mutations create binding sites for ETS-family transcription factors to upregulate TERT. ETS1 is reported to be important for TERT upregulation in melanoma. However it is unclear when in melanoma progression TERT and ETS1 proteins are expressed. To elucidate this question, ETS1 and TERT immunohistochemistry were performed on a panel of benign (n=27) and dysplastic nevi (n=34), radial growth phase (n=29), vertical growth phase (n=25) and metastatic melanomas (n=27). Lesions were scored by percentage of positive cells. ETS1 was readily detectable in all lesions, but not in normal melanocytes. TERT was located in either the nucleolus, the nucleoplasm (non-nucleolar) or both. Non-nucleolar TERT increased in prevalence with progression, from 19% of benign nevi to 78% of metastases. It did not however correlate with cell proliferation (Ki-67 immunostaining), nor differ significantly in prevalence between primary melanomas with or without a TERT promoter mutation. These results demonstrate that ETS1 is expressed very early in melanoma progression, and interestingly only non-nucleolar TERT correlates clearly in prevalence with melanoma progression. It can be acquired at various stages and by mechanisms other than promoter mutations., Competing Interests: CONFLICTS OF INTEREST The authors declare no conflicts of interest.
- Published
- 2017
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37. A 'synthetic-sickness' screen for senescence re-engagement targets in mutant cancer backgrounds.
- Author
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Cairney CJ, Godwin LS, Bilsland AE, Burns S, Stevenson KH, McGarry L, Revie J, Moore JD, Wiggins CM, Collinson RS, Mudd C, Tsonou E, Sadaie M, Bennett DC, Narita M, Torrance CJ, and Keith WN
- Subjects
- Caspase 3 genetics, Caspase 3 metabolism, Caspase 7 genetics, Caspase 7 metabolism, Cell Proliferation, Cyclin-Dependent Kinase Inhibitor p21 genetics, Cyclin-Dependent Kinase Inhibitor p21 metabolism, Genetic Markers, HCT116 Cells, Humans, Mutation, Phosphatidylinositol 3-Kinases genetics, Phosphatidylinositol 3-Kinases metabolism, RNA, Small Interfering genetics, RNA, Small Interfering metabolism, Reproducibility of Results, Tumor Suppressor Protein p53 genetics, Tumor Suppressor Protein p53 metabolism, Tumor Suppressor p53-Binding Protein 1 genetics, Tumor Suppressor p53-Binding Protein 1 metabolism, beta-Galactosidase genetics, beta-Galactosidase metabolism, Cellular Senescence genetics, Gene Expression Regulation, Neoplastic, Melanoma genetics
- Abstract
Senescence is a universal barrier to immortalisation and tumorigenesis. As such, interest in the use of senescence-induction in a therapeutic context has been gaining momentum in the past few years; however, senescence and immortalisation remain underserved areas for drug discovery owing to a lack of robust senescence inducing agents and an incomplete understanding of the signalling events underlying this complex process. In order to address this issue we undertook a large-scale morphological siRNA screen for inducers of senescence phenotypes in the human melanoma cell line A375P. Following rescreen and validation in a second cancer cell line, HCT116 colorectal carcinoma, a panel of 16 of the most robust hits were selected for further validation based on significance and the potential to be targeted by drug-like molecules. Using secondary assays for detection of senescence biomarkers p21, 53BP1 and senescence associated beta-galactosidase (SAβGal) in a panel of HCT116 cell lines carrying cancer-relevant mutations, we show that partial senescence phenotypes can be induced to varying degrees in a context dependent manner, even in the absence of p21 or p53 expression. However, proliferation arrest varied among genetic backgrounds with predominantly toxic effects in p21 null cells, while cells lacking PI3K mutation failed to arrest. Furthermore, we show that the oncogene ECT2 induces partial senescence phenotypes in all mutant backgrounds tested, demonstrating a dependence on activating KRASG13D for growth suppression and a complete senescence response. These results suggest a potential mechanism to target mutant KRAS signalling through ECT2 in cancers that are reliant on activating KRAS mutations and remain refractory to current treatments.
- Published
- 2017
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38. The ocular albinism type 1 protein, an intracellular G protein-coupled receptor, regulates melanosome transport in pigment cells.
- Author
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Palmisano I, Bagnato P, Palmigiano A, Innamorati G, Rotondo G, Altimare D, Venturi C, Sviderskaya EV, Piccirillo R, Coppola M, Marigo V, Incerti B, Ballabio A, Surace EM, Tacchetti C, Bennett DC, and Schiaffino MV
- Published
- 2017
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39. BRG1 interacts with SOX10 to establish the melanocyte lineage and to promote differentiation.
- Author
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Marathe HG, Watkins-Chow DE, Weider M, Hoffmann A, Mehta G, Trivedi A, Aras S, Basuroy T, Mehrotra A, Bennett DC, Wegner M, Pavan WJ, and de la Serna IL
- Subjects
- Animals, Cell Line, Enhancer Elements, Genetic, Gene Expression, Gene Expression Regulation, Melanins biosynthesis, Membrane Glycoproteins genetics, Mice, Inbred BALB C, Mice, Inbred C57BL, Mice, Transgenic, Oxidoreductases genetics, Cell Differentiation, DNA Helicases metabolism, Melanocytes physiology, Nuclear Proteins metabolism, SOXE Transcription Factors metabolism, Transcription Factors metabolism
- Abstract
Mutations in SOX10 cause neurocristopathies which display varying degrees of hypopigmentation. Using a sensitized mutagenesis screen, we identified Smarca4 as a modifier gene that exacerbates the phenotypic severity of Sox10 haplo-insufficient mice. Conditional deletion of Smarca4 in SOX10 expressing cells resulted in reduced numbers of cranial and ventral trunk melanoblasts. To define the requirement for the Smarca4 -encoded BRG1 subunit of the SWI/SNF chromatin remodeling complex, we employed in vitro models of melanocyte differentiation in which induction of melanocyte-specific gene expression is closely linked to chromatin alterations. We found that BRG1 was required for expression of Dct, Tyrp1 and Tyr, genes that are regulated by SOX10 and MITF and for chromatin remodeling at distal and proximal regulatory sites. SOX10 was found to physically interact with BRG1 in differentiating melanocytes and binding of SOX10 to the Tyrp1 distal enhancer temporally coincided with recruitment of BRG1. Our data show that SOX10 cooperates with MITF to facilitate BRG1 binding to distal enhancers of melanocyte-specific genes. Thus, BRG1 is a SOX10 co-activator, required to establish the melanocyte lineage and promote expression of genes important for melanocyte function., (© The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.)
- Published
- 2017
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40. Common Delayed Senescence of Melanocytes from Multiple Primary Melanoma Patients.
- Author
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Kohli JS, Tolomio E, Frigerio S, Maurichi A, Rodolfo M, and Bennett DC
- Subjects
- Cellular Senescence, Humans, Melanocytes pathology, Melanoma pathology, Neoplasms, Multiple Primary, Skin Neoplasms pathology
- Published
- 2017
- Full Text
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41. Screening for PTSD among detained adolescents: Implications of the changes in the DSM-5.
- Author
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Modrowski CA, Bennett DC, Chaplo SD, and Kerig PK
- Subjects
- Adolescent, Adult, Female, Humans, Male, Psychological Trauma classification, Stress Disorders, Post-Traumatic classification, Young Adult, Diagnostic and Statistical Manual of Mental Disorders, Juvenile Delinquency statistics & numerical data, Psychological Trauma diagnosis, Stress Disorders, Post-Traumatic diagnosis
- Abstract
Objective: Screening for posttraumatic stress disorder (PTSD) is highly relevant for youth involved in the juvenile justice system given their high rates of trauma exposure and posttraumatic stress symptoms. However, to date, no studies have investigated the implications of the recent revisions to the Diagnostic and Statistical Manual for Mental Disorders (5th ed., DSM-5; American Psychiatric Association [APA], 2013) diagnostic criteria for PTSD for screening in this population. To this end, the present study compared PTSD screening rates using the Diagnostic and Statistical Manual of Mental Disorders (4th ed., text rev., DSM-IV-TR; APA, 2013) versus DSM-5 criteria in a group of detained adolescents., Method: Participants included 209 youth (60 girls) aged 13-19 (M = 15.97, SD = 1.24). Youth completed measures of lifetime trauma exposure and past-month posttraumatic stress symptoms., Results: Over 95% of youth in the sample reported exposure to at least 1 type of traumatic event. Approximately 19.60% of the sample screened positive for PTSD according to the DSM-5 compared to 17.70% according to the DSM-IV-TR. Girls were more likely than boys to screen positive for PTSD according to the DSM-IV-TR compared to the DSM-5., Conclusion: The main factors accounting for the differences in screening rates across the versions of PTSD criteria involved the removal of Criterion A2 from the DSM-5, the separation of avoidance symptoms (Criterion C) into their own cluster, the addition of a cluster involving negative alterations in cognitions and mood (Criterion D), and revisions to the cluster of arousal symptoms (Criterion E). Future research should continue to investigate gender differences in PTSD symptoms in youth and consider the implications of these diagnostic changes for the accurate diagnosis and referral to treatment of adolescents who demonstrate posttraumatic stress reactions. (PsycINFO Database Record, ((c) 2017 APA, all rights reserved).)
- Published
- 2017
- Full Text
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42. Genome-wide association studies of autoimmune vitiligo identify 23 new risk loci and highlight key pathways and regulatory variants.
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Jin Y, Andersen G, Yorgov D, Ferrara TM, Ben S, Brownson KM, Holland PJ, Birlea SA, Siebert J, Hartmann A, Lienert A, van Geel N, Lambert J, Luiten RM, Wolkerstorfer A, Wietze van der Veen JP, Bennett DC, Taïeb A, Ezzedine K, Kemp EH, Gawkrodger DJ, Weetman AP, Kõks S, Prans E, Kingo K, Karelson M, Wallace MR, McCormack WT, Overbeck A, Moretti S, Colucci R, Picardo M, Silverberg NB, Olsson M, Valle Y, Korobko I, Böhm M, Lim HW, Hamzavi I, Zhou L, Mi QS, Fain PR, Santorico SA, and Spritz RA
- Subjects
- Female, Genome-Wide Association Study, Genotype, Humans, Male, Melanoma genetics, Quantitative Trait Loci, Risk Assessment, Autoimmune Diseases genetics, Genetic Predisposition to Disease, Vitiligo genetics
- Abstract
Vitiligo is an autoimmune disease in which depigmented skin results from the destruction of melanocytes, with epidemiological association with other autoimmune diseases. In previous linkage and genome-wide association studies (GWAS1 and GWAS2), we identified 27 vitiligo susceptibility loci in patients of European ancestry. We carried out a third GWAS (GWAS3) in European-ancestry subjects, with augmented GWAS1 and GWAS2 controls, genome-wide imputation, and meta-analysis of all three GWAS, followed by an independent replication. The combined analyses, with 4,680 cases and 39,586 controls, identified 23 new significantly associated loci and 7 suggestive loci. Most encode immune and apoptotic regulators, with some also associated with other autoimmune diseases, as well as several melanocyte regulators. Bioinformatic analyses indicate a predominance of causal regulatory variation, some of which corresponds to expression quantitative trait loci (eQTLs) at these loci. Together, the identified genes provide a framework for the genetic architecture and pathobiology of vitiligo, highlight relationships with other autoimmune diseases and melanoma, and offer potential targets for treatment.
- Published
- 2016
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43. Validation of the factor structure of the adolescent dissociative experiences scale in a sample of trauma-exposed detained youth.
- Author
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Kerig PK, Charak R, Chaplo SD, Bennett DC, Armour C, Modrowski CA, and McGee AB
- Subjects
- Adolescent, Dissociative Disorders diagnosis, Female, Humans, Male, Adolescent Behavior psychology, Depersonalization physiopathology, Dissociative Disorders physiopathology, Juvenile Delinquency psychology, Psychiatric Status Rating Scales standards, Psychological Trauma physiopathology, Stress Disorders, Post-Traumatic physiopathology
- Abstract
Objective: The inclusion of a dissociative subtype in the Diagnostic and Statistical Manual of Mental Disorders (5th ed.; DSM–5 ) criteria for the diagnosis of posttraumatic stress disorder (PTSD) has highlighted the need for valid and reliable measures of dissociative symptoms across developmental periods. The Adolescent Dissociative Experiences Scale (A-DES) is 1 of the few measures validated for young persons, but previous studies have yielded inconsistent results regarding its factor structure. Further, research to date on the A-DES has been based upon nonclinical samples of youth or those without a known history of trauma. To address these gaps in the literature, the present study investigated the factor structure and construct validity of the A-DES in a sample of highly trauma-exposed youth involved in the juvenile justice system., Method: A sample of 784 youth (73.7% boys) recruited from a detention center completed self-report measures of trauma exposure and the A-DES, a subset of whom (n = 212) also completed a measure of PTSD symptoms., Results: Confirmatory factor analyses revealed a best fitting 3-factor structure comprised of depersonalization or derealization, amnesia, and loss of conscious control, with configural and metric invariance across gender. Logistic regression analyses indicated that the depersonalization or derealization factor effectively distinguished between those youth who did and did not likely meet criteria for a diagnosis of PTSD as well as those with PTSD who did and did not likely meet criteria for the dissociative subtype., Conclusions: These results provide support for the multidimensionality of the construct of posttraumatic dissociation and contribute to the understanding of the dissociative subtype of PTSD among adolescents. (PsycINFO Database Record, (PsycINFO Database Record (c) 2016 APA, all rights reserved)
- Published
- 2016
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44. BLOC-1 and BLOC-3 regulate VAMP7 cycling to and from melanosomes via distinct tubular transport carriers.
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Dennis MK, Delevoye C, Acosta-Ruiz A, Hurbain I, Romao M, Hesketh GG, Goff PS, Sviderskaya EV, Bennett DC, Luzio JP, Galli T, Owen DJ, Raposo G, and Marks MS
- Subjects
- Animals, Cell Membrane metabolism, Cell Membrane ultrastructure, Green Fluorescent Proteins metabolism, Humans, Intracellular Signaling Peptides and Proteins, Melanocytes metabolism, Melanocytes ultrastructure, Melanosomes ultrastructure, Membrane Glycoproteins metabolism, Mice, Inbred C57BL, Mitochondrial Proteins, Oxidoreductases metabolism, Pigmentation, Protein Transport, Qa-SNARE Proteins metabolism, Recombinant Fusion Proteins metabolism, Transport Vesicles ultrastructure, rab GTP-Binding Proteins metabolism, Carrier Proteins metabolism, Endocytosis, Lectins metabolism, Melanosomes metabolism, Nerve Tissue Proteins metabolism, R-SNARE Proteins metabolism, Transport Vesicles metabolism
- Abstract
Endomembrane organelle maturation requires cargo delivery via fusion with membrane transport intermediates and recycling of fusion factors to their sites of origin. Melanosomes and other lysosome-related organelles obtain cargoes from early endosomes, but the fusion machinery involved and its recycling pathway are unknown. Here, we show that the v-SNARE VAMP7 mediates fusion of melanosomes with tubular transport carriers that also carry the cargo protein TYRP1 and that require BLOC-1 for their formation. Using live-cell imaging, we identify a pathway for VAMP7 recycling from melanosomes that employs distinct tubular carriers. The recycling carriers also harbor the VAMP7-binding scaffold protein VARP and the tissue-restricted Rab GTPase RAB38. Recycling carrier formation is dependent on the RAB38 exchange factor BLOC-3. Our data suggest that VAMP7 mediates fusion of BLOC-1-dependent transport carriers with melanosomes, illuminate SNARE recycling from melanosomes as a critical BLOC-3-dependent step, and likely explain the distinct hypopigmentation phenotypes associated with BLOC-1 and BLOC-3 deficiency in Hermansky-Pudlak syndrome variants., (© 2016 Dennis et al.)
- Published
- 2016
- Full Text
- View/download PDF
45. Numbing of Positive, Negative, and General Emotions: Associations With Trauma Exposure, Posttraumatic Stress, and Depressive Symptoms Among Justice-Involved Youth.
- Author
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Kerig PK, Bennett DC, Chaplo SD, Modrowski CA, and McGee AB
- Subjects
- Adolescent, Criminal Law, Depressive Disorder psychology, Diagnostic and Statistical Manual of Mental Disorders, Female, Humans, Male, Psychiatric Status Rating Scales, Psychological Trauma psychology, Social Justice, Stress Disorders, Post-Traumatic psychology, Depressive Disorder physiopathology, Emotions physiology, Psychological Trauma physiopathology, Stress Disorders, Post-Traumatic physiopathology
- Abstract
Increasing attention has been drawn to the symptom of emotional numbing in the phenomenology of posttraumatic stress disorder (PTSD), particularly regarding its implications for maladaptive outcomes in adolescence such as delinquent behavior. One change in the definition of emotional numbing according to the Diagnostic and Statistical Manual of Mental Disorders (5th ed.; DSM-5; American Psychiatric Association, 2013) was the limitation to the numbing of positive emotions. Previous research with youth, however, has implicated general numbing or numbing of negative emotions in PTSD, whereas numbing of positive emotions may overlap with other disorders, particularly depression. Consequently, the goal of this study was to investigate whether numbing of positive emotions was associated with PTSD symptoms above and beyond numbing of negative emotions, general emotional numbing, or depressive symptoms among at-risk adolescents. In a sample of 221 detained youth (mean age = 15.98 years, SD = 1.25; 50.7% ethnic minority), results of hierarchical multiple regressions indicated that only general emotional numbing and numbing of anger accounted for significant variance in PTSD symptoms (total R(2) = .37). In contrast, numbing of sadness and positive emotions were statistical correlates of depressive symptoms (total R(2) = .24). Further tests using Hayes' Process macro showed that general numbing, 95% CI [.02, .45], and numbing of anger, 95% CI [.01, .42], demonstrated indirect effects on the association between trauma exposure and PTSD symptoms., (Copyright © 2016 International Society for Traumatic Stress Studies.)
- Published
- 2016
- Full Text
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46. Genetics of melanoma progression: the rise and fall of cell senescence.
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Bennett DC
- Subjects
- Animals, Cyclin-Dependent Kinase Inhibitor p16 metabolism, Humans, Melanoma metabolism, Melanoma pathology, Neoplasm Metastasis, Neoplasm Proteins metabolism, Skin Neoplasms metabolism, Skin Neoplasms pathology, Telomere metabolism, Cellular Senescence genetics, Cyclin-Dependent Kinase Inhibitor p16 genetics, Genetic Predisposition to Disease, Melanoma genetics, Neoplasm Proteins genetics, Skin Neoplasms genetics, Telomere genetics, Telomere Homeostasis genetics
- Abstract
There are many links between cell senescence and the genetics of melanoma, meaning both familial susceptibility and somatic-genetic changes in sporadic melanoma. For example, CDKN2A, the best-known melanoma susceptibility gene, encodes two effectors of cell senescence, while other familial melanoma genes are related to telomeres and their maintenance. This article aimed to analyze our current knowledge of the genetic or epigenetic driver changes necessary to generate a cutaneous metastatic melanoma, the commonest order in which these occur, and the relation of these changes to the biology and pathology of melanoma progression. Emphasis is laid on the role of cell senescence and the escape from senescence leading to cellular immortality, the ability to divide indefinitely., (© 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)
- Published
- 2016
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47. Transcription factor LSF (TFCP2) inhibits melanoma growth.
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Goto Y, Yajima I, Kumasaka M, Ohgami N, Tanaka A, Tsuzuki T, Inoue Y, Fukushima S, Ihn H, Kyoya M, Ohashi H, Kawakami T, Bennett DC, and Kato M
- Subjects
- Animals, Cell Line, Tumor, Cell Proliferation genetics, Chromatin Immunoprecipitation, DNA-Binding Proteins biosynthesis, Electrophoretic Mobility Shift Assay, G1 Phase Cell Cycle Checkpoints genetics, Humans, Melanocytes metabolism, Mice, Transcription Factors biosynthesis, Cyclin-Dependent Kinase Inhibitor p21 genetics, DNA-Binding Proteins genetics, Melanoma, Experimental pathology, Skin Neoplasms pathology, Transcription Factors genetics
- Abstract
Late SV40 factor 3 (LSF), a transcription factor, contributes to human hepatocellular carcinoma (HCC). However, decreased expression level of LSF in skin melanoma compared to that in benign melanocytic tumors and nevi in mice and humans was found in this study. Anchorage-dependent and -independent growth of melanoma cells was suppressed by LSF overexpression through an increased percentage of G1 phase cells and an increased p21CIP1 expression level in vitro and in vivo. Anchorage-dependent growth in LSF-overexpressed melanoma cells was promoted by depletion of LSF in the LSF-overexpressed cells. Integrated results of our EMSA and chromatin immunoprecipitation assays showed binding of LSF within a 150-bp upstream region of the transcription start site of p21CIP1 in melanoma cells. Taken together, our results suggest potential roles of LSF as a growth regulator through control of the transcription of p21CIP1 in melanocytes and melanoma cells as well as a biomarker for nevus.
- Published
- 2016
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48. The effect of diet and host genotype on ceca microbiota of Japanese quail fed a cholesterol enriched diet.
- Author
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Liu S, Bennett DC, Tun HM, Kim JE, Cheng KM, Zhang H, and Leung FC
- Abstract
Two Japanese quail strains, respectively atherosclerosis-susceptible (SUS) and -resistant (RES), have been shown to be good models to study cholesterol metabolism and transportation associated with atherosclerosis. Our objective was to examine possible difference in cecal microbiota between these strains when fed a control diet and a cholesterol enriched diet, to determine how host genotype and diet could affect the cecal microbiome that may play a part in cholesterol metabolism. A factorial study with both strains and two diets (control, cholesterol) was carried out. Cecal content was collected from 12 week old quail that have been on their respective diets for 6 weeks. DNA was extracted from the samples and the variable region 3-5 of the bacterial 16S rRNA gene was amplified. The amplicon libraries were subjected to pyrosequencing. Principal Component Analysis (PCA) of β-diversity showed four distinct microbiota communities that can be assigned to the 4 treatment groups (RES/control, RES/cholesterol, SUS/control, SUS/cholesterol). At the Phylum level, the 4 treatment groups has distinct Firmicutes community characteristics but no significant difference in Bacteroidetes. Eubacterium dolichum was rare in RES/control but became overabundant in RES/cholesterol. An unclassified species of Lactobacillaceae was found in abundance in SUS/control but the same species was rare in RES/cholesterol. On the other hand, two Lactobacillus species were only found in RES/control and an unclassified Lachnospiraceae species was abundant in RES/cholesterol but rare in SUS/control. The abundance of four species of Lachnospiraceae, three species of Ruminococcaceae and one species of Coprobacillaceae was positively correlated with plasma Total Cholesterol, plasma LDL, and LDL/HDL ratio. Our study of cecal microbiota in these quail has demonstrated that selection for susceptibility/resistance to diet induced atherosclerosis has also affected the quail's cecal environment to host distinctly different cecal microbiome.
- Published
- 2015
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49. Genomic analysis reveals distinct mechanisms and functional classes of SOX10-regulated genes in melanocytes.
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Fufa TD, Harris ML, Watkins-Chow DE, Levy D, Gorkin DU, Gildea DE, Song L, Safi A, Crawford GE, Sviderskaya EV, Bennett DC, Mccallion AS, Loftus SK, and Pavan WJ
- Subjects
- Animals, Binding Sites, Cell Line, Chromatin genetics, Chromatin metabolism, Epigenomics methods, Melanocytes cytology, Mice, SOXE Transcription Factors chemistry, SOXE Transcription Factors genetics, Gene Expression Profiling methods, Gene Regulatory Networks, Melanocytes metabolism, Oligonucleotide Array Sequence Analysis methods, SOXE Transcription Factors metabolism
- Abstract
SOX10 is required for melanocyte development and maintenance, and has been linked to melanoma initiation and progression. However, the molecular mechanisms by which SOX10 guides the appropriate gene expression programs necessary to promote the melanocyte lineage are not fully understood. Here we employ genetic and epigenomic analysis approaches to uncover novel genomic targets and previously unappreciated molecular roles of SOX10 in melanocytes. Through global analysis of SOX10-binding sites and epigenetic characteristics of chromatin states, we uncover an extensive catalog of SOX10 targets genome-wide. Our findings reveal that SOX10 predominantly engages 'open' chromatin regions and binds to distal regulatory elements, including novel and previously known melanocyte enhancers. Integrated chromatin occupancy and transcriptome analysis suggest a role for SOX10 in both transcriptional activation and repression to regulate functionally distinct classes of genes. We demonstrate that distinct epigenetic signatures and cis-regulatory sequence motifs predicted to bind putative co-regulatory transcription factors define SOX10-activated and SOX10-repressed target genes. Collectively, these findings uncover a central role of SOX10 as a global regulator of gene expression in the melanocyte lineage by targeting diverse regulatory pathways., (Published by Oxford University Press 2015. This work is written by (a) US Government employee(s) and is in the public domain in the US.)
- Published
- 2015
- Full Text
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50. Ratite oils promote keratinocyte cell growth and inhibit leukocyte activation.
- Author
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Bennett DC, Leung G, Wang E, Ma S, Lo BK, McElwee KJ, and Cheng KM
- Subjects
- Animals, Ducks, Humans, Olive Oil, Plant Oils pharmacology, Tea Tree Oil pharmacology, Anti-Inflammatory Agents pharmacology, Cell Proliferation drug effects, Keratinocytes drug effects, Leukocytes, Mononuclear drug effects, Oils pharmacology, Palaeognathae
- Abstract
Traditionally, native Australian aborigines have used emu oil for the treatment of inflammation and to accelerate wound healing. Studies on mice suggest that topically applied emu oil may have anti-inflammatory properties and may promote wound healing. We investigated the effects of ratite oils (6 emu, 3 ostrich, 1 rhea) on immortalized human keratinocytes (HaCaT cells) in vitro by culturing the cells in media with oil concentrations of 0%, 0.5%, and 1.0%. Peking duck, tea tree, and olive oils were used as comparative controls. The same oils at 0.5% concentration were evaluated for their influence on peripheral blood mononuclear cell (PBMC) survival over 48 hr and their ability to inhibit IFNγ production in PBMCs activated by phytohemagglutinin (PHA) in ELISpot assays. Compared to no oil control, significantly shorter population doubling time durations were observed for HaCaT cells cultured in emu oil (1.51×faster), ostrich oil (1.46×faster), and rhea oil (1.64×faster). Tea tree oil demonstrated significant antiproliferative activity and olive oil significantly prolonged (1.35×slower) cell population doubling time. In contrast, almost all oils, particularly tea tree oil, significantly reduced PBMC viability. Different oils had different levels of inhibitory effect on IFNγ production with individual emu, ostrich, rhea, and duck oil samples conferring full inhibition. This preliminary investigation suggests that emu oil might promote wound healing by accelerating the growth rate of keratinocytes. Combined with anti-inflammatory properties, ratite oil may serve as a useful component in bandages and ointments for the treatment of wounds and inflammatory skin conditions., (© 2015 Poultry Science Association Inc.)
- Published
- 2015
- Full Text
- View/download PDF
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