116 results on '"Okabe J"'
Search Results
2. SAHA attenuates Takotsubo-like myocardial injury by targeting an epigenetic Ac/Dc axis
- Author
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Khurana, I, Maxwell, S, Royce, S, Mathiyalagan, P, Karagiannis, T, Mazarakis, N, Vongsvivut, J, Harikrishnan, KN, Okabe, J, Al-Hasani, K, Samuel, C, El-Osta, A, Khurana, I, Maxwell, S, Royce, S, Mathiyalagan, P, Karagiannis, T, Mazarakis, N, Vongsvivut, J, Harikrishnan, KN, Okabe, J, Al-Hasani, K, Samuel, C, and El-Osta, A
- Published
- 2021
3. Sex-based Mhrt Methylation chromatinizes MeCP2 in the heart
- Author
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Harikrishnan, K. N., Okabe, J., Mathiyalagan, P., Khan, A. W., Jadaan, S. A., Sarila, G., Ziemann, M., Khurana, I., Maxwell, S.S ., Du, X. J., El-Osta, A., Harikrishnan, K. N., Okabe, J., Mathiyalagan, P., Khan, A. W., Jadaan, S. A., Sarila, G., Ziemann, M., Khurana, I., Maxwell, S.S ., Du, X. J., and El-Osta, A.
- Abstract
© 2019 The Author(s) In the heart, primary microRNA-208b (pri-miR-208b) and Myheart (Mhrt) are long non-coding RNAs (lncRNAs) encoded by the cardiac myosin heavy chain genes. Although preclinical studies have shown that lncRNAs regulate gene expression and are protective for pathological hypertrophy, the mechanism underlying sex-based differences remains poorly understood. In this study, we examined DNA- and RNA-methylation-dependent regulation of pri-miR-208b and Mhrt. Expression of pri-miR-208b is elevated in the left ventricle of the female heart. Despite indistinguishable DNA methylation between sexes, the interaction of MeCP2 on chromatin is subject to RNase digestion, highlighting that affinity of the methyl-CG reader is broader than previously thought. A specialized procedure to isolate RNA from soluble cardiac chromatin emphasizes sex-based affinity of an MeCP2 co-repressor complex with Rest and Hdac2. Sex-specific Mhrt methylation chromatinizes MeCP2 at the pri-miR-208b promoter and extends the functional relevance of default transcriptional suppression in the heart.
- Published
- 2019
4. Sex-Based Mhrt Methylation Chromatinizes MeCP2 in the Heart
- Author
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Harikrishnan, KN, Okabe, J, Mathiyalagan, P, Khan, AW, Jadaan, SA, Sarila, G, Ziemann, M, Khurana, I, Maxwell, SS, Du, X-J, El-Osta, A, Harikrishnan, KN, Okabe, J, Mathiyalagan, P, Khan, AW, Jadaan, SA, Sarila, G, Ziemann, M, Khurana, I, Maxwell, SS, Du, X-J, and El-Osta, A
- Abstract
In the heart, primary microRNA-208b (pri-miR-208b) and Myheart (Mhrt) are long non-coding RNAs (lncRNAs) encoded by the cardiac myosin heavy chain genes. Although preclinical studies have shown that lncRNAs regulate gene expression and are protective for pathological hypertrophy, the mechanism underlying sex-based differences remains poorly understood. In this study, we examined DNA- and RNA-methylation-dependent regulation of pri-miR-208b and Mhrt. Expression of pri-miR-208b is elevated in the left ventricle of the female heart. Despite indistinguishable DNA methylation between sexes, the interaction of MeCP2 on chromatin is subject to RNase digestion, highlighting that affinity of the methyl-CG reader is broader than previously thought. A specialized procedure to isolate RNA from soluble cardiac chromatin emphasizes sex-based affinity of an MeCP2 co-repressor complex with Rest and Hdac2. Sex-specific Mhrt methylation chromatinizes MeCP2 at the pri-miR-208b promoter and extends the functional relevance of default transcriptional suppression in the heart.
- Published
- 2019
5. Development and characterization of anti-Gal B-cell receptor transgenic Gal−/− mice
- Author
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Xu, H., Lei, Y., Shama, A., Wan, H., Okabe, J., Logan, J., and Byrne, G.
- Published
- 2001
6. ESTUDO DA SECAGEM DO PINHÃO EM SECADOR DE BANDEJAS
- Author
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VIEIRA, M. E., additional, KITAWARA, A. M., additional, OKABE, J. N., additional, SOUZA, L. F. G., additional, ANDREOLA, K., additional, and NITZ, M., additional
- Published
- 2018
- Full Text
- View/download PDF
7. NET silencing by let-7i in postural tachycardia syndrome
- Author
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Khan, AW, Ziemann, Mark, Corcoran, SJ, K N, H, Okabe, J, Rafehi, H, Maxwell, SS, Esler, MD, El-Osta, A, Khan, AW, Ziemann, Mark, Corcoran, SJ, K N, H, Okabe, J, Rafehi, H, Maxwell, SS, Esler, MD, and El-Osta, A
- Published
- 2017
8. Set7 mediated interactions regulate transcriptional networks in embryonic stem cells
- Author
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Tuano, NK, Okabe, J, Ziemann, M, Cooper, ME, El-Osta, A, Tuano, NK, Okabe, J, Ziemann, M, Cooper, ME, and El-Osta, A
- Abstract
Histone methylation by lysine methyltransferase enzymes regulate the expression of genes implicated in lineage specificity and cellular differentiation. While it is known that Set7 catalyzes mono-methylation of histone and non-histone proteins, the functional importance of this enzyme in stem cell differentiation remains poorly understood. We show Set7 expression is increased during mouse embryonic stem cell (mESC) differentiation and is regulated by the pluripotency factors, Oct4 and Sox2. Transcriptional network analyses reveal smooth muscle (SM) associated genes are subject to Set7-mediated regulation. Furthermore, pharmacological inhibition of Set7 activity confirms this regulation. We observe Set7-mediated modification of serum response factor (SRF) and mono-methylation of histone H4 lysine 4 (H3K4me1) regulate gene expression. We conclude the broad substrate specificity of Set7 serves to control key transcriptional networks in embryonic stem cells.
- Published
- 2016
9. Current perspectives in Set7 mediated stem cell differentiation.
- Author
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Karimnia, N, Rafehi, H, Tuano, NK, Ziemann, M, K N, H, Okabe, J, El-Osta, A, Karimnia, N, Rafehi, H, Tuano, NK, Ziemann, M, K N, H, Okabe, J, and El-Osta, A
- Abstract
Set7 is a key regulatory enzyme involved in the methylation of lysine residues of histone and non-histone proteins. This lysine methyltransferase is induced during stem cell differentiation and regulates lineage specific gene transcription and cell fate. In this article we discuss recent experimental evidence identifying regulatory targets under the control of Set7 as well as emerging evidence of regulation in stem cell differentiation. Furthermore, we discuss the function of non-coding RNAs regulated by Set7 implicated in cell plasticity.
- Published
- 2016
10. Regulation of inflammatory gene expression by histone acetylation and HDAC inhibition in human aortic endothelial cells
- Author
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Rafehi, H., primary, Balcerczyk, A., additional, Lunke, S., additional, Kaspi, A., additional, Ziemann, M., additional, Harikrishnan, K.N., additional, Okabe, J., additional, Khurana, I., additional, Ooi, J., additional, Khan, A.W., additional, Du, X., additional, Chang, L., additional, Haviv, I., additional, Keating, S., additional, Karagiannis, T., additional, and El-Osta, A., additional
- Published
- 2015
- Full Text
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11. THE INCORPORATION OF p-HYDROXYBENZOIC ACID INTO LIGNINS
- Author
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KRATZL, K., primary and OKABE, J., additional
- Published
- 1966
- Full Text
- View/download PDF
12. Hyperglycemia Induces a Dynamic Cooperativity of Histone Methylase and Demethylase Enzymes Associated With Gene-Activating Epigenetic Marks That Coexist on the Lysine Tail
- Author
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Brasacchio, D, Okabe, J, Tikellis, C, Balcerczyk, A, George, P, Baker, EK, Calkin, AC, Brownlee, M, Cooper, ME, El-Osta, A, Brasacchio, D, Okabe, J, Tikellis, C, Balcerczyk, A, George, P, Baker, EK, Calkin, AC, Brownlee, M, Cooper, ME, and El-Osta, A
- Abstract
OBJECTIVE: Results from the Diabetes Control Complications Trial (DCCT) and the subsequent Epidemiology of Diabetes Interventions and Complications (EDIC) Study and more recently from the U.K. Prospective Diabetes Study (UKPDS) have revealed that the deleterious end-organ effects that occurred in both conventional and more aggressively treated subjects continued to operate >5 years after the patients had returned to usual glycemic control and is interpreted as a legacy of past glycemia known as "hyperglycemic memory." We have hypothesized that transient hyperglycemia mediates persistent gene-activating events attributed to changes in epigenetic information. RESEARCH DESIGN AND METHODS: Models of transient hyperglycemia were used to link NFkappaB-p65 gene expression with H3K4 and H3K9 modifications mediated by the histone methyltransferases (Set7 and SuV39h1) and the lysine-specific demethylase (LSD1) by the immunopurification of soluble NFkappaB-p65 chromatin. RESULTS: The sustained upregulation of the NFkappaB-p65 gene as a result of ambient or prior hyperglycemia was associated with increased H3K4m1 but not H3K4m2 or H3K4m3. Furthermore, glucose was shown to have other epigenetic effects, including the suppression of H3K9m2 and H3K9m3 methylation on the p65 promoter. Finally, there was increased recruitment of the recently identified histone demethylase LSD1 to the p65 promoter as a result of prior hyperglycemia. CONCLUSIONS: These studies indicate that the active transcriptional state of the NFkappaB-p65 gene is linked with persisting epigenetic marks such as enhanced H3K4 and reduced H3K9 methylation, which appear to occur as a result of effects of the methyl-writing and methyl-erasing histone enzymes.
- Published
- 2009
13. The primary microRNA-208b interacts with Polycomb-group protein, Ezh2, to regulate gene expression in the heart
- Author
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Mathiyalagan, P., primary, Okabe, J., additional, Chang, L., additional, Su, Y., additional, Du, X.-J., additional, and El-Osta, A., additional
- Published
- 2013
- Full Text
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14. Directed Iron-Catalyzed Arylation of Olefins
- Author
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Nakamura, E., primary, Ilies, L., additional, Okabe, J., additional, and Yoshikai, N., additional
- Published
- 2010
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- View/download PDF
15. Limited capacity of the nuclear matrix to bind telomere repeat binding factor TRF1 may restrict the proliferation of mortal human fibroblasts
- Author
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Okabe, J., primary
- Published
- 2003
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16. TRF1 is a critical trans-acting factor required for de novo telomere formation in human cells
- Author
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Okabe, J., primary
- Published
- 2000
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17. Reduction in the level of Gal(alpha1,3)Gal in transgenic mice and pigs by the expression of an alpha(1,2)fucosyltransferase.
- Author
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Sharma, A, primary, Okabe, J, additional, Birch, P, additional, McClellan, S B, additional, Martin, M J, additional, Platt, J L, additional, and Logan, J S, additional
- Published
- 1996
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18. Influence of the chemical nature of side chain at beta 108 of hemoglobin A on the modulation of the oxygen affinity by chloride ions. Low oxygen affinity variants of human hemoglobin expressed in transgenic pigs: hemoglobins Presbyterian and Yoshizuka.
- Author
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O'Donnell, J K, primary, Birch, P, additional, Parsons, C T, additional, White, S P, additional, Okabe, J, additional, Martin, M J, additional, Adams, C, additional, Sundarapandiyan, K, additional, Manjula, B N, additional, and Acharya, A S, additional
- Published
- 1994
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19. Gene transfer vectors based on Sendai virus
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Nakanishi, M., Mizuguchia, H., Ashihara, K.-I., Senda, T., Akuta, T., Okabe, J., Nagoshi, E., Masago, A., Eguchi, A., and Suzuki, Y.
- Published
- 1998
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20. Replacement of serum by insulin, transferrin, albumin, phosphatidyl choline, cholesterol, and some trace elements in cultures of mouse myeloid leukemia cells sensitive to inducers of differentiation
- Author
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Honma, Y., primary, Kasukabe, T., additional, Okabe, J., additional, and Hozumi, M., additional
- Published
- 1979
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21. Directed Iron-Catalyzed Arylation of Olefins.
- Author
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Ilies, L., Okabe, J., Yoshikai, N., and Nakamura, E.
- Published
- 2010
- Full Text
- View/download PDF
22. Role of GABA within the nucleus tractus solitarii in the hypoxic ventilatory decline of awake rats.
- Author
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Massao Tabata, J. P., Hajime Kurosawa, J. P., Yoshihiro Kikuchi, J. P., Wataru Hida, J. P., Hiromasa Ogawa, J. P., Shinichi Okabe, J. P., Ye Tun, J. P., Toshio Hattori, and Kunio Shirato
- Subjects
GABA ,AMINO acid neurotransmitters ,AMINOBUTYRIC acid ,SOLITARY nucleus ,HYPOXEMIA ,CHEMORECEPTORS - Abstract
Cites a study to examines the role of GABA within the nucleus tractus solitarii in the hypoxic ventilatory decline of awake rats. Role of chemoreceptor stimulation to activate the mechanism; Chemical composition of GABA.
- Published
- 2001
23. CHAPTER 7 - THE INCORPORATION OF p-HYDROXYBENZOIC ACID INTO LIGNINS
- Author
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KRATZL, K. and OKABE, J.
- Published
- 1966
- Full Text
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24. Effectiveness of perampanel for focal seizures determined by interictal gamma oscillation regularity analysis.
- Author
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Okabe J and Sato Y
- Subjects
- Humans, Male, Female, Adult, Seizures drug therapy, Middle Aged, Young Adult, Treatment Outcome, Adolescent, Pyridones therapeutic use, Pyridones pharmacology, Nitriles therapeutic use, Electroencephalography, Anticonvulsants therapeutic use, Epilepsies, Partial drug therapy, Gamma Rhythm drug effects
- Abstract
Although perampanel (PER) has received approval as an antiseizure medication, reports quantifying its antiseizure effects using electroencephalography (EEG) remain scarce. In a previous study, we demonstrated that the interictal high gamma oscillation regularity (GOR) on scalp EEG is an excellent marker of epileptogenicity. Herein, we investigated whether the antiseizure effect of PER could be quantified through interictal GOR analysis of scalp EEG data. To investigate this, we examined the interictal GOR from 20 s of scalp EEG data before and after PER administration collected from five patients with epilepsy with focal seizures. Prior to PER administration, each patient presented with localized areas with high GOR consistent with brain lesions or seizure semiology. In all patients, the seizures improved following PER administration, and the localized high GOR, which is considered an epileptogenic focus, disappeared. These results indicate that interictal GOR analysis may be a useful tool for the quantitative assessments of the antiseizure effects of PER in focal epilepsy. PLAIN LANGUAGE SUMMARY: This study explored whether perampanel (PER)'s antiseizure effects can be quantified using interictal high gamma oscillation regularity (GOR) analysis from scalp EEG data. Analyzing 20-second EEG segments before and after PER administration in five patients with focal epilepsy, we found that high GOR areas, indicative of epileptogenic foci, disappeared following PER administration. The results suggest that interictal GOR analysis could effectively quantify the antiseizure effects of PER., (© 2024 The Author(s). Epilepsia Open published by Wiley Periodicals LLC on behalf of International League Against Epilepsy.)
- Published
- 2024
- Full Text
- View/download PDF
25. Maternal Diet and Gut Microbiota Influence Predisposition to Cardiovascular Disease in Offspring.
- Author
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Jama HA, Dona MSI, Dinakis E, Nakai M, Paterson MR, Shihata WA, Krstevski C, Cohen CD, Weeks KL, Farrugia GE, Johnson C, Salimova E, Donner DG, Kiriazis H, Kaipananickal H, Okabe J, Anderson D, Creek DJ, Mackay CR, El-Osta A, Pinto AR, Kaye DM, and Marques FZ
- Subjects
- Humans, Female, Pregnancy, Animals, Maternal Nutritional Physiological Phenomena, Gastrointestinal Microbiome, Cardiovascular Diseases microbiology, Cardiovascular Diseases etiology, Diet adverse effects, Prenatal Exposure Delayed Effects microbiology
- Abstract
Competing Interests: None.
- Published
- 2024
- Full Text
- View/download PDF
26. N-Nitrosodimethylamine formation from anthropogenic nitrogenous compounds during preozonation and post-chloramination with characteristic low treatment dose.
- Author
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Hinneh KDC, Okabe J, Kosaka K, Echigo S, and Itoh S
- Subjects
- Water Purification, Drinking Water chemistry, Dimethylnitrosamine chemistry, Water Pollutants, Chemical chemistry, Ozone chemistry, Nitrogen Compounds chemistry
- Abstract
One effective option to minimize N-nitrosodimethylamine (NDMA) in finished drinking water is to identify and control its precursors. However, previous works to identify significant precursors use formation potential (FP) tests using high doses to assure the maximum NDMA formation rather than the NDMA formation in finished waters. In this study, we applied characteristic low treatment doses of ozone (O
3 )-to-dissolved organic carbon (DOC) of target compounds of 0.8 mg/mg and NH2 Cl of 2.5 ± 0.2 mg Cl2 /L to evaluate the NDMAFP yields of organic compounds bearing N,N-dimethylamine (DMA) and N,N-dimethylhydrazine (DMH) during preozonation and post-chloramination. The results in pH-buffered Milli-Q water showed a significant decrease from ≤ 52% to non-detectable levels in the O3 -NDMAFP yields of O3 -reactive precursors (i.e., DMH-like compounds) after preozonation and post-chloramination. Similarly, a significant decrease from 0.5 to 12% to nonquantifiable levels was observed for the NH2 Cl-NDMAFP yields of NH2 Cl-reactive precursors; however, the NH2 Cl-NDMAFP yields of N,N-dimethylbenzylamine (DMBzA)-like compounds only decreased from ~ 110 to ≤ 43%, suggesting that these compounds could contribute to NH2 Cl-NDMAFPs even after preozonation. The effect of the matrix in sewage-effluent and lake water samples varied and was specific for precursors; for example, the O3 -NDMAFP yield of 1,1,1',1'-tetramethyl-4,4'-(methylene-di-p-phenylene) disemicarbazide (TMDS), an important O3 -reactive NDMA precursor, did not significantly decrease when tested in sewage-effluent samples. Based on the previous occurrence concentration of TMDS in sewage samples, we estimated an NDMAFP of ~ 315 ng/L. This estimate exceeds the guidance concentrations of NDMA (3-100 ng/L), highlighting the importance of TMDS and its related compounds for NDMA formation., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)- Published
- 2024
- Full Text
- View/download PDF
27. Set7 Methyltransferase and Phenotypic Switch in Diabetic Glomerular Endothelial Cells.
- Author
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Maxwell S, Okabe J, Kaipananickal H, Rodriguez H, Khurana I, Al-Hasani K, Chow BSM, Pitsillou E, Karagiannis TC, Jandeleit-Dahm K, Ma RCW, Huang Y, Chan JCN, Cooper ME, and El-Osta A
- Subjects
- Animals, Humans, Mice, Endothelial Cells, Kidney Glomerulus pathology, Kidney Glomerulus blood supply, Histone-Lysine N-Methyltransferase genetics, Histone-Lysine N-Methyltransferase metabolism, Phenotype, Diabetic Nephropathies enzymology
- Published
- 2024
- Full Text
- View/download PDF
28. γH2AX in mouse embryonic stem cells: Distribution during differentiation and following γ-irradiation.
- Author
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Karagiannis TC, Orlowski C, Ververis K, Pitsillou E, Sarila G, Keating ST, Foong LJ, Fabris S, Ngo-Nguyen C, Malik N, Okabe J, Hung A, Mantamadiotis T, and El-Osta A
- Subjects
- Animals, Mice, Cell Differentiation genetics, DNA Breaks, Double-Stranded, Embryonic Stem Cells, DNA Repair genetics, Mouse Embryonic Stem Cells, Histones metabolism, Histones radiation effects
- Abstract
Phosphorylated histone H2AX (γH2AX) represents a sensitive molecular marker of DNA double-strand breaks (DSBs) and is implicated in stem cell biology. We established a model of mouse embryonic stem cell (mESC) differentiation and examined the dynamics of γH2AX foci during the process. Our results revealed high numbers of γH2AX foci in undifferentiated mESCs, decreasing as the cells differentiated towards the endothelial cell lineage. Notably, we observed two distinct patterns of γH2AX foci: the typical discrete γH2AX foci, which colocalize with the transcriptionally permissive chromatin mark H3K4me3, and the less well-characterized clustered γH2AX regions, which were only observed in intermediate progenitor cells. Next, we explored responses of mESCs to γ-radiation (
137 Cs). Following exposure to γ-radiation, mESCs showed a reduction in cell viability and increased γH2AX foci, indicative of radiosensitivity. Despite irradiation, surviving mESCs retained their differentiation potential. To further exemplify our findings, we investigated neural stem progenitor cells (NSPCs). Similar to mESCs, NSPCs displayed clustered γH2AX foci associated with progenitor cells and discrete γH2AX foci indicative of embryonic stem cells or differentiated cells. In conclusion, our findings demonstrate that γH2AX serves as a versatile marker of DSBs and may have a role as a biomarker in stem cell differentiation. The distinct patterns of γH2AX foci in differentiating mESCs and NSPCs provide valuable insights into DNA repair dynamics during differentiation, shedding light on the intricate balance between genomic integrity and cellular plasticity in stem cells. Finally, the clustered γH2AX foci observed in intermediate progenitor cells is an intriguing feature, requiring further exploration., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2023 Elsevier B.V. All rights reserved.)- Published
- 2024
- Full Text
- View/download PDF
29. The relationship between observation interval and prognosis in pancreatic cancer concomitant with intraductal papillary mucinous neoplasia.
- Author
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Yoshioka T, Shigekawa M, Ikezawa K, Hirao M, Ishii S, Suda T, Kegasawa T, Matsumoto K, Iwahashi K, Murata J, Kaneko A, Nakazuru S, Yamamoto S, Matsumae T, Kozumi K, Sato Y, Okabe J, Sato K, Hikita H, Sakamori R, Tatsumi T, and Takehara T
- Subjects
- Humans, Prognosis, Retrospective Studies, Magnetic Resonance Imaging, Carcinoma, Pancreatic Ductal complications, Carcinoma, Pancreatic Ductal diagnostic imaging, Carcinoma, Pancreatic Ductal pathology, Pancreatic Intraductal Neoplasms, Adenocarcinoma, Mucinous complications, Adenocarcinoma, Mucinous diagnostic imaging, Adenocarcinoma, Mucinous pathology, Pancreatic Neoplasms complications, Pancreatic Neoplasms diagnostic imaging
- Abstract
Background: Intraductal papillary mucinous neoplasia (IPMN) is a risk factor for pancreatic cancer (PC). PC concomitant with IPMN shows rapid progression similar to de novo PC, therefore, the appropriate observation interval (OI) is not yet clear., Patients and Method: This was a multicenter retrospective observational study, and patients with PC concomitant with IPMN were analyzed. OI was defined as the interval between the date of imaging at PC diagnosis and just before the diagnosis. Clinical factors of PC and prognosis were assessed according to OI., Results: From January 2010 to December 2018, 73 patients from 11 institutions were enrolled. The images performed just before PC diagnosis were contrast-enhanced CT/magnetic resonance imaging/endoscopic ultrasonography in 44/27/2 patients, respectively. The median cyst size was 14.0 mm, and the median main pancreatic duct diameter was 3.0 mm. The median OI was 6.8 months. In OI 6 months or less (OI ≤ 6 M)/OI more than 6 months (OI > 6 M), the mean tumor size, the frequencies of metastatic PC, resectable PC and early-stage PC were 20.1/21.5 mm (P = 0.91), 12.1 %/32.5 % (P = 0.05), 72.7 %/52.5 % (P = 0.09) and 27.3 %/25.0 % (P = 1.00), respectively. The median overall survival was 35.5 months in OI ≤ 6 M and 16.2 months in OI > 6 M (P = 0.05)., Conclusion: In OI 6 months or less, the rate of resectable PC was high, however, the rate of early PC was almost the same as that of OI more than 6 months. Approximately 10 % of cases found in the advanced stage with metastasis even if OI 6 months or less., Competing Interests: Declaration of competing interest There are no conflicts of interest to declare in this manuscript., (Copyright © 2023. Published by Elsevier B.V.)
- Published
- 2024
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- View/download PDF
30. Potential of Modulating Aldosterone Signaling and Mineralocorticoid Receptor with microRNAs to Attenuate Diabetic Kidney Disease.
- Author
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Hagiwara S, Gohda T, Kantharidis P, Okabe J, Murakoshi M, and Suzuki Y
- Subjects
- Humans, Aldosterone, Fibrosis, Inflammation, Mineralocorticoids, Receptors, Mineralocorticoid genetics, Diabetic Nephropathies genetics, MicroRNAs genetics
- Abstract
Diabetic Kidney Disease (DKD) is a significant complication of diabetes and primary cause of end-stage renal disease globally. The exact mechanisms underlying DKD remain poorly understood, but multiple factors, including the renin-angiotensin-aldosterone system (RAAS), play a key role in its progression. Aldosterone, a mineralocorticoid steroid hormone, is one of the key components of RAAS and a potential mediator of renal damage and inflammation in DKD. miRNAs, small noncoding RNA molecules, have attracted interest due to their regulatory roles in numerous biological processes. These processes include aldosterone signaling and mineralocorticoid receptor (MR) expression. Numerous miRNAs have been recognized as crucial regulators of aldosterone signaling and MR expression. These miRNAs affect different aspects of the RAAS pathway and subsequent molecular processes, which impact sodium balance, ion transport, and fibrosis regulation. This review investigates the regulatory roles of particular miRNAs in modulating aldosterone signaling and MR activation, focusing on their impact on kidney injury, inflammation, and fibrosis. Understanding the complex interaction between miRNAs and the RAAS could lead to a new strategy to target aldosterone signaling and MR activation using miRNAs. This highlights the potential of miRNA-based interventions for DKD, with the aim of enhancing kidney outcomes in individuals with diabetes.
- Published
- 2024
- Full Text
- View/download PDF
31. EZH2 inhibitors promote β-like cell regeneration in young and adult type 1 diabetes donors.
- Author
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Al-Hasani K, Marikar SN, Kaipananickal H, Maxwell S, Okabe J, Khurana I, Karagiannis T, Liang JJ, Mariana L, Loudovaris T, Kay T, and El-Osta A
- Subjects
- Humans, Insulin metabolism, Cell Differentiation genetics, Chromatin metabolism, Enhancer of Zeste Homolog 2 Protein genetics, Enhancer of Zeste Homolog 2 Protein metabolism, Diabetes Mellitus, Type 1 drug therapy, Diabetes Mellitus, Type 1 genetics, Diabetes Mellitus, Type 1 metabolism, Islets of Langerhans metabolism
- Abstract
β-cells are a type of endocrine cell found in pancreatic islets that synthesize, store and release insulin. In type 1 diabetes (T1D), T-cells of the immune system selectively destroy the insulin-producing β-cells. Destruction of these cells leads to a lifelong dependence on exogenous insulin administration for survival. Consequently, there is an urgent need to identify novel therapies that stimulate β-cell growth and induce β-cell function. We and others have shown that pancreatic ductal progenitor cells are a promising source for regenerating β-cells for T1D owing to their inherent differentiation capacity. Default transcriptional suppression is refractory to exocrine reaction and tightly controls the regenerative potential by the EZH2 methyltransferase. In the present study, we show that transient stimulation of exocrine cells, derived from juvenile and adult T1D donors to the FDA-approved EZH2 inhibitors GSK126 and Tazemetostat (Taz) influence a phenotypic shift towards a β-like cell identity. The transition from repressed to permissive chromatin states are dependent on bivalent H3K27me3 and H3K4me3 chromatin modification. Targeting EZH2 is fundamental to β-cell regenerative potential. Reprogrammed pancreatic ductal cells exhibit insulin production and secretion in response to a physiological glucose challenge ex vivo. These pre-clinical studies underscore the potential of small molecule inhibitors as novel modulators of ductal progenitor differentiation and a promising new approach for the restoration of β-like cell function., (© 2023. The Author(s).)
- Published
- 2024
- Full Text
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32. Regnase-1 downregulation promotes pancreatic cancer through myeloid-derived suppressor cell-mediated evasion of anticancer immunity.
- Author
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Okabe J, Kodama T, Sato Y, Shigeno S, Matsumae T, Daiku K, Sato K, Yoshioka T, Shigekawa M, Higashiguchi M, Kobayashi S, Hikita H, Tatsumi T, Okamoto T, Satoh T, Eguchi H, Akira S, and Takehara T
- Subjects
- Animals, Humans, Mice, Cell Line, Tumor, Down-Regulation, Inflammation metabolism, Mice, Knockout, Pancreatic Neoplasms, Carcinoma, Pancreatic Ductal pathology, Myeloid-Derived Suppressor Cells, Pancreatic Neoplasms pathology, Ribonucleases genetics
- Abstract
Background: Pancreatitis is known to be an important risk factor for pancreatic ductal adenocarcinoma (PDAC). However, the exact molecular mechanisms of how inflammation promotes PDAC are still not fully understood. Regnase-1, an endoribonuclease, regulates immune responses by degrading mRNAs of inflammation-related genes. Herein, we investigated the role of Regnase-1 in PDAC., Methods: Clinical significance of intratumor Regnase-1 expression was evaluated by immunohistochemistry in 39 surgically-resected PDAC patients. The functional role of Regnase-1 was investigated by pancreas-specific Regnase-1 knockout mice and Kras-mutant Regnase-1 knockout mice. The mechanistic studies with gene silencing, RNA immunoprecipitation sequencing (RIP-seq) and immune cell reconstitution were performed in human/mouse PDAC cell lines and a syngeneic orthotopic tumor transplantation model of KrasG12D-mutant and Trp53-deficient PDAC cells., Results: Regnase-1 expression was negatively correlated with the clinical outcomes and an independent predictor of poor relapse-free and overall survival in PDAC patients. Pancreas-specific Regnase-1 deletion in mice promoteed pancreatic cancer with PMN-MDSC infiltration and shortened their survival. A syngeneic orthotopic PDAC model exhibited that Regnase-1 downregulation accelerated tumor progression via recruitment of intratumor CD11b
+ MDSCs. Mechanistically, Regnase-1 directly negatively regulated a variety of chemokines/cytokines important for MDSC recruitment and activation, including CXCL1, CXCL2, CSF2, and TGFβ, in pancreatic cancer cells. We subsequently showed that IL-1β-mediated Regnase-1 downregulation recruited MDSCs to tumor sites and promoted pancreatic cancer progression via mitigation of cytotoxic T lympohocytes-mediated antitumor immunity., Conclusions: IL-1b-mediated Regnase-1 downregulation induces MDSCs and promotes pancreatic cancer through the evasion of anticancer immunity., (© 2023. Italian National Cancer Institute ‘Regina Elena’.)- Published
- 2023
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33. Circulating epigenomic biomarkers correspond with kidney disease susceptibility in high-risk populations with type 2 diabetes mellitus.
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Khurana I, Howard NJ, Maxwell S, Du Preez A, Kaipananickal H, Breen J, Buckberry S, Okabe J, Al-Hasani K, Nakasatien S, Himathongkam T, Cooper ME, Maple-Brown L, Thewjitcharoen Y, Brown A, and El-Osta A
- Subjects
- Humans, Albuminuria complications, Disease Susceptibility complications, Epigenomics, Australia, Kidney, Biomarkers, Glomerular Filtration Rate, Diabetes Mellitus, Type 2 complications, Diabetic Nephropathies diagnosis, Diabetic Nephropathies genetics, Diabetic Nephropathies metabolism
- Abstract
Aims: To investigate epigenomic indices of diabetic kidney disease (DKD) susceptibility among high-risk populations with type 2 diabetes mellitus., Methods: KDIGO (Kidney Disease: Improving Global Outcomes) clinical guidelines were used to classify people living with or without DKD. Differential gene methylation of DKD was then assessed in a discovery Aboriginal Diabetes Study cohort (PROPHECY, 89 people) and an external independent study from Thailand (THEPTARIN, 128 people). Corresponding mRNA levels were also measured and linked to levels of albuminuria and eGFR., Results: Increased DKD risk was associated with reduced methylation and elevated gene expression in the PROPHECY discovery cohort of Aboriginal Australians and these findings were externally validated in the THEPTARIN diabetes registry of Thai people living with type 2 diabetes mellitus., Conclusions: Novel epigenomic scores can improve diagnostic performance over clinical modelling using albuminuria and GFR alone and can distinguish DKD susceptibility., Competing Interests: Declaration of Competing Interest 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., (Copyright © 2023 The Author(s). Published by Elsevier B.V. All rights reserved.)
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- 2023
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34. Advances in Design and Development of Lumi-Solve: A Novel Drug-Eluting Photo-Angioplasty Device.
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Sangeetha Menon A, Subasic de Azevedo I, Choong K, Bhatnagar D, Wang C, Sluka P, Chisholm DR, Pasic P, Thissen H, Sama G, Robinson A, Rodda A, Tria A, Spiegel L, Dharma A, Kaipananickal H, Okabe J, El-Osta A, Mountford S, Thompson P, and Dear AE
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- Humans, Human Umbilical Vein Endothelial Cells, Angioplasty, Balloon adverse effects, Vascular Access Devices
- Abstract
Purpose: The Lumi-Solve photo-angioplasty drug eluting balloon catheter (DEBc) may afford safety advantages over current DEBc. Lumi-Solve utilises the guidewire (GW) port and lumen to deliver fibre-optic UV365nm light to the angioplasty balloon which may be problematic. We explore and evaluate alternative Lumi-Solve design options to circumvent fibre-optic use of the GW port and lumen which may enhance efficacy and clinical utility., Methods: Effects of guidewire shadowing (GWS) on visible and UV365nm light transmission were evaluated and modelled in-silico. To evaluate the effect of a dedicated intra-balloon fibre-optic port, modified angioplasty balloons and sections of translucent polyethylene terephthalate (PET) GW port tubing were utilised. Investigation of the effect of GWS on chemical and biological photo-activation of balloon surface drug was performed utilising LCMS analysis and inhibition of histone deacetylase activity (HDACi) was measured in human umbilical vein endothelial cells (HUVEC)., Results: Parallel fibre-optic and GW port configurations generated a GWS of approximately 18.0% of the evaluable balloon surface area and attenuated both visible and UV light intensity by 20.0-25.0% and reduced chemical photo-activation of balloon surface drug and HDACi by at least 40-45%. Alternative fibre-optic port configurations including a spiral design significantly mitigated GWS effects on UV light transmission., Conclusions: To avoid use of the GW port and its associated complications a dedicated third port and lumen for the Lumi-Solve fibre-optic may be required. To maximize balloon surface chemical and biological photo-activation, non-parallel, intra-balloon, fibre-optic lumen trajectories, including a spiral design may be useful., (© 2023. The Author(s).)
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- 2023
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35. Pharmacological inhibition of human EZH2 can influence a regenerative β-like cell capacity with in vitro insulin release in pancreatic ductal cells.
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Naina Marikar S, Al-Hasani K, Khurana I, Kaipananickal H, Okabe J, Maxwell S, and El-Osta A
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- Adult, Humans, Histones, DNA Methylation, Epithelial Cells, Enhancer of Zeste Homolog 2 Protein, Insulin, Diabetes Mellitus, Type 1
- Abstract
Background: Therapeutic replacement of pancreatic endocrine β-cells is key to improving hyperglycaemia caused by insulin-dependent diabetes . Whilst the pool of ductal progenitors, which give rise to the endocrine cells, are active during development, neogenesis of islets is repressed in the human adult. Recent human donor studies have demonstrated the role of EZH2 inhibition in surgically isolated exocrine cells showing reactivation of insulin expression and the influence on the H3K27me3 barrier to β-cell regeneration. However, those studies fall short on defining the cell type active in transcriptional reactivation events. This study examines the role of the regenerative capacity of human pancreatic ductal cells when stimulated with pharmacological inhibitors of the EZH2 methyltransferase., Results: Human pancreatic ductal epithelial cells were stimulated with the EZH2 inhibitors GSK-126, EPZ6438, and triptolide using a 2- and 7-day protocol to determine their influence on the expression of core endocrine development marker NGN3, as well as β-cell markers insulin, MAFA, and PDX1. Chromatin immunoprecipitation studies show a close correspondence of pharmacological EZH2 inhibition with reduced H3K27me3 content of the core genes, NGN3, MAFA and PDX1. Consistent with the reduction of H3K27me3 by pharmacological inhibition of EZH2, we observe measurable immunofluorescence staining of insulin protein and glucose-sensitive insulin response., Conclusion: The results of this study serve as a proof of concept for a probable source of β-cell induction from pancreatic ductal cells that are capable of influencing insulin expression. Whilst pharmacological inhibition of EZH2 can stimulate secretion of detectable insulin from ductal progenitor cells, further studies are required to address mechanism and the identity of ductal progenitor cell targets to improve likely methods designed to reduce the burden of insulin-dependent diabetes., (© 2023. The Author(s).)
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- 2023
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36. Reduced methylation correlates with diabetic nephropathy risk in type 1 diabetes.
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Khurana I, Kaipananickal H, Maxwell S, Birkelund S, Syreeni A, Forsblom C, Okabe J, Ziemann M, Kaspi A, Rafehi H, Jørgensen A, Al-Hasani K, Thomas MC, Jiang G, Luk AO, Lee HM, Huang Y, Thewjitcharoen Y, Nakasatien S, Himathongkam T, Fogarty C, Njeim R, Eid A, Hansen TW, Tofte N, Ottesen EC, Ma RC, Chan JC, Cooper ME, Rossing P, Groop PH, and El-Osta A
- Subjects
- Humans, Genome-Wide Association Study, Endothelial Cells metabolism, DNA Methylation, Insulin metabolism, Diabetes Mellitus, Type 1 complications, Diabetes Mellitus, Type 1 genetics, Diabetic Nephropathies genetics, Diabetic Nephropathies metabolism
- Abstract
Diabetic nephropathy (DN) is a polygenic disorder with few risk variants showing robust replication in large-scale genome-wide association studies. To understand the role of DNA methylation, it is important to have the prevailing genomic view to distinguish key sequence elements that influence gene expression. This is particularly challenging for DN because genome-wide methylation patterns are poorly defined. While methylation is known to alter gene expression, the importance of this causal relationship is obscured by array-based technologies since coverage outside promoter regions is low. To overcome these challenges, we performed methylation sequencing using leukocytes derived from participants of the Finnish Diabetic Nephropathy (FinnDiane) type 1 diabetes (T1D) study (n = 39) that was subsequently replicated in a larger validation cohort (n = 296). Gene body-related regions made up more than 60% of the methylation differences and emphasized the importance of methylation sequencing. We observed differentially methylated genes associated with DN in 3 independent T1D registries originating from Denmark (n = 445), Hong Kong (n = 107), and Thailand (n = 130). Reduced DNA methylation at CTCF and Pol2B sites was tightly connected with DN pathways that include insulin signaling, lipid metabolism, and fibrosis. To define the pathophysiological significance of these population findings, methylation indices were assessed in human renal cells such as podocytes and proximal convoluted tubule cells. The expression of core genes was associated with reduced methylation, elevated CTCF and Pol2B binding, and the activation of insulin-signaling phosphoproteins in hyperglycemic cells. These experimental observations also closely parallel methylation-mediated regulation in human macrophages and vascular endothelial cells.
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- 2023
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37. Inhibition of pancreatic EZH2 restores progenitor insulin in T1D donor.
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Al-Hasani K, Khurana I, Mariana L, Loudovaris T, Maxwell S, Harikrishnan KN, Okabe J, Cooper ME, and El-Osta A
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- Adolescent, Chromatin, Enhancer of Zeste Homolog 2 Protein genetics, Enhancer of Zeste Homolog 2 Protein metabolism, Female, Humans, Insulin genetics, Insulin metabolism, Pancreas metabolism, Diabetes Mellitus, Type 1 genetics, Pancreas, Exocrine metabolism
- Abstract
Type 1 diabetes (T1D) is an autoimmune disease that selectively destroys insulin-producing β-cells in the pancreas. An unmet need in diabetes management, current therapy is focussed on transplantation. While the reprogramming of progenitor cells into functional insulin-producing β-cells has also been proposed this remains controversial and poorly understood. The challenge is determining why default transcriptional suppression is refractory to exocrine reactivation. After the death of a 13-year-old girl with established insulin-dependent T1D, pancreatic cells were harvested in an effort to restore and understand exocrine competence. The pancreas showed classic silencing of β-cell progenitor genes with barely detectable insulin (Ins) transcript. GSK126, a highly selective inhibitor of EZH2 methyltransferase activity influenced H3K27me3 chromatin content and transcriptional control resulting in the expression of core β-cell markers and ductal progenitor genes. GSK126 also reinstated Ins gene expression despite absolute β-cell destruction. These studies show the refractory nature of chromatin characterises exocrine suppression influencing β-cell plasticity. Additional regeneration studies are warranted to determine if the approach of this n-of-1 study generalises to a broader T1D population., (© 2022. The Author(s).)
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- 2022
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38. Independent of Renox, NOX5 Promotes Renal Inflammation and Fibrosis in Diabetes by Activating ROS-Sensitive Pathways.
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Jha JC, Dai A, Garzarella J, Charlton A, Urner S, Østergaard JA, Okabe J, Holterman CE, Skene A, Power DA, Ekinci EI, Coughlan MT, Schmidt HHHW, Cooper ME, Touyz RM, Kennedy CR, and Jandeleit-Dahm K
- Subjects
- Animals, Fibrosis, Humans, Inflammation metabolism, Mice, NADPH Oxidase 4 genetics, NADPH Oxidase 5 genetics, NADPH Oxidase 5 metabolism, NADPH Oxidases genetics, NADPH Oxidases metabolism, Reactive Oxygen Species metabolism, Diabetes Mellitus, Diabetic Nephropathies genetics, Diabetic Nephropathies metabolism
- Abstract
Excessive production of renal reactive oxygen species (ROS) plays a major role in diabetic kidney disease (DKD). Here, we provide key findings demonstrating the predominant pathological role of the pro-oxidant enzyme NADPH oxidase 5 (NOX5) in DKD, independent of the previously characterized NOX4 pathway. In patients with diabetes, we found increased expression of renal NOX5 in association with enhanced ROS formation and upregulation of ROS-sensitive factors early growth response 1 (EGR-1), protein kinase C-α (PKC-α), and a key metabolic gene involved in redox balance, thioredoxin-interacting protein (TXNIP). In preclinical models of DKD, overexpression of NOX5 in Nox4-deficient mice enhances kidney damage by increasing albuminuria and augmenting renal fibrosis and inflammation via enhanced ROS formation and the modulation of EGR1, TXNIP, ERK1/2, PKC-α, and PKC-ε. In addition, the only first-in-class NOX inhibitor, GKT137831, appears to be ineffective in the presence of NOX5 expression in diabetes. In vitro, silencing of NOX5 in human mesangial cells attenuated upregulation of EGR1, PKC-α, and TXNIP induced by high glucose levels, as well as markers of inflammation (TLR4 and MCP-1) and fibrosis (CTGF and collagens I and III) via reduction in ROS formation. Collectively, these findings identify NOX5 as a superior target in human DKD compared with other NOX isoforms such as NOX4, which may have been overinterpreted in previous rodent studies., (© 2022 by the American Diabetes Association.)
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- 2022
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39. Initial drainage-related prognostic factors for perihilar cholangiocarcinoma: A single-center retrospective study.
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Sato K, Shigekawa M, Kozumi K, Okabe J, Sato Y, Tamura T, Yoshioka T, Sakamori R, Iwagami Y, Yamada D, Tomimaru Y, Noda T, Takahashi H, Kobayashi S, Eguchi H, Tatsumi T, and Takehara T
- Abstract
Objectives: Perihilar cholangiocarcinoma (PCC) is a complex disorder involving the hepatic hilum. Multiple endoscopic retrograde cholangiopancreatography sessions are necessary for diagnosis and treatment with underlying cholangitis risk. Our aim is to clarify the initial-drainage-related prognostic factors of PCC., Methods: This study was a single-center retrospective study. A total of 104 consecutive patients diagnosed with PCC from January 2010 to February 2020 were enrolled. We defined the diagnostic period as the time between the first biliary drainage attempt and the final drainage when treatment, including surgery or chemotherapy, was started. We focused on this initial period and analyzed the endoscopy-related factors that affected mortality., Results: Overall survival of all PCC patients was 599 days. Overall survival of surgically treated patients and unresectable patients were 893 days and 512 days, respectively. In 48 surgically treated patients, drainage-related cholangitis within the diagnostic period, defined as new cholangitis that occurred after the first biliary drainage attempt, worsened overall survival from 1460 days to 607 days. Endoscopic sphincterotomy, the first drainage method other than endoscopic nasobiliary drainage, and four or more endoscopic retrograde cholangiopancreatography sessions were risk factors for drainage-related cholangitis. Drainage-related cholangitis increased pathological lymph node metastasis. Percutaneous transhepatic biliary drainage as final drainage was the only prognostic factor in unresectable chemotherapy-treated patients., Conclusions: Drainage-related cholangitis worsened the prognosis in PCC patients who underwent surgery. Appropriate endoscopic retrograde cholangiopancreatography strategies, especially during the diagnostic period, are of great importance in PCC., Competing Interests: The authors declare no conflict of interest., (© 2022 The Authors. DEN Open published by John Wiley & Sons Australia, Ltd on behalf of Japan Gastroenterological Endoscopy Society.)
- Published
- 2022
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40. SAHA attenuates Takotsubo-like myocardial injury by targeting an epigenetic Ac/Dc axis.
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Khurana I, Maxwell S, Royce S, Mathiyalagan P, Karagiannis T, Mazarakis N, Vongsvivut J, K N H, Okabe J, Al-Hasani K, Samuel C, and El-Osta A
- Subjects
- Acetylation drug effects, Animals, Disease Models, Animal, Mice, Epigenesis, Genetic drug effects, Takotsubo Cardiomyopathy drug therapy, Takotsubo Cardiomyopathy metabolism, Takotsubo Cardiomyopathy physiopathology, Vorinostat pharmacology
- Published
- 2021
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41. Epigenetic evidence of an Ac/Dc axis by VPA and SAHA.
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Lunke S, Maxwell S, Khurana I, K N H, Okabe J, Al-Hasani K, and El-Osta A
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- Acetylation drug effects, Cells, Cultured drug effects, Epigenesis, Genetic drug effects, Epilepsy genetics, Gene Expression Regulation, Histone Deacetylases genetics, Histones genetics, Humans, Epilepsy drug therapy, Histone Deacetylase Inhibitors metabolism, Histone Deacetylases metabolism, Histones metabolism, Valproic Acid adverse effects, Valproic Acid therapeutic use, Vorinostat adverse effects, Vorinostat therapeutic use
- Abstract
Background: Valproic acid (VPA) is one of the most commonly used anti-epileptic drugs with pharmacological actions on GABA and blocking voltage-gated ion channels. VPA also inhibits histone deacetylase (HDAC) activity. Suberoylanilide hydroxamic acid is also a member of a larger class of compounds that inhibit HDACs. At the time of this article, there are 123 active international clinical trials for VPA (also known as valproate, convulex, divalproex, and depakote) and SAHA (vorinostat, zolinza). While it is well known that VPA and SAHA influence the accumulation of acetylated lysine residues on histones, their true epigenetic complexity remains poorly understood., Results: Primary human cells were exposed to VPA and SAHA to understand the extent of histone acetylation (H3K9/14ac) using chromatin immunoprecipitation followed by sequencing (ChIP-seq). Because histone acetylation is often associated with modification of lysine methylation, we also examined H3K4me3 and H3K9me3. To assess the influence of the HDAC inhibitors on gene expression, we used RNA sequencing (RNA-seq). ChIP-seq reveals a distribution of histone modifications that is robust and more broadly regulated than previously anticipated by VPA and SAHA. Histone acetylation is a characteristic of the pharmacological inhibitors that influenced gene expression. Surprisingly, we observed histone deacetylation by VPA stimulation is a predominant signature following SAHA exposure and thus defines an acetylation/deacetylation (Ac/Dc) axis. ChIP-seq reveals regionalisation of histone acetylation by VPA and broader deacetylation by SAHA. Independent experiments confirm H3K9/14 deacetylation of NFκB target genes by SAHA., Conclusions: The results provide an important framework for understanding the Ac/Dc axis by highlighting a broader complexity of histone modifications by the most established and efficacious anti-epileptic medication in this class, VPA and comparison with the broad spectrum HDAC inhibitor, SAHA.
- Published
- 2021
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42. Branched-chain amino acids and l-carnitine attenuate lipotoxic hepatocellular damage in rat cirrhotic liver.
- Author
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Tamai Y, Chen Z, Wu Y, Okabe J, Kobayashi Y, Chiba H, Hui SP, Eguchi A, Iwasa M, Ito M, and Takei Y
- Subjects
- Animals, Carbon Tetrachloride, Cell Death drug effects, Chemical and Drug Induced Liver Injury etiology, Chemical and Drug Induced Liver Injury metabolism, Chemical and Drug Induced Liver Injury pathology, Fatty Liver chemically induced, Fatty Liver metabolism, Fatty Liver pathology, Hepatocytes metabolism, Hepatocytes pathology, Liver metabolism, Liver pathology, Liver Cirrhosis, Experimental chemically induced, Liver Cirrhosis, Experimental metabolism, Liver Cirrhosis, Experimental pathology, Male, Mitochondria, Liver drug effects, Mitochondria, Liver metabolism, Mitochondria, Liver pathology, Rats, Wistar, Rats, Amino Acids, Branched-Chain pharmacology, Carnitine pharmacology, Chemical and Drug Induced Liver Injury prevention & control, Fatty Liver prevention & control, Hepatocytes drug effects, Lipid Peroxidation drug effects, Liver drug effects, Liver Cirrhosis, Experimental prevention & control
- Abstract
Branched-chain amino acids (BCAA) reverse malnutrition and l-carnitine leads to the reduction of hyperammonemia and muscle cramps in cirrhotic patients. BCAA and l-carnitine are involved in glucose and fatty acid metabolism, however their mechanistic activity in cirrhotic liver is not fully understood. We aim to define the molecular mechanism(s) and combined effects of BCAA and l-carnitine using a cirrhotic rat model. Rats were administered carbon tetrachloride for 10 weeks to induce cirrhosis. During the last 6 weeks of administration, cirrhotic rats received BCAA, l-carnitine or a combination of BCAA and l-carnitine daily via gavage. We found that BCAA and l-carnitine treatments significantly improved hepatocellular function associated with reduced triglyceride level, lipid deposition and adipophilin expression, in cirrhotic liver. Lipidomic analysis revealed dynamic changes in hepatic lipid composition by BCAA and l-carnitine administrations. BCAA and l-carnitine globally increased molecular species of phosphatidylcholine. Liver triacylglycerol and phosphatidylcholine hydroperoxides were significantly decreased by BCAA and l-carnitine. Furthermore, serum and liver ATP levels were significantly increased in all treatments, which were attributed to the elevation of mature cardiolipins and mitochondrial component gene expressions. Finally, BCAA and l-carnitine dramatically reduced hepatocellular death. In conclusion, BCAA and l-carnitine treatments attenuate hepatocellular damage through the reduction of lipid peroxides and the overall maintenance of mitochondrial integrity within the cirrhotic liver. These effectiveness of BCAA and l-carnitine support the therapeutic strategies in human chronic liver diseases., (Copyright © 2020 The Author(s). Published by Elsevier Masson SAS.. All rights reserved.)
- Published
- 2021
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43. Macrophage ubiquitin-specific protease 2 contributes to motility, hyperactivation, capacitation, and in vitro fertilization activity of mouse sperm.
- Author
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Hashimoto M, Kimura S, Kanno C, Yanagawa Y, Watanabe T, Okabe J, Takahashi E, Nagano M, and Kitamura H
- Subjects
- Animals, Calcium metabolism, Down-Regulation drug effects, Fertilization in Vitro, Freezing, Granulocyte-Macrophage Colony-Stimulating Factor pharmacology, Hydrogen-Ion Concentration, Macrophages cytology, Macrophages immunology, Male, Membrane Potential, Mitochondrial drug effects, Mice, Mice, Inbred C57BL, Mice, Knockout, Sperm Motility drug effects, Testis anatomy & histology, Testis physiology, Testosterone metabolism, Tretinoin metabolism, Ubiquitin Thiolesterase deficiency, Ubiquitin Thiolesterase genetics, Macrophages metabolism, Sperm Capacitation physiology, Sperm Motility physiology, Spermatozoa metabolism, Ubiquitin Thiolesterase metabolism
- Abstract
Macrophages are innate immune cells that contribute to classical immune functions and tissue homeostasis. Ubiquitin-specific protease 2 (USP2) controls cytokine production in macrophages, but its organ-specific roles are still unknown. In this study, we generated myeloid-selective Usp2 knockout (msUsp2KO) mice and specifically explored the roles of testicular macrophage-derived USP2 in reproduction. The msUsp2KO mice exhibited normal macrophage characteristics in various tissues. In the testis, macrophage Usp2 deficiency negligibly affected testicular macrophage subpopulations, spermatogenesis, and testicular organogenesis. However, frozen-thawed sperm derived from msUsp2KO mice exhibited reduced motility, capacitation, and hyperactivation. In addition, macrophage Usp2 ablation led to a decrease in the sperm population exhibiting high intracellular pH, calcium influx, and mitochondrial membrane potential. Interrupted pronuclei formation in eggs was observed when using frozen-thawed sperm from msUsp2KO mice for in vitro fertilization. Administration of granulocyte macrophage-colony stimulating factor (GM-CSF), whose expression was decreased in testicular macrophages derived from msUsp2KO mice, restored mitochondrial membrane potential and total sperm motility. Our observations demonstrate a distinct role of the deubiquitinating enzyme in organ-specific macrophages that directly affect sperm function.
- Published
- 2021
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44. DNA methylation status correlates with adult β-cell regeneration capacity.
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Khurana I, Al-Hasani K, Maxwell S, K N H, Okabe J, Cooper ME, Collombat P, and El-Osta A
- Abstract
The role of DNA methylation in β-cell neogenesis is poorly understood. We report that during the process of induced cell reprogramming, methylation content of the Ngn3 and Sox11 genes are diminished. These findings emphasise DNA methylation is a barrier in β-cell regeneration in adulthood, a well described pathophysiological phenomenon of major significance in explaining β-cell deficiency in diabetes in the adult pancreas.
- Published
- 2021
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45. Valproic acid influences the expression of genes implicated with hyperglycaemia-induced complement and coagulation pathways.
- Author
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Felisbino MB, Ziemann M, Khurana I, Okabe J, Al-Hasani K, Maxwell S, Harikrishnan KN, de Oliveira CBM, Mello MLS, and El-Osta A
- Subjects
- Blood Coagulation drug effects, Complement System Proteins drug effects, Hep G2 Cells, Hepatocytes drug effects, Hepatocytes metabolism, Histones metabolism, Humans, Promoter Regions, Genetic genetics, Reproducibility of Results, Blood Coagulation genetics, Complement System Proteins genetics, Gene Expression Regulation drug effects, Hyperglycemia blood, Hyperglycemia genetics, Valproic Acid pharmacology
- Abstract
Because the liver plays a major role in metabolic homeostasis and secretion of clotting factors and inflammatory innate immune proteins, there is interest in understanding the mechanisms of hepatic cell activation under hyperglycaemia and whether this can be attenuated pharmacologically. We have previously shown that hyperglycaemia stimulates major changes in chromatin organization and metabolism in hepatocytes, and that the histone deacetylase inhibitor valproic acid (VPA) is able to reverse some of these metabolic changes. In this study, we have used RNA-sequencing (RNA-seq) to investigate how VPA influences gene expression in hepatocytes. Interesting, we observed that VPA attenuates hyperglycaemia-induced activation of complement and coagulation cascade genes. We also observe that many of the gene activation events coincide with changes to histone acetylation at the promoter of these genes indicating that epigenetic regulation is involved in VPA action.
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- 2021
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46. The Set7 Lysine Methyltransferase Regulates Plasticity in Oxidative Phosphorylation Necessary for Trained Immunity Induced by β-Glucan.
- Author
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Keating ST, Groh L, van der Heijden CDCC, Rodriguez H, Dos Santos JC, Fanucchi S, Okabe J, Kaipananickal H, van Puffelen JH, Helder L, Noz MP, Matzaraki V, Li Y, de Bree LCJ, Koeken VACM, Moorlag SJCFM, Mourits VP, Domínguez-Andrés J, Oosting M, Bulthuis EP, Koopman WJH, Mhlanga M, El-Osta A, Joosten LAB, Netea MG, and Riksen NP
- Subjects
- Animals, Humans, Immunity, Mice, Oxidative Phosphorylation, Histone-Lysine N-Methyltransferase metabolism, Lysine metabolism, beta-Glucans metabolism
- Abstract
Trained immunity confers a sustained augmented response of innate immune cells to a secondary challenge, via a process dependent on metabolic and transcriptional reprogramming. Because of its previous associations with metabolic and transcriptional memory, as well as the importance of H3 histone lysine 4 monomethylation (H3K4me1) to innate immune memory, we hypothesize that the Set7 methyltransferase has an important role in trained immunity induced by β-glucan. Using pharmacological studies of human primary monocytes, we identify trained immunity-specific immunometabolic pathways regulated by Set7, including a previously unreported H3K4me1-dependent plasticity in the induction of oxidative phosphorylation. Recapitulation of β-glucan training in vivo additionally identifies Set7-dependent changes in gene expression previously associated with the modulation of myelopoiesis progenitors in trained immunity. By revealing Set7 as a key regulator of trained immunity, these findings provide mechanistic insight into sustained metabolic changes and underscore the importance of characterizing regulatory circuits of innate immune memory., Competing Interests: Declaration of Interests W.J.H.K. is a scientific advisor of Khondrion (Nijmegen, the Netherlands) and of Fortify Therapeutics. These subject matter experts had no involvement in the data collection, analysis and interpretation, writing of the manuscript, and the decision to submit the manuscript for publication., (Copyright © 2020 The Author(s). Published by Elsevier Inc. All rights reserved.)
- Published
- 2020
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47. Targeting Treatment Refractory NET by EZH2 Inhibition in Postural Tachycardia Syndrome.
- Author
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Kaipananickal H, Waheed Khan A, Okabe J, Corcoran SJ, Esler MD, and El-Osta A
- Subjects
- Cells, Cultured, Dose-Response Relationship, Drug, Heart Rate drug effects, Heart Rate physiology, Histone Deacetylase Inhibitors administration & dosage, Humans, Indoles administration & dosage, Nylons, Postural Orthostatic Tachycardia Syndrome drug therapy, Pyridones administration & dosage, Pyrroles administration & dosage, Drug Delivery Systems methods, Enhancer of Zeste Homolog 2 Protein antagonists & inhibitors, Enhancer of Zeste Homolog 2 Protein metabolism, Norepinephrine Plasma Membrane Transport Proteins metabolism, Postural Orthostatic Tachycardia Syndrome metabolism
- Published
- 2020
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48. Sex-Based Mhrt Methylation Chromatinizes MeCP2 in the Heart.
- Author
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K N H, Okabe J, Mathiyalagan P, Khan AW, Jadaan SA, Sarila G, Ziemann M, Khurana I, Maxwell SS, Du XJ, and El-Osta A
- Abstract
In the heart, primary microRNA-208b (pri-miR-208b) and Myheart (Mhrt) are long non-coding RNAs (lncRNAs) encoded by the cardiac myosin heavy chain genes. Although preclinical studies have shown that lncRNAs regulate gene expression and are protective for pathological hypertrophy, the mechanism underlying sex-based differences remains poorly understood. In this study, we examined DNA- and RNA-methylation-dependent regulation of pri-miR-208b and Mhrt. Expression of pri-miR-208b is elevated in the left ventricle of the female heart. Despite indistinguishable DNA methylation between sexes, the interaction of MeCP2 on chromatin is subject to RNase digestion, highlighting that affinity of the methyl-CG reader is broader than previously thought. A specialized procedure to isolate RNA from soluble cardiac chromatin emphasizes sex-based affinity of an MeCP2 co-repressor complex with Rest and Hdac2. Sex-specific Mhrt methylation chromatinizes MeCP2 at the pri-miR-208b promoter and extends the functional relevance of default transcriptional suppression in the heart., (Copyright © 2019 The Author(s). Published by Elsevier Inc. All rights reserved.)
- Published
- 2019
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49. Discovery of evocalcet, a next-generation calcium-sensing receptor agonist for the treatment of hyperparathyroidism.
- Author
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Miyazaki H, Ikeda Y, Sakurai O, Miyake T, Tsubota R, Okabe J, Kuroda M, Hisada Y, Yanagida T, Yoneda H, Tsukumo Y, Tokunaga S, Kawata T, Ohashi R, Fukuda H, Kojima K, Kannami A, Kifuji T, Sato N, Idei A, Iguchi T, Sakairi T, and Moritani Y
- Subjects
- Animals, Cytochrome P-450 Enzyme Inhibitors chemical synthesis, Cytochrome P-450 Enzyme Inhibitors chemistry, Dose-Response Relationship, Drug, Humans, Models, Molecular, Molecular Structure, Pyrrolidines chemical synthesis, Pyrrolidines chemistry, Rats, Structure-Activity Relationship, Cytochrome P-450 Enzyme Inhibitors pharmacology, Cytochrome P-450 Enzyme System metabolism, Drug Discovery, Hyperparathyroidism drug therapy, Pyrrolidines pharmacology, Receptors, Calcium-Sensing agonists
- Abstract
The calcium-sensing receptor (CaSR) plays an important role in sensing extracellular calcium ions and regulating parathyroid hormone secretion by parathyroid gland cells, and the receptor is a suitable target for the treatment of hyperparathyroidism. Cinacalcet hydrochloride is a representative CaSR agonist which widely used for the hyperparathyroidism. However, it has several issues to clinical use, such as nausea/vomiting and strong inhibition of CYP2D6. We tried to improve these issues of cinacalcet for a new pharmaceutical agent as a preferable CaSR agonist. Optimization from cinacalcet resulted in the identification of pyrrolidine compounds and successfully led to the discovery of evocalcet as an oral allosteric CaSR agonist. Evocalcet, which exhibited highly favorable profiles such as CaSR agonistic activity and good DMPK profiles, will provide a novel therapeutic option for secondary hyperparathyroidism., (Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.)
- Published
- 2018
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50. NADPH Oxidase Nox5 Accelerates Renal Injury in Diabetic Nephropathy.
- Author
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Jha JC, Banal C, Okabe J, Gray SP, Hettige T, Chow BSM, Thallas-Bonke V, De Vos L, Holterman CE, Coughlan MT, Power DA, Skene A, Ekinci EI, Cooper ME, Touyz RM, Kennedy CR, and Jandeleit-Dahm K
- Subjects
- Animals, Blotting, Western, Cell Line, Diabetic Nephropathies genetics, Enzyme-Linked Immunosorbent Assay, Humans, Inflammation metabolism, Kidney metabolism, Kidney Glomerulus metabolism, Mesangial Cells metabolism, Mice, Mice, Transgenic, NADPH Oxidases genetics, Protein Kinase C beta metabolism, Reactive Oxygen Species metabolism, Reverse Transcriptase Polymerase Chain Reaction, Diabetic Nephropathies metabolism, NADPH Oxidases metabolism
- Abstract
NADPH oxidase-derived excessive production of reactive oxygen species (ROS) in the kidney plays a key role in mediating renal injury in diabetes. Pathological changes in diabetes include mesangial expansion and accumulation of extracellular matrix (ECM) leading to glomerulosclerosis. There is a paucity of data about the role of the Nox5 isoform of NADPH oxidase in animal models of diabetic nephropathy since Nox5 is absent in the mouse genome. Thus, we examined the role of Nox5 in human diabetic nephropathy in human mesangial cells and in an inducible human Nox5 transgenic mouse exposed to streptozotocin-induced diabetes. In human kidney biopsies, Nox5 was identified to be expressed in glomeruli, which appeared to be increased in diabetes. Colocalization demonstrated Nox5 expression in mesangial cells. In vitro, silencing of Nox5 in human mesangial cells was associated with attenuation of the hyperglycemia and TGF-β1-induced enhanced ROS production, increased expression of profibrotic and proinflammatory mediators, and increased TRPC6, PKC-α, and PKC-β expression. In vivo, vascular smooth muscle cell/mesangial cell-specific overexpression of Nox5 in a mouse model of diabetic nephropathy showed enhanced glomerular ROS production, accelerated glomerulosclerosis, mesangial expansion, and ECM protein (collagen IV and fibronectin) accumulation as well as increased macrophage infiltration and expression of the proinflammatory chemokine MCP-1. Collectively, this study provides evidence of a role for Nox5 and its derived ROS in promoting progression of diabetic nephropathy., (© 2017 by the American Diabetes Association.)
- Published
- 2017
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