scholarly journals Large parental differences in chromatin organization in pancreatic beta cell line explaining diabetes susceptibility effects

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Xing Jian ◽  
Gary Felsenfeld

AbstractPrevious GWAS studies identified non-coding loci with parent-of-origin-specific effects on Type 2 diabetes susceptibility. Here we report the molecular basis for one such locus near the KRTAP5-6 gene on chromosome 11. We determine the pattern of long-range contacts between an enhancer in this locus and the human INS promoter 460 kb away, in the human pancreatic β-cell line, EndoC-βH1. 3C long range contact experiments distinguish contacts on the two sister chromosomes. Coupling with allele-specific SNPs allows construction of maps revealing marked differences in organization of the two sister chromosomes in the entire region between KRTAP5-6 and INS. Further mapping distinguishes maternal and paternal alleles. This reveals a domain of parent-of-origin-specific chromatin structure extending in the telomeric direction from the INS locus. This suggests more generally that imprinted loci may extend their influence over gene expression beyond those loci through long range chromatin structure, resulting in parent-of-origin-biased expression patterns over great distances.

Diabetes ◽  
1996 ◽  
Vol 45 (12) ◽  
pp. 1766-1773 ◽  
Author(s):  
M. Noda ◽  
M. Komatsu ◽  
G. W. Sharp

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Latif Rachdi ◽  
Alicia Maugein ◽  
Severine Pechberty ◽  
Mathieu Armanet ◽  
Juliette Hamroune ◽  
...  

Diabetes ◽  
1998 ◽  
Vol 47 (9) ◽  
pp. 1419-1425 ◽  
Author(s):  
N. Fleischer ◽  
C. Chen ◽  
M. Surana ◽  
M. Leiser ◽  
L. Rossetti ◽  
...  

2018 ◽  
Vol 52 (1) ◽  
pp. 21-26 ◽  
Author(s):  
Eiji Yamato

Abstract Objective. Histone deacytylase inhibitors (HDACis) inhibit the deacetylation of the lysine residue of proteins, including histones, and regulate the transcription of a variety of genes. Recently, HDACis have been used clinically as anti-cancer drugs and possible anti-diabetic drugs. Even though HDACis have been proven to protect the cytokine-induced damage of pancreatic beta cells, evidence also shows that high doses of HDACis are cytotoxic. In the present study, we, therefore, investigated the eff ect of HDACis on insulin secretion in a pancreatic beta cell line. Methods. Pancreatic beta cells MIN6 were treated with selected HDACis (trichostatin A, TSA; valproic acid, VPA; and sodium butyrate, NaB) in medium supplemented with 25 mM glucose and 13% heat-inactivated fetal bovine serum (FBS) for indicated time intervals. Protein expression of Pdx1 and Mafa in MIN6 cells was demonstrated by immunohistochemistry and immunocytochemistry, expression of Pdx1 and Mafa genes was measured by quantitative RT-PCR method. Insulin release from MIN6 cells and insulin cell content were estimated by ELISA kit. Superoxide production in MIN6 cells was measured using a Total ROS/Superoxide Detection System. Results. TSA, VPA, and NaB inhibited the expression of Pdx1 and Mafa genes and their products. TSA treatment led to beta cell malfunction, characterized by enhanced insulin secretion at 3 and 9 mM glucose, but impaired insulin secretion at 15 and 25 mM glucose. Th us, TSA induced dysregulation of the insulin secretion mechanism. TSA also enhanced reactive oxygen species production in pancreatic beta cells. Conclusions. Our results showed that HDACis caused failure to suppress insulin secretion at low glucose concentrations and enhance insulin secretion at high glucose concentrations. In other words, when these HDACis are used clinically, high doses of HDACis may cause hypoglycemia in the fasting state and hyperglycemia in the fed state. When using HDACis, physicians should, therefore, be aware of the capacity of these drugs to modulate the insulin secretory capacity of pancreatic beta cells.


Diabetologia ◽  
1996 ◽  
Vol 39 (11) ◽  
pp. 1293-1298 ◽  
Author(s):  
E. Yamato ◽  
H. Ikegami ◽  
J.-I. Miyazaki ◽  
T. Ogihara

1996 ◽  
Vol 271 (42) ◽  
pp. 26194-26199 ◽  
Author(s):  
Aki Soejima ◽  
Kimiko Inoue ◽  
Daisaku Takai ◽  
Motohisa Kaneko ◽  
Hisamitsu Ishihara ◽  
...  

2004 ◽  
Vol 22 (Suppl. 2) ◽  
pp. S367
Author(s):  
M. Kaihara ◽  
Y. Nakamura ◽  
T. Sugimoto ◽  
H. Uchida ◽  
H. Norii ◽  
...  

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