» Articles » PMID: 20682694

Insulin Transactivator MafA Regulates Intrathymic Expression of Insulin and Affects Susceptibility to Type 1 Diabetes

Overview
Journal Diabetes
Specialty Endocrinology
Date 2010 Aug 5
PMID 20682694
Citations 17
Authors
Affiliations
Soon will be listed here.
Abstract

Objective: Tissue-specific self-antigens are ectopically expressed within the thymus and play an important role in the induction of central tolerance. Insulin is expressed in both pancreatic islets and the thymus and is considered to be the primary antigen for type 1 diabetes. Here, we report the role of the insulin transactivator MafA in the expression of insulin in the thymus and susceptibility to type 1 diabetes.

Research Design And Methods: The expression profiles of transcriptional factors (Pdx1, NeuroD, Mafa, and Aire) in pancreatic islets and the thymus were examined in nonobese diabetic (NOD) and control mice. Thymic Ins2 expression and serum autoantibodies were examined in Mafa knockout mice. Luciferase reporter assay was performed for newly identified polymorphisms of mouse Mafa and human MAFA. A case-control study was applied for human MAFA polymorphisms.

Results: Mafa, Ins2, and Aire expression was detected in the thymus. Mafa expression was lower in NOD thymus than in the control and was correlated with Ins2 expression. Targeted disruption of MafA reduced thymic Ins2 expression and induced autoantibodies against pancreatic islets. Functional polymorphisms of MafA were newly identified in NOD mice and humans, and polymorphisms of human MAFA were associated with susceptibility to type 1 diabetes but not to autoimmune thyroid disease.

Conclusions: These data indicate that functional polymorphisms of MafA are associated with reduced expression of insulin in the thymus and susceptibility to type 1 diabetes in the NOD mouse as well as human type 1 diabetes.

Citing Articles

Genetics of type-1 diabetes.

Ikegami H, Noso S Diabetol Int. 2024; 15(4):688-698.

PMID: 39469551 PMC: 11512969. DOI: 10.1007/s13340-024-00754-1.


Modelling human diabetes : a glance at maturity onset diabetes of the young.

Ka M, Hawkins E, Pouponnot C, Duvillie B Front Endocrinol (Lausanne). 2024; 15:1427413.

PMID: 39387055 PMC: 11461259. DOI: 10.3389/fendo.2024.1427413.


Epigenetic modulation of cell fate during pancreas development.

Bele S, Wokasch A, Gannon M Trends Dev Biol. 2024; 16:1-27.

PMID: 38873037 PMC: 11173269.


An Insight into Vital Genes Responsible for β-cell Formation.

Narayan G, Ronima K R , Agrawal A, Thummer R Adv Exp Med Biol. 2023; 1450:1-27.

PMID: 37432546 DOI: 10.1007/5584_2023_778.


Development of thymic tumor in [LSL:Kras; Pdx1-CRE] mice, an adverse effect associated with accelerated pancreatic carcinogenesis.

Liot S, El Kholti N, Balas J, Genestier L, Verrier B, Valcourt U Sci Rep. 2021; 11(1):15075.

PMID: 34302028 PMC: 8302691. DOI: 10.1038/s41598-021-94566-x.


References
1.
Levi D, Polychronakos C . Regulation of insulin gene expression by cytokines and cell-cell interactions in mouse medullary thymic epithelial cells. Diabetologia. 2009; 52(10):2151-8. DOI: 10.1007/s00125-009-1448-y. View

2.
Barrett J, Clayton D, Concannon P, Akolkar B, Cooper J, Erlich H . Genome-wide association study and meta-analysis find that over 40 loci affect risk of type 1 diabetes. Nat Genet. 2009; 41(6):703-7. PMC: 2889014. DOI: 10.1038/ng.381. View

3.
Wang N, Akey J, Zhang K, Chakraborty R, Jin L . Distribution of recombination crossovers and the origin of haplotype blocks: the interplay of population history, recombination, and mutation. Am J Hum Genet. 2002; 71(5):1227-34. PMC: 385104. DOI: 10.1086/344398. View

4.
Ueda H, Howson J, Esposito L, Heward J, Snook H, Chamberlain G . Association of the T-cell regulatory gene CTLA4 with susceptibility to autoimmune disease. Nature. 2003; 423(6939):506-11. DOI: 10.1038/nature01621. View

5.
Palumbo M, Levi D, Chentoufi A, Polychronakos C . Isolation and characterization of proinsulin-producing medullary thymic epithelial cell clones. Diabetes. 2006; 55(9):2595-601. DOI: 10.2337/db05-1651. View