When less is more: the forbidden fruits of gene repression in the adult β-cell
- PMID: 23121289
- DOI: 10.1111/dom.12029
When less is more: the forbidden fruits of gene repression in the adult β-cell
Abstract
Outside of the biological arena the term 'repression' often has a negative connotation. However, in the pancreatic β-cell a small group of genes, which are abundantly expressed in most if not all other mammalian tissues, are highly selectively repressed, with likely functional consequences. The two 'founder' members of this group, lactate dehydrogenase A (Ldha) and monocarboxylate transporter-1 (MCT-1/Slc16a1), are inactivated by multiple mechanisms including histone modifications and microRNA-mediated silencing. Their inactivation ensures that pyruvate and lactate, derived from muscle during exercise, do not stimulate insulin release inappropriately. Correspondingly, activating mutations in the MCT-1 promoter underlie 'exercise-induced hyperinsulinism' (EIHI) in man, a condition mimicked by forced over-expression of MCT-1 in the β-cell in mice. Furthermore, LDHA expression in the β-cell is upregulated in both human type 2 diabetes and in rodent models of the disease. Recent work by us and by others has identified a further ∼60 genes which are selectively inactivated in the β-cell, a list which we refine here up to seven by detailed comparison of the two studies. These genes include key regulators of cell proliferation and stimulus-secretion coupling. The present, and our earlier results, thus highlight the probable importance of shutting down a subset of 'disallowed' genes for the differentiated function of β-cells, and implicate previously unsuspected signalling pathways in the control of β-cell expansion and insulin secretion. Targeting of deregulated 'disallowed' genes in these cells may thus, in the future, provide new therapeutic avenues for type 2 diabetes.
© 2012 Blackwell Publishing Ltd.
Similar articles
-
Overexpression of monocarboxylate transporter-1 (SLC16A1) in mouse pancreatic β-cells leads to relative hyperinsulinism during exercise.Diabetes. 2012 Jul;61(7):1719-25. doi: 10.2337/db11-1531. Epub 2012 Apr 20. Diabetes. 2012. PMID: 22522610 Free PMC article.
-
miR-29a and miR-29b contribute to pancreatic beta-cell-specific silencing of monocarboxylate transporter 1 (Mct1).Mol Cell Biol. 2011 Aug;31(15):3182-94. doi: 10.1128/MCB.01433-10. Epub 2011 Jun 6. Mol Cell Biol. 2011. PMID: 21646425 Free PMC article.
-
Physical exercise-induced hypoglycemia caused by failed silencing of monocarboxylate transporter 1 in pancreatic beta cells.Am J Hum Genet. 2007 Sep;81(3):467-74. doi: 10.1086/520960. Epub 2007 Jul 26. Am J Hum Genet. 2007. PMID: 17701893 Free PMC article.
-
Metabolic and functional specialisations of the pancreatic beta cell: gene disallowance, mitochondrial metabolism and intercellular connectivity.Diabetologia. 2020 Oct;63(10):1990-1998. doi: 10.1007/s00125-020-05205-5. Epub 2020 Sep 7. Diabetologia. 2020. PMID: 32894309 Free PMC article. Review.
-
Monocarboxylate transporters in cancer.Mol Metab. 2020 Mar;33:48-66. doi: 10.1016/j.molmet.2019.07.006. Epub 2019 Jul 27. Mol Metab. 2020. PMID: 31395464 Free PMC article. Review.
Cited by
-
Hypoxia lowers SLC30A8/ZnT8 expression and free cytosolic Zn2+ in pancreatic beta cells.Diabetologia. 2014 Aug;57(8):1635-44. doi: 10.1007/s00125-014-3266-0. Epub 2014 May 28. Diabetologia. 2014. PMID: 24865615 Free PMC article.
-
Analysis of Purified Pancreatic Islet Beta and Alpha Cell Transcriptomes Reveals 11β-Hydroxysteroid Dehydrogenase (Hsd11b1) as a Novel Disallowed Gene.Front Genet. 2017 Apr 10;8:41. doi: 10.3389/fgene.2017.00041. eCollection 2017. Front Genet. 2017. PMID: 28443133 Free PMC article.
-
Loss of β-cell identity and diabetic phenotype in mice caused by disruption of CNOT3-dependent mRNA deadenylation.Commun Biol. 2020 Aug 28;3(1):476. doi: 10.1038/s42003-020-01201-y. Commun Biol. 2020. PMID: 32859966 Free PMC article.
-
MicroRNA Expression Analysis of In Vitro Dedifferentiated Human Pancreatic Islet Cells Reveals the Activation of the Pluripotency-Related MicroRNA Cluster miR-302s.Int J Mol Sci. 2018 Apr 12;19(4):1170. doi: 10.3390/ijms19041170. Int J Mol Sci. 2018. PMID: 29649109 Free PMC article.
-
Single-cell transcriptomics of human islet ontogeny defines the molecular basis of β-cell dedifferentiation in T2D.Mol Metab. 2020 Dec;42:101057. doi: 10.1016/j.molmet.2020.101057. Epub 2020 Jul 30. Mol Metab. 2020. PMID: 32739450 Free PMC article.
Publication types
MeSH terms
Substances
Grants and funding
LinkOut - more resources
Full Text Sources
Medical
Miscellaneous