Transcriptional activation of the Myc gene by glucose in β-cells requires a ChREBP-dependent 3-D chromatin interaction between the Myc and Pvt1 genes.

Autor:	Katz LS; Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1152, New York, NY 10029, USA., Brill G; Pharmacologic Sciences Department, Stony Brook University, Stony Brook, NY, USA(5)., Wang P; Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1152, New York, NY 10029, USA., Lambertini L; Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1152, New York, NY 10029, USA., Zhang P; Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1152, New York, NY 10029, USA., Haldeman JM; Stedman Center, Duke University School of Medicine, USA., Liu H; Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1152, New York, NY 10029, USA., Newgard CB; Stedman Center, Duke University School of Medicine, USA., Stewart AF; Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1152, New York, NY 10029, USA., Garcia-Ocaña A; Arthur Riggs Diabetes & Metabolism Research Institute, City of Hope, 1500 E Duarte Rd, Duarte, CA 91010, USA., Scott DK; Diabetes, Obesity and Metabolism Institute, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1152, New York, NY 10029, USA. Electronic address: donald.scott@mssm.edu.
Jazyk:	angličtina
Zdroj:	Molecular metabolism [Mol Metab] 2024 Jan; Vol. 79, pp. 101848. Date of Electronic Publication: 2023 Nov 30.
DOI:	10.1016/j.molmet.2023.101848
Abstrakt:	Objective: All forms of diabetes result from insufficient functional β-cell mass. Thus, achieving the therapeutic goal of expanding β-cell mass requires a better mechanistic understanding of how β-cells proliferate. Glucose is a natural β-cell mitogen that mediates its effects in part through the glucose-responsive transcription factor, carbohydrate response element binding protein (ChREBP) and the anabolic transcription factor, MYC. However, mechanistic details by which glucose activates Myc at the transcriptional level are poorly understood. Methods: Here, siRNA was used to test the role of ChREBP in the glucose response of MYC, ChIP and ChIPseq to identify potential regulatory binding sites, chromatin conformation capture to identify DNA/DNA interactions, and an adenovirus was constructed to expresses x-dCas9 and an sgRNA that specifically disrupts the recruitment of ChREBP to a specific targeted ChoRE. Results: We found that ChREBP is essential for glucose-mediated transcriptional induction of Myc, and for increases in Myc mRNA and protein abundance. Further, ChIPseq revealed that the carbohydrate response element (ChoRE) nearest to the Myc transcriptional start site (TSS) is immediately upstream of the gene encoding the lncRNA, Pvt1, 60,000 bp downstream of the Myc gene. Chromatin Conformation Capture (3C) confirmed a glucose-dependent interaction between these two sites. Transduction with an adenovirus expressing x-dCas9 and an sgRNA specifically targeting the highly conserved Pvt1 ChoRE, attenuates ChREBP recruitment, decreases Myc-Pvt1 DNA/DNA interaction, and decreases expression of the Pvt1 and Myc genes in response to glucose. Importantly, isolated and dispersed rat islet cells transduced with the ChoRE-disrupting adenovirus also display specific decreases in ChREBP-dependent, glucose-mediated expression of Pvt1 and Myc, as well as decreased glucose-stimulated β-cell proliferation. Conclusions: The mitogenic glucose response of Myc is mediated via glucose-dependent recruitment of ChREBP to the promoter of the Pvt1 gene and subsequent DNA looping with the Myc promoter. Competing Interests: Declaration of competing interest The Icahn School of Medicine at Mount Sinai has filed patents on related work on behalf of AFS, PW and AGO. The other authors declare that they have no conflicts of interest for this study. (Copyright © 2023 The Authors. Published by Elsevier GmbH.. All rights reserved.)
Databáze:	MEDLINE
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