MicroRNA-194: a novel regulator of glucagon-like peptide-1 synthesis in intestinal L cells

Cell Death Dis. 2021 Jan 21;12(1):113. doi: 10.1038/s41419-020-03366-0.

Abstract

In the status of obesity, the glucagon-like peptide-1 (GLP-1) level usually declines and results in metabolic syndrome. This study aimed to investigate the intracellular mechanism of GLP-1 synthesis in L cells from the perspective of microRNA (miRNA). In the present study, we found that GLP-1 level was down-regulated in the plasma and ileum tissues of obese mice, while the ileac miR-194 expression was up-regulated. In vitro experiments indicated that miR-194 overexpression down-regulated GLP-1 level, mRNA levels of proglucagon gene (gcg) and prohormone convertase 1/3 gene (pcsk1), and the nuclear protein level of beta-catenin (β-catenin). Further investigation confirmed that β-catenin could promote gcg transcription through binding to transcription factor 7-like 2 (TCF7L2). miR-194 suppressed gcg mRNA level via negatively regulating TCF7L2 expression. What's more, forkhead box a1 (Foxa1) could bind to the promoter of pcsk1 and enhanced its transcription. miR-194 suppressed pcsk1 transcription through targeting Foxa1. Besides, the interference of miR-194 reduced palmitate (PA)-induced cell apoptosis and the anti-apoptosis effect of miR-194 inhibitor was abolished by TCF7L2 knockdown. Finally, in HFD-induced obese mice, the silence of miR-194 significantly elevated GLP-1 level and improved the metabolic symptoms caused by GLP-1 deficiency. To sum up, our study found that miR-194 suppressed GLP-1 synthesis in L cells via inhibiting TCF7L2-mediated gcg transcription and Foxa1-mediated pcsk1 transcription. Meanwhile, miR-194 took part in the PA-induced apoptosis of L cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Enteroendocrine Cells / metabolism*
  • Glucagon-Like Peptide 1 / biosynthesis*
  • Glucagon-Like Peptide 1 / genetics
  • Glucagon-Like Peptide 1 / metabolism
  • L Cells
  • Male
  • Mice
  • MicroRNAs / genetics
  • MicroRNAs / metabolism*
  • Obesity / genetics
  • Obesity / metabolism*
  • Transfection

Substances

  • MIRN194 microRNA, mouse
  • MicroRNAs
  • Glucagon-Like Peptide 1