Lipid Droplets Protect Human β-Cells From Lipotoxicity-Induced Stress and Cell Identity Changes

Diabetes. 2021 Nov;70(11):2595-2607. doi: 10.2337/db21-0261. Epub 2021 Aug 25.

Abstract

Free fatty acids (FFAs) are often stored in lipid droplet (LD) depots for eventual metabolic and/or synthetic use in many cell types, such a muscle, liver, and fat. In pancreatic islets, overt LD accumulation was detected in humans but not mice. LD buildup in islets was principally observed after roughly 11 years of age, increasing throughout adulthood under physiologic conditions, and also enriched in type 2 diabetes. To obtain insight into the role of LDs in human islet β-cell function, the levels of a key LD scaffold protein, perilipin 2 (PLIN2), were manipulated by lentiviral-mediated knockdown (KD) or overexpression (OE) in EndoCβH2-Cre cells, a human cell line with adult islet β-like properties. Glucose-stimulated insulin secretion was blunted in PLIN2KD cells and improved in PLIN2OE cells. An unbiased transcriptomic analysis revealed that limiting LD formation induced effectors of endoplasmic reticulum (ER) stress that compromised the expression of critical β-cell function and identity genes. These changes were essentially reversed by PLIN2OE or using the ER stress inhibitor, tauroursodeoxycholic acid. These results strongly suggest that LDs are essential for adult human islet β-cell activity by preserving FFA homeostasis.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Calcium
  • Cell Differentiation
  • Cell Line
  • Diabetes Mellitus, Type 2 / metabolism*
  • Glucose / pharmacology
  • Homeostasis
  • Humans
  • Insulin Secretion / drug effects
  • Insulin-Secreting Cells / metabolism*
  • Lipid Droplets / metabolism*
  • Lipid Metabolism
  • Lipids / toxicity*
  • Perilipin-2 / genetics
  • Perilipin-2 / metabolism
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Stress, Physiological

Substances

  • Lipids
  • PLIN2 protein, human
  • Perilipin-2
  • RNA, Messenger
  • Glucose
  • Calcium

Associated data

  • figshare/10.2337/figshare.15747093