Upregulation of caveolin-1 and its colocalization with cytokine receptors contributes to beta cell apoptosis

Sci Rep. 2019 Nov 14;9(1):16785. doi: 10.1038/s41598-019-53278-z.

Abstract

Caveolin-1 (cav-1), the principal structural and signalling protein of caveolae, is implicated in various signalling events, including apoptotic cell death in type 2 diabetes. However, the precise role of beta cells in apoptosis has not been clearly defined. In this study, we investigated the involvement of cav-1 in cytokine-induced beta cell apoptosis and its underlying mechanisms in the rat beta cell line, INS-1 and isolated islets. Treatment of cytokine mixture (CM, TNFα + IL-1β) significantly increased the mRNA and protein expression of cav-1, and resulting in increased formation of caveolae. We found that IL-1 receptor 1 and TNF receptor localized to plasma membrane lipid rafts in the control cells and CM treatment recruited these receptors to the caveolae domain. After cav-1 siRNA transfection, CM-dependent NF-κB activation was reduced and consequently downregulated the mRNA expression of iNOS and IL-1β. Finally, decreased cell viability by CM treatment was ameliorated in both INS-1 cells and isolated islets treated with cav-1 siRNA. These results suggest that increased cav-1 expression and recruitment of cytokine receptors into caveolae contribute to CM-induced beta cell apoptosis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis
  • Caveolae / metabolism
  • Caveolin 1 / antagonists & inhibitors
  • Caveolin 1 / genetics*
  • Caveolin 1 / metabolism*
  • Cell Survival / drug effects
  • Cells, Cultured
  • Cytokines / pharmacology*
  • Insulin-Secreting Cells / cytology*
  • Interleukin-1beta / pharmacology
  • RNA, Small Interfering / pharmacology
  • Rats
  • Receptors, Cytokine / metabolism*
  • Tumor Necrosis Factor-alpha / pharmacology
  • Up-Regulation / drug effects

Substances

  • Cav1 protein, rat
  • Caveolin 1
  • Cytokines
  • Interleukin-1beta
  • RNA, Small Interfering
  • Receptors, Cytokine
  • Tumor Necrosis Factor-alpha