Mitigation of ROS-triggered endoplasmic reticulum stress by upregulating Nrf2 retards diabetic nephropathy

Biochem Biophys Res Commun. 2024 Aug 20:721:149972. doi: 10.1016/j.bbrc.2024.149972. Epub 2024 Apr 25.

Abstract

Endoplasmic reticulum stress (ERS) plays a crucial role in the pathogenesis of diabetic nephropathy (DN), and it is often accompanied by an increase in reactive oxygen species (ROS) production. However, the precise relationship between NFE2-related factor-2 (Nrf2), a key regulator of ROS balance, and ERS in DN remains elusive. This study aimed to investigate the impact of Nrf2 on ERS and its therapeutic potential in DN. Herein, ERS-related changes, including increased activating transcription factor-6 (ATF6), glucose-regulated protein 78 (GRP78), and transcription factor C/EBP homologous protein (CHOP) expression, were observed in the renal tissues of streptozotocin-induced DN mice and high glucose cultured human renal proximal tubular (HK-2) cells. Nrf2 knockdown increased the sensitivity of HK-2 cells to ERS under high glucose conditions, underscoring the regulatory role of Nrf2 in ERS modulation. Notably, upregulating Nrf2 in ezetimibe-treated diabetic mice restored ERS markers and ameliorated albuminuria, glomerular hypertrophy, mesangial expansion, and tubulointerstitial fibrosis. Furthermore, the inhibition of ERS in HK-2 cells by the ROS scavenger, N-acetylcysteine, highlights the interplay between ROS and ERS. This study, for the first time, elucidates that the upregulation of Nrf2 may alleviate the negative influence of ROS-mediated ERS, presenting a promising therapeutic avenue for delaying the progression of DN. These findings suggest a potential strategy for targeting Nrf2 and ERS in developing novel therapeutic interventions for DN.

Keywords: Diabetic nephropathy; Endoplasmic reticulum stress; NFE2-Related factor 2; Reactive oxygen species.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Line
  • Diabetes Mellitus, Experimental* / metabolism
  • Diabetes Mellitus, Experimental* / pathology
  • Diabetic Nephropathies* / drug therapy
  • Diabetic Nephropathies* / metabolism
  • Diabetic Nephropathies* / pathology
  • Endoplasmic Reticulum Chaperone BiP* / metabolism
  • Endoplasmic Reticulum Stress* / drug effects
  • Humans
  • Male
  • Mice
  • Mice, Inbred C57BL*
  • NF-E2-Related Factor 2* / metabolism
  • Reactive Oxygen Species* / metabolism
  • Up-Regulation* / drug effects

Substances

  • Endoplasmic Reticulum Chaperone BiP
  • HSPA5 protein, human
  • Hspa5 protein, mouse
  • NF-E2-Related Factor 2
  • Nfe2l2 protein, mouse
  • Reactive Oxygen Species
  • NFE2L2 protein, human