β-Arrestin 1/2 Aggravates Podocyte Apoptosis of Diabetic Nephropathy via Wnt/β-Catenin Pathway

Med Sci Monit. 2018 Mar 24:24:1724-1732. doi: 10.12659/msm.905642.

Abstract

BACKGROUND β-arrestins have been shown to play a critical role in the progression of diabetic nephropathy. Nevertheless, the potential mechanism of β-arrestins on the regulation of podocyte apoptosis has rarely been discussed. This study aimed to elucidate the regulation of β-arrestin 1/2 on podocyte apoptosis through the Wnt/b-catenin pathway. MATERIAL AND METHODS This study structured β-arrestin 1/2 down-regulated and up-regulated expression by plasmid transfection. The protein levels were detected with Western blotting, and mRNA expression was detected with RT-qPCR. The apoptotic cells were measured by flow cytometry. RESULTS β-arrestin 1/2 expression levels of podocytes were up-regulated in high-glucose-induced podocytes. β-arrestin 1/2 overexpression inhibited the expression of nephrin and podocin protein. Up-regulated β-arrestin 1/2 promoted podocyte apoptosis and p53 pathway by increasing Bax, cleaved caspase-3, and p-p53 levels in high-glucose-induced podocytes. Flow cytometry showed that the apoptotic cells were markedly higher in the b-arrestin 1/2 up-regulated group compared with the scramble group. Expression of β-catenin was increased in the β-arrestin 1/2 up-regulated group, which indicated that the Wnt/b-catenin pathway was activated. Wnt/b-catenin pathway inhibitor (Dkk1) distinctly suppressed the apoptosis induced by β-arrestin 1/2 overexpression and high glucose. CONCLUSIONS These results provide a molecular pathomechanism of β-arrestin 1/2 and Wnt/β-catenin pathway on podocyte apoptosis and provide new ideas for the treatment of diabetic nephropathy, which paves the way for the future study of diabetic nephropathy and podocytes.

MeSH terms

  • Animals
  • Apoptosis / physiology
  • Cell Line
  • Diabetic Nephropathies / metabolism*
  • Diabetic Nephropathies / pathology*
  • Down-Regulation
  • Intracellular Signaling Peptides and Proteins / biosynthesis
  • Membrane Proteins / biosynthesis
  • Mice
  • Mice, Transgenic
  • Podocytes / metabolism*
  • Podocytes / pathology*
  • Transcriptional Activation
  • Up-Regulation
  • Wnt Signaling Pathway*
  • beta Catenin / metabolism
  • beta-Arrestin 1 / metabolism*
  • beta-Arrestin 2 / metabolism*

Substances

  • CTNNB1 protein, mouse
  • Intracellular Signaling Peptides and Proteins
  • Membrane Proteins
  • NPHS2 protein
  • beta Catenin
  • beta-Arrestin 1
  • beta-Arrestin 2
  • nephrin