Effects of serum from chronic renal failure rats on endoplasmic reticulum stress and activation of activating transcription factor 4 of rat arterial smooth muscle cells cultured in vitro / 中华肾脏病杂志

ABSTRACT

Objective To investigate the effects of the serum from chronic renal failure (CRF) rats on endoplasmic reticulum stress (ERS) and activation of activating transcription factor 4 (ATF4) of rat arterial smooth muscle cells (ASMCs) cultured in vitro and explore the possible mechanism. Methods The rat model of CRF was established by 5/6 nephrectomy. ASMCs were incubated in the media with 10% or 20% serum of CRF rats cultured in vitro. ATF4 nuclear translocation were analyzed by immunofluorescence. GRP78 (glucose regulated protein 78), p-PERK (pancreatic ER kinase) and ATF4 proteins in response to the CRF serum in ASMCs were determined by Western blot. The ATF4-DNA binding activity was analyzed by electrophoretic mobility shift assay (EMSA). Results The CRF serum could significantly promote the expression of GRP78 of ASMCs in dose-dependent manner. Under the stimulation of 20% CRF serum, nuclear translocation of ATF4 in ASMCs was found. Compared with control serum group, the expression of ATF4 and p-PERK of CRF serum group was increased significantly (P<0.01). The CRF serum could increase the ATF4-DNA binding activity. Conclusion The CRF rat serum can effectively induce ERS of ASMCs and activate the pathway of PERK-ATF4.