|
Effects of sera of rats fed with Huganqingzhi tablets on endoplasmic reticulum stress in a
HepG2 cell model of nonalcoholic fatty liver disease
Journal of Southern Medical University
2018, 38 (11):
1277-.
DOI: 10.12122/j.issn.1673-4254.2018.11.01
Objective To investigate the effects of sera from rats fed with Huganqingzhi tablets (HGT) on endoplasmic reticulum
(ER) stress in a steatotic hepatocyte model of free fatty acids (FFAs)- induced nonalcoholic fatty liver disease (NAFLD) and
explore the possible mechanism. Methods FFAs prepared by mixing oleic acid and palmitic acid at the ratio of 2∶1. HepG2
cells were treated with the sera from rats fed with low- , moderate-or high-dose HGT (HGT sera) or sera of rats fed with
fenofibrate (fenofibrate sera), followed by treatment with 1 mmol/L FFAs for 24 h to induce hepatic steatosis. Oil red O staining
was used to observe the distribution of lipid droplets in the cells. The biochemical parameters including triglyceride (TG),
lactated hydrogenase (LDH), aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were measured using a
commercial kit. The morphological changes of the ER in the cells were observed using transmission electron microscopy. The
protein/mRNA expressions of ER stress-related signal molecules including GRP78, PERK, p-PERK, ATF6, ATF4, CASPASE-12,
CHOP, XBP-1, PKC, and p-PKC-δ were detected using Western blotting and/or quantitative real- time PCR (qRT- PCR). The
changes in the protein expressions of GRP78, p-PERK, CASPASE-12 and CHOP were also detected in cells with transient
transfection of PKC-δ siRNA for PKC-δ knockdown. Results Compared with the control cells, the cells treated with FFAs
showed significantly increased levels of TG, AST, and ALT (P<0.05). Compared with FFAs- treated cells, the cells pretreated
with HGT sera or fenofibrate sera all showed significantly decreased TG, AST and ALT levels (P<0.05), reduced accumulation
of the lipid droplets (P<0.05), and lowered protein or
mRNA expression levels of GRP78, p-PERK, ATF6,
ATF4, CHOP, CASPASE-12, XBP-1 and p-PKC-δ (P<
0.05). PKC-δ knockdown caused significantly reduced
protein expressions of GRP78, p-PERK, CASPASE-12
and CHOP in the cells with FFA- induced hepatic
steatosis (P<0.001); treatment with high-dose HGT
serum more significantly reduced the expressions of
GRP78 (P<0.001) and P-PERK (P<0.01) in FFAs-induced cells with PKC-δ knockdown. Conclusion HGT serum can effectively prevent FFAs-induced steatosis in HepG2
cells by alleviating ER stress, in which PKC-δ may act as an important target.
Related Articles |
Metrics |
Comments(0)
|
|