Bile salt hydrolase-overexpressing strains can improve hepatic lipid accumulation in an NAFLD cell model.

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) includes a range of liver diseases that occur in the absence of significant alcohol consumption. The probiotic bacterial strains LC2W, which overexpresses the bile salt hydrolase (BSH) gene (referred to as pWQH01), and AR113, which exhibits high BSH activity, have been shown to improve hepatic lipid accumulation and may lower cholesterol levels . These effects may be BSH-dependent, as LC2W without BSH activity did not exert these beneficial effects.

OBJECTIVE

This study aimed to investigate the effects of with high BSH activity on cholesterol accumulation and lipid metabolism abnormalities in oleic acid (OA)- and cholesterol-induced HepG2 cell models, and to determine the mechanism underlying the effects.

DESIGN

A HepG2 cell model of OA-induced steatosis and cholesterol-induced cholesterol accumulation was developed. OA- and cholesterol-treated HepG2 cells were incubated with AR113, LC2W or pWQH01 for 6 h at 37°C with 5% CO. Subsequently, a series of indicators and gene expressions were analysed.

RESULTS

Both AR113 and L. pWQH01 significantly reduced lipid accumulation, total cholesterol (TC) levels and 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase (HMGCR) mRNA expression relative to the control group, whereas L. casei LC2W had no similar effect. Additionally, exposure to AR113 or pWQH01 significantly reduced the expression of sterol regulatory element-binding protein 1c (SREBP-1c), Acetyl-CoA carboxylase (ACC), fatty acid synthase (FAS) and tumour necrosis factor-α (TNF-α) andsignificantly increased the expression of 5' adenosine monophosphate-activated protein kinase (AMPK) and peroxisome proliferator-activated receptor alpha (PPARα).

CONCLUSION

Both AR113 and pWQH01 appear to improve steatosis in a BSH-dependent manner.