Biomedical and Biotechnology Research Journal (Jan 2021)
The effect of three acid-resistant isolated proteins from Lactobacillus casei on lipid and carbohydrate metabolism pathway-related genes: An In vitro study
Abstract
Background: The role of Lactobacillus casei on human health is well documented. However, little is known about their protein effects on food digestion. Therefore, in the present study, we aimed to investigate the efficacy of three proteins of L. casei on lipid and carbohydrate digestion that was identified at acidic pH in our previous study. Methods: Chaperonin (Ch), metal-dependent hydrolase (HYD), and lysozyme (LYS) proteins that were expressed by cultivated L. casei at pH 5 were extracted. HepG2 cell line was used to elucidate the effect of the considered three proteins on gene expression related to fat and glucose metabolism. The target genes were determined by Kyoto Encyclopedia of Genes and Genomes pathway analysis and extracted proteins were transfected into HepG2 cells. After 48 and 120 h, the mRNA expression of the following genes was analyzed using real-time polymerase chain reaction, insulin receptor substrate 2, (IRS-2), Protein kinase Bβ (AKT2), insulin-like growth factor 1, angiopoietin-like 4 (Angptl-4), and lipoprotein lipase (LPL). Results: The expression of all of the genes was significantly increased in comparison to control under the effect of Ch and metal-dependent HYDs after 48 h of culture. By increasing the duration of transfection from 48 h to 120 h, the expression of Angptl-4 from Ch and metal-dependent HYDs was reduced significantly, whereas the expression of LPL and Angptl-4 genes after 5 days was significantly increased in LYS compared to the last 3 days. Conclusions: L. casei secrets acidic proteins such as Ch, metal-dependent HYD, and LYS in bloodstream are involved in the digestion of carbohydrates and fats in the liver.
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