Lactobacillus gasseri LA39 promotes hepatic primary bile acid biosynthesis and intestinal secondary bile acid biotransformation / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

A growing body of evidence has linked the gut microbiota to liver metabolism. The manipulation of intestinal microflora has been considered as a promising avenue to promote liver health. However, the effects of Lactobacillus gasseri LA39, a potential probiotic, on liver metabolism remain unclear. Accumulating studies have investigated the proteomic profile for mining the host biological events affected by microbes, and used the germ-free (GF) mouse model to evaluate host-microbe interaction. Here, we explored the effects of L. gasseri LA39 gavage on the protein expression profiles of the liver of GF mice. Our results showed that a total of 128 proteins were upregulated, whereas a total of 123 proteins were downregulated by treatment with L. gasseri LA39. Further bioinformatics analyses suggested that the primary bile acid (BA) biosynthesis pathway in the liver was activated by L. gasseri LA39. Three differentially expressed proteins (cytochrome P450 family 27 subfamily A member 1 (CYP27A1), cytochrome P450 family 7 subfamily B member 1 (CYP7B1), and cytochrome P450 family 8 subfamily B member 1 (CYP8B1)) involved in the primary BA biosynthesis pathway were further validated by western blot assay. In addition, targeted metabolomic analyses demonstrated that serum and fecal β‍-muricholic acid (a primary BA), dehydrolithocholic acid (a secondary BA), and glycolithocholic acid-3-sulfate (a secondary BA) were significantly increased by L. gasseri LA39. Thus, our data revealed that L. gasseri LA39 activates the hepatic primary BA biosynthesis and promotes the intestinal secondary BA biotransformation. Based on these findings, we suggest that L. gasseri LA39 confers an important function in the gut‒liver axis through regulating BA metabolism.

Cellular stress and redox activity proteins are involved in gastric carcinogenesis associated with Helicobacter pylori infection expressing high levels of thioredoxin-1 / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Helicobacter pylori infection is related to the development of gastric diseases. Our previous studies showed that high thioredoxin-1 (Trx1) expression in H. pylori can promote gastric carcinogenesis. To explore the underlying molecular mechanisms, we performed an isobaric tags for relative and absolute quantitation (iTRAQ)-based quantitative proteomic analysis of stomach tissues from Mongolian gerbil infected with H. pylori expressing high and low Trx1. Differences in the profiles of the expressed proteins were analyzed by bioinformatics and verified using Western blot analysis. We found three candidate proteins, 14-3-3α/β, glutathione-S-transferase (GST), and heat shock protein 70 (HSP70), in high Trx1 tissues compared with low Trx1 tissues and concluded that cellular stress and redox activity-related proteins were involved in the pathogenesis of gastric cancer associated with H. pylori Trx1.

Study on serum proteomics in rats after accumulated irradiation with 137Cs γ-rays / 中华放射医学与防护杂志

Objective To investigate the changes of proteomics in serum of Sprague-Dawley(SD) rats after accumulated irradiation with 137Cs γ-rays.Methods A total of thirty mature SD rats were randomly divided into three groups:0.2 Gy group,2 Gy group and healthy control group.Rats were irradiated at a dose rate of 0.336 mGy/min for 10 d and 20 d continuously.Isobaric tags for relative and absolute quantitation (iTRAQ) was used to analyze the different protein expression in serum of irradiated rats.Gene Ontology,KEGG pathway and protein-protein interaction network analysis were conducted using softwares.Results In total,363 protein spots were identified.Twenty nine proteins were differentially expressed in both groups compared with control,of which 10 proteins were up-regulated and 19 proteins were down-regulated.Based on the information of GO categories,these differentially expressed proteins were mainly located in the cytoplasm and membrane concerning the function of binding and catalytic activity.Analysis with the PAJEK software demonstrated that 16 differentially expressed proteins could form a complicated interaction network where glutathione S-transferase P1 (GSTP1),phosphoglycerate kinase 1 (PGK1) and protein disulfide-isomerase (PDI) might be key nodes.Conclusions Accumulated irradiation can induce differentially expressed proteins in serum of irradiated rats.Analysis on functional roles of the screened proteins GSTP1,PGK1 and PDI may provide insight into further mechanistic investigations and underlying molecular biomarkers induced by accumulated irradiation.