Recent studies revealed that acetylation is a widely used protein modification in prokaryotic organisms. The major protein acetylation acetyltransferase YfiQ and the sirtuin-like deacetylase CobB have been found to be involved in basic physiological processes, such as primary metabolism, chemotaxis, and stress responses, in and However, little is known about protein acetylation modifications in , a lethal pathogen responsible for millions of human deaths in three worldwide pandemics. Here we found that and of encode the major protein acetylation acetyltransferase YfiQ and the sirtuin-like deacetylase CobB, respectively, which can acetylate and deacetylate PhoP enzymatically Protein acetylation impairment in and mutants greatly decreased bacterial tolerance to cold, hot, high-salt, and acidic environments. Our comparative transcriptomic data revealed that the strongly decreased tolerance to stress stimuli was probably related to downregulation of the genes encoding the heat shock proteins (HtpG, HslV, HslR, and IbpA), cold shock proteins (CspC and CspA1), and acid resistance proteins (HdeB and AdiA). We found that the reversible acetylation mediated by CobB and YfiQ conferred attenuation of virulence, probably partially due to the decreased expression of the operon, which encodes Psa fimbriae that play a key role in virulence of This is the first report, to our knowledge, on the roles of protein acetylation modification in stress responses, biofilm formation, and virulence of.

During the liver fibrosis recovery stage tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) can effectively induce apoptosis of activated hepatic stellate cells (HSCs). Normal hepatic stellate cells are resistant to TRAIL cytotoxicity. Therefore, enhancing the sensitivity of TRAIL-induced apoptosis of HSCs may be useful to treat hepatic fibrogenesis. Here, we demonstrated that miR-145 and TRAIL were down-regulated in both liver fibrosis tissue samples and transforming growth factor-β1 induced HSCs, concomitant with increased the expression of ZEB2. In addition, we found that mimics-mediated over-expression of miR-145 led to resistance to the ZEB2 expression and up-regulation of the TRAIL-induced apoptosis after treatment of LX-2 cells with TRAIL. Furthermore, ZEB2-siRNA transfected LX-2 cells showed the increased sensitivity to TRAIL-induced apoptosis. Whereas, opposite results were obtained in miR-145-inhibitor group or ZEB2 plasmid group. Moreover, miR-145 regulated ZEB2 gene expression by specifically interacting with the 3′-UTR of ZEB2 mRNA to inhibit the expression of ZEB2. Further studies showed that the over-expression of ZEB2 could inhibit TRAIL-induced apoptosis via inhibiting nuclear factor-κB (NF-κB) signaling pathway in LX-2 cells. Collectively, our data suggest that up-regulation of miR-145 can down-regulate ZEB2 expression, consequently promoting TRAIL-induced apoptosis in LX-2 cells through NF-κB signaling pathway, which facilitates the resolution of liver fibrosis.

Hepatic stellate cells (HSCs) play an important role in the initiation and development of liver fibrogenesis, and abnormal glucose metabolism is increasingly being considered a crucial factor controlling phenotypic transformation in HSCs. However, the role of the factors affecting glycolysis in HSCs in the experimental models of liver fibrosis has not been completely elucidated. In this study, we showed that glycolysis was significantly enhanced, while the expression of brain and muscle arnt-like protein-1 (Bmal1) was downregulated in fibrotic liver tissues of mice, primary HSCs, and transforming growth factor-β1 (TGF-β1)-induced LX2 cells. Overexpression of Bmal1 in TGF-β1-induced LX2 cells blocked glycolysis and inhibited the proliferation and phenotypic transformation of activated HSCs. We further confirmed the protective effect of Bmal1 in liver fibrosis by overexpressing Bmal1 from hepatic adeno-associated virus 8 in mice. In addition, we also showed that the regulation of glycolysis by Bmal1 is mediated by the isocitrate dehydrogenase 1/α-ketoglutarate (IDH1/α-KG) pathway. Collectively, our results indicated that a novel Bmal1-IDH1/α-KG axis may be involved in regulating glycolysis of activated HSCs and might hence be used as a therapeutic target for alleviating liver fibrosis.