The regulatory roles of aquaporins in the digestive system

Aquaporins(AQPs)are highly conserved small transmembrane proteins,which are responsible for the water transport across the cell membrane.AQPs are abundantly expressed in numerous types of cells such as epithelial and endothelial cells.The expression of AQP-1,-3,-4,-5,-8 and-9 were found in the digestive system,where these six AQP isoforms serve essen-tial roles including mediating the transmembrane water transport and regulating the secretion of gastrointestinal(GI)fluids,consequently facilitating the digestion and absorption of GI con-tents.In addition,the expression levels of AQPs are controlled by various factors,and AQPs can stimulate numerous signaling pathways;however,aberrant expression of AQPs in the GI tracts are associated with the initiation and development of numerous diseases.Thus,this re-view provides an overview of the expression and functions of AQPs in the digestive system.

Transcriptomic profiling of peroxisome-related genes reveals a novel prognostic signature in hepatocellular carcinoma

Emerging evidence suggests that peroxisomes play a role in the regulation of tumorigenesis and cancer progression.However,the prognostic value of peroxisome-related genes has been rarely investigated.This study aimed to establish a peroxisome-related gene signature for overall survival(OS)prediction in patients with hepatocellular carcinoma(HCC).First,univariate Cox regression analysis was employed to identify prognostic peroxisome-related genes in The Cancer Genome Atlas liver cancer cohort,and least absolute shrinkage and selection operator Cox regression analysis was used to construct a 10-gene signature.The risk score based on the signature was positively correlated with poor prognosis(HR=4.501,95%CI=3.021–6.705,P=1.39e−13).Second,multivariate Cox regression incorporating additional characteristics revealed that the signature was an independent predictor.Time-dependent ROC curves demonstrated good performance of the signature in predicting the OS of HCC patients.The prognostic performance was validated using International Cancer Genome Consortium HCC cohort data.Gene set enrichment analysis revealed that the signature-related alterations in biological processes mainly involved peroxisomal functions.Finally,we developed a nomogram model based on the gene signature and TNM stage,which showed a superior prognostic power(C-index=0.702).Thus,our study revealed a novel peroxisome-related gene signature that may help improve personalized OS prediction in HCC patients.

Inflammatory cytokines,T lymphocyte subsets,and ritonavir involved in liver injury of COVID-19 patients

Dear Editor,Coronavirus disease 2019(COVID-19)is a type of novel coronavirus and no specific treatment is currently available.Apart from damages to the lung,COVID-19 is also able to trigger liver injury.Numerous observational studies have revealed that elevation of liver enzymes,including alanine aminotransferase(ALT)and aspartate aminotransferase(AST),was detected in some COVID-19 patients,especially in severe cases.1 Unfortunately,the underlying mechanisms and risk factors of COVID-19-induced liver damage have not been completely elucidated.Therefore,identification of novel risk factors in liver injury of COVID-19 patients is essential for the prevention and treatment of liver damage.In this study,192 patients with COVID-19 hospitalized in Chongqing Public Health Center were recruited to identify the risk factors in COVID-19 patients with liver injury.