S100 calcium binding protein A6 and associated long noncoding ribonucleic acids as biomarkers in the diagnosis and staging of primary biliary cholangitis

BACKGROUND Primary biliary cholangitis(PBC)is a chronic and slowly progressing cholestatic disease,which causes damage to the small intrahepatic bile duct by immunoregulation,and may lead to cholestasis,liver fibrosis,cirrhosis and,eventually,liver failure.AIM To explore the potential diagnosis and staging value of plasma S100 calcium binding protein A6(S100A6)messenger ribonucleic acid(mRNA),LINC00312,LINC00472,and LINC01257 in primary biliary cholangitis.METHODS A total of 145 PBC patients and 110 healthy controls(HCs)were enrolled.Among them,80 PBC patients and 60 HCs were used as the training set,and 65 PBC patients and 50 HCs were used as the validation set.The relative expression levels of plasma S100A6 mRNA,long noncoding ribonucleic acids LINC00312,LINC00472 and LINC01257 were analyzed using quantitative reverse transcription-polymerase chain reaction.The bile duct ligation(BDL)mouse model was used to simulate PBC.Then double immunofluorescence was conducted to verify the overexpression of S100A6 protein in intrahepatic bile duct cells of BDL mice.Human intrahepatic biliary epithelial cells were treated with glycochenodeoxycholate to simulate the cholestatic environment of intrahepatic biliary epithelial cells in PBC.RESULTS The expression of S100A6 protein in intrahepatic bile duct cells was up-regulated in the BDL mouse model compared with sham mice.The relative expression levels of plasma S100A6 mRNA,log10 LINC00472 and LINC01257 were upregulated while LINC00312 was down-regulated in plasma of PBC patients compared with HCs(3.01±1.04 vs 2.09±0.87,P<0.0001;2.46±1.03 vs 1.77±0.84,P<0.0001;3.49±1.64 vs 2.37±0.96,P<0.0001;1.70±0.33 vs 2.07±0.53,P<0.0001,respectively).The relative expression levels of S100A6 mRNA,LINC00472 and LINC01257 were up-regulated and LINC00312 was down-regulated in human intrahepatic biliary epithelial cells treated with glycochenodeoxycholate compared with control(2.97±0.43 vs 1.09±0.08,P=0.0018;2.70±0.26 vs 1.10±0.10,P=0.0006;2.23±0.21 vs 1.10±0.10,P=0.0011;1.20±0.04 vs 3.03±0.15,P<0.0001,respectively).The mean expression of S100A6 in the advanced stage(III and IV)of PBC was up-regulated compared to that in HCs and the early stage(II)(3.38±0.71 vs 2.09±0.87,P<0.0001;3.38±0.71 vs 2.57±1.21,P=0.0003,respectively);and in the early stage(II),it was higher than that in HCs(2.57±1.21 vs 2.09±0.87,P=0.03).The mean expression of LINC00312 in the advanced stage was lower than that in the early stage and HCs(1.39±0.29 vs 1.56±0.33,P=0.01;1.39±0.29 vs 2.07±0.53,P<0.0001,respectively);in addition,the mean expression of LINC00312 in the early stage was lower than that in HCs(1.56±0.33 vs 2.07±0.53,P<0.0001).The mean expression of log10 LINC00472 in the advanced stage was higher than those in the early stage and HCs(2.99±0.87 vs 1.81±0.83,P<0.0001;2.99±0.87 vs 1.77±0.84,P<0.0001,respectively).The mean expression of LINC01257 in both the early stage and advanced stage were up-regulated compared with HCs(3.88±1.55 vs 2.37±0.96,P<0.0001;3.57±1.79 vs 2.37±0.96,P<0.0001,respectively).The areas under the curves(AUC)for S100A6,LINC00312,log10 LINC00472 and LINC01257 in PBC diagnosis were 0.759,0.7292,0.6942 and 0.7158,respectively.Furthermore,the AUC for these four genes in PBC staging were 0.666,0.661,0.839 and 0.5549,respectively.The expression levels of S100A6 mRNA,log10 LINC00472,and LINC01257 in plasma of PBC patients were decreased(2.35±1.02 vs 3.06±1.04,P=0.0018;1.99±0.83 vs 2.33±0.96,P=0.036;2.84±0.92 vs 3.69±1.54,P=0.0006),and the expression level of LINC00312 was increased(1.95±0.35 vs 1.73±0.32,P=0.0007)after treatment compared with before treatment using the paired t-test.Relative expression of S100A6 mRNA was positively correlated with log10 LINC00472(r=0.683,P<0.0001);serum level of collagen type IV was positively correlated with the relative expression of log10 LINC00472(r=0.482,P<0.0001);relative expression of S100A6 mRNA was positively correlated with the serum level of collagen type IV(r=0.732,P<0.0001).The AUC for the four biomarkers obtained in the validation set were close to the training set.CONCLUSION These four genes may potentially act as novel biomarkers for the diagnosis of PBC.Moreover,LINC00472 acts as a potential biomarker for staging in PBC.

Anti-sense RNA Inhibits the Expression of Synaptotagmin Ⅱ in RBL-2H3 and Enhances the Exocytosis of Lysosomes in RBL-2H3

Summary: The expression of synaptotagmin Ⅱ(Syt2) in RBL-2H3 (RBL) and its role during exocytosis of RBL was investigated. The expression of Syt2 in RBL was detected by western blot and Syt2 gene was amplified by PCR. The anti-sense full length Syt2 cDNA expression vector was constructed with pEGFP-N1 and transfected into RBL by electroporation, and stable transfectants were selected by using G418. To analyze the role of Syt2 during exocytosis of RBL, the release of cathepsin D was assayed by immunoblotting. The results showed that Syt2 was expressed in RBL. The anti-sense expression vector pEGFP-N1-Syt2-AS was constructed and the sequence of insertion was completely consistent with rat Syt2 (accession number in GeneBank : NM012665). The stable transfectants (RBL-Syt2-AS) were obtained. Western blot showed that RBL-Syt2-AS expressed a lower level of Syt2 (8 % and 10 % of control cells), indicating that the expression of Syt2 in RBL-Syt2-AS was markedly down-regulated by anti-RNA. Compared with control, the release of cathepsin D by RBL-Syt2-AS was increased. It was concluded that Syt2 expressed in RBL and could inhibit exocytosis of lysosomes in RBL.

Association of Serum Antioxidant Enzymes and Nervous Tissue Markers in Hypertensive Patients

Background and Purpose: Hypertension has serious effects on cerebral blood vessels. Oxidative stress seems to be implicated in blood pressure elevation, through increased reactive oxygen species and/or decreased antioxidant capacity. Recently blood markers indicating damage to the central nervous system were reported to be increased in hypertensive patients. However, it is unknown whether antioxidant capacity is related to these changes. This study was designed to explore if the concentration of blood markers for nervous tissue damage was associated to antioxidant capacity in hypertensive patients. Methods: Twenty hypertensive patients and 23 healthy controls were studied. They were paired by age, sex, ethnicity, or risk factors. Serum neuron specific enolase (NSE) and S100 calcium binding protein B (S100B) were measured as nervous tissue damage markers, as well as the activity of antioxidant enzymes (catalase, glutathione peroxidase, glutathione reductase and gamma-glutamyltransferase). Results: Serum neuronal specific enolase (NSE) and S100 calcium binding protein B (S100B) concentrations determined by immunoassay were significantly increased in patients vs. controls. The activities of antioxidant enzymes measured by spectrophotometry showed that plasmatic catalase and erythrocytic glutathione peroxidase were significantly increased in patients, but erythocytic catalase was decreased. Gamma-glutamyltransferase activity was significantly correlated with S100B in hypertensive patients, while erythrocytic catalase activity was decreased in subjects with higher NSE levels. Conclusion: This preliminary investigation suggested that antioxidant status might be modulated through changes in antioxidant enzymatic activity in hypertensive patients. The association of some of these changes with peripheral markers of damage to the central nervous system could indicate that the increased levels of these proteins in hypertension are partly related to oxidative stress.

The Distribution of Synaptotagmin Ⅱ in RBL-2H3 and Its Regulation on Exocytosis of Lysosomes in RBL-2H3

Synaptotagmin （Syt） constitutes a family of membrane-trafficking proteins, so far nearly 20 Syts have been discovered. Extensive work showed that synatotagmins were a potential Ca^2＋ sensor for regulated exocytosis. This study was to investigate the expression and location of synaptotagmin II （Syt2） in RBL-2H3 （RBL） and its role in regulating exocytosis of RBL. The expression of Syt2 in RBL was confirmed by Western blot. The recombinant expression vector pEGFP-N1-Syt2 was constructed and transfected into RBL by electroporation, the stable transfectant RBL-Syt2-S expressing fusion protein Syt2-EGFP were obtained and Syt2 was highly concentrated at plasma membrane with little detected in cytoplasm. To analyze the role of Syt2 during exocytosis of RBL, the release of cathepsin D was assayed by immunoblotting. Compared with control, the release of cathepsin D by RBL-Syt2-S was markedly decreased. The results indicated that Syt2 played a negative regulation in exocytosis of lysosomes in RBL. Cellular ＆ Molecular Immunology. 2005;2（3）：205-209.