Senescence in oral lichen planus as assessed by the immunohistochemical evaluation of senescence marker protein-30 (Regucalcin)

Background: Oral lichen planus is a T-cell-mediated chronic inflammatory disease affecting approximately 1% to 2% of the population, the etiology of which is currently unknown. The objectives of this study were to observe if senescence occurs in oral lichen planus, through the assessment of the immunohistochemical expression of a novel marker for senescence called Senescence marker protein-30 or regucalcin, and compare the expression to that in oral lichenoid reaction and non-specific inflammation. Subjects and Methods: The study material consisted of 30 cases of oral lichen planus, 15 cases of oral lichenoid reaction and 15 cases of non-specific inflammation. The number of positive cells in ten randomly selected high power fields were counted in the epithelium and the connective tissue separately and the mean was determined. Results: Mann–Whitney U test was used to statistically analyze if there was any significant difference in the expression of Senescence marker protein-30 between oral lichen planus, oral lichenoid reaction and non-specific inflammation. Even though a greater expression was seen in the oral lichen planus cases than oral lichenoid reaction, the difference in both the epithelium and connective tissue was not statistically significant. Conclusion: This study shows that in addition to the already known mechanisms like apoptosis and increased cell proliferation rates, the activated T-lymphocytes may also trigger a senescent change in the cells of oral lichen planus. As with the other mechanisms, this is also seen only in a small proportion of the cases.

Serum regucalcin is a useful indicator of liver injury severity in patients with hepatitis B virus-related liver diseases

Regucalcin is a soluble protein that is principally expressed in hepatocytes. Studies of regucalcin have mainly been conducted in animals due to a lack of commercially available kits. We aimed to develop an enzyme-linked immunosorbent assay (ELISA) to quantify serum regucalcin in patients with hepatitis B virus (HBV)-related disease. High-titer monoclonal antibodies and a polyclonal antibody to regucalcin were produced, a double-antibody sandwich ELISA method was established, and serum regucalcin was determined in 47 chronic hepatitis B (CHB) patients, 91 HBV-related acute-on-chronic liver failure (HBV-ACLF) patients, and 33 healthy controls. The ELISA demonstrated an appropriate linear range, and high levels of reproducibility, sensitivity, specificity, accuracy, and stability. The median serum regucalcin concentrations in HBV-ACLF and CHB patients were 5.46 and 3.76 ng/mL, respectively (P<0.01), which were much higher than in healthy controls (1.72 ng/mL, both P<0.01). For the differentiation of CHB patients and healthy controls, the area under curve (AUC) was 0.86 with a cut-off of 2.42 ng/mL, 85.7% sensitivity, and 78.8% specificity. In contrast, the AUC of alanine aminotransferase (ALT) was lower (AUC=0.80, P=0.01). To differentiate ACLF from CHB, the AUC was 0.72 with a cut-off of 4.26 ng/mL, 77.0% sensitivity, and 61.2% specificity while the AUC of ALT was 0.41 (P=0.07). Thus, we have developed an ELISA that is suitable for measuring serum regucalcin and have shown that serum regucalcin increased with the severity of liver injury due to HBV-related diseases, such that it appears to be more useful than ALT as a marker of liver injury.

Study of compound glutathione inosine injection effect on expression of regucalcin in liver tissue of rats with immune hepatic fibrosis / 中华肝脏病杂志

Objective@#To investigate the change in expression of anti-senescence marker protein calmodulin (RGN) in liver tissues of rats with immune hepatic fibrosis, and to observe the effect of compound glutathione inosine injection (CGII) on it.@*Methods@#Rat liver fibrosis model was induced by intraperitoneal injection of porcine serum, and CGII intervention was administered at the appropriate time. Rat liver tissues were stained with HE and Masson. RGN and protein expression at mRNA in liver tissues was detected by fluorescence quantitative PCR and immunohistochemistry. One-way Anova was used for measurement data. LDS test was used for two-way comparison, and pathological semi-quantitative results were analyzed by rank-sum test.@*Results@#The relative expression of RGN mRNA and protein in liver tissue of fibrotic rats was 82.23 ± 15.21 and 12.52 ± 3.23, respectively, which were significantly lower than that of normal rats 176.39 ± 11.35 and 59.23 ± 9.13 (P < 0.01). The degree of liver fibrosis in fibrotic rats after CGII intervention was significantly lower than fibrotic rats. The relative expression of RGN mRNA and protein in the intervention group was 168.78 ± 21.31 and 46.42 ± 4.71, respectively, which were significantly higher than fibrosis and spontaneous recovery group. The difference was statistically significant (P < 0.01). The relative expression of RGN mRNA and protein in the spontaneous recovery group was 86.23 ± 17.16 and 14.34 ± 5.16, which was higher than model group. The difference was not statistically significant (P > 0.05).@*Conclusion@#The expression of RGN in liver tissue of rats with hepatic fibrosis induced by porcine serum is decreased, while the expression of RGN increases with the decrease of fibrosis after CGII intervention, suggesting that the protein may play an important role in the development of liver fibrosis.