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.

Hesperidin inhibits the epithelial to mesenchymal transition induced by transforming growth factor-ß1 in A549 cells through Smad signaling in the cytoplasm

Hesperidin, a natural compound, suppresses the epithelial-to-mesenchymal transition through the TGF-ß1/Smad signaling pathway. However, studies on the detailed effects and mechanisms of hesperidin are rare. The present study showed that, for A549 alveolar epithelial cells, the anti-proliferative effects of hesperidin occurred in a dose-dependent manner, with an IC50= 216.8 µM at 48 h. TGF-ß1 was used to activate the Smad signaling pathway and induce the epithelial to mesenchymal transition in cells. Treatment with hesperidin or SB431542 was used for antagonism of Smad pathway activation. Hesperidin inhibited the increase in ɑ-SMA and Col1ɑ-1 and the decrease in E-cadherin in a dose-dependent manner from concentration of 20 µM to 60 µM, as assessed by both ELISA and Western blotting assays; however, there was no significant effect on cellular morphological alterations. Moreover, the Western blotting assay showed that, in the cytoplasm, hesperidin and SB431542 had no significant effect on the protein expression of Smad 2, 3, 4, or 7 as well as 2/3. However, 60 µM hesperidin and SB431542 significantly decreased p-Smad2/3 protein expression. From the above results, it is concluded that hesperidin can partly inhibit the epithelial to mesenchymal transition in human alveolar epithelial cells; the effect accounts for the blockage of the phosphorylation of Smad2/3 in the cytoplasm rather than a change in Smad protein production in the cytoplasm