Dual proteotoxic stress accelerates liver injury via activation of p62-Nrf2

Anti-inflammation treatment for protection of hepatocytes and amelioration of hepatic fibrosis in rats

Chronic inflammation is considered as an important pathophysiologic mechanism of hepatic cirrhosis, which induces hepatocyte injury and activates hepatic stellate cells (HSCs), thus resulting in hepatic fibrosis. Previous studies have reported that cyclooxygenase-2 (COX-2) inhibitor can effectively treat liver fibrosis, while somatostatin (SST) analogues inhibit the activation of HSCs. The present study aimed to investigate the effects of a COX-2 inhibitor, celecoxib, combined with a SST analogue, octreotide, for protection of hepatocytes and prevention of fibrosis in a rat model of hepatic fibrosis. Therefore, a hepatic fibrosis rat model was established following peritoneal injection of thioacetamide (TAA), and the rats were then treated with a combination of celecoxib and octreotide (TAA + C). Immunohistochemistry and western blotting assays were used to assess the expression levels of proteins associated with inflammation, epithelial-mesenchymal transition (EMT), proliferation, apoptosis and autophagy. H&E staining, transmission electron microscopy and scanning electron microscopy were used to evaluate the destruction of hepatocytes. Masson's Trichrome and Sirius Red were used to measure the degree of liver fibrosis. The results demonstrated that, compared with those of the control group, the degree of liver fibrosis and the expression of the intrahepatic inflammation factors were aggravated in the TAA group. Furthermore, the apoptosis rate, EMT and autophagy of hepatocytes were also increased in the TAA group. However, treatment with TAA + C restored the aforementioned increased levels compared with the TAA group. In conclusion, treatment of rats with the combination of celecoxib and octreotide could attenuate the progress of hepatic fibrosis via protection of hepatocytes by reducing apoptosis, EMT and autophagy in hepatocytes.