Octreotide-based therapies effectively protect mice from acute and chronic gastritis

Gastritis is a common inflammation of stomach with multiple pathogenesis. This study was designed to investigate the protective effects of oral octreotide (OCT) against ethanol-induced acute gastric injury and H. pylori-induced chronic gastritis via promoting gastric mucosa restoration, reducing gastric acid secretion and inflammation. Male C57BL/6J mice were randomly divided and treated with three doses of OCT (0.5, 2.5, 10 mg/kg) alone or combined respectively with 10 mg/kg omeprazole (OME), 0.2 g/L metronidazole (MTZ)/0.1 g/L clarithromycin (CLR) in drinking water. Oxidative stress analysis, bacterial load analysis, qPCR, gastric histopathology examinations were performed in our study. Ethanol-induced acute gastric ulcer was restored by OCT alone at doses of 2.5 mg/kg, or combined with OME as indicated by markedly reducing Gastrin, Il-6 and Il1b expression through induction of Muc5ac and Occludin, significantly improving hyperacidity and gastric bleeding. As well, OCT combined with MTZ/CLR restored the integrity of gastric mucosa damaged by H. pylori via elevating the expression of Muc5ac and somatostatin receptor 2, decreasing inflammation and increasing the number of chorionic or glands. Besides, OCT is more suitable for long-term medication in the treatment of chronic gastritis than OME. In conclusion, our results proved that the newly developed oral OCT-based therapies were more effective to reverse gastric mucosa damage and inflammation in ethanol and H. pylori infection-induced gastric injury, it is of great significance for supplementing new clinical regimens for the treatment of acute and chronic gastritis.

Gasdermin E-derived caspase-3 inhibitors effectively protect mice from acute hepatic failure

Programmed cell death (PCD), including apoptosis, apoptotic necrosis, and pyroptosis, is involved in various organ dysfunction syndromes. Recent studies have revealed that a substrate of caspase-3, gasdermin E (GSDME), functions as an effector for pyroptosis; however, few inhibitors have been reported to prevent pyroptosis mediated by GSDME. Here, we developed a class of GSDME-derived inhibitors containing the core structure of DMPD or DMLD. Ac-DMPD-CMK and Ac-DMLD-CMK could directly bind to the catalytic domains of caspase-3 and specifically inhibit caspase-3 activity, exhibiting a lower IC50 than that of Z-DEVD-FMK. Functionally, Ac-DMPD/DMLD-CMK substantially inhibited both GSDME and PARP cleavage by caspase-3, preventing apoptotic and pyroptotic events in hepatocytes and macrophages. Furthermore, in a mouse model of bile duct ligation that mimics intrahepatic cholestasis-related acute hepatic failure, Ac-DMPD/DMLD-CMK significantly alleviated liver injury. Together, this study not only identified two specific inhibitors of caspase-3 for investigating PCD but also, more importantly, shed light on novel lead compounds for treating liver failure and organ dysfunctions caused by PCD.