Phosphocreatine alleviates monocrotaline-induced liver injury dependent on PSRC1-regulated endoplasmic reticulum stress

Abstract

Monocrotaline (MCT), a pyrrolizidine alkaloid (PA), is naturally found in certain plants and known for its hepatotoxic effects. In our prior research, we identified that phosphocreatine (PCr) mitigates PA-induced liver damage. However, the specific mechanism of PCr remains unknown. The objective of the present study was to elucidate the mechanism through which PCr shields against MCT-induced hepatic injury. In vitro assays demonstrated that PCr mitigated the MCT-induced ER stress and apoptosis. This alleviation was similarly observed with the use of the ER stress inhibitor 4-PBA, hinting at the role of ER stress in the protective mechanism of PCr against MCT-induced hepatic damage. In the MCT group, an upregulation of proline/serine-rich coiled-coil protein 1 (PSRC1) was evident, but this was notably downregulated following PCr treatment in vitro. The silencing of PSRC1 diminished the ER stress and apoptosis triggered by MCT, and the protective effect of PCr on liver injury remained evident. Overexpressing PSRC1 increased MCT-induced apoptosis and ER stress, and PCr still plays a protective role. In vivo experiments, we observed a notable attenuation of MCT-induced liver damage by PCr. Employing RNA sequencing and immunohistochemical staining techniques, we ascertained that endoplasmic reticulum (ER) stress, apoptosis and PSRC1 were significantly elevated in the liver samples treated with MCT. Notably, these alterations were counteracted by the presence of PCr. In conclusion, our findings suggest that PCr counteracts ER stress via modulation of PSRC1, which consequently confers protection against MCT-induced liver injury. Furthermore, this study offers potential therapeutic avenues for addressing hepatic damages attributable to MCT.