Updating mRNA variants of the human RSK4 gene and their expression in different stressed situations.

We determined RNA spectrum of the human RSK4 (hRSK4) gene (also called RPS6KA6) and identified 29 novel mRNA variants derived from alternative splicing, which, plus the NCBI-documented ones and the five we reported previously, totaled 50 hRSK4 RNAs that, by our bioinformatics analyses, encode 35 hRSK4 protein isoforms of 35-762 amino acids. Many of the mRNAs are bicistronic or tricistronic for hRSK4. The NCBI-normalized NM_014496.5 and the protein it encodes are designated herein as the Wt-1 mRNA and protein, respectively, whereas the NM_001330512.1 and the long protein it encodes are designated as the Wt-2 mRNA and protein, respectively. Many of the mRNA variants responded differently to different situations of stress, including serum starvation, a febrile temperature, treatment with ethanol or ethanol-extracted clove buds (an herbal medicine), whereas the same stressed situation often caused quite different alterations among different mRNA variants in different cell lines. Mosifloxacin, an antibiotics and also a functional inhibitor of hRSK4, could inhibit the expression of certain hRSK4 mRNA variants. The hRSK4 gene likely uses alternative splicing as a handy tool to adapt to different stressed situations, and the mRNA and protein multiplicities may partly explain the incongruous literature on its expression and comports.

Hesperidin Protects Against High-Fat Diet-Induced Lipotoxicity in Rats by Inhibiting Pyroptosis.

It is currently thought that excess fatty acid-induced lipotoxicity in hepatocytes is a critical initiator in the development of nonalcoholic fatty liver disease (NAFLD). Lipotoxicity can induce hepatocyte death; thus, reducing lipotoxicity is one of the most effective therapeutic methods to combat NAFLD. Abundant evidence has shown that hesperidin (HSP), a type of flavanone mainly found in citrus fruits, is able to ameliorate NAFLD, but the molecular mechanisms are unclear. We previously reported that pyroptosis contributed to NAFLD development and that inhibiting pyroptosis contributed to blunting the progression of NAFLD in rat models. Therefore, we questioned whether HSP could contribute to ameliorating NAFLD by modulating pyroptosis. In this study, a high-fat diet (HFD) induced dyslipidemia and hepatic lipotoxicity in rats, and HSP supplementation ameliorated dyslipidemia and insulin resistance. In addition, the HFD also caused pyroptosis in the liver and pancreas, while HSP supplementation ameliorated pyroptosis. In vitro, we found that HSP ameliorated palmitic acid-induced lipotoxicity and pyroptosis in HepG2 and INS-1E cells. In conclusion, we showed for the first time that HSP has a protective effect against liver and pancreas damage in terms of pyroptosis and provides a novel mechanism for the protective effects of HSP on NAFLD.