PIK3R3 regulates PPARα expression to stimulate fatty acid β-oxidation and decrease hepatosteatosis

Phosphatidylinositol 3-kinase (PI3K) signaling plays an important role in the regulation of cellular lipid metabolism and non-alcoholic fatty liver disease (NAFLD). However, little is known about the role of the regulatory subunits of PI3K in lipid metabolism and NAFLD. In this study, we characterized the functional role of PIK3R3 in fasting-induced hepatic lipid metabolism. In this study, we showed that the overexpression of PIK3R3 promoted hepatic fatty acid oxidation via PIK3R3-induced expression of PPARα, thus improving the fatty liver phenotype in high-fat diet (HFD)-induced mice. By contrast, hepatic PIK3R3 knockout in normal mice led to increased hepatic TG levels. Our study also showed that PIK3R3-induced expression of PPARα was dependent on HNF4α. The novel PIK3R3-HNF4α-PPARα signaling axis plays a significant role in hepatic lipid metabolism. As the activation of PIK3R3 decreased hepatosteatosis, PIK3R3 can be considered a promising novel target for developing NAFLD and metabolic syndrome therapies.

p53 inhibits the proliferation of lung cancer cell PC-9 by regulating miR-148b / 实用医学杂志

Objective To explore the function of p53 on regulating the expression of miR-148b in lung cancer cell line PC-9 and its corresponding molecular mechanism and the impact on cell proliferation. Methods Transient transfection of p53 eukaryotic expressing plasmids into lung cancer cell line PC-9 was performed to establish a cell model over-expressing p53. RT-PCR was used to explicit the impact of p53 on the expression of miR-148b. A reporter vector containing miR-148b promoter was used to investigate the function of p53 on regulating the transcription of miR-148b. Low-expressing miR-148b by transfecting its specific inhibitors , a CCK-8 assay was performed to explore the influence of miR-148b on the lung cancer cell proliferation inhibited by p53. Results Over-expression of p53 promoted miR-148b expression in lung cancer cell line PC-9. P53 could increase the luciferase activity driven by miR-148b promoters. Knockdown of miR-148b attenuated the impact of p53 on inhibiting the proliferation of PC-9 cells. Conclusion P53 inhibits the proliferation of lung cancer cell line PC-9 partially depending on miR-148b.