Simultaneous Induction of Glycolysis and Oxidative Phosphorylation during Activation of Hepatic Stellate Cells Reveals Novel Mitochondrial Targets to Treat Liver Fibrosis

Upon liver injury, hepatic stellate cells (HSCs) transdifferentiate to migratory, proliferative and extracellular matrix-producing myofibroblasts (e.g., activated HSCs; aHSCs) causing liver fibrosis. HSC activation is associated with increased glycolysis and glutaminolysis. Here, we compared the contribution of glycolysis, glutaminolysis and mitochondrial oxidative phosphorylation (OXPHOS) in rat and human HSC activation. Basal levels of glycolysis (extracellular acidification rate ~3-fold higher) and particularly mitochondrial respiration (oxygen consumption rate ~5-fold higher) were significantly increased in rat aHSCs, when compared to quiescent rat HSC. This was accompanied by extensive mitochondrial fusion in rat and human aHSCs, which occurred without increasing mitochondrial DNA content and electron transport chain (ETC) components. Inhibition of glycolysis (by 2-deoxy-D-glucose) and glutaminolysis (by CB-839) did not inhibit rat aHSC proliferation, but did reduce Acta2 (encoding α-SMA) expression slightly. In contrast, inhibiting mitochondrial OXPHOS (by rotenone) significantly suppressed rat aHSC proliferation, as well as Col1a1 and Acta2 expression. Other than that observed for rat aHSCs, human aHSC proliferation and expression of fibrosis markers were significantly suppressed by inhibiting either glycolysis, glutaminolysis or mitochondrial OXPHOS (by metformin). Activation of HSCs is marked by simultaneous induction of glycolysis and mitochondrial metabolism, extending the possibilities to suppress hepatic fibrogenesis by interfering with HSC metabolism.

FOXO3a shRNA and simultaneous induction of P27Kip1gene Inhibit the Breast Cancer Growth in Nude Mice

Background: FOXO proteins, which are overexpressed in multiple human tumors, belong to the Forkhead family of transcription factors that are involved in cell-cycle regulation, cell apoptosis, differentiation, stress response, and metabolism. The p27Kip1 gene leads to cell cycle arrest, cell apoptosis, tumor suppressor genes, and cell adhesion. The low expression level of the p27Kip1 gene is attributed to poor prognosis in patients with colorectal, gastric, pulmonary, and breast cancers. Accordingly, the present study aimed to investigate the possibility of tumor growth inhibition in a mouse model by targeting FOXO3a shRNA and the simultaneous induction of P27Kip1gene.Methods: The tumor model was generated by intratumoral inoculating with plasmids. When tumor size reached an average volume of 8 mm in diameter, the mice received injections of construct and control plasmids three times a week for two weeks, followed by tumor growth assessment.Results: Based on the obtained results, the delivery of construct plasmid significantly inhibited tumor growth in nude mice, as compared to the control plasmid. Moreover, the immunohistochemical analysis indicated that the delivery of construct plasmid significantly suppressed expression of FOXo3a and induced P27Kip1 in tumor samples.Conclusion: The findings of the present study revealed that FOXO3a shRNA, along with simultaneous induction of P27Kip1gene using a useful in vivo gene delivery strategy, seems a practical therapeutic approach for breast cancer treatment and may provide profound insight into gene therapy of solid cancers.