α-Lipoic Acid Targeting PDK1/NRF2 Axis Contributes to the Apoptosis Effect of Lung Cancer Cells

Figure 4

PDK1 inhibition by LA exerts proapoptotic effects through downregulating NRF2. (a) WB analysis of PDK1 and PDH expression in A549 and PC9 cells after LA exposure for 24 h. (b) LA (1.5 mM) slightly improves pyruvate dehydrogenase activity of A549 cells. (c) Glycolysis rate and oxygen consumption rate (OCR) were measured using glycolysis rate assay kit and Mito Stress Test kit. Calculated parameters of the assays are indicated in bar graphs. (d) Silencing of PDK1 by siRNA downregulates NRF2 expression. (e) PDK1 inhibition results in apoptosis and LA (1.5 mM) could enhance the proapoptosis effect of DCA (5 mM). Results are shown as the ; . (f) Endogenous coimmunoprecipitation between phosphorylated PDH and Keap1 in human lung cancer cells. A549 cells were collected and lysed to undergo Co-IP assay according to the manufacturer’s protocol. After incubating with anti-P-PDH and anti-Keap1 beads, the elutes and flowthroughs (flowthrough 1 from anti-p-PDH beads; flowthrough 2 from anti-Keap beads) were checked by western blotting assay.

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