mtDNA as a Mediator for Expression of Hypoxia-Inducible Factor 1α and ROS in Hypoxic Neuroblastoma Cells
AbstractMitochondria consume O2 to produce ATP and are critical for adaption of hypoxia, but the role of mitochondria in HIF-1α pathway is as yet unclear. In this study, mitochondrial DNA (mtDNA) enriched (SK-N-AS) and depleted (ρ0) cells of neuroblastoma were cultured in a hypoxic chamber to simulate a hypoxic condition and then the major components involved in mitochondrial related pathways, hypoxia-inducible factor 1α (HIF-1α) and reactive oxygen species (ROS) were measured. The results showed that hypoxia-stimulated exposure elevated expression of HIF-1α, which was additionally influenced by level of generated ROS within the cytosol. Moreover, elevation of HIF-1α also resulted in increases of lactate dehydrogenase A (LDH-A) and pyruvate dehydrogenase kinase 1 (PDK1) in both hypoxic cells. The expression of mitochondrial biogenesis related proteins and metabolic components were noted to increase significantly in hypoxic SK-N-AS cells, indicating that mtDNA was involved in mitochondrial retrograde signaling and metabolic pathways. An analysis of dynamic proteins found elevated levels of HIF-1α causing an increased expression of dynamin-related protein 1 (DRP1) during hypoxia; further, the existence of mtDNA also resulted in higher expression of DRP1 during hypoxia. By using siRNA of HIF-1α or DRP1, expression of DRP1 decreased after suppression of HIF-1α; moreover, the expression of HIF-1α was also affected by the suppression of DRP1. In this study, we demonstrated that mtDNA is a mediator of HIF-1α in eliciting metabolic reprogramming, and mitochondrial biogenesis. Identification of a mutual relationship between HIF-1α and DRP1 may be a critical tool in the future development of clinical applications. View Full-Text
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Kuo, C.-W.; Tsai, M.-H.; Lin, T.-K.; Tiao, M.-M.; Wang, P.-W.; Chuang, J.-H.; Chen, S.-D.; Liou, C.-W. mtDNA as a Mediator for Expression of Hypoxia-Inducible Factor 1α and ROS in Hypoxic Neuroblastoma Cells. Int. J. Mol. Sci. 2017, 18, 1220.
Kuo C-W, Tsai M-H, Lin T-K, Tiao M-M, Wang P-W, Chuang J-H, Chen S-D, Liou C-W. mtDNA as a Mediator for Expression of Hypoxia-Inducible Factor 1α and ROS in Hypoxic Neuroblastoma Cells. International Journal of Molecular Sciences. 2017; 18(6):1220.Chicago/Turabian Style
Kuo, Chung-Wen; Tsai, Meng-Han; Lin, Tsu-Kung; Tiao, Mao-Meng; Wang, Pei-Wen; Chuang, Jiin-Haur; Chen, Shang-Der; Liou, Chia-Wei. 2017. "mtDNA as a Mediator for Expression of Hypoxia-Inducible Factor 1α and ROS in Hypoxic Neuroblastoma Cells." Int. J. Mol. Sci. 18, no. 6: 1220.
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