FIGURE 2.

Regulation of mitochondria biogenesis by SIRT1 and HIF‐1α during hypoxia. During hypoxia, the activity of SIRT1 in the nucleus is reduced, which decreases Von Hippel Lindau tumor suppressor levels and subsequently stabilizes HIF‐1α. Activated HIF‐1α reduces c‐Myc activity and subsequently reduces transcription of mitochondrial transcription factor A. PGC‐1β activity is also inhibited by HIF‐1α, resulting in the downregulation of mitochondrial genes. SIRT1 reduction suppresses PGC‐1α activity and prevents mitochondrial synthesis