FIGURE 4.

Regulation of mitochondrial biogenesis in adipocytes. Mitochondrial biogenesis in adipocytes is mainly regulated by the lipogenic gene PGC-1α. PGC-1α protein is activated through phosphorylation and acetylation. Once activated, PGC-1α promotes the transcription levels of NRF1 and NRF2, which in turn leads to the upregulation of TFAM. TFAM promotes the transcription and replication of mtDNA, resulting in mitochondrial biogenesis. However, the expression of PGC-1α is downregulated in mice with obesity and those fed a high-fat diet. Furthermore, the activation of AMPK promotes the transcription levels of NRFs and PGC-1α.