PPARGC1A and Alzheimer disease: Mitochondrial biogenesis in AD neurons is impaired [117]: the number of mitochondria and the levels of NRF-1, NRF-2 and TFAM together with the nuclear levels of PGC-1α are reduced in the AD hippocampal tissues and also in M17 cells expressing the human double Swedish mutation of APP695 isoform (APPswe M17 cells) (for refs, see [92]).