PPARGC1A and Alzheimer disease: Levels of proteins regulating mitochondrial biogenesis, such as peroxisome proliferator-activated receptor (PPAR)-γ coactivator-1α (PGC-1α), nuclear respiratory factors 1 (NRF1) and 2 (NRF2), and mitochondrial transcription factor A (Tfam), were significantly reduced in human AD hippocampus and cellular models overexpressing APP Swedish mutation [78,79].