PPARGC1A and Alzheimer disease: Mfn-2 gene knockout or Mfn-2 disease-expressing mutants affect the transport of axonal mitochondria [22], and on this basis, PGC-1α possibly contributes to the rescue underlying the defection of axonal integrity and reduction in synaptic function in AD [22] by stimulating the activity of the Mfn-2 promoter [12].