Fig. 7

NMN function in CKD. NMN inhibits the functions of TGF-β1 and other factors involved in fibrosis. HIF-1α and TGF-β1 cell signals promote the activation of Twist2, which in turn activates nicotinamide mononucleotide adenylyltransferases (NMNAT1). NMNAT1 catalyzes the transformation of NMN into NAD. Poly-ADP ribose polymerase (PARP1) and SIRT1 can recruit NMNAT to promote their catalytic activity. PARP1 activity is associated with renal tubular necrosis. SIRT1 activity. SIRT1 deacetylates DNA methyltransferase (DNMT1) and promotes its activation. DNMT1 methylates CLAUDIN-1 and TWIST2 and is renal protective