the transcription factor Kruppel-like factor 4 (KLF4) governs mitochondrial biogenesis, metabolic function, dynamics, and autophagic clearance. Adult mice with cardiac-specific Klf4 deficiency developed cardiac dysfunction with aging or in response to pressure overload that was characterized by reduced myocardial ATP levels, elevated ROS, and marked alterations in mitochondrial shape, size, ultrastructure, and alignment ... [Source]
a cardiac specific KLF4 deficient mouse line that is sensitive to stress, we found mitochondrial protein hyperacetylation coupled with reduced Sirt3 and NAD+ levels in the heart before stress, suggesting that the KLF4-deficient heart is predisposed to NAD+-associated defects.
Further, we demonstrated that short-term administration of Nicotinamide Mononucleotide (NMN) successfully protected the mutant mice from pressure overload-induced heart failure. Mechanically, we showed that NMN preserved mitochondrial ultrastructure, reduced ROS and prevented cell death in the heart. In cultured cardiomyocytes, NMN treatment significantly increased long-chain fatty acid oxidation despite no direct effect on pyruvate oxidation. [Source]