Pyruvate protects against cellular senescence through the control of mitochondrial and lysosomal function in dermal fibroblasts.

Mitochondrial dysfunction can drive cellular senescence, which is accompanied by changes in metabolism and increases in senescence-associated secretory phenotypes (SASP). Although pyruvate, a key metabolite for numerous aspects of metabolism, has been used as general supplement in synthetic media, the physiological function of pyruvate underlying its protective role against cellular senescence under normal conditions has remained unknown. Here, we show that extracellular pyruvate prevents senescence in normal human dermal fibroblasts (NHDFs) through increasing the generation of NAD during the conversion to lactate. Acetylated PGC-1α, v-ATPaseV0A1, RelA, and histoneH3 accumulate under pyruvate deprivation conditions, resulting in the onset of senescence in NHDFs through the accumulation of abnormal mitochondria generated by lysosomal inactivation-induced mitophagy defects, and through an increase in SASP. Furthermore, pyruvate showed a protective effect against aging phenotypes in skin equivalents, which consist of a dermis and epidermis that act similarly to in vivo skin tissues. Our findings reveal a connection between pyruvate and mitochondrial dysfunction in the progression of senescence to our knowledge previously unreported. These results suggest that the pyruvate deprivation-induced senescence model can be used to study the connection between metabolism and senescence under normal conditions.