Aging-Induced Brain-Derived Neurotrophic Factor in Adipocyte Progenitors Contributes to Adipose Tissue Dysfunction

Aging-related adipose tissue dysfunction contributes to the progression of chronic metabolic diseases. We investigated the role of age-dependent expression of a neurotrophin, brain-derived neurotrophic factor (BDNF) in adipose tissue. Pro-BDNF expression was elevated in epididymal white adipose tissue (eWAT) with advanced age, which was associated with the reduction in sympathetic innervation. Interestingly, BDNF expression was enriched in PDGFRα⁺ adipocyte progenitors isolated from eWAT, with age-dependent increase in expression. In vitro pro-BDNF treatment caused apoptosis in adipocytes differentiated from C3H10T1/2 cells, and siRNA knockdown of sortilin mitigated these effects. Tamoxifen-inducible PDGFRα⁺ cell-specific deletion of BDNF (BDNF^Pdgfra KO) reduced pro-BDNF expression in eWAT, prevented age-associated declines in sympathetic innervation and mitochondrial content in eWAT, and improved insulin sensitivity. Moreover, BDNF^Pdgfra KO mice showed reduced expression of aging-induced inflammation and senescence markers in eWAT. Collectively, these results identified the upregulation of pro-BDNF expression in adipocyte progenitors as a feature of visceral white adipose tissue aging and suggested that inhibition of BDNF expression in adipocyte progenitors is potentially beneficial to prevent aging-related adipose tissue dysfunction.