Endurance Training Reprograms the White Adipose Tissue Proteome of Rats in A Sex-specific Manner

PURPOSE: To determine whether 8-wks of endurance training (ET) differentially affects white adipose (WAT) proteome and phosphoproteome signatures in male and female rats. METHODS: The Molecular Transducers of Physical Activity (MoTrPAC) Consortium utilizes a multi-omic, multi-tissue design to uncover molecular transducers of exercise and how conditions, such as gender, alter systemic responses. Rats were treadmill trained 5 days/wk at ~70% of VO2Max for 8 wks. Subcutaneous WAT from trained and sedentary rats (n = 6 per sex, per condition) was collected. 11-plex Tandem mass tag (TMT) labeling was utilized in combination with offline fractionation and phosphopeptide enrichment followed by LC-MS/MS analysis to evaluate protein abundance and phosphorylation levels. Data was analyzed with limma statistical methods and corrected for multiple hypothesis testing. Pathway analysis on differentially regulated proteins with ET (adjusted p-value p < 0.05) was performed in G:Profiler. RESULTS: Characterizing tissue responses to exercise carries the potential to unlock key pathways involved in the systemic response. Adipose tissue dynamics impact systemic metabolic health, however, proteomic and phosphoproteomic responses to ET have not been well characterized. Here, we focus on the impact of ET on adipose tissue proteomic and phosphoproteomic responses. In total, over 9,900 proteins and 29,000 distinct phosphorylation sites were quantified from WAT. Global proteomic and phosphoproteomics signatures reveled sex-specific training responses; in males 436 proteins and 999 phosphosites displayed differential expression (p < 0.05) following ET compared to only 49 proteins and 7 phosphosites in females. Top GO pathways enriched in male WAT included proteins involved in mitochondrial respiration and fatty acid flux, whereas females primarily displayed enrichment in extracellular remodeling proteins. CONCLUSIONS: The WAT proteome and phosphoproteome displayed enhanced responsiveness to ET in male vs. female rats. Pathway analysis suggests enhanced metabolic adaptations in the WAT of male rats following 8-wks of ET. Integration of additional multi-omics datasets generated in MoTrPAC will elucidate sex-specific molecular metabolic responses of WAT and other tissues. Supported by NIH Grant U24 DK112349