Jianting Sheng, Shaohua Qi, Michael Chan, Elaine Wang, Xianlin Han, Willa A Hsueh, Li Yang, Stephen T C Wong
Obesity is associated with the enrichment of unsaturated triacylglycerol (TAG) species in adipose tissue, but the mechanism driving this selective lipid accumulation remains unclear. We investigated whether substrate-selective lipolysis contributes to the retention of unsaturated fatty acids (FAs) in obese adipose tissue. Lipidomic profiling revealed predominant enrichment of FA 18:1 and FA 18:2 in midlife-predominant obese adipose TAGs, and functional assays showed that adipose triglyceride lipase preferentially hydrolyzes saturated TAGs under conditions of sufficient substrate supply. These results identify lipase substrate selectivity as a mechanistic contributor to lipid remodeling in obesity and a potential target for modulating adipose lipid turnover.