A PPAR?-lncRNA axis modulatesthermoneutral remodeling of white adipose tissue

Interplay between parenchymal energy-storing white adipose cells and thermogenic beige adipocytes contributes to obesity and insulin resistance. Irrespective of cellular origin or specialized niche, adipocytes require the activity of the nuclear receptor peroxisome proliferator activated receptor gamma (PPAR?) for proper function. Exposure to cold or adrenergic signaling enriches thermogenic cells though multiple pathways that act synergistically with PPAR?, however, the molecular mechanisms by which PPAR? licenses white adipose tissue (WAT) to preferentially adopt a thermogenic or white adipose fate in response to dietary cues or thermoneutral conditions are not fully elucidated. Here, we show that a PPAR?-long noncoding RNA (lncRNA) axis integrates canonical and noncanonical thermogenesis to restrain white adipose tissue heat dissipation during thermoneutrality and diet-induced obesity (DIO). Pharmacologic inhibition or genetic deletion of the lncRNA Lexis, enhances UCP-1 dependent and independent thermogenesis. Adipose tissue specific deletion of Lexis counteracted diet-induced obesity, improved insulin sensitivity, and enhanced energy expenditure. Single-nuclei transcriptomics revealed that Lexis regulates a distinct population of thermogenic adipocytes. We systematically map Lexis motif preferences and show that it regulates the thermogenic program through the activity of the metabolic GWAS gene and WNT modulator TCF7L2. Collectively, our studies uncover a new mode of crosstalk between PPAR? and WNT signaling that preserves white adipose tissue plasticity. Overall design: Bulk RNAseq was used for gene expression from Lexis WT or KO mice iWAT