Endothelial TFEB improves glucose intolerance via upregulation of IRS1 and IRS2

To determine whether endothelial TFEB is critical for glucose metabolism in vivo, we utilized EC-selective TFEB knockout mice and EC selective TFEB transgenic mice fed a high fat diet (HFD). EC-TFEB knockout mice exhibited significantly impaired glucose tolerance compared with control mice. Consistently, EC-TFEB transgenic mice showed improved glucose intolerance. In primary human ECs, small interfering RNA-mediated TFEB knockdown blunts the Akt signaling. adenovirus-mediated overexpression of TFEB consistently activates Akt signaling and significantly increases glucose uptake in ECs. Mechanically, TFEB upregulates insulin receptor substrate 1 and 2 (IRS1 and IRS2). TFEB increases IRS2 transcription measured by reporter gene and chromatin immunoprecipitation assays. Furthermore, we found that TFEB increases IRS1 protein via downregulation of microRNAs (miR-335, miR-495 and miR548o). In vivo, Akt signaling in the skeletal muscle and adipose tissue was significantly impaired in EC-TFEB knockout mice and consistently improved in EC-TFEB transgenic mice on HFD Comparison of human endothelial small RNA profiles infected with adenovirus encoding LacZ or adenovirus encoding TFEB (4 replicates for each group).