White and brown adipose tissues are highly vascularized organs, capable of plasticity based on metabolic demands and energy expenditure, which if maladaptive can lead to insulin resistance. Critical gaps remain in our understanding of how angiogenesis impacts adipose tissue dysfunction and overall metabolism. MicroRNAs (miRs) are implicated in the regulation of the angiogenic response to pathophysiological stimuli. Function of miRNAs regulating the angiogenic response in diet-induced insulin resistance remains poorly understood. Using a miRNA-Seq approach, we identified that miR-409-3p expression was significantly increased in endothelial cells (ECs) of brown adipose tissue (BAT) of diet-induced obese (DIO) mice and in human diabetic plasma samples compared to nondiabetic patients. Overexpression of miR-409-3p markedly inhibited EC growth and migration, whereas miR-409-3p inhibition had the opposite effects. miR-409-3p targets the 3’UTR of Zinc Finger E-box binding Homeobox 1 (ZEB1). Overexpression of miR-409-3p decreased ZEB1 expression in ECs and in human subcutaneous white adipose tissue (sWAT). SiRNA knock down of ZEB1 expression in ECs phenocopied the effects of miR-409-3p overexpression and significantly decreased cell proliferation and migration. In addition, 3T3-L1 cells co-cultured with supe harvested from ECs deficient in miR-409-3p had increased expression of brown fat markers (UCP1, Cidea, PGC1-α) by RT-qPCR and Western blot analyses. Systemic intravenous delivery of LNA-anti-miR-409-3p inhibitor to DIO mice significantly increased angiogenesis by CD31 staining, accompanied by higher UCP-1 in BAT and sWAT by RT-qPCR, Western blot and immunohistochemistry analyses, while improving glucose tolerance and overall metabolism. miR-409-3p plays a key regulatory role between impaired angiogenesis in diet-induced obesity and adipose tissue dysfunction, an effect that could be exploited for therapeutic intervention in obesity-induced insulin resistance.
D.R. Becker-Greene: None. H. Li: None. W. Wu: None. D. Ozdemir: None. I. Hollan: None. M.W. Feinberg: None. B. Icli: None.
American Diabetes Association (1-16-JDF-046 to B.I.)