Overexpression of PTPN2 in Visceral Adipose Tissue Ameliorated Atherosclerosis via T Cells Polarization Shift in Diabetic Apoe-/- Mice

Abstract

Background/Aims: Dysregulated inflammation in adipose tissue, marked by increased pro-inflammatory T-cell accumulation and reduced regulatory T cells (Treg), contributes to diabetes-associated insulin resistance and atherosclerosis. However, the molecular mechanisms underlying T-cell-mediated inflammation in adipose tissue remain largely unknown. Methods: Sixty apolipoprotein E (ApoE-/-) mice were randomly divided into chow and diabetes groups. Diabetes was induced by a high-fat and high-sugar diet combined with low-dose streptozotocin. Then we transferred a recombinant adenovirus carrying the protein tyrosine phosphatase non-receptor type 2 (PTPN2) gene into epididymal white adipose tissue (EWAT) of ApoE-/- mice. After transfection, all mice were euthanized to evaluate the effects of PTPN2 on T cells polarization and atherosclerosis. Results: PTPN2 was downregulated in EWAT of diabetic ApoE-/- mice. PTPN2 overexpression in EWAT reversed the high Th1/Treg and Th17/Treg ratios in EWAT of diabetic mice. In addition, PTPN2 overexpression in EWAT could significantly reduce macrophages infiltration, the ratio of M1/M2 macrophages and the expression of pro-inflammatory cytokines in EWAT, improving insulin resistance. In aortic root lesions, the vulnerability index were significantly decreased by overexpression of PTPN2 in EWAT. Conclusion: These data suggested that PTPN2 overexpression in EWAT would inhibit systemic inflammation and increase the plaque stability via T cells polarization shift in diabetic mice.