Expression of the Renin-Angiotensin System in the Heart, Aorta, and Perivascular Adipose Tissue in an Animal Model of Type 1 Diabetes.

This study examined the expression of the renin-angiotensin system (RAS) and inflammatory markers in cardiovascular complications associated with long-term type 1 diabetes (T1D) using a rat model. After 24 weeks of streptozotocin-induced T1D, the animals exhibited metabolic alterations indicative of both cardiac and renal dysfunction. Tissue-specific dysregulation of RAS components and pro-inflammatory markers were observed in the heart, aorta, and perivascular adipose tissue (PVAT). In the heart, there was a significant upregulation of both classical (AT1R, 1.00 (0.22) vs. 1.70 (0.45) R.U.) and counter-regulatory RAS components (ACE2, 1.00 (0.43) vs. 1.96 (0.67) R.U.; p < 0.001) and MasR (1.00 (0.56) vs. 1.33 (0.29) R.U.; p = 0.004). The aorta displayed increased expression of classical RAS components alongside a significant reduction in ACE2 expression (1.00 (0.74) vs. 0.51 (0.48) R.U.; p < 0.032). Notably, PVAT showed a significant overexpression of classical RAS components (ACE 1.00 (0.22) vs. 4.08 (1.32) R.U.; p < 0.001, AT1R 1.00 (0.59) vs. 7.22 (4.14) R.U.; p < 0.001) and MasR (1.00 (0.70) vs. 4.52 (1.91) R.U.; p < 0.001), accompanied by increased expression of TNFα and ADAM17. These findings suggest that long-term T1D induces tissue-specific activation patterns of the RAS and inflammatory pathways within the cardiovascular system, which may contribute to the progression of diabetic cardiovascular complications. Therapeutic targeting of RAS components may represent a viable strategy for mitigating cardiovascular damage in T1D.