Tacrolimus Induced Hypertension and Vascular Remodeling Includes Mechanisms of Cellular Senescence-The Protective Effect of Valsartan

AIM: Calcineurin inhibitors (CNI) such as tacrolimus (Tac) are the first-line treatment to prevent transplant rejection. However, CNI have adverse effects on blood vessels and renal function, which may be linked to cellular senescence. Valsartan, a common angiotensin II type 1 receptor (AT₁R) blocker, exhibits anti-senescence properties. We tested the hypothesis that tacrolimus causes hypertension and microvascular remodeling that involves induction of senescence, and that valsartan is protective. METHODS: Microperfusion and wire myography were employed to assess the contractile and dilatory functions of renal afferent arterioles (Af-Art) and mesenteric arteries, respectively. The expression of components of the renin-angiotensin system (RAS) and senescence-associated biomarkers was investigated using qPCR and immunohistochemistry. RESULTS: Long-term administration of Tac activated the RAS. Tac-induced microvascular remodeling in mesenteric arteries and Af-Art was mitigated by treatment with valsartan. Mice treated with Tac exhibited increased vasoconstriction in response to angiotensin II and reduced dilation to acetylcholine. Both effects were abolished by valsartan. Additionally, senescence-associated biomarkers were upregulated in mesenteric and renal resistance arteries from Tac-treated mice. Co-administration of Tac with valsartan or ABT-263, a senolytic agent, rescued Tac-induced microvascular injury and reduced hypertension (conscious mice, noninvasive tail-cuff system). Treatment with the antihypertensive drug amlodipine normalized blood pressure and downregulated senescence-associated beta-galactosidase in mesenteric arteries. CONCLUSION: These findings suggest that cellular senescence contributes to Tac-induced microvascular injury and hypertension and demonstrate the effectiveness of senolytic treatment for protection. Valsartan could reduce senescence indirectly by lowering blood pressure; a direct anti-senescence effect might also play a role in this context.