Transplantation of skin mesenchymal stem cells attenuated AngII-induced hypertension and vascular injury

Skin mesenchymal stem cells (S-MSCs) revealed an important immunomodulatory activity to markedly suppress the formation of the atherosclerosis (AS) plaque by modulating macrophages, and also inhibit the development of experimental autoimmune encephalomyelitis (EAE) by regulating T helper 17 (Th17) cell differentiation. Macrophages and Th17 cells play important roles in hypertension. However, it remains unclear whether S-MSCs are capable of improving angiotensin (AngII)-induced hypertension by acting on inflammatory cells. Therefore, we studied a direct effect of S-MSC treatment on an AngII-induced hypertensive mouse model. Twenty-seven C57BL/6 (WT) mice were divided into three groups: Control group (WT-NC), AngII-infused group (WT-AngII), and S-MSC treatment group (WT-AngII + S-MSCs). In contrast to WT-AngII group, systolic blood pressure (SBP) and vascular damage were strikingly attenuated after tail-vein injection of S-MSCs. Numbers of Th17 cells in mouse peripheral blood of S-MSC treated group were significantly decreased, and IL-17 mRNA and protein levels were also reduced in the aorta and serum compared with WT-AngII group. Furthermore, macrophages in S-MSC treated group were switched to a regulatory profile characterized by a low ability to produce pro-inflammatory cytokine TNF-α and a high ability to produce anti-inflammatory cytokines Arg1 and IL-10. Mechanistically, we found that S-MSCs inhibited Th17 cell differentiation and induced M2 polarization. Moreover, we found proliferation and migration of S-MSCs were elevated, and expression of CXCR4, the receptor for Stromal derivated factor −1(SDF-1), was markedly increased in lipopolysaccharide (LPS)- stimulated S-MSCs. Given that SDF-1 expression was increased in the serum and aorta in AngII- induced hypertensive mice, the immunomodulatory effects exerted by S-MSCs involved the CXCR4/SDF-1 signaling. Collectively, our data demonstrated that S-MSCs attenuated AngII-induced hypertension by inhibiting Th17 cell differentiation and by modulating macrophage M2 polarization, suggesting that S-MSCs potentially have a role in stem cell based therapy for hypertension.