Arterial aging is a major risk factor for the occurrence of cardiovascular diseases. The aged artery is characterized by endothelial dysfunction and vascular smooth muscle cells altered physiology together with low-grade chronic inflammation. MicroRNA-34a (miR-34a) has been recently implicated in cardiac, endothelial, and endothelial progenitor cell senescence; however, its contribution to aging-associated vascular smooth muscle cells phenotype has not been explored so far. We found that miR-34a was highly expressed in aortas isolated from old mice. Moreover, its well-known target, the longevity-associated protein SIRT1, was significantly downregulated during aging in both endothelial cells and vascular smooth muscle cells. Increased miR-34a as well as decreased SIRT1 expression was also observed in replicative-senescent human aortic smooth muscle cells. miR-34a overexpression in proliferative human aortic smooth muscle cells caused cell cycle arrest along with enhanced p21 protein levels and evidence of cell senescence. Furthermore, miR-34a ectopic expression induced pro-inflammatory senescence-associated secretory phenotype molecules. Finally, SIRT1 protein significantly decreased upon miR-34a overexpression and restoration of its levels rescued miR-34a-dependent human aortic smooth muscle cells senescence, but not senescence-associated secretory phenotype factors upregulation. Taken together, our findings suggest that aging-associated increase of miR-34a expression levels, by promoting vascular smooth muscle cells senescence and inflammation through SIRT1 downregulation and senescence-associated secretory phenotype factors induction, respectively, may lead to arterial dysfunctions
MicroRNA-34a Induces Vascular Smooth Muscle Cells Senescence by SIRT1 Downregulation and Promotes the Expression of Age-Associated Pro-inflammatory Secretory Factors / I. Badi, I. Burba, C. Ruggeri, F. Zeni, M. Bertolotti, A. Scopece, G. Pompilio, A. Raucci. - In: JOURNALS OF GERONTOLOGY SERIES A-BIOLOGICAL SCIENCES AND MEDICAL SCIENCES. - ISSN 1079-5006. - 70:11(2015 Nov), pp. 1304-1311. [10.1093/gerona/glu180]
MicroRNA-34a Induces Vascular Smooth Muscle Cells Senescence by SIRT1 Downregulation and Promotes the Expression of Age-Associated Pro-inflammatory Secretory Factors.
G. PompilioPenultimo
;
2015
Abstract
Arterial aging is a major risk factor for the occurrence of cardiovascular diseases. The aged artery is characterized by endothelial dysfunction and vascular smooth muscle cells altered physiology together with low-grade chronic inflammation. MicroRNA-34a (miR-34a) has been recently implicated in cardiac, endothelial, and endothelial progenitor cell senescence; however, its contribution to aging-associated vascular smooth muscle cells phenotype has not been explored so far. We found that miR-34a was highly expressed in aortas isolated from old mice. Moreover, its well-known target, the longevity-associated protein SIRT1, was significantly downregulated during aging in both endothelial cells and vascular smooth muscle cells. Increased miR-34a as well as decreased SIRT1 expression was also observed in replicative-senescent human aortic smooth muscle cells. miR-34a overexpression in proliferative human aortic smooth muscle cells caused cell cycle arrest along with enhanced p21 protein levels and evidence of cell senescence. Furthermore, miR-34a ectopic expression induced pro-inflammatory senescence-associated secretory phenotype molecules. Finally, SIRT1 protein significantly decreased upon miR-34a overexpression and restoration of its levels rescued miR-34a-dependent human aortic smooth muscle cells senescence, but not senescence-associated secretory phenotype factors upregulation. Taken together, our findings suggest that aging-associated increase of miR-34a expression levels, by promoting vascular smooth muscle cells senescence and inflammation through SIRT1 downregulation and senescence-associated secretory phenotype factors induction, respectively, may lead to arterial dysfunctionsPubblicazioni consigliate
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