Total flavonoids from the Carya cathayensis Sarg. leaves inhibit HUVEC senescence through the miR-34a/SIRT1 pathway
JOURNAL OF CELLULAR BIOCHEMISTRY
Authors: Guo, Yan; Xing, Liwan; Chen, Nipi; Gao, Chengxian; Ding, Zhishan; Jin, Bo
Abstract
Aging shows a significant relationship with changed vascular structure and function, and advancing age is a major nonmodifiable risk factor in the occurrence of cardiovascular diseases. The senescence of endothelial cells is one of the hallmarks of vascular aging and can induce vascular dysfunction. This study aimed to investigate the effect of total flavonoids (TFs) on human umbilical vein endothelial cells (HUVEC) senescence and identify the potential mechanisms involved. A HUVEC senescence model was induced by angiotensin II. The senescence markers, including senescence-associated beta-galactosidase (SA-beta-gal), p53, p21, and stagnate G0/G1, were measured. The effects of TFs on miR-34/ SIRT1 were examined by quantitative polymerase chain reaction analysis and Western blot analysis. TFs decreased the percentage of SA-beta-gal-positive cells and resulted in G0/G1 cell cycle arrest, while the percentage of cells in the S phase increased. Furthermore, TFs reduced miR-34a expression and increased the expression of SIRT1. After treatment with TFs and a miR-34a inhibitor, the percentage of SA-beta-gal-positive cells and the expression of miR-34a decreased, and the expression of SIRT1 increased. The TFs inhibited HUVEC senescence, and the mechanism was related to the miR-34a/Sirtuin1 pathway.
LncRNA-ANRIL inhibits cell senescence of vascular smooth muscle cells by regulating miR-181a/Sirt1
BIOCHEMISTRY AND CELL BIOLOGY
Authors: Tan, Pan; Guo, Yong-Hong; Zhan, Jun-Kun; Long, Li-Min; Xu, Mei-Li; Ye, Ling; Ma, Xin-Yu; Cui, Xing-Jun; Wang, Hai-Qin
Abstract
Background: Cardiovascular disease is one of the major threats to human life and health, and vascular aging is an important cause of its occurrence. Antisense non-coding RNA in the INK4 locus (ANRIL) is a kind of long non-coding RNA (lncRNA) that plays important roles in cell senescence. However, the role and mechanism of ANRIL in senescence of vascular smooth muscle cells (VSMCs) are unclear. Methods: Cell viability and cell cycle were evaluated using an MTT assay and flow cytometry analysis, respectively. Senescence-associated (SA)-beta-galactosidase (gal) staining was used to determine cell senescence. Dual luciferase reporter assays were conducted to confirm the binding of ANRIL and miR-181a, as well as miR-181a and Sirt1. The expression of ANRIL, miR-181a, and Sirt1 was determined using qRT-PCR and protein levels of SA-beta-gal and p53-p21 pathway-related proteins were evaluated by Western blotting. Results: ANRIL and Sirt1 were down-regulated, whereas miR-181a was up-regulated in aging VSMCs. In young and aging VSMCs, over-expression of ANRIL could down-regulate miR-181a and up-regulate Sirt1. MTT and SA-beta-gal staining assays showed that over-expression of ANRIL and inhibition of miR-181a promoted cell viability and inhibited VSMC senescence. The dual-luciferase reporter assay determined that miR-181a directly targets ANRIL and the 3'-UTR of Sirt1. Furthermore, over-expression of ANRIL inhibited cell cycle arrest and the p53-p21 pathway. Conclusion: ANRIL promotes cell viability and inhibits senescence in VSMCs, possibly by regulating miR-181a/Sirt1, and alleviating cell cycle arrest by inhibiting the p53-p21 pathway. This study provides novel insights for the role of ANRIL in the development of cell senescence.