米雪楠
中国医学科学院阜外医院 基因与临床实验室
BACKGROUND:The endothelium is the first line of defence against harmful microenvironment risks, and microRNAs (miRNAs) involved in vascular inflammation may be promising therapeutic targets to modulate atherosclerosis progression. In this study, we aimed to investigate the mechanism by which microRNA-216a (miR-216a) modulated inflammation activation of endothelial cells. Methods. A replicative senescence model of human umbilical vein endothelial cells (HUVECs) was established, and population-doubling levels (PDLs) were defined during passages. PDL8 HUVECs were transfected with miR-216a mimics/inhibitor or small interfering RNA (siRNA) of SMAD family member 7 (Smad7). Real-time PCR and Western blot assays were performed to detect the regulatory role of miR-216a on Smad7 and NF-κB inhibitor alpha (IκBα) expression. The effect of miR-216a on adhesive capability of HUVECs to THP-1 cells was examined. MiR-216a and Smad7 expression in vivo were measured using human carotid atherosclerotic plaques of the patients who underwent carotid endarterectomy (n = 41).RESULTS:Luciferase assays showed that Smad7 was a direct target of miR-216a. Smad7 mRNA expression, negatively correlated with miR-216a during endothelial aging, was downregulated in senescent PDL44 cells, compared with young PDL8 HUVECs. MiR-216a markedly increased endothelial inflammation and adhesive capability to monocytes in PDL8 cells by promoting the phosphorylation and degradation of IκBα and then activating NF-κB signalling pathway. The effect of miR-216a on endothelial cells was consistent with that blocked Smad7 by siRNAs. When inhibiting endogenous miR-216a, the Smad7/IκBα expression was rescued, which led to decreased endothelial inflammation and monocytes recruitment. In human carotid atherosclerotic plaques, Smad7 level was remarkably decreased in high miR-216a group compared with low miR-216a group. Moreover, miR-216a was negatively correlated with Smad7 and IκBα levels and positively correlated with interleukin 1 beta (IL1β) expression in vivo.CONCLUSION:In summary, our findings suggest a new mechanism of vascular endothelial inflammation involving Smad7/IκBα signalling pathway in atherosclerosis.
Disease markers 2020
The role of angiotensin II (Ang II) in hypertension has been clarified, but recent studies show that aging-associated arterial changes and those with hypertension as well as atherosclerosis may have some common pathogenesis. This study aimed to clarify the effects of Ang II on endothelial senescence by establishing a replicative senescence model of human umbilical vein endothelial cells (HUVECs) in vitro. The population-doubling level (PDL) was calculated, PDL5 and PDL25 respectively referred to cells cultured for 2 days and 30 days. Compared with Ang II-treated young PDL5 cells, chronic stimulation of Ang II significantly promoted the senescence-associated β-galactosidase activity and expression of senescence-related genes p16 and p21, slowed down cell growth rate, and decreased expression of longevity-related genes sirtuin1 as well as telomerase activity in senescent PDL25 cells (all P < 0.05). Moreover, expression of pro-inflammatory cytokines and adhesion molecules were up-regulated in Ang II-treated PDL25 cells (all P < 0.05). Ang II-induced senescent progression and inflammation were attenuated by angiotensin receptor blocker valsartan. In young PDL5 cells, Ang II promoted the endothelial viability including cell proliferation, migration, angiogenesis and cell adhesion to monocytes; however, chronic stimulation of Ang II suppressed the cell viability, promoted cell adhesion and apoptosis in senescent PDL25 cells, which could be ameliorated by short-term valsartan, but long-term valsartan had no effects. In addition, Ang II-induced senescent features could be partly recovered if Ang II was stopped at PDL20. These findings suggested that chronic stimulation of Ang II can accelerate the endothelial senescence process which is implicated in aging-related atherosclerosis.
Experimental gerontology 2019
Vascular endothelial senescence contributes to atherosclerosis and coronary artery disease (CAD), but the mechanisms are yet to be clarified. We identified that microRNA-216a (miR-216a) significantly increased in senescent endothelial cells. The replicative senescence model of human umbilical vein endothelial cells (HUVECs) was established to explore the role of miR-216a in endothelial ageing and dysfunction. Luciferase assay indicated that Smad3 was a direct target of miR-216a. Stable expression of miR-216a induced a premature senescence-like phenotype in HUVECs with an impairment in proliferation and migration and led to an increased adhesion to monocytes by inhibiting Smad3 expression and thereafter modulating the degradation of NF-κB inhibitor alpha (IκBα) and activation of adhesion molecules. Conversely, inhibition of endogenous miR-216a in senescent HUVECs rescued Smad3 and IκBα expression and inhibited monocytes attachment. Plasma miR-216a was significantly higher in old CAD patients (>50 years) and associated with increased 31% risk for CAD (odds ratio 1.31, 95% confidence interval 1.03-1.66; P = .03) compared with the matched healthy controls (>50 years). Taken together, our data suggested that miR-216a promotes endothelial senescence and inflammation as an endogenous inhibitor of Smad3/IκBα pathway, which might serve as a novel target for ageing-related atherosclerotic diseases.
Journal of cellular and molecular medicine 2018
The effect of tea intake on blood pressure (BP) is controversial. We performed a meta-analysis of randomised controlled trials to determine the changes in systolic and diastolic BP due to the intake of black and green tea. A systematic search was conducted in MEDLINE, EMBASE and the Cochrane Controlled Trials Register up to May 2014. The weighted mean difference was calculated for net changes in systolic and diastolic BP using fixed-effects or random-effects models. Previously defined subgroup analyses were performed to explore the influence of study characteristics. A total of twenty-five eligible studies with 1476 subjects were selected. The acute intake of tea had no effects on systolic and diastolic BP. However, after long-term tea intake, the pooled mean systolic and diastolic BP were lower by - 1·8 (95 % CI - 2·4, - 1·1) and - 1·4 (95 % CI - 2·2, - 0·6) mmHg, respectively. When stratified by type of tea, green tea significantly reduced systolic BP by 2·1 (95 % CI - 2·9, - 1·2) mmHg and decreased diastolic BP by 1·7 (95 % CI - 2·9, - 0·5) mmHg, and black tea showed a reduction in systolic BP of 1·4 (95 % CI - 2·4, - 0·4) mmHg and a decrease in diastolic BP of 1·1 (95 % CI - 1·9, - 0·2) mmHg. The subgroup analyses showed that the BP-lowering effect was apparent in subjects who consumed tea more than 12 weeks (systolic BP - 2·6 (95 % CI - 3·5, - 1·7) mmHg and diastolic BP - 2·2 (95 % CI - 3·0, - 1·3) mmHg, both P< 0·001). The present findings suggest that long-term ( ≥ 12 weeks) ingestion of tea could result in a significant reduction in systolic and diastolic BP.
The British journal of nutrition 2014
BACKGROUND:The development of peripheral arterial disease (PAD) is heterogeneous even in the presence of similar risk factors. Our aim was to determine whether inter-individual differences in leukocyte telomere length contribute to the susceptibility of PAD.METHODS:A total of 485 patients with PAD (defined by the ankle-brachial index) and 970 age- and gender-matched controls were recruited from seven rural communities in Henan Province in China. The relative leukocyte telomere length was determined by a quantitative PCR-based method. Two common promoter variants of the hTERT gene were genotyped to assess their effects on telomere length and the risk of PAD. In vivo luciferase assay was performed to study the transcriptional activity.RESULTS:After adjustment for vascular risk factors and genetic variants in the hTERT gene, individuals in the lowest and middle tertiles of telomere length had a significantly higher risk of PAD than did those in the highest tertile (odds ratio [OR] 1.73, 95% confidence interval [CI] 1.29-2.49 in the middle tertile; 3.15, 95%CI 2.31-4.29 in the lowest tertile). Haplotype analysis using the 2 variants (rs2735940 and rs2853669) showed that subjects with the at-risk C-C haplotype had shorter telomere length than those individuals with the T-T haplotype and consistently had 1.30-fold (OR 1.30, 95%CI 1.06-1.58; P=0.005) increased risk for PAD. The C-C haplotype had 43% lowered transcription activity of hTERT promoter (P<0.001).CONCLUSION:The associations between the functional haplotype of hTERT gene and telomere length and the risk of atherosclerotic PAD suggested that mean leukocyte telomere length may independently serve as a potential predictor of PAD.
PloS one 2012
