Mitochondrial dysfunction-mediated decline in angiogenic capacity of endothelial progenitor cells is associated with capillary rarefaction in patients with hypertension via downregulation of CXCR4/JAK2/SIRT5 signaling.

BACKGROUND: Hypertensive patients exhibit decline in capillary density and endothelial progenitor cells (EPCs). However, whether capillary rarefaction in hypertension is associated with defect angiogenesis of EPCs remains unknown. We hypothesized that impaired mitochondrial function of late EPCs in hypertension is associated with the structural lack of capillary microcirculation via deficient CXCR4/JAK2/SIRT5 signaling. METHODS: We performed capillary microcirculation detection in hypertensive patients and healthy subjects. Angiogenic capacity and mitochondrial function of circulating EPCs were evaluated. The underlying mechanisms were further investigated by genetic inhibition and overexpression. FINDINGS: Capillary density of nail fold and eye fundus were significantly reduced in hypertensive patients, which was paralleled to decreased in vitro late EPC function and in vivo angiogenic capacity. Meanwhile the decline of EPC function in hypertension was accompanied by impaired mitochondrial ultrastructure, diminished mitochondrial membrane potential, reduced oxygen consumption, increased ROS generation and NADH level. Rotenone induced inhibition of oxygen consumption rate, excessive ROS generation and loss of MMP, which markedly decreased the in vitro functions of EPCs. Furthermore, SIRT5 expression of EPCs in hypertension was markedly reduced, which was correlated to mitochondrial dysfunction. CXCR4 gene transfer enhanced SIRT5 expression, improved mitochondrial functions and augmented angiogenic capacity of EPCs. The beneficial impacts of SIRT5 up-regulation on late EPC-mediated angiogenesis can be abrogated by blockade of CXCR4/JAK2/SIRT5 signaling pathway. INTERPRETATION: Mitochondrial dysfunction-mediated fall in angiogenic capacity due to deficient CXCR4/JAK2/SIRT5 signaling of late EPCs is probably responsible for the capillary rarefaction in hypertension. Our findings provide insight into the potential of EPC mitochondria as a novel target for the treatment of hypertension-related loss of microvascular density. FUNDS: National Nature Science Foundation of China, 973Program, the Nature Science Foundation of Guangdong.

First-generation versus second-generation drug-eluting stents in patients with chronic kidney disease: a systematic review and meta-analysis.

BACKGROUND: Chronic kidney disease (CKD) patients are associated with very high rate of adverse cardiovascular outcomes after drug-eluting stents (DES) implantation. The clinical outcomes of second-generation DES versus first-generation DES in CKD patients remain controversial. OBJECTIVE: The aim of the current study was to perform a systematic review and meta-analysis to assess the safety and efficacy of second-generation DES versus first-generation DES in CKD patients. METHODS: A systematical search of databases of PubMed, EMBASE, and Cochrane Library was conducted for eligible studies comparing the clinical outcomes of first-generation DES versus second-generation DES. Sirolimus-eluting and paclitaxel-eluting stents were classified as first-generation DES, and everolimus-eluting, zotarolimus-eluting, and biolimus-eluting stent (BES) were classified as second-generation DES. A pooled odds ratio (OR) and 95% confidence interval (CI) were used to summary the estimates. Heterogeneity, subgroup analysis, sensitivity analysis and publication bias were also performed. RESULTS: We identified 14 trials involving 9,542 patients with CKD undergoing percutaneous coronary intervention. First-generation DES implantation was associated with higher risk of long-term all-cause mortality (OR, 1.31; 95% CI, 1.02-1.69; P = 0.04; I2 = 0%), in stent restenosis (OR, 1.69; 95% CI, 1.14-2.49; P = 0.008; I2 = 49%) and stent thrombosis (OR, 1.64; 95% CI, 1.00-2.69; P = 0.05; I2 = 49%) compared with second-generation DES implantation. First-generation DES and second-generation DES showed similar efficacy in decreasing risk of repeat revascularization, myocardial infarction (MI), or major adverse cardiac events (MACE) between first-generation and second-generation DES implantation. CONCLUSIONS: In CKD patients, the use of second-generation DES was associated with lower risk of long-term all-cause mortality, in stent restenosis and stent thrombosis as compared with first-generation DES. No differences were found regarding repeat revascularization, MI, and MACE.

Lacidipine improves endothelial repair capacity of endothelial progenitor cells from patients with essential hypertension.

BACKGROUND: Endothelial progenitor cells (EPCs) play a critical role in maintaining the integrity of vascular endothelium following arterial injury. Lacidipine has a beneficial effect on endothelium of hypertensive patients, but limited data are available on EPCs-mediated endothelial protection. This study tests the hypothesis that lacidipine treatment can improve endothelial repair capacity of EPCs from hypertensive patients through increasing CXC chemokine receptor four (CXCR4) signaling. METHODS: In vivo reendothelialization capacity of EPCs from hypertensive patients with or without in vitro lacidipine treatment was examined in a nude mouse model of carotid artery injury. Expression of CXCR4 and alteration in migration and adhesion functions of EPCs were evaluated. RESULTS: Basal CXCR4 expression was markedly reduced in EPCs from hypertensive patients compared with normal subjects. In parallel, the phosphorylation of Janus kinase-2 (JAK-2) of EPCs, a CXCR4 downstream signaling, was also significantly decreased. Lacidipine promoted CXCR4/JAK-2 signaling expression of in vitro EPCs. Transplantation of EPCs pretreated with lacidipine significantly accelerated in vivo reendothelialization. The enhanced in vitro function and in vivo reendothelialization capacity of EPCs were inhibited by shRNA-mediated knockdown of CXCR4 expression or pretreatment with JAK-2 inhibitor AG490, respectively. In hypertensive patients, lacidipine treatment for 4 weeks also resulted in an upregulation of CXCR4/JAK-2 signaling of EPCs, which was associated with augmented EPCs-mediated reendothelialization and improved endothelial function. CONCLUSION: Deterioration of CXCR4 signaling may lead to impaired EPCs-mediated reendothelialization of hypertensive patients. Lacidipine-modified EPCs via a partially CXCR4 signaling contribute to enhanced endothelial repair capacity in hypertension.