Endothelial progenitor cells correlate with endothelial function in patients with coronary artery disease

Endothelial progenitor cells (EPC) predict morbidity and mortality in patients at cardiovascular risk.Patients with low EPC counts and impaired endothelial colony forming activity have a higher incidence for cardiovascular events compared to patients with high EPC counts and favorable colony forming activity. The pathophysiological basis for this finding may be an insufficient endothelial cell repair by EPC.We postulate that EPC influence coronary endothelial function which itself is relevant for the outcome of patients at cardiovascular risk. To test this hypothesis in humans, endothelial function was invasively assessed in 90 patients with coronary heart disease by quantitative coronary angiography during intracoronary acetylcholine infusion. Flow cytometry of mononuclear cells isolated from peripheral blood was performed to assess CD133(+) or CD34(+)/KDR(+) EPC. EPC function was assessed ex vivo by determination of endothelial colony forming units. Low EPC number as well as impaired endothelial colony forming activity correlated with severely impaired coronary endothelial function in univariate analysis. Multivariate analysis revealed that only the number of EPC predicts severe endothelial dysfunction independent of classical cardiovascular risk factors. Endothelial function closely correlates with the number of circulating EPC providing new mechanistic insights and options for risk assessment in patients with coronary heart disease.     

稳定性冠心病患者循环内皮祖细胞与冠状动脉病变严重程度的分析

目的观察稳定性冠心病患者循环内皮祖细胞(EPCs)数量与冠状动脉病变严重程度的关系。方法对80例冠状动脉造影患者(排除急性冠状动脉综合征、心肌梗死)作病变严重程度及危险因素分析;以CD133/KDR作为EPCs标记物,用流式细胞仪检测患者的CD133/KDR双标记细胞数量。结果外周血EPCs数量与年龄、血清肌酐清除率(Ccr)、左室心肌重量指数(LVMI)呈负相关(P值分别=0.004,0.015,0.014);冠心病伴高血压患者较不伴高血压者EPCs数量显著减少(P=0.004)。冠状动脉造影阳性者EPCs数量较阴性者显著降低(P<0.01);EPCs数量与Gensini评分呈负相关(n=49,r=-0.305,P=0.039)。结论在稳定性冠心病患者循环EPCs数量与心血管危险因素及冠状动脉病变相关。     

Endurance training increases the number of endothelial progenitor cells in patients with cardiovascular risk and coronary artery disease

OBJECTIVE: As regular physical exercise improves endothelial dysfunction and promotes cardiovascular health, we investigated the effect of training on angiogenesis by measuring the number of circulating endothelial progenitor cells (EPC), the level of EPC-mobilizing growth factors and tested vascular function by flow-mediated dilation (FMD) in patients with coronary artery disease (CAD) and cardiovascular risk factors (CVRF). In addition, degradation products of the NO pathway (NOx) were determined. METHODS AND RESULTS: Twenty patients with documented CAD and/or CVRF joined a 12-week supervised running training. Circulating EPCs--defined by the surface markers CD34, KDR and CD133--were measured at baseline and after exercise training by flow cytometry. We found a significant increase in circulating EPCs (2.9+/-0.4-fold increase; P < .0001), which was positively correlated with both, the change of FMD (r = .81, P < .001) and the increase of NOx synthesis (r = .83, P < .001). Plasma VEGF and erythropoietin did not change in response to exercise. However, we observed a positive correlation between the number of EPCs and erythropoietin at baseline (r = .70, P < .01) and after training (r = .73, P < .01). CONCLUSIONS: Regular exercise training augments the number of circulating EPCs in patients with CVRF and CAD and is associated with improved vascular function and NO synthesis.     

瑞舒伐他汀对老年稳定性冠心病患者外周血中血管内皮祖细胞的影响

目的通过观察老年稳定性冠心病患者应用瑞舒伐他汀或阿托伐他汀后,外周血中血脂水平及血管内皮祖细胞(endothelial progenitor cells,EPCs)频率的变化,探讨瑞舒伐他汀在治疗稳定性冠心病过程中的调脂及非调脂作用。方法选择稳定性冠心病患者60例,根据用药不同随机分为3组,每组20例:A组:瑞舒伐他汀10 mg/d;B组:阿托伐他汀20 mg/d;C组:安慰剂(淀粉)1片/d。4周后,全自动生化分析仪检测患者血脂水平,流式细胞仪检测患者外周血中EPCs(CD34~+、血管内皮生长因子受体~+)频率。结果治疗前,3组患者TC、TG、LDL-C、HDL-C水平及外周血中EPCs频率差异无统计学意义(P>0.05)。治疗4周后,与C组比较,A组和B组患者TC、TG、LDL-C水平均明显降低,差异有统计学意义(P<0.05);与C组比较,A组和B组患者外周血中EPCs频率明显升高,差异有统计学意义(P<0.05)。结论瑞舒伐他汀不仅可以有效降低老年稳定性冠心病患者TC、LDL-C及TG水平,还可以有效升高外周血中EPCs频率,同时发挥调脂及非调脂作用,对减少心血管事件的发生起着重要的作用。     

Circulating endothelial progenitor cells are reduced in SLE in the absence of coronary artery calcification

Circulating endothelial progenitor cells (EPCs) are reduced in patients with systemic lupus erythematosus (SLE). A reduced number of EPCs are associated with the presence of atherosclerosis in other populations. We sought to determine whether the reduction in EPC numbers in SLE is dependent on the presence of advanced coronary artery calcification (CAC). Patients with SLE had previous coronary calcium scores which placed them in either the >75th percentile or <25th percentile for their age. Seventeen patients with SLE and 13 healthy controls (HC) were included in the study. White blood cells were stained for EPC and progenitor cell markers including CD34, CD133, and VEGFR and analyzed by flow cytometry. SLE patients had repeated coronary imaging as well as carotid ultrasound. There was no difference in age between groups. SLE patients with advanced CAC were more likely to be hypertensive, to be smokers, and to have longer disease duration than SLE patients without CAC. SLE patients without evidence of CAC had a significantly lower number of EPCs (CD34+/CD133+/VEGFR+) compared to HC (median (IQR)) 0 (0, 6.7) vs. 10.2 (5.8, 12.3) (P = 0.02). Total numbers of PCs (CD133+/CD34+) were not significantly decreased in patients with SLE ((mean ± SEM) 1,007 ± 154 vs. 824 ± 170 (P = 0.20)). No significant difference was seen in EPC number between SLE patients without CAC and those with advanced CAC. Increased carotid intima-media thickness did not correlate with CAC or EPC number in SLE patients. Reduced numbers of EPCs in SLE patients may be observed compared to HC even in the absence of CAC. Differences in measured risk factor profiles and depletion of total circulating PCs do not fully explain this finding.     

Reduced numbers of circulating endothelial progenitor cells in patients with coronary artery disease associated with long-term statin treatment

While statin treatment may transiently mobilize endothelial progenitor cells (EPCs), the dose-dependent effects of a continuous statin therapy on EPCs in patients with chronic coronary artery disease (CAD) have not been analyzed. In 209 patients with angiographically documented CAD, 144 of which received 10-40 mg/day of statins for >8 weeks, the EPC number was determined by flow cytometry directly (CD34(+)/KDR(+), n=58) and after in vitro-culture (1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine-labeled Ac-LDL (DiI-Ac-LDL(+))/lectin(+), n=209). EPC function was assessed by the formation of colony forming units (CFUs). Univariate analysis revealed that the dose of continuous statin therapy inversely correlated with the EPC number. Treatment with 40 mg/day significantly reduced EPC counts. Multivariate analysis unveiled the statin dose and extent of CAD as independent predictors of reduced EPC numbers. Conversely, obesity predicted increased counts, while CFU development was not detectable in all patients and augmented in females and smokers but not in statin-treated patients. Compared with matched controls, statin-treated patients showed significantly reduced absolute and relative EPC counts. In a prospective analysis, initiation of statin therapy significantly diminished the number of circulating and isolated EPCs after 3 but not after 1 month(s). Thus, the statin dose during chronic and continuous treatment independently predicts reduced numbers of circulating as well as isolated EPCs in patients with CAD.     

Statin therapy in patients with coronary artery disease improves the impaired endothelial progenitor cell differentiation into cardiomyogenic cells

Human endothelial progenitor cells (EPCs) can differentiate into cardiomyogenic cells in vitro. We tested the effects of statin therapy on the differentiation rate of EPCs from patients with coronary artery disease (CAD), who may benefit from autologous cell therapy.EPCs from 3 age-matched groups were tested: No CAD (n = 13), CAD patients with (n = 10) or without (n = 16) statin therapy. From 4 CAD patients, EPCs were tested before and after 4 weeks of therapy with 20 mg atorvastatin. After 6 days of co-culture with rat neonatal cardiomyocytes, EPC differentiation was quantified by immunostaining for -sarcomeric actinin flow cytometry analysis. After 6 days of co-culture, the percentage of -sarcomeric actinin–positive EPCs was significantly (p = 0.014) higher in EPCs from adults without CAD (8.07% ± 1.48% of EPCs) compared to EPCs from CAD patients without statin (3.56% ± 0.72%). Importantly, patients with statin therapy revealed significantly higher numbers of -sarcomeric actinin-positive EPCs (6.36% ± 0.69%, p = 0.01) compared to CAD patients without statin. In addition, statin therapy resulted in a significant (p = 0.017) increase of EPC differentiation in all 4 CAD patients investigated before and 4 weeks after statin therapy. The survival of EPCs did not differ between the different groups suggesting that the regulation of EPC differentiation is not secondary to altered EPC survival. In vitro, EPC treatment with 0.1 µM atorvastatin did not affect EPC differentiation (116.15% ± 49.11% of control).EPCs from patients with CAD display impaired differentiation into cardiomyogenic cells. This defect can be improved by in vivo, statin therapy.     

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.     

Circulating endothelial progenitor cells, C-reactive protein and severity of coronary stenosis in Chinese patients with coronary artery disease.

We sought to investigate whether numbers and activity of circulating endothelial progenitor cells (EPCs) correlate with severity of coronary stenosis as well as cardiovascular risk factors in patients with stable coronary artery disease (CAD). Number of circulating EPCs was analyzed in 104 consecutive patients with proven or clinically suspected CAD. Adhesive and migratory activity was also determined. The number of EPCs was lower in patients with a single diseased coronary artery (Group II, n=35, p<0.05 vs. Group I) or multiple diseased arteries (Group III, n=25, p<0.01 vs. Group I, p<0.05 vs. Group II) compared to those with normal coronary arteries (Group I, n=44). The number of EPCs was also related with angiographic Gensini score (r=-0.355, p=0.006). In addition, concentrations of C-reactive protein (CRP) were elevated in patients with CAD, and positively correlated with Gensini score (r=0.476, p=0.001). As for the risk factors, the number of EPCs was also inversely correlated with age (p=0.001), high sensitivity-CRP (p=0.012), hypertension (p=0.042) and family history of CAD (p=0.043). Most importantly, the migratory capacity of EPCs was compromised in patients with CAD, and inversely correlated with the angiographic Gensini score (r=-0.315, p=0.021). EPCs isolated from patients with CAD also showed an impaired adhesive activity (p<0.05). In conclusion, in patients with stable CAD, reduction in the number and impairment in the function of circulating EPCs were correlated with the severity of coronary stenosis. CRP may play an important role in reducing the number of EPCs and accelerating atherosclerosis. Given the important role of EPCs in neovascularization of ischemic tissue, a decrease in the number and activity of EPCs may contribute to the impaired vascularization in patients with CAD.     

冠心病患者胰岛素水平与内皮祖细胞及冠状动脉病变的相关性

目的 探讨冠心病患者不同胰岛素水平与循环内皮祖细胞(EPC)数量、功能及冠状动脉病变程度的关系并探讨相关临床意义.方法 69例经选择性冠状动脉造影证实的冠心病患者,按胰岛素水平高低分为胰岛素抵抗(IR)组和胰岛素敏感(IS)组,另设25例健康对照者.采集研究对象外周血以激酶插入区域受体(KDR)和CD133双阳性为循环EPC标记行流式细胞分析,同时采血进行EPC的分离培养,7 d后鉴定并检测增殖及迁移能力,将各组的一般临床资料,循环EPC数量、迁移、增殖能力指标、稳态模型胰岛素抵抗指数(HOMA-IR)及冠状动脉病变Gensini评分进行统计学分析.结果 IR组循环EPC数量明显少于IS组[(0.34±0.08)‰比(0.47±0.09)‰,P<0.01],HOMA-IR自然对数与循环EPC数量呈负相关(r=-0.291,P=0.01),循环EPC数量与Gensini评分呈负相关(r=-0.3984,P=0.006).IR组的增殖能力和迁移能力均低于IS组减弱(P<0.05).结论 冠心病患者血清胰岛素水平与循环EPC数量呈负相关.循环EPC数量及功能与冠状动脉病变程度呈负相关;IR或高胰岛素血症可能部分通过损害循环EPC的数量及功能,从而影响冠状动脉病变程度.     

Genetic engineering with endothelial nitric oxide synthase improves functional properties of endothelial progenitor cells from patients with coronary artery disease: an in vitro study

Recent studies have reported a marked impairment in the number and functions of endothelial progenitor cells (EPCs) in patients with coronary artery disease (CAD). In view of an important role of eNOS in angiogenesis, in the present study, we evaluated the effects of eNOS gene transfer in ex vivo expanded EPCs isolated from patients with CAD. The expanded EPCs were transfected with mammalian expression vector pcDNA3.1-eNOS containing the full-length human eNOS gene using lipofectamine. About 35–40% of the eNOS–EPCs had higher expression of eNOS as compared to untransfected EPCs. EPCs transfected with pcDNA3.0-EGFP, the plasmid vector expressing green fluorescent protein (GFP) were used as control. The untransfected, GFP-transfected and eNOS-transfected EPCs were compared in terms of important functional attributes of angiogenesis such as proliferation, migration, differentiation and adhesion/integration into tube-like structures in vitro. Functional studies revealed that in the presence of defined growth conditions, compared to the untransfected and GFP-transfected cells, eNOS–EPCs from patients with CAD have a significant increase in [³H] thymidine-labeled DNA (P < 0.01), migration (14.6 ± 1.8 and 16.5 ± 1.9 vs. 23.5 ± 3.4 cells/field, P < 0.01), ability to differentiate into endothelial-like spindle-shaped cells (46 ± 4.5 and 56.5 ± 2.1 vs. 93.2 ± 6.6 cells/field, P < 0.001) and also incorporation into tube-like structures on the matrigel (GFP-EPCs: 21.25 ± 2.9 vs. GFP-eNOS-EPCs: 34.5 ± 5.5 cells/field, P < 0.05). We conclude that eNOS gene transfection is a valuable approach to augment angiogenic properties of ex vivo expanded EPCs and eNOS-modified EPCs may offer significant advantages than EPCs alone in terms of their clinical use in patients with myocardial ischemia.