Disturbed angiogenic activity of adipose-derived stromal cells obtained from patients with coronary artery disease and diabetes mellitus type 2.

BACKGROUND: Multipotent mesenchymal stem/stromal cells (MSC) including adipose-derived stromal cells (ADSC) have been successfully applied for cardiovascular diseases treatment. Their regenerative potential is considered due to the multipotency, paracrine activity and immunologic privilege. However, therapeutic efficacy of autologous MSC for myocardial ischemia therapy is modest. We analyzed if ADSC properties are attenuated in patients with chronic diseases such as coronary artery disease (CAD) and diabetes mellitus type 2 (T2DM). METHODS AND RESULTS: ADSC were isolated from subcutaneous fat tissue of patients without established cardiovascular diseases and metabolic disorders (control group, n = 19), patients with CAD only (n = 32) and patients with CAD and T2DM (n = 28). ADSC phenotype (flow cytometry) was CD90(+)/CD73(+)/CD105(+)/CD45(-)/CD31(-) and they were capable of adipogenic and osteogenic differentiation. ADSC morphology and immunophenotype were similar for all patients, but ADSC from patients with CAD and T2DM had higher proliferation activity and shorter telomeres compared to control patients. ADSC conditioned media stimulated capillary-like tubes formation by endothelial cells (EA.hy926), but this effect significantly decreased for patients with CAD (p = 0.03) and with CAD + T2DM (p = 0.017) compared to the control group. Surprisingly we revealed significantly higher secretion of some pro-angiogenic factors (ELISA) by ADSC: vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF) for patients with CAD and HGF and placental growth factor (PlGF) for patients with CAD + T2DM. Among angiogenesis inhibitors such as thrombospondin-1, endostatin and plasminogen activator inhibitor-1 (PAI-1) level of PAI-1 in ADSC conditioned media was significantly higher for patients with CAD and CAD + T2DM compared to the control group (p < 0.01). Inhibition of PAI-1 in ADSC conditioned media by neutralizing antibodies partially restored ADSC angiogenic activity (p = 0.017). CONCLUSIONS: ADSC angiogenic activity is significantly declined in patients with CAD and T2DM, which could restrict the effectiveness of autologous ADSC cell therapy in these cohorts of patients. This impairment might be due to the disturbance in coordinated network of pro- and anti-angiogenic growth factors secreted by ADSC. Changes in ADSC secretome differ between patients with CAD and T2DM and further investigation are necessary to reveal the MSC-involved mechanisms of cardiovascular and metabolic diseases and develop novel approaches to their correction using the methods of regenerative medicine.

Hyperlipoproteinemia(a) and Severe Coronary Artery Lesion Types.

Diffuse atherosclerosis and calcification of the coronary arteries (CA) create serious difficulties for coronary artery bypass grafting (CABG). The aim of this study was to compare demographic indicators, lipids, and clinical results one year after CABG in patients with different phenotypes of coronary artery (CA) disease. In total, 390 patients hospitalized for elective CABG were included in a single-center prospective study. Demographic data, lipids (total, low-density lipoprotein and high-density lipoprotein cholesterol, and triglycerides), and lipoprotein(a) (Lp(a)) concentrations were analyzed for all patients. Major adverse cardiovascular events (MACE) included myocardial infarction, stroke, percutaneous coronary intervention, and death from cardiac causes within one year after surgery. No significant outcome differences were found between the groups with diffuse vs. segmental lesions, nor the groups with and without calcinosis for all studied parameters except for Lp(a). Median Lp(a) concentrations were higher in the group of patients with diffuse compared to segmental lesions (28 vs. 16 mg/dL, p = 0.023) and in the group with calcinosis compared to the group without it (35 vs. 19 mg/dL, p = 0.046). Lp(a) ≥ 30 mg/dL was associated with the presence of diffuse lesions (OR = 2.18 (95% CI 1.34-3.54), p = 0.002), calcinosis (2.15 (1.15-4.02), p = 0.02), and its combination (4.30 (1.81-10.19), p = 0.0009), irrespective of other risk factors. The risk of MACE within one year after CABG was higher for patients with combined diffuse and calcified lesions vs. patients with a segmental lesion without calcinosis (relative risk = 2.38 (1.13-5.01), p = 0.02). Conclusion: Diffuse atherosclerosis and coronary calcinosis are associated with elevated Lp(a) levels, independent of other risk factors. The risk of MACE in the first year after surgery is significantly higher in patients with diffuse atherosclerosis and coronary calcinosis, which should be considered when prescribing postoperative treatment for such patients.

Association of lipoprotein(a) level with short- and long-term outcomes after CABG: The role of lipoprotein apheresis.

OBJECTIVE: To evaluate the association of lipoprotein(a) [Lp(a)] level with short- and long-term outcomes after coronary artery bypass grafting (CABG) and to assess the effect of a 12 month course of weekly lipoprotein apheresis on vein graft patency and coronary atherosclerosis course in post-CABG patients with hyperlipidemia. METHODS: This study was performed in patients after successful CABG and consisted of three parts: a) a retrospective part with computed tomography assessment of vein graft patency in patients with first-year recurrence of chest pain after CABG (n = 102); b) a prospective trial with evaluation of cardiovascular outcomes during follow up time up to 15 years in relation to baseline Lp(a) levels (n = 356); c) an 12-months interventional controlled study in 50 patients with low-density lipoprotein cholesterol (LDL-C) levels >2.6 mmol/L prior to the operation despite statin treatment that allocated into 2 groups: active (n = 25, weekly apheresis by cascade plasma filtration (CPF) plus atorvastatin), and control (n = 25, atorvastatin alone). RESULTS: Patients subjected to computed tomography were divided in two groups: 66 (65%) with at least one vein graft occlusion and 36 (35%) without occlusions. Lp(a) levels were significantly higher in patients with occluded grafts with a median (95% confidence intervals (CI)) of 24 (17-42) mg/dL vs. 12 (6-24) mg/dL in patients with patent grafts, p < 0.01. Over a mean of 8.5 ± 3.5 years (range 0.9-15.0 years), the primary and secondary endpoints were registered in 46 (13%) and 107 (30%) patients, respectively. Patients with Lp(a) ≥30 mg/dL were at significantly greater risk for the primary endpoint (hazard ratio (HR) 2.98, 95% confidence interval (CI) 1.76-5.03, p < 0.001) and secondary endpoint (HR 3.47, 95%CI 2.48-4.85, p < 0.001) than patients with Lp(a) values <30 mg/dL. During the CPF procedure LDL-C levels decreased by 59 ± 14%, Lp(a) levels by 49 ± 15. The frequency of vein graft occlusions at study end was 14.3% (11 of 77) in the apheresis group and 27.4% (23 of 84) in the control group, p < 0.05. Progression of atherosclerosis was obtained in 26 (14.2%) segments of native coronary arteries in the apheresis group and in 50 (25.0%) segments of the control group. Regression signs were found in 30 (16.4%) and 19 (9.5%) segments, stabilization in 127 (69.4%) and 131 (65.5%) segments, respectively (χ2 = 9.37, p < 0.01). A Lp(a) level higher than 30 mg/dL was associated with a three-fold increased risk of vein grafts occlusion during first year after CABG, p < 0.001. CONCLUSION: Our data suggest that elevated Lp(a) is associated with a significantly increasing rate of one-year vein graft occlusions and adverse long-term cardiovascular outcomes whereas the use of lipoprotein apheresis improves vein graft patency during the first year after CABG.

Atrial appendage transcriptional profile in patients with atrial fibrillation with structural heart diseases.

During the last few years DNA microarray studies of gene expression changes in human atrial tissues from patients with and without atrial fibrillation (AF) have been performed. For this purpose, tissue samples are usually collected from AF patients undergoing open heart surgery. These investigations have limitations associated with the unavoidable heterogeneity of compared groups which is due to the presence of various structural changes accompanying different sets of underlying heart diseases in both groups. It is thus reasonable to compare the atrial tissue samples from AF patients with those from individuals without signs of cardiovascular disease. To address this, we selected the atrial tissue samples from 12 AF patients (who underwent open heart surgery) and compared them with control atrial tissue samples from 10 individuals with no signs of cardiovascular diseases (those who died due to street accident). cDNA microarray method and reverse transcription-polymerase chain reaction (RT-PCR) analysis were used to identify genes which can discriminate between control and pathologically altered atrial tissues. Thirty-nine genes were found to be differentially expressed in pathologically altered tissues samples independently of the type of the underlying structural heart disease. These genes are involved in signal transduction, gene transcription regulation, cell proliferation, and apoptosis. The greatest alterations were observed for NOR1, DEC1, MSF, and Bcl2A1 genes (5 to 28-fold decrease, P < 0.05). Additional studies are needed to determine the specific role of each selected gene in pathophysiological changes leading to AF.

Circulating bone marrow stem/progenitor cells in vascular atherogenesis and in the noninvasive diagnosis of coronary stenosis.

Using autopsy specimens and clonal technique, the authors showed that hematopoietic and stromal stem colony-forming units are present in human atheromatous vascular intima. Stromal colony-forming units were also detected in the mononuclear fraction of the blood of patients with hyperlipidemia and coronary stenosis, and were not found in the peripheral blood of normolipidemic volunteers. Using flow cytometry, the absence of stromal circulating colony-forming units in healthy volunteers and their presence in coronary patients was confirmed. It was thought that the presence of circulating stromal precursors with a certain phenotype and variations in their level in blood could serve as an informative noninvasive indicator of coronary stenosis.

Association of lipoprotein(a) excess with early vein graft occlusions in middle-aged men undergoing coronary artery bypass surgery.

OBJECTIVE: To assess the relationship of lipoprotein(a) to early vein graft occlusions in patients after coronary artery bypass grafting. METHODS: We studied 102 male patients (mean age 52.3 +/- 8.6 years) with chest pain occurrence during the first year (mean time 5.3 +/- 3.0 months) after surgical myocardial revascularization. Graft patency was examined by electron-beam computed tomography (n = 102) and quantitative coronary angiography (n = 31). RESULTS: Patients were divided into 2 groups according to graft patency data: 66 (65%) with occlusions and 36 (35%) without occlusions at follow-up. No significant differences were found between the groups concerning age, smoking, family history of coronary heart disease, previous myocardial infarction, hypertension, serum lipids, and apolipoprotein B. Lipoprotein(a) level was significantly higher in patients with occluded grafts with a median (95% confidence intervals) of 24 mg/dL (17-42 mg/dL) versus 12 mg/dL (6-24 mg/dL) in patients with patent grafts, P <.01. More patients with nonoccluded grafts were taking statins postoperatively: 42% versus 18% of patients with occluded grafts, P <.05. The sensitivity and specificity of electron-beam computed tomography in revealing vein graft occlusion was close to 100%. CONCLUSION: There is an association between high lipoprotein(a) level and vein graft occlusions in middle-aged men during the first year after coronary artery bypass grafting. Use of statins is associated with a lower rate of vein graft occlusion. Electron-beam tomography could be useful for assessing graft occlusions.

Cascade plasma filtration during the first year after CABG in patients with hyperlipidemia refractory to statins.

OBJECTIVE: To evaluate the effect of a 12-month course of weekly lipid apheresis on vein graft patency after coronary artery bypass grafting (CABG) in patients with hyperlipidemia refractory to statins. METHODS: In a 12-month prospective controlled clinical trial we enrolled 34 male patients (mean age 57 ± 8 years) who passed through successful CABG and low-density lipoprotein cholesterol (LDL-C) level >2.6 mmol/L prior to the operation despite statin treatment. Patients were allocated into 2 groups: active (n = 17, weekly apheresis by cascade plasma filtration (CPF) plus atorvastatin), and control (n = 17, atorvastatin alone). Graft patency was evaluated by multislice computed tomography at 3 months and by angiography at 12 months after an operation. RESULTS: Both groups were comparable in clinical and biochemical characteristics. During each CPF procedure, LDL-C level decreased by 64 ± 9%, apoB - by 65 ± 8%, Lp(a) - by 52 ± 15%,; these changes were significant compared to baseline and the control group. Mean net difference in LDL-C level between apheresis and control groups was 1.1 ± 0.3 mmol/L. Vein graft patency at study end was 88.2% (45 of 51) in the apheresis group versus 72.7% (40 of 55) in the control group (p = 0.05). Use of apheresis was associated with decreased vein graft occlusions by 46%: relative risk 0.54; 95% confidence interval 0.27 to 1.02; p = 0.05. CONCLUSION: Our data suggest that the use of lipoprotein apheresis with CPF results in a better vein graft patency during the first year after CABG in patients with hyperlipidemia refractory to statins.

Circulating stromal osteonectin-positive progenitor cells and stenotic coronary atherosclerosis.

The level of circulating stromal progenitor cells carrying osteonectin (ON), a marker of osteogenic differentiation, was evaluated by flow cytometry in blood of patients with coronary artery disease (CAD). Ninety-nine patients with CAD were included into the study. Coronary angiography of all patients showed critical stenosis of at least 2 coronary arteries or their major branches. The control groups included 8 patients without CAD and 19 healthy volunteers. In control patients, no lesions of the coronary bed were found by angiography. The absence of CAD in the volunteers was confirmed by bicycle stress test. The content of ON-positive cells in blood was examined in various populations of lymphocyte-like cells. It was found that the number of ON+ lymphocyte-like cells with CD41 positivity in blood of patients without coronary stenosis (0.27%+/-0.11%, mean+/-SD) did not differ significantly from corresponding value in healthy volunteers (0.26%+/-0.07%, p=0.94). In CAD patients, the percent of these ON+ cells was 1.01%+/-0.49% and was significantly higher than in blood of healthy volunteers (p<0.0001) and patients without CAD (p<0.0001). High content of ON+ lymphocyte-like cells with CD41 positivity in blood may serve as noninvasive marker of arterial atherosclerosis.