Anti-Lipoprotein Lipase Antibody as a Useful Marker for Plaque Vulnerability in Patients with Stable Angina.

AIMS: Identifying patients with vulnerable plaque who have poor prognosis among those with coronary artery disease (CAD) is crucial to deciding future therapeutic interventions. We previously reported that male CAD patients with low anti-apolipoprotein B-100 autoantibody (anti-apoB-100 Ab) levels were at an increased risk of developing unstable plaque lesions. This study focused on the autoantibodies against lipoprotein lipase (LPL), a key enzyme in triglyceride metabolism, which is another risk factor for atherosclerosis, and investigated their association with plaque characteristics. METHODS: We measured serum anti-LPL Ab levels using a homemade enzyme-linked immunosorbent assay in 80 male CAD patients. Coronary plaque properties were evaluated using iMAP®-intravascular ultrasound. RESULTS: Serum anti-LPL Ab levels were not correlated with plaque burden but were significantly negatively and positively correlated with fibrotic and necrotic plaques, respectively. High-risk patients with low anti-apoB-100 Ab levels were divided into groups according to their anti-LPL Ab levels. The group with high anti-LPL Ab levels exhibited more necrotic plaques and fewer fibrotic plaques as well as higher remnant-like lipoprotein particle levels than the group with low anti-LPL Ab levels. CONCLUSIONS: Serum anti-LPL Ab levels can serve as a marker of plaque instability in CAD patients and can help identify higher-risk cases when combined with anti-apoB-100 Ab levels.

Relationship Between Systemic Immune-Inflammation Index (SII) and the Severity of Stable Coronary Artery Disease.

Systemic immune-inflammation index (SII; platelet count × neutrophil-to-lymphocyte ratio), a novel marker, predicts adverse clinical outcomes in coronary artery diseases (CAD). We hypothesized that SII could provide more valuable information in assessing the severity of CAD than ratios obtained from other white blood cell subtypes. Patients (n = 669) who underwent coronary angiography were analyzed in this retrospective study. We analyzed the relation between the SII and the angiographic severity of CAD. The severity of coronary atherosclerosis was determined by the SYNTAX score (SxS). Patients with CAD were divided into 3 groups according to the SxS. Multivariate logistic analysis was used to assess risk factors of CAD. In multivariate logistic regression analysis, the SII (odds ratio: 1.004; 95% CI: 1.001-1.007; P = .015) was an independent predictor of high SxS. Additionally, there was a positive correlation between SII and SxS (Rho: 0.630, P ≤ .001). In the receiver-operating characteristic curve analysis, SII with an optimal cutoff value of 750 × 103 predicted the severe coronary lesion with a sensitivity of 86.2% and specificity of 87.3%. The SII, an inexpensive and easily measurable laboratory variable, was significantly associated with the severity of CAD and high SxS in patients with stable angina pectoris.

Prognostic Value of Human Peripheral Monocyte Subsets for Future Coronary Events in Patients Without Significant Coronary Artery Stenosis.

BACKGROUND: Monocytes in human peripheral blood are heterogeneous and can be divided into 2 groups, inflammatory and pro-inflammatory, according to the differential expression of CD14 and CD16. Pro-inflammatory monocytes (CD14+CD16+) seem to contribute to the development of coronary artery disease. This study aimed to investigate the involvement of specific human peripheral monocyte subsets in the development of future coronary events.Methods and Results:We enrolled 271 patients who were suspected to have either stable angina pectoris or silent myocardial ischemia and underwent coronary angiography (CAG). Two monocyte subsets (CD14+CD16-and CD14+CD16+) were measured by flow cytometry. Patients who did not undergo coronary artery revascularization at initial CAG were followed as the medical therapy group, which included 136 patients among whom 15 had future coronary events. The frequency of CD14+CD16+monocytes was significantly higher in patients who had future coronary events than in those who did not (P<0.01). Furthermore, the frequencies of CD14+CD16+monocyte were not significantly different between patients who had future coronary events and those who underwent coronary revascularization at initial CAG (P<0.33). Multivariate analysis revealed that the frequency of CD14+CD16+monocytes was an independent predictor for future coronary events (P<0.01). CONCLUSIONS: An increase in the abundance of human peripheral pro-inflammatory monocytes is related to the development of future coronary events.

Trimethylamine N-Oxide, Circulating Endothelial Progenitor Cells, and Endothelial Function in Patients with Stable Angina.

Trimethylamine N-oxide (TMAO) is a metabolite originated from bacterial metabolism of choline-rich foods. Evidence suggests an association between TMAO and atherosclerosis, but the relationship between TMAO and endothelial progenitor cells (EPCs) remains unclear. This study aimed to identify the relationship between TMAO concentrations, circulating EPCs, and endothelial function in patients with stable angina. Eighty-one stable angina subjects who underwent coronary angiography were enrolled. The circulating EPCs and flow-mediated vasodilation (FMD) were measured to evaluate endothelial function. Plasma TMAO and inflammatory markers, such as hsCRP and IL-1ß, were determined. Furthermore, the effect of TMAO on EPCs was assessed in vitro. Patients with lower FMD had significantly decreased circulating EPCs, elevated TMAO, hsCRP, and IL-1ß concentrations. Plasma TMAO levels were negatively correlated with circulating EPC numbers and the FMD, and positively correlated with hsCRP, IL-1ß concentrations. In in vitro studies, incubation of TMAO in cultured EPCs promoted cellular inflammation, elevated oxidative stress, and suppressed EPC functions. Enhanced plasma TMAO levels were associated with reduced circulating EPCs numbers, endothelial dysfunction, and more adverse cardiovascular events. These findings provided evidence of TMAO's toxicity on EPCs, and delivered new insight into the mechanism of TMAO-mediated atherosclerosis, which could be derived from TMAO-downregulated EPC functions.

Loss of Regulatory Immune Function in Coronary Artery Disease Patients from the Indian Population.

The pathogenic roles of inflammatory T cells and monocytes subsets have not been explored in different manifestations of coronary artery disease. We studied the frequency of these cells, their response to autoantigens, regulatory cell functional assay, foam cell formation and macrophage differentiation in 181 patients (stable angina, ST-elevated myocardial infarction (STEMI), NSTEMI, and unstable angina), and 34 controls and in samples collected during recurrent cardiac events and from patients showing clinical improvement. The proportion of Th17 cells and monocytes gradually increased in patients with stable angina at one end of the spectrum followed by NSTEMI, STEMI, and unstable angina at other end. Inflammatory cells were positively and inversely associated with recurrent events and clinical improvement, respectively. Patients showed expansion of Th17 cells in response to autoantigen (HSP60) and compromised Treg function. Our results suggest that stress-induced activation of inflammatory cells expands in the absence of regulatory control in CAD patients.

Low Blood Content of IL-10-Producing CD4+ T Cells as a Risk Factor for Progression of Coronary Atherosclerosis.

In a 2-year prospective study, prognostic significance of the blood content of IL-10-producing CD4+ T lymphocytes for progression of coronary artery atherosclerosis was assessed. Patients with verified stable angina (n=36) admitted for scheduled coronary angiography and coronary stenting were enrolled. The blood levels of CD4+FoxpP3+ Treg, CD4+IFNγ+ Th1, CD4+IL17+ Th17, CD4+IL10+ cells, sCD25, IL-10, IL-17, C-reactive protein, and lipoprotein (a) were assayed before endovascular interventions. The blood content of CD4+IL10+ T cells below 3.3% was associated with progression of coronary artery atherosclerosis (OR 12.0 (2.3, 61.0), sensitivity 77%, specificity 78%, p=0.003). No differences in other immunological parameters and common atherosclerosis risk factors in the groups were revealed. We hypothesize that the content of CD4+IL10+ T cells can be an important predictive marker for the progression of coronary atherosclerosis.

Cytokine expression profile and blood parameter evaluation of patients undergoing cardiac surgery.

Cardiac surgery is accompanied by an important immune response that is poorly understood. This inflammatory response is caused by several stimuli: surgical trauma, cardiopulmonary bypass apparatus, aortic-cross clamping, reperfusion injury and hypothermia. The aim of the present study is to investigate the cytokine level profile involved in the inflammatory pathway of patients undergoing cardiac surgery. One hundred and two patients undergoing elective cardiac surgery utilizing cardiopulmonary bypass (CPB) apparatus were enrolled in the study. In the hematological and biochemical profiles investigated, we observed a significant increase of WBC and blood glucose concentration and a strong decrease of RBC, HB, HCT and PLT 24 h post-surgery compared to baseline and immediately after surgery groups. Furthermore, we found a modulation of cytokine levels mostly for IL-10 and an increase of IL-6, detected at 6 h post-surgery, IL-8 at 6 and 24 h, and TNFα only at 24 h post-surgery. In conclusion, these findings evidence a time course profile on cytokine levels and a balance between pro- and anti-inflammatory cytokine activation during and after cardiac surgery. In fact, IL-6 and IL-10, a pro- and an anti-inflammatory cytokine, respectively, increased immediately after surgery. The plasma level of TNF-α could be inhibited by the high concentration of IL-10 up to 6 h post-surgery. An IL-10 reduction at baseline level, after 24 h post-surgery, could explain a rise of TNF-α plasma concentration. On the other hand, considering the dual role of IL-6 on inflammation acting both as an activator of inflammatory cascade or an anti-inflammatory agent, the increased IL-6 levels 24 h after surgery could be related to the negative feedback action on TNFα activity.

Immune Cell Repertoire and Their Mediators in Patients with Acute Myocardial Infarction or Stable Angina Pectoris.

Background: To evaluate the natural innate and adaptive immunity through gene expression and cytology levels in peripheral blood mononuclear cells in patients with acute myocardial infarction (AMI), stable angina pectoris (SAP) and controls. Methods: 210 patients with AMI, 210 with SAP, and 250 clinical controls were recruited. Whole human genome microarray analysis was performed in 20 randomly chosen subjects per group were examined to detect the expressions of complement markers, natural killer cells, T cells and B cells. The quantity of these cells and related cytokines as well as immunoglobulin levels were measured in all subjects. Results: In AMI group, the mRNA expressions of late complement component, markers of natural killer cells, CD3+, CD8+ T cells and B cells were down-regulated, while those of early complement component and CD4+T cells were up-regulated (p<0.05). In both AMI and SAP patients, the quantity of natural killer cells, CD3+, CD8+ T cells, B cells, IgM and IgG were significantly lower than those of the controls. CD4+ T cells, CH50, C3, C4, IL-2, IL-4, IL-6 and IFN-γ were significantly higher (p<0.05). Conclusions: In AMI patients, both of gene expressions related to complement, natural killer cells, CD3+, CD8+ T cells, B cells and the quantity of these immune cells decreased while cell number reduced in SAP patients. Immune function in both AMI and SAP patients decreased especially in AMI patients with declined gene and protein levels. To improve the immune system is a potential target for medical interventions and prevention in AMI.

Thrombospondin-1-Derived Peptide RFYVVMWK Improves the Adhesive Phenotype of CD34+ Cells From Atherosclerotic Patients With Type 2 Diabetes.

CD34+ progenitor cells are growing in use for vascular repair. However, in diabetic individuals with cardiovascular diseases, these cells have dysfunctional engraftment capabilities, which compromise their use for autologous cell therapy. The thrombospondin-1-derived peptide RFYVVMWK has previously been reported to stimulate cell adhesiveness through CD47 and integrin activation pathways. Our aim was to test whether RFYVVMWK preconditioning could modulate CD34+ cell phenotype and enhance its proadhesive properties in diabetic patients. Peripheral blood mononuclear CD34+ cells isolated from 40 atherosclerotic patients with type 2 diabetes (T2D; n = 20) or without (non-T2D; n = 20) were preconditioned with 30 µM RFYVVMWK or truncated peptide RFYVVM. CD34+ cell adhesion was assessed on a vitronectin-collagen matrix and on TNF-α or IL-1ß-stimulated HUVEC monolayers. Adhesion receptors, platelet/CD34+ cell conjugates, and cell viability were analyzed by flow cytometry and confocal microscopy. RFYVVMWK increased the adhesion of T2D CD34+ cells by eightfold to the vitronectin-collagen matrix (p < 0.001) corresponding to a threefold increase compared to unstimulated non-T2D CD34+ cells. The peptide induced the formation of platelet/CD34+ conjugates and increased the expression of TSP-1, CD29, CD51/CD61, and CD62P in both T2D and non-T2D cells. However, RFYVVMWK treatment did not affect the viability/apoptosis of CD34+ progenitor cells. In conclusion, priming CD34+ cells with RFYVVMWK may enhance their vascular engraftment during autologous proangiogenic cell therapy.

Neutrophil-derived microparticles are released into the coronary circulation following percutaneous coronary intervention in acute coronary syndrome patients.

To evaluate (i) local coronary and systemic levels of microparticles (MP) in acute coronary syndrome (ACS) and stable angina pectoris (SAP) patients and (ii) their release after plaque disruption with percutaneous coronary intervention (PCI). MP are small vesicles originating from plasma membranes of cells after activation or apoptosis and are implicated in the pathogenesis of atherosclerosis. Neutrophils play a role in plaque destabilization and shed neutrophil-derived MP that have the potential to drive significant proinflammatory and thrombotic downstream effects. Eight ACS and eight SAP patients were included. Coronary sinus (CS) samples pre-intervention (CS1), 45 s following balloon angioplasty (CS2) and at 45 s intervals following stent deployment (CS3, CS4 and CS5), together with peripheral vein samples, pre- and post-PCI were analysed for neutrophil-derived (CD66b+), endothelial-derived (CD144+), platelet-derived (CD41a+), monocyte-derived (CD14+) and apoptotic (Annexin V+) MP. ELISA for interleukin (IL)-6, myeloperoxidase (MPO) and P-selectin was also performed. CD66b+ MP levels were similar in both groups pre-intervention. Post-PCI, CS levels rose significantly in ACS but not SAP patients (ACS area under the curve (AUC): 549 ± 83, SAP AUC: 24 ± 29, P<0.01). CS CD41a+, CD144+, CD14+ and Annexin V+ MP levels did not differ between groups. Acute neutrophil-derived MP release post-PCI occurs in ACS compared with stable patients, likely to be reflective of plaque MP content in vulnerable lesions.

Depletion of complement system immunity in patients with myocardial infarction.

The aim of the present study was to evaluate differences in the expression of complement system genes, and serum levels of CH50, C3 and C4 in peripheral blood mononuclear cells from patients with myocardial infarction (AMI), stable angina pectoris (SA) and controls. A total of 100 patients with AMI, 100 with SA and 100 clinical controls were recruited in the present study. In each group, 20 randomly selected individuals were examined using whole human genome microarray analysis to detect the expression of genes of the complement system. The serum levels of CH50, C3 and C4 were measured in all 300 subjects. In the patients with AMI, the expression levels of genes encoding C1qα, C1qß, C1qγ, C1r, Factor P, C5a (complement component), CR1, integrin αM, integrin αX, integrin ß2, C5aR, CRIg (complement receptors) and CD46, CD55 and CD59 (complement regulators) were significantly higher, compared with the respective genes in the SA patients and controls (P<0.05), whereas the mRNA levels of C1s, C7, C8ß and C9 were the lowest in this group (P<0.05). No statistically significant differences were found in the gene expression levels of complement components or regulators between the SA and control groups. The serum levels of CH50, C3 and C4 were significantly increased in the AMI and SA groups, compared with the controls. In the AMI and SA groups, the complement system was activated. However, the differential mRNA expression of complement components, receptors and regulators in the AMI group suggested the dysfunction of the C5b-9 complex. The depression of complement system immunity in the patients with AMI may be associated with the pathogenesis of AMI.

Allergic Inflammation Is Associated With Coronary Instability and a Worse Clinical Outcome After Acute Myocardial Infarction.

BACKGROUND: The role of allergic inflammation in acute coronary syndromes (ACS) has not been clearly defined to date. Aim of this study was to assess eosinophil and basophil activation in ACS and the prognostic role of eosinophil cationic protein in ST-segment-elevation myocardial infarction. METHODS AND RESULTS: In a cross-sectional study, we prospectively enrolled 51 patients undergoing percutaneous coronary intervention (60.8% patients with ACS and 39.2% with stable angina). Flow cytometry analysis assessed CD66b, CD69, and CD203c median fluorescence intensity expression. In a follow-up study, 181 patients presenting with ST-segment-elevation myocardial infarction, undergoing primary percutaneous coronary intervention, were prospectively enrolled with a follow-up of 24 months. Eosinophil activation (CD66b) was similar in patients with ACS and stable angina (6.61 [4.91-7.72] versus 6.62 [5.27-8.73], P=0.63), whereas eosinophil degranulation (CD69) and basophil activation (CD203c) were higher in ACS patients compared with stable angina patients (1.38 [1.16-1.52] versus 1.17 [1-1.31], P=0.01); 0.97 [0.89-1.11] versus 0.92 [0.87-0.95], P=0.03, respectively). Eosinophil cationic protein serum levels were significantly higher in ST-segment-elevation myocardial infarction patients with major adverse cardiac events as compared with those without (21.1 [10.37-25.65] versus 7.83 [3.37-12.8] µg/L, P=0.01) and in patients with thrombus score >3 compared with those with thrombus score ≤3 (15.0 [9.8-24.7] versus 5.2 [3.5-22.9] µg/L, P=0.006). Eosinophil cationic protein serum levels predicted major adverse cardiac events during follow-up (odds ratio =1.041, 95% confidence interval 1.012-1.071, P=0.005). C-reactive protein serum levels showed a borderline statistical significance (odds ratio =0.904, 95% confidence interval 0.806-1.014, P=0.085). CONCLUSIONS: These findings are the first demonstration of in vivo eosinophil degranulation and basophil activation during ACS and of the prognostic role of eosinophil cationic protein in ST-segment-elevation myocardial infarction.

Role of Th1 and Th17 cells in the development and complexity of coronary artery disease: comparison analysis by the methods of flow cytometry and SYNTAX score.

BACKGROUND: There have been few reports on the relationship between the expression of the CD4⁺ T cells producing interferon-γ (Th1)/interleukin-17 (Th17) and degree of atherosclerosis. Thus, we analyzed Th1 and Th17 cell frequencies in patients with noncardiac chest pain (control), stable angina (SA), and acute myocardial infarction (AMI), and compared the complexity of the coronary artery with the SYNTAX score. PATIENTS AND METHODS: This study included 124 patients with a complaint of chest pain who underwent coronary angiography (control: 30 patients, SA: 47 patients, AMI: 47 patients). Peripheral blood was sampled during coronary angiography. Mononuclear cells from patients were stimulated for 4 h ex vivo. After staining with specific antibodies and fluorescence, the frequencies of Th1 and Th17 cells were measured by flow cytometry. The SYNTAX score was calculated by coronary angiography and a web-based calculator. RESULTS: There was no significant difference in the baseline characteristics, except the higher frequencies of hypertension in SA patients (76.1%) and smoking in AMI patients (53.3%). Patients with SA showed a significantly higher frequency of Th1 cells (21.56±9.57%) compared with controls (14.84±8.58%) and patients with AMI (9.04±7.02%) (P<0.001). The frequency of Th17 cells also increased in SA patients (control: 1.90±1.05%, SA: 2.96±1.42%, AMI: 1.32±0.92%, P<0.001). The SYNTAX score was significantly higher in SA patients (SA: 21.51±11.67, AMI: 15.36±8.84, P=0.006) and correlated with the frequencies of Th1 and Th17 cells (r=0.359, P=0.001; r=0.248, P=0.031; respectively). CONCLUSION: Th1 and Th17 cells were related to the development of SA, but not AMI. They could be a useful marker for the complexity of atherosclerosis in coronary artery disease.

Expression of coinhibitory PD-L1 on CD4⁺CD25⁺FOXP3⁺ regulatory T cells is elevated in patients with acute coronary syndrome.

OBJECTIVE: Coronary heart disease (CHD) is associated with high morbidity and mortality worldwide. CD4⁺CD25⁺FOXP3⁺ regulatory T cells (Tregs) play a role in the modulation of vascular inflammation. The negatively costimulatory molecule programmed cell death ligand 1 (PD-L1) exerts a prominent effect on the adjustment of immune responses. We investigated the relationship between the expression of PD-L1 on peripheral blood Tregs and the severity of CHD. METHODS AND RESULTS: Human peripheral blood was collected from 59 patients with CHD and 11 healthy volunteers. The expression of PD-L1 on peripheral blood Tregs was detected by flow cytometry, and the production of interleukin 2 (IL-2), IL-4, IL-10, and transforming growth factor ß1 in plasma was determined using enzyme-linked immunosorbent assay. The subgroup of patients with acute coronary syndrome (ACS), which includes unstable angina pectoris, non-ST-segment elevation myocardial infarction, and ST-segment elevation myocardial infarction, showed a significant reduction of FOXP3 and PD-L1 expression on Tregs compared with the subgroup of patients with chronic coronary artery disease, comprising stable angina pectoris, silent myocardial ischemia, and ischemic heart failure, and the control group. Moreover, the ACS group showed significantly increased production of IL-2, and decreased production of IL-4, IL-10, and transforming growth factor ß1, compared with the coronary artery disease and control groups. CONCLUSION: Expression of the coinhibitory molecule PD-L1 on peripheral blood Tregs is correlated negatively with the severity of CHD and could serve as a novel indicator of ACS.

Serum CD121a (Interleukin 1 Receptor, Type I): A Potential Novel Inflammatory Marker for Coronary Heart Disease.

Inflammation is now believed to be responsible for coronary heart disease (CHD). This belief has stimulated the evaluation of various inflammatory markers for predicting CHD. This study was designed to investigate the association between four inflammatory cytokines (CD121a, interleukin [IL]-1ß, IL-8, and IL-11) and CHD. Here, we evaluated 443 patients with CHD and 160 CHD-free controls who underwent coronary angiography. Cytokines were evaluated using flow cytometry, and statistical analyses were performed to investigate the association between cytokine levels and the risk of CHD. Patients with CHD had significantly higher levels of CD121a. The odds ratios for CHD according to increasing CD121a quartiles were 1.00, 1.47 [95% confidence interval (CI): 0.79-2.72], 2.67 (95% CI: 1.47-4.84), and 4.71 (95% CI: 2.65-8.37) in an age- and sex-adjusted model, compared to 1.00, 1.48 (95% CI: 0.70-3.14), 2.25 (95% CI: 1.10-4.62), and 4.39 (95% CI: 2.19-8.79) in a model that was adjusted for multiple covariates. A comparison of the stable angina, unstable angina, and acute myocardial infarction (AMI) subgroups revealed that patients with AMI had the highest CD121a levels, although IL-1ß levels were similar across all groups. IL-8 levels were also increased in AMI patients, and IL-11 levels were higher in CHD patients than in non-CHD patients. Correlation analysis revealed a positive association between CD121a, IL-8, and the Gensini score. Together, the significant increase in CD121a levels among CHD patients suggests that it may be a novel inflammatory marker for predicting CHD.

Serum chemokine CCL17/thymus activation and regulated chemokine is correlated with coronary artery diseases.

OBJECTIVE: It was recently reported that chemokine CC-motif ligand 17 (CCL17)-expressing dendritic cells drove atherosclerosis by restraining regulatory T cell homeostasis in an animal model. Our preliminary study has shown that serum CCL17 levels may be associated with coronary artery disease (CAD). The aim of this study was to confirm the relationship between serum CCL17 levels and CAD. METHODS: Patients presenting to our center for coronary angiography between January 2013 and December 2013 were recruited for the study. Serum CCL17 levels were determined by enzyme-linked immunosorbent assay. Atherosclerosis severity was assessed in each patient according to the Gensini score. RESULTS: In total, 971 consecutive patients were enrolled in this study, including 158 non-CAD patients and 813 CAD patients (238 with stable angina pectoris, 321 with unstable angina, 128 with non-ST elevation myocardial infarction, and 126 with ST elevation myocardial infarction). CAD patients had higher serum CCL17 levels compared to patients without CAD [265.90 (170.80-376.65) pg/mL versus 218.35 (142.83-293.45) pg/mL, p < 0.001]. After adjusting for traditional risk factors, serum CCL17 levels remained associated with CAD. Meanwhile, there was a significant linear trend between serum CCL17 levels and the different CAD subtypes (p for linear trend = 0.002). Finally, serum CCL17 levels (per 100 pg/mL) were positively associated with the Gensini score (B 2.310; 95% CI 0.503-4.118; p = 0.012) even after adjusting for confounding factors. CONCLUSION: Serum CCL17 levels are associated with CAD and atherosclerosis severity independently of traditional cardiovascular risk factors.

Modulation of STAT3 and STAT5 activity rectifies the imbalance of Th17 and Treg cells in patients with acute coronary syndrome.

The signal transducer and activator of transcription (STAT) activity plays an important role in the differentiation and imbalance of Th17 and Treg cells in acute coronary syndrome (ACS) patients. We determined that the basal STAT3 phosphorylation level was significantly increased and exhibited a positive relationship with Th17 cells but was negatively correlated with Treg cells in ACS patients. Opposite effects were observed for STAT5 activity. Using the pharmaceutical inhibitor TG101348 or knockdown of STAT3 reduced the number of Th17 cells while promoting the number and function of Treg cells via the Janus kinase2 (JAK2)/STAT3 pathway in ACS patients. Significantly more STAT5 bound to the Foxp3 locus when STAT3 was knocked down, and overexpression of STAT5 led to an increased number of Treg cells but a decreased number of Th17 cells in ACS patients. Our findings demonstrate that modulation of STAT3/STAT5 activity rectifies the imbalance of Th17/Treg cells in ACS patients.

Heme oxygenase-1 restores impaired GARPCD4⁺CD25⁺ regulatory T cells from patients with acute coronary syndrome by upregulating LAP and GARP expression on activated T lymphocytes.

BACKGROUND: Accumulating evidence shows that the pathological autoreactive immune response is responsible for plaque rupture and the subsequent onset of acute coronary syndrome (ACS). Naturally occurring CD4(+)CD25(+)regulatory T cells (nTregs) are indispensable in suppressing the pathological autoreactive immune response and maintaining immune homeostasis. However, the number and the suppressive function of glycoprotein-A repetitions predominant (GARP) (+) CD4(+) CD25(+) activated nTregs were impaired in patients with ACS. Recent evidence suggests that heme oxygenase-1 (HO-1) can regulate the adaptive immune response by promoting the expression of Foxp3. We therefore hypothesized that HO-1 may enhance the function of GARP(+) CD4(+) CD25(+)Tregs in patients with ACS and thus regulate immune imbalance. METHODS: T lymphocytes were isolated from healthy volunteers (control, n=30) and patients with stable angina (SA, n=40) or ACS (n=51). Half of these cells were treated with an HO-1 inducer (hemin) for 48 h, and the other half were incubated with complete RPMI-1640 medium. The frequencies of T-helper 1 (Th1), Th2, Th17 and latency-associated peptide (LAP) (+)CD4(+) T cells and the expression of Foxp3 and GARP by CD4(+)CD25(+)T cells were then assessed by measuring flow cytometry after stimulation in vitro. The suppressive function of activated Tregs was measured by thymidine uptake. The levels of transforming growth factor-1 (TGF-ß1) in the plasma were measured using enzyme-linked immunosorbent assay (ELISA). The expression levels of the genes encoding these proteins were analyzed by real-time polymerase chain reaction. RESULTS: Patients with ACS exhibited an impaired number and suppressive function of GARP(+) CD4(+) CD25(+)Tregs and a mixed Th1/Th17-dominant T cell response when compared with the SA and control groups. The expression of LAP in T cells was also lower in patients with ACS compared to patients with SA and the control individuals. Treatment with an HO-1 inducer enhanced the biological activity of GARP(+) CD4(+) CD25(+)Tregs and resulted in increased expression of LAP and GARP by activated T cells. CONCLUSIONS: The reduced number and impaired suppressive function of GARP(+) CD4(+) CD25(+)Tregs result in excess effector T cell proliferation, leading to plaque instability and the onset of ACS. HO-1 can effectively restore impaired GARP(+) CD4(+) CD25(+)Tregs from patients with ACS by promoting LAP and GARP expression on activated T cells.

Differential loss of natural killer cell activity in patients with acute myocardial infarction and stable angina pectoris.

BACKGROUND: To evaluate the activity of natural killer cells through their inhibitory and activating receptors and quantity in peripheral blood mononuclear cells extracted from patients with acute myocardial infarction, stable angina pectoris and the controls. METHODS: 100 patients with myocardial infarction, 100 with stable angina, and 20 healthy volunteers were recruited into the study. 20 randomly chosen people per group were examined for the whole human genome microarray analysis to detect the gene expressions of all 40 inhibitory and activating natural killer cell receptors. Flow cytometry analysis was applied to all 200 patients to measure the quantity of natural killer cells. RESULTS: In myocardial infarction group, the mRNA expressions of six inhibitory receptors KIR2DL2, KIR3DL3, CD94, NKG2A, KLRB1, KLRG1, and eight activating receptors KIR2DS3, KIR2DS5, NKp30, NTB-A, CRACC, CD2, CD7 and CD96 were significantly down-regulated (P<0.05) compared with both angina patients and the controls. There was no statistical difference in receptor expressions between angina patients and control group. The quantity of natural killer cells was significantly decreased in both infarction and angina patients compared with normal range (P<0.001). CONCLUSIONS: The significant mRNAs down-regulation of several receptors in myocardial infarction group and reduction in the quantity of natural killer cells in both myocardial infarction and angina patients showed a quantitative loss and dysfunction of natural killer cells in myocardial infarction patients.

The measurement of circulating matrix metalloproteinase-8 and its tissue inhibitor and their association with inflammatory mediators in patients with acute coronary syndrome.

BACKGROUND: The aim of the present study was to investigate differences of matrix metalloproteinase-8 and tissue inhibitor of metalloproteinase-1 in the peripheral blood of patients admitted with acute coronary syndrome (ACS) and its correlation with the widely accepted markers of inflammatory activity, C-reactive protein, fibrinogen, and white blood cell number. METHODS: 315 patients with ACS (165 unstable angina pectoris/non-ST-elevation myocardial infarction, 150 ST elevation myocardial infarction), 111 stable angina (SA) patients, and 296 control subjects were enrolled in the study. All biochemical analyses were carried out using a Hitachi 912 analyzer (Roche). Matrix metalloproteinase-8 (MMP-8) and tissue inhibitor of metalloproteinase-1 (TIMP-1) levels were determined in citrate plasma by ELISA methods. White blood cells (WBC) and fibrinogen were also determined. RESULTS: The plasma concentrations of matrix metalloproteinase-8, tissue inhibitor of metalloproteinase-1, C-reactive protein, fibrinogen, and WBCs in patients with acute coronary syndrome were significantly higher than those in the control group (p < 0.001). Strong positive associations were observed between MMP-8 and TIMP-1 (r = 0.328, p < 0.001), MMP-8 and CRP (r = 0.171, p < 0.001), MMP-8 and Fibrinogen (r = 0.267, p < 0.001), MMP-8 and WBC (r = 0.163, p < 0.01), TIMP-1 and CRP (r = 0.219, p < 0.01), TIMP-1 and fibrinogen (r = 0.226, p < 0.01), TIMP-1 and WBC (r = 0.094, p < 0.1). Other positive correlations were observed between CRP and fibrinogen, CRP and WBC and fibrinogen and WBC in the patients with ACS. CONCLUSIONS: Observations suggest that ACS show an increase in both remodeling and inflammation markers. In addition, the strong relationship with MMP-8 and inflammatory mediators such as CRP, fibrinogen and WBC in ACS patients suggests that MMP-8 might be an additional marker and/or consequence of inflammatory components in ACS.