CCL4 contributes to aging related angiogenic insufficiency through activating oxidative stress and endothelial inflammation.

Aging is a natural process associated with chronic inflammation in the development of vascular dysfunction. We hypothesized that chemokine C-C motif ligands 4 (CCL4) might play a vital role in aging-related vascular dysfunction. Circulating CCL4 was up-regulated in elderly subjects and in aged animals. CCL4 inhibition reduced generation of reactive oxygen species (ROS), attenuated inflammation, and restored cell functions in endothelial progenitor cells from elderly subjects and in aged human aortic endothelial cells. CCL4 promoted cell aging, with impaired cell functioning, by activating ROS production and inflammation. CCL4 knockout mice and therapeutic administration of anti-CCL4 neutralizing antibodies exhibited vascular and dermal anti-aging effects, with improved wound healing, via the down-regulation of inflammatory proteins and the activation of angiogenic proteins. Altogether, our findings suggested that CCL4 may contribute to aging-related vascular dysfunction via activating oxidative stress and endothelial inflammation. CCL4 may be a potential therapeutic target for vascular protections during aging.

CXCL5 inhibition improves kidney function by protecting renal tubular epithelial cells in diabetic kidney disease.

Inflammation is one of exacerbating factors of diabetic kidney disease (DKD). Upregulated CXCL5 is found in clinical and experimental diabetes studies. This study aimed to investigate the impact and mechanism of CXCL5 on DKD. DKD patients with different levels of urine albumin-to-creatinine ratio were enrolled. Leprdb/db mice and CXCL5-knockout diabetic mice were used as mouse models for DKD. Human renal tubular epithelial cells were used for in vitro experiments. Circulating CXCL5 were increased in DKD patients compared to the non-DKD subjects. CXCL5 inhibition through CXCL5-neutralizing antibodies or genetic knockout improved kidney function and ameliorated tubular injury and renal fibrosis. In high-glucose-stimulated tubular epithelial cells, administration of CXCL5-neutralizing antibodies or siRNA resulted in reduced phospho-JNK/c-JUN/p65 and the downstream inflammatory, fibrotic, and apoptotic protein expressions. Administration of CXCR2 and JNK inhibitors impeded the CXCL5-induced tubular epithelial cell damages. In conclusion, these findings indicated that anti-CXCL5 strategies may be potential treatments for DKD.

CXCL5 suppression recovers neovascularization and accelerates wound healing in diabetes mellitus.

BACKGROUND: Higher chemokine C-X-C motif ligand 5 (CXCL5) level was observed in type 2 diabetes mellitus (DM) patients; however, its role in diabetic vasculopathy was not clarified. This study aimed to explore the impacts and mechanistic insights of CXCL5 in neovasculogenesis and wound healing in DM. METHODS: Endothelial progenitor cells (EPCs) and human aortic endothelial cells (HAECs) were used in vitro. Streptozotocin-induced diabetic mice and Leprdb/JNarl mice were used as type 1 and type 2 DM models. Moreover, CXCL5 knockout mice were used to generate diabetic mice. Hindlimb ischemia surgery, aortic ring assays, matrigel plug assay, and wound healing assay were conducted. RESULTS: CXCL5 concentrations were increased in plasma and EPCs culture medium from type 2 DM patients. CXCL5 neutralizing antibody upregulated vascular endothelial growth factor (VEGF)/stromal cell-derived factor-1 (SDF-1) and promoted cell function in EPCs from type 2 DM patients and high glucose-treated EPCs from non-DM subjects as well as HAECs. CXCL5 directly up-regulated interleukin (IL)-1ß/IL-6/tumor necrosis factor-α and down-regulated VEGF/SDF-1 via ERK/p65 activation through chemokine C-X-C motif receptor 2 (CXCR2). CXCL5 neutralizing antibody recovered the blood flow after hindlimb ischemia, increased circulating EPC number, and enhanced VEGF and SDF-1 expression in ischemic muscle. CXCL5 suppression promoted neovascularization and wound healing in different diabetic animal models. The above observation could also be seen in streptozotocin-induced CXCL5 knockout diabetic mice. CONCLUSIONS: CXCL5 suppression could improve neovascularization and wound healing through CXCR2 in DM. CXCL5 may be regarded as a potential therapeutic target for vascular complications of DM.

Inflammation and renal function decline in chronic coronary syndrome: a prospective multicenter cohort study.

BACKGROUND: Renal function decline is a frequently encountered complication in patients with chronic coronary syndrome. Aside from traditional cardiovascular risk factors, the inflammatory burden emerged as the novel phenotype that compromised renal prognosis in such population. METHODS: A cohort with chronic coronary syndrome was enrolled to investigate the association between inflammatory status and renal dysfunction. Levels of inflammatory markers, including high-sensitivity C-reactive protein (hs-CRP), tumour necrosis factor-α (TNF-α), adiponectin, matrix metalloproteinase-9, interleukin-6, lipoprotein-associated phospholipase A2, were assessed. Renal event was defined as > 25% decline in estimated glomerular filtration rate (eGFR). Inflammatory scores were calculated based on the aggregate of hs-CRP, TNF-α, and adiponectin levels. RESULTS: Among the 850 enrolled subjects, 145 patients sustained a renal event during an averaged 3.5 years follow-up. Multivariate analysis with Cox regression suggested elevations in hs-CRP, TNF-α, and adiponectin levels were independent risk factors for the occurrence of a renal event. Whereas, Kaplan-Meier curve illustrated significant correlation between high TNF-α (P = 0.005), adiponectin (P < 0.001), but not hs-CRP (P = 0.092), and eGFR decline. The aggregative effect of these biomarkers was also distinctly correlated with renal events (score 2: P = 0.042; score 3: P < 0.001). CONCLUSIONS: Inflammatory burden was associated with eGFR decline in patients with chronic coronary syndrome.

The clinical significance of osteopontin on the cardiovascular outcomes in patients with stable coronary artery disease.

BACKGROUND: Osteopontin (OPN) is a noncollagenous matricellular protein which is mainly present in bone matrix. A high OPN level has been associated with heart failure and acute coronary syndrome, however data on patients with chronic coronary syndrome (CCS) are lacking. The present study aimed to evaluate the association between OPN and the prognosis of Taiwanese patients with CCS. METHODS: We enrolled participants from the Biosignature Registry, a nationwide prospective cohort study conducted at nine different medical centers throughout Taiwan. The inclusion criteria were participants who had received successful percutaneous coronary intervention at least once previously, and stable under medical therapy for at least 1 month before enrollment. They were followed for at least 72 months. Logistic regression and Cox proportional hazard model were used to investigate the association between OPN and clinical outcomes. The outcomes of this study were the first occurrence of hard cardiovascular events and composite cardiovascular outcomes including cardiovascular mortality, revascularization, hospitalization for acute myocardial infarction (AMI) or heart failure. RESULTS: A total of 666 patients with both hs-CRP and osteopontin measurements were enrolled and followed for 72 months. OPN was correlated positively with AMI-related hospitalization, where the highest tertile (Tertile 3) of baseline OPN had the highest risk of AMI-related hospitalization, which remained significant after multivariate adjustments (HR 3.20, p = 0.017). In contrast, combining OPN and hs-CRP did not improve the prediction of CV outcomes. CONCLUSION: OPN may be a potentially valuable biomarker in predicting CV outcomes. During 6 years of follow-up period, an OPN level >4810 pg/ml was associated with a significantly higher incidence of AMI-related hospitalization in CCS patients who received successful PCI before the enrollment.

Tributyrin Intake Attenuates Angiotensin II-Induced Abdominal Aortic Aneurysm in LDLR-/- Mice.

Abdominal aortic aneurysm (AAA) is a multifactorial cardiovascular disease with a high risk of death, and it occurs in the infrarenal aorta with vascular dilatation. High blood pressure acts on the aortic wall, resulting in rupture and causing life-threatening intra-abdominal hemorrhage. Vascular smooth muscle cell (VSMC) dysregulation and extracellular matrix (ECM) degradation, especially elastin breaks, contribute to structural changes in the aortic wall. The pathogenesis of AAA includes the occurrence of oxidative stress, inflammatory cell infiltration, elastic fiber fragmentation, VSMC apoptosis, and phenotypic transformation. Tributyrin (TB) is decomposed by intestinal lipase and has a function similar to that of butyrate. Whether TB has a protective effect against AAA remains uncertain. In the present study, we established an AAA murine model by angiotensin II (AngII) induction in low-density lipoprotein receptor knockout (LDLR-/-) mice and investigated the effects of orally administered TB on the AAA size, ratio of macrophage infiltration, levels of matrix metalloproteinase (MMP) expression, and epigenetic regulation. TB attenuates AngII-induced AAA size and decreases elastin fragmentation, macrophage infiltration, and MMP expression in the medial layer of the aorta and reduces the levels of SBP (systolic blood pressure, p < 0.001) and MMP-2 (p < 0.02) in the serum. TB reduces the AngII-stimulated expression levels of MMP2 (p < 0.05), MMP9 (p < 0.05), MMP12, and MMP14 in human aortic smooth muscle cells (HASMCs). Moreover, TB and valproic acid (VPA), a histone deacetylase (HDAC) inhibitor, suppress AngII receptor type 1 (AT1R, p < 0.05) activation and increase the expression of acetyl histone H3 by HDAC activity inhibition (p < 0.05). Our findings suggest that TB exerts its protective effect by suppressing the activation of HDAC to attenuate the AngII-induced AT1R signaling cascade.

Machine Learning Models for ASCVD Risk Prediction in an Asian Population - How to Validate the Model is Important.

Introduction: Atherosclerotic cardiovascular disease (ASCVD) is prevalent worldwide including Taiwan, however widely accepted tools to assess the risk of ASCVD are lacking in Taiwan. Machine learning models are potentially useful for risk evaluation. In this study we used two cohorts to test the feasibility of machine learning with transfer learning for developing an ASCVD risk prediction model in Taiwan. Methods: Two multi-center observational registry cohorts, T-SPARCLE and T-PPARCLE were used in this study. The variables selected were based on European, U.S. and Asian guidelines. Both registries recorded the ASCVD outcomes of the patients. Ten-fold validation and temporal validation methods were used to evaluate the performance of the binary classification analysis [prediction of major adverse cardiovascular (CV) events in one year]. Time-to-event analyses were also performed. Results: In the binary classification analysis, eXtreme Gradient Boosting (XGBoost) and random forest had the best performance, with areas under the receiver operating characteristic curve (AUC-ROC) of 0.72 (0.68-0.76) and 0.73 (0.69-0.77), respectively, although it was not significantly better than other models. Temporal validation was also performed, and the data showed significant differences in the distribution of various features and event rate. The AUC-ROC of XGBoost dropped to 0.66 (0.59-0.73), while that of random forest dropped to 0.69 (0.62-0.76) in the temporal validation method, and the performance also became numerically worse than that of the logistic regression model. In the time-to-event analysis, most models had a concordance index of around 0.70. Conclusions: Machine learning models with appropriate transfer learning may be a useful tool for the development of CV risk prediction models and may help improve patient care in the future.

CCL7 as a novel inflammatory mediator in cardiovascular disease, diabetes mellitus, and kidney disease.

Chemokines are key components in the pathology of chronic diseases. Chemokine CC motif ligand 7 (CCL7) is believed to be associated with cardiovascular disease, diabetes mellitus, and kidney disease. CCL7 may play a role in inflammatory events by attracting macrophages and monocytes to further amplify inflammatory processes and contribute to disease progression. However, CCL7-specific pathological signaling pathways need to be further confirmed in these chronic diseases. Given the multiple redundancy system among chemokines and their receptors, further experimental and clinical studies are needed to clarify whether direct CCL7 inhibition mechanisms could be a promising therapeutic approach to attenuating the development of cardiovascular disease, diabetes mellitus, and kidney disease.

Gal-1 (Galectin-1) Upregulation Contributes to Abdominal Aortic Aneurysm Progression by Enhancing Vascular Inflammation.

OBJECTIVE: Abdominal aortic aneurysm (AAA) is a vascular degenerative disease causing sudden rupture of aorta and significant mortality in elders. Nevertheless, no prognostic and therapeutic target is available for disease management. Gal-1 (galectin-1) is a ß-galactoside-binding lectin constitutively expressed in vasculature with roles in maintaining vascular homeostasis. This study aims to investigate the potential involvement of Gal-1 in AAA progression. Approach and Results: Gal-1 was significantly elevated in circulation and aortic tissues of Ang II (angiotensin II)-infused apoE-deficient mice developing AAA. Gal-1 deficiency reduced incidence and severity of AAA with lower expression of aortic MMPs (matrix metalloproteases) and proinflammatory cytokines. TNFα (tumor necrosis factor alpha) induced Gal-1 expression in cultured vascular smooth muscle cells and adventitial fibroblasts. Gal-1 deletion enhanced TNFα-induced MMP9 expression in fibroblasts but not vascular smooth muscle cells. Cysteinyl-labeling assay demonstrated that aortic Gal-1 exhibited susceptibility to oxidation in vivo. Recombinant oxidized Gal-1 induced expression of MMP9 and inflammatory cytokines to various extents in macrophages, vascular smooth muscle cells, and fibroblasts through activation of MAP (mitogen-activated protein) kinase signaling. Clinically, serum MMP9 level was significantly higher in both patients with AAA and coronary artery disease than in control subjects, whereas serum Gal-1 level was elevated in patients with AAA but not coronary artery disease when compared with controls. CONCLUSIONS: Gal-1 is highly induced and contributes to AAA by enhancing matrix degradation activity and inflammatory responses in experimental model. The pathological link between Gal-1 and AAA is also observed in human patients. These findings support the potential of Gal-1 as a disease biomarker and therapeutic target of AAA.

Circulating fatty-acid binding-protein 4 levels predict CV events in patients after coronary interventions.

BACKGROUND: Fatty-acid binding protein-4 (FABP4) has been associated with the metabolic syndrome, diabetes mellitus, atherosclerosis, incident heart failure, and the prognosis of coronary heart disease (CHD). However, recent studies have not reported a significant correlation between FABP4 and cardiovascular (CV) mortality in high-risk patients or those with documented CHD. The present study aimed to evaluate the association between FABP4 and the prognosis in a cohort of patients with CHD who received coronary interventions. METHODS: Serum FABP4 levels were measured in 973 patients after a successful intervention for CHD, who were then prospectively followed for 30 months. RESULT: During this period, 223 patients experienced composite CV outcomes (22.92%), defined as cardiovascular/cerebrovascular death, nonfatal myocardial infarction (MI), nonfatal stroke, hospitalization for refractory or unstable angina, hospitalization for heart failure, and peripheral artery occlusive disease. Kaplan-Meier curves showed a significant association between FABP4 levels at baseline (categorized in tertiles) and composite CV outcomes during follow-up (log-rank test, p < 0.003). The patients with the highest tertile of baseline FABP4 had an increased risk of composite CV outcomes (hazard ratio (HR) 1.662; 95% confidence interval (CI), 1.2-2.302; p = 0.0022), which remained significant after multivariate adjustments for traditional risk factors and hs-CRP (HR 1.596; 95% CI, 1.088-2.342; p = 0.0168). In contrast, FABP4 failed to show a significant association with cardiovascular/cerebrovascular death, nonfatal MI, or nonfatal stroke after multivariate adjustments (HR, 1.594; 95% CI, 0.651-3.904, p = 0.3073). CONCLUSION: In conclusion, circulating FABP4 is an independent prognostic predictor for the composite cardiovascular events in the patients with stable CHD after coronary interventions.

Deletion of the FHL2 gene attenuates intima-media thickening in a partially ligated carotid artery ligated mouse model.

The four and a half LIM domain protein 2 (FHL2) is a member of the four and a half LIM domain (FHL) gene family, and it is associated with cholesterol-enriched diet-promoted atherosclerosis. However, the effect of FHL2 protein on vascular remodelling in response to hemodynamic alterations remains unclear. Here, we investigated the role of FHL2 in a model of restricted blood flow-induced atherosclerosis. To promote neointimal hyperplasia in vivo, we subjected FHL2+/+ and FHL2-/- mice to partial ligation of the left carotid artery (LCA). The expression of p-ERK and p-AKT was decreased in FHL2-/- mice. FHL2 bound to AKT regulated AKT phosphorylation and led to Rac1-GTP inactivation. FHL2 silencing in human aortic smooth muscle cells down-regulated the PDGF-induced phosphorylation of ERK and AKT. Furthermore, FHL2 silencing reduced cytoskeleton conformational changes and caused cell cycle arrest. We concluded that FHL2 is essential for the regulation of arterial smooth muscle cell function. FHL2 modulates proliferation and migration via mitogen-activated protein kinase (MAPK) and PI3K-AKT signalling, leading to arterial wall thickening and thus neointimal hyperplasia.

Pulmonary hemodynamics and wave reflections in adults with atrial septal defects.

Using high-fidelity micromanometers and flow velocity sensors at right heart catheterization, we compared pulmonary hemodynamics and wave reflections in age-matched normal adults and those with atrial septal defects, separated into three subgroups based on levels of mean pulmonary artery pressure: low (<17 mmHg), intermediate (17-26 mmHg), high (>26 mmHg). We made baseline measurements in all groups and after intravenous sodium nitroprusside in the subgroups. All of the subgroups had higher than normal baseline pulmonary flows and corresponding power that did not differ among the subgroups. The pulmonary vascular resistance, input resistance, and characteristic impedance in the subgroups did not differ from normal. Aside from the elevated flow and power, the hemodynamics in the low subgroup did not differ from normal. The intermediate subgroup had significantly higher than normal right ventricular and pulmonary artery pressures, wave reflections, and shorter wave reflection time, which all reverted to normal after nitroprusside. The high subgroup had similar changes as the intermediate subgroup. Unlike that subgroup, however, the pressures, wave reflections, and reflection return time did not revert to normal after nitroprusside. Hence, elevated wave reflections, but not resistance or characteristic impedance, are the hallmark of pulmonary hypertension in adults with atrial septal defects. Our results demonstrate that detailed measurements of hemodynamics and assessment of responsiveness to vasodilators provide important information about the pulmonary circulation in atrial septal defect. Coupled with studies after defect closure, those results may be a better foundation than current ones for clinical decisions.

Systemic immune-inflammation index (SII) predicted clinical outcome in patients with coronary artery disease.

BACKGROUND: This study examines the predictive value of a novel systemic immune-inflammation index (SII, platelet × neutrophil/lymphocyte ratio) in coronary artery disease (CAD) patients. METHODS: A total of 5602 CAD patients who had undergone a percutaneous coronary intervention (PCI) were enrolled. They were divided into two groups by baseline SII score (high SII vs low SII) to analyse the relationship between SII groups and the long-term outcome. The primary outcomes were major cardiovascular events (MACE) which includes nonfatal myocardial infarction (MI), nonfatal stroke and cardiac death. Secondary outcomes included a composite of MACE and hospitalization for congestive heart failure. RESULTS: An optimal SII cut-off point of 694.3 × 109 was identified for MACE in the CAD training cohort (n = 373) and then verified in the second larger CAD cohort (n = 5602). Univariate and multivariate analyses showed that a higher SII score (≥694.3) was independently associated with increased risk of developing cardiac death (HR: 2.02; 95% CI: 1.43-2.86), nonfatal MI (HR: 1.42; 95% CI: 1.09-1.85), nonfatal stroke (HR: 1.96; 95% CI: 1.28-2.99), MACE (HR: 1.65; 95% CI: 1.36-2.01) and total major events (HR: 1.53; 95% CI: 1.32-1.77). In addition, the SII significantly improved risk stratification of MI, cardiac death, heart failure, MACE and total major events than conventional risk factors in CAD patients by the significant increase in the C-index (P < .001) and reclassification risk categories by significant NRI (P < .05) and IDI (P < .05). CONCLUSIONS: SII had a better prediction of major cardiovascular events than traditional risk factors in CAD patients after coronary intervention.

Hydralazine improves ischemia-induced neovasculogenesis via xanthine-oxidase inhibition in chronic renal insufficiency.

Oxidative stress is related to the progression of renal diseases and modulation of oxidative stress can lead to a reduction in vascular events in patients with chronic renal insufficiency (CRI). Indoxyl sulfate (IS) and xanthine oxidase (XO) are related to impaired neovasculogenesis in CRI. Hydralazine is suggested for blood pressure control in CRI. This study aimed to investigate whether hydralazine could improve ischemia-induced neovasculogenesis in CRI animals by reducing reactive oxygen species (ROS) levels. Mice underwent subtotal nephrectomy or sham surgery. Nitrendipine, probenecid, and allopurinol were used to reduce blood pressure, uric acid (UA), and XO activity levels, respectively, for comparison. Blood pressure, XO activity and UA levels that were increased after subtotal nephrectomy were reduced by hydralazine treatment. Allopurinol decreased blood XO activity and UA levels. Only hydralazine and allopurinol increased the number of circulating endothelial progenitor cells (EPCs) and improved neovasculogenesis in CRI mice. IS activated XO mRNA and ROS and inhibited the functions of EPCs and endothelial cells, which could be reversed by hydralazine. However, no additional beneficial effects were observed when XO was inhibited with both hydralazine and siRNA. In conclusion, hydralazine, as a potential XO inhibitor, not only reduced blood pressure and UA levels but also increased the number of circulating EPCs and improved neovasculogenesis in CRI animals. Hydralazine directly inhibited IS-induced ROS and XO activation in EPCs and endothelial cells, and restored their functions in vitro. Future studies should evaluate whether hydralazine could provide additional vascular protection in patients with CRI.

Circulating TNFSF14 (Tumor Necrosis Factor Superfamily 14) Predicts Clinical Outcome in Patients With Stable Coronary Artery Disease.

Objective- Basic research indicates that TNFSF14 (tumor necrosis factor superfamily 14) may be involved in the pathogenesis of atherosclerosis. Given the requirements of new biomarkers for risk classification in coronary artery disease (CAD), we conducted a longitudinal analysis to investigate if TNFSF14 levels are associated with the risk of cardiovascular events among patients with stable CAD. Approach and Results- In total, 894 patients with CAD were enrolled in a multicenter prospective study. The primary outcome was the occurrence of cardiovascular death, nonfatal myocardial infarction, and stroke. The secondary outcome was the occurrence of all-cause death, nonfatal myocardial infarction, stroke, revascularization, and hospitalization because of angina or heart failure. During the mean follow-up period of 22±9 months, 32 patients reached the primary outcome and 166 patients reached the secondary outcome. Kaplan-Meier analysis showed that the event-free survival was significantly different in the first and fourth quartile groups in subjects categorized by TNFSF14 levels. In multivariate Cox proportional hazard regression analysis, TNFSF14 was independently associated with the risk of cardiovascular events after adjustment for various relevant factors (adjusted hazard ratio, 1.14; 95% CI, 1.04-1.25). In the validation cohort of 126 multivessel patients with CAD, TNFSF14 was confirmed to provide good prognostic predictive value for composite cardiovascular events (adjusted hazard ratio, 1.11; 95% CI, 1.04-1.19). Conclusions- This is the first study to demonstrate that increased TNFSF14 levels were independently associated with the occurrence of cardiovascular events in patients with stable CAD. Future studies are worthy to validate if TNFSF14 could be a novel prognostic biomarker for CAD outcomes over different populations.

A performance guide for major risk factors control in patients with atherosclerotic cardiovascular disease in Taiwan.

Atherosclerotic cardiovascular disease (ASCVD), including coronary artery disease, cerebrovascular disease, and peripheral artery disease, carries a high morbidity and mortality. Risk factor control is especially important for patients with ASCVD to reduce recurrent cardiovascular events. Clinical guidelines have been developed by the Taiwan Society of Cardiology, Taiwan Society of Lipids and Atherosclerosis, and Diabetes Association of Republic of China (Taiwan) to assist health care professionals in Taiwan about the control of hypertension, hypercholesterolemia and diabetes mellitus. This article is to highlight the recommendations about blood pressure, cholesterol, and sugar control for ASCVD. Some medications that are beneficial for ASCVD were also reviewed. We hope the clinical outcomes of ASCVD can be improved in Taiwan through the implementation of these recommendations.

The Role of Chemokines and Chemokine Receptors in Diabetic Nephropathy.

Kidney function decline is one of the complications of diabetes mellitus and may be indicated as diabetic nephropathy (DN). DN is a chronic inflammatory disease featuring proteinuria and a decreasing glomerular filtration rate. Despite several therapeutic options being currently available, DN is still the major cause of end-stage renal disease. Accordingly, widespread innovation is needed to improve outcomes in patients with DN. Chemokines and their receptors are critically involved in the inflammatory progression in the development of DN. Although recent studies have shown multiple pathways related to the chemokine system, the specific and direct effects of chemokines and their receptors remain unclear. In this review, we provide an overview of the potential role and mechanism of chemokine systems in DN proposed in recent years. Chemokine system-related mechanisms may provide potential therapeutic targets in DN.

CCL4 Inhibition in Atherosclerosis: Effects on Plaque Stability, Endothelial Cell Adhesiveness, and Macrophages Activation.

Atherosclerosis is an arterial inflammatory disease. The circulating level of the C-C chemokine ligand (CCL4) is increased in atherosclerotic patients. This study aimed to investigate whether CCL4 inhibition could retard the progression of atherosclerosis. In ApoE knockout mice, CCL4 antibody treatment reduced circulating interleukin-6 (IL-6) and tumor necrosis factor (TNF)-α levels and improved lipid profiles accompanied with upregulation of the liver X receptor. CCL4 inhibition reduced the atheroma areas and modified the progression of atheroma plaques, which consisted of a thicker fibrous cap with a reduced macrophage content and lower matrix metalloproteinase-2 and -9 expressions, suggesting the stabilization of atheroma plaques. Human coronary endothelial cells (HCAECs) and macrophages were stimulated with TNF-α or oxidized LDL (ox-LDL). The induced expression of E-selectin, vascular cell adhesion molecule-1 (VCAM-1), and intercellular adhesion molecule-1 (ICAM-1) were attenuated by the CCL4 antibody or CCL4 si-RNA. CCL4 inhibition reduced the adhesiveness of HCAECs, which is an early sign of atherogenesis. CCL4 blockade reduced the activity of metalloproteinase-2 and -9 and the production of TNF-α and IL-6 in stimulated macrophages. The effects of CCL4 inhibition on down-regulating adhesion and inflammation proteins were obtained through the nuclear factor kappa B (NFκB) signaling pathway. The direct inhibition of CCL4 stabilized atheroma and reduced endothelial and macrophage activation. CCL4 may be a novel therapeutic target for modulating atherosclerosis.

Fatty-Acid-Binding Protein 4 as a Novel Contributor to Mononuclear Cell Activation and Endothelial Cell Dysfunction in Atherosclerosis.

Background-Elevated circulating fatty-acid-binding protein 4 (FABP4) levels may be linked with cardiovascular events. This study aimed to investigate the mechanistic role of FABP4 in atherosclerosis. Methods-We recruited 22 patients with angiographically proven coronary artery disease (CAD) and 40 control subjects. Mononuclear cells (MNCs) and human coronary endothelial cells (HCAECs) were used for in vitro study. Results-Patients with CAD were predominantly male with an enhanced prevalence of hypertension, diabetes, and smoking history. FABP4 concentrations were up-regulated in culture supernatants of MNCs from CAD patients, which were positively correlated with the patients' age, waist-hip ratio, body mass index, serum creatinine, type 2 diabetes, and the presence of hypertension. The adhesiveness of HCAECs to monocytic cells can be activated by FABP4, which was reversed by an FABP4 antibody. FABP4 blockade attenuated the oxidized low-density lipoprotein (oxLDL)-induced expression of ICAM-1, VCAM-1, and P-selectin. FABP4 impaired the tube formation and migration via the ERK/JNK/STAT-1 signaling pathway. FABP4 suppressed phosphorylation of eNOS and expression of SDF-1 protein, both of which can be reversed by treatment with VEGF. Blockade of FABP4 also improved the oxLDL-impaired cell function. Conclusion-We discovered a novel pathogenic role of FABP4 in MNC activation and endothelial dysfunction in atherosclerosis. FABP4 may be a therapeutic target for modulating atherosclerosis.

Inhibition of macrophage inflammatory protein-1ß improves endothelial progenitor cell function and ischemia-induced angiogenesis in diabetes.

Systemic inflammation might contribute to the impairment of neovasculogenesis and endothelial progenitor cell (EPC) function in clinical diabetes mellitus (DM). Macrophage inflammatory protein-1ß (MIP-1ß) is an inflammatory chemokine that may be up-regulated in clinical DM. Its role in diabetic vasculopathy was not clarified. This study aimed to investigate the role of MIP-1ß in human EPCs and in neovasculogenesis in different diabetic animal models with hindlimb ischemia. EPCs chamber assay and in vitro tube formation assay were used to estimate the degree of EPC migration and tube formation abilities. Leprdb/JNarl mice, C57BL/6 mice fed a high-fat diet, and streptozotocin-induced diabetic mice were used as different diabetic animal models. Laser Doppler imaging and flow cytometry were used to evaluate the degree of neovasculogenesis and the circulating levels of EPCs, respectively. MIP-1ß impaired human EPC function for angiogenesis in vitro. Plasma MIP-1ß levels were up-regulated in type 2 DM patients. MIP-1ß inhibition enhanced the function and the C-X-C chemokine receptor type 4 expression of EPCs from type 2 diabetic patients, and improved EPC homing for ischemia-induced neovasculogenesis in different types of diabetic animals. MIP-1ß directly impaired human EPC function. Inhibition of MIP-1ß improved in vitro EPC function, and enhanced in vivo EPC homing and ischemia-induced neovasculogenesis, suggesting the critical role of MIP-1ß for vasculopathy in the presence of DM.