Platelet expression of transforming growth factor beta 1 is enhanced and associated with cardiovascular prognosis in patients with acute coronary syndrome

Coronary artery bypass grafting (CABG) induces pro-inflammatory and immunomodulatory phenotype of platelets in the absence of a pro-aggregatory state

BACKGROUND

Coronary artery bypass grafting (CABG) is considered the choice treatment for patients suffering from coronary artery disease (CAD). In the inflammatory milieu of cardiopulmonary bypass (CPB), systemic inflammatory response syndrome (SIRS) can induce a platelet pro-inflammatory state which could exacerbate post-CABG inflammatory status while affecting hemostatic function in patients. Therefore, focusing on platelets, the study presented here attempted to evaluate the pro-inflammatory and immunomodulatory profile of platelets as well as pro-aggregatory status during CABG.

METHODS

Platelets from patients undergoing CABG were subjected to flowcytometry analysis to evaluate P-selectin and CD40L expressions and PAC-1 binding in five intervals of 24 h before surgery, immediately, 2 h, 24 h, and one week after surgery. Moreover, intra-platelet TGF-β1 was also examined with western blotting.

RESULTS

Data showed increases of P-selectin and CD40L expressions in patients, with the meaningful loss of platelet contents of TGF-β1 after CABG (p < 0.001), where the changes tended to recover by day 7 of surgery while remaining above baseline (p < 0.001). Meanwhile, no significant change in PAC-1 binding capacity was shown.

CONCLUSION

The study presented here suggests that although the release of pro-inflammatory substances from platelets during CABG supports the post-operative inflammatory state, platelets are not pro-aggregatory enough to enhance thrombotic events after surgery. Whilst these observations could be due to successful medical interventions to optimize hemostasis during and after surgery, post-CABG reversal of anticoagulant by protamine is considered as another factor that may also have contributed to preventing pro-aggregatory but not pro-inflammatory and immunomodulatory functions of platelets.

Prognostic value of 11-factor modified frailty index in postoperative adverse outcomes of elderly gastric cancer patients in China

BACKGROUND

Preoperative evaluation of frailty is limited to a few surgical procedures. However, the evaluation in Chinese elderly gastric cancer (GC) patients remains blank.

AIM

To validate and estimate the prognostic value of the 11-index modified frailty index (mFI-11) for predicting postoperative anastomotic fistula, intensive care unit (ICU) admission, and long-term survival in elderly patients (over 65 years of age) undergoing radical GC.

METHODS

This study was a retrospective cohort study which included patients who underwent elective gastrectomy with D2 Lymph node dissection between April 1, 2017 and April 1, 2019. The primary outcome was 1-year all-cause mortality. The secondary outcomes were admission to ICU, anastomotic fistula, and 6-mo mortality. Patients were divided into two groups according to the optimal grouping cutoff of 0.27 points from previous studies: High risk of frailty marked as mFI-11^High and low risk of frailty marked as mFI-11^Low. Survival curves between the two groups were compared, and univariate and multivariate regression analyses were performed to explore the relationship between preoperative frailty and postoperative complications in elderly patients undergoing radical GC. The discrimination ability of the mFI-11, prognostic nutritional index, and tumor-node-metastasis pathological stage to identify adverse postoperative outcomes was assessed by calculating the area under the receiver operating characteristic (ROC) curve.

RESULTS

A total of 1003 patients were included, of which 13.86% (139/1003) were defined as having mFI-11^High and 86.14% (864/1003) as having mFI-11^Low. By comparing the incidence of postoperative complications in the two groups of patients, it was found that mFI-11^High patients had higher rates of 1-year postoperative mortality, admission to ICU, anastomotic fistula, and 6-mo mortality than the mFI-11^Low group (18.0% vs 8.9%, P = 0.001; 31.7% vs 14.7%, P < 0.001; 7.9% vs 2.8%, P < 0.001; and 12.2% vs 3.6%, P < 0.001). Multivariate analysis revealed mFI-11 as an independent predictive indicator for postoperative outcome [1-year postoperative mortality: Adjusted odds ratio (aOR) = 4.432, 95% confidence interval (95%CI): 2.599-6.343, P = 0.003; admission to ICU: aOR = 2.058, 95%CI: 1.188-3.563, P = 0.010; anastomotic fistula: aOR = 2.852, 95%CI: 1.357-5.994, P = 0.006; 6-mo mortality: aOR = 2.438, 95%CI: 1.075-5.484, P = 0.033]. mFI-11 showed better prognostic efficacy in predicting 1-year postoperative mortality [area under the ROC curve (AUROC): 0.731], admission to ICU (AUROC: 0.776), anastomotic fistula (AUROC: 0.877), and 6-mo mortality (AUROC: 0.759).

CONCLUSION

Frailty as measured by mFI-11 could provide prognostic information for 1-year postoperative mortality, admission to ICU, anastomotic fistula, and 6-mo mortality in patients over 65 years old undergoing radical GC.

Hypercholesterolemic Dysregulation of Calpain in Lymphatic Endothelial Cells Interferes With Regulatory T-Cell Stability and Trafficking

BACKGROUND

Although hypercholesterolemia reportedly counteracts lymphocyte trafficking across lymphatic vessels, the roles of lymphatic endothelial cells (LECs) in the lymphocyte regulations remain unclear. Previous studies showed that calpain-an intracellular modulatory protease-interferes with leukocyte dynamics in the blood microcirculation and is associated with hypercholesterolemic dysfunction in vascular endothelial cells.

METHODS

This study investigated whether the calpain systems in LECs associate with the LEC-lymphocyte interaction under hypercholesterolemia using gene-targeted mice.

RESULTS

Lipidomic analysis in hypercholesterolemic mice showed that several lysophospholipids, including lysophosphatidic acid, accumulated in the lymphatic environment. Lysophosphatidic acid enables the potentiation of calpain systems in cultured LECs, which limits their ability to stabilize regulatory T cells (Treg) without altering Th1/Th2 (T helper type1/2) subsets. This occurs via the proteolytic degradation of MEKK1 (mitogen-activated protein kinase kinase kinase 1) and the subsequent inhibition of TGF (transforming growth factor)-β1 production in LECs. Targeting calpain systems in LECs expanded Tregs in the blood circulation and reduced aortic atherosclerosis in hypercholesterolemic mice, concomitant with the reduction of proinflammatory macrophages in the lesions. Treg expansion in the blood circulation and atheroprotection in calpain-targeted mice was prevented by the administration of TGF-β type-I receptor inhibitor. Moreover, lysophosphatidic acid-induced calpain overactivation potentiated the IL (interleukin)-18/NF-κB (nuclear factor κB)/VCAM1 (vascular cell adhesion molecule 1) axis in LECs, thereby inhibiting lymphocyte mobility on the cells. Indeed, VCAM1 in LECs was upregulated in hypercholesterolemic mice and human cases of coronary artery disease. Neutralization of VCAM1 or targeting LEC calpain systems recovered afferent Treg transportation via lymphatic vessels in mice.

CONCLUSIONS

Calpain systems in LECs have a key role in controlling Treg stability and trafficking under hypercholesterolemia.

Stable CAD patients show higher levels of platelet-borne TGF-β1 associated with a superior pro-inflammatory state than the pro-aggregatory status; Evidence highlighting the importance of platelet-derived TGF-β1 in atherosclerosis

Activated platelets are involved in the atherogenic stage of atherosclerosis, while they can also progress it to atherothrombosis which may cause an ischemic state and organ failure. In general, coronary artery disease (CAD) is considered as common and severe clinical consequence of atherosclerosis, manifesting as a chronic inflammatory condition with the release of platelet mediators, among which the importance of platelet-borne TGF-β1 is not yet well understood. Hence, for the first time, this study aimed to examine platelet level of TGF-β1 (latent/mature) in CAD-patients and its association with the expression of platelet pro-inflammatory molecules. Platelet from stable CAD-patients candidate for CABG and healthy controls were subjected to flowcytometry analysis to evaluate P-selectin and CD40L expressions and PAC-1 binding. Platelet-borne and soluble TGF-β1, both mature/active and latent forms were also examined with western blotting. Higher expression levels of P-selectin and CD40L in patients with CAD than in controls were associated with comparable levels of PAC-1 binding in both groups. Platelet TGF-β1 levels were also significantly higher in patients, while their platelets showed clear bands of mature TGF-β1 that were barely visible in healthy individuals. Soluble TGF-β1 was also higher in patients. Significant correlations between mature/active TGF-β1 and platelet pro-inflammatory markers (P-selectin and CD40L) as well as common indicators of inflammation (CRP and ESR) were observed in CAD patients. In this study, given the insignificant changes in pro-aggregatory potentials in stable CAD, the pro-inflammatory state of platelets may be more involved in disease development and progression. Direct correlations between active platelet-borne TGF-β1 and pro-inflammatory markers with its presence in CAD-patients, which was almost absent in the platelets of healthy individuals, may also underscore the significant contribution of platelet-borne TGF-β1 to the pathogenesis of the disease.

TGF-beta signal transduction: biology, function and therapy for diseases

The transforming growth factor beta (TGF-β) is a crucial cytokine that get increasing concern in recent years to treat human diseases. This signal controls multiple cellular responses during embryonic development and tissue homeostasis through canonical and/or noncanonical signaling pathways. Dysregulated TGF-β signal plays an essential role in contributing to fibrosis via promoting the extracellular matrix deposition, and tumor progression via inducing the epithelial-to-mesenchymal transition, immunosuppression, and neovascularization at the advanced stage of cancer. Besides, the dysregulation of TGF-beta signal also involves in other human diseases including anemia, inflammatory disease, wound healing and cardiovascular disease et al. Therefore, this signal is proposed to be a promising therapeutic target in these diseases. Recently, multiple strategies targeting TGF-β signals including neutralizing antibodies, ligand traps, small-molecule receptor kinase inhibitors targeting ligand-receptor signaling pathways, antisense oligonucleotides to disrupt the production of TGF-β at the transcriptional level, and vaccine are under evaluation of safety and efficacy for the forementioned diseases in clinical trials. Here, in this review, we firstly summarized the biology and function of TGF-β in physiological and pathological conditions, elaborated TGF-β associated signal transduction. And then, we analyzed the current advances in preclinical studies and clinical strategies targeting TGF-β signal transduction to treat diseases.

Platelets in Myocardial Ischemia/Reperfusion Injury

Coronary artery disease, including myocardial infarction (MI), remains a leading cause of global mortality. Rapid reperfusion therapy is key to the improvement of patient outcome but contributes substantially to the final cardiac damage. This phenomenon is called "ischemia/reperfusion injury (IRI)." The underlying mechanisms of IRI are complex and not fully understood. Contributing cellular and molecular mechanisms involve the formation of microthrombi, alterations in ion concentrations, pH shifts, dysregulation of osmolality, and, importantly, inflammation. Beyond their known action as drivers of the development of coronary plaques leading to MI, platelets have been identified as important mediators in myocardial IRI. Circulating platelets are activated by the IRI-provoked damages in the vascular endothelium. This leads to platelet adherence to the reperfused endothelium, aggregation, and the formation of microthrombi. Furthermore, activated platelets release vasoconstrictive substances, act via surface molecules, and enhance leukocyte infiltration into post-IR tissue, that is, via platelet-leukocyte complexes. A better understanding of platelet contributions to myocardial IRI, including their interaction with other lesion-associated cells, is necessary to develop effective treatment strategies to prevent IRI and further improve the condition of the reperfused myocardium. In this review, we briefly summarize platelet properties that modulate IRI. We also describe the beneficial impacts of antiplatelet agents as well as their mechanisms of action in IRI beyond classic effects.

Cardiovascular Disease in Myeloproliferative Neoplasms: JACC: CardioOncology State-of-the-Art Review

Myeloproliferative neoplasms are associated with increased risk for thrombotic complications. These conditions most commonly involve somatic mutations in genes that lead to constitutive activation of the Janus-associated kinase signaling pathway (eg, Janus kinase 2, calreticulin, myeloproliferative leukemia protein). Acquired gain-of-function mutations in these genes, particularly Janus kinase 2, can cause a spectrum of disorders, ranging from clonal hematopoiesis of indeterminate potential, a recently recognized age-related promoter of cardiovascular disease, to frank hematologic malignancy. Beyond thrombosis, patients with myeloproliferative neoplasms can develop other cardiovascular conditions, including heart failure and pulmonary hypertension. The authors review the pathophysiologic mechanisms of cardiovascular complications of myeloproliferative neoplasms, which involve inflammation, prothrombotic and profibrotic factors (including transforming growth factor-beta and lysyl oxidase), and abnormal function of circulating clones of mutated leukocytes and platelets from affected individuals. Anti-inflammatory therapies may provide cardiovascular benefit in patients with myeloproliferative neoplasms, a hypothesis that requires rigorous evaluation in clinical trials.

Identification of an miRNA Regulatory Network and Candidate Markers for Ischemic Stroke Related to Diabetes

Purpose

Type 2 diabetes mellitus (T2DM) increases the risk of ischemic stroke and poor prognosis. This study aimed to identify molecular mechanisms that are dysregulated in T2DM-associated ischemic stroke and candidate genes that might serve as biomarkers.

Methods

The top 25% variance genes in the GSE21321 and GSE22255 datasets were analyzed for coexpression. The differentially expressed mRNAs (DEmRs) between patients with T2DM or ischemic stroke and controls were analyzed. Then, the union of overlapping coexpressed genes and overlapping DEmRs was analyzed. The miRNAs differentially expressed in T2DM-associated ischemic stroke were also analyzed. CIBERSORT was used to evaluate the levels of infiltration by immune cells in T2DM-associated stroke.

Results

Thirteen coexpression modules were identified in T2DM and 10 in ischemic stroke, and 594 module genes were shared between the two conditions. A total of 4452 mRNAs differentially expressed between T2DM patients and controls were identified, as were 2390 mRNAs differentially expressed between ischemic stroke and controls. The 771 union genes were enriched mainly in immune-related biological functions and signaling pathways. UBE2N, TGFB3, EXOSC1, and VIM were identified as candidate markers. In addition, we identified miR-576-3p as having the most regulatory roles in both T2DM and ischemic stroke. Mast cell activation was significantly down-regulated in T2DM but up-regulated in ischemic stroke.

Conclusion

These findings provide numerous testable hypotheses about the pathways underlying T2DM-associated ischemic stroke, which may help identify therapeutic targets.

Protective Role of Platelets in Myocardial Infarction and Ischemia/Reperfusion Injury

Thrombotic occlusion of the coronary artery is a key component in the pathogenesis of myocardial ischemia and myocardial infarction (MI). The standard therapy for ischemia is revascularization and restoration of blood flow to previously ischemic myocardium. Paradoxically, reperfusion may result in further tissue damage called ischemia/reperfusion injury (IRI). Platelets play a major role in the pathogenesis of MI and IRI, since they contribute to the thrombus and microthrombi formation, inflammation, release of immunomodulatory mediators, and vasoconstrictive molecules. Antiplatelet therapies have proven efficacy in the prevention of thrombosis and play a protective role in cardiac IRI. Beyond the deterioration effect of platelets in MI and IRI, in the 90s the first reports on a protective effect of molecules released from platelets during MI appeared. However, the role of platelets in cardioprotection is still poorly understood. This review describes the involvement of platelets in MI, IRI, and inflammation. It mainly focuses on the protective role of platelets in MI and IRI. Platelets are involved in cardioprotection based on platelet-releasing molecules and antiplatelet therapy, apart from antiaggregatory effects. Additionally, the use of platelet-derived microparticles as possible markers of MI, with and without comorbidities, and their role in cardioprotection are discussed. This review is aimed at illustrating the present knowledge on the role of platelets in MI and IRI, especially in a context of cardioprotection.

Circulating osteogenic proteins are associated with coronary artery calcification and increase after myocardial infarction

BACKGROUND

Coronary artery calcification (CAC) and atherosclerotic inflammation associate with increased risk of myocardial infarction (MI). Vascular calcification is regulated by osteogenic proteins (OPs). It is unknown whether an association exists between CAC and plasma OPs and if they are affected by atherothrombotic inflammation. We tested the association of osteogenic and inflammatory proteins with CAC and assessed these biomarkers after MI.

METHODS

Circulating OPs (osteoprotegerin, RANKL, fetuin-A, Matrix Gla protein [MGP]) and inflammatory proteins (C-reactive protein, oxidized-LDL, tumoral necrosis factor-α, transforming growth factor [TGF]-β1) were compared between stable patients with CAC (CAC ≥ 100 AU, n = 100) and controls (CAC = 0 AU, n = 30). The association between biomarkers and CAC was tested by multivariate analysis. In patients with MI (n = 40), biomarkers were compared between acute phase and 1-2 months post-MI, using controls as a baseline.

RESULTS

MGP and fetuin-A levels were higher within individuals with CAC. Higher levels of MGP and RANKL were associated with CAC (OR 3.12 [95% CI 1.20-8.11], p = 0.02; and OR 1.75 [95% CI 1.04-2.94] respectively, p = 0.035). After MI, C-reactive protein, OPG and oxidized-LDL levels increased in the acute phase, whereas MGP and TGF-β1 increased 1-2 months post-MI.

CONCLUSIONS

Higher MGP and RANKL levels associate with CAC. These findings highlight the potential role of these proteins as modulators and markers of CAC. In addition, the post-MI increase in OPG and MGP, as well as of inflammatory proteins suggest that the regulation of these OPs is affected by atherothrombotic inflammation.

Transforming Growth Factor-β Protects against Inflammation-Related Atherosclerosis in South African CKD Patients

Background

Transforming growth factor-β (TGF-β) may inhibit the development of atherosclerosis. We evaluated serum levels of TGF-β isoforms concurrently with serum levels of endotoxin and various inflammatory markers. In addition, we determined if any association exists between polymorphisms in the TGF-β1 gene and atherosclerosis in South African CKD patients.

Methods

We studied 120 CKD patients and 40 healthy controls. Serum TGF-β1, TGF-β2, TGF-β3, endotoxin, and inflammatory markers were measured. Functional polymorphisms in the TGF-β1 genes were genotyped using a polymerase chain reaction-sequence specific primer method and carotid intima media thickness (CIMT) was assessed by B-mode ultrasonography.

Results

TGF-β isoforms levels were significantly lower in the patients with atherosclerosis compared to patients without atherosclerosis (p<0.001). Overall, TGF-β isoforms had inverse relationships with CIMT. TGF-β1 and TGF-β2 levels were significantly lower in patients with carotid plaque compared to those without carotid plaque [TGF-β1: 31.9 (17.2 – 42.2) versus 45.9 (35.4 – 58.1) ng/ml, p=0.016; and TGF-β2: 1.46 (1.30 – 1.57) versus 1.70 (1.50 – 1.87) ng/ml, p=0.013]. In multiple logistic regression, age, TGF-β2, and TGF-β3 were the only independent predictors of subclinical atherosclerosis in CKD patients [age: odds ratio (OR), 1.054; 95% confidence interval (CI): 1.003 – 1.109, p=0.039; TGF-β2: OR, 0.996; 95% CI: 0.994–0.999, p=0.018; TGF-β3: OR, 0.992; 95% CI: 0.985–0.999, p=0.029). TGF-β1 genotypes did not influence serum levels of TGF-β1 and no association was found between the TGF-β1 gene polymorphisms and atherosclerosis risk.

Conclusion

TGF-β isoforms seem to offer protection against the development of atherosclerosis among South African CKD patients.

Absence of transforming growth factor beta 1 in murine platelets reduces neointima formation without affecting arterial thrombosis

Platelet degranulation at the site of vascular injury prevents bleeding and may affect the chronic vascular wound healing response. Transforming Growth Factor (TGF)-β1 is a major component of platelet α-granules known to accumulating in thrombi. It was our aim to determine the role of TGFβ1 released from activated platelets for neointima formation following arterial injury and thrombosis. Mice with platelet-specific deletion of TGFβ1 (Plt.TGFβ-KO) underwent carotid artery injury. Immunoassays confirmed the absence of active TGFβ1 in platelet releasates and plasma of Plt.TGFβ-KO mice. Whole blood analyses revealed similar haematological parameters, and tail cut assays excluded major bleeding defects. Platelet aggregation and the acute thrombotic response to injury in vivo did not differ between Plt.TGFβ-KO and Plt.TGFβ-WT mice. Morphometric analysis revealed that absence of TGFβ1 in platelets resulted in a significant reduction of neointima formation with lower neointima area, intima-to-media ratio, and lumen stenosis. On the other hand, the media area was enlarged in mice lacking TGFβ1 in platelets and contained increased amounts of proteases involved in latent TGFβ activation, including MMP2, MMP9 and thrombin. Significantly increased numbers of proliferating cells and cells expressing the mesenchymal markers platelet-derived growth factor receptor-β or fibroblast-specific protein-1, and the macrophage antigen F4/80, were observed in the media of Plt.TGFβ-KO mice, whereas the medial smooth muscle-actin-immunopositive area and collagen content did not differ between genotypes. Our findings support an essential role for platelet-derived TGFβ1 for the vascular remodelling response to arterial injury, apparently independent from the role of platelets in thrombosis or haemostasis.

MicroRNA‑126 inhibits endothelial permeability and apoptosis in apolipoprotein E‑knockout mice fed a high‑fat diet

Endothelial dysfunction and apoptosis have key roles in the initiation and progression of atherosclerosis (AS). AS has been demonstrated to be associated with a high-fat diet, which may increase endothelial permeability and apoptosis; however, the exact mechanisms underlying the development of AS remain poorly understood. MicroRNAs (miRNAs) are vital for the regulation of cardiovascular disease, and dysregulated miRNAs have been implicated in AS. The present study investigated whether miRNA (miR)-126 regulates high-fat diet-induced endothelial permeability and apoptosis by targeting transforming growth factor β (TGFβ), a secreted protein that controls cellular proliferation and apoptosis. In the present study, apolipoprotein E (apoE)^−/− mice were fed a high-fat diet in order to establish a model of AS. Mice were subcutaneously injected with a miR-126 mimic, a miR-126 antagomir or control miRNA. Reverse transcription-quantitative polymerase chain reaction was used to assess miR-126 expression, and a fluorometric assay was used to evaluate caspase-3 activity. The effects of miR-126 on the endothelial permeability of the aortic intima were also explored. Western blotting and immunohistochemical analysis were used to investigate the effects of miR-126 on B-cell lymphoma-2 (Bcl-2) and transforming growth factor (TGF) β protein expression levels. Furthermore, a luciferase assay was performed to verify whether TGFβ may be a direct target gene of miR-126. In apolipoprotein E-knockout mice, a high-fat diet reduced miR-126 expression and induced apoptosis as determined by the upregulation of caspase-3 activity. A miR-126 antagomir increased endothelial permeability and apoptosis in mice fed a high-fat diet. By contrast, an miR-126 mimic attenuated endothelial permeability and apoptosis. The reduction in miR-126 was associated with a reduction in protein expression levels of Bcl-2 and an increase of TGFβ in mice fed a high-fat diet. In addition, the present study demonstrated that miR-126 reduced TGFβ expression following binding to the 3′-untranslated region of TGFβ mRNA. The current study demonstrated a role for miR-126 in AS and identified TGFβ as a direct target of miR-126. Furthermore, the present study demonstrated that miR-126 contributed to endothelial permeability and apoptosis, and suggested that the downregulation of TGFβ may be involved in the molecular mechanisms underlying the actions of miR-126. miR-126 may therefore have potential as a novel therapeutic target for the treatment of AS.

Circulating miR-30 is related to carotid artery atherosclerosis

OBJECTIVES

The aim of this study is to evaluate the relationship of miR-30 with office and ambulatory blood pressure parameters and carotid intima-media thickness (CIMT) in patients with hypertension and healthy controls.

METHODS

We assessed the expression level of miR-30 in 40 patients with essential hypertension and 40 healthy individuals. All patients underwent carotid artery ultrasonography, and office and ambulatory blood pressure monitoring. Quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) was used to evaluate the expression level of selected miR-30. The miR-30 expression level correlation between blood pressure parameters and CIMT was assessed using the Spearman correlation coefficient. Multiple logistic regression analysis was performed to assess independent association between miR-30 expression level and CIMT.

RESULTS

We observed lower expression level of miR-30 (26.01 ± 2.40 vs. 28.26 ± 1.28; p < 0.001) in hypertensive patients compared with healthy control individuals, as well as in increased CIMT group compared with normal CIMT group (25.09 ± 1.84 vs. 27.81 ± 2.37; p < 0.001). miR-30 expression level showed significant negative correlation with 24 h mean SBP (r = -0.51, p < 0.001), 24 h mean DBP(r = -0.316, p = 0.004), office SBP(r = -0.502, p < 0.001), office DBP (r = -0.205, p = 0.068), and CIMT (r = -0.578, p < 0.001), respectively. The odds ratio for CIMT was 0.519 (B = -0.748, CI 95% 0.278, 0.806; p = 0.006).

CONCLUSION

Our study suggests that circulating miR-30 might be used as a biomarker for atherosclerosis in essential hypertensive patients.

Evidence of an interaction between TGF-β1 and the SDF-1/CXCR4/CXCR7 axis in human platelets

BACKGROUND

TGF-β1, SDF-1 and its cognate receptors CXCR4 and CXCR7 are expressed on the surface of human platelets and their expression levels are differently regulated in symptomatic coronary artery disease (CAD). All these proteins and receptors influence outcome in patients with symptomatic CAD. There might be a crosstalk between TGF-β1 and the SDF-1/CXCR4/CXCR7 axis. Interrelations in CAD, especially in the context of platelets, are poorly understood. Therefore, we aimed to provide clinical and experimental evidence of interactions between TGF-β1 and the SDF-1/CXCR4/CXCR7 axis in human platelets.

METHODS AND RESULTS

Blood samples of the complete cohort (n=284) were analysed for platelet surface expression levels of TGF-β1, SDF-1, CXCR4 and CXCR7 by flow cytometry. For stimulation assays platelet rich plasma was treated with TGF-β1 or SDF-1 and then analysed by flow cytometry. Multiple regression analyses were run to show independent associations of TGF-β1 with SDF-1, CXCR4, CXCR7 and clinical cofactors. Both, CXCR4 and CXCR7 significantly predicted TGF-β1 (p<0.001 and p<0.001, respectively). After stimulation with SDF-1, surface expression of TGF-β1 increased significantly when compared to resting platelets [mean TGF-β1 MFI 19.01 vs. mean TGF-β1 MFI 14.01, p<0.001]. Upon receptor blocking with either anti-CXCR4 or anti-CXCR7 monoclonal antibodies the enhancing effect of SDF-1 on TGF-β1 surface expression was significantly blunted. Stimulation with TGF-β1 did not alter SDF-1, CXCR4 or CXCR7 expression significantly.

CONCLUSIONS

We provide first clinical and experimental data suggesting a cross-talk between TGF-β and the SDF-1/CXCR4/CXCR7 axis in platelets which does not involve transcriptional modulation as shown previously for other cellular systems.

Oleic acid activates MMPs up-regulation through SIRT1/PPAR-γ inhibition: a probable linkage between obesity and coronary arterial disease

Obesity is positively related to the growing prevalence of coronary arterial disease (CAD). It is well established in terms of the plasma concentrations of free fatty acid (FFA) that are up-regulated in cases associating with obesity. Oleic acid (OA) is known as the most abundant monounsaturated fatty acid in the human circulatory system. Several pro-atherosclerotic responses of OA have been established. Sirtuin 1 (SIRT1) acts as a key role in regulating the normal physical function in smooth muscle cells (SMCs). SIRT1 activation is developed as a novel approach to delay the progression of atherosclerotic injuries. However, the mechanism is still unclear as to whether OA affects SIRT1 expression and its activity in SMCs. We confirmed that OA treatment represses SIRT1 and peroxisome proliferator-activated receptors-γ levels in SMCs. Moreover, OA enhances by transforming the growth factor-β1 (TGF-β1) release via activation of NF-κB. OA causes NO production by inducing the inducible nitric oxide synthase overexpression, thereby promoting the secretions of matrix metalloproteinases-1 (MMP-1) and MMP-3. Overall, we suggested that OA enhances MMPs activation through SIRT1 down-regulation. Therefore, our findings might provide a novel route for developing new therapeutic treatments for FFAs-related CADs.

Transforming growth-beta 1 contributes to isoflurane postconditioning against cerebral ischemia-reperfusion injury by regulating the c-Jun N-terminal kinase signaling pathway

AIM

Cerebral ischemia-reperfusion (I/R) injury is a devastating complication in the perioperative period. Transforming growth factor beta (TGF-β) is a key protein that can participate in the repair and control process responses after I/R injury. Isoflurane is widely used in neurosurgery. Previous studies have shown that isoflurane preconditioning plays an important role in neuroprotection. However, the effects of isoflurane postconditioning on cerebral I/R injury have not yet been elucidated. In the present study, we evaluated the protective effect of isoflurane postconditioning against cerebral I/R injury and investigated the role of the TGF-β signaling pathway and the downstream c-Jun N-terminal kinase (JNK) signaling pathway in neuroprotective mechanism. In particular, the JNK signaling pathway emerges as a possible target for brain repair after stroke.

METHODS

Cerebral I/R injury was produced in SD rat by using the middle cerebral artery occlusion model for 90 min, followed by 24h reperfusion. Postconditioning by inhalation of isoflurane was performed at different concentrations (1.5%, 3.0%, and 4.5%) for 1h after ischemia at the starting time point of reperfusion. The protective effect was tested by neurological deficit scoring with 2,3,5-triphenyl tetrazolium chloride and propidium iodide (PI) staining. Apoptosis of CA1 cells in the hippocampus was detected by TUNEL method. Expression levels of TGF-β1, Smad 2/3, p-Smad2/3, JNK, and p-JNK were determined by immunostaining and Western blot.

RESULTS

Postconditioning by isoflurane at 1.5% and 3.0% concentrations significantly decreased the neurobehavioral deficit scores and infarct volume compared with the I/R group, but no significant difference in neurobehavioral deficit score was detected between the I/R and 4.5% isoflurane postconditioning groups. Additionally, 1.5% isoflurane postconditioning decreased the numbers of PI-positive cells at 24h after reperfusion compared with the I/R group. TGF-β1 and p-Smad2/3 protein gradually increased after I/R injury, with the highest values observed in the 1.5% and 3% isoflurane postconditioning groups. For Smad2/3 protein expression, no differences existed among all groups. After inducing the TGF-β/SMAD3 signaling pathway specific blocker (LY2157299), the neurological deficit scores increased, infarct volumes enlarged, apoptosis increased, and PI-positive CA1 cells in the hippocampus also increased. The expression levels of TGF-β1 and p-Smad2/3 proteins were downregulated. During the pre-injection of LY2157299, the expression levels of TGF-β1 and p-Smad2/3 decreased significantly, but compared with the sham group, the expression level of p-JNK significantly increased. When the injection of LY2157299 was abolished, the expression of p-JNK significantly decreased. The expression levels of p-JNK and TGF-β1 significantly decreased when LY2157299 and SP600125 were injected simultaneously. However, the protective effect mediated by SP600125 completely disappeared, and the role of LY2157299 became dominant. Compared with the sham group, the expression of TGF-β1 was almost unchanged by the injection of SP600125 alone, but the expression of p-JNK significantly decreased.

CONCLUSIONS

Up to 1.5% isoflurane can upregulate the expression of TGF-β1 and downregulate that of p-JNK, which significantly mitigated I/R injury, leading to cerebral injury. However, this protective effect was abrogated when the TGF-β1 signaling pathway was blocked by LY2157299. Overall, the present results provided valid evidence to demonstrate that TGF-β1 contributes to isoflurane postconditioning against cerebral I/R injury by inhibiting the JNK signaling pathway.