Appraisal of guidelines for managing contrast medium in patients with metformin: consensuses, controversies, and gaps.

OBJECTIVES: The current guidelines contain substantial inconsistency regarding the use of metformin concomitantly with contrast media. The objective of this study is to appraise the guidelines and summarize the agreements and differences among recommendations. METHODS: Our search focused on English language guidelines published between 2018 and 2021. Guidelines for the management of contrast media in patients with continuous metformin were included. Guidelines were assessed using the Appraisal of Guidelines for Research and Evaluation II instrument. RESULTS: Six guidelines out of 1134 fulfilled the inclusion criteria with an AGREE II score of 79.2% (IQR 72.7 to 85.1%). There was good overall quality of the guidelines, with six considered "strongly recommended." CPGs scored poorly in "Clarity of Presentation" and "Applicability," with scores of 75.9% and 76.4%, respectively. The intraclass correlation coefficients were excellent in each domain. There are some guidelines (33.3%) that recommend discontinuation of metformin in patients with an eGFR of < 30 mL/min/1.73 m2, while some guidelines (16.7%) suggest the threshold of renal function should be eGFR < 40 mL/min/1.73 m2. CONCLUSIONS: Most guidelines recommend withdrawing metformin before using contrast agents in diabetic patients with severely impaired kidney function but disagree on the renal function thresholds. Furthermore, the gaps regarding discontinuing metformin with moderate renal impairment (30 mL/min/1.73 m2 < eGFR < 60 mL/min/1.73 m2) must be considered in future studies. KEY POINTS: • Guidelines involving metformin and contrast agents are reliable and optimal. • Most guidelines advocate discontinuing metformin before using contrast agents in diabetic patients with advanced renal failure, but there are controversial suggestions regarding kidney function thresholds. • The gaps regarding the time of discontinuation of the metformin with moderate renal impairment (30 mL/min/1.73 m2 < eGFR < 60 mL/min/1.73 m2) must be considered in the extensive RCT studies.

Red blood cell distribution width and maximum left ventricular wall thickness predict poor outcomes in patients with hypertrophic cardiomyopathy.

AIM: To evaluate the prognostic utility of red blood cell distribution width (RDW) and maximum left ventricular wall thickness (MLVWT) in patients with hypertrophic cardiomyopathy (HCM). PATIENTS AND METHODS: This study is a retrospective cohort analysis. Patients diagnosed with HCM at the First Affiliated Hospital of Sun Yat-sen University from March 2014 to March 2019 were included. HCM patients were stratified into two groups based on the occurrence of major adverse cardiac events (MACE). Receiver operating characteristic (ROC) curves were then constructed and Cox regression models were employed to gauge the prognostic relevance of RDW and MLVWT for HCM patients. Kaplan-Meier analysis evaluated the survival and MACE-free rate in patients with different level of RDW and MLVWT. RESULTS: A total of 300 patients with HCM were enrolled in this study and followed up for 40.56±18.33 months. Among them, 117 MACE (39.00%), 40 all-cause deaths (13.33%), and 29 cardiovascular deaths (9.67%). The level of RDW, MLVWT, creatinine (Cr), and B-type pro-brain natriuretic peptide (NT-ProBNP) were statistically different between the MACE group and non-MACE group (P < .05). Multivariate analysis showed that after adjusting for confounding factors, RDW and MLVWT were independent predictors of all-cause mortality and MACE in HCM patients. ROC showed that RDW > .13 and MLVWT > 23 mm are the cut-off value to predict all-cause mortality and MACE. The area under the ROC curve AUC of the combination predicting the occurrence of all-cause mortality and MACE are .823 and .820, respectively. Kaplan-Meier analysis showed that the survival rate and MACE-free survival rate of group 1 (RDW≦.13 and MLVWT≦23 mm) were significantly higher than group 2 (RDW > .13 or MLVWT > 23 mm), and group 3 (RDW > .13 and MLVWT > 23 mm) (P = .000). CONCLUSION: We determined that increased RDW and MLVWT was independently associated with MACE incidence and risk of mortality in HCM patients. Combined evaluation of RDW and MLVWT yielded a more accurate predictive model of HCM patient outcomes relative to the use of either of these metrics in isolation. Our research can provide a theoretical basis in the occurrence of MACE for the high-risk HCM and intervene them properly and timely.

Berberine reduces endothelial injury and arterial stiffness in spontaneously hypertensive rats.

Background: Changes in circulating endothelial microparticles (EMPs) and endothelial progenitor cells (EPCs) are considered as a new perspective reflection of the endothelial injury and repair status. Our previous studies have demonstrated that berberine improved endothelial function and arterial stiffness in healthy subjects. In this study, we further investigated the effects of berberine on regulating the circulating EMPs and EPCs, and preventing endothelial dysfunction and arterial stiffness in spontaneously hypertensive rats (SHRs). Methods: Twenty male SHRs were randomly divided into two groups: Berberine-treated SHR group and vehicle-treated SHR group. The SHR rats were intragastrically treated with physiologic saline, berberine 50 mg/kg.d or vehicle for 4 weeks, respectively. Ten male Wistar-Kyoto (WKY) rats treated with vehicle served as normotensive controls. Tail systolic blood pressure was monitored every 2 weeks. At the end of the study, aortic pulse wave velocity (aPWV) was measured in vivo, and aorta were collected for measurement of endothelium-dependent vasodilation and immunohistological staining of elastic fiber. Peripheral blood was collected for circulating EMP detection and EPC culture. Results: Compared to normotensive rats, hypertensive rats displayed significantly higher circulating CD31+/CD42- MPs, lower number and colony-forming units (CFUs) of EPCs, worse endothelium-dependent vasodilation, and faster aPWV. Berberine treatment in SHRs partly reduced the blood pressure and circulating EMPs, and augmented EPC numbers and CFUs. In addition, berberine preserved arterial elasticity by lowering aPWV and increasing the content of arterial media elastin fiber, and improved endothelial function by maintaining better endothelium-dependent vasodilation. Robust relationship was observed among circulating CD31+/CD42- MPs, EPC numbers and aPWV. Conclusions: Abnormal changes of circulating EMPs and EPCs in SHRs are associated with endothelial dysfunction and arterial stiffness. Berberine may be a novel therapeutic option for the hypertension-related vascular injury in SHRs.

Fluid upstream shear stress of rabbit aortic stenosis inhibits neointimal hyperplasia by promoting endothelization after balloon injury.

BACKGROUND: Atherosclerosis is associated with disturbed blood flow characterized by low and oscillatory shear stress (SS), however, few study directly links SS to neointimal hyperplasia in animal model. This study was focused on the effects of changed SS upon the neointimal hyperplasia which responded to balloon injury in a novel rabbit model with partially-constricted abdominal aorta. METHODS: We established a rabbit model subjected to partial abdominal aortic constriction with a cylinder-shaped cannula as a model of disturbed flow, which was similar to the hemodynamic features of stenosis caused by atherosclerosis plaque. Further, balloon injury was performed to investigate the relationship between SS and neointimal hyperplasia. Four weeks later, the abdominal aorta was assessed with digital subtraction angiography (DSA) and intravascular ultrasound (IVUS). The vascular sections were embedded in paraffin blocks for morphometric analysis to evaluate neointimal hyperplasia, and anti-CD31 immunohistochemical staining was for endothelialization ratio. RESULTS: In upstream the stenosis, the changed SS leads to neointimal hyperplasia compared with normal SS (11,729 ± 1205 vs 8418 ± 737, P = 0.023). However, the upstream SS of the stenosis can promote vascular re-endothelialization after balloon injury compared with normal SS, verified by endothelialization ratio (0.36 ± 0.03 vs 0.32 ± 0.03, P = 0.017), thereby attenuate neointimal hyperplasia (64,851 ± 3995 vs 68,335 ± 3867, P = 0.018). CONCLUSION: The upstream SS of stenosis, not downstream SS, inhibits the neointimal hyperplasia after balloon injury by promoting vascular re-endothelializtion.

The critical role of Sestrin 1 in regulating the proliferation of cardiac fibroblasts.

The proliferation of cardiac fibroblasts is pivotal in the development of cardiac fibrosis. Sestrin 1, which functions as antioxidant, plays diverse roles in the regulation of proliferation and cellular injury that is induced by oxidative stress. However, little is known regarding the impact of Sestrin 1 on the proliferation of cardiac fibroblasts. In the present study, with knockdown of Sestrin 1 by siRNA, we surveyed the effect of Sestrin 1 on cardiac fibroblast proliferation. Downregulation of Sestrin 1 promotes Ang II-induced proliferation of cardiac fibroblasts, leading to increased DNA synthesis and collagen production. Moreover, in the absence of Ang II, a similar phenotype to the basal condition was detected with silencing of Sestrin 1. Further analysis of the pro-proliferating signals revealed that knockdown of Sestrin 1 significantly activated ERK1/2 and mTOR, meanwhile, downregulation of Sestrin 1 also enhanced the expression of collagen type I and CTGF, which play important role in the cardiac fibrosis. Consistent with the antioxidant property of Sestrin 1, we determined that the proliferation induced by silence of Sestrin 1 was accompanied by a remarkably enhanced production of reactive oxygen species (ROS). However, diminishing ROS by NAC, a potent antioxidant, could only partly repress the pro-proliferative effect of Sestrin 1-downregulation. Consequently, our study demonstrated that Sestrin 1 plays an important role in the proliferation of cardiac fibroblasts, and the effect could be partly mediated by decreased oxidative stress.

Relationship between Coronary Artery Calcium Score and Coronary Stenosis.

Background: The coronary artery calcium score (CACS) is commonly employed to quantify the degree of calcification in coronary atherosclerosis. Indeed, increased coronary stenosis severity is associated with a progressive increase in CACS. Objectives: This study sought to explore the association between CACS and coronary stenosis of ≥50% and ≥70%. Methods: We conducted a retrospective analysis of patient data collected between July 1, 2017, and March 3, 2022, at Jiangmen Central Hospital. A total of 208 patients, presenting with both symptomatic and asymptomatic manifestations and suspected coronary artery disease (CAD), were included. Statistical analyses included ROC curve assessments, subgroup analyses based on age, and comparisons of CACS values against the presence of coronary stenosis ≥50% and ≥70%. Results: Ultimately, 208 patients were included, with a median age of 65.0 years and a median CACS of 115.7 (interquartile range: 13.7-369.4). A CACS threshold of ≥1300 demonstrated a specificity of 100% for coronary stenosis of ≥50%. Notably, the percentage of patients with obstructive CAD showing CACS = 0 was significantly higher in those under 65 years (15.1%) compared to patients over 65 years (3.8%) (P=0.005). The inflection point, at which the risk probability for coronary stenosis of ≥50% shifted from being a protective factor to a risk factor, was observed when CACS fell within the range of 63.3 to 66.0. Conclusion: CACS demonstrates good performance for the detection of coronary artery stenosis.

Characteristics of Patent Foramen Ovale: Analysis from a Single Center.

Objective: To collect and analyze data of patent foramen ovale (PFO). Methods: This study included a total of 260 patients diagnosed with PFO. We analyzed basic clinical data such as sex, age, transesophageal echocardiography as well as other symptoms. Results: Our data showed that females accounted for the highest proportion of PFO (166 females, 64%), with the highest number of patients (65 patients) having between 45 and 55 years. Transesophageal echocardiography examination demonstrated frequent occurrence of tunnel-like anatomical structures. In addition, PFO was associated with symptoms such as migraine, stroke or TIA, syncope, chest tightness, and palpitations, with dizziness being the most common symptom in the patients with PFO. Conclusion: Our data demonstrated that females accounted for the highest proportion of PFO patients, with those aged between 45 and 55 years being most affected. The most frequently encountered clinical symptom was dizziness. Taken together, these findings may help doctors to better understand and screen for PFO patients.

Critical Appraisal of Guidelines for Antithrombotic Therapy in Atrial Fibrillation Post-Percutaneous Coronary Intervention.

Objective: In our present study, our objective was to appraise guidelines on antithrombotic therapy in atrial fibrillation post-percutaneous coronary intervention and to explore the differences in treatment practices for better informed decision-making. Methods: We searched for English language guidelines published between January 2000 and December 2020 at MEDLINE, Embase and websites of guideline organizations. Guidelines with recommendations on antithrombotic regimens for patients with AF undergoing PCI were included. Appraisal of Guidelines for Research and Evaluation II (AGREE II) instrument was applied to assess guidelines. The reporting of conflicts of interest (COI) was evaluated separately by the RIGHT (Reporting Item for Practice Guidelines in Healthcare) checklist as supplementary items. Results: Sixteen guidelines were included, among which 13 (81.25%) were considered as 'recommended' and 1 (6.25%) as 'unrecommended.' The average scores of guidelines ranged from 55% to 88% (<60% as low quality, 60-70% as sufficient quality, and >70% as good quality). Among the 6 domains of AGREE II, scope and purpose (84%) and editorial independence(87%) were considered to be the fields in which CPGs performed best, evidenced by the highest mean AGREE II scores. The domains in which the reviewed CPGs received the lowest mean scores were stakeholder involvement (63%) and applicability (58%). The intraclass correlation coefficient scores were excellent in each domain. The overall quality of the selected CPGs was optimal, with the highest score in domain 'scope and purpose', and the lowest score in the domain 'applicability.' The reporting of COI was satisfactory. Conclusions: For the recommendations on antithrombotic strategies, guidelines with high AGREE II scores still exist discrepancy on the timing and selection. Current guidance documents on the treatment vary in methodological rigor and recommendations are not always consistent.

Impaired activity of circulating EPCs and endothelial function are associated with increased Syntax score in patients with coronary artery disease.

It has previously been shown that the number of endothelial progenitor cells (EPCs) is negatively correlated with Syntax score in patients with coronary artery disease (CAD). However, the association between alterations in EPC function and Syntax score is still unknown. The present study evaluated the association between the activity of EPCs as well as endothelial function and Syntax score in patients with CAD and investigated the underlying mechanisms. A total of 60 patients with CAD were enrolled in 3 groups according to Syntax score, and 20 healthy subjects were recruited as the control group. The number and migratory, proliferative and adhesive activities of circulating EPCs were studied. The endothelial function was measured by flow­mediated dilatation (FMD) and the levels of nitric oxide (NO) in plasma or secreted by EPCs were detected. The number and activity of circulating EPCs were lower in patients with a high Syntax score, which was similar to the alteration in FMD. The level of NO in plasma or secreted by EPCs also decreased as Syntax score increased. There was a negative association between FMD or circulating EPCs and Syntax score. A similar association was observed between the levels of NO in plasma or secreted by EPCs and Syntax score. Patients with CAD who had a higher Syntax score exhibited lower EPC numbers or activity and weaker endothelial function, which may be associated with attenuated NO production. These findings provide novel surrogate parameters for evaluation of the severity and complexity of CAD.

Circulating senescent angiogenic T cells are linked with endothelial dysfunction and systemic inflammation in hypertension.

OBJECTIVE: Angiogenic T cells (Tang cells), a recently discovered T-cell subset, have been reported involved in the repair of endothelial injury. The purpose of this study was to explore the correlation of immunologic senescence and pro-inflammatory capacity of Tang cells with endothelial dysfunction in hypertensive patients. METHODS: Immunological characteristics of Tang cells (CD3+CD31+CXCR4+) from hypertensive patients with or without endothelial dysfunction were elucidated by surface immunophenotyping and intracellular cytokine staining. Endothelial function was measured by flow-mediated dilation (FMD). RESULTS: The frequency of CD28null subset in CD4+ Tang cells was notably elevated in hypertensive patients with endothelial dysfunction, which was negatively associated with FMD. The high frequency of CD28nullCD4+ Tang cells was an independent risk factor of endothelial dysfunction with good diagnostic performance in ROC curve analysis. Immunophenotyping revealed that this specific subset of Tang cells exhibited senescent profile and has low hTERT expression. CD28nullCD4+ Tang cells produced high levels of inflammatory cytokines, IL-6, IFN-γ and TNF-α, and significantly correlated with the systemic inflammation in hypertensive patients with endothelial dysfunction. CONCLUSION: Collectively, our findings demonstrate for the first time that CD28null subset in CD4+ Tang cells with senescent and pro-inflammatory phenotype is dependently correlated with impaired FMD and systemic inflammation, which might contribute to the immunopathologic mechanism of endothelial dysfunction. Identification of a pathogenic CD4+ Tang-cell subset lacking CD28 may offer opportunities for the evaluation and management of endothelial dysfunction in hypertension.

MiR-126-HMGB1-HIF-1 Axis Regulates Endothelial Cell Inflammation during Exposure to Hypoxia-Acidosis.

Crosstalk between molecular regulators miR-126, hypoxia-inducible factor 1-alpha (HIF-1-α), and high-mobility group box-1 (HMGB1) contributes to the regulation of inflammation and angiogenesis in multiple physiological and pathophysiological settings. Here, we present evidence of an overriding role for miR-126 in the regulation of HMGB1 and its downstream proinflammatory effectors in endothelial cells subjected to hypoxia with concurrent acidosis (H/A). Methods. Primary mouse endothelial cells (PMEC) were exposed to hypoxia or H/A to simulate short or chronic low-flow ischemia, respectively. RT-qPCR quantified mRNA transcripts, and proteins were measured by western blot. ROS were quantified by fluorogenic ELISA and luciferase reporter assays employed to confirm an active miR-126 target in the HMGB1 3'UTR. Results. Enhanced expression of miR-126 in PMECs cultured under neutral hypoxia was suppressed under H/A, whereas the HMGB1 expression increased sequentially under both conditions. Enhanced expression of HMGB1 and downstream inflammation markers was blocked by the premiR-126 overexpression and optimized by antagomiR. Compared with neutral hypoxia, H/A suppressed the HIF-1α expression independently of miR-126. The results show that HMGB1 and downstream effectors are optimally induced by H/A relative to neutral hypoxia via crosstalk between hypoxia signaling, miR-126, and HIF-1α, whereas B-cell lymphoma 2(Bcl2), a HIF-1α, and miR-126 regulated gene expressed optimally under neutral hypoxia. Conclusion. Inflammatory responses of ECs to H/A are dynamically regulated by the combined actions of hypoxia, miR-126, and HIF-1α on the master regulator HMGB1. The findings may be relevant to vascular diseases including atherosclerotic occlusion and interiors of plaque where coexisting hypoxia and acidosis promote inflammation as a defining etiology.

Effect of Chinese Medicine Xinmaitong on Blood Pressure in Spontaneously Hypertensive Rats.

OBJECTIVE: To investigate the effect of traditional Chinese antihypertensive compound Xinmaitong on blood pressure and vasoactive factors of vasoconstrictor endothelin-1 (ET-1) and vasodilator calcitonin gene related peptide (CGRP) in spontaneously hypertensive rats (SHRs) with early stage hypertension. METHODS: Twenty male SHRs were randomly divided into two groups: 10 for hypertensive control group and 10 for hypertensive treatment group. In addition, 10 Wistar rats were used as the normal control group without any intervention. SHRs of hypertensive treatment group were orally treated with Xinmaitong, while the hypertensive control group was treated with the normal saline (NS) for a total of eight weeks. The blood pressure in SHRs was examined before and after the end of the eight-week study. After treatment, the rats were killed and the blood samples were collected to measure plasma levels of ET-1 and CGRP by ELISA method, respectively. Meanwhile, the aorta rings were isolated for measuring the mRNA expression of ET-1 and CGRP by PCR. Moreover, the protein levels of ET-1 and CGRP were studied by immunohistochemical. RESULTS: Daily oral administration of Xinmaitong resulted in significant fall in the SHRs' blood pressure, including systolic and diastolic blood pressures (SBP and DBP), mean blood pressure (MBP), and pulse pressure (PP). The plasma ET-1 levels were reduced and CGRP increased. In parallel, the mRNA and protein expression of ET-1 were decreased, whereas the mRNA and protein expression of CGRP were enhanced in SHRs treated with Xinmaitong. CONCLUSION: The present study demonstrated for the first time that Xinmaitong leads to the fall in blood pressure of SHRs and that this antihypertensive effect is, at least in part, due to improvement of arterial tone.

Allisartan Isoproxil Improves Endothelial Function and Vascular Damage in Patients with Essential Hypertension: A Single-Center, Open-Label, Randomized Controlled Trial.

INTRODUCTION: Allisartan isoproxil is a novel angiotensin II type 1 receptor antagonist that has been confirmed to lower blood pressure and protect target organs effectively. However, its role in improving endothelial function and vascular damage has not been investigated yet. METHODS: Patients with initially diagnosed mild essential hypertension (BP ranging from 140/90 to 159/99 mmHg) with age from 25-75 years were randomly assigned 1:1 to either the allisartan group (allisartan 240 mg/day and lifestyle modification) or the lifestyle modification group and were followed up for 30 days. Flow-mediated dilation (FMD), brachial-ankle pulse wave velocity (baPWV) and endothelial microparticles (EMPs) were measured for evaluation of endothelial function and vascular damage. In addition, we enrolled 36 normotensive individuals as healthy control. RESULTS: Seventy-two mildly hypertensive patients were enrolled in this study. After 30 days of treatment, a significant increase in FMD was observed in the allisartan group (0.9 ± 0.7%, p < 0.001) and remained unchanged in the lifestyle modification group, but the difference between the two groups did not reach statistical significance (p = ns). EMPs, baPWV, SBP and DBP decreased by 251.0 ± 255.9 counts/µl (p < 0.001), 102.8 ± 84.2 cm/s (p < 0.001), 13.20 ± 3.9 mmHg (p < 0.001) and 9.35 ± 2.5 mmHg (p < 0.001), respectively, in the allisartan group, while by 21.3 ± 84.3 counts/µl (p = ns), 0.4 ± 22.0 cm/s (p = ns), 3.2 ± 6.0 mmHg (p < 0.01) and 1.0 ± 2.5 mmHg (p = ns), respectively, in the lifestyle modification group. All of the indexes above achieved statistical significance between the allisartan and lifestyle modification groups (p < 0.05). Besides, after 30 days of allisartan administration baPWV and EMPs were comparable to those measured in the healthy control group, while the difference in SBP, DBP and FMD remained significant between the allisartan and healthy control groups (p < 0.05). CONCLUSION: The present study demonstrates for the first time that allisartan isoproxil exerts a favorable effect on improving endothelial function and vascular damage in patients with mild EH, making it a promising drug for management of EH. CLINICAL TRIAL REGISTRATION: ChiCTR2000032332.

First-generation versus second-generation drug-eluting stents in patients with chronic kidney disease: a systematic review and meta-analysis.

BACKGROUND: Chronic kidney disease (CKD) patients are associated with very high rate of adverse cardiovascular outcomes after drug-eluting stents (DES) implantation. The clinical outcomes of second-generation DES versus first-generation DES in CKD patients remain controversial. OBJECTIVE: The aim of the current study was to perform a systematic review and meta-analysis to assess the safety and efficacy of second-generation DES versus first-generation DES in CKD patients. METHODS: A systematical search of databases of PubMed, EMBASE, and Cochrane Library was conducted for eligible studies comparing the clinical outcomes of first-generation DES versus second-generation DES. Sirolimus-eluting and paclitaxel-eluting stents were classified as first-generation DES, and everolimus-eluting, zotarolimus-eluting, and biolimus-eluting stent (BES) were classified as second-generation DES. A pooled odds ratio (OR) and 95% confidence interval (CI) were used to summary the estimates. Heterogeneity, subgroup analysis, sensitivity analysis and publication bias were also performed. RESULTS: We identified 14 trials involving 9,542 patients with CKD undergoing percutaneous coronary intervention. First-generation DES implantation was associated with higher risk of long-term all-cause mortality (OR, 1.31; 95% CI, 1.02-1.69; P = 0.04; I2 = 0%), in stent restenosis (OR, 1.69; 95% CI, 1.14-2.49; P = 0.008; I2 = 49%) and stent thrombosis (OR, 1.64; 95% CI, 1.00-2.69; P = 0.05; I2 = 49%) compared with second-generation DES implantation. First-generation DES and second-generation DES showed similar efficacy in decreasing risk of repeat revascularization, myocardial infarction (MI), or major adverse cardiac events (MACE) between first-generation and second-generation DES implantation. CONCLUSIONS: In CKD patients, the use of second-generation DES was associated with lower risk of long-term all-cause mortality, in stent restenosis and stent thrombosis as compared with first-generation DES. No differences were found regarding repeat revascularization, MI, and MACE.

MicroRNA-25 Protects Smooth Muscle Cells against Corticosterone-Induced Apoptosis.

BACKGROUND AND AIMS: Vascular smooth muscle cells (VSMCs) are central components of atherosclerotic plaque. Loss of VSMCs through apoptotic cell death can cause fibrous cap thinning, necrotic core formation, and calcification that may destabilize plaque. Elevated glucocorticoid levels caused by psychological stress promote VSMC apoptosis and can exacerbate atherosclerosis in mice and humans. Changes in the levels of antiapoptosis microRNA-25 (miR-25) have been linked with heart disease, inflammation, VSMC phenotype, oxidative stress, and apoptosis. Here, we investigated the pathways and mechanisms of glucocorticoid-induced apoptosis of mouse VSMCs and the protective role of miR-25. METHODS: Primary mouse VSMCs were cultured +/- corticosterone for 48 h. Apoptosis, ROS, apoptotic protein activities, miR-25, MOAP1, a miR-25 target, and p70S6 kinase were quantified at intervals. The roles of miR-25 were assessed by treating cells with lenti-pre-miR-25 and anti-miR-25. RESULTS: VSMC apoptosis, caspase-3 activity, and Bax were increased by corticosterone, and cell death was paralleled by marked loss of miR-25. Protection was conferred by pre-miR-25 and exacerbated by anti-miR-25. Pre-miR-25 conferred reduced expression of the proapoptotic protein MOAP1, and the protective effects of pre-miR-25 were abrogated by overexpressing MOAP1. The antiapoptotic effects of miR-25 were paralleled by inhibition of the p70S6K pathway, a convergence target for the survival signaling pathways, and protection by pre-miR-25 was abrogated by the p70S6k inhibitor rapamycin. CONCLUSIONS: MicroRNA-25 blocks corticosterone-induced VSMC apoptosis by targeting MOAP1 and the p70S6k pathway. Therapeutic manipulation of miR-25 may reduce atherosclerosis and unstable plaque formation associated with chronic stress.

Mitochondrial dysfunction-mediated decline in angiogenic capacity of endothelial progenitor cells is associated with capillary rarefaction in patients with hypertension via downregulation of CXCR4/JAK2/SIRT5 signaling.

BACKGROUND: Hypertensive patients exhibit decline in capillary density and endothelial progenitor cells (EPCs). However, whether capillary rarefaction in hypertension is associated with defect angiogenesis of EPCs remains unknown. We hypothesized that impaired mitochondrial function of late EPCs in hypertension is associated with the structural lack of capillary microcirculation via deficient CXCR4/JAK2/SIRT5 signaling. METHODS: We performed capillary microcirculation detection in hypertensive patients and healthy subjects. Angiogenic capacity and mitochondrial function of circulating EPCs were evaluated. The underlying mechanisms were further investigated by genetic inhibition and overexpression. FINDINGS: Capillary density of nail fold and eye fundus were significantly reduced in hypertensive patients, which was paralleled to decreased in vitro late EPC function and in vivo angiogenic capacity. Meanwhile the decline of EPC function in hypertension was accompanied by impaired mitochondrial ultrastructure, diminished mitochondrial membrane potential, reduced oxygen consumption, increased ROS generation and NADH level. Rotenone induced inhibition of oxygen consumption rate, excessive ROS generation and loss of MMP, which markedly decreased the in vitro functions of EPCs. Furthermore, SIRT5 expression of EPCs in hypertension was markedly reduced, which was correlated to mitochondrial dysfunction. CXCR4 gene transfer enhanced SIRT5 expression, improved mitochondrial functions and augmented angiogenic capacity of EPCs. The beneficial impacts of SIRT5 up-regulation on late EPC-mediated angiogenesis can be abrogated by blockade of CXCR4/JAK2/SIRT5 signaling pathway. INTERPRETATION: Mitochondrial dysfunction-mediated fall in angiogenic capacity due to deficient CXCR4/JAK2/SIRT5 signaling of late EPCs is probably responsible for the capillary rarefaction in hypertension. Our findings provide insight into the potential of EPC mitochondria as a novel target for the treatment of hypertension-related loss of microvascular density. FUNDS: National Nature Science Foundation of China, 973Program, the Nature Science Foundation of Guangdong.

Endothelial progenitor cells in cardiovascular diseases.

Cardiovascular diseases (CVDs) are the leading cause of death in both developed and developing countries. Endothelial progenitor cells (EPCs) are derived from hematopoietic stem cells with powerful function of angiogenesis. There are many studies on the relation between coronary heart disease and circulating EPCs. In this review, we discuss biological characteristics of endothelial progenitor cells, some influencing factors of the number and function of EPCs, and the role of EPCs in the treatment of cardiovascular disease. At last, we bring some perspectives on the future of endothelial progenitor cell therapy.

Lacidipine improves endothelial repair capacity of endothelial progenitor cells from patients with essential hypertension.

BACKGROUND: Endothelial progenitor cells (EPCs) play a critical role in maintaining the integrity of vascular endothelium following arterial injury. Lacidipine has a beneficial effect on endothelium of hypertensive patients, but limited data are available on EPCs-mediated endothelial protection. This study tests the hypothesis that lacidipine treatment can improve endothelial repair capacity of EPCs from hypertensive patients through increasing CXC chemokine receptor four (CXCR4) signaling. METHODS: In vivo reendothelialization capacity of EPCs from hypertensive patients with or without in vitro lacidipine treatment was examined in a nude mouse model of carotid artery injury. Expression of CXCR4 and alteration in migration and adhesion functions of EPCs were evaluated. RESULTS: Basal CXCR4 expression was markedly reduced in EPCs from hypertensive patients compared with normal subjects. In parallel, the phosphorylation of Janus kinase-2 (JAK-2) of EPCs, a CXCR4 downstream signaling, was also significantly decreased. Lacidipine promoted CXCR4/JAK-2 signaling expression of in vitro EPCs. Transplantation of EPCs pretreated with lacidipine significantly accelerated in vivo reendothelialization. The enhanced in vitro function and in vivo reendothelialization capacity of EPCs were inhibited by shRNA-mediated knockdown of CXCR4 expression or pretreatment with JAK-2 inhibitor AG490, respectively. In hypertensive patients, lacidipine treatment for 4 weeks also resulted in an upregulation of CXCR4/JAK-2 signaling of EPCs, which was associated with augmented EPCs-mediated reendothelialization and improved endothelial function. CONCLUSION: Deterioration of CXCR4 signaling may lead to impaired EPCs-mediated reendothelialization of hypertensive patients. Lacidipine-modified EPCs via a partially CXCR4 signaling contribute to enhanced endothelial repair capacity in hypertension.