Hypertension (HTN) is a global public health concern and a major risk factor for cardiovascular disease (CVD) and mortality. Insulin resistance (IR) plays a crucial role in HTN-related metabolic dysfunction, but its assessment remains challenging. The triglyceride–glucose (TyG) index and its derivatives (TyG–BMI, TyG–WC, and TyG–WHtR) have emerged as reliable IR markers. In this study, we evaluated their associations with all-cause and cardiovascular mortality in hypertensive patients using machine learning techniques. Data from 9432 hypertensive participants in the National Health and Nutrition Examination Survey (NHANES) 1999–2018 were analysed. Cox proportional hazards models and restricted cubic splines were employed to explore mortality risk and potential nonlinear relationships. Machine learning models were utilized to assess the predictive value of the TyG index and its derivatives for mortality outcomes. The TyG index and its derivatives were independent predictors of both all-cause and cardiovascular mortality in hypertensive patients. The TyG–WHtR exhibited the strongest association, with each 1-unit increase linked to a 41.7% and 48.1% higher risk of all-cause and cardiovascular mortality, respectively. L-shaped relationships were observed between TyG-related indices and mortality. The incorporation of the TyG index or its derivatives into predictive models modestly improved the prediction performance for mortality outcomes. The TyG index and its derivatives are significant predictors of mortality in hypertensive patients. Their inclusion in predictive models enhances risk stratification and may aid in the early identification of high-risk individuals in this population. Further studies are needed to validate these findings in external hypertensive cohorts.
18 May 2020 in Journal of Cellular and Molecular Medicine
Human umbilical cord mesenchymal stem cell‐derived exosomes (hucMSC‐exosomes) have been implicated as a novel therapeutic approach for tissue injury repair and regeneration, but the effects of hucMSC‐exosomes on coxsackievirus B3 (CVB3)‐induced myocarditis remain unknown. The object of the present study is to investigate whether hucMSC‐exosomes have therapeutic effects on CVB3‐induced myocarditis (VMC). HucMSC‐exosomes were identified using nanoparticle tracking analysis (NTA), transmission electron microscopy (TEM) and Western blot. The purified hucMSC‐exosomes tagged with PKH26 were tail intravenously injected into VMC model mice in vivo and used to administrate CVB3‐infected human cardiomyocytes (HCMs) in vitro, respectively. The effects of hucMSC‐exosomes on myocardial pathology injury, proinflammatory cytokines and cardiac function were evaluated through haematoxylin and eosin (H&E) staining, quantitative polymerase chain reaction (qPCR) and Doppler echocardiography. The anti‐apoptosis role and potential mechanism of hucMSC‐exosomes were explored using TUNEL staining, flow cytometry, immunohistochemistry, Ad‐mRFP‐GFP‐LC3 transduction and Western blot. In vivo results showed that hucMSC‐exosomes (50 μg iv) significantly alleviated myocardium injury, shrank the production of proinflammatory cytokines and improved cardiac function. Moreover, in vitro data showed that hucMSC‐exosomes (50 μg/mL) inhibited the apoptosis of CVB3‐infected HCM through increasing pAMPK/AMPK ratio and up‐regulating autophagy proteins LC3II/I, BECLIN‐1 and anti‐apoptosis protein BCL‐2 as well as decreasing pmTOR/mTOR ratio, promoting the degradation of autophagy flux protein P62 and down‐regulating apoptosis protein BAX. In conclusion, hucMSC‐exosomes could alleviate CVB3‐induced myocarditis via activating AMPK/mTOR‐mediated autophagy flux pathway to attenuate cardiomyocyte apoptosis, which will be benefit for MSC‐exosome therapy of myocarditis in the future.
27 December 2018 in Journal of Cellular and Molecular Medicine
The aggressive immunological activity elicited by acute viral myocarditis contributes to a large amount of cardiomyocytes loss and poor prognosis of patients in clinic. Low‐intensity pulsed ultrasound (LIPUS), which is an effective treatment modality for osteoarthropathy, has been recently illustrated regulating the overactive inflammatory response in various diseases. Here, we aimed to investigate whether LIPUS could attenuate coxsackievirus B3 (CVB3) infection‐induced injury by coordinating the inflammatory response. Male BALB/c mice were inoculated intraperitoneally with CVB3 to establish the model of acute viral myocarditis. LIPUS treatment was given on Day 1, Day 1, 3 and Day 1, 3, 5 post‐inoculation, respectively. All mice were followed up for 14 days. Day 1, 3, 5 LIPUS treatment significantly improved the survival rate, attenuated the ventricular dysfunction and ameliorated the cardiac histopathological injury of CVB3‐infected mice. Western blotting analysis showed Day 1, 3, 5 LIPUS treatment decreased pro‐inflammatory cytokines, increased the activation of caveolin‐1 and suppressed p38 mitogen‐activated protein kinase (MAPK) and extracellular signal‐regulated kinase (ERK) signallings in heart tissue. RAW264.7 cells were treated with lipopolysaccharides (LPS) to simulate the augmented inflammatory response in vivo. LIPUS treatment on RAW264.7 inhibited the expression of pro‐inflammatory cytokines, activated caveolin‐1 and suppressed p38 MAPK and ERK signallings. Transfecting RAW264.7 with caveolin‐1 siRNA blunted the suppression of pro‐inflammatory cytokines and MAPK signallings by LIPUS treatment. Taken together, we demonstrated for the first time that LIPUS treatment attenuated the aggressive inflammatory response during acute viral myocarditis. The underlying mechanism may be activating caveolin‐1 and suppressing MAPK signallings.
Elevated heart rate is associated with increased cardiovascular morbidity. The selective If current inhibitor ivabradine reduces heart rate without affecting cardiac contractility, and has been shown to be cardioprotective in the failing heart. Ivabradine also exerts some of its beneficial effects by decreasing cardiac proinflammatory cytokines and inhibiting peroxidants and collagen accumulation in atherosclerosis or congestive heart failure. However, the effects of ivabradine in the setting of acute viral myocarditis and on the cytokines, oxidative stress and cardiomyocyte apoptosis have not been investigated. The study was designed to compare the effects of ivabradine and carvedilol in acute viral myocarditis. In a coxsackievirus B3 murine myocarditis model (Balb/c), effects of ivabradine and carvedilol (a nonselective β-adrenoceptor antagonist) on myocardial histopathological changes, cardiac function, plasma noradrenaline, cytokine levels, cardiomyocyte apoptosis, malondialdehyde and superoxide dismutase contents were studied. Both ivabradine and carvedilol similarly and significantly reduced heart rate, attenuated myocardial lesions and improved the impairment of left ventricular function. In addition, ivabradine treatment as well as carvedilol treatment showed significant effects on altered myocardial cytokines with a decrease in the amount of plasma noradrenaline. The increased myocardial MCP-1, IL-6, and TNF-α. in the infected mice was significantly attenuated in the ivabradine treatment group. Only carvedilol had significant anti-oxidative and anti-apoptoic effects in coxsackievirus B3-infected mice. These results show that the protective effects of heart rate reduction with ivabradine and carvedilol observed in the acute phase of coxsackievirus B3 murine myocarditis may be due not only to the heart rate reduction itself but also to the downregulation of inflammatory cytokines.
22 September 2017 in Journal of the American Heart Association
Background: With chronic ischemia after myocardial infarction, the resulting scar tissue result in electrical and structural remodeling vulnerable to an arrhythmogenic substrate. The cholinergic anti‐inflammatory pathway elicited by vagal nerve via α7 nicotinic acetylcholine receptors (α7‐n AC hR) can modulate local and systemic inflammatory responses. Here, we aimed to clarify a novel mechanism for the antiarrhythmogenic properties of vagal nerve during the ischemic cardiomyopathy ( ICM ). Methods and Results: Left anterior descending artery of adult male Sprague‐Dawley rats was ligated for 4 weeks to develop ICM . Western blot revealed that eliciting the cholinergic anti‐inflammatory pathway by nicotine treatment showed a significant reduction in the amounts of collagens, cytokines, and other inflammatory mediators in the left ventricular infarcted border zone via inhibited NF ‐ κB activation, whereas it increased the phosphorylated connexin 43. Vagotomy inhibited the anti‐inflammatory, anti‐fibrosis, and anti‐arrhythmogenic effect of nicotine administration. And immunohistochemistry confirmed that the nicotine administration‐induced increase of connexin 43 was located in intercellular junctions. Furthermore nicotine treatment suppressed NF ‐κB activation in lipopolysaccharide‐stimulated RAW 264.7 cells, and α‐bungarotoxin (an α7‐n AC hR selective antagonist) partly inhibited the nicotine‐treatment effect. In addition, 4‐week nicotine administration slightly improved the cardiac function, increased cardiac parasympathetic tone, decreased the prolonged QT c, and decreased the arrhythmia score of programmed electric stimulation‐induced ventricular arrhythmia. Conclusions: Eliciting the cholinergic anti‐inflammatory pathway exerts anti‐arrhythmogenic effects against ICM ‐induced ventricular arrhythmia accompanied by downregulation of cytokines, downgenerating of collagens, decrease in sympathetic/parasympathetic ratio, and prevention of the loss of phosphorylated connexin 43 during ICM . Our findings may suggest a promising therapy for the generation of ICM ‐induced ventricular arrhythmia by eliciting the cholinergic anti‐inflammatory pathway.