陈桂浩
中国医学科学院阜外医院 心血管内科
The management of myocardial ischemia/reperfusion (I/R) damage in the context of reperfusion treatment remains a significant hurdle in the field of cardiovascular disorders. The injured lesions exhibit distinctive features, including abnormal accumulation of necrotic cells and subsequent inflammatory response, which further exacerbates the impairment of cardiac function. Here, we report genetically engineered hybrid nanovesicles (hNVs), which contain cell-derived nanovesicles overexpressing high-affinity SIRPα variants (SαV-NVs), exosomes (EXOs) derived from human mesenchymal stem cells (MSCs), and platelet-derived nanovesicles (PLT-NVs), to facilitate the necrotic cell clearance and inhibit the inflammatory responses. Mechanistically, the presence of SαV-NVs suppresses the CD47-SIRPα interaction, leading to the promotion of the macrophage phagocytosis of dead cells, while the component of EXOs aids in alleviating inflammatory responses. Moreover, the PLT-NVs endow hNVs with the capacity to evade immune surveillance and selectively target the infarcted area. In I/R mouse models, coadministration of SαV-NVs and EXOs showed a notable synergistic effect, leading to a significant enhancement in the left ventricular ejection fraction (LVEF) on day 21. These findings highlight that the hNVs possess the ability to alleviate myocardial inflammation, minimize infarct size, and improve cardiac function in I/R models, offering a simple, safe, and robust strategy in boosting cardiac repair after I/R.
ACS nano 2024
BACKGROUND:Extracellular vesicles (EVs) derived from bone marrow mesenchymal stem cells (MSCs) pretreated with atorvastatin (ATV) (MSCATV-EV) have a superior cardiac repair effect on acute myocardial infarction (AMI). The mechanisms, however, have not been fully elucidated. This study aims to explore whether inflammation alleviation of infarct region via macrophage polarization plays a key role in the efficacy of MSCATV-EV.METHODS:MSCATV-EV or MSC-EV were intramyocardially injected 30 min after coronary ligation in AMI rats. Macrophage infiltration and polarization (day 3), cardiac function (days 0, 3, 7, 28), and infarct size (day 28) were measured. EV small RNA sequencing and bioinformatics analysis were conducted for differentially expressed miRNAs between MSCATV-EV and MSC-EV. Macrophages were isolated from rat bone marrow for molecular mechanism analysis. miRNA mimics or inhibitors were transfected into EVs or macrophages to analyze its effects on macrophage polarization and cardiac repair in vitro and in vivo.RESULTS:MSCATV-EV significantly reduced the amount of CD68+ total macrophages and increased CD206+ M2 macrophages of infarct zone on day 3 after AMI compared with MSC-EV group (P < 0.01-0.0001). On day 28, MSCATV-EV much more significantly improved the cardiac function than MSC-EV with the infarct size markedly reduced (P < 0.05-0.0001). In vitro, MSCATV-EV also significantly reduced the protein and mRNA expressions of M1 markers but increased those of M2 markers in lipopolysaccharide-treated macrophages (P < 0.05-0.0001). EV miR-139-3p was identified as a potential cardiac repair factor mediating macrophage polarization. Knockdown of miR-139-3p in MSCATV-EV significantly attenuated while overexpression of it in MSC-EV enhanced the effect on promoting M2 polarization by suppressing downstream signal transducer and activator of transcription 1 (Stat1). Furthermore, MSCATV-EV loaded with miR-139-3p inhibitors decreased while MSC-EV loaded with miR-139-3p mimics increased the expressions of M2 markers and cardioprotective efficacy.CONCLUSIONS:We uncovered a novel mechanism that MSCATV-EV remarkably facilitate cardiac repair in AMI by promoting macrophage polarization via miR-139-3p/Stat1 pathway, which has the great potential for clinical translation.
BMC medicine 2023
The increasing burden of heart failure with preserved ejection fraction (HFpEF) has become a global health problem. HFpEF is characterized by systematic inflammation, cardiac metabolic remodeling, and fibrosis. Eosinophils act as an essential but generally overlooked subgroup of white blood cells, which participate in cardiac fibrosis, as reported in several recent studies. Herein, we explored the role of eosinophils in a "two-hit" preclinical HFpEF model. The peripheral eosinophil counts were comparable between the normal chow and HFpEF mice. Deficiency of eosinophils failed to alter the phenotype of HFpEF. Conclusively, the development of HFpEF is independent of eosinophils in terms of the functional, biochemical, and histological results.
Immunity, inflammation and disease 2023
Importance:Tongxinluo, a traditional Chinese medicine compound, has shown promise in in vitro, animal, and small human studies for myocardial infarction, but has not been rigorously evaluated in large randomized clinical trials.Objective:To investigate whether Tongxinluo could improve clinical outcomes in patients with ST-segment elevation myocardial infarction (STEMI).Design, Setting, and Participants:Randomized, double-blind, placebo-controlled clinical trial was conducted among patients with STEMI within 24 hours of symptom onset from 124 hospitals in China. Patients were enrolled from May 2019 to December 2020; the last date of follow-up was December 15, 2021.Interventions:Patients were randomized 1:1 to receive either Tongxinluo or placebo orally for 12 months (a loading dose of 2.08 g after randomization, followed by the maintenance dose of 1.04 g, 3 times a day), in addition to STEMI guideline-directed treatments.Main Outcomes and Measures:The primary end point was 30-day major adverse cardiac and cerebrovascular events (MACCEs), a composite of cardiac death, myocardial reinfarction, emergent coronary revascularization, and stroke. Follow-up for MACCEs occurred every 3 months to 1 year.Results:Among 3797 patients who were randomized, 3777 (Tongxinluo: 1889 and placebo: 1888; mean age, 61 years; 76.9% male) were included in the primary analysis. Thirty-day MACCEs occurred in 64 patients (3.4%) in the Tongxinluo group vs 99 patients (5.2%) in the control group (relative risk [RR], 0.64 [95% CI, 0.47 to 0.88]; risk difference [RD], -1.8% [95% CI, -3.2% to -0.6%]). Individual components of 30-day MACCEs, including cardiac death (56 [3.0%] vs 80 [4.2%]; RR, 0.70 [95% CI, 0.50 to 0.99]; RD, -1.2% [95% CI, -2.5% to -0.1%]), were also significantly lower in the Tongxinluo group than the placebo group. By 1 year, the Tongxinluo group continued to have lower rates of MACCEs (100 [5.3%] vs 157 [8.3%]; HR, 0.64 [95% CI, 0.49 to 0.82]; RD, -3.0% [95% CI, -4.6% to -1.4%]) and cardiac death (85 [4.5%] vs 116 [6.1%]; HR, 0.73 [95% CI, 0.55 to 0.97]; RD, -1.6% [95% CI, -3.1% to -0.2%]). There were no significant differences in other secondary end points including 30-day stroke; major bleeding at 30 days and 1 year; 1-year all-cause mortality; and in-stent thrombosis (<24 hours; 1-30 days; 1-12 months). More adverse drug reactions occurred in the Tongxinluo group than the placebo group (40 [2.1%] vs 21 [1.1%]; P = .02), mainly driven by gastrointestinal symptoms.Conclusions and Relevance:In patients with STEMI, the Chinese patent medicine Tongxinluo, as an adjunctive therapy in addition to STEMI guideline-directed treatments, significantly improved both 30-day and 1-year clinical outcomes. Further research is needed to determine the mechanism of action of Tongxinluo in STEMI.Trial Registration:ClinicalTrials.gov Identifier: NCT03792035.
JAMA 2023
PURPOSE:In recent decades, the occurrence of heart failure with preserved ejection fraction (HFpEF) has outweighed that of heart failure with reduced ejection fraction by degrees, but few drugs have been demonstrated to improve long-term clinical outcomes in patients with HFpEF. Levosimendan, a calcium-sensitizing cardiotonic agent, improves decompensated heart failure clinically. However, the anti-HFpEF activities of levosimendan and underlying molecular mechanisms are unclear.METHODS:In this study, a double-hit HFpEF C57BL/6N mouse model was established, and levosimendan (3 mg/kg/week) was administered to HFpEF mice aged 13 to 17 weeks. Different biological experimental techniques were used to verify the protective effects of levosimendan against HFpEF.RESULTS:After four weeks of drug treatment, left ventricular diastolic dysfunction, cardiac hypertrophy, pulmonary congestion, and exercise exhaustion were significantly alleviated. Junction proteins in the endothelial barrier and between cardiomyocytes were also improved by levosimendan. Among the gap junction channel proteins, connexin 43, which was especially highly expressed in cardiomyocytes, mediated mitochondrial protection. Furthermore, levosimendan reversed mitochondrial malfunction in HFpEF mice, as evidenced by increased mitofilin and decreased ROS, superoxide anion, NOX4, and cytochrome C levels. Interestingly, after levosimendan administration, myocardial tissue from HFpEF mice showed restricted ferroptosis, indicated by an increased GSH/GSSG ratio; upregulated GPX4, xCT, and FSP-1 expression; and reduced intracellular ferrous ion, MDA, and 4-HNE levels.CONCLUSION:Regular long-term levosimendan administration can benefit cardiac function in a mouse model of HFpEF with metabolic syndromes (namely, obesity and hypertension) by activating connexin 43-mediated mitochondrial protection and sequential ferroptosis inhibition in cardiomyocytes.
Cardiovascular drugs and therapy 2023
BACKGROUND:Bone marrow cells (BMCs), especially mesenchymal stem cells (MSCs), have shown attractive application prospects in acute myocardial infarction (AMI). However, the weak efficacy becomes their main limitation in clinical translation. Based on the anti-inflammation and anti-apoptosis effects of a Chinese medicine-Tongxinluo (TXL), we aimed to explore the effects of TXL-pretreated MSCs (MSCsTXL) in enhancing cardiac repair and further investigated the underlying mechanism.METHODS:MSCsTXL or MSCs and the derived exosomes (MSCsTXL-exo or MSCs-exo) were collected and injected into the infarct zone of rat hearts. In vivo, the anti-apoptotic and anti-inflammation effects, and cardiac functional and histological recovery were evaluated. In vitro, the apoptosis was evaluated by western blotting and flow cytometry. miRNA sequencing was utilized to identify the significant differentially expressed miRNAs between MSCsTXL-exo and MSCs-exo, and the miRNA mimics and inhibitors were applied to explore the specific mechanism.RESULTS:Compared to MSCs, MSCsTXL enhanced cardiac repair with reduced cardiomyocytes apoptosis and inflammation at the early stage of AMI and significantly improved left ventricular ejection fraction (LVEF) with reduced infarct size in an exosome-dependent way. Similarly, MSCsTXL-exo exerted superior therapeutic effects in anti-apoptosis and anti-inflammation, as well as improving LVEF and reducing infarct size compared to MSCs-exo. Further exosomal miRNA analysis demonstrated that miR-146a-5p was the candidate effector of the superior effects of MSCsTXL-exo. Besides, miR-146a-5p targeted and decreased IRAK1, which inhibited the nuclear translocation of NF-κB p65 thus protecting H9C2 cells from hypoxia injury.CONCLUSIONS:This study suggested that MSCsTXL markedly facilitated cardiac repair via a new mechanism of the exosomal transfer of miR-146a-5p targeting IRAK1/NF-κB p65 pathway, which has great potential for clinical translation.
Stem cell research & therapy 2022
BACKGROUND:Bone marrow-derived mesenchymal stem cells (MSCs), which possess immunomodulatory characteristic, are promising candidates for the treatment of acute myocardial infarction (AMI). However, the low retention and survival rate of MSCs in the ischemic heart limit their therapeutic efficacy. Strategies either modifying MSCs or alleviating the inflammatory environment, which facilitates the recruitment and survival of the engrafted MSCs, may solve the problem. Thus, we aimed to explore the therapeutic efficacy of sequential transplantation of exosomes and combinatorial pretreated MSCs in the treatment of AMI.METHODS:Exosomes derived from MSCs were delivered to infarcted hearts through intramyocardial injection followed by the intravenous infusion of differentially pretreated MSCs on Day 3 post-AMI. Enzyme linked immunosorbent assay (ELISA) was performed to evaluate the inflammation level as well as the SDF-1 levels in the infarcted border zone of the heart. Echocardiography and histological analysis were performed to assess cardiac function, infarct size, collagen area and angiogenesis.RESULTS:Sequential transplantation of exosomes and the combinatorial pretreated MSCs significantly facilitated cardiac repair compared to AMI rats treated with exosomes alone. Notably, compared to the other three methods of cotransplantation, combinatorial pretreatment with hypoxia and Tongxinluo (TXL) markedly enhanced the CXCR4 level of MSCs and promoted recruitment, which resulted in better cardiac function, smaller infarct size and enhanced angiogenesis. We further demonstrated that exosomes effectively reduced apoptosis in MSCs in vitro.CONCLUSION:Sequential delivery of exosomes and pretreated MSCs facilitated cardiac repair post-AMI, and combined pretreatment with hypoxia and TXL better enhanced the cardioprotective effects. This method provides new insight into the clinical translation of stem cell-based therapy for AMI.
Stem cell research & therapy 2022
Over the past decade, histone deacetylases (HDACs) has been proven to manipulate development and exacerbation of cardiovascular diseases, including myocardial ischemia/reperfusion injury, cardiac hypertrophy, ventricular remodeling, and myocardial fibrosis. Inhibition of HDACs, especially class-I HDACs, is potent to the protection of ischemic myocardium after ischemia/reperfusion (I/R). Herein, we examine whether mocetinostat (MGCD0103, MOCE), a class-I selective HDAC inhibitor in phase-II clinical trial, shows cardioprotection under I/R in vivo and in vitro, if so, reveal its potential pharmacological mechanism to provide an experimental and theoretical basis for mocetinostat usage in a clinical setting. Human cardiac myocytes (HCMs) were exposed to hypoxia and reoxygenation (H/R), with or without mocetinostat treatment. H/R reduced mitochondrial membrane potential and induced HCMs apoptosis. Mocetinostat pretreatment reversed these H/R-induced mitochondrial damage and cellular apoptosis and upregulated CREB, p-CREB, and PGC-1α in HCMs during H/R. Transfection with small interfering RNA against PGC-1α or CREB abolished the protective effects of mocetinostat on cardiomyocytes undergoing H/R. In vivo, mocetinostat was demonstrated to protect myocardial injury posed by myocardial I/R via the activation of CREB and upregulation of PGC-1α. Mocetinostat (MGCD0103) can protect myocardium from I/R injury through mitochondrial protection mediated by CREB/PGC-1α pathway. Therefore, activation of the CREB/PGC-1α signaling pathway via the inhibition of Class-I HDACs may be a promising new therapeutic strategy for alleviating myocardial reperfusion injury.
Journal of cardiovascular pharmacology 2022
Monocytes and macrophages are cellular forces that drive and resolve inflammation triggered by acute myocardial ischemia. One of the most important but least understood regulatory mechanisms is how these cells sense cues from the micro-milieu and integrate environmental signals with their response that eventually determines the outcome of myocardial repair. In the current study, we investigated if the mechanistic target of rapamycin (mTOR) complex 1 (mTORC1) plays this role. We present evidence that support a robustly activated mTORC1 pathway in monocytes and macrophages in the infarcting myocardium.. Specific mTORC1 inhibition transformed the landscape of cardiac monocytes and macrophages into reparative cells that promoted myocardial healing. As the result, mTORC1 inhibition diminished remodeling and reduced mortality from acute ischemia by 80%. In conclusion, our data suggest a critical role of mTORC1 in regulating the functions of cardiac monocytes and macrophages, and specific mTORC1 inhibition protects the heart from inflammatory injury in acute ischemia. As mTOR/mTORC1 is a master regulator that integrates external signals with cellular responses, the study sheds light on how the cardiac monocytes and macrophages sense and respond to the ischemic environment..
Journal of molecular and cellular cardiology 2021
AIMS:Naturally secreted nanovesicles, known as exosomes, play important roles in stem cell-mediated cardioprotection. We have previously demonstrated that atorvastatin (ATV) pretreatment improved the cardioprotective effects of mesenchymal stem cells (MSCs) in a rat model of acute myocardial infarction (AMI). The aim of this study was to investigate if exosomes derived from ATV-pretreated MSCs exhibit more potent cardioprotective function in a rat model of AMI and if so to explore the underlying mechanisms.METHODS AND RESULTS:Exosomes were isolated from control MSCs (MSC-Exo) and ATV-pretreated MSCs (MSCATV-Exo) and were then delivered to endothelial cells and cardiomyocytes in vitro under hypoxia and serum deprivation (H/SD) condition or in vivo in an acutely infarcted Sprague-Dawley rat heart. Regulatory genes and pathways activated by ATV pretreatment were explored using genomics approaches and functional studies. In vitro, MSCATV-Exo accelerated migration, tube-like structure formation, and increased survival of endothelial cells but not cardiomyocytes, whereas the exosomes derived from MSCATV-Exo-treated endothelial cells prevented cardiomyocytes from H/SD-induced apoptosis. In a rat AMI model, MSCATV-Exo resulted in improved recovery in cardiac function, further reduction in infarct size and reduced cardiomyocyte apoptosis compared to MSC-Exo. In addition, MSCATV-Exo promoted angiogenesis and inhibited the elevation of IL-6 and TNF-α in the peri-infarct region. Mechanistically, we identified lncRNA H19 as a mediator of the role of MSCATV-Exo in regulating expression of miR-675 and activation of proangiogenic factor VEGF and intercellular adhesion molecule-1. Consistently, the cardioprotective effects of MSCATV-Exo was abrogated when lncRNA H19 was depleted in the ATV-pretreated MSCs and was mimicked by overexpression of lncRNA H19.CONCLUSION:Exosomes obtained from ATV-pretreated MSCs have significantly enhanced therapeutic efficacy for treatment of AMI possibly through promoting endothelial cell function. LncRNA H19 mediates, at least partially, the cardioprotective roles of MSCATV-Exo in promoting angiogenesis.
Cardiovascular research 2020
