Association between living alone and all-cause mortality of young and middle-aged patients with acute myocardial infarction: analysis of the China Acute Myocardial Infarction (CAMI) registry.

BACKGROUND: Lack of social support is a known predictor of the prognosis after acute myocardial infarction (AMI). Although as a common factor associated with social support, there are limited data on long-term prognostic impact of living status in young and middle-aged patients with AMI. METHODS: We analyzed data from the China Acute Myocardial Infarction (CAMI) Registry, consecutive AMI young and middle-aged patients admitted at 108 hospitals in China between January 2013 and September 2014 were included. Eligible patients were assigned to living alone and not living alone groups based on their living status. The primary endpoint was 2-year all-cause mortality. The secondary endpoints included in-hospital mortality and 2-year major adverse cardiac and cerebrovascular events (MACCEs; a composite of all-cause mortality, MI, or stroke). Multilevel logistic and multilevel Cox regression models were used to evaluate the effect of living status on short-term and long-term outcomes. RESULTS: A total of 8307 consecutive AMI young and middle-aged patients were included, 192 (2.3%) patients were living alone. Of the analyzed patients, living alone was associated with 2-year all-cause mortality and MACCEs among all analyzed patients after multivariate adjustment (adjusted hazard ratio [HR] = 2.171 [1.210-3.895], P = 0.009; adjusted HR = 2.169 [1.395-3.370], P = 0.001), but not with poorer in-hospital mortality. CONCLUSIONS: The analysis suggested that living alone was associated with both 2-year all-cause mortality and MACCEs in AMI young and middle-aged patients but did not show an extra effect on the in-hospital mortality after covariate adjustment. TRIAL REGISTRATION: Trial registration number: NCT01874691; Registered 31 October 2012.

Transcription factors: key regulatory targets of vascular smooth muscle cell in atherosclerosis.

Atherosclerosis (AS), leading to gradual occlusion of the arterial lumen, refers to the accumulation of lipids and inflammatory debris in the arterial wall. Despite therapeutic advances over past decades including intervention or surgery, atherosclerosis is still the most common cause of cardiovascular diseases and the main mechanism of death and disability worldwide. Vascular smooth muscle cells (VSMCs) play an imperative role in the occurrence of atherosclerosis and throughout the whole stages. In the past, there was a lack of comprehensive understanding of VSMCs, but the development of identification technology, including in vivo single-cell sequencing technology and lineage tracing with the CreERT2-loxP system, suggests that VSMCs have remarkable plasticity and reevaluates well-established concepts about the contribution of VSMCs. Transcription factors, a kind of protein molecule that specifically recognizes and binds DNA upstream promoter regions or distal enhancer DNA elements, play a key role in the transcription initiation of the coding genes and are necessary for RNA polymerase to bind gene promoters. In this review, we highlight that, except for environmental factors, VSMC genes are transcriptionally regulated through complex interactions of multiple conserved cis-regulatory elements and transcription factors. In addition, through a series of transcription-related regulatory processes, VSMCs could undergo phenotypic transformation, proliferation, migration, calcification and apoptosis. Finally, enhancing or inhibiting transcription factors can regulate the development of atherosclerotic lesions, and the downstream molecular mechanism of transcriptional regulation has also been widely studied.

The influence of pre-existing hypertension on coronavirus disease 2019 patients.

Hypertension represents one of the most common pre-existing conditions and comorbidities in Coronavirus disease 2019 (COVID-19) patients. To explore whether hypertension serves as a risk factor for disease severity, a multi-centre, retrospective study was conducted in COVID-19 patients. A total of 498 consecutively hospitalised patients with lab-confirmed COVID-19 in China were enrolled in this cohort. Using logistic regression, we assessed the association between hypertension and the likelihood of severe illness with adjustment for confounders. We observed that more than 16% of the enrolled patients exhibited pre-existing hypertension on admission. More severe COVID-19 cases occurred in individuals with hypertension than those without hypertension (21% vs. 10%, P = 0.007). Hypertension associated with the increased risk of severe illness, which was not modified by other demographic factors, such as age, sex, hospital geological location and blood pressure levels on admission. More attention and treatment should be offered to patients with underlying hypertension, who usually are older, have more comorbidities and more susceptible to cardiac complications.

Stenting for left subclavian artery stenosis in patients scheduled for left internal mammary artery-coronary artery bypass grafting.

OBJECTIVES: To evaluate the early and long-term outcomes of stent placement for left subclavian artery stenosis (LSAS) in patients scheduled for left internal mammary artery-coronary artery bypass grafting (LIMA-CABG). BACKGROUND: Few studies have demonstrated the safety and effectiveness of endovascular therapy for the treatment of LSAS before LIMA-CABG; therefore, use of this therapy requires further exploration and evaluation. METHODS: Between February 2000 and April 2014, the clinical data of 167 consecutive patients (mean age 64 ± 9 years, 141 males) scheduled for LIMA-CABG with LSAS who were treated by stenting at the Fuwai Hospital were collected and analyzed retrospectively. RESULTS: The technical success rate of the procedure was 97.6% (163/167). The mean stenosis of target lesions decreased from 86.5 ± 9.9% to 7.6 ± 4.6% (P < 0.001). The incidences of death, stroke, and myocardial infarction, as well as the combined incidence of death, stroke, and myocardial infarction from the time of stenting to 30 days after the stenting procedure were 0.6% (n = 1), 1.8% (n = 3), 0% (n = 0), and 1.8% (n = 3), respectively. The 10-year rate of follow-up was 94.6%. The overall survival rate was 98.8% at 1 year, 97.5% at 2 years, 93.9% at 5 years, and 86.2% at 10 years. A total of 14.1% (23/163) of patients developed in-stent restenosis. Stent restenosis-related angina and myocardial infarction were observed in 13 and 3 patients, respectively. The patency rates of the left subclavian artery were 95.7, 93.8, 86.5, and 75.2% at 1, 2, 5, and 10 years, respectively. The target vessel reconstruction rate was 8.0% (13/163). CONCLUSIONS: Stenting of LSAS at experienced medical centers for patients scheduled for LIMA-CABG was safe and effective with a low incidence of complication and in-stent restenosis.

Attenuating Hypoxia-Induced Apoptosis and Autophagy of Mesenchymal Stem Cells: the Potential of Sitagliptin in Stem Cell-Based Therapy.

BACKGROUND/AIMS: Dipeptidyl peptidase-4 (DPP-4) inhibitors have pleiotropic effects on cardiovascular protection beyond the antidiabetic property. However, it remains unknown that the impact of one DPP-4 inhibitor sitagliptin on the survival of mesenchymal stem cells (MSCs) in hypoxia and serum deprivation (H/SD) environment. METHODS: The apoptosis and autophagy of MSCs were analyzed in different concentrations of sitagliptin under H/SD condition. For later studies, we tested the relationship between anti-apoptotic and anti-autophagic effects of sitagliptin. The level of cell apoptosis was analyzed by Annexin V-FITC/PI staining, western blot of Bcl-2 and Bax proteins. Autophagy flux was assessed by multiple autophagy related proteins and substrates. Cell autophagy was identified by acridine orange staining, western blot of Beclin 1 and light chain 3 protein, and transmission electron microscopy. RESULTS: We demonstrated that sitagliptin attenuated hypoxia-induced apoptosis and autophagy of MSCs. Furthermore, sitagliptin regulated cell autophagy by Bcl-2/ Beclin 1 pathway in H/SD condition. CONCLUSIONS: This study provides insight into the utility of the DPP-4 inhibitor sitagliptin for MSCs transplantation in the ischemic microenvironment that extends its antidiabetic property.

Tongxinluo decreases apoptosis of mesenchymal stem cells concentration-dependently under hypoxia and serum deprivation conditions through the AMPK/eNOS pathway.

Tongxinluo (TXL), a traditional Chinese medicine, is widely used to treat cardiovascular diseases in China. Our previous study has demonstrated the pro-survival role of TXL on mesenchymal stem cells (MSCs) in vivo. But whether TXL could decrease apoptosis of MSCs in vitro, and the underlying mechanism are still unknown. Moreover, AMPK/eNOS pathway is crucial in regulating cell apoptosis. Therefore, we designed the study to investigate whether TXL could decrease MSCs apoptosis under hypoxia and serum deprivation (H/SD) conditions and to determine the role of AMPK/eNOS pathway. To test the hypothesis, MSCs were treated with TXL (50-400 µg/mL) under H/SD for 6 hours. For inhibitor studies, the cells were preincubated with AMPK inhibitor compound C. Results indicated that TXL decreased MSCs apoptosis concentration-dependently evidenced by reduced Annexin V+/PI- cells and increased red/green ratio of JC-1. Further, TXL enhanced the phosphorylation of AMPK and eNOS. Whereas, treatment with compound C decreased the phosphorylation of AMPK and eNOS and was accompanied by attenuated anti-apoptotic effect of TXL. In conclusion, TXL protected MSCs against H/SD-induced injury at least in part through the AMPK/eNOS pathway, which provides a novel explanation for the multi-effect of TXL on cardiovascular system.

Platelet-inspired targeting delivery for coronary heart disease.

Platelets play a pivotal role in many physiological and pathological processes, with their special targeting/adhering properties towards infarcted myocardium, injured or dysfunctional endothelium, and growing thrombus. Leveraging the site-targeting/adhering property, a variety of platelet-inspired targeting delivery（PITD）designs have been developed, the majority of which are reached by hitchhiking live platelets, cloaking nanoparticles with platelet membranes and mimicking platelet functions. With PITD, drugs or regenerative cells can directly reach targeted sites with minimized systematical distribution thus being of great clinical benefits. Coronary heart disease (CHD) is a major health burden worldwide. Plenty of PITD designs have shown promising outcomes for the treatment of CHD in preclinical models, especially in thrombolysis and post-percutaneous coronary intervention (post-PCI) anti-restenosis. Besides, PITD applications in cardiac protection and atherosclerotic plaque imaging are also under investigation. What's more, the potential benefits of PITD in the field of cell-based therapy are also attracting growing attention since it may resolve the problem of low arriving and retention efficiency, which are also particularly discussed in this review. In brief, our focus is putting on PITD strategies designed for the treatment of CHD, which hopefully can facilitate further optimization of this direction.

Targeted Delivery of Mesenchymal Stem Cell-Derived Bioinspired Exosome-Mimetic Nanovesicles with Platelet Membrane Fusion for Atherosclerotic Treatment.

Purpose: Accumulating evidence indicates that mesenchymal stem cells (MSCs)-derived exosomes hold significant potential for the treatment of atherosclerosis. However, large-scale production and organ-specific targeting of exosomes are still challenges for further clinical applications. This study aims to explore the targeted efficiency and therapeutic potential of biomimetic platelet membrane-coated exosome-mimetic nanovesicles (P-ENVs) in atherosclerosis. Methods: To produce exosome-mimetic nanovesicles (ENVs), MSCs were successively extruded through polycarbonate porous membranes. P-ENVs were engineered by fusing MSC-derived ENVs with platelet membranes and characterized using transmission electron microscopy (TEM), nanoparticle tracking analysis (NTA), and Western blot. The stability and safety of P-ENVs were also assessed. The targeted efficacy of P-ENVs was evaluated using an in vivo imaging system (IVIS) spectrum imaging system and immunofluorescence. Histological analyses, Oil Red O (ORO) staining, and Western blot were used to investigate the anti-atherosclerotic effectiveness of P-ENVs. Results: Both ENVs and P-ENVs exhibited similar characteristics to exosomes. Subsequent miRNA sequencing of P-ENVs revealed their potential to mitigate atherosclerosis by influencing biological processes related to cholesterol metabolism. In an ApoE-/- mice model, the intravenous administration of P-ENVs exhibited enhanced targeting of atherosclerotic plaques, resulting in a significant reduction in lipid deposition and necrotic core area. Our in vitro experiments showed that P-ENVs promoted cholesterol efflux and reduced total cholesterol content in foam cells. Further analysis revealed that P-ENVs attenuated intracellular cholesterol accumulation by upregulating the expression of the critical cholesterol transporters ABCA1 and ABCG1. Conclusion: This study highlighted the potential of P-ENVs as a novel nano-drug delivery platform for enhancing drug delivery efficiency while concurrently mitigating adverse reactions in atherosclerotic therapy.

The impacts of percutaneous coronary intervention to treat chronic total occlusion of right coronary artery on the 5-year prognosis: A single-centered retrospective study.

BACKGROUND: Chronic total occlusions (CTO) occur in about 20% of patients referred for coronary angiography, and right coronary artery (RCA) CTO has been reported in 38-50% of the entire CTO population. Limited data on angiographic and procedural characteristics of RCA-CTO and the risk of adverse cardiac events asks for a detailed study. METHODS: From 2010 to 2013, patients with attempted revascularization of at least one CTO lesion were included and followed up to 5 years after PCI. Eligible patients are assigned to RCA-CTO and non-RCA-CTO groups based on their target vessels. The primary endpoint was major adverse cardiovascular events (MACEs; a composite of all-cause death, myocardial infarction (MI) or rehospitalization for heart failure), and secondary endpoints were cardiac death, target lesion revascularization (TLR) and target vessel revascularization (TVR). RESULTS: The present study included 2659 eligible patients, among which 1285 patients were assigned to the RCA-CTO group, whereas 1374 patients were assigned to the non-RCA-CTO group. Lesions in RCA had longer lesion length, higher J-CTO score, higher rates of severe vessel tortuosity, a higher percentage of Rentrop grade 2-3, and more likely to be re-try lesion than those in LAD or LCX (all P < 0.01). CTO lesions in RCA reached less successful recanalization and post-procedural TIMI 3 flow (all <0.01). Multivariate Cox analysis revealed that RCA-CTO was not associated with primary outcome MACEs. Besides MACEs, RCA-CTO was also not associated with cardiac death, but was significantly associated with TLR and TVR (adjusted HR: 1.37 [95% CI:1.07-1.76], P = 0.01; adjusted HR: 1.43 [95% CI:1.13-1.82], P = 0.003). CONCLUSION: RCA-CTO lesions, which had more complex angiographic features, independently contributed to TLR and TVR but not to MACEs or cardiac death in the 5 years of follow-up.

Gomisin N in the herbal drug gomishi (Schisandra chinensis) suppresses inducible nitric oxide synthase gene via C/EBPß and NF-κB in rat hepatocytes.

Gomishi is the dried fruit of Schisandra chinensis Baillon (Fructus Schisandrae chinensis, FSC) and has been used in Japanese Kampo medicine to treat inflammatory and liver diseases. However, it is unclear which constituent of FSC is primarily responsible for its pharmacological effects. FSC was extracted with methanol, fractionated by hydrophobicity, and further purified. We measured the effects of each fraction or constituent thereof on the induction of the inflammatory mediator nitric oxide (NO), which was induced by interleukin 1ß in primary cultured rat hepatocytes. The hydrophobic fraction markedly suppressed NO induction and reduced the expression of inducible nitric oxide syntheses (iNOS) in interleukin 1ß-treated hepatocytes. Gomisin N and γ-schizandrin, two major constituents of the hydrophobic fraction, significantly reduced NO production and the levels of the iNOS protein, mRNA, and antisense transcript. Gomisin N and γ-schizandrin also decreased the transcription of interleukin 1ß and inflammatory chemokines. The overexpression of the p65 subunit of nuclear factor κB or CCAAT/enhancer-binding protein ß increased the promoter activity of the iNOS gene in the firefly luciferase assay, whereas gomisin N decreased the promoter activity. The anti-inflammatory activity of FSC and its constituents were analysed, and we demonstrated that gomisin N and γ-schizandrin are involved in the hepatoprotective effect of the FSC extract, which has therapeutic potential for liver disease.

Melatonin ameliorates vascular endothelial dysfunction, inflammation, and atherosclerosis by suppressing the TLR4/NF-κB system in high-fat-fed rabbits.

Vascular endothelial dysfunction (VED) and inflammation contribute to the initiation and progression of atherosclerosis. Melatonin (MLT) normalizes lipid profile, improves endothelial function, and possesses anti-inflammatory properties. However, the precise mechanisms are still unclear. This study investigated whether MLT could ameliorate VED, inflammation, and atherosclerosis by suppressing the Toll-like receptor 4 (TLR4)/nuclear factor kappa B (NF-κB) system in high-fat-fed rabbits. Rabbits were randomly divided into three groups that received a standard diet (control group), high-cholesterol diet (atherosclerosis group), or high-cholesterol diet plus 10 mg/kg/day MLT (MLT group) for 12 wk. After treatment, high-fat diet significantly increased serum lipid and inflammatory markers in rabbits in atherosclerosis group compared with that in control group. In addition, high-fat diet also induced VED and typical atherosclerotic plaque formation and increased intima/media thickness ratio, which were significantly improved by MLT therapy as demonstrated in MLT group. Histological and immunoblot analysis further showed that high-fat diet enhanced the expressions of TLR4, myeloid differentiation primary response protein (MyD88), and NF-κB p65, but decreased inhibitor of NF-κB (IκB) expression. By contrast, MLT therapy decreased the expressions of TLR4, MyD88, and NF-κB p65 and increased IκB expression. This study has demonstrated that MLT ameliorates lipid metabolism, VED, and inflammation and inhibits the progression of atherosclerosis in high-fat-fed rabbits. Moreover, our study indicates for the first time that suppression of the TLR4/NF-κB system in local vasculature with atherosclerotic damage is important for the protective effects of MLT.

Folic acid conjugated palygorskite/Au hybrid microgels: Temperature, pH and light triple-responsive and its application in drug delivery.

Herein, folic acid conjugated poly (NIPAM-co-functional palygorskite-Au-co-acrylic acid) (FA-PNFA) hybrid microgels were fabricated by emulsion polymerization. The introduction of acrylic acid can increase the low critical solution temperature (LCST) of FA-PNFA from 36 °C at pH 5.5-42 °C at pH 7.4. Doxorubicin hydrochloride (DOX) was chosen as the load drug, the results show that the DOX release behavior is driven by temperature, pH and light. Cumulative drug release rate can reach 74 % at 37 °C and pH 5.5 while only 20 % at 37 °C and pH 7.4, which effectively avoided the early leakage of the drug. In addition, by exposing FA-PNFA hybrid microgels to laser irradiation, the cumulative release rate was increased by 5 % compared to the release rate under dark conditions. Functional palygorskite-Au as physical crosslinkers not only improves the drug loading content of microgels but also promotes the release of DOX through light drive. Methyl thiazolyl tetrazolium bromide (MTT) assay demonstrated that the FA-PNFA are nontoxic up to 200 µg mL-1 towards 4T1 breast cancer cell. Meanwhile, DOX-loaded FA-PNFA show more significant cytotoxicity than the free DOX. Confocal laser scanning microscope (CLSM) revealed that the DOX-loaded FA-PNFA could be efficiently taken by 4T1 breast cancer cells. FA-PNFA hybrid microgels not only improve the LCST of PNIPAM, but also endow the microgels with photostimulation responsiveness, which can release drugs in response to the triple stimulation response of temperature, pH and light, thus effectively reducing the activity of cancer cells, making them more promising for wider medical applications.

Resveratrol in cardiovascular disease: what is known from current research?

Resveratrol is a well-known antioxidant that exists in grape skin/seed, red wine, and the root of Polygonum cuspidatum, a traditional Chinese and Japanese medicinal material. Studies have found that resveratrol has many interesting properties, including anti-carcinogenic properties, anti-microbial and antiviral effects, the ability to reverse dyslipidemia and obesity, the ability to attenuate hyperglycemia and hyperinsulinemia, and the ability to protect endothelial function. Heart failure is the final consequence of the majority of cardiovascular diseases, and resveratrol has been shown to directly attenuate heart contraction. The cardiovascular protective capacities of resveratrol are associated with multiple molecular targets and may lead to the development of novel therapeutic strategies for atherosclerosis, ischemia/reperfusion, metabolic syndrome, and heart failure. This article will mainly review recently published basic researches about the protective cardiovascular effects of resveratrol because these results may lead to the development of new clinical therapeutics in patients.

Impact of Marital Status on Management and Outcomes of Patients With Acute Myocardial Infarction: Insights From the China Acute Myocardial Infarction Registry.

Background Acute myocardial infarction (AMI) is one of the leading causes of mortality worldwide, whereas social support is a known predictor of the prognosis after AMI. As a common factor influencing social support, the impact of marital status on care quality, in-hospital mortality, and long-term prognosis of patients with AMI remains largely unknown. Methods and Results The present study analyzed data from the CAMI (China Acute Myocardial Infarction) registry involving 19 912 patients with AMI admitted at 108 hospitals in China between January 2013 and September 2014 and aimed to evaluate marital status-based differences in acute management, medical therapies, and short-term and long-term outcomes. The primary end point was 2-year all-cause death. The secondary end points included in-hospital death and 2-year major adverse cardiac and cerebrovascular events (a composite of all-cause death, myocardial infarction, or stroke). After multivariable adjustment, 1210 (6.1%) unmarried patients received less reperfusion treatment in patients with both ST-segment-elevation myocardial infarction and non-ST-segment-elevation myocardial infarction (adjusted odds ratio [OR], 0.520 [95% CI, 0.437-0.618]; P<0.0001; adjusted OR, 0.489 [95% CI, 0.364-0.656]; P<0.0001). Being unmarried was not associated with poorer in-hospital outcome but with long-term all-cause mortality and major adverse cardiac and cerebrovascular events in both ST-segment-elevation myocardial infarction (adjusted hazard ratio [HR], 1.225 [95% CI, 1.031-1.456]; P=0.0209; adjusted HR, 1.277 [95% CI, 1.089-1.498]; P=0.0027) and non-ST-segment-elevation myocardial infarction (adjusted HR, 1.302 [95% CI, 1.036-1.638]; P=0.0239; adjusted HR, 1.368 [95% CI, 1.105-1.694]; P=0.0040) populations. Conclusions The present study suggests that being unmarried is independently related to less reperfusion received, but could not explain the higher in-hospital mortality rate after covariate adjustment. Being unmarried is associated with a substantially increased risk of adverse events over at least the first 24 months after AMI. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT01874691.

Interleukin-5-induced eosinophil population improves cardiac function after myocardial infarction.

AIMS: Interleukin (IL)-5 mediates the development of eosinophils (EOS) that are essential for tissue post-injury repair. It remains unknown whether IL-5 plays a role in heart repair after myocardial infarction (MI). This study aims to test whether IL-5-induced EOS population promotes the healing and repair process post-MI and to reveal the underlying mechanisms. METHODS AND RESULTS: MI was induced by permanent ligation of the left anterior descending coronary artery in wild-type C57BL/6 mice. Western blot and real-time polymerase chain reaction revealed elevated expression of IL-5 in the heart at 5 days post-MI. Immunohistostaining indicated that IL-5 was secreted mainly from macrophages and CD127+ cells in the setting of experimental MI. External supply of recombinant mouse IL-5 (20 min, 1 day, and 2 days after MI surgery) reduced the infarct size and increased ejection fraction and angiogenesis in the border zone. A significant expansion of EOS was detected in both the peripheral blood and infarcted myocardium after IL-5 administration. Pharmacological depletion of EOS by TRFK5 pretreatment muted the beneficial effects of IL-5 in MI mice. Mechanistic studies demonstrated that IL-5 increased the accumulation of CD206+ macrophages in infarcted myocardium at 7 days post-MI. In vitro co-culture experiments showed that EOS shifted bone marrow-derived macrophage polarization towards the CD206+ phenotypes. This activity of EOS was abolished by IL-4 neutralizing antibody, but not IL-10 or IL-13 neutralization. Western blot analyses demonstrated that EOS promoted the macrophage downstream signal transducer and activator of transcription 6 (STAT6) phosphorylation. CONCLUSION: IL-5 facilitates the recovery of cardiac dysfunction post-MI by promoting EOS accumulation and subsequent CD206+ macrophage polarization via the IL-4/STAT6 axis.

No-reflow disrupts the expression and distribution of connexin 43 in a swine model.

INTRODUCTION AND OBJECTIVES: Ischemia and ischemia/reperfusion can dephosphorylate and redistribute connexin 43 (Cx43). But it is unknown whether no-reflow phenomenon has an effect on the expression and distribution of Cx43 after acute infarction and reperfusion. METHODS: 21 open-chest pigs were divided into three groups. Left anterior descending artery (LAD) occlusion for 90 min before 180 min of reperfusion was made in ischemia/reperfusion group. The pigs in ischemia groups were either subjected to LAD ligation for 90 min or for 270 min. No-reflow and risk regions were determined pathologically by dye staining. Cx43 expression was measured by western blotting and quantitative RT-PCR analysis. Cx43 spatial distribution was shown by immunofluorescence examination. RESULTS: The content of phosphorylated and mRNA of Cx43 were higher in reflow region than in the no-reflow or sustained ischemic region. The distribution of Cx43 was also altered in no-reflow region. CONCLUSIONS: There are some differences in synthesis, expression and distribution of myocardial Cx43 at microvascular level after ischemia/reperfusion. Cx43 is partially rephosphorylated with reperfusion only in the reflow myocardium.

Rosuvastatin treatment activates JAK-STAT pathway and increases efficacy of allogeneic mesenchymal stem cell transplantation in infarcted hearts.

BACKGROUND: Widespread death of implanted cells hampers the development of stem cell therapy for acute myocardial infarction (AMI). Our previous studies indicated that statins can protect implanted mesenchymal stem cells (MSCs) against the post-infarct microenvironment, thus increasing the therapeutic effect. However, the underlying mechanisms are unclear. The JAK-STAT pathway participates in regulation of stress responses of the myocardium to various insults. This study aimed to detect whether rosuvastatin (ROSU) facilitates the survival, engraftment, and differentiation of allogeneic bone marrow-derived MSCs in the post-infarct heart via the JAK-STAT signaling pathway. METHODS AND RESULTS: Female Sprague-Dawley rats were randomized into 5 groups: AMI (control), ROSU gavage (group R), MSCs transplantation (group M), MSCs and ROSU (group M+R), or MSCs, ROSU and a JAK2 inhibitor AG-490 (group M+R+AG). MSCs from male rats were injected into the myocardium 1 week after AMI. Cardiac function and histology, as well as the expression of Y-chromosomal genes and JAK-STAT signaling proteins, were examined at 4 weeks after transplantation. Better functional recovery, increased survival and differentiation of MSCs occurred in group M+R. Furthermore, phosphorylation of JAK2 and STAT3 was higher in group M+R. The effects of ROSU, as well as of activated JAK-STAT proteins, could be attenuated by AG-490. CONCLUSIONS: ROSU treatment improves the efficacy of stem cell transplantation in infarcted hearts by activation of the JAK2-STAT3 signaling pathway.

[Atorvastatin protects swine bone marrow mesenchymal stem cells from apoptosis through AMPK but not PI3K/Akt pathway].

OBJECTIVE: The effect of mesenchymal stem cells (MSCs) transplantation is poor because of the harsh environment post infarction. Our previous studies have proven that Statins could enhance the implanted bone marrow MSCs survival, but the exact mechanism remained to be clarified. We hypothesized that atorvastatin (Ator) could protect MSCs from hypoxia and serum-free (H/SF) induced apoptosis and investigated the potential mechanisms. METHODS: Chinese mini-swine's bone marrow derived MSCs were cultured in vitro and exposed to hypoxia and H/SF, Ator of various concentrations (0.001 - 10 µmol/L), AMPK inhibitor-compound C (CC), PI3K inhibitor-LY294002 (LY), Ator + CC and Ator + LY. Cell apoptosis was assessed using Annexin V/Prospidine Iodine kit by flow cytometry. Phosphorylation of AMPK, Akt, endothelial nitric oxide synthase (eNOS) level and phosphorylation were tested with Western blot. Real Time-PCR was performed to analyze the gene expression of AMPK, Akt and eNOS. RESULTS: MSCs apoptosis in Ator (0.01 - 10 µmol/L) treated H/SF groups was significantly reduced compared with H/SF group (1.94% - 6.10% vs. 10.94%, P < 0.01 or 0.05). Apoptosis was higher in Ator + CC group than in 1 µmol/L Ator group (4.94% ± 0.98% vs. 2.59% ± 0.84%, P < 0.01) and similar between Ator + LY and 1 µmol/L Ator group (2.02% ± 0.45% vs. 2.59% ± 0.84%, P > 0.05). The gene expressions of AMPK, Akt and eNOS were significantly upregulated in atorvastatin treated groups. Meanwhile, phosphorylation of AMPK and eNOS increased in MSCs treated with atorvastatin (P < 0.01 or 0.05). Phosphorylation of eNOS significantly correlated with AMPK phosphorylation (r = 0.599, P = 0.004), but not with Akt phosphorylation (P = 0.263). CONCLUSIONS: Atorvastatin can protect MSCs from H/SF induced apoptosis through AMPK pathway, which resulting in activation of eNOS.

Tongxinluo reduces myocardial no-reflow and ischemia-reperfusion injury by stimulating the phosphorylation of eNOS via the PKA pathway.

The objective of the present study was to investigate whether pretreatment with single low loading dose of tongxinluo (TXL), a traditional Chinese medicine, 1 h before myocardial ischemia could attenuate no-reflow and ischemia-reperfusion injury by regulating endothelial nitric oxide synthase (eNOS) via the PKA pathway. In a 90-min ischemia and 3-h reperfusion model, minipigs were randomly assigned to the following groups: sham, control, TXL (0.05 g/kg, gavaged 1 h before ischemia), TXL + H-89 (a PKA inhibitor, intravenously infused at a dose of 1.0 µg·kg(-1)·min(-1) 30 min before ischemia), and TXL + N(ω)-nitro-L-arginine (L-NNA; an eNOS inhibitor, intravenously administered at a dose of 10 mg/kg 30 min before ischemia). TXL decreased creatine kinase (CK) activity (P < 0.05) and reduced the no-reflow area from 48.6% to 9.5% and infarct size from 78.5% to 59.2% (P < 0.05), whereas these effects of TXL were partially abolished by H-89 and completely reversed by L-NNA. TXL elevated PKA activity and the expression of PKA, Thr(198) phosphorylated PKA, Ser(1179) phosphorylated eNOS, and Ser(635) phosphorylated eNOS in the ischemic myocardium. H-89 repressed the TXL-induced enhancement of PKA activity and phosphorylation of eNOS at Ser(635), and L-NNA counteracted the phosphorylation of eNOS at Ser(1179) and Ser(635) without an apparent influence on PKA activity. In conclusion, pretreatment with a single low loading dose of TXL 1 h before ischemia reduces myocardial no-reflow and ischemia-reperfusion injury by upregulating the phosphorylation of eNOS at Ser(1179) and Ser(635), and this effect is partially mediated by the PKA pathway.

Combined therapy with simvastatin and bone marrow-derived mesenchymal stem cells increases benefits in infarcted swine hearts.

OBJECTIVE: Widespread death of implanted cells hampers stem cell therapy for acute myocardial infarction (AMI). Based on the pleiotropic beneficial effects of statins, we examined whether simvastatin (SIMV) increased the efficacy of mesenchymal stem cell (MSC) transplantation after AMI. METHODS AND RESULTS: Chinese miniswine (n=28) were randomized to 1 of 4 groups (n=7 per group): control, SIMV (0.25 mg/kg x d), MSC transplantation, and SIMV+MSCs. AMI was created by ligating the left anterior descending coronary artery; MSCs were injected immediately into the cyanotic myocardium. At 6 weeks, MRI showed the number of dyskinetic segments and the infarct size were significantly decreased in the SIMV group. Cardiac function improved and the perfusion defect decreased significantly in the SIMV+MSC group but not in the MSC-only group (P<0.05, versus control group). MSC survival and differentiation were significantly better in the combination group than in the MSC-only group (P<0.01). Cell apoptosis decreased significantly in both the SIMV and the SIMV+MSC groups but not in the MSC-only group when compared with controls (P<0.05). Furthermore, oxidative stress and inflammatory response was significantly reduced in the infarcted regions in both the SIMV and the SIMV+MSCs groups. CONCLUSIONS: SIMV treatment improves the therapeutic efficacy of MSC transplantation in acutely infarcted hearts by promoting cell survival and cardiovascular differentiation.