Case report: Malignant vasovagal reflex syndrome during percutaneous transcatheter closure of patent foramen ovale.

Malignant vasovagal reflex syndrome can be induced by pulling of cardiac tissue during percutaneous transcatheter closure of patent foramen ovale. In this case, a patient presented with a malignant vasovagal reflex syndrome characterized by decreased heart rate, cardiac arrest, and ventricular tachycardia. Therefore, it's particularly important to observe patients' heart rate and timely deal with vasovagal reflex syndrome during the operation.

Effects of IL-38 on Macrophages and Myocardial Ischemic Injury.

Macrophages play an important role in clearing necrotic myocardial tissues, myocardial ischemia-reperfusion injury, and ventricular remodeling after myocardial infarction. M1 macrophages not only participate in the inflammatory response in myocardial tissues after infarction, which causes heart damage, but also exert a protective effect on the heart during ischemia. In contrast, M2 macrophages exhibit anti-inflammatory and tissue repair properties by inducing the production of high levels of anti-inflammatory cytokines and fibro-progenitor cells. Interleukin (IL)-38, a new member of the IL-1 family, has been reported to modulate the IL-36 signaling pathway by playing a role similar to that of the IL-36 receptor antagonist, which also affects the production and secretion of macrophage-related inflammatory factors that play an anti-inflammatory role. IL-38 can relieve myocardial ischemia-reperfusion injury by promoting the differentiation of M1 macrophages into M2 macrophages, inhibit the activation of NOD-like receptor thermal protein domain-associated protein 3 (NLRP3) inflammasome, and increase the secretion of anti-inflammatory cytokines, such as IL-10 and transforming growth factor-ß. The intact recombinant IL-38 can also bind to interleukin 1 receptor accessory protein-like 1 (IL-1RAPL1) to activate the c-jun N-terminal kinase/activator protein 1 (JNK/AP1) pathway and increase the production of IL-6. In addition, IL-38 regulates dendritic cell-induced cardiac regulatory T cells, thereby regulating macrophage polarization and improving ventricular remodeling after myocardial infarction. Accordingly, we speculated that IL-38 and macrophage regulation may be therapeutic targets for ameliorating myocardial ischemic injury and ventricular remodeling after myocardial infarction. However, the specific mechanism of the IL-38 action warrants further investigation.

IL-37 Expression in Patients with Abdominal Aortic Aneurysm and Its Role in the Necroptosis of Vascular Smooth Muscle Cells.

Background: Our previous studies have shown that interleukin- (IL-) 37 plays a protective role in patients and animal models with coronary artery disease. However, the role of IL-37 in patients with abdominal aortic aneurysm (AAA), another artery disease, is yet to be elucidated. Methods and Results: AAA tissues and plasma samples were obtained from patients with or without surgical intervention. Normal renal aortic tissues were collected from kidney transplant donors. Our findings established that in AAA, IL-37 was distributed in endothelial cells, macrophages, and vascular smooth muscle cells (VSMCs) and that it was chiefly concentrated in VSMCs. Furthermore, the expression was found to be downregulated compared with that in normal artery tissues. Immunofluorescence showed that, unlike normal arteries, IL-37 was translocated to the nucleus of VSMCs in AAA. Moreover, in patients with AAA, the expressions of IL-37, IL-6, and tumor necrosis factor- (TNF-) α were increased in the plasma in comparison with the healthy controls. Correlation analysis revealed that IL-37 was positively correlated with IL-6, TNF-α, age, aneurysm diameter, and blood pressure. Furthermore, human aortic vascular smooth muscle cells (HASMCs) were stimulated with angiotensin II (AngII) in vitro to simulate smooth muscle cell (SMC) damage in AAA. A decrease in IL-37 expression and an increase in receptor-interacting serine/threonine-protein kinase 3 (RIPK3) expression were observed in HASMCs stimulated with AngII. On this basis, inhibition of RIPK3 with GSK'872 significantly attenuated necroptosis. Moreover, the necroptosis rates were significantly lowered in HASMCs treated with recombinant IL-37, whereas the rates were enhanced when the cells were depleted of the interleukin. Immunoblotting results showed that both exogenous and endogenous IL-37 could affect the expressions of RIPK3, NLRP3, and IL-1ß. Also, the phosphorylation of RIPK3 and p65 was affected. Meanwhile, IL-37 promoted the transition of SMC from proliferative type to contractile type. Conclusions: The expression of IL-37 in VSMCs decreases in patients with AAA, whereas IL-37 supplementation suppresses RIPK3-mediated necroptosis and promotes the transition of VSMCs from proliferative to contractile type.

Clinical Characteristics and Prognosis of 244 Cardiovascular Patients Suffering From Coronavirus Disease in Wuhan, China.

Background The coronavirus disease 2019 (COVID-19) has developed into a global outbreak. Patients with cardiovascular disease (CVD) with COVID-19 have different clinical characteristics and prognostic outcomes. This study aimed to summarize the clinical characteristics and laboratory indicators of patients with COVID-19 with CVD, especially the critically ill patients. Methods and Results This study included 244 patients diagnosed with COVID-19 and CVD (hypertension, coronary heart disease, or heart failure). The patients were categorized into critical (n=36) and noncritical (n=208) groups according to the interim guidance of China's National Health Commission. Clinical, laboratory, and outcome data were collected from the patients' medical records and compared between the 2 groups. The average body mass index of patients was significantly higher in the critical group than in the noncritical group. Neutrophil/lymphocyte ratio, and C-reactive protein, procalcitonin, and fibrinogen, and d-dimer levels at admission were significantly increased in the critical group. The all-cause mortality rate among cases of COVID-19 combined with CVD was 19.26%; the proportion of coronary heart disease and heart failure was significantly higher in deceased patients than in recovered patients. High body mass index, previous history of coronary heart disease, lactic acid accumulation, and a decrease in the partial pressure of oxygen were associated with death. Conclusions All-cause mortality in patients with COVID-19 with CVD in hospitals is high. The high neutrophil/lymphocyte ratio may be a predictor of critical patients. Overweight/obesity combined with coronary heart disease, severe hypoxia, and lactic acid accumulation resulting from respiratory failure are related to poor outcomes. Registration URL: https://www.chictr.org.cn; Unique identifier: ChiCTR2000029865.

Heat Shock Protein 22 Attenuates Doxorubicin-Induced Cardiotoxicity via Regulating Inflammation and Apoptosis.

BACKGROUND: The antitumor effect of doxorubicin (DOX) is limited by its acute and chronic toxicity to the heart, which causes heart injury. Heat shock protein 22 (Hsp22) is a protein proved to exert anti-apoptosis and anti-inflammatory effects in other diseases and physical conditions. In this study, we aim to explore whether Hsp22 could exert a protective role during cardiac injury in response to DOX. METHODS: The overexpression of Hsp22 was mediated via adenovirus vector to clarify the role of Hsp22 in the cardiac injury caused by DOX. DOX-induced acute heart injury mouse model was established by single intraperitoneal injection of DOX (15 mg/kg). Subsequently, cardiac staining and molecular biological analysis were performed to analyze the morphological and biochemical effects of Hsp22 on cardiac injury. H9c2 cells were used for validation in vitro. RESULTS: An increase in the expression level of Hsp22 was observed in DOX-treated heart tissue. Furthermore, cardiac-specific overexpression of Hsp22 showed reduced cardiac dysfunction, decrease in inflammatory response, and reduction in cell apoptosis in injury heart and cardiomyocytes induced by DOX in vivo and in vitro. Moreover, the suppression of Toll-like receptor (TLR)4/NOD-, LRR-, and pyrin domain-containing protein 3 (NLRP3) was associated with the protective effect of Hsp22. Finally, the protective effect of Hsp22 cardiac function was almost abolished by overexpression of NLRP3 in DOX-treated mice. CONCLUSION: In summary, Hsp22 overexpression in the heart could suppress cardiac injury in response to DOX treatment through blocking TLR4/NLRP3 activation. Hsp22 may become a new therapeutic method for treating cardiac injury induced by DOX in cancer patients.

The Long Noncoding RNA Hotair Regulates Oxidative Stress and Cardiac Myocyte Apoptosis during Ischemia-Reperfusion Injury.

Oxidative stress and subsequent cardiac myocyte apoptosis play central roles in the initiation and progression of myocardial ischemia-reperfusion (I/R) injury. Homeobox transcript antisense intergenic RNA (Hotair) was previously implicated in various heart diseases, yet its role in myocardial I/R injury has not been clearly demonstrated. Mice with cardiac-restricted knockdown or overexpression of Hotair were exposed to I/R surgery. H9c2 cells were cultured and subjected to hypoxia/reoxygenation (H/R) stimulation to further verify the role and underlying mechanisms of Hotair in vitro. Histological examination, molecular detection, and functional parameters were determined in vivo and in vitro. In response to I/R or H/R treatment, Hotair expression was increased in a bromodomain-containing protein 4-dependent manner. Cardiac-restricted knockdown of Hotair exacerbated, whereas Hotair overexpression prevented I/R-induced oxidative stress, cardiac myocyte apoptosis, and cardiac dysfunction. Mechanistically, we observed that Hotair exerted its beneficial effects via activating AMP-activated protein kinase alpha (AMPKα). Further detection revealed that Hotair activated AMPKα through regulating the enhancer of zeste homolog 2/microRNA-451/calcium-binding protein 39 (EZH2/miR-451/Cab39) axis. We provide the evidence that endogenous lncRNA Hotair is an essential negative regulator for oxidative stress and cardiac myocyte apoptosis in myocardial I/R injury, which is dependent on AMPKα activation via the EZH2/miR-451/Cab39 axis.

Knockdown of TRIM28 inhibits PDGF-BB-induced vascular smooth muscle cell proliferation and migration.

Atherosclerosis is a common type of cardiovascular disease (CVD), remaining one of the leading causes of global death. Tripartite motif-containing 28 (TRIM28) is a member of TRIM family that has been found to be involved in atherosclerosis. However, the role of TRIM28 in atherosclerosis remains unknown. This study aimed to investigate the effects of TRIM28 on the phenotypic switching of human aortic smooth muscle cells (HASMCs), which is considered as a fundamental event during the development of atherosclerosis. The results showed that TRIM28 was highly expressed in human atherosclerotic tissues, as well in cultured HASMCs stimulated by platelet-derived growth factor subunit B homodimer (PDGF-BB). Knockdown of TRIM28 by transfection with siRNA targeting TRIM28 (si-TRIM28) significantly suppressed the PDGF-BB-induced cell proliferation and migration of HASMCs. Besides, knockdown of TRIM28 inhibited the expressions of matrix metalloproteinase (MMP)-2 and MMP-9. The VSMC markers including α-smooth muscle actin (α-SMA), calponin and SM22α were upregulated in TRIM28 knocked down HASMCs. Furthermore, knockdown of TRIM28 blocked PDGF-BB-induced NF-κB activation in HASMCs. Collectively, knockdown of TRIM28 prevented PDGF-BB-induced phenotypic switching of HASMCs, which might be mediated by the regulation of NF-κB signaling pathway.

Circulating myocardial microRNAs from infarcted hearts are carried in exosomes and mobilise bone marrow progenitor cells.

Myocardial microRNAs (myo-miRs) are released into the circulation after acute myocardial infarction (AMI). How they impact remote organs is however largely unknown. Here we show that circulating myo-miRs are carried in exosomes and mediate functional crosstalk between the ischemic heart and the bone marrow (BM). In mice, we find that AMI is accompanied by an increase in circulating levels of myo-miRs, with miR-1, 208, and 499 predominantly in circulating exosomes and miR-133 in the non-exosomal component. Myo-miRs are imported selectively to peripheral organs and preferentially to the BM. Exosomes mediate the transfer of myo-miRs to BM mononuclear cells (MNCs), where myo-miRs downregulate CXCR4 expression. Injection of exosomes isolated from AMI mice into wild-type mice downregulates CXCR4 expression in BM-MNCs and increases the number of circulating progenitor cells. Thus, we propose that myo-miRs carried in circulating exosomes allow a systemic response to cardiac injury that may be leveraged for cardiac repair.

Thymic stromal lymphopoietin-induced HOTAIR activation promotes endothelial cell proliferation and migration in atherosclerosis.

Endothelial cells' (EC) injury is a major step for the pathological progression of atherosclerosis. Recent study demonstrated that thymic stromal lymphopoietin (TSLP) exerts a protective role in atherosclerosis. However, the effect of TSLP and the exact molecular mechanism involved in EC remains unknown. In the present study, we found that long noncoding RNA (lncRNA) HOTAIR was much lower in EC from atherosclerotic plaque. Functional assays showed that HOTAIR facilitated cell proliferation and migration, and suppressed apoptosis in EC. Moreover, we demonstrated that TSLP functions upstream of HOTAIR. We found that serum level of TSLP was decreased in atherosclerosis patients and serum TSLP level positively correlated with HOTAIR expression in EC. Further investigation demonstrated that TSLP activated HOTAIR transcription through PI3K/AKT-IRF1 pathway and then regulates the EC proliferation and migration. TSLP-HOTAIR axis also plays a protective role in low-density lipoprotein (ox-LDL)-induced EC injury. Taken together, TSLP-HOTAIR may be a potential therapy for EC dysfunction in atherosclerosis.

Cardioprotective Effects of Malvidin Against Isoproterenol-Induced Myocardial Infarction in Rats: A Mechanistic Study.

BACKGROUND Malvidin (alvidin-3-glucoside) is a polyphenol that belongs to the class of natural anthocyanin, which is abundantly found in red wines, colored fruits, and the skin of red grapes. Therefore, the current investigation was intended to evaluate the effect of malvidin against myocardial infarction induced by isoproterenol in the rats. MATERIAL AND METHODS The cardioprotective effects was assessed by determining the effect of malvidin on the activities of endogenous antioxidants - catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH) - and on the levels of lipid peroxidation and serum marker enzymes. The serum levels of IL-6 and TNF-α were also determined using an enzyme-linked immunosorbent assay (ELISA) kit. RESULTS The present study demonstrated a significant cardioprotective effect of malvidin by restoring the defensive activities of endogenous antioxidants - catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH) - and by reducing the levels of lipid peroxidation and serum marker enzymes lactate dehydrogenase (LD) and creatine kinase (CK). Malvidin significantly ameliorated the histopathological changes and impaired mitochondria in the cardiac necrosis stimulated with isoproterenol. Additionally, the results also demonstrated that nuclear translocation of Nrf-2 and subsequent HO-1 expression might be associated with nuclear factor kappa B (NF-κB) pathway activation. CONCLUSIONS Our findings suggest that malvidin exerts cardioprotective effects that might be due to possible strong antioxidant and anti-inflammatory activities. Therefore, this study provides the basis for the development of malvidin as a safe and effective treatment of myocardial infarction.

Genome-Wide Analysis of DNA Methylation and Acute Coronary Syndrome.

RATIONALE: Acute coronary syndrome (ACS) is a leading cause of death worldwide. Immune functions play a vital role in ACS development; however, whether epigenetic modulation contributes to the regulation of blood immune cells in this disease has not been investigated. OBJECTIVE: We conducted an epigenome-wide analysis with circulating immune cells to identify differentially methylated genes in ACS. METHODS AND RESULTS: We examined genome-wide methylation of whole blood in 102 ACS patients and 101 controls using HumanMethylation450 array, and externally replicated significant discoveries in 100 patients and 102 controls. For the replicated loci, we further analyzed their association with ACS in 6 purified leukocyte subsets, their correlation with the expressions of annotated genes, and their association with cardiovascular traits/risk factors. We found novel and reproducible association of ACS with blood methylation at 47 cytosine-phosphoguanine sites (discovery: false discovery rate <0.005; replication: Bonferroni corrected P<0.05). The association of methylation levels at these cytosine-phosphoguanine sites with ACS was further validated in at least 1 of the 6 leukocyte subsets, with predominant contributions from CD8+ T cells, CD4+ T cells, and B cells. Blood methylation of 26 replicated cytosine-phosphoguanine sites showed significant correlation with expressions of annotated genes (including IL6R, FASLG, and CCL18; P<5.9×10-4), and differential gene expression in case versus controls corroborated the observed differential methylation. The replicated loci suggested a role in ACS-relevant functions including chemotaxis, coronary thrombosis, and T-cell-mediated cytotoxicity. Functional analysis using the top ACS-associated methylation loci in purified T and B cells revealed vital pathways related to atherogenic signaling and adaptive immune response. Furthermore, we observed a significant enrichment of the replicated cytosine-phosphoguanine sites associated with smoking and low-density lipoprotein cholesterol (Penrichment≤1×10-5). CONCLUSIONS: Our study identified novel blood methylation alterations associated with ACS and provided potential clinical biomarkers and therapeutic targets. Our results may suggest that immune signaling and cellular functions might be regulated at an epigenetic level in ACS.

A Potential Mechanism of High-Dose Ticagrelor in Modulating Platelet Activity and Atherosclerosis Mediated by Thymic Stromal Lymphopoietin Receptor.

Abnormal expression of thymic stromal lymphopoietin (TSLP) and its receptor (TSLPR) was found in patients with acute coronary syndrome. Ticagrelor, an oral platelet ADP P2Y12 receptor antagonist, is widely used in these patients. The aim of this study was to verify whether different doses of ticagrelor regulated plaque progression and platelet activity by modulating TSLP/TSLPR. Seventy-five ApoE-/- mice were randomly divided into five groups: (1) high-cholesterol diet (HCD, n = 15); (2) HCD plus ticagrelor 25 mg/kg/d (T1, n = 15); (3) HCD plus ticagrelor 50 mg/kg/d (T2, n = 15); (4) HCD plus ticagrelor 100 mg/kg/d (T3, n = 15); and (5) a normal diet group (ND, n = 15). At day 0 and at week 16, blood lipids and serum TSLP levels, expression of TSLPR, CD62, and CD63, platelet aggregation, platelet ATP release, PI3K/Akt signaling pathway, and plaque morphology were assessed. HCD increased TSLPR expression and atherosclerosis progression but high-dose ticagrelor (100 mg/kg) moderated this trend. TSLPR was positively correlated with Akt1, platelet aggregation, corrected plaque area, and vulnerability index in the T3 group (P<0.01). In conclusion, low-dose ticagrelor only inhibited platelet activity. Besides this inhibition, high-dose ticagrelor modulated platelet activity and atherosclerosis mediated by TSLPR, potentially through the PI3K/Akt signal pathway.

Chemerin15-Ameliorated Cardiac Ischemia-Reperfusion Injury Is Associated with the Induction of Alternatively Activated Macrophages.

Chemerin15 (C15), an endogenous anti-inflammatory component, inhibits the activity of neutrophils and macrophages through G protein-coupled receptor ChemR23; however, its role as well as functional mechanism in mouse myocardial ischemia/reperfusion (I/R) injury remains unknown. Methods. Sham or I/R operations were performed on C57BL/6J mice. The I/R mice received an injection of C15 immediately before reperfusion. Serum troponin T levels, infarct size, cardiomyocyte apoptosis, reactive oxygen species (ROS) production, and infiltration of neutrophils were assessed 24 h after reperfusion, while the macrophage phenotypes, macrophage infiltration, and inflammatory cytokine levels were assessed 48 h after reperfusion. Results. Compared with the control group, the C15-treated mice showed an obvious amelioration of I/R injury and displayed less ROS, accompanied by reduced neutrophil recruitment. C15 decreased the tumor necrosis factor- (TNF-) α and interleukin- (IL-) 6 levels and increased the IL-10 levels in the serum of the I/R mice, which suggested a suppressed inflammatory response that could be related to elevated alternatively activated M2 macrophages with characteristic skewed expression of M2 markers and inhibition of classically activated M1 marker expression. Conclusion. C15 may induce alternatively activated M2 macrophage polarization and suppress the inflammatory response to protect against myocardial I/R injury in mice.

Disruption of the TSLP-TSLPR-LAP signaling between epithelial and dendritic cells through hyperlipidemia contributes to regulatory T-Cell defects in atherosclerotic mice.

Regulatory T-Cells (Tregs) play a protective role against the development of atherosclerosis. Moreover, thymic stromal lymphopoietin (TSLP)/thymic stromal lymphopoietin receptor (TSLPR) signaling in myeloid dendritic cells (DCs) promote Treg differentiation. Here, we examined the potential role of TSLP/TSLPR on Treg homeostasis in atherosclerosis. The frequencies of both latency-associated peptide (LAP)(+) and Foxp3(+) Tregs were reduced in the thymus and spleen of ApoE(-/-) mice compared with C57BL/6 mice, and this effect was associated with decreased thymic output. The tolerogenic function of DCs obtained from ApoE(-/-) mice was compromised compared with those from C57BL/6 mice. The expression of TSLP and TSLPR was also inhibited in ApoE(-/-) mice. In addition, we found that ox-LDL attenuated TSLP expression in cultured thymic epithelial cells (TECs) through the activation of retinoid X receptor alpha (RXRA) and IL-1ß and decreased LAP and PD-L1 expression in oxLDL-activated DCs while both were up-regulated in TSLP-activated DCs. We also observed that the TSLP-DCs mediated differentiation of Tregs was abrogated through LAP neutralization. Furthermore, TSLP injection rescued Treg defects in ApoE(-/-) mice. These findings suggest that Treg defects in ApoE(-/-) mice might partially be attributed to the disruption of TSLP-TSLPR-LAP signaling in epithelial cells (ECs) and DCs.

Autoantibodies targeting AT1 receptor from patients with acute coronary syndrome upregulate proinflammatory cytokines expression in endothelial cells involving NF-κB pathway.

Our study intended to prove whether agonistic autoantibodies to angiotensin II type 1 receptor (AT1-AAs) exist in patients with coronary heart disease (CHD) and affect the human endothelial cell (HEC) by upregulating proinflammatory cytokines expression involved in NF-κB pathway. Antibodies were determined by chronotropic responses of cultured neonatal rat cardiomyocytes coupled with receptor-specific antagonists (valsartan and AT1-EC2) as described previously. Interleukin-6 (IL-6), vascular cell adhesion molecule-1 (VCAM-1), and monocyte chemotactic protein-1 (MCP-1) expression were improved at both mRNA and protein levels in HEC, while NF-κB in the DNA level was improved detected by electrophoretic mobility shift assays (EMSA). These improvements could be inhibited by specific AT1 receptor blocker valsartan, NF-κB blocker pyrrolidine dithiocarbamate (PDTC), and specific short peptides from the second extracellular loop of AT1 receptor. These results suggested that AT1-AAs, via the AT1 receptor, induce expression of proinflammatory cytokines involved in the activation of NF-κB. AT1-AAs may play a great role in the pathogenesis of the acute coronary syndrome by mediating vascular inflammatory effects involved in the NF-κB pathway.

Circulating Th22 and Th9 levels in patients with acute coronary syndrome.

BACKGROUND: CD4+ T helper (Th) cells play critical roles in the development and progression of atherosclerosis and the onset of acute coronary syndromes (ACS, including acute myocardial infarction (AMI) and unstable angina pectoris (UAP)). In addition to Th1, Th2, and Th17 cells, Th22 and Th9 subsets have been identified in humans. In the present study, we investigated whether Th22 cells and Th9 cells are involved in the onset of ACS. METHODS: The frequencies of Th22 and Th9 cells were detected using a flow cytometric analysis and their related cytokine and transcription factor were measured in the AMI, UAP, stable angina pectoris (SAP), and control groups. RESULTS: The results revealed a significant increase in the peripheral Th22 number, AHR expression, and IL-22 levels in patients with ACS compared with those in the SAP and control groups. Although there was no difference in the peripheral Th9 number among the four groups, the PU.1 expression and IL-9 levels were significantly increased in patients with ACS compared with the SAP and control groups. CONCLUSIONS: Circulating Th22 and Th9 type responses may play a potential role in the onset of ACS symptom.

[Therapeutic effect of transplantation of bone marrow mesenchymal stem cells over-expressing Cx43 on heart failure in post-infarction rats].

OBJECTIVE: To explore the therapeutic effect of transplantation of bone marrow mesenchymal stem cells (BMSCs) over-expressing Cx43 on heart failure in post-infarction rats. METHODS: Sixty SD rats were randomly divided equally into 4 groups: sham group, DMEM/F12 group injected with DMEM/F12, EGFP group with transplanted EGFP transfected BMSCs and Cx43 group with transplanted Cx43 transfected BMSCs. Myocardial infarction model was established by ligating anterior descending branch and the cells were transplanted after 30 minutes. At Week 4 post-infarction, the heart functions of rats were evaluated by echocardiography. After the rats were sacrificed, their tissue samples were collected. The areas of myocardial infarction and the levels of collagen fiber content were measured. And the expressions of EGFR and Cx43 were observed under laser confocal microscopy. The level of Cx43 mRNA was measured by reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: As compared with the DMEM/F12 group, cardiac function was improved significantly, myocardial infarct area shrunk and collagen fiber content decreased significantly in the EGFP and group in Cx43 groups the. Survival of BMSCs and the formation of gap junction between BMSCs and the host myocardium could be observed under laser confocal microscopy both in EGFP group and Cx43 groups. And the post-infarction, expression of Cx43 mRNA in myocardial tissue decreased significantly in the group DMEM/F12, when compared with sham group (0.18 ± 0.05 vs 0.78 ± 0.14, P < 0.01). There was no significant difference on expression of Cx43 mRNA between DMEM/F12 group and EGFP group (0.18 ± 0.05 vs 0.20 ± 0.09, P > 0.05). The lever of Cx43 mRNA was higher in group Cx43 than in group DMEM/F12 and group EGFP(0.39 ± 0.14 vs 0.18 ± 0.05, P < 0.01; 0.39 ± 0.14 vs 0.20 ± 0.09, P < 0.05). CONCLUSION: Transplantation of BMSCs attenuates ventricular remodeling and improves cardiac functions. It may result from the over-expression of Cx43 gene through its effects of improving gap junction remodeling and increasing electro-mechanical coupling between myocardial cells in peri-infarct area.

Overexpression of CXCL16 promotes a vulnerable plaque phenotype in Apolipoprotein E-Knockout Mice.

BACKGROUND: CXCL16 has been shown to be involved in atherosclerotic lesion development, but its role in preexisting lesions is still unclear. This study aims to assess the effect of CXCL16 on the stability of preexisting lesions. METHODS: We firstly measured plasma CXCL16 level in Apolipoprotein E-Knockout (ApoE KO) mice with either high-cholesterol diet (HCD) or normal diet (ND) by enzyme-linked immunosorbent assay (ELISA). Then, silastic collars were placed around the carotid arteries in HCD-ApoE KO mice to accelerate atherosclerotic lesions. Five weeks later, CXCL16 was overexpressed by intravenous injection of lentivirus carrying CXCL16 transgene. Two weeks after infection, lesions were stained with hematoxylin and eosin (HE) and with oil red O. Biomarkers in the lesions, such as MMPs, CCL2, VCAM-1 and TNF-α were measured by real-time polymerase chain reaction (RT-PCR), which indicate the instability of plaques. RESULTS: The level of CXCL16 in plasma was higher in HCD-ApoE KO mice as compared to ND-ApoE KO mice. Circulating CXCL16 overexpression does not affect the size of preexisting plaques, but it leads to vulnerable plaque morphology and increases the expression of markers of plaque destabilization. CONCLUSION: Systemic CXCL16 becomes much higher in atherosclerosis, and it could be a potential atherogenic biomarker. Overexpression of CXCL16 promotes the evolution of preexisting lesions to vulnerable plaques in ApoE KO mice.

Ischemia-reperfusion injury up-regulates Pim-3 gene expression in myocardial tissue.

This study examined the effect of ischemia-reperfusion injury on the expression of Pim-3 gene in myocardial tissues and their underlying mechanism. Rat models of myocardial ischemia-reperfusion injury were established by ligating the left anterior descending coronary artery of the rats. A total of 30 SD male adult rats were randomly divided into 5 groups: group A (sham operation, n=6); group B (in which the rats were subjected to 15 min of ischemia by ligation of the left anterior descending coronary artery, n=6); group C (in which the rats received 30 min of ischemia, n=6), group D and group E (in which the left anterior descending coronary artery of the rats were ligated for 30 min and then reperfused for 30 min or 120 min, n=6 in each). The left ventricular tissues were removed immediately after the ischemia-reperfusion injury. Neonatal cardiomyocytes were cultured and treated with different concentrations of H(2)O(2) (0, 5, 10, 20 µmol/L) or tumor necrosis factor-α (TNF-α, 0, 1, 5, 10 ng/mL). The mRNA and protein expression of Pim-3 gene was determined by using RT-PCR, western blotting and immunohistochemistry. Additionally, neonatal cardiomyocytes were transfected with Pim-3 siRNA, and induced to develop apoptosis by using H(2)O(2). The results showed that normal myocardial tissues expressed a quantity of Pim-3 gene mRNA and protein. Ischemia-reperfusion injury could up-regulate the mRNA and protein expression of Pim-3 gene in myocardial tissues. Furthermore, H(2)O(2) but not TNF-α up-regulated the Pim-3 gene expression in cultured cardiomyocytes. And Pim-3 silencing failed to strengthen the H(2)O(2)-inducing apoptosis in cardiomyocytes. It was concluded that ischemia-reperfusion injury up-regulated the Pim-3 gene expression through oxidative stress signaling pathway in myocardial tissues.

Improved myocardial perfusion and cardiac function by controlled-release basic fibroblast growth factor using fibrin glue in a canine infarct model.

OBJECTIVE: Angiogenic therapy is emerging as a potential strategy for the treatment of ischemic heart disease but is limited by a relatively short half-life of growth factors. Fibrin glue (FG) provides a reservoir for controlled-release of growth factors. The aim of this study was to evaluate the effects of basic fibroblast growth factor (bFGF) incorporating FG on angiogenesis and cardiac performance in a canine infarct model. METHODS: Acute myocardial infarction was induced by ligation of the left anterior descending coronary artery (LAD). Group I (n=6) underwent ligation of LAD alone. In Group II, transmural channels were created in the infarct area (n=6). In Group III, non-transmural channels were created to locate FG cylinders containing bFGF (n=6). Eight weeks after operation, myocardial perfusion was assessed by single photon emission computed tomography, cardiac function by echocardiography, and vascular development by immunohistochemical staining. RESULTS: Total vascular density and the number of large vessels (internal diameter ≥50 µm) were dramatically higher in Group III than in Groups I and II at eight weeks. Only the controlled-release group exhibited an improvement in regional myocardial perfusion associated with lower defect score. Animals in Group III presented improved cardiac regional systolic and diastolic functions as well as global systolic function in comparison with the other two groups. CONCLUSIONS: Enhanced and sustained angiogenic response can be achieved by controlled-release bFGF incorporating FG within transmyocardial laser channels, thus enabling improvement in myocardial perfusion and cardiac function.