Screening Organic Components and Toxicogenic Structures from Regional Fine Particulate Matters Responsible for Myocardial Fibrosis in Male Mice.

Numerous studies indicate that fine particulate matters (PM2.5) and its organic components are urgent risk factors for cardiovascular diseases (CVDs). Combining toxicological experiments, effect-directed analyses, and nontarget identification, this study aims to explore whether PM2.5 exposure in coal-combustion areas induces myocardial fibrosis and how to identify the effective organic components and their toxic structures to support regional risk control. First, we constructed an animal model of real-world PM2.5 exposure during the heating season and found that the exposure impaired cardiac systolic function and caused myocardial fibrosis, with chemokine Ccl2-mediated inflammatory response being the key cause of collagen deposition. Then, using the molecular event as target coupled with two-stage chromatographic isolation and mass spectrometry analyses, we identified a total of 171 suspect organic compounds in the PM2.5 samples. Finally, using hierarchical characteristic fragment analysis, we predicted that 40 of them belonged to active compounds with 6 alert structures, including neopentane, butyldimethylamine, 4-ethylphenol, hexanal, decane, and dimethylaniline. These findings provide evidence for risk management and prevention of CVDs in polluted areas.

Efficacy and safety of stem cell therapy in patients with dilated cardiomyopathy: a systematic appraisal and meta-analysis.

BACKGROUND: The clinical significance of stem cell therapy in the treatment of dilated cardiomyopathy remains unclear. This systemic appraisal and meta-analysis aimed to assess the efficacy and safety of stem cell therapy in patients with dilated cardiomyopathy. After searching the PubMed, Embase, and Cochrane library databases until November 2017, we conducted a meta-analysis to evaluate the efficacy and safety of stem cell therapy in patients with dilated cardiomyopathy. METHODS: The weighted mean difference (WMD), standard mean difference (SMD), relative risk (RR), and 95% confidence interval (CI) were summarized in this meta-analysis. Both fixed effects and random effects models were used to combine the data. Sensitivity analyses were conducted to evaluate the impact of an individual dataset on the pooled results. RESULTS: A total of eight randomized controlled trials, which involved 531 participants, met the inclusion criteria in this systematic appraisal and meta-analysis. Our meta-analysis showed that stem cell therapy improves left ventricular ejection fraction (SMD = 1.09, 95% CI 0.29 to 1.90, I2 = 92%) and reduces left ventricular end-systolic volume (SMD = - 0.36, 95% CI - 0.61 to - 0.10, I2 = 20.5%) and left ventricular end-diastolic chamber size (SMD = - 0.48, 95% CI - 0.89 to - 0.07, I2 = 64.8%) in patients with dilated cardiomyopathy. However, stem cell therapy has no effect on mortality (RR = 0.72, 95% CI 0.50 to 1.02, I2 = 30.2%) and 6-min-walk test (WMD = 51.52, 95% CI - 24.52 to 127.55, I2 = 94.8%). CONCLUSIONS: This meta-analysis suggests that stem cell therapy improves left ventricular ejection fraction and reduces left ventricular end-systolic volume and left ventricular end-diastolic chamber size in patients with dilated cardiomyopathy. However, future well-designed large studies might be necessary to clarify the effect of stem cell therapy in patients with dilated cardiomyopathy.

Anti-inflammatory activities of hepatocyte growth factor in post-ischemic heart failure.

Hepatocyte growth factor (HGF) alleviates acute and chronic inflammation in experimental inflammatory bowel disease, glomerulonephritis, and airway inflammation. However, the anti-inflammatory effects of HGF on myocardial infarction are not defined. The current study assessed the anti-inflammatory effects of HGF in post-ischemic heart failure. The left anterior descending coronary artery was ligated in rats, and adenovirus containing human HGF (Ad-HGF) or control virus (Ad-GFP) was administered intramyocardially. The quantity of proinflammatory cytokines secreted by cardiomyocytes, such as tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and IL-1ß, was evaluated. Cardiac function and LV remodeling were assessed using echocardiography and collagen deposition, respectively. Left ventricular fractional shortening (LVFS) and left ventricular ejection fraction (LVEF) four weeks after injection were significantly increased in Ad-HGF-treated animals compared to the Ad-GFP group. HGF gene therapy improved ventricular geometry with a significantly decreased left ventricular end-diastolic diameter (LVEDD) and markedly reduced myocardial collagen deposition. Treatment with Ad-HGF significantly decreased the mRNA levels of TNF-α, IL-6, and IL-1ß in the non-infarcted region four weeks after injection. Changes of the TNF-α, IL-6, and IL-1ß levels in the non-infarcted region positively correlated with the LVEDD 4 weeks after infarction. Treatment of acute myocardial infarction (AMI) with Ad-HGF in the early stage of MI reduced the pro-inflammatory cytokine levels and preserved cardiac function. These findings indicated that Ad-HGF gene therapy alleviated ventricular remodeling after infarction by reducing inflammation.

[Early treatment with hepatocyte growth factor improves pulmonary artery and right ventricular remodeling in rats with pulmonary artery hypertension by modulating cytokines expression].

OBJECTIVE: To investigate the effect of early treatment with hepatocyte growth factor (HGF) on the cytokine expression and pulmonary artery, right ventricular (RV) remodeling in the rat model of pulmonary artery hypertension (PAH). METHODS: The rat model of PAH was produced by injecting monocrotaline, and the model rats were randomly divided into empty adenovirus transfection group (MCT group, n = 10) and HGF gene transfection group(HGF group, n = 10). Another group of rats served as the Sham operation group (Sham group n = 10). After 4 weeks of HGF gene transfection, the histological sections of the lungs and right ventricular (RV) were stained with hematoxylin-eosin (HE) and the pulmonary artery and RV remodeling were examined. The rat lung sections were also immunostained with antibodies against factor VIII, and the capillary density were calculated. Meanwhile, the mRNA expression of TNF-α, IL-6, IL-1ß and TGF-ß1 in pulmonary arteries and RV were detected by RT-PCR. RESULTS: HGF gene treatment significantly decreased the ratio of vessel wall thickness to pulmonary artery diameter and the ratio of vessel wall area to total area, and increased the capillary density of lung in PAH rats. HGF gene treatment also significantly decreased cross-sectional area of cardiomyocytes and collagen deposited in RV. Moreover, HGF gene treatment significantly decreased the expression of cytokines in pulmonary artery (TNF-α: 0.82 ± 0.07 vs 0.49 ± 0.09, IL-6: 1.13 ± 0.19 vs 0.68 ± 0.09, IL-1ß: 0.86 ± 0.11 vs 0.51 ± 0.07, TGF-ß1: 1.18 ± 0.12 vs 0.59 ± 0.10) and RV (TNF-α: 0.79 ± 0.11 vs 0.48 ± 0.08, IL-6: 1.03 ± 0.11 vs 0.63 ± 0.09, IL-1ß: 0.81 ± 0.11 vs 0.52 ± 0.07, TGF-ß1: 0.94 ± 0.12 vs 0.53 ± 0.10) in MCT induced PAH rats (P < 0.05) . CONCLUSION: Early treatment with HGF improves pulmonary artery and RV remodeling, possibly by decreasing the expression of TNF-α, IL-6, IL-1ß and TGF-ß1 in pulmonary arteries and RV.

Expression levels and clinical significance of ferroptosis-related genes in patients with myocardial infarction.

Myocardial infarction (MI) is the most serious type of cardiovascular disease and the leading cause of cardiac death.Ferroptosis is one of the newly discovered programmed cell death modes in MI, but its mechanism of action in MI has not been clarified.In this study, we analyzed the expression changes of ferroptosis-related genes in MI and explored the potential mechanisms of ferroptosis-related functions in myocardial infarction. Public data sets GSE19339, GSE97320 and GSE141512 were retrieved from the Gene Expression Omnibus (GEO) Datasets public database. After data preprocessing, differentially expressed genes were screened, and differentially expressed ferroptosis-related genes associated with myocardial infarction were obtained. The biological function and signaling pathway enrichment analysis were performed to establish the PPI interaction network specific to heart tissue, and the differential diagnosis significance of differentially expressed ferroptosis-related genes associated with myocardial infarction was analyzed by ROC curve and decision tree model.A total of 317 genes showed significant changes in expression levels in patients with myocardial infarction, including 205 down-regulated genes and 112 up-regulated genes.Gene Ontology (GO) enrichment analysis and functional classification of Kyoto Encyclopedia of Genes and Genomes (KEGG) signaling pathways showed that these genes were mainly involved in signaling pathways or biological functions related to inflammation and apoptosis.Five differentially expressed ferroptosis-related genes (SLC2A3, EPAS1, HMOX1, ATM, FANCD2) were obtained, all of which played key biological functions in cardiac tissue function. SLC2A3, EPAS1, HMOX1, ATM and FANCD2 genes all had good diagnostic value for myocardial infarction (P < 0.05). The increase of SLC2A3, EPAS1 and HMOX1 are risk factors for myocardial infarction, while ATM and FANCD2 are protective factors.Decision tree analysis showed that SLC2A3, HMOX1, ATM, FANCD2 gene had higher net yield in diagnosing myocardial infarction. In summary, the mechanism of ferroptosis is involved in the occurrence and progression of myocardial infarction. In this study, five differentially expressed ferroptosis-related genes associated with myocardial infarction were retrieved, which may be good biomarkers of ferroptosis after MI.These findings also suggest that the differential expression of ferroptosis-related genes associated with myocardial infarction has significant diagnostic significance for myocardial infarction.

The Emerging Role of CircRNAs in Atherosclerosis.

Cardiovascular diseases (CVDs) based on atherosclerosis remain the main reason for death in Western countries and China. Cardiovascular research has demonstrated that its pathogenesis is closely associated with endothelial cell (EC) injury, the phenotypic transformation of vascular smooth muscle cells (VSMCs), and the abnormal biological behaviour of macrophages. In recent years, circular RNAs (circRNAs) have received much attention for their unique role in the pathogenesis of atherosclerosis. In this review, we discussed the mechanisms associated with ECs, VSMCs, and macrophages in atherosclerosis and summarized the role of circRNAs in atherosclerosis. This review aims to provide a basis for the prevention and treatment of atherosclerosis.

Intravenous Injection of SDF-1α-overexpressing Bone Marrow Mesenchymal Stem Cells has a Potential Protective Effect on Myocardial Ischemia in Mice.

BACKGROUND: Neutrophils are involved in the injury of myocytes during myocardial ischemia (MI). Stem cells migrate to the site of myocardial injury under homing signals and play a protective role, such as inhibiting inflammation. Chemokine SDF-1α and its related receptor CXCR4 are upregulated after myocardial infarction, which may play an important role in stem cell homing. OBJECTIVES: This study aimed to explore the potential therapeutic effect of SDF-1α-modified bone marrow mesenchymal stem cells on myocardial ischemia/reperfusion (I/R) injury. METHODS: We explored the role of SDF-1α modified bone marrow mesenchymal stem cells in vivo and in vitro. SDF-1α and CXCR4 expression was detected under hypoxia/reoxygenation (H/R) condition. Cell migration was detected by the transwell method. The levels of SDF-1α and IL-1ß, IL-6, IL-10, and TNF-α were detected in different groups. RESULTS: In vitro, SDF-1α was mainly upregulated and secreted by cardiomyocytes, and cardiomyocytes recruited stem cells through the SDF-1/CXCR4 pathway to reduce the damage of polymorphic mononuclear neutrophils to cardiomyocytes under H/R. Upregulation of SDF-1α increased the migration ability of BMSC Stem Cells to H/R-induced cardiomyocytes. In vivo, intravenous injection of SDF-1α genemodified BMSC Stem Cells reduced inflammatory infiltration in the injured area as well as the level of systemic inflammatory factors. CONCLUSION: SDF-1α-overexpressing BMSC Stem Cells protected the heart function of mice and significantly reduced I/R-induced myocardial injury, which has a potential protective effect on MI.

Global research trends in in-stent neoatherosclerosis: A CiteSpace-based visual analysis.

Background: Recent studies have shown that in-stent neoatherosclerosis (ISNA/NA) is an important cause of late stent failure. A comprehensive understanding of the current state of research in this field will facilitate the analysis of its development trends and hot frontiers. However, no bibliometric correlation has been reported yet. Here, we analyze the relevant literature since the emergence of the concept and provide valuable insights. Methods: Publications were collected from the Web of Science Core Collection (WoSCC) and PubMed. Microsoft Excel, SPSS and CiteSpace were used to analyze and present the data. Results: A total of 498 articles were collected, with Japan and Cardiovasc Res Fdn being the main publishing forces in all country/region and institutions. J AM COLL CARDIOL is the journal with the most published and co-cited articles. According to co-citation analysis, optical coherence tomography, thrombosis, implantation, restenosis, drug-eluting stent, and bare metal stent have become more and more popular recently. Conclusion: ISNA is a niche and emerging field. How to reduce the incidence of ISNA and improve the late patency rate of coronary stents may remain a hot spot for future research. The pathogenesis of ISNA also needs to be explored in more depth.

Liver proteomics analysis reveals abnormal metabolism of bile acid and arachidonic acid in Chinese hamsters with type 2 diabetes mellitus.

Non-obese, spontaneous, and genetically predisposed type 2 diabetic Chinese hamsters exhibit metabolic abnormalities similar to those observed in human T2DM. Here, tandem mass tag (TMT)-based quantitative proteomics technology was used to screen and identify differentially abundant proteins in the liver that are associated with diabetes in Chinese hamsters. GO and KEGG pathway enrichment analysis were conducted to validate the findings, as well as qRT-PCR and western blotting. In total, 103 proteins were identified in the livers of diabetic hamsters, of which 48 were up-regulated and 55 were down-regulated. KEGG pathway enrichment analysis further demonstrated that linoleic acid metabolism, arachidonic acid metabolism, bile secretion, and other pathways were affected. Moreover, AQP9 and EPHX1 were significantly down-regulated in the bile secretion pathway, whereas PTGES2, Cyp2c27, and Cyp2c70 were associated with the arachidonic acid metabolic pathway. Serum levels of bile acid (BA) and arachidonic acid (AA) in diabetic Chinese hamsters were significantly higher than those in control hamsters. Cumulatively, our findings indicate that the five candidate proteins may be associated with abnormal BA and AA metabolism, suggesting their involvement in pathological changes in the livers of Chinese hamsters with T2DM. SIGNIFICANCE: The liver proteomics of Chinese hamsters describes differentially abundant proteins associated with T2DM, while promoting this animal model as an appropriate and ideal platform for investigating underlying molecular mechanisms of T2DM. This study reveals abnormal bile acid and arachidonic acid metabolism in T2DM hamsters, which may provide insights for studying the relationship between candidate proteins and KEGG pathways to elucidate the underlying molecular mechanism associated with T2DM.

MicroRNA-17 as a potential diagnostic biomarker in pulmonary arterial hypertension.

OBJECTIVE: This study aimed to detect circulating microRNA (miR)-17 and miR-20a levels in patients with pulmonary arterial hypertension (PAH), and to investigate whether circulating miR-17 levels are associated with PAH. METHODS: Thirty-five PAH patients and 20 healthy controls were enrolled in the study. Circulating miR-17 and miR-20a levels were measured using real-time PCR analysis. RESULTS: miR-17 levels were significantly increased in PAH patients compared with healthy controls. They were also higher in PAH patients at World Health Organization functional class (WHO FC) III-IV than WHO FC I-II PAH patients. There was no significant difference in miR-20a levels between PAH patients and controls. miR-17 had a high area under the corresponding receiver operating characteristic curve. Further, we found that circulating miR-17 levels correlated with the 6-minute walk distance, mean pulmonary artery pressure, and mean right atrial pressure in PAH patients. CONCLUSION: Circulating miR-17 levels may be associated with human PAH. Therefore, miR-17 could be used as a diagnostic index and prognostic factor for PAH patients.

Glutathione S-Transferase M1 and T1 polymorphisms and hypertension risk: an updated meta-analysis.

Recently, Glutathione S-transferase M1 (GSTM1), glutathione S-transferase T1 (GSTT1), and their interaction with hypertension risk have been focused on. However, the results of previous studies have been inconsistent. Hence, the present meta-analysis was performed to explore the association. Twenty-two case-control studies met the inclusion criteria for GSTM1 (including 3577 hypertension cases and 3784 controls), twenty-two for GSTT1 (including 3741 cases and 4444 controls), and nine for their combined effects (including 1073 cases and 781 controls). Pooled analyses on the association between GSTM1 present/null polymorphism and hypertension risk were observed to be insignificant in overall and subgroup analyses. The individual who carries the GSTT1 null-genotype had a statistically significant overall population (OR = 1.28, 95% CI: 1.03, 1.60), Indians (OR = 2.45, 95% CI: 1.08, 5.59), and hospital-based controls (OR = 1.53, 95% CI: 1.21, 1.94). For the GSTM1-GSTT1 interaction, we found that the GSTM1/GSTT1 double-null-genotype was significantly associated with hypertension risks (double-null vs. double-present: OR = 2.68, 95% CI: 1.06, 6.81). To summarize, this meta-analysis indicates that Indians with the GSTT1 null-genotype has a raised hypertension risks; the GSTM1 null/GSTT1 null-genotype is association with raised hypertension risks, while the GSTM1 null-genotype is not associated with hypertension risks. In addition, I2 > 75% cannot be eliminated for GSTM1 in Indians or Asians, hence, it will be very important to explore the GSTM1 null-genotype and hypertension susceptibility in Indians and Asians for a large new sample, on population-based control study.

Effects of transplanted myoblasts transfected with human growth hormone gene on improvement of ventricular function of rats.

BACKGROUND: Cell transplantation for myocardial repair is limited by early cell death. Gene therapy with human growth hormone (hGH) has been shown to promote angiogenesis and attenuate apoptosis in the experimental animal. This study was conducted to explore the effects of myoblast-based hGH gene therapy on heart function restoration and angiogenesis after myocardial infarction, and to compare the differences between myoblast-based hGH gene therapy and myoblast therapy. METHODS: Myoblasts were isolated from several SD rats, cultured, purified, and transfected with plasmid pLghGHSN and pLgGFPSN. Radioimmunoassay (RIA) was used to detect the expression of hGH in these myoblasts. SD rats underwent the ligation of the left anterior descending coronary artery so as to establish a heart ischemia model. Thirty surviving rats that underwent ligation were randomly divided into 3 equal groups 2 weeks after left coronary artery occlusion: pLghGHSN group received myoblast infected with hGH gene transplantation; pLgGFPSN group received myoblast infected with GFP gene transplantation; control group: received cultured medium only. Four weeks after the injection the surviving rat underwent evaluation of cardiac function by echocardiography. The rats were killed and ventricular samples were undergone immunohistochemistry with hematoxylin-eosin and factor VIII. Cryosection was analyzed by fluorescence microscopy to examine the expression of green fluorescent protein. Reverse transcriptase-polymerase chain reaction (RT-PCR) was used to examine the mRNA expression of vascular endothelial growth factor (VEGF), bax and Bcl-2. hGH expression in myocardium was examined by Western blot. RESULTS: Myoblast can be successfully isolated, cultured and transfected. The expression of hGH in transfected myoblast was demonstrated with RIA. Four weeks after therapy, the cardiac function was improved significantly in pLghGHSN group and pLgGFPSN group. Fractional shortening (FS) and ejection fraction (EF) in pLghGHSN group were elevated significantly compared with pLgGFPSN group and control group after therapy (FS: 36.9+/-5.3 vs 29.5+/-3.5, 21.8+/-2.9; EF: 56.9+/-4.3 vs 47.1+/-3.6, 38.4+/-4.8, P<0.05). Left ventricular end-diastolic dimension (LVEDD) and heart infracted size in pLghGHSN group were decreased significantly compared with pLgGFPSN group and control group after therapy (LVEDD: 5.9+/-0.3 vs 6.8+/-0.2, 8.6+/-0.3; heart infracted size: (34.5+/-4.2)% vs (40.0+/-3.9)%, (46.1+/-3.8)%, P<0.05); Green fluorescence was detected in cryosection of pLgGFPSN group. The capillary density of the pLgGFPSN group was significantly greater than those of the pLghGHSN group and control group (P<0.05). The mRNA expression of VEGF and Bcl-2/bax in pLghGHSN group was higher than in pLgGFPSN group or control group (P<0.05). The expression of hGH gene in myocardium tissue can be detected by Western blot assay in pLghGHSN group. CONCLUSIONS: Transplantation of heart cells transfected with hGH induced greater angiogenesis and effect of antiapoptosis than transplantation of cells transfected with GFP. Combined GH gene transfer and cell transplantation provided an effective strategy for improving postinfarction ventricular function.

Change of p16(INK4a) and PCNA protein expression in myocardium after injection of hIGF-1 gene modified skeletal myoblasts into post-infarction rats.

This study examined the change of p16(INK4a) and PCNA protein expression in myocardium after injection of hIGF-1 gene modified skeletal myoblasts into post-infarction rats. HIGF-1 gene modified skeletal myoblasts (hIGF-1-myoblasts) were injected into hind limb muscles of 18 post-infraction rats (experimental group). Primary-myoblasts were injected into 18 post-infraction rats (control group) and 12 non-infarction rats (sham group). Expression of p16(INK4a) and PCNA protein in myocardiums were separately detected immunocytochemically 1, 2 and 4 weeks after the injection. The level of hIGF-1 and rIGF-1 protein in serum and myocardium were detected by enzyme-linked immunosorbent assay (ELISA). Compared with the sham group, the percentage of p16(INK4a) and PCNA positive cells reached a peak after 1 week in the control group and the experimental group (P<0.01). Moreover, the percentage of p16(INK4a)-positive cells in the experimental group was lower than in control group whereas the percentage of PCNA-positive cells was lower in the control group than in the experimental group (P<0.01). The percentage of p16(INK4a)-positive cells in the experimental group and the percentage of PCNA-positive cells in the control group were close to that in the sham group from the 2nd week (P>0.05). ELISA analysis disclosed that the myocardium level of rIGF-1 protein increased gradually in the controls and especially in the experimental group (P<0.01). The serum level of rIGF-1 decreased significantly in post-infraction rats, but these conditions were improved in the experimental group (P<0.01). The hIGF-1 protein in serum and myocardium were detected from the 1st week to the 4th week in the experimental group. Statistical analysis revealed significant associations of myocardium level of hIGF-1 protein with expression of p16(INK4a) and PCNA protein (r=-0.323, P<0.05; r=0.647, P<0.01). It is concluded that genetically hIGF-1-myoblast provides a means for constant synthesis and release of hIGF-1. It could not only improve the expression of rIGF-1 and PCNA protein in myocardium, but also suppress the expression of p16(INK4a) protein for 30 days in post-infraction rats. Myoblasts-mediated IGF-1 gene therapy may provide a new alternative for the clinical treatment of heart failure.

Correction: Transplantation of HGF gene-engineered skeletal myoblasts improve infarction recovery in a rat myocardial ischemia model.

[This corrects the article DOI: 10.1371/journal.pone.0175807.].

Transplantation of HGF gene-engineered skeletal myoblasts improve infarction recovery in a rat myocardial ischemia model.

BACKGROUND: Skeletal myoblast transplantation seems a promising approach for the repair of myocardial infarction (MI). However, the low engraftment efficacy and impaired angiogenic ability limit the clinical efficiency of the myoblasts. Gene engineering with angiogenic growth factors promotes angiogenesis and enhances engraftment of transplanted skeletal myoblasts, leading to improved infarction recovery in myocardial ischemia. The present study evaluated the therapeutic effects of hepatocyte growth factor (HGF) gene-engineered skeletal myoblasts on tissue regeneration and restoration of heart function in a rat MI model. METHODS AND RESULTS: The skeletal myoblasts were isolated, expanded, and transduced with adenovirus carrying the HGF gene (Ad-HGF). Male SD rats underwent ligation of the left anterior descending coronary artery. After 2 weeks, the surviving rats were randomized into four groups and treated with skeletal myoblasts by direct injection into the myocardium. The survival and engraftment of skeletal myoblasts were determined by real-time PCR and in situ hybridization. The cardiac function with hemodynamic index and left ventricular architecture were monitored; The adenovirus-mediated-HGF gene transfection increases the HGF expression and promotes the proliferation of skeletal myoblasts in vitro. Transplantation of HGF-engineered skeletal myoblasts results in reduced infarct size and collagen deposition, increased vessel density, and improved cardiac function in a rat MI model. HGF gene modification also increases the myocardial levels of HGF, VEGF, and Bcl-2 and enhances the survival and engraftment of skeletal myoblasts. CONCLUSIONS: HGF engineering improves the regenerative effect of skeletal myoblasts on MI by enhancing their survival and engraftment ability.

Effects of recombinant retroviral vector mediated human insulin like growth factor-1 gene transfection on skeletal muscle growth in rat.

BACKGROUND: This study transferred a recombinant gene encoding human insulin like growth factor-1 (hIGF-1) into modified primary skeletal myoblasts with a retroviral vector (pLgXSN) and determined whether the hIGF-1 promoted growth of skeletal muscle in rat. METHODS: hIGF-1cDNA was amplified in vitro from normal human liver cells by using RT-PCR and cloned into plasmid vector pLgXSN. The recombinant vector pLghIGF-1SN and control vector pLgGFPSN were transfected into packaging cell PT67 and G418 was used to select positive colony. Myoblasts were infected with a high titre viral supernatant and transduction efficiency was evaluated as GFP expression. The expression of hIGF-1 mRNA in myoblasts was investigated by immunocytochemistry and RT-PCR. MTT assays detected the growth of myoblasts in vitro. Myoblasts transduced with pLghIGF-1SN were injected into hind limb muscles of 10 - 12 week male SD rats. Formed tissues were harvested 4 weeks later. Myocyte diameter, mean weight of hind limb and body were measured to evaluate the skeletal muscle growth. RESULTS: Recombinant retroviral plasmid vector pLghIGF-1SN was constructed successfully. The titre of the packaged recombinant retrovirus was 1 x 10(6) cfu/ml. The transfection rate of PT67 cells reached 100% after G418 screening. hIGF-1 expression was positive in myoblast-IGF-1. The proliferation rate of myoblast-IGF-1 in vitro was higher than GFP-myoblast or myoblast (P < 0.05). The mean weights of hind limb and body of rats injected myoblast-IGF-1 were higher than those of the rats injected with myoblast-GFP or myoblast (P < 0.05). Myocyte diameter had a significant increase in IGF-1 group compared to GFP group and myoblast group (P < 0.05). CONCLUSIONS: The transfection of the human IGF-1 gene mediated by a retroviral vector can promote the growth of skeletal muscle in rats. Genetically modified primary skeletal myoblasts provide a possibly effective approach to treat some skeletal muscle diseases.

Hepatocyte growth factor improves right ventricular remodeling in pulmonary arterial hypertensive rats via decreasing neurohormonal activation and inhibiting apoptosis.

BACKGROUND: Hepatocyte growth factor (HGF) inhibits the development of pulmonary artery hypertension (PAH) by reducing pulmonary artery pressure and right ventricle (RV) hypertrophy. However, whether HGF can prevent RV remodeling via inhibiting apoptosis in RV cardiomyocytes and decreasing neurohormonal activation remains unknown. METHODS: The PAH and subsequent RV remodeling in rats were induced by subcutaneous injection of monocrotaline (MCT). The PAH rats were transfected with adenovirus carrying HGF (Ad-HGF) via intratracheal instillation. Three weeks after transfection, the hemodynamics indexes were measured, serum levels for angiotonin II (ANG II) and brain natriuretic peptide (BNP) were determined by ELISA. Histological analysis was used to assess the RV hypertrophy and fibrosis. The cardiomyocyte apoptosis in RV was assayed by TUNEL staining. The mRNA expression of BNP, angiotensin-converting enzyme (ACE), Bax and Bcl-2 in RV was determined by reverse transcriptase polymerase chain reaction (RT-PCR), the protein expression of transforming growth factor (TGF)-ß1 and tumor necrosis factor (TNF)-α in RV was determined by Western blotting. RESULTS: HGF treatment significantly decreased the mean PAH, RV systolic pressure, serum ANG II and BNP levels. HGF treatment also significantly decreased the RV hypertrophy, collagen deposition, and the number of apoptotic cardiomyocytes. Moreover, HGF treatmemt significantly decreased the expression of BNP, ACE, Bax, TGF-ß1, and TNF-α, while it significantly increased the expression of Bcl-2. CONCLUSIONS: Gene transfer of HGF decreases MCT-induced PAH and improves RV remodeling. This effect is mediated not only by improving the hemodynamics but also by decreasing neurohormonal activation and inhibiting cardiomyocytes apoptosis. HGF gene treatment may be an effective strategy for improving RV remodeling in MCT-induced PAH.

Recombinant proteins secreted from tissue-engineered bioartificial muscle improve cardiac dysfunction and suppress cardiomyocyte apoptosis in rats with heart failure.

BACKGROUND: Tissue-engineered bioartificial muscle-based gene therapy represents a promising approach for the treatment of heart diseases. Experimental and clinical studies suggest that systemic administration of insulin-like growth factor-1 (IGF-1) protein or overexpression of IGF-1 in the heart exerts a favorable effect on cardiovascular function. This study aimed to investigate a chronic stage after myocardial infarction (MI) and the potential therapeutic effects of delivering a human IGF-1 gene by tissue-engineered bioartificial muscles (BAMs) following coronary artery ligation in Sprague-Dawley rats. METHODS: Ligation of the left coronary artery or sham operation was performed. Primary skeletal myoblasts were retrovirally transduced to synthesize and secrete recombinant human insulin-like growth factor-1 (rhIGF-1), and green fluorescent protein (GFP), and tissue-engineered into implantable BAMs. The rats that underwent ligation were randomly assigned to 2 groups: MI-IGF group (n = 6) and MI-GFP group (n = 6). The MI-IGF group received rhIGF-secreting BAM (IGF-BAMs) transplantation, and the MI-GFP group received GFP-secreting BAM (GFP-BAMs) transplantation. Another group of rats served as the sham operation group, which was also randomly assigned to 2 subgroups: S-IGF group (n = 6) and S-GFP group (n = 6). The S-IGF group underwent IGF-1-BAM transplantation, and S-GFP group underwent GFP-BAM transplantation. IGF-1-BAMs and GFP-BAMs were implanted subcutaneously into syngeneic rats after two weeks of operation was performed. Four weeks after the treatment, hemodynamics was performed. IGF-1 was measured by radioimmunoassay, and then the rats were sacrificed and ventricular samples were subjected to immunohistochemistry. Reverse transcriptase-polymerase chain reaction (RT-PCR) was used to examine the mRNA expression of bax and Bcl-2. TNF-α and caspase 3 expression in myocardium was examined by Western blotting. RESULTS: Primary rat myoblasts were retrovirally transduced to secrete rhIGF-1 and tissue-engineered into implantable BAMs containing parallel arrays of postmitotic myofibers. In vitro, they secreted consistent levels of hIGF (0.4 - 1.2 µg×BAM(-1)×d(-1)). When implanted into syngeneic rat, IGF-BAMs secreted and delivered rhIGF. Four weeks after therapy, the hemodynamics was improved significantly in MI rats treated with IGF-BAMs compared with those treated with GFP-BAMs. The levels of serum IGF-1 were increased significantly in both MI and sham rats treated with IGF-BAM. The mRNA expression of bax was lower and Bcl-2 expression was higher in MI-IGF group than MI-GFP group (P < 0.05). Western blotting assay showed TNF-α and caspase 3 expression was lower in MI-IGF group than MI-GFP group after therapy. CONCLUSIONS: rhIGF-1 significantly improves left ventricular function and suppresses cardiomyocyte apoptosis in rats with chronic heart failure. Genetically modified tissue-engineered BAMs provide a method delivering recombinant protein for the treatment of heart failure.

Recombinant human growth hormone secreted from tissue-engineered bioartificial muscle improves left ventricular function in rat with acute myocardial infarction.

BACKGROUND: Experimental studies and preliminary clinical studies have suggested that growth hormone (GH) treatment may improve cardiovascular parameters in chronic heart failure (CHF). Recombinant human GH (rhGH) has been delivered by a recombinant protein, by plasmid DNA, and by genetically engineered cells with different pharmacokinetic and physiological properties. The present study aimed to examine a new method for delivery of rhGH using genetically modified bioartificial muscles (BAMs), and investigate whether the rhGH delivered by this technique improves left ventricular (LV) function in rats with CHF. METHODS: Primary skeletal myoblasts were isolated from several Sprague-Dawley (SD) rats, cultured, purified, and retrovirally transduced to synthesize and secrete human rhGH, and tissue-engineered into implantable BAMs. Ligation of the left coronary artery or sham operation was performed. The rats that underwent ligation were randomly assigned to 2 groups: CHF control group (n = 6) and CHF treatment group (n = 6). The CHF control group received non-rhGH-secreting BAM (GFP-BAMs) transplantation, and the CHF treatment group received rhGH-secreting BAM (GH-BAMs) transplantation. Another group of rats served as the sham operation group, which was also randomly assigned to 2 subgroups: sham control group (n = 6) and sham treatment group (n = 6). The sham control group underwent GFP-BAM transplantation, and the sham treatment group underwent GH-BAM transplantation. GH-BAMs and GFP-BAMs were implanted subcutaneously into syngeneic rats with ligation of the left coronary artery or sham operation was performed. Eight weeks after the treatment, echocardiography was performed. hGH, insulin-like growth factor-1 (IGF-1) and TNF-alpha levels in rat serum were measured by radioimmunoassay and ELISA, and then the rats were killed and ventricular samples were subjected to immunohistochemistry. RESULTS: Primary rat myoblasts were retrovirally transduced to secrete rhGH and tissue-engineered into implantable BAMs containing parallel arrays of postmitotic myofibers. In vitro, they secreted 1 to 2 microg of bioactive rhGH per day. When implanted into syngeneic rat, GH-BAMs secreted and delivered rhGH. Eight weeks after therapy, LV ejection fraction (EF) and fractional shortening (FS) were significantly higher in CHF rats treated with GH-BAMs than in those treated with GFP-BAMs ((65.0 +/- 6.5)% vs (48.1 +/- 6.8)%, P < 0.05), ((41.3 +/- 7.4)% vs (26.5 +/- 7.1)%, P < 0.05). LV end-diastolic dimension (LVEDD) was significantly lower in CHF rats treated with GH-BAM than in CHF rats treated with GFP-BAM (P < 0.05). The levels of serum GH and IGF-1 were increased significantly in both CHF and sham rats treated with GH-BAM. The level of serum TNF-alpha decreased more significantly in the CHF treatment group than in the CHF control group. CONCLUSIONS: rhGH significantly improves LV function and prevents cardiac remodeling in rats with CHF. Genetically modified tissue-engineered bioartificial muscle provides a method delivering recombinant protein for the treatment of heart failure.