No abstract

Decreased miR-26b expression in VAT may be involved in obesity-related IR by interrupting the PTEN/PI3K/AKT pathway.

Induced pluripotent stem (iPS) cells have the potential to differentiate to various types of cardiovascular cells to repair an injured heart. The potential therapeutic benefits of iPS cell based treatment have been established in small-animal models of myocardial infarction (MI). We hypothesize that porcine iPS (piPS) cell transplantation may be an effective treatment for MI. After a 90-minute occlusion of the left anterior descending artery in a porcine model, undifferentiated piPS cells or PBS were injected into the ischemic myocardium. Cardiac function, myocardial perfusion and cell differentiation were investigated. One week after piPS cell delivery, global left ventricular ejection fraction (LVEF) significantly decreased in both the iPS group and the PBS group compared to the Sham group (p<0.05, respectively). Six weeks after piPS cell delivery, LVEF of the iPS group significantly improved compared to the PBS group (56.68% vs. 50.93%, p = 0.04) but was still lower than the Sham group. Likewise, the piPS cell transplantation improved the regional perfusion compared to the PBS injection (19.67% vs. 13.67%, p = 0.02). The infarct area was significantly smaller in the iPS group than the PBS group (12.04% vs. 15.98% p = 0.01). PiPS cells engrafted into the myocardium can differentiate into vessel cells, which result in increased formation of new vessels in the infarcted heart. Direct intramyocardial injection of piPS cells can decrease infarct size and improve left ventricular function and perfusion for an immunosuppressed porcine AMI model.

Ventricular septal defects (VSD) are the most common form of congenital heart disease, which is the leading non-infectious cause of death in children; nevertheless, the exact cause of VSD is not yet fully understood. Long non-coding RNAs (lncRNAs) have been shown to play key roles in various biological processes, such as imprinting control, circuitry controlling pluripotency and differentiation, immune responses and chromosome dynamics. Notably, a growing number of lncRNAs have been implicated in disease etiology, although an association with VSD has not been reported. In the present study, we conducted an integrated analysis of dysregulated lncRNAs, focusing specifically on the identification and characterization of lncRNAs potentially involving in initiation of VSD. Comparison of the transcriptome profiles of cardiac tissues from VSD-affected and normal hearts was performed using a second-generation lncRNA microarray, which covers the vast majority of expressed RefSeq transcripts (29,241 lncRNAs and 30,215 coding transcripts). In total, 880 lncRNAs were upregulated and 628 were downregulated in VSD. Furthermore, our established filtering pipeline indicated an association of two lncRNAs, ENST00000513542 and RP11-473L15.2, with VSD. This dysregulation of the lncRNA profile provides a novel insight into the etiology of VSD and furthermore, illustrates the intricate relationship between coding and ncRNA transcripts in cardiac development. These data may offer a background/reference resource for future functional studies of lncRNAs related to VSD.

No abstract

Our previous study reported that microRNA-375 (miR-375) is significantly upregulated in ventricular septal myocardial tissues from 22-week-old fetuses with ventricular septal defect as compared with normal controls. In the present study, the specific effects of miR-375 on P19 cell differentiation into cardiomyocyte-like cells were investigated. Stable P19 cell lines overexpressing miR-375 or containing empty vector were established, which could be efficiently induced into cardiomyocyte-like cells in the presence of dimethyl sulfoxide in vitro. miR-375 overexpression was verified using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Cell proliferation was determined according to total cell counts; cell cycle distribution and apoptosis levels were examined using flow cytometry. Apoptosis-related morphological changes were observed using Hoechst staining and fluorescence microscopy. During P19 cell differentiation, the cardiomyogenesis-related mRNAs (cardiac troponin T, GATA binding protein 4, myocyte-specific enhancer factor 2C) and mRNAs involved in the Notch signaling pathway (Notch2, Delta-like 1 and hes family bHLH transcription factor 1) were detected at days 0, 4, 6 and 10. Their differential expression was examined using RT-qPCR; the apoptosis-related genes BAX and Bcl-2 were also detected using this method. The corresponding proteins were evaluated by western blotting. Compared with the control group, miR-375 overexpression inhibited proliferation but promoted apoptosis in P19 cells, and the associated mRNAs and proteins were decreased during differentiation. miR-375 has an important role in cardiomyocyte differentiation, and can disrupt this process via the Notch signaling pathway. The present findings contribute to the understanding of the mechanisms of congenital heart disease and facilitate the development of new gene therapies.

Background/Aims: Previous studies have indicated that long non-coding RNAs (lncRNA) are related to the occurrence and development of many human diseases, such as cancer and the HELLP and the brachydactyly syndromes. However, studies of LncRNA in heart failure have not yet been reported. Here, we investigated cardiac lncRNA expression profiles in the myocardial-specific knockout pdk1 gene (KO) mouse model of heart failure. Methods: Cardiac samples were obtained from PDK1 KO and WT mice on postnatal (P) day 8 (P8) and day 40 (P40), and lncRNA expression profiles were analyzed by sequencing and screening using the Arraystar mouse lncRNA microarray. Quantitative real-time PCR analysis of these lncRNAs confirmed the identity of some genes. Results: Comparisons of the KO and control groups showed fold changes of >1.5 in the expression levels of 2,024 lncRNAs at P8, while fold changes of >2 in the expression levels of 4,095 lncRNAs were detected at P40. Nineteen lncRNAs were validated by RT-PCR. Bioinformatic and pathway analyses indicated that mkk7, a sense overlap lncRNA, may be involved in the pathological processes of heart failure through the MAPK signaling pathway. Conclusion: These data reveal differentially expressed lncRNA in mice with a myocardial-specific deletion of the pdk1 gene, which may provide new insights into the mechanism of heart failure in PDK1 knockout mice.

BackgroundVentricular septal defect (VSD) is a highly prevalent fetal congenital heart defect, which can become spontaneously closed during infancy. The current study aims to characterize fetal VSDs that were subsequently spontaneously closed in the first 2 years of life in eastern China.MethodsBetween January 2011 and December 2013, 257 fetal patients diagnosed with isolated VSD by fetal echocardiography at Nanjing Maternity and Child Health Care Hospital, China, were enrolled in the study. Subjects were divided into three groups: group 1 = persistent VSD; group 2 = closed after birth; group 3 = closed during gestation. Fetal echocardiography data, physical features at birth and follow-up outcomes for 2 years were compared to identify factors contributing to spontaneous closure (SC) of VSD. A predictive formula was applied to patients admitted to hospital in the first quarter of 2014 (n = 23) for validation.ResultsSC occurred in 42.8% patients. Birth weight (3.095 ± 0.774, 3.174 ± 0.535, 3.499 ± 0.532 kg in groups 1, 2 and 3, respectively) and defect diameter (3.422 ± 0.972, 2.426 ± 0.599, 2.292 ± 0.479 mm, in groups 1, 2 and 3, respectively) showed statistically significant differences between the three groups (P = 0.004 and P = 0.000, respectively). Receiver operating characteristic (ROC) curves identified cut-off value for the defect diameter as 2.55 mm, and logistic regression analysis identified the SC probability = (1 + exp -[-2.151 − 0.716*birth weight + 1.393*diameter])-1. Results indicated that male fetuses, full-term birth, muscular VSD, and defects without blood flow crossing the septum, have higher incidence of SC.ConclusionsThe major determinants of SC of isolated VSD are birth weight and diameter of the defect. In addition, VSD location may also affect the SC incidence.