Epigenetic role of N6-methyladenosine (m6A) RNA methylation in the cardiovascular system / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

As the most prevalent and abundant transcriptional modification in the eukaryotic genome, the continuous and dynamic regulation of N6-methyladenosine (m6A) has been shown to play a vital role in physiological and pathological processes of cardiovascular diseases (CVDs), such as ischemic heart failure (HF), myocardial hypertrophy, myocardial infarction (MI), and cardiomyogenesis. Regulation is achieved by modulating the expression of m6A enzymes and their downstream cardiac genes. In addition, this process has a major impact on different aspects of internal biological metabolism and several other external environmental effects associated with the development of CVDs. However, the exact molecular mechanism of m6A epigenetic regulation has not been fully elucidated. In this review, we outline recent advances and discuss potential therapeutic strategies for managing m6A in relation to several common CVD-related metabolic disorders and external environmental factors. Note that an appropriate understanding of the biological function of m6A in the cardiovascular system will pave the way towards exploring the mechanisms responsible for the development of other CVDs and their associated symptoms. Finally, it can provide new insights for the development of novel therapeutic agents for use in clinical practice.

Late recurrent high degree atrioventricular block after percutaneous closure of a perimembranous ventricular septal defect / 中华医学杂志(英文版)

High degree atrioventricular block (HDAVB) is a serious complication of transcatheter closure of a perimembranous ventricular septal defect (PMVSD). We report one patient who developed transient HDAVB seven days after transcathter closure of PMVSD and had recurrent HDAVB 42 months after the procedure.

Resveratrol-induced augmentation of telomerase activity delays senescence of endothelial progenitor cells / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Previous studies have shown that resveratrol increases endothelial progenitor cell (EPC) numbers and functional activity. Increased EPC numbers and activity are associated with the inhibition of EPC senescence. In this study, we investigated the effect of resveratrol on the senescence of EPCs, leading to potentiation of cellular function.</p><p><b>METHODS</b>EPCs were isolated from human peripheral blood and identified immunocytochemically. EPCs were incubated with resveratrol (1, 10, and 50 µmol/L) or control for specified times. After in vitro cultivation, acidic β-galactosidase staining revealed the extent of senescence in the cells. To gain further insight into the underlying mechanism of the effect of resveratrol, we measured telomerase activity using a polymerase chain reaction (PCR)-enzyme-linked immunosorbent assay (ELISA) technique. Furthermore, we measured the expression of human telomerase reverse transcriptase (hTERT) and the phosphorylation of Akt by immunoblotting.</p><p><b>RESULTS</b>Resveratrol dose-dependently inhibited the onset of EPC senescence in culture. Resveratrol also significantly increased telomerase activity. Interestingly, quantitative real-time PCR analysis demonstrated that resveratrol dose-dependently increased the expression of the catalytic subunit, hTERT, an effect that was significantly inhibited by pharmacological phosphatidylinositol 3-kinase (PI3-K) blockers (wortmannin). The expression of hTERT is regulated by the PI3-K/Akt pathway; therefore, we examined the effect of resveratrol on Akt activity in EPCs. Immunoblotting analysis revealed that resveratrol led to dose-dependent phosphorylation and activation of Akt in EPCs.</p><p><b>CONCLUSION</b>Resveratrol delayed EPCs senescence in vitro, which may be dependent on telomerase activation.</p>

Generation of a P19-alphaMHC-EGFP reporter line and cardiomyocyte differentiation / 中华心血管病杂志

<p><b>OBJECTIVE</b>To generate a P19-alphaMHC-EGFP reporter line and induce cardiomyocyte differentiation of this reporter line.</p><p><b>METHODS</b>The P19 cells were transfected with palphaMHC-EGFP, a P19-alphaMHC-EGFP reporter line was obtained after G418 selection and limited dilution of recombinant clones. The reporter line was induced to differentiate into cardiomyocytes which would beat and express green fluorescent protein. A comparison of cardiomyocyte differentiation rate and cTnI expression amount between the reporter line and the untransfected P19 cells was also performed. The ultrastructure was observed under transmission electron microscope.</p><p><b>RESULTS</b>The ultrastructure characteristics indicated cardiomyocytes-like changes on induction day 10. The beating cardiomyocytes which express GFP appear in the seventh induction day. The cardiomyocyte differentiation rate and cTnI expression amount of P19-alphaMHC-EGFP reporter line were similar as those in untransfected P19 cells (P > 0.05).</p><p><b>CONCLUSION</b>The P19-alphaMHC-EGFP reporter line is of great benefit for identifying and purifying cardiomyocytes from undifferentiated P19 cells without influencing the differentiation of P19 cells. This feature makes P19-alphaMHC-EGFP reporter line a promising cell source for clinical cardiomyocyte replacement therapy.</p>

Expression of Cardiotrophin-1 in Myocardium and Peripheral Blood Plasma of Neonatal Rat with Asphyxia and Regulative Effect of Neuregulin-1 / 实用儿科临床杂志

Objective To explore the expression of cardiotrophin-1(CT-1) in myocardium and peripheral blood plasma of neonatal rat with asphyxia and the regulative effect of neuregulin-1(NRG-1).Methods Ninety seven-day-old neonatal rats were randomly divided into 3 groups:asphyxia group (n=40),normal control group (n=10)and NRG-1 pretreatment group (n=40).The model of neonatal rat with asphyxia was prepared by the way of ligation of carotid combined with low supply of oxygen.NRG-1(1 mg/kg) was given to NRG-1 pretreatment group by intraperitoneal injection 30 min before asphyxia.The separated plasma of peripheral blood and myocardium antetheca of aortic ventricle of heart were taken at the time point of 6,12,24 and 48 h.The expression of CT-1 in peripheral blood plasma was detected by enzyme linked immunoadsorbent assay,and that of myocardium was determined by Western blot.Results The expressions of CT-1 protein in peripheral blood plasma of asphyxia group were significantly higher than those of normal control group at each time point,and reached the peak at 24 h(Pa

A correlative study between prevalence of chondromalacia patellae and sports injury in 4068 students / 中华创伤杂志(英文版)

<p><b>OBJECTIVE</b>To study the prevalence of chondromalacia patella among college students and the correlation with sports injury.</p><p><b>METHODS</b>354 students from gymnastic department and 429 from nongymnastic department with knee joint pain were selected. 184 students from gymnastic department and 342 from nongymnastic department were checked randomly by a surgeon. 77 patients (37 males, 40 females) from gymnastic department and 119 patients (62 males, 57 females) from nongymnastic department were diagnosed as chondromalacia patellae. The amount of exercise and the occurrence of sports injury were investigated in each student. All data were analyzed with SPSS 10.0 statistical software.</p><p><b>RESULTS</b>The prevalence of chondromalacia patella was 20.1% in female students and 11.6% in male students from gymnastic department, and 5.61% in female students and 4.92% in male students from nongymnastic department. The amount of exercise and the occurrence of sports injury to the knee joint in students from gymnastic department were greater than those from nongymnastic department.</p><p><b>CONCLUSIONS</b>In both female and male students, the prevalence of chondromalacia patella is higher in gymnastic department than nongymnastic department. Sports injury is an important cause of chondromalacia patella.</p>

Expression of HCK Gene in Cardiomyocyte Differentiation of Mouse Embryonic Stem Cells / 实用儿科临床杂志

Objective To explore the expression of HCK gene during the cardiomyocyte differentiation of mouse embryonic stem cells and analyze the role of HCK gene in maintenance of pluripotency of embryonic stem cells.Methods Mouse embryonic stem cells were cultured,then induced to differentiate into cardiomyocytes.Total RNAs were isolated from mouse embryonic stem cells in the differentiation days:0 day(D0),the second day(D2),the fourth day(D4),the sixth day(D6),the eighth day(D8),respectively.The levels of HCK mRNAs were assessed by the method of semi-quantitive reverse transcriptase-polymerase chain reaction(RT-PCR).In the meanwhile,Total proteins were also isolated from mouse embryonic stem cells in the differentiation D0,D2,D4,D6,D8,and the levels of HCK proteins were evaluated by Western-blot.Results HCK mRNAs could be detected in the mouse embryonic stem cells in D0 and D2,however,they were undetectable from D4 to D8.The expression of HCK mRNAs was rapidly down-regulated during cardiomyocyte differentiation of mouse embryonic stem cells.Expression of HCK proteins,which coincided with HCK mRNAs,down-regulated during differentiation and couldn't be detected in D4.Conclusions With the cardiomyocyte differentiation of mouse embryonic stem cells,the expression of HCK in the levels of mRNA and proteins are sharply down-regulated;HCK may play an important role in maintaining the pluripotency of embryonic stem cell.

Expression and Regulation of Cardiotrophin-1 in Ischemia1 Reinfusion Cardiac Muscle of Rats and Effect of Neuregwlin-1 / 实用儿科临床杂志

Objective To observe the expression of cardiotrophin-1(CT-1) in ischemia-reinfusion cardiac muscle of rats and the effect of neuregulin-1(NRG-1).Methods The model of ischemia-reinfusion cardiac muscle of rats were prepared,35 rats were randomly divided into 4 groups:model group(n=8),NRG-1 pretreatment group(n=9),pseudo-surgery group(n=8) and normal control group(n=10).The CT-1 mRNA in the observed cardiac muscle of all groups was measured by RT-PCR and the relative amount of CT-1 mRNA were calculated,and for statistical treatment.Results The CT-1 mRNA of model group was(63.96?9.34),and it was higher than that of pseudo-surgery group(36.16?5.43)and normal control group(36.84?4.64).The significant differences were found in 3 groups(F=47.37 P