title: Protective effects of Notch1 signaling activation against high glucose-induced myocardial cell injury: Analysis of its mechanisms of action.
abstract: Notch1 plays an important role in cardiomyocyte apoptosis and cardiac fibrosis. However, the effects of Notch1 on diabetic cardiomyopathy (DCM) and its mechanisms of action remain unclear. In the present study, we sought to investigate the role of Notch1 in, and its effects on high glucose (HG)‑induced myocardial cell apoptosis and myocardial fibrosis. H9c2 cells exposed to HG were used to establish an in vitro model of myocardial injury. The H9c2 cells were cultured with normal glucose (NG; 5.5 mmol/L‑ NG), and were then epxosed to HG (33 mmol/L‑ HG), a γ‑secretase inhibitor (DAPT), and were transfected with a lentiviral vector containing the Notch1 intracellular domain (N1ICD; lentivirus‑N1ICD). At 72 h following exposure to HG, DAPT or transfection with lentivirus‑N1ICD, myocardial cell viability was assessed using a Cell Counting kit‑8 (CCK‑8) assay. Cell apoptosis was measured using Annexin V/propidium iodide (PI) double staining and flow cytometry. The mRNA expression levels of hairy/enhancer of split‑1 (Hes‑1) and hairy/enhancer-of-split related with YRPW motif‑1 (Hey‑1) were measured by quantitative PCR (qPCR), while the protein expression of N1ICD, Bax, Bcl‑2, transforming growth factor‑β1 (TGF‑β1) and connective tissue growth factor (CTGF), and the levels of phosphorylated (p-)AKT, total (t-)AKT, p‑phosphoinositide 3-kinase (PI3K) and t‑AKT were measured by western blot analysis. Our results revealed that exposure to HG induced apoptosis and upregulated TGF‑β1 and CTGF expression in the H9c2 cardiomyocytes. Furthermore, the Notch1 and PI3K/AKT signaling pathways were activated following transfection with lentivirus‑N1ICD, and this activation enhanced myocardial cell viability, prevented cardiomyocyte apoptosis and decreased TGF‑β1 and CTGF expression. On the whole, our data demonstrate that the overexpression of Notch1 prevents HG‑induced cardiomyocyte apoptosis and decreases CTGF expression in H9c2 cells exposed to HG. Thus, Notch1 may be used to prevent the development of DCM and to inhibit cardiac fibrosis. The findings of our study may prove to be of use in the development of novel therapeutic strategies for DCM.
authors.affiliation: Department of Cardiology, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, P.R. China.
authors.forename: Jian
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Department of Cardiology, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, P.R. China.
authors.forename: Bingong
authors.initials: B
authors.lastname: Li
authors.affiliation: Department of Cardiology, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, P.R. China.
authors.forename: Zeqi
authors.initials: Z
authors.lastname: Zheng
authors.affiliation: Department of Cardiology, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, P.R. China.
authors.forename: Ting
authors.initials: T
authors.lastname: Kang
authors.affiliation: Department of Cardiology, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, P.R. China.
authors.forename: Minghui
authors.initials: M
authors.lastname: Zeng
authors.affiliation: Department of Cardiology, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, P.R. China.
authors.forename: Yanhua
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Department of Cardiology, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, P.R. China.
authors.forename: Baohua
authors.initials: B
authors.lastname: Xia
mesh_terms: D000818:Animals; D017209:Apoptosis; D002460:Cell Line; D002470:Cell Survival; D005947:Glucose / Q000378:metabolism*; D032383:Myocytes, Cardiac / Q000166:cytology / Q000378:metabolism* / Q000473:pathology*; D051381:Rats; D051881:Receptor, Notch1 / Q000378:metabolism*; D015398:Signal Transduction
chemical_list: D051881:Receptor, Notch1; D005947:Glucose