The Role of the Notch Signaling Pathway in the Differentiation of Human Umbilical Cord-Derived Mesenchymal Stem Cells.

Human umbilical cord mesenchymal stem cells (hUCMSCs) exhibit potent self-renewal and multilineage differentiation characteristics. They have garnered substantial attention within the domain of regenerative medicine owing to their therapeutic potential, such as in tissue repair, regeneration, immunomodulation, anti-inflammation, angiogenesis, wound healing, neuroprotection, and neuroregeneration. The process of fate determination is initiated by multiple signaling molecules. During development and tissue homeostasis, the Notch signaling pathway assumes a pivotal function in cell differentiation and the renewal of stem cells. A growing body of research has revealed that the Notch signaling pathwayplays a pivotal role in hUCMSC proliferation and differentiation. The latest progress concerning the crucial functions of the Notch signaling pathway in maintaining homeostasis and determining the cell fate of hUCMSCs is summarized. Furthermore, the authors also summarized the mediators related to the Notch signaling pathway in hUCMSC differentiation, as well as the pathway alterations and mechanisms involved in hUCMSC therapy.

MiR-32-5p influences high glucose-induced cardiac fibroblast proliferation and phenotypic alteration by inhibiting DUSP1.

BACKGROUND: The current study aimed to investigate the effects of miR-32-5p on cardiac fibroblasts (CFs) that were induced with high levels of glucose; we also aimed to identify the potential mechanisms involved in the regulation of DUSP1 expression. METHODS: Human CFs were transfected with a miR-32-5p inhibitor or mimic and were treated with a normal concentration or a high concentration of glucose. Flow cytometry analysis was performed to identify cardiac fibroblasts by examining vimentin, fibronectin (FN) and α-actin expression in human CFs. qRT-PCR and western blot assays were performed to confirm the expression of miR-32-5p, DUSP1 and cardiac fibrosis relevant proteins. The proliferation of CFs was assessed by using MTT assay. An immunocytofluorescent staining assay was performed to determine the protein level of α-SMA and to investigate the degree of phenotypic changes in human CFs. The specific relationship between miR-32-5p and DUSP1 was investigated by a dual luciferase reporter assay. Cell apoptosis rates were measured with flow cytometry and the annexin V-FITC and propidine iodide (PI) staining method. RESULTS: A luciferase reporter assay indicated that miR-32-5p could directly target DUSP1. High glucose levels resulted in the overexpression of miR-32-5p, which downregulated DUSP1 expression. Both the upregulation of miR-32-5p and the downregulation of DUSP1 promoted cell apoptosis, proliferation and phenotypic changes in human CFs. CONCLUSIONS: All findings in this study provide further evidence for the positive effects of miR-32-5p on cell proliferation and the phenotypic changes in CFs by inhibiting DUSP1 expression, and reveal that miR-32-5p could serve as prognostic diagnostic target for cardiac fibrosis.

MiR-150-5p retards the progression of myocardial fibrosis by targeting EGR1.

To investigate the differential expression of microRNA-150-5p (miR-150-5p) and early growth response 1 (EGR1) in myocardial fibrosis (MF) cells, and determine the effect between miR-150-5p and EGR1 on MF. Human MF cells were generated via Trypanosoma cruzi (T. cruzi) infection, a mouse model of MF was generated via angiotensin II. The expression levels of miR-150-5p and EGR1 were detected by quantitative real-time polymerase chain reaction (qRT-PCR) and western blot assay. The correlation between miR-150-5p and EGR1 was confirmed by a luciferase reporter assay. The viability, proliferation, and apoptotic rate were detected by cell counting kit-8 (CCK-8), colony-formation and flow cytometry assays. Hematoxylin-eosin (HE) staining and Masson staining visualized the degree of MF. Echocardiography was performed to obtain the levels of left ventricle fractional shortening (LVFS) and left ventricle ejection fraction (LVEF), computer algorithms and a videographics program were used to obtain the levels of left ventricular systolic pressure (LVSP), left ventricular end diastolic pressure (LVEDP) and ±left ventricular dp/dt maximum (LV dp/dtmax). We found that the expression of miR-150-5p in MF cells was lower than normal cardiomyocytes, while the expression level of EGR1 in MF cells were higher than normal cardiomyocytes. Cell experiments demonstrated that EGR1 and miR-150-5p could influence the development of MF, and the expression of EGR1 in cardiomyocytes was regulated by miR-150-5p directly. Lastly, we confirmed that sh-Egr1 would decrease the severity of MF, while miR-150-5p antagomir could aggravate MF. Our results illustrate the mechanism of MF development, and provide a potential target for MF treatment.

Progress in Gene Therapy for Chronic Heart Failure.

Chronic heart failure (CHF) is still the leading cause of morbidity and mortality worldwide, and carries with it large economic and social burdens. Although steady and substantial progress has been made in reducing mortality from heart failure using conventional treatments, novel pharmacologic and surgical interventions have not been effective in extending five year survival rates. Therefore, it is necessary to explore new therapies. Gene therapy was introduced in 1970s with the development of recombinant DNA technology. Due to recent progress in the understanding of myocardial metabolism and application of vector based gene transfer strategies in animal models and initial clinical trials, gene therapy possibly affords an ideal treatment alternative for CHF. In last 2 decades, much research has been done on gene therapy, using various genes, signal transduction passages and delivery methods to treat advanced heart failure. Current research in ischemic heart disease (IHD) mainly focuses on stimulating angiogenesis, modifying the coronary vascular environment, and improving the vascular endothelial function with localized gene coated catheters and stents. Compared with standard ischemic heart disease treatment, the main goal of gene therapy for CHF is to inhibit apoptosis, reduce the undesirable remodeling and increase contractility through the most efficient cardiomyocyte transfection [Katz 2012a]. In this paper, we review various gene transfer technologies in ischemic heart disease and heart failure models, and discuss the advantages and disadvantages of these strategies in vector-mediated cardiac gene delivery, with the main focus on the high efficiency approach of a molecular cardiac surgery delivery system.