• International Journal of Stem Cells
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• 제15권4호
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• pp.395-404
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• 2022

Background and Objectives: Chronic obstructive pulmonary disease (COPD) is a common, frequently-occurring disease and poses a major health concern. Unfortunately, there is current no effective treatment for COPD, particularly emphysema. Recently, experimental treatment of COPD using mesenchymal stem cells (MSCs) mainly focused on bone marrow-derived MSCs (BM-MSCs). Human umbilical cord-derived MSCs (hUC-MSCs) have more advantages compared to BM-MSCs. However, studies on the role of hUC-MSCs in management of COPD are limited. This study sought to explore the role of hUC-MSCs and its action mechanisms in a rat model of VEGF receptor blocker SU5416-injured emphysema. Methods and Results: hUC-MSCs were characterized by immunophenotype and differentiation analysis. Rats were divided into four groups: Control, Control+MSC, SU5416 and SU5416+MSC. Rats in model group were administered with SU5416 for three weeks. At the end of the second week after SU5416 administration, model group were infused with 3×10⁶ hUC-MSCs through tail vein. After 14 days from hUC-MSCs transplantation, rats were euthanized and data were analyzed. HE staining and mean linear intercepts showed that SU5416-treated rats exhibited typical emphysema while emphysematous changes in model rats after hUC-MSCs transplantation disappeared completely and were restored to normal phenotype. Furthermore, hUC-MSCs inhibited apoptosis as shown by TUNEL and Western blotting. ELISA and Western blotting showed hUC-MSCs rescued VEGF-VEGFR2-AKT pathway in emphysematous lungs. Conclusions: The findings show that hUC-MSCs effectively repair the emphysema injury. This study provides the first evidence that hUC-MSCs inhibit apoptosis via rescuing VEGF- VEGFR2-AKT pathway in a rat model of emphysema.

• Biomolecules & Therapeutics
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• 제27권5호
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• pp.474-483
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• 2019

Vascular endothelial growth factor (VEGF) plays a pivotal role in pathologic ocular neovascularization and vascular leakage via activation of VEGF receptor 2 (VEGFR2). This study was undertaken to evaluate the therapeutic mechanisms and effects of the tetrapeptide Arg-Leu-Tyr-Glu (RLYE), a VEGFR2 inhibitor, in the development of vascular permeability and choroidal neovascularization (CNV). In cultured human retinal microvascular endothelial cells (HRMECs), treatment with RLYE blocked VEGF-A-induced phosphorylation of VEGFR2, Akt, ERK, and endothelial nitric oxide synthase (eNOS), leading to suppression of VEGF-A-mediated hyper-production of NO. Treatment with RLYE also inhibited VEGF-A-stimulated angiogenic processes (migration, proliferation, and tube formation) and the hyperpermeability of HRMECs, in addition to attenuating VEGF-A-induced angiogenesis and vascular permeability in mice. The anti-vascular permeability activity of RLYE was correlated with enhanced stability and positioning of the junction proteins VE-cadherin, ${\beta}$-catenin, claudin-5, and ZO-1, critical components of the cortical actin ring structure and retinal endothelial barrier, at the boundary between HRMECs stimulated with VEGF-A. Furthermore, intravitreally injected RLYE bound to retinal microvascular endothelium and inhibited laser-induced CNV in mice. These findings suggest that RLYE has potential as a therapeutic drug for the treatment of CNV by preventing VEGFR2-mediated vascular leakage and angiogenesis.

• International Journal of Oncology
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• 제54권2호
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• pp.753-763
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• 2019

The mutation of isocitrate dehydrogenase (IDH)1 (R132H) and IDH2 (R172K) and the induction of hypoxia in various solid tumors results in alterations in metabolic profiles, including the production of the d- or l-forms of 2-hydroxyglutarate (2HG) from α-ketoglutarate in aerobic metabolism in the tricarboxylic acid (TCA) cycle. However, it is unclear whether the oncometabolite d-2HG increases angiogenesis in endothelial cells. Therefore, in this study, we analyzed the levels of various metabolites, including d-2HG, under hypoxic conditions and in IDH2R172K mutant breast cancer cells by mass spectrometry. We then further evaluated the effects of this metabolite on angiogenesis in breast cancer cells. The results revealed that treatment with d-2HG increased the levels of secreted vascular endothelial growth factor (VEGF) in cancer cells and enhanced endothelial cell proliferation in a concentration-dependent manner. Wound healing and cell migration (examined by Transwell assay) were significantly increased by d-2HG to a level similar to that induced by VEGF. Tube formation was significantly stimulated by d-2HG, and chick chorioallantoic membrane angiogenesis was also enhanced by d-2HG. d-2HG activated VEGF receptor (VEGFR)2 and VEGFR2 downstream signaling, extracellular signal-regulated kinase 1/2, focal adhesion kinase, AKT and matrix metalloproteinase (MMP)2. Taken together, the findings of this study suggested that d-2HG induced angiogenic activity via VEGFR2 signaling and increased MMP2 activity.