Journal of Vascular Research最新文献

Revascularization of transplanted pancreatic islets is critical for survival and treatment of type 1 diabetes. Questions concerning how islets influence local microvascular networks and how networks form connections with islets remain understudied and motivate the need for new models that mimic the complexity of real tissue. Recently, our laboratory established the rat mesentery culture model as a tool to investigate cell dynamics involved in microvascular growth. An advantage is the ability to observe blood vessels, lymphatics, and immune cells. The objective of this study was to establish the rat mesentery tissue culture model as a useful tool to investigate islet tissue integration. DiI-labeled islets were seeded onto adult rat mesentery tissues and cultured for up to 3 days. Live lectin labeling enabled time-lapse observation of vessel growth. During culture, DiI-positive islets remained intact. Radial lectin-positive capillary sprouts with DiI labeling were observed to form from islets and connect to host networks. Lectin-positive vessels from host networks were also seen growing toward islets. PECAM and NG2 labeling confirmed that vessels sprouting from islets contained endothelial cells and pericytes. Our results introduce the rat mesentery culture model as a platform for investigating dynamics associated with the initial revascularization of transplanted islets.

Objective: Follicle-stimulating hormone (FSH) level changes may be another reason for increasing the risk of cardiovascular disease. In this study, we aimed to investigate the role of FSH in atherosclerosis and its underlying mechanism.

Methods: ApoE-/- mice were divided into 4 groups, namely, the sham group, bilaterally orchidectomized group, FSH group, and testosterone-only group. Blood lipid and hormone levels were tested, aorta Oil Red O staining; the levels of NF-κB, Akt, eNOS, and FSH receptors in the aorta were measured by Western blotting. Expression of VCAM-1 was detected via Western blotting and immunohistochemical staining. Human umbilical vein endothelial cells (HUVECs) were used to induce endothelial injury model by adding FSH, and the levels of NF-κB, Akt, eNOS, and FSHR were tested in HUVECs.

Results: FSH treatment exacerbated atherosclerotic lesions in ApoE-/- mice. Moreover, FSH could promote the expression of VCAM-1 protein in HUVECs, and this effect was possibly mediated by the activation of NF-κB, while NF-κB activation was further enhanced by the activation of the PI3K/Akt/eNOS pathway. FSH failed to activate Akt and NF-κB in the presence of the PI3K inhibitor LY294002 in HUVECs.

Conclusion: FSH promoted the development of atherosclerosis by increasing VCAM-1 protein expression via activating PI3K/Akt/NF-κB pathway.

Tumors induce angiogenesis to acquire oxygen and nutrition from their adjacent microenvironment. Tumor angiogenesis has been believed to be induced primarily by the secretion of vascular endothelial growth factor-A (VEGF-A) from various tumors. VEGF-A binds to VEGF receptor 2 (VEGFR2), resulting in subsequent activation of cellular substances regulating cell proliferation, survival, and angiogenesis. Antiangiogenic therapies targeting the VEGF-A/VEGFR2 axis, including bevacizumab and ramucirumab, humanized monoclonal antibodies against VEGF-A and VEGFR2, respectively, have been proposed as a promising strategy aimed at preventing tumor growth, invasion, and metastasis. Phase III clinical trials using bevacizumab and ramucirumab have shown that not all tumor patients benefit from such antiangiogenic agents, and that some patients who initially benefit subsequently become less responsive to these antibodies, suggesting the possible existence of VEGF-independent angiogenic factors. In this review, we focus on VEGF-independent and VEGFR2-dependent tumor angiogenesis, as well as VEGFR2-independent tumor angiogenesis. Additionally, we discuss VEGF-independent angiogenic factors which have been reported in previous studies. Various molecular targeting drugs are currently being evaluated as potential antitumor therapies. We expect that precision medicine will permit the development of innovative antiangiogenic therapies targeting individual angiogenic factors selected on the basis of the genetic screening of tumors.

Extracellular matrix proteins are regulated by metzincin proteases, like the disintegrin metalloproteinases with thrombospondin motifs (ADAMTS) family members. This review focuses on the emerging role which ADAMTS-4 might play in vascular pathology, which has implications for atherosclerosis and vessel wall abnormalities, as well as for the resulting diseases, such as cardiovascular and cerebrovascular disease, aortic aneurysms, and dissections. Major substrates of ADAMTS-4 are proteoglycans expressed physiologically in smooth muscle cells of blood vessels. Good examples are versican and aggrecan, principal vessel wall proteoglycans that are targeted by ADAMTS-4, driving blood vessel atrophy, which is why this metzincin protease was implicated in the pathophysiology of vascular diseases with an atherosclerotic background. Despite emerging evidence, it is important not to exaggerate the role of ADAMTS-4 as it is likely only a small piece of the complex atherosclerosis puzzle and one that could be functionally redundant due to its high structural similarity to other ADAMTS family members. The therapeutic potential of inhibiting ADAMTS-4 to halt the progression of vascular disease after initialization of treatment is unlikely. However, it is not excluded that it might find a purpose as a biomarker of vascular disease, possibly as an indicator in a larger cytokine panel.

Adipose-derived stromal vascular fraction (SVF) has emerged as a potential regenerative therapy, but few studies utilize SVF in a setting of advanced age. Additionally, the specific cell population in SVF providing therapeutic benefit is unknown. We hypothesized that aging would alter the composition of cell populations present in SVF and its ability to promote angiogenesis following injury, a mechanism that is T cell-mediated. SVF isolated from young and old Fischer 344 rats was examined with flow cytometry for cell composition. Mesenteric windows from old rats were isolated following exteriorization-induced (EI) hypoxic injury and intravenous injection of one of four cell therapies: (1) SVF from young or (2) old donors, (3) SVF from old donors depleted of or (4) enriched for T cells. Advancing age increased the SVF T-cell population but reduced revascularization following injury. Both young and aged SVF incorporated throughout the host mesenteric microvessels, but only young SVF significantly increased vascular area following EI. This study highlights the effect of donor age on SVF angiogenic efficacy and demonstrates how the ex vivo mesenteric-window model can be used in conjunction with SVF therapy to investigate its contribution to angiogenesis.