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Vascular Regeneration (vascular + regeneration)
Selected AbstractsVascular regeneration and angiogenic-like sprouting mechanism in a compound ascidian is similar to vertebratesEVOLUTION AND DEVELOPMENT, Issue 5 2008Fabio Gasparini SUMMARY Tunicates are useful models for comparing differing developmental processes such as embryogenesis, asexual reproduction, and regeneration, because they are the closest relatives to vertebrates and are the only chordates to reproduce both sexually and asexually. Among them, the ascidian Botryllus schlosseri displays high regenerative potential of the colonial circulatory system (CCS). The CCS runs in the common tunic, forming an anastomized network of vessels defined by simple epithelia and connected to the open circulatory system of the zooids. During asexual propagation, new vessels form by means of a tubular-sprouting mechanism, resembling that occurring in other metazoans, particularly during vertebrate angiogenesis. We studied the regeneration of experimentally ablated CCS by analyzing the general dynamics of reorganization of vessels and tunic, their ultrastructure, cell proliferation, and the immunohistology of regenerating structures using antibodies against vertebrate angiogenic factors-vascular endothelial growth factor (VEGF), fibroblast growth factor-2 (FGF-2), epidermal growth factor (EGF), and receptors: VEGFR-1, VEGFR-2, and EGFR. Results show that the regenerative process of CCS occurs by a sprouting mechanism, with participation of angiogenic factors. They also show correspondence between the CCS sprouting of B. schlosseri and angiogenic sprouting in vertebrates, during both normal development and regeneration, and support the idea that this morphogenetic mechanism was co-opted during the evolution of various developmental processes in different taxa. [source] Transplantation of umbilical cord blood-derived endothelial progenitor cells: a promising method of therapeutic revascularisationEUROPEAN JOURNAL OF HAEMATOLOGY, Issue 1 2006Lei Zhang Abstract:, Therapeutic neovascularisation by endothelial progenitor cells (EPCs) mediated vascular regeneration is becoming a novel option for the treatment of ischaemic diseases. Recently, human umbilical cord blood (CB) has been found to contain a large number of EPCs and transplantation of CB EPCs led to a successful salvage of the ischaemic limbs through improvement in blood perfusion, indicating the feasibility of using CB cells for therapeutic revascularisation. This review will summarise recent studies in therapeutic revascularisation using CB cells and discuss the potential clinical utilisation of CB cells in ischaemic diseases. [source] Thrombin and PAR-1 stimulate differentiation of bone marrow-derived endothelial progenitor cellsJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 3 2006S. T. TARZAMI Summary., Endothelial progenitor cells (EPCs) from the bone marrow play an important role in vascular response to injury and ischemia. The mediators involved in the mobilization, recruitment, proliferation and differentiation of EPCs are not fully understood. In this study, the role of coagulation factor thrombin and protease-activated receptor-1 (PAR-1) on bone marrow-derived cell proliferation and differentiation was investigated. Bone marrow cells (BMCs) were isolated from C57/BL6 mice and plated on fibronectin-coated flasks. Cell characteristics, proliferation and the expression of endothelial cell markers were determined using immunohistochemistry, thymidine uptake and fluorescence activated-cell sorting (FACS), respectively. The results show that thrombin stimulated enrichment of bone marrow cells with endothelial morphology, exhibiting acetylated-low-density lipoprotein (LDL) uptake and isolectin staining. Thrombin or PAR-1-activating peptide produced a 2- to 3-fold increase in the total number of cells as well as an increase in vascular endothelial (VE)-cadherin-positive cells. Thrombin treatment of VE-cadherin-negative cells prepared after cell sorting resulted in the generation of 3- to 4-fold higher VE-cadherin-positive cells than the untreated cultures. Increase in VE-cadherin-positive cells was inhibited by hirudin and efegatran. These results provide first evidence for a novel activity of thrombin and PAR-1 on bone marrow progenitor cell proliferation and EPC differentiation, and suggest their potential role in vascular regeneration and recanalization of thrombus. [source] Role of progenitor endothelial cells in cardiovascular disease and upcoming therapiesCATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS, Issue 4 2007Atsuhiko Kawamoto MD Abstract The field of cell-based transplantation has expanded considerably and is poised to become an established cardiovascular therapy in the near future. In this review, we will focus on endothelial progenitor cells (EPCs), which are immature cells capable of differentiating into mature endothelial cells. EPCs share many surface marker antigens such as CD34, AC133, Flk-1, etc. with hematopoietic stem cells (HSCs) and the major source of EPCs as well as HSCs is the bone marrow (BM). BM-derived EPCs are mobilized into peripheral blood and recruited to the foci of pathophysiological neovascularization and reendothelialization, thereby contributing to vascular regeneration. Severe EPC dysfunction is an indicator of poor prognosis and severe endothelial dysfunction. Indeed, number of circulating EPCs and their migratory activity are reduced in patients with diabetes, coronary artery disease (CAD), or subjects with multiple coronary risk factors. Effective neovascularization induced by EPC transplantation for hindlimb, myocardial, and cerebral ischemia has been demonstrated in many preclinical studies, and early clinical trials of EPC transplantation in chronic and acute CAD indicate safety and feasibility of myocardial cell-based therapies. For therapeutic reendothelialization in patients undergoing percutaneous coronary intervention, CD34 antibody-coated stents have been used clinically to capture circulating EPCs at the injury sites and enhance reendothelialization and safety of stents. Further development in cell processing technology for efficient isolation, expansion, mobilization, recruitment, and transplantation of EPCs into target tissues are underway and expected to be tested in clinical trials in the near future. © 2007 Wiley-Liss, Inc. 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