腺病毒介导的肝细胞生长因子/血管内皮生长因子双基因转染骨髓间充质干细胞移植治疗心肌梗死***

背景：骨髓间充质干细胞可以分化为心肌细胞,促进血管再生,但在移植早期其自身分泌的细胞因子不足以维持良好的分化和再生。 目的：验证腺病毒介导的肝细胞生长因子和血管内皮生长因子双基因转染新西兰兔骨髓间充质干细胞移植对新西兰兔梗死心肌组织的修复重建和血管再生的影响。 方法：腺病毒介导肝细胞生长因子/血管内皮生长因子双基因转染BrdU标记的新西兰兔骨髓间充质干细胞。取新西兰兔50只建立急性心肌梗死模型,4周后随机分为5组,分别于梗死心肌内注射：①骨髓间充质干细胞/Ad.血管内皮生长因子+肝细胞生长因子。②骨髓间充质干细胞/Ad. 肝细胞生长因子。③骨髓间充质干细胞/Ad.血管内皮生长因子。④骨髓间充质干细胞。⑤对照组注射等量无血清IMDM培养液。移植4周后观察移植细胞的分化和新生血管的形成,并通过超声多普勒检测心功能变化。 结果与结论：除对照组外,其余4组兔心功能都较移植前有明显改善(P < 0.05),其中移植双基因转染骨髓间充质干细胞/Ad.血管内皮生长因子+肝细胞生长因子组兔的心功能改善程度要明显高于其他3组。部分BrdU染色阳性的细胞可以分化成为内皮细胞,参与构成了梗死区域的新生毛细血管。与对照组比较,其余4组都有明显的血管新生(P < 0.05),而以骨髓间充质干细胞/Ad.血管内皮生长因子+肝细胞生长因子组最显著。提示肝细胞生长因子/血管内皮生长因子双基因转染新西兰兔骨髓间充质干细胞移植于梗死心肌可以促进心肌再生和新生血管的形成,明显改善心功能。 关键词：基因转染;骨髓间充质干细胞;血管内皮生长因子;肝细胞生长因子;移植 doi:10.3969/j.issn.1673-8225.2012.10.029     

Hepatocyte growth factor increases expression of vascular endothelial growth factor and plasminogen activator inhibitor-1 in human keratinocytes and the vascular endothelial growth factor receptor flk-1 in human endothelial cells

The pleiotropic growth factor hepatocyte growth factor/scatter factor (HGF/SF) has been implicated by clinical and experimental studies in repair mechanisms in different organs and tissues. However, no data on the impact of HGF/SF in wound healing in the skin are yet available. Proliferating and migrating keratinocytes play a major role in repair processes in the skin by closing the wound. Recent evidence gathered from studies that used gene-deficient mice has implicated the plasminogen activator (PA)/plasmin system in wound healing, which depends on controlled matrix degradation and deposition during cell migration and proliferation. Furthermore, keratinocytes are an important source of vascular endothelial growth factor (VEGF), which is a potent inducer of angiogenesis. In this study, we show that in human keratinocytes HGF/SF but not the related cytokine macrophage stimulating protein (MSP) significantly increases expression of VEGF and plasminogen activator inhibitor-1 (PAI-1) on the level of protein and mRNA. Furthermore, we demonstrate that HGF/SF increases the expression of the VEGF receptor flk-1 in human endothelial cells and that, in an angiogenesis co-culture assay of endothelial cells and keratinocytes, HGF/SF increases endothelial cell tube formation significantly. Therefore, we propose a role for HGF/SF in wound repair in the skin: HGF/SF--produced by activated fibroblasts--increases in keratinocytes the expression of PAI-1, which leads to increased matrix stability during the repair process and which could also limit activation of HGF/SF by proteases such as urokinase-type PA (u-PA) or tissue-type PA (t-PA). Furthermore HGF/SF also increases the expression of VEGF in these cells, thereby initiating angiogenesis in a paracrine manner. This effect would be enhanced by an increased responsiveness of endothelial cells toward VEGF, resulting from the HGF/SF-induced up-regulation of flk-1 on these cells.     

New Approaches to Coronary Heart Disease

Currently available approaches for treating human coronary heart disease aim to relieve symptoms and the risk of myocardial infarction by reducing myocardial oxygen demand (drugs), preventing further disease progression (drugs), restoring coronary blood flow either pharmacologically (thrombolysis) or mechanically (angioplasty), or bypassing the stenotic lesions and obstructed coronary artery segments (surgery). Direct gene therapy, as well as gene-derived therapy, especially by angiogenic growth factors, is emerging as a potential new treatment for cardiovascular disease. After extensive experimental research on angiogenic growth factors, the first clinical studies on patients with coronary heart disease or peripheral vascular lesions are being performed. The polypeptides fibroblast growth factor (FGF) and vascular endothelial growth factor seem to be effective in initiating neovascularisation (neo-angiogenesis) in hypoxic or ischaemic tissues. The first clinical study on patients with coronary heart disease treated by local injection of FGF-1 into the compromised underperfused myocardial tissue showed a 3-fold increase of capillary density mediated by the growth factor. Angiogenic therapy of the human myocardium introduces a new modality of treatment for coronary heart disease in terms of regulation of blood vessel growth. Beyond drug therapy, angioplasty and bypass surgery, this therapy may evolve to be a fourth principle of treatment of atherosclerotic cardiovascular disease.     

Therapeutic angiogenesis in ischemic heart disease: gene or recombinant vascular growth factor protein therapy?

In the last decennium the challenge to research has been to find methods of inducing new vascular growth in ischemic myocardium due to atherosclerotic coronary artery disease, which could not be treated with balloon angioplasty or coronary artery by-pass grafting. Therapeutic angiogenesis with recombinant vascular endothelial growth factor proteins or gene encoding for the proteins is a new potential treatment for cardiovascular disease. The greatest interest and research has been concentrated on basic Fibroblast Growth Factor (FGF1 and FGF2) and Vascular Endothelial Growth Factor A (VEGF-A165 and VEGF-A121). Several small clinical phase I-II safety and efficacy trials with recombinant vascular endothelial growth factor proteins or gene encoding for the proteins have demonstrated that these treatment regimes seem to be safe and the results have been encouraging. However, two large doubleblind randomized placebo-controlled studies with intracoronary infusions of the recombinant proteins FGF2 and VEGF-A165 could not detect any clinical effect. Large scaled phase II studies with gene therapy are in progress. Therapeutic angiogenesis is still a promising new treatment in patients with coronary artery disease. However, more research including large scaled clinical trials is needed before deciding whether the vascular endothelial growth factor therapy either as a gene or a recombinant slow-release protein formulation therapy can be offered to patients with severe coronary artery disease, which cannot be treated with conventional revascularization.     

Interleukin-17 enhances bFGF-, HGF- and VEGF-induced growth of vascular endothelial cells

Interleukin-17 (IL-17) is a CD4 T cell-derived proinflammatry and proangiogenic cytokine. In this study, we investigated the effects of this cytokine on vascular endothelial cell growth induced by a well-known direct angiogenic factor bFGF, HGF, VEGF, CXCL5/ENA-78 or CXCL8/IL-8. While a wide range of doses of IL-17 alone did not show the ability to stimulate the growth of human dermal microvascular endothelial cells (HMVECs), bFGF, HGF, VEGF, CXCL5 or CXCL8 significantly induced the growth of HMVECs in vitro. When bFGF and IL-17 were used in combination, 10 or 100 ng/ml IL-17 enhanced 10 ng/ml bFGF-induced growth of HMVECs. Similarly, when HGF and IL-17 were combined together, 10 or 100 ng/ml IL-17 potentiated 10 ng/ml HGF-induced growth of HMVECs. When VEGF and IL-17 were used together, 10 ng/ml IL-17 did not significantly enhance 10 ng/ml VEGF-induced growth, whereas 100 ng/ml IL-17 clearly promoted 10ng/ml VEGF-mediated proliferation of HMVECs. On the contrary, IL-17 did not augment CXCL5- and CXCL8-mediated growth. These results indicate that IL-17 itself does not have the capability to stimulate the growth of vascular endothelial cells, whereas IL-17 is able to selectively enhance the mitogenic activity of bFGF, HGF, and VEGF for vascular endothelial cells. Our findings also suggest that IL-17 may promote bFGF-, HGF- and VEGF-mediated angiogenesis through enhancing bFGF-, HGF- and VEGF-induced growth of vascular endothelial cells.     

Angiogenesis: mechanistic insights,neovascular diseases,and therapeutic prospects

This review of angiogenesis aims to describe (a) stimuli that either elicit or antagonize angiogenesis, (b) the response of the vasculature to angiogenic or antiangiogenic stimuli, i.e., processes required for the formation of new vessels, (c) aspects of angiogenesis relating to tissue remodeling and disease, and (d) the potential of angiogenic or antiangiogenic therapeutic measures. Angiogenesis, the formation of new vessels from existing microvessels, is important in embryogenesis, wound healing, diabetic retinopathy, tumor growth, and other diseases. Hypoxia and other as yet ill-defined stimuli drive tumor, inflammatory, and connective tissue cells to generate angiogenic molecules such as vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF), transforming growth factor- (TGF-), platelet-derived growth factor (PDGF), and others. Natural and synthetic angiogenesis inhibitors such as angiostatin and thalidomide can repress angiogenesis. Angiogenic and antiangiogenic molecules control the formation of new vessels via different mechanisms. VEGF and FGF elicit their effects mainly via direct action on relevant endothelial cells. TGF- and PDGF can attract inflammatory or connective tissue cells which in turn control angiogenesis. Additionally, PDGF may act differently on specific phenotypes of endothelial cells that are engaged in angiogenesis or that are of microvascular origin. Thus phenotypic traits of endothelial cells committed to angiogenesis may determine their cellular responses to given stimuli. Processes necessary for new vessel formation and regulated by angiogenic/antiangiogenic molecules include the migration and proliferation of endothelial cells from the microvasculature, the controlled expression of proteolytic enzymes, the breakdown and reassembly of extracellular matrix, and the morphogenic process of endothelial tube formation. In animal models some angiogenesis-dependent diseases can be controlled via induction or inhibition of new vessel formation. Lifethreatening infantile hemangiomas are a first established indication for antiangiogenic therapy in humans. Treatment of other diseases by modulation of angiogenesis are currently tested in clinical trials. Thus the manipulation of new vessel formation in angiogenesis-dependent conditions such as wound healing, inflammatory diseases, ischemic heart and peripheral vascular disease, myocardial infarction, diabetic retinopathy, and cancer is likely to create new therapeutic options.Abbreviations VEGF Vascular endothelial growth factor - FGF Fibroblast growth factor - TGF Transforming growth factor - PDGF Platelet-derived growth factor - CAM Chorionic allantoic membrane assay     

Hepatocyte growth factor enhances vascular endothelial growth factor-induced angiogenesis in vitro and in vivo

Vascular endothelial growth factor (VEGF) is an important mediator of angiogenesis in both physiological and pathological processes. Hepatocyte growth factor (HGF) is a mesenchyme-derived mitogen that also stimulates cell migration, and branching and/or tubular morphogenesis of epithelial and endothelial cells. In the present study, we tested the hypothesis that simultaneous administration of HGF and VEGF would synergistically promote new blood vessel formation. HGF acted in concert with VEGF to promote human endothelial cell survival and tubulogenesis in 3-D type I collagen gels, a response that did not occur with either growth factor alone. The synergistic effects of VEGF and HGF on endothelial survival correlated with greatly augmented mRNA levels for the anti-apoptotic genes Bcl-2 and A1. Co-culture experiments with human neonatal dermal fibroblasts and human umbilical vein endothelial cells demonstrated that neonatal dermal fibroblasts, in combination with VEGF, stimulated human umbilical vein endothelial cells tubulogenesis through the paracrine secretion of HGF. Finally, in vivo experiments demonstrated that the combination of HGF and VEGF increased neovascularization in the rat corneal assay greater than either growth factor alone. We suggest that combination therapy using HGF and VEGF co-administration may provide a more effective strategy to achieve therapeutic angiogenesis.     

血管内皮生长因子的研究和应用进展

血管内皮生长因子是一种多功能的细胞因子 ,参与机体多种生理、病理过程。近年来 ,大量动物实验和临床研究均表明 ,它可通过促进新生血管形成 ,加速侧枝循环建立而改善心肌血供 ,称为“治疗性血管生成”或“分子搭桥术” ,为治疗心肌缺血提供了新思路。     

血管内皮生长因子与甲状腺疾病研究进展

血管内皮生长因子(VEGF)的基本功能是促进血管生长。近年研究表明,VEGF通过影响病灶处血管或癌细胞自身的生成从而在多种甲状腺疾病中发挥着重要作用。但VEGF的功能以及在不同甲状腺疾病中的具体变化情况仍然需要进一步探索。本文对VEGF的分子生物学及生物学特性、在多种甲状腺疾病中的作用及其临床应用进行简要综述。     

Vascular Changes in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the most vascular solid tumors, in which angiogenesis plays an important role. The status of angiogenesis in HCC correlates with the disease progression and prognosis, and thus provides a potential therapeutic target. This review summarizes the vascular changes and molecular and cellular basis of angiogenesis in HCC. Development of HCC is characterized by arterialization of its blood supply and sinusoidal capillarization. Vascular endothelial growth factor (VEGF) is a potent angiogenic factor that plays a critical role in mediating angiogenesis in HCC. The VEGF can function on various types of cells, such as endothelial cells, hepatic stellate cells, endothelial progenitor cells and hemangiocytes, to induce vascular changes in HCC. Therefore, blockade of VEGF‐mediated pathways, either by anti‐VEGF neutralizing antibody or tyrosine kinase inhibitors that target VEGF receptors, suppresses carcinogenesis and angiogenesis in HCC. In addition to VEGF, several other angiogenic factors in HCC have recently been identified. These factors can also regulate angiogenic processes through interaction with VEGF or VEGF‐independent pathways. Despite the fact that treatment of HCC remains a tough task due to lack of effective systemic therapy, antiangiogenic therapy has already entered clinical trials in HCC patients and sheds light on a promising novel treatment for this disease. Anat Rec, 291:721–734, 2008. © 2008 Wiley‐Liss, Inc.     

Gene therapy for ischemic brain diseases

We discuss possible gene therapies for the treatment of ischemic diseases in the central nervous system (CNS). These therapies aim at the prevention of carotid artery restenosis, stimulation of angiogenesis for ischemic brain, protection of neurons against ischemia, and prevention of vasospasm due to subarachnoid hemorrhage (SAH). Carotid artery restenosis can perhaps be approached by preventing vascular smooth muscle cell proliferation via gene therapy in addition to surgical treatment. Cerebral angiogenesis therapy might be applicable to moyamoya disease. Gene therapies with VEGF and HGF to stimulate angiogenesis have been successful in muscle; however, efficacy in the CNS is unknown. Gene transfection efficiency of viral vectors has been poor in the CNS, and the safety of such vectors is questionable. Therefore, development of gene therapy is for neural protection and prevention of vasospasm due to SAH has been limited. Infusion of HVJ-AVE liposomes into monkey cerebrospinal fluid (CSF) space yielded wide-spread gene transfection. HVJ-AVE liposomes may be a promising vector for use in the human CNS. Few currently available gene therapies appear to be options for clinical treatment of cerebral ischemia despite many experimental designs. In addition to the inherent difficulties of treating the CNS, vectors and methods for introducing vectors into the CNS must be improved.     

肝细胞生长因子在缺血性疾病的研究及进展

肝细胞生长因子(hepatocyte growth factor，HGF)是一类具有多功能生物活性的生长因子，参与机体多种组织器官及细胞的生长、再生、重塑、促血管新生等过程。因其具有生物活性的多样性，被广泛用于基础实验及临床研究，然而其对血管内皮细胞的增生及维护内皮细胞功能从而促进血管新生加速其侧枝循环作用，被广泛用于缺血性疾病的研究，本文就近年来HGF在缺血性疾病等方面进行综述。     

姜黄素抑制HGF诱导血管内皮细胞迁移和VEGF表达的体内外研究

目的:探索姜黄素抑制肝细胞生长因子(HGF)诱导血管生成的分子机制。方法:利用管腔形成实验、划痕实验、Western blot实验和动物实验观察姜黄素、c-Met抑制剂SU11274、磷脂酰肌醇3-激酶(PI3K)抑制剂LY294002和m TOR抑制剂rapamycin对HGF诱导的内皮细胞迁移、管腔形成能力、血管内皮生长因子(VEGF)表达、相关信号通路和瘤体内血管密度的影响。结果:姜黄素可显著抑制HGF诱导内皮细胞发生迁移、小管形成及VEGF的表达,同时抑制c-Met/AKT/m TOR/S6通路的磷酸化,并可减少瘤体内VEGF的表达和微血管密度。使用c-Met抑制剂SU11274、PI3K抑制剂LY294002或m TOR抑制剂rapamycin能得到和姜黄素相似的效应。结论:姜黄素抑制HGF诱导的血管生成可能是通过抑制c-Met/AKT/m TOR/S6信号通路活化实现的。     

Mechanisms of neovascularization and resistance to anti-angiogenic therapies in glioblastoma multiforme

Glioblastoma multiforme (GBM) is the most malignant brain tumor and highly resistant to intensive combination therapies. GBM is one of the most vascularized tumors and vascular endothelial growth factor (VEGF) produced by tumor cells is a major factor regulating angiogenesis. Successful results of preclinical studies of anti-angiogenic therapies using xenograft mouse models of human GBM cell lines encouraged clinical studies of anti-angiogenic drugs, such as bevacizumab (Avastin), an anti-VEGF antibody. However, these clinical studies have shown that most patients become resistant to anti-VEGF therapy after an initial response. Recent studies have revealed some resistance mechanisms against anti-VEGF therapies involved in several types of cancer. In this review, we address mechanisms of angiogenesis, including unique features in GBMs, and resistance to anti-VEGF therapies frequently observed in GBM. Enhanced invasiveness is one such resistance mechanism and recent works report the contribution of activated MET signaling induced by inhibition of VEGF signaling. On the other hand, tumor cell-originated neovascularization including tumor-derived endothelial cell-induced angiogenesis and vasculogenic mimicry has been suggested to be involved in the resistance to anti-VEGF therapy. Therefore, these mechanisms should be targeted in addition to anti-angiogenic therapies to achieve better results for patients with GBM.     

血管内皮细胞生长因子在心梗模型治疗中的形态学观察

目的:探讨VEGF在实验性心肌梗塞中促血管生成的形态学依据和作用机理。方法:结扎30只家兔左冠状动脉的前降支,造成实验性心肌梗塞。15支兔作为实验组,在梗塞区内注射VEGF;其余15只兔作为对照组,仅作前降支单纯性结扎。两组动物分别于结扎后1,2,4周处死,利用组织切片染色法,观察梗塞区血管的生成与重建及相关的病理学变化。结果:实验组梗塞区内,可见许多呈岛状存活的心肌组织,对照组则极为少见。术后2周为血管形成的高峰期,实验组梗塞区内新生血管的数量和密度明显高于对照组,两组具有极为显著性差异(血管密度实验组为24.19±0.77条/4×10倍,对照组为1.01±0.21条/4×10倍)。结论:VEGF对急性实验性心肌梗塞后的血管形成及心肌组织存活具有明显的促进作用。     

Vascular endothelial growth factor and hepatocyte growth factor levels are differentially elevated in patients with advanced retinopathy of prematurity

Although the roles of vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF) in angiogenesis are well described, the putative roles of these factors in retinopathy of prematurity (ROP) remain unknown. We evaluated VEGF and HGF protein levels in subretinal fluid of eyes with ROP, and expression of their corresponding receptors in retrolental membranes associated with stage 5 ROP. We examined subretinal fluid samples from eyes using rhegmatogenous retinal detachment as a control. VEGF and HGF were differentially elevated in eyes with ROP. In Stage 5 ROP (n = 22), the mean VEGF and HGF levels were 14.77 +/- 14.01 ng/ml and 16.56 +/- 9.62 ng/ml, respectively. Interestingly, in patients with active stage 4 ROP, mean VEGF levels were highly elevated (44.16 +/- 18.72 ng/ml), whereas mean HGF levels remained very low (4.77 +/- 2.50 ng/ml). Next, we investigated in vivo expression of VEGF receptor-2 and HGF receptor in retrolental membranes from 16 patients with stage 5 ROP. Both VEGF receptor-2 and HGF receptor proteins were detected mainly in posterior portions of the membrane as well as in vessel walls and along the retinal interface where angiogenesis was active. These findings together suggest that VEGF and HGF play important roles in the pathogenesis of ROP.     

Functional characteristics of coronary vasomotor function following intramyocardial gene therapy with naked DNA encoding for vascular endothelial growth factor165.

Vascular endothelial growth factor (VEGF) is a potent angiogenic factor. VEGF gene therapy improves perfusion of ischemic myocardium in experimental models and possibly in patients with end-stage coronary artery disease. In addition to its proliferative and migratory effect on endothelial cells, it also activates and up-regulates endothelial nitric oxide synthase (eNOS). Therefore, the authors investigated coronary endothelium-dependent vasodilatation in patients before and after VEGF gene therapy. The effect of intracoronary acetylcholine infusion on coronary diameter was assessed at baseline and after 3 months follow-up in patients with end-stage coronary artery disease treated with VEGF gene and in controls scheduled for elective percutaneous transluminal coronary angioplasty (PTCA) (acetylcholine test at diagnostic angiography and before a subsequently scheduled PTCA). Five out of six VEGF patients experienced a reduction in anginal complaints. Angiographic evidence for improved collateral filling was evident in two out of six patients. The vasoconstrictive response to acetylcholine was partly converted into dilatation. In contrast, the acetylcholine response in control patients remained vasoconstrictive. In conclusion, VEGF gene therapy has an important beneficial effect on the functional characteristics of the myocardial vascular network. Therefore, this therapy can potentially play an important role in all stages of the atherosclerotic process.     

Vascular wall maturation and prolonged angiogenic effect by endothelial-specific platelet-derived growth factor expression.

BACKGROUND: The implementation of angiogenic gene therapy at clinics is hindered by the transience of the therapeutic effect. Recruiting vascular wall smooth muscle cells, a process termed 'maturation', can stabilize newly formed vessels. OBJECTIVE: To induce angiogenesis followed by vessel maturation in a murine ischemic limb model by endothelial cell-specific promoter regulated expression of vascular endothelial growth factor (VEGF) and platelet-derived growth factor-BB (PDGF-BB). METHODS: We constructed adenoviral vectors containing angiogenic factors VEGF and PDGF-B regulated by a modified preproendothelin-1 (PPE-1-3x) promoter and investigated their angiogenic effect in a murine ischemic limb model. Results: VEGF gene therapy increased perfusion and the vessel density in the limb shortly after expression with PPE-1-3x promoter or cytomegalovirus (CMV) promoter vectors, but only PPE-1-3xVEGF treatment exhibited a sustained effect. Expression of PDGF-B by PPE-1-3x promoter resulted in morphological maturation of the vasculature and further increased the perfusion, while nonspecific expression of PDGF-B with CMV promoter had no therapeutic effect. Regulation of dual therapy with VEGF and PDGF-B by PPE-1-3x promoter resulted in an early-onset, sustained angiogenic effect accompanied by vessel maturation. CONCLUSIONS: Systemic gene therapy with the angiogenic factors VEGF and PDGF-B under angiogenic- endothelial cell-specific regulation was effective in inducing functionally and morphologically mature vasculature.