Obesity is a risk factor for the development of many severe human diseases such as cardiovascular disorders, diabetes, and cancer, which are tightly linked to angiogenesis. The adipose tissue produces several growth factors/hormones including leptin, tumor necrosis factor α, and adiponectin. It has been found that adiponectin levels are reduced in obesity. Here, we report a unique function of adiponectin as a negative regulator of angiogenesis. In vitro , adiponectin potently inhibits endothelial cell proliferation and migration. In the chick chorioallantoic membrane and the mouse corneal angiogenesis assays, adiponectin remarkably prevents new blood vessel growth. Further, we demonstrate that the antiendothelial mechanisms involve activation of caspase-mediated endothelial cell apoptosis. Adiponectin induces a cascade activation of caspases-8, -9, and -3, which leads to cell death. In a mouse tumor model, adiponectin significantly inhibits primary tumor growth. Impaired tumor growth is associated with decreased neovascularization, leading to significantly increased tumor cell apoptosis. These data demonstrate induction of endothelial apoptosis as an unique mechanism of adiponectin-induced antiangiogenesis. Adiponectin, as a direct endogenous angiogenesis inhibitor, may have therapeutic implications in the treatment of angiogenesis-dependent diseases.

Most endocrine hormones are produced in tissues and organs with permeable microvessels that may provide an excess of hormones to be transported by the blood circulation to the distal target organ. Here, we investigate whether leptin, an endocrine hormone, induces the formation of vascular fenestrations and permeability, and we characterize its angiogenic property in the presence of other angiogenic factors. We provide evidence that leptin-induced new blood vessels are fenestrated. Under physiological conditions, capillary fenestrations are found in the leptin-producing adipose tissue in lean mice. In contrast, no vascular fenestrations were detected in the adipose tissue of leptin-deficient ob/ob mice. Thus, leptin plays a critical role in the maintenance and regulation of vascular fenestrations in the adipose tissue. Leptin induces a rapid vascular permeability response when administrated intradermally. Further, leptin synergistically stimulates angiogenesis with fibroblast growth factor (FGF)-2 and vascular endothelial growth factor (VEGF), the two most potent and commonly expressed angiogenic factors. These findings demonstrate that leptin has another new function—the increase of vascular permeability.

Background—: The lymphatic system regulates interstitial tissue fluid balance, and lymphatic malfunction causes edema. The heart has an extensive lymphatic network displaying a dynamic range of lymph flow in physiology. Myocardial edema occurs in many cardiovascular diseases, eg, myocardial infarction (MI) and chronic heart failure, suggesting that cardiac lymphatic transport may be insufficient in pathology. Here, we investigate in rats the impact of MI and subsequent chronic heart failure on the cardiac lymphatic network. Further, we evaluate for the first time the functional effects of selective therapeutic stimulation of cardiac lymphangiogenesis post-MI. Methods and Results—: We investigated cardiac lymphatic structure and function in rats with MI induced by either temporary occlusion (n=160) or permanent ligation (n=100) of the left coronary artery. Although MI induced robust, intramyocardial capillary lymphangiogenesis, adverse remodeling of epicardial precollector and collector lymphatics occurred, leading to reduced cardiac lymphatic transport capacity. Consequently, myocardial edema persisted for several months post-MI, extending from the infarct to noninfarcted myocardium. Intramyocardial-targeted delivery of the vascular endothelial growth factor receptor 3–selective designer protein VEGF-C _C152S , using albumin-alginate microparticles, accelerated cardiac lymphangiogenesis in a dose-dependent manner and limited precollector remodeling post-MI. As a result, myocardial fluid balance was improved, and cardiac inflammation, fibrosis, and dysfunction were attenuated. Conclusions—: We show that, despite the endogenous cardiac lymphangiogenic response post-MI, the remodeling and dysfunction of collecting ducts contribute to the development of chronic myocardial edema and inflammation-aggravating cardiac fibrosis and dysfunction. Moreover, our data reveal that therapeutic lymphangiogenesis may be a promising new approach for the treatment of cardiovascular diseases.

Adipose tissue growth has been proposed to involve recruitment of new blood vessels. Here, we test the hypothesis that delivery of an angiogenesis inhibitor in mice may prevent diet-induced obesity, the most common type of obesity in humans. We show that systemic administration of a selective angiogenesis inhibitor, TNP-470 (AGM-1470), prevents obesity in high caloric diet-fed wt mice as well as in genetically leptin-deficient ob/ob mice. Inhibition of obesity in mice by TNP-470 involves a reduction of vascularity in the adipose tissue. This therapeutic strategy appears to selectively affect the growth of adipose tissue as measured by the ratio between total fat and lean body mass. Interestingly, the treatment with TNP-470 results in decreased serum levels of low-density lipoprotein cholesterol. Furthermore, insulin levels are reduced, which indicates increased insulin sensitivity, suggesting that angiogenesis inhibitors may prevent the development of type II diabetes. Our findings suggest that similarly to growth and organogenesis in other tissues, adipose tissue growth is dependent on angiogenesis. Our observations may have conceptual implications for the prevention of obesity and related disorders.

Resveratrol (3,5,4′‐trihydroxystilbene) is a natural compound found in several plants, including grapes, peanuts, and pines, and in their related products. Red wine is probably the most frequently consumed drink that is enriched in resveratrol. We investigated whether drinking resveratrol could suppress angiogenesis, a process of blood vessel growth involved in initiation, development, and progression of many diseases, including cancer, metastasis, and diabetic retinopathy. We found that resveratrol suppresses the growth of new blood vessels in animals. It directly inhibits capillary endothelial cell growth. It blocks both VEGF‐ and FGF‐receptor‐mediated angiogenic responses. In addition, resveratrol inhibits the phosphorylation of mitogen‐activated kinase isoforms (MAPK ^p44 /MAPK ^p42 ) induced by fibroblast growth factor‐2 in proliferating endothelial cells in a dose‐dependent manner. Oral administration of resveratrol significantly inhibits the growth of a murine fibrosarcoma in mice, and it significantly delays angiogenesis‐dependent wound healing in mice. Our findings suggest that ingestion of resveratrol‐enriched food could be beneficial for the prevention of cancer. However, its antiangiogenic effect could delay wound healing and possibly other angiogenesis‐dependent processes under physiological conditions.