Study On The Effect And Mechanism Of Small Molecules In Angiogenesis Related Diseases

Cancer and diabetes are the diseases that threat the health of human, angiogenesis plays a key role in development of these diseases. Angiogenesis means the new capillary growth from the original blood vessels, it occurs in the normal physiological state and disease state, and is closely related with human. Normal angiogenesis is regulated by proangiogenic factors and antiangiogenic factors. Once the balance is broken, imbalance results in the excessive angiogenesis and insufficient angiogenesis. Excessive angiogenesis involves in the growth and metastasis of cancer. Insufficient angiogenesis involves in impaired wound healing, impaired peripheral vessel formation, stroke, heart disease and so on.Recently, angiogenesis becomes the therapeutic target for many diseases incluing cancer and diabetic complications. So, to explore the new drugs influencing angiogenesis could lay the foundation for diseases related with vascular dysfunction including cancer and diabetes. The natural small molecules and novel synthetic small molecules are the sources of these new drugs. Based on the above, firstly, we screened some natural small molecules using in vitro, ex vivo and in vivo models according to the previous researches, and identified harmine was a potential angiogenesis inhibitor. In vitro, harmine inhibited the human umbilial vein endothelial cell proliferation, migration invasion and induced apoptosis of human umbilial vein endothelial cell. In rat aortic ring assays and mouse corneal micropocket assays, harmine suppressed the formation of new capillary ex vivo and in vivo. Xenograft tumor assay displayed that harmine inhibited tumor growth via blocking tumor angioenesis and the proliferation of lung cancer cell A549. For the detail mechanisms, we found harmine inhibited the p53-MDM2interaction, and induced the phosphorylation of p53. Further study showed that hamine activated the activity of p53and promoted its nucleus accumulation and transcriptional activities. Secondly, to explore the role of promoting angiogenesis in the vascular diseases of diabetes, we synthesized a series of small molecules that have potential proangiogenic effect. Using the angiogenesis assays in vitro, we found a small molecule, named361B, promoted HUVEC sprouting, tube formation, migration and inhibited starvation-induced apoptosis. In rat aortic ring assays and mouse corneal micropocket assays,361B induced the formation of new micro vessels. We also found361B promoted the blood flow and reduced severity of necrosis in ischemia hindlimb of diabetic mouse. Further study showed361B enhanced angiogenesis in ischemia hindlimb. Microarray data showed that many genes related with angiogenesis were regulated by361B. To further dermine the proteins which361B binds to regulating the function of361B in angiogenesis, we synthesized biotin-361B. The results of pull down assays and mass spectrometry (MS\MS) analysis showed that bio-361B bound to the determined proteins vimentin expressed in human umbilial vein endothelial cell.All together, in terms of anti-tumor angiogenesis, we found that harmine inhibited angiogenesis via p53signal pathway, resulting in the inhibition of tumor growth. In terms of diabetes angigoenesis, we showed that the small molecule361B bound to vimentin to regulate the occurrence of angiogenesis, by which361B promoted the recovery of ischemic hindlimb in diabetic mice. Our studies provided theretical foundation for the research of anticancer drugs and the drugs to treat diabetic vascular diseases.