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Blood vessels supply oxygen and nutrients to all the cells in a living body, and provide essential transport routes for collecting waste products. For these functions, blood vessel networks should be appropriately formed in each tissue. Therefore, blood vessels are one of the earliest organs formed during the developmental process. Development of the blood vessel system promotes tissue differentiation and organ morphogenesis, allowing each organ to maintain its unique functions under changing metabolic conditions. Blood vessels have a relatively simple structure, consisting of endothelial cells covering the inner layer, and pericytes or smooth muscle cells surrounding the outside. The structure of the vascular network is extremely diverse, with blood vessels uniquely organized depending on the tissues they serve, to create tissue-specific microenvironments. How are such tissue-specific vascular environments generated? Over the years, anatomical findings have accumulated to confirm this vascular diversity. However, the molecular basis for this diversity has remained unclear. In the present article, we review the mechanisms of coordinated developmental control of the vascular and neural systems in the cerebral cortex from the viewpoint of the accurate expression control of vascular endothelial growth factor (VEGF) signaling, and describe future perspectives.

Brain edema is a severe morbid complication of brain injury, characterized by excessive fluid accumulation and an elevation of intracranial pressure. However, effective anti-brain edema drugs are lacking. One of the causes of brain edema is disruption of blood-brain barrier (BBB) function, which results in extravasation of intravascular fluid. After brain damage, astrocytes are activated, and astrocyte-derived vascular endothelial growth factor-A (VEGF-A) is known to induce BBB dysfunction. Therefore maintaining BBB integrity by regulating astrocyte function is a potentially effective strategy for treating brain edema. In this review, we focus on the endothelin ET B receptor and its role in regulation of astrocyte functions. In mice, brain damage was induced by fluid percussion injury (FPI), and the resulting BBB disruption and brain edema were observed in the mouse cerebrum. BQ788, a selective ET B receptor antagonist, attenuated the FPI-induced BBB disruption and brain edema. Levels of brain VEGF-A increased after FPI, mainly in reactive astrocytes. BQ788 suppressed the FPI-induced increase in VEGF-A expression in reactive astrocytes. Moreover, intraventricular administration of VEGF neutralizing antibody also attenuated FPI-induced BBB disruption and brain edema. Claudin-5 is an endothelial tight junction protein essential for normal BBB structure and function. Levels of claudin-5 protein were reduced by FPI. Furthermore, VEGF neutralizing antibody blocked FPI-induced decrease in claudin-5. These results suggest that the ET B receptor antagonist BQ788 protects against brain edema by inhibiting VEGF-A-mediated decrease in claudin-5.

Monosodium glutamate (MSG) is known to provide the umami taste in the food. We have recently reported that glutamate has the potential to protect the small intestine against non-steroidal anti-inflammatory drugs (NSAIDs)-induced lesions in rats. In this paper, we examined this protective effect using sodium loxoprofen, one of the NSAIDs frequently used in Asian countries, to determine whether MSG accelerates the healing of loxoprofen-induced small intestinal lesions in rats. Loxoprofen at 60 mg/kg caused hemorrhagic lesions in the small intestine, mainly in the jejunum and ileum. These lesions spontaneously healed within 7 days, but this healing process was delayed by repeated administration of loxoprofen at low doses (10, 30 mg/kg) for 5 d after lesion induction. The healing-impairment action of loxoprofen was accompanied by the down-regulation of vascular endothelium-derived growth factor (VEGF) expression and an angiogenic response. The impaired healing caused by loxoprofen was significantly restored by co-treatment with a diet containing 5% MSG for 5 d, accompanied by the enhancement of VEGF expression and angiogenesis. We suggest that daily intake of MSG not only protects the small intestine against NSAIDs-induced damage but also exerts healing-promoting effects on these lesions.

Kidney stone disease is a common condition, affecting up to 10% of the population in Japan as well as in the industrial world. Calcium oxalate is major stone composition, consists of crystal and stone matrix, and arises from a combination of environmental and genetic factors. To date, considerable progress has been made identifying the metabolic risk factors predisposing to this complex disease. The familial association of calcium oxalate stone has been corroborated by numerous studies. The specific genetic and epigenetic factors have remained less clear. However genetic variations have indicated using single nucleotide polymorphism (SNP) , and recent technological advances by way of commercially available SNP array or chips, which capture common human variation across the entire genome, have been revolutionizing the study and identifying a new gene as a risk locus in idiopathic calcium oxalate kidney stone disease.

Purpose: Metastatic activity is one parameter indicating the malignancy of tumor cells. Angiogenesis has now been extensively studied to clarify the mechanisms of tumor growth and metastasis. Vascular endothelial growth factor (VEGF) is an angiogenic cytokine expressed by many human and animal tumors. We studied the role of VEGF in tumor growth by transfecting the VEGF gene into tumor cells and analyzing the survival period of nude mice implanted with these transfected tumor cells., Materials and Methods: Cell line: The tumor cell line, OKK-LN, was established from human maxillary squamous cell carcinoma and used in this study. The tumor cells did not produce VEGF in the culture supernatant. Transfection: OKK-LN cells were stably transfected with sense VEGF165 cDNA or with the vector alone. The full-length VEGF165 cDNA was cloned into an expression vector (pCIneo). The DNA transfection was performed by the lipofection method, and the limiting dilution method was used for cloning. ELISA was used to measure VEGF in the culture supernatant. As a control, OKK-LN cells were transfected with the vector alone without VEGF (OKK-LN/pCIneo). The tumor cells were subcutaneously injected into nude mice (Balb/c nu/nu, 6W), and the survival period and tumor volume were analyzed. Effects of angio-suppressive agent, TNP-470, and anti-VEGF antibody on tumor growth and angiogenesis: TNP-470 (supplied by Takeda Pharmaceutical Co., Ltd.) and monoclonal anti-human VEGF antibodies were intraperitoneally administered to mice implanted with tumor cells once a week and twice a week for 5 weeks, respectively. The effects of TNP-470 and anti-VEGF antibodies were analyzed by examining tumor size and survival rate and immunohistologically using CD31 monoclonal antibody., Results: Tumor cells transfected with sense VEGF 165 cDNA (referred to as OKK-LN/pCIneo VEGF ) produced VEGF in the supernatant permanently, confirming the establishment of a VEGF-producing human cancer cell line. We observed marked tumor growth and a shortened survival period by nine days in the OKK-LN/pCIneo-VEGF group, compared to the control group. The administration of TNP-470 and anti-VEGF antibody significantly suppressed tumor growth. The immunohistological study showed the significant suppression of a number of tumor vessels in anti-VEGF antibody-administered mice., Conclusion: Our data strongly suggests that VEGF plays an important role in tumor growth and that treatment by anti-VEGF antibody may be a promising strategy against head and neck cancers.

Purpose: To demonstrate the role of the retinal pigment epithelial cells (RPE) in subretinal neovascularization during maturation and fenestration of endothelial cells in vascular endothelial growth factor (VEGF) transgenic mice., Methods: VEGF transgenic mice were given an intraperitoneal injection of 50 mg/kg of sodium iodate (treated) or physiological saline (controls) on postnatal day 10. Fluorescein angiography (FAG) was carried out and the mice were sacrificed on postnatal day 31. The eyes were removed and processed for light and electron microscopy., Results: FAG showed leakage from neovascularization in both groups, but there were fewer leakages in the treated group than in the control group. Electron microscopy showed subretinal neovascularization in both groups, but there were fewer fenestrations and less maturity of endothelial cells in the new vessels of mice in the treated group. In the treated mice, damaged RPE cells did not completely enclose new vessels and the endothelial cells were immature., Conclusions: It is suggested that RPE cells promote endothelial cell maturation and formation of fenestrations in VEGF-induced subretinal neovascularization.