Effect of thiazolidinedione on the proliferation of bovine retinal endothelial cells stimulated by vascular endothelial cell growth factor

Role of Junctional Adhesion Molecule-C in the Regulation of Inner Endothelial Blood-Retinal Barrier Function

Although JAM-C is abundantly expressed in the retinae and upregulated in choroidal neovascularization (CNV), it remains thus far poorly understood whether it plays a role in the blood-retinal barrier, which is critical to maintain the normal functions of the eye. Here, we report that JAM-C is highly expressed in retinal capillary endothelial cells (RCECs), and VEGF or PDGF-C treatment induced JAM-C translocation from the cytoplasm to the cytomembrane. Moreover, JAM-C knockdown in RCECs inhibited the adhesion and transmigration of macrophages from wet age-related macular degeneration (wAMD) patients to and through RCECs, whereas JAM-C overexpression in RCECs increased the adhesion and transmigration of macrophages from both wAMD patients and healthy controls. Importantly, the JAM-C overexpression-induced transmigration of macrophages from wAMD patients was abolished by the administration of the protein kinase C (PKC) inhibitor GF109203X. Of note, we found that the serum levels of soluble JAM-C were more than twofold higher in wAMD patients than in healthy controls. Mechanistically, we show that JAM-C overexpression or knockdown in RCECs decreased or increased cytosolic Ca²⁺ concentrations, respectively. Our findings suggest that the dynamic translocation of JAM-C induced by vasoactive molecules might be one of the mechanisms underlying inner endothelial BRB malfunction, and inhibition of JAM-C or PKC in RCECs may help maintain the normal function of the inner BRB. In addition, increased serum soluble JAM-C levels might serve as a molecular marker for wAMD, and modulating JAM-C activity may have potential therapeutic value for the treatment of BRB malfunction-related ocular diseases.

Increased vascular permeability after cardiopulmonary bypass in patients with diabetes is associated with increased expression of vascular endothelial growth factor and hepatocyte growth factor

BACKGROUND

Several inflammatory mediators such as vascular endothelial growth factor and hepatocyte growth factor are known to play a critical role in the regulation of vascular permeability and angiogenesis. We studied the serum levels of growth factors and gene expression profiles of genes involved in growth factor signaling in the peripheral blood of patients with and patients without diabetes following cardiopulmonary bypass and cardioplegic arrest.

METHODS

Serum and total RNA were obtained from the blood samples collected from patients with diabetes and matched patients without diabetes (n = 7 patients each) who had coronary artery bypass graft before and 6 hours and 4 days after cardiopulmonary bypass/cardioplegic arrest. The cytokine panel, consisting of growth factors such as vascular endothelial growth factor, hepatocyte growth factor, fibroblast growth factor, and epidermal growth factor, was quantified in patients with diabetes and patients without diabetes before and 6 hours and 4 days post-cardiopulmonary bypass/cardioplegic arrest using multiplex cytokine quantification system. cDNA microarray analysis was performed and fold-change was calculated.

RESULTS

Length of hospitalization (10 vs 6 days; P = .04) and weight gain (5 vs 2.5 kg; P = .001) were significantly greater for patients with diabetes compared with patients without diabetes. The serum levels of vascular endothelial growth factor and hepatocyte growth factor were significantly elevated in patients with diabetes when compared with patients without diabetes before versus 6 hours post-cardiopulmonary bypass/cardioplegic arrest. In addition, significantly elevated mRNA expression of hypoxia-inducible factor-1alpha, cyclic adenosine monophosphate response element binding protein, and E1A binding protein p300 (more than twofold) was observed 4 days post-cardiopulmonary bypass/cardioplegic arrest exclusively in patients with diabetes.

CONCLUSIONS

The differential profile of gene and protein expression of growth factors and their related genes in patients with diabetes and patients without diabetes could be associated with increased edema and weight gain in patients with diabetes after cardiopulmonary bypass/cardioplegic arrest.