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Adipose tissue is critical in obesity and type II diabetes. Blocking of adipocyte differentiation is one of the anti-obesity strategies targeting on strong rise in fat storage and secretion of adipokine(s). However, the molecular basis of adipocyte differentiation and its regulation remains obscure. Therefore, we exposed 3T3-L1 cell line to appropriate hormonal inducers as adipocyte differentiation model. Using iTRAQ-coupled 2D LC-MS/MS, a successfully exploited high-throughput proteomic technology, we nearly quantitated 1,000 protein species and found 106 significantly altered proteins during adipocyte differentiation. The great majority of differentially expressed proteins were related to metabolism enzymes, structural molecules, and proteins involved in signal transduction. In addition to previously reported differentially expressed molecules, more than 20 altered proteins previously unknown to be involved with adipogenic process were firstly revealed (e.g., HEXB, DPP7, PTTG1IP, PRDX5, EPDR1, SPNB2, STEAP3, TPP1, etc.). The partially differential proteins were verified by Western blot and/or real-time PCR analysis. Furthermore, the association of PCX and VDAC2, two altered proteins, with adipocyte conversion was analyzed using siRNA method, and the results showed that they could contribute considerably to adipogenesis. In conclusion, our data provide valuable information for further understanding of adipogenesis.

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Macrophage invasion is an important event during arteriogenesis, but the underlying mechanism is still only partially understood. The present study tested the hypothesis that nitric oxide (NO) and VE-cadherin, two key mediators for vascular permeability, contribute to this event in a rat ischemic hindlimb model. In addition, the effect of NO on expression of VE-caherin and endothelial permeability was also studied in cultured HUVECs. We found that: 1) in normal arteriolar vessels (NAV), eNOS was moderately expressed in endothelial cells (EC) and iNOS was rarely detected. In contrast, in collateral vessels (CVs) induced by simple femoral artery ligation, both eNOS and iNOS were significantly upregulated (P<0.05). Induced iNOS was found mainly in smooth muscle cells, but also in other vascular cells and macrophages; 2) in NAV VE-cadherin was strongly expressed in EC. In CVs, VE-cadherin was significantly downregulated, with a discontinuous and punctate pattern. Administration of nitric oxide donor DETA NONOate (NONOate) further reduced the amounts of Ve-cadherin in CVs, whereas NO synthase inhibitor L-NAME inhibited downregulation of VE-cadherin in CVs; 3) in normal rats Evans blue extravasation (EBE) was low in the musculus gracilis, FITC-dextron leakage was not detected in the vascular wall and few macrophages were observed in perivascular space. In contrast, EBE was significantly increased in femoral artery ligation rats, FITC-dextron leakage and increased amounts of macrophages were detected in CVs, which were further enhanced by administration of NONOate, but inhibited by L-NAME supplement; 4) in vitro experiments confirmed that an increase in NO production reduced VE-cadherin expression, correlated with increases in the permeability of HUVECs. In conclusion, our data for the first time reveal the expression profile of VE-cadherin and alterations of vascular permeability in CVs, suggesting that NO-mediated VE-cadherin pathway may be one important mechanism responsible, at least in part, for macrophage invasion during arteriogenesis.