Study on the mechanism of vascular injury by novel species of advanced glycation endoproducts

在这项研究中，我们揭示了糖尿病患者血清中水平升高的新物种高级糖基化终产物(AGE)确实与其细胞受体RAGE结合并诱导细胞内信号。我们还发现了RAGE的一个新的剪接变体-内源性分泌RAGE(EsRAGE)-并发现该变体对新AGE物种引起的血管损伤具有保护作用。此外，我们还发现血清esRAGE水平与某些生活方式相关疾病的易感性显著相关。(1)我们证明了由牛血清白蛋白与甘油醛或乙醇醛孵育产生的新年龄物种，(2)我们将新型AGEs与RAGE的结合区定位在其N端的蛋白球蛋白V域样区域。(3)我们证明了新的AGEs与RAGE激活的MAPK信号通路的相互作用，并诱导培养的人内皮细胞VCAM-I的表达。(4)我们建立了RAGE基因敲除小鼠，证明了在没有RAGE的情况下，糖尿病肾病的发展被显著抑制。(5)我们从人内皮细胞中分离出一种新的RAGE剪接变异体，该剪接变体缺乏跨膜结构域，由细胞分泌。并将其命名为esRAGE(内源性分泌型RAGE)。(6)此外，我们还发现esRAGE通过细胞外捕获RAGE舌头，对新AGE诱导的血管形成具有保护作用。(7)建立了esRAGE-EL ISA体系，并分析了生活方式相关疾病患者的血清esRAGE水平。然后我们发现血清esRAGE水平与一些生活方式相关疾病的易感性显著相关，提示。血清esRAGE水平可作为生活方式相关疾病的一个有用的危险指标。

In this research, we revealed that the novel species of advance glycation endproducts (AGE), whose level in serum is elevated in diabetic patients, do bind to their cellular receptor RAGE and induce intracellular signals.We also identified a novel splicing variant of RAGE-endogenous secretory RAGE (esRAGE)-and found that this variant has protective effect against vascular injury induced by the novel AGE species. Moreover, we found the significant coirelation between serwn esRAGE level and susceptibility of some life-style related diseases.(1) We demonstrated that the novel AGE species, which is generated by incubating bovine serum albumin with glyceraldehyde or glycolaldehyde, strongly binds to cellular RAGE at comparable dissociation constants calculated by the suiface plasmon resonance method.(2) We mapped the binding region of the novel AGEs on RAGE at an inununoglobulin V-domain-like region on its N-terminal end.(3) We demonstrated that the interaction of the new AGEs to RAGE activated MAP kinase signaling pathway and induced V CAM-i expression in cultured human endothelialcells.(4) We created RAGE knockout mice and demonstrated that the development of diabetic nephropa thy was dramatically suppressed in the absence of RAGE..(5) We isolated a novel splicing variant of RAGE from human endothelial cells that lacks transmembrane domain and is secreted from cells, and termed this novel variant esRAGE (~ndogenous secretory RAGE).(6) Furthennore we found that esRAGE has a protective effect against the vascular injuly induced by the novel AGEs, by extracellular capture of the RAGE lingads.(7) We established esRAGE ELISA system and analyzed serum level of esRAGE in patients with life-style related deseases. Then we found significant correlation between serum esRAGE level and susceptibility of some life-style related diseases, suggesting that. the serum esRAGE level could be a useful risk marker for some life-style related deseases.