Schalkwijk Casper G, van Bezu Jan, van der Schors Roel C, Uchida Koji, Stehouwer Coen D A, van Hinsbergh Victor W M
Department of Clinical Chemistry, Vrije Universiteit Medical Center, Amsterdam, The Netherlands.
FEBS Lett. 2006 Mar 6;580(6):1565-70. doi: 10.1016/j.febslet.2006.01.086. Epub 2006 Feb 3.
In endothelial cells cultured under high glucose conditions, methylglyoxal is the major intracellular precursor in the formation of advanced glycation endproducts. We found that endothelial cells incubated with 30 mM d-glucose produced approximately 2-fold higher levels of methylglyoxal but not 3-deoxyglucosone and glyoxal, as compared to 5 mM d-glucose. Under hyperglycaemic conditions, the methylglyoxal-arginine adduct argpyrimidine as detected with a specific antibody, but not N(e)-(carboxymethyl)lysine and N(e)-(carboxyethyl)lysine, was significantly elevated. The glyoxylase I inhibitor HCCG and the PPARgamma ligand troglitazone also increased argpyrimidine levels. Increased levels of argpyrimidine by glucose, HCCG and troglitazone are accompanied by a decrease in proliferation of endothelial cells. A 27 kDa protein was detected as a major argpyrimidine-modified protein. With in-gel digestion and mass spectrometric analysis, we identified this major protein as heat-shock protein 27 (Hsp27). This argpyrimidine modification of Hsp27 may contribute to changes in endothelial cell function associated to diabetes.
在高糖条件下培养的内皮细胞中，甲基乙二醛是晚期糖基化终产物形成过程中的主要细胞内前体物质。我们发现，与5 mM d-葡萄糖相比，用30 mM d-葡萄糖孵育的内皮细胞产生的甲基乙二醛水平大约高出2倍，但3-脱氧葡萄糖酮和乙二醛的水平并未升高。在高血糖条件下，用特异性抗体检测到的甲基乙二醛-精氨酸加合物精脒嘧啶显著升高，而Nε-(羧甲基)赖氨酸和Nε-(羧乙基)赖氨酸则未升高。乙二醛酶I抑制剂HCCG和过氧化物酶体增殖物激活受体γ（PPARγ）配体曲格列酮也会增加精脒嘧啶水平。葡萄糖、HCCG和曲格列酮导致精脒嘧啶水平升高的同时，内皮细胞的增殖会减少。检测到一种27 kDa的蛋白质是主要的精脒嘧啶修饰蛋白。通过凝胶内消化和质谱分析，我们确定这种主要蛋白质为热休克蛋白27（Hsp27）。Hsp27的这种精脒嘧啶修饰可能导致与糖尿病相关的内皮细胞功能变化。
