Department of Endocrinology and Metabolism, The Second Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, People's Republic of China.
Arch Dermatol Res. 2011 Jul;303(5):339-50. doi: 10.1007/s00403-010-1102-z. Epub 2010 Dec 4.
The migration and proliferation of keratinocytes is critical to wound re-epithelialization and defects in this function are associated with the clinical phenomenon of chronic non-healing wounds. Advanced glycation end products (AGEs) occur through non-enzymatic glycation of long-lived proteins in diabetes and play important roles in diabetic complications. However, specific roles for AGEs in keratinocyte migration and proliferation, and the underlying molecular mechanisms, have not been fully established. The aim of the current study was to elucidate the interaction between AGE-modified bovine serum albumin (AGE-BSA) and keratinocytes. As a result, we found that AGE-BSA had no effect on the viability of keratinocytes for up to 48 h of incubation with 50 μg/ml of AGE-BSA. AGE-BSA (but not non-glycated BSA) exerted a concentration-dependent suppression of keratinocyte migration at a range of concentrations. The expression of matrix metalloproteinase-9 (MMP-9) was significantly up-regulated in keratinocytes incubated with increasing AGE-BSA, but tissue inhibitor of metalloproteinases-1 (TIMP-1) expression was down-regulated. AGE-BSA also profoundly depressed phospho-focal adhesion kinase-Tyr397 (p-FAK) and α2β1 integrin expression, while total-FAK expression levels remained constant, in keratinocytes. The proliferative capacity of keratinocytes was diminished after 72 h AGE-BSA incubation. Taken together, these findings suggested that in the presence of AGE-BSA, keratinocytes lose their migratory and proliferation abilities. These data also indicated that, in the context of the chronic hyperglycemia in diabetes, the effects of AGE-BSA on keratinocyte migration might be mediated through MMP-9/TIMP-1, p-FAK and α2β1 integrin.
角质形成细胞的迁移和增殖对于伤口再上皮化至关重要，而该功能的缺陷与慢性难愈性伤口的临床现象有关。晚期糖基化终末产物（AGEs）通过糖尿病中长寿命蛋白质的非酶糖基化产生，并在糖尿病并发症中发挥重要作用。然而，AGEs 在角质形成细胞迁移和增殖中的具体作用及其潜在的分子机制尚未完全确定。本研究旨在阐明 AGE 修饰的牛血清白蛋白（AGE-BSA）与角质形成细胞之间的相互作用。结果发现，在 50μg/ml 的 AGE-BSA 孵育下，AGE-BSA 对角质形成细胞活力在长达 48 小时的时间内没有影响。AGE-BSA（而非非糖基化的 BSA）以浓度依赖性方式抑制角质形成细胞迁移。随着 AGE-BSA 浓度的增加，角质形成细胞中基质金属蛋白酶-9（MMP-9）的表达显著上调，而组织金属蛋白酶抑制剂-1（TIMP-1）的表达下调。AGE-BSA 还显著抑制了角质形成细胞中磷酸化粘着斑激酶-Tyr397（p-FAK）和α2β1 整合素的表达，而总 FAK 表达水平保持不变。角质形成细胞在 AGE-BSA 孵育 72 小时后增殖能力下降。综上所述，这些发现表明，在 AGE-BSA 存在的情况下，角质形成细胞丧失了迁移和增殖能力。这些数据还表明，在糖尿病中慢性高血糖的情况下，AGE-BSA 对角质形成细胞迁移的影响可能是通过 MMP-9/TIMP-1、p-FAK 和α2β1 整合素介导的。
