Effect of advanced glycation endproducts on gene expression profiles of human dermal fibroblasts

The Maillard reaction and its end products, AGE-s (Advanced Glycation End products) are rightly considered as one of the important mechanisms of post-translational tissue modifications with aging. We studied the effect of two AGE-products prepared by the glycation of lysozyme and of BSA, on the expression profile of a large number of genes potentially involved in the above mentioned effects of AGE-s. The two AGE-products were added to human skin fibroblasts and gene expression profiles investigated using microarrays. Among the large number of genes monitored the expression of 16 genes was modified by each AGE-preparations, half of them only by both of them. Out of these 16 genes, 12 were more strongly affected, again not all the same for both preparations. Both of them upregulated MMP and serpin-expression and downregulated some of the collagen-chain coding genes, as well as the cadherin- and fibronectin genes. The BSA-AGE preparation downregulated 10 of the 12 genes strongly affected, only the serpin-1 and MMP-9 genes were upregulated. The lysozyme-AGE preparation upregulated selectively the genes coding for acid phosphatase (ACP), integrin chain alpha5 (ITGA5) and thrombospondin (THBS) which were unaffected by the BSA-AGE preparation. It was shown previously that the lysozyme-AGE strongly increased the rate of proliferation and also cell death, much more than the BSA-AGE preparation. These differences between these two AGE-preparations tested suggest the possibility of different receptor-mediated transmission pathways activated by these two preparations. Most of the gene-expression modifications are in agreement with biological effects of Maillard products, especially interference with normal tissue structure and increased tissue destruction.