Objective: To explore the impact of advanced glycosylation end products (AGE)-modified human serum albumin (AGE-HSA) on keratinocyte migration and the mechanism thereof.
Methods: AGE-HSA was prepared in vitro. Epidermal keratinocytes from Sprague-Dawley rats' back were cultured and treated with AGE-HSA of the terminal concentrations of 0, 30, 60, 90, 120, and 150 microg/ml for 1, 3, 5, and 7 days respectively. MTT method was used to detect the keratinocyte adhesion rate, expressed by absorbance. Keratinocyte migration ability was assessed by scratch wound healing assay and Transwell assay. Expression of integrin alpha3 was determined by flow cytometry. Scanning electron and inverted microscopes were used to observe the pseudopodium and microfilament of the keratinocytes. Immunofluorescence staining was used to detect the form of F-actin in the cells.
Results: The adhesion rates of the keratinocyte cultured with AGE-HSA for 12 and 24 hours were (0.112 +/- 0.022) and (0.173 +/- 0.012) respectively, both significantly lower than those of the control group [(0.122 +/- 0.004) and (0.267 +/- 0.024) respectively, both P < 0.05)]. Scratch wound healing assay showed that the amount of migrating cells in the AGE-HSA group was (7 +/- 4)/HP, significantly less than that of the control group [(61 +/- 11)/HP, P < 0.05)], and Transwell assay showed that the amount of migrating cells in the AGE-HSA group was (72 +/- 18)/HP, significantly less than that of the control group [(288 +/- 52)/HP, P < 0.05]. The expression rate of keratinocyte integrin alpha3 in the AGE-HSA group was (3.2 +/- 1.2)%, significantly lower than that in the control group [(36.6 +/- 11.2)%, P < 0.05]. The spreading of cell body, and the formation of pseudopodium and microfilament of the AGE-HSA group were all depressed in comparison with the control group.
Conclusion: Keratinocyte migration is inhibited by AGE accumulation in high glucose condition. The mechanism may be the abnormality in the integrin inside-out signaling pathway and AGE-RAGE signaling pathway.