Mechanism of SPRY1 methylation regulating natural aging of skin epidermal cells.

Objective: To investigate the relationship among natural aging of epidermal cells, epigenetics, and SPRY1 methylation mechanism. Methods: Immunohistochemistry, reverse transcription‐PCR (RT‐PCR), and Western blot were used to detect the expression of DNA methyltransferase 1 (DNMT1) and Sprouty1 (SPRY1) in skin epithelial cells from different age groups. An aging model of HaCaT cells was constructed. In HaCaT cells and their aging groups, DNMT1 and SPRY1 expression were detected by RT‐PCR and WB. SPRY1 methylation status in epidermal cells from different age groups and HaCaT cells were detected by Methylation‐Specific PCR (MS‐PCR). Results: The expression of DNMT1 and SPRY1 in skin epithelial cells from natural aging groups decreased with age; there was no significant difference in the expression of DNMT1 in HaCaT cells and the different age groups. The expression of SPRY1 in HaCaT cells was lower than it was in the aging groups. The methylation status of SPRY1 gradually decreased as the age of skin epidermal cells increased, while the methylation status of SPRY1 was not different between HaCaT cells and the aging group. Conclusion: DNMT1 is involved in the regulation of natural aging of skin epidermal cells but has a nominal role in our induced aging model. SPRY1 is involved in natural aging and induced aging of skin epidermal cells. The regulation of SPRY1 methylation is involved in the natural senescence of skin epidermal cells, while the induced aging of epidermal cells is nominally involved in the mechanism of SPRY1 methylation. [ABSTRACT FROM AUTHOR]