FP17 ELF5 can regulate normal skin development and homeostasis by regulating cytokeratins 1 and 15
Maryam Ammani Lawal, Mohammed AhmedAbstract
Introduction and aims
Skin development is regulated by complex programmes of gene activation and silencing of gene expression to maintain normal skin development and homeostasis. ELF5 is a member of the ETS family of transcription factors and has been shown to be crucial for regulating cellular proliferation and differentiation process of stem/progenitor cells in epithelial tissues, such as the mammary gland. In mouse skin, we have shown that ELF5 is essential for skin development and stem/progenitor maintenance. However, ELF5 role in human skin development and homeostasis is unknown. The aim was to evaluate ELF5 impact on keratinocyte proliferation, differentiation and cell migration after overexpressing and/or knockdown of ELF5 expression in primary keratinocytes using lentiviral.
Methods
Expression of ELF5 was determined in human tissue by immunohistochemistry. Antibiotic-selected human primary keratinocytes (using control, ELF5 knockdown and ELF5 overexpression lentiviruses) were assessed for expressional and functional impact after gain or loss of ELF5 using reverse transcriptase quantitative polymerase chain reaction, Western blot analysis and flow cytometry. RNA sequencing along with ingenuity pathway analysis reveals differentially expressed genes.
Results
Endogenous expression of ELF5 was observed predominantly in basal (stem/progenitor cells) and suprabasal (differentiated) layers of the human epidermis suggesting a potential conserved role of ELF5 in maintaining healthy skin. Loss of ELF5, leads to decreased ability of cells to differentiate, and increase ability to proliferate and migrate, in vitro. Further analysis using RNA sequencing analysis (ingenuity pathway analysis) has revealed cytokeratin 1 and cytokeratin 15 genes, which play an important role in regulating keratinocyte differentiation, cell migration and proliferation potentially via ELF5 direct regulation.
Conclusions
Our data demonstrate an important understanding of ELF5 as a crucial regulator and maintainer of stem/progenitor cell functions during normal tissue homeostasis and regeneration and will provide better understanding of the novel transcriptional regulator in skin in many areas of research, including stem cell, cancer biology, regenerative medicine and ageing.