NFAT5 Controls the Integrity of Epidermis

Area of Science:

• Dermatology
• Molecular Biology
• Cell Biology

Background:

• The skin's primary role is protection against dehydration and external challenges.
• Keratinocytes (KCs) are key epidermal cells involved in barrier function and osmolality regulation.
• NFAT5 is a transcription factor activated by osmotic stress, with a potential role in KCs.

Purpose of the Study:

• To investigate the role of NFAT5 in keratinocytes and its impact on skin physiology.
• To identify proteins and genes regulated by NFAT5 in epidermal cells.
• To understand NFAT5's contribution to skin development and adult epidermal integrity.

Main Methods:

• Culturing adult mouse keratinocytes.
• Ablation of NFAT5 in cultured KCs.
• Proteomic analysis of secreted proteins.
• Transcriptome analysis (RNA sequencing) of KCs.
• Immunohistochemical analysis of skin tissues.

Main Results:

• NFAT5 ablation in KCs enhanced secretion of matrix proteinases like Mmp3 and Klk7.
• Increased Mmp3 and Klk7 RNA levels were observed in Nfat5-deficient KCs.
• NFAT5 deficiency led to increased expression of Epidermal Differentiation Complex (EDC) genes.
• NFAT5 and Mmp3/Klk7 show inverse co-expression patterns in fetal, adult, and newborn epidermis.
• NFAT5 deficiency correlates with fragile adult epidermis.

Conclusions:

• NFAT5 acts as a suppressor of matrix protease expression in the epidermis.
• NFAT5-mediated regulation of matrix proteases is crucial for normal skin development and adult epidermal integrity.
• Dysregulation of NFAT5 contributes to skin fragility and developmental abnormalities.