Claudin Tight Junction: What's Your Function? The Role of Claudin 6 in Epidermal and Hair Follicle Differentiation

The study investigated the role of Claudin 6 in skin by overexpressing it in mice, revealing that homozygous animals had severe epidermal differentiation issues leading to neonatal death, while heterozygotes survived with milder defects and abnormal hair characterized by fuzziness and a matte texture. The hair cycle was disrupted, with a shortened anagen phase and prolonged catagen-telogen transition. Expression of several epidermal differentiation markers was altered, and hair keratin expression was downregulated in hair follicles. These findings suggested that Claudin 6 played a crucial role in signaling pathways affecting cell physiology and differentiation in the epidermis and hair follicles.