The Roles of Smad2 and Smad3 in Mouse Skin Development

The study investigated the roles of Smad2 and Smad3 in mouse skin development and tumorigenesis by deleting these proteins in murine skin to assess their impact on TGF-β signaling. Smad2 and Smad3 deletions resulted in severe skin defects, including abnormal skin texture, hair loss, and early death, which were more pronounced than those observed in Smad4 mutants. Histological analysis showed hyperkeratosis, abnormal hair follicle positioning, increased apoptosis, and cell proliferation abnormalities. Additionally, Smad3 heterozygous mice with Smad2 knocked out in fibroblasts developed skin and oral cancerous lesions, aligning with findings in Smad4 mutants. The study concluded that Smad2 and Smad3 are crucial for normal skin development and that their disruption leads to significant skin abnormalities and tumorigenesis, highlighting the importance of TGF-β signaling in these processes.