Sonic Hedgehog signalling in the regulation of barrier tissue homeostasis and inflammation.

Epithelial barrier tissues such as the skin and airway form an essential interface between the mammalian host and its external environment. These physical barriers are crucial to prevent damage and disease from environmental insults and allergens. Failure to maintain barrier function against such risks can lead to severe inflammatory disorders, including atopic dermatitis and asthma. Here, we discuss the role of the morphogen Sonic Hedgehog in postnatal skin and lung and the impact of Shh signalling on repair, inflammation, and atopic disease in these tissues.