SPINK7 is located on chromosome 5q32 and codes for a protein of the same name, the serine peptidase inhibitor Kazal type 7. SPINK7 has previously been described as a cancer-relevant gene in the oesophagus. However, it is also expressed in healthy human skin. In addition, SPINK7 is upregulated in inflammatory skin diseases such as psoriasis and eczema (Weber C et al. 2017).
SPINK7 has been shown to be part of the differentiation program of the human esophageal epithelium. The absence of SPINK7 in the epithelial cells of the oesophagus appears to lead to a dysfunction of the epithelial barrier in humans (Lyles J et al. 2019).SPINK7 (as well as SPINK5) is only expressed to a small extent in eosinophilic oesophagitis. Its depletion is of pathogenetic relevance for eosinophilic oesophagitis (Azouz NP et al.(2018). Apparently, the loss of cellular differentiation and the altered gene expression lead to an allergic immune reaction.
Furthermore, epithelial silencing of SPINK7 promotes the production of proinflammatory cytokines, including thymic stromal lymphopoietin(TSLP). Loss of SPINK7 increased the activity of urokinase plasminogen-type activator (uPA) (Azouz NP et al. 2018).