Expression of involucrin in normal, hyperproliferative and neoplastic mouse keratinocytes

The study focused on the expression of involucrin, a protein precursor of the epidermal cornified envelope, in normal, hyperproliferative, and neoplastic mouse keratinocytes. Researchers produced recombinant mouse involucrin and developed rabbit antisera for effective immunohistochemistry and Western blotting. In normal mouse epidermis, involucrin expression began in the upper spinous layers and inner root sheath of the hair follicle, and was also found in differentiating epithelial cells of the tongue, oesophagus, and bladder. In hyperproliferative epidermis, such as healing wounds, involucrin was expressed in most suprabasal layers, and its expression in epidermal papillomas and carcinomas correlated with histological differentiation. The study highlighted inter-strain variation in involucrin's electrophoretic mobility due to differences in tandem repeats. The development of new antibodies was expected to make involucrin a widely used marker for keratinocyte differentiation in mice, similar to its use in humans.