Expression of the 8 kDa heat shock protein (Ubiquitin) in psoriasis

The 8kDa protein (ubiquitin) is a member of the small heat shock protein (hsb) family. Ubiquitin may additionally be involved in the pathogenesis of various diseases. Intracellular accumulation of ubiquitin has been detected in patients with neurodegenerative disease, brain ischemia, cancer, rheumatoid arthritis and haemodialysis. Sixteen biopsy samples from patients with psoriasis who were treated by PUVA and the same samples from these patients before PUVA treatment were investigated by immunohistochemistry on formalin-fixed paraffin- embedded tissue sections, using anti-ubiquitin antibody. In psoriatic epidermis, ubiquitin was mostly expressed in basal layers with a cytoplasmic staining pattern. Various cells of the dermis layer with psoriasis were stained with anti-ubiquitin antibody. Staining was again confined to the cytoplasmic region and lesions with or without PUVA treatment did not exhibit a different staining pattern. It did, however, seem to have higher staining insity in PUVA-treated psoriatic lesions than untreated ones. We conclude that ubiquitin might be regarded as a useful marker of cell injury during the stressful conditions of tissue and as an indication of cell vitality and viability.