Evaluation of Hsp70 and Apoptotic Markers in Canine Cutaneous Lupus Erythematosus

Heat shock proteins 70 (HSP 70) are molecular chaperonins ubiquitously expressed in both prokaryotes and eukaryotes and are involved in the modulation and exacerbation of the immune response. The present study aimed to assess the immunohistochemical expression of HSP70 and apoptosis markers, such as TUNEL and Caspase-3, in 17 cases of cutaneous lupus erythematosus (CLE) in dogs to determine whether HSP70 expression correlates with cell apoptosis and to highlight possible involvement of HSP70 in the pathogenesis of CLE. The results revealed positive HSP70 expression in epidermal and inflammatory cells across all cases, with a significant correlation between HSP70 expression score and TUNEL-positive cells but not with Caspase-3-positive cells. This correlation could indicate a possible role for HSP70 in cell death via a caspase-independent apoptotic mechanism or other programmed cell death mechanisms, such as pyroptosis or necroptosis. The precise mechanisms by which HSP70 acts in this specific pathological context remain incompletely understood, but the results of this study provide important information for future investigations into autoimmune skin disease in dogs.