THE CHAPERONE SYSTEM IN SALIVARY GLAND DEVELOPMENT

The chaperone system (CS) canonical function is to maintain protein homeostasis. Proper folding of nascent peptides is crucial in developing tissue. The chief components of the CS are 95th National Congress of the Italian Society for Experimental Biology | Trieste, Italy, 12-15 April 2023Non-commercial use only the molecular chaperones, which play key roles in development as indicated by their presence in embryonic tissue as early as at two-cell stage. However, scarce information on the CS in developing tissues is available, especially at advanced stages of embryogenesis and its role is not fully understood. In our previous study, we reported the presence of molecular chaperones in the ducts and acini of human adult salivary glands. Here, we extend our work and report the distribution pattern of the molecular chaperones Hsp10, Hsp27, Hsp60, and Hsp90 in adult mice submandibular glands (SMG) and in human and mice embryos at late stages of development. We also report tissue levels and expression of these molecular chaperones determined by means of immunohistochemistry, Western blot, and RT-PCR. The four molecular chaperones were present in salivary gland tissue with Hsp90 levels being the highest at both stages, embryonic and adult. The data indicate that the CS is active throughout the ontogeny of salivary glands, with time-course changes in levels and distribution that reflect a dynamic functional involvement specific for each developmental step. The implications of these findings for understanding the pathology of salivary glands with roots in abnormal development are worth exploring, and the data presented here should serve as a basis for such studies and, consequently, boost the invention of novel diagnostic and treatment tools.