Chaperones in the parotid gland: Localization of heat shock proteins in human adult salivary glands

Heat shock proteins (HSPs) are expressed or increased in response to variou s biological stresses. Moreover, these 'stress proteins' seem to be express ed by some cells living in physiological conditions. From then on, they cou ld play an important physiological role in normal cell functioning. The bes t-known physiological role of these HSP proteins is to act as 'molecular ch aperones'. In this context, we have investigated the immunohistochemical ex pression of HSP27, HSP70, HSP90 and HSP110 in 10 human adult salivary gland s. To highlight the presence of RNAm encoding HSP70, an in situ hybridizati on was performed. In our material, HSP27 was strongly expressed in the cyto plasm of striated duct cells and in some myoepithelial cells. The same loca lization was less stained for HSP70 and HSP90. The immunocytochemical react ion was weak or negative for HSP110 in striated ducts. HSPs were not expres sed in acinic cells. In situ hybridization gave a positive signal in striat ed ducts with ducts and myoepithelial cells expressed HSP27, HSP70 and HSP9 0. These HSPs probably act in part as molecular chaperones for protein synt hesis, transport and for several interactions between HSPs and different pr oteins. Copyright (C) 2000 S. Karger AG. Basel.