BCL-2 FAMILY EXPRESSION IN SALIVARY-GLANDS FROM PATIENTS WITH PRIMARYSJOGRENS-SYNDROME - INVOLVEMENT OF BAX IN SALIVARY-GLAND DESTRUCTION

To investigate the molecular mechanism of glandular parenchyma destruc tion in Sjogren's syndrome (SS), Bcl-2, Bar, Ecl-X, and Bak expression were studied. SS (n = 18) and control salivary glands (n = 6) were ex amined by immunohistochemistry. Apoptosis was assessed by in situ DNA nick end labeling. Infiltrating mononuclear cells in the SS salivary g land showed elevated Bcl-2. These mononuclear cells expressed increase d Bar but did not undergo apoptosis. Both SS and control salivary glan d ductal epithelial cells expressed Bcl-2, Bar, and Bcl-X. SS, but not nor mal, salivary gland acinar cells expressed Bar and underwent apop tosis. These results suggest that elevated Bar expression in SS saliva ry gland acinar cells may play an important role in the apoptotic path way. In contrast, Bcl-2 expression in SS infiltrating mononuclear cell s and ductal cells may contribute to their survival. (C) 1998 Academic Press.