The Bcl-2/Bax ratio of lymphocytes from human systemic lupus erythematosus patients

Antiapoptotic proteins. The bcl-2 and inhibitor of apoptosis protein families

The balance between pro- and antiapoptotic proteins can determine cellular fate. In this regard, the Bcl-2 and IAP protein families have evolved as highly conserved regulators of cell death. A further testament to their critical roles in maintaining balance between cell life and death may be the increasing implication of Bcl-2 and TAP proteins in the pathologies of human diseases. Although much has been learned about these families of proteins, future studies of the Bcl-2 and IAP families are sure to hold more exciting discoveries and will continue to reveal new strategies for combating human diseases.

Bcl-2 family expression in salivary glands from patients with primary Sjögren's syndrome: involvement of Bax in salivary gland destruction

To investigate the molecular mechanism of glandular parenchyma destruction in Sjögren's syndrome (SS), Bcl-2, Bax, Bcl-X, and Bak expression were studied. SS (n = 18) and control salivary glands (n = 6) were examined by immunohistochemistry. Apoptosis was assessed by in situ DNA nick end labeling. Infiltrating mononuclear cells in the SS salivary gland showed elevated Bcl-2. These mononuclear cells expressed increased Bax but did not undergo apoptosis. Both SS and control salivary gland ductal epithelial cells expressed Bcl-2, Bax, and Bcl-X. SS, but not normal, salivary gland acinar cells expressed Bax and underwent apoptosis. These results suggest that elevated Bax expression in SS salivary gland acinar cells may play an important role in the apoptotic pathway. In contrast, Bcl-2 expression in SS infiltrating mononuclear cells and ductal cells may contribute to their survival.