Apoptosis and related gene expression in lacrimal gland of cases with Sjögren's syndrome

Objective: To assess the roles of apoptosis and expression of the related genes in lacrimal glandular destruction of patients with Sjögren's syndrome (SS).

Methods: Small pieces of palpebral lobes of lacrimal glands were obtained from 12 patients (10 with primary Sjögren's syndrome, 2 with secondary Sjögren's syndrome) and 7 normal controls. They had been investigated by the in situ end labeling and immunohistochemical staining to detect the apoptotic cells and the expression of Fas, FasL, bcl-2 and Bax.

Results: The number of epithelial apoptotic cells in lacrimal glands of patients with SS was significantly higher than that in normal glands, and SS epithelial cells showed increased expression of Fas, FasL and Bax. There was significant positive correlation between the number of the apoptotic cells and that of the cells expressing Fas, FasL and Bax, respectively, and there was significant negative correlation between the number of the apoptotic cells and that of the cells expressing bcl-2.

Conclusions: The apoptosis of the epithelial cells in the lacrimal gland may be one of the mechanisms leading to the glandular destruction found in SS. In SS lacrimal glands, the expression of Fas, FasL and Bax may promote apoptosis, and the expression of bcl-2 may inhibit apoptosis.