Apoptosis And Related Gene Expression In Minor Labial Salivary Gland Of Patients With Primary Sjogren's Syndrome

Objective To study the roles of apoptosis and expression of the related genes in the minor labial salivary glandular destruction of patients with primary Sjogren's syndrome (pSS). Methods Minor submucosal labial salivary gland (SG) biopsies were obtained from 30 patients with primary Sjogren's syndrome and 10 normal controls. Terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate marker nick end-labeling (TUNEL)and immunohistochemical staining was used to detect the apoptotic cells and the expression of Fas, Fasl and bcl-2. SPSS 11.5 statistics software was applied to analyze the data. Results The percentage of acinar epithelial (AE) and ductal epithelial (DE) apoptotic cells in labial salivary glands of patients with pSS was significantly higher than that in normal glands respectively, and pSS AEC and DEC showed increased expression of Fas/Fasl and decreased expression of Bcl-2 compared with that in normal glands. Among pSS AEC, DEC and infiltrating mononuclear cells (IMC), the percentage of apoptotic cells and that of cells expressing Fasl and Bcl-2 was observed significant difference, whereas the percentage of cells expressing Fas wasn't observed significant difference. There was significant positivecorrelation between the percentage of the apoptotic cells and the cells expressing Fas and Fasl in pSS AEC, DEC and IMC, respectively, and there was significant negative correlation between the percentage of the apoptotic cells and that of the cells expressing Bcl-2 in pSS DEC and IMC, but there wasn't correlation between the percentage of the apoptotic cells and that of the cells expressing Bcl-2 in pSS AEC. Conclusions The apoptotic cells increasing in the epithelial cells and descreasing in IMC of the labial salivary glands may be one of the mechanisms leading to the glandular destruction found in pSS; The epithelial cells themselves and IMC of the labial salivary glands may be all active participants in the process of apoptosis found in pSS AEC and DEC; The Fas/Fas Ligand ( FasL ) pathway of apoptosis may be an important pathway inducing glandular apoptosis found in pSS ; In pSS labial salivary glands, the expression of Fas and Fasl may promote the apoptosis, and the expression of Bcl-2 may inhibit apoptosis; The elevated expression of Bcl-2 in pSS IMC indicating that IMC seem to be able to escape apoptosis, resulting in foci of inflammating cells.