| Objectives:Sj?gren's syndrome(SS),also called sicca syndrome, is a chronic and inflammatory autoimmune disorder characterized by the progressive lymphocytic and plasma cell infiltration of salivary and lacrimal glands, which eventually results in xerostomia and xerophthalmia. SS can be classified as either primary or secondary based on the symptom with other connective tissue disorder or not. SS is a familiar disorder in the world, whose incidence is the second in the autoimmune disorder. In China, the incidence of SS is 0.29%~0.77%. The etiology of SS is unknown. But recent researches show that abnormalities in the metabolism of sex hormones and activities of some apoptotic factors could be responsible for the etiology and development of SS. In comparison with normal people, estrogen was increased and androgen was decreased in the salivary tissues and circulating sera of patients with SS. However, the reason why abnormalities in the metabolism of sex hormones were occurred in SS is unclear. In the process of conversion from androgen to estrogen, cytochrome P450 aromatase plays an important role. It can transform androgen to estrogen, andmodulate estrogenic and/or androgenic actions.Some researches have shown that the roles of apoptosis are important in destruction of salivary gland and lymphocytic hyperplasia of SS. Abnormal expressions of some gene products that can induce or inhibit apoptosis could be correlative with SS, in which, Fas and its ligand FasL were focused on. In some animal experiments, aromatase and sex hormones can induce the changes of some apoptotic factors.We adopted immunohistochemical method in the study to investigate the expression and immunolocation of aromatase and apoptotic factors Fas,Fas ligand(FasL)in salivary tissues of Sj?gren's syndrome (SS), in order to study the reason on abnormalities in the metabolism of sex hormones in SS,and evaluate the relation between SS and cell apoptosis, then to provide theoretical evidences for treating SS by aromatase inhibitor. Methods: Paraffin-embedded blocks of 23 salivary tissues with SS and 16 normal salivary tissues were selected and divided into experimental group (SS) and control group (normal), respectively. 5 sections with thickness of 4-5μm were cut from each block, one for HE staining, one for negative control, the others for immunohistochemical staining of Fas, FasL and aromatase, respectively. The immunohistochemical staining was operated as following: the paraffin sections were deparaffinized by normal method;placed them in methanol containing 5% H2O2 for 25 min to block endogenous peroxidase activity; put them into microwave oven to repair antigens for 15 min at 92-98℃, cooled at room temperature; the section were treated with normal goats serum for 30min at 37℃; after wiped the serum off, the sections were incubated with the primary antibodies for one night at 4℃; the sections were treated with biotinglated secondary antibodies for 25 min at 37℃; and with peroxidaze-conjugated streptavidin for 20 min at 37℃; stained with DAB and conterstained with hematoxylin, dehydrated in graded rthamal, cleared in xylene and finally mounted. Except for the normal goat serum-blocking step, the sections were washed with PBS for 3×5 min after each treatment. The positive control was positive breast carcinoma tissues expressing Fas, FasL and aromatase. As a negative control, the sections were treated with PBS instead of the primary antibodies. Specific staining was identified by the presence of yellow or brown reaction products in cytoplasm and/or membrane. A semiquantitative scoring system was used for aromatase as follows: no stain cell means negative (-); <5% cell positive means weak positive (+); 5%~25% means positive (++); >25% means strong positive (+++). And for Fas, FasL as follows: <25% means negative (-); 25%~50% means weak positive (+); 50%~75% means positive (++); >75% means strong positive (+++). Aromatase, Fas and FasL in salivary tissues from bothgroups were detected. And thei...
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