Objective. Sjögren's syndrome (SS), an autoimmune disease of exocrine glands, typically starts at the time of adrenopause. We undertook this study to test the hypothesis that SS is characterized by an insufficient androgen effect at the target tissue level.Methods. We searched for androgen response elements (AREs) in the cysteine-rich secretory protein 3 (crisp-3) gene. Dehydroepiandrosterone (DHEA) responsiveness was experimentally studied using quantitative reverse transcriptase-polymerase chain reaction and immunofluorescence staining of human submandibular gland-derived acinar cells and labial salivary gland explants with or without DHEA. Finally, glandular and salivary CRISP-3 in healthy controls and SS patients was analyzed using immunohistochemistry, in situ hybridization, and enzyme-linked immunosorbent assay. Serum DHEA sulfate (DHEAS) and salivary DHEA levels were measured using a radioimmunometric method.Results. Literature analysis and a search for AREs in gene banks suggested androgen dependency of human CRISP-3, and this was verified by studies of human submandibular gland acinar cells cultured with or without DHEA, in which DHEA increased CRISP-3 messenger RNA (mRNA) levels (P ؍ 0.018). This finding was confirmed by the results of DHEA stimulation of labial salivary gland explants. Glandular CRISP-3 mRNA and protein labeling was weak and diffuse, coupled with low secretion in saliva (mean ؎ SEM 21.1 ؎ 2.7 g CRISP-3/15 minutes in SS patients versus 97.6 ؎ 12.0 g CRISP-3/15 minutes in healthy controls; P < 0.0001). Compared with healthy controls, SS patients had low serum levels of DHEAS (P ؍ 0.008) and also low salivary levels of DHEA (mean ؎ SEM 224 ؎ 33 pmoles versus 419 ؎ 98 pmoles; P ؍ 0.005).Conclusion. CRISP-3 pathology was seen in acini remote from lymphocyte foci and is apparently not secondary to local inflammation, but may represent some systemic effect in SS. Indeed, androgen deprivation in the salivary glands of SS patients is evidenced both by low salivary levels of DHEA and by low levels of DHEA-regulated CRISP-3. This may explain some of the characteristic features of SS.
DHEA and DHT upregulate CRISP-3, which is reportedly low in SS. The effect of DHEA on CRISP-3 is indirect and is inhibited by dutasteride, showing that there is intracrine processing of DHEA in salivary glands. In healthy glands, but not in SS, DHEA is effectively taken up and converted to DHT. Sex steroid concentrations in saliva in part reflect glandular uptake of DHEA-sulfate and local intracrine DHEA metabolism, which seem to be defective in SS. Our study demonstrates a prominent androgen deficiency and a defect in intracrine production of active androgens in SS salivary glands, also suggesting that salivary DHT cannot be maintained at a normal level in this female-dominant autoimmune exocrinopathy.
Sjögren’s syndrome (SS) patients have low salivary dehydroepiandrosterone (DHEA) and androgen biomarker levels, but high salivary oestrogen levels. The hypothesis was that the healthy glands contain DHEA-sulphate processing intracrine machinery; the local androgen/oestrogen imbalance suggests that this is disarranged in SS. Indirect immunofluorescence and quantitative real-time PCR (qRT-PCR) of steroid sulphatase, sulfotransferase, 3β- and 17β-hydroxysteroid dehydrogenases (3β- and 17β-HSD), 5α-reductase and aromatase were performed for labial salivary glands of healthy controls and persons with SS. In control acini steroid sulphatase and sulfotransferase immunoreactivities were located in the basolateral cell parts. 3β- and 17β-HSD formed strong, interrupted bands along the basal cell parts. 5α-reductase was mainly located in acinar cell nuclei and aromatase in the apical cell membrane. All enzymes were more widespread in ducts. In SS, steroid sulphatase was weak and deranged, 3β- and 17β-HSD had lost their strict basal acinar cell localization and 5α-reductase was mainly found in the cytoplasm of the acinar cells, whereas aromatase showed similar staining in SS and controls. qRT-PCR of labial salivary glands disclosed all corresponding enzyme mRNAs with the levels of 3β-HSD in SS being the lowest. Healthy tubuloacinar epithelial cells contain complete intracrine machineries for DHEA(-sulphate) pro-hormone processing. These enzymes have in healthy acini an organized architecture, which corresponds with DHEA uptake from the circulation, nuclear site of production of the active dihydrotestosterone (DHT) end product and production of oestrogens into saliva for export to ductal and oral epithelial cells. SS is characterized by low 3β-HSD levels, which together with impaired subcellular compartmentalization of HSDs and 5α-reductase may explain the low local DHT and androgen biomarker levels in SS.
Objective. To assess the laminins in basement membrane of the labial salivary glands of patients with Sjögren's syndrome (SS) and healthy controls.Methods. Labeling of laminin ␣1-␣5, 1, 2, ␥1, and ␥2 chains was performed using immunohistochemistry with chain-specific monoclonal antibodies and pattern recognition analysis of the labeled specimens.Results. Laminin ␣1, ␣2, and ␣4 chains were detected exclusively in the acinar basement membranes, whereas laminin ␣3, ␣5, 1, ␥1, and ␥2 chains were also detected in ductal basement membranes. Laminin 2 chain was not found. In patients with SS, laminin ␣1 and ␣2 chains were weakly labeled, but laminin ␣4 labeling was also intense in areas not infiltrated by lymphocytes. Pattern recognition analysis suggested that laminin ␣1, ␣2, and ␣4 chains were associated with acinar cells, myoepithelial cells, and tissue damage/ repair, respectively.Conclusion. All salivary gland basement membranes signal through laminin 5, laminin 6, and laminin 10 trimers, but acinar basement membranes also signal through laminin 1, laminin 2, and laminin 8 trimers. Laminin ␣1 chain/laminin 1 may play a central role in the maintenance of acinar cells in healthy glands. This possibility was supported by the finding of variable expression of laminin ␣1 chain/laminin 1 in acinar basement membrane and its weak expression in SS with acinar cell atrophy. The impairment of myoepithelial laminin ␣2 chain/laminin 2 in patients with SS indicates a double defect in the acinar compartment and pathologic extracellular matrix-to-cell signaling, which may contribute to structural deterioration and functional abnormality of the exocrine glands.
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