Katsiougiannis Stergios, Kapsogeorgou Efstathia K, Manoussakis Menelaos N, Skopouli Fotini N
University of Athens, Athens, Greece.
Arthritis Rheum. 2006 Jul;54(7):2295-9. doi: 10.1002/art.21944.
Adiponectin is an adipocytokine that displays insulin-sensitizing and immunoregulatory properties. Adipocyte development in association with fibrosis is frequently detected in primary Sjögren's syndrome lesions, connoting a healing process. The aim of this study was to examine the expression of adiponectin in minor salivary gland biopsy specimens obtained from patients with primary SS and controls.
The expression of adiponectin in minor salivary gland biopsy specimens and in long-term-cultured non-neoplastic salivary gland epithelial cell (SGEC) lines obtained from patients with primary SS and control subjects was examined, using immunohistochemistry and immunoblotting, respectively. The expression of adiponectin, adiponectin receptor 1 (AdipoR1), and AdipoR2 messenger RNA (mRNA) by SGECs was investigated by reverse transcription-polymerase chain reaction.
Immunohistochemical analysis for adiponectin revealed positive staining of adipocytes from primary SS lesions as well as ductal epithelial cells from both patients with primary SS and controls. All of the SGEC lines tested were shown to express adiponectin, AdipoR1, and AdipoR2 mRNA, whereas adiponectin protein expression was detected by immunoblotting in SGECs from patients with primary SS but not in those from controls. The analysis of concentrated culture supernatants also revealed increased adiponectin expression by SGECs from patients with SS compared with controls.
Our findings provide novel evidence that adiponectin is produced by SGECs. The high constitutive expression of adiponectin by SGECs from patients with primary SS is likely attributable to aberrant activation of these cells. Although the significance of adiponectin expression remains unknown, it is possible that adiponectin functions in an autocrine manner, as suggested by concurrent expression of the relevant receptors.
脂联素是一种具有胰岛素增敏和免疫调节特性的脂肪细胞因子。在原发性干燥综合征病变中经常检测到与纤维化相关的脂肪细胞发育，这意味着一个愈合过程。本研究的目的是检测原发性干燥综合征患者和对照组小唾液腺活检标本中脂联素的表达。
分别采用免疫组织化学和免疫印迹法检测原发性干燥综合征患者和对照组小唾液腺活检标本以及长期培养的非肿瘤性唾液腺上皮细胞（SGEC）系中脂联素的表达。通过逆转录-聚合酶链反应研究SGECs中脂联素、脂联素受体1（AdipoR1）和AdipoR2信使核糖核酸（mRNA）的表达。
脂联素的免疫组织化学分析显示，原发性干燥综合征病变中的脂肪细胞以及原发性干燥综合征患者和对照组的导管上皮细胞均呈阳性染色。所有测试的SGEC系均显示表达脂联素、AdipoR1和AdipoR2 mRNA，而免疫印迹法在原发性干燥综合征患者的SGECs中检测到脂联素蛋白表达，而对照组中未检测到。对浓缩培养上清液的分析还显示，与对照组相比，干燥综合征患者的SGECs中脂联素表达增加。
我们的研究结果提供了新的证据，表明脂联素由SGECs产生。原发性干燥综合征患者的SGECs中脂联素的高组成性表达可能归因于这些细胞的异常激活。尽管脂联素表达的意义尚不清楚，但正如相关受体的同时表达所表明的那样，脂联素可能以自分泌方式发挥作用。
