Goicovich Eduardo, Molina Claudio, Pérez Paola, Aguilera Sergio, Fernández Juan, Olea Nancy, Alliende Cecilia, Leyton Cecilia, Romo Rafael, Leyton Lisette, González María-Julieta
University of Chile, Santiago, Chile.
Arthritis Rheum. 2003 Sep;48(9):2573-84. doi: 10.1002/art.11178.
To determine the effect of matrix metalloproteinase (MMP) activity from the labial salivary glands (LSGs) of Sjögren's syndrome (SS) patients on proteins of the extracellular matrix (ECM) that form the basal lamina and stroma, and to compare this effect with the structural integrity of acini and ducts as well as the functionality of the LSGs.
Gelatinase activity was determined by zymography. The digestion pattern of extracellular matrix (ECM) macromolecules was detected by gel electrophoresis and quantified by densitometry. The structural integrity of acini and ducts was evaluated by light and electron microscopy. Secretory function was evaluated by measuring unstimulated salivary flow and by scintigraphy.
LSG extracts showed increased levels of proteolytic activity toward purified proteins of the basal lamina (laminin and type IV collagen) and stroma (types I and III collagen and fibronectin). Enhanced degradation was most evident for fibronectin, laminin, and type IV collagen. Analysis of the ultrastructure of the acinar and ductal basal lamina revealed abnormalities ranging from disorganization to disappearance of this ECM structure. These changes were paralleled by an important loss of microvilli on the apical surface, as well as decreased unstimulated salivary flow. Interestingly, the results were similar in LSGs from all SS patients, regardless of the proximity of infiltrating mononuclear cell foci.
Our observation that the proteolytic action of MMPs toward ECM macromolecules is increased in SS patients provides a rationale for understanding the dramatic changes in the structural organization observed in the basal lamina and apical surface of acini in these patients. The results provide new evidence that acinar and ductal cells from the LSGs of SS patients display a molecular potential, with increased capacity to markedly disorganize their ECM environment and, thus, damage their architecture and functionality.
确定干燥综合征（SS）患者唇唾液腺（LSG）中基质金属蛋白酶（MMP）活性对构成基底膜和基质的细胞外基质（ECM）蛋白的影响，并将这种影响与腺泡和导管的结构完整性以及LSG的功能进行比较。
通过酶谱法测定明胶酶活性。通过凝胶电泳检测细胞外基质（ECM）大分子的消化模式，并通过光密度法进行定量。通过光学显微镜和电子显微镜评估腺泡和导管的结构完整性。通过测量非刺激性唾液流量和闪烁显像评估分泌功能。
LSG提取物对基底膜（层粘连蛋白和IV型胶原）和基质（I型和III型胶原以及纤连蛋白）的纯化蛋白显示出蛋白水解活性水平升高。纤连蛋白、层粘连蛋白和IV型胶原的降解增强最为明显。对腺泡和导管基底膜超微结构的分析显示，这种ECM结构存在从紊乱到消失的异常情况。这些变化伴随着顶端表面微绒毛的大量丧失以及非刺激性唾液流量的减少。有趣的是，所有SS患者的LSG结果相似，无论浸润单核细胞灶的接近程度如何。
我们观察到SS患者中MMP对ECM大分子的蛋白水解作用增强，这为理解这些患者腺泡基底膜和顶端表面观察到的结构组织的显著变化提供了理论依据。结果提供了新的证据，表明SS患者LSG的腺泡和导管细胞具有分子潜能，具有明显破坏其ECM环境的能力增强，从而损害其结构和功能。
