Ivanovski S, Komaki M, Bartold P M, Narayanan A S
Department of Dentistry, University of Queensland, Brisbane, Australia.
J Periodontal Res. 1999 Apr;34(3):154-9. doi: 10.1111/j.1600-0765.1999.tb02236.x.
A specific collagenous cementum attachment protein (CAP) has been identified in human cementum which promotes selective cell migration towards and attachment of various periodontal derived cell populations to root surfaces in vitro. The CAP is known to support attachment of periodontal-derived cell via an RGD motif, which suggests an integrin-mediated mode of attachment. The purpose of the present study was to ascertain which integrin(s) are involved in the attachment of periodontal-derived cells to CAP. The integrins examined comprised subunits of the major receptors for fibronectin (alpha 5) and collagen (alpha 2, alpha 3), as well as the common beta 1 subunit which is present in many extracellular matrix receptors. The wells of 48-well non-tissue culture treated plates were coated with CAP (2 micrograms/ml). For negative and positive controls the wells were coated with bovine serum albumin and fibronectin (5 micrograms/ml), respectively. Human gingival fibroblasts and periodontal ligament fibroblasts were labeled with [3H]-proline, incubated with anti-integrin antibodies and added to the precoated wells. Attachment was assessed after incubating the cells for 1 h at 37 degrees C in the presence of the antibodies. Antibodies to alpha 5 and beta 1 inhibited the attachment of both human gingival fibroblasts and human periodontal ligament fibroblasts to CAP, while anti alpha 2 and alpha 3 antibodies did not affect the attachment. The binding of the fibroblasts to fibronectin was also inhibited by anti-alpha 5 and beta 1 antibodies, both of which are components of the "classical" fibronectin receptor and remained unaffected by the addition of anti-alpha 2 and alpha 3 antibodies. Proteins migrating in SDS-polyacrylamide gels in positions similar to the alpha 5 and beta 1 integrin subunits were present in fractions bound to a column of CAP coupled to Sepharose CL-4B. These results indicate that the attachment to CAP of the periodontal-derived cells, human gingival fibroblasts and human periodontal ligament fibroblasts, is mediated primarily via the integrin alpha 5 beta 1.
在人牙骨质中已鉴定出一种特定的胶原性牙骨质附着蛋白（CAP），它能在体外促进各种牙周来源的细胞群体向根面选择性迁移并附着于根面。已知CAP通过RGD基序支持牙周来源细胞的附着，这提示了一种整合素介导的附着模式。本研究的目的是确定哪些整合素参与牙周来源细胞与CAP的附着。所检测的整合素包括纤连蛋白主要受体的亚基（α5）和胶原蛋白的亚基（α2、α3），以及存在于许多细胞外基质受体中的共同β1亚基。将48孔未进行组织培养处理的平板孔用CAP（2微克/毫升）包被。阴性和阳性对照孔分别用牛血清白蛋白和纤连蛋白（5微克/毫升）包被。用人牙龈成纤维细胞和牙周膜成纤维细胞用[3H]-脯氨酸标记，与抗整合素抗体一起孵育，然后加入预先包被的孔中。在37℃、有抗体存在的条件下将细胞孵育1小时后评估附着情况。针对α5和β1的抗体抑制了人牙龈成纤维细胞和人牙周膜成纤维细胞与CAP的附着，而抗α2和α3抗体不影响附着。抗α5和β1抗体也抑制了成纤维细胞与纤连蛋白的结合，这两种抗体都是“经典”纤连蛋白受体的组成部分，并且添加抗α2和α3抗体后其不受影响。在与偶联到琼脂糖CL-4B的CAP柱结合的组分中存在迁移到SDS-聚丙烯酰胺凝胶中与α5和β1整合素亚基位置相似的蛋白质。这些结果表明，牙周来源细胞、人牙龈成纤维细胞和人牙周膜成纤维细胞与CAP的附着主要是通过整合素α5β1介导的。
