Narani Nazanin, Owen Gethin Rhys, Häkkinen Lari, Putnins Edward, Larjava Hannu
Faculty of Dentistry, Department of Oral, Biological and Medical Sciences, Laboratory of Periodontal Biology, University of British Columbia, Vancouver, BC, Canada.
Eur J Oral Sci. 2007 Aug;115(4):288-95. doi: 10.1111/j.1600-0722.2007.00467.x.
Enamel matrix proteins (EMP) induce periodontal regeneration and accelerate dermal wound healing, but the cellular mechanisms of these processes are unclear. We investigated the binding of EMP to the wound matrix proteins fibronectin, laminin-1, collagen type I, and collagen type IV and analyzed the interaction of epithelial cells and periodontal ligament fibroblasts (PDLF) with EMP and composite matrices of EMP + fibronectin or EMP + collagen. The adhesion of PDLF to EMP was concentration- and integrin-dependent and did not require de novo protein synthesis. EMP supported PDLF migration. In contrast, keratinocytes did not adhere to EMP if their protein synthesis was blocked. EMP showed concentration-dependent binding of fibronectin, peaking at 100 microg ml(-1) (before the precipitation point) of EMP. Type I collagen binding to EMP peaked at a low (1 microg ml(-1)) and narrow concentration range. Neither laminin-1 nor type IV collagen bound to EMP. Collagen and fibronectin, bound to EMP, showed significantly reduced (> 50%) binding of both epithelial cells and PDLF compared with the equivalent concentration of these proteins alone. PDLF, but not epithelial cell, adhesion was rescued by increasing the EMP concentration. These findings show that EMP binds to wound extracellular matrix proteins and regulates their adhesive properties. Such interactions may favor fibroblast adhesion over epithelial cells, potentially promoting connective tissue regeneration.
釉基质蛋白（EMP）可诱导牙周组织再生并加速皮肤伤口愈合，但这些过程的细胞机制尚不清楚。我们研究了EMP与伤口基质蛋白纤连蛋白、层粘连蛋白-1、I型胶原蛋白和IV型胶原蛋白的结合情况，并分析了上皮细胞和牙周膜成纤维细胞（PDLF）与EMP以及EMP + 纤连蛋白或EMP + 胶原蛋白复合基质之间的相互作用。PDLF对EMP的黏附具有浓度依赖性和整合素依赖性，且不需要从头合成蛋白质。EMP支持PDLF迁移。相反，如果角质形成细胞的蛋白质合成被阻断，它们就不会黏附于EMP。EMP对纤连蛋白的结合呈浓度依赖性，在EMP浓度为100 μg ml⁻¹（在沉淀点之前）时达到峰值。I型胶原蛋白与EMP的结合在低浓度（1 μg ml⁻¹）且狭窄的浓度范围内达到峰值。层粘连蛋白-1和IV型胶原蛋白均不与EMP结合。与单独相同浓度的这些蛋白质相比，与EMP结合的胶原蛋白和纤连蛋白显示上皮细胞和PDLF两者的结合显著减少（> 50%）。通过增加EMP浓度可挽救PDLF而非上皮细胞的黏附。这些发现表明，EMP与伤口细胞外基质蛋白结合并调节其黏附特性。这种相互作用可能有利于成纤维细胞而非上皮细胞的黏附，从而潜在地促进结缔组织再生。
