Expression of TGF-beta in foreign body reaction and fibrosis agaist titanium implant.

本文用20例病例研究了转化生长因子- β (tgf - β)、血小板源性生长因子（PDGF）及其受体在体外抗异物包封过程中的原位表达。我们将微型钛板作为异物模型，用于临床固定下颌骨骨折。在包封过程中形成的纤维囊由瘢痕样层和纤维原层组成，瘢痕样层直接面向异物。通过预先固定的冷冻切片免疫组化，只有纤维原层有I型前胶原（PC-I）的表达。纤维原层梭形间充质细胞表达tgf - β亚型和受体，以及PDGF亚型和PDGF β受体。相比之下，疤痕层几乎没有这样的细胞。两层梭形细胞的细胞核中均未表达Ki-67。双免疫荧光显微镜细胞鉴定显示，大多数pc - i阳性成纤维细胞在纤维原层表达tgf - β和PDGF的亚型和受体。相反，少量cd68阳性巨噬细胞表达这些。我们的研究结果表明，在人体抗异物包封过程的维持阶段，tgf - β和PDGF通过其在纤维化层的受体协同起作用，这种刺激在瘢痕样层明显减弱。

The present paper addresses in situ expression of transforming growth factor-beta (TGF-beta), platelet-derived growth factor (PDGF), and their receptors in the encapsulation process against foreign body using 20 cases. We dealt with titanium miniplate as a model of foreign body, which was used clinically to fix fractured mandible. Fibrous capsule formed as the encapsulation process was composed of scar-like-and fibrogenic layrs, with the former directly facing the foreign body. By immunohistochemistry using pre-fixed frozen sections, only the fibrogenic layr was characterized by an expression of type I procollagen (PC-I). Spindle-shaped mesenchymal cells in the fibrogenic layr expressed TGF-beta isoforms and receptors, and PDGF isoforms and PDGF beta-receptor. In contrast, the scar-like layr had few such cells. In both layrs, spindle-shaped cells did not expressed Ki-67 in their nuclei.Double immunofluorescence microscopy for the cell identification revealed that most PC-I-positive fibroblasts expressed both isoforms and receptors of TGF-beta and PDGF in the fibrogenic layr. In contrast, a small number of CD68-positive macrophages expressed these.Our results suggest that in the maintenance stage of the human encapsulation process against foreign body, both TGF-beta and PDGF function cooperatively via their receptors in the fibrogenic layr, with such stimuli markedly diminished in the scar-like layr.