Skalli O, Schürch W, Seemayer T, Lagacé R, Montandon D, Pittet B, Gabbiani G
Department of Pathology, University of Geneva, Switzerland.
Lab Invest. 1989 Feb;60(2):275-85.
We examined by immunofluorescence the distribution of vimentin, desmin, alpha-smooth muscle actin and alpha-sarcomeric actin in normal human soft tissues and in pathologic tissues containing myofibroblasts, including normally healing granulation tissue, hypertrophic scar, and fibromatosis. The pattern of actin isoforms was also documented biochemically by two-dimensional gel electrophoresis. Fibroblastic and/or myofibroblastic cells in each setting always expressed vimentin and never alpha-sarcomeric actin. Moreover, these cells showed an heterogeneous cytoskeletal composition which defined four phenotypes: (a) cells expressing only vimentin; (b) cells expressing vimentin, alpha-smooth muscle actin and desmin; (c) cells expressing vimentin and alpha-smooth muscle actin; and (d) cells expressing vimentin and desmin. Given this, two groups of lesions are distinguished: the first contains only vimentin cells and consists of normally healing granulation tissue, eschars and normally healed scars; the second contains vimentin cells admixed with variable proportions of vimentin, alpha-smooth muscle actin and desmin, vimentin and alpha-smooth muscle actin, and vimentin and desmin cells and consists of hypertrophic scars and fibromatoses. Immunogold electron microscopy showed that alpha-smooth muscle actin was present in a proportion of cells with ultrastructural features of myofibroblasts. Our findings suggest that contrary to myofibroblasts of normally healing granulation tissue and normally healed scars, myofibroblasts of pathologic conditions characterized by chronic retraction express always immunochemical features indicative of smooth muscle differentiation.
我们通过免疫荧光检查了波形蛋白、结蛋白、α-平滑肌肌动蛋白和α-肌节肌动蛋白在正常人体软组织以及含有肌成纤维细胞的病理组织中的分布，这些病理组织包括正常愈合的肉芽组织、肥厚性瘢痕和纤维瘤病。肌动蛋白同工型的模式也通过二维凝胶电泳进行了生化记录。每种情况下的成纤维细胞和/或肌成纤维细胞总是表达波形蛋白，从不表达α-肌节肌动蛋白。此外，这些细胞显示出异质性的细胞骨架组成，可定义为四种表型：(a) 仅表达波形蛋白的细胞；(b) 表达波形蛋白、α-平滑肌肌动蛋白和结蛋白的细胞；(c) 表达波形蛋白和α-平滑肌肌动蛋白的细胞；(d) 表达波形蛋白和结蛋白的细胞。据此，可区分出两组病变：第一组仅包含波形蛋白细胞，由正常愈合的肉芽组织、焦痂和正常愈合的瘢痕组成；第二组包含波形蛋白细胞与不同比例的波形蛋白、α-平滑肌肌动蛋白和结蛋白、波形蛋白和α-平滑肌肌动蛋白以及波形蛋白和结蛋白细胞混合，由肥厚性瘢痕和纤维瘤病组成。免疫金电子显微镜显示，α-平滑肌肌动蛋白存在于一部分具有肌成纤维细胞超微结构特征的细胞中。我们的研究结果表明，与正常愈合的肉芽组织和正常愈合的瘢痕中的肌成纤维细胞相反，以慢性收缩为特征的病理状态下的肌成纤维细胞总是表达指示平滑肌分化的免疫化学特征。
