Department of Orthopedic Surgery, Mayo Clinic, Rochester, Minnesota, USA.
Department of Biochemistry, University of Vermont, Burlington, Vermont, USA.
J Cell Biochem. 2022 May;123(5):878-892. doi: 10.1002/jcb.30230. Epub 2022 Feb 28.
Arthrofibrosis is characterized by excessive extracellular matrix (ECM) deposition that results in restricted joint motion after total knee arthroplasties (TKAs). Currently, treatment options are limited. Therefore, an in vitro model of knee-related myofibroblastogenesis is valuable to facilitate investigation of the arthrofibrotic process, diagnostic and therapeutic options. In this study, we obtained intraoperative posterior capsule (PC), quadriceps tendon (QT), and suprapatellar pouch (SP) tissues from the knees of four patients undergoing primary TKAs for osteoarthritis. From these tissues, we isolated primary cells by the outgrowth method and subsequently characterized these cells in the absence and presence of the pro-myofibroblastic cytokine, transforming growth factor beta 1 (TGFβ1). Light microscopy of knee outgrowth cells revealed spindle-shaped cells, and immunofluorescence (IF) analysis demonstrated staining for the fibroblast-specific markers TE-7 and vimentin (VIM). These knee outgrowth fibroblasts differentiated readily into myofibroblasts as reflected by enhanced α-smooth muscle actin (ACTA2) mRNA and protein expression and increased mRNA expression of collagen type 1 (COL1A1) and type 3 (COL3A1) with collagenous matrix deposition in the presence of TGFβ1. Outgrowth knee fibroblasts were more sensitive to TGFβ1-mediated myofibroblastogenesis than adipose-derived mesenchymal stromal/stem cells (MSCs). While outgrowth knee fibroblasts isolated from three anatomical regions in four patients exhibited similar gene expression, these cells are distinct from other fibroblastic cell types (i.e., Dupuytren's fibroblasts) as revealed by RNA-sequencing. In conclusion, our study provides an in vitro myofibroblastic model of outgrowth knee fibroblasts derived from patients undergoing primary TKA that can be utilized to study myofibroblastogenesis and assess therapeutic strategies for arthrofibrosis.
关节纤维组织增生症的特征是细胞外基质（ECM）过度沉积，导致全膝关节置换术后（TKA）关节活动受限。目前，治疗方法有限。因此，膝关节相关肌成纤维细胞发生的体外模型对于促进对关节纤维组织增生症过程、诊断和治疗方法的研究具有重要价值。在这项研究中，我们从 4 名接受原发性膝关节骨关节炎 TKA 的患者的术中后囊（PC）、股四头肌肌腱（QT）和髌上囊（SP）组织中获得了膝关节组织。我们通过体外培养法从这些组织中分离出原代细胞，并在不存在和存在促肌成纤维细胞的细胞因子转化生长因子-β1（TGFβ1）的情况下对这些细胞进行了特征描述。膝关节培养细胞的光镜下观察到梭形细胞，免疫荧光（IF）分析显示纤维母细胞特异性标志物 TE-7 和波形蛋白（VIM）的染色。这些膝关节培养的成纤维细胞很容易分化为肌成纤维细胞，表现为α-平滑肌肌动蛋白（ACTA2）mRNA 和蛋白表达增强，以及 COL1A1 和 COL3A1 基因表达增强，在 TGFβ1 存在的情况下胶原蛋白沉积增加。与脂肪来源的间充质基质/干细胞（MSCs）相比，膝关节培养的成纤维细胞对 TGFβ1 介导的肌成纤维细胞发生更为敏感。尽管来自 4 名患者的三个解剖区域的膝关节培养的成纤维细胞的基因表达相似，但这些细胞与其他成纤维细胞类型（即，掌腱膜挛缩症的成纤维细胞）不同，这是通过 RNA 测序揭示的。总之，我们的研究提供了一种源自接受原发性 TKA 患者的膝关节培养的肌成纤维细胞体外模型，可用于研究肌成纤维细胞发生和评估关节纤维组织增生症的治疗策略。
