Fu Sai-Chuen, Cheuk Yau-Chuk, Chan Kai-Ming, Hung Leung-Kim, Wong Margaret Wan-Nar
Department of Orthopaedics & Traumatology, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong.
J Orthop Res. 2008 Mar;26(3):374-83. doi: 10.1002/jor.20483.
Cultured tendon fibroblasts (CTFs) from intact explants are widely used to study tendon healing in vitro. The significance of these findings may rely on similarities between CTFs and healing tendon fibroblasts in situ. Our purpose was to compare CTFs with fibroblasts cultured from healing tendons. We cultured CTFs from intact and healing tendons at day 7 and day 14 postinjury in a rat model of patellar donor site injury. The mRNA expression of COL1A1, COL3A1, decorin, and biglycan, with or without supplementation of 1 ng/mL TGF-beta1, was compared by quantitative real-time RT-PCR. The expression of proliferation cell nuclear antigen (PCNA) and alpha-smooth muscle actin (alpha-SMA) was determined by immunostain. COL3A1 and decorin mRNA in CTFs was lower as compared to day 7 healing fibroblasts, but its biglycan mRNA level was higher than day 14 healing fibroblasts. TGF-beta1 increased COL1A1 and decorin mRNA in CTFs, but decreased the mRNA of all four genes in day 7 healing tendon fibroblasts. CTFs exhibited lower PCNA immunopositivity as compared to day 7 and day 14 healing fibroblasts, but a higher alpha-SMA immunopositivity than cultured day 14 healing fibroblasts. These findings showed that CTFs did not resemble healing tendon cells with respect to major cellular activities related to tendon healing. Thus, fibroblasts from healing tendon may be a more appropriate model for studying cellular activities in tendon healing.
来自完整外植体的培养肌腱成纤维细胞（CTFs）被广泛用于体外研究肌腱愈合。这些发现的意义可能取决于CTFs与原位愈合的肌腱成纤维细胞之间的相似性。我们的目的是比较CTFs与从愈合肌腱中培养的成纤维细胞。在大鼠髌腱供区损伤模型中，我们在损伤后第7天和第14天从完整和愈合的肌腱中培养CTFs。通过定量实时RT-PCR比较了COL1A1、COL3A1、核心蛋白聚糖和双糖链蛋白聚糖在有无1 ng/mL TGF-β1补充情况下的mRNA表达。通过免疫染色测定增殖细胞核抗原（PCNA）和α-平滑肌肌动蛋白（α-SMA）的表达。与第7天的愈合成纤维细胞相比，CTFs中的COL3A1和核心蛋白聚糖mRNA较低，但其双糖链蛋白聚糖mRNA水平高于第14天的愈合成纤维细胞。TGF-β1增加了CTFs中COL1A1和核心蛋白聚糖mRNA，但降低了第7天愈合肌腱成纤维细胞中所有四个基因的mRNA。与第7天和第14天的愈合成纤维细胞相比，CTFs表现出较低的PCNA免疫阳性，但α-SMA免疫阳性高于培养第14天的愈合成纤维细胞。这些发现表明，在与肌腱愈合相关的主要细胞活动方面，CTFs与愈合的肌腱细胞并不相似。因此，来自愈合肌腱的成纤维细胞可能是研究肌腱愈合中细胞活动的更合适模型。
