Fang Zhi, Zhu Ting, Shen Wei Liang, Tang Qiao Mei, Chen Jia Lin, Yin Zi, Ji Jun Feng, Heng Boon Chin, Ouyang Hong Wei, Chen Xiao
1 Zhejiang Provincial Key Laboratory of Tissue Engineering and Regenerative Medicine , Hangzhou, China .
Tissue Eng Part A. 2014 Jul;20(13-14):1815-26. doi: 10.1089/ten.TEA.2013.0296. Epub 2014 May 15.
Although cell transplantation therapy can effectively promote functional tendon repair, occasional ectopic ossification during tendon regeneration undermines its efficacy. The effect of transplanted cell types on ectopic ossification has not yet been systematically evaluated. This study compared the rate of ectopic ossification during tendon repair upon transplantation with mouse fetal fibroblasts (FFs) and their adult counterparts (adult fibroblasts [AFs]). Alkaline phosphatase (ALP) staining, immunofluorescence, and gene expression analysis were used to compare the spontaneous osteogenic differentiation of FFs and AFs in vitro. X-ray, histology, and gene expression analysis were used to investigate the ectopic ossification in a mouse Achilles tendon repair model in vivo. ALP staining and immunofluorescence data in vitro showed that FFs had less spontaneous osteogenic differentiation capacity, and lower expression of runt-related transcription factor 2 (runx2). For the in vivo study, the FFs transplant group displayed reduced ectopic ossification (2/7 vs. 7/7, Mann-Whitney test p<0.01) at 14 weeks post-transplantation and enhanced tendon repair (general histological score at week 6, 7.53 vs. 10.56, p<0.05). More chondrocytes formed at 6 weeks, and all mice developed bone marrow at 14 weeks post-transplantation in the AFs transplant group. Gene expression analysis of the regenerated tissue showed significantly higher expression levels of transforming growth factor beta1 (TGF-β1) and transforming growth factor beta3 (TGF-β3) in the AFs group during the early stages of tendon repair. Our study demonstrates that transplantation of fetal instead of AFs is more promising for tendon repair, underscoring the importance of the origin of seed cells for tendon repair.
尽管细胞移植疗法能有效促进肌腱功能修复，但肌腱再生过程中偶尔出现的异位骨化会削弱其疗效。移植细胞类型对异位骨化的影响尚未得到系统评估。本研究比较了将小鼠胎儿成纤维细胞（FFs）及其成年对应细胞（成年成纤维细胞[AFs]）移植到肌腱修复部位时异位骨化的发生率。采用碱性磷酸酶（ALP）染色、免疫荧光和基因表达分析来比较FFs和AFs在体外的自发成骨分化情况。利用X射线、组织学和基因表达分析来研究小鼠跟腱修复模型中的异位骨化情况。体外ALP染色和免疫荧光数据显示，FFs的自发成骨分化能力较低，且 runt相关转录因子2（runx2）的表达也较低。在体内研究中，FFs移植组在移植后14周时异位骨化减少（2/7比7/7，Mann-Whitney检验p<0.01），肌腱修复增强（第6周时一般组织学评分，7.53比10.56，p<0.05）。AFs移植组在移植后6周时形成了更多软骨细胞，且所有小鼠在14周时都发育出了骨髓。对再生组织的基因表达分析显示，在肌腱修复早期，AFs组中转化生长因子β1（TGF-β1）和转化生长因子β3（TGF-β3）的表达水平显著更高。我们的研究表明，移植胎儿成纤维细胞而非AFs对肌腱修复更有前景，强调了种子细胞来源对肌腱修复的重要性。
