Department of Oral and Maxillofacial Surgery, Special Dental Care and Orthodontics, Erasmus MC, 3000 DR Rotterdam, the Netherlands.
Eur Cell Mater. 2019 Sep 18;38:106-122. doi: 10.22203/eCM.v038a09.
in tissue engineering, endochondral ossification (EO) is often replicated by chondrogenically differentiating mesenchymal stromal cells (MSCs) in vitro and achieving bone formation through in vivo implantation. The resulting marrow-containing bone constructs are promising as a treatment for bone defects. However, limited bone formation capacity has prevented them from reaching their full potential. This is further complicated since it is not fully understood how this bone formation is achieved. Acellular grafts derived from chondrogenically differentiated MSCs can initiate bone formation; however, which component within these decellularised matrices contribute to bone formation has yet to be determined. Collagen type X (COLX), a hypertrophy-associated collagen found within these constructs, is involved in matrix organisation, calcium binding and matrix vesicle compartmentalisation. However, the importance of COLX during tissue-engineered chondrogenesis and subsequent bone formation is unknown. The present study investigated the importance of COLX by shRNA-mediated gene silencing in primary MSCs. A significant knock-down of COLX disrupted the production of extracellular matrix key components and the secretion profile of chondrogenically differentiated MSCs. Following in vivo implantation, disrupted bone formation in knock-down constructs was observed. The importance of COLX was confirmed during both chondrogenic differentiation and subsequent EO in this tissue engineered setting.
在组织工程中，通常通过体外诱导间充质基质细胞（MSCs）向软骨分化来复制骺软骨内骨化（EO），并通过体内植入来实现骨形成。由此产生的含骨髓的骨构建物有望成为治疗骨缺损的一种方法。然而，由于不完全清楚如何实现这种骨形成，其有限的骨形成能力限制了其充分发挥潜力。这进一步复杂化了，因为还不完全清楚这种骨形成是如何实现的。源自软骨分化的 MSCs 的去细胞移植物可以启动骨形成；然而，这些脱细胞基质中的哪个成分有助于骨形成尚未确定。COLX（X 型胶原）是存在于这些构建体中的一种与肥大相关的胶原，参与基质组织、钙结合和基质小泡区室化。然而，COLX 在组织工程软骨形成和随后的骨形成中的重要性尚不清楚。本研究通过 shRNA 介导的基因沉默在原代 MSCs 中研究了 COLX 的重要性。COLX 的显著敲低破坏了细胞外基质关键成分的产生和软骨分化的 MSCs 的分泌谱。在体内植入后，观察到敲低构建体中的骨形成受到破坏。在这种组织工程环境中，COLX 在软骨分化和随后的 EO 过程中都具有重要作用。
