National Institute of Dental and Craniofacial Research (NIDCR), National Institutes of Health (NIH), Department of Health and Human Services, Bethesda, MD, USA.
Centre for Biomedical Technologies (CBT), Queensland University of Technology (QUT), Brisbane, Queensland, Australia.
Commun Biol. 2021 Jan 4;4(1):29. doi: 10.1038/s42003-020-01520-0.
Virtually all bone marrow-derived stromal cell (BMSC) chondrogenic induction cultures include greater than 2 weeks exposure to transforming growth factor-β (TGF-β), but fail to generate cartilage-like tissue suitable for joint repair. Herein we used a micro-pellet model (5 × 10 BMSC each) to determine the duration of TGF-β1 exposure required to initiate differentiation machinery, and to characterize the role of intrinsic programming. We found that a single day of TGF-β1 exposure was sufficient to trigger BMSC chondrogenic differentiation and tissue formation, similar to 21 days of TGF-β1 exposure. Despite cessation of TGF-β1 exposure following 24 hours, intrinsic programming mediated further chondrogenic and hypertrophic BMSC differentiation. These important behaviors are obfuscated by diffusion gradients and heterogeneity in commonly used macro-pellet models (2 × 10 BMSC each). Use of more homogenous micro-pellet models will enable identification of the critical differentiation cues required, likely in the first 24-hours, to generate high quality cartilage-like tissue from BMSC.
几乎所有骨髓基质细胞(BMSC)的软骨诱导培养都包括超过 2 周的转化生长因子-β(TGF-β)暴露,但无法生成适合关节修复的软骨样组织。在此,我们使用微球模型(每个微球含有 5×10 个 BMSC)来确定启动分化机制所需的 TGF-β1 暴露时间,并研究内在编程的作用。我们发现,TGF-β1 暴露 1 天足以触发 BMSC 软骨分化和组织形成,与 21 天 TGF-β1 暴露相似。尽管在 24 小时后停止 TGF-β1 暴露,内在编程仍介导进一步的软骨和成骨细胞肥大 BMSC 分化。这些重要行为被常用的大球模型(每个球含有 2×10 个 BMSC)中的扩散梯度和异质性所掩盖。使用更均匀的微球模型将能够确定所需的关键分化线索,可能在最初的 24 小时内,从 BMSC 产生高质量的软骨样组织。