1. A single day of TGF-β1 exposure activates chondrogenic and hypertrophic differentiation pathways in bone marrow-derived stromal cells.
- Author
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Futrega, Kathryn, Robey, Pamela G., Klein, Travis J., Crawford, Ross W., and Doran, Michael R.
- Subjects
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MESENCHYMAL stem cells , *TRANSFORMING growth factors , *HYPERTROPHY , *CHONDROGENESIS , *CELL differentiation - Abstract
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 × 103 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 × 105 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. Futrega et al. challenge the long established chondrogenic differentiation protocol used to induce bone marrow-derived stromal cell (BMSC) differentiation which presumes the need for more than 2 weeks of continuous TGF-β1 exposure. Using a micro-pellet model, they show that BMSC differentiation is triggered by a single day of TGF-β1 exposure. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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