Futrega K, Music E, Robey P G, Gronthos S, Crawford R, Saifzadeh S, Klein T J, Doran M R
Centre for Biomedical Technologies (CBT), Queensland University of Technology (QUT), Brisbane, Queensland, Australia.
National Institute of Dental and Craniofacial Research (NIDCR), National Institutes of Health (NIH), Bethesda, Maryland, USA.
Stem Cell Res Ther. 2021 Jan 7;12(1):26. doi: 10.1186/s13287-020-02045-3.
Bone marrow stromal cells (BMSC) show promise in cartilage repair, and sheep are the most common large animal pre-clinical model.
The objective of this study was to characterise ovine BMSC (oBMSC) in vitro, and to evaluate the capacity of chondrogenic micro-pellets manufactured from oBMSC or ovine articular chondrocytes (oACh) to repair osteochondral defects in sheep.
oBMSC were characterised for surface marker expression using flow cytometry and evaluated for tri-lineage differentiation capacity. oBMSC micro-pellets were manufactured in a microwell platform, and chondrogenesis was compared at 2%, 5%, and 20% O. The capacity of cartilage micro-pellets manufactured from oBMSC or oACh to repair osteochondral defects in adult sheep was evaluated in an 8-week pilot study.
Expanded oBMSC were positive for CD44 and CD146 and negative for CD45. The common adipogenic induction ingredient, 3-Isobutyl-1-methylxanthine (IBMX), was toxic to oBMSC, but adipogenesis could be restored by excluding IBMX from the medium. BMSC chondrogenesis was optimal in a 2% O atmosphere. Micro-pellets formed from oBMSC or oACh appeared morphologically similar, but hypertrophic genes were elevated in oBMSC micro-pellets. While oACh micro-pellets formed cartilage-like repair tissue in sheep, oBMSC micro-pellets did not.
The sensitivity of oBMSC, compared to human BMSC, to IBMX in standard adipogenic assays highlights species-associated differences. Micro-pellets manufactured from oACh were more effective than micro-pellets manufactured from oBMSC in the repair of osteochondral defects in sheep. While oBMSC can be driven to form cartilage-like tissue in vitro, the effective use of these cells in cartilage repair will depend on the successful mitigation of hypertrophy and tissue integration.
骨髓基质细胞（BMSC）在软骨修复方面显示出前景，而绵羊是最常用的大型动物临床前模型。
本研究的目的是在体外对绵羊骨髓基质细胞（oBMSC）进行表征，并评估由oBMSC或绵羊关节软骨细胞（oACh）制成的软骨形成微球修复绵羊骨软骨缺损的能力。
使用流式细胞术对oBMSC的表面标志物表达进行表征，并评估其三系分化能力。在微孔平台中制造oBMSC微球，并在2%、5%和20%氧气条件下比较软骨形成情况。在一项为期8周的初步研究中，评估了由oBMSC或oACh制成的软骨微球修复成年绵羊骨软骨缺损的能力。
扩增的oBMSC对CD44和CD146呈阳性，对CD45呈阴性。常见的成脂诱导成分3-异丁基-1-甲基黄嘌呤（IBMX）对oBMSC有毒，但通过从培养基中排除IBMX可恢复成脂作用。BMSC软骨形成在2%氧气气氛中最佳。由oBMSC或oACh形成的微球在形态上相似，但oBMSC微球中的肥大基因升高。虽然oACh微球在绵羊中形成了软骨样修复组织，但oBMSC微球没有。
与人类BMSC相比，oBMSC在标准成脂试验中对IBMX的敏感性突出了物种相关差异。由oACh制成的微球在修复绵羊骨软骨缺损方面比由oBMSC制成的微球更有效。虽然oBMSC可在体外被诱导形成软骨样组织，但这些细胞在软骨修复中的有效应用将取决于成功减轻肥大和组织整合。
