University Hospital of Munich (LMU), Campus Grosshadern, Department of Orthopedic Surgery, Physical Medicine and Rehabilitation, Munich, DE, Germany.
University Hospital of Munich (LMU), Biobank under the administration of the Human Tissue and Cell Research (HTCR) Foundation, Department of General, Visceral, Transplantation, Vascular and Thoracic Surgery, Munich, DE, Germany.
Sci Rep. 2017 Jan 5;7:39712. doi: 10.1038/srep39712.
Conventional bone tissue engineering approaches require isolation and in vitro propagation of autologous cells, followed by seeding on a variety of scaffolds. Those protracted procedures impede the clinical applications. Here we report the transdifferentiation of human fat tissue fragments retrieved from subcutaneous fat into tissue with bone characteristics in vitro without prior cell isolation and propagation. 3D collagen-I cultures of human fat tissue were cultivated either in growth medium or in osteogenic medium (OM) with or without addition of Bone Morphogenetic Proteins (BMPs) BMP-2, BMP-7 or BMP-9. Ca depositions were observed after two weeks of osteogenic induction which visibly increased when either type of BMP was added. mRNA levels of alkaline phosphatase (ALP) and osteocalcin (OCN) increased when cultured in OM alone but addition of BMP-2, BMP-7 or BMP-9 caused significantly higher expression levels of ALP and OCN. Immunofluorescent staining for OCN, osteopontin and sclerostin supported the observed real-time-PCR data. BMP-9 was the most effective osteogenic inducer in this system. Our findings reveal that tissue regeneration can be remarkably simplified by omitting prior cell isolation and propagation, therefore removing significant obstacles on the way to clinical applications of much needed regeneration treatments.
传统的骨组织工程方法需要分离和体外培养自体细胞，然后接种到各种支架上。这些冗长的程序阻碍了临床应用。在这里，我们报告了从皮下脂肪中提取的人体脂肪组织碎片在体外无需事先细胞分离和培养即可向具有骨特征的组织转化。在生长培养基或成骨培养基（OM）中培养人脂肪组织的 3D 胶原-I 培养物，有或没有添加骨形态发生蛋白（BMPs）BMP-2、BMP-7 或 BMP-9。在成骨诱导两周后观察到钙沉积，当添加任何一种 BMP 时，钙沉积明显增加。单独在 OM 中培养时，碱性磷酸酶（ALP）和骨钙素（OCN）的 mRNA 水平增加，但添加 BMP-2、BMP-7 或 BMP-9 会导致 ALP 和 OCN 的表达水平显著升高。OCN、骨桥蛋白和硬化蛋白的免疫荧光染色支持实时 PCR 数据。在该系统中，BMP-9 是最有效的成骨诱导剂。我们的发现表明，通过省略先前的细胞分离和培养，可以显著简化组织再生，从而消除急需再生治疗的临床应用的重大障碍。
