Division of Molecular and Regenerative Prosthodontics, Tohoku University Graduate School of Dentistry, Sendai, Miyagi 980-8575, Japan.
Weintraub Center for Reconstructive Biotechnology, UCLA (University of California, Los Angeles) School of Dentistry, Los Angeles, CA 90095-1668, USA.
Int J Mol Sci. 2020 Jan 16;21(2):581. doi: 10.3390/ijms21020581.
Cell condensation and mechanical stimuli play roles in osteogenesis and chondrogenesis; thus, they are promising for facilitating self-organizing bone/cartilage tissue formation in vitro from induced pluripotent stem cells (iPSCs). Here, single mouse iPSCs were first seeded in micro-space culture plates to form 3-dimensional spheres. At day 12, iPSC spheres were subjected to shaking culture and maintained in osteogenic induction medium for 31 days (Os induction). In another condition, the osteogenic induction medium was replaced by chondrogenic induction medium at day 22 and maintained for a further 21 days (Os-Chon induction). Os induction produced robust mineralization and some cartilage-like tissue, which promoted expression of osteogenic and chondrogenic marker genes. In contrast, Os-Chon induction resulted in partial mineralization and a large area of cartilage tissue, with greatly increased expression of chondrogenic marker genes along with and . Os-Chon induction enhanced mesodermal lineage commitment with brachyury expression followed by high expression of lateral plate and paraxial mesoderm marker genes. These results suggest that combined use of micro-space culture and mechanical stimuli facilitates hybrid bone/cartilage tissue formation from iPSCs, and that the bone/cartilage tissue ratio in iPSC constructs could be manipulated through the induction protocol.
细胞凝聚和机械刺激在成骨和成软骨中起作用；因此，它们有望促进诱导多能干细胞（iPSC）在体外自组织骨/软骨组织的形成。在这里，首先将单个小鼠 iPSC 接种在微空间培养板中以形成 3 维球体。在第 12 天，将 iPSC 球体进行摇动培养，并在成骨诱导培养基中维持 31 天（Os 诱导）。在另一种条件下，在第 22 天将成骨诱导培养基替换为软骨诱导培养基，并进一步维持 21 天（Os-Chon 诱导）。Os 诱导产生了强烈的矿化和一些软骨样组织，促进了成骨和成软骨标记基因的表达。相比之下，Os-Chon 诱导导致部分矿化和大面积软骨组织，软骨形成标记基因的表达大大增加，同时还增加了 和 的表达。Os-Chon 诱导增强了中胚层谱系的承诺，表现为 brachyury 的表达，随后是侧板和轴旁中胚层标记基因的高表达。这些结果表明，微空间培养和机械刺激的联合使用促进了 iPSC 杂交骨/软骨组织的形成，并且可以通过诱导方案来操纵 iPSC 构建体中的骨/软骨组织比例。
