He Sihao, Hou Tianyong, Zhou Jiangling, Yu Bo, Cai Juan, Luo Fei, Xu Jianzhong, Xing Junchao
Department of Orthopedics, National & Regional United Engineering Laboratory of Tissue Engineering, Southwest Hospital, the Third Military Medical University, Chongqing, China.
Center of Regenerative and Reconstructive Engineering Technology in Chongqing City, Chongqing, China.
NPJ Regen Med. 2024 Sep 20;9(1):24. doi: 10.1038/s41536-024-00364-0.
Application of tissue-engineered bones (TEBs) is hindered by challenges associated with incorporated viable cells. Previously, we employed freeze-drying techniques on TEBs to devitalize mesenchymal stem cells (MSCs) while preserving functional proteins, yielding functional proteins-based TEBs (FP-TEBs). Here, we aimed to elucidate their in vivo angiogenic and osteogenic capabilities and the mechanisms. qPCR arrays were employed to evaluate chemokines and receptors governing EC migration. Identified C-X-C chemokine receptors (CXCRs) were substantiated using shRNAs, and the pivotal role of CXCR2 was validated via conditional knockout mice. Finally, signaling molecules downstream of CXCR2 were identified. Additionally, Src, MAP4K4, and p38 MAPK were identified indispensable for CXCR2 function. Further investigations revealed that regulation of p38 MAPK by Src was mediated by MAP4K4. In conclusion, FP-TEBs promoted EC migration, angiogenesis, and osteogenesis via the CXCR2-Src-Map4k4-p38 MAPK axis.
组织工程骨（TEB）的应用受到与活细胞整合相关挑战的阻碍。此前，我们对TEB采用冷冻干燥技术使间充质干细胞（MSC）失活，同时保留功能蛋白，从而制备出基于功能蛋白的TEB（FP-TEB）。在此，我们旨在阐明其体内血管生成和成骨能力及相关机制。采用qPCR芯片评估调控内皮细胞（EC）迁移的趋化因子和受体。使用短发夹RNA（shRNA）证实已鉴定出的C-X-C趋化因子受体（CXCR），并通过条件性敲除小鼠验证CXCR2的关键作用。最后，鉴定出CXCR2下游的信号分子。此外，还确定Src、丝裂原活化蛋白激酶4（MAP4K4）和p38丝裂原活化蛋白激酶（p38 MAPK）对CXCR2功能不可或缺。进一步研究表明，Src对p38 MAPK的调控由MAP4K4介导。总之，FP-TEB通过CXCR2-Src-Map4k4-p38 MAPK轴促进EC迁移、血管生成和成骨。
