Fujita Shinse, Tani Shoichiro, Okada Hiroyuki, Saito Taku, Tanaka Sakae, Ohba Shinsuke, Chung Ung-Il, Hojo Hironori
Division of Clinical Biotechnology, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
Department of Orthopaedic Surgery, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
Dev Growth Differ. 2025 Sep;67(7):406-416. doi: 10.1111/dgd.70023. Epub 2025 Sep 2.
Osteoblast differentiation is essential for skeletal development and homeostasis. Although bone marrow-derived mesenchymal stem/stromal cells (BM-MSCs) are commonly used to study osteoblast differentiation in the context of bone homeostasis, their relevance to osteoblast differentiation during human skeletal development remains unclear. To understand the regulatory mechanisms underlying osteoblast differentiation in a human developmental context, we performed Assay for Transposase-Accessible Chromatin sequencing (ATAC-seq) and RNA-seq analyses on osteoblasts isolated from an in vivo implantation system using induced sclerotome derived from Col2.3-GFP reporter human embryonic stem cells (hESCs). The resulting datasets revealed skeletal development-associated chromatin accessibility and transcriptional profiles. Comparative analysis with BM-MSC-derived osteoblasts revealed that hESC-derived osteoblasts were enriched for regulatory gene sets associated with ossification. Notably, we identified a super-enhancer associated with DLX5, a known osteoblast regulator, consisting of multiple cooperative enhancer elements to drive transcription. Taken together, this study provides a valuable resource for examining cis-trans regulatory mechanisms in human skeletal development and highlights DLX5 as a key transcriptional regulator controlled by an osteoblast super-enhancer.
成骨细胞分化对于骨骼发育和稳态至关重要。尽管骨髓间充质干/基质细胞（BM-MSCs）通常用于在骨稳态背景下研究成骨细胞分化，但其在人类骨骼发育过程中与成骨细胞分化的相关性仍不清楚。为了了解人类发育背景下成骨细胞分化的调控机制，我们对从使用源自Col2.3-GFP报告基因人类胚胎干细胞（hESCs）诱导的硬骨节构建的体内植入系统中分离出的成骨细胞进行了转座酶可及染色质测序分析（ATAC-seq）和RNA测序分析。所得数据集揭示了与骨骼发育相关的染色质可及性和转录谱。与BM-MSC来源的成骨细胞进行比较分析表明，hESC来源的成骨细胞富含与骨化相关的调控基因集。值得注意的是，我们鉴定出一个与已知的成骨细胞调节因子DLX5相关的超级增强子，它由多个协同增强子元件组成以驱动转录。综上所述，本研究为研究人类骨骼发育中的顺式-反式调控机制提供了宝贵资源，并突出了DLX5作为由成骨细胞超级增强子控制的关键转录调节因子。
