Department of Orthopaedics, First People's Hospital of Fuzhou, Fuzhou, China.
Hospital-Acquired Infection Control Department, First People's Hospital of Fuzhou, Fuzhou, China.
Orthop Surg. 2023 Sep;15(9):2423-2434. doi: 10.1111/os.13803. Epub 2023 Jul 10.
Bone marrow mesenchymal stromal cells (BMSCs) are major sources of osteogenic precursor cells in bone remodeling, which directly participate in osteoporosis (OP) progression. However, the involved specific mechanisms of BMSCs in OP warrant mass investigations. Initially, our bioinformatics analysis uncovered the prominent up-regulation of Asporin (ASPN) and proteoglycan link protein 1 (HAPLN1) in osteoblasts (OBs) of OP patients and their possible protein interaction. Hence, this study aimed to explore the effects of ASPN and HAPLN1 on osteogenic differentiation of BMSCs, extracellular matrix (ECM) mineralization of OBs, and osteoclastogenesis, hoping to offer research basis for OP treatment.
GSE156508 dataset was used for analysis and screening to acquire the differentially expressed genes in OBs of OP patients, followed by the predicative analysis via STRING. OP mouse models were induced by ovariectomy (OVX), and ASPN and HAPLN1 expression was determined. BMSCs and bone marrow macrophages (BMMs) were isolated from OVX mice and induced for osteogenic differentiation and osteoclastogenesis, respectively. After knockdown experiments, we assessed adipogenic differentiation and osteogenic differentiation in BMSCs. Osteogenic (OPN, OCN, and COL1A1) and osteoclast (Nfatc1 and c-Fos) marker protein expression was determined. The binding of ASPN to HAPLN1 was analyzed.
High expression of ASPN and HAPLN1 and their protein interaction were observed in OBs of OP patients via bioinformatics and in bone tissues of OVX mice. ASPN interacted with HAPLN1 in BMSCs of OVX mice. ASPN/HAPLN1 knockdown increased ALP, OPN, OCN, and COL1A1 protein expression and ECM mineralization in BMSCs while decreasing Nfatc1 and c-Fos expression in BMMs. These effects were aggravated by the simultaneous knockdown of ASPN and HAPLN1.
Our results indicate that ASPN synergises with HAPLN1 to suppress the osteogenic differentiation of BMSCs and ECM mineralization of OBs and promote the osteoclastogenesis in OP.
骨髓间充质基质细胞（BMSCs）是骨重塑中成骨前体细胞的主要来源，它们直接参与骨质疏松症（OP）的进展。然而，BMSCs 在 OP 中涉及的具体机制仍需要大量研究。最初，我们的生物信息学分析揭示了骨质疏松症患者成骨细胞（OBs）中 Asporin（ASPN）和蛋白聚糖连接蛋白 1（HAPLN1）的显著上调及其可能的蛋白质相互作用。因此，本研究旨在探讨 ASPN 和 HAPLN1 对 BMSCs 成骨分化、OBs 细胞外基质（ECM）矿化和破骨细胞形成的影响，以期为 OP 治疗提供研究基础。
使用 GSE156508 数据集进行分析和筛选，以获得骨质疏松症患者 OBs 中的差异表达基因，然后通过 STRING 进行预测分析。通过卵巢切除术（OVX）诱导 OP 小鼠模型，并确定 ASPN 和 HAPLN1 的表达。从 OVX 小鼠中分离出 BMSCs 和骨髓巨噬细胞（BMMs），分别诱导其成骨分化和破骨细胞形成。在进行敲低实验后，我们评估了 BMSCs 的成脂分化和成骨分化。检测成骨（OPN、OCN 和 COL1A1）和破骨（Nfatc1 和 c-Fos）标志物蛋白的表达。分析 ASPN 与 HAPLN1 的结合情况。
通过生物信息学和 OVX 小鼠骨组织观察到，OP 患者 OBs 中 ASPN 和 HAPLN1 表达上调，且二者存在蛋白相互作用。在 OVX 小鼠的 BMSCs 中，ASPN 与 HAPLN1 相互作用。ASPN/HAPLN1 敲低增加了 BMSCs 中 ALP、OPN、OCN 和 COL1A1 蛋白的表达和 ECM 矿化，同时降低了 BMMs 中 Nfatc1 和 c-Fos 的表达。同时敲低 ASPN 和 HAPLN1 则加剧了这些效应。
我们的研究结果表明，ASPN 与 HAPLN1 协同抑制 BMSCs 的成骨分化和 OBs 的 ECM 矿化，并促进 OP 中的破骨细胞形成。
