Laboratory of Molecular Medicine, College of Life Science and State Key Laboratory of Cell Differentiation and Regulation, Henan Normal University, Xinxiang 453007, China.
Longhua Hospital & Spine Institute, Shanghai University of Traditional Chinese Medicine, Shanghai 200032, China.
J Zhejiang Univ Sci B. 2024 Jan 15;25(1):38-50. doi: 10.1631/jzus.B2300180.
Gorham-Stout disease (GSD) is a sporadic chronic disease characterized by progressive bone dissolution, absorption, and disappearance along with lymphatic vessel infiltration in bone-marrow cavities. Although the osteolytic mechanism of GSD has been widely studied, the cause of lymphatic hyperplasia in GSD is rarely investigated. In this study, by comparing the RNA expression profile of osteoclasts (OCs) with that of OC precursors (OCPs) by RNA sequencing, we identified a new factor, semaphorin 3A (Sema3A), which is an osteoprotective factor involved in the lymphatic expansion of GSD. Compared to OCPs, OCs enhanced the growth, migration, and tube formation of lymphatic endothelial cells (LECs), in which the expression of Sema3A is low compared to that in OCPs. In the presence of recombinant Sema3A, the growth, migration, and tube formation of LECs were inhibited, further confirming the inhibitory effect of Sema3A on LECs in vitro. Using an LEC-induced GSD mouse model, the effect of Sema3A was examined by injecting lentivirus-expressing Sema3A into the tibiae in vivo. We found that the overexpression of Sema3A in tibiae suppressed the expansion of LECs and alleviated bone loss, whereas the injection of lentivirus expressing Sema3A short hairpin RNA (shRNA) into the tibiae caused GSD-like phenotypes. Histological staining further demonstrated that OCs decreased and osteocalcin increased after Sema3A lentiviral treatment, compared with the control. Based on the above results, we propose that reduced Sema3A in OCs is one of the mechanisms contributing to the pathogeneses of GSD and that expressing Sema3A represents a new approach for the treatment of GSD.
戈勒姆-斯托特病（Gorham-Stout disease，GSD）是一种散发性慢性疾病，其特征为骨髓腔中的骨溶解、吸收和消失，同时伴有淋巴管浸润。尽管 GSD 的溶骨性机制已被广泛研究，但 GSD 中淋巴管增生的原因很少被研究。在这项研究中，我们通过 RNA 测序比较破骨细胞（osteoclasts，OCs）和 OC 前体（OC precursors，OCPs）的 RNA 表达谱，鉴定了一种新的因子，即 Sema3A，它是一种参与 GSD 淋巴扩张的骨保护因子。与 OCPs 相比，OCs 增强了淋巴管内皮细胞（lymphatic endothelial cells，LECs）的生长、迁移和管形成，其中 Sema3A 的表达低于 OCPs。在存在重组 Sema3A 的情况下，LECs 的生长、迁移和管形成受到抑制，进一步证实了 Sema3A 对体外 LECs 的抑制作用。通过使用 LEC 诱导的 GSD 小鼠模型，我们通过体内注射表达 Sema3A 的慢病毒来检查 Sema3A 的作用。我们发现，在胫骨中过表达 Sema3A 抑制了 LECs 的扩张并缓解了骨质流失，而在胫骨中注射表达 Sema3A 短发夹 RNA（short hairpin RNA，shRNA）的慢病毒则导致 GSD 样表型。组织学染色进一步表明，与对照组相比，Sema3A 慢病毒处理后 OCs 减少，骨钙素增加。基于上述结果，我们提出 OCs 中 Sema3A 的减少是 GSD 发病机制之一，而表达 Sema3A 代表了治疗 GSD 的一种新方法。
