Yu Manya, Cai Zhiguo, Zhang Jie, Zhang Yanyu, Fu Jiaqi, Cui Xing
The First School of Clinical Medicine, Shandong University of Traditional Chinese Medicine, No. 16369 Jingshi Road, Jinan, 250014, China.
Department of Quality Control, Affiliated Hospital of Shandong University of Traditional Chinese Medicine, Jinan, Shandong Province, 250014, China.
Commun Biol. 2024 Oct 2;7(1):1249. doi: 10.1038/s42003-024-06918-8.
The impact of exosome-mediated crosstalk between multiple myeloma (MM) cells and osteoclasts (OCs) on bone lesions remains to be investigated. Here, we identified NSUN2 and YBX1-mediated m5C modifications upregulated LncRNA MALAT1 expression in MM cells, which could be transported to OCs via exosomes and promote bone lesions. Methodologically, RNA-seq was carried out to detect the cargoes of exosomes. TRAP staining and WB were used to evaluate osteoclastogenesis in vitro. Micro-CT and bone histomorphometric analyses were performed to identify bone destruction in vivo. RNA pull-down, RIP, MeRIP, and luciferase reporter assays were used to test the interactions between molecules. The clinical features of MALAT1, NSUN2 and YBX1 were verified through public datasets and clinicopathological data analyses. Mechanistically, MALAT1 was the highest expressed lncRNA in U266 exosomes and could be transported to RAW264.7 cells. MALAT1 could enhance the differentiation of RAW264.7 cells into OCs by stimulating RANKL expression and its downstream AKT and MAPKs signaling pathways via a ceRNA mechanism. Additionally, MALAT1 could be modified by NSUN2, an m5C methyltransferase, which in turn stabilized MALAT1 through the "reader" YBX1. Clinical studies indicated a notable positive correlation between MALAT1, NSUN2, YBX1 levels and bone destruction features, as well as with RANKL expression.
多发性骨髓瘤（MM）细胞与破骨细胞（OCs）之间通过外泌体介导的串扰对骨病变的影响仍有待研究。在此，我们发现NSUN2和YBX1介导的m5C修饰上调了MM细胞中LncRNA MALAT1的表达，其可通过外泌体转运至OCs并促进骨病变。在方法上，进行RNA测序以检测外泌体的货物。采用抗酒石酸酸性磷酸酶（TRAP）染色和蛋白质免疫印迹（WB）来评估体外破骨细胞生成。进行显微计算机断层扫描（Micro-CT）和骨组织形态计量学分析以鉴定体内骨破坏。采用RNA下拉、RNA免疫沉淀（RIP）、甲基化RNA免疫沉淀（MeRIP）和荧光素酶报告基因检测来测试分子间的相互作用。通过公共数据集和临床病理数据分析验证了MALAT1、NSUN2和YBX1的临床特征。机制上，MALAT1是U266外泌体中表达最高的lncRNA，可转运至RAW264.7细胞。MALAT1可通过ceRNA机制刺激核因子κB受体活化因子配体（RANKL）表达及其下游的蛋白激酶B（AKT）和丝裂原活化蛋白激酶（MAPKs）信号通路，从而增强RAW264.7细胞向OCs的分化。此外，MALAT1可被m5C甲基转移酶NSUN2修饰，而NSUN2又通过“读取器”YBX1使MALAT1稳定。临床研究表明，MALAT1、NSUN2、YBX1水平与骨破坏特征以及RANKL表达之间存在显著正相关。
