Division of Nephrology and Endocrinology, The University of Tokyo Hospital, Tokyo 113-8655, Japan.
Department of Rehabilitation for Motor Functions, Research Institute, National Rehabilitation Center for Persons with Disabilities, Tokorozawa 359-8555, Japan.
Int J Mol Sci. 2023 Sep 4;24(17):13633. doi: 10.3390/ijms241713633.
The vast majority of transcribed RNAs are noncoding RNAs. Among noncoding RNAs, long noncoding RNAs (lncRNAs), which contain hundreds to thousands of bases, have received attention in many fields. The vast majority of the constituent cells in bone tissue are osteocytes, but their regulatory mechanisms are incompletely understood. Considering the wide range of potential contributions of lncRNAs to physiological processes and pathological conditions, we hypothesized that lncRNAs in osteocytes, which have not been reported, could be involved in bone metabolism. Here, we first isolated osteocytes from femurs of mice with osteocyte-specific GFP expression. Then, through RNA-sequencing, we identified osteocyte-specific lncRNAs and focused on a novel lncRNA, 9530026P05Rik (lncRNA953Rik), which strongly suppressed osteogenic differentiation. In the IDG-SW3 osteocyte line with lncRNA953Rik overexpression, the expression of and its downstream genes was reduced. RNA pull-down and subsequent LC-MS/MS analysis revealed that lncRNA953Rik bound the nuclear protein CCAR2. We demonstrated that CCAR2 promoted Wnt/β-catenin signaling and that lncRNA953Rik inhibited this pathway. lncRNA953Rik sequestered CCAR2 from HDAC1, leading to deacetylation of H3K27 in the promoter and consequent transcriptional downregulation of . This research is the first to clarify the role of a lncRNA in osteocytes. Our findings can pave the way for novel therapeutic options targeting lncRNAs in osteocytes to treat bone metabolic diseases such as osteoporosis.
转录 RNA 绝大多数是非编码 RNA。在非编码 RNA 中，长链非编码 RNA（lncRNA），包含数百至数千个碱基，在许多领域都受到了关注。骨组织中绝大多数组成细胞是骨细胞，但它们的调节机制尚未完全了解。考虑到 lncRNA 对生理过程和病理状况可能有广泛的潜在贡献，我们假设骨细胞中的 lncRNA 尚未报道，可能参与骨代谢。在这里，我们首先从具有骨细胞特异性 GFP 表达的小鼠股骨中分离出骨细胞。然后，通过 RNA-seq 鉴定骨细胞特异性 lncRNA，并重点研究一种新型 lncRNA，9530026P05Rik（lncRNA953Rik），它强烈抑制成骨分化。在 lncRNA953Rik 过表达的 IDG-SW3 骨细胞系中， 的表达及其下游基因的表达减少。RNA 下拉和随后的 LC-MS/MS 分析表明，lncRNA953Rik 与核蛋白 CCAR2 结合。我们证明 CCAR2 促进了 Wnt/β-catenin 信号通路，而 lncRNA953Rik 抑制了该通路。lncRNA953Rik 将 CCAR2 与 HDAC1 隔离，导致 启动子上 H3K27 的去乙酰化，从而导致 的转录下调。这项研究首次阐明了 lncRNA 在骨细胞中的作用。我们的发现为针对骨细胞中的 lncRNA 的新型治疗方法开辟了道路，以治疗骨质疏松症等骨代谢疾病。
