Department of Periodontics, School of Dentistry, Virginia Commonwealth University, Richmond, VA, USA.
Department of Biomedical Engineering, School of Engineering, Virginia Commonwealth University, Richmond, VA, USA.
Sci Rep. 2018 Feb 26;8(1):3609. doi: 10.1038/s41598-018-21517-4.
Chondrocytes at different maturation states in the growth plate produce matrix vesicles (MVs), membrane organelles found in the extracellular matrix, with a wide range of contents, such as matrix processing enzymes and receptors for hormones. We have shown that MVs harvested from growth zone (GC) chondrocyte cultures contain abundant small RNAs, including miRNAs. Here, we determined whether RNA also exists in MVs produced by less mature resting zone (RC) chondrocytes and, if so, whether it differs from the RNA in MVs produced by GC cells. Our results showed that RNA, small RNA specifically, was present in RC-MVs, and it was well-protected from RNase by the phospholipid membrane. A group of miRNAs was enriched in RC-MVs compared RC-cells, suggesting that miRNAs are selectively packaged into MVs. High throughput array and RNA sequencing showed that ~39% miRNAs were differentially expressed between RC-MVs and GC-MVs. Individual RT-qPCR also confirmed that miR-122-5p and miR-150-5p were expressed at significantly higher levels in RC-MVs compared to GC-MVs. This study showed that growth plate chondrocytes at different differentiation stages produce different MVs with different miRNA contents, further supporting extracellular vesicle miRNAs play a role as "matrisomes" that mediate the cell-cell communication in cartilage and bone development.
处于不同成熟状态的软骨细胞在生长板中产生基质小泡（MVs），MVs 是存在于细胞外基质中的膜细胞器，其内容物广泛，包括基质处理酶和激素受体。我们已经表明，从生长区（GC）软骨细胞培养物中收获的 MV 含有丰富的小 RNA，包括 miRNA。在这里，我们确定了较少成熟的静止区（RC）软骨细胞产生的 MV 是否也含有 RNA，如果有，其与 GC 细胞产生的 MV 中的 RNA 是否不同。我们的结果表明，RNA，特别是小 RNA，存在于 RC-MVs 中，并且其被磷脂膜很好地保护免受 RNase 的影响。与 RC 细胞相比，一组 miRNA 在 RC-MVs 中富集，这表明 miRNA 被选择性地包装到 MV 中。高通量阵列和 RNA 测序显示，RC-MVs 和 GC-MVs 之间有约 39%的 miRNA 表达存在差异。个别 RT-qPCR 也证实，与 GC-MVs 相比，miR-122-5p 和 miR-150-5p 在 RC-MVs 中的表达水平显著升高。本研究表明，处于不同分化阶段的生长板软骨细胞产生具有不同 miRNA 含量的不同 MV，进一步支持细胞外囊泡 miRNA 作为“细胞外基质”发挥作用，介导软骨和骨骼发育中的细胞间通讯。
