Accumulating evidence has demonstrated that apoptotic vesicles (apoVs) derived from mesenchymal stem cells (MSCs; MSC-apoVs) are vital for bone regeneration, and possess superior capabilities compared to MSCs and other extracellular vesicles derived from MSCs (such as exosomes). The osteoinductive effect of MSC-apoVs is attributed to their diverse contents, especially enriched proteins or microRNAs (miRNAs). To optimize their osteoinduction activity, it is necessary to determine the unique cargo profiles of MSC-apoVs. We previously established the protein landscape and identified proteins specific to MSC-apoVs. However, the features and functions of miRNAs enriched in MSC-apoVs are unclear. In this study, we compared MSCs, MSC-apoVs, and MSC-exosomes from two types of MSC. We generated a map of miRNAs specific to MSC-apoVs and identified seven miRNAs specifically enriched in MSC-apoVs compared to MSCs and MSC-exosomes, which we classified as apoV-specific miRNAs. Among these seven specific miRNAs, hsa-miR-4485-3p was the most abundant and stable. Next, we explored its function in apoV-mediated osteoinduction. Unexpectedly, hsa-miR-4485-3p enriched in MSC-apoVs inhibited osteogenesis and promoted adipogenesis by targeting the AKT pathway. Tailored apoVs with downregulated hsa-miR-4485-3p exhibited a greater effect on bone regeneration than control apoVs. Like releasing the brake, we acquired more powerful osteoinductive apoVs. In summary, we identified the miRNA cargos, including miRNAs specific to MSC-apoVs, and generated tailored apoVs with high osteoinduction activity, which is promising in apoV-based therapies for bone regeneration.

越来越多的证据表明，源自间充质干细胞（MSC；MSC-apoV）的凋亡囊泡（apoV）对于骨再生至关重要，并且与MSC和其他源自MSC的细胞外囊泡（例如外泌体）相比，具有更优越的能力。 MSC-apoV 的骨诱导作用归因于其不同的含量，特别是富集的蛋白质或 microRNA (miRNA)。为了优化其骨诱导活性，有必要确定 MSC-apoV 的独特货物特征。我们之前建立了蛋白质图谱并鉴定了 MSC-apoV 特异的蛋白质。然而，MSC-apoV 中富集的 miRNA 的特征和功能尚不清楚。在这项研究中，我们比较了来自两种类型 MSC 的 MSC、MSC-apoV 和 MSC-外泌体。我们生成了 MSC-apoV 特异性的 miRNA 图谱，并鉴定了与 MSC 和 MSC 外泌体相比，MSC-apoV 中特异性富集的 7 个 miRNA，我们将其归类为 apoV 特异性 miRNA。在这7个特定的miRNA中，hsa-miR-4485-3p是最丰富和稳定的。接下来，我们探讨了其在 apoV 介导的骨诱导中的功能。出乎意料的是，富含MSC-apoV的hsa-miR-4485-3p通过靶向AKT途径抑制成骨并促进脂肪生成。下调 hsa-miR-4485-3p 的定制 apoV 对骨再生的影响比对照 apoV 更大。就像松开刹车一样，我们获得了更强大的骨诱导性apoV。总之，我们鉴定了 miRNA 货物，包括 MSC-apoV 特异性的 miRNA，并生成了具有高骨诱导活性的定制 apoV，这在基于 apoV 的骨再生疗法中很有前景。