Purpose

Mesenchymal stem cells (MSCs) have appeared as a promising regenerative cell-based therapeutic, for degenerative conditions, such as OA, while the beneficial results from the application of MSCs have been attributed to the MSCs-derived secretome, which is the sum of cytoprotective factors produced by the MSCs. Aim of this study was to systematically review the literature in order to assess whether stem cell secretome (conditioned medium-CM, exosome-Exos or microvesicles-MV)(CM/Exos/MVs) treatment reduces inflammation and enhances cartilage regeneration in preclinical studies of experimental arthritis.

Materials and Methods

An extensive electronic search was conducted by 2 independent reviewers by using the PubMed, Cochrane Library, Web of Science, and Scopus database, as well as Google Scholar, in order to identify the studies that met our inclusion criteria until August 2019. Included studies were assessed for quality and Risk of Bias (RoB) using the ARRIVE (Animal Research: Reporting In Vivo Experiments) guidelines and a modification of Systematic Review Centre for Laboratory animal Experimentation (SYRCLE) RoB tool for animal studies, respectively.

Results

The initial search provided 525 records, with 28 fulfilling the inclusion criteria. The included studies presented great heterogeneity regarding the stem cells used, the preparation of therapeutic agent as well as the animal models used for testing. In addition, most studies presented with an unclear or high risk bias.

Conclusion

In summary, the positive results of CM/Exos/MVs application in preclinical models of experimentally induced OA in terms of resolution of inflammation and cartilage regeneration are highlighted in this review, presenting a promising therapeutic solution for OA.

中文翻译：

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干细胞分泌组应用在骨关节炎中的功效：体内研究的系统评价。

目的

间充质干细胞 (MSCs) 已成为一种有前途的基于再生细胞的治疗剂，用于退行性疾病，如 OA，而应用 MSCs 的有益结果归因于 MSCs 衍生的分泌组，它是细胞保护作用的总和。 MSCs 产生的因素。本研究的目的是系统地回顾文献，以评估干细胞分泌组（条件培养基-CM、外泌体-Exos 或微泡-MV）（CM/Exos/MVs）治疗是否能减轻炎症并增强软骨再生。实验性关节炎。

材料和方法

2 位独立评审员使用 PubMed、Cochrane 图书馆、Web of Science 和 Scopus 数据库以及 Google Scholar 进行了广泛的电子搜索，以确定在 2019 年 8 月之前符合我们纳入标准的研究。分别使用 ARRIVE（动物研究：体内实验报告）指南和用于动物研究的实验室动物实验系统审查中心 (SYRCLE) RoB 工具的修改来评估质量和偏差风险 (RoB)。

结果

最初的搜索提供了 525 条记录，其中 28 条符合纳入标准。纳入的研究在所使用的干细胞、治疗剂的制备以及用于测试的动物模型方面存在很大的异质性。此外，大多数研究存在不明确或高风险的偏倚。

结论

总之，本综述强调了 CM/Exos/MVs 在实验诱导的 OA 临床前模型中在炎症消退和软骨再生方面的积极结果，为 OA 提供了一种有前途的治疗解决方案。