ABSTRACT

Background

Exosomes are extracellular vesicles involved in intercellular communication. The objectives were to characterize bovine milk exosomes (BME) and determine its effect on RAW 264.7 macrophages.

Methods

BME were isolated using differential centrifugation and characterized by particle size and the presence of exosomal markers Alix, TSG101, and CD81. The effect of in vitro digestion and different pH on the stability of BME was investigated. The biological activity of BME in RAW 264.7 macrophages was conducted by assessing proliferation and cell cycle. Moreover, the protective effect of exosomes on cisplatin-induced cytotoxicity was evaluated.

Results

BME have an average particle size of 106.8 ± 3.4 nm and expressed Alix, TSG101, and CD81. TSG101 was detected after digestion and exposure to different pH values. Cell-cycle analysis showed that BME reduced the percentage of apoptotic cells while arresting the cells in G2/M phase accompanied by differential expression of proliferation markers p53, p21, cyclin D1, and β-catenin. Exosomes protected macrophages against cisplatin-induced cytotoxicity.

Conclusion

Our results showed for the first time the effect of BME on the proliferation of RAW 264.7 macrophages and its protective effect against chemotherapeutic drug-induced cytotoxicity. Potential effect of BME on immune system must be studied.

中文翻译：

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牛乳外泌体影响增殖并保护巨噬细胞免受顺铂诱导的细胞毒性作用。

摘要

背景

外泌体是参与细胞间通讯的细胞外囊泡。目的是表征牛乳外泌体（BME）并确定其对RAW 264.7巨噬细胞的影响。

方法

使用差速离心法分离BME，并以粒径和外泌体标记Alix，TSG101和CD81的存在为特征。研究了体外消化和不同pH值对BME稳定性的影响。通过评估增殖和细胞周期来进行RAW 264.7巨噬细胞中BME的生物活性。此外，评估了外来体对顺铂诱导的细胞毒性的保护作用。

结果

BME的平均粒径为106.8±3.4 nm，表示为Alix，TSG101和CD81。消化并暴露于不同pH值后检测到TSG101。细胞周期分析表明，BME可降低凋亡细胞的百分比，同时将细胞停滞在G2 / M期，并伴随增殖标志物p53，p21，cyclin D1和β-catenin的差异表达。外泌体保护巨噬细胞免受顺铂诱导的细胞毒性作用。

结论

我们的结果首次显示了BME对RAW 264.7巨噬细胞增殖的影响及其对化疗药物诱导的细胞毒性的保护作用。必须研究BME对免疫系统的潜在作用。