Aims

Mesenchymal stromal/stem cell (MSC)-derived extracellular vesicles (EVs) shuttle select MSC contents and are endowed with an ability to repair ischemic tissues. We hypothesized that exposure to cardiovascular risk factors may alter the microRNA cargo of MSC-derived EVs, blunting their capacity to repair the post-stenotic kidney in pigs with metabolic syndrome (MetS) and renal artery stenosis (RAS).

Methods

Porcine MSCs were harvested from abdominal fat after 16wks of Lean- or MetS-diet, and their EVs isolated and characterized using microRNA-sequencing. Lean- and MetS-EV protective effects were assessed in-vitro in human umbilical endothelial cells (HUVECs). To compare their in-vivo efficacy to repair ischemic tissues, allogeneic-EVs were intrarenally delivered in pigs after 6wks of MetS + RAS, and 4wks later, single-kidney renal blood flow (RBF) and glomerular filtration rate (GFR) were studied in-vivo, and microvascular architecture and injury ex-vivo. Lean-, MetS-, and MetS + RAS-sham served as controls (n = 6 each).

Results

Ten microRNAs, capable of targeting several pro-angiogenic genes, were upregulated in MetS-EVs versus Lean-EVs. In vitro, MetS-EVs failed to increase tube number and length, and to boost HUVEC migration compared to Lean-EVs. Lean- and MetS-EVs were detected in the stenotic-kidney 4wks after injection in the vicinity of small vessels. RBF and GFR were lower in MetS + RAS versus MetS, and restored in MetS + RAS + Lean-EVs, but not in MetS + RAS + MetS-EVs. Furthermore, MetS-EVs failed to restore renal expression of angiogenic factors, improve microvascular density, or attenuate fibrosis.

Conclusions

MetS alters the microRNA cargo of MSC-derived EVs and impairs their functional potency, limiting the therapeutic efficacy of this endogenous cellular repair system.

中文翻译：

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来自肥胖猪的脂肪组织来源的间充质基质/干细胞释放的细胞外囊泡无法修复受损的肾脏。

宗旨

间充质基质/干细胞 (MSC) 衍生的细胞外囊泡 (EV) 穿梭选择 MSC 内容物，并具有修复缺血组织的能力。我们假设暴露于心血管危险因素可能会改变 MSC 衍生的 EV 的 microRNA 货物，削弱其修复代谢综合征 (MetS) 和肾动脉狭窄 (RAS) 猪狭窄后肾脏的能力。

方法

在 16 周的瘦肉或 MetS 饮食后从腹部脂肪中收获猪 MSC，并使用 microRNA 测序分离和表征它们的 EV。在人脐带内皮细胞 (HUVEC) 中体外评估了精益和 MetS-EV 的保护作用。为了比较它们修复缺血组织的体内功效，在使用 MetS + RAS 6 周后，将同种异体 EV 注入猪体内，4 周后，研究了单肾肾血流量 (RBF) 和肾小球滤过率 (GFR)。 -体内，以及体外微血管结构和损伤。Lean-、MetS- 和 MetS + RAS-sham 作为对照（每个 n = 6）。

结果

与 Lean-EVs 相比，MetS-EVs 中 10 种能够靶向多种促血管生成基因的 microRNAs 上调。在体外，与精益 EV 相比，MetS-EV 未能增加管数和长度，也未能促进 HUVEC 迁移。在小血管附近注射后 4wks 在狭窄肾中检测到 Lean-EVs 和 MetS-EVs。RBF 和 GFR 在 MetS + RAS 中低于 MetS，在 MetS + RAS + Lean-EV 中恢复，但在 MetS + RAS + MetS-EV 中没有恢复。此外，MetS-EVs 未能恢复血管生成因子的肾脏表达、改善微血管密度或减轻纤维化。

结论

MetS 改变了 MSC 衍生的 EV 的 microRNA 货物并削弱了它们的功能效力，限制了这种内源性细胞修复系统的治疗效果。