MSC 来源的小细胞外囊泡通过递送 miR-22-3p 抑制 NLRP3 炎症小体激活来缓解糖尿病视网膜病变。

MSC-Derived Small Extracellular Vesicles Alleviate Diabetic Retinopathy by Delivering miR-22-3p to Inhibit NLRP3 Inflammasome Activation.

机构信息

Department of Ophthalmology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, Jiangsu, People's Republic of China.

Department of Rheumatology and Immunology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, Jiangsu, People's Republic of China.

出版信息

Stem Cells. 2024 Jan 13;42(1):64-75. doi: 10.1093/stmcls/sxad078.

DOI:10.1093/stmcls/sxad078

PMID:37847598

Abstract

PURPOSE

This study aimed to investigate the effect of mesenchymal stem cell (MSC)-derived small extracellular vesicles (sEVs) on diabetic retinopathy (DR) and its underlying mechanism.

METHODS

In vivo, MSC-sEVs were injected intravitreally into diabetic rats to determine the therapeutic efficacy. In vitro, MSC-sEVs with/without miR-22-3p inhibition were cocultured with advanced glycation end-products (AGEs)-induced microglia with/without NLRP3 overexpression to explore the molecular mechanism.

RESULTS

In vivo, MSC-sEVs inhibited NLRP3 inflammasome activation, suppressed microglial activation, decreased inflammatory cytokines levels in the retina, and alleviated DR as evidenced by improved histological morphology and blood-retinal barrier function. Based on miRNA sequencing of MSC-sEVs, bioinformatic software, and dual-luciferase reporter assay, miR-22-3p stood out as the critical molecule for the role of MSC-sEVs in regulating NLRP3 inflammasome activation. Diabetic rats had lower level of miR-22-3p in their retina than those of control and sEV-treated rats. Confocal microscopy revealed that sEV could be internalized by microglia both in vivo and in vitro. In vitro, compared with sEV, the anti-inflammation effect of sEVmiR-22-3p(-) on AGEs-induced microglia was compromised, as they gave a lower suppression of NLRP3 inflammasome activation and inflammatory cytokines. In addition, NLRP3 overexpression in microglia damped the anti-inflammatory effect of sEV.

CONCLUSION

These results indicated that MSC-sEVs alleviated DR via delivering miR-22-3p to inhibit NLRP3 inflammasome activation. Our findings indicate that MSC-sEVs might be a potential therapeutic method for DR.

摘要

目的

本研究旨在探讨间充质干细胞（MSC）衍生的小细胞外囊泡（sEVs）对糖尿病视网膜病变（DR）的影响及其作用机制。

方法

体内实验中，将 MSC-sEVs 玻璃体腔内注射入糖尿病大鼠以确定治疗效果。体外实验中，将 MSC-sEVs 与/或 miR-22-3p 抑制物共培养，与高糖诱导的小胶质细胞（NLRP3 过表达）共培养，以探讨其分子机制。

结果

体内实验中，MSC-sEVs 抑制 NLRP3 炎症小体激活，抑制小胶质细胞激活，降低视网膜中炎症细胞因子水平，改善组织形态学和血视网膜屏障功能，从而缓解 DR。基于 MSC-sEVs 的 miRNA 测序、生物信息学软件和双荧光素酶报告基因检测，miR-22-3p 是 MSC-sEVs 调节 NLRP3 炎症小体激活的关键分子。与对照组和 sEV 治疗组相比，糖尿病大鼠视网膜中 miR-22-3p 水平较低。共聚焦显微镜显示，sEV 可被体内和体外的小胶质细胞内化。体外实验中，与 sEV 相比，sEVmiR-22-3p(-) 对 AGEs 诱导的小胶质细胞的抗炎作用减弱，因为它们对 NLRP3 炎症小体激活和炎症细胞因子的抑制作用降低。此外，小胶质细胞中 NLRP3 的过表达削弱了 sEV 的抗炎作用。