Department of Neurosurgery, Central South University Xiangya School of Medicine Affiliated Haikou Hospital, Haikou, 570208, Hainan Province, People's Republic of China.
Mol Neurobiol. 2023 Jan;60(1):1-17. doi: 10.1007/s12035-022-03037-5. Epub 2022 Oct 8.
Exosomes generated by BMSCs contribute to functional recovery in ischemic stroke. However, the regulatory mechanism is largely unknown. Exosomes were isolated from BMSCs. Tube formation, MTT, TUNEL, and flow cytometry assays were applied to examine cell angiogenesis, viability, and apoptosis. Protein and DNA interaction was evaluated by ChIP and luciferase assays. LDH release into the culture medium was examined. Infarction area was evaluated by TTC staining. Immunofluorescence staining was applied to examine CD31 expression. A mouse model of MCAO/R was established. BMSC-derived exosomes attenuated neuronal cell damage and facilitated angiogenesis of brain endothelial cells in response to OGD/R, but these effects were abolished by the knockdown of Egr2. Egr2 directly bound to the promoter of SIRT6 to promote its expression. The incompetency of Egr2-silencing exosomes was reversed by overexpression of SIRT6. Furthermore, SIRT6 inhibited Notch signaling via suppressing Notch1. Overexpression of SIRT6 and inhibition of Notch signaling improved cell injury and angiogenesis in OGD/R-treated cells. BMSC-derived exosomal Egr2 ameliorated MCAO/R-induced brain damage via upregulating SIRT6 to suppress Notch signaling in mice. BMSC-derived exosomes ameliorate OGD/R-induced injury and MCAO/R-caused cerebral damage in mice by delivering Egr2 to promote SIRT6 expression and subsequently suppress Notch signaling. Our study provides a potential exosome-based therapy for ischemic stroke.
BMSC 来源的外泌体有助于缺血性脑卒中的功能恢复。然而，其调控机制在很大程度上尚不清楚。我们从 BMSC 中分离出外泌体。通过管形成、MTT、TUNEL 和流式细胞术检测来评估细胞血管生成、活力和凋亡。通过 ChIP 和荧光素酶检测评估蛋白质和 DNA 相互作用。通过测定 LDH 释放到培养基中来评估其损伤。通过 TTC 染色评估梗死面积。通过免疫荧光染色检测 CD31 表达。建立 MCAO/R 小鼠模型。BMSC 来源的外泌体减轻了 OGD/R 诱导的神经元细胞损伤，并促进了脑内皮细胞的血管生成，但这些作用被 Egr2 的敲低所消除。Egr2 直接与 SIRT6 的启动子结合以促进其表达。通过过表达 SIRT6 逆转了 Egr2 沉默外泌体的无能。此外，SIRT6 通过抑制 Notch1 抑制 Notch 信号。过表达 SIRT6 和抑制 Notch 信号改善了 OGD/R 处理细胞中的细胞损伤和血管生成。BMSC 来源的外泌体 Egr2 通过上调 SIRT6 抑制 Notch 信号来改善 MCAO/R 诱导的脑损伤，从而在小鼠中减轻脑缺血再灌注损伤。BMSC 来源的外泌体通过向细胞内递送 Egr2 来促进 SIRT6 表达，从而抑制 Notch 信号，从而改善 OGD/R 诱导的损伤和 MCAO/R 引起的脑损伤，为缺血性脑卒中提供了一种潜在的基于外泌体的治疗方法。
