Department of Neurosurgery, Affiliated Beijing Shijitan Hospital, Capital Medical University, Beijing, 100038, China.
Department of Neurosurgery, Affiliated Beijing Jishuitan Hospital, Capital Medical University, Beijing, China.
J Nanobiotechnology. 2024 Jul 19;22(1):426. doi: 10.1186/s12951-024-02708-w.
Subarachnoid hemorrhage (SAH) is a severe stroke subtype that lacks effective treatment. Exosomes derived from human dental pulp stem cells (DPSCs) are a promising acellular therapeutic strategy for neurological diseases. However, the therapeutic effects of DPSC-derived exosomes (DPSC-Exos) on SAH remain unknown. In this study, we investigated the therapeutic effects and mechanisms of action of DPSC-Exos in SAH.
SAH was established using 120 male Sprague-Dawley rats. One hour after SAH induction, DPSC-Exos were administered via tail vein injection. To investigate the effect of DPSC-Exos, SAH grading, short-term and long-term neurobehavioral assessments, brain water content, western blot (WB), immunofluorescence staining, Nissl staining, and HE staining were performed. The role of miR-197-3p/FOXO3 in regulating pyroptosis was demonstrated through miRNA sequencing, bioinformatics analysis, and rescue experiments. The SAH model in vitro was established by stimulating BV2 cells with hemoglobin (Hb) and the underlying mechanism of DPSC-Exos was investigated through WB and Hoechst/PI staining.
The expressions of pro-inflammatory cytokines (IL-1β, IL-6, and TNF-α) were increased after SAH. DPSC-Exos alleviated brain edema and neuroinflammation by inhibiting the expression of FOXO3 and reducing NLRP3 inflammasome activation, leading to improved neurobehavioral functions at 24 h after SAH. In vitro, the expression of the NLRP3 inflammasome components (NLRP3 and caspase1-p20), GSDMD-N, and IL-18 was inhibited in BV2 cells pretreated with DPSC-Exos. Importantly, DPSC-Exos overexpressing miR-197-3p had a more obvious protective effect than those from NC-transfected DPSCs, while those from DPSCs transfected with the miR-197-3p inhibitor had a weaker protective effect. Functional studies indicated that miR-197-3p bound to the 3'-untranslated region of FOXO3, inhibiting its transcription. Furthermore, the overexpression of FOXO3 reversed the protective effects of miR-197-3p.
DPSC-Exos inhibited activation of the NLRP3 inflammasome and related cytokine release via the miR-197-3p/FOXO3 pathway, alleviated neuroinflammation, and inhibited microglial pyroptosis. These findings suggest that using DPSC-Exos is a promising therapeutic strategy for SAH.
蛛网膜下腔出血（SAH）是一种缺乏有效治疗方法的严重中风亚型。人牙髓干细胞（DPSC）衍生的外泌体是一种有前途的神经疾病无细胞治疗策略。然而，DPSC 衍生的外泌体（DPSC-Exos）对 SAH 的治疗效果尚不清楚。在这项研究中，我们研究了 DPSC-Exos 在 SAH 中的治疗效果和作用机制。
使用 120 只雄性 Sprague-Dawley 大鼠建立 SAH。在 SAH 诱导后 1 小时，通过尾静脉注射给予 DPSC-Exos。为了研究 DPSC-Exos 的作用，进行了 SAH 分级、短期和长期神经行为评估、脑水含量、western blot（WB）、免疫荧光染色、尼氏染色和 HE 染色。通过 miRNA 测序、生物信息学分析和挽救实验证明了 miR-197-3p/FOXO3 在调节细胞焦亡中的作用。通过刺激 BV2 细胞用血红蛋白（Hb）建立体外 SAH 模型，并通过 WB 和 Hoechst/PI 染色研究 DPSC-Exos 的潜在机制。
SAH 后促炎细胞因子（IL-1β、IL-6 和 TNF-α）的表达增加。DPSC-Exos 通过抑制 FOXO3 的表达和减少 NLRP3 炎性小体的激活来减轻脑水肿和神经炎症，从而在 SAH 后 24 小时改善神经行为功能。在体外，用 DPSC-Exos 预处理的 BV2 细胞中 NLRP3 炎性小体成分（NLRP3 和 caspase1-p20）、GSDMD-N 和 IL-18 的表达受到抑制。重要的是，过表达 miR-197-3p 的 DPSC-Exos 比转染 NC 的 DPSCs 的 DPSC-Exos 具有更明显的保护作用，而转染 miR-197-3p 抑制剂的 DPSCs 的 DPSC-Exos 的保护作用较弱。功能研究表明，miR-197-3p 与 FOXO3 的 3'-非翻译区结合，抑制其转录。此外，FOXO3 的过表达逆转了 miR-197-3p 的保护作用。
DPSC-Exos 通过 miR-197-3p/FOXO3 途径抑制 NLRP3 炎性小体的激活和相关细胞因子的释放，减轻神经炎症，抑制小胶质细胞细胞焦亡。这些发现表明，使用 DPSC-Exos 是治疗 SAH 的一种有前途的治疗策略。
