iPSC-sEVs alleviate microglia senescence to protect against ischemic stroke in aged mice

Xinyu Niu; Yuguo Xia; Lei Luo; Yu Chen; Ji Yuan; Juntao Zhang; Xianyou Zheng; Qing Li; Zhifeng Deng; Yang Wang

doi:10.1016/j.mtbio.2023.100600

iPSC-sEVs alleviate microglia senescence to protect against ischemic stroke in aged mice

Mater Today Bio. 2023 Mar 4:19:100600. doi: 10.1016/j.mtbio.2023.100600. eCollection 2023 Apr.

Authors

Xinyu Niu¹, Yuguo Xia², Lei Luo³, Yu Chen⁴, Ji Yuan⁴, Juntao Zhang⁴, Xianyou Zheng⁴, Qing Li⁴, Zhifeng Deng¹, Yang Wang⁴

Affiliations

¹ Department of Neurosurgery, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200233, China.
² Department of Neurosurgery; National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan, 410008, China.
³ School of Biomedical Engineering, Shanghai Jiao Tong University, 1954, Huashan Road, Shanghai 200030, China.
⁴ The Institute of Microsurgery on Extremities, Department of Orthopedic Surgery, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200233, China.

Abstract

The polarization of microglia plays an important role in the outcome of ischemic stroke (IS). In the aged population, senescent microglia show a predominant pro-inflammatory phenotype, which leads to worse outcomes in aged ischemic stroke compared to young ischemic stroke. Recent research demonstrated that inducible pluripotent stem cell-derived small extracellular vesicles (iPSC-sEVs) possess the significant anti-ageing ability. We hypothesized that iPSC-sEVs could alleviate microglia senescence to regulate microglia polarization in aged ischemic stroke. In this study, we showed that treatment with iPSC-sEVs significantly alleviated microglia senescence as indicated by the decreased senescence-associated proteins including P16, P21, P53, and γ-H2AX as well as the activity of SA-β-gal, and inhibited pro-inflammatory activation of microglia both in vivo and in vitro. Furthermore, iPSC-sEVs shifted microglia from pro-inflammatory phenotype to anti-inflammatory phenotype, which reduced the apoptosis of neurons, and improved the outcome of aged stroke mice. Mechanism studies showed that iPSC-sEVs reversed the loss of Rictor and downstream p-AKT (s473) in senescent microglia, which was involved in the senescence and pro-inflammatory phenotype regulation of microglia. Inhibition of Rictor abolished the iPSC-sEVs-afforded phosphorylation of AKT and alleviation of inflammation of senescent microglia. Proteomics results indicated that iPSC-sEVs carried transforming growth factor-β1 (TGF-β1) to upregulate Rictor and p-AKT in senescent microglia, which could be hindered by blocking TGF-β1. Taken together, our work demonstrates iPSC-sEVs reverse the senescent characteristic of microglia in aged brains and therefore improve the outcome after stroke, at least, via delivering TGF-β1 to upregulate Rictor and p-AKT. Our data suggest that iPSC-sEVs might be a novelty therapeutic method for aged ischemic stroke and other diseases involving senescent microglia.

Keywords: Aging; Induced pluripotent stem cell-derived small extracellular vesicles (iPSC-sEVs); Ischemic stroke; Senescent microglia.