Neural stem cell-derived exosomes-loaded adhesive hydrogel controlled-release promotes cerebral angiogenesis and neurological function in ischemic stroke.

OBJECTIVE: Ischemic stroke has become one of the leading diseases for international death, which brings burden to the economy and society. Exosomes (Exos) derived following neural stem cells (NSCs) stimulation promote neurogenesis and migration of NSCs. However, Exos themselves are easily to be removed in vivo. Our study is to investigate whether adhesive hyaluronic acid (HAD) hydrogel loading NSCs-derived-Exo (HAD-Exo) would promote the recovery of ischemic stroke. METHODS: A mouse model of middle cerebral artery occlusion (MCAO) was established. PBS, Exo, HAD, and HAD-Exo groups were independently stereotactically injected in mice, respectively. The modified neurological severity score scale and behaviour tests were used to evaluate neurological improvement. Neuroimagings were used to observe the improvement of cerebral infarct volume and vessels. Immunofluorescence staining was used to verify the expression of vascular and cell proliferation-related proteins. RESULTS: The structural and mechanical property of HAD and HAD-Exo were detected. Behavioral results showed that HAD-Exo significantly improved neurological functions, especially motor function. Neuroimagings showed that HAD-Exo significantly promoted infarct volume and angiogenesis. Immunofluorescence staining showed that HAD-Exo significantly promoted the cerebral angiogenesis and anti-inflammation. CONCLUSION: NSCs derived exosomes-loaded adhesive HAD hydrogel controlled-release could promote cerebral angiogenesis and neurological function for ischemic stroke.

Lycium barbarum polysaccharide inhibits ischemia-induced autophagy by promoting the biogenesis of neural stem cells-derived extracellular vesicles to enhance the delivery of miR-133a-3p.

BACKGROUND: Neural stem cell-derived extracellular vesicles (NSC-EVs) mediated endogenous neurogenesis determines a crucial impact on spontaneous recovery after stroke. Here, we checked the influence of Lycium barbarum polysaccharide (LBP) on the biogenesis of NSC-EVs and then focused on studying mechanisms of LBP in ameliorating ischemic stroke outcome. METHODS: LBP was prepared to precondition NSCs and isolate EVs. MCAO models and primary NSCs were administrated to evaluate the therapeutic effect. RT-PCR, western blot, flow cytometry, and immunofluorescence techniques were performed to explore the mechanism. RESULTS: LBP pretreatment increased the production of NSC-EVs and improved the neuroprotective and recovery effects of NSC-EV in ischemic stroke mice. LBP-pretreated NSC-EV in a dose-dependent manner substantially reduced neuronal death compared with NSC-EV. Screening of the signaling cascade involved in the interaction between NSC-EV and neurons revealed that AMPK/mTOR signaling pathway inhibited autophagic activity in neurons receiving either treatment paradigm. NSC-EVs but not EVs collected from NSCs pretreated with the anti-miR-133a-3p oligonucleotide reduced cell death, whereas the anti-oligonucleotide promoted autophagy activity and cell death by modulating AMPK/mTOR signaling in OGD-induced primary neurons. CONCLUSION: LBP activated AMPK/mTOR signaling pathway by increasing the enrichment and transfer of miR-133a-3p in NSC-EVs to inhibit stroke-induced autophagy activity.