Peripheral nerve injury is a salient clinical problem but lacks successful treatment schemes. Here we show the protective mechanism of hypoxia-induced Schwann cells-derived extracellular vesicles (H-E Show more
Peripheral nerve injury is a salient clinical problem but lacks successful treatment schemes. Here we show the protective mechanism of hypoxia-induced Schwann cells-derived extracellular vesicles (H-EVs) carrying lncRNA TNXA-PS1 in peripheral nerve injury. EVs isolated from RSC96 cells undergo hypoxia (H) induction. Sciatic nerve injury is induced in rats, and the animals are evaluated by Sciatic Nerve Function Index, gastrocnemius muscle mass ratio, hematoxylin & eosin stain, and sensory recovery tests. LncRNA TNXA-PS1, miR-338-3p, and EGFL7 expression is tested by RT-qPCR and Western blot. Proliferation, migration, and angiogenesis of H-EVs- treated endothelial cells are assessed by CCK-8, EdU staining, transwell, and tubular formation assays. Nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), NF200, P0, CD31, and vascular endothelial growth factor (VEGF) are detected. Dual luciferase assay analyzes the binding of lncRNA TNXA-PS1, miR-338-3p, and EGFL7. Results reveal that H-EVs alleviate gastrocnemius muscle atrophy, facilitate motor function recovery, and elevate NGF, BDNF, NF200, P0, CD31, and VEGF in tissues. H-EVs promote endothelial cell proliferation, migration, and tubular formation. Mechanistically, H-EVs carry lncRNA TNXA-PS1 into endothelial cells, thus upregulating EGFL7 expression by sponging miR-338-3p. Collectively, H-EVs carrying lncRNA TNXA-PS1 promote angiogenesis and nerve function recovery post sciatic nerve injury via miR-338-3p/EGFL7 axis. Show less
In the core of a stroke, cell death occurs within minutes. In the penumbra, activity quickly drops, but cells typically remain viable for several hours. Improving neuronal survival in the penumbra is Show more
In the core of a stroke, cell death occurs within minutes. In the penumbra, activity quickly drops, but cells typically remain viable for several hours. Improving neuronal survival in the penumbra is crucial for enhancing recovery in patients with stroke. Earlier work showed that mild activation may improve recovery, but the mechanisms are unclear. Brain-derived neurotrophic factor (BDNF) is well recognized for its neuroprotective functions via activation of tyrosine receptor kinase B (TrkB) receptors, and its release is activity-dependent. This study explored the role of BDNF/TrkB signaling in neuronal survival under hypoxic conditions, using cultures of dissociated cortical rat neurons. When exposed to hypoxia, activity quickly drops and cells become apoptotic after ∼12 h, similar to observations in the ischemic penumbra. Inhibition of the TrkB receptor in healthy, normoxic cultures led to a fivefold increase in apoptosis, confirming the importance of BDNF/TrkB signaling for cell viability in these preparations. The addition of BDNF to hypoxic cultures significantly improved neuronal survival, comparable with the effects of mild activation. These findings suggest that the beneficial effect of mild stimulation to prevent apoptosis in hypoxic cultures is mediated by BDNF/TrkB signaling, offering insights for potential therapeutic strategies aimed at promoting neuronal recovery after a stroke. Show less