C-Src/β-DG-mediated impairment of glia-vascular unit integrity via AQP4 depolarization contributes to secondary hydrocephalus after intraventricular hemorrhage

Background: Hydrocephalus is represents a serious complication of intraventricular hemorrhage (IVH). Our study aimed to explore the pathogenesis of hydrocephalus after IVH from the perspective of glymphatic system dysfunction to provide new ideas for the clinical diagnosis and treatment of hydrocephalus after IVH. Materials and Methods: In total, 303 Sprague-Dawley (SD) rats were included in this study. A rat model of IVH-induced hydrocephalus was established by injecting autologous blood. On days 1, 3, and 14 following IVH induction, c-Src inhibitors (PP2) and agonists (periplocin) were stereotaxically injected into the brain ventricle. Neurofunctional scoring and magnetic resonance imaging (MRI) examinations were performed 3 and 21 days after IVH. Furthermore, a cell model was constructed using thrombin-induced astrocytes, and cell proliferation experiments were performed to assess phenotypic changes in the cells. Finally, the specific mechanism was verified using western blot (WB), immunofluorescence staining, and other pathological staining methods. Results: After induction of IVH, c-Src expression is increased in the brain, accompanied by increased expression of phosphorylation-β-dystroglycan (p-β-DG)/β-DG and glial fibrillary acidic protein (GFAP). Experimental studies have shown that c-Src induces impairment of the structural integrity of the glymphatic-vascular unit (GVU) through phosphorylation of β-DG, leading to depolarization of aquaporin-4 (AQP4), resulting in neurological dysfunction and ultimately hydrocephalus in rats. Conclusion: c-Src kinase has been markedly activated after IVH, triggering β-DG phosphorylation, facilitating its internalization and trafficking, and ultimately causing AQP4 depolarization. This disturbance in cerebrospinal fluid homeostasis stems from dysfunction of the glymphatic system, which contributes to the pathogenesis of hydrocephalus. Therefore, β-DG phosphorylation has been proposed as a critical molecular target for modulating glymphatic impairment after IVH.