RESUMEN
Astrocytes play vital roles in blood-brain barrier (BBB) maintenance, yet how they support BBB integrity under normal or pathological conditions remains poorly defined. Recent evidence suggests that ion homeostasis is a cellular mechanism important for BBB integrity. In the current study, we investigated the function of an astrocyte-specific pH regulator, Slc4a4, in BBB maintenance and repair. We show that astrocytic Slc4a4 is required for normal astrocyte morphological complexity and BBB function. Multi-omics analyses identified increased astrocytic secretion of CCL2 coupled with dysregulated arginine-NO metabolism after Slc4a4 deletion. Using a model of ischemic stroke, we found that loss of Slc4a4 exacerbates BBB disruption, which was rescued by pharmacological or genetic inhibition of the CCL2-CCR2 pathway in vivo. Together, our study identifies the astrocytic Slc4a4-CCL2 and endothelial CCR2 axis as a mechanism controlling BBB integrity and repair, while providing insights for a therapeutic approach against BBB-related CNS disorders.
Asunto(s)
Astrocitos , Barrera Hematoencefálica , Quimiocina CCL2 , Receptores CCR2 , Simportadores de Sodio-Bicarbonato , Accidente Cerebrovascular , Animales , Humanos , Masculino , Ratones , Astrocitos/metabolismo , Astrocitos/patología , Barrera Hematoencefálica/metabolismo , Barrera Hematoencefálica/patología , Encéfalo/metabolismo , Encéfalo/patología , Quimiocina CCL2/metabolismo , Ratones Endogámicos C57BL , Receptores CCR2/metabolismo , Transducción de Señal , Accidente Cerebrovascular/metabolismo , Accidente Cerebrovascular/patología , Simportadores de Sodio-Bicarbonato/genética , Simportadores de Sodio-Bicarbonato/metabolismoRESUMEN
Astrocytes play vital roles in blood-brain barrier (BBB) maintenance, yet how they support BBB integrity under normal or pathological conditions remains poorly defined. Recent evidence suggests pH homeostasis is a new cellular mechanism important for BBB integrity. In the current study, we investigated the function of an astrocyte-specific pH regulator, Slc4a4, in BBB maintenance and repair. We show that astrocytic Slc4a4 is required for normal astrocyte morphological complexity and BBB function. Multi-omics analyses identified increased astrocytic secretion of CCL2 coupled with dysregulated arginine-NO metabolism after Slc4a4 deletion. Using a model of ischemic stroke, we found that loss of Slc4a4 exacerbates BBB disruption and reactive gliosis, which were both rescued by pharmacological or genetic inhibition of the NO-CCL2 pathway in vivo. Together, our study identifies the astrocytic Slc4a4-NO-CCL2 axis as a pivotal mechanism controlling BBB integrity and repair, while providing insights for a novel therapeutic approach against BBB-related CNS disorders.