Exosomal miR-149 from human umbilical cord mesenchymal stem cells attenuates spinal cord injury-induced blood-spinal cord barrier disruption by suppressing the ET-1/PI3K/Akt signaling pathway

hUC-MSC-derived exosomal miR-149 preserves BSCB integrity and promotes functional recovery after SCI by targeting ET-1 and inhibiting the PI3K/Akt pathway, thereby enhancing junctional protein expression. The miR-149/ET-1 axis may represent a promising therapeutic target for SCI.