Rasd1 aggravates white matter injury after subarachnoid hemorrhage in rats by promoting ferroptosis in oligodendrocytes

Abstract

Objective To explore the underlying mechanism in which Ras related dexamethasone induced 1(Rasd1) is involved in white matter injury through neuron-oligodendrocyte communication after subarachnoid hemorrhage (SAH) in SD rats. Methods Ninety male SD rats (180~250 g) were randomly divided into sham operation group, SAH group, SAH+LV-NC group, SAH+LV-Rasd1 group and SAH+sh-Rasd1 group, with 12 rats in each group.Intravascular puncture was used to construct the rat model of SAH.Rasd1 overexpression/knockdown lentivirus was injected into the lateral ventricle.Neurobehavioral rating scale was used to observe the changes in neural function, transmission electron microscopy was employed to detect the myelin detachment in callosum region and the occurrence of ferroptosis in oligodendrocytes, and Prussian blue staining was applied to measure iron deposition.Malondialdehyde (MDA) and glutathione (GSH) contents were detected with corresponding reagent kits, Rasd1 mRNA level was detected by PCR, and protein levels of nuclear receptor coactivator 4(NCOA4), 2′, 3′-cyclic-nucleotide 3′-phosphodiesterase (CNPase), glutathione peroxidase 4(GPX4) and ferritin were measured with Western blotting. Results SAH resulted in significantly highly expressed Rasd1, which was mainly distributed in the cortical neurons (P < 0.01), myelin loss, and ferroptosis in oligodendrocytes.Rasd1 overexpression significantly reduced the neurobehavioral scores, but increased myelin loss, ferroptosis and iron deposition in oligodendrocytes, elevated MDA content (P < 0.01) but decreased GSH content (P < 0.01), and up-regulation of NCOA4 expression (P < 0.01) and down-regulation of ferritin and GPX4(P < 0.01).However, Rasd1 knockdown reversed all above changes with statistical significances (all P < 0.01). Conclusion Rasd1 promotes ferroptosis in oligodendrocytes through ferritinophagy, and then is involved in white matter injury after SAH.

Keywords

• subarachnoid hemorrhage
• rasd1
• ferroptosis
• white matter injury