title: Role of hepcidin and its downstream proteins in early brain injury after experimental subarachnoid hemorrhage in rats.
abstract: Early brain injury (EBI) is a major cause of mortality from subarachnoid hemorrhage (SAH). We aimed to study the pathophysiology of EBI and explore the role of hepcidin, a protein involved in iron homeostatic regulation, and its downstream proteins. One hundred and thirty-two male Sprague-Dawley rats were assigned into groups (n = 24/group): sham, SAH, SAH + hepcidin, SAH + hepcidin-targeting small interfering ribonucleic acid (siRNA), and SAH + scramble siRNA. Three hepcidin-targeting siRNAs and one scramble siRNA for hepcidin were injected 24 h before hemorrhage induction, and hepcidin protein was injected 30 min before induction. The rats were neurologically evaluated at 24 h and euthanized at 72 h. Hepcidin, ferroportin-1, and ceruloplasmin protein expression were measured by immunohistochemistry and Western blotting. Brain water content, blood-brain barrier (BBB) leakage, non-heme tissue iron and Garcia scale were evaluated. Hepcidin expression increased in the cerebral cortex and hippocampus after experimental SAH (P < 0.05 compared to sham), while ferroportin-1 and ceruloplasmin decreased (P < 0.05). Hepcidin injection lowered the expression of ferroportin-1 and ceruloplasmin further but siRNA reduced the levels of hepcidin (P < 0.05 compared to SAH) resulting in recovery of ferroportin-1 and ceruloplasmin levels. Apoptosis was increased in SAH rats compared to sham (P < 0.05) and increased slightly more by hepcidin, but decreased by siRNA (P < 0.05 compared to SAH). SAH rats had lower neurological scores, high brain water content, BBB permeability, and non-heme tissue iron (P < 0.05). In conclusion, downregulation of ferroportin-1 and ceruloplasmin caused by hepcidin enhanced iron-dependent oxidative damage and may be the potential mechanism of SAH.
authors.affiliation: Department of Neurosurgery, First Affiliated Hospital of Chongqing Medical University, Chongqing, 400042, China.
authors.forename: Guanping
authors.initials: G
authors.lastname: Tan
authors.affiliation: Department of Neurosurgery, First Affiliated Hospital of Chongqing Medical University, Chongqing, 400042, China.
authors.forename: Liu
authors.initials: L
authors.lastname: Liu
authors.affiliation: Department of Neurosurgery, First Affiliated Hospital of Chongqing Medical University, Chongqing, 400042, China. geno_he@163.com.
authors.forename: Zhaohui
authors.initials: Z
authors.lastname: He
authors.affiliation: Department of Neurosurgery, First Affiliated Hospital of Chongqing Medical University, Chongqing, 400042, China.
authors.forename: Jiujun
authors.initials: J
authors.lastname: Sun
authors.affiliation: Department of Neurosurgery, First Affiliated Hospital of Chongqing Medical University, Chongqing, 400042, China.
authors.forename: Wenli
authors.initials: W
authors.lastname: Xing
authors.affiliation: Department of Neurosurgery, First Affiliated Hospital of Chongqing Medical University, Chongqing, 400042, China.
authors.forename: Xiaochuan
authors.initials: X
authors.lastname: Sun
mesh_terms: D000818:Animals; D001812:Blood-Brain Barrier / Q000378:metabolism* / Q000473:pathology; D001930:Brain Injuries / Q000378:metabolism* / Q000473:pathology; D064451:Hepcidins / Q000378:metabolism*; D008297:Male; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013345:Subarachnoid Hemorrhage / Q000378:metabolism* / Q000473:pathology
chemical_list: D064451:Hepcidins; D009419:Nerve Tissue Proteins
keywords: Apoptosis; Early brain injury; Hepcidin; Rats; Subarachnoid hemorrhage; siRNA