The Study On Brain Injury Of N-methyl-D-aspartate-induced Infantile Spasms Rat Model By Differential Proteomic Analysis

Objective Infantile spasms (IS) is s an age-specific epileptic encephalopathycharacterized by flexor, extensor, mixed flexor-extensor spasms, hypsarrhythmia andmental retardation. About70%to90%of patients associated with severe cognitiveimpairment. The causes of disease may be over200. From clinical epidemiologyinvestigation, we found that the onset risk of infantile spasms correspondinglyincreased with the degree of maternal prenatal stress. Infantile spasms is a refractoryepilepsy, poor response to nearly all traditional anti-epileptic drugs exceptadrenocorticotropic hormone (ACTH). The study aimed to investigate thepathogenesis of infantile spasms, effect of prenatal stress, and protective mechanismof ACTH treatment.Methods An infantile spasm rat model induced by N-methyl-D-aspartate(NMDA) in neonate rats was used. A proteomics-based approach was used to detectthe differential expression proteins as following:(1) Spasm Model group vs NormalControl group to study pathogenesis of infantile spasms;(2)Prenatal Stress-SpasmsModel group vs Spasms Model group to study effect of prenatal stress;(3) PrenatalStress-Spasms Model-ACTH treatment group vs Prenatal Stress-Spasms Modelgroup to reseach protective mechanism of ACTH. Gel image analysis was followedby mass spectrometric protein identification, bioinformatics analysis.Draw differential expression proteins interaction networks to explore the biologicalfunctions. Some differential expression proteins were verified by western-blotanalysis. Five paraffin-embedded surgery resected epileptogenic foci tissues ofinfantile spasms patients were obtained. And the very important differential expression protein was verified by immunohistochemistry.Results (1) Compared with Spasms Model group, the Prenatal Stress-SpasmsModel group exhibited a shorter latency period (t=3.96, P <0.001), and an increasedspasm frequency (t=8.65, P <0.001); compared with Prenatal Stress-Spasms Modelgroup，the Prenatal Stress-Spasms Model-ACTH treatment group exhibited a longerlatency period (t=6.9, P <0.001), and an decreased spasm frequency (t=5.75, P<0.001).(2) Compared with Normal Control, Pkm2, ATP6V1B2, Prps2, ARHGDIA,CFL1, DPYSL3were down regulation in Spasm Model.(3) The YWHAZ proteindown regulated in Prenatal Stress-Spasms Model compared with Spasms Model.(4)Proteomic analysis for ACTH treatment group and non-treatment group, we founddifferential expression proteins including Tuba1a, CFL1, SNAP-25, ARHGDIA,MDH, DDAH1and ANNEX3.(5) ARHGDIA expressions were more obvious (nostatistical analysis was performed due to the small sample size) in epileptogenic focitissues of ACTH treated patients.Conclusion (1) Prenatal stress exposure resulted in more severe seizures andbetter response to ACTH treatment, which is correlative with the infantile spasms.(2)Pkm2, ATP6V1B2, Prps2, ARHGDIA, CFL1, DPYSL3were down regulation inspasm model, it suggests that the energy metabolism dysfunction,encephalodysplasia and synaptic reorganization maybe the damage factors of neuron.(3) The down regulation of YWHAZ maybe one of important causes for aggravatingspasm in prenatal stress group.(4) Compared ACTH treatment group withnon-treatment group, the differential proteins involved in the cytoskeleton, synapses,energy metabolism, vascular regulation, and implied that protective mechanismmaybe related to signal transduction, nerve conduction, synaptic reorganization andacetylation.(5) Differential expression of ARHGDIA in5cases of IS patientssurgical specimens, which maybe related to ACTH treatment and worth furtherstudying.