Changes In The Heart Of SOD1G93A Transgenic Mice

Objective: Amyotrophic lateral sclerosis(ALS),also known as motor neuron disease(MND),is a fatal degenerative disease that affects motor neurons.There is no effective treatment at present,and the survival time is 3-5 years.Due to progressive degeneration and death of the upper and lower motor neurons,progressively aggravated muscle atrophy,muscle weakness,muscle bundle tremor,muscle spasm,hypertenoid reflex,and positive pathological signs,and severe respiratory paralysis occurs in severe cases.ALS appears as familial ALS(FALS)(about 5%-10% of cases)and sporadic ALS(SALS)(about 90%-95% of cases).Mutations in the copper / zinc(Cu / Zn)superoxide dismutase(SOD1)gene account for approximately 20% of FALS cases.SOD1G93 A transgenic mice show progressive motor neuron degeneration,similar to human ALS,and are recognized animal models of ALS in the world.They have been widely used in ALS pathogenesis and drug screening.In recent years,research has found that ALS not only affects upper and lower motor neurons,but also affects multiple systems.For example,patients with ALS can be combined with unclassified cardiomyopathy(CMP),including left ventriculazr trabeculae or compactness(LVHT).And Takotsubo syndrome(TTS),cardiac magnetic resonance(CMR)imaging and other examinations have significant changes.However,little research has been done on the heart of SOD1G93 A transgenic mice models.Therefore,in this study,the hearts of SOD1G93 A transgenic mice at different stages were observed through histopathological and immunohistochemical methods.Methods:1.Animal modelMale B6SJL-Tg(SOD1-G93A)1 Gur / J mice were crossed with female B6 SJL / F1 mice to generate transgenic mice with the SOD1G93 A mutation gene.The mice were subjected to polymerase chain reaction at 21 days.)Identified transgenic mice bearing the SOD1G93 A mutation.As the experimental group,non-transgenic mice of the same litter and the same month age were used as the control group,with 3 animals in each group.2.Tissue processing and HE,immunohistochemical stainingTake samples at 60 d,90d and end stage,weigh the weight of the mice and heart;perform HE staining and immunohistochemical staining3.Statistical processingSPSS22.0 statistical software was used for statistical processing.Mean ± SD is used to represent the sum of mice heart weight,mice body weight,mice heart weight / mice body weight,mice cardiac CD11 b expression counts,and cardiac Collagen-1 expression area / single visual field area,.The t test was used to compare the two groups of data,and P <0.05 was considered statistically significant.Results:1.Compared with wild type,the heart weight of SOD1G93 A transgenic mice decreased significantly with the onset of time and the end-stage heart weight P <0.05 and the mice body weight P <0.05,which was statistically different.But heart weight / body weight,P > 0.05,there is no statistical difference.2.Compared with wild-type,end-stage SOD1G93 A transgenic mice myocardial HE staining showed that myocardial fibers were disorderly arranged,unevenly distributed,morphologically different,and cell nuclei were aggregated.3.Compared with the wild type,at 60 d,90d,endstage,SOD1G93 A transgenic mice cardiac CD11 b expressing cell number P<0.05,which was statistically different.4.Compared with the wild type,at 60 days,the collagen-1 expression area / single visual field area of the mice myocardium P value was >0.05,and there was no statistical difference.At 90 days,at the end stage,the collagen-1 expression area / single visual field area of the mice myocardium P value was <0.05,which was statistically different.Conclusions:The SOD1G93 A transgenic mice had significantly reduced heart weight and body weight at the end-stage,but the heart weight / body weight remained basically unchanged;myocardial structural disturbances,myocardial cell nucleus aggregation,and inward migration;myocardial inflammatory response increased;and end-stage myocardial fibrosis changed significantly.