Background:Multiple mitochondrial dysfunction syndromes(MMDS)are rare mitochondrial diseases caused by mutation of mitochondrial iron–sulfur cluster synthesis proteins.This study established a rat model simulating MM...Background:Multiple mitochondrial dysfunction syndromes(MMDS)are rare mitochondrial diseases caused by mutation of mitochondrial iron–sulfur cluster synthesis proteins.This study established a rat model simulating MMDS5 disease in the nervous system to investigate its pathological features and neuronal death.Methods:We generated neuron-specific Isca1 knockout rat(Isca1 flox/flox-NeuN-Cre)using CRISPR-Cas9 technology.The brain structure changes of CKO rats were studied with MRI,and the behavior abnormalities were analyzed through gait analysis and open field tests,Y maze tests and food maze tests.The pathological changes of neurons were analyzed through H&E staining,Nissl staining,and Golgi staining.Mitochondrial damage was assessed by TEM,western blot and ATP assay,and the morphology of neurons was assessed by WGA immunofluorescence to detect the death of neurons.Results:This study established the disease model of MMDS5 in the nervous system for the first time,and found that after Isca1 loss,the rats suffered from developmental retardation,epilepsy,memory impairment,massive neuronal death,reduced number of Nissl bodies and dendritic spines,mitochondrial fragmentation,cristae fracture,reduced content of respiratory chain complex protein,and reduced production of ATP.Isca1 knockout caused neuronal oncosis.Conclusions:This rat model can be used to study the pathogenesis of MMDS.In addition,compared with human MMDS5,the rat model can survive up to 8 weeks of age,effectively extending the window of clinical treatment research,and can be used for the treatment of neurological symptoms in other mitochondrial diseases.展开更多
Background:Multiple mitochondrial dysfunction syndromes(MMDS)presents as complex mitochondrial damage,thus impairing a variety of metabolic pathways.Heart dysplasia has been reported in MMDS patients;however,the speci...Background:Multiple mitochondrial dysfunction syndromes(MMDS)presents as complex mitochondrial damage,thus impairing a variety of metabolic pathways.Heart dysplasia has been reported in MMDS patients;however,the specific clinical symptoms and pathogenesis remain unclear.More urgently,there is a lack of an animal model to aid research.Therefore,we selected a reported MMDS causal gene,Isca1,and established an animal model of MMDS complicated with cardiac dysplasia.Methods:The myocardium-specific Isca1 knockout heterozygote(Isca1 HET)rat was obtained by crossing the Isca1 conditional knockout(Isca1 cKO)rat with theαmyosin heavy chain Cre(α-MHC-Cre)rat.Cardiac development characteristics were determined by ECG,blood pressure measurement,echocardiography and histopatho-logical analysis.The responsiveness to pathological stimuli were observed through adriamycin treatment.Mitochondria and metabolism disorder were determined by activity analysis of mitochondrial respiratory chain complex and ATP production in myocardium.Results:ISCA1 expression in myocardium exhibited a semizygous effect.Isca1 HET rats exhibited dilated cardiomyopathy characteristics,including thin-walled ventri-cles,larger chambers,cardiac dysfunction and myocardium fibrosis.Downregulated ISCA1 led to deteriorating cardiac pathological processes at the global and organiza-tional levels.Meanwhile,HET rats exhibited typical MMDS characteristics,including damaged mitochondrial morphology and enzyme activity for mitochondrial respira-tory chain complexesⅠ,ⅡandⅣ,and impaired ATP production.Conclusion:We have established a rat model of MMDS complicated with cardiomyopathy,it can also be used as model of myocardial energy metabolism dysfunction and mitochondrial cardiomyopathy.This model can be applied to the study of the mechanism of energy metabolism in cardiovascular diseases,as well as research and development of drugs.展开更多
基金CAMS Innovation Fund for Medical Sciences CIFMSGrant/Award Number:2021-I2M-1-034+3 种基金National Key Research and Development Program of ChinaGrant/Award Number:2022YFF0710702National Natural Science Foundation of ChinaGrant/Award Number:31970508。
文摘Background:Multiple mitochondrial dysfunction syndromes(MMDS)are rare mitochondrial diseases caused by mutation of mitochondrial iron–sulfur cluster synthesis proteins.This study established a rat model simulating MMDS5 disease in the nervous system to investigate its pathological features and neuronal death.Methods:We generated neuron-specific Isca1 knockout rat(Isca1 flox/flox-NeuN-Cre)using CRISPR-Cas9 technology.The brain structure changes of CKO rats were studied with MRI,and the behavior abnormalities were analyzed through gait analysis and open field tests,Y maze tests and food maze tests.The pathological changes of neurons were analyzed through H&E staining,Nissl staining,and Golgi staining.Mitochondrial damage was assessed by TEM,western blot and ATP assay,and the morphology of neurons was assessed by WGA immunofluorescence to detect the death of neurons.Results:This study established the disease model of MMDS5 in the nervous system for the first time,and found that after Isca1 loss,the rats suffered from developmental retardation,epilepsy,memory impairment,massive neuronal death,reduced number of Nissl bodies and dendritic spines,mitochondrial fragmentation,cristae fracture,reduced content of respiratory chain complex protein,and reduced production of ATP.Isca1 knockout caused neuronal oncosis.Conclusions:This rat model can be used to study the pathogenesis of MMDS.In addition,compared with human MMDS5,the rat model can survive up to 8 weeks of age,effectively extending the window of clinical treatment research,and can be used for the treatment of neurological symptoms in other mitochondrial diseases.
基金The present work was supported in part by the Beijing Natural Science Foundation(5212017)CAMS Innovation Fund for Medical Sciences(CIFMS,2016-I2M-1-015)National Natural Science Foundation(31872314 and 31970508).
文摘Background:Multiple mitochondrial dysfunction syndromes(MMDS)presents as complex mitochondrial damage,thus impairing a variety of metabolic pathways.Heart dysplasia has been reported in MMDS patients;however,the specific clinical symptoms and pathogenesis remain unclear.More urgently,there is a lack of an animal model to aid research.Therefore,we selected a reported MMDS causal gene,Isca1,and established an animal model of MMDS complicated with cardiac dysplasia.Methods:The myocardium-specific Isca1 knockout heterozygote(Isca1 HET)rat was obtained by crossing the Isca1 conditional knockout(Isca1 cKO)rat with theαmyosin heavy chain Cre(α-MHC-Cre)rat.Cardiac development characteristics were determined by ECG,blood pressure measurement,echocardiography and histopatho-logical analysis.The responsiveness to pathological stimuli were observed through adriamycin treatment.Mitochondria and metabolism disorder were determined by activity analysis of mitochondrial respiratory chain complex and ATP production in myocardium.Results:ISCA1 expression in myocardium exhibited a semizygous effect.Isca1 HET rats exhibited dilated cardiomyopathy characteristics,including thin-walled ventri-cles,larger chambers,cardiac dysfunction and myocardium fibrosis.Downregulated ISCA1 led to deteriorating cardiac pathological processes at the global and organiza-tional levels.Meanwhile,HET rats exhibited typical MMDS characteristics,including damaged mitochondrial morphology and enzyme activity for mitochondrial respira-tory chain complexesⅠ,ⅡandⅣ,and impaired ATP production.Conclusion:We have established a rat model of MMDS complicated with cardiomyopathy,it can also be used as model of myocardial energy metabolism dysfunction and mitochondrial cardiomyopathy.This model can be applied to the study of the mechanism of energy metabolism in cardiovascular diseases,as well as research and development of drugs.
