2023 Fiscal Year Research-status Report
Unraveling the genetic modifier, and molecular and neural basis of intractable epilepsy in a mouse model of CDKL5 deficiency disorder
| Project/Area Number |
23K05614
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| Research Institution | Tokyo Metropolitan Institute of Medical Science |
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Principal Investigator |
曹 麗琴 公益財団法人東京都医学総合研究所, 基礎医科学研究分野, 研究員 (60399475)
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| Project Period (FY) |
2023-04-01 – 2026-03-31
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| Keywords | CDKL5 / seizure / 睡眠 / マウス / 神経発達障害 / 脳・神経 / 遺伝学 |
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| Outline of Annual Research Achievements |
CDKL5 deficiency disorder (CDD) is a devastating X-linked neurodevelopmental disorder caused by pathogenic mutations in the cyclin-dependent kinase-like 5 (CDKL5) gene. A core feature of CDD is the severe, early-onset refractory seizures, with 90% of patients displaying seizures by three months of age, which greatly impact the quality of life of patients and their families. However, little is known about the molecular and neural basis underlying seizures in CDD patients. We found that spontaneous seizures were present in Cdkl5 knockout mice (KO) on a C57BL/6J but absent on a C57BL/6N background, suggesting that genetic modifier(s) may influence seizure susceptibility in CDD. In this study, we will identify for the first time the modifier gene(s) regulating seizure susceptibility in CDD by genetic mapping and exome sequencing in a Cdkl5 knockout mouse model. The results will provide novel insights into the molecular and neural basis of epilepsy in CDD, and will open a new avenue for developing novel and effective therapeutics for refractory seizures in CDD patients.
In this year we examined whether seizure occurs in F1 Cdkl5 KO mice (B6N;B6J mixed background). Based on the results from F1 mice, we have generated N2 Cdkl5 KO mice suitable for further modifier gene mapping.
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| Current Status of Research Progress |
Current Status of Research Progress
2: Research has progressed on the whole more than it was originally planned.
Reason
We have finished phenotyping of F1 Cdkl5 KO mice for seizure occurrence using video-electroencephalography (video-EEG) and electromyography (EMG) recording. The results enabled us to determine which type of N2 Cdkl5 KO mice should be used for modifier gene mapping. We have produced desired N2 Cdkl5 KO mice accordingly for further genetic mapping of modifier.
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| Strategy for Future Research Activity |
We will examine the seizure in N2 Cdkl5 KO mice using video-EEG/EMG recording. After phenotyping N2 mice, we will extract the genomic DNA from more than 50 N2 mice with and without seizures, respectively, and perform modifier gene mapping using genetic linkage analysis and subsequently identify the gene. After identifying the modifier gene, we will analyse the physiological functions of modifier gene by molecular, biochemical and neuroscience studies.
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| Causes of Carryover |
Some expensive reagents and materials for the experiments will be purchased in FY2024. We will purchase antibodies and reagent kits for immunohistochemistry experiments and electrodes for electroencephalogram recordings.
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