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Saeko Ishida - One of the best experts on this subject based on the ideXlab platform.
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DEPDC5 knockdown causes mtor dependent motor hyperactivity in zebrafish
Annals of clinical and translational neurology, 2018Co-Authors: Stéphanie Baulac, Saeko Ishida, Elise Marsan, Eric Leguern, Hortense De Calbiac, Adriana Dabacan, Herve Tostivint, Gabrielle Devienne, Raul C MuresanAbstract:Objective DEPDC5 was identified as a major genetic cause of focal epilepsy with deleterious mutations found in a wide range of inherited forms of focal epilepsy, associated with malformation of cortical development in certain cases. Identification of frameshift, truncation, and deletion mutations implicates haploinsufficiency of DEPDC5 in the etiology of focal epilepsy. DEPDC5 is a component of the GATOR1 complex, acting as a negative regulator of mTOR signaling. Methods Zebrafish represents a vertebrate model suitable for genetic analysis and drug screening in epilepsy-related disorders. In this study, we defined the expression of DEPDC5 during development and established an epilepsy model with reduced DEPDC5 expression. Results Here we report a zebrafish model of DEPDC5 loss-of-function that displays a measurable behavioral phenotype, including hyperkinesia, circular swimming, and increased neuronal activity. These phenotypic features persisted throughout embryonic development and were significantly reduced upon treatment with the mTORC1 inhibitor, rapamycin, as well as overexpression of human WT DEPDC5 transcript. No phenotypic rescue was obtained upon expression of epilepsy-associated DEPDC5 mutations (p.Arg487* and p.Arg485Gln), indicating that these mutations cause a loss of function of the protein. Interpretation This study demonstrates that DEPDC5 knockdown leads to early-onset phenotypic features related to motor and neuronal hyperactivity. Restoration of phenotypic features by WT but not epilepsy-associated DEPDC5 mutants, as well as by mTORC1 inhibition confirm the role of DEPDC5 in the mTORC1-dependent molecular cascades, defining this pathway as a potential therapeutic target for DEPDC5-inherited forms of focal epilepsy.
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DEPDC5 a new key to understand various epilepsies
Folia Pharmacologica Japonica, 2018Co-Authors: Saeko IshidaAbstract:Epilepsy is one of the most frequent neurological disorders characterized by spontaneous and recurrent seizures. Most seizures last for the lifetime and the patients require long term therapies. However, about 30% of the patients are refractory to antiepileptic drugs. Therefore, the need for newer and more effective therapies is urgent. Focal epilepsies, in which the abnormal electrical discharges occur within neuronal networks limited to one hemisphere, accounts for about 60% of all adult idiopathic epilepsy cases. Recently, mutations of DEPDC5 gene has been reported in wide spectrum of focal epilepsy syndromes. Most epilepsy genes encode ion channel or transmitter receptor, but DEPDC5 has no homology with them. DEPDC5 forms a complex, named GATOR1, together with other focal epilepsy related proteins NPRL2 and NPRL3. GATOR1 inhibits the mTORC1 pathway, regulating multiple cellular processes including cell growth and proliferation. The role of DEPDC5 in neuronal system is becoming clear from recent studies using the animal models. Because DEPDC5 is the most common causative gene in focal epilepsies and different from other epilepsy genes, DEPDC5 will be a key to understand epileptogenesis of various epilepsies, and provide new insight to develop new versatile therapies.
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DEPDC5 knockout rat: A novel model of mTORopathy
Neurobiology of Disease, 2016Co-Authors: Elise Marsan, Saeko Ishida, Adrien Schramm, Sarah Weckhuysen, Giuseppe Muraca, Sarah Lecas, Ning Liang, Caroline Treins, Mario Pende, Delphine RousselAbstract:DEP-domain containing 5 (DEPDC5), encoding a repressor of the mechanistic target of rapamycin complex 1 (mTORC1) signaling pathway, has recently emerged as a major gene mutated in familial focal epilepsies and focal cortical dysplasia. Here we established a global knockout rat using TALEN technology to investigate in vivo the impact of DEPDC5-deficiency. Homozygous DEPDC5−/− embryos died from embryonic day 14.5 due to a global growth delay. Constitutive mTORC1 hyperactivation was evidenced in the brains and in cultured fibroblasts of DEPDC5−/− embryos, as reflected by enhanced phosphorylation of its downstream effectors S6K1 and rpS6. Consistently, prenatal treatment with mTORC1 inhibitor rapamycin rescued the phenotype of DEPDC5−/− embryos. Heterozygous DEPDC5+/− rats developed normally and exhibited no spontaneous electroclinical seizures, but had altered cortical neuron excitability and firing patterns. DEPDC5+/− rats displayed cortical cytomegalic dysmorphic neurons and balloon-like cells strongly expressing phosphorylated rpS6, indicative of mTORC1 upregulation, and not observed after prenatal rapamycin treatment. These neuropathological abnormalities are reminiscent of the hallmark brain pathology of human focal cortical dysplasia. Altogether, DEPDC5 knockout rats exhibit multiple features of rodent models of mTORopathies, and thus, stand as a relevant model to study their underlying pathogenic mechanisms.
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familial focal epilepsy with focal cortical dysplasia due to DEPDC5 mutations
Annals of Neurology, 2015Co-Authors: Stéphanie Baulac, Dang Khoa Nguyen, Saeko Ishida, Elise Marsan, Catherine Miquel, Arnaud Biraben, Doug Nordli, Patrick Cossette, Sylvie Nguyen, Virginie LambrecqAbstract:Objective The DEPDC5 (DEP domain-containing protein 5) gene, encoding a repressor of the mTORC1 signaling pathway, has recently emerged as a major gene mutated in familial focal epilepsies. We aimed to further extend the role of DEPDC5 to focal cortical dysplasias (FCDs). Methods Seven patients from 4 families with DEPDC5 mutations and focal epilepsy associated with FCD were recruited and investigated at the clinical, neuroimaging, and histopathological levels. The DEPDC5 gene was sequenced from genomic blood and brain DNA. Results All patients had drug-resistant focal epilepsy, 5 of them underwent surgery, and 1 had a brain biopsy. Electroclinical phenotypes were compatible with FCD II, although magnetic resonance imaging (MRI) was typical in only 4 cases. Histopathology confirmed FCD IIa in 2 patients (including 1 MRI-negative case) and showed FCD I in 2 other patients, and remained inconclusive in the last 2 patients. Three patients were seizure-free postsurgically, and 1 had a worthwhile improvement. Sequencing of blood DNA revealed truncating DEPDC5 mutations in all 4 families; 1 mutation was found to be mosaic in an asymptomatic father. A brain somatic DEPDC5 mutation was identified in 1 patient in addition to the germline mutation. Interpretation Germline, germline mosaic, and brain somatic DEPDC5 mutations may cause epilepsy associated with FCD, reinforcing the link between mTORC1 pathway and FCDs. Similarly to other mTORopathies, a “2-hit” mutational model could be responsible for cortical lesions. Our study also indicates that epilepsy surgery is a valuable alternative in the treatment of drug-resistant DEPDC5-positive focal epilepsies, even if the MRI is unremarkable.
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DEPDC5 mutations in families presenting as autosomal dominant nocturnal frontal lobe epilepsy
Neurology, 2014Co-Authors: Fabienne Picard, Saeko Ishida, Sarah Weckhuysen, Vincent Navarro, Periklis Makrythanasis, Julitta De Bellescize, Dorothee Ville, Erwin Fosselle, Arvid Suls, Peter De JongheAbstract:Objective: To study the prevalence of DEPDC5 mutations in a series of 30 small European families with a phenotype compatible with autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE). Methods: Thirty unrelated families referred with ADNFLE were recruited in France, Italy, Germany, Belgium, and Norway. Whole-exome sequencing was performed in 10 probands and direct sequencing of the DEPDC5 coding sequence in 20 probands. Testing for nonsense-mediated messenger RNA decay (NMD) was performed in lymphoblastic cells. Results: Exome sequencing revealed a splice acceptor mutation (c.2355-2A>G) in DEPDC5 in the proband of a German family. In addition, 3 nonsense DEPDC5 mutations (p.Arg487*, p.Arg1087*, and p.Trp1369*) were detected in the probands of 2 French and one Belgian family. The nonsense mutations p.Arg487* and p.Arg1087* were targeted by NMD, leading to the degradation of the mutated transcripts. At the clinical level, 78% of the patients with DEPDC5 mutations were drug resistant. Conclusions: DEPDC5 loss-of-function mutations were found in 13% of the families with a presentation of ADNFLE. The rate of drug resistance was high in patients with DEPDC5 mutations. Small ADNFLE pedigrees with DEPDC5 mutations might actually represent a part of the broader familial focal epilepsy with variable foci phenotype.
Stéphanie Baulac - One of the best experts on this subject based on the ideXlab platform.
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Acute knockdown of DEPDC5 leads to synaptic defects in mTOR-related epileptogenesis
Neurobiology of Disease, 2020Co-Authors: Antonio De Fusco, Stéphanie Baulac, Maria Sabina Cerullo, Antonella Marte, Caterina Michetti, Alessandra Romei, Enrico Castroflorio, Fabio BenfenatiAbstract:DEP-domain containing 5 (DEPDC5) is part of the GATOR1 complex that functions as key inhibitor of the mechanistic target of rapamycin complex 1 (mTORC1). Loss-of-function mutations in DEPDC5 leading to mTOR hyperactivation have been identified as the most common cause of either lesional or non-lesional focal epilepsy. However, the precise mechanisms by which DEPDC5 loss-of-function triggers neuronal and network hyperexcitability are still unclear. In this study, we investigated the cellular mechanisms of hyperexcitability by comparing the constitutive heterozygous DEPDC5 knockout mouse versus different levels of acute DEPDC5 deletion (≈40% and ≈80% neuronal knockdown of DEPDC5 protein) by RNA interference in primary cortical cultures. While heterozygous DEPDC5+/- neurons have only a subtle phenotype, acutely knocked-down neurons exhibit a strong dose-dependent phenotype characterized by mTOR hyperactivation, increased soma size, dendritic arborization, excitatory synaptic transmission and intrinsic excitability. The robust synaptic phenotype resulting from the acute knockdown DEPDC5 deficiency highlights the importance of the temporal dynamics of DEPDC5 knockdown in triggering the phenotypic changes, reminiscent of the somatic second-hit mechanism in patients with focal cortical dysplasia. These findings uncover a novel synaptic phenotype that is causally linked to DEPDC5 knockdown, highlighting the developmental role of DEPDC5. Interestingly, the synaptic defect appears to affect only excitatory synapses, while inhibitory synapses develop normally. The increased frequency and amplitude of mEPSCs, paralleled by increased density of excitatory synapses and expression of glutamate receptors, may generate an excitation/inhibition imbalance that triggers epileptogenesis.
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DEPDC5 knockdown causes mtor dependent motor hyperactivity in zebrafish
Annals of clinical and translational neurology, 2018Co-Authors: Stéphanie Baulac, Saeko Ishida, Elise Marsan, Eric Leguern, Hortense De Calbiac, Adriana Dabacan, Herve Tostivint, Gabrielle Devienne, Raul C MuresanAbstract:Objective DEPDC5 was identified as a major genetic cause of focal epilepsy with deleterious mutations found in a wide range of inherited forms of focal epilepsy, associated with malformation of cortical development in certain cases. Identification of frameshift, truncation, and deletion mutations implicates haploinsufficiency of DEPDC5 in the etiology of focal epilepsy. DEPDC5 is a component of the GATOR1 complex, acting as a negative regulator of mTOR signaling. Methods Zebrafish represents a vertebrate model suitable for genetic analysis and drug screening in epilepsy-related disorders. In this study, we defined the expression of DEPDC5 during development and established an epilepsy model with reduced DEPDC5 expression. Results Here we report a zebrafish model of DEPDC5 loss-of-function that displays a measurable behavioral phenotype, including hyperkinesia, circular swimming, and increased neuronal activity. These phenotypic features persisted throughout embryonic development and were significantly reduced upon treatment with the mTORC1 inhibitor, rapamycin, as well as overexpression of human WT DEPDC5 transcript. No phenotypic rescue was obtained upon expression of epilepsy-associated DEPDC5 mutations (p.Arg487* and p.Arg485Gln), indicating that these mutations cause a loss of function of the protein. Interpretation This study demonstrates that DEPDC5 knockdown leads to early-onset phenotypic features related to motor and neuronal hyperactivity. Restoration of phenotypic features by WT but not epilepsy-associated DEPDC5 mutants, as well as by mTORC1 inhibition confirm the role of DEPDC5 in the mTORC1-dependent molecular cascades, defining this pathway as a potential therapeutic target for DEPDC5-inherited forms of focal epilepsy.
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DEPDC5 related epilepsy
2016Co-Authors: Stéphanie Baulac, Sarah WeckhuysenAbstract:Clinical characteristics DEPDC5-related epilepsy encompasses a range of epilepsy syndromes, almost all of which are characterized by focal seizures, with seizure onset in a discrete area of the brain. While most individuals with DEPDC5-related epilepsy have a normal brain MRI, some have epilepsy associated with a cortical malformation, usually focal cortical dysplasia. Seizure syndromes include familial focal epilepsy with variable foci (FFEVF), autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE), familial mesial temporal lobe epilepsies (FMTLE), autosomal dominant epilepsy with auditory features (ADEAF), and infantile spasms. Although psychomotor development is usually normal, intellectual disability or autism spectrum disorder has been reported in some individuals. Diagnosis/testing The diagnosis of DEPDC5-related epilepsy is established in a proband with focal epilepsy and identification of a heterozygous pathogenic variant in DEPDC5 on molecular genetic testing. Management Treatment of manifestations: The response to antiepileptic drugs (AEDs) is variable. While some individuals respond well to first-line AEDs, others are more refractory to treatment. There is currently no evidence that seizures respond better to one particular AED. In patients with focal cortical dysplasia, the possibility of epilepsy surgery should be explored early in the disease course. Surveillance: Serial EEGs are appropriate when seizure frequency increases or when seizures of new symptomatology occur. Repeat brain MRI with a higher resolution technique is recommended in individuals with treatment-resistant seizures whose first brain MRI was normal. Genetic counseling DEPDC5-related epilepsy is inherited in an autosomal dominant manner. Although de novo DEPDC5 pathogenic variants have been reported, the overall proportion of cases caused by a de novo pathogenic variant is unknown. Each child of an individual with DEPDC5-related epilepsy is at a 50% risk of inheriting the DEPDC5 pathogenic variant. Once the DEPDC5 pathogenic variant has been identified in an affected family member, prenatal testing for a pregnancy at increased risk and preimplantation genetic testing are possible.
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familial focal epilepsy with focal cortical dysplasia due to DEPDC5 mutations
Annals of Neurology, 2015Co-Authors: Stéphanie Baulac, Dang Khoa Nguyen, Saeko Ishida, Elise Marsan, Catherine Miquel, Arnaud Biraben, Doug Nordli, Patrick Cossette, Sylvie Nguyen, Virginie LambrecqAbstract:Objective The DEPDC5 (DEP domain-containing protein 5) gene, encoding a repressor of the mTORC1 signaling pathway, has recently emerged as a major gene mutated in familial focal epilepsies. We aimed to further extend the role of DEPDC5 to focal cortical dysplasias (FCDs). Methods Seven patients from 4 families with DEPDC5 mutations and focal epilepsy associated with FCD were recruited and investigated at the clinical, neuroimaging, and histopathological levels. The DEPDC5 gene was sequenced from genomic blood and brain DNA. Results All patients had drug-resistant focal epilepsy, 5 of them underwent surgery, and 1 had a brain biopsy. Electroclinical phenotypes were compatible with FCD II, although magnetic resonance imaging (MRI) was typical in only 4 cases. Histopathology confirmed FCD IIa in 2 patients (including 1 MRI-negative case) and showed FCD I in 2 other patients, and remained inconclusive in the last 2 patients. Three patients were seizure-free postsurgically, and 1 had a worthwhile improvement. Sequencing of blood DNA revealed truncating DEPDC5 mutations in all 4 families; 1 mutation was found to be mosaic in an asymptomatic father. A brain somatic DEPDC5 mutation was identified in 1 patient in addition to the germline mutation. Interpretation Germline, germline mosaic, and brain somatic DEPDC5 mutations may cause epilepsy associated with FCD, reinforcing the link between mTORC1 pathway and FCDs. Similarly to other mTORopathies, a “2-hit” mutational model could be responsible for cortical lesions. Our study also indicates that epilepsy surgery is a valuable alternative in the treatment of drug-resistant DEPDC5-positive focal epilepsies, even if the MRI is unremarkable.
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Genetics advances in autosomal dominant focal epilepsies: focus on DEPDC5
Progress in Brain Research, 2014Co-Authors: Stéphanie BaulacAbstract:Rare multiplex families with autosomal dominant focal epilepsies have been described with specific age-related and electroclinical syndromes: autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE), familial temporal lobe epilepsy (FTLE), and familial focal epilepsy with variable foci (FFEVF). Molecular genetic advances in inherited focal epilepsies have pinpointed their genetic heterogeneity and the fact that they are mediated by different biological pathways: ion channel subunit genes have been linked to ADNFLE (CHRNA4, CHRNA2, CHRNB2, and KCNT1, encoding, respectively, the α4, α2, and β2 subunits of the neuronal nicotinic acetylcholine receptor, and a potassium channel subunit); neuronal secreted protein (LGI1-encoding epitempin) has been linked to autosomal dominant epilepsy with auditory features; and mTORC1-repressor DEPDC5 (DEP domain-containing protein 5) gene has recently been reported in a broad spectrum of inherited focal epilepsies (ADNFLE, FTLE, FFEVF). This chapter focuses on DEPDC5, a newly identified gene.
Patrick Cossette - One of the best experts on this subject based on the ideXlab platform.
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two definite sudden unexpected deaths in epilepsy in a family with a DEPDC5 mutation p6 365
Neurology, 2016Co-Authors: Fabio Nascimento E Silva, Patrick Cossette, Felippe Borlot, Berge A Minassian, Danielle M AndradeAbstract:OBJECTIVE and BACKGROUND: DEPDC5 gene, mapped to 22q12.2-q12.3, has been associated with a variety of familial epilepsies. Notably, DEPDC5 has never been linked to increased risk of sudden unexpected death in epilepsy (SUDEP). METHODS: Case report. RESULTS: We studied a three-generation, non-consanguineous, French-Canadian family with nine clinically affected individuals. Interestingly, all but one are males. The index case is a 39-year-old man who started having seizures at the age of 13 years. His seizures were characterized by a “dream-like” aura followed by loss of consciousness and tonic-clonic movements. Initially, seizures were mainly diurnal. In his mid-20s, the episodes became exclusively nocturnal. EEGs showed interictal epileptiform discharges over the right anterior-temporal region. Brain MRI was unremarkable. Two of the index case9s paternal uncles suffered definite autopsy-confirmed SUDEP, at the ages of 58 and 50 years, respectively. Seizure-history in this family can be summarized by an onset before reaching adulthood, followed by subsequent progressive decrease in seizure frequency. Seizures were predominantly nocturnal secondarily generalized tonic-clonic. All the subjects were cognitively intact. There was no history of any cardiac symptomatology, cardiovascular risk factor, or definite cardiac condition. Genetic analysis of the index case revealed a pathogenic heterozygous variant in the DEDPC5 gene (p.Gln216, c.646C>T; ENST00000536766). The index case was also tested for genes associated with SUDEP, none of which showed mutations. All living affected relatives, as well as four healthy family members, were clinically evaluated and had DEPDC5 Sanger sequenced. All affected subjects and one healthy individual were found to carry the same DEPDC5 pathogenic variant as the index case. CONCLUSIONS: Several genes have been linked with SUDEP. These are associated with cardiac arrhythmias and/or severe epilepsies, both of which do not apply to this family’s phenotype. The finding in this family suggests that DEPDC5 mutations may be a risk factor for SUDEP. Disclosure: Dr. Nascimento e Silva has nothing to disclose. Dr. Borlot has nothing to disclose. Dr. Cossette has nothing to disclose. Dr. Minassian has nothing to disclose. Dr. Andrade has nothing to disclose.
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two definite cases of sudden unexpected death in epilepsy in a family with a DEPDC5 mutation
Neurology Genetics, 2015Co-Authors: Fabio A Nascimento, Patrick Cossette, Felippe Borlot, Berge A Minassian, Danielle M AndradeAbstract:The DEPDC5 gene (OMIM #614191), mapped to 22q12.2-q12.3, encodes the DEP domain-containing protein 5. DEPDC5 has been associated with a variety of familial epilepsies, including familial focal epilepsy with variable foci, autosomal dominant nocturnal frontal lobe epilepsy, familial temporal lobe epilepsy, epileptic spasms, and cortical dysplasia.(1-4) Notably, DEPDC5 has never been linked to increased risk of sudden unexpected death in epilepsy (SUDEP). We report a family with epilepsy due to DEPDC5 mutation and 2 definite cases of SUDEP within this family.
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familial focal epilepsy with focal cortical dysplasia due to DEPDC5 mutations
Annals of Neurology, 2015Co-Authors: Stéphanie Baulac, Dang Khoa Nguyen, Saeko Ishida, Elise Marsan, Catherine Miquel, Arnaud Biraben, Doug Nordli, Patrick Cossette, Sylvie Nguyen, Virginie LambrecqAbstract:Objective The DEPDC5 (DEP domain-containing protein 5) gene, encoding a repressor of the mTORC1 signaling pathway, has recently emerged as a major gene mutated in familial focal epilepsies. We aimed to further extend the role of DEPDC5 to focal cortical dysplasias (FCDs). Methods Seven patients from 4 families with DEPDC5 mutations and focal epilepsy associated with FCD were recruited and investigated at the clinical, neuroimaging, and histopathological levels. The DEPDC5 gene was sequenced from genomic blood and brain DNA. Results All patients had drug-resistant focal epilepsy, 5 of them underwent surgery, and 1 had a brain biopsy. Electroclinical phenotypes were compatible with FCD II, although magnetic resonance imaging (MRI) was typical in only 4 cases. Histopathology confirmed FCD IIa in 2 patients (including 1 MRI-negative case) and showed FCD I in 2 other patients, and remained inconclusive in the last 2 patients. Three patients were seizure-free postsurgically, and 1 had a worthwhile improvement. Sequencing of blood DNA revealed truncating DEPDC5 mutations in all 4 families; 1 mutation was found to be mosaic in an asymptomatic father. A brain somatic DEPDC5 mutation was identified in 1 patient in addition to the germline mutation. Interpretation Germline, germline mosaic, and brain somatic DEPDC5 mutations may cause epilepsy associated with FCD, reinforcing the link between mTORC1 pathway and FCDs. Similarly to other mTORopathies, a “2-hit” mutational model could be responsible for cortical lesions. Our study also indicates that epilepsy surgery is a valuable alternative in the treatment of drug-resistant DEPDC5-positive focal epilepsies, even if the MRI is unremarkable.
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a recurrent mutation in DEPDC5 predisposes to focal epilepsies in the french canadian population
Clinical Genetics, 2014Co-Authors: Caroline Martin, Dang Khoa Nguyen, Caroline Meloche, Mariefrance Rioux, L Carmant, Eva Andermann, Micheline Gravel, Patrick CossetteAbstract:Familial focal epilepsy with variable foci (FFEVF) is a heterogeneous epilepsy syndrome originally described in the French-Canadian (FC) population. Mutations in DEPDC5 have recently been identified in multiple cases of FFEVF as well as in a wide spectrum of other familial focal epilepsies. In this study, we aimed to determine the frequency of mutation of this gene in our large cohort of FC individuals with FFEVF, as well as familial and sporadic cases with focal epilepsy. We report a recurrent p.R843X protein-truncating mutation segregating in one large FFEVF and two small focal epilepsy FC families. Fine genotyping suggests an ancestral allele. A new p.T864M variant, predicted to be disease-causing, was also identified in a small FC family. Overall, we identified DEPDC5 mutations in 5% of our familial and sporadic focal epilepsy cases (4/79). Our results support the view that mutations in the DEPDC5 gene are an important cause of autosomal dominant focal epilepsies in the FC population, including a founder mutation that is specific to this population. These findings may facilitate molecular diagnosis in clinical practice.
Guojin Huang - One of the best experts on this subject based on the ideXlab platform.
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dep domain containing 1 suppresses apoptosis via inhibition of a20 expression which activates the nuclear factor κb signaling pathway in hepg2 cells
Oncology Letters, 2018Co-Authors: Qingqing Wang, Junfei Jin, Guojin HuangAbstract:A previous study revealed that DEP domain containing 1 (DEPDC1) is involved in the carcinogenesis of bladder cancer via forming a complex with zinc finger protein 224 (ZNF224) to suppress A20 expression, resulting in the activation of the nuclear factor (NF)-κB signaling pathway; however, the role of DEPDC1 in liver cancer remains unclear. Hep G2 cells were treated with 11R-DEP: 611-628, a peptide capable of disrupting the DEPDC1-ZNF224 complex. Cell proliferation was examined using an MTT assay and apoptosis was analyzed via detection of the apoptotic marker caspase-3 using western blot analysis. A20 expression was examined via reverse transcription-quantitative polymerase chain reaction and NF-κB subcellular localization was determined via immunofluorescence staining. microRNA (miR)-130a was overexpressed in HepG2 cells and its effects on proliferation and apoptosis were examined. The results demonstrated that 11R-DEP: 611-628 (3 µM) and miR-130a inhibited cell proliferation and promoted apoptosis in HepG2 cells by activating A20 expression, which blocks the nuclear transportation of NF-κB. In addition, the results demonstrated that the 11R-DEP: 611-628 (3 µM) treatment resulted in downregulation of DEPDC1 expression, indicating that DEPDC1 expression is regulated by the DEPDC1-ZNF224 complex. In conclusion, the data indicated that DEPDC1 suppresses apoptosis to promote cell proliferation through the NF-κB signaling pathway in HepG2 cells and that DEPDC1 is a potential target for the treatment of liver cancer.
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targeted interfering dep domain containing 1 protein induces apoptosis in a549 lung adenocarcinoma cells through the nf κb signaling pathway
OncoTargets and Therapy, 2017Co-Authors: Qingqing Wang, Junfei Jin, Guojin HuangAbstract:Ectopic expression of DEP domain containing 1 (DEPDC1) in lung adenocarcinomas is associated with poor prognosis, but its role and the underlying mechanism remain unknown. In this study, DEPDC1 expression in lung cancer cell lines was examined with Western blot assay, and DEPDC1-positive cell A549 was selected for further experiments. DEPDC1 inhibitor miR-130a was overexpressed in A549 cells, and the proliferation and apoptosis of these cells were analyzed with cell counting and flow cytometry assay. Interfering peptide 11R-DEP:611-628 and JNK inhibitor SP600125 were used alone or in combination to treat A549 cells, and the cell proliferation and apoptosis were assessed by flow cytometry assay; caspase 3 and cleaved caspase 3, phosphor-JNK, and total JNK were detected by Western blotting; and nuclear factor kappa B (NF-κB) localization was determined by immunofluorescence staining. We found that miR-130a and 11R-DEP:611-628 peptides (5 μM) both inhibited A549 proliferation and induced apoptosis. We observed that 11R-DEP:611-628 peptide treatment resulted in elevated A20 expression, dramatically reduced nuclear NF-κB, and increased phosphor-JNK. These findings indicate that DEPDC1 inhibits apoptosis of A549 cell by suppressing A20 expression to regulate NF-κB activity, and that JNK plays a protective role upon 11R-DEP:611-628 peptide treatment. In conclusion, DEPDC1 might be a novel therapeutic target for lung cancer, and the 11R-DEP:611-628 peptide is a potent apoptosis inducer in A549 cells.
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DEP domain containing 1 is a novel diagnostic marker and prognostic predictor for hepatocellular carcinoma.
Asian Pacific journal of cancer prevention : APJCP, 2015Co-Authors: Shengguang Yuan, Guojin Huang, Wei-jia Liao, Jianjun Yang, Zhao-quan HuangAbstract:Background: This study was conducted to determine DEPDC1 expression in hepatocelluar carcinomas (HCCs) and to reveal its potential role in diagnosis and prognosis of affected patients. Materials and Methods: DEPDC1 expression at the mRNA level was detected by quantitative real-time PCR (qRT-PCR) in 205 cases of HCC and paired adjacent normal liver tissues, and by semi-quantitative RT-PCR in 20 cases. Survival curves were obtained by using Kaplan-Meier method and Log-rank test. Independent predictors associated with regard to disease free survival (DFS) and overall survival (OS) were identified using the Cox proportional hazard model. Results: High DEPDC1 mRNA levels were detected in 144 out of 205 cases (70.24%) of HCC, significantly associated with clinicopathological parameters, including tumor size (≥4cm), alpha-fetoprotein (≥100ng/ml), B-C of BCLC stage and recurrence. Kaplan-Meier survival analysis revealed that HCC patients with high DEPDC1 expression had poor OS and DFS. Multivariate analysis demonstrated that high DEPDC1 expression was an independent predictor for OS (HR=1.651; 95% 95%CI, 1.041- 2.617; p=0.033) and DFS (HR=1.583; 95%CI, 1.01- 2.483; p=0.045). Conclusions: Our results indicate DEPDC1 might be a novel diagnostic marker and an independent prognostic predictor for HCC patients.
Sarah Weckhuysen - One of the best experts on this subject based on the ideXlab platform.
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DEPDC5 related epilepsy
2016Co-Authors: Stéphanie Baulac, Sarah WeckhuysenAbstract:Clinical characteristics DEPDC5-related epilepsy encompasses a range of epilepsy syndromes, almost all of which are characterized by focal seizures, with seizure onset in a discrete area of the brain. While most individuals with DEPDC5-related epilepsy have a normal brain MRI, some have epilepsy associated with a cortical malformation, usually focal cortical dysplasia. Seizure syndromes include familial focal epilepsy with variable foci (FFEVF), autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE), familial mesial temporal lobe epilepsies (FMTLE), autosomal dominant epilepsy with auditory features (ADEAF), and infantile spasms. Although psychomotor development is usually normal, intellectual disability or autism spectrum disorder has been reported in some individuals. Diagnosis/testing The diagnosis of DEPDC5-related epilepsy is established in a proband with focal epilepsy and identification of a heterozygous pathogenic variant in DEPDC5 on molecular genetic testing. Management Treatment of manifestations: The response to antiepileptic drugs (AEDs) is variable. While some individuals respond well to first-line AEDs, others are more refractory to treatment. There is currently no evidence that seizures respond better to one particular AED. In patients with focal cortical dysplasia, the possibility of epilepsy surgery should be explored early in the disease course. Surveillance: Serial EEGs are appropriate when seizure frequency increases or when seizures of new symptomatology occur. Repeat brain MRI with a higher resolution technique is recommended in individuals with treatment-resistant seizures whose first brain MRI was normal. Genetic counseling DEPDC5-related epilepsy is inherited in an autosomal dominant manner. Although de novo DEPDC5 pathogenic variants have been reported, the overall proportion of cases caused by a de novo pathogenic variant is unknown. Each child of an individual with DEPDC5-related epilepsy is at a 50% risk of inheriting the DEPDC5 pathogenic variant. Once the DEPDC5 pathogenic variant has been identified in an affected family member, prenatal testing for a pregnancy at increased risk and preimplantation genetic testing are possible.
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DEPDC5 knockout rat: A novel model of mTORopathy
Neurobiology of Disease, 2016Co-Authors: Elise Marsan, Saeko Ishida, Adrien Schramm, Sarah Weckhuysen, Giuseppe Muraca, Sarah Lecas, Ning Liang, Caroline Treins, Mario Pende, Delphine RousselAbstract:DEP-domain containing 5 (DEPDC5), encoding a repressor of the mechanistic target of rapamycin complex 1 (mTORC1) signaling pathway, has recently emerged as a major gene mutated in familial focal epilepsies and focal cortical dysplasia. Here we established a global knockout rat using TALEN technology to investigate in vivo the impact of DEPDC5-deficiency. Homozygous DEPDC5−/− embryos died from embryonic day 14.5 due to a global growth delay. Constitutive mTORC1 hyperactivation was evidenced in the brains and in cultured fibroblasts of DEPDC5−/− embryos, as reflected by enhanced phosphorylation of its downstream effectors S6K1 and rpS6. Consistently, prenatal treatment with mTORC1 inhibitor rapamycin rescued the phenotype of DEPDC5−/− embryos. Heterozygous DEPDC5+/− rats developed normally and exhibited no spontaneous electroclinical seizures, but had altered cortical neuron excitability and firing patterns. DEPDC5+/− rats displayed cortical cytomegalic dysmorphic neurons and balloon-like cells strongly expressing phosphorylated rpS6, indicative of mTORC1 upregulation, and not observed after prenatal rapamycin treatment. These neuropathological abnormalities are reminiscent of the hallmark brain pathology of human focal cortical dysplasia. Altogether, DEPDC5 knockout rats exhibit multiple features of rodent models of mTORopathies, and thus, stand as a relevant model to study their underlying pathogenic mechanisms.
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Involvement of GATOR complex genes in familial focal epilepsies and focal cortical dysplasia
Epilepsia, 2016Co-Authors: Sarah Weckhuysen, Virginie Lambrecq, Elise Marsan, Cecile Marchal, Mélanie Morin-brureau, Isabelle An-gourfinkel, Michel Baulac, Martine Fohlen, Christine Kallay Zetchi, Margitta SeeckAbstract:Objective The discovery of mutations in DEPDC5 in familial focal epilepsies has introduced a novel pathomechanism to a field so far dominated by ion channelopathies. DEPDC5 is part of a complex named GAP activity toward RAGs (GATOR) complex 1 (GATOR1), together with the proteins NPRL2 and NPRL3, and acts to inhibit the mechanistic target of rapamycin (mTOR) complex 1 (mTORC1) pathway. GATOR1 is in turn inhibited by the GATOR2 complex. The mTORC1 pathway is a major signaling cascade regulating cell growth, proliferation, and migration. We aimed to study the contribution of GATOR complex genes to the etiology of focal epilepsies and to describe the associated phenotypical spectrum. Methods We performed targeted sequencing of the genes encoding the components of the GATOR1 (DEPDC5, NPRL2, and NPRL3) and GATOR2 (MIOS, SEC13, SEH1L, WDR24, and WDR59) complex in 93 European probands with focal epilepsy with or without focal cortical dysplasia. Phospho-S6 immunoreactivity was used as evidence of mTORC1 pathway activation in resected brain tissue of patients carrying pathogenic variants. Results We identified four pathogenic variants in DEPDC5, two in NPRL2, and one in NPRL3. We showed hyperactivation of the mTORC1 pathway in brain tissue from patients with NPRL2 and NPRL3 mutations. Collectively, inactivating mutations in GATOR1 complex genes explained 11% of cases of focal epilepsy, whereas no pathogenic mutations were found in GATOR2 complex genes. GATOR1-related focal epilepsies differ clinically from focal epilepsies due to mutations in ion channel genes by their association with focal cortical dysplasia and seizures emerging from variable foci, and might confer an increased risk of sudden unexplained death in epilepsy (SUDEP). Significance GATOR1 complex gene mutations leading to mTORC1 pathway upregulation is an important cause of focal epilepsy with cortical malformations and represents a potential target for novel therapeutic approaches.
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DEPDC5 mutations in families presenting as autosomal dominant nocturnal frontal lobe epilepsy
Neurology, 2014Co-Authors: Fabienne Picard, Saeko Ishida, Sarah Weckhuysen, Vincent Navarro, Periklis Makrythanasis, Julitta De Bellescize, Dorothee Ville, Erwin Fosselle, Arvid Suls, Peter De JongheAbstract:Objective: To study the prevalence of DEPDC5 mutations in a series of 30 small European families with a phenotype compatible with autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE). Methods: Thirty unrelated families referred with ADNFLE were recruited in France, Italy, Germany, Belgium, and Norway. Whole-exome sequencing was performed in 10 probands and direct sequencing of the DEPDC5 coding sequence in 20 probands. Testing for nonsense-mediated messenger RNA decay (NMD) was performed in lymphoblastic cells. Results: Exome sequencing revealed a splice acceptor mutation (c.2355-2A>G) in DEPDC5 in the proband of a German family. In addition, 3 nonsense DEPDC5 mutations (p.Arg487*, p.Arg1087*, and p.Trp1369*) were detected in the probands of 2 French and one Belgian family. The nonsense mutations p.Arg487* and p.Arg1087* were targeted by NMD, leading to the degradation of the mutated transcripts. At the clinical level, 78% of the patients with DEPDC5 mutations were drug resistant. Conclusions: DEPDC5 loss-of-function mutations were found in 13% of the families with a presentation of ADNFLE. The rate of drug resistance was high in patients with DEPDC5 mutations. Small ADNFLE pedigrees with DEPDC5 mutations might actually represent a part of the broader familial focal epilepsy with variable foci phenotype.