Electrobehavioral phenotype and seizure pharmacosensitivity in a novel mouse model of patient-derived SLC6A1 S295L mutation-associated neurodevelopmental epilepsy

Solute carrier family 6 member 1 (SLC6A1) gene encodes GAT-1, a GABA transporter expressed on glia and presynaptic terminals of inhibitory neurons. Mutations in SLC6A1 are associated with myoclonic atonic epilepsy, absence epilepsy, autism, and intellectual disability. However, the mechanisms leading to these defects are unknown. Here, we used a novel mouse model harboring a point mutation (S295L) recently identified in the human SLC6A1 gene that results in impaired membrane trafficking of the GAT-1 protein. We performed chronic wireless telemetry recordings of heterozygous (GAT-1S295L/+) mice, and of mice lacking one or both copies of the Slc6a1 gene (GAT-1+/- and GAT-1-/-). We assessed their behaviors and pharmacosensitivity, and investigated the relationship between seizure burden and behavioral performance. GAT-1S295L/+ mice exhibited frequent spike-wave discharges (SWDs) associated with behavioral arrest, and there was a dose-effect relationship between GAT-1 gene copy number and the severity of electrocorticogram (ECoG) abnormalities. Seizure burden was inversely correlated with behavioral performance. Forelimb grip strength was reduced in female mice. Acute administration of GAT-1 antagonist NO-711 induced SWDs in wild-type mice, exacerbated the phenotype in GAT-1S295L/+ and GAT-1+/- mice, and had no effect on GAT-1-/- mice lacking the drug target. By contrast, ethosuximide normalized the ECoG in GAT-1S295L/+ and GAT-1+/- mice. In conclusion, GAT-1S295L/+ mice show haploinsufficiency with evidence of GAT-1 hypofunction. This mouse model reconstitutes major aspects of human disease and thus provides a useful preclinical model for drug screening and gene therapy.

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Targeting the RHOA pathway improves learning and memory in adult Kctd13 and 16p11.2 deletion mouse models

Molecular Autism ◽

10.1186/s13229-020-00405-7 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Sandra Martin Lorenzo ◽

Valérie Nalesso ◽

Claire Chevalier ◽

Marie-Christine Birling ◽

Yann Herault

Keyword(s):

Locomotor Activity ◽

Mouse Model ◽

Learning And Memory ◽

Mouse Models ◽

Genetic Background ◽

Gene Copy Number ◽

Chronic Administration ◽

Autism Spectrum ◽

Gene Copy ◽

Homologous Region

Abstract Background Gene copy number variants play an important role in the occurrence of neurodevelopmental disorders. Particularly, the deletion of the 16p11.2 locus is associated with autism spectrum disorder, intellectual disability, and several other features. Earlier studies highlighted the implication of Kctd13 genetic imbalance in 16p11.2 deletion through the regulation of the RHOA pathway. Methods Here, we generated a new mouse model with a small deletion of two key exons in Kctd13. Then, we targeted the RHOA pathway to rescue the cognitive phenotypes of the Kctd13 and 16p11.2 deletion mouse models in a pure genetic background. We used a chronic administration of fasudil (HA1077), an inhibitor of the Rho-associated protein kinase, for six weeks in mouse models carrying a heterozygous inactivation of Kctd13, or the deletion of the entire 16p11.2 BP4-BP5 homologous region. Results We found that the small Kctd13 heterozygous deletion induced a cognitive phenotype similar to the whole deletion of the 16p11.2 homologous region, in the Del/+ mice. We then showed that chronic fasudil treatment can restore object recognition memory in adult heterozygous mutant mice for Kctd13 and for 16p11.2 deletion. In addition, learning and memory improvement occurred in parallel to change in the RHOA pathway. Limitations The Kcdt13 mutant line does not recapitulate all the phenotypes found in the 16p11.2 Del/+ model. In particular, the locomotor activity was not altered at 12 and 18 weeks of age and the object location memory was not defective in 18-week old mutants. Similarly, the increase in locomotor activity was not modified by the treatment in the 16p11.2 Del/+ mouse model, suggesting that other loci were involved in such defects. Rescue was observed only after four weeks of treatment but no long-term experiment has been carried out so far. Finally, we did not check the social behaviour, which requires working in another hybrid genetic background. Conclusion These findings confirm KCTD13 as one target gene causing cognitive deficits in 16p11.2 deletion patients, and the relevance of the RHOA pathway as a therapeutic path for 16p11.2 deletion. In addition, they reinforce the contribution of other gene(s) involved in cognitive defects found in the 16p11.2 models in older mice.

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Targeting the RHOA pathway improves learning and memory in adult Kctd13 and 16p11.2 deletion mouse models

10.21203/rs.3.rs-60136/v2 ◽

2020 ◽

Author(s):

Sandra Martin Lorenzo ◽

Valérie Nalesso ◽

Claire Chevalier ◽

Marie-Christine Birling ◽

Yann HERAULT

Keyword(s):

Locomotor Activity ◽

Mouse Model ◽

Learning And Memory ◽

Mouse Models ◽

Genetic Background ◽

Gene Copy Number ◽

Chronic Administration ◽

Autism Spectrum ◽

Gene Copy ◽

Homologous Region

Abstract Background: Gene copy number variants play an important role in the occurrence of neurodevelopmental disorders. Particularly, the deletion of the 16p11.2 locus is associated with autism spectrum disorder, intellectual disability, and several other features. Earlier studies highlighted the implication of Kctd13 genetic imbalance in 16p11.2 deletion through the regulation of the RHOA pathway. Methods: Here, we generated a new mouse model with a small deletion of two key exons in Kctd13. Then, we targeted the RHOA pathway to rescue the cognitive phenotypes of the Kctd13 and 16p11.2 deletion mouse models in a pure genetic background. We used a chronic administration of fasudil (HA1077), an inhibitor of the Rho-associated protein kinase (ROCK), for six weeks in mouse models carrying a heterozygous inactivation of Kctd13, or the deletion of the entire 16p11.2 BP4-BP5 homologous region. Results: We found that the small Kctd13 heterozygous deletion induced a cognitive phenotype similar to the whole deletion of the 16p11.2 homologous region, in the Del/+ mice. We then showed that chronic fasudil treatment can restore object recognition memory in adult heterozygous mutant mice for Kctd13 and for 16p11.2 deletion. In addition, learning and memory improvement occurred in parallel to change in the RHOA pathway. Limitations: The Kcdt13 mutant line does not recapitulate all the phenotypes found in the 16p11.2 Del/+ model. In particular, the locomotor activity was not altered at 12 and 18 weeks of age and the object location memory was not defective in 18-week old mutants. Similarly, the increase in locomotor activity was not modified by the treatment in the 16p11.2 Del/+ mouse model, suggesting that other loci were involved in such defects. Rescue was observed only after four weeks of treatment but no long-term experiment has been carried out so far. Finally, we did not check the social behaviour, which requires working in another hybrid genetic background.Conclusion: These findings confirm KCTD13 as one target gene causing cognitive deficits in 16p11.2 deletion patients, and the relevance of the RHOA pathway as a therapeutic path for 16p11.2 deletion. In addition, they reinforce the contribution of other gene(s) involved in cognitive defects found in the 16p11.2 models in older mice.

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Assessment of HER-2/neu, с-MYC and CCNE1 gene copy number variations and protein expression in endometrial carcinomas

Experimental Oncology ◽

10.32471/exp-oncology.2312-8852.vol-41-no-2.12973 ◽

2019 ◽

Vol 41 (2) ◽

Author(s):

L.G. Buchynska ◽

◽

O.V. Brieieva* ◽

N.P. Iurchenko ◽

◽

...

Keyword(s):

Protein Expression ◽

Copy Number ◽

Gene Copy Number ◽

Copy Number Variations ◽

Gene Copy ◽

Her 2 ◽

Endometrial Carcinomas

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Faculty Opinions recommendation of Diet and the evolution of human amylase gene copy number variation.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1092307.546722 ◽

2007 ◽

Author(s):

Magnus Ingelman-Sundberg

Keyword(s):

Copy Number Variation ◽

Copy Number ◽

Gene Copy Number ◽

Gene Copy ◽

Amylase Gene ◽

Gene Copy Number Variation ◽

Number Variation

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Faculty Opinions recommendation of RNA polymerase I activators count and adjust ribosomal RNA gene copy number.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.734776122.793556076 ◽

2019 ◽

Author(s):

Angela Taddei

Keyword(s):

Rna Polymerase ◽

Ribosomal Rna ◽

Copy Number ◽

Gene Copy Number ◽

Rna Polymerase I ◽

Gene Copy ◽

Ribosomal Rna Gene ◽

Polymerase I

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Estimating Copy-Number Proportions: The Comeback of Sanger Sequencing

Genes ◽

10.3390/genes12020283 ◽

2021 ◽

Vol 12 (2) ◽

pp. 283

Author(s):

Eyal Seroussi

Keyword(s):

Copy Number ◽

Sanger Sequencing ◽

Cytosine Methylation ◽

Direct Sequencing ◽

Information Source ◽

Gene Copy Number ◽

Cost Effective ◽

Gene Copy ◽

Base Editing ◽

Recent Developments

Determination of the relative copy numbers of mixed molecular species in nucleic acid samples is often the objective of biological experiments, including Single-Nucleotide Polymorphism (SNP), indel and gene copy-number characterization, and quantification of CRISPR-Cas9 base editing, cytosine methylation, and RNA editing. Standard dye-terminator chromatograms are a widely accessible, cost-effective information source from which copy-number proportions can be inferred. However, the rate of incorporation of dye terminators is dependent on the dye type, the adjacent sequence string, and the secondary structure of the sequenced strand. These variable rates complicate inferences and have driven scientists to resort to complex and costly quantification methods. Because these complex methods introduce their own biases, researchers are rethinking whether rectifying distortions in sequencing trace files and using direct sequencing for quantification will enable comparable accurate assessment. Indeed, recent developments in software tools (e.g., TIDE, ICE, EditR, BEEP and BEAT) indicate that quantification based on direct Sanger sequencing is gaining in scientific acceptance. This commentary reviews the common obstacles in quantification and the latest insights and developments relevant to estimating copy-number proportions based on direct Sanger sequencing, concluding that bidirectional sequencing and sophisticated base calling are the keys to identifying and avoiding sequence distortions.

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Nongenotoxic ABCB1 activator tetraphenylphosphonium can contribute to doxorubicin resistance in MX-1 breast cancer cell line

Scientific Reports ◽

10.1038/s41598-021-86120-6 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Raimonda Kubiliute ◽

Indre Januskeviciene ◽

Ruta Urbanaviciute ◽

Kristina Daniunaite ◽

Monika Drobniene ◽

...

Keyword(s):

Breast Cancer ◽

Cell Line ◽

Protein Level ◽

Copy Number ◽

Gene Copy Number ◽

Gene Copy ◽

Common Mechanism ◽

Dna Hypomethylation ◽

Mesenchymal Transition ◽

Molecular Features

AbstractHyperactivation of ABC transporter ABCB1 and induction of epithelial–mesenchymal transition (EMT) are the most common mechanism of acquired cancer chemoresistance. This study describes possible mechanisms, that might contribute to upregulation of ABCB1 and synergistically boost the acquisition of doxorubicin (DOX) resistance in breast cancer MX-1 cell line. DOX resistance in MX-1 cell line was induced by a stepwise increase of drug concentration or by pretreatment of cells with an ABCB1 transporter activator tetraphenylphosphonium (TPP+) followed by DOX exposure. Transcriptome analysis of derived cells was performed by human gene expression microarrays and by quantitative PCR. Genetic and epigenetic mechanisms of ABCB1 regulation were evaluated by pyrosequencing and gene copy number variation analysis. Gradual activation of canonical EMT transcription factors with later activation of ABCB1 at the transcript level was observed in DOX-only treated cells, while TPP+ exposure induced considerable activation of ABCB1 at both, mRNA and protein level. The changes in ABCB1 mRNA and protein level were related to the promoter DNA hypomethylation and the increase in gene copy number. ABCB1-active cells were highly resistant to DOX and showed morphological and molecular features of EMT. The study suggests that nongenotoxic ABCB1 inducer can possibly accelerate development of DOX resistance.

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What a finding of gene copy number variation can add to the diagnosis of developmental neuropsychiatric disorders

Current Opinion in Genetics & Development ◽

10.1016/j.gde.2020.12.017 ◽

2021 ◽

Vol 68 ◽

pp. 18-25

Author(s):

Jacob Vorstman ◽

Stephen W Scherer

Keyword(s):

Copy Number Variation ◽

Copy Number ◽

Gene Copy Number ◽

Neuropsychiatric Disorders ◽

Gene Copy ◽

Gene Copy Number Variation ◽

Number Variation

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Chromosome X aneusomy and androgen receptor gene copy number aberrations in apocrine carcinoma of the breast

Virchows Archiv ◽

10.1007/s00428-021-03028-2 ◽

2021 ◽

Author(s):

Anna Cremonini ◽

Luca Saragoni ◽

Luca Morandi ◽

Angelo G. Corradini ◽

Caterina Ravaioli ◽

...

Keyword(s):

Androgen Receptor ◽

Receptor Gene ◽

Gene Copy Number ◽

Androgen Receptor Gene ◽

Gene Copy ◽

Immunohistochemical Expression ◽

Neoplastic Cells ◽

Genetic Changes ◽

Rare Tumours ◽

Regulator Genes

AbstractCarcinomas with apocrine differentiation (CAD) of the breast are rare tumours typically presenting high immunohistochemical expression of androgen receptor (AR) which is a target molecule for personalised therapy. To date, no studies have evaluated the genetic changes that are associated with AR immunohistochemical expression in CADs. The present work aims to characterise AR status in CADs. Twenty CAD tumours were studied with immunohistochemistry, in situ fluorescence hybridization and DNA methylation analysis, to evaluate AR expression and its regulator status. All tumours demonstrated high AR immunohistochemical expression, with over 95% of the neoplastic cells showing AR positivity in 19/20 cases. CADs showed AR gene copy loss in a percentage of neoplastic cells ranging from 5 to 84% (mean 48.93%). AR regulator genes, including the MAGE family, UXT and FLNA, presented variable methylation levels, but were mainly hypomethylated and therefore all transcriptionally active. The results of this study indicate that CADs present AR monosomy, paralleled by higher transcriptional activity of the gene with potential to influence response to AR deprivation therapy.

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