FAST Bioresources for Angelman Syndrome Research

The E6-AP (Ube3atm1Alb) mouse model is the most widely used and published in preclinical research for AS. When maternally inherited, this knock-out allele leads to heterozygous mice that exhibit the AS phenotype. The B6.129S7-Ube3atm1Alb/J mice display motor delays, cognitive impairments, behavioral deficits, and distinctive EEG patterns due to the loss of Ube3a, effectively mirroring the clinical characteristics of AS.

• Primary Investigator: Drs. Art Beaudet and Yong-Hui Jiang

• Availability: https://www.jax.org/strain/016590

Selected Reference(s):

• Mutation of the Angelman Ubiquitin Ligase in Mice Causes Increased Cytoplasmic P53 and Deficits of Contextual Learning and Long-Term Potentiation

Identical to the B6.129S7-Ube3atm1Alb/J mouse except bred on the pure 129/SVJ background strain resulting in strain-dependent phenotypic differences. This includes an increased seizure propensity outlined in the attached reference.

• Primary Investigator: Dr. Art Beaudet

• Availability: https://www.jax.org/strain/004477

Selected Reference(s):

• Strain-dependence of the Angelman Syndrome Phenotypes in Ube3a Maternal Deficiency Mice

Since deletions are responsible for the majority (~70%) of individuals living with AS, developing an in vivo model that features a similar large deletion is essential for understanding the effects of losing Ube3a and the surrounding genes. As part of a FAST-funded initiative, a novel mouse model with a ~6MB full deletion associated with AS has been created. In addition to this large deletion model, another model has been developed that lacks all Class I deleted genes but retains Ube3a expression. This second model aims to help understand how Ube3a, in conjunction with the other haploinsufficient genes, contributes to the phenotypic features observed in individuals living with AS.

• Primary Investigator: Dr. Yong-Hui Jiang

• Availability: Please contact us at science@cureangelman.org

Selected Reference(s):

• Watch the 2023 FAST Summit talk given by Dr. Xiaona Lu, a Postdoctoral Fellow in Dr. Yong-Hui Jiang’s laboratory at Yale.

This model is generated by creating a knock-in allele where Yellow Fluorescent Protein (YFP) is fused to exon 10 of the Ube3a gene. The greatest utility of this mouse model is for the production of paternal Ube3a-YFP mice where strategies for paternal allele unsilencing can be explored. Paternal Ube3a expression levels and CNS distribution of expression can be quantified with this useful reporter model for paternal reactivation.

• Primary Investigator: Drs. Art Beaudet and Scott Dindot

• Availability: https://www.jax.org/strain/017765

Selected Reference(s):

• The Angelman Syndrome Ubiquitin Ligase Localizes to the Synapse and Nucleus, and Maternal Deficiency Results in Abnormal Dendritic Spine Morphology

This model was created through a larger exon 6 deletion of the Ube3a locus using CRISPR/Cas9 resulting in a null allele. When inherited maternally, the exon 6 deletion model displays the common pre-clinical phenotypes that align with the clinical presentation of AS. This model was created with a larger deletion of the Ube3a gene resulting in the maintenance of consistent neurobehavioral phenotypes throughout multiple generations.

• Primary Investigator: Dr. Mingshan Xue

• Availability: https://www.jax.org/strain/038093

Selected Reference(s):

• Circadian Rhythms and Sleep Are Dependent Upon Expression Levels of Key Ubiquitin Ligase Ube3a

(Please note these lists are not exhaustive and additional research may not be publicly available or is ongoing):

• Miura K, Kishino T, Li E, Webber H, Dikkes P, Holmes GL, Wagstaff J. Neurobehavioral and electroencephalographic abnormalities in Ube3a maternal-deficient mice. Neurobiol Dis. 2002 Mar;9(2):149-59. doi: 10.1006/nbdi.2001.0463. PMID: 11895368. https://pubmed.ncbi.nlm.nih.gov/11895368/

• Jiang YH, Pan Y, Zhu L, Landa L, Yoo J, Spencer C, Lorenzo I, Brilliant M, Noebels J, Beaudet AL. Altered ultrasonic vocalization and impaired learning and memory in Angelman syndrome mouse model with a large maternal deletion from Ube3a to Gabrb3. PLoS One. 2010 Aug 20;5(8):e12278. doi: 10.1371/journal.pone.0012278. PMID: 20808828; PMCID: PMC2924885. https://pubmed.ncbi.nlm.nih.gov/20808828/

• Wang T, van Woerden GM, Elgersma Y, Borst JGG. Enhanced Transmission at the Calyx of Held Synapse in a Mouse Model for Angelman Syndrome. Front Cell Neurosci. 2018 Jan 4;11:418. doi: 10.3389/fncel.2017.00418. PMID: 29354033; PMCID: PMC5758499. https://pubmed.ncbi.nlm.nih.gov/29354033/

• Avagliano Trezza R, Sonzogni M, Bossuyt SNV, Zampeta FI, Punt AM, van den Berg M, Rotaru DC, Koene LMC, Munshi ST, Stedehouder J, Kros JM, Williams M, Heussler H, de Vrij FMS, Mientjes EJ, van Woerden GM, Kushner SA, Distel B, Elgersma Y. Loss of nuclear UBE3A causes electrophysiological and behavioral deficits in mice and is associated with Angelman syndrome. Nat Neurosci. 2019 Aug;22(8):1235-1247. doi: 10.1038/s41593-019-0425-0. Epub 2019 Jun 24. PMID: 31235931. https://pubmed.ncbi.nlm.nih.gov/31235931/

• Avagliano Trezza R, Sonzogni M, Bossuyt SNV, Zampeta FI, Punt AM, van den Berg M, Rotaru DC, Koene LMC, Munshi ST, Stedehouder J, Kros JM, Williams M, Heussler H, de Vrij FMS, Mientjes EJ, van Woerden GM, Kushner SA, Distel B, Elgersma Y. Loss of nuclear UBE3A causes electrophysiological and behavioral deficits in mice and is associated with Angelman syndrome. Nat Neurosci. 2019 Aug;22(8):1235-1247. doi: 10.1038/s41593-019-0425-0. Epub 2019 Jun 24. PMID: 31235931. https://pubmed.ncbi.nlm.nih.gov/31235931/

• Silva-Santos S, van Woerden GM, Bruinsma CF, Mientjes E, Jolfaei MA, Distel B, Kushner SA, Elgersma Y. Ube3a reinstatement identifies distinct developmental windows in a murine Angelman syndrome model. J Clin Invest. 2015 May;125(5):2069-76. doi: 10.1172/JCI80554. Epub 2015 Apr 13. PMID: 25866966; PMCID: PMC4463212. https://pubmed.ncbi.nlm.nih.gov/25866966/

• Bruinsma CF, Schonewille M, Gao Z, Aronica EM, Judson MC, Philpot BD, Hoebeek FE, van Woerden GM, De Zeeuw CI, Elgersma Y. Dissociation of locomotor and cerebellar deficits in a murine Angelman syndrome model. J Clin Invest. 2015 Nov 2;125(11):4305-15. doi: 10.1172/JCI83541. Epub 2015 Oct 20. PMID: 26485287; PMCID: PMC4639977. https://pubmed.ncbi.nlm.nih.gov/26485287/

Advances in genetic models, facilitated by FAST, herald a new era of in vivo tools for translational neuroscience. Rats are considered to have a more evolved and complex CNS. These features make the rat a more translatable model to assess social communication and cognitive outcomes that are a challenge to reliably and robustly measure in the mouse model. In addition, the body mass of a rat makes assessment of the biodistribution of therapeutics more translatable for preclinical studies and allows for superior collection of tissue, blood, and CSF. Through a FAST-funded project, a novel 90 kb deletion AS rat model has been generated using CRISPR/Cas9 to delete the Ube3a gene on the maternal allele.

• Primary Investigators: Drs. Edwin Weeber, Dave Segal and Scott Dindot

• Availability: Please contact us at science@cureangelman.org

Selected Reference(s):

• Generation of a Novel Rat Model of Angelman Syndrome with a Complete Ube3a Gene Deletion

• Altered Ultrasonic Vocalizations, Microcephaly, and Translational Outcomes in the Ube3a Deletion Rat Model of Angelman Syndrome

• Early Developmental EEG and Seizure Phenotypes in a Full Gene Deletion of Ubiquitin Protein Ligase E3A Rat Model of Angelman Syndrome

• Translational Outcomes in a Full Gene Deletion of Ubiquitin Protein Ligase E3A Rat Model of Angelman Syndrome

There are limitations of existing rodent animal models, particularly in their ability to replicate the full spectrum of symptoms and physiological characteristics associated with AS. While traditional models have been instrumental in genetic research, they often fall short in mirroring the complex behavioral, cognitive, and motor impairments seen in individuals living with AS. Pigs, on the other hand, possess significant anatomical and physiological similarities to humans, including comparable brain structure, neuroanatomy, and brain size. These features make pigs potentially suitable for modeling human AS and can be used for therapeutic safety assessments, biodistribution analysis, complex phenotypic assessment and biomarker exploration.

• Primary Investigator: Dr. Scott Dindot

• Availability: Please contact science@cureangelman.org

Selected Reference(s):

• Texas A&M Researchers Detail Groundbreaking Angelman Syndrome Development

• Watch this talk given by Dr. Scott Dindot at the FAST Science Summit

• Unique Features of the Gut Microbiome Characterized in Animal Models of Angelman Syndrome

Several drosophila models have been developed for AS. These models have been used to understand the role of DUbe3a during development, recapitulate translational phenotypes, and screen for therapeutic candidates.

• Availability: https://bdsc.indiana.edu/stocks/hd/angelman.html

Selected Reference(s):

• A Drosophila model for Angelman syndrome

• The Drosophila melanogaster homolog of UBE3A is not imprinted in neurons

Both models were created to overexpress specific isoforms of Ube3a (isoforms 1 and 2) to determine if unique phenotypic outcomes can be associated with either isoform overexpression, with a goal of modeling the duplication 15q phenotype. Here, the model is also conditional, using a Tet-on/Tet-off system to overexpress FLAG-tagged Ube3a isoforms in excitatory forebrain neurons.

• Primary Investigator: Dr. Scott Dindot

• Availability: Isoform 2 - https://www.jax.org/strain/026279; Isoform 1 - https://www.jax.org/strain/026278

Selected Reference(s):

• Neuronal Overexpression of Ube3a Isoform 2 Causes Behavioral Impairments and Neuroanatomical Pathology Relevant to 15q11.2-q13.3 Duplication Syndrome

(Please note these lists are not exhaustive and additional research may not be publicly available or is ongoing):

• Punt AM, Judson MC, Sidorov MS, Williams BN, Johnson NS, Belder S, den Hertog D, Davis CR, Feygin MS, Lang PF, Jolfaei MA, Curran PJ, van IJcken WF, Elgersma Y, Philpot BD. Molecular and behavioral consequences of Ube3a gene overdosage in mice. JCI Insight. 2022 Sep 22;7(18):e158953. doi: 10.1172/jci.insight.158953. PMID: 36134658; PMCID: PMC9675564. https://pubmed.ncbi.nlm.nih.gov/36134658/

• Krishnan V, Stoppel DC, Nong Y, Johnson MA, Nadler MJ, Ozkaynak E, Teng BL, Nagakura I, Mohammad F, Silva MA, Peterson S, Cruz TJ, Kasper EM, Arnaout R, Anderson MP. Autism gene Ube3a and seizures impair sociability by repressing VTA Cbln1. Nature. 2017 Mar 23;543(7646):507-512. doi: 10.1038/nature21678. Epub 2017 Mar 15. PMID: 28297715; PMCID: PMC5364052. https://pubmed.ncbi.nlm.nih.gov/28297715/

• Nakatani J, Tamada K, Hatanaka F, Ise S, Ohta H, Inoue K, Tomonaga S, Watanabe Y, Chung YJ, Banerjee R, Iwamoto K, Kato T, Okazawa M, Yamauchi K, Tanda K, Takao K, Miyakawa T, Bradley A, Takumi T. Abnormal behavior in a chromosome-engineered mouse model for human 15q11-13 duplication seen in autism. Cell. 2009 Jun 26;137(7):1235-46. doi: 10.1016/j.cell.2009.04.024. PMID: 19563756; PMCID: PMC3710970. https://pubmed.ncbi.nlm.nih.gov/19563756/

Patient-derived iPSCs play a crucial role in screening potential gene-specific and molecular therapeutic candidates for AS. Through a FAST-funded project, we have established a robust biorepository containing AS patient-derived iPSC lines of all genotypes (deletion, mutation, UPD, and ICD) as well as cell lines derived from neurotypical siblings. This resource will be publicly shareable with the AS research community, including industry and academic institutions, through EBiSC.

• Primary Investigator: Dr. Yong-Hui Jiang

• Availability: EBiSC Link Coming Soon; please contact us at science@cureangelman.org

Selected Reference(s):

• Check out more from this talk given by Dr. Yong-Hui at the FAST Science Summit

Class I and Class II deletions account for the majority of individuals living with AS. These large 15q11-13 deletions include UBE3A and other protein-coding genes that may contribute to the clinical phenotype. In an effort to understand how UBE3A and these additional genes contribute to the clinical presentation of AS, a recombinase-based landing pad has been incorporated into a Class I deletion human pluripotent stem cell line with the capability to rescue the expression of each of these happloinsufficient genes in order to screen for their individual roles and responses to putative therapeutics.

• Primary Investigator: Dr. Albert Keung

• Availability: Please contact us at science@cureangelman.org

Selected Reference(s):

• Check out this FAST Summit talk to learn more.

Shareable human stem cell lines are being designed to model the biology of ICD and UPD genotypes. These stem cell lines have built-in landing pads to artificially control the expression of UBE3A and other genes/snoRNAs that, in UPD/ICD, are differentially expressed due to abnormal imprinting. The UPD/ICD lines will be useful in understanding the impact of varied gene/snoRNA expression due to altered imprinting and address the potential of overexpressing UBE3A in therapeutic candidates designed to activate paternal UBE3A.

• Primary Investigator: Dr. Albert Keung

• Availability: Please contact us at science@cureangelman.org

Selected Reference(s):

Check out this FAST Summit talk to learn more.

A GFP reporter stem cell line has been generated using Class II deletion human pluripotent stem cells to test for efficacy in paternal UBE3A activation studies.

• Primary Investigator: Dr. Albert Keung

• Availability: Please contact us at science@cureangelman.org

Selected Reference(s):

• Coming Soon

A GFP reporter stem cell line has been generated using a human pluripotent stem cell line with a Class I (~6MB) deletion to test for efficacy in paternal UBE3A activation studies.

• Primary Investigator: Dr. Yong-Hui Jiang

• Availability: Please contact us at science@cureangelman.org

Selected Reference(s):

• Coming Soon

Cerebral organoids are useful tools as they can embody the molecular diversity of AS and serve to screen potential therapeutic candidates and their direct effects on neuronal function in a 3-dimensional model. Cerebral organoid models derived from the cell lines listed may be available for assessment.

• Primary Investigators: Drs. Albert Keung and Yong-Hui Jiang (separate organoid lines available from each investigator.

• Availability: Please contact us at science@cureangelman.org

Selected Reference(s):

• Check out this talk to learn more from Dr. Albert Keung.

(Please note these lists are not exhaustive and additional research may not be publicly available or is ongoing):

• Chamberlain SJ, Chen PF, Ng KY, Bourgois-Rocha F, Lemtiri-Chlieh F, Levine ES, Lalande M. Induced pluripotent stem cell models of the genomic imprinting disorders Angelman and Prader-Willi syndromes. Proc Natl Acad Sci U S A. 2010 Oct 12;107(41):17668-73. doi: 10.1073/pnas.1004487107. Epub 2010 Sep 27. PMID: 20876107; PMCID: PMC2955112. https://pubmed.ncbi.nlm.nih.gov/20876107/

• Fink JJ, Robinson TM, Germain ND, Sirois CL, Bolduc KA, Ward AJ, Rigo F, Chamberlain SJ, Levine ES. Disrupted neuronal maturation in Angelman syndrome-derived induced pluripotent stem cells. Nat Commun. 2017 Apr 24;8:15038. doi: 10.1038/ncomms15038. PMID: 28436452; PMCID: PMC5413969. https://pubmed.ncbi.nlm.nih.gov/28436452/

• Neureiter A, Brändl B, Hiber M, Tandon R, Müller FJ, Steenpass L. Generation of an iPSC line of a patient with Angelman syndrome due to an imprinting defect. Stem Cell Res. 2018 Dec;33:20-24. doi: 10.1016/j.scr.2018.09.015. Epub 2018 Sep 24. PMID: 30296670. https://pubmed.ncbi.nlm.nih.gov/30296670/

• Takahashi Y, Wu J, Suzuki K, Martinez-Redondo P, Li M, Liao HK, Wu MZ, Hernández-Benítez R, Hishida T, Shokhirev MN, Esteban CR, Sancho-Martinez I, Belmonte JCI. Integration of CpG-free DNA induces de novo methylation of CpG islands in pluripotent stem cells. Science. 2017 May 5;356(6337):503-508. doi: 10.1126/science.aag3260. PMID: 28473583; PMCID: PMC5654639. https://pubmed.ncbi.nlm.nih.gov/28473583/

• Niki T, Imamura K, Enami T, Kinoshita M, Inoue H. Establishment of human induced pluripotent stem cell line from a patient with Angelman syndrome carrying the deletion of maternal chromosome 15q11.2-q13. Stem Cell Res. 2019 Jan;34:101363. doi: 10.1016/j.scr.2018.101363. Epub 2018 Dec 10. PMID: 30605843. https://pubmed.ncbi.nlm.nih.gov/30605843/

• Pólvora-Brandão D, Joaquim M, Godinho I, Aprile D, Álvaro AR, Onofre I, Raposo AC, Pereira de Almeida L, Duarte ST, da Rocha ST. Loss of hierarchical imprinting regulation at the Prader-Willi/Angelman syndrome locus in human iPSCs. Hum Mol Genet. 2018 Dec 1;27(23):3999-4011. doi: 10.1093/hmg/ddy274. PMID: 30102380; PMCID: PMC6240739. https://pubmed.ncbi.nlm.nih.gov/30102380/

The development of several therapeutic approaches for AS involve replacing the missing UBE3A gene or protein, which his an enzyme that functions as a ubiquitin ligase. In order to understand the function of this therapeutics product (transgene or protein product), it can be best in a functional assay by assessing ubiquitin ligase activity. Prior commercial assays leveraged Western blot to detect shifts in substrate size due to ubiquitination, but these suffered from long assay times, poor specificity, and have recently been commercially discontinued. This new assay quantifies UBE3A protein activity in vitro by measuring fluorescence intensity of ubiquitinated P53 substrates with a microplate reader, eliminating the need for Western blot assessment and enabling timely detection within 1-hr. FAST supported the development of this assay and is available for the research and commercial community to have access to.

• Primary Investigator: Dr. Albert Keung

• Availability: Please contact us at science@cureangelman.org

Selected Reference(s):

• Coming Soon

PHA533533 is a compound that has been investigated primarily for its role as a selective inhibitor of the enzyme protein kinase C (PKC). Specifically, it targets the PKCθ isoform, which is involved in various cellular processes, including cell growth, differentiation, and survival. It has been recently shown that PHA533533 can induce widespread paternal allele Ube3a expression in an AS mouse model through an unknown mechanism of action.

• Primary Investigator: Dr. Ben Philpot

• Availability: MedChemExpress (MCE) (Cat. No.: HY-162683) / ProChem (Catalog No.: PC-22640)

Selected Reference(s):

• Ube3a Unsilencer for the Potential Treatment of Angelman Syndrome

Topotecan is a chemotherapeutic drug primarily used to treat certain types of cancer. It belongs to a class of drugs called topoisomerase inhibitors, which work by interfering with DNA replication in rapidly dividing cells.

In AS, topotecan has been studied for its potential to reactivate the paternally inherited Ube3a gene, which is normally silenced due to genomic imprinting. Research has shown that topotecan can inhibit topoisomerase enzymes that are involved in gene silencing mechanisms, including the silencing of the paternal Ube3a gene. By inhibiting these enzymes, topotecan has been found to partially unsilence the paternal Ube3a allele in neurons, leading to an increase in paternal Ube3a expression. Topotecan has served as an in vitro positive control for paternal Ube3a reactivation studies, though it is not well tolerated in vivo.

• Primary Investigator: Dr. Ben Philpot

• Availability: https://www.caymanchem.com/product/14129/topotecan-(hydrochloride)

Selected Reference(s):

• Topoisomerase Inhibitors Unsilence the Dormant Allele of Ube3a in Neurons

Antisense oligonucleotides (ASO) are synthetic molecules designed to bind to RNA, alterning or blocking the expression of specific genes. In the context of AS, ASOs hold significant potential because they can be used to target and reactivate the silenced paternal copy of the UBE3A gene by targeting the long noncoding RNA called the UBE3A-ATS, which is present on the paternal allele. By reactivating this gene on the paternal allele, ASOs offer a promising therapeutic approach to address the underlying genetic cause of AS, the overall lack of UBE3A expression in neurons.

ASO-A sequence: 5′- GATCCATTTGTGTTAAGCTG-3′

• Primary Investigator: Dr. Art Beaudet

Selected Reference(s):

• Towards a Therapy for Angelman Syndrome by Targeting a Long Non-Coding RN