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Lara MK, Brabec JL, Hernan AE, Scott RC, Tyler AL, Mahoney JM. Network-based analysis predicts interacting genetic modifiers from a meta-mapping study of spike-wave discharge in mice. Genes Brain Behav 2024; 23:e12879. [PMID: 38444174 PMCID: PMC10915378 DOI: 10.1111/gbb.12879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Revised: 11/29/2023] [Accepted: 12/19/2023] [Indexed: 03/07/2024]
Abstract
Absence seizures are characterized by brief lapses in awareness accompanied by a hallmark spike-and-wave discharge (SWD) electroencephalographic pattern and are common to genetic generalized epilepsies (GGEs). While numerous genes have been associated with increased risk, including some Mendelian forms with a single causal allele, most cases of GGE are idiopathic and there are many unknown genetic modifiers of GGE influencing risk and severity. In a previous meta-mapping study, crosses between transgenic C57BL/6 and C3HeB/FeJ strains, each carrying one of three SWD-causing mutations (Gabrg2tm1Spet(R43Q) , Scn8a8j or Gria4spkw1 ), demonstrated an antagonistic epistatic interaction between loci on mouse chromosomes 2 and 7 influencing SWD. These results implicate universal modifiers in the B6 background that mitigate SWD severity through a common pathway, independent of the causal mutation. In this study, we prioritized candidate modifiers in these interacting loci. Our approach integrated human genome-wide association results with gene interaction networks and mouse brain gene expression to prioritize candidate genes and pathways driving variation in SWD outcomes. We considered candidate genes that are functionally associated with human GGE risk genes and genes with evidence for coding or non-coding allele effects between the B6 and C3H backgrounds. Our analyses output a summary ranking of gene pairs, one gene from each locus, as candidates for explaining the epistatic interaction. Our top-ranking gene pairs implicate microtubule function, cytoskeletal stability and cell cycle regulation as novel hypotheses about the source of SWD variation across strain backgrounds, which could clarify underlying mechanisms driving differences in GGE severity in humans.
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Affiliation(s)
- Montana Kay Lara
- Department of Neurological SciencesUniversity of VermontBurlingtonVermontUSA
| | - Jeffrey L. Brabec
- Department of Neurological SciencesUniversity of VermontBurlingtonVermontUSA
| | - Amanda E. Hernan
- Department of Neurological SciencesUniversity of VermontBurlingtonVermontUSA
- Division of NeuroscienceNemours Children's HealthWilmingtonDelawareUSA
- Department of Psychological and Brain SciencesUniversity of DelawareNewarkDelawareUSA
| | - Rod C. Scott
- Division of NeuroscienceNemours Children's HealthWilmingtonDelawareUSA
- Department of Psychological and Brain SciencesUniversity of DelawareNewarkDelawareUSA
| | | | - J. Matthew Mahoney
- Department of Neurological SciencesUniversity of VermontBurlingtonVermontUSA
- The Jackson LaboratoryBar HarborMaineUSA
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Lara MK, Chitre AS, Chen D, Johnson BB, Nguyen KM, Cohen KA, Muckadam SA, Lin B, Ziegler S, Beeson A, Sanches T, Solberg Woods LC, Polesskaya O, Palmer AA, Mitchell SH. Genome-wide association study of delay discounting in Heterogenous Stock rats. bioRxiv 2023:2023.12.12.570851. [PMID: 38168347 PMCID: PMC10760013 DOI: 10.1101/2023.12.12.570851] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
Delay discounting refers to the behavioral tendency to devalue rewards as a function of their delay in receipt. Heightened delay discounting has been associated with substance use disorders, as well as multiple co-occurring psychopathologies. Genetic studies in humans and animal models have established that delay discounting is a heritable trait, but only a few specific genes have been associated with delay discounting. Here, we aimed to identify novel genetic loci associated with delay discounting through a genome-wide association study (GWAS) using Heterogenous Stock rats, a genetically diverse outbred population derived from eight inbred founder strains. We assessed delay discounting in 650 male and female rats using an adjusting amount procedure in which rats chose between smaller immediate sucrose rewards or a larger reward at variable delays. Preference switch points were calculated for each rat and both exponential and hyperbolic functions were fitted to these indifference points. Area under the curve (AUC) and the discounting parameter k of both functions were used as delay discounting measures. GWAS for AUC, exponential k, and indifference points for a short delay identified significant loci on chromosomes 20 and 14. The gene Slc35f1, which encodes a member of the solute carrier family of nucleoside sugar transporters, was the only gene within the chromosome 20 locus. That locus also contained an eQTL for Slc35f1, suggesting that heritable differences in the expression of that gene might be responsible for the association with behavior. The gene Adgrl3, which encodes a member of the latrophilin family of G-protein coupled receptors, was the only gene within the chromosome 14 locus. These findings implicate novel genes in delay discounting and highlight the need for further exploration.
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Affiliation(s)
- Montana Kay Lara
- Department of Psychiatry, University of California San Diego, La Jolla, CA, 92093, USA
| | - Apurva S. Chitre
- Department of Psychiatry, University of California San Diego, La Jolla, CA, 92093, USA
| | - Denghui Chen
- Department of Psychiatry, University of California San Diego, La Jolla, CA, 92093, USA
| | - Benjamin B. Johnson
- Department of Psychiatry, University of California San Diego, La Jolla, CA, 92093, USA
| | - Khai-Minh Nguyen
- Department of Psychiatry, University of California San Diego, La Jolla, CA, 92093, USA
| | - Katarina A. Cohen
- Department of Psychiatry, University of California San Diego, La Jolla, CA, 92093, USA
| | - Sakina A. Muckadam
- Department of Psychiatry, University of California San Diego, La Jolla, CA, 92093, USA
| | - Bonnie Lin
- Department of Psychiatry, University of California San Diego, La Jolla, CA, 92093, USA
| | - Shae Ziegler
- Department of Psychiatry, University of California San Diego, La Jolla, CA, 92093, USA
| | - Angela Beeson
- Department of Internal Medicine, Wake Forest School of Medicine, Winston-Salem, NC, 27157, USA
| | - Thiago Sanches
- Department of Psychiatry, University of California San Diego, La Jolla, CA, 92093, USA
| | - Leah C. Solberg Woods
- Department of Internal Medicine, Wake Forest School of Medicine, Winston-Salem, NC, 27157, USA
| | - Oksana Polesskaya
- Department of Psychiatry, University of California San Diego, La Jolla, CA, 92093, USA
| | - Abraham A. Palmer
- Department of Psychiatry, University of California San Diego, La Jolla, CA, 92093, USA
- Institute for Genomic Medicine, University of California San Diego, La Jolla, CA, 92093, USA
| | - Suzanne H. Mitchell
- Departments of Behavioral Neuroscience, Psychiatry, the Oregon Institute of Occupational Health Sciences, Oregon Health & Science University, Portland, OR, 97239 USA
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Parker D, Zambelli J, Lara MK, Wolf TH, McDonald A, Lee E, Abou-Elkacem L, Gordon EJ, Baum RP. Case Report: Long-term complete response to PSMA-targeted radioligand therapy and abiraterone in a metastatic prostate cancer patient. Front Oncol 2023; 13:1192792. [PMID: 37188199 PMCID: PMC10175697 DOI: 10.3389/fonc.2023.1192792] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Accepted: 04/14/2023] [Indexed: 05/17/2023] Open
Abstract
Despite decades of research and clinical trials, metastatic castration-resistant prostate cancer (mCRPC) remains incurable and typically fatal. Current treatments may provide modest increases in progression-free survival but can come with significant adverse effects and are disaggregated from the diagnostic imaging needed to fully assess the spread of metastatic disease. A theranostic approach, using radiolabeled ligands that target the cell surface protein PSMA, simplifies the visualization and disease treatment process by enabling both to use similar agents. Here, we describe an exemplary case wherein a gentleman in his 70s with mCRPC on diagnosis was treated with 177Lu-PSMA-617 and abiraterone, and remains disease-free to date, over five years later.
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Affiliation(s)
- David Parker
- Private Health Management, Los Angeles, CA, United States
| | | | | | | | - Amber McDonald
- Private Health Management, Los Angeles, CA, United States
| | - Erica Lee
- Private Health Management, Los Angeles, CA, United States
| | | | - Eva J. Gordon
- Private Health Management, Los Angeles, CA, United States
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Brabec JL, Lara MK, Tyler AL, Mahoney JM. System-Level Analysis of Alzheimer's Disease Prioritizes Candidate Genes for Neurodegeneration. Front Genet 2021; 12:625246. [PMID: 33889174 PMCID: PMC8056044 DOI: 10.3389/fgene.2021.625246] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Accepted: 02/22/2021] [Indexed: 12/11/2022] Open
Abstract
Alzheimer’s disease (AD) is a debilitating neurodegenerative disorder. Since the advent of the genome-wide association study (GWAS) we have come to understand much about the genes involved in AD heritability and pathophysiology. Large case-control meta-GWAS studies have increased our ability to prioritize weaker effect alleles, while the recent development of network-based functional prediction has provided a mechanism by which we can use machine learning to reprioritize GWAS hits in the functional context of relevant brain tissues like the hippocampus and amygdala. In parallel with these developments, groups like the Alzheimer’s Disease Neuroimaging Initiative (ADNI) have compiled rich compendia of AD patient data including genotype and biomarker information, including derived volume measures for relevant structures like the hippocampus and the amygdala. In this study we wanted to identify genes involved in AD-related atrophy of these two structures, which are often critically impaired over the course of the disease. To do this we developed a combined score prioritization method which uses the cumulative distribution function of a gene’s functional and positional score, to prioritize top genes that not only segregate with disease status, but also with hippocampal and amygdalar atrophy. Our method identified a mix of genes that had previously been identified in AD GWAS including APOE, TOMM40, and NECTIN2(PVRL2) and several others that have not been identified in AD genetic studies, but play integral roles in AD-effected functional pathways including IQSEC1, PFN1, and PAK2. Our findings support the viability of our novel combined score as a method for prioritizing region- and even cell-specific AD risk genes.
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Affiliation(s)
- Jeffrey L Brabec
- Department of Neurological Sciences, University of Vermont, Burlington, VT, United States
| | - Montana Kay Lara
- Department of Neurological Sciences, University of Vermont, Burlington, VT, United States
| | - Anna L Tyler
- The Jackson Laboratory, Bar Harbor, ME, United States
| | - J Matthew Mahoney
- Department of Neurological Sciences, University of Vermont, Burlington, VT, United States.,The Jackson Laboratory, Bar Harbor, ME, United States
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