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James K, Oluwole OG. Leveraging human-mouse studies to advance the genetics of hearing impairment in Africa. J Gene Med 2024; 26:e3714. [PMID: 38949079 DOI: 10.1002/jgm.3714] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2023] [Revised: 04/10/2024] [Accepted: 06/02/2024] [Indexed: 07/02/2024] Open
Abstract
Mouse models are used extensively to understand human pathobiology and mechanistic functions of disease-associated loci. However, in this review, we investigate the potential of using genetic mouse models to identify genetic markers that can disrupt hearing thresholds in mice and then target the hearing-enriched orthologues and loci in humans. Currently, little is known about the real prevalence of genes that cause hearing impairment (HI) in Africa. Pre-screening mouse cell lines to identify orthologues of interest has the potential to improve the genetic diagnosis for HI in Africa to a significant percentage, for example, 10-20%. Furthermore, the functionality of a candidate gene derived from mouse screening with heterogeneous genetic backgrounds and multi-omic approaches can shed light on the molecular, genetic heterogeneity and plausible mode of inheritance of a gene in hearing-impaired individuals especially in the absence of large families to investigate.
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Affiliation(s)
- Kili James
- Department of Pathology, Division of Human Genetics, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Oluwafemi G Oluwole
- Department of Pathology, Division of Human Genetics, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
- Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
- Biomedical Research Centre, Centre for Human Genetics, Nuffield Department of Medicine, University of Oxford, Oxford, UK
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Zapata RC, Zhang D, Yoon D, Nasamran CA, Chilin-Fuentes DR, Libster A, Chaudry BS, Lopez-Valencia M, Ponnalagu D, Singh H, Petrascheck M, Osborn O. Targeting Clic1 for the treatment of obesity: A novel therapeutic strategy to reduce food intake and body weight. Mol Metab 2023; 76:101794. [PMID: 37604246 PMCID: PMC10480059 DOI: 10.1016/j.molmet.2023.101794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 08/13/2023] [Accepted: 08/17/2023] [Indexed: 08/23/2023] Open
Abstract
OBJECTIVE Despite great advances in obesity therapeutics in recent years, there is still a need to identify additional therapeutic targets for the treatment of this disease. We previously discovered a signature of genes, including Chloride intracellular channel 1 (Clic1), whose expression was associated with drug-induced weight gain, and in these studies, we assess the effect of Clic1 inhibition on food intake and body weight in mice. METHODS We studied the impact of Clic1 inhibition in mouse models of binge-eating, diet-induced obese mice and genetic models of obesity (Magel2 KO mice). RESULTS Clic1 knockout (KO) mice ate significantly less and had a lower body weight than WT littermates when either fed chow or high fat diet. Furthermore, pharmacological inhibition of Clic1 in diet-induced obese mice resulted in suppression of food intake and promoted highly efficacious weight loss. Clic1 inhibition also reduced food intake in binge-eating models and hyperphagic Magel2 KO mice. We observed that chronic obesity resulted in a significant change in subcellular localization of Clic1 with an increased ratio of Clic1 in the membrane in the obese state. These observations provide a novel therapeutic strategy to block Clic1 translocation as a potential mechanism to reduce food intake and lower body weight. CONCLUSIONS These studies attribute a novel role of Clic1 as a driver of food intake and overconsumption. In summary, we have identified hypothalamic expression of Clic1 plays a key role in food intake, providing a novel therapeutic target to treat overconsumption that is the root cause of modern obesity.
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Affiliation(s)
- Rizaldy C Zapata
- Division of Endocrinology and Metabolism, School of Medicine, University of California San Diego, La Jolla, CA, 92093, USA
| | - Dinghong Zhang
- Division of Endocrinology and Metabolism, School of Medicine, University of California San Diego, La Jolla, CA, 92093, USA
| | - Dongmin Yoon
- Division of Endocrinology and Metabolism, School of Medicine, University of California San Diego, La Jolla, CA, 92093, USA
| | - Chanond A Nasamran
- Center for Computational Biology & Bioinformatics, Department of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Daisy R Chilin-Fuentes
- Center for Computational Biology & Bioinformatics, Department of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Avraham Libster
- Division of Endocrinology and Metabolism, School of Medicine, University of California San Diego, La Jolla, CA, 92093, USA
| | - Besma S Chaudry
- Division of Endocrinology and Metabolism, School of Medicine, University of California San Diego, La Jolla, CA, 92093, USA
| | - Mariela Lopez-Valencia
- Division of Endocrinology and Metabolism, School of Medicine, University of California San Diego, La Jolla, CA, 92093, USA
| | - Devasena Ponnalagu
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH, USA; Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, USA
| | - Harpreet Singh
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, OH, USA; Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, USA
| | - Michael Petrascheck
- Department of Molecular Medicine, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA; Department of Neuroscience, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA, 92037, USA
| | - Olivia Osborn
- Division of Endocrinology and Metabolism, School of Medicine, University of California San Diego, La Jolla, CA, 92093, USA.
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Tekola-Ayele F, Doumatey AP, Shriner D, Bentley AR, Chen G, Zhou J, Fasanmade O, Johnson T, Oli J, Okafor G, Eghan BA, Agyenim-Boateng K, Adebamowo C, Amoah A, Acheampong J, Adeyemo A, Rotimi CN. Genome-wide association study identifies African-ancestry specific variants for metabolic syndrome. Mol Genet Metab 2015; 116:305-13. [PMID: 26507551 PMCID: PMC5292212 DOI: 10.1016/j.ymgme.2015.10.008] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Revised: 10/21/2015] [Accepted: 10/21/2015] [Indexed: 12/21/2022]
Abstract
The metabolic syndrome (MetS) is a constellation of metabolic disorders that increase the risk of developing several diseases including type 2 diabetes and cardiovascular diseases. Although genome-wide association studies (GWAS) have successfully identified variants associated with individual traits comprising MetS, the genetic basis and pathophysiological mechanisms underlying the clustering of these traits remain unclear. We conducted GWAS of MetS in 1427 Africans from Ghana and Nigeria followed by replication testing and meta-analysis in another continental African sample from Kenya. Further replication testing was performed in an African American sample from the Atherosclerosis Risk in Communities (ARIC) study. We found two African-ancestry specific variants that were significantly associated with MetS: SNP rs73989312[A] near CA10 that conferred increased risk (P=3.86 × 10(-8), OR=6.80) and SNP rs77244975[C] in CTNNA3 that conferred protection against MetS (P=1.63 × 10(-8), OR=0.15). Given the exclusive expression of CA10 in the brain, our CA10 finding strengthens previously reported link between brain function and MetS. We also identified two variants that are not African specific: rs76822696[A] near RALYL associated with increased MetS risk (P=7.37 × 10(-9), OR=1.59) and rs7964157[T] near KSR2 associated with reduced MetS risk (P=4.52 × 10(-8), Pmeta=7.82 × 10(-9), OR=0.53). The KSR2 locus displayed pleiotropic associations with triglyceride and measures of blood pressure. Rare KSR2 mutations have been reported to be associated with early onset obesity and insulin resistance. Finally, we replicated the LPL and CETP loci previously found to be associated with MetS in Europeans. These findings provide novel insights into the genetics of MetS in Africans and demonstrate the utility of conducting trans-ethnic disease gene mapping studies for testing the cosmopolitan significance of GWAS signals of cardio-metabolic traits.
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Affiliation(s)
- Fasil Tekola-Ayele
- Center for Research on Genomics and Global Health, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA.
| | - Ayo P Doumatey
- Center for Research on Genomics and Global Health, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Daniel Shriner
- Center for Research on Genomics and Global Health, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Amy R Bentley
- Center for Research on Genomics and Global Health, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Guanjie Chen
- Center for Research on Genomics and Global Health, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Jie Zhou
- Center for Research on Genomics and Global Health, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | | | | | - Johnnie Oli
- University of Nigeria Teaching Hospital, Enugu, Nigeria
| | | | - Benjami A Eghan
- University of Science and Technology, Department of Medicine, Kumasi, Ghana
| | | | - Clement Adebamowo
- Department of Epidemiology and Public Health, School of Medicine, University of Maryland, Baltimore, MD, USA
| | - Albert Amoah
- University of Ghana Medical School, Department of Medicine, Accra, Ghana
| | - Joseph Acheampong
- University of Science and Technology, Department of Medicine, Kumasi, Ghana
| | - Adebowale Adeyemo
- Center for Research on Genomics and Global Health, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA
| | - Charles N Rotimi
- Center for Research on Genomics and Global Health, National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA.
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Nikolskiy I, Conrad DF, Chun S, Fay JC, Cheverud JM, Lawson HA. Using whole-genome sequences of the LG/J and SM/J inbred mouse strains to prioritize quantitative trait genes and nucleotides. BMC Genomics 2015; 16:415. [PMID: 26016481 PMCID: PMC4445795 DOI: 10.1186/s12864-015-1592-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Accepted: 04/28/2015] [Indexed: 12/04/2022] Open
Abstract
Background The laboratory mouse is the most commonly used model for studying variation in complex traits relevant to human disease. Here we present the whole-genome sequences of two inbred strains, LG/J and SM/J, which are frequently used to study variation in complex traits as diverse as aging, bone-growth, adiposity, maternal behavior, and methamphetamine sensitivity. Results We identified small nucleotide variants (SNVs) and structural variants (SVs) in the LG/J and SM/J strains relative to the reference genome and discovered novel variants in these two strains by comparing their sequences to other mouse genomes. We find that 39% of the LG/J and SM/J genomes are identical-by-descent (IBD). We characterized amino-acid changing mutations using three algorithms: LRT, PolyPhen-2 and SIFT. We also identified polymorphisms between LG/J and SM/J that fall in regulatory regions and highly informative transcription factor binding sites (TFBS). We intersected these functional predictions with quantitative trait loci (QTL) mapped in advanced intercrosses of these two strains. We find that QTL are both over-represented in non-IBD regions and highly enriched for variants predicted to have a functional impact. Variants in QTL associated with metabolic (231 QTL identified in an F16 generation) and developmental (41 QTL identified in an F34 generation) traits were interrogated and we highlight candidate quantitative trait genes (QTG) and nucleotides (QTN) in a QTL on chr13 associated with variation in basal glucose levels and in a QTL on chr6 associated with variation in tibia length. Conclusions We show how integrating genomic sequence with QTL reduces the QTL search space and helps researchers prioritize candidate genes and nucleotides for experimental follow-up. Additionally, given the LG/J and SM/J phylogenetic context among inbred strains, these data contribute important information to the genomic landscape of the laboratory mouse. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-1592-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Igor Nikolskiy
- Department of Genetics, Washington University School of Medicine, Campus Box 8108, 660 S Euclid Ave, St Louis, MO, 63110, USA.
| | - Donald F Conrad
- Department of Genetics, Washington University School of Medicine, Campus Box 8108, 660 S Euclid Ave, St Louis, MO, 63110, USA.
| | - Sung Chun
- Division of Genetics, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA.
| | - Justin C Fay
- Department of Genetics, Washington University School of Medicine, Campus Box 8108, 660 S Euclid Ave, St Louis, MO, 63110, USA.
| | | | - Heather A Lawson
- Department of Genetics, Washington University School of Medicine, Campus Box 8108, 660 S Euclid Ave, St Louis, MO, 63110, USA.
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Mei H, Li L, Liu S, Jiang F, Griswold M, Mosley T. The uniform-score gene set analysis for identifying common pathways associated with different diabetes traits. BMC Genomics 2015; 16:336. [PMID: 25898945 PMCID: PMC4415316 DOI: 10.1186/s12864-015-1515-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2015] [Accepted: 04/09/2015] [Indexed: 02/07/2023] Open
Abstract
Background Genetic heritability and expression study have shown that different diabetes traits have common genetic components and pathways. A computationally efficient pathway analysis of GWAS results will benefit post-GWAS study of SNP associations and identification of common genetic pathways from diabetes GWAS can help to improve understanding of the disease pathogenesis. Results We proposed a uniform-score gene-set analysis (USGSA) with implemented package to unify different gene measures by a uniform score for identifying pathways from GWAS data, and use a pre-generated permutation distribution table to quickly obtain multiple-testing adjusted p-value. Simulation studies of uniform score for four gene measures (minP, 2ndP, simP and fishP) have shown that USGSA has strictly controlled family-wise error rate. The power depends on types of gene measure. USGSA with a two-stage study strategy was applied to identify common pathways associated with diabetes traits based on public dbGaP GWAS results. The study identified 7 gene sets that contain binding motifs at promoter region of component genes for 5 transcription factors (TFs) of FOXO4, TCF3, NFAT, VSX1 and POU2F1, and 1 microRNA of mir-218. These gene sets include 25 common genes that are among top 5% of the gene associations over genome for all GWAS. Previous evidences showed that nearly all of these genes are mainly expressed in the brain. Conclusions USGSA is a computationally efficient approach for pathway analysis of GWAS data with promoted interpretability and comparability. The pathway analysis suggested that different diabetes traits share common pathways and component genes are potentially regulated by common TFs and microRNA. The result also indicated that the central nervous system has a critical role in diabetes pathogenesis. The findings will be important in formulating novel hypotheses for guiding follow-up studies. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-1515-3) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Hao Mei
- Center of Biostatistics & Bioinformatics, University of Mississippi Medical Center, Jackson, MS, USA. .,Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
| | - Lianna Li
- Department of Biology, Tougaloo College, Jackson, MS, USA.
| | - Shijian Liu
- Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
| | - Fan Jiang
- Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
| | - Michael Griswold
- Center of Biostatistics & Bioinformatics, University of Mississippi Medical Center, Jackson, MS, USA.
| | - Thomas Mosley
- Department of Neurology, University of Mississippi Medical Center, Jackson, MS, USA.
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Gonzales NM, Palmer AA. Fine-mapping QTLs in advanced intercross lines and other outbred populations. Mamm Genome 2014; 25:271-92. [PMID: 24906874 DOI: 10.1007/s00335-014-9523-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Accepted: 04/25/2014] [Indexed: 12/16/2022]
Abstract
Quantitative genetic studies in model organisms, particularly in mice, have been extremely successful in identifying chromosomal regions that are associated with a wide variety of behavioral and other traits. However, it is now widely understood that identification of the underlying genes will be far more challenging. In the last few years, a variety of populations have been utilized in an effort to more finely map these chromosomal regions with the goal of identifying specific genes. The common property of these newer populations is that linkage disequilibrium spans relatively short distances, which permits fine-scale mapping resolution. This review focuses on advanced intercross lines (AILs) which are the simplest such population. As originally proposed in 1995 by Darvasi and Soller, an AIL is the product of intercrossing two inbred strains beyond the F2 generation. Unlike recombinant inbred strains, AILs are maintained as outbred populations; brother-sister matings are specifically avoided. Each generation of intercrossing beyond the F2 further degrades linkage disequilibrium between adjacent makers, which allows for fine-scale mapping of quantitative trait loci (QTLs). Advances in genotyping technology and techniques for the statistical analysis of AILs have permitted rapid advances in the application of AILs. We review some of the analytical issues and available software, including QTLRel, EMMA, EMMAX, GEMMA, TASSEL, GRAMMAR, WOMBAT, Mendel, and others.
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Affiliation(s)
- Natalia M Gonzales
- Department of Human Genetics, University of Chicago, Chicago, IL, 60637, USA
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Takeshita S, Suzuki T, Kitayama S, Moritani M, Inoue H, Itakura M. Bhlhe40, a potential diabetic modifier gene on Dbm1 locus, negatively controls myocyte fatty acid oxidation. Genes Genet Syst 2013; 87:253-64. [PMID: 23229312 DOI: 10.1266/ggs.87.253] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
We have previously identified significant quantitative trait loci (QTL) Dbm1 (diabetic modifier QTL 1) on chromosome 6, affecting plasma glucose and insulin concentrations and body weight on F(2) progeny of hypoinsulinemic diabetic Akita mice, with the heterozygous Ins2 gene Cys96Tyr mutation, and non-diabetic A/J mice. To discover diabetic modifier genes on Dbm1, we constructed congenic strain for Dbm1 using the Akita allele as donor in A/J allele genetic background, and compared diabetes-related phenotypes to control mice. The homozygote for Akita allele of Dbm1 was associated with lower plasma glucose concentrations in glucose tolerance test (GTT) in the hypoinsulinemic condition derived from the Ins2 mutation and lower plasma insulin concentrations and body weight in the normoinsulinemic condition without the Ins2 mutation than the homozygote for A/J allele, as we performed QTL analysis on F(2) intercross mice. The Akita allele also decreased the epididymal white adipose tissue (EWAT) weight. According to the analysis of sub-congenic strains, we narrowed down the responsible diabetic modifier region to 9 Mb. As fourteen candidate genes exist in this region, we analyzed genomic variants of these genes and gene expression in the muscle, liver, and EWAT and identified that Bhlhe40 gene expression in muscle is decreased in congenic mice. According to the in vitro functional analyses, Bhlhe40 was shown to negatively control fatty acid oxidation in cultured myocyte. Based on these, we conclude that Bhlhe40 is a possible candidate diabetic modifier gene responsible for Dbm1 locus affecting diabetes and/or obesity through negatively controlling fatty acid oxidation in muscle.
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Affiliation(s)
- Shigeru Takeshita
- Department of Metabolic Diseases, Pharmacology Research Labs., Astellas Pharma Inc., 21 Miyukigaoka, Tsukuba, Ibaraki 305-8585, Japan
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Lee KM, Yang SJ, Kim YD, Choi YD, Nam JH, Choi CS, Choi HS, Park CS. Disruption of the cereblon gene enhances hepatic AMPK activity and prevents high-fat diet-induced obesity and insulin resistance in mice. Diabetes 2013; 62:1855-64. [PMID: 23349485 PMCID: PMC3661653 DOI: 10.2337/db12-1030] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
A nonsense mutation in cereblon (CRBN) causes a mild type of mental retardation in humans. An earlier study showed that CRBN negatively regulates the functional activity of AMP-activated protein kinase (AMPK) in vitro by binding directly to the α1-subunit of the AMPK complex. However, the in vivo role of CRBN was not studied. For elucidation of the physiological functions of Crbn, a mouse strain was generated in which the Crbn gene was deleted throughout the whole body. In Crbn-deficient mice fed a normal diet, AMPK in the liver showed hyperphosphorylation, which indicated the constitutive activation of AMPK. Since Crbn-deficient mice showed significantly less weight gain when fed a high-fat diet and their insulin sensitivity was considerably improved, the functions of Crbn in the liver were primarily investigated. These results provide the first in vivo evidence that Crbn is a negative modulator of AMPK, which suggests that Crbn may be a potential target for metabolic disorders of the liver.
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Affiliation(s)
- Kwang Min Lee
- School of Life Sciences and Cell Dynamics Research Center and National Leading Research Laboratory for Ion Channels, Gwangju Institute of Science and Technology, Gwangju, Republic of Korea
| | - Seung-Joo Yang
- School of Life Sciences and Cell Dynamics Research Center and National Leading Research Laboratory for Ion Channels, Gwangju Institute of Science and Technology, Gwangju, Republic of Korea
| | - Yong Deuk Kim
- National Creative Research Initiatives Center for Nuclear Receptor Signals, Hormone Research Center, School of Biological Sciences and Technology, Chonnam National University, Gwangju, Republic of Korea
| | - Yoo Duk Choi
- Department of Pathology, Chonnam National University Medical School, Gwangju, Republic of Korea
| | - Jong Hee Nam
- Department of Pathology, Chonnam National University Medical School, Gwangju, Republic of Korea
| | - Cheol Soo Choi
- Korea Mouse Metabolic Phenotyping Center, Lee Gil Ya Cancer and Diabetes Institute, Incheon, Republic of Korea
- Division of Endocrinology, Gil Medical Center, Gachon University, Incheon, Republic of Korea
| | - Hueng-Sik Choi
- National Creative Research Initiatives Center for Nuclear Receptor Signals, Hormone Research Center, School of Biological Sciences and Technology, Chonnam National University, Gwangju, Republic of Korea
| | - Chul-Seung Park
- School of Life Sciences and Cell Dynamics Research Center and National Leading Research Laboratory for Ion Channels, Gwangju Institute of Science and Technology, Gwangju, Republic of Korea
- Corresponding author: Chul-Seung Park,
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