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Esdaile E, Knickelbein KE, Donnelly CG, Ferneding M, Motta MJ, Story BD, Avila F, Finno CJ, Gilger BC, Sandmeyer L, Thomasy S, Bellone RR. Additional evidence supports GRM6 p.Thr178Met as a cause of congenital stationary night blindness in three horse breeds. Vet Ophthalmol 2024; 27:248-255. [PMID: 37815029 DOI: 10.1111/vop.13151] [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: 06/09/2023] [Revised: 09/11/2023] [Accepted: 09/19/2023] [Indexed: 10/11/2023]
Abstract
Congenital stationary night blindness (CSNB) is an ocular disorder characterized by nyctalopia. An autosomal recessive missense mutation in glutamate metabotropic receptor 6 (GRM6 c.533C>T, p.(Thr178Met)), called CSNB2, was previously identified in one Tennessee Walking Horse and predicted to reduce binding affinity of the neurotransmitter glutamate, impacting the retinal rod ON-bipolar cell signaling pathway. Thus, the first aim was to identify the allele frequency (AF) of CSNB2 in breeds with reported cases of CSNB and breeds closely related to the Tennessee Walking Horse. The second aim was to perform ocular examinations in multiple breeds to confirm the link between genotype and CSNB phenotype. In evaluating 3518 horses from 14 breeds, the CSNB2 allele was identified in nine previously unreported breeds. The estimated AF was highest in pacing Standardbreds (0.17) and lowest in American Quarter Horses (0.0010). Complete ophthalmic examinations and electroretinograms (ERG) were performed on 19 horses from three breeds, including one CSNB2 homozygote from each breed. All three CSNB2/CSNB2 horses had an electronegative ERG waveform under scotopic light conditions consistent with CSNB. The remaining 16 horses (seven CSNB2/N and nine N/N) had normal scotopic ERG results. All horses had normal photopic ERGs. This study provides additional evidence that GRM6 c.533C>T homozygosity is likely causal to CSNB in Tennessee Walking Horses, Standardbreds, and Missouri Fox Trotting Horses. Genetic testing is recommended for breeds with the CSNB2 allele to limit the production of affected horses. This study represents the largest across-breed identification of CSNB in the horse and suggests that this disorder is likely underdiagnosed.
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Affiliation(s)
- Elizabeth Esdaile
- Veterinary Genetics Laboratory, School of Veterinary Medicine, University of California, Davis, Davis, California, USA
| | - Kelly E Knickelbein
- Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA
| | - Callum G Donnelly
- Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA
- Department of Population Health and Reproduction, School of Veterinary Medicine, University of California, Davis, Davis, California, USA
| | - Michelle Ferneding
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, Davis, California, USA
| | - Monica J Motta
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, Davis, California, USA
| | - Brett D Story
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, Davis, California, USA
| | - Felipe Avila
- Veterinary Genetics Laboratory, School of Veterinary Medicine, University of California, Davis, Davis, California, USA
| | - Carrie J Finno
- Department of Population Health and Reproduction, School of Veterinary Medicine, University of California, Davis, Davis, California, USA
| | - Brian C Gilger
- Department of Clinical Sciences, North Carolina State University, Raleigh, North Carolina, USA
- Department of Ophthalmology, School of Medicine, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Lynne Sandmeyer
- Department of Small Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Sara Thomasy
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, Davis, California, USA
- Department of Ophthalmology & Vision Science, School of Medicine, University of California, Davis, Sacramento, California, USA
| | - Rebecca R Bellone
- Veterinary Genetics Laboratory, School of Veterinary Medicine, University of California, Davis, Davis, California, USA
- Department of Population Health and Reproduction, School of Veterinary Medicine, University of California, Davis, Davis, California, USA
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2
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Hasan N, Gregg RG. Cone Synaptic function is modulated by the leucine rich repeat (LRR) adhesion molecule LRFN2. eNeuro 2024; 11:ENEURO.0120-23.2024. [PMID: 38408870 PMCID: PMC10957230 DOI: 10.1523/eneuro.0120-23.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Revised: 02/11/2024] [Accepted: 02/18/2024] [Indexed: 02/28/2024] Open
Abstract
Daylight vision is mediated by cone photoreceptors in vertebrates, which synapse with bipolar cells (BCs) and horizontal (HCs) cells. This cone synapse is functionally and anatomically complex, connecting to 8 types of depolarizing BCs (DBCs) and 5 types of hyperpolarizing BCs (HBCs) in mice. The dendrites of DBCs and HCs cells make invaginating ribbon synapses with the cone axon terminal, while HBCs form flat synapses with the cone pedicles. The molecular architecture that underpins this organization is relatively poorly understood. To identify new proteins involved in synapse formation and function we used an unbiased proteomic approach and identified LRFN2 (leucine-rich repeat and fibronectin III domain-containing 2) as a component of the DBC signaling complex. LRFN2 is selectively expressed at cone terminals and co-localizes with PNA, and other DBC signalplex members. In LRFN2 deficient mice, the synaptic markers: LRIT3, ELFN2, mGluR6, TRPM1 and GPR179 are properly localized. Similarly, LRFN2 expression and localization is not dependent on these synaptic proteins. In the absence of LRFN2 the cone-mediated photopic electroretinogram b-wave amplitude is reduced at the brightest flash intensities. These data demonstrate that LRFN2 absence compromises normal synaptic transmission between cones and cone DBCs.Significance Statement Signaling between cone photoreceptors and the downstream bipolar cells is critical to normal vision. Cones synapse with 13 different types of bipolar cells forming an invaginating ribbon synapses with 8 types, and flat synapses with 5 types, to form one of the most complex synapses in the brain. In this report a new protein, LRFN2 (leucine-rich repeat and fibronectin III domain-containing 2), was identified that is expressed at the cone synapse. Using Lrfn2 knockout mice we show LRFN2 is required for the normal cone signaling.
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Affiliation(s)
- Nazarul Hasan
- Departments of Biochemistry & Molecular Genetics, University of Louisville, Louisville, Kentucky 40202
- Ophthalmology & Visual Sciences, University of Louisville, Louisville, Kentucky 40202
| | - Ronald G. Gregg
- Departments of Biochemistry & Molecular Genetics, University of Louisville, Louisville, Kentucky 40202
- Ophthalmology & Visual Sciences, University of Louisville, Louisville, Kentucky 40202
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Križaj D, Cordeiro S, Strauß O. Retinal TRP channels: Cell-type-specific regulators of retinal homeostasis and multimodal integration. Prog Retin Eye Res 2023; 92:101114. [PMID: 36163161 PMCID: PMC9897210 DOI: 10.1016/j.preteyeres.2022.101114] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 08/03/2022] [Accepted: 08/08/2022] [Indexed: 02/05/2023]
Abstract
Transient receptor potential (TRP) channels are a widely expressed family of 28 evolutionarily conserved cationic ion channels that operate as primary detectors of chemical and physical stimuli and secondary effectors of metabotropic and ionotropic receptors. In vertebrates, the channels are grouped into six related families: TRPC, TRPV, TRPM, TRPA, TRPML, and TRPP. As sensory transducers, TRP channels are ubiquitously expressed across the body and the CNS, mediating critical functions in mechanosensation, nociception, chemosensing, thermosensing, and phototransduction. This article surveys current knowledge about the expression and function of the TRP family in vertebrate retinas, which, while dedicated to transduction and transmission of visual information, are highly susceptible to non-visual stimuli. Every retinal cell expresses multiple TRP subunits, with recent evidence establishing their critical roles in paradigmatic aspects of vertebrate vision that include TRPM1-dependent transduction of ON bipolar signaling, TRPC6/7-mediated ganglion cell phototransduction, TRP/TRPL phototransduction in Drosophila and TRPV4-dependent osmoregulation, mechanotransduction, and regulation of inner and outer blood-retina barriers. TRP channels tune light-dependent and independent functions of retinal circuits by modulating the intracellular concentration of the 2nd messenger calcium, with emerging evidence implicating specific subunits in the pathogenesis of debilitating diseases such as glaucoma, ocular trauma, diabetic retinopathy, and ischemia. Elucidation of TRP channel involvement in retinal biology will yield rewards in terms of fundamental understanding of vertebrate vision and therapeutic targeting to treat diseases caused by channel dysfunction or over-activation.
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Affiliation(s)
- David Križaj
- Departments of Ophthalmology, Neurobiology, and Bioengineering, University of Utah, Salt Lake City, USA
| | - Soenke Cordeiro
- Institute of Physiology, Faculty of Medicine, Christian-Albrechts-University Kiel, Germany
| | - Olaf Strauß
- Experimental Ophthalmology, Department of Ophthalmology, Charité - Universitätsmedizin Berlin, a Corporate Member of Freie Universität, Humboldt-University, The Berlin Institute of Health, Berlin, Germany.
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4
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Kingsley NB, Sandmeyer L, Norton EM, Speed D, Dwyer A, Lassaline M, McCue M, Bellone RR. Heritability of insidious uveitis in Appaloosa horses. Anim Genet 2022; 53:872-877. [DOI: 10.1111/age.13267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 09/09/2022] [Accepted: 09/20/2022] [Indexed: 11/28/2022]
Affiliation(s)
- Nicole B. Kingsley
- Veterinary Genetics Laboratory, School of Veterinary Medicine University of California – Davis Davis California USA
- Department of Population Health and Reproduction, School of Veterinary Medicine University of California – Davis Davis California USA
| | - Lynne Sandmeyer
- Department of Small Animal Clinical Sciences, Western College of Veterinary Medicine University of Saskatchewan Saskatoon Saskatchewan Canada
| | - Elaine M. Norton
- School of Animal and Comparative Biomedical Sciences University of Arizona Tucson Arizona USA
| | - Doug Speed
- Center for Quantitative Genetics and Genomics Aarhus University Aarhus Denmark
| | - Ann Dwyer
- Genesee Valley Equine Clinic, LLC Scottsville New York USA
| | - Mary Lassaline
- School of Veterinary Medicine University of Pennsylvania Philadelphia Pennsylvania USA
| | - Molly McCue
- Veterinary Population Medicine Department, College of Veterinary Medicine University of Minnesota St Paul Minnesota USA
| | - Rebecca R. Bellone
- Veterinary Genetics Laboratory, School of Veterinary Medicine University of California – Davis Davis California USA
- Department of Population Health and Reproduction, School of Veterinary Medicine University of California – Davis Davis California USA
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5
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Unilateral cataract and congenital stationary night blindness in a child with novel variants in TRPM1. J AAPOS 2022; 26:202-205. [PMID: 35872165 DOI: 10.1016/j.jaapos.2022.03.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 02/16/2022] [Accepted: 03/06/2022] [Indexed: 11/21/2022]
Abstract
Unilateral cataract can cause pediatric vision impairment. Although the majority of unilateral cataracts are idiopathic in nature, genetic causes have been reported. We present the case of a 4-week-old child of nonconsanguineous parents who was affected with unilateral cataract. Whole-genome sequencing using DNA extracted from blood and the lens epithelial cells following cataract surgery revealed two presumed pathogenic variants in the TRPM1 gene, the founding member of the melanoma-related transient receptor potential (TRPM) subfamily. TRPM1 is responsible for regulating cation influx to hyperpolarized retinal ON bipolar cells, and mutations in this gene are a major cause of autosomal recessive congenital stationary night blindness (CSNB). Electroretinography revealed findings consistent with CSNB, a phenotype that was not initially suspected, and which would likely have been missed without genome sequencing. It remains unclear whether the TRPM1 variants are associated with the cataract phenotype.
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6
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Colpitts J, McLoughlin PD, Poissant J. Runs of homozygosity in Sable Island feral horses reveal the genomic consequences of inbreeding and divergence from domestic breeds. BMC Genomics 2022; 23:501. [PMID: 35820826 PMCID: PMC9275264 DOI: 10.1186/s12864-022-08729-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 06/29/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Understanding inbreeding and its impact on fitness and evolutionary potential is fundamental to species conservation and agriculture. Long stretches of homozygous genotypes, known as runs of homozygosity (ROH), result from inbreeding and their number and length can provide useful population-level information on inbreeding characteristics and locations of signatures of selection. However, the utility of ROH for conservation is limited for natural populations where baseline data and genomic tools are lacking. Comparing ROH metrics in recently feral vs. domestic populations of well understood species like the horse could provide information on the genetic health of those populations and offer insight into how such metrics compare between managed and unmanaged populations. Here we characterized ROH, inbreeding coefficients, and ROH islands in a feral horse population from Sable Island, Canada, using ~41 000 SNPs and contrasted results with those from 33 domestic breeds to assess the impacts of isolation on ROH abundance, length, distribution, and ROH islands. RESULTS ROH number, length, and ROH-based inbreeding coefficients (FROH) in Sable Island horses were generally greater than in domestic breeds. Short runs, which typically coalesce many generations prior, were more abundant than long runs in all populations, but run length distributions indicated more recent population bottlenecks in Sable Island horses. Nine ROH islands were detected in Sable Island horses, exhibiting very little overlap with those found in domestic breeds. Gene ontology (GO) enrichment analysis for Sable Island ROH islands revealed enrichment for genes associated with 3 clusters of biological pathways largely associated with metabolism and immune function. CONCLUSIONS This study indicates that Sable Island horses tend to be more inbred than their domestic counterparts and that most of this inbreeding is due to historical bottlenecks and founder effects rather than recent mating between close relatives. Unique ROH islands in the Sable Island population suggest adaptation to local selective pressures and/or strong genetic drift and highlight the value of this population as a reservoir of equine genetic variation. This research illustrates how ROH analyses can be applied to gain insights into the population history, genetic health, and divergence of wild or feral populations of conservation concern.
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Affiliation(s)
- Julie Colpitts
- Department of Biology, University of Saskatchewan, Saskatchewan, Canada.
| | | | - Jocelyn Poissant
- Faculty of Veterinary Medicine, University of Calgary, Calgary, Alberta, Canada.
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7
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Kingsley NB, Sandmeyer L, Bellone RR. A review of investigated risk factors for developing equine recurrent uveitis. Vet Ophthalmol 2022; 26:86-100. [PMID: 35691017 DOI: 10.1111/vop.13002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 04/25/2022] [Accepted: 05/27/2022] [Indexed: 12/01/2022]
Abstract
Equine recurrent uveitis (ERU) is an ocular inflammatory disease that can be difficult to manage clinically. As such, it is the leading cause of bilateral blindness for horses. ERU is suspected to have a complex autoimmune etiology with both environmental and genetic risk factors contributing to onset and disease progression in some or all cases. Work in recent years has aimed at unraveling the primary triggers, such as infectious agents and inherited breed-specific risk factors, for disease onset, persistence, and progression. This review has aimed at encompassing those factors that have been associated, implicated, or substantiated as contributors to ERU, as well as identifying areas for which additional knowledge is needed to better understand risk for disease onset and progression. A greater understanding of the risk factors for ERU will enable earlier detection and better prognosis through prevention and new therapeutics.
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Affiliation(s)
- Nicole B Kingsley
- Veterinary Genetics Laboratory, School of Veterinary Medicine, University of California - Davis, Davis, California, USA.,Department of Population Health and Reproduction, School of Veterinary Medicine, University of California - Davis, Davis, California, USA
| | - Lynne Sandmeyer
- Department of Small Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Rebecca R Bellone
- Veterinary Genetics Laboratory, School of Veterinary Medicine, University of California - Davis, Davis, California, USA.,Department of Population Health and Reproduction, School of Veterinary Medicine, University of California - Davis, Davis, California, USA
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8
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Mishra A, Prabha PK, Singla R, Kaur G, Sharma AR, Joshi R, Suroy B, Medhi B. Epigenetic Interface of Autism Spectrum Disorders (ASDs): Implications of Chromosome 15q11-q13 Segment. ACS Chem Neurosci 2022; 13:1684-1696. [PMID: 35635007 DOI: 10.1021/acschemneuro.2c00060] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Autism spectrum disorders (ASDs) are multifactorial in nature and include both genetic and environmental factors. The increasing evidence advocates an important role of epigenetics in ASD etiology. One of the most common forms of epigenetic changes observed in the case of neurodevelopmental disorders is imprinting which is tightly regulated by developmental and tissue-specific mechanisms. Interestingly, many of these disorders that demonstrate autism-like phenotypes at varying degrees have found involvement of chromosome 15q11-q13 segment. Numerous studies demonstrate occurrence of ASD in the presence of chromosomal abnormalities located mainly in Chr15q11-q13 region. Several plausible candidate genes associated with ASD are in this chromosomal segment, including gamma aminobutyric acid A (GABAA) receptor genes GABRB3, GABRA5 and GABRG3, UBE3A, ATP 10A, MKRN3, ZNF, MAGEL2, Necdin (NDN), and SNRPN. The main objective of this review is to highlight the contribution of epigenetic modulations in chromosome 15q11-q13 segment toward the genetic etiology and pathophysiology of ASD. The present review reports the abnormalities in epigenetic regulation on genes and genomic regions located on chromosome 15 in relation to either syndromic (15q11-q13 maternal duplication) or nonsyndromic forms of ASD. Furthermore, studies reviewed in this article demonstrate conditions in which epigenetic dysregulation has been found to be a pathological factor for ASD development, thereby supporting a role for epigenetics in the multifactorial etiologies of ASD. Also, on the basis of the evidence found so far, we strongly emphasize the need to develop future therapeutic strategies as well as screening procedures for ASD that target mechanisms involving genes located on the chromosomal 15q11-q13 segment.
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Affiliation(s)
- Abhishek Mishra
- Dept. of Pharmacology, Post Graduate Institute of Medical Education & Research (PGIMER), Chandigarh 160012, India
| | - Praisy K Prabha
- Dept. of Pharmacology, Post Graduate Institute of Medical Education & Research (PGIMER), Chandigarh 160012, India
| | - Rubal Singla
- Dept. of Pharmacology, Post Graduate Institute of Medical Education & Research (PGIMER), Chandigarh 160012, India
| | - Gurjeet Kaur
- Dept. of Pharmacology, Post Graduate Institute of Medical Education & Research (PGIMER), Chandigarh 160012, India
| | - Amit Raj Sharma
- Dept. of Neurology, Post Graduate Institute of Medical Education & Research (PGIMER), Chandigarh 160012, India
| | - Rupa Joshi
- Dept. of Pharmacology, Post Graduate Institute of Medical Education & Research (PGIMER), Chandigarh 160012, India
| | - Benjamin Suroy
- Dept. of Pharmacology, Post Graduate Institute of Medical Education & Research (PGIMER), Chandigarh 160012, India
| | - Bikash Medhi
- Dept. of Pharmacology, Post Graduate Institute of Medical Education & Research (PGIMER), Chandigarh 160012, India
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9
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Souza Bomfim GH, Niemeyer BA, Lacruz RS, Lis A. On the Connections between TRPM Channels and SOCE. Cells 2022; 11:1190. [PMID: 35406753 PMCID: PMC8997886 DOI: 10.3390/cells11071190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 03/23/2022] [Accepted: 03/30/2022] [Indexed: 12/02/2022] Open
Abstract
Plasma membrane protein channels provide a passageway for ions to access the intracellular milieu. Rapid entry of calcium ions into cells is controlled mostly by ion channels, while Ca2+-ATPases and Ca2+ exchangers ensure that cytosolic Ca2+ levels ([Ca2+]cyt) are maintained at low (~100 nM) concentrations. Some channels, such as the Ca2+-release-activated Ca2+ (CRAC) channels and voltage-dependent Ca2+ channels (CACNAs), are highly Ca2+-selective, while others, including the Transient Receptor Potential Melastatin (TRPM) family, have broader selectivity and are mostly permeable to monovalent and divalent cations. Activation of CRAC channels involves the coupling between ORAI1-3 channels with the endoplasmic reticulum (ER) located Ca2+ store sensor, Stromal Interaction Molecules 1-2 (STIM1/2), a pathway also termed store-operated Ca2+ entry (SOCE). The TRPM family is formed by 8 members (TRPM1-8) permeable to Mg2+, Ca2+, Zn2+ and Na+ cations, and is activated by multiple stimuli. Recent studies indicated that SOCE and TRPM structure-function are interlinked in some instances, although the molecular details of this interaction are only emerging. Here we review the role of TRPM and SOCE in Ca2+ handling and highlight the available evidence for this interaction.
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Affiliation(s)
- Guilherme H. Souza Bomfim
- Department of Molecular Pathobiology, New York University College of Dentistry, New York, NY 10010, USA;
| | - Barbara A. Niemeyer
- Department of Molecular Biophysics, Center for Integrative Physiology and Molecular Medicine, School of Medicine, Saarland University, 66421 Homburg, Germany;
| | - Rodrigo S. Lacruz
- Department of Molecular Pathobiology, New York University College of Dentistry, New York, NY 10010, USA;
| | - Annette Lis
- Department of Biophysics, Center for Integrative Physiology and Molecular Medicine, School of Medicine, Saarland University, 66421 Homburg, Germany
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10
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Chambers S, Leftwich T, Pamonag M, Rice J, Walker MT. Trpm1: Novel function at the intersection of light and pain response in the iris. Exp Eye Res 2021; 215:108897. [PMID: 34954202 DOI: 10.1016/j.exer.2021.108897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 12/06/2021] [Accepted: 12/09/2021] [Indexed: 11/16/2022]
Abstract
In mammals, the retina is the photosensitive tissue that is responsible for the capture of light and the transduction of the light-initiated signals to the brain. These visual signals help to drive image and non-image forming behaviors. The pupillary light reflex (PLR) is an involuntary non-image forming behavior which involves the constriction of the iris muscle tissue in response to ambient light intensity. A subset of photosensitive retinal ganglion cells provides the principal pathway for all light input to the olivary pretectal nucleus which directs the neuronal input to drive iris constriction. Transient receptor potential melastatin 1 (Trpm1) knockout mice have a severe defect in PLR, but it remains unclear how the Trpm1 channel contributes to this behavior. We have demonstrated that the reduced PLR in Trpm1-/- mice at scotopic and photopic intensities is due to a functional loss of Trpm1 in the retina as well as the iris sphincter muscle. We have also tested constriction in isolated eyes and have shown that light-driven constriction independent of signaling from the brain also requires Trpm1 expression. In both the in vivo PLR and the iris photomechanical response, melanopsin is required for the light-dependent activation. Finally, pharmacological experiments using capsaicin to activate pain afferents in the eye demonstrate that Trpm1 expression is required for all sensory driven iris constriction. Our results demonstrate for the first time that Trpm1 has a novel and necessary role in iridial cells and is required for all sensory-driven constriction in the iris.
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Affiliation(s)
- Shane Chambers
- Department of Biology, James Madison University, Harrisonburg, VA, 22807, USA
| | - Tess Leftwich
- Department of Biology, James Madison University, Harrisonburg, VA, 22807, USA
| | - Michael Pamonag
- Department of Biology, James Madison University, Harrisonburg, VA, 22807, USA
| | - Jeremy Rice
- Department of Biology, James Madison University, Harrisonburg, VA, 22807, USA
| | - Marquis T Walker
- Department of Biology, James Madison University, Harrisonburg, VA, 22807, USA.
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11
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Zhao S, Rohacs T. The newest TRP channelopathy: Gain of function TRPM3 mutations cause epilepsy and intellectual disability. Channels (Austin) 2021; 15:386-397. [PMID: 33853504 PMCID: PMC8057083 DOI: 10.1080/19336950.2021.1908781] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 02/25/2021] [Accepted: 02/25/2021] [Indexed: 12/13/2022] Open
Abstract
Transient Receptor Potential Melastatin 3 (TRPM3) is a Ca2+ permeable nonselective cation channel, activated by heat and chemical agonists, such as the endogenous neuro-steroid Pregnenolone Sulfate (PregS) and the chemical compound CIM0216. TRPM3 is expressed in peripheral sensory neurons of the dorsal root ganglia (DRG), and its role in noxious heat sensation in mice is well established. TRPM3 is also expressed in a number of other tissues, including the brain, but its role there has been largely unexplored. Recent reports showed that two mutations in TRPM3 are associated with a developmental and epileptic encephalopathy, pointing to an important role of TRPM3 in the human brain. Subsequent reports found that the two disease-associated mutations increased basal channel activity, and sensitivity of the channel to activation by heat and chemical agonists. This review will discuss these mutations in the context of human diseases caused by mutations in other TRP channels, and in the context of the biophysical properties and physiological functions of TRPM3.
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Affiliation(s)
- Siyuan Zhao
- Department of Pharmacology, Physiology and Neuroscience, Rutgers, New Jersey Medical School, Newark, NJ, USA
| | - Tibor Rohacs
- Department of Pharmacology, Physiology and Neuroscience, Rutgers, New Jersey Medical School, Newark, NJ, USA
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12
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Sagar V, Kaelin CB, Natesh M, Reddy PA, Mohapatra RK, Chhattani H, Thatte P, Vaidyanathan S, Biswas S, Bhatt S, Paul S, Jhala YV, Verma MM, Pandav B, Mondol S, Barsh GS, Swain D, Ramakrishnan U. High frequency of an otherwise rare phenotype in a small and isolated tiger population. Proc Natl Acad Sci U S A 2021; 118:e2025273118. [PMID: 34518374 PMCID: PMC8488692 DOI: 10.1073/pnas.2025273118] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/09/2021] [Indexed: 11/18/2022] Open
Abstract
Most endangered species exist today in small populations, many of which are isolated. Evolution in such populations is largely governed by genetic drift. Empirical evidence for drift affecting striking phenotypes based on substantial genetic data are rare. Approximately 37% of tigers (Panthera tigris) in the Similipal Tiger Reserve (in eastern India) are pseudomelanistic, characterized by wide, merged stripes. Camera trap data across the tiger range revealed the presence of pseudomelanistic tigers only in Similipal. We investigated the genetic basis for pseudomelanism and examined the role of drift in driving this phenotype's frequency. Whole-genome data and pedigree-based association analyses from captive tigers revealed that pseudomelanism cosegregates with a conserved and functionally important coding alteration in Transmembrane Aminopeptidase Q (Taqpep), a gene responsible for similar traits in other felid species. Noninvasive sampling of tigers revealed a high frequency of the Taqpep p.H454Y mutation in Similipal (12 individuals, allele frequency = 0.58) and absence from all other tiger populations (395 individuals). Population genetic analyses confirmed few (minimal number) tigers in Similipal, and its genetic isolation, with poor geneflow. Pairwise FST (0.33) at the mutation site was high but not an outlier. Similipal tigers had low diversity at 81 single nucleotide polymorphisms (mean heterozygosity = 0.28, SD = 0.27). Simulations were consistent with founding events and drift as possible drivers for the observed stark difference of allele frequency. Our results highlight the role of stochastic processes in the evolution of rare phenotypes. We highlight an unusual evolutionary trajectory in a small and isolated population of an endangered species.
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Affiliation(s)
- Vinay Sagar
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore 560065, India;
| | - Christopher B Kaelin
- Department of Genetics, Stanford University, Palo Alto, CA 94309
- HudsonAlpha Institute for Biotechnology, Huntsville, AL 35806
| | - Meghana Natesh
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore 560065, India
- Biology Department, Indian Institute of Science Education and Research, Tirupati 411008, India
| | - P Anuradha Reddy
- Laboratory for Conservation of Endangered Species, Center for Cellular & Molecular Biology, Hyderabad 500048, India
| | | | - Himanshu Chhattani
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore 560065, India
| | - Prachi Thatte
- World Wide Fund for Nature - India, New Delhi 110003 India
| | - Srinivas Vaidyanathan
- Foundation for Ecological Research, Advocacy and Learning, Auroville Post, Tamil Nadu 605101 India
| | | | | | - Shashi Paul
- Odisha Forest Department, Bhubaneswar 751023, India
| | - Yadavendradev V Jhala
- Wildlife Institute of India, Dehradun 248001, India
- National Tiger Conservation Authority, Wildlife Institute of India Tiger Cell, Wildlife Institute of India, Dehradun 248001, India
| | | | | | | | - Gregory S Barsh
- Department of Genetics, Stanford University, Palo Alto, CA 94309
- HudsonAlpha Institute for Biotechnology, Huntsville, AL 35806
| | - Debabrata Swain
- Former Member Secretary, National Tiger Conservation Authority, New Delhi 110003, India
- Former Principal Chief Conservator of Forest and Head of Forest Force, Indian Forest Service, Bhubaneswar 751023, India
| | - Uma Ramakrishnan
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore 560065, India;
- DBT - Wellcome Trust India Alliance, Hyderabad 500034, India
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13
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Abstract
Background Ocular adverse events are common dose-limiting toxicities in cancer patients treated with HSP90 inhibitors, such as AUY922; however, the pathology and molecular mechanisms that mediate AUY922-induced retinal toxicity remain undescribed. Methods The impact of AUY922 on mouse retinas and cell lines was comprehensively investigated using isobaric tags for relative and absolute quantitation (iTRAQ)‑based proteomic profiling and pathway enrichment analysis, immunohistochemistry and immunofluorescence staining, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, MTT assay, colony formation assay, and western blot analysis. The effect of AUY922 on the Transient Receptor Potential cation channel subfamily M member 1 (TRPM1)-HSP90 chaperone complex was characterized by coimmunoprecipitation. TRPM1-regulated gene expression was analyzed by RNAseq analysis and gene set enrichment analysis (GSEA). The role of TRPM1 was assessed using both loss-of-function and gain-of-function approaches. Results Here, we show that the treatment with AUY922 induced retinal damage and cell apoptosis, dysregulated the photoreceptor and retinal pigment epithelium (RPE) layers, and reduced TRPM1 expression. Proteomic profiling and functional annotation of differentially expressed proteins reveals that those related to stress responses, protein folding processes, regulation of apoptosis, cell cycle and growth, reactive oxygen species (ROS) response, cell junction assembly and adhesion regulation, and proton transmembrane transport were significantly enriched in AUY922-treated cells. We found that AUY922 triggered caspase-3-dependent cell apoptosis, increased ROS production and inhibited cell growth. We determined that TRPM1 is a bona fide HSP90 client and characterized that AUY922 may reduce TRPM1 expression by disrupting the CDC37-HSP90 chaperone complex. Additionally, GSEA revealed that TRPM1-regulated genes were associated with retinal morphogenesis in camera-type eyes and the JAK-STAT cascade. Finally, gain-of-function and loss-of-function analyses validated the finding that TRPM1 mediated the cell apoptosis, ROS production and growth inhibition induced by AUY922. Conclusions Our study demonstrates the pathology of AUY922-induced retinal toxicity in vivo. TRPM1 is an HSP90 client, regulates photoreceptor morphology and function, and mediates AUY922-induced cytotoxicity. Supplementary Information The online version contains supplementary material available at 10.1186/s12929-021-00751-5.
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14
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Kingsley NB, Hamilton NA, Lindgren G, Orlando L, Bailey E, Brooks S, McCue M, Kalbfleisch TS, MacLeod JN, Petersen JL, Finno CJ, Bellone RR. "Adopt-a-Tissue" Initiative Advances Efforts to Identify Tissue-Specific Histone Marks in the Mare. Front Genet 2021; 12:649959. [PMID: 33841506 PMCID: PMC8033197 DOI: 10.3389/fgene.2021.649959] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Accepted: 03/01/2021] [Indexed: 12/13/2022] Open
Affiliation(s)
- N B Kingsley
- Veterinary Genetics Laboratory, School of Veterinary Medicine, University of California, Davis, Davis, CA, United States.,Department of Population Health and Reproduction, School of Veterinary Medicine, University of California, Davis, Davis, CA, United States
| | - Natasha A Hamilton
- Faculty of Science, School of Life and Environmental Science, University of Sydney, Camperdown, NSW, Australia
| | - Gabriella Lindgren
- Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Uppsala, Sweden.,Livestock Genetics, Department of Biosystems, KU Leuven, Leuven, Belgium
| | - Ludovic Orlando
- Centre d'Anthropobiologie et Génomique de Toulouse (CAGT), Faculté de Médecine Purpan, Université Toulouse III-Paul Sabatier, Toulouse, France
| | - Ernie Bailey
- Maxwell H. Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, KY, United States
| | - Samantha Brooks
- Department of Animal Sciences, University of Florida, Gainesville, FL, United States
| | - Molly McCue
- Department of Veterinary Population Medicine, College of Veterinary Medicine, University of Minnesota, St. Paul, MN, United States
| | - T S Kalbfleisch
- Maxwell H. Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, KY, United States
| | - James N MacLeod
- Maxwell H. Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, KY, United States
| | - Jessica L Petersen
- Department of Animal Science, University of Nebraska-Lincoln, Lincoln, NE, United States
| | - Carrie J Finno
- Department of Population Health and Reproduction, School of Veterinary Medicine, University of California, Davis, Davis, CA, United States
| | - Rebecca R Bellone
- Veterinary Genetics Laboratory, School of Veterinary Medicine, University of California, Davis, Davis, CA, United States.,Department of Population Health and Reproduction, School of Veterinary Medicine, University of California, Davis, Davis, CA, United States
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15
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Jimenez I, Prado Y, Marchant F, Otero C, Eltit F, Cabello-Verrugio C, Cerda O, Simon F. TRPM Channels in Human Diseases. Cells 2020; 9:E2604. [PMID: 33291725 PMCID: PMC7761947 DOI: 10.3390/cells9122604] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 11/30/2020] [Accepted: 12/01/2020] [Indexed: 12/11/2022] Open
Abstract
The transient receptor potential melastatin (TRPM) subfamily belongs to the TRP cation channels family. Since the first cloning of TRPM1 in 1989, tremendous progress has been made in identifying novel members of the TRPM subfamily and their functions. The TRPM subfamily is composed of eight members consisting of four six-transmembrane domain subunits, resulting in homomeric or heteromeric channels. From a structural point of view, based on the homology sequence of the coiled-coil in the C-terminus, the eight TRPM members are clustered into four groups: TRPM1/M3, M2/M8, M4/M5 and M6/M7. TRPM subfamily members have been involved in several physiological functions. However, they are also linked to diverse pathophysiological human processes. Alterations in the expression and function of TRPM subfamily ion channels might generate several human diseases including cardiovascular and neurodegenerative alterations, organ dysfunction, cancer and many other channelopathies. These effects position them as remarkable putative targets for novel diagnostic strategies, drug design and therapeutic approaches. Here, we review the current knowledge about the main characteristics of all members of the TRPM family, focusing on their actions in human diseases.
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Affiliation(s)
- Ivanka Jimenez
- Faculty of Life Science, Universidad Andrés Bello, Santiago 8370186, Chile; (I.J.); (Y.P.); (F.M.); (C.C.-V.)
- Millennium Nucleus of Ion Channel-Associated Diseases (MiNICAD), Universidad de Chile, Santiago 8380453, Chile;
| | - Yolanda Prado
- Faculty of Life Science, Universidad Andrés Bello, Santiago 8370186, Chile; (I.J.); (Y.P.); (F.M.); (C.C.-V.)
- Millennium Nucleus of Ion Channel-Associated Diseases (MiNICAD), Universidad de Chile, Santiago 8380453, Chile;
| | - Felipe Marchant
- Faculty of Life Science, Universidad Andrés Bello, Santiago 8370186, Chile; (I.J.); (Y.P.); (F.M.); (C.C.-V.)
- Millennium Nucleus of Ion Channel-Associated Diseases (MiNICAD), Universidad de Chile, Santiago 8380453, Chile;
| | - Carolina Otero
- Faculty of Medicine, School of Chemistry and Pharmacy, Universidad Andrés Bello, Santiago 8370186, Chile;
| | - Felipe Eltit
- Vancouver Prostate Centre, Vancouver, BC V6Z 1Y6, Canada;
- Department of Urological Sciences, University of British Columbia, Vancouver, BC V6Z 1Y6, Canada
| | - Claudio Cabello-Verrugio
- Faculty of Life Science, Universidad Andrés Bello, Santiago 8370186, Chile; (I.J.); (Y.P.); (F.M.); (C.C.-V.)
- Center for the Development of Nanoscience and Nanotechnology (CEDENNA), Universidad de Santiago de Chile, Santiago 7560484, Chile
- Millennium Institute on Immunology and Immunotherapy, Santiago 8370146, Chile
| | - Oscar Cerda
- Millennium Nucleus of Ion Channel-Associated Diseases (MiNICAD), Universidad de Chile, Santiago 8380453, Chile;
- Program of Cellular and Molecular Biology, Institute of Biomedical Sciences (ICBM), Faculty of Medicine, Universidad de Chile, Santiago 8380453, Chile
| | - Felipe Simon
- Faculty of Life Science, Universidad Andrés Bello, Santiago 8370186, Chile; (I.J.); (Y.P.); (F.M.); (C.C.-V.)
- Millennium Nucleus of Ion Channel-Associated Diseases (MiNICAD), Universidad de Chile, Santiago 8380453, Chile;
- Millennium Institute on Immunology and Immunotherapy, Santiago 8370146, Chile
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16
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Hack YL, Crabtree EE, Avila F, Sutton RB, Grahn R, Oh A, Gilger B, Bellone RR. Whole-genome sequencing identifies missense mutation in GRM6 as the likely cause of congenital stationary night blindness in a Tennessee Walking Horse. Equine Vet J 2020; 53:316-323. [PMID: 32654228 DOI: 10.1111/evj.13318] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Revised: 06/01/2020] [Accepted: 06/25/2020] [Indexed: 11/26/2022]
Abstract
BACKGROUND The only known genetic cause of congenital stationary night blindness (CSNB) in horses is a 1378 bp insertion in TRPM1. However, an affected Tennessee Walking Horse was found to have no copies of this variant. OBJECTIVES To identify the genetic cause for CSNB in an affected Tennessee Walking Horse. STUDY DESIGN Case report detailing a whole-genome sequencing (WGS) approach to identify a causal variant. METHODS A complete ophthalmic exam, including an electroretinogram (ERG), was performed on suspected CSNB-affected horse. WGS data were generated from the case and compared with data from seven other breeds (n = 29). One hundred candidate genes were evaluated for coding variants homozygous in the case and absent in all other horses. Protein modelling was used to assess the functional effects of the identified variant. A random cohort of 90 unrelated Tennessee Walking Horses and 273 horses from additional breeds were screened to estimate allele frequency of the GRM6 variant. RESULTS ERG results were consistent with CSNB. WGS analysis identified a missense mutation in metabotropic glutamate receptor 6 (GRM6) (c.533C>T p.Thr178Met). This single nucleotide polymorphism (SNP) is predicted to be deleterious and protein modelling supports impaired binding of the neurotransmitter glutamate. This variant was not detected in 273 horses from three additional breeds. The estimated allele frequency in Tennessee Walking Horses is 10%. MAIN LIMITATIONS Limited phenotype information for controls and no additional cases with which to replicate this finding. CONCLUSIONS We identified a likely causal recessive missense variant in GRM6. Based on protein modelling, this variant alters GRM6 binding, and thus signalling from the retinal rod cell to the ON-bipolar cell, impairing vision in low light conditions. Given the 10% population allele frequency, it is likely that additional affected horses exist in this breed and further work is needed to identify and examine these animals.
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Affiliation(s)
- Yael L Hack
- Veterinary Genetics Laboratory, School of Veterinary Medicine, University of California, Davis, California, USA
| | - Elizabeth E Crabtree
- College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, USA
| | - Felipe Avila
- Veterinary Genetics Laboratory, School of Veterinary Medicine, University of California, Davis, California, USA
| | - Roger B Sutton
- Cell Physiology and Molecular Biophysics, School of Medicine, Texas Tech University Health Sciences Center, Lubbock, Texas, USA
| | - Robert Grahn
- Veterinary Genetics Laboratory, School of Veterinary Medicine, University of California, Davis, California, USA
| | - Annie Oh
- College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, USA
| | - Brian Gilger
- College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, USA
| | - Rebecca R Bellone
- Veterinary Genetics Laboratory, School of Veterinary Medicine, University of California, Davis, California, USA.,Population Health and Reproduction, School of Veterinary Medicine, University of California, Davis, California, USA
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17
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Abstract
Horses perform in a variety of disciplines that are visually demanding, and any disease impacting the eye has the potential to threaten vision and thus the utility of the horse. Advances in equine genetics have enabled the understanding of some inherited ocular disorders and ocular manifestations and are enabling cross-species comparisons. Genetic testing for multiple congenital ocular anomalies, congenital stationary night blindness, equine recurrent uveitis, and squamous cell carcinoma can identify horses with or at risk for disease and thus can assist in clinical management and breeding decisions. This article describes the current knowledge of inherited ocular disorders.
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Affiliation(s)
- Rebecca R Bellone
- Department of Population Health and Reproduction, Veterinary Genetics Laboratory, School of Veterinary Medicine, University of California-Davis, One Shields Avenue, Davis, CA 95616, USA.
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18
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Jiang YK, Wang RY, Wang X, Zhao HZ, Zhou LH, Huang LP, Yip CW, Cheng JH, Que CX, Jiang C, Zhu LP. Genetic polymorphisms of transient receptor potential melastatin 1 correlate with voriconazole-related visual adverse events. Mycoses 2020; 63:579-587. [PMID: 32222082 DOI: 10.1111/myc.13080] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 03/14/2020] [Accepted: 03/19/2020] [Indexed: 02/02/2023]
Abstract
BACKGROUND Causes of voriconazole-related visual adverse events (VVAE) remained controversial. OBJECTIVES We aimed to explore the relationship between voriconazole serum concentrations and VVAE as well as the potential influence of transient receptor potential melastatin 1 (TRPM1) on VVAE. PATIENTS/METHODS This prospective observational cohort study was done in two stages. Patients who received voriconazole for invasive fungal diseases were consecutively enrolled. Correlations between voriconazole trough levels and VVAE were explored in 76 patients. Genotyping was further conducted for 17 tag SNPs of TRPM1 in a larger population of 137 patients. Genotype distributions were compared between patients with and without VVAE. RESULT Of the 76 patients, a total of 229 steady-state voriconazole trough levels were evaluated, 69.9% of which were within the target range (1-5.5 mg/L). No correlations were found between voriconazole trough levels and VVAE. Of the total 137 patients, VVAE occurred in 37 (27.0%) patients, including visual hallucination (13.9%, 19/137) and visual disturbances (19.0%, 26/137). Significant difference in TRPM1 genotype distribution was only observed in patients with visual hallucination but not with visual disturbances. We found that rs890160 G/T genotype was under-presented (OR, 0.11; 95% CI, 0.01-0.84; P = .011) and rs1378847 C/C genotype was more frequently detected (OR, 8.89; 95% CI, 1.14-69.02; P = .013) in patients with visual hallucination when compared with those without. CONCLUSION Transient receptor potential melastatin 1 was genetically associated with voriconazole-related visual hallucination. The correlation was failed to found between voriconazole trough levels and VVAE.
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Affiliation(s)
- Ying-Kui Jiang
- Department of Infectious Diseases, Huashan Hospital, Fudan University, Shanghai, China
| | - Rui-Ying Wang
- Department of Infectious Diseases, Huashan Hospital, Fudan University, Shanghai, China
| | - Xuan Wang
- Department of Infectious Diseases, Huashan Hospital, Fudan University, Shanghai, China
| | - Hua-Zhen Zhao
- Department of Infectious Diseases, Huashan Hospital, Fudan University, Shanghai, China
| | - Ling-Hong Zhou
- Department of Infectious Diseases, Huashan Hospital, Fudan University, Shanghai, China
| | - Li-Ping Huang
- Department of Infectious Diseases, Huashan Hospital, Fudan University, Shanghai, China
| | - Ching-Wan Yip
- Department of Infectious Diseases, Huashan Hospital, Fudan University, Shanghai, China
| | - Jia-Hui Cheng
- Department of Infectious Diseases, Huashan Hospital, Fudan University, Shanghai, China
| | - Chun-Xing Que
- Department of Infectious Diseases, Huashan Hospital, Fudan University, Shanghai, China
| | - Chen Jiang
- Department of Pharmaceutics, School of Pharmacy, Shanghai Medical College, Fudan University, Shanghai, China
| | - Li-Ping Zhu
- Department of Infectious Diseases, Huashan Hospital, Fudan University, Shanghai, China
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19
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Winkler PA, Occelli LM, Petersen-Jones SM. Large Animal Models of Inherited Retinal Degenerations: A Review. Cells 2020; 9:cells9040882. [PMID: 32260251 PMCID: PMC7226744 DOI: 10.3390/cells9040882] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2020] [Revised: 03/30/2020] [Accepted: 03/31/2020] [Indexed: 12/13/2022] Open
Abstract
Studies utilizing large animal models of inherited retinal degeneration (IRD) have proven important in not only the development of translational therapeutic approaches, but also in improving our understanding of disease mechanisms. The dog is the predominant species utilized because spontaneous IRD is common in the canine pet population. Cats are also a source of spontaneous IRDs. Other large animal models with spontaneous IRDs include sheep, horses and non-human primates (NHP). The pig has also proven valuable due to the ease in which transgenic animals can be generated and work is ongoing to produce engineered models of other large animal species including NHP. These large animal models offer important advantages over the widely used laboratory rodent models. The globe size and dimensions more closely parallel those of humans and, most importantly, they have a retinal region of high cone density and denser photoreceptor packing for high acuity vision. Laboratory rodents lack such a retinal region and, as macular disease is a critical cause for vision loss in humans, having a comparable retinal region in model species is particularly important. This review will discuss several large animal models which have been used to study disease mechanisms relevant for the equivalent human IRD.
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20
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Sandmeyer LS, Kingsley NB, Walder C, Archer S, Leis ML, Bellone RR, Bauer BS. Risk factors for equine recurrent uveitis in a population of Appaloosa horses in western Canada. Vet Ophthalmol 2020; 23:515-525. [PMID: 32086865 DOI: 10.1111/vop.12749] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 01/22/2020] [Accepted: 01/23/2020] [Indexed: 12/12/2022]
Abstract
OBJECTIVE To characterize clinical manifestations, measure frequency, and evaluate risk factors for equine recurrent uveitis (ERU) in Appaloosa horses in western Canada. ANIMALS 145 Appaloosa horses. PROCEDURES Ophthalmic examinations were completed and eyes were classified as having no or mild clinical signs, or moderate, or severe damage from ERU. Clinical signs, age, sex, base coat color, and pattern were recorded. Whole blood and/or mane hair follicles were collected for DNA extraction, and all horses were tested for the leopard complex (LP) spotting pattern allele. Pedigree analysis was completed on affected and unaffected horses, and coefficients of coancestry (CC) and inbreeding (COI) were determined. RESULTS Equine recurrent uveitis was confirmed in 20 (14%) horses. The mean age of affected horses was 12.3 years (±5.3; range 3-25). Age was a significant risk factor for ERU diagnosis (ORyear = 1.15) and classification (ORyear = 1.19). The fewspot coat pattern was significantly associated with increased risk for ERU compared to horses that were minimally patterned or true solids. The LP/LP genotype was at a significantly greater risk for ERU compared to lp/lp (OR = 19.4) and LP/lp (OR = 6.37). Classification of ERU was greater in the LP/LP genotype compared to LP/lp. Affected horses had an average CC of 0.066, and there was a significant difference in the distribution of CC for affected horses versus the control group (P = .021). One affected horse was the sire or grandsire of nine other affected. CONCLUSIONS Age, coat pattern, and genetics are major risk factors for the diagnosis and classification of ERU in the Appaloosa.
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Affiliation(s)
- Lynne S Sandmeyer
- Small Animal Clinical Sciences, University of Saskatchewan, Saskatoon, Sask, Canada
| | - Nicole B Kingsley
- Equine Research Unit, University of California Davis Veterinary Genetics Laboratory, Davis, CA, USA
| | - Cheryl Walder
- Large Animal Clinical Sciences, University of Saskatchewan College of Veterinary Medicine, Saskatoon, Sask, Canada
| | | | - Marina L Leis
- Small Animal Clinical Sciences, University of Saskatchewan, Saskatoon, Sask, Canada
| | - Rebecca R Bellone
- Veterinary Genetics Laboratory and the Department of Population Health and Reproduction, University of California-Davis, Davis, CA, USA
| | - Bianca S Bauer
- Small Animal Clinical Sciences, University of Saskatchewan, Saskatoon, Sask, Canada
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21
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Liang Q, Dharmat R, Owen L, Shakoor A, Li Y, Kim S, Vitale A, Kim I, Morgan D, Liang S, Wu N, Chen K, DeAngelis MM, Chen R. Single-nuclei RNA-seq on human retinal tissue provides improved transcriptome profiling. Nat Commun 2019; 10:5743. [PMID: 31848347 PMCID: PMC6917696 DOI: 10.1038/s41467-019-12917-9] [Citation(s) in RCA: 76] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Accepted: 10/02/2019] [Indexed: 12/23/2022] Open
Abstract
Single-cell RNA-seq is a powerful tool in decoding the heterogeneity in complex tissues by generating transcriptomic profiles of the individual cell. Here, we report a single-nuclei RNA-seq (snRNA-seq) transcriptomic study on human retinal tissue, which is composed of multiple cell types with distinct functions. Six samples from three healthy donors are profiled and high-quality RNA-seq data is obtained for 5873 single nuclei. All major retinal cell types are observed and marker genes for each cell type are identified. The gene expression of the macular and peripheral retina is compared to each other at cell-type level. Furthermore, our dataset shows an improved power for prioritizing genes associated with human retinal diseases compared to both mouse single-cell RNA-seq and human bulk RNA-seq results. In conclusion, we demonstrate that obtaining single cell transcriptomes from human frozen tissues can provide insight missed by either human bulk RNA-seq or animal models.
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Affiliation(s)
- Qingnan Liang
- HGSC, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, 77030, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, 77030, TX, USA
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Rachayata Dharmat
- HGSC, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, 77030, USA
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, 77030, TX, USA
- St. Jude Children's Research Hospital, 262 Danny Thomas Pl, Memphis, TN, 38105, USA
| | - Leah Owen
- Department of Ophthalmology and Visual Sciences, University of Utah School of Medicine, Salt Lake City, UT, 84132, USA
| | - Akbar Shakoor
- Department of Ophthalmology and Visual Sciences, University of Utah School of Medicine, Salt Lake City, UT, 84132, USA
| | - Yumei Li
- HGSC, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Sangbae Kim
- HGSC, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Albert Vitale
- Department of Ophthalmology and Visual Sciences, University of Utah School of Medicine, Salt Lake City, UT, 84132, USA
| | - Ivana Kim
- Department of Ophthalmology and Visual Sciences, University of Utah School of Medicine, Salt Lake City, UT, 84132, USA
| | - Denise Morgan
- Department of Ophthalmology and Visual Sciences, University of Utah School of Medicine, Salt Lake City, UT, 84132, USA
- Department of Pharmacotherapy, the College of Pharmacy, University of Utah, Salt Lake City, UT, 84132, USA
| | - Shaoheng Liang
- Department of Bioinformatics and Computational Biology, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Nathaniel Wu
- HGSC, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Ken Chen
- Department of Bioinformatics and Computational Biology, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Margaret M DeAngelis
- Department of Ophthalmology and Visual Sciences, University of Utah School of Medicine, Salt Lake City, UT, 84132, USA.
- Department of Pharmacotherapy, the College of Pharmacy, University of Utah, Salt Lake City, UT, 84132, USA.
- Department of Population Health Sciences, University of Utah School of Medicine, Salt Lake City, UT, 84132, USA.
| | - Rui Chen
- HGSC, Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, 77030, USA.
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, 77030, TX, USA.
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, 77030, USA.
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22
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Frameshift Variant in MFSD12 Explains the Mushroom Coat Color Dilution in Shetland Ponies. Genes (Basel) 2019; 10:genes10100826. [PMID: 31635058 PMCID: PMC6827053 DOI: 10.3390/genes10100826] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 10/16/2019] [Accepted: 10/17/2019] [Indexed: 01/09/2023] Open
Abstract
Mushroom is a unique coat color phenotype in Shetland Ponies characterized by the dilution of the chestnut coat color to a sepia tone and is hypothesized to be a recessive trait. A genome wide association study (GWAS), utilizing the Affymetrix 670K array (MNEc670k) and a single locus mixed linear model analysis (EMMAX), identified a locus on ECA7 for further investigation (Pcorrected = 2.08 × 10−10). This locus contained a 3 Mb run of homozygosity in the 12 mushroom ponies tested. Analysis of high throughput Illumina sequencing data from one mushroom Shetland pony compared to 87 genomes from horses of various breeds, uncovered a frameshift variant, p.Asp201fs, in the MFSD12 gene encoding the major facilitator superfamily domain containing 12 protein. This variant was perfectly concordant with phenotype in 96 Shetland Ponies (P = 1.15 × 10−22), was identified in the closely related Miniature Horse for which the mushroom phenotype is suspected to occur (fmu = 0.02), and was absent in 252 individuals from seven additional breeds not reported to have the mushroom phenotype. MFSD12 is highly expressed in melanocytes and variants in this gene in humans, mice, and dogs impact pigmentation. Given the role of MFSD12 in melanogenesis, we propose that p.Asp201fs is causal for the dilution observed in mushroom ponies.
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23
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A founder deletion in the TRPM1 gene associated with congenital stationary night blindness and myopia is highly prevalent in Ashkenazi Jews. Hum Genome Var 2019; 6:45. [PMID: 31645983 PMCID: PMC6804618 DOI: 10.1038/s41439-019-0076-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 08/08/2019] [Accepted: 08/09/2019] [Indexed: 02/07/2023] Open
Abstract
Congenital stationary night blindness (CSNB) is a disease affecting the night vision of individuals. Previous studies identified TRPM1 as a gene involved in reduced night vision. Homozygous deletion of TRPM1 was the cause of CSNB in several children in 6 Ashkenazi Jewish families, thereby prompting further investigation of the carrier status within the families as well as in large cohorts of unrelated Ashkenazi and Sephardi individuals. Affected children were tested with a CSNB next-generation (NextGen) sequencing panel. A deletion of TRPM1 exons 2 through 7 was detected and confirmed by PCR and sequence analysis. A TaqMan-based assay was used to assess the frequency of this deletion in 18266 individuals of Jewish descent. High-throughput amplicon sequencing was performed on 380 samples to determine the putative deletion-flanking founder haplotype. Heterozygous TRPM1 deletions were found in 2.75% (1/36) of Ashkenazi subjects and in 1.22% (1/82) individuals of mixed Ashkenazi/Sephardic origin. The homozygous deletion frequency in our data was 0.03% (1/4025) and was only found in Ashkenazi Jewish individuals. Homozygous deletion of exons 2–7 in TRPM1 is a common cause of CSNB and myopia in many Ashkenazi Jewish patients. This deletion is a founder Ashkenazi Jewish deletion. A genetic mutation found in Ashkenazi Jewish population causes an eye disease that leads to poor vision in dim light. Yoel Hirsch and Martin M. Johansson from Dor Yeshorim, together with colleagues determined the genetic etiology of congenital stationary night blindness (CSNB) in children from six Ashkenazi families. Each affected child harbored two mutant versions of TRPM1, a gene involved in the transmission of light-elicited signals within the retina of the eye. Notably, all the children had the same large chunk of DNA missing from the gene. The researchers next screened for this genetic deletion in >18,000 individuals of Jewish descent, finding single copies of the mutation in 2.75% of Ashkenazi subjects. The findings should help doctors better diagnose CSNB and care for Jewish patients with eyesight problems.
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TRPM1 Mutations are the Most Common Cause of Autosomal Recessive Congenital Stationary Night Blindness (CSNB) in the Palestinian and Israeli Populations. Sci Rep 2019; 9:12047. [PMID: 31427709 PMCID: PMC6700182 DOI: 10.1038/s41598-019-46811-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Accepted: 06/14/2019] [Indexed: 11/08/2022] Open
Abstract
Precise genetic and phenotypic characterization of congenital stationary night blindness (CSNB) patients is needed for future therapeutic interventions. The aim of this study was to estimate the prevalence of CSNB in our populations and to study clinical and genetic aspects of the autosomal recessive (AR) form of CSNB. This is a retrospective cohort study of Palestinian and Israeli CSNB patients harboring mutations in TRPM1 underwent comprehensive ocular examination. Genetic analysis was performed using homozygosity mapping and sequencing. 161 patients (from 76 families) were recruited for this study, leading to a prevalence of 1:6210 in the vicinity of Jerusalem, much higher than the worldwide prevalence. 61% of the families were consanguineous with AR inheritance pattern. Biallelic pathogenic TRPM1 mutations were identified in 36 families (72 patients). Two founder mutations explain the vast majority of cases: a nonsense mutation c.880A>T (p.Lys294*) identified in 22 Palestinian families and a large genomic deletion (36,445 bp) encompassing exons 2-7 of TRPM1 present in 13 Ashkenazi Jewish families. Most patients were myopic (with mean BCVA of 0.40 LogMAR) and all had absent rod responses in full field electroretinography. To the best of our knowledge, this is the largest report of a clinical and genetic analysis of patients affected with CSNB due to TRPM1 mutations.
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25
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Peng Y, Wang Y, Wang R, Geng L, Ma R, Zhang C, Liu Z, Gong Y, Li J, Li X. Exploring differentially expressed genes associated with coat color in goat skin using RNA-seq. CANADIAN JOURNAL OF ANIMAL SCIENCE 2019. [DOI: 10.1139/cjas-2018-0026] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Fur color in domestic goats is an important, genetically determined characteristic that is associated with economic value. This study was designed to perform a comprehensive expression profiling of genes expressed in the skin tissues from Laiwu Black goat and Lubei White goat. Comparisons of black and white goat skin transcriptomes revealed 102 differentially expressed genes (DEGs), of which 38 were upregulated and 64 downregulated in black skin compared with white skin. Among the DEGs, we identified six genes involved in pigmentation, including agouti signaling protein (ASIP), CAMP responsive element binding protein 3-like 1 (CREB3L1), dopachrome tautomerase (DCT), premelanosome protein (PMEL), transient receptor potential cation channel subfamily M member 1 (TRPM1), and tyrosinase-related protein 1 (TYRP1). Notably, there were no significant differences in the expression of melanocortin 1 receptor, microphthalmia-associated transcription factor, tyrosinase, and KIT proto-oncogene receptor tyrosine kinase between the black and white skin samples, whereas ASIP expression was detected only in white skin. PMEL, TRPM1, TYRP1, and DCT showed higher expression in black goat skin, but ASIP and CREB3L1 had higher expression in white goat skin. Quantitative polymerase chain reaction results for PMEL, TRPM1, DCT, TYRP1, and CREB3L1 expression were consistent with those for RNA-seq. These results will expand our understanding of the complex molecular mechanisms of skin physiology and melanogenesis in goats, and provide a foundation for future studies.
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Affiliation(s)
- Yongdong Peng
- College of Animal Science and Technology, Hebei Normal University of Science and Technology, Qinhuangdao, Hebei 066004, People’s Republic of China
| | - Yaqi Wang
- College of Animal Science and Technology, Hebei Normal University of Science and Technology, Qinhuangdao, Hebei 066004, People’s Republic of China
| | - Ruining Wang
- College of Animal Science and Technology, Hebei Normal University of Science and Technology, Qinhuangdao, Hebei 066004, People’s Republic of China
| | - Liying Geng
- College of Animal Science and Technology, Agricultural University of Hebei Province, Baoding, Hebei 071001, People’s Republic of China
| | - Ruxue Ma
- College of Animal Science and Technology, Hebei Normal University of Science and Technology, Qinhuangdao, Hebei 066004, People’s Republic of China
| | - Chuansheng Zhang
- College of Animal Science and Technology, Hebei Normal University of Science and Technology, Qinhuangdao, Hebei 066004, People’s Republic of China
| | - Zhengzhu Liu
- College of Animal Science and Technology, Hebei Normal University of Science and Technology, Qinhuangdao, Hebei 066004, People’s Republic of China
| | - Yuanfang Gong
- College of Animal Science and Technology, Hebei Normal University of Science and Technology, Qinhuangdao, Hebei 066004, People’s Republic of China
| | - Jingshi Li
- College of Animal Science and Technology, Agricultural University of Hebei Province, Baoding, Hebei 071001, People’s Republic of China
| | - Xianglong Li
- College of Animal Science and Technology, Hebei Normal University of Science and Technology, Qinhuangdao, Hebei 066004, People’s Republic of China
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Nigenda‐Morales SF, Hu Y, Beasley JC, Ruiz‐Piña HA, Valenzuela‐Galván D, Wayne RK. Transcriptomic analysis of skin pigmentation variation in the Virginia opossum (
Didelphis virginiana
). Mol Ecol 2018; 27:2680-2697. [DOI: 10.1111/mec.14712] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Revised: 04/05/2018] [Accepted: 04/17/2018] [Indexed: 12/19/2022]
Affiliation(s)
- Sergio F. Nigenda‐Morales
- Department of Ecology and Evolutionary Biology University of California, Los Angeles Los Angeles California
| | - Yibo Hu
- Key Lab of Animal Ecology and Conservation Biology Institute of Zoology Chinese Academy of Sciences Chaoyang, Beijing China
| | - James C. Beasley
- Savannah River Ecology Lab Warnell School of Forestry and Natural Resources University of Georgia Aiken South Carolina
| | - Hugo A. Ruiz‐Piña
- Centro de Investigaciones Regionales “Dr. Hideyo Noguchi” Universidad Autónoma de Yucatán Mérida Yucatán Mexico
| | - David Valenzuela‐Galván
- Departamento de Ecología Evolutiva Centro de Investigación en Biodiversidad y Conservación Universidad Autónoma del Estado de Morelos Cuernavaca Morelos Mexico
| | - Robert K. Wayne
- Department of Ecology and Evolutionary Biology University of California, Los Angeles Los Angeles California
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27
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Genetic Testing as a Tool to Identify Horses with or at Risk for Ocular Disorders. Vet Clin North Am Equine Pract 2017; 33:627-645. [DOI: 10.1016/j.cveq.2017.08.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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28
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Corneal Nerve Fiber Structure, Its Role in Corneal Function, and Its Changes in Corneal Diseases. BIOMED RESEARCH INTERNATIONAL 2017; 2017:3242649. [PMID: 29238714 PMCID: PMC5697388 DOI: 10.1155/2017/3242649] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Revised: 09/27/2017] [Accepted: 10/15/2017] [Indexed: 01/04/2023]
Abstract
Recently, in vivo confocal microscopy is used to examine the human corneal nerve fibers morphology. Corneal nerve fiber architecture and its role are studied in healthy and pathological conditions. Corneal nerves of rats were studied by nonspecific acetylcholinesterase (NsAchE) staining. NsAchE-positive subepithelial (stromal) nerve fiber has been found to be insensitive to capsaicin. Besides, NsAchE-negative but capsaicin-sensitive subbasal nerve (leash) fibers formed thick mesh-like structure showing close interconnections and exhibit both isolectin B4- and transient receptor potential vanilloid channel 1- (TRPV1-) positive. TRPV1, TRPV3, TRPA (ankyrin) 1, and TRPM (melastatin) 8 are expressed in corneal nerve fibers. Besides the corneal nerve fibers, the expressions of TRPV (1, 3, and 4), TRPC (canonical) 4, and TRPM8 are demonstrated in the corneal epithelial cell membrane. The realization of the importance of TRP channels acting as polymodal sensors of environmental stresses has identified potential drug targets for corneal disease. The pathophysiological conditions of corneal diseases are associated with disruption of normal tissue innervation, especially capsaicin-sensitive small sensory nerve fibers. The relationships between subbasal corneal nerve fiber morphology and neurotrophic keratopathy in corneal diseases are well studied. The recommended treatment for neurotrophic keratopathy is administration of preservative free eye drops.
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29
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Peng Y, Liu X, Geng L, Ma R, Li L, Li J, Zhang C, Liu Z, Gong Y, Li X. Illumina-sequencing based transcriptome study of coat color phenotypes in domestic goats. Genes Genomics 2017. [DOI: 10.1007/s13258-017-0543-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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30
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Martemyanov KA, Sampath AP. The Transduction Cascade in Retinal ON-Bipolar Cells: Signal Processing and Disease. Annu Rev Vis Sci 2017; 3:25-51. [PMID: 28715957 DOI: 10.1146/annurev-vision-102016-061338] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Our robust visual experience is based on the reliable transfer of information from our photoreceptor cells, the rods and cones, to higher brain centers. At the very first synapse of the visual system, information is split into two separate pathways, ON and OFF, which encode increments and decrements in light intensity, respectively. The importance of this segregation is borne out in the fact that receptive fields in higher visual centers maintain a separation between ON and OFF regions. In the past decade, the molecular mechanisms underlying the generation of ON signals have been identified, which are unique in their use of a G-protein signaling cascade. In this review, we consider advances in our understanding of G-protein signaling in ON-bipolar cell (BC) dendrites and how insights about signaling have emerged from visual deficits, mostly night blindness. Studies of G-protein signaling in ON-BCs reveal an intricate mechanism that permits the regulation of visual sensitivity over a wide dynamic range.
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Affiliation(s)
| | - Alapakkam P Sampath
- Jules Stein Eye Institute, University of California, Los Angeles, California 90095;
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31
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Sandmeyer LS, Bauer BS, Feng CX, Grahn BH. Equine recurrent uveitis in western Canadian prairie provinces: A retrospective study (2002-2015). THE CANADIAN VETERINARY JOURNAL = LA REVUE VETERINAIRE CANADIENNE 2017; 58:717-722. [PMID: 28698690 PMCID: PMC5501119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The objectives of this study were to determine the demographics of horses with equine recurrent uveitis (ERU) presenting to the Western College of Veterinary Medicine and to describe and compare the prognosis of ERU in the Appaloosa with that in other breeds. Horses diagnosed with ERU by a veterinary ophthalmologist between 2002 and 2015 were included. Eye lesions were classified as mild, moderate, or severe based on clinical manifestations. Breed, age, severity, blindness, and final outcome were evaluated. Thirty-two horses fit the inclusion criteria; 62.5% were Appaloosas. Mean age at presentation was 12.13 ± 4.6 years. Equine recurrent uveitis was bilateral in 93.6% of horses and was severe in 59.4% of eyes at presentation. Bilateral blindness was present in 59.4% of horses at last follow-up. Of 27 horses available for follow-up, 63% were euthanized due to ERU. No significant differences in age, severity, blindness, or rate of euthanasia were noted between Appaloosas and other breeds. The Appaloosa is at increased risk for ERU, which is a devastating ocular disease.
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32
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The Evolutionary Origin and Genetic Makeup of Domestic Horses. Genetics 2017; 204:423-434. [PMID: 27729493 DOI: 10.1534/genetics.116.194860] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Accepted: 08/17/2016] [Indexed: 12/21/2022] Open
Abstract
The horse was domesticated only 5.5 KYA, thousands of years after dogs, cattle, pigs, sheep, and goats. The horse nonetheless represents the domestic animal that most impacted human history; providing us with rapid transportation, which has considerably changed the speed and magnitude of the circulation of goods and people, as well as their cultures and diseases. By revolutionizing warfare and agriculture, horses also deeply influenced the politico-economic trajectory of human societies. Reciprocally, human activities have circled back on the recent evolution of the horse, by creating hundreds of domestic breeds through selective programs, while leading all wild populations to near extinction. Despite being tightly associated with humans, several aspects in the evolution of the domestic horse remain controversial. Here, we review recent advances in comparative genomics and paleogenomics that helped advance our understanding of the genetic foundation of domestic horses.
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33
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Broadgate S, Yu J, Downes SM, Halford S. Unravelling the genetics of inherited retinal dystrophies: Past, present and future. Prog Retin Eye Res 2017; 59:53-96. [PMID: 28363849 DOI: 10.1016/j.preteyeres.2017.03.003] [Citation(s) in RCA: 80] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Revised: 03/21/2017] [Accepted: 03/23/2017] [Indexed: 02/07/2023]
Abstract
The identification of the genes underlying monogenic diseases has been of interest to clinicians and scientists for many years. Using inherited retinal dystrophies as an example of monogenic disease we describe the history of molecular genetic techniques that have been pivotal in the discovery of disease causing genes. The methods that were developed in the 1970's and 80's are still in use today but have been refined and improved. These techniques enabled the concept of the Human Genome Project to be envisaged and ultimately realised. When the successful conclusion of the project was announced in 2003 many new tools and, as importantly, many collaborations had been developed that facilitated a rapid identification of disease genes. In the post-human genome project era advances in computing power and the clever use of the properties of DNA replication has allowed the development of next-generation sequencing technologies. These methods have revolutionised the identification of disease genes because for the first time there is no need to define the position of the gene in the genome. The use of next generation sequencing in a diagnostic setting has allowed many more patients with an inherited retinal dystrophy to obtain a molecular diagnosis for their disease. The identification of novel genes that have a role in the development or maintenance of retinal function is opening up avenues of research which will lead to the development of new pharmacological and gene therapy approaches. Neither of which can be used unless the defective gene and protein is known. The continued development of sequencing technologies also holds great promise for the advent of truly personalised medicine.
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Affiliation(s)
- Suzanne Broadgate
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Levels 5 and 6 West Wing, John Radcliffe Hospital, Headley Way, Oxford, OX3 9DU, UK
| | - Jing Yu
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Levels 5 and 6 West Wing, John Radcliffe Hospital, Headley Way, Oxford, OX3 9DU, UK
| | - Susan M Downes
- Oxford Eye Hospital, Oxford University Hospitals NHS Trust, Oxford, OX3 9DU, UK
| | - Stephanie Halford
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Levels 5 and 6 West Wing, John Radcliffe Hospital, Headley Way, Oxford, OX3 9DU, UK.
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Brożyna AA, Guo H, Yang S, Cornelius L, Linette G, Murphy M, Sheehan C, Ross J, Slominski A, Carlson JA. TRPM1
(melastatin) expression is an independent predictor of overall survival in clinical
AJCC
stage I and
II
melanoma patients. J Cutan Pathol 2017; 44:328-337. [DOI: 10.1111/cup.12872] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Revised: 11/11/2016] [Accepted: 12/13/2016] [Indexed: 11/29/2022]
Affiliation(s)
- Anna A. Brożyna
- Department of Tumor Pathology and Pathomorphology, Oncology Centre—Prof. Franciszek Łukaszczyk Memorial Hospital, Department of Tumor Pathology and Pathomorphology, Faculty of Health SciencesNicolaus Copernicus University Collegium Medicum in Bydgoszcz Bydgoszcz Poland
| | - Huazhang Guo
- Department of PathologyUniversity of Pittsburgh Medical Center, UPMC Cancer Pavilion Pittsburgh Pennsylvania
| | - Sun‐Eun Yang
- Department of PathologyAlbany Medical College MC‐81 Albany New York
| | - Lynn Cornelius
- Division of Dermatology, Washington University School of Medicine St. Louis Missouri
| | - Gerald Linette
- Division of Oncology, Washington University School of Medicine St. Louis Missouri
| | - Michael Murphy
- Department of Dermatology, MC‐6230University of Connecticut Health Center Farmington Connecticut
| | | | - Jeffrey Ross
- Department of PathologyAlbany Medical College MC‐81 Albany New York
| | - Andrzej Slominski
- Department of DermatologyUniversity of Alabama at Birmingham Birmingham Alabama
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35
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TRP Channels in Skin Biology and Pathophysiology. Pharmaceuticals (Basel) 2016; 9:ph9040077. [PMID: 27983625 PMCID: PMC5198052 DOI: 10.3390/ph9040077] [Citation(s) in RCA: 334] [Impact Index Per Article: 41.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Revised: 12/08/2016] [Accepted: 12/09/2016] [Indexed: 11/17/2022] Open
Abstract
Ion channels of the Transient Receptor Potential (TRP) family mediate the influx of monovalent and/or divalent cations into cells in response to a host of chemical or physical stimuli. In the skin, TRP channels are expressed in many cell types, including keratinocytes, sensory neurons, melanocytes, and immune/inflammatory cells. Within these diverse cell types, TRP channels participate in physiological processes ranging from sensation to skin homeostasis. In addition, there is a growing body of evidence implicating abnormal TRP channel function, as a product of excessive or deficient channel activity, in pathological skin conditions such as chronic pain and itch, dermatitis, vitiligo, alopecia, wound healing, skin carcinogenesis, and skin barrier compromise. These diverse functions, coupled with the fact that many TRP channels possess pharmacologically accessible sites, make this family of proteins appealing therapeutic targets for skin disorders.
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36
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Scott ML, John EE, Bellone RR, Ching JCH, Loewen ME, Sandmeyer LS, Grahn BH, Forsyth GW. Redundant contribution of a Transient Receptor Potential cation channel Member 1 exon 11 single nucleotide polymorphism to equine congenital stationary night blindness. BMC Vet Res 2016; 12:121. [PMID: 27329127 PMCID: PMC4915136 DOI: 10.1186/s12917-016-0745-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Accepted: 06/14/2016] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Congenital stationary night-blindness (CSNB) is a recessive autosomal defect in low-light vision in Appaloosa and other horse breeds. This condition has been mapped by linkage analysis to a gene coding for the Transient Receptor Potential cation channel Member 1 (TRPM1). TRPM1 is normally expressed in the ON-bipolar cells of the inner nuclear layer of the retina. Down-regulation of TRPM1 expression in CSNB results from a transposon-like insertion in intron 1 of the TRPM1 gene. Stop transcription signals in this transposon significantly reduce TRPM1 primary transcript levels in CSNB horses. This study describes additional contributions by a second mutation of the TRPM1 gene, the ECA1 108,249,293 C > T SNP, to down-regulation of transcription of the TRPM1 gene in night-blind horses. This TRPM1 SNP introduces a consensus binding site for neuro-oncological ventral antigen 1 (Nova-1) protein in the primary transcript. Nova-1 binding disrupts normal splicing signals, producing unstable, non-functional mRNA transcripts. RESULTS Retinal bipolar cells express both TRPM1 and Nova-1 proteins. In vitro addition of Nova-1 protein retards electrophoretic migration of TRPM1 RNA containing the ECA1 108,249,293 C > T SNP. Up-regulating Nova-1 expression in primary cultures of choroidal melanocytes carrying the intron 11 SNP caused an average log 2-fold reduction of ~6 (64-fold) of TRPM1 mRNA expression. CONCLUSIONS These finding suggest that the equine TRPM1 SNP can act independently to reduce survival of TRPM1 mRNA escaping the intron 1 transcriptional stop signals in CSNB horses. Coexistence and co-inheritance of two independent TRPM1 mutations across 1000 equine generations suggests a selective advantage for the apparently deleterious CSNB trait.
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Affiliation(s)
- Michelle L Scott
- Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, S7N 5B4, Canada
| | - Emily E John
- Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, S7N 5B4, Canada
| | | | - John C H Ching
- Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, S7N 5B4, Canada
| | - Matthew E Loewen
- Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, S7N 5B4, Canada
| | - Lynne S Sandmeyer
- Small Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Canada
| | - Bruce H Grahn
- Small Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Canada
| | - George W Forsyth
- Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, S7N 5B4, Canada.
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37
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Staiger EA, Tseng CT, Miller D, Cassano JM, Nasir L, Garrick D, Brooks SA, Antczak DF. Host genetic influence on papillomavirus-induced tumors in the horse. Int J Cancer 2016; 139:784-92. [PMID: 27037728 DOI: 10.1002/ijc.30120] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Revised: 01/27/2016] [Accepted: 02/16/2016] [Indexed: 01/26/2023]
Abstract
The common equine skin tumors known as sarcoids have been causally associated with infection by bovine papillomavirus (BPV). Additionally, there is evidence for host genetic susceptibility to sarcoids. We investigated the genetic basis of susceptibility to sarcoid tumors on a cohort of 82 affected horses and 270 controls genotyped on a genome-wide platform and two custom panels. A Genome Wide Association Study (GWAS) identified candidate regions on six chromosomes. Bayesian probability analysis of the same dataset verified only the regions on equine chromosomes (ECA) 20 and 22. Fine mapping using custom-produced SNP arrays for ECA20 and ECA22 regions identified two marker loci with high levels of significance: SNP BIEC2-530826 (map position 32,787,619) on ECA20 in an intron of the DQA1 gene in the Major Histocompatibility Complex (MHC) class II region (p = 4.6e-06), and SNP BIEC2-589604 (map position 25,951,536) on ECA22 in a 200 kb region containing four candidate genes: PROCR, EDEM2, EIF6 and MMP24 (p = 2.14e-06). The marker loci yielded odds ratios of 5.05 and 4.02 for ECA20 and ECA22, respectively. Associations between genetic MHC class II variants and papillomavirus-induced tumors have been reported for human papillomavirus and cottontail rabbit papillomavirus infections. This suggests a common mechanism for susceptibility to tumor progression that may involve subversion of the host immune response. This study also identified a genomic region other than MHC that influenced papillomavirus-induced tumor development in the studied population.
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Affiliation(s)
| | - Chia T Tseng
- Baker Institute for Animal Health, Cornell University, Ithaca, NY
| | - Donald Miller
- Baker Institute for Animal Health, Cornell University, Ithaca, NY
| | | | - Lubna Nasir
- MRC-University of Glasgow Centre for Virus Research, Institute of Infection, Immunity and Inflammation, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Dorian Garrick
- Department of Animal Science, Iowa State University, Ames, IA
| | - Samantha A Brooks
- Department of Animal Science, University of Florida, Gainesville, FL
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38
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Vincent A, Audo I, Tavares E, Maynes J, Tumber A, Wright T, Li S, Michiels C, Condroyer C, MacDonald H, Verdet R, Sahel JA, Hamel CP, Zeitz C, Héon E, Banin E, Bocquet B, De Baere E, Casteels I, Defoort-Dhellemmes S, Drumare I, Friedburg C, Gottlob I, Jacobson S, Kellner U, Koenekoop R, Kohl S, Leroy B, Lorenz B, McLean R, Meire F, Meunier I, Munier F, de Ravel T, Reiff C, Mohand-Saïd S, Sharon D, Schorderet D, Schwartz S, Zanlonghi X. Biallelic Mutations in GNB3 Cause a Unique Form of Autosomal-Recessive Congenital Stationary Night Blindness. Am J Hum Genet 2016; 98:1011-1019. [PMID: 27063057 DOI: 10.1016/j.ajhg.2016.03.021] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Accepted: 03/18/2016] [Indexed: 01/13/2023] Open
Abstract
Congenital stationary night blindness (CSNB) is a heterogeneous group of non-progressive inherited retinal disorders with characteristic electroretinogram (ERG) abnormalities. Riggs and Schubert-Bornschein are subtypes of CSNB and demonstrate distinct ERG features. Riggs CSNB demonstrates selective rod photoreceptor dysfunction and occurs due to mutations in genes encoding proteins involved in rod phototransduction cascade; night blindness is the only symptom and eye examination is otherwise normal. Schubert-Bornschein CSNB is a consequence of impaired signal transmission between the photoreceptors and bipolar cells. Schubert-Bornschein CSNB is subdivided into complete CSNB with an ON bipolar signaling defect and incomplete CSNB with both ON and OFF pathway involvement. Both subtypes are associated with variable degrees of night blindness or photophobia, reduced visual acuity, high myopia, and nystagmus. Whole-exome sequencing of a family screened negative for mutations in genes associated with CSNB identified biallelic mutations in the guanine nucleotide-binding protein subunit beta-3 gene (GNB3). Two siblings were compound heterozygous for a deletion (c.170_172delAGA [p.Lys57del]) and a nonsense mutation (c.1017G>A [p.Trp339(∗)]). The maternal aunt was homozygous for the nonsense mutation (c.1017G>A [p.Trp339(∗)]). Mutational analysis of GNB3 in a cohort of 58 subjects with CSNB identified a sporadic case individual with a homozygous GNB3 mutation (c.200C>T [p.Ser67Phe]). GNB3 encodes the β subunit of G protein heterotrimer (Gαβγ) and is known to modulate ON bipolar cell signaling and cone transducin function in mice. Affected human subjects showed an unusual CSNB phenotype with variable degrees of ON bipolar dysfunction and reduced cone sensitivity. This unique retinal disorder with dual anomaly in visual processing expands our knowledge about retinal signaling.
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The TRPM1 channel in ON-bipolar cells is gated by both the α and the βγ subunits of the G-protein Go. Sci Rep 2016; 6:20940. [PMID: 26883481 PMCID: PMC4756708 DOI: 10.1038/srep20940] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Accepted: 12/16/2015] [Indexed: 12/25/2022] Open
Abstract
Transmission from photoreceptors to ON bipolar cells in mammalian retina is mediated by a sign-inverting cascade. Upon binding glutamate, the metabotropic glutamate receptor mGluR6 activates the heterotrimeric G-protein Gαoβ3γ13, and this leads to closure of the TRPM1 channel (melastatin). TRPM1 is thought to be constitutively open, but the mechanism that leads to its closure is unclear. We investigated this question in mouse rod bipolar cells by dialyzing reagents that modify the activity of either Gαo or Gβγ and then observing their effects on the basal holding current. After opening the TRPM1 channels with light, a constitutively active mutant of Gαo closed the channel, but wild-type Gαo did not. After closing the channels by dark adaptation, phosducin or inactive Gαo (both sequester Gβγ) opened the channel while the active mutant of Gαo did not. Co-immunoprecipitation showed that TRPM1 interacts with Gβ3 and with the active and inactive forms of Gαo. Furthermore, bioluminescent energy transfer assays indicated that while Gαo interacts with both the N- and the C- termini of TRPM1, Gβγ interacts only with the N-terminus. Our physiological and biochemical results suggest that both Gαo and Gβγ bind TRPM1 channels and cooperate to close them.
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Holl HM, Brooks SA, Archer S, Brown K, Malvick J, Penedo MCT, Bellone RR. Variant in theRFWD3gene associated withPATN1, a modifier of leopard complex spotting. Anim Genet 2015; 47:91-101. [DOI: 10.1111/age.12375] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/31/2015] [Indexed: 01/11/2023]
Affiliation(s)
- H. M. Holl
- Department of Animal Science; Cornell University; Ithaca NY 14853 USA
| | - S. A. Brooks
- Department of Animal Science; Cornell University; Ithaca NY 14853 USA
| | | | - K. Brown
- Department of Biology; University of Tampa; Tampa FL 33606 USA
| | - J. Malvick
- Veterinary Genetics Laboratory; School of Veterinary Medicine; University of California-Davis; Davis CA 95616 USA
| | - M. C. T. Penedo
- Veterinary Genetics Laboratory; School of Veterinary Medicine; University of California-Davis; Davis CA 95616 USA
| | - R. R. Bellone
- Department of Population Health and Reproduction; Veterinary Genetics Laboratory; School of Veterinary Medicine; University of California-Davis; Davis CA 95616 USA
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A Naturally Occurring Canine Model of Autosomal Recessive Congenital Stationary Night Blindness. PLoS One 2015; 10:e0137072. [PMID: 26368928 PMCID: PMC4569341 DOI: 10.1371/journal.pone.0137072] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Accepted: 08/12/2015] [Indexed: 11/20/2022] Open
Abstract
Congenital stationary night blindness (CSNB) is a non-progressive, clinically and genetically heterogeneous disease of impaired night vision. We report a naturally-occurring, stationary, autosomal recessive phenotype in beagle dogs with normal daylight vision but absent night vision. Affected dogs had normal retinas on clinical examination, but showed no detectable rod responses. They had “negative-type” mixed rod and cone responses in full-field ERGs. Their photopic long-flash ERGs had normal OFF-responses associated with severely reduced ON-responses. The phenotype is similar to the Schubert-Bornschein form of complete CSNB in humans. Homozygosity mapping ruled out most known CSNB candidates as well as CACNA2D4 and GNB3. Three remaining genes were excluded based on sequencing the open reading frame and intron-exon boundaries (RHO, NYX), causal to a different form of CSNB (RHO) or X-chromosome (NYX, CACNA1F) location. Among the genes expressed in the photoreceptors and their synaptic terminals, and mGluR6 cascade and modulators, reduced expression of GNAT1, CACNA2D4 and NYX was observed by qRT-PCR in both carrier (n = 2) and affected (n = 2) retinas whereas CACNA1F was down-regulated only in the affecteds. Retinal morphology revealed normal cellular layers and structure, and electron microscopy showed normal rod spherules and synaptic ribbons. No difference from normal was observed by immunohistochemistry (IHC) for antibodies labeling rods, cones and their presynaptic terminals. None of the retinas showed any sign of stress. Selected proteins of mGluR6 cascade and its modulators were examined by IHC and showed that PKCα weakly labeled the rod bipolar somata in the affected, but intensely labeled axonal terminals that appeared thickened and irregular. Dendritic terminals of ON-bipolar cells showed increased Goα labeling. Both PKCα and Goα labeled the more prominent bipolar dendrites that extended into the OPL in affected but not normal retinas. Interestingly, RGS11 showed no labeling in the affected retina. Our results indicate involvement of a yet unknown gene in this canine model of complete CSNB.
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Abstract
Although deafness can be acquired throughout an animal's life from a variety of causes, hereditary deafness, especially congenital hereditary deafness, is a significant problem in several species. Extensive reviews exist of the genetics of deafness in humans and mice, but not for deafness in domestic animals. Hereditary deafness in many species and breeds is associated with loci for white pigmentation, where the cochlear pathology is cochleo-saccular. In other cases, there is no pigmentation association and the cochlear pathology is neuroepithelial. Late onset hereditary deafness has recently been identified in dogs and may be present but not yet recognized in other species. Few genes responsible for deafness have been identified in animals, but progress has been made for identifying genes responsible for the associated pigmentation phenotypes. Across species, the genes identified with deafness or white pigmentation patterns include MITF, PMEL, KIT, EDNRB, CDH23, TYR, and TRPM1 in dog, cat, horse, cow, pig, sheep, ferret, mink, camelid, and rabbit. Multiple causative genes are present in some species. Significant work remains in many cases to identify specific chromosomal deafness genes so that DNA testing can be used to identify carriers of the mutated genes and thereby reduce deafness prevalence.
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Affiliation(s)
- George M. Strain
- Comparative Biomedical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA, USA
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Ludwig A, Reissmann M, Benecke N, Bellone R, Sandoval-Castellanos E, Cieslak M, Fortes GG, Morales-Muñiz A, Hofreiter M, Pruvost M. Twenty-five thousand years of fluctuating selection on leopard complex spotting and congenital night blindness in horses. Philos Trans R Soc Lond B Biol Sci 2015; 370:20130386. [PMID: 25487337 DOI: 10.1098/rstb.2013.0386] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Leopard complex spotting is inherited by the incompletely dominant locus, LP, which also causes congenital stationary night blindness in homozygous horses. We investigated an associated single nucleotide polymorphism in the TRPM1 gene in 96 archaeological bones from 31 localities from Late Pleistocene (approx. 17 000 YBP) to medieval times. The first genetic evidence of LP spotting in Europe dates back to the Pleistocene. We tested for temporal changes in the LP associated allele frequency and estimated coefficients of selection by means of approximate Bayesian computation analyses. Our results show that at least some of the observed frequency changes are congruent with shifts in artificial selection pressure for the leopard complex spotting phenotype. In early domestic horses from Kirklareli-Kanligecit (Turkey) dating to 2700-2200 BC, a remarkably high number of leopard spotted horses (six of 10 individuals) was detected including one adult homozygote. However, LP seems to have largely disappeared during the late Bronze Age, suggesting selection against this phenotype in early domestic horses. During the Iron Age, LP reappeared, probably by reintroduction into the domestic gene pool from wild animals. This picture of alternating selective regimes might explain how genetic diversity was maintained in domestic animals despite selection for specific traits at different times.
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Affiliation(s)
- Arne Ludwig
- Department of Evolutionary Genetics, Leibniz Institute for Zoo and Wildlife Research, Berlin, Germany
| | - Monika Reissmann
- Department for Crop and Animal Sciences, Humboldt University Berlin, Berlin, Germany
| | - Norbert Benecke
- Department of Natural Sciences, German Archaeological Institute, Berlin, Germany
| | - Rebecca Bellone
- Department of Population Health and Reproduction and the Veterinary Genetics Laboratory, School of Veterinary Medicine, University of California-Davis, Davis, CA 95616, USA
| | | | - Michael Cieslak
- Department of Evolutionary Genetics, Leibniz Institute for Zoo and Wildlife Research, Berlin, Germany
| | - Gloria G Fortes
- Department of Biology, University of York, Heslington, York, UK Instituto Universitario de Xeología (IUX), A Coruña, Spain
| | | | - Michael Hofreiter
- Department of Biology, University of York, Heslington, York, UK Adaptive and Evolutionary Genomics, Institute for Biochemistry and Biology, Faculty of Mathematics and Natural Sciences, University of Potsdam, Karl-Liebknecht-Strasse 24-24, 14476 Potsdam, Germany
| | - Melanie Pruvost
- Department of Evolutionary Genetics, Leibniz Institute for Zoo and Wildlife Research, Berlin, Germany Department of Natural Sciences, German Archaeological Institute, Berlin, Germany Institut Jacques Monod, UMR 7592 CNRS, Université Paris Diderot, Paris, France
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Schneider FM, Mohr F, Behrendt M, Oberwinkler J. Properties and functions of TRPM1 channels in the dendritic tips of retinal ON-bipolar cells. Eur J Cell Biol 2015; 94:420-7. [PMID: 26111660 DOI: 10.1016/j.ejcb.2015.06.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
An increase in light intensity induces a depolarization in retinal ON-bipolar cells via a reduced glutamate release from presynaptic photoreceptor cells. The underlying transduction cascade in the dendritic tips of ON-bipolar cells involves mGluR6 glutamate receptors signaling to TRPM1 proteins that are an indispensable part of the transduction channel. Several other proteins are recognized to participate in the transduction machinery. Deficiency in many of these leads to congenital stationary night blindness, because rod bipolar cells, a subgroup of ON-bipolar cells, constitute the main route for sensory information under scotopic conditions. Here, we review the current knowledge about TRPM1 ion channels and how their activity is regulated within the postsynaptic compartment of ON-bipolar cells. The functional properties of TRPM1 channels in the dendritic compartment are not well understood as they differ substantially from those of recombinant TRPM1 channels. Critical evaluation of possible explanations of these discrepancies indicates that some key components of this transduction pathway might still not be known. The continued exploration of this pathway will yield further clinically useful insights.
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Affiliation(s)
- Franziska M Schneider
- Institut für Physiologie und Pathophysiologie, Philipps-Universität Marburg, Deutschhausstr. 1-2, D-35037 Marburg, Germany
| | - Florian Mohr
- Institut für Physiologie und Pathophysiologie, Philipps-Universität Marburg, Deutschhausstr. 1-2, D-35037 Marburg, Germany
| | - Marc Behrendt
- Institut für Physiologie und Pathophysiologie, Philipps-Universität Marburg, Deutschhausstr. 1-2, D-35037 Marburg, Germany
| | - Johannes Oberwinkler
- Institut für Physiologie und Pathophysiologie, Philipps-Universität Marburg, Deutschhausstr. 1-2, D-35037 Marburg, Germany.
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45
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Abstract
Horses are valued for the beauty and variety of colouration and coat patterning. To date, eleven different genes have been characterized that contribute to the variation observed in the horse. Unfortunately, mutations involving pigmentation often lead to deleterious effects in other systems, some of which have been described in the horse. This review focuses on six such pleiotropic effects or associations with pigmentation genes. These include neurological defects (lethal white foal syndrome and lavender foal syndrome), hearing defects, eye disorders (congenital stationary night blindness and multiple congenital ocular anomalies), as well as horse-specific melanoma. The pigmentation phenotype, disorder phenotype, mode of inheritance, genetic or genomic methods utilized to identify the genes involved and, if known, the causative mutations, molecular interactions and other susceptibility loci are discussed. As our understanding of pigmentation in the horse increases, through the use of novel genomic tools, we are likely to unravel yet unknown pleiotropic effects and determine additional interactions between previously discovered loci.
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Affiliation(s)
- R R Bellone
- Department of Biology, University of Tampa, 401 W. Kennedy Blvd., Tampa, FL 33606, USA.
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46
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Congenital stationary night blindness: An analysis and update of genotype–phenotype correlations and pathogenic mechanisms. Prog Retin Eye Res 2015; 45:58-110. [DOI: 10.1016/j.preteyeres.2014.09.001] [Citation(s) in RCA: 207] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Revised: 09/25/2014] [Accepted: 09/30/2014] [Indexed: 01/18/2023]
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47
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Tóth BI, Oláh A, Szöllősi AG, Bíró T. TRP channels in the skin. Br J Pharmacol 2014; 171:2568-81. [PMID: 24372189 DOI: 10.1111/bph.12569] [Citation(s) in RCA: 84] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2013] [Revised: 11/28/2013] [Accepted: 12/03/2013] [Indexed: 12/16/2022] Open
Abstract
Emerging evidence suggests that transient receptor potential (TRP) ion channels not only act as 'polymodal cellular sensors' on sensory neurons but are also functionally expressed by a multitude of non-neuronal cell types. This is especially true in the skin, one of the largest organs of the body, where they appear to be critically involved in regulating various cutaneous functions both under physiological and pathophysiological conditions. In this review, we focus on introducing the roles of several cutaneous TRP channels in the regulation of the skin barrier, skin cell proliferation and differentiation, and immune functions. Moreover, we also describe the putative involvement of several TRP channels in the development of certain skin diseases and identify future TRP channel-targeted therapeutic opportunities.
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Affiliation(s)
- Balázs I Tóth
- Laboratory of Ion Channel Research and TRP Research Platform Leuven (TRPLe), Department of Cellular and Molecular Medicine, KU Leuven, Leuven, Belgium; DE-MTA 'Lendület' Cellular Physiology Research Group, Department of Physiology, University of Debrecen, Medical and Health Science Center, Research Center for Molecular Medicine, Debrecen, Hungary
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48
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Bennett TM, Mackay DS, Siegfried CJ, Shiels A. Mutation of the melastatin-related cation channel, TRPM3, underlies inherited cataract and glaucoma. PLoS One 2014; 9:e104000. [PMID: 25090642 PMCID: PMC4121231 DOI: 10.1371/journal.pone.0104000] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Accepted: 07/04/2014] [Indexed: 11/19/2022] Open
Abstract
Inherited forms of cataract are a clinically important and genetically heterogeneous cause of visual impairment that usually present at an early age with or without systemic and/or other ocular abnormalities. Here we have identified a new locus for inherited cataract and high-tension glaucoma with variable anterior segment defects, and characterized an underlying mutation in the gene coding for transient receptor potential cation channel, subfamily M, member-3 (TRPM3, melastatin-2). Genome-wide linkage analysis mapped the ocular disease locus to the pericentric region of human chromosome 9. Whole exome and custom-target next-generation sequencing detected a heterozygous A-to-G transition in exon-3 of TRPM3 that co-segregated with disease. As a consequence of alternative splicing this missense mutation was predicted to result in the substitution of isoleucine-to-methionine at codon 65 (c.195A>G; p.I65 M) of TRPM3 transcript variant 9, and at codon 8 (c.24A>G; p.I8 M) of a novel TRPM3 transcript variant expressed in human lens. In both transcript variants the I-to-M substitution was predicted in silico to exert damaging effects on protein function. Furthermore, transient expression studies of a recombinant TRPM3-GFP reporter product predicted that the I-to-M substitution introduced an alternative translation start-site located 89 codons upstream from the native initiator methionine found in eight other TRPM3 transcript variants (1-8). Collectively, these studies have provided the first evidence that TRPM3 is associated with inherited ocular disease in humans, and further provide support for the important role of this cation channel in normal eye development.
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Affiliation(s)
- Thomas M. Bennett
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Donna S. Mackay
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Carla J. Siegfried
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Alan Shiels
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, Missouri, United States of America
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49
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Bellono NW, Oancea EV. Ion transport in pigmentation. Arch Biochem Biophys 2014; 563:35-41. [PMID: 25034214 DOI: 10.1016/j.abb.2014.06.020] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Revised: 06/01/2014] [Accepted: 06/03/2014] [Indexed: 12/01/2022]
Abstract
Skin melanocytes and ocular pigment cells contain specialized organelles called melanosomes, which are responsible for the synthesis of melanin, the major pigment in mammals. Defects in the complex mechanisms involved in melanin synthesis and regulation result in vision and pigmentation deficits, impaired development of the visual system, and increased susceptibility to skin and eye cancers. Ion transport across cellular membranes is critical for many biological processes, including pigmentation, but the molecular mechanisms by which it regulates melanin synthesis, storage, and transfer are not understood. In this review we first discuss ion channels and transporters that function at the plasma membrane of melanocytes; in the second part we consider ion transport across the membrane of intracellular organelles, with emphasis on melanosomes. We discuss recently characterized lysosomal and endosomal ion channels and transporters associated with pigmentation phenotypes. We then review the evidence for melanosomal channels and transporters critical for pigmentation, discussing potential molecular mechanisms mediating their function. The studies investigating ion transport in pigmentation physiology open new avenues for future research and could reveal novel molecular mechanisms underlying melanogenesis.
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Affiliation(s)
- Nicholas W Bellono
- Department of Molecular Physiology, Pharmacology and Biotechnology, Brown University, Providence, RI 02912, United States
| | - Elena V Oancea
- Department of Molecular Physiology, Pharmacology and Biotechnology, Brown University, Providence, RI 02912, United States.
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50
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Masurel-Paulet A, Drumare I, Holder M, Cuisset JM, Vallée L, Defoort S, Bourgois B, Pernes P, Cuvellier JC, Huet F, Chehadeh SE, Thevenon J, Callier P, Thauvin C, Faivre L, Andrieux J. Further delineation of eye manifestations in homozygous 15q13.3 microdeletions including TRPM1: a differential diagnosis of ceroid lipofuscinosis. Am J Med Genet A 2014; 164A:1537-44. [PMID: 24668847 DOI: 10.1002/ajmg.a.36471] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2013] [Accepted: 12/31/2013] [Indexed: 11/11/2022]
Abstract
The 15q13.3 heterozygous microdeletion is a fairly common microdeletion syndrome with marked clinical variability and incomplete penetrance. The average size of the deletion, which comprises six genes including CHRNA7, is 1.5 Mb. CHRNA7 has been identified as the gene responsible for the neurological phenotype in this microdeletion syndrome. Only seven patients with a homozygous microdeletion that includes at least CHRNA7, and is inherited from both parents have been described in the literature. The aim of this study was to further describe the distinctive eye manifestations from the analysis in the three French patients diagnosed with the classical 1.5 Mb homozygous microdeletion. Patients' ages ranged from 30 months to 9 years, and included one sib pair. They all displayed a remarkably severe identifiable clinical phenotype that included congenital blindness and convulsive encephalopathy with inconstant abnormal movements. The ophthalmological examination revealed a lack of eye tracking, optic nerve pallor, an immature response with increased latencies with no response to the checkerboard stimulations at the visual evoked potential examination, and a distinctive retina dystrophy with a negative electroretinogram in which the "b" wave was smaller than the "a" wave after a dark adapted pupil and bright flash in all patients. Clear genotype-phenotype correlations emerged, showing that this eye phenotype was secondary to homozygous deletion of TRPM1, the gene responsible for autosomal recessive congenital stationary night blindness. The main differential diagnosis is ceroid lipofuscinosis.
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Affiliation(s)
- Alice Masurel-Paulet
- Centre de Génétique et Centre de Référence Anomalies du Développement et Syndromes Malformatifs, Hôpital d'Enfants, CHU Dijon, France
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