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Cozzitorto C, Peltz Z, Flores LM, Della Santina L, Mao M, Gould DB. Evaluating neural crest cell migration in a Col4a1 mutant mouse model of ocular anterior segment dysgenesis. Cells Dev 2024:203926. [PMID: 38729574 DOI: 10.1016/j.cdev.2024.203926] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Revised: 05/02/2024] [Accepted: 05/06/2024] [Indexed: 05/12/2024]
Abstract
The periocular mesenchyme (POM) is a transient migratory embryonic tissue derived from neural crest cells (NCCs) and paraxial mesoderm that gives rise to most of the structures in front of the eye. Morphogenetic defects of these structures can impair aqueous humor outflow, leading to elevated intraocular pressure and glaucoma. Mutations in collagen type IV alpha 1 (COL4A1) and alpha 2 (COL4A2) cause Gould syndrome - a multisystem disorder often characterized by variable cerebrovascular, ocular, renal, and neuromuscular manifestations. Approximately one-third of individuals with COL4A1 and COL4A2 mutations have ocular anterior segment dysgenesis (ASD), including congenital glaucoma resulting from abnormalities of POM-derived structures. POM differentiation has been a major focus of ASD research, but the underlying cellular mechanisms are still unclear. Moreover, earlier events including NCC migration and survival defects have been implicated in ASD; however, their roles are not as well understood. Vascular defects are among the most common consequences of COL4A1 and COL4A2 mutations and can influence NCC survival and migration. We therefore hypothesized that NCC migration might be impaired by COL4A1 and COL4A2 mutations. In this study, we used 3D confocal microscopy, gross morphology, and quantitative analyses to test NCC migration in Col4a1 mutant mice. We show that homozygous Col4a1 mutant embryos have severe embryonic growth retardation and lethality, and we identified a potential maternal effect on embryo development. Cerebrovascular defects in heterozygous Col4a1 mutant embryos were present as early as E9.0, showing abnormal cerebral vasculature plexus remodeling compared to controls. We detected abnormal NCC migration within the diencephalic stream and the POM in heterozygous Col4a1 mutants whereby mutant NCCs formed smaller diencephalic migratory streams and POMs. In these settings, migratory NCCs within the diencephalic stream and POM localize farther away from the developing vasculature. Our results show for the first time that Col4a1 mutations lead to cranial NCCs migratory defects in the context of early onset defective angiogenesis without affecting cell numbers, possibly impacting the relation between NCCs and the blood vessels during ASD development.
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Affiliation(s)
- Corinna Cozzitorto
- Department of Ophthalmology, University of California, San Francisco, CA 94158, United States.
| | - Zoe Peltz
- Department of Ophthalmology, University of California, San Francisco, CA 94158, United States
| | - Lourdes M Flores
- Department of Ophthalmology, University of California, San Francisco, CA 94158, United States
| | - Luca Della Santina
- Department of Ophthalmology, University of California, San Francisco, CA 94158, United States.
| | - Mao Mao
- Department of Ophthalmology, University of California, San Francisco, CA 94158, United States
| | - Douglas B Gould
- Department of Ophthalmology, University of California, San Francisco, CA 94158, United States; Department of Anatomy, Cardiovascular Research Institute, Bakar Aging Research Institute, and Institute for Human Genetics, University of California, San Francisco, United States.
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2
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Mao M, Kuo YM, Yu AK, Labelle-Dumais C, Ou Y, Gould DB. TGFβ Signaling Dysregulation May Contribute to COL4A1-Related Glaucomatous Optic Nerve Damage. Invest Ophthalmol Vis Sci 2024; 65:15. [PMID: 38717426 PMCID: PMC11090142 DOI: 10.1167/iovs.65.5.15] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Accepted: 04/22/2024] [Indexed: 05/15/2024] Open
Abstract
Purpose Mutations in the genes encoding type IV collagen alpha 1 (COL4A1) and alpha 2 (COL4A2) cause a multisystem disorder that includes ocular anterior segment dysgenesis (ASD) and glaucoma. We previously showed that transforming growth factor beta (TGFβ) signaling was elevated in developing anterior segments from Col4a1 mutant mice and that reducing TGFβ signaling ameliorated ASD, supporting a role for the TGFβ pathway in disease pathogenesis. Here, we tested whether altered TGFβ signaling also contributes to glaucoma-related phenotypes in Col4a1 mutant mice. Methods To test the role of TGFβ signaling in glaucoma-relevant phenotypes, we genetically reduced TGFβ signaling using mice with mutated Tgfbr2, which encodes the common receptor for all TGFβ ligands in Col4a1+/G1344D mice. We performed slit-lamp biomicroscopy and optical coherence tomography for qualitative and quantitative analyses of anterior and posterior ocular segments, histological analyses of ocular tissues and optic nerves, and intraocular pressure assessments using rebound tonometry. Results Col4a1+/G1344D mice showed defects of the ocular drainage structures, including iridocorneal adhesions, and phenotypes consistent with glaucomatous neurodegeneration, including thinning of the nerve fiber layer, retinal ganglion cell loss, optic nerve head excavation, and optic nerve degeneration. We found that reducing TGFβ receptor 2 (TGFBR2) was protective for ASD, ameliorated ocular drainage structure defects, and protected against glaucomatous neurodegeneration in Col4a1+/G1344D mice. Conclusions Our results suggest that elevated TGFβ signaling contributes to glaucomatous neurodegeneration in Col4a1 mutant mice.
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Affiliation(s)
- Mao Mao
- Department of Ophthalmology, University of California, San Francisco, San Francisco, California, United States
| | - Yien-Ming Kuo
- Department of Ophthalmology, University of California, San Francisco, San Francisco, California, United States
| | - Alfred K. Yu
- Department of Ophthalmology, University of California, San Francisco, San Francisco, California, United States
| | - Cassandre Labelle-Dumais
- Department of Ophthalmology, University of California, San Francisco, San Francisco, California, United States
| | - Yvonne Ou
- Department of Ophthalmology, University of California, San Francisco, San Francisco, California, United States
| | - Douglas B. Gould
- Department of Ophthalmology, University of California, San Francisco, San Francisco, California, United States
- Department of Anatomy, Institute for Human Genetics, Cardiovascular Research Institute, and Bakar Aging Research Institute, University of California, San Francisco, San Francisco, California, United States
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Yin M, Smith JA, Chou M, Chan J, Jittayasothorn Y, Gould DB, Caspi RR, Anderson MS, DeFranco AL. Tracking the role of Aire in immune tolerance to the eye with a TCR transgenic mouse model. Proc Natl Acad Sci U S A 2024; 121:e2311487121. [PMID: 38261611 PMCID: PMC10835137 DOI: 10.1073/pnas.2311487121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Accepted: 12/04/2023] [Indexed: 01/25/2024] Open
Abstract
Roughly one-half of mice with partial defects in two immune tolerance pathways (AireGW/+Lyn-/- mice) spontaneously develop severe damage to their retinas due to T cell reactivity to Aire-regulated interphotoreceptor retinoid-binding protein (IRBP). Single-cell T cell receptor (TCR) sequencing of CD4+ T cells specific for a predominate epitope of IRBP showed a remarkable diversity of autoantigen-specific TCRs with greater clonal expansions in mice with disease. TCR transgenic mice made with an expanded IRBP-specific TCR (P2.U2) of intermediate affinity exhibited strong but incomplete negative selection of thymocytes. This negative selection was absent in IRBP-/- mice and greatly defective in AireGW/+ mice. Most P2.U2+/- mice and all P2.U.2+/-AireGW/+ mice rapidly developed inflammation of the retina and adjacent uvea (uveitis). Aire-dependent IRBP expression in the thymus also promoted Treg differentiation, but the niche for this fate determination was small, suggesting differences in antigen presentation leading to negative selection vs. thymic Treg differentiation and a stronger role for negative selection in preventing autoimmune disease in the retina.
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Affiliation(s)
- Mianmian Yin
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94143
| | - Jennifer A Smith
- Diabetes Center, University of California, San Francisco, San Francisco, CA 94143
| | - Marissa Chou
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94143
| | - Jackie Chan
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94143
| | | | - Douglas B Gould
- Department of Ophthalmology, Institute for Human Genetics, University of California, San Francisco, San Francisco, CA 94143
- Department of Anatomy, Cardiovascular Research Institute, Bakar Aging Research Institute, and Institute for Human Genetics, University of California, San Francisco, San Francisco, CA 94143
| | - Rachel R Caspi
- Laboratory of Immunology, National Eye Institute, NIH, Bethesda, MD 20892-1857
| | - Mark S Anderson
- Diabetes Center, University of California, San Francisco, San Francisco, CA 94143
- Department of Medicine, University of California, San Francisco, San Francisco, CA 94143
| | - Anthony L DeFranco
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA 94143
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Yamasaki E, Thakore P, Ali S, Solano AS, Wang X, Gao X, Labelle-Dumais C, Chaumeil MM, Gould DB, Earley S. Impaired intracellular Ca 2+ signaling contributes to age-related cerebral small vessel disease in Col4a1 mutant mice. Sci Signal 2023; 16:eadi3966. [PMID: 37963192 PMCID: PMC10726848 DOI: 10.1126/scisignal.adi3966] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2023] [Accepted: 10/25/2023] [Indexed: 11/16/2023]
Abstract
Humans and mice with mutations in COL4A1 and COL4A2 manifest hallmarks of cerebral small vessel disease (cSVD). Mice with a missense mutation in Col4a1 at amino acid 1344 (Col4a1+/G1344D) exhibit age-dependent intracerebral hemorrhages (ICHs) and brain lesions. Here, we report that this pathology was associated with the loss of myogenic vasoconstriction, an intrinsic vascular response essential for the autoregulation of cerebral blood flow. Electrophysiological analyses showed that the loss of myogenic constriction resulted from blunted pressure-induced smooth muscle cell (SMC) membrane depolarization. Furthermore, we found that dysregulation of membrane potential was associated with impaired Ca2+-dependent activation of large-conductance Ca2+-activated K+ (BK) and transient receptor potential melastatin 4 (TRPM4) cation channels linked to disruptions in sarcoplasmic reticulum (SR) Ca2+ signaling. Col4a1 mutations impair protein folding, which can cause SR stress. Treating Col4a1+/G1344D mice with 4-phenylbutyrate, a compound that promotes the trafficking of misfolded proteins and alleviates SR stress, restored SR Ca2+ signaling, maintained BK and TRPM4 channel activity, prevented loss of myogenic tone, and reduced ICHs. We conclude that alterations in SR Ca2+ handling that impair ion channel activity result in dysregulation of SMC membrane potential and loss of myogenic tone and contribute to age-related cSVD in Col4a1+/G1344D mice.
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Affiliation(s)
- Evan Yamasaki
- Department of Pharmacology, Center for Molecular and Cellular Signaling in the Cardiovascular System, University of Nevada, Reno School of Medicine, Reno, NV 89557-0318, USA
| | - Pratish Thakore
- Department of Pharmacology, Center for Molecular and Cellular Signaling in the Cardiovascular System, University of Nevada, Reno School of Medicine, Reno, NV 89557-0318, USA
| | - Sher Ali
- Department of Pharmacology, Center for Molecular and Cellular Signaling in the Cardiovascular System, University of Nevada, Reno School of Medicine, Reno, NV 89557-0318, USA
| | - Alfredo Sanchez Solano
- Department of Pharmacology, Center for Molecular and Cellular Signaling in the Cardiovascular System, University of Nevada, Reno School of Medicine, Reno, NV 89557-0318, USA
| | - Xiaowei Wang
- Department of Ophthalmology, UCSF School of Medicine, San Francisco, CA 94158, USA
| | - Xiao Gao
- Department of Physical Therapy and Rehabilitation Science, UCSF School of Medicine, San Francisco, CA 94143, USA
- Department of Radiology and Biomedical Imaging, UCSF School of Medicine, San Francisco, CA 94143, USA
| | | | - Myriam M. Chaumeil
- Department of Physical Therapy and Rehabilitation Science, UCSF School of Medicine, San Francisco, CA 94143, USA
- Department of Radiology and Biomedical Imaging, UCSF School of Medicine, San Francisco, CA 94143, USA
| | - Douglas B. Gould
- Department of Ophthalmology, UCSF School of Medicine, San Francisco, CA 94158, USA
- Department of Anatomy, Institute for Human Genetics, Cardiovascular Research Institute, Bakar Aging Research Institute, UCSF School of Medicine, San Francisco, CA 94158, USA
| | - Scott Earley
- Department of Pharmacology, Center for Molecular and Cellular Signaling in the Cardiovascular System, University of Nevada, Reno School of Medicine, Reno, NV 89557-0318, USA
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Ishikawa Y, Bonna A, Gould DB, Farndale RW. Local Net Charge State of Collagen Triple Helix Is a Determinant of FKBP22 Binding to Collagen III. Int J Mol Sci 2023; 24:15156. [PMID: 37894834 PMCID: PMC10607241 DOI: 10.3390/ijms242015156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Revised: 10/10/2023] [Accepted: 10/10/2023] [Indexed: 10/29/2023] Open
Abstract
Mutations in the FKBP14 gene encoding the endoplasmic reticulum resident collagen-related proline isomerase FK506 binding protein 22 kDa (FKBP22) result in kyphoscoliotic Ehlers-Danlos Syndrome (EDS), which is characterized by a broad phenotypic outcome. A plausible explanation for this outcome is that FKBP22 participates in the biosynthesis of subsets of collagen types: FKBP22 selectively binds to collagens III, IV, VI, and X, but not to collagens I, II, V, and XI. However, these binding mechanisms have never been explored, and they may underpin EDS subtype heterogeneity. Here, we used collagen Toolkit peptide libraries to investigate binding specificity. We observed that FKBP22 binding was distributed along the collagen helix. Further, it (1) was higher on collagen III than collagen II peptides and it (2) was correlated with a positive peptide charge. These findings begin to elucidate the mechanism by which FKBP22 interacts with collagen.
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Affiliation(s)
- Yoshihiro Ishikawa
- Department of Ophthalmology, University of California San Francisco, School of Medicine, San Francisco, CA 941583, USA
| | - Arkadiusz Bonna
- Department of Biochemistry, Downing Site, Cambridge CB2 1QW, UK
| | - Douglas B. Gould
- Department of Ophthalmology, University of California San Francisco, School of Medicine, San Francisco, CA 941583, USA
- Department of Anatomy, University of California, San Francisco, CA 94143, USA
- Cardiovascular Research Institute, University of California, San Francisco, CA 94158, USA
- Bakar Aging Research Institute, University of California, San Francisco, CA 94143, USA
- Institute for Human Genetics, University of California, San Francisco, CA 94143, USA
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Thakore P, Yamasaki E, Ali S, Sanchez Solano A, Labelle-Dumais C, Gao X, Chaumeil MM, Gould DB, Earley S. PI3K block restores age-dependent neurovascular coupling defects associated with cerebral small vessel disease. Proc Natl Acad Sci U S A 2023; 120:e2306479120. [PMID: 37607233 PMCID: PMC10467353 DOI: 10.1073/pnas.2306479120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Accepted: 07/17/2023] [Indexed: 08/24/2023] Open
Abstract
Neurovascular coupling (NVC), a vital physiological process that rapidly and precisely directs localized blood flow to the most active regions of the brain, is accomplished in part by the vast network of cerebral capillaries acting as a sensory web capable of detecting increases in neuronal activity and orchestrating the dilation of upstream parenchymal arterioles. Here, we report a Col4a1 mutant mouse model of cerebral small vessel disease (cSVD) with age-dependent defects in capillary-to-arteriole dilation, functional hyperemia in the brain, and memory. The fundamental defect in aged mutant animals was the depletion of the minor membrane phospholipid phosphatidylinositol 4,5 bisphosphate (PIP2) in brain capillary endothelial cells, leading to the loss of inwardly rectifying K+ (Kir2.1) channel activity. Blocking phosphatidylinositol-3-kinase (PI3K), an enzyme that diminishes the bioavailability of PIP2 by converting it to phosphatidylinositol (3, 4, 5)-trisphosphate (PIP3), restored Kir2.1 channel activity, capillary-to-arteriole dilation, and functional hyperemia. In longitudinal studies, chronic PI3K inhibition also improved the memory function of aged Col4a1 mutant mice. Our data suggest that PI3K inhibition is a viable therapeutic strategy for treating defective NVC and cognitive impairment associated with cSVD.
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Affiliation(s)
- Pratish Thakore
- Department of Pharmacology, Center for Molecular and Cellular Signaling in the Cardiovascular System University of Nevada, Reno School of Medicine, Reno, NV89557-0318
| | - Evan Yamasaki
- Department of Pharmacology, Center for Molecular and Cellular Signaling in the Cardiovascular System University of Nevada, Reno School of Medicine, Reno, NV89557-0318
| | - Sher Ali
- Department of Pharmacology, Center for Molecular and Cellular Signaling in the Cardiovascular System University of Nevada, Reno School of Medicine, Reno, NV89557-0318
| | - Alfredo Sanchez Solano
- Department of Pharmacology, Center for Molecular and Cellular Signaling in the Cardiovascular System University of Nevada, Reno School of Medicine, Reno, NV89557-0318
| | - Cassandre Labelle-Dumais
- Department of Ophthalmology and Anatomy, Institute for Human Genetics, University of California San Francisco School of Medicine, San Francisco, CA94143
| | - Xiao Gao
- Department of Physical Therapy and Rehabilitation Science, University of California, San Francisco, CA94158
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA94143-0628
| | - Myriam M. Chaumeil
- Department of Physical Therapy and Rehabilitation Science, University of California, San Francisco, CA94158
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA94143-0628
| | - Douglas B. Gould
- Department of Ophthalmology and Anatomy, Institute for Human Genetics, University of California San Francisco School of Medicine, San Francisco, CA94143
| | - Scott Earley
- Department of Pharmacology, Center for Molecular and Cellular Signaling in the Cardiovascular System University of Nevada, Reno School of Medicine, Reno, NV89557-0318
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Massoudi D, Gorman S, Kuo YM, Iwawaki T, Oakes SA, Papa FR, Gould DB. Deletion of the Unfolded Protein Response Transducer IRE1α Is Detrimental to Aging Photoreceptors and to ER Stress-Mediated Retinal Degeneration. Invest Ophthalmol Vis Sci 2023; 64:30. [PMID: 37097227 PMCID: PMC10148664 DOI: 10.1167/iovs.64.4.30] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/26/2023] Open
Abstract
Purpose The unfolded protein response (UPR) is triggered when the protein folding capacity of the endoplasmic reticulum (ER) is overwhelmed and misfolded proteins accumulate in the ER, a condition referred to as ER stress. IRE1α is an ER-resident protein that plays major roles in orchestrating the UPR. Several lines of evidence implicate the UPR and its transducers in neurodegenerative diseases, including retinitis pigmentosa (RP), a group of inherited diseases that cause progressive dysfunction and loss of rod and cone photoreceptors. This study evaluated the contribution of IRE1α to photoreceptor development, homeostasis, and degeneration. Methods We used a conditional gene targeting strategy to selectively inactivate Ire1α in mouse rod photoreceptors. We used a combination of optical coherence tomography (OCT) imaging, histology, and electroretinography (ERG) to assess longitudinally the effect of IRE1α deficiency in retinal development and function. Furthermore, we evaluated the IRE1α-deficient retina responses to tunicamycin-induced ER stress and in the context of RP caused by the rhodopsin mutation RhoP23H. Results OCT imaging, histology, and ERG analyses did not reveal abnormalities in IRE1α-deficient retinas up to 3 months old. However, by 6 months of age, the Ire1α mutant animals showed reduced outer nuclear layer thickness and deficits in retinal function. Furthermore, conditional inactivation of Ire1α in rod photoreceptors accelerated retinal degeneration caused by the RhoP23H mutation. Conclusions These data suggest that IRE1α is dispensable for photoreceptor development but important for photoreceptor homeostasis in aging retinas and for protecting against ER stress-mediated photoreceptor degeneration.
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Affiliation(s)
- Dawiyat Massoudi
- Department of Ophthalmology, University of California, San Francisco, San Francisco, California, United States
| | - Seán Gorman
- Department of Ophthalmology, University of California, San Francisco, San Francisco, California, United States
| | - Yien-Ming Kuo
- Department of Ophthalmology, University of California, San Francisco, San Francisco, California, United States
| | - Takao Iwawaki
- Division of Cell Medicine, Medical Research Institute, Kanazawa Medical University, Ishikawa, Japan
| | - Scott A Oakes
- Department of Pathology, Pritzker School of Medicine, University of Chicago, Chicago, Illinois, United States
| | - Feroz R Papa
- Department of Medicine, Diabetes Center, Quantitative Biosciences Institute and Lung Biology Center University of California, San Francisco, San Francisco, California, United States
| | - Douglas B Gould
- Department of Ophthalmology, University of California, San Francisco, San Francisco, California, United States
- Department of Anatomy, Institute for Human Genetics, Cardiovascular Research Institute, Bakar Aging Research Institute, University of California, San Francisco, California, United States
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8
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Thakore P, Yamasaki E, Ali S, Solano AS, Labelle-Dumais C, Gao X, Chaumeil MM, Gould DB, Earley S. PI3K block restores age-dependent neurovascular coupling defects associated with cerebral small vessel disease. bioRxiv 2023:2023.03.03.531032. [PMID: 36945616 PMCID: PMC10028793 DOI: 10.1101/2023.03.03.531032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/10/2023]
Abstract
Neurovascular coupling (NVC), a vital physiological process that rapidly and precisely directs localized blood flow to the most active regions of the brain, is accomplished in part by the vast network of cerebral capillaries acting as a sensory web capable of detecting increases in neuronal activity and orchestrating the dilation of upstream parenchymal arterioles. Here, we report a Col4a1 mutant mouse model of cerebral small vessel disease (cSVD) with age-dependent defects in capillary-to-arteriole dilation, functional hyperemia in the brain, and memory. The fundamental defect in aged mutant animals was the depletion of the minor membrane phospholipid phosphatidylinositol 4,5 bisphosphate (PIP 2 ) in brain capillary endothelial cells, leading to the loss of inwardly rectifier K + (Kir2.1) channel activity. Blocking phosphatidylinositol-3-kinase (PI3K), an enzyme that diminishes the bioavailability of PIP 2 by converting it to phosphatidylinositol (3,4,5)-trisphosphate (PIP 3 ), restored Kir2.1 channel activity, capillary-to-arteriole dilation, and functional hyperemia. In longitudinal studies, chronic PI3K inhibition also improved the memory function of aged Col4a1 mutant mice. Our data suggest that PI3K inhibition is a viable therapeutic strategy for treating defective NVC and cognitive impairment associated with cSVD. One-sentence summary PI3K inhibition rescues neurovascular coupling defects in cerebral small vessel disease.
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9
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Yamasaki E, Ali S, Sanchez Solano A, Thakore P, Smith M, Wang X, Labelle-Dumais C, Gould DB, Earley S. Faulty TRPM4 channels underlie age-dependent cerebral vascular dysfunction in Gould syndrome. Proc Natl Acad Sci U S A 2023; 120:e2217327120. [PMID: 36693102 PMCID: PMC9945977 DOI: 10.1073/pnas.2217327120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Accepted: 12/27/2022] [Indexed: 01/25/2023] Open
Abstract
Gould syndrome is a rare multisystem disorder resulting from autosomal dominant mutations in the collagen-encoding genes COL4A1 and COL4A2. Human patients and Col4a1 mutant mice display brain pathology that typifies cerebral small vessel diseases (cSVDs), including white matter hyperintensities, dilated perivascular spaces, lacunar infarcts, microbleeds, and spontaneous intracerebral hemorrhage. The underlying pathogenic mechanisms are unknown. Using the Col4a1+/G394V mouse model, we found that vasoconstriction in response to internal pressure-the vascular myogenic response-is blunted in cerebral arteries from middle-aged (12 mo old) but not young adult (3 mo old) animals, revealing age-dependent cerebral vascular dysfunction. The defect in the myogenic response was associated with a significant decrease in depolarizing cation currents conducted by TRPM4 (transient receptor potential melastatin 4) channels in native cerebral artery smooth muscle cells (SMCs) isolated from mutant mice. The minor membrane phospholipid phosphatidylinositol 4,5 bisphosphate (PIP2) is necessary for TRPM4 activity. Dialyzing SMCs with PIP2 and selective blockade of phosphoinositide 3-kinase (PI3K), an enzyme that converts PIP2 to phosphatidylinositol (3, 4, 5)-trisphosphate (PIP3), restored TRPM4 currents. Acute inhibition of PI3K activity and blockade of transforming growth factor-beta (TGF-β) receptors also rescued the myogenic response, suggesting that hyperactivity of TGF-β signaling pathways stimulates PI3K to deplete PIP2 and impair TRPM4 channels. We conclude that age-related cerebral vascular dysfunction in Col4a1+/G394V mice is caused by the loss of depolarizing TRPM4 currents due to PIP2 depletion, revealing an age-dependent mechanism of cSVD.
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Affiliation(s)
- Evan Yamasaki
- Department of Pharmacology, Center for Molecular and Cellular Signaling in the Cardiovascular System, University of Nevada, Reno School of Medicine, Reno, NV89557-0318
| | - Sher Ali
- Department of Pharmacology, Center for Molecular and Cellular Signaling in the Cardiovascular System, University of Nevada, Reno School of Medicine, Reno, NV89557-0318
| | - Alfredo Sanchez Solano
- Department of Pharmacology, Center for Molecular and Cellular Signaling in the Cardiovascular System, University of Nevada, Reno School of Medicine, Reno, NV89557-0318
| | - Pratish Thakore
- Department of Pharmacology, Center for Molecular and Cellular Signaling in the Cardiovascular System, University of Nevada, Reno School of Medicine, Reno, NV89557-0318
| | - Megan Smith
- Departments of Ophthalmology, Institute for Human Genetics, UCSF School of Medicine, San Francisco, CA94158
| | - Xiaowei Wang
- Departments of Ophthalmology, Institute for Human Genetics, UCSF School of Medicine, San Francisco, CA94158
| | - Cassandre Labelle-Dumais
- Departments of Ophthalmology, Institute for Human Genetics, UCSF School of Medicine, San Francisco, CA94158
| | - Douglas B. Gould
- Departments of Ophthalmology, Institute for Human Genetics, UCSF School of Medicine, San Francisco, CA94158
- Department of Anatomy, Institute for Human Genetics, Cardiovascular Research Institute, Bakar Aging Research Institute, UCSF School of Medicine, San Francisco, CA94158
| | - Scott Earley
- Department of Pharmacology, Center for Molecular and Cellular Signaling in the Cardiovascular System, University of Nevada, Reno School of Medicine, Reno, NV89557-0318
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10
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Branyan K, Labelle-Dumais C, Wang X, Hayashi G, Lee B, Peltz Z, Gorman S, Li BQ, Mao M, Gould DB. Elevated TGFβ signaling contributes to cerebral small vessel disease in mouse models of Gould syndrome. Matrix Biol 2023; 115:48-70. [PMID: 36435425 PMCID: PMC10393528 DOI: 10.1016/j.matbio.2022.11.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2022] [Revised: 11/21/2022] [Accepted: 11/21/2022] [Indexed: 11/25/2022]
Abstract
Cerebral small vessel disease (CSVD) is a leading cause of stroke and vascular cognitive impairment and dementia. Studying monogenic CSVD can reveal pathways that are dysregulated in common sporadic forms of the disease and may represent therapeutic targets. Mutations in collagen type IV alpha 1 (COL4A1) and alpha 2 (COL4A2) cause highly penetrant CSVD as part of a multisystem disorder referred to as Gould syndrome. COL4A1 and COL4A2 form heterotrimers [a1α1α2(IV)] that are fundamental constituents of basement membranes. However, their functions are poorly understood and the mechanism(s) by which COL4A1 and COL4A2 mutations cause CSVD are unknown. We used histological, molecular, genetic, pharmacological, and in vivo imaging approaches to characterize central nervous system (CNS) vascular pathologies in Col4a1 mutant mouse models of monogenic CSVD to provide insight into underlying pathogenic mechanisms. We describe developmental CNS angiogenesis abnormalities characterized by impaired retinal vascular outgrowth and patterning, increased numbers of mural cells with abnormal morphologies, altered contractile protein expression in vascular smooth muscle cells (VSMCs) and age-related loss of arteriolar VSMCs in Col4a1 mutant mice. Importantly, we identified elevated TGFβ signaling as a pathogenic consequence of Col4a1 mutations and show that genetically suppressing TGFβ signaling ameliorated CNS vascular pathologies, including partial rescue of retinal vascular patterning defects, prevention of VSMC loss, and significant reduction of intracerebral hemorrhages in Col4a1 mutant mice aged up to 8 months. This study identifies a novel biological role for collagen α1α1α2(IV) as a regulator of TGFβ signaling and demonstrates that elevated TGFβ signaling contributes to CNS vascular pathologies caused by Col4a1 mutations. Our findings suggest that pharmacologically suppressing TGFβ signaling could reduce the severity of CSVD, and potentially other manifestations associated with Gould syndrome and have important translational implications that could extend to idiopathic forms of CSVD.
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Affiliation(s)
- Kayla Branyan
- Department of Ophthalmology, University of California, 555 Mission Bay Boulevard South, San Francisco, CA 94158, United States
| | - Cassandre Labelle-Dumais
- Department of Ophthalmology, University of California, 555 Mission Bay Boulevard South, San Francisco, CA 94158, United States
| | - Xiaowei Wang
- Department of Ophthalmology, University of California, 555 Mission Bay Boulevard South, San Francisco, CA 94158, United States
| | - Genki Hayashi
- Department of Ophthalmology, University of California, 555 Mission Bay Boulevard South, San Francisco, CA 94158, United States
| | - Bryson Lee
- Department of Ophthalmology, University of California, 555 Mission Bay Boulevard South, San Francisco, CA 94158, United States
| | - Zoe Peltz
- Department of Ophthalmology, University of California, 555 Mission Bay Boulevard South, San Francisco, CA 94158, United States
| | - Seán Gorman
- Department of Ophthalmology, University of California, 555 Mission Bay Boulevard South, San Francisco, CA 94158, United States
| | - Bo Qiao Li
- Department of Ophthalmology, University of California, 555 Mission Bay Boulevard South, San Francisco, CA 94158, United States
| | - Mao Mao
- Department of Ophthalmology, University of California, 555 Mission Bay Boulevard South, San Francisco, CA 94158, United States
| | - Douglas B Gould
- Department of Ophthalmology, University of California, 555 Mission Bay Boulevard South, San Francisco, CA 94158, United States; Department of Anatomy, Cardiovascular Research Institute, Bakar Aging Research Institute, and Institute for Human Genetics, University of California, San Francisco, United States.
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11
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Ishikawa Y, Taga Y, Coste T, Tufa SF, Keene DR, Mizuno K, Tournier-Lasserve E, Gould DB. Lysyl hydroxylase 3-mediated post-translational modifications are required for proper biosynthesis of collagen α1α1α2(IV). J Biol Chem 2022; 298:102713. [PMID: 36403858 PMCID: PMC9761383 DOI: 10.1016/j.jbc.2022.102713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Revised: 11/05/2022] [Accepted: 11/09/2022] [Indexed: 11/19/2022] Open
Abstract
Collagens are the most abundant proteins in the body and among the most biosynthetically complex. A molecular ensemble of over 20 endoplasmic reticulum resident proteins participates in collagen biosynthesis and contributes to heterogeneous post-translational modifications. Pathogenic variants in genes encoding collagens cause connective tissue disorders, including osteogenesis imperfecta, Ehlers-Danlos syndrome, and Gould syndrome (caused by mutations in COL4A1 and COL4A2), and pathogenic variants in genes encoding proteins required for collagen biosynthesis can cause similar but overlapping clinical phenotypes. Notably, pathogenic variants in lysyl hydroxylase 3 (LH3) cause a multisystem connective tissue disorder that exhibits pathophysiological features of collagen-related disorders. LH3 is a multifunctional collagen-modifying enzyme; however, its precise role(s) and substrate specificity during collagen biosynthesis has not been defined. To address this critical gap in knowledge, we generated LH3 KO cells and performed detailed quantitative and molecular analyses of collagen substrates. We found that LH3 deficiency severely impaired secretion of collagen α1α1α2(IV) but not collagens α1α1α2(I) or α1α1α1(III). Amino acid analysis revealed that LH3 is a selective LH for collagen α1α1α2(IV) but a general glucosyltransferase for collagens α1α1α2(IV), α1α1α2(I), and α1α1α1(III). Importantly, we identified rare variants that are predicted to be pathogenic in the gene encoding LH3 in two of 113 fetuses with intracranial hemorrhage-a cardinal feature of Gould syndrome. Collectively, our findings highlight a critical role of LH3 in α1α1α2(IV) biosynthesis and suggest that LH3 pathogenic variants might contribute to Gould syndrome.
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Affiliation(s)
- Yoshihiro Ishikawa
- Department of Ophthalmology, University of California San Francisco, School of Medicine, California, USA.
| | - Yuki Taga
- Nippi Research Institute of Biomatrix, Ibaraki, Japan
| | - Thibault Coste
- Université Paris Cité, Inserm Neurodiderot, AP-HP Paris, France
| | - Sara F Tufa
- Research Department, Shriners Hospital for Children, Portland, Oregon, USA
| | - Douglas R Keene
- Research Department, Shriners Hospital for Children, Portland, Oregon, USA
| | | | | | - Douglas B Gould
- Department of Ophthalmology, University of California San Francisco, School of Medicine, California, USA; Department Anatomy, Cardiovascular Research Institute, Bakar Aging Research Institute, and Institute for Human Genetics, University of California, San Francisco, California, USA.
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12
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Mao M, Labelle-Dumais C, Tufa SF, Keene DR, Gould DB. Elevated TGFβ signaling contributes to ocular anterior segment dysgenesis in Col4a1 mutant mice. Matrix Biol 2022; 110:151-173. [PMID: 35525525 PMCID: PMC10410753 DOI: 10.1016/j.matbio.2022.05.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 04/08/2022] [Accepted: 05/02/2022] [Indexed: 10/18/2022]
Abstract
Ocular anterior segment dysgenesis (ASD) refers to a collection of developmental disorders affecting the anterior structures of the eye. Although a number of genes have been implicated in the etiology of ASD, the underlying pathogenetic mechanisms remain unclear. Mutations in genes encoding collagen type IV alpha 1 (COL4A1) and alpha 2 (COL4A2) cause Gould syndrome, a multi-system disorder that often includes ocular manifestations such as ASD and glaucoma. COL4A1 and COL4A2 are abundant basement membrane proteins that provide structural support to tissues and modulate signaling through interactions with other extracellular matrix proteins, growth factors, and cell surface receptors. In this study, we used a combination of histological, molecular, genetic and pharmacological approaches to demonstrate that altered TGFβ signaling contributes to ASD in mouse models of Gould syndrome. We show that TGFβ signaling was elevated in anterior segments from Col4a1 mutant mice and that genetically reducing TGFβ signaling partially prevented ASD. Notably, we identified distinct roles for TGFβ1 and TGFβ2 in ocular defects observed in Col4a1 mutant mice. Importantly, we show that pharmacologically promoting type IV collagen secretion or reducing TGFβ signaling ameliorated ocular pathology in Col4a1 mutant mice. Overall, our findings demonstrate that altered TGFβ signaling contributes to COL4A1-related ocular dysgenesis and implicate this pathway as a potential therapeutic target for the treatment of Gould syndrome.
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Affiliation(s)
- Mao Mao
- Department of Ophthalmology, University of California, San Francisco, San Francisco, CA 94143, United States
| | - Cassandre Labelle-Dumais
- Department of Ophthalmology, University of California, San Francisco, San Francisco, CA 94143, United States
| | - Sara F Tufa
- Shriners Children's, Micro-Imaging Center, Portland, Oregon 97239, United States
| | - Douglas R Keene
- Shriners Children's, Micro-Imaging Center, Portland, Oregon 97239, United States
| | - Douglas B Gould
- Department of Ophthalmology, University of California, San Francisco, San Francisco, CA 94143, United States; Department of Anatomy, University of California, San Francisco, San Francisco, CA 94143, United States; Institute for Human Genetics, University of California, San Francisco, San Francisco, CA 94143, United States; Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA 94143, United States; Bakar Aging Research Institute, University of California, San Francisco, San Francisco, CA 94143, United States.
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13
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Yin M, Hiam KJ, Proekt I, Chan J, Hu Y, Lowell CA, Gould DB, Spitzer M, Anderson MS, DeFranco AL. Development of uveitis in a mouse model of spontaneous autoimmunity correlates with frequency of autoantigen-specific regulatory T cells. The Journal of Immunology 2022. [DOI: 10.4049/jimmunol.208.supp.44.07] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Abstract
B6 AireGW/+Lyn−/− mice are a model of spontaneously autoimmunity in which 50% of mice develop uveitis by 9 weeks of age, and the remaining mice do not develop autoimmunity. Uveitis results from CD4+ T cells responding to the retina protein interphotoreceptor retinoid-binding protein (IRBP). To define cellular mechanisms that determine whether mice developed autoimmunity or not, we did single-cell RNA sequencing (scRNA-seq) of eye-draining lymph node (LN) CD4+ T cells that recognize the P2 epitope of IRBP (amino acid 271–290). Uniform manifold approximation and projection (UMAP) analysis showed that these CD4+ T cells included distinct subsets that were Ly6c1hi, Pdcd1hi and Treg, with the Treg population being overrepresented in the mice without disease. Pseudotime analysis indicated that the Ly6c1hi T cell subset represented an earlier stage in activation, whereas the Pdcd1hi subset represented a later stage. The two types of effector CD4+ T cells of mice with and without disease largely clustered together relative to their gene expression. Similar analysis of P2-specific CD4+ T cells from retinas with inflammation indicated a progression from proliferative (Mki67hi) cells to a Lag3hi subset to a Lag3hi/Pdcd1hi subset. In mice without uveitis, depletion of Treg by treatment of AireGW/+Lyn−/− Foxp3DTR+/Y mice with diphtheria toxin resulted in rapid expansion of P2–specific CD4+T cells in the draining LN, development of inflammation in the retina, and immune activation in other locations leading to lethality. Ongoing experiments are further testing the hypothesis that the fraction of Treg within the IRBP-specific CD4+ T cells determines whether or not these genetically susceptible mice develop eye-specific autoimmunity.
Supported by AI138479
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Affiliation(s)
- Mianmian Yin
- 1Microbiology and Immunology, University of California, San Francisco
| | - Kamir J Hiam
- 2Departments of Otolaryngology and Microbiology & Immunology, Helen Diller Family Comprehensive Cancer Center, Parker Institute for Cancer Immunotherapy, Chan Zuckerberg Biohub, University of California, San Francisco
| | - Irina Proekt
- 3Diabetes Center, University of California, San Francisco
| | - Jackie Chan
- 1Microbiology and Immunology, University of California, San Francisco
| | - Yongmei Hu
- 4Department of Laboratory Medicine, University of California, San Francisco
| | - Clifford A Lowell
- 4Department of Laboratory Medicine, University of California, San Francisco
| | - Douglas B Gould
- 5Departments of Ophthalmology and Anatomy, Institute for Human Genetics, University of California, San Francisco
| | - Matthew Spitzer
- 2Departments of Otolaryngology and Microbiology & Immunology, Helen Diller Family Comprehensive Cancer Center, Parker Institute for Cancer Immunotherapy, Chan Zuckerberg Biohub, University of California, San Francisco
| | - Mark S Anderson
- 3Diabetes Center, University of California, San Francisco
- 6Department of Medicine, University of California, San Francisco
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14
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Yin M, Smith JA, Chou M, Chan J, Hu Y, Lowell CA, Gould DB, Anderson MS, DeFranco AL. Autoantigen specific T-cell receptor induces organ-specific autoimmunity by escaping T cell negative selection. The Journal of Immunology 2022. [DOI: 10.4049/jimmunol.208.supp.104.02] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Abstract
Previously we reported a new model of spontaneous autoimmune uveitis in which mice with a hypomorphic mutation of Aire (AireGW/+) are combined with deletion of Lyn. The key autoantigen in this model is interphotoreceptor retinoid-binding protein (IRBP) as AireGW/+Lyn−/−IRBP−/− mice failed to develop uveitis. We performed single-cell RNA-seq with TCR sequencing for IRBP 271–290 (P2)-specific CD4+ T cells from eye-draining lymph nodes (LN) of these mice with and without uveitis. Both mice showed an expansion of these T cells in eye-draining LNs, but it was greater in mice with disease. A remarkable clonal diversity of TCRs was seen. Expansions of particular T cell clonotypes were more evident in LN of mice with disease, and even greater in the retinas of mice with disease. We reconstituted several P2–specific TCR clonotypes in a T cell hybridoma line and verified their specificity. One of the TCRs was expressed in thymocytes by retroviral transduction of bone marrow stem cells from Rag2−/− mice and transplanted into WT or AireGW/+ recipient mice. Remarkably, the small residual expression of IRBP in the thymus of AireGW/+ mice was sufficient to induce substantial negative selection of thymocytes with this TCR. In addition, we generated TCR transgenic mice with this TCR clonotype. The TCR transgenic mice spontaneously developed uveitis with expansion of P2-specific CD4+ T cells. Combined with AireGW/+ or IRBP−/−, there were more P2-specific CD4+ T cells in the thymus of TCR transgenic mice. Thus, suboptimal Aire function in AireGW/+Lyn−/− mice results in a partial defect in negative selection of T cells recognizing IRBP in the thymus, promoting development of uveitis. This disease is accelerated in mice expressing a TCR transgene recognizing IRBP.
Supported by AI138479
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Affiliation(s)
- Mianmian Yin
- 1Microbiology and Immunology, University of California, San Francisco
| | | | - Marissa Chou
- 1Microbiology and Immunology, University of California, San Francisco
| | - Jackie Chan
- 1Microbiology and Immunology, University of California, San Francisco
| | - Yongmei Hu
- 3Department of Laboratory Medicine, University of California, San Francisco
| | - Clifford A Lowell
- 3Department of Laboratory Medicine, University of California, San Francisco
| | - Douglas B Gould
- 4Departments of Ophthalmology and Anatomy, Institute for Human Genetics, University of California, San Francisco
| | - Mark S Anderson
- 2Diabetes Center, University of California, San Francisco
- 5Department of Medicine, University of California, San Francisco
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15
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Coste T, Vincent-Delorme C, Stichelbout M, Devisme L, Gelot A, Deryabin I, Pelluard F, Aloui C, Leutenegger AL, Jouannic JM, Héron D, Gould DB, Tournier-Lasserve E. COL4A1/COL4A2 and inherited platelet disorder gene variants in fetuses showing intracranial hemorrhage. Prenat Diagn 2022; 42:601-610. [PMID: 35150448 PMCID: PMC10434296 DOI: 10.1002/pd.6113] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 01/12/2022] [Accepted: 02/09/2022] [Indexed: 11/08/2022]
Abstract
BACKGROUND Variants of COL4A1/COL4A2 genes have been reported in fetal intracranial hemorrhage (ICH) cases but their prevalence and characteristics have not been established in a large series of fetuses. Fetal neonatal alloimmune thrombocytopenia is a major acquired ICH factor but the prevalence and characteristics of inherited platelet disorder (IPD) gene variants leading to thrombocytopenia are unknown. Herein, we screened COL4A1/COL4A2 and IPD genes in a large series of ICH fetuses. METHODS A cohort of 194 consecutive ICH fetuses were first screened for COL4A1/COL4A2 variants. We manually curated a list of 64 genes involved in IPD and investigated them in COL4A1/COL4A2 negative fetuses, using exome sequencing data from 101 of these fetuses. RESULT Pathogenic variants of COL4A1/COL4A2 genes were identified in 36 fetuses (19%). They occurred de novo in 70% of the 32 fetuses for whom parental DNA was available. Pathogenic variants in two megakaryopoiesis genes (MPL and MECOM genes) were identified in two families with recurrent and severe fetal ICH, with variable extraneurological pathological features. CONCLUSION Our study emphasizes the genetic heterogeneity of fetal ICH and the need to screen both COL4A1/COL4A2 and IPD genes in the etiological investigation of fetal ICH to allow proper genetic counseling.
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Affiliation(s)
- Thibault Coste
- AP-HP, Service de génétique moléculaire Neurovasculaire, Hôpital Saint-Louis, Paris, France
- Université de Paris, INSERM UMR-1141 Neurodiderot, Paris, France
| | | | | | | | - Antoinette Gelot
- APHP, Service de fœtopathologie, Hôpital Trousseau, Paris, France
| | - Igor Deryabin
- APHP, Service de fœtopathologie, Hôpital Trousseau, Paris, France
| | - Fanny Pelluard
- University Bordeaux, INSERM, BaRITOn, U1053, Bordeaux, France
| | - Chaker Aloui
- Université de Paris, INSERM UMR-1141 Neurodiderot, Paris, France
| | | | - Jean-Marie Jouannic
- APHP Sorbonne Université, Service de médecine fœtale, Hôpital Trousseau, Paris, France
| | - Delphine Héron
- AP-HP, Service de génétique clinique, Hôpital de la Pitié-Salpêtrière, Paris, France
| | - Douglas B Gould
- Department of Ophthalmology, University of California San Francisco, San Francisco, California, USA
| | - Elisabeth Tournier-Lasserve
- AP-HP, Service de génétique moléculaire Neurovasculaire, Hôpital Saint-Louis, Paris, France
- Université de Paris, INSERM UMR-1141 Neurodiderot, Paris, France
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16
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Whitehead SN, Bruno A, Burns JM, Carmichael ST, Csiszar A, Edwards JD, Elahi FM, Faraco G, Gould DB, Gustafson DR, Hachinski V, Rosenberg G, Sorond FA, Shih AY, Tse KH, Ungvari Z, Wilcock DM, Zuloaga KL, Barone FC. Expanding the horizon of research into the pathogenesis of the white matter diseases: Proceedings of the 2021 Annual Workshop of the Albert Research Institute for White Matter and Cognition. GeroScience 2022; 44:25-37. [PMID: 34606040 PMCID: PMC8488071 DOI: 10.1007/s11357-021-00461-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 09/14/2021] [Indexed: 12/14/2022] Open
Abstract
White matter pathologies are critically involved in the etiology of vascular cognitive impairment-dementia (VCID), Alzheimer's disease (AD), and Alzheimer's disease and related diseases (ADRD), and therefore need to be considered a treatable target ( Roseborough A, Hachinski V, Whitehead S. White matter degeneration - a treatable target? Roseborough et al. JAMA Neurol [Internet]. 2020 Apr 27;77(7):793-4, [1] . To help address this often-missed area of research, several workshops have been sponsored by the Leo and Anne Albert Charitable Trust since 2015, resulting in the incorporation of "The Albert Research Institute for White Matter and Cognition" in 2020. The first annual "Institute" meeting was held virtually on March 3-4, 2021. The Institute provides a forum and workspace for communication and support of the advancement of white matter science and research to better understand the evolution and prevention of dementia. It serves as a platform for young investigator development, to introduce new data and debate biology mechanisms and new ideas, and to encourage and support new research collaborations and directions to clarify how white matter changes, with other genetic and health risk factors, contribute to cognitive impairment. Similar to previous Albert Trust-sponsored workshops (Barone et al. in J Transl Med 14:1-14, [2]; Sorond et al. in GeroScience 42:81-96, [3]), established expert investigators were identified and invited to present. Opportunities to attend and present were also extended by invitation to talented research fellows and younger scientists. Also, updates on institute-funded research collaborations were provided and discussed. The summary that follows is a synopsis of topics and discussion covered in the workshop.
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Affiliation(s)
- Shawn N Whitehead
- Department of Anatomy and Cell Biology, Western University, London, ON, N6A 3K7, Canada.
| | - Askiel Bruno
- Department of Neurology, Medical College of Georgia at Augusta University, Augusta, GA, 30912, USA
| | - Jeffrey M Burns
- Department of Neurology, University of Kansas Medical Center, Kansas City, KS, USA
| | - S Thomas Carmichael
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA, 90095, USA
| | - Anna Csiszar
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Department of Translational Medicine, Semmelweis University, Budapest, Hungary
| | - Jodi D Edwards
- University of Ottawa Heart Institute, Ottawa, Canada
- School of Epidemiology and Public Health, University of Ottawa, Ottawa, K1G 5Z3, Canada
| | - Fanny M Elahi
- Memory and Aging Center, UCSF Weill Institute for Neurosciences, 675 Nelson Rising Lane, Suite 190, San Francisco, CA, 94158, USA
| | - Giuseppe Faraco
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, 10065, USA
| | - Douglas B Gould
- Departments of Ophthalmology and Anatomy, and Institute for Human Genetics, School of Medicine, University of California, San Francisco, 94143, USA
| | - Deborah R Gustafson
- Department of Neurology, Section for NeuroEpidemiology, State University of New York Downstate Health Sciences University, New York, Brooklyn, 11203, USA
| | - Vladimir Hachinski
- Department of Clinical Neurological Sciences, Western University, London, ON, N6A 5C1, Canada
| | - Gary Rosenberg
- UNM Health Sciences Center, University of New Mexico, Albuquerque, NM, 87106, USA
| | | | - Andy Y Shih
- Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute; Department of Pediatrics; Department of Bioengineering, University of Washington, Seattle, WA, USA
| | - Kai Hei Tse
- Department of Health Technology and Informatics, The Hong Kong Polytechnic University, Kowloon, Hong Kong
| | - Zoltan Ungvari
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Department of Translational Medicine, Semmelweis University, Budapest, Hungary
| | - Donna M Wilcock
- Sanders-Brown Center on Aging; Department of Neurology, Department of Behavioral Science, University of Kentucky, Lexington, KY, 40536, USA
| | - Kristen L Zuloaga
- Department of Neuroscience and Experimental Therapeutics, Albany Medical College, Albany, NY, 12208, USA
| | - Frank C Barone
- Department of Neurology, SUNY Downstate Health Sciences University, Brooklyn, NY, 11203, USA
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17
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Yin M, Hiam K, Proekt I, Chan J, Hu Y, Lowell CA, Gould DB, Anderson MS, DeFranco AL. Correlation of autoantigen-specific Treg frequency with development of spontaneous organ-specific autoimmunity in a mouse model of uveitis. The Journal of Immunology 2021. [DOI: 10.4049/jimmunol.206.supp.51.05] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
Abstract
About 50% of AireGW/+Lyn−/− mice developed autoimmune uveitis, and this was accompanied by the expansion of interphotoreceptor retinoid-binding protein (IRBP) specific CD4+T cells. Moreover, the response to IRBP was necessary for disease initiation, as deletion of IRBP prevented uveitis. Mass cytometry (CyTOF) analysis of CD4+T cells in the retina of the mice with uveitis identified activated T cell subsets characterized as Ly6Chi effectors, PD-1hi effectors, and Treg. To study cellular mechanisms that promoted development of uveitis, we did single-cell RNA sequencing (scRNA-seq) of eye-draining lymph node (LN) CD4+T cells that recognize the P2 epitope of IRBP (amino acid 271–290). Uniform manifold approximation and projection (UMAP) analysis showed that these CD4+T cells included distinct subsets that were Ly6c1hi , Pdcd1hi and Treg, with the Treg population being overrepresented in the mice without disease. Pseudotime analysis indicated that the Ly6c1hi T cell subset represented an earlier stage in activation, whereas the Pdcd1hi subset represented a later stage. Similar analysis of P2–specific CD4+T cells from the retina of mice with uveitis identified 6 subsets of P2-specific T cells, and was largely consistent with the CyTOF analysis of total CD4+ T cells from the retina. Pseudotime analysis indicated that toward the earlier time were cells characterized by being proliferative (Mki67hi), followed by a Lag3hi subset and at other end of the pseudotime axis by a Lag3hi / Pdcd1hi subset. Our results are consistent with the hypothesis that the fraction of Treg within the IRBP-specific CD4+ T cells in the draining LN determines whether these genetically susceptible mice develop eye-specific autoimmunity or are protected.
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Affiliation(s)
| | - Kamir Hiam
- 2Otolaryngology and Microbiology & Immunology, Helen Diller Family Comprehensive Cancer Ctr., Parker Inst. for Cancer Immunotherapy, Chan Zuckerberg Biohub, UCSF
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18
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Yin M, Smith JA, Chou M, Chan J, Hu Y, Lowell CA, Gould DB, Anderson MS, DeFranco AL. T-cell receptor repertoire of mice with organ-specific autoimmunity resulting from a partial defect in T cell negative selection and dendritic cell enhancement. The Journal of Immunology 2021. [DOI: 10.4049/jimmunol.206.supp.51.06] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
Abstract
Previously, we reported a new genetic model of spontaneous autoimmune disease in which mice with a hypomorphic mutation of Aire (AireGW/+) combined with deletion of Lyn in dendritic cells develop autoimmune uveitis with a 50% penetrance. Here we demonstrate that a key autoantigen in this model is interphotoreceptor retinoid-binding protein (IRBP) as AireGW/+ Lyn−/− IRBP−/− mice failed to develop uveitis. The expansion of CD4+ T cells recognizing amino acids 271–290 (“P2”) of IRBP correlated strongly with autoimmune disease in mice with intact IRBP. To study the role of these T cells, we did single-cell RNA-seq with TCR sequencing for P2-specific CD4+ T cells isolated from eye-draining lymph nodes (LN) of AireGW/+ Lyn−/− mice with and without uveitis. Both mice showed an expansion of these T cells in eye-draining LNs, but it was greater in mice with disease. A remarkable clonal diversity of TCRs was seen, with some sharing of TCR Vα or Vβ sequences. Expansions of particular T cell clonotypes were more evident in LN of mice with disease, and even greater in the retinas of mice with disease. We reconstituted several P2–specific TCR clonotypes in a T cell hybridoma line and verified their specificity. One of the TCR clonotypes was expressed in developing thymocytes by retroviral transduction of bone marrow stem cells from Rag2−/− mice and transplanted into WT or AireGW/+ recipient mice. Remarkably, the small residual expression of IRBP in the thymus of AireGW/+ mice was sufficient to induce substantial negative selection of thymocytes with this TCR clonotype. Thus, deficiency of negative selection of P2 tetramer–specific TCR promotes the development of uveitis in AireGW/+ Lyn−/− mice, even if negative selection is only partly compromised.
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19
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Mao M, Popli T, Jeanne M, Hoff K, Sen S, Gould DB. Identification of fibronectin 1 as a candidate genetic modifier in a Col4a1 mutant mouse model of Gould syndrome. Dis Model Mech 2021; 14:dmm048231. [PMID: 34424299 PMCID: PMC8106953 DOI: 10.1242/dmm.048231] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Accepted: 03/02/2021] [Indexed: 12/12/2022] Open
Abstract
Collagen type IV alpha 1 and alpha 2 (COL4A1 and COL4A2) are major components of almost all basement membranes. COL4A1 and COL4A2 mutations cause a multisystem disorder that can affect any organ but typically involves the cerebral vasculature, eyes, kidneys and skeletal muscles. In recent years, patient advocacy and family support groups have united under the name of Gould syndrome. The manifestations of Gould syndrome are highly variable, and animal studies suggest that allelic heterogeneity and genetic context contribute to the clinical variability. We previously characterized a mouse model of Gould syndrome caused by a Col4a1 mutation in which the severities of ocular anterior segment dysgenesis (ASD), myopathy and intracerebral hemorrhage (ICH) were dependent on genetic background. Here, we performed a genetic modifier screen to provide insight into the mechanisms contributing to Gould syndrome pathogenesis and identified a single locus [modifier of Gould syndrome 1 (MoGS1)] on Chromosome 1 that suppressed ASD. A separate screen showed that the same locus ameliorated myopathy. Interestingly, MoGS1 had no effect on ICH, suggesting that this phenotype could be mechanistically distinct. We refined the MoGS1 locus to a 4.3 Mb interval containing 18 protein-coding genes, including Fn1, which encodes the extracellular matrix component fibronectin 1. Molecular analysis showed that the MoGS1 locus increased Fn1 expression, raising the possibility that suppression is achieved through a compensatory extracellular mechanism. Furthermore, we found evidence of increased integrin-linked kinase levels and focal adhesion kinase phosphorylation in Col4a1 mutant mice that is partially restored by the MoGS1 locus, implicating the involvement of integrin signaling. Taken together, our results suggest that tissue-specific mechanistic heterogeneity contributes to the variable expressivity of Gould syndrome and that perturbations in integrin signaling may play a role in ocular and muscular manifestations.
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Affiliation(s)
- Mao Mao
- Department of Ophthalmology, University of California San Francisco, San Francisco, CA 94143, USA
| | - Tanav Popli
- Department of Ophthalmology, University of California San Francisco, San Francisco, CA 94143, USA
| | - Marion Jeanne
- Department of Ophthalmology, University of California San Francisco, San Francisco, CA 94143, USA
| | - Kendall Hoff
- Department of Ophthalmology, University of California San Francisco, San Francisco, CA 94143, USA
| | - Saunak Sen
- Department of Epidemiology and Biostatistics, University of California San Francisco, San Francisco, CA 94143, USA
- Institute of Human Genetics, University of California San Francisco, San Francisco, CA 94143, USA
- Department of Preventive Medicine, University of Tennessee Health Science Center, 66 North Pauline St, Memphis, TN 38163, USA
| | - Douglas B. Gould
- Department of Ophthalmology, University of California San Francisco, San Francisco, CA 94143, USA
- Institute of Human Genetics, University of California San Francisco, San Francisco, CA 94143, USA
- Department of Anatomy, University of California San Francisco, San Francisco, CA 94143, USA
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20
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Ishikawa Y, Taga Y, Zientek K, Mizuno N, Salo AM, Semenova O, Tufa SF, Keene DR, Holden P, Mizuno K, Gould DB, Myllyharju J, Bächinger HP. Type I and type V procollagen triple helix uses different subsets of the molecular ensemble for lysine posttranslational modifications in the rER. J Biol Chem 2021; 296:100453. [PMID: 33631195 PMCID: PMC7988497 DOI: 10.1016/j.jbc.2021.100453] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 02/12/2021] [Accepted: 02/19/2021] [Indexed: 11/25/2022] Open
Abstract
Collagen is the most abundant protein in humans. It has a characteristic triple-helix structure and is heavily posttranslationally modified. The complex biosynthesis of collagen involves processing by many enzymes and chaperones in the rough endoplasmic reticulum. Lysyl hydroxylase 1 (LH1) is required to hydroxylate lysine for cross-linking and carbohydrate attachment within collagen triple helical sequences. Additionally, a recent study of prolyl 3-hydroxylase 3 (P3H3) demonstrated that this enzyme may be critical for LH1 activity; however, the details surrounding its involvement remain unclear. If P3H3 is an LH1 chaperone that is critical for LH1 activity, P3H3 and LH1 null mice should display a similar deficiency in lysyl hydroxylation. To test this hypothesis, we compared the amount and location of hydroxylysine in the triple helical domains of type V and I collagen from P3H3 null, LH1 null, and wild-type mice. The amount of hydroxylysine in type V collagen was reduced in P3H3 null mice, but surprisingly type V collagen from LH1 null mice contained as much hydroxylysine as type V collagen from wild-type mice. In type I collagen, our results indicate that LH1 plays a global enzymatic role in lysyl hydroxylation. P3H3 is also involved in lysyl hydroxylation, particularly at cross-link formation sites, but is not required for all lysyl hydroxylation sites. In summary, our study suggests that LH1 and P3H3 likely have two distinct mechanisms to recognize different collagen types and to distinguish cross-link formation sites from other sites in type I collagen.
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Affiliation(s)
- Yoshihiro Ishikawa
- Department of Biochemistry and Molecular Biology, Oregon Health & Science University, Portland, Oregon, USA; Research Department, Shriners Hospital for Children, Portland, Oregon, USA; Department of Ophthalmology, University of California San Francisco, School of Medicine, San Francisco, California, USA.
| | - Yuki Taga
- Nippi Research Institute of Biomatrix, Ibaraki, Japan
| | - Keith Zientek
- Research Department, Shriners Hospital for Children, Portland, Oregon, USA
| | - Nobuyo Mizuno
- Research Department, Shriners Hospital for Children, Portland, Oregon, USA
| | - Antti M Salo
- Oulu Center for Cell-Matrix Research, Biocenter Oulu and Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
| | - Olesya Semenova
- Research Department, Shriners Hospital for Children, Portland, Oregon, USA
| | - Sara F Tufa
- Research Department, Shriners Hospital for Children, Portland, Oregon, USA
| | - Douglas R Keene
- Research Department, Shriners Hospital for Children, Portland, Oregon, USA
| | - Paul Holden
- Research Department, Shriners Hospital for Children, Portland, Oregon, USA
| | | | - Douglas B Gould
- Department of Ophthalmology, University of California San Francisco, School of Medicine, San Francisco, California, USA; Department of Anatomy, University of California, San Francisco, School of Medicine, San Francisco, California USA
| | - Johanna Myllyharju
- Oulu Center for Cell-Matrix Research, Biocenter Oulu and Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
| | - Hans Peter Bächinger
- Department of Biochemistry and Molecular Biology, Oregon Health & Science University, Portland, Oregon, USA
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21
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Syx D, Ishikawa Y, Gebauer J, Boudko SP, Guillemyn B, Van Damme T, D’hondt S, Symoens S, Nampoothiri S, Gould DB, Baumann U, Bächinger HP, Malfait F. Aberrant binding of mutant HSP47 affects posttranslational modification of type I collagen and leads to osteogenesis imperfecta. PLoS Genet 2021; 17:e1009339. [PMID: 33524049 PMCID: PMC7877763 DOI: 10.1371/journal.pgen.1009339] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Revised: 02/11/2021] [Accepted: 01/05/2021] [Indexed: 12/21/2022] Open
Abstract
Heat shock protein 47 (HSP47), encoded by the SERPINH1 gene, is a molecular chaperone essential for correct folding of collagens. We report a homozygous p.(R222S) substitution in HSP47 in a child with severe osteogenesis imperfecta leading to early demise. p.R222 is a highly conserved residue located within the collagen interacting surface of HSP47. Binding assays show a significantly reduced affinity of HSP47-R222S for type I collagen. This altered interaction leads to posttranslational overmodification of type I procollagen produced by dermal fibroblasts, with increased glycosylation and/or hydroxylation of lysine and proline residues as shown by mass spectrometry. Since we also observed a normal intracellular folding and secretion rate of type I procollagen, this overmodification cannot be explained by prolonged exposure of the procollagen molecules to the modifying hydroxyl- and glycosyltransferases, as is commonly observed in other types of OI. We found significant upregulation of several molecular chaperones and enzymes involved in procollagen modification and folding on Western blot and RT-qPCR. In addition, we showed that an imbalance in binding of HSP47-R222S to unfolded type I collagen chains in a gelatin sepharose pulldown assay results in increased binding of other chaperones and modifying enzymes. The elevated expression and binding of this molecular ensemble to type I procollagen suggests a compensatory mechanism for the aberrant binding of HSP47-R222S, eventually leading to overmodification of type I procollagen chains. Together, these results illustrate the importance of HSP47 for proper posttranslational modification and provide insights into the molecular pathomechanisms of the p.(R222S) alteration in HSP47, which leads to a severe OI phenotype. Heat shock protein 47 (HSP47) is essential for correct collagen folding. We report a homozygous p.(R222S) substitution in HSP47 in a child with severe osteogenesis imperfecta. The highly conserved p.R222 residue is located within the collagen interacting surface and HSP47-R222S shows a significantly reduced affinity for type I collagen. This altered interaction leads to posttranslational overmodification of type I procollagen. In contrast to other types of OI, this overmodification is not caused by prolonged exposure of procollagen to modifying enzymes, since the intracellular folding rate of type I procollagen appears to be normal. We show significant upregulation of several molecular chaperones and collagen-modifying enzymes and increased binding of several of these molecules to unfolded type I collagen chains upon abnormal HSP47-R222S binding. This suggests a compensatory mechanism for aberrant HSP47-R222S binding, eventually leading to overmodification of type I procollagen chains, and underscores the importance of HSP47 for proper posttranslational modification.
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Affiliation(s)
- Delfien Syx
- Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium
| | - Yoshihiro Ishikawa
- Department of Biochemistry and Molecular Biology, Oregon Health & Science University, Portland, Oregon, United States of America
- Department of Ophthalmology, UCSF School of Medicine, San Francisco, California, United States of America
| | - Jan Gebauer
- Institute of Biochemistry, University of Cologne, Cologne, Germany
| | - Sergei P. Boudko
- Department of Biochemistry and Molecular Biology, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Brecht Guillemyn
- Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium
| | - Tim Van Damme
- Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium
| | - Sanne D’hondt
- Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium
| | - Sofie Symoens
- Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium
| | - Sheela Nampoothiri
- Amrita Institute of Medical Sciences and Research Center, Cochin, Kerala, India
| | - Douglas B. Gould
- Department of Ophthalmology, UCSF School of Medicine, San Francisco, California, United States of America
- Department of Anatomy, Institute for Human Genetics, UCSF School of Medicine, San Francisco, California, United States of America
| | - Ulrich Baumann
- Institute of Biochemistry, University of Cologne, Cologne, Germany
| | - Hans Peter Bächinger
- Department of Biochemistry and Molecular Biology, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Fransiska Malfait
- Center for Medical Genetics, Ghent University Hospital, Ghent, Belgium
- * E-mail:
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22
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Labelle-Dumais C, Schuitema V, Hayashi G, Hoff K, Gong W, Dao DQ, Ullian EM, Oishi P, Margeta M, Gould DB. COL4A1 Mutations Cause Neuromuscular Disease with Tissue-Specific Mechanistic Heterogeneity. Am J Hum Genet 2019; 104:847-860. [PMID: 31051113 DOI: 10.1016/j.ajhg.2019.03.007] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Accepted: 03/05/2019] [Indexed: 01/18/2023] Open
Abstract
Collagen type IV alpha 1 and alpha 2 chains form heterotrimers ([α1(IV)]2α2(IV)) that represent a fundamental basement membrane constituent. Dominant COL4A1 and COL4A2 mutations cause a multisystem disorder that is marked by clinical heterogeneity and variable expressivity and that is generally characterized by the presence of cerebrovascular disease with ocular, renal, and muscular involvement. Despite the fact that muscle pathology is reported in up to one-third of individuals with COL4A1 and COL4A2 mutations and in animal models with mutations in COL4A1 and COL4A2 orthologs, the pathophysiological mechanisms underlying COL4A1-related myopathy are unknown. In general, mutations are thought to impair [α1(IV)]2α2(IV) secretion. Whether pathogenesis results from intracellular retention, extracellular deficiency, or the presence of mutant proteins in basement membranes represents an important gap in knowledge and a major obstacle for developing targeted interventions. We report that Col4a1 mutant mice develop progressive neuromuscular pathology that models human disease. We demonstrate that independent muscular, neural, and vascular insults contribute to neuromyopathy and that there is mechanistic heterogeneity among tissues. Importantly, we provide evidence of a COL4A1 functional subdomain with disproportionate significance for tissue-specific pathology and demonstrate that a potential therapeutic strategy aimed at promoting [α1(IV)]2α2(IV) secretion can ameliorate or exacerbate myopathy in a mutation-dependent manner. These data have important translational implications for prediction of clinical outcomes based on genotype, development of mechanism-based interventions, and genetic stratification for clinical trials. Collectively, our data underscore the importance of the [α1(IV)]2α2(IV) network as a multifunctional signaling platform and show that allelic and tissue-specific mechanistic heterogeneities contribute to the variable expressivity of COL4A1 and COL4A2 mutations.
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23
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Hayashi G, Labelle-Dumais C, Gould DB. Use of sodium 4-phenylbutyrate to define therapeutic parameters for reducing intracerebral hemorrhage and myopathy in Col4a1 mutant mice. Dis Model Mech 2018; 11:dmm.034157. [PMID: 29895609 PMCID: PMC6078406 DOI: 10.1242/dmm.034157] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Accepted: 05/31/2018] [Indexed: 12/24/2022] Open
Abstract
Collagen type IV alpha 1 (COL4A1) and alpha 2 (COL4A2) form heterotrimers that constitute a major component of nearly all basement membranes. COL4A1 and COL4A2 mutations cause a multisystem disorder that includes variable cerebrovascular and skeletal muscle manifestations. The pathogenicity of COL4A1 and COL4A2 mutations is generally attributed to impaired secretion into basement membranes. Sodium 4-phenylbutyrate (4PBA) is a US Food and Drug Administration-approved drug that promotes mutant heterotrimer secretion in vitro and in vivo. Here, we use different 4PBA treatment paradigms to define therapeutic parameters for preventing cerebrovascular and muscular pathologies in Col4a1 mutant mice. We show the efficacy of long-term 4PBA treatment in reducing the severity of intracerebral hemorrhages (ICHs) in Col4a1 mutant mice aged up to 8 months. In addition, we demonstrate that maximal efficacy of 4PBA on ICH and myopathy was achieved when treatment was initiated prenatally, whereby even transient 4PBA administration had lasting benefits after being discontinued. Importantly, postnatal treatment with 4PBA also reduced ICH and skeletal myopathy severities in Col4a1 mutant mice, which has significant clinical implications for patients with COL4A1 and COL4A2 mutations. This article has an associated First Person interview with the first author of the paper. Summary:COL4A1 mutations cause a multisystem disorder by impairing secretion of COL4A1/A2 heterotrimers. We define parameters for reducing stroke and myopathy in Col4a1 mutant mice by pharmacologically promoting heterotrimer secretion.
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Affiliation(s)
- Genki Hayashi
- Department of Ophthalmology, Department of Anatomy, Institute for Human Genetics, University of California, San Francisco, CA 94143-0730, USA
| | - Cassandre Labelle-Dumais
- Department of Ophthalmology, Department of Anatomy, Institute for Human Genetics, University of California, San Francisco, CA 94143-0730, USA
| | - Douglas B Gould
- Department of Ophthalmology, Department of Anatomy, Institute for Human Genetics, University of California, San Francisco, CA 94143-0730, USA
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24
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Protas ME, Weh E, Footz T, Kasberger J, Baraban SC, Levin AV, Katz LJ, Ritch R, Walter MA, Semina EV, Gould DB. Mutations of conserved non-coding elements of PITX2 in patients with ocular dysgenesis and developmental glaucoma. Hum Mol Genet 2017; 26:3630-3638. [PMID: 28911203 PMCID: PMC5886142 DOI: 10.1093/hmg/ddx251] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Revised: 06/09/2017] [Accepted: 06/27/2017] [Indexed: 12/11/2022] Open
Abstract
Mutations in FOXC1 and PITX2 constitute the most common causes of ocular anterior segment dysgenesis (ASD), and confer a high risk for secondary glaucoma. The genetic causes underlying ASD in approximately half of patients remain unknown, despite many of them being screened by whole exome sequencing. Here, we performed whole genome sequencing on DNA from two affected individuals from a family with dominantly inherited ASD and glaucoma to identify a 748-kb deletion in a gene desert that contains conserved putative PITX2 regulatory elements. We used CRISPR/Cas9 to delete the orthologous region in zebrafish in order to test the pathogenicity of this structural variant. Deletion in zebrafish reduced pitx2 expression during development and resulted in shallow anterior chambers. We screened additional patients for copy number variation of the putative regulatory elements and found an overlapping deletion in a second family and in a potentially-ancestrally-related index patient with ASD and glaucoma. These data suggest that mutations affecting conserved non-coding elements of PITX2 may constitute an important class of mutations in patients with ASD for whom the molecular cause of their disease have not yet been identified. Improved functional annotation of the human genome and transition to sequencing of patient genomes instead of exomes will be required before the magnitude of this class of mutations is fully understood.
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Affiliation(s)
- Meredith E. Protas
- Departments of Ophthalmology and Anatomy and Institute for Human Genetics, University of California, San Francisco, CA 94143, USA
| | - Eric Weh
- Department of Pediatrics, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Tim Footz
- Department of Medical Genetics, University of Alberta, Edmonton, AB T6G 2H7, Canada
| | - Jay Kasberger
- Celgene Quanticel Research, San Francisco, CA 94158, USA
| | - Scott C. Baraban
- Department of Neurological Surgery, University of California, San Francisco, CA 94143, USA
| | - Alex V. Levin
- Pediatric Ophthalmology and Ocular Genetics, Wills Eye Hospital, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - L. Jay Katz
- Glaucoma Service, Wills Eye Hospital, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Robert Ritch
- Einhorn Clinical Research Center, The New York Eye and Ear Infirmary of Mount Sinai, New York, NY 10003, USA
| | - Michael A. Walter
- Department of Medical Genetics, University of Alberta, Edmonton, AB T6G 2H7, Canada
| | - Elena V. Semina
- Department of Pediatrics, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Douglas B. Gould
- Departments of Ophthalmology and Anatomy and Institute for Human Genetics, University of California, San Francisco, CA 94143, USA
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25
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Mao M, Kiss M, Ou Y, Gould DB. Genetic dissection of anterior segment dysgenesis caused by a Col4a1 mutation in mouse. Dis Model Mech 2017; 10:475-485. [PMID: 28237965 PMCID: PMC5399567 DOI: 10.1242/dmm.027888] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Accepted: 02/20/2017] [Indexed: 12/21/2022] Open
Abstract
Ocular anterior segment dysgenesis (ASD) describes a spectrum of clinically and genetically heterogeneous congenital disorders affecting anterior structures that often lead to impaired vision. More importantly, 50-75% of patients with ASD develop early onset and aggressive glaucoma. Although several genes have been implicated in the etiology of ASD, the underlying mechanisms remain elusive. Type IV collagen alpha 1 (COL4A1) is an extracellular matrix protein and a critical component of nearly all basement membranes. COL4A1 mutations cause multi-system disorders in patients, including ASD (congenital cataracts, Axenfeld-Rieger's anomaly, Peter's anomaly and microphthalmia) and congenital or juvenile glaucoma. Here, we use a conditional Col4a1 mutation in mice to determine the location and timing of pathogenic events underlying COL4A1-related ocular dysgenesis. Our results suggest that selective expression of the Col4a1 mutation in neural crest cells and their derivatives is not sufficient to cause ocular dysgenesis and that selective expression of the Col4a1 mutation in vascular endothelial cells can lead to mild ASD and optic nerve hypoplasia but only on a sensitized background. In contrast, lens-specific expression of the conditional Col4a1 mutant allele led to cataracts, mild ASD and optic nerve hypoplasia, and age-related intraocular pressure dysregulation and optic nerve damage. Finally, ubiquitous expression of the conditional Col4a1 mutation at distinct developmental stages suggests that pathogenesis takes place before E12.5. Our results show that the lens and possibly vasculature play important roles in Col4a1-related ASD and that the pathogenic events occur at mid-embryogenesis in mice, during early stages of ocular development. Summary: Key pathogenic events in anterior segment dysgenesis, a congenital ocular disease with complex etiology, are recapitulated in a mouse model of Col4a1-related ASD.
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Affiliation(s)
- Mao Mao
- Department of Ophthalmology, Institute for Human Genetics, UCSF School of Medicine, San Francisco, CA 94143, USA
| | - Márton Kiss
- Department of Genetics, University of Szeged, Középfasor 52, Szeged H-6726, Hungary
| | - Yvonne Ou
- Department of Ophthalmology, Institute for Human Genetics, UCSF School of Medicine, San Francisco, CA 94143, USA
| | - Douglas B Gould
- Department of Ophthalmology, Institute for Human Genetics, UCSF School of Medicine, San Francisco, CA 94143, USA .,Department of Anatomy, Institute for Human Genetics, UCSF School of Medicine, San Francisco, CA 94143, USA
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26
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Jeanne M, Gould DB. Genotype-phenotype correlations in pathology caused by collagen type IV alpha 1 and 2 mutations. Matrix Biol 2016; 57-58:29-44. [PMID: 27794444 DOI: 10.1016/j.matbio.2016.10.003] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Accepted: 10/10/2016] [Indexed: 12/11/2022]
Abstract
COL4A1 and COL4A2 are extracellular matrix proteins that form heterotrimers and are present in nearly all basement membranes in every organ. In the past decade, COL4A1 and COL4A2 mutations have been identified to cause a multi-system disorder for which penetrance and severity of constituent phenotypes can greatly vary. Here, we compare the outcomes of more than 100 mutations identified in patients and data from a murine allelic series to explore the presence of genotype-phenotype correlations - many of which are shared among other types of collagen. We find that there is a frequency bias for COL4A1 over COL4A2 mutations and that glycine (Gly) substitutions within the triple helical domain are the most common class of mutations. Glycine is most often replaced by a charged amino acid, however the position of the mutation, and not the properties of the substituting amino acid, appears to have a greater influence on disease severity. Moreover, the impact of position is not straightforward. Observations from a murine allelic series suggest that mutations in the NC1 domain may result in relatively mild phenotypes via a 'quantitative' mechanism similar to other types of collagens, however, this effect was not apparent in human reports. Importantly, other position-dependent effects had differential impacts depending on the phenotype of interest. For example, the severity of cerebrovascular disease correlated with an amino-to-carboxy severity gradient for triple-helical glycine substitutions whereas the penetrance and severity of myopathy and nephropathy appear to involve a functional sub-domain(s). Greater understanding of genotype-phenotype correlations and the interaction of consequences of different mutations will be important for patient prognosis and care and for developing mechanism-based therapeutics to treat individual components of this emerging syndrome.
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Affiliation(s)
- Marion Jeanne
- Genentech Inc, 1 DNA Way, South San Francisco, CA 94080, USA.
| | - Douglas B Gould
- Department of Ophthalmology, Department of Anatomy, Institute for Human Genetics, UCSF School of Medicine, San Francisco, CA 94143, USA.
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27
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Proekt I, Miller CN, Jeanne M, Fasano KJ, Moon JJ, Lowell CA, Gould DB, Anderson MS, DeFranco AL. LYN- and AIRE-mediated tolerance checkpoint defects synergize to trigger organ-specific autoimmunity. J Clin Invest 2016; 126:3758-3771. [PMID: 27571405 PMCID: PMC5087700 DOI: 10.1172/jci84440] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Accepted: 07/22/2016] [Indexed: 01/07/2023] Open
Abstract
Studies of the genetic factors associated with human autoimmune disease suggest a multigenic origin of susceptibility; however, how these factors interact and through which tolerance pathways they operate generally remain to be defined. One key checkpoint occurs through the activity of the autoimmune regulator AIRE, which promotes central T cell tolerance. Recent reports have described a variety of dominant-negative AIRE mutations that likely contribute to human autoimmunity to a greater extent than previously thought. In families with these mutations, the penetrance of autoimmunity is incomplete, suggesting that other checkpoints play a role in preventing autoimmunity. Here, we tested whether a defect in LYN, an inhibitory protein tyrosine kinase that is implicated in systemic autoimmunity, could combine with an Aire mutation to provoke organ-specific autoimmunity. Indeed, mice with a dominant-negative allele of Aire and deficiency in LYN spontaneously developed organ-specific autoimmunity in the eye. We further determined that a small pool of retinal protein-specific T cells escaped thymic deletion as a result of the hypomorphic Aire function and that these cells also escaped peripheral tolerance in the presence of LYN-deficient dendritic cells, leading to highly destructive autoimmune attack. These findings demonstrate how 2 distinct tolerance pathways can synergize to unleash autoimmunity and have implications for the genetic susceptibility of autoimmune disease.
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Affiliation(s)
| | | | - Marion Jeanne
- Departments of Ophthalmology and Anatomy, Institute for Human Genetics, UCSF, San Francisco, California, USA
| | | | - James J. Moon
- Center for Immunology and Inflammatory Diseases and Division of Pulmonary and Critical Care Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | | | - Douglas B. Gould
- Departments of Ophthalmology and Anatomy, Institute for Human Genetics, UCSF, San Francisco, California, USA
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28
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Loscertales M, Nicolaou F, Jeanne M, Longoni M, Gould DB, Sun Y, Maalouf FI, Nagy N, Donahoe PK. Erratum to: Type IV collagen drives alveolar epithelial-endothelial association and the morphogenetic movements of septation. BMC Biol 2016; 14:73. [PMID: 27587011 PMCID: PMC5009649 DOI: 10.1186/s12915-016-0297-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Affiliation(s)
- Maria Loscertales
- The Pediatric Surgical Research Laboratories, Massachusetts General Hospital, Boston, MA, 02114, USA. .,Department of Surgery, Harvard Medical School, Boston, MA, 02115, USA.
| | - Fotini Nicolaou
- The Pediatric Surgical Research Laboratories, Massachusetts General Hospital, Boston, MA, 02114, USA
| | - Marion Jeanne
- Departments of Ophthalmology and Anatomy, Institute for Human Genetics, University of California, San Francisco, School of Medicine, San Francisco, CA, 94143, USA
| | - Mauro Longoni
- The Pediatric Surgical Research Laboratories, Massachusetts General Hospital, Boston, MA, 02114, USA.,Department of Surgery, Harvard Medical School, Boston, MA, 02115, USA
| | - Douglas B Gould
- Departments of Ophthalmology and Anatomy, Institute for Human Genetics, University of California, San Francisco, School of Medicine, San Francisco, CA, 94143, USA
| | - Yunwei Sun
- The Pediatric Surgical Research Laboratories, Massachusetts General Hospital, Boston, MA, 02114, USA
| | - Faouzi I Maalouf
- The Pediatric Surgical Research Laboratories, Massachusetts General Hospital, Boston, MA, 02114, USA
| | - Nandor Nagy
- The Pediatric Surgical Research Laboratories, Massachusetts General Hospital, Boston, MA, 02114, USA.,Department of Surgery, Harvard Medical School, Boston, MA, 02115, USA.,Department of Human Anatomy, Histology and Embryology, Faculty of Medicine, Semmelweis University, Budapest, 1094, Hungary
| | - Patricia K Donahoe
- The Pediatric Surgical Research Laboratories, Massachusetts General Hospital, Boston, MA, 02114, USA.,Department of Surgery, Harvard Medical School, Boston, MA, 02115, USA.,Broad Institute of MIT and Harvard, Cambridge, MA, 02142, USA
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Loscertales M, Nicolaou F, Jeanne M, Longoni M, Gould DB, Sun Y, Maalouf FI, Nagy N, Donahoe PK. Type IV collagen drives alveolar epithelial-endothelial association and the morphogenetic movements of septation. BMC Biol 2016; 14:59. [PMID: 27412481 PMCID: PMC4942891 DOI: 10.1186/s12915-016-0281-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Accepted: 07/01/2016] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND Type IV collagen is the main component of the basement membrane that gives strength to the blood-gas barrier (BGB). In mammals, the formation of a mature BGB occurs primarily after birth during alveologenesis and requires the formation of septa from the walls of the saccule. In contrast, in avians, the formation of the BGB occurs rapidly and prior to hatching. Mutation in basement membrane components results in an abnormal alveolar phenotype; however, the specific role of type IV collagen in regulating alveologenesis remains unknown. RESULTS We have performed a microarray expression analysis in late chick lung development and found that COL4A1 and COL4A2 were among the most significantly upregulated genes during the formation of the avian BGB. Using mouse models, we discovered that mutations in murine Col4a1 and Col4a2 genes affected the balance between lung epithelial progenitors and differentiated cells. Mutations in Col4a1 derived from the vascular component were sufficient to cause defects in vascular development and the BGB. We also show that Col4a1 and Col4a2 mutants displayed disrupted myofibroblast proliferation, differentiation and migration. Lastly, we revealed that addition of type IV collagen protein induced myofibroblast proliferation and migration in monolayer culture and increased the formation of mesenchymal-epithelial septal-like structures in co-culture. CONCLUSIONS Our study showed that type IV collagen and, therefore the basement membrane, play fundamental roles in coordinating alveolar morphogenesis. In addition to its role in the formation of epithelium and vasculature, type IV collagen appears to be key for alveolar myofibroblast development by inducing their proliferation, differentiation and migration throughout the developing septum.
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Affiliation(s)
- Maria Loscertales
- The Pediatric Surgical Research Laboratories, Massachusetts General Hospital, Boston, MA, 02114, USA.
- Department of Surgery, Harvard Medical School, Boston, MA, 02115, USA.
| | - Fotini Nicolaou
- The Pediatric Surgical Research Laboratories, Massachusetts General Hospital, Boston, MA, 02114, USA
| | - Marion Jeanne
- Departments of Ophthalmology and Anatomy, Institute for Human Genetics, University of California, San Francisco, School of Medicine, San Francisco, CA, 94143, USA
| | - Mauro Longoni
- The Pediatric Surgical Research Laboratories, Massachusetts General Hospital, Boston, MA, 02114, USA
- Department of Surgery, Harvard Medical School, Boston, MA, 02115, USA
| | - Douglas B Gould
- Departments of Ophthalmology and Anatomy, Institute for Human Genetics, University of California, San Francisco, School of Medicine, San Francisco, CA, 94143, USA
| | - Yunwei Sun
- The Pediatric Surgical Research Laboratories, Massachusetts General Hospital, Boston, MA, 02114, USA
| | - Faouzi I Maalouf
- The Pediatric Surgical Research Laboratories, Massachusetts General Hospital, Boston, MA, 02114, USA
| | - Nandor Nagy
- The Pediatric Surgical Research Laboratories, Massachusetts General Hospital, Boston, MA, 02114, USA
- Department of Surgery, Harvard Medical School, Boston, MA, 02115, USA
- Department of Human Anatomy, Histology and Embryology, Faculty of Medicine, Semmelweis University, Budapest, 1094, Hungary
| | - Patricia K Donahoe
- The Pediatric Surgical Research Laboratories, Massachusetts General Hospital, Boston, MA, 02114, USA
- Department of Surgery, Harvard Medical School, Boston, MA, 02115, USA
- Broad Institute of MIT and Harvard, Cambridge, MA, 02142, USA
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Mao M, Smith RS, Alavi MV, Marchant JK, Cosma M, Libby RT, John SWM, Gould DB. Strain-Dependent Anterior Segment Dysgenesis and Progression to Glaucoma in Col4a1 Mutant Mice. Invest Ophthalmol Vis Sci 2016; 56:6823-31. [PMID: 26567795 DOI: 10.1167/iovs.15-17527] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
PURPOSE Mutations in the gene encoding collagen type IV alpha 1 (COL4A1) cause multisystem disorders including anterior segment dysgenesis (ASD) and optic nerve hypoplasia. The penetrance and severity of individual phenotypes depends on genetic context. Here, we tested the effects of a Col4a1 mutation in two different genetic backgrounds to compare how genetic context influences ocular dysgenesis, IOP, and progression to glaucoma. METHODS Col4a1 mutant mice maintained on a C57BL/6J background were crossed to either 129S6/SvEvTac or CAST/EiJ and the F1 progeny were analyzed by slit-lamp biomicroscopy and optical coherence tomography. We also measured IOPs and compared tissue sections of eyes and optic nerves. RESULTS We found that the CAST/EiJ inbred strain has a relatively uniform and profound suppression on the effects of Col4a1 mutation and that mutant CASTB6F1 mice were generally only very mildly affected. In contrast, mutant 129B6F1 mice had more variable and severe ASD and IOP dysregulation that were associated with glaucomatous signs including lost or damaged retinal ganglion cell axons and excavation of the optic nerve head. CONCLUSIONS Ocular defects in Col4a1 mutant mice model ASD and glaucoma that are observed in a subset of patients with COL4A1 mutations. We demonstrate that different inbred strains of mice give graded severities of ASD and we detected elevated IOP and glaucomatous damage in 129B6F1, but not CASTB6F1 mice that carried a Col4a1 mutation. These data demonstrate that genetic context differences are one factor that may contribute to the variable penetrance and severity of ASD and glaucoma in patients with COL4A1 mutations.
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Affiliation(s)
- Mao Mao
- Departments of Ophthalmology and Anatomy Institute for Human Genetics, UCSF School of Medicine, San Francisco, California, United States
| | | | - Marcel V Alavi
- Departments of Ophthalmology and Anatomy Institute for Human Genetics, UCSF School of Medicine, San Francisco, California, United States
| | - Jeffrey K Marchant
- The Jackson Laboratory, Bar Harbor, Maine, United States 3Department of Anatomy and Cell Biology, Department of Ophthalmology, Tufts University School of Medicine, Boston, Massachusetts, United States
| | - Mihai Cosma
- The Jackson Laboratory, Bar Harbor, Maine, United States
| | - Richard T Libby
- Flaum Eye Institute, Department of Biomedical Genetics, The Center for Visual Sciences, University of Rochester Medical Center, Rochester, New York, United States
| | - Simon W M John
- The Jackson Laboratory, Bar Harbor, Maine, United States 3Department of Anatomy and Cell Biology, Department of Ophthalmology, Tufts University School of Medicine, Boston, Massachusetts, United States 5The Howard Hughes Medical Institute, Bar Harbor, Main
| | - Douglas B Gould
- Departments of Ophthalmology and Anatomy Institute for Human Genetics, UCSF School of Medicine, San Francisco, California, United States
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Alavi MV, Chiang WC, Kroeger H, Yasumura D, Matthes MT, Iwawaki T, LaVail MM, Gould DB, Lin JH. In Vivo Visualization of Endoplasmic Reticulum Stress in the Retina Using the ERAI Reporter Mouse. Invest Ophthalmol Vis Sci 2016; 56:6961-70. [PMID: 26513501 DOI: 10.1167/iovs.15-16969] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
PURPOSE Endoplasmic reticulum (ER) stress activates inositol requiring enzyme 1 (IRE1), a key regulator of the unfolded protein response. The ER stress activated indicator (ERAI) transgenic mouse expresses a yellow fluorescent GFP variant (Venus) when IRE1 is activated by ER stress. We tested whether ERAI mice would allow for real-time longitudinal studies of ER stress in living mouse eyes. METHODS We chemically and genetically induced ER stress, and qualitatively and quantitatively studied the Venus signal by fluorescence ophthalmoscopy. We determined retinal cell types that contribute to the signal by immunohistology, and we performed molecular and biochemical assays using whole retinal lysates to assess activity of the IRE1 pathway. RESULTS We found qualitative increase in vivo in fluorescence signal at sites of intravitreal tunicamycin injection in ERAI eyes, and quantitative increase in ERAI mice mated to RhoP23H mice expressing ER stress-inducing misfolded rhodopsin protein. As expected, we found that increased Venus signal arose primarily from photoreceptors in RhoP23H/+;ERAI mice. We found increased Xbp1S and XBP1s transcriptional target mRNA levels in RhoP23H/+;ERAI retinas compared to Rho+/+;ERAI retinas, and that Venus signal increased in ERAI retinas as a function of age. CONCLUSIONS Fluorescence ophthalmoscopy of ERAI mice enables in vivo visualization of retinas undergoing ER stress. ER stress activated indicator mice enable identification of individual retinal cells undergoing ER stress by immunohistochemistry. ER stress activated indicator mice show higher Venus signal at older ages, likely arising from amplification of basal retinal ER stress levels by GFP's inherent stability.
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Affiliation(s)
- Marcel V Alavi
- Department of Ophthalmology, University of California, San Francisco, San Francisco, California, United States
| | - Wei-Chieh Chiang
- Department of Pathology, University of California, San Diego, La Jolla, California, United States
| | - Heike Kroeger
- Department of Pathology, University of California, San Diego, La Jolla, California, United States
| | - Douglas Yasumura
- Department of Ophthalmology, University of California, San Francisco, San Francisco, California, United States
| | - Michael T Matthes
- Department of Ophthalmology, University of California, San Francisco, San Francisco, California, United States
| | - Takao Iwawaki
- Advanced Scientific Research Leaders Development Unit, Gunma University, Gunma, Japan
| | - Matthew M LaVail
- Department of Ophthalmology, University of California, San Francisco, San Francisco, California, United States
| | - Douglas B Gould
- Department of Ophthalmology, University of California, San Francisco, San Francisco, California, United States 4Department of Anatomy and Institute for Human Genetics, University of California, San Francisco, San Francisco, California, United States
| | - Jonathan H Lin
- Department of Pathology, University of California, San Diego, La Jolla, California, United States 5VA San Diego Healthcare System, San Diego, California, United States
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Stahl BA, Gross JB, Speiser DI, Oakley TH, Patel NH, Gould DB, Protas ME. A Transcriptomic Analysis of Cave, Surface, and Hybrid Isopod Crustaceans of the Species Asellus aquaticus. PLoS One 2015; 10:e0140484. [PMID: 26462237 PMCID: PMC4604090 DOI: 10.1371/journal.pone.0140484] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Accepted: 09/25/2015] [Indexed: 12/14/2022] Open
Abstract
Cave animals, compared to surface-dwelling relatives, tend to have reduced eyes and pigment, longer appendages, and enhanced mechanosensory structures. Pressing questions include how certain cave-related traits are gained and lost, and if they originate through the same or different genetic programs in independent lineages. An excellent system for exploring these questions is the isopod, Asellus aquaticus. This species includes multiple cave and surface populations that have numerous morphological differences between them. A key feature is that hybrids between cave and surface individuals are viable, which enables genetic crosses and linkage analyses. Here, we advance this system by analyzing single animal transcriptomes of Asellus aquaticus. We use high throughput sequencing of non-normalized cDNA derived from the head of a surface-dwelling male, the head of a cave-dwelling male, the head of a hybrid male (produced by crossing a surface individual with a cave individual), and a pooled sample of surface embryos and hatchlings. Assembling reads from surface and cave head RNA pools yielded an integrated transcriptome comprised of 23,984 contigs. Using this integrated assembly as a reference transcriptome, we aligned reads from surface-, cave- and hybrid- head tissue and pooled surface embryos and hatchlings. Our approach identified 742 SNPs and placed four new candidate genes to an existing linkage map for A. aquaticus. In addition, we examined SNPs for allele-specific expression differences in the hybrid individual. All of these resources will facilitate identification of genes and associated changes responsible for cave adaptation in A. aquaticus and, in concert with analyses of other species, will inform our understanding of the evolutionary processes accompanying adaptation to the subterranean environment.
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Affiliation(s)
- Bethany A. Stahl
- Department of Biological Sciences, University of Cincinnati, Cincinnati, Ohio, United States of America
- Department of Biological Sciences, Florida Atlantic University, Jupiter, FL, 33458, United States of America
| | - Joshua B. Gross
- Department of Biological Sciences, University of Cincinnati, Cincinnati, Ohio, United States of America
| | - Daniel I. Speiser
- Department of Biological Sciences, University of South Carolina, Columbia, SC, United States of America
| | - Todd H. Oakley
- Department of Ecology, Evolution, and Marine Biology, University of California Santa Barbara, Santa Barbara, CA, United States of America
| | - Nipam H. Patel
- Department of Molecular and Cell Biology & Department of Integrative Biology, University of California, Berkeley, CA, United States of America
| | - Douglas B. Gould
- Departments of Ophthalmology and Anatomy, Institute for Human Genetics, UCSF School of Medicine, San Francisco, CA, United States of America
| | - Meredith E. Protas
- Department of Natural Sciences and Mathematics, Dominican University of California, San Rafael, CA, United States of America
- * E-mail:
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Alavi MV, Gould DB. In vivo longitudinal assessment of cellular processes using fluorescence reporters. Mitochondrion 2015. [DOI: 10.1016/j.mito.2015.07.066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Jeanne M, Jorgensen J, Gould DB. Molecular and Genetic Analyses of Collagen Type IV Mutant Mouse Models of Spontaneous Intracerebral Hemorrhage Identify Mechanisms for Stroke Prevention. Circulation 2015; 131:1555-65. [PMID: 25753534 DOI: 10.1161/circulationaha.114.013395] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Accepted: 02/26/2015] [Indexed: 02/06/2023]
Abstract
BACKGROUND Collagen type IV alpha1 (COL4A1) and alpha2 (COL4A2) form heterotrimers critical for vascular basement membrane stability and function. Patients with COL4A1 or COL4A2 mutations suffer from diverse cerebrovascular diseases, including cerebral microbleeds, porencephaly, and fatal intracerebral hemorrhage (ICH). However, the pathogenic mechanisms remain unknown, and there is a lack of effective treatment. METHODS AND RESULTS Using Col4a1 and Col4a2 mutant mouse models, we investigated the genetic complexity and cellular mechanisms underlying the disease. We found that Col4a1 mutations cause abnormal vascular development, which triggers small-vessel disease, recurrent hemorrhagic strokes, and age-related macroangiopathy. We showed that allelic heterogeneity, genetic context, and environmental factors such as intense exercise or anticoagulant medication modulated disease severity and contributed to phenotypic heterogeneity. We found that intracellular accumulation of mutant collagen in vascular endothelial cells and pericytes was a key triggering factor of ICH. Finally, we showed that treatment of mutant mice with a US Food and Drug Administration-approved chemical chaperone resulted in a decreased collagen intracellular accumulation and a significant reduction in ICH severity. CONCLUSIONS Our data are the first to show therapeutic prevention in vivo of ICH resulting from Col4a1 mutation and imply that a mechanism-based therapy promoting protein folding might also prevent ICH in patients with COL4A1 and COL4A2 mutations.
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Affiliation(s)
- Marion Jeanne
- From Departments of Ophthalmology and Anatomy, Institute for Human Genetics, University of California, San Francisco (UCSF)
| | - Jeff Jorgensen
- From Departments of Ophthalmology and Anatomy, Institute for Human Genetics, University of California, San Francisco (UCSF)
| | - Douglas B Gould
- From Departments of Ophthalmology and Anatomy, Institute for Human Genetics, University of California, San Francisco (UCSF).
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Ghosh R, Wang L, Wang ES, Perera BGK, Igbaria A, Morita S, Prado K, Thamsen M, Caswell D, Macias H, Weiberth KF, Gliedt MJ, Alavi MV, Hari SB, Mitra AK, Bhhatarai B, Schürer SC, Snapp EL, Gould DB, German MS, Backes BJ, Maly DJ, Oakes SA, Papa FR. Allosteric inhibition of the IRE1α RNase preserves cell viability and function during endoplasmic reticulum stress. Cell 2014; 158:534-48. [PMID: 25018104 DOI: 10.1016/j.cell.2014.07.002] [Citation(s) in RCA: 340] [Impact Index Per Article: 34.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2014] [Revised: 06/09/2014] [Accepted: 07/01/2014] [Indexed: 12/31/2022]
Abstract
Depending on endoplasmic reticulum (ER) stress levels, the ER transmembrane multidomain protein IRE1α promotes either adaptation or apoptosis. Unfolded ER proteins cause IRE1α lumenal domain homo-oligomerization, inducing trans autophosphorylation that further drives homo-oligomerization of its cytosolic kinase/endoribonuclease (RNase) domains to activate mRNA splicing of adaptive XBP1 transcription factor. However, under high/chronic ER stress, IRE1α surpasses an oligomerization threshold that expands RNase substrate repertoire to many ER-localized mRNAs, leading to apoptosis. To modulate these effects, we developed ATP-competitive IRE1α Kinase-Inhibiting RNase Attenuators-KIRAs-that allosterically inhibit IRE1α's RNase by breaking oligomers. One optimized KIRA, KIRA6, inhibits IRE1α in vivo and promotes cell survival under ER stress. Intravitreally, KIRA6 preserves photoreceptor functional viability in rat models of ER stress-induced retinal degeneration. Systemically, KIRA6 preserves pancreatic β cells, increases insulin, and reduces hyperglycemia in Akita diabetic mice. Thus, IRE1α powerfully controls cell fate but can itself be controlled with small molecules to reduce cell degeneration.
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Affiliation(s)
- Rajarshi Ghosh
- Department of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA; Department of Pathology, University of California, San Francisco, San Francisco, CA 94143, USA; Diabetes Center, University of California, San Francisco, San Francisco, CA 94143, USA; Lung Biology Center, University of California, San Francisco, San Francisco, CA 94143, USA; California Institute for Quantitative Biosciences, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Likun Wang
- Department of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA; Diabetes Center, University of California, San Francisco, San Francisco, CA 94143, USA; Lung Biology Center, University of California, San Francisco, San Francisco, CA 94143, USA; California Institute for Quantitative Biosciences, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Eric S Wang
- Department of Pathology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - B Gayani K Perera
- Department of Chemistry, University of Washington, Seattle, WA 98195, USA
| | - Aeid Igbaria
- Department of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA; Diabetes Center, University of California, San Francisco, San Francisco, CA 94143, USA; Lung Biology Center, University of California, San Francisco, San Francisco, CA 94143, USA; California Institute for Quantitative Biosciences, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Shuhei Morita
- Department of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA; Diabetes Center, University of California, San Francisco, San Francisco, CA 94143, USA; Lung Biology Center, University of California, San Francisco, San Francisco, CA 94143, USA; California Institute for Quantitative Biosciences, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Kris Prado
- Department of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA; Diabetes Center, University of California, San Francisco, San Francisco, CA 94143, USA; Lung Biology Center, University of California, San Francisco, San Francisco, CA 94143, USA; California Institute for Quantitative Biosciences, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Maike Thamsen
- Department of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA; Diabetes Center, University of California, San Francisco, San Francisco, CA 94143, USA; Lung Biology Center, University of California, San Francisco, San Francisco, CA 94143, USA; California Institute for Quantitative Biosciences, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Deborah Caswell
- Department of Pathology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Hector Macias
- Department of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA; Diabetes Center, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Kurt F Weiberth
- Department of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA; Diabetes Center, University of California, San Francisco, San Francisco, CA 94143, USA; Lung Biology Center, University of California, San Francisco, San Francisco, CA 94143, USA; California Institute for Quantitative Biosciences, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Micah J Gliedt
- Department of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA; Lung Biology Center, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Marcel V Alavi
- Department of Ophthalmology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Sanjay B Hari
- Department of Chemistry, University of Washington, Seattle, WA 98195, USA
| | - Arinjay K Mitra
- Department of Chemistry, University of Washington, Seattle, WA 98195, USA
| | - Barun Bhhatarai
- Department of Molecular and Cellular Pharmacology,, Miller School of Medicine, University of Miami, FL 33136, USA
| | - Stephan C Schürer
- Center for Computational Science, Miller School of Medicine, University of Miami, FL 33136, USA; Department of Molecular and Cellular Pharmacology,, Miller School of Medicine, University of Miami, FL 33136, USA
| | - Erik L Snapp
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Douglas B Gould
- Department of Ophthalmology, University of California, San Francisco, San Francisco, CA 94143, USA; Department of Anatomy, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Michael S German
- Department of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA; Diabetes Center, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Bradley J Backes
- Department of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA; Lung Biology Center, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Dustin J Maly
- Department of Chemistry, University of Washington, Seattle, WA 98195, USA
| | - Scott A Oakes
- Department of Pathology, University of California, San Francisco, San Francisco, CA 94143, USA; Diabetes Center, University of California, San Francisco, San Francisco, CA 94143, USA.
| | - Feroz R Papa
- Department of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA; Diabetes Center, University of California, San Francisco, San Francisco, CA 94143, USA; Lung Biology Center, University of California, San Francisco, San Francisco, CA 94143, USA; California Institute for Quantitative Biosciences, University of California, San Francisco, San Francisco, CA 94143, USA.
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Chen YF, Zhou D, Metzger T, Gallup M, Jeanne M, Gould DB, Anderson MS, McNamara NA. Spontaneous development of autoimmune uveitis Is CCR2 dependent. Am J Pathol 2014; 184:1695-705. [PMID: 24736166 DOI: 10.1016/j.ajpath.2014.02.024] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2013] [Revised: 02/07/2014] [Accepted: 02/27/2014] [Indexed: 10/25/2022]
Abstract
Development of novel strategies to treat noninfectious posterior uveitis is an ongoing challenge, in part because of limited availability of animal models that mimic the naturally occurring disease in humans. Mice deficient in the autoimmune regulatory gene Aire develop a spontaneous T-cell and macrophage-mediated autoimmune uveitis that closely recapitulates human endogenous uveitis and thus provide a useful model for mechanistic and therapeutic investigations. Lymphocytic and mononuclear infiltration of the retina in Aire knockout (KO) mice triggers the onset of uveitis from initial retinal inflammation to eventual destruction of the neuroretina with loss of photoreceptors. The C-C chemokine receptor type 2 protein (CCR2) functions in directing monocyte and macrophage migration to inflamed tissues via interaction with monocyte chemotactic proteins. Using the Aire KO mouse model, we demonstrated an essential role for CCR2 in the pathogenesis of autoimmune-mediated uveitis. Loss of functional CCR2 effectively reduced immune cell infiltration and rescued the retina from destruction. CCR2-dependent migration of bone marrow-derived cells provided the driving force for retinal inflammation, with CCR2-expressing mononuclear cells contributing to retinal damage via recruitment of CD4(+) T cells. These studies identify the CCR2 pathway as a promising therapeutic target that may prove an effective approach to treat uveitis associated with autoimmunity.
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Affiliation(s)
- YuTing Feeling Chen
- Francis I. Proctor Foundation, University of California, San Francisco, California
| | - Delu Zhou
- Francis I. Proctor Foundation, University of California, San Francisco, California
| | - Todd Metzger
- Diabetes Center, University of California, San Francisco, California
| | - Marianne Gallup
- Francis I. Proctor Foundation, University of California, San Francisco, California
| | - Marion Jeanne
- Department of Ophthalmology, University of California, San Francisco, California
| | - Douglas B Gould
- Department of Ophthalmology, University of California, San Francisco, California
| | - Mark S Anderson
- Diabetes Center, University of California, San Francisco, California
| | - Nancy A McNamara
- Francis I. Proctor Foundation, University of California, San Francisco, California; Department of Ophthalmology, University of California, San Francisco, California; Department of Anatomy, University of California, San Francisco, California; School of Optometry, University of California, Berkeley, California; Vision Science Program, University of California, Berkeley, California.
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Aikio M, Hurskainen M, Brideau G, Hägg P, Sormunen R, Heljasvaara R, Gould DB, Pihlajaniemi T. Collagen XVIII Short Isoform Is Critical for Retinal Vascularization, and Overexpression of the Tsp-1 Domain Affects Eye Growth and Cataract Formation. ACTA ACUST UNITED AC 2013; 54:7450-62. [DOI: 10.1167/iovs.13-13039] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- Mari Aikio
- Oulu Center for Cell-Matrix Research, Department of Medical Biochemistry and Molecular Biology, University of Oulu, Oulu, Finland 2Biocenter Oulu, Oulu, Finland
| | - Merja Hurskainen
- Oulu Center for Cell-Matrix Research, Department of Medical Biochemistry and Molecular Biology, University of Oulu, Oulu, Finland
| | - Gaëlle Brideau
- Oulu Center for Cell-Matrix Research, Department of Medical Biochemistry and Molecular Biology, University of Oulu, Oulu, Finland 2Biocenter Oulu, Oulu, Finland
| | - Pasi Hägg
- Department of Ophthalmology, Oulu University Hospital, University of Oulu, Oulu, Finland
| | - Raija Sormunen
- Biocenter Oulu, Oulu, Finland 4Departments of Pathology, University of Oulu and Oulu University Hospital, Oulu, Finland
| | - Ritva Heljasvaara
- Oulu Center for Cell-Matrix Research, Department of Medical Biochemistry and Molecular Biology, University of Oulu, Oulu, Finland 2Biocenter Oulu, Oulu, Finland
| | - Douglas B. Gould
- Departments of Ophthalmology and Anatomy, Institute for Human Genetics, University of California, San Francisco, School of Medicine, San Francisco, California
| | - Taina Pihlajaniemi
- Oulu Center for Cell-Matrix Research, Department of Medical Biochemistry and Molecular Biology, University of Oulu, Oulu, Finland 2Biocenter Oulu, Oulu, Finland
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Kuo DS, Labelle-Dumais C, Mao M, Jeanne M, Kauffman WB, Allen J, Favor J, Gould DB. Allelic heterogeneity contributes to variability in ocular dysgenesis, myopathy and brain malformations caused by Col4a1 and Col4a2 mutations. Hum Mol Genet 2013; 23:1709-22. [PMID: 24203695 PMCID: PMC3943517 DOI: 10.1093/hmg/ddt560] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Collagen type IV alpha 1 and 2 (COL4A1 and COL4A2) are present in nearly all basement membranes. COL4A1 and COL4A2 mutations are pleiotropic, affecting multiple organ systems to differing degrees, and both genetic-context and environmental factors influence this variable expressivity. Here, we report important phenotypic and molecular differences in an allelic series of Col4a1 and Col4a2 mutant mice that are on a uniform genetic background. We evaluated three organs commonly affected by COL4A1 and COL4A2 mutations and discovered allelic heterogeneity in the penetrance and severity of ocular dysgenesis, myopathy and brain malformations. Similarly, we show allelic heterogeneity in COL4A1 and COL4A2 biosynthesis. While most mutations that we examined caused increased intracellular and decreased extracellular COL4A1 and COL4A2, we identified three mutations with distinct biosynthetic signatures. Reduced temperature or presence of 4-phenylbutyrate ameliorated biosynthetic defects in primary cell lines derived from mutant mice. Together, our data demonstrate the effects and clinical implications of allelic heterogeneity in Col4a1- and Col4a2-related diseases. Understanding allelic differences will be valuable for increasing prognostic accuracy and for the development of therapeutic interventions that consider the nature of the molecular cause in patients with COL4A1 and COL4A2 mutations.
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Kuo DS, Labelle-Dumais C, Gould DB. COL4A1 and COL4A2 mutations and disease: insights into pathogenic mechanisms and potential therapeutic targets. Hum Mol Genet 2012; 21:R97-110. [PMID: 22914737 PMCID: PMC3459649 DOI: 10.1093/hmg/dds346] [Citation(s) in RCA: 197] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Heterotrimers composed of collagen type IV alpha 1 (COL4A1) and alpha 2 (COL4A2) constitute one of the most abundant components of nearly all basement membranes. Accordingly, mutations in COL4A1 or COL4A2 are pleiotropic and contribute to a broad spectrum of disorders, including myopathy, glaucoma and hemorrhagic stroke. Here, we summarize the contributions of COL4A1 and COL4A2 mutations in human disease, integrate knowledge gained from model organisms and evaluate the implications for pathogenic mechanisms and therapeutic approaches.
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Affiliation(s)
- Debbie S Kuo
- Department of Ophthalmology, UCSF School of Medicine, San Francisco, CA 94143, USA
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Weng YC, Sonni A, Labelle-Dumais C, de Leau M, Kauffman WB, Jeanne M, Biffi A, Greenberg SM, Rosand J, Gould DB. COL4A1 mutations in patients with sporadic late-onset intracerebral hemorrhage. Ann Neurol 2012; 71:470-7. [PMID: 22522439 DOI: 10.1002/ana.22682] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
OBJECTIVE Mutations in the type IV collagen alpha 1 gene (COL4A1) cause dominantly inherited cerebrovascular disease. We seek to determine the extent to which COL4A1 mutations contribute to sporadic, nonfamilial, intracerebral hemorrhages (ICHs). METHODS We sequenced COL4A1 in 96 patients with sporadic ICH. The presence of putative mutations was tested in 145 ICH-free controls. The effects of rare coding variants on COL4A1 biosynthesis were compared to previously validated mutations that cause porencephaly, small vessel disease, and hereditary angiopathy, nephropathy, aneurysms, and cramps (HANAC) syndrome. RESULTS We identified 2 rare nonsynonymous variants in ICH patients that were not detected in controls, 2 rare nonsynonymous variants in controls that were not detected in patients, and 2 common nonsynonymous variants that were detected in patients and controls. No variant found in controls affected COL4A1 biosynthesis. Both variants (COL4A1(P352L) and COL4A1(R538G)) found only in patients changed conserved amino acids and impaired COL4A1 secretion much like mutations that cause familial cerebrovascular disease. INTERPRETATION This is the first assessment of the broader role for COL4A1 mutations in the etiology of ICH beyond a contribution to rare and severe familial cases and the first functional evaluation of the biosynthetic consequences of an allelic series of COL4A1 mutations that cause cerebrovascular disease. We identified 2 putative mutations in 96 patients with sporadic ICH and showed that these and other previously validated mutations inhibit secretion of COL4A1. Our data support the hypothesis that increased intracellular accumulation of COL4A1, decreased extracellular COL4A1, or both, contribute to sporadic cerebrovascular disease and ICH.
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Affiliation(s)
- Yi-Chinn Weng
- Department of Ophthalmology, Institute for Human Genetics, UCSF School of Medicine, San Francisco, CA, USA
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Verbeek E, Meuwissen MEC, Verheijen FW, Govaert PP, Licht DJ, Kuo DS, Poulton CJ, Schot R, Lequin MH, Dudink J, Halley DJ, de Coo RIF, den Hollander JC, Oegema R, Gould DB, Mancini GMS. COL4A2 mutation associated with familial porencephaly and small-vessel disease. Eur J Hum Genet 2012; 20:844-51. [PMID: 22333902 DOI: 10.1038/ejhg.2012.20] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Familial porencephaly, leukoencephalopathy and small-vessel disease belong to the spectrum of disorders ascribed to dominant mutations in the gene encoding for type IV collagen alpha-1 (COL4A1). Mice harbouring mutations in either Col4a1 or Col4a2 suffer from porencephaly, hydrocephalus, cerebral and ocular bleeding and developmental defects. We observed porencephaly and white matter lesions in members from two families that lack COL4A1 mutations. We hypothesized that COL4A2 mutations confer genetic predisposition to porencephaly, therefore we sequenced COL4A2 in the family members and characterized clinical, neuroradiological and biochemical phenotypes. Genomic sequencing of COL4A2 identified the heterozygous missense G1389R in exon 44 in one family and the c.3206delC change in exon 34 leading to frame shift and premature stop, in the second family. Fragmentation and duplication of epidermal basement membranes were observed by electron microscopy in a c.3206delC patient skin biopsy, consistent with abnormal collagen IV network. Collagen chain accumulation and endoplasmic reticulum (ER) stress have been proposed as cellular mechanism in COL4A1 mutations. In COL4A2 (3206delC) fibroblasts we detected increased rates of apoptosis and no signs of ER stress. Mutation phenotypes varied, including porencephaly, white matter lesions, cerebellar and optic nerve hypoplasia and unruptured carotid aneurysm. In the second family however, we found evidence for additional factors contributing to the phenotype. We conclude that dominant COL4A2 mutations are a novel major risk factor for familial cerebrovascular disease, including porencephaly and small-vessel disease with reduced penetrance and variable phenotype, which might also be modified by other contributing factors.
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Affiliation(s)
- Elly Verbeek
- Department of Clinical Genetics, Erasmus University Medical Center, Rotterdam, The Netherlands
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Jeanne M, Weng YC, de Leau M, Labelle-Dumais C, Kauffman BW, Greenberg SM, Rosand J, Gould DB. Abstract 3665: COL4A1 and COL4A2 Mutations cause Genetically Modifiable Cerebrovascular Diseases. Stroke 2012. [DOI: 10.1161/str.43.suppl_1.a3665] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Mutations in the type IV collagen alpha 1 gene (COL4A1) cause Cerebrovascular Diseases (CVDs) in mice and human patients. Patients with COL4A1 mutations suffer from a broad range of CVDs, from infantile porencephaly to debilitating or fatal intracerebral hemorrhage (ICH), to subclinical cerebral microbleeds, suggesting that environmental and other genetic factors may influence their phenotypes. COL4A1 is one of the most abundant proteins in basement membranes and forms heterotrimers with COL4A2. Among possible pathogenic mechanisms are cellular stress due to the toxic intracellular aggregation of the COL4A1 and COL4A2 proteins and/or their absence in the basement membrane. Our first goal is to identify the relative contributions of COL4A1 and COL4A2 mutations to sporadic ICH and to understand the cellular mechanisms and genetic complexity underlying the disease. We identified novel COL4A1 mutations and for the first time, we discovered COL4A2 mutations in a cohort of 96 patients with sporadic ICH. Using a cell-based assay we determined that the mutations impair COL4A1 and COL4A2 secretion. We showed that mutant COL4A1 or COL4A2 proteins accumulate within the cell where they titrate normal COL4A1 and COL4A2 proteins. Interestingly, we found that some of the mutations can ultimately result in endoplasmic reticulum (ER) stress and activation of the Unfolded Protein Response. Our second goal was to test the hypothesis that differences in genetic context could contribute to phenotypic variability in human patients. Thus, we characterized CVD in Col4a1 mutant mice with two different genetic backgrounds. Using cerebral magnetic resonance imaging and histological analysis, we show that one or more genetic modifiers from the CAST/EiJ strain significantly reduce the size and frequency of ICHs detected in Col4a1 mutant mice on a C57BL/6J background. In conclusion, we found that both COL4A1 and COL4A2 mutations cause ICH in human patients, our results support that ER stress could be involved in the pathogenesis and we showed that genetic context is crucial for expressivity and severity of the CVD. We predict that ongoing experiments to better understand the cell biology of COL4A1 and COL4A2 mutations and the mechanisms of genetic modification could lead to targeted therapeutics to reduce the risk of CVD in patients with COL4A1 or COL4A2 mutations.
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Affiliation(s)
- Marion Jeanne
- Univ of California, San Francisco (UCSF), San Francisco, CA
| | - Yi-Chinn Weng
- Univ of California, San Francisco (UCSF), San Francisco, CA
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Labelle-Dumais C, Dilworth DJ, Harrington EP, de Leau M, Lyons D, Kabaeva Z, Manzini MC, Dobyns WB, Walsh CA, Michele DE, Gould DB. COL4A1 mutations cause ocular dysgenesis, neuronal localization defects, and myopathy in mice and Walker-Warburg syndrome in humans. PLoS Genet 2011; 7:e1002062. [PMID: 21625620 PMCID: PMC3098190 DOI: 10.1371/journal.pgen.1002062] [Citation(s) in RCA: 99] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2010] [Accepted: 03/18/2011] [Indexed: 01/10/2023] Open
Abstract
Muscle-eye-brain disease (MEB) and Walker Warburg Syndrome (WWS) belong to a spectrum of autosomal recessive diseases characterized by ocular dysgenesis, neuronal migration defects, and congenital muscular dystrophy. Until now, the pathophysiology of MEB/WWS has been attributed to alteration in dystroglycan post-translational modification. Here, we provide evidence that mutations in a gene coding for a major basement membrane protein, collagen IV alpha 1 (COL4A1), are a novel cause of MEB/WWS. Using a combination of histological, molecular, and biochemical approaches, we show that heterozygous Col4a1 mutant mice have ocular dysgenesis, neuronal localization defects, and myopathy characteristic of MEB/WWS. Importantly, we identified putative heterozygous mutations in COL4A1 in two MEB/WWS patients. Both mutations occur within conserved amino acids of the triple-helix-forming domain of the protein, and at least one mutation interferes with secretion of the mutant proteins, resulting instead in intracellular accumulation. Expression and posttranslational modification of dystroglycan is unaltered in Col4a1 mutant mice indicating that COL4A1 mutations represent a distinct pathogenic mechanism underlying MEB/WWS. These findings implicate a novel gene and a novel mechanism in the etiology of MEB/WWS and expand the clinical spectrum of COL4A1-associated disorders. Muscle-eye-brain disease (MEB) and Walker-Warburg Syndrome (WWS) are devastating childhood diseases that belong to a subgroup of congenital muscular dystrophies (CMDs) characterized by ocular dysgenesis, neuronal migration defects, and congenital myopathy. Genetic studies have revealed a number of genes involved in the etiology of CMDs, and subsequent studies show that alterations in dystroglycan glycosylation underlie MEB/WWS. However, over half of MEB/WWS patients do not have mutations in known genes encoding glycosyltransferases, suggesting that other genes are involved. Here, we describe a novel and genetically complex mouse model for MEB/WWS and identify putative heterozygous mutations in COL4A1 in two MEB/WWS patients. We identify a novel gene implicated in the etiology of MEB/WWS, provide evidence of mechanistic heterogeneity for this subgroup of congenital muscular dystrophies, and develop an assay to test the functional significance of putative COL4A1 mutations. Our findings represent the first evidence for a dominant mutation leading to MEB/WWS–like diseases and expand the spectrum of clinical disorders resulting from Col4a1/COL4A1 mutations.
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Affiliation(s)
- Cassandre Labelle-Dumais
- Departments of Ophthalmology and Anatomy, Institute for Human Genetics, University of California San Francisco School of Medicine, San Francisco, California, United States of America
| | - David J. Dilworth
- Departments of Ophthalmology and Anatomy, Institute for Human Genetics, University of California San Francisco School of Medicine, San Francisco, California, United States of America
| | - Emily P. Harrington
- Departments of Ophthalmology and Anatomy, Institute for Human Genetics, University of California San Francisco School of Medicine, San Francisco, California, United States of America
| | - Michelle de Leau
- Departments of Ophthalmology and Anatomy, Institute for Human Genetics, University of California San Francisco School of Medicine, San Francisco, California, United States of America
| | - David Lyons
- Departments of Ophthalmology and Anatomy, Institute for Human Genetics, University of California San Francisco School of Medicine, San Francisco, California, United States of America
| | - Zhyldyz Kabaeva
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - M. Chiara Manzini
- Division of Genetics and The Manton Center for Orphan Disease Research, Children's Hospital Boston, Howard Hughes Medical Institute, and Harvard Medical School, Boston, Massachusetts, United States of America
| | - William B. Dobyns
- Departments of Human Genetics, Neurology, and Pediatrics, University of Chicago, Chicago, Illinois, United States of America
| | - Christopher A. Walsh
- Division of Genetics and The Manton Center for Orphan Disease Research, Children's Hospital Boston, Howard Hughes Medical Institute, and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Daniel E. Michele
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Douglas B. Gould
- Departments of Ophthalmology and Anatomy, Institute for Human Genetics, University of California San Francisco School of Medicine, San Francisco, California, United States of America
- * E-mail:
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Slavotinek AM, Baranzini SE, Schanze D, Labelle-Dumais C, Short KM, Chao R, Yahyavi M, Bijlsma EK, Chu C, Musone S, Wheatley A, Kwok PY, Marles S, Fryns JP, Maga AM, Hassan MG, Gould DB, Madireddy L, Li C, Cox TC, Smyth I, Chudley AE, Zenker M. Manitoba-oculo-tricho-anal (MOTA) syndrome is caused by mutations in FREM1. J Med Genet 2011; 48:375-82. [PMID: 21507892 DOI: 10.1136/jmg.2011.089631] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
BACKGROUND Manitoba-oculo-tricho-anal (MOTA) syndrome is a rare condition defined by eyelid colobomas, cryptophthalmos and anophthalmia/microphthalmia, an aberrant hairline, a bifid or broad nasal tip, and gastrointestinal anomalies such as omphalocele and anal stenosis. Autosomal recessive inheritance had been assumed because of consanguinity in the Oji-Cre population of Manitoba and reports of affected siblings, but no locus or cytogenetic aberration had previously been described. METHODS AND RESULTS This study shows that MOTA syndrome is caused by mutations in FREM1, a gene previously mutated in bifid nose, renal agenesis, and anorectal malformations (BNAR) syndrome. MOTA syndrome and BNAR syndrome can therefore be considered as part of a phenotypic spectrum that is similar to, but distinct from and less severe than, Fraser syndrome. Re-examination of Frem1(bat/bat) mutant mice found new evidence that Frem1 is involved in anal and craniofacial development, with anal prolapse, eyelid colobomas, telecanthus, a shortened snout and reduced philtral height present in the mutant mice, similar to the human phenotype in MOTA syndrome. CONCLUSIONS The milder phenotypes associated with FREM1 deficiency in humans (MOTA syndrome and BNAR syndrome) compared to that resulting from FRAS1 and FREM2 loss of function (Fraser syndrome) are also consistent with the less severe phenotypes resulting from Frem1 loss of function in mice. Together, Fraser, BNAR and MOTA syndromes constitute a clinically overlapping group of FRAS-FREM complex diseases.
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Affiliation(s)
- Anne M Slavotinek
- Department of Pediatrics, Division of Genetics, University of California, 533 Parnassus Street, Room U585P, San Francisco, CA 94143-0748, USA.
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46
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Chao R, Nevin L, Agarwal P, Riemer J, Bai X, Delaney A, Akana M, JimenezLopez N, Bardakjian T, Schneider A, Chassaing N, Schorderet DF, FitzPatrick D, Kwok PY, Ellgaard L, Gould DB, Zhang Y, Malicki J, Baier H, Slavotinek A. A male with unilateral microphthalmia reveals a role for TMX3 in eye development. PLoS One 2010; 5:e10565. [PMID: 20485507 PMCID: PMC2868029 DOI: 10.1371/journal.pone.0010565] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2009] [Accepted: 04/08/2010] [Indexed: 01/01/2023] Open
Abstract
Anophthalmia and microphthalmia are important birth defects, but their pathogenesis remains incompletely understood. We studied a patient with severe unilateral microphthalmia who had a 2.7 Mb deletion at chromosome 18q22.1 that was inherited from his mother. In-situ hybridization showed that one of the deleted genes, TMX3, was expressed in the retinal neuroepithelium and lens epithelium in the developing murine eye. We re-sequenced TMX3 in 162 patients with anophthalmia or microphthalmia, and found two missense substitutions in unrelated patients: c.116G>A, predicting p.Arg39Gln, in a male with unilateral microphthalmia and retinal coloboma, and c.322G>A, predicting p.Asp108Asn, in a female with unilateral microphthalmia and severe micrognathia. We used two antisense morpholinos targeted against the zebrafish TMX3 orthologue, zgc:110025, to examine the effects of reduced gene expression in eye development. We noted that the morphant larvae resulting from both morpholinos had significantly smaller eye sizes and reduced labeling with islet-1 antibody directed against retinal ganglion cells at 2 days post fertilization. Co-injection of human wild type TMX3 mRNA rescued the small eye phenotype obtained with both morpholinos, whereas co-injection of human TMX3(p.Arg39Gln) mutant mRNA, analogous to the mutation in the patient with microphthalmia and coloboma, did not rescue the small eye phenotype. Our results show that haploinsufficiency for TMX3 results in a small eye phenotype and represents a novel genetic cause of microphthalmia and coloboma. Future experiments to determine if other thioredoxins are important in eye morphogenesis and to clarify the mechanism of function of TMX3 in eye development are warranted.
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Affiliation(s)
- Ryan Chao
- Division of Genetics, Department of Pediatrics, University of California San Francisco, San Francisco, California, United States of America
| | - Linda Nevin
- Department of Physiology, University of California San Francisco, San Francisco, California, United States of America
| | - Pooja Agarwal
- Cardiovascular Research Institute, University of California San Francisco, San Francisco, California, United States of America
| | - Jan Riemer
- Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Xiaoyang Bai
- Departments of Ophthalmology, Anatomy and the Institute for Human Genetics, University of California San Francisco, San Francisco, California, United States of America
| | - Allen Delaney
- Genome Sciences Center, BC Cancer Research Center, Vancouver, British Columbia, Canada
| | - Matthew Akana
- Department of Dermatology, Cardiovascular Research Institute and Institute for Human Genetics, University of California San Francisco, San Francisco, California, United States of America
| | - Nelson JimenezLopez
- Division of Genetics, Department of Pediatrics, University of California San Francisco, San Francisco, California, United States of America
| | - Tanya Bardakjian
- Clinical Genetics Division, Albert Einstein Medical Center, Philadelphia, Pennsylvania, United States of America
| | - Adele Schneider
- Clinical Genetics Division, Albert Einstein Medical Center, Philadelphia, Pennsylvania, United States of America
| | - Nicolas Chassaing
- Service de Génétique Médicale, Université de Toulouse, Toulouse, France
| | - Daniel F. Schorderet
- Institut de Recherche en Ophtalmologie, University of Lausanne and Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - David FitzPatrick
- Medical Research Council Human Genetics Unit, Western General Hospital, Edinburgh, United Kingdom
| | - Pui-yan Kwok
- Department of Dermatology, Cardiovascular Research Institute and Institute for Human Genetics, University of California San Francisco, San Francisco, California, United States of America
| | - Lars Ellgaard
- Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Douglas B. Gould
- Departments of Ophthalmology, Anatomy and the Institute for Human Genetics, University of California San Francisco, San Francisco, California, United States of America
| | - Yan Zhang
- Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Jarema Malicki
- Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Herwig Baier
- Department of Physiology, University of California San Francisco, San Francisco, California, United States of America
| | - Anne Slavotinek
- Division of Genetics, Department of Pediatrics, University of California San Francisco, San Francisco, California, United States of America
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Firtina Z, Danysh BP, Bai X, Gould DB, Kobayashi T, Duncan MK. Abnormal expression of collagen IV in lens activates unfolded protein response resulting in cataract. J Biol Chem 2010; 284:35872-84. [PMID: 19858219 DOI: 10.1074/jbc.m109.060384] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Human diseases caused by mutations in extracellular matrix genes are often associated with an increased risk of cataract and lens capsular rupture. However, the underlying mechanisms of cataract pathogenesis in these conditions are still unknown. Using two different mouse models, we show that the accumulation of collagen chains in the secretory pathway activates the stress signaling pathway termed unfolded protein response (UPR). Transgenic mice expressing ectopic Col4a3 and Col4a4 genes in the lens exhibited activation of IRE1, ATF6, and PERK associated with expansion of the endoplasmic reticulum and attenuation of general protein translation. The expression of the transgenes had adverse effects on lens fiber cell differentiation and eventually induced cell death in a group of transgenic fiber cells. In Col4a1(+/Deltaex40) mutant mice, the accumulation of mutant chains also caused low levels of UPR activation. However, cell death was not induced in mutant lenses, suggesting that low levels of UPR activation are not proapoptotic. Collectively, the results provide in vivo evidence for a role of UPR in cataract formation in response to accumulation of terminally unfolded proteins in the endoplasmic reticulum.
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Affiliation(s)
- Zeynep Firtina
- Department of Biological Sciences, University of Delaware, Newark, Delaware 19716, USA
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Libby RT, Gould DB. Endoplasmic reticulum stress as a primary pathogenic mechanism leading to age-related macular degeneration. Adv Exp Med Biol 2010; 664:403-9. [PMID: 20238041 DOI: 10.1007/978-1-4419-1399-9_46] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Age-related macular degeneration (AMD) is a multi-factorial disease and a leading cause of blindness. Proteomic and genetic data suggest that activation or de-repression of the alternate complement cascade of innate immunity is involved in end-stage disease. Several lines of evidence suggest that production of reactive oxygen species and chronic oxidative stress lead to protein and lipid modifications that initiate the complement cascade. Understanding the triggers of these pathogenic pathways and the site of the primary insult will be important for development of targeted therapeutics. Endoplasmic reticulum (ER) stress from misfolded mutant proteins and other sources are an important potential tributary mechanism. We propose that misfolded-protein-induced ER stress in the retinal-pigmented epithelium and/or choroid could lead to chronic oxidative stress, complement deregulation and AMD. Small molecules targeted to ER stress and oxidative stress could allow for a shift from disease treatment to disease prevention.
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Affiliation(s)
- Richard T Libby
- Department of Ophthalmology and Biomedical Genetics, University of Rochester Medical School, Rochester, NY 14642, USA
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Bai X, Dilworth DJ, Weng YC, Gould DB. Developmental distribution of collagen IV isoforms and relevance to ocular diseases. Matrix Biol 2009; 28:194-201. [PMID: 19275937 DOI: 10.1016/j.matbio.2009.02.004] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2008] [Revised: 02/20/2009] [Accepted: 02/24/2009] [Indexed: 12/31/2022]
Abstract
Type IV collagens are the most abundant proteins in basement membranes. Distinct genes encode each of six isoforms, alpha1(IV) through alpha6(IV), which assemble into one of three characteristic heterotrimers. Disease-causing mutations in each of the six genes are identified in humans or mice and frequently include diverse ocular pathogenesis that encompass common congenital and progressive blinding diseases, such as optic nerve hypoplasia, glaucoma, and retinal degeneration. Understanding where and when collagen IV molecules are expressed is important because it defines limits for the location and timing of primary pathogenesis. Although localization of collagen IV isoforms in developed human eyes is known, the spatial and temporal distribution of type IV collagens throughout ocular development has not been determined in humans or in mice. Here, we use isoform-specific monoclonal antibodies to systematically reveal the localization of all six collagen IV isoforms in developing mouse eyes. We found that alpha1(IV) and alpha2(IV) always co-localized and were ubiquitously expressed throughout development. alpha3(IV) and alpha4(IV) also always co-localized but in a much more spatially and temporally specific manner than alpha1(IV) and alpha2(IV). alpha5(IV) co-localized both with alpha3(IV)/alpha4(IV), and with alpha6(IV), consistent with alpha5(IV) involvement in two distinct heterotrimers. alpha5(IV) was present in all basement membranes except those of the vasculature. alpha6(IV) was not detected in vasculature or in Bruch's membrane, indicating that alpha5(IV) in Bruch's membrane is part of the alpha3alpha4alpha5 heterotrimer. This comprehensive analysis defines the spatial and temporal distribution of type IV collagen isoforms in the developing eye, and will contribute to understanding the mechanisms underlying collagen IV-related ocular diseases that collectively lead to blindness in millions of people worldwide.
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Affiliation(s)
- Xiaoyang Bai
- Departments of Ophthalmology and Anatomy, Institute of Human Genetics, University of California, San Francisco, CA 94143, USA
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50
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Affiliation(s)
- K Vahedi
- Service de Neurologie, Assistance Publique-Hôpitaux de Paris, Hôpital Lariboisière, Service de Neurologie, 2 rue Ambroise Paré, 75010 Paris, France.
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