1
|
Vergaro A, Pankievic M, Jedlickova J, Dudakova L, Vajter M, Michaelides M, Meliska M, Nemec P, Babincova D, Kousal B, Liskova P. Disease-Causing TIMP3 Variants and Deep Phenotyping of Two Czech Families with Sorsby Fundus Dystrophy Associated with Novel p.(Tyr152Cys) Mutation. Int J Mol Sci 2024; 25:3744. [PMID: 38612555 PMCID: PMC11011298 DOI: 10.3390/ijms25073744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2024] [Revised: 03/20/2024] [Accepted: 03/25/2024] [Indexed: 04/14/2024] Open
Abstract
We aim to report the ocular phenotype and molecular genetic findings in two Czech families with Sorsby fundus dystrophy and to review all the reported TIMP3 pathogenic variants. Two probands with Sorsby fundus dystrophy and three first-degree relatives underwent ocular examination and retinal imaging, including optical coherence tomography angiography. The DNA of the first proband was screened using a targeted ocular gene panel, while, in the second proband, direct sequencing of the TIMP3 coding region was performed. Sanger sequencing was also used for segregation analysis within the families. All the previously reported TIMP3 variants were reviewed using the American College of Medical Genetics and the Association for Molecular Pathology interpretation framework. A novel heterozygous variant, c.455A>G p.(Tyr152Cys), in TIMP3 was identified in both families and potentially de novo in one. Optical coherence tomography angiography documented in one patient the development of a choroidal neovascular membrane at 54 years. Including this study, 23 heterozygous variants in TIMP3 have been reported as disease-causing. Application of gene-specific criteria denoted eleven variants as pathogenic, eleven as likely pathogenic, and one as a variant of unknown significance. Our study expands the spectrum of TIMP3 pathogenic variants and highlights the importance of optical coherence tomography angiography for early detection of choroidal neovascular membranes.
Collapse
Affiliation(s)
- Andrea Vergaro
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, 121 08 Prague, Czech Republic; (A.V.); (J.J.); (L.D.); (M.V.)
- Department of Ophthalmology, First Faculty of Medicine, Charles University and General University Hospital in Prague, 128 08 Prague, Czech Republic; (M.M.); (B.K.)
| | - Monika Pankievic
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, 121 08 Prague, Czech Republic; (A.V.); (J.J.); (L.D.); (M.V.)
| | - Jana Jedlickova
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, 121 08 Prague, Czech Republic; (A.V.); (J.J.); (L.D.); (M.V.)
| | - Lubica Dudakova
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, 121 08 Prague, Czech Republic; (A.V.); (J.J.); (L.D.); (M.V.)
| | - Marie Vajter
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, 121 08 Prague, Czech Republic; (A.V.); (J.J.); (L.D.); (M.V.)
- Department of Ophthalmology, First Faculty of Medicine, Charles University and General University Hospital in Prague, 128 08 Prague, Czech Republic; (M.M.); (B.K.)
| | - Michel Michaelides
- UCL Institute of Ophthalmology, University College London and Moorfields Eye Hospital, London EC1V 9EL, UK;
| | - Martin Meliska
- Department of Ophthalmology, First Faculty of Medicine, Charles University and General University Hospital in Prague, 128 08 Prague, Czech Republic; (M.M.); (B.K.)
| | - Pavel Nemec
- Department of Ophthalmology, First Faculty of Medicine and Military University Hospital Prague, 162 00 Prague, Czech Republic;
| | - Daniela Babincova
- Laboratory of Molecular Biology, AGEL, 741 01 Nový Jíčín, Czech Republic;
| | - Bohdan Kousal
- Department of Ophthalmology, First Faculty of Medicine, Charles University and General University Hospital in Prague, 128 08 Prague, Czech Republic; (M.M.); (B.K.)
| | - Petra Liskova
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, 121 08 Prague, Czech Republic; (A.V.); (J.J.); (L.D.); (M.V.)
- Department of Ophthalmology, First Faculty of Medicine, Charles University and General University Hospital in Prague, 128 08 Prague, Czech Republic; (M.M.); (B.K.)
| |
Collapse
|
2
|
Shaw PX, Stiles T, Douglas C, Ho D, Fan W, Du H, Xiao X. Oxidative stress, innate immunity, and age-related macular degeneration. AIMS MOLECULAR SCIENCE 2016; 3:196-221. [PMID: 27239555 PMCID: PMC4882104 DOI: 10.3934/molsci.2016.2.196] [Citation(s) in RCA: 120] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Age-related macular degeneration (AMD) is a leading cause of vision loss affecting tens of millions of elderly worldwide. Early AMD is characterized by the appearance of soft drusen, as well as pigmentary changes in the retinal pigment epithelium (RPE). These soft, confluent drusen can progress into two forms of advanced AMD: geographic atrophy (GA, or dry AMD) or choroidal neovascularization (CNV, or wet AMD). Both forms of AMD result in a similar clinical progression in terms of loss of central vision. The exact mechanism for developing early AMD, as well as triggers responsible for progressing to advanced stage of disease, is still largely unknown. However, significant evidence exists demonstrating a complex interplay of genetic and environmental factors as causes of AMD progression. Multiple genes and/or single nucleotide polymorphisms (SNPs) have been found associated with AMD, including various genes involved in the complement pathway, lipid metabolism and extracellular matrix (ECM) remodeling. Of the known genetic contributors to disease risk, the CFH Y402H and HTRA1/ARMS polymorphisms contribute to more than 50% of the genetic risk for AMD. Environmentally, oxidative stress plays a critical role in many aging diseases including cardiovascular disease, cancer, Alzheimer’s disease and AMD. Due to the exposure to sunlight and high oxygen concentration, the oxidative stress burden is higher in the eye than other tissues, which can be further complicated by additional oxidative stressors such as smoking. Increasingly, evidence is accumulating suggesting that functional abnormalities of the innate immune system incurred via high risk genotypes may be contributing to the pathogenesis of AMD by altering the inflammatory homeostasis in the eye, specifically in the handling of oxidation products. As the eye in non-pathological instances maintains a low level of inflammation despite the presence of a relative abundance of potentially inflammatory molecules, we have previously hypothesized that the tight homeostatic control of inflammation via the innate immune system is likely critical for avoidance of disease progression. However, the presence of a multitude of potential triggers of inflammation results in a sensitive balance in which perturbations thereof would subsequently alter the inflammatory state of the retina, leading to a state of chronic inflammation and pathologic progression. In this review, we will highlight the background literature surrounding the known genetic and environmental contributors to AMD risk, as well as a discussion of the potential mechanistic interplay of these factors that lead to disease pathogenesis with particular emphasis on the delicate control of inflammatory homeostasis and the centrality of the innate immune system in this process.
Collapse
Affiliation(s)
- Peter X Shaw
- Department of Ophthalmology and Shiley Eye Institute, University of California San Diego, San Diego, CA, USA
| | - Travis Stiles
- Department of Ophthalmology and Shiley Eye Institute, University of California San Diego, San Diego, CA, USA
| | - Christopher Douglas
- Department of Ophthalmology and Shiley Eye Institute, University of California San Diego, San Diego, CA, USA
| | - Daisy Ho
- Department of Ophthalmology and Shiley Eye Institute, University of California San Diego, San Diego, CA, USA
| | - Wei Fan
- Huaxi Hospital, Sichuan University, China
| | | | - Xu Xiao
- Sichuan People's Hospital, Chengdu, Sichuan, China
| |
Collapse
|
3
|
Abstract
PURPOSE To report a novel mutation occurring in the N-terminal domain of the tissue inhibitor of metalloproteinase 3 (TIMP3) gene in Sorsby fundus dystrophy. METHODS Retrospective review of medical records of two patients who had clinical features consistent with Sorsby fundus dystrophy. Genetic testing confirmed a mutation in the TIMP3 gene in both patients. RESULTS Both patients had findings of drusenlike deposits, retinal pigment epithelial and photoreceptor atrophy, and bilateral, recurrent choroidal neovascularization. A strong family history of early onset macular degeneration was present in both. The patients developed choroidal neovascularization at the age of 45 and 48 years, and both had multiple recurrences in both eyes. Genetic testing in both patients confirmed a heterozygous nucleotide change of C113G, causing a Ser38Cys change in Exon 1 of the N-terminal domain of the TIMP3 gene. CONCLUSION All previously reported mutations in Sorsby fundus dystrophy occur at Exon 5 in the C-terminal domain. We report 2 patients with novel mutations in Exon 1 of the N-terminal domain. Although the mutation occurs at a different location on the TIMP3 gene, the clinical features are similar to other reported patients with Sorsby fundus dystrophy. This finding assists in understanding the pathogenesis of this disorder.
Collapse
|
4
|
A Review and Update on the Molecular Basis of Pathogenesis of Sorsby Fundus Dystrophy. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 723:261-7. [DOI: 10.1007/978-1-4614-0631-0_34] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
|
5
|
Bourboulia D, Jensen-Taubman S, Stetler-Stevenson WG. TIMP-2: An Endogenous Angiogenesis Inhibitor with Distinct Antitumoral Properties. TREATMENT STRATEGIES. HEMATOLOGY 2012; 2:31-35. [PMID: 31380106 PMCID: PMC6677273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Affiliation(s)
- Dimitra Bourboulia
- Radiation Oncology Branch, Center for Cancer Research, NCI/NIH, Advanced Technology Center, Bethesda, Maryland
| | - Sandra Jensen-Taubman
- Radiation Oncology Branch, Center for Cancer Research, NCI/NIH, Advanced Technology Center, Bethesda, Maryland
| | - William G Stetler-Stevenson
- Chief, Extracellular Matrix Pathology Section, Radiation Oncology Branch, Center for Cancer Research, NCI/NIH, Advanced Technology Center, Bethesda, Maryland
| |
Collapse
|
6
|
Fogarasi M, Janssen A, Weber BHF, Stöhr H. Molecular dissection of TIMP3 mutation S156C associated with Sorsby fundus dystrophy. Matrix Biol 2008; 27:381-92. [PMID: 18295466 DOI: 10.1016/j.matbio.2008.01.008] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2007] [Revised: 12/20/2007] [Accepted: 01/22/2008] [Indexed: 01/09/2023]
Abstract
Sorsby fundus dystrophy (SFD) is an autosomal dominant macular degeneration of late onset. A key feature of the disease is the thickening of Bruch's membrane, an ECM structure located between the RPE and the choroid. SFD is caused by mutations in the gene encoding the ECM-associated tissue inhibitor of metalloproteases-3 (TIMP3). We have recently generated two Timp3 gene-targeted mouse lines, one deficient for the murine gene (Timp3-/-) and one carrying an SFD-related S156C mutation. Based on extracts and cell cultures derived from tissues of these animals we now evaluated TIMP3 functionality and its contribution to SFD. We show that the activity levels of TIMP3 target proteases including TACE, ADAMTS4/5 and aggrecan-cleaving MMPs are similar in Timp3S156/+ and Timp3S156C/S156C mice when compared to controls. In Timp3-/- mice, a significant enhancement of enzyme activity was observed for TACE but not for ADAMTS4/5 and MMPs indicating a compensatory effect of other inhibitors regulating the latter two groups of proteases. Fibrin bead assays show that angiogenesis in Timp3S156/+ and Timp3S156C/S156C mice is not altered whereas increased formation of capillary tubes was observed in Timp3-/- animals over controls. Rescue experiments using recombinant proteins demonstrate that the inhibitory activities of TIMP3 towards TACE and aggrecan-cleaving MMPs as well as the anti-angiogenic properties of TIMP3 are not impaired by SFD mutation S156C. We finally demonstrate that wild-type and S156C-TIMP3 proteins block the binding of VEGF to its receptor VEGFR2 to a similar extent. Taken together, this study shows that S156C-TIMP3 retains its known functional properties suggesting that causes other than an imbalance in protease or angiogenic activities represent the primary molecular defect underlying SFD.
Collapse
Affiliation(s)
- Marton Fogarasi
- Institute of Human Genetics, University of Regensburg, Franz-Josef-Strauss-Allee 11, D-93053 Regensburg, Germany
| | | | | | | |
Collapse
|
7
|
Kothapalli KS, Anthony JC, Pan BS, Hsieh AT, Nathanielsz PW, Brenna JT. Differential cerebral cortex transcriptomes of baboon neonates consuming moderate and high docosahexaenoic acid formulas. PLoS One 2007; 2:e370. [PMID: 17426818 PMCID: PMC1847718 DOI: 10.1371/journal.pone.0000370] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2007] [Accepted: 03/20/2007] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Docosahexaenoic acid (DHA, 22:6n-3) and arachidonic acid (ARA, 20:4n-6) are the major long chain polyunsaturated fatty acids (LCPUFA) of the central nervous system (CNS). These nutrients are present in most infant formulas at modest levels, intended to support visual and neural development. There are no investigations in primates of the biological consequences of dietary DHA at levels above those present in formulas but within normal breastmilk levels. METHODS AND FINDINGS Twelve baboons were divided into three formula groups: Control, with no DHA-ARA; "L", LCPUFA, with 0.33%DHA-0.67%ARA; "L3", LCPUFA, with 1.00%DHA-0.67%ARA. All the samples are from the precentral gyrus of cerebral cortex brain regions. At 12 weeks of age, changes in gene expression were detected in 1,108 of 54,000 probe sets (2.05%), with most showing <2-fold change. Gene ontology analysis assigns them to diverse biological functions, notably lipid metabolism and transport, G-protein and signal transduction, development, visual perception, cytoskeleton, peptidases, stress response, transcription regulation, and 400 transcripts having no defined function. PLA2G6, a phospholipase recently associated with infantile neuroaxonal dystrophy, was downregulated in both LCPUFA groups. ELOVL5, a PUFA elongase, was the only LCPUFA biosynthetic enzyme that was differentially expressed. Mitochondrial fatty acid carrier, CPT2, was among several genes associated with mitochondrial fatty acid oxidation to be downregulated by high DHA, while the mitochondrial proton carrier, UCP2, was upregulated. TIMM8A, also known as deafness/dystonia peptide 1, was among several differentially expressed neural development genes. LUM and TIMP3, associated with corneal structure and age-related macular degeneration, respectively, were among visual perception genes influenced by LCPUFA. TIA1, a silencer of COX2 gene translation, is upregulated by high DHA. Ingenuity pathway analysis identified a highly significant nervous system network, with epidermal growth factor receptor (EGFR) as the outstanding interaction partner. CONCLUSIONS These data indicate that LCPUFA concentrations within the normal range of human breastmilk induce global changes in gene expression across a wide array of processes, in addition to changes in visual and neural function normally associated with formula LCPUFA.
Collapse
Affiliation(s)
- Kumar S.D. Kothapalli
- Division of Nutritional Sciences, Cornell University, Savage Hall, Ithaca, New York, United States of America
| | - Joshua C. Anthony
- Mead Johnson and Company, Evansville, Indiana, United States of America
| | - Bruce S. Pan
- Division of Nutritional Sciences, Cornell University, Savage Hall, Ithaca, New York, United States of America
| | - Andrea T. Hsieh
- Division of Nutritional Sciences, Cornell University, Savage Hall, Ithaca, New York, United States of America
| | - Peter W. Nathanielsz
- Center for Pregnancy and Newborn Research, University of Texas Health Science Center, San Antonio, Texas, United States of America
| | - J. Thomas Brenna
- Division of Nutritional Sciences, Cornell University, Savage Hall, Ithaca, New York, United States of America
| |
Collapse
|
8
|
Majid MA, Smith VA, Newby AC, Dick AD. Matrix bound SFD mutant TIMP-3 is more stable than wild type TIMP-3. Br J Ophthalmol 2007; 91:1073-6. [PMID: 17383996 PMCID: PMC1954801 DOI: 10.1136/bjo.2006.113225] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND Sorsby's fundus dystrophy (SFD) is a degenerative retinopathy characterised by accumulation of mutant TIMP-3 protein in Bruch's membrane. AIM To compare the stability of matrix bound SFD mutant TIMP-3s with wild type TIMP-3. METHODS COS-7 cells were transfected with plasmids containing wild type, Ser 181, Gly-167, Ser-156, and Tyr-168 TIMP-3 cDNA. The cells and their matrices were subsequently harvested and homogenised. After measuring the bound wild type and SFD mutant TIMP-3 concentrations by ELISA, aliquots of the homogenates were heated to 100 degrees C. The rates of denaturation of the TIMP proteins at this temperature were monitored by reverse zymography. RESULTS Over a period of 24 h at 100 degrees C the biological activity of both wild type and SFD mutant TIMP-3 was lost. Over a period of 6 h at this temperature the biological activity of the SFD mutant TIMP-3s was fully retained whereas that of the wild type TIMP-3 was lost. CONCLUSION Matrix bound SFD mutant TIMP-3s are thermodynamically more stable than wild type. This may explain why SFD starts earlier in life than age related macular degeneration.
Collapse
|
9
|
Pasqualetti G, Danesi R, Del Tacca M, Bocci G. Vascular endothelial growth factor pharmacogenetics: a new perspective for anti-angiogenic therapy. Pharmacogenomics 2007; 8:49-66. [PMID: 17187509 DOI: 10.2217/14622416.8.1.49] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The pharmacogenetic approach to anti-angiogenic therapy should be considered a possible strategy for many pathological conditions with high incidence in Western countries, including solid tumors, age-related macular degeneration or endometriosis. While pharmacogenetic studies are building stronger foundations for the systematic investigations of phenotype–genotype relationships in many research and clinical fields of medicine, pharmacogenetic data regarding anti-angiogenic drugs are still lacking. Here we review preclinical and clinical genetic studies on angiogenic determinants such as vascular endothelial growth factor and vascular endothelial growth factor receptor-2. We suggest that pharmacogenetic profiling of patients who are candidates for the currently available anti-angiogenic agents targeting vascular endothelial growth factor and vascular endothelial growth factor receptor-2 may aid the selection of patients on the basis of their likelihood of responding to the drugs or suffering from toxicity.
Collapse
Affiliation(s)
- Giuseppe Pasqualetti
- University of Pisa, Division of Pharmacology and Chemotherapy, Department of Internal Medicine, Via Roma, 55, I-56126 Pisa, Italy
| | | | | | | |
Collapse
|
10
|
Lin RJ, Blumenkranz MS, Binkley J, Wu K, Vollrath D. A novel His158Arg mutation in TIMP3 causes a late-onset form of Sorsby fundus dystrophy. Am J Ophthalmol 2006; 142:839-48. [PMID: 16989765 DOI: 10.1016/j.ajo.2006.06.003] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2006] [Revised: 05/27/2006] [Accepted: 06/01/2006] [Indexed: 10/24/2022]
Abstract
PURPOSE To describe the phenotype and genotype of a family with suspected Sorsby fundus dystrophy (SFD). DESIGN Case reports and results of deoxyribonucleic acid (DNA) analysis. METHODS Clinical features were determined by complete ophthalmologic examination or by review of medical records. Mutational analysis of the tissue inhibitor of metalloproteinase (TIMP)3 gene was performed by DNA resequencing. Biochemical properties of the mutant TIMP3 protein were studied, and phylogenetic and molecular modeling analyses of TIMP proteins were performed. RESULTS Fundi of four affected family members demonstrated active or regressed bilateral choroidal neovascularization, whereas another affected individual displayed severe diffuse pigmentary degeneration associated with nyctalopia characteristic of SFD. Onset of disease occurred in the fifth to seventh decades of life. A heterozygous His158Arg mutation was found in seven affected family members and was absent from an unaffected member and 98 unrelated controls. Bioinformatic analyses indicate that histidine 158 is an evolutionarily conserved residue in most vertebrate TIMP homologs and predict that substitution by arginine disrupts TIMP3 function. The mutant protein appears to be expressed by fibroblasts from an affected family member. Molecular modeling suggests that TIMP3 residue 158 may be part of a protein-protein interaction interface. CONCLUSION A novel mutation in TIMP3 causes a late-onset form of SFD in this family. His158Arg is the first reported TIMP3 SFD coding sequence mutation that does not create an unpaired cysteine. Further study of this unusual mutation may provide insight into the mechanism of SFD pathogenesis.
Collapse
Affiliation(s)
- Ruth J Lin
- Department of Genetics, Stanford University School of Medicine, Stanford, California 94305-5120, USA
| | | | | | | | | |
Collapse
|
11
|
Langton KP, McKie N, Smith BM, Brown NJ, Barker MD. Sorsby's fundus dystrophy mutations impair turnover of TIMP-3 by retinal pigment epithelial cells. Hum Mol Genet 2005; 14:3579-86. [PMID: 16223891 DOI: 10.1093/hmg/ddi385] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Sorsby's fundus dystrophy (SFD) is an autosomal dominant degenerative disease of the retina, caused by mutations in exon 5 of the gene for tissue inhibitor of metalloproteinases-3 (TIMP-3). The mechanism by which these mutations give rise to the disease phenotype is unknown. In an attempt to identify common properties of these molecules that might underlie the disease phenotype, a range of SFD mutants were expressed from human retinal pigment epithelial (RPE) cells. This showed that resistance to turnover, resulting from intermolecular disulfide bond formation, was a common property of all the SFD mutants examined, providing a possible explanation for the increased deposition of the protein observed in eyes from SFD patients. In contrast, SFD mutants varied in their ability to inhibit cell-surface activation of matrix metalloproteinase-2 (MMP-2), a potent mediator of angiogenesis, ranging from being fully active to totally inactive. These data show that increased deposition of active TIMP-3, rather than dysregulation of metalloproteinase inhibition, is likely to be the primary, initiating event in SFD.
Collapse
Affiliation(s)
- Kevin P Langton
- Academic Unit of Pathology, Division of Genomic Medicine, University of Sheffield, Sheffield S10 1EW, UK
| | | | | | | | | |
Collapse
|
12
|
Soboleva G, Geis B, Schrewe H, Weber BHF. Sorsby fundus dystrophy mutation Timp3(S156C) affects the morphological and biochemical phenotype but not metalloproteinase homeostasis. J Cell Physiol 2003; 197:149-56. [PMID: 12942551 DOI: 10.1002/jcp.10361] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The tissue inhibitor of metalloproteinases-3 (TIMP3) is a multifunctional protein tightly associated with the extracellular matrix (ECM). A specific type of mutation in TIMP3 which results in potentially unpaired cysteine residues at the C-terminus of the protein has been shown to cause Sorsby fundus dystrophy (SFD), an autosomal dominant retinopathy of late onset. An early finding in SFD is a striking accumulation of protein and lipid material in Bruch's membrane, a multilayered ECM structure located between the choroid and the RPE. To study the molecular mechanisms underlying SFD pathology, we recently generated two mouse lines, one deficient in Timp3 (Timp3(-/-)) and one carrying an SFD-related mutation in the orthologous murine Timp3 gene (Timp3(S156C/S156C)). We now established immortalized fibroblast cells from the mutant mouse strains and provide evidence that the various cell lines display distinct morphological and physiological features that are dependent on the mutational status of the Timp3 protein in the secreted ECM. We show that matrix metalloproteinase (MMP) activity and inhibitory properties of Timp3 are not affected by the SFD-associated mutation. We further demonstrate that Timp3(S156C) protein accumulates in the ECM of the mutant fibroblast cells and that this accumulation is not due to a prolonged turnover rate of mutant vs. normal Timp3. We also show that the relative abundance of mutant and normal Timp3 in the ECM has no measurable effects on cellular phenotypes. Together, these findings suggest (i) a functional role of normal Timp3 in pathways determining cellular morphology and (ii) a loss of this particular function as a consequence of the Ser156Cys mutation. We therefore hypothesize that SFD pathogenesis is due to a loss-of-function mutation in TIMP3.
Collapse
Affiliation(s)
- Galina Soboleva
- Institut für Humangenetik, Biozentrum, Julius-Maximilians-Universität Würzburg, Würzburg, Germany
| | | | | | | |
Collapse
|
13
|
Arris CE, Bevitt DJ, Mohamed J, Li Z, Langton KP, Barker MD, Clarke MP, McKie N. Expression of mutant and wild-type TIMP3 in primary gingival fibroblasts from Sorsby's fundus dystrophy patients. BIOCHIMICA ET BIOPHYSICA ACTA 2003; 1638:20-8. [PMID: 12757930 DOI: 10.1016/s0925-4439(03)00036-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Gingival fibroblast cell lines were derived from Sorsby's fundus dystrophy (SFD) patients carrying the S181C TIMP3 and the E139X TIMP3 mutations. These cell lines were grown in culture to study expression of the wild-type and mutant tissue inhibitor of metalloproteinase 3 (TIMP3) alleles from a normal diploid cell type. Firstly, patient cells were found to co-express the wild-type and mutant TIMP3 alleles, S181C TIMP3 or E139X TIMP3, at the mRNA level using restriction fragment length polymorphism (RFLP) analysis. A SpeI RFLP for E139X TIMP3 is described. Low levels of endogenous TIMP3 protein expression were elevated using the natural polysaccharide calcium pentosan polysulfate (CaPPs) in combination with the cytokine IL-1alpha. Immunoblotting detected protein expression from both wild-type and mutant alleles, S181C TIMP3 or E139X TIMP3. S181C TIMP3 from these cells was found to dimerise and retain MMP2 inhibitory activity. To facilitate studies of the E139X TIMP3 protein, the allele was expressed using HighFive insect cells. In this cell type, the E139X TIMP3 was synthesised as a mixture of monomer and dimer. Both monomeric and dimeric E139X TIMP3 protein retained MMP2 inhibitory activity in gelatin zymography. Expression of mutant E139X or S181C TIMP3 protein from a normal diploid patient-derived fibroblast cell had no effect on either MMP2 or MMP9 expression or activation whilst transcribed from their normal promoter context.
Collapse
Affiliation(s)
- Christine E Arris
- Department of Rheumatology and Gerentology, University of Newcastle Medical School, Framlington Place, NE2 4HH, Newcastle, UK
| | | | | | | | | | | | | | | |
Collapse
|