Papers by Cheryl Gregory-Evans
Autosomal Dominant Macular Dystrophy Simulating North Carolina Macular Dystrophy
Archives of Ophthalmology, 1995
To characterize an autosomal dominant macular dystrophy with highly variable expression that does... more To characterize an autosomal dominant macular dystrophy with highly variable expression that does not fall clearly into a known disease entity. Clinical, angiographic, and electrophysiologic data of five affected members in a family of Indian origin were evaluated. Molecular genetic analysis was undertaken to assess whether the gene responsible for the phenotype in this pedigree mapped to a region previously assigned to dominantly inherited macular dystrophies, including North Carolina macular dystrophy. The fundus appearance in the proband simulated stage 3 North Carolina macular dystrophy. Affected relatives had features in common with pattern dystrophy, fundus flavimaculatus with a dark choroid, and dominantly inherited drusen. Linkage to loci assigned to a number of retinal dystrophies principally affecting the posterior pole, including the North Carolina macular dystrophy locus, was excluded. The findings support the view that different genotypes are associated with similar phenotypes in autosomal dominant macular dystrophy.
Optimized cell-handling of human embryonic stem cells in the differentiation of photoreceptor precursor cells
International Journal of Inflammation, 2013
Genetic retinal diseases such as age-related macular degeneration and monogenic diseases such as ... more Genetic retinal diseases such as age-related macular degeneration and monogenic diseases such as retinitis pigmentosa account for some of the commonest causes of blindness in the developed world. Diverse genetic abnormalities and environmental causes have been implicated in triggering multiple pathological mechanisms such as oxidative stress, lipofuscin deposits, neovascularisation, and programmed cell death. In recent years, inflammation has also been highlighted although whether inflammatory mediators play a central role in pathogenesis or a more minor secondary role has yet to be established. Despite this, numerous interventional studies, particularly targeting the complement system, are underway with the promise of novel therapeutic strategies for these important blinding conditions.
Autosomal dominant cone–rod retinal dystrophy (CORD6) from heterozygous mutation of GUCY2D , which encodes retinal guanylate cyclase 1 1The authors have no proprietary interests in the materials mentioned in the study
Ophthalmology, 2000
To describe the clinical features of autosomal dominant cone-rod retinal dystrophy (CRD) in a Bri... more To describe the clinical features of autosomal dominant cone-rod retinal dystrophy (CRD) in a British family mapping to chromosome 17p12-p13 (CORD6), with a heterozygous mutation (Glu837Asp/ Arg838Ser) of GUCY2D. A prospective, clinical family survey. Ten affected members of a family with autosomal dominant CRD. Full clinical examinations were undertaken. Selected affected family members underwent electrophysiologic evaluation, scotopic static perimetry, dark adaptometry, and color vision assessment. Clinical appearance and electroretinographic responses. Typical clinical and electroretinographic features of childhood-onset CRD were recorded. In addition, moderate myopia and pendular nystagmus were seen in affected individuals. Color vision assessment in the youngest affected individual showed no color discrimination on a tritan axis, but retention of significant red-green discrimination. Electronegative electroretinogram responses were seen on electrophysiology in the only young family member examined. The phenotype associated with GUCY2D CRD is clinically distinct from that associated with other dominant CRD loci. Unusual electroretinographic responses may indicate that this mutation of GUCY2D is associated with early defects in photoreceptor synaptic transmission to second-order neurons.
IEEE Transactions on Magnetics, 2013
Mesenchymal stem cells (MSCs) have well-established paracrine effects that are proving to be ther... more Mesenchymal stem cells (MSCs) have well-established paracrine effects that are proving to be therapeutically useful. This potential is based on the ability of MSCs to secrete a range of neuroprotective and anti-inflammatory molecules. Previous work in our laboratory has demonstrated that intravenous injection of MSCs, treated with superparamagnetic iron oxide nanoparticle fluidMAG-D resulted in enhanced levels of glial-derived neurotrophic factor, ciliary neurotrophic factor, hepatocyte growth factor and interleukin-10 in the dystrophic rat retina. In this present study we investigated whether the concentration of fluidMAG-D in cell culture media affects the secretion of these four molecules in vitro. In addition, we assessed the effect of fluidMAG-D concentration on retinoschisin secretion from genetically modified MSCs. ELISA-assayed secretion of these molecules was measured using escalating concentrations of fluidMAG-D which resulted in MSC iron loads of 0, 7, 120, or 274 pg iron oxide per cell respectively. Our results demonstrated glial-derived neurotrophic factor and hepatocyte growth factor secretion was significantly decreased but only at the 96 hour's time-point whereas no statistically significant effect was seen with ciliary neurotrophic factor secretion. Whereas no effect was observed on culture media concentrations of retinoschisin with increasing iron oxide load, a statistically significant increase in cell lysate retinoschisin concentration was observed suggesting that increasing fluidMAG-D concentration did increase retinoschisin production but this did not lead to greater secretion. We hypothesize that higher concentrations of iron-oxide nanoparticle fluidMAG-D have an effect on the innate ability of MSCs to secrete therapeutically useful molecules and also on secretion from genetically modified cells. Further work is required to verify these in vitro finding using in vivo model systems.
Cell Transplantation, 2012
Developing new ways of delivering cells to diseased tissue will be a key factor in translating ce... more Developing new ways of delivering cells to diseased tissue will be a key factor in translating cell therapeutics research into clinical use. Magnetically targeting cells enables delivery of significant numbers of cells to key areas of specific organs. To demonstrate feasibility in neurological tissue, we targeted cells magnetically to the upper hemisphere of the rodent retina. Rat mesenchymal stem cells (MSCs) were magnetized using superparamagnetic iron oxide nanoparticles (SPIONs). In vitro studies suggested that magnetization with fluidMAG-D was well tolerated, that cells remained viable, and they retained their differentiation capabilities. FluidMAG-D-labeled MSCs were injected intravitreally or via the tail vein of the S334ter-4 transgenic rat model of retinal degeneration with or without placing a gold-plated neodymium disc magnet within the orbit, but outside the eye. Retinal flatmount and cryosection imaging demonstrated that after intravitreal injection cells localized to t...
British Journal of Ophthalmology, 1998
Aims-To document the phenotype of an autosomal dominant macular dystrophy diagnosed as having Nor... more Aims-To document the phenotype of an autosomal dominant macular dystrophy diagnosed as having North Carolina macular dystrophy (NCMD) in this British family, and to verify that the disease locus corresponds with that of MCDR1 on chromosome 6q. Methods-37 family members were examined and the phenotype characterised. DNA samples from the aVected members, 19 unaVected and five spouses, were used to perform linkage analysis with six microsatellite marker loci situated within the MCDR1 region of chromosome 6q. Results-Every aVected family member had lesions characteristic of NCMD, which developed early in life and usually remain stable thereafter. Although fundus changes are evident in the periphery, all tests revealed that functional loss is restricted to the macula. Some patients with large macular lesions had good visual acuity with fixation at the edge of the lesion at 5°eccentricity. Significant linkage to the MCDR1 locus on chromosome 6q was obtained with three marker loci, with a maximum lod score of 5.9 (q = 0.00) obtained with D6S249. Conclusion-This family has the typical phenotype NCMD, and the causative gene was linked to the disease locus (MCDR1) on chromosome 6q. Early onset and localisation of the disease to the central macula allow specialisation of eccentric retina in some eyes with resultant good visual acuity.
The American Journal of Human Genetics, 1998
Localization of a Gene (CORD7) for a Dominant Cone-Rod Dystrophy to Chromosome 6q To the Editor: ... more Localization of a Gene (CORD7) for a Dominant Cone-Rod Dystrophy to Chromosome 6q To the Editor: The cone-rod dystrophies are a heterogeneous group of retinal disorders, often leading to registrable blindness, that are characterized by an initial loss of cone photoreceptors, followed by the degeneration of rod photoreceptors. Recent genetic studies have mapped the disorder to a number of different chromosomal locations (Evans et al. 1994; Kelsell et al. 1997), although, to date, mutations have been identified in only three genes, peripherin/RDS (Nakazawa et al. 1994, 1996a, 1996b; Kohl et al. 1997), CRX (Freund et al. 1997), and retinal guanylate cyclase (Kelsell et al., in press). In the present study, a new chromosomal localization for an autosomal dominant cone-rod dystrophy is reported. In accordance with the guidelines of the Nomenclature Review Committee, "CORD7" has been assigned as the gene designation for this disorder. A four-generation British family was recruited for the study. Affected members of the family first became aware of reduced color vision and visual acuity between the ages of 20 and 40 years. As the disorder progressed, they reported difficulty seeing in bright light, and one individual (IV-1; fig. 1A) reported visual problems in dim light. At the onset of symptoms, retinal pigmentary changes were already present around the fovea, simulating a bull's eye dystrophy, which developed to macular atrophy. Electrophysiological tests in advanced disease showed that scotopic rod responses were barely detectable and that all cone responses were severely attenuated (fig. 1B) but with no change in implicit time. Pattern electroretinography (ERG) was extinguished, in keeping with the severe macular dysfunction. No significant intraocular asymmetry was present. EDTA blood samples were obtained from eight affected family members, eight unaffected family members, and four spouses, for linkage analysis (fig. 1). DNA was extracted from these samples with a Nucleon II extraction kit (Scotlab Bioscience).
Strabismus is a common condition, affecting 1-4% of individuals. Isolated strabismus has been stu... more Strabismus is a common condition, affecting 1-4% of individuals. Isolated strabismus has been studied in families with Mendelian inheritance patterns. Despite the identification of multiple loci via linkage analyses, no specific genes have been identified from these studies. The current study is based on a seven-generation family with isolated strabismus inherited in an autosomal dominant manner. A total of 13 individuals from a common ancestor have been included for linkage analysis, and a single linkage signal has been identified at chromosome 14q12 with a multipoint LOD score of 4.69. Disruption of this locus is known to cause FOXG1 syndrome (or congenital Rett syndrome; OMIM #613454 and *164874), in which 84% of affected individuals present with strabismus. With the incorporation of next generation sequencing and in-depth bioinformatic analyses, a 4bp non-coding deletion was prioritized as the top candidate for the observed strabismus phenotype. The deletion is predicted to disr...
Human Molecular Genetics
Mutations in KIF14 have previously been associated with either severe, isolated or syndromic micr... more Mutations in KIF14 have previously been associated with either severe, isolated or syndromic microcephaly with renal hypodysplasia (RHD). Syndromic microcephaly-RHD was strongly reminiscent of clinical ciliopathies, relating to defects of the primary cilium, a signalling organelle present on the surface of many quiescent cells. KIF14 encodes a mitotic kinesin which plays a key role at the midbody during cytokinesis and has not previously been shown to be involved in cilia-related functions. Here, we analysed four families with foetuses presenting with the syndromic form and harbouring biallelic variants in KIF14. Our functional analyses show that the identified variants severely impact the activity of KIF14 and likely correspond to loss-of-function mutations. Analysis in human foetal tissues further revealed the accumulation of KIF14-positive midbody remnants in the lumen of ureteric bud tips indicating a shared function of KIF14 during brain and kidney development. Subsequently, analysis of a kif14 mutant zebrafish line showed a conserved role for this mitotic kinesin. Interestingly, ciliopathy-associated phenotypes were also present in mutant embryos, supporting a potential direct or indirect role for KIF14 at cilia. However, our in vitro and in vivo analyses did not provide evidence of a direct role for KIF14 in ciliogenesis and suggested that loss of kif14 causes ciliopathy-like phenotypes through an accumulation of mitotic cells in ciliated tissues. Altogether, our results demonstrate that KIF14 mutations result in a severe syndrome associating microcephaly and RHD through its conserved function in cytokinesis during kidney and brain development.
Scientific reports, Jan 20, 2018
Zebrafish have been used to investigate motor neuron degeneration, including as a model system to... more Zebrafish have been used to investigate motor neuron degeneration, including as a model system to examine the pathogenesis of amyotrophic lateral sclerosis (ALS). The use of zebrafish for this purpose has some advantages over other in vivo model systems. In the current paper, we show that bisphenol A (BPA) exposure in zebrafish embryos results in motor neuron degeneration with affected motor function, reduced motor axon length and branching, reduced neuromuscular junction integrity, motor neuron cell death and the presence of activated microglia. In zebrafish, motor axon length is the conventional method for estimating motor neuron degeneration, yet this measurement has not been confirmed as a valid surrogate marker. We also show that reduced motor axon length as measured from the sagittal plane is correlated with increased motor neuron cell death. Our preliminary timeline studies suggest that axonopathy precedes motor cell death. This outcome may have implications for early phase t...
Correlation of novel PAX6 gene abnormalities in aniridia and clinical presentation
Canadian Journal of Ophthalmology / Journal Canadien d'Ophtalmologie
Necroptosis in amyotrophic lateral sclerosis and other neurological disorders
Biochimica et Biophysica Acta (BBA) - Molecular Basis of Disease, 2016
Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder characterized by the progress... more Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder characterized by the progressive degeneration of upper and lower motor neurons. Cell death in ALS and in general was previously believed to exist as a dichotomy between apoptosis and necrosis. Most research investigating cell death mechanisms in ALS was conducted before the discovery of programmed necrosis thus did not use selective cell death pathway-specific markers. Recently, a new form of programmed cell death, termed "necroptosis", has been characterized and has been recently implicated in ALS as a primary mechanism driving motor neuron cell death in different forms of ALS. The present review is aimed at summarizing cell death pathways that are currently implicated in ALS and highlighting the emerging evidence on necroptosis as a major driver of motor neuron cell death.
European Journal of Human Genetics, 2016
An ex vivo gene therapy approach in X-linked retinoschisis
Molecular vision, 2016
X-linked retinoschisis (XLRS) is juvenile-onset macular degeneration caused by haploinsufficiency... more X-linked retinoschisis (XLRS) is juvenile-onset macular degeneration caused by haploinsufficiency of the extracellular cell adhesion protein retinoschisin (RS1). RS1 mutations can lead to either a non-functional protein or the absence of protein secretion, and it has been established that extracellular deficiency of RS1 is the underlying cause of the phenotype. Therefore, we hypothesized that an ex vivo gene therapy strategy could be used to deliver sufficient extracellular RS1 to reverse the phenotype seen in XLRS. Here, we used adipose-derived, syngeneic mesenchymal stem cells (MSCs) that were genetically modified to secrete human RS1 and then delivered these cells by intravitreal injection to the retina of the Rs1h knockout mouse model of XLRS. MSCs were electroporated with two transgene expression systems (cytomegalovirus (CMV)-controlled constitutive and doxycycline-induced Tet-On controlled inducible), both driving expression of human RS1 cDNA. The stably transfected cells, us...
JCI Insight, 2016
Table 1. Brief representation of clinical characteristics presented in more than 50% of subjects ... more Table 1. Brief representation of clinical characteristics presented in more than 50% of subjects with 2p15p16.1 microdeletion syndrome Patient (subject no.) Florisson et al., 2013 (1) Rajcan-Separovic et al., 2007 (2) Case 1
Characterization of the canine rod-cone dysplasia type one gene (rod photoreceptor cGMP phosphodiesterase beta subunit (PDEB) – A model for human retinitis pigmentosa
ABSTRACT
Influence of Iron Oxide Nanoparticles on Innate and Genetically Modified 2013
Confirmation of the rod cGMP phosphodiesterase beta subunit (PDE beta) nonsense mutation in affected rcd-1 Irish setters in the UK and development of a diagnostic test
Current eye research, 1993
Rod/cone dysplasia type one (rcd-1) is an early onset inherited retinal dystrophy segregating in ... more Rod/cone dysplasia type one (rcd-1) is an early onset inherited retinal dystrophy segregating in the Irish setter breed. It is classed as one of the autosomal recessive canine generalised Progressive Retinal Atrophies (PRA). The disease results in complete loss of photoreceptors by approximately one year of age. Levels of retinal cGMP are markedly elevated and of abnormal distribution in rod photoreceptors. Rod phosphodiesterase activity is absent and mRNA encoding the beta subunit (PDE beta) of the holoenzyme is uniquely reduced in predegenerate retinae. Using retinae from normal, unrelated adult dogs we have PCR-amplified and sequenced the cDNA for PDE beta. The cDNA is almost identical to that recently described for the Irish setter in the USA apart from two translationally silent single nucleotide changes. Using carrier and affected setters from a UK breeding colony we have screened genomic DNA and can confirm the G to A transition in rcd-1 affected dogs at position 2420, creati...
Molecular and Cellular Biology, 2012
Nr2e1 encodes a stem cell fate determinant of the mouse forebrain and retina. Abnormal regulation... more Nr2e1 encodes a stem cell fate determinant of the mouse forebrain and retina. Abnormal regulation of this gene results in retinal, brain, and behavioral abnormalities in mice. However, little is known about the functionality of human NR2E1 . We investigated this functionality using a novel knock-in humanized-mouse strain carrying a single-copy bacterial artificial chromosome (BAC). We also documented, for the first time, the expression pattern of the human BAC, using an NR2E1-lacZ reporter strain. Unexpectedly, cerebrum and olfactory bulb hypoplasia, hallmarks of the Nr2e1 -null phenotype, were not fully corrected in animals harboring one functional copy of human NR2E1 . These results correlated with an absence of NR2E1 - lacZ reporter expression in the dorsal pallium of embryos and proliferative cells of adult brains. Surprisingly, retinal histology and electroretinograms demonstrated complete correction of the retina-null phenotype. These results correlated with appropriate expres...
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Papers by Cheryl Gregory-Evans