581 research outputs found

    Analysis of six candidate genes as potential modifiers of disease expression in canine XLPRA1, a model for human X-linked retinitis pigmentosa 3

    Get PDF
    Purpose: Canine X-linked progressive retinal atrophy (XLPRA) is caused by mutations in RPGR exon ORF15, which is also a mutation hotspot in human X-linked retinitis pigmentosa 3 (RP3). The XLPRA1 form of disease has shown extensive phenotypic variability in a colony of dogs that all inherited the same mutant X-chromosome. This variability in onset and severity makes XLPRA1 a valuable model to use to identify genes influencing photoreceptors degeneration in dog and to elucidate molecular mechanisms underlying RP in its human homolog. In this study, RPGRIP1, RANBP2, NPM1, PDE6D, NPHP5, and ABCA4 genes were selected on the basis of interaction with RPGR or RPGRIP1 or their implication in related retinal diseases, and were investigated as candidate genetic modifiers of XLPRA1. Methods: A pedigree derived from an affected male dog outcrossed to unrelated normal mix bred or purebred females was used. Morphologic examination revealed phenotypic variability in the affected dogs characterized as mild, moderate, or severe. Single nucleotide polymorphisms (SNPs) and indel-containing markers spanning the entire genes were designed, based on the canine sequence and the Broad Institute SNP library, and genotyped on the pedigree. For each candidate gene, haplotypes were identified and their frequencies in severely and moderately affected dogs were compared to detect a putative correlation between a gene-specific haplotype(s), and severity level of the disease. Primers were derived from expressed sequence tags (ESTs) and predicted transcripts to assess the relative retinal expression of the six genes of interest in normal and affected retinas of different ages. Results: Four to seven haplotypes per gene were identified. None of the haplotypes of RPGRIP1, NPM1, PDE6D, NPHP5, RANBP2, and ABCA4 were found to co-segregate with the moderate or severe phenotype. No significant difference in the retinal expression levels of the candidate genes was observed between normal and affected dogs. Conclusions: The haplotype distribution of RPGRIP1, NPM1, PDE6D, NPHP5, RANBP2, and ABCA4 suggests these genes are not modifiers of the disease phenotype observed in the XLPRA1 pedigree. The RPGRORF15 stop mutation does not affect the retinal expression of these genes at the mRNA level in the pre-degenerate stage of disease, but no conclusions can be made at this time about changes that may occur at the protein level

    Doxorubicin-Induced Cardiotoxicity in Collaborative Cross (CC) Mice Recapitulates Individual Cardiotoxicity in Humans.

    Get PDF
    Anthracyclines cause progressive cardiotoxicity whose ultimate severity is individual to the patient. Genetic determinants contributing to this variation are difficult to study using current mouse models. Our objective was to determine whether a spectrum of anthracycline induced cardiac disease can be elicited across 10 Collaborative Cross mouse strains given the same dose of doxorubicin. Mice from ten distinct strains were given 5 mg/kg of doxorubicin intravenously once weekly for 5 weeks (total 25 mg/kg). Mice were killed at acute or chronic timepoints. Body weight was assessed weekly, followed by terminal complete blood count, pathology and a panel of biomarkers. Linear models were fit to assess effects of treatment, sex, and sex-by-treatment interactions for each timepoint. Impaired growth and cardiac pathology occurred across all strains. Severity of these varied by strain and sex, with greater severity in males. Cardiac troponin I and myosin light chain 3 demonstrated strain- and sex-specific elevations in the acute phase with subsequent decline despite ongoing progression of cardiac disease. Acute phase cardiac troponin I levels predicted the ultimate severity of cardiac pathology poorly, whereas myosin light chain 3 levels predicted the extent of chronic cardiac injury in males. Strain- and sex-dependent renal toxicity was evident. Regenerative anemia manifested during the acute period. We confirm that variable susceptibility to doxorubicin-induced cardiotoxicity observed in humans can be modeled in a panel of CC strains. In addition, we identified a potential predictive biomarker in males. CC strains provide reproducible models to explore mechanisms contributing to individual susceptibility in humans

    Unified Treatment of Asymptotic van der Waals Forces

    Full text link
    In a framework for long-range density-functional theory we present a unified full-field treatment of the asymptotic van der Waals interaction for atoms, molecules, surfaces, and other objects. The only input needed consists of the electron densities of the interacting fragments and the static polarizability or the static image plane, which can be easily evaluated in a ground-state density-functional calculation for each fragment. Results for separated atoms, molecules, and for atoms/molecules outside surfaces are in agreement with those of other, more elaborate, calculations.Comment: 6 pages, 5 figure

    Safety in Nonhuman Primates of Ocular AAV2-\u3cem\u3eRPE65\u3c/em\u3e, a Candidate Treatment for Blindness in Leber Congenital Amaurosis

    Get PDF
    Leber congenital amaurosis (LCA) is a molecularly heterogeneous disease group that leads to blindness. LCA caused by RPE65 mutations has been studied in animal models and vision has been restored by subretinal delivery of AAV- RPE65 vector. Human ocular gene transfer trials are being considered. Our safety studies of subretinal AAV-2/2. RPE65 in RPE65 -mutant dogs showed evidence of modest photoreceptor loss in the injection region in some animals at higher vector doses. We now test the hypothesis that there can be vector-related toxicity to the normal monkey, with its human-like retina. Good Laboratory Practice safety studies following single intraocular injections of AAV-2/2. RPE65 in normal cynomolgus monkeys were performed for 1-week and 3-month durations. Systemic toxicity was not identified. Ocular-specific studies included clinical examinations, electroretinography, and retinal histopathology. Signs of ocular inflammation postinjection had almost disappeared by 1 week. At 3 months, electroretinography in vector-injected eyes was no different than in vehicle-injected control eyes or compared with presurgical recordings. Healed sites of retinal perforation from subretinal injections were noted clinically and by histopathology. Foveal architecture in subretinally injected eyes, vector or vehicle, could be abnormal. Morphometry of central retina showed no photoreceptor layer thickness abnormalities occurring in a dose-dependent manner. Vector sequences were present in the injected retina, vitreous, and optic nerve at 1 week but not consistently in the brain. At 3 months, there were no vector sequences in optic nerve and brain. The results allow for consideration of an upper range for no observed adverse effect level in future human trials of subretinal AAV-2/2. RPE65. The potential value of foveal treatment for LCA and other retinal degenerations warrants further research into how to achieve gene transfer without retinal injury from surgical detachment of the retina

    Genetic deficiency or pharmacological inhibition of miR-33 protects from kidney fibrosis

    Get PDF
    Previous work has reported the important links between cellular bioenergetics and the development of chronic kidney disease, highlighting the potential for targeting metabolic functions to regulate disease progression. More recently, it has been shown that alterations in fatty acid oxidation (FAO) can have an important impact on the progression of kidney disease. In this work, we demonstrate that loss of miR-33, an important regulator of lipid metabolism, can partially prevent the repression of FAO in fibrotic kidneys and reduce lipid accumulation. These changes were associated with a dramatic reduction in the extent of fibrosis induced in 2 mouse models of kidney disease. These effects were not related to changes in circulating leukocytes because bone marrow transplants from miR-33–deficient animals did not have a similar impact on disease progression. Most important, targeted delivery of miR-33 peptide nucleic acid inhibitors to the kidney and other acidic microenvironments was accomplished using pH low insertion peptides as a carrier. This was effective at both increasing the expression of factors involved in FAO and reducing the development of fibrosis. Together, these findings suggest that miR-33 may be an attractive therapeutic target for the treatment of chronic kidney disease

    Orally Active Multi-Functional Antioxidants Are Neuroprotective in a Rat Model of Light-Induced Retinal Damage

    Get PDF
    Progression of age-related macular degeneration has been linked to iron dysregulation and oxidative stress that induce apoptosis of neural retinal cells. Since both antioxidants and chelating agents have been reported to reduce the progression of retinal lesions associated with AMD in experimental animals, the present study evaluates the ability of multi-functional antioxidants containing functional groups that can independently chelate redox metals and quench free radicals to protect the retina against light-induced retinal degeneration, a rat model of dry atrophic AMD.Proof of concept studies were conducted to evaluate the ability of 4-(5-hydroxypyrimidin-2-yl)-N,N-dimethyl-3,5-dioxopiperazine-1-sulfonamide (compound 4) and 4-(5-hydroxy-4,6-dimethoxypyrimidin-2-yl)-N,N-dimethyl-3,5-dioxopiperazine-1-sulfonamide (compound 8) to reduce retinal damage in 2-week dark adapted Wistar rats exposed to 1000 lx of light for 3 hours. Assessment of the oxidative stress markers 4- hydroxynonenal and nitrotyrosine modified proteins and Thioredoxin by ELISA and Western blots indicated that these compounds reduced the oxidative insult caused by light exposure. The beneficial antioxidant effects of these compounds in providing significant functional and structural protection were confirmed by electroretinography and quantitative histology of the retina.The present study suggests that multi-functional compounds may be effective candidates for preventive therapy of AMD

    Quality of Life and Affective Well-Being in Middle-Aged and Older People with Chronic Medical Illnesses: A Cross-Sectional Population Based Study

    Get PDF
    Background: There has been considerable research into the impact of chronic illness on health-related quality of life. However, few studies have assessed the impact of different chronic conditions on general quality of life (QOL). The objective of this paper was to compare general (rather than health-related) QOL and affective well-being in middle aged and older people across eight chronic illnesses.Methods and Findings: This population-based, cross-sectional study involved 11,523 individuals aged 50 years and older, taking part in wave 1 of the English Longitudinal Study of Ageing. General QOL was assessed using the CASP-19, happiness was evaluated using two items drawn from the GHQ-12, and depression was measured with the CES-D. Analysis of covariance and logistic regression, adjusting for age, gender and wealth, were performed. General QOL was most impaired in people with stroke (mean 37.56, CI 36.73-38.39), and least in those reporting cancer (mean 41.78, CI 41.12-42.44, respectively), compared with no illness (mean 44.15, CI 43.92-44.39). Stroke (mean 3.65, CI 3.58-3.73) was also associated with the greatest reduction in positive well-being whereas diabetes (mean 3.81, CI 3.76-3.86) and cancer were least affected (3.85, CI 3.79-3.91), compared with no illness (mean 3.97, CI 3.95-4.00). Depression was significantly elevated in all conditions, but was most common in chronic lung disease (OR 3.04, CI 2.56-3.61), with more modest elevations in those with osteoarthritis (OR 2.08, CI 1.84-2.34) or cancer (OR 2.07, CI 1.69-2.54). Multiple co-morbidities were associated with greater decrements in QOL and affective well-being.Conclusion: The presence of chronic illness is associated with impairments in broader aspects of QOL and affective wellbeing, but different conditions vary in their impact. Further longitudinal work is needed to establish the temporal links between chronic illness and impairments in QOL and affective well-being
    corecore