Search results for "CELLULAR"
showing 10 items of 6449 documents
Mboat7 down-regulation by hyper-insulinemia induces fat accumulation in hepatocytes.
2020
Background: Naturally occurring variation in Membrane-bound O-acyltransferase domain-containing 7 (MBOAT7), encoding for an enzyme involved in phosphatidylinositol acyl-chain remodelling, has been associated with fatty liver and hepatic disorders. Here, we examined the relationship between hepatic Mboat7 down-regulation and fat accumulation. Methods: Hepatic MBOAT7 expression was surveyed in 119 obese individuals and in experimental models. MBOAT7 was acutely silenced by antisense oligonucleotides in C57Bl/6 mice, and by CRISPR/Cas9 in HepG2 hepatocytes. Findings: In obese individuals, hepatic MBOAT7 mRNA decreased from normal liver to steatohepatitis, independently of diabetes, inflammatio…
Confinement stress in sea bass (Dicentrarchus labrax) depresses peritoneal leukocyte cytotoxicity
2002
Fish respond to stressful conditions via neuroendocrine responses (primary response) which result in increased levels of plasma cortisol which is considered immunosuppressive. Sea bass were confined at low (10 kg/m3) and high (60 kg/m3) density for 3-48 h. Plasma cortisol and glucose were evaluated and two principal cellular immune responses were assayed. A significant increase in plasma cortisol and glucose levels, as well as osmolarity, was found following stress. In addition, phagocytic activity, as shown by reactive oxygen species (ROS) production by challenged head kidney phagocytes and cytotoxic activity of eosinophilic granule cells from peritoneal cavity against K562 tumour cell lin…
Retinal ultrastructure of neuronal ceroid-lipofuscinosis in the Dalmatian dog
1985
Ultrastructural studies of the retinae in two NCL-affected Dalmatian dogs revealed ubiquitous accumulation of lipopigments in numerous cell types of the retina, the fine structure of which closely resembled that seen in NCL-affected English setters. Photoreceptors and other retinal cell types were largely intact. These findings show that the retinal involvement in NCL of our Dalmatian dogs is identical to that of NCL-affected English setters. It also shows that in canine NCL a severe retinopathy, regularly encountered in human childhood NCL, does not develop. Thus, the NCL of Dalmatian dogs —and English setters — represents a reliable model to study human NCL, but for human retinopathia pig…
A new vicious cycle involving glutamate excitotoxicity, oxidative stress and mitochondrial dynamics
2011
Glutamate excitotoxicity leads to fragmented mitochondria in neurodegenerative diseases, mediated by nitric oxide and S-nitrosylation of dynamin-related protein 1, a mitochondrial outer membrane fission protein. Optic atrophy gene 1 (OPA1) is an inner membrane protein important for mitochondrial fusion. Autosomal dominant optic atrophy (ADOA), caused by mutations in OPA1, is a neurodegenerative disease affecting mainly retinal ganglion cells (RGCs). Here, we showed that OPA1 deficiency in an ADOA model influences N-methyl-D-aspartate (NMDA) receptor expression, which is involved in glutamate excitotoxicity and oxidative stress. Opa1enu/+mice show a slow progressive loss of RGCs, activation …
Ultrastructural study of the retina in late infantile metachromatic leukodystrophy.
1992
The autopsy of a 2-year-old girl revealed a clinically unrecognized metachromatic leukodystrophy (MLD) due to an aryl-sulfatase A deficiency, characteristically affecting the central and peripheral nervous system by demyelination and by accumulation of metachromatic material. The retina though reported clinically as normal, showed the same demyelinating process in the optic nerve including the papilla but an additional intraneuronal storage of MLD-typical lysosomal residual bodies in ganglion cell perikarya of the retina. Cells of the bipolar and photoreceptor layers as well as pigment epithelial cells were not affected by MLD-specific lysosomal storage. Thus, sulfatides seem to play a part…
Role of nitric oxide synthase isoforms for ophthalmic artery reactivity in mice.
2014
Abstract Nitric oxide synthases (NOS) are involved in regulation of ocular vascular tone and blood flow. While endothelial NOS (eNOS) has recently been shown to mediate endothelium-dependent vasodilation in mouse retinal arterioles, the contribution of individual NOS isoforms to vascular responses is unknown in the retrobulbar vasculature. Moreover, it is unknown whether the lack of a single NOS isoform affects neuron survival in the retina. Thus, the goal of the present study was to examine the hypothesis that the lack of individual nitric oxide synthase (NOS) isoforms affects the reactivity of mouse ophthalmic arteries and neuron density in the retinal ganglion cell (RGC) layer. Mice defi…
p27Kip1participates in the regulation of endoreplication in differentiating chick retinal ganglion cells
2015
Nuclear DNA duplication in the absence of cell division (i.e. endoreplication) leads to somatic polyploidy in eukaryotic cells. In contrast to some invertebrate neurons, whose nuclei may contain up to 200,000-fold the normal haploid DNA amount (C), polyploid neurons in higher vertebrates show only 4C DNA content. To explore the mechanism that prevents extra rounds of DNA synthesis in these latter cells we focused on the chick retina, where a population of tetraploid retinal ganglion cells (RGCs) has been described. We show that differentiating chick RGCs that express the neurotrophic receptors p75 and TrkB while lacking retinoblastoma protein, a feature of tetraploid RGCs, also express p27K…
A novel automated segmentation method for retinal layers in OCT images proves retinal degeneration after optic neuritis.
2015
Aim The evaluation of inner retinal layer thickness can serve as a direct biomarker for monitoring the course of inflammatory diseases of the central nervous system such as multiple sclerosis (MS). Using optical coherence tomography (OCT), thinning of the retinal nerve fibre layer and changes in deeper retinal layers have been observed in patients with MS. Here, we first compare a novel method for automated segmentation of OCT images with manual segmentation using two cohorts of patients with MS. Using this method, we also aimed to reproduce previous findings showing retinal degeneration following optic neuritis (ON) in MS. Methods Based on a 5×5 expansion of the Prewitt operator to efficie…
Retinal neurodegenerative changes in the adult insulin receptor substrate-2 deficient mouse.
2014
Abstract Insulin receptor substrate-2 (Irs2) mediates peripheral insulin action and is essential for retinal health. Previous investigations have reported severe photoreceptor degeneration and abnormal visual function in Irs2-deficient mice. However, molecular changes in the Irs2 − / − mouse retina have not been described. In this study, we examined retinal degenerative changes in neuronal and glial cells of adult (9- and 12-week old) Irs2 − / − mice by immunohistochemistry. 9-week old Irs2 − / − mice showed significant thinning of outer retinal layers, concomitant to Muller and microglial cell activation. Photoreceptor cells displayed different signs of degeneration, such as outer/inner…
Vesicle transport and photoreceptor death: fishing for molecular links.
2013
Intracellular vesicle transport defects can induce retinal degeneration and photoreceptor cell death, but the molecular connections between these processes remains poorly understood. Reporting in Developmental Cell, Nishiwaki et al. (2013) suggest that a vesicle fusion cis-SNARE complex component translates vesicular transport defects into photoreceptor cell apoptosis.