Search results for "pigmentos"
showing 10 items of 95 documents
Translational read-through of the RP2 Arg120stop mutation in patient iPSC-derived retinal pigment epithelium cells.
2014
Mutations in the RP2 gene lead to a severe form of X-linked retinitis pigmentosa. RP2 patients frequently present with nonsense mutations and no treatments are currently available to restore RP2 function. In this study, we reprogrammed fibroblasts from an RP2 patient carrying the nonsense mutation c.519C>T (p.R120X) into induced pluripotent stem cells (iPSC), and differentiated these cells into retinal pigment epithelial cells (RPE) to study the mechanisms of disease and test potential therapies. RP2 protein was undetectable in the RP2 R120X patient cells, suggesting a disease mechanism caused by complete lack of RP2 protein. The RP2 patient fibroblasts and iPSC-derived RPE cells showed phe…
A comparative evaluation of NB30, NB54 and PTC124 in translational read-through efficacy for treatment of an USH1C nonsense mutation
2012
Translational read-through-inducing drugs (TRIDs) promote read-through of nonsense mutations, placing them in the spotlight of current gene-based therapeutic research. Here, we compare for the first time the relative efficacies of new-generation aminoglycosides NB30, NB54 and the chemical compound PTC124 on retinal toxicity and read-through efficacy of a nonsense mutation in the USH1C gene, which encodes the scaffold protein harmonin. This mutation causes the human Usher syndrome, the most common form of inherited deaf-blindness. We quantify read-through efficacy of the TRIDs in cell culture and show the restoration of harmonin function. We do not observe significant differences in the read…
Mutation ofPOC1Bin a Severe Syndromic Retinal Ciliopathy
2014
We describe a consanguineous Iraqi family with Leber congenital amaurosis (LCA), Joubert syndrome (JBTS), and polycystic kidney disease (PKD). Targeted next-generation sequencing for excluding mutations in known LCA and JBTS genes, homozygosity mapping, and whole-exome sequencing identified a homozygous missense variant, c.317G>C (p.Arg106Pro), in POC1B, a gene essential for ciliogenesis, basal body, and centrosome integrity. In silico modeling suggested a requirement of p.Arg106 for the formation of the third WD40 repeat and a protein interaction interface. In human and mouse retina, POC1B localized to the basal body and centriole adjacent to the connecting cilium of photoreceptors and in …
USH3A transcripts encode clarin-1, a four-transmembrane-domain protein with a possible role in sensory synapses.
2002
Usher syndrome type 3 (USH3) is an autosomal recessive disorder characterised by the association of post-lingual progressive hearing loss, progressive visual loss due to retinitis pigmentosa and variable presence of vestibular dysfunction. Because the previously defined transcripts do not account for all USH3 cases, we performed further analysis and revealed the presence of additional exons embedded in longer human and mouse USH3A transcripts and three novel USH3A mutations. Expression of Ush3a transcripts was localised by whole mount in situ hybridisation to cochlear hair cells and spiral ganglion cells. The full length USH3A transcript encodes clarin-1, a four-transmembrane-domain protein…
Detection of a novel Cys628STOP mutation of the myosin VIIA gene in Usher syndrome type Ib.
1998
A Spanish family with three Usher I syndrome-affected members was linked to markers located on chromosome 11q. A search for mutations on the myosin VIIA gene revealed a novel mutation (Cys628STOP) on exon 16 segregating with the disorder in a homozygous state. This nonsense mutation could be responsible for the disease since it leads to a truncated protein that presumably has no function.
Familial insulin resistant diabetes associated with acanthosis nigricans, polycystic ovaries, hypogonadism, pigmentary retinopathy, labyrinthine deaf…
1993
Two sibs, whose parents are first cousins, had diabetes mellitus with hyperinsulinism, insensitive insulin receptors, and acanthosis nigricans. Both patients had pigmentary retinopathy, secondary cataracts, labyrinthine deafness, mental retardation, and cerebral atrophy. They were disproportionately short with relatively broad hands and feet and slightly coarse face. The young woman had secondary amenorrhea and polycystic ovaries and the boy gynecomastia and hypergonadotrophic hypogonadism. This appears to be the second family with a new autosomal recessive disorder differing from Alstrom syndrome by the presence of mental retardation and absence of renal insufficiency. Impaired insulin rec…
Transcriptional regulation of nucleoredoxin-like genes takes place on a daily basis in the retina and pineal gland of rats.
2015
AbstractThe nucleoredoxin-like gene Nxnl1 (Txnl6) and its paralogue Nxnl2 encode the rod-derived cone viability factors (RdCVF and RdCVF2), which increase the resistance to photooxidative damage and have therapeutic potential for the survival of cones in retinitis pigmentosa. In this study, the transcription of Nxnl genes was investigated as a function of the day/night cycle in rats. The transcript levels of Nxnl1 and Nxnl2 were seen to display daily rhythms with steadily increasing values during the light phase and peak expression around dark onset in preparations of whole retina, photoreceptor cells and—but only in regard to Nxnl1—in photoreceptor-related pinealocytes. The cycling of Nxnl…
Retinopathia Pigmentosa Plus - the Value of Ultra-Structural Examination of the Human Retina
1993
Retinopathia pigmentosa is more widely, but somewhat incorrectly known as Retinitis pigmentosa (RP). Its course as a primary exclusively retinal disease follows autosomal-dominant, autosomal-recessive, or X-linked recessive modes of inheritance, or it may be sporadic. However, a progressive retinopathy, also called tapeto-retinal degeneration, may also be associated with numerous disorders: retinopathia pigmentosa plus (RPP). Among these RPP are those which form part of certain syndromes, e.g. Laurence-Moon-Bardet-Biedl syndrome, the Hallgren syndrome, the Marinesco-Sjogren syndrome, to name a few. Other RPP are associated with disorders of different organs, the skin, e.g. Werner disease, t…
Leucine Aminopeptidase Activity in Mast Cells
1959
DURING investigations of the behaviour of leucine aminopeptidase activity of blood-serum in patients with dermatoses and tumours1–3, in a case of diffuse skin mastocytosis of a new-born, we detected heightened activity of leucine aminopeptidase. After mechanical friction of the affected skin, greater activity of leucine aminopeptidase occurred. From this we supposed a release of leucine aminopeptidase from the mast cell infiltrates of the skin. As is well known, in urticaria pigmentosa mechanical irritation of the skin lesions give rise to a degranulation of mast cells4,5 with liberation of histamine and serotonin. Indeed, there is no doubt that mast cells contain the enzyme leucine aminope…
Síntesis y caracterización de nanopartículas de TiO2 y ZrO2 dopadas con cationes de metales de transición. Aplicaciones como nanopigmentos y en fotoc…
2017
En la presente tesis doctoral se pretende por una parte sintetizar en la escala nanométrica pigmentos cerámicos clásicos de uso industrial, como son el pigmento de color amarillo V-ZrO2, y el pigmento de color naranja-amarillo Cr,Sb-TiO2, mediante métodos de síntesis no convencionales. Para llevar a cabo dichas síntesis se van a utilizar dos métodos de síntesis relativamente sencillos y fácilmente reproducibles a escala industrial, como son el método del poliol y el método hidrotermal, los resultados que se obtengan mediante los dos métodos serán comparados y se hará hincapié en sus ventajas e inconvenientes. Las composiciones nominales estudiadas serán en el caso del VxZr1-xO2 valores 0 ≤ …