Search results for "Protein transport"
showing 10 items of 197 documents
Compound heterozygosity in the SPG4 gene causes hereditary spastic paraplegia
2008
The SPG4 gene is frequently mutated in autosomal dominant form of hereditary spastic paraplegia (HSP). We report that the compound heterozygous sequence variants S44L, a known polymorphism, and c.1687G>A, a novel mutation in SPG4 cause a severe form of HSP in a patient. The family members carrying solely c.1687G>A mutation are asymptomatic for HSP. The reverse transcriptase-polymerase chain reaction (RT-PCR) analysis revealed that the c.1687G>A mutation is a splice site mutation and causes skipping of the exon 15 of spastin. Furthermore, quantification of RT-PCR products by sequencing and quantification of allele-specific expression by pyrosequencing assay revealed that c.1687G>A is a leaky…
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…
The Insulin Receptor Substrate 1 (Irs1) in Intestinal Epithelial Differentiation and in Colorectal Cancer
2012
Colorectal cancer (CRC) is associated with lifestyle factors that affect insulin/IGF signaling, of which the insulin receptor substrate 1 (IRS1) is a key transducer. We investigated expression, localization and pathologic correlations of IRS1 in cancer-uninvolved colonic epithelium, primary CRCs with paired liver metastases and in vitro polarizing Caco2 and HT29 cells. IRS1 mRNA and protein resulted higher, relative to paired mucosa, in adenomas of familial adenomatous polyposis patients and in CRCs that overexpressed c-MYC, ß-catenin, InsRß, and IGF1R. Analysis of IRS1 immunostaining in 24 cases of primary CRC with paired colonic epithelium and hepatic metastasis showed that staining inten…
Synaptic vesicle alterations in rod photoreceptors of synaptophysin-deficient mice.
2001
Abstract The abundance of the integral membrane protein synaptophysin in synaptic vesicles and its multiple possible functional contributions to transmitter exocytosis and synaptic vesicle formation stand in sharp contrast to the observed lack of defects in synaptophysin knockout mice. Assuming that deficiencies are compensated by the often coexpressed synaptophysin isoform synaptoporin, we now show that retinal rod photoreceptors, which do not synthesize synaptoporin either in wild-type or in knockout mice, are affected by the loss of synaptophysin. Multiple pale-appearing photoreceptors, as seen by electron microscopy, possess reduced cytoplasmic electron density, swollen mitochondria, an…
2-Hydroxyoleate, a nontoxic membrane binding anticancer drug, induces glioma cell differentiation and autophagy
2012
Despite recent advances in the development of new cancer therapies, the treatment options for glioma remain limited, and the survival rate of patients has changed little over the past three decades. Here, we show that 2-hydroxyoleic acid (2OHOA) induces differentiation and autophagy of human glioma cells. Compared to the current reference drug for this condition, temozolomide (TMZ), 2OHOA combated glioma more efficiently and, unlike TMZ, tumor relapse was not observed following 2OHOA treatment. The novel mechanism of action of 2OHOA is associated with important changes in membrane-lipid composition, primarily a recovery of sphingomyelin (SM) levels, which is markedly low in glioma cells bef…
Proteomic analysis of the somatic and surface compartments from Dirofilaria immitis adult worms.
2014
31 páginas, 1 tabla, 4 figuras.-- The definitive version is available at http://www.elsevier.com
INTACT vs. FANS for Cell-Type-Specific Nuclei Sorting: A Comprehensive Qualitative and Quantitative Comparison
2021
Increasing numbers of studies seek to characterize the different cellular sub-populations present in mammalian tissues. The techniques “Isolation of Nuclei Tagged in Specific Cell Types” (INTACT) or “Fluorescence-Activated Nuclei Sorting” (FANS) are frequently used for isolating nuclei of specific cellular subtypes. These nuclei are then used for molecular characterization of the cellular sub-populations. Despite the increasing popularity of both techniques, little is known about their isolation efficiency, advantages, and disadvantages or downstream molecular effects. In our study, we compared the physical and molecular attributes of sfGFP+ nuclei isolated by the two methods—INTACT and FAN…
Identification and quantification of a new family of peptide endocannabinoids (Pepcans) showing negative allosteric modulation at CB1 receptors.
2012
The α-hemoglobin-derived dodecapeptide RVD-hemopressin (RVDPVNFKLLSH) has been proposed to be an endogenous agonist for the cannabinoid receptor type 1 (CB(1)). To study this peptide, we have raised mAbs against its C-terminal part. Using an immunoaffinity mass spectrometry approach, a whole family of N-terminally extended peptides in addition to RVD-Hpα were identified in rodent brain extracts and human and mouse plasma. We designated these peptides Pepcan-12 (RVDPVNFKLLSH) to Pepcan-23 (SALSDLHAHKLRVDPVNFKLLSH), referring to peptide length. The most abundant Pepcans found in the brain were tested for CB(1) receptor binding. In the classical radioligand displacement assay, Pepcan-12 was th…
Treating cachexia using soluble ACVR2B improves survival, alters mTOR localization, and attenuates liver and spleen responses.
2018
Background Cancer cachexia increases morbidity and mortality, and blocking of activin receptor ligands has improved survival in experimental cancer. However, the underlying mechanisms have not yet been fully uncovered. Methods The effects of blocking activin receptor type 2 (ACVR2) ligands on both muscle and non‐muscle tissues were investigated in a preclinical model of cancer cachexia using a recombinant soluble ACVR2B (sACVR2B‐Fc). Treatment with sACVR2B‐Fc was applied either only before the tumour formation or with continued treatment both before and after tumour formation. The potential roles of muscle and non‐muscle tissues in cancer cachexia were investigated in order to understand th…
ALS-Related Mutant FUS Protein Is Mislocalized to Cytoplasm and Is Recruited into Stress Granules of Fibroblasts from Asymptomatic FUS P525L Mutation…
2017
Background: Amyotrophic lateral sclerosis (ALS) shows a strong genetic basis, with SOD1, FUS, TARDBP, and C9ORF72 being the genes most frequently involved. This has allowed identification of asymptomatic mutation carriers, which may be of help in understanding the molecular changes preceding disease onset. Objectives: We studied the cellular expression of FUS protein and the effect of heat-shock-and dithiothreitol-induced stress in fibroblasts from FUS P525L mutation carriers, healthy controls, and patients with sporadic ALS. Methods: Western blots and immunocytochemistry were performed to study the subcellular localization of FUS protein. Control and stressed cells were double stained with…