[{"id":442222,"pmid":29090971,"pmcid":null,"title":"Downregulation of microRNA-483-5p Promotes Cell Proliferation and Invasion by Targeting GFRA4 in Hirschsprung's Disease.","year":2017,"pages":null,"doi":null,"keywords":[],"mesh":[],"abstractText":"Recent studies have suggested the critical roles of miRNAs for disease progression. miRNA-483-5p (miR-483-5p) was previously found to have a relationship with tumor cell behavior, but its biological function in Hirschsprung's disease (HSCR) remains undefined. Thus, we explored the role of miR-483-5p in the pathogenesis of HSCR. Histological changes of colonic tissues were evaluated by hematoxylin and eosin (HE) staining. Quantitative real-time PCR and western blotting were used to determine relative expression levels of miRNA, mRNA, and proteins in 20 HSCR patients and 20 normal colon tissues. In this study, we found that miR-483-5p expression in HSCR tissues was significantly increased and their downregulation promoted cell proliferation, cell cycle progression and invasion and inhibited cell apoptosis in human 293T and SH-SY5Y cell lines by the CCK-8, flow cytometry, and Transwell assay. GNDF family receptor alpha 4 (GFRA4) was confirmed as a downstream target of miR-483-5p by dual-luciferase reporter gene assay and inversely correlated with miR-483-5p expression in cell lines. Taken together, miR-483-5p may play a crucial role in the pathogenesis of HSCR by targeting GFRA4.","journal":null,"figures":[],"_authors":null},{"id":1214,"pmid":23376485,"pmcid":null,"title":"Proteomic analysis of podocyte exosome-enriched fraction from normal human urine.","year":2013,"pages":null,"doi":null,"keywords":[],"mesh":[],"abstractText":"Urine results from a coordinated activity of glomerular and tubular compartments of the kidney. As a footprint of these cellular functional processes, urinary exosomes, and 40-80 nm membrane vesicles released after fusion with the plasma membrane into the extracellular environment by renal epithelial cells, are a source for identification of proteins and investigation of their role in the kidney. The aim of the present study was the identification of podocyte exosome proteins based on urine immunoabsorption using podocyte-specific CR1-immunocoated beads followed by proteomic analysis using LC MS/MS techniques. This methodology allowed the identification of 1195 proteins. By using a bioinformatic approach, 27 brain-expressed proteins were identified, in which 14 out of them were newly demonstrated to be expressed in the kidney at a mRNA level, and, one of them, the COMT protein, was demonstrated to be expressed in podocytes at a protein level. These results, attesting the reliability of the methodology to identify podocyte proteins, need now to be completed by further experiments to analyze more precisely their biological function(s) in the podocytes.","journal":null,"figures":[],"_authors":null},{"id":442221,"pmid":15225646,"pmcid":null,"title":"PSPN/GFRalpha4 has a significantly weaker capacity than GDNF/GFRalpha1 to recruit RET to rafts, but promotes neuronal survival and neurite outgrowth.","year":2004,"pages":null,"doi":null,"keywords":[],"mesh":[],"abstractText":"Previously, it was shown that the recruitment of RET into lipid rafts by glial cell line-derived neurotrophic factor (GDNF)/GFRalpha1 is crucial for efficient signal transduction. Here, we show that the mouse GFRalpha4 is a functional, N-glycosylated, glycosylphosphatidylinositol (GPI)-anchored protein, which mediates persephin (PSPN)-induced phosphorylation of RET, but has an almost undetectable capacity to recruit RET into the 0.1% Triton X-100 insoluble membrane fraction. In spite of this, PSPN/mGFRalpha4 promotes neurite outgrowth in PC6-3 cells and survival of cerebellar granule neurons. As we show that also human PSPN/GFRalpha4 is unable to recruit RET into lipid rafts, we propose that the mammalian GFRalpha4 in this respect differs from GFRalpha1.","journal":null,"figures":[],"_authors":null},{"id":383028,"pmid":12624147,"pmcid":null,"title":"Investigation of germline GFRA4 mutations and evaluation of the involvement of GFRA1, GFRA2, GFRA3, and GFRA4 sequence variants in Hirschsprung disease.","year":2003,"pages":null,"doi":null,"keywords":[],"mesh":[],"abstractText":null,"journal":null,"figures":[],"_authors":null},{"id":4624,"pmid":11780052,"pmcid":null,"title":"The DNA sequence and comparative analysis of human chromosome 20.","year":2001,"pages":null,"doi":null,"keywords":[],"mesh":[],"abstractText":"The finished sequence of human chromosome 20 comprises 59,187,298 base pairs (bp) and represents 99.4% of the euchromatic DNA. A single contig of 26 megabases (Mb) spans the entire short arm, and five contigs separated by gaps totalling 320 kb span the long arm of this metacentric chromosome. An additional 234,339 bp of sequence has been determined within the pericentromeric region of the long arm. We annotated 727 genes and 168 pseudogenes in the sequence. About 64% of these genes have a 5' and a 3' untranslated region and a complete open reading frame. Comparative analysis of the sequence of chromosome 20 to whole-genome shotgun-sequence data of two other vertebrates, the mouse Mus musculus and the puffer fish Tetraodon nigroviridis, provides an independent measure of the efficiency of gene annotation, and indicates that this analysis may account for more than 95% of all coding exons and almost all genes.","journal":null,"figures":[],"_authors":null},{"id":442220,"pmid":11551746,"pmcid":null,"title":"hGFRalpha-4: a new member of the GDNF receptor family and a candidate for NBIA.","year":2001,"pages":null,"doi":null,"keywords":[],"mesh":[],"abstractText":"Hallervorden-Spatz syndrome (neurodegeneration with brain iron accumulation type 1; OMIM entry 234200) is a rare inherited neurodegenerative disease. In this article, evidence for a newly identified gene as a candidate for Hallervorden-Spatz syndrome is given. Previously Hallervorden-Spatz syndrome was mapped to a 4-cm region in 20p12.3-13. During positional cloning efforts a new member of the glial-derived neurotrophic factor receptor family was discovered in this region. Like other members of this receptor family, this new gene is predicted to be secreted and glycosyl-phosphatidylinositol linked, and it maintains conserved cysteine residues. However, cDNA and genomic studies in both humans and mice indicate that this gene lacks the sequence corresponding to exons 2 and 3 in other family members. In situ hybridization reveals that it is expressed primarily in the brain and bladder in the embryonic mouse. Mutation analysis of patients with Hallervorden-Spatz syndrome revealed two potentially significant amino acid changes in two patients but failed to identify mutations in the remaining 10 subjects. The implication of these findings for the relationship between this gene and Hallervorden-Spatz syndrome is discussed.","journal":null,"figures":[],"_authors":null},{"id":442219,"pmid":11116144,"pmcid":null,"title":"Human glial cell line-derived neurotrophic factor receptor alpha 4 is the receptor for persephin and is predominantly expressed in normal and malignant thyroid medullary cells.","year":2001,"pages":null,"doi":null,"keywords":[],"mesh":[],"abstractText":"Glial cell line-derived neurotrophic factor (GDNF) family ligands signal through receptor complex consisting of a glycosylphosphatidylinositol-linked GDNF family receptor (GFR) alpha subunit and the transmembrane receptor tyrosine kinase RET. The inherited cancer syndrome multiple endocrine neoplasia type 2 (MEN2), associated with different mutations in RET, is characterized by medullary thyroid carcinoma. GDNF signals via GFRalpha1, neurturin via GFRalpha2, artemin via GFRalpha3, whereas the mammalian GFRalpha receptor for persephin (PSPN) is unknown. Here we characterize the human GFRalpha4 as the ligand-binding subunit required together with RET for PSPN signaling. Human and mouse GFRalpha4 lack the first Cys-rich domain characteristic of other GFRalpha receptors. Unlabeled PSPN displaces (125)I-PSPN from GFRA4-transfected cells, which express endogenous Ret. PSPN can be specifically cross-linked to mammalian GFRalpha4 and Ret, and is able to promote autophosphorylation of Ret in GFRA4-transfected cells. PSPN, but not other GDNF family ligands, promotes the survival of cultured sympathetic neurons microinjected with GFRA4. We identified different splice forms of human GFRA4 mRNA encoding for two glycosylphosphatidylinositol-linked and one putative soluble isoform that were predominantly expressed in the thyroid gland. Overlapping expression of RET and GFRA4 but not other GFRA mRNAs in normal and malignant thyroid medullary cells suggests that GFRalpha4 may restrict the MEN2 syndrome to these cells.","journal":null,"figures":[],"_authors":null},{"id":442218,"pmid":10958791,"pmcid":null,"title":"Mammalian GFRalpha -4, a divergent member of the GFRalpha family of coreceptors for glial cell line-derived neurotrophic factor family ligands, is a receptor for the neurotrophic factor persephin.","year":2000,"pages":null,"doi":null,"keywords":[],"mesh":[],"abstractText":"Four members of the glial cell line-derived neurotrophic factor family have been identified (GDNF, neurturin, persephin, and enovin/artemin). They bind to a specific membrane-anchored GDNF family receptor as follows: GFRalpha-1 for GDNF, GFRalpha-2 for neurturin, GFRalpha-3 for enovin/artemin, and (chicken) GFRalpha-4 for persephin. Subsequent signaling occurs through activation of a common transmembrane tyrosine kinase, cRET. GFRalpha-4, the coreceptor for persephin, was previously identified in chicken only. We describe the cloning and characterization of a mammalian persephin receptor GFRalpha-4. The novel GFRalpha receptor is substantially different in sequence from all known GFRalphas, including chicken GFRalpha-4, and lacks the first cysteine-rich domain present in all previously characterized GFRalphas. At least two different GFRalpha-4 splice variants exist in rat tissues, differing at their respective COOH termini. GFRalpha-4 mRNA is expressed at low levels in different brain areas in the adult as well as in some peripheral tissues including testis and heart. Recombinant rat GFRalpha-4 variants were expressed in mammalian cells and shown to be at least partially secreted from the cells. Persephin binds specifically and with high affinity (K(D) = 6 nm) to the rat GFRalpha-4 receptor, but no cRET activation could be demonstrated. Although the newly characterized mammalian GFRalpha-4 receptor is structurally divergent from previously characterized GFRalpha family members, we suggest that it is a mammalian orthologue of the chicken persephin receptor. This discovery will allow a more detailed investigation of the biological targets of persephin action and its potential involvement in diseases of the nervous system.","journal":null,"figures":[],"_authors":null},{"id":383054,"pmid":9740802,"pmcid":null,"title":"GFR alpha-4 and the tyrosine kinase Ret form a functional receptor complex for persephin.","year":1998,"pages":null,"doi":null,"keywords":[],"mesh":[],"abstractText":"Glial-cell-line-derived neurotrophic factor (GDNF), neurturin and persephin are structurally related, secreted proteins that are widely expressed in the nervous system and other tissues and promote the survival of a variety of neurons during development. GDNF and neurturin signal through multicomponent receptors that consist of the Ret receptor tyrosine kinase and one of two structurally related glycosyl-phosphatidylinositol (GPI)-linked ligand-binding subunits: GFR alpha-1 is the preferred ligand-binding subunit for GDNF, and GFR alpha-2 is the preferred ligand-binding subunit for neurturin. Two additional members of the GFR alpha family of GPI-linked proteins have recently been cloned: GFR alpha-3 and GFR alpha-4. We have shown that persephin binds efficiently only to GFR alpha-4, and labelled persephin is effectively displaced from cells expressing GFR alpha-4 by persephin but not by GDNF or neurturin. Using microinjection to introduce expression plasmids into cultured neurons, we have also shown that coexpression of Ret with GFR alpha-4, confers a marked survival response to persephin but not to GDNF or neurturin. These results demonstrate that GFR alpha-4 is the ligand-binding subunit for persephin and that persephin, like GDNF and neurturin, also requires Ret for signalling.","journal":null,"figures":[],"_authors":null},null]