56,466 research outputs found
Toward regaining hearing using multipotent stem cells.
No full textMesenchymal stem cells (MSC) are currently being investigated in numerous pre-clinical and clinical settings of regenerative medicine. We had previously reported (Revoltella et al., Cell Transplant. 2008; 17, 665-678) that human umbilical cord blood CD133+ stem cells transplanted intravenously (IV) into pre-irradiated nod-scid mice made permanently deaf by ototoxic treatment with kanamycin or intense sound, were able to engraft the cochlea and contribute to inner ear restoration, in vivo. We further investigated here whether human adult MSC derived from either bone marrow or fat (lipid suction), if injected IV to deafened nod-scid mice pre-treated with kanamycin , were able to engraft the damaged cochlea regaining hearing. We tested HLA-DQa1 DNA and three human microsatellites (CODIS) as indicators of engrafted cells, finding polymerase chain reaction evidence of chimaerism in various tissues of the host, including the Organ of Corti in the cochlea, at 7 and 31 days following MSC transplantation. Histology, immunohistochemistry, and lectin staining confirmed the repair process and stimulation ex novo of morphological recovery in the inner ear, contrasting with the lack of morphological and hearing loss repair in control similarly injured but non-transplanted mice. FISH analysis, to detect human genomic sequences from different chromosomes, confirmed persistent engraftment of the regenerating inner ear with a very limited number of chimaeric cells. Dual color FISH analysis provided evidence of positive engraftment in the inner ear and in other mouse tissues, also revealing small numbers of possible heterokaryons, probably resulting from unstable clones derived from fusion of donor with endogenous cells, up to 2 months following transplantation. Stem cells and differentiation pathways focused PCR arrays favoured to select MSC inducing the best response . These findings support the concept that transplanted MSC migrating to the damaged inner ear area provide conditions for the resumption of a damaged cochlea , emerging as a potential strategy for hearing rehabilitation
Autoantibodies directed against ribosomal P proteins: use of a multiple antigen peptide as the coating agent in ELISA.
No full textAutoantibodies directed against the ribosomal proteins P0, P1 and P2 (P proteins) are specific for systemic lupus erythematosus (SLE) and there are some evidences that they could be related to the neuropsychiatric manifestations of the disease. In this study, a multiple antigen peptide (MAP) carrying four copies of the C-terminal peptide (13 residues) of the P2 protein, which is a common epitope of the three P proteins, was prepared for use in an ELISA assay. It was employed to detect antibodies directed against the ribosomal P proteins in 102 SLE patients and the results were compared with those obtained using immunoblotting (IB). With this new ELISA, antiribosomal P protein antibodies were found in 15/102 SLE sera. These results correlated well with the results of IB. Furthermore, we confirmed that naturally occurring antiribosomal P protein antibodies are directed mainly against the epitope containing the C-terminal sequence and shared by the three P proteins. MAP appears to be an excellent coating agent for ELISA assays designed to detect anti-P antibodies. Further experiments showed the superiority of MAP, compared to the free peptide, in the detection of weakly positive sera. This ELISA can also be used for the serological follow-up of SLE patients
Stem cells transplantation supports the repair of injured olfactory neuroepithelium after permanent lesion.
No full textWe investigated whether human cord blood-selected CD133+ stem cells (HSC) may engraft the olfactory mucosa and contribute to restoration of neurolfactory epithelium (NE) in nod-scid mice damaged by dichlobenil. The herbicide dichlobenil selectively causes necrosis of the dorsomedial part of the NE and underlying mucosa, while the lateral part of the olfactory region remains undamaged. The aim of this research was to demonstrate that HSC stimulate self-renewal of neuronal stem cells and promote their differentiation into bipolar olfactory neurons to replace the injured NE. By PCR, we tested the presence of 3 human specific microsatellites (CODIS), used as DNA markers for traceability of the engrafted cells, demonstrating their presence in various tissues of the host, including the olfactory mucosa, after one month from transplantation. By immunohistochemistry and lectin staining, we demonstated that, in injured mice, HSC contributed to stimulating residual endogenous olfactory neurons, promoting recovery of the original phenotype of the NE, in contrast to the lack of spontaneous regeneration in similar injured areas always seen in the non-transplanted control mice. Multiple color-FISH (M-FISH) analysis detecting 7 human genomic sequences present in different chromosomes provided further evidence of positive prolonged engraftment of chimeric cells in the olfactory mucosa. This study provides the first evidence that transplanted HSC migrating to the neurolfactory mucosa may contribute to NE structure restoration with resumption of the sensorineural olfactory loss
Tumor-associated neural differentiation antigens detected on C1300 neuroblastoma cells by hybridoma monoclonal auto-antibodies.
No full textDetection and epitope mapping of immunoreactive human endothelin-1 using ELISA and a surface plasmon resonance based biosensor.
No full textDesign, Synthesis and Conformational Studies of the hGM-CSF-Derived Peptide (13-27)-Gly-(75-87).
No full textAn analogue of the human granulocyte-macrophage colony-stimulating factor (hGM-CSF), hGM-CSF(13-27)-Gly-(75-87) was synthesized by solid phase methodology. This analogue was designed to comprise helices A and C of the native growth factor, linked by a glycine bridge. Helices A and C form half of a four-helix bundle motif in the crystal structure of the native factor and are involved in the interaction with alpha- and beta-chains of the heterodimeric receptor. A conformational analysis of the synthetic analogue by CD, two-dimensional nmr spectroscopy, and molecular dynamics calculations is reported. The analogue is in a random structure in water and assumes a partially alpha-helical conformation in a 1 : 1 trifluoroethanol/water mixture. The helix content in this medium is approximately 70%. By 2D-nmr spectroscopy, two helical segments were identified in the sequences corresponding to helices A and C. In addition to medium- and short-range NOESY connectivities, a long-range cross peak was found between the Cbeta proton of Val(16) and NH proton of His(87) (using the numbering of the native protein). Experimentally derived interproton distances were used as restraints in molecular dynamics calculations, utilizing the x-ray coordinates as the initial structure. The final structure is characterized by two helical segments in close spatial proximity, connected by a loop region. This structure is similar to that of the corresponding domain in the x-ray structure of the native growth factor in which helices A and C are oriented in an antiparallel fashion. The N-terminal residues Gly-Pro of helix C are involved in an irregular turn connecting the two helical segments. As a consequence, helix C is appreciably shifted and slightly rotated with respect to helix A compared to the x-ray structure of the native growth factor. These small differences in the topology of the two helices could explain the lower biological activity of this analogue with respect to that of the native growth factor
Cochlear repair and hair cells regeneration after human pluripotent stem cell transplatation to NOD-SCID mice made deaf with kanamycin and intense noise
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Conformation of four peptides corresponding to the alpha-helical segments of human GM-CSF
No full textThe conformation of segments corresponding to the four a-helical stretches found in human granulocyte-macrophage colony-stimulating factor was studied in water solution in the presence of different amounts of 2,2,2-trifluoroethanol (TFE). The CD spectra reveal the onset of secondary structure upon addition of TFE. The final amount of helical conformation varies among the four peptides. In all cases, the conformational transition Is complete before 50% TFE (v/v). H-1-NMR studies were conducted at this solvent composition, leading to the assignment of all the resonances and to the definition of the secondary structure for all four fragments. (C) 1997 European Peptide Society and John Wiley & Sons, Ltd
[Further observations on the ophthalmoscopic picture during chronic renal insufficiency treated with periodic hemodialysis]
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