Browsing by Subject "Schwann cell"
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- PublicationOpen AccessA method for obtaining Schwann cell cultures from adult rabbit nerve based on “in vitro” pre-degeneration and neuregulin treatment(F. Hernández y Juan F. Madrid. Universidad de Murcia: Departamento de Biología Celular e Histología, 2012) de la Fuente, Isabel; Alcalde, Ignacio; Gamboa, Olga L.; Garrosa, Manuel; Gayoso, Manuel J.Schwann cells (SCs) are basic elements for cell therapy and tissue engineering in the central and peripheral nervous system. Therefore, the development of a reliable method to obtain SC cultures is required. For possible therapeutic applications the cultures need to produce a sufficiently large number of SCs with a high level of purity in a relatively short period of time. To increase SC yield and purity we pre-degenerated pieces of 1-2 mm of adult rabbit sciatic nerves by incubating them for seven days in Dulbecco’s Modified Eagle’s Medium supplemented with 10% fetal bovine serum, penicillin/streptomycin and NRG1-ß1. Following pre-degeneration the nerve pieces were dissociated and then cultured for 6 or 15 days in the same culture medium. After 6 days of culture we obtained around 9.5x103 cells/mg with approximately 94% SCs (S-100 positive) purity. After 15 days of culture the yield was about 80x103 cells/mg and the purity was approximately 75%. Pre-degeneration and subsequent culture of small pieces of adult nerve with NRG1-ß1 supplemented medium increased the number of SCs and restricted the overgrowth of fibroblast-like cells
- PublicationOpen AccessAbsence of relevant effects of 5 mT static magnetic field on morphology, orientation and growth of a rat Schwann cell line in culture(Murcia : F. Hernández, 2007) Gamboa, O.L.; Gutiérrez, P.M.; Alcalde, I.; De la Fuente, I.; Gayoso, M.J.The aim of this study is to observe possible changes in the morphology, orientation or cell growth of an in vitro cultured Schwann cell line by 24 h exposure to 5 mT static magnetic fields. The magnetic field generator basically consists of a pair of circular coils in a Helmholtz arrangement and enables temperature to be controlled (37±0.1°C). We did not find any statistically significant differences in the cell growth rate between control and exposed cells, nor did we observe any differences in cell morphology or orientation.
- PublicationOpen AccessContribution of the proximal and distal nerve stumps to peripheral nerve regeneration in silicone chambers(Murcia : F. Hernández, 1995) Díaz-Flores, Lucio; Gutiérrez, Ricardo; Varela, H.; Evora, P.; Valladares, Francisco; Rodríguez, M.; Rancel, N.; Álvarez-Argüelles, H.The specific contnbution of the proximal and distal neme stumps across an 8 mm gap within silicone chamber regeneration models was studied. For this, proximal and distal (Group A), distal and distal (Group B) and proximal and proximal (Group C) neme stumps were placed in opposite ends of silicone chambers. In al1 the groups, a tissue cable forms between the nerve stumps, demonstrating that, without distinction, proximal or distal stumps can stimulate the growth of other proximal or distal stumps. Furthermore, in Group B, the newly formed pseudo-nerve, in the absence of regenerating axons, contains a number of Schwann cells significantly similar to Group A, which confirms that proliferation and migration of Schwann cells do not require axonal presence or contact. Likewise, the findings demonstrate that, with the exception of the axons, the distal stump contributes to the peripheral nerve regeneration in the same way as the proximal stump. Finally, when proximal stumps are placed in both the opposite ends of the silicone chamber, Schwann cells and regenerating axons grow into the chamber gap from both inserts, and myelination also proceeds from both ends to the centre ofthe chambers.
- PublicationOpen AccessMolecular mechanisms of gap junction mutations in myelinating cells(Murcia : F. Hernández, 2010) Sargiannidou, Irene; Markoullis, Kyriaki; Kleopa, Kleopas A.There is an emerging group of neurological disorders that result from genetic mutations affecting gap junction proteins in myelinating cells. The X-linked form of Charcot Marie Tooth disease (CMT1X) is caused by numerous mutations in the GJB1 gene encoding the gap junction protein connexin32 (Cx32), which is expressed in both Schwann cells in the PNS and oligodendrocytes in the CNS. Patients with CMT1X present mainly with a progressive peripheral neuropathy, showing mixed axonal and demyelinating features. In many cases there is also clinical or subclinical involvement of the CNS with acute or chronic phenotypes of encephalopathy. Furthermore, mutations in the GJA12/GJC2 gene encoding the gap junction protein Cx47, which is expressed in oligodendrocytes, have been identified in families with progressive leukodystrophy, known as Pelizaeus-Merzbacher-like disease, as well as in patients with hereditary spastic paraplegia. Recent studies have provided insights into the pattern of gap junction protein expression and function in CNS and PNS myelinating cells. Furthermore, in vitro and in vivo disease models have clarified some of the molecular and cellular mechanisms underlying these disorders. Here we provide an overview of the clinical, genetic, and neurobiological aspects of gap junction disorders affecting the nervous system.
- PublicationOpen AccessPathological changes of human unmyelinated nerve fibers: a review(Murcia : F. Hernández, 2000) Kanda, T.In the cutaneous nerves, unmyelinated nerve fibers outnumber the myelinated ones but are scarcely analyzed, especially at autopsy. This indifference toward the pathology of unmyelinated nerve fibers may be due to the necessity of electron microscopic analyses and, more importantly, the obscurity of pathological alteration of unmyelinated nerve fibers in aging as well as in peripheral nerve disorders. The aim of this article is to review (1) the normal appearance including postmortem changes, (2) the age-related changes, and (3) the pathological alteration in various neuropathic and nonneuropathic conditions, of unmyelinated nerve fibers in the sural nerve. For the complete analyses of sural nerve, qualitative and quantitative estimation of unmyelinated nerve fibers in all specimens should be recommended and it sometimes has an important diagnostic value
- PublicationOpen AccessPresence of melanin in normal human Schwann cells(Murcia : F. Hernández, 1992) Carbonell, A.L.; Boya, J.; García-Mauriño, J.E.The presence of melanin granules in Schwann cells of unmyelinated neme fibres in the normal skin of a black woman is demonstrated by electron microscopy. Pathological conditions associated with the differentiation ability of Schwann cells for melanogenic are reviewed. This capacity may be due to the common origin of Schwann cells and melanocytes in the neural crest.
- PublicationOpen AccessSchwann cell extracellular matrix molecules and their receptors(Murcia : F. Hernández, 2000) Chernousov, M.A.; Carey, D.J.The major cellular constituents of the mammalian peripheral nervous system are neurons (axons) and Schwann cells. During peripheral nerve development Schwann cells actively deposit extracellular matrix (ECM), comprised of basal lamina sheets that surround individual axon-Schwann cell units and collagen fibrils. These ECM structures are formed from a diverse set of macromolecules, consisting of glyco-proteins, collagens and proteoglycans. To,interact with ECM, Schwann cells express a number of integrin and non-integrin cell surface receptors. The expression of many Schwann cell ECM proteins and their receptors is developmentally regulated and, in some cases, dependent on axonal contact. Schwann cell ECM acts as an organizer of peripheral nerve tissue and strongly influences Schwann cell adhesion, growth and differentiation and regulates axonal growth during development and regeneration.
- PublicationOpen AccessTranscriptional mRNA of BMP-2, 3, 4 and 5 in trigeminal nerve, benign and malignant peripheral nerve sheath tumors(F. Hernández y Juan F. Madrid. Universidad de Murcia: Departamento de Biología Celular e Histología, 2001) Jin, Y.; Lu, H. B.; Liong, E.; Lau, T. Y. H.; Tipoe, G. L.The aim of our study was to document whether relationships existed among bone morphogenetic proteins (BMPs), peripheral nerve and neoplastic lesions of nerve sheath tumors. The mRNA transcriptions of BMP-2, 3, 4 and 5 in 10 cases of schwannoma, three cases of malignant schwannoma and two cases of trigeminal neuralgia were detected using an in situ hybridization technique. Our results demonstrated that the myelin sheaths of Schwann cell from the pe ripheral neuroectomy of trigeminal neuralgia positively expressed mRNA of BMP-2, 3, 4, and 5. The most interesting finding was that the nerve fibers of trigeminal nerve showed only BMP-2 positive staining. All of the neoplastic lesions of nerve sheath showed a consistent but variant expression of BMP-2, 3, 4, and 5. The expression signals of BMP-2 , 3, 5 mRNA in malignant schwannoma were relatively lower than in benign lesions except for the expression of BMP-4 mRNA. Our results indicated that selected members of BMPs were expressed in the peripheral nerves that might contribute to the health maintenance, proliferation, regeneration and neoplastic transformation of the peripheral nerve system. Furthermore, the effects of BMP-2, 3, 4 and 5 on peripheral nervous system during neoplastic transformation might be widespread, diverse and antagonistic.