TY - JOUR A1 - Carroll, Patrick A1 - Sendtner, Michael A1 - Meyer, Michael A1 - Thoenen, Hans T1 - Rat ciliary neurothrophic factor (CNTF): gene structure and regulation of mRNA levels in glial cell cultures. N2 - The structure of the rat ciliary neurotrophic factor (CNTF) gene and the regulation ofCNTF mRNA levels in cultured glial cells were investigated. The rat mRNA is encoded by a simple two-exon transcription unit. Sequence analysis of the region upstream of the transcription start-site did not reveal a typical TATA-box consensus sequence. Low levels of CNTF mRNA were detected in cultured Schwann cells, and CNTF mRNA was not increased by a variety of treatments. Three-week-old astrocyteenriched cell cultures from new-born rat brain contained easily detectable CNTF mRNA. In astrocyte-enriched cultures, upregulation of CNTF mRNA levels was observed after treatment with IFN-gamma. CNTF mRNA levels were down-regulated in these cells by treatments that elevate intracellular cyclic AMP and by members of the fibroblast growth factor (FGF) family. The implications of these results for potential in vivo functions of CNTF are discussed. KW - Astrocytes ; Schwann cells ; Interferon-gamma ; Fibroblast growth factor ; Cyclic AMP Y1 - 1993 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-31763 ER - TY - JOUR A1 - Sendtner, Michael T1 - Neurotrophic factors and their action on motoneuron survival: Implications for neuromuscular disorders N2 - Motoneuron diseases represent a m&jor challenge to modern neurology, yet their clinical manifestations ware first described more than hundred years ago, and despite many studies the etiology of these diseases ramd,ns obscure with no effective treatments having been reported. Although progress has been made in establishing genetic linkage in the rare inherited for.ms of these diseases such as familial amyotrophic lateral scleriosisl , spinal mDscular atrophy and X-linked bulbo-spinal-mDscular atrophy, this new information has not yet affected therapeutic techniques. During the last few years several important steps have been taken concerning the physiological mechanisms involved in motoneuron survival during development, after lesion and in animal models of degenerative diseases, the molecular clOning of several new neurotrophic factors (brain-derived neurotrophic factor (BDNP), neurotrophin-3 and-4 (NT-3 and NT-4) and ciliary neurotrophic factor (CNTP)); the identification of a gene family of receptor molecules for same of these factors, progress in the understanding of the effects of polypeptide growth factors on muscle cell differentiation, neuronal sprouting (insulin-like growth factor-I and -11 (IGF-I and IGF-II), and in vitro motoneuronal survival (CNTF, IGF-I and -II and basic FGF). These findings have raised new hopes in that they could lead to a better understanding of the pathophysiological processes underlying these diseases, and that the pharmacological use of same of these newly characterized neurotrophic factors could present new possibilities for the treatment of these diseases. Y1 - 1993 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-31149 ER - TY - JOUR A1 - Masu, Yasuo A1 - Wolf, Eckhard A1 - Holtmann, Bettina A1 - Sendtner, Michael A1 - Brem, Gottfried A1 - Thoenen, Hans T1 - Disruption of the CNTF gene results in motor neuron degeneration N2 - CNTF is a cytosolic molecule expressed postnatally in myelinating Schwann cells and in a subpopulation of astrocytes. Although CNTF administration prevents lesion-mediated and genetically determined motor neuron degeneration, its physiological function remained elusive. Here it is reported that abolition of CNTF gene expression by homologous recombination results in a progressive atrophy and loss of motor neurons in adult mice, which is functionally reflected by a small but significant reduction in muscle strength. Y1 - 1993 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-33038 ER - TY - JOUR A1 - Thoenen, Hans A1 - Hughes, Richard A. A1 - Sendtner, Michael T1 - Trophic support of motoneurons: physiological, pathophysiological, and therapeutic implications. N2 - No abstract available Y1 - 1993 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-31746 ER - TY - JOUR A1 - Hughes, Richard A. A1 - Sendtner, Michael A1 - Goldfarb, Mitchell A1 - Lindholm, Dan A1 - Thoenen, Hans T1 - Evidence that fibroblast growth factor 5 is a major muscle-derived survival factor for cultured spinal motoneurons N2 - We examined the potential role of fibroblast growth factor 5 (FGF-5) as a target-derived trophic factor for spinal motoneurons. Northern analysis of total RNA from rat skeletal muscle revealed an FGF-5 mRNA transcript both during the period of embryonic motoneuron death and in the adult. Recombinant human FGF-5 supported the survival of highly enriched cultures of embryonic chick motoneurons. Significant proportions of the motoneuron survival activity of rat skeletal muscle extracts could be immunoprecipitated using an antiserum to FGF-5. The immunoprecipitable activity was present in soluble and matrix-bound forms in embryonic muscle, but bound exclusively to the extracellular matrix in adult muscle. These results, along with the secretory nature of FGF-5, suggest that FGF-5 may act as a target-derived trophic factor for motoneurons. Y1 - 1993 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-42588 ER - TY - CHAP A1 - Thoenen, Hans A1 - Hughes, Richard A. A1 - Sendtner, Michael T1 - Towards a comprehensive understanding of the trophic support of motoneurons N2 - Motoneurons played an essential role in establishing the concept of target-mediated support of innervating neurons. However, it took several decades until molecules were identined which trophically support motoneurons in vitro and in vivo. The most potent molecule identined so far is ciliary neurotrophic factor (CNTF). It is expressed as a cytosolic molecule in myelinating Schwann cells rather than in skeletal muscle in the postnatal period and therefore does not qualify as a target-derived neurotrophic factor regulating motoneuron survival during embryonic development. However, the inactivation of CNTF by gene targeting experiments results in progressive atrophy and degeneration of motoneurons, demonstrating that CNTF plays an essential role as a maintenance factor for motoneurons postnatally. Secretory molecules which are expressed in skeletal muscle during embryonic development and which support motoneurons in culture and partially also in vivo include members of the NGF gene family (BDNF, NT-3, NT-4/S) , FGF-S, IGF-I, and UF. The evaluation of the physiological importance of these molecules is under investigation. KW - neurotrophic molecules KW - CNTF KW - gene targeting KW - NGF gene family KW - FGF-5 KW - lIF KW - IGF-I Y1 - 1993 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-31117 ER - TY - JOUR A1 - Sendtner, Michael A1 - Thoenen, Hans A1 - Hughes, R. A. T1 - Members of several gene families influence survival of rat motoneurons in vitro and in vivo N2 - The survival and functional maintenance of spinal motoneurons, both during the period of developmental cell death and in adulthood, have been shown to be dependent on trophic factors. In vitro experiments have previously been used to identify several survival factors for motoneurons, including CNTF, UF, and members of the neurotrophin, FGF, and IGF gene families. Some of these factors have also been shown to be active in vivo, either on chick motoneurons during embryonic development or on lesioned facial and spinal motoneurons of the newborn rat. Here we demonstrate that lesioned newborn rat facial motoneurons can be rescued by NT-4/5, IGF-I, and UF. Furthermore, in contrast to chick motoneurons, the survival of isolated embryonic rat motoneurons can be maintained by the neurotrophins BDNF, NT-3, and NT-4/5. IGF-I and FGF-5 were also active in this system, each supporting more than 50% of the originally plated neurons. The responsiveness of motoneurons to multiple factors in vitro and in vivo suggests that motoneuron survival and function are regulated by the coordinated actions of members of different gene families. KW - Immunopanning KW - Facial Nerve Transection KW - Neurotrophin KW - Fibroblast Growth Factor KW - Insulinlike Growth Factor Y1 - 1993 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-42652 ER - TY - JOUR A1 - Barres, B. A. A1 - Schmid, R. A1 - Sendtner, Michael A1 - Raff, Martin C. T1 - Multiple extracellular signals are required for long-term oligodendrocyte survival N2 - We showed previously that oligodendrocytes and their precursors require continuous signalling by protein trophic factors to avoid programmed cell death in culture. Here we show that three classes of such trophic factors promote oligodendrocyte survival in vitro: (1) insulin and insulin-like growth factors (IGFs), (2) neurotrophins, particularly neurotrophin-3 (NT -3), and (3) ciliary-neurotrophic factor (CNTF), leukemia inhibitory factor (LIF) and interleukin 6 (IL-6). A single factor, or combinations of factors within the same class, promote only short-term survival of oligodendrocytes and their precursors, while combinations of factors from different classes promote survival additively. Long-term survival of oligodendrocytes in vitro requires at least one factor from each class, suggesting that multiple signals may be required for long-term oligodendrocyte survival in vivo. We also show that CNTF promotes oligodendrocyte survival in vivo, that platelet-derived growth factor (PDGF) can promote the survival of oligodendrocyte precursors in vitro by acting on a novel, very high affinity PDGF receptor, and that, in addition to its effect on survival, NT-3 is a potent mitogen for oligodendrocyte precursor cells. KW - neurotrophins KW - programmed cell death KW - apoptosis KW - ciliary-neurotrophic factor KW - interleukin 6 KW - insulin KW - insulin-likegrowth factor I Y1 - 1993 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-42644 ER -