摘要:

AbstractRabbit antibodies raised against a 135‐ to 140‐kD glycoprotein isolated from the culture medium of mouse forebrain explants were used for the identification and cloning of a complex of mouse neural cell surface glycoproteins. The antibodies recognized a 135‐kD surface protein which shared the L2/HNK‐1 epitope with several neural cell adhesion molecules. Three homologous complementary deoxyribonucleic acid (cDNA) clones were isolated from a mouse brain cDNA library prepared in the expression vector lambda gt11, one of which was sequenced and found to lack sequence homologies with known proteins. In Northern blots, this clone hybridized with a single 6.3 kb messenger ribonucleic acid (mRNA). In immunoblots of mouse brain extracts, antibodies raised in rabbits against the fusion protein encoded by it stained two glycoproteins of 135 and 90 kD, which we designatedF3.135andF3.90. In the developing mouse cerebellum, F3 antigenic sites were found predominantly on parallel fibers and on postmitotic neurons. In fetal brain cell cultures, F3 antigen was detected at the surface of cells with neuronal morphology, but the antibodies also stained some non‐neuronal cells in a pattern characteristic of matrix components. Because all proteins carrying the L2/HNK‐1 epitope identified so far have a role in cell adhesion, it can be anticipated that the F3 surface proteins also are involved in cellinteractio

ISSN:0360-4012    

DOI:10.1002/jnr.490220102

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1989

数据来源: WILEY

摘要:

AbstractThe complete mouse prepro‐nerve growth factor (NGF) DNA was fused to the carboxyl terminus of the β‐galactosidase (lac‐z) gene ofEscherichia coli. Similarly, a genomic fragment encoding the human NGF comprising codons 11 to 106 (from a total of 118) was fused to the fifth codon of the amino terminus of β‐galactosidase. Both bacterial vectors produce high amounts of the chimeric proteins. After cell lysis most of the chimeric mouse preproNGF protein is insoluble and appears in the pellet, whereas the majority of the chimeric human β‐NGF remains in the supernatant.Purification of the fusion proteins from the soluble fraction was achieved by affinity chromatography to p‐aminophenyl β‐D‐thio‐galactoside Sepharose. Yields of the purified chimeric proteins were increased threefold to fourfold by the addition of protease inhibitors in the lysis and chromatography buffers. Their antigenic similarity to the preproNGF and mouse β‐NGF was examined by their interaction to sera raised against synthetic peptides which reproduce sequences of the precursor protein and to sera directed against native and denatured mouse β‐NGF using enzymelinked immunoabsorbent assay (ELISA) techniques. Antibodies to the peptide N2(—163 to —139) interacted with high affinity with the chimeric mouse preproNGF protein. Antisera to native and denatured mouse β‐NGF interacted with both chimeric proteins but with a variable degree of affinity. These results provide direct evidence that certain antisera to mouse β‐NGF can cros

ISSN:0360-4012    

DOI:10.1002/jnr.490220103

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1989

数据来源: WILEY

摘要:

AbstractPhorbol 12‐myristate 13‐acetate (PMA) has been shown to stimulate DNA synthesis and cell proliferation in a population of glial cells isolated from newborn rat brain. The non‐tumor promoter 4α‐phorbol 12,13‐didecanoate (4α‐PDD), on the other hand, was without an effect. The cultures treated with PMA displayed an extensive process formation and an increase in cell content. The tumor promoter‐induced [3H]thymidine incorporation into acid‐precipitable material was completely blocked by 1‐(5‐isoquinolinylsulfonyl)‐2‐methylpiperazine (H‐7), a potent inhibitor of protein kinase C (PKC), thereby suggesting a role for PKC in the control of DNA synthesis in glial cells. Subcellular fractionation and in vitro assay of PKC activity revealed a translocation of the enzyme from cytosol to particulate fract

ISSN:0360-4012    

DOI:10.1002/jnr.490220104

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1989

数据来源: WILEY

摘要:

AbstractThe astrocyte mitogenic activity of normal and injured rat brain extracts was greatly enhanced by antibodies to epidermal growth factor receptor (EGFR). The antibodies appear to act by removing from the extracts inhibitory molecules immunologically related to EGFR. Three molecular species recognized by anti‐EGFR antibody in brain extracts (molecular weights 41, 52, and 69 kilodaltons) did not seem to originate from EGFR proteolysis. The increase in astrocyte mitogenic activity in brain tissue following injury correlated with a reduction in the levels of soluble EFGR‐cross‐reacting material and a decrease in mitogen inhibitory activity. The decrease in EGFR‐related mitogen inhibitor also correlated with a large increase in astrocyte membrane EGFR immunoreactivity, and intracerebral injection of antibodies to EGFR caused the appearance at the injection site of numerous EGFR‐positive reactive astrocytes. Invasion of brain tissue by EGF/EGFR‐related blood components may be the signal that initiates astrocyte activation. EGFR‐related immunoreactive molecules are also present in extracts of other tissues and may have a general role in the control of

ISSN:0360-4012    

DOI:10.1002/jnr.490220105

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1989

数据来源: WILEY

摘要:

AbstractMonoclonal antibody J1‐31 (MAb J1‐31, isotype IgG 2b) was raised against crude homogenate of brain tissue from a multiple sclerosis (MS) patient (autopsy sample; Malhotra et al.:Microbios Letters26:151–157, 1984). In human brain, MAb J1‐31 recognizes an intracellular protein antigen (J1‐31 antigen), which bands at approximately 30,000 daltons under reducing conditions for sodium dodecyl sulfate gel electrophoresis (Singh et al.:Bioscience Reports6:73‐79, 1986). By immunofluorescence microscopy, MAb J1‐31 stains those cells that are also stained by antiserum to glial fibrillary acidic protein (GFAP), namely astrocytes, retinal Müller cells, and tanycytes in the ependyma (Predy et al.:Bioscience Reports7:491–502, 1987). In addition, MAb J1‐31 stains ciliated ependymal cells that do not express GFAP.Using a model system for gliosis (laceration‐type injury of rat spinal cord), we were able to show that astrocytes responding to central nervous system injury exhibit greatly enhanced staining for J1‐31 antigen (Predy et al.:Journal of Neuroscience Research19:397–404, 1988; Predy and Malhotra:Brain Research Bulletinin press, 1989). In this article, we demonstrate that immunofluorescence staining owing to MAb J1‐31 is greatly enhanced in MS plaques, as compared to adjacent “apparently normal” white matter. (This is consistent with previous results as MS plaques characteristically show an astroglial response [reactive gliosis] leading to the formation of a glial scar [McKhann:Annual Review of Neuroscience5:219–239, 1982].) In addition, we present further evidence that J1‐31 antigen is distinct from GFAP, although these two proteins may be ass

ISSN:0360-4012    

DOI:10.1002/jnr.490220106

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1989

数据来源: WILEY

摘要:

AbstractIn this report we examined the phenotypic expressions and the proliferative capability of cultured human fetal Schwann cells. Antigens that were expressed included laminin, nerve growth factor receptor, neural cell adhesion molecule, S‐100 protein, and that recognized by the monoclonal antibody HNK‐1. In addition, HLA‐A,B,C and HLA‐DR, respectively, class I and class II antigens of the major histocompatibility complex, were demonstrated on Schwann cells. Mitotic capability was high, with an average of 34% of Schwann cells undergoing proliferation over a 2‐d

ISSN:0360-4012    

DOI:10.1002/jnr.490220107

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1989

数据来源: WILEY

摘要:

AbstractFour monoclonal antibodies to a purified ciliary neurotrophic factor have been produced by a combination of in vivo and in vitro immunization of mouse lymphocytes. Three of the antibodies—3D12, an 1gA subtype, and 5G9 and 2B11, both IgM subtypes—bound to the single band on immunoblots of the purified factor. Of the four clones only one, 3D12, produced antibodies able to inhibit the biological activity of the neurotrophic factor in promoting the survival of ciliary neurones in dissociated cult

ISSN:0360-4012    

DOI:10.1002/jnr.490220108

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1989

数据来源: WILEY

摘要:

AbstractThe sugar part of cellular glycoconjugates and specific endogenous sugar receptors, i.e., lectins, can establish a system of biological recognition based on proteincarbohydrate interactions. An assortment of labelled (neo)glycoproteins, carrying different types of sugar moieties, is synthesized to localize respective sugar receptors. With these tools, the histochemical patterns of endogenous carbohydrate‐binding receptors of the epi‐, peri‐, and endoneurium were analyzed in human sural and accessory nerves and in swine sciatic nerve. This approach is complementary to the application of plant lectins, focusing on endogenous carbohydrate‐binding proteins (lectins). In contrast to the epi‐ and endoneurium, which bound certain types of carbohydrates, such endogenous sugar receptors were histochemically not detectable in the perineurial cells. Moreover, no histochemical reaction was present in the “connective tissue septa” localized in the endoneurium in which the endoneurial vessels were embedded. This common property supplies evidence that these septa are composed of perineurial cells. They may represent a barrier in addition to the capillary endothelium. Our observations suggest histogenetical differences between the cell populations of epi‐and endoneurium vs. perineurium. This significant difference in the ability to bind carbohydrate residues, conjugated to a carrier protein, is contradictory to the assumption that perineurial cells and fibroblasts are functional variants of the same cell type.The histochemical patterns of endogenous carbohydrate‐binding receptors found in human and swine nerves were similar but not identical, with exception of the perineurium, reflecting phylogenetic differences in the expression of sugar‐binding proteins. The absence of specific sugar receptors in perineurial cells, however, seems to be a more general phenomenon. It can lead to a profoundly limited recognitive capacity of these cells within a sugar‐code system of biological information, possibly contributing to the molecular basis of

ISSN:0360-4012    

DOI:10.1002/jnr.490220109

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1989

数据来源: WILEY

摘要:

AbstractSynaptic circuitry in the upper dorsal horn, disorganized due to transganglionic degenerative atrophy (evoked by blockade of retrograde axoplasmic transport in the related peripheral nerve), begins to be reestablished by a process of regenerative synaptoneogenesis as soon as retrograde transport is resumed. Central axons of type C primary sensory neurons, terminating in substantia gelatinosa Rolandi, as well as their cells of origin in dorsal root ganglia are specifically and selectively labeled by the enzyme thiamine monophosphatase (TMPase). Under normal conditions, TMPase is localized in axolemmal membranes at the electron histochemical level. In axonal growth cones of regenerating central terminals, only negligible TMPase reaction was found. In axonal filopodia and young nerve sprouts, there appears an increasing number of intraaxonal grains of the reaction product. Vanicous swellings (beads) of regenerating axonal sprouts are transformed into scalloped (sinusoid) en passant terminals. TMPase reaction end product, present initially in the axoplasm of beads and scalloped terminals, is successively translocated to the axolemmal membrane in the course of cytochemical maturation. Structural regeneration and cytochemical maturation of central terminals of primary sensory neurons are completed 60 days after crush injury to the related peripheral axons, i.e., about 7 weeks after the peripheral nerve has regenerated.

ISSN:0360-4012    

DOI:10.1002/jnr.490220110

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1989

数据来源: WILEY

摘要:

AbstractBasic fibroblast growth factor (bFGF) recently has been established as a survival‐ and transmitter‐promoting neurotrophic agent for embryonic neurons in vitro. Its local application to lesioned adult optic and sciatic nerves has been shown to rescue axotomized retinal and sensory neurons that otherwise die. Following transection of the fimbria fornix pathway connecting the medial septum (MS) to the hippocampus, MS neurons undergo severe cell death, which can be prevented partially by infusion of nerve growth factor (NGF). In the same lesion paradigm, we find that 87% of these neurons visualized by cresyl‐violet staining have disappeared by 4 weeks after unilateral fimbria fornix transection in adult rats. Implantation of gel foam soaked with 8 μg bFGF reduced neuron death to 68%. A similar rescue effect was seen with 0.3 μg NGF. NGF administered at 20 μg reduced cell losses to 54%. Thus, bFGF rescued 22% and NGF at 20 μg 38% of the neurons that otherwise would have died. Choline acetyltransferase immunocytochemistry revealed dramatic losses of cholinergic neurons on the lesioned, compared with the unlesioned, side. Cholinergic neuron death was clearly reduced by the bFGF and NGF treatments. Basic FGF, in contrast to NGF, did not prevent a reduction in size of surviving neuronal cell bodies. Considered in the context of FGF being present in brain and hippocampal neurons, our results suggest a possible role for FGF as a neurotrophic factor for CNS neuron

ISSN:0360-4012    

DOI:10.1002/jnr.490220111

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1989

数据来源: WILEY