Remarkable Reduction of MAP2 in the Brains of Scrapie-Infected Rodents and Human Prion Disease Possibly Correlated with the Increase of Calpain

Microtubule-associated protein 2 (MAP2) belongs to the family of heat stable MAPs, which takes part in neuronal morphogenesis, maintenance of cellular architecture and internal organization, cell division and cellular processes. To obtain insight into the possible alteration and the role of MAP2 in transmissible spongiform encephalopathies (TSEs), the MAP2 levels in the brain tissues of agent 263K-infected hamsters and human prion diseases were evaluated. Western blots and IHC revealed that at the terminal stages of the diseases, MAP2 levels in the brain tissues of scrapie infected hamsters, a patient with genetic Creutzfeldt-Jakob disease (G114V gCJD) and a patient with fatal familial insomnia (FFI) were almost undetectable. The decline of MAP2 was closely related with prolonged incubation time. Exposure of SK-N-SH neuroblastoma cell line to cytotoxic PrP106-126 peptide significantly down-regulated the cellular MAP2 level and remarkably disrupted the microtubule structure, but did not alter the level of tubulin. Moreover, the levels of calpain, which mediated the degradation of a broad of cytoskeletal proteins, were significantly increased in both PrP106-126 treated SK-N-SH cells and brain tissues of 263K prion-infected hamsters. Our data indicate that the decline of MAP2 is a common phenomenon in TSEs, which seems to occur at an early stage of incubation period. Markedly increased calpain level might contribute to the reduction of MAP2

Oligodendroglial neoplasms with ganglioglioma-like maturation: a diagnostic pitfall

Although oligodendroglial neoplasms are traditionally considered purely glial, increasing evidence suggests that they are capable of neuronal or neurocytic differentiation. Nevertheless, ganglioglioma-like foci (GGLF) have not been previously described. Herein, we report seven examples where the primary differential diagnosis was a ganglioglioma with an oligodendroglial component. These five male and two female patients ranged in age from 29 to 63 (median 44) years at initial presentation and neuroimaging features were those of diffuse gliomas in general. At presentation, the glial component was oligodendroglioma in six and oligoastrocytoma in one; one was low-grade and six were anaplastic. A sharp demarcation from adjacent GGLF was common, although some intermingling was always present. The GGLF included enlarged dysmorphic and occasionally binucleate ganglion cells, Nissl substance, expression of neuronal antigens, GFAP-positive astrocytic elements, and low Ki-67 labeling indices. In contrast to classic ganglioglioma, however, cases lacked eosinophilic granular bodies and CD34-positive tumor cells. Scattered bizarre astrocytes were also common and one case had focal neurocytic differentiation. By FISH analysis, five cases showed 1p/19q codeletion. In the four cases with deletions and ample dysmorphic ganglion cells for analysis, the deletions were found in both components. At last follow-up, two patients suffered recurrences, one developed radiation necrosis mimicking recurrence, and one died of disease 7.5 years after initial surgery. We conclude that GGLF represents yet another form of neuronal differentiation in oligodendroglial neoplasms. Recognition of this pattern will prevent a misdiagnosis of ganglioglioma with its potential for under-treatment

GAS6 Enhances Repair Following Cuprizone-Induced Demyelination

Growth arrest-specific protein 6 (gas6) activities are mediated through the Tyro3, Axl, and Mer family of receptor tyrosine kinases. Gas6 is expressed and secreted by a wide variety of cell types, including cells of the central nervous system (CNS). In this study, we tested the hypothesis that administration of recombinant human Gas6 (rhGas6) protein into the CNS improves recovery following cuprizone withdrawal. After a 4-week cuprizone diet, cuprizone was removed and PBS or rhGas6 (400 ng/ml, 4 µg/ml and 40 µg/ml) was delivered by osmotic mini-pump into the corpus callosum of C57Bl6 mice for 14 days. Nine of 11 (82%) PBS-treated mice had abundant lipid-associated debris in the corpus callosum by Oil-Red-O staining while only 4 of 19 (21%) mice treated with rhGas6 had low Oil-Red-O positive droplets. In rhGas6-treated mice, SMI32-positive axonal spheroids and APP-positive deposits were reduced in number relative to PBS-treated mice. Compared to PBS, rhGas6 enhanced remyelination as revealed by MBP immunostaining and electron microscopy. The rhGas6-treated mice had more oligodendrocytes expressing Olig1 in the cytoplasm, indicative of oligodendrocyte progenitor cell maturation. Relative to PBS-treated mice, rhGas6-treated mice had fewer activated microglia in the corpus callosum by Iba1 immunostaining. The data show that rhGas6 treatment resulted in more efficient repair following cuprizone-induced injury

Products of cells from gliomas: IX. Evidence that two fundamentally different mechanisms change extracellular matrix expression by gliomas

Four human astrocytic gliomas of high grade of malignancy were each evaluated in tissue and in vitro for percentages of cells expressing glial fibrillary acidic protein (GFAP), collagen type IV, laminin and fibronectin assessed by immunofluorescence with counterstaining of nuclear DNA. Percentages of cells with reticulin and cells binding fluorescein-labeled Ulex europaeus agglutinin were also assessed. In tissue, each extracellular matrix (ECM) component was associated with cells in the walls of abnormal proliferations of glioma vessels, and all four tumors had the same staining pattern. Two strikingly different patterns of conversion of gene product expression emerged during in vitro cultivation. (1). In the most common pattern, percentages of all six markers consistently shifted toward the exact phenotype of mesenchymal cells in abnormal vascular proliferations: increased reticulin, collagen type IV, laminin and fibronectin; markedly decreased glial marker GFAP and absent endothelial marker Ulex europaeus agglutinin. The simplest explanation of this constellation of changes coordinated toward expression of vascular ECM markers is that primary glioma cell cultures are overgrown by mesenchymal cells from the abnormal vascular proliferations of the original glioma. These cell cultures were tested for in situ hybridization (ISH) signals of chromosomes 7 and 10. Cells from one glioma had diploid signals. Cells from the other glioma had aneuploid signals indicating they were neoplastic; however, their signals reflected different numerical chromosomal aberrations than those common to neoplastic glia. (2). The second pattern was different. Cells with ISH chromosomal signals of neoplastic glia retained GFAP, and gained collagen type IV. Their laminin and fibronectin diminished, but persisted among a lower percentage of cells. Cloning and double immunofluorescence confirmed the presence of individual cells with glial and mesenchymal markers. A cell expressing GFAP in addition to either fibronectin, reticulin or collagen type IV is not a known constituent of glioblastoma tissue. This provides evidence of a second mechanism of conversion of gene expression in gliomas.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45382/1/11060_2005_Article_BF01052843.pd

KpnI families of long, interspersed repetitive DNAs in human and other primate genomes.

KpnI restriction of DNAs from all anthropoid primates studied releases a conspicuous series of segments representing families of long, interspersed repetitive DNAs termed here the KpnI 1.2, 1.5, 1.8 and 1.9 kb families. Human KpnI 1.2 to 1.9 kb segments representative of these families were isolated and separately cloned in the KpnI site of a plasmid pBK5, specially constructed for this purpose. The KpnI clones did not cross-hybridize with cloned, primate alphoid sequences, suggesting that the KpnI families represent sequences separate and distinct from the alphoid DNAs. Secondary restriction analyses of cloned KpnI segments demonstrated microheterogeneity among individual members within the same KpnI family. Autoradiograms of capuchin monkey, AGM and human DNA cleaved with HaeIII, AluI or RsaI and hybridized to various cloned human KpnI sequences demonstrated a remarkable conservatism and relative simplicity in the organization of the KpnI families in the genomes of these widely divergent primates. The KpnI 1.2 kb and 1.5 kb families occur in high frequency (15%) among all plaques in two recombinant human genome libraries. Evidence is presented suggesting that the bulk of the KpnI families occur in the genome as clusters or congeries of higher molecular weight segments (greater than 2 kb) containing sequences homologous to the low molecular weight segments (1.2 to 1.9 kb)

Regional assignment of the structural gene for human acid beta-glucosidase to q42 leads to qter on chromosome 1.

The structural gene for human acid beta-glucosidase (GBA) has been regionally assigned to a narrow region on chromosome 1 using somatic cell hybridization, specific immunoprecipitation, and assay with the natural substrate. A human fibroblast line, 46,XX,del(1)(pter leads to q42:), was fused with mouse RAG fibroblasts and the heterokaryons were subcloned. All hybrid subclones containing a normal chromosome 1 were positive for GBA. In contrast, subclones with a single del(1) were negative for GBA by both immunoprecipitation and natural substrate assays. These results were consistent with the previous assignment of GBA to the region 1p11 leads to qter and further localized the gene to the narrow region 1q42 leads to qter