Anim Biotechnol. 2003 May;14(1):31-49. Patterns of cellular gene expression in cells infected with cytopathic or non-cytopathic bovine viral diarrhea virus.
Risatti GR, Pomp D, Donis RO.
Department of Veterinary and Biomedical Sciences, University of Nebraska, Lincoln, Nebraska 68583-0905, USA.
Bovine viral diarrhea virus (BVDV) infection in cattle is responsible for mucosal disease; an invariably fatal syndrome characterized by the recovery of two BVDV strains: cytopathic (cp) or noncytopathic (ncp). To understand the cellular responses to cp BVDV infection, we carried out differential display-polymerase chain reaction (DD-PCR) analysis of gene expression in infected cells. Altered expression of 14 genes involved in several functions was observed in cells infected with cp BVDV: (1) immune regulation, such as CD46, FKBP-12, and osteopontin (OPN); (2) apoptosis-related cysteine proteases like calpain; (3) signaling plasma membrane proteins such as integrin beta1, and prion protein; and (4) unknown function genes. Northern blot analysis of the expression of these genes in ncp BVDV infected cells revealed that while the expression of some genes was affected as in cp BVDV infected cells, others show a clearly contrary change. We postulate that a cause-effect relationship may exist between the differential gene expression alterations that characterize cp and ncp BVDV infections and the unique diseases associated with each BVDV biotype.
PMID:_12887178 [PubMed - in process]
Mol Microbiol. 2003 Aug;49(4):1005-17. Prion protein gene polymorphisms in Saccharomyces cerevisiae.
Research School of Biosciences, University of Kent, Canterbury, Kent CT2 7NJ, UK.
The yeast Saccharomyces cerevisiae genome encodes several proteins that, in laboratory strains, can take up a stable, transmissible prion form. In each case, this requires the Asn/Gln-rich prion-forming domain (PrD) of the protein to be intact. In order to further understand the evolutionary significance of this unusual property, we have examined four different prion genes and their corresponding PrDs, from a number of naturally occurring strains of S. cerevisiae. In 4 of the 16 strains studied we identified a new allele of the SUP35 gene (SUP35delta19) that contains a 19-amino-acid deletion within the N-terminal PrD, a deletion that eliminates the prion property of Sup35p. In these strains a second prion gene, RNQ1, was found to be highly polymorphic, with eight different RNQ1 alleles detected in the six diploid strains studied. In contrast, for one other prion gene (URE2) and the sequence of the NEW1 gene encoding a PrD, no significant degree of DNA polymorphism was detected. Analysis of the naturally occurring alleles of RNQ1 and SUP35 indicated that the various polymorphisms identified were associated with DNA tandem repeats (6, 12, 33, 42 or 57 bp) within the coding sequences. The expansion and contraction of DNA repeats within the RNQ1 gene may provide an evolutionary mechanism that can ensure rapid change between the [PRION+] and [prion-] states.
PMID:_12890024 [PubMed - in process]
Biochem Biophys Res Commun. 2003 Aug 1;307(3):678-83. Absence of superoxide dismutase activity in a soluble cellular isoform of prion protein produced by baculovirus expression system.
Sakudo A, Hamaishi M, Hosokawa-Kanai T, Tuchiya K, Nishimura T, Saeki K, Matsumoto Y, Ueda S, Onodera T.
Department of Molecular Immunology, School of Agricultural and Life Sciences, University of Tokyo, Bunkyo-ku, Tokyo 113-8657, Japan.
A method for expression and purification of a soluble form of histidine (HIS)-tagged murine prion protein (bacMuPrP), which lacks the entire C-terminal cleavage and glycosyl phosphatidyl inositol (GPI) addition site, has been developed using a recombinant baculovirus expression system and purification with Ni-NTA agarose affinity chromatography. In mammalian sources, PrP(C) is attached to the cell membrane by a GPI anchor. However, in our system, bacMuPrP was secreted into the media, enabling its easy purification in abundance. Indirect immunofluorescence studies and immunoblot analysis localized not in cell membrane but in the perinuclear endoplasmic reticulum region in cells and is secreted into the media. Tunicamycin treatment revealed non-glycosylated proteins were secreted into the media, suggesting that glycosylation is not necessary for bacMuPrP secretion. Density-gradient sedimentation analysis demonstrated a sedimentation coefficient of secretory bacMuPrP as 2.3 S, indicating a monomeric form. Although affinity-purified PrP from mouse brain or recombinant prion protein (PrP) produced by Escherichia coli and refolded in the presence of copper has been reported to display superoxide dismutase (SOD) activity, bacMuPrP did not show SOD activity. These results suggest that bacMuPrP has a different biochemical and biophysical characterization from mammalian and bacterial-derived PrP. Furthermore, this simple expression system may provide an adequate source for structural, functional, and biochemical analyses of PrP.
PMID:_12893277
Neurosci Lett. 2003 Sep 4;348(1):37-40. Does the neuropathology of human patients with variant Creutzfeldt-Jakob disease reflect haematogenous spread of the disease?
Armstrong RA, Cairns NJ, Ironside JW, Lantos PL.
Vision Sciences, Aston University, Birmingham, B4 7ET, UK. r.a.armstronston.ac.uk
To test the hypothesis that the distribution of the pathology in variant Creutzfeldt-Jakob disease (vCJD) represents haematogenous spread of the disease, we studied the spatial correlation between the vacuolation, prion protein (PrP) deposits, and the blood vessel profiles in the cerebral cortex, hippocampus, dentate gyrus, and cerebellum of 11 cases of the disease. In the majority of areas, there were no significant spatial correlations between either the vacuolation or the diffuse type of PrP deposit and the blood vessels. By contrast, a consistent pattern of spatial correlation was observed between the florid PrP deposits and blood vessels mainly in the cerebral cortex. The frequency of positive spatial correlations was similar in different anatomical areas of the cerebral cortex and in the upper compared with the lower laminae. Hence, with the exception of the florid deposits, the data do not demonstrate a spatial relationship between the pathological features of vCJD and blood vessels. The spatial correlation of the florid deposits and blood vessels may be attributable to factors associated with the blood vessels that promote the aggregation of PrP to form a condensed core rather than reflecting the haematogenous spread of the disease.
Hair loss is a problem in modern soceity. Examining the factors of hair growth may
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How long can hair grow before it stops growing eventually, if it does?
Given that the hair growth rate is quite uniform and constant, somewhere between 0.3-0.5 millimeters per day, it's believed that the length of anagen, the growth phase, differs among individuals, and this is the major determinant to the maximum hair length. For some individuals, anagen may last ten years.
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