Amyloid plaques have been found in the brains of some patients with Creutzfeldt-Jakob disease (CJD) and all patients with Gerstmann-Sträussler syndrome (GSS). We examined paraffin sections from 45 ...patients with CJD or GSS and from 51 patients with other neurologic diseases, using an antiserum against GSS amyloid plaque cores. The GSS amyloid plaque core antiserum revealed not only birefringent amyloid plaques but also small plaques that cannot be detected by the staining with Congo red dye. Positive immunolabeling was demonstrated in 59% of 34 Japanese patients with CJD, in 100% of 11 patients with GSS, and in none with other neurologic diseases. All cases of CJD of short duration (less than 11 months) were evaluated as being negative, and 95% of 21 long survivors (over 12 months) were positive. This immunohistochemical approach revealed that amyloid plaque is a hallmark of CJD with a long clinical course.
The distribution and sequential development of prion protein (PrP) accumulation in the central nervous system (CNS) and non-neuronal organs of mice infected with Creutzfeldt-Jakob disease (CJD) were ...investigated immunohistochemically using a new pretreatment method that greatly enhanced the immunoreactivity of PrP. Prion protein accumulation in the CNS was first detected at 30 days after inoculation and then developed near the inoculation site or periventricular area, and later spread to the whole cerebrum and then to the pons. Its staining took some characteristic forms. Among non-neuronal organs, PrP accumulated in the follicular dendritic cells (FDCs) in spleen, lymph node, Peyer's patch, and thymus. FDCs staining appeared in spleen, lymph node, and Peyer's patch at 21 or 30 days after inoculation, and in thymus at 90 days. Germinal centers developed in the thymus of some CJD-infected mice. No PrP staining was detected in any examined organs of age-matched control mice.
Mutations in the
amnesiac gene in
Drosophila affect both memory retention and ethanol sensitivity. The predicted
amnesiac gene product, AMN, is an apparent preproneuropeptide, and previous studies ...suggest that it stimulates cAMP synthesis. Here we show that, unlike other learning-related
Drosophila proteins, AMN is not preferentially expressed in mushroom bodies. Instead, it is strongly expressed in two large neurons that project over all the lobes of the mushroom bodies, a finding that suggests a modulatory role for AMN in memory formation. Genetically engineered blockade of vesicle recycling in these cells abbreviates memory as in the
amnesiac mutant. Moreover, restoration of
amn gene expression to these cells reestablishes normal olfactory memory in an
amn deletion background. These results indicate that AMN neuropeptide release onto the mushroom bodies is critical for normal olfactory memory.
Using immunostaining with anti-prion protein (PrP) antiserum, we detected numerous kuru plaques in the brain of a 24-year-old man with Gerstmann-Sträussler-Scheinker syndrome. Immunoreactivity on ...Western blotting of the protease-resistant PrP fraction from the frozen brain was weak. PrP gene analysis showed substitution of alanine to valine in codon 117 but no substitution in codon 102. As the experimental transmission of the disease to mice was negative, a pathogen of a relatively low infectivity may cause the disease in predisposed family members.
The phosphorylation of the human estrogen receptor (ER) serine residue at position 118 is required for full activity of the ER activation function 1 (AF-1). This Ser$^{118}$ is phosphorylated by ...mitogen-activated protein kinase (MAPK) in vitro and in cells treated with epidermal growth factor (EGF) and insulin-like growth factor (IGF) in vivo. Overexpression of MAPK kinase (MAPKK) or of the guanine nucleotide binding protein Ras, both of which activate MAPK, enhanced estrogen-induced and antiestrogen (tamoxifen)-induced transcriptional activity of wild-type ER, but not that of a mutant ER with an alanine in place of Ser$^{118}$. Thus, the activity of the amino-terminal AF-1 of the ER is modulated by the phosphorylation of Ser$^{118}$ through the Ras-MAPK cascade of the growth factor signaling pathways.
We examined paraffin-embedded brain sections from three patients with Creutzfeldt-Jakob disease (CJD) and four patients with Gerstmann-Sträussler syndrome (GSS) who also had beta protein deposits in ...the brains. Immunostaining using anti-prion protein (PrP) and anti-beta protein coupled with formic acid pretreatment, revealed PrP deposits and beta protein deposits, respectively. In all four GSS patients examined, sequential double immunostaining and single immunostaining in serial sections or simultaneous double immunofluorescence revealed the colocalization of PrP and beta protein in the same amyloid plaques. The plaques labeled with both antibodies were designated as beta-PrP plaques. Small kuru plaques of less than 15 microns in diameter were rarely found to coexist with beta deposits. The percentages of beta-PrP plaques in larger kuru plaques were not constant among the four GSS patients. The colocalization patterns of both deposits were observed as being roughly of two types as follows: (1) diffuse beta protein deposits located around the PrP core; and (2) a beta protein core and PrP core simultaneously existing in one amyloid plaque. Under an electron microscope, we were able to confirm the presence of both beta protein and PrP in a single plaque in four GSS patients older than 60 years old. In contrast, no colocalization of either deposits was seen in the amyloid plaque core fractions of a young GSS patient who had no beta protein deposits, even at the electron microscopic level. Therefore, the colocalization of both proteins in a single plaque is believed to be age-related and incidental in GSS patients but suggests a similar morphogenesis of both amyloid deposits.
Recent molecular genetic studies revealed that human prion protein (PrP) gene has a large repertoire of polymorphisms and mutations. Each variant PrP seems to correspond to the distinct type of prion ...diseases. We report herein that it is useful to classify prion diseases into Creutzfeldt-Jakob disease (CJD) type or Gerstmann-Sträussler syndrome (GSS) type, based on the distribution of PrP in the central nervous system. The variant PrP including codon 102, codon 105, codon 129, codon 145 and insertional mutations belong to the GSS type, while the wild type PrP and the variants including codon 180, codon 200, codon 210, and codon 232 mutations belong to the CJD type. The CJD type prion diseases showed a rapidly progressive dementia, myoclonus, and periodic synchronous discharges in the electroencephalogram, and showed diffuse gray matter PrP accumulations including the synaptic structures in the pathological findings. The GSS type prion diseases showed a long clinical course without myoclonus and periodic synchronous discharges, and the major PrP accumulation sites were extracellular PrP plaques. The distribution of PrP deposit in the central nervous system influences the clinical and pathological aspects of prion diseases.
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