Genomic effects of IFN-beta in multiple sclerosis patients

The purpose of this report was to characterize the dynamics of the gene expression cascades induced by an IFN-beta-1a treatment regimen in multiple sclerosis patients and to examine the molecular mechanisms potentially capable of causing heterogeneity in response to therapy. In this open-label pharmacodynamic study design, peripheral blood was obtained from eight relapsing-remitting multiple sclerosis patients just before and at 1, 2, 4, 8, 24, 48, 120, and 168 h after i.m. injection of 30 micro g of IFN-beta-1a. The total RNA was isolated from monocyte-depleted PBL and analyzed using cDNA microarrays containing probes for >4000 known genes. IFN-beta-1a treatment resulted in selective, time-dependent effects on multiple genes. The mRNAs for genes implicated in the anti-viral response, e.g., double-stranded RNA-dependent protein kinase, myxovirus resistance proteins 1 and 2, and guanylate binding proteins 1 and 2 were rapidly induced within 1-4 h of IFN-beta treatment. The mRNAs for several genes involved in IFN-beta signaling, such as IFN-alpha/beta receptor-2 and Stat1, were also increased. The mRNAs for lymphocyte activation markers, such as IFN-induced transmembrane protein 1 (9-27), IFN-induced transmembrane protein 2 (1-8D), beta(2)-microglobulin, and CD69, were also increased in a time-dependent manner. The findings demonstrate that IFN-beta treatment induces specific and time-dependent changes in multiple mRNAs in lymphocytes of multiple sclerosis patients that could provide a framework for rapid monitoring of the response to therapy.     

Human catecholamine sulfotransferase (SULT1A3) pharmacogenetics: functional genetic polymorphism

Sulfotransferase (SULT) 1A3 catalyzes the sulfate conjugation of catecholamines and structurally related drugs. As a step toward studies of the possible contribution of inherited variation in SULT1A3 to the pathophysiology of human disease and/or variation in response to drugs related to catecholamines, we have resequenced all seven coding exons, three upstream non-coding exons, exon-intron splice junctions and the 5'-flanking region of SULT1A3 using DNA samples from 60 African-American (AA) and 60 Caucasian-American (CA) subjects. Eight single nucleotide polymorphisms (SNPs) were observed in AA and five in CA subjects, including one non-synonymous cSNP (Lys234Asn) that was observed only in AA subjects with an allele frequency of 4.2%. This change in amino acid sequence resulted in only 28 +/- 4.5% (mean +/- SEM) of the enzyme activity of the wild-type (WT) sequence after transient expression in COS-1 cells, with a parallel decrease (54 +/- 2.2% of WT) in level of SULT1A3 immunoreactive protein. Substrate kinetic studies failed to show significant differences in apparent Km values of the two allozymes for either dopamine (10.5 versus 10.2 micro m for WT and variant, respectively) or the cosubstrate 3'-phosphoadenosine 5'-phosphosulfate (0.114 versus 0.122 micro m, respectively). The decrease in level of immunoreactive protein in response to this single change in amino acid sequence was due, at least in part, to accelerated SULT1A3 degradation through a proteasome-mediated process. These observations raise the possibility of ethnic-specific inherited alterations in catecholamine sulfation in humans.     

A mutation in the fibroblast growth factor 14 gene is associated with autosomal dominant cerebellar ataxia [corrected

Hereditary spinocerebellar ataxias (SCAs) are a clinically and genetically heterogeneous group of neurodegenerative disorders for which >/=14 different genetic loci have been identified. In some SCA types, expanded tri- or pentanucleotide repeats have been identified, and the length of these expansions correlates with the age at onset and with the severity of the clinical phenotype. In several other SCA types, no genetic defect has yet been identified. We describe a large, three-generation family with early-onset tremor, dyskinesia, and slowly progressive cerebellar ataxia, not associated with any of the known SCA loci, and a mutation in the fibroblast growth factor 14 (FGF14) gene on chromosome 13q34. Our observations are in accordance with the occurrence of ataxia and paroxysmal dyskinesia in Fgf14-knockout mice. As indicated by protein modeling, the amino acid change from phenylalanine to serine at position 145 is predicted to reduce the stability of the protein. The present FGF14 mutation represents a novel gene defect involved in the neurodegeneration of cerebellum and basal ganglia.     

Gerstmann-Sträussler-Scheinker disease with P102L-V129 mutation: a case with psychiatric manifestations at onset

Gerstmann-Str?ussler-Scheinker disease (GSS) is an adult onset, rare, genetically determined autosomal dominant prion disease. Clinically, it is characterized predominantly by slowly progressive spino-cerebellar dysfunction with ataxia, absent reflexes in the legs and cognitive impairment. Onset is usually in the fifth decade and in the early phase, ataxia is predominant. Mutations in the prion protein gene (PRNP) had been identified and the most important of these is at codon 129. A genotype-phenotype relationship with genetic polymorphism at residue 129 between methionine and valine has been supposed. We describe a patient with GSS and P102L-V129 mutation in which the onset with prominent psychiatric features characterized by apathy and depression and not with cerebellar sign and the clinical course with seizures, nor observed in P102L-V129 cases, allow us to confirm observations that the GSS caused by the 102 mutation is influenced by the codon 129 polymorphism with a specific genotype-phenotype influence, but probably other additional factors might be considered as background for phenotypic variability.     

Molecular aspects of photodynamic therapy: low energy pre-sensitization of hypericin-loaded human endometrial carcinoma cells enhances photo-tolerance, alters gene expression and affects the cell cycle

Photosensitization of HEC1-B cells with a low concentration of hypericin and doses of light below 10 J/cm(2) caused cell death (apoptosis occurred mainly at doses between 2 and 5 J/cm(2), whereas necrosis prevailed above 6 J/cm(2)). However, pre-exposure of cells to innocuous irradiation (2 J/cm(2)) and successive challenge with a light dose that normally induced apoptosis (5 J/cm(2)) altered the expression of the proteins involved in the regulation of apoptosis, stress response and cell cycle. This change resulted in a significant increase in cell photo-tolerance.     

Confirmation of the potential usefulness of two human beta globin pseudogene markers to estimate gene flows to and from sub-Saharan Africans

Two polymorphic sites, -107 and -100 with respect to the "cap" site of the human beta globin pseudogene, recently discovered in our laboratory, turned out to have an ethnically complementary distribution. The first site is polymorphic in Europeans, North Africans, Indians (Hindu), and Oriental Asians, and monomorphic in sub-Saharan Africans. Conversely, the second site is polymorphic in sub-Saharan African populations and monomorphic in the aforementioned populations. Here we report the gene frequencies of these two polymorphic sites in nine additional populations (Egyptians, Spaniards, Japanese, Chinese, Filipinos, Vietnamese, Africans from Togo and from Benin, and Pygmies), confirming their ethnospecificity and, through the analysis of these two markers in Oromo and Amhara of Ethiopia (two mixed populations), their usefulness in genetic admixture studies. Moreover, we studied another marker polymorphic in sub-Saharan African populations only, a TaqI restriction fragment length polymorphism located in the same region as the present markers, demonstrating the absence of linkage disequilibrium between it and the -100 site, so that we can exclude that the information they provide is redundant.     

Astrocytic but not neuronal increased expression and redistribution of parkin during unfolded protein stress

Parkin is a ubiquitin ligase that facilitates proteasomal protein degradation and is involved in a common autosomal recessive form of Parkinson's disease. Its expression is part of the unfolded protein response in cell lines where its overexpression protects against unfolded protein stress. How parkin expression is regulated in brain primary cells under stress situations is however, less well established. Here, the cellular and subcellular localization of parkin under basal conditions and during unfolded protein stress was investigated in primary cultures of rat astrocytes and hippocampal neurons. Immunofluorescense microscopy and biochemical analysis demonstrated that parkin is mainly associated with the endoplasmic reticulum (ER) in hippocampal neurons while it is associated with Golgi membranes, the nuclei and light vesicles in astrocytes. The constitutive parkin expression was high in neurons as compared with astrocytes. However, unfolded protein stress elicited a selective increase in astrocytic parkin expression and a change in distribution, whereas neuronal parkin remained largely unmodified. The cell specific differences argue in favour of different cellular binding sites and substrates for the protein and a pathogenic role for astrocytes in Parkinson's disease caused by parkin dysfunction.