504 research outputs found

    Global transcript and phenotypic analysis of yeast cells expressing Ssa1, Ssa2, Ssa3 or Ssa4 as sole source of cytosolic Hsp70-Ssa chaperone activity.

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    BACKGROUND: Cytosolic Hsp70 is a ubiquitous molecular chaperone that is involved in responding to a variety of cellular stresses. A major function of Hsp70 is to prevent the aggregation of denatured proteins by binding to exposed hydrophobic regions and preventing the accumulation of amorphous aggregates. To gain further insight into the functional redundancy and specialisation of the highly homologous yeast Hsp70-Ssa family we expressed each of the individual Ssa proteins as the sole source of Hsp70 in the cell and assessed phenotypic differences in prion propagation and stress resistance. Additionally we also analysed the global gene expression patterns in yeast strains expressing individual Ssa proteins, using microarray and RT-qPCR analysis. RESULTS: We confirm and extend previous studies demonstrating that cells expressing different Hsp70-Ssa isoforms vary in their ability to propagate the yeast [PSI+] prion, with Ssa3 being the most proficient. Of the four Ssa family members the heat inducible isoforms are more proficient in acquiring thermotolerance and we show a greater requirement than was previously thought, for cellular processes in addition to the traditional Hsp104 protein disaggregase machinery, in acquiring such thermotolerance. Cells expressing different Hsp70-Ssa isoforms also display differences in phenotypic response to exposure to cell wall damaging and oxidative stress agents, again with the heat inducible isoforms providing better protection than constitutive isoforms. We assessed global transcriptome profiles for cells expressing individual Hsp70-Ssa isoforms as the sole source of cytosolic Hsp70, and identified a significant difference in cellular gene expression between these strains. Differences in gene expression profiles provide a rationale for some phenotypic differences we observed in this study. We also demonstrate a high degree of correlation between microarray data and RT-qPCR analysis for a selection of genes. CONCLUSIONS: The Hsp70-Ssa family provide both redundant and variant-specific functions within the yeast cell. Yeast cells expressing individual members of the Hsp70-Ssa family as the sole source of Ssa protein display differences in global gene expression profiles. These changes in global gene expression may contribute significantly to the phenotypic differences observed between the Hsp70-Ssa family members

    Penyuluhan Bahaya Penyalahgunaan Napza Bagi Pelajar dan Remaja

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    Penyalahgunaan NAPZA (Narkotika, Psikotropika, dan Zat-zat Adiktif) merupakan suatu pola perilaku yang bersifat patologik, dan biasanya dilakukan oleh individu yang mempunyai kepribadian rentan atau mempunyai resiko tinggi, dan jika dilakukan dalam jangka waktu tertentu akan menimbulkan gangguan bio-psiko-sosial-spiritual. NAPZA bersifat psikotropika dan psikoaktif yang mempunyai pengaruh terhadap sistem syaraf dan biasanya digunakan sebagai analgetika (pengurang rasa sakit) dan memberikan pengaruh pada aktifitas mental dan perilaku serta digunakan sebagai terapi gangguan psikiatrik pada dunia kedokteran. Secara farmakologik, yang termasuk NAPZA antara lain ganja, morfin, sabu, ekstasi, marijuana, putau, kokain, pil koplo, dan sebagainya. Obat-obatan ini termasuk dalam daftar obat G yang artinya dalam penggunaannya harus disertai dengan kontrol dosis yang sangat ketat oleh dokter. Pelajar (siswi) adalah istilah bagi peserta didik pada jenjang pendidikan menengah pertama dan menengah atas. Siswa adalah komponen dalam sistem pendidikan, yang selanjutnya menjalani proses pendidikan, sehingga menjadi manusia yang berkualitas sesuai dengan tujuan pendidikan nasional. Penyuluhan ini menempatkan pelajar sebagai suatu komponen ditinjau dari pendekatan sosial, dan psikologis

    Borderline personality disorder co-morbidity: Relationship to the internalizing–externalizing structure of common mental disorders

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    Background. Borderline personality disorder (BPD) shows high levels of co-morbidity with an array of psychiatric disorders. The meaning and causes of this co-morbidity are not fully understood. Our objective was to investigate and clarify the complex co-morbidity of BPD by integrating it into the structure of common mental disorders. Method. We conducted exploratory and confirmatory factor analyses on diagnostic interview data from a representative US population-based sample of 34 653 civilian, non-institutionalized individuals aged o18 years. We modeled the structure of lifetime DSM-IV diagnoses of BPD and antisocial personality disorder (ASPD), major depressive disorder, dysthymic disorder, panic disorder with agoraphobia, social phobia, specific phobia, generalized anxiety disorder, post-traumatic stress disorder, alcohol dependence, nicotine dependence, marijuana dependence, and any other drug dependence. Results. In both women and men, the internalizing-externalizing structure of common mental disorders captured the co-morbidity among all disorders including BPD. Although BPD was unidimensional in terms of its symptoms, BPD as a disorder showed associations with both the distress subfactor of the internalizing dimension and the externalizing dimension. Conclusions. The complex patterns of co-morbidity observed with BPD represent connections to other disorders at the level of latent internalizing and externalizing dimensions. BPD is meaningfully connected with liabilities shared with common mental disorders, and these liability dimensions provide a beneficial focus for understanding the co-morbidity, etiology and treatment of BPD

    Psychiatric Context of Acute/Early HIV Infection. The NIMH Multisite Acute HIV Infection Study: IV

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    Acute/early HIV infection is a period of high risk for HIV transmission. Better understanding of behavioral aspects during this period could improve interventions to limit further transmission. Thirty-four participants with acute/early HIV infection from six US cities were assessed with the Mini International Diagnostic Interview, Beck Depression Inventory II, State-Trait Anxiety Inventory, Brief COPE, and an in-depth interview. Most had a pre-HIV history of alcohol or substance use disorder (85%); a majority (53%) had a history of major depressive or bipolar disorder. However, post-diagnosis coping was predominantly adaptive, with only mild to moderate elevations of anxious or depressive mood. Respondents described challenges managing HIV in tandem with pre-existing substance abuse problems, depression, and anxiety. Integration into medical and community services was associated with adaptive coping. The psychiatric context of acute/early HIV infection may be a precursor to infection, but not necessarily a barrier to intervention to reduce forward transmission of HIV among persons newly infected

    Neurochemical Changes in the Mouse Hippocampus Underlying the Antidepressant Effect of Genetic Deletion of P2X7 Receptors.

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    Recent investigations have revealed that the genetic deletion of P2X7 receptors (P2rx7) results in an antidepressant phenotype in mice. However, the link between the deficiency of P2rx7 and changes in behavior has not yet been explored. In the present study, we studied the effect of genetic deletion of P2rx7 on neurochemical changes in the hippocampus that might underlie the antidepressant phenotype. P2X7 receptor deficient mice (P2rx7-/-) displayed decreased immobility in the tail suspension test (TST) and an attenuated anhedonia response in the sucrose preference test (SPT) following bacterial endotoxin (LPS) challenge. The attenuated anhedonia was reproduced through systemic treatments with P2rx7 antagonists. The activation of P2rx7 resulted in the concentration-dependent release of [3H]glutamate in P2rx7+/+ but not P2rx7-/- mice, and the NR2B subunit mRNA and protein was upregulated in the hippocampus of P2rx7-/- mice. The brain-derived neurotrophic factor (BDNF) expression was higher in saline but not LPS-treated P2rx7-/- mice; the P2rx7 antagonist Brilliant blue G elevated and the P2rx7 agonist benzoylbenzoyl ATP (BzATP) reduced BDNF level. This effect was dependent on the activation of NMDA and non-NMDA receptors but not on Group I metabotropic glutamate receptors (mGluR1,5). An increased 5-bromo-2-deoxyuridine (BrdU) incorporation was also observed in the dentate gyrus derived from P2rx7-/- mice. Basal level of 5-HT was increased, whereas the 5HIAA/5-HT ratio was lower in the hippocampus of P2rx7-/- mice, which accompanied the increased uptake of [3H]5-HT and an elevated number of [3H]citalopram binding sites. The LPS-induced elevation of 5-HT level was absent in P2rx7-/- mice. In conclusion there are several potential mechanisms for the antidepressant phenotype of P2rx7-/- mice, such as the absence of P2rx7-mediated glutamate release, elevated basal BDNF production, enhanced neurogenesis and increased 5-HT bioavailability in the hippocampus

    Bringing Lived Lives to Swift’s Asylum: a psychiatric hospital perspective

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    Background: Few “interventions” around suicide and stigma have reached into psychiatric institutions. Lived Lives is a science-arts approach to addressing suicide and stigma, informed by a psychobiographical and visual arts autopsy. The resulting artworks and mediated exhibition (Lived Lives), with artist, scientist and the Lived Lives families, co-curated by communities, has facilitated dialogue, response and public action around stigma-reduction, consistent with a community intervention. Recent evidence from Lived Lives moved us to consider how it may situate within a psychiatric institution, where stigma is chronically apparent. Methods: Lived Lives manifested in St. Patrick’s University Hospital (Ireland’s oldest and largest psychiatric hospital) in November 2017. The mediated exhibition was open to the public for 4 days. Audiences included service users, policy makers, health professionals, senior hospital administrators and members of the public. Opinions and feelings were collected. The event was documented. Bereavement support was available. A Clinician and an artist provided independent evaluation. Results: 86 participants engaged with the exhibition. 62% of participants were suicide-bereaved; 46% had experienced a mental health difficulty, and 35% had been suicidal in the past. 91% thought Lived Lives could be of benefit in the aftermath of a suicide death. Half of participants thought Lived Lives could help reduce suicidal feelings, whereas 88% thought it could benefit those with Mental Health difficulties. The emotional response was of a visceral nature, including fear, anger, sadness, disgust and anxiety. Bereavement support was occasionally called upon in a supportive capacity. Conclusions: Lived Lives sits comfortably in discomfort, unafraid to call out the home-truths about stigma and its pervasive and pernicious impact, and with restoring identity at its core. Lived Lives can operate within a psychiatric hospital, as well as in community. The challenge is to move it forward for greater exposure and impacts in at-risk communities

    Rapid deacetylation of yeast Hsp70 mediates the cellular response to heat stress

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    Hsp70 is a highly conserved molecular chaperone critical for the folding of new and denatured proteins. While traditional models state that cells respond to stress by upregulating inducible HSPs, this response is relatively slow and is limited by transcriptional and translational machinery. Recent studies have identified a number of post-translational modifications (PTMs) on Hsp70 that act to fine-tune its function. We utilized mass spectrometry to determine whether yeast Hsp70 (Ssa1) is differentially modified upon heat shock. We uncovered four lysine residues on Ssa1, K86, K185, K354 and K562 that are deacetylated in response to heat shock. Mutation of these sites cause a substantial remodeling of the Hsp70 interaction network of co-chaperone partners and client proteins while preserving essential chaperone function. Acetylation/deacetylation at these residues alter expression of other heat-shock induced chaperones as well as directly influencing Hsf1 activity. Taken together our data suggest that cells may have the ability to respond to heat stress quickly though Hsp70 deacetylation, followed by a slower, more traditional transcriptional response

    Genome-Wide Mapping of Copy Number Variation in Humans: Comparative Analysis of High Resolution Array Platforms

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    Accurate and efficient genome-wide detection of copy number variants (CNVs) is essential for understanding human genomic variation, genome-wide CNV association type studies, cytogenetics research and diagnostics, and independent validation of CNVs identified from sequencing based technologies. Numerous, array-based platforms for CNV detection exist utilizing array Comparative Genome Hybridization (aCGH), Single Nucleotide Polymorphism (SNP) genotyping or both. We have quantitatively assessed the abilities of twelve leading genome-wide CNV detection platforms to accurately detect Gold Standard sets of CNVs in the genome of HapMap CEU sample NA12878, and found significant differences in performance. The technologies analyzed were the NimbleGen 4.2 M, 2.1 M and 3×720 K Whole Genome and CNV focused arrays, the Agilent 1×1 M CGH and High Resolution and 2×400 K CNV and SNP+CGH arrays, the Illumina Human Omni1Quad array and the Affymetrix SNP 6.0 array. The Gold Standards used were a 1000 Genomes Project sequencing-based set of 3997 validated CNVs and an ultra high-resolution aCGH-based set of 756 validated CNVs. We found that sensitivity, total number, size range and breakpoint resolution of CNV calls were highest for CNV focused arrays. Our results are important for cost effective CNV detection and validation for both basic and clinical applications

    Protein Folding Activity of the Ribosome is involved in Yeast Prion Propagation.

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    6AP and GA are potent inhibitors of yeast and mammalian prions and also specific inhibitors of PFAR, the protein-folding activity borne by domain V of the large rRNA of the large subunit of the ribosome. We therefore explored the link between PFAR and yeast prion [PSI(+)] using both PFAR-enriched mutants and site-directed methylation. We demonstrate that PFAR is involved in propagation and de novo formation of [PSI(+)]. PFAR and the yeast heat-shock protein Hsp104 partially compensate each other for [PSI(+)] propagation. Our data also provide insight into new functions for the ribosome in basal thermotolerance and heat-shocked protein refolding. PFAR is thus an evolutionarily conserved cell component implicated in the prion life cycle, and we propose that it could be a potential therapeutic target for human protein misfolding diseases
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