24 research outputs found

    Mmf1p, a novel yeast mitochondrial protein conserved throughout evolution and involved in maintenance of the mitochondrial genome

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    A novel protein family (p14.5, or YERO57c/YJGFc) highly conserved throughout evolution has recently been identified. The biological role of these proteins is not yet well characterized. Two members of the p14.5 family are present in the yeast Saccharomyces cerevisiae. In this study, we have characterized some of the biological functions of the two yeast proteins. Mmf1p is a mitochondrial matrix factor, and homologous Mmf1p factor (Hmf1p) copurifies with the soluble cytoplasmic fraction. Δmmf1 cells lose mitochondrial DNA (mtDNA) and have a decreased growth rate, while Δhmf1 cells do not display any visible phenotype. Furthermore, we demonstrate by genetic analysis that Mmf1p does not play a direct role in replication and segregation of the mtDNA. rho(+) Δmmf1 haploid cells can be obtained when tetrads are directly dissected on medium containing a nonfermentable carbon source. Our data also indicate that Mmf1p and Hmf1p have similar biological functions in different subcellular compartments. Hmf1p, when fused with the Mmf1p leader peptide, is transported into mitochondria and is able to functionally replace Mmf1p. Moreover, we show that homologous mammalian proteins are functionally related to Mmf1p. Human p14.5 localizes in yeast mitochondria and rescues the Δmmf1-associated phenotypes. In addition, fractionation of rat liver mitochondria showed that rat p14.5, like Mmf1p, is a soluble protein of the matrix. Our study identifies a biological function for Mmf1p and furthermore indicates that this function is conserved between members of the p14.5 family

    Role of the HSP90-Associated Cochaperone p23 in Enhancing Activity of the Androgen Receptor and Significance for Prostate Cancer

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    Prostate tumor growth initially depends on androgens, which act via the androgen receptor (AR). Despite androgen ablation therapy, tumors eventually progress to a castrate-resistant stage in which the AR remains active. The mechanisms are poorly understood but it may be that changes in levels or activity of AR coregulators affect trafficking and activation of the receptor. A key stage in AR signaling occurs in the cytoplasm, where unliganded receptor is associated with the heat shock protein (HSP)90 foldosome complex. p23, a key component of this complex, is best characterized as a cochaperone for HSP90 but also has HSP90-independent activity and has been re-ported as having differential effects on the activity of different steroid receptors. Here we report that p23 increases activity of the AR, and this appears to involve steps both in the cytoplasm (increasing ligand-binding capacity, possibly via direct interaction with AR) and the nucleus (en-hancing AR occupancy at target promoters). We show, for the first time, that AR and p23 can interact, perhaps directly, when HSP90 is not present in the same complex. The effects of p23 on AR activity are at least partly HSP90 independent because a mutant form of p23, unable to bind HSP90, nevertheless increases AR activity. In human prostate tumors, nuclear p23 was higher in malignant prostate cells compared with benign/normal cells, supporting the utility of p23 as a therapeutic target in prostate cancer. © 2012 by The Endocrine Society

    The effects of thiopurine therapy on health-related quality of life in Inflammatory Bowel Disease patients

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    <p>Abstract</p> <p>Background</p> <p>The effect of thiopurine immunomodulators on health-related quality of life (HRQoL) in patients with inflammatory bowel disease (IBD) has been controversial. The aims were to evaluate the HRQoL in patients with IBD treated with thiopurines and assess the short- and long-term impacts of the treatment on HRQoL.</p> <p>Methods</p> <p>Ninety-two consecutive patients who started treatment with thiopurines were prospectively included. Evaluation of HRQoL was performed at months 0, 6, and 12 using two questionnaires, the Short-Form Health Survey (SF-36) and the Inflammatory Bowel Disease Questionnaire (IBDQ).</p> <p>Results</p> <p>Baseline score of IBDQ was 4,6, range (2,31-6,84), with an impairment of the five dimensions of HRQoL compared with inactive patients. Results obtained in 8 dimensions of SF-36 showed worse HRQoL than Spanish general population. At 6 months patients had a significant improvement in overall IBDQ score -5,8 (1,58 -6,97)- and also in all IBDQ dimensions. All the 8 dimensions of SF-36 obtained a significant improvement. At twelve months score of IBDQ was 6,1, range (2,7-6,98), with improvement in all dimensions compared with baseline and 6 months. SF-36 showed a similar significant improvement in all subscales.</p> <p>Conclusions</p> <p>Thiopurine immunomodulators alone or with other treatments have a positive and long lasting impact on HRQoL of IBD patients.</p

    Identification of Stage-Specific Breast Markers using Quantitative Proteomics

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    YesMatched healthy and diseased tissues from breast cancer patients were analyzed by quantitative proteomics. By comparing proteomic profiles of fibroadenoma (benign tumors, three patients), DCIS (noninvasive cancer, three patients), and invasive ductal carcinoma (four patients), we identified protein alterations that correlated with breast cancer progression. Three 8-plex iTRAQ experiments generated an average of 826 protein identifications, of which 402 were common. After excluding those originating from blood, 59 proteins were significantly changed in tumor compared with normal tissues, with the majority associated with invasive carcinomas. Bioinformatics analysis identified relationships between proteins in this subset including roles in redox regulation, lipid transport, protein folding, and proteasomal degradation, with a substantial number increased in expression due to Myc oncogene activation. Three target proteins, cofilin-1 and p23 (increased in invasive carcinoma) and membrane copper amine oxidase 3 (decreased in invasive carcinoma), were subjected to further validation. All three were observed in phenotype-specific breast cancer cell lines, normal (nontransformed) breast cell lines, and primary breast epithelial cells by Western blotting, but only cofilin-1 and p23 were detected by multiple reaction monitoring mass spectrometry analysis. All three proteins were detected by both analytical approaches in matched tissue biopsies emulating the response observed with proteomics analysis. Tissue microarray analysis (361 patients) indicated cofilin-1 staining positively correlating with tumor grade and p23 staining with ER positive status; both therefore merit further investigation as potential biomarkers.Cyprus Research Promotion Foundation, Yorkshire Cancer Researc

    Health-promoting factors in higher education for a sustainable working life - protocol for a multicenter longitudinal study.

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    BACKGROUND: The World Health Organization has highlighted the importance of health promotion for health service providers in order to ensure sustainable working life for individuals involved in providing health services. Such sustainability begins when students are preparing to manage their own future health and welfare in working life. It has been suggested that universities, employees and trainee health professionals should adopt or follow a salutogenic approach that not only complements the providing of information on known health risks but also favors health promotion strategies. This paper describes the study design and data collection methods in a planned study aiming to explore health-promoting factors for a sustainable working life among students in higher education within healthcare and social work. METHODS: This protocol describes a multicenter longitudinal study involving Swedish students on higher education programs in the healthcare and social work sectors. In 2018, the study invited students on seven education programs at six universities to participate. These programs were for qualification as: biomedical laboratory scientists (n = 121); dental hygienists (n = 87); nurses (n = 1411); occupational therapists (n = 111); physiotherapists (n = 48); radiographers (n = 60); and, social workers (n = 443). In total, 2283 students were invited to participate. Participants completed a baseline, a self-reported questionnaire including six validated instruments measuring health-promoting factors and processes. There are to be five follow-up questionnaires. Three while the students are studying, one a year after graduating, and one three years after graduating. Each questionnaire captures different health-promoting dimensions, namely: health-promoting resources (i.e. sense of coherence); occupational balance; emotional intelligence; health and welfare; social interaction; and work and workplace experiences/perceptions. DISCUSSION: This study focuses on the vastly important aspect of promoting a sustainable working life for healthcare and social work employees. In contrast to previous studies in this area, the present study uses different, validated instruments in health promotion, taking a salutogenic approach. It is hoped that, by stimulating the implementation of new strategies, the study's findings will lead to education programs that prepare students better for a sustainable working life in healthcare and social work
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