61 research outputs found

    Integrin-linked kinase is required for TGF-_1 induction of dermal myofibroblast differentiation

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    Cutaneous repair after injury requires activation of resident dermal fibroblasts and their transition to myofibroblasts. The key stimuli for myofibroblast formation are activation of transforming growth factor-b (TGF-b) receptors and mechanotransduction mediated by integrins and associated proteins. We investigated the role of integrin-linked kinase (ILK) in TGF-b1 induction of dermal fibroblast transition to myofibroblasts. ILK-deficient fibroblasts treated with TGF-b1 exhibited attenuation of Smad 2 and 3 phosphorylation, accompanied by impaired transcriptional activation of Smad targets, such as a-smooth muscle actin. These alterations were not limited to Smad-associated TGF-b1 responses, as stimulation of noncanonical mitogenactivated protein kinase pathways by this growth factor was also diminished in the absence of ILK. ILK-deficient fibroblasts exhibited abnormalities in the actin cytoskeleton, and did not form supermature focal adhesions or contractile F-actin stress fibers, indicating a severe impairment in their capacity to differentiate into myofibroblasts. These defects extended to the inability of cells to contract extracellular matrices when embedded in collagen lattices. We conclude that ILK is necessary to transduce signals implicated in the transition of dermal fibroblasts to myofibroblasts originating from matrix substrates and TGF-b1

    Modulation of type II TGF-β receptor degradation by integrin-linked kinase

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    Cutaneous responses to injury, infection, and tumor formation involve the activation of resident dermal fibroblasts and subsequent transition to myofibroblasts. The key for induction of myofibroblast differentiation is the activation of transforming growth factor-β (TGF-β) receptors and stimulation of integrins and their associated proteins, including integrin-linked kinase (ILK). Cross-talk processes between TGF-β and ILK are crucial for myofibroblast formation, as ILK-deficient dermal fibroblasts exhibit impaired responses to TGF-β receptor stimulation. We now show that ILK associates with type II TGF-β receptors (TβRII) in ligand- and receptor kinase activity-independent manners. In cells with targeted Ilk gene inactivation, cellular levels of TβRII are decreased, through mechanisms that involve enhanced ubiquitination and proteasomal degradation. Partitioning of TGF-β receptors into membrane has been linked to proteasome-dependent receptor degradation. We found that interfering with membrane raft formation in ILK-deficient cells restored TβRII levels and signaling. These observations support a model whereby ILK functions in fibroblasts to direct TβRII away from degradative pathways during their differentiation into myofibroblasts

    Diet and Physical Activity for the Prevention of Noncommunicable Diseases in Low- and Middle-Income Countries: A Systematic Policy Review

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    Background: Diet-related noncommunicable diseases (NCDs) are increasing rapidly in low-and middle-income countries (LMICs) and constitute a leading cause of mortality. Although a call for global action has been resonating for years, the progress in national policy development in LMICs has not been assessed. This review of strategies to prevent NCDs in LMICs provides a benchmark against which policy response can be tracked over time. Methods and Findings: We reviewed how government policies in LMICs outline actions that address salt consumption, fat consumption, fruit and vegetable intake, or physical activity. A structured content analysis of national nutrition, NCDs, and health policies published between 1 January 2004 and 1 January 2013 by 140 LMIC members of the World Health Organization (WHO) was carried out. We assessed availability of policies in 83% (116/140) of the countries. NCD strategies were found in 47% (54/116) of LMICs reviewed, but only a minority proposed actions to promote healthier diets and physical activity. The coverage of policies that specifically targeted at least one of the risk factors reviewed was lower in Africa, Europe, the Americas, and the Eastern Mediterranean compared to the other two World Health Organization regions, South-East Asia and Western Pacific. Of the countries reviewed, only 12% (14/116) proposed a policy that addressed all four risk factors, and 25% (29/116) addressed only one of the risk factors reviewed. Strategies targeting the private sector were less frequently encountered than strategies targeting the general public or policy makers. Conclusions: This review indicates the disconnection between the burden of NCDs and national policy responses in LMICs. Policy makers urgently need to develop comprehensive and multi-stakeholder policies to improve dietary quality and physical activity

    APOE ε4 lowers age at onset and is a high risk factor for Alzheimer's disease; A case control study from central Norway

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    <p>Abstract</p> <p>Background</p> <p>The objective of this study was to analyze factors influencing the risk and timing of Alzheimer's disease (AD) in central Norway. The <it>APOE </it>ε4 allele is the only consistently identified risk factor for late onset Alzheimer's disease (LOAD). We have described the allele frequencies of the apolipoprotein E gene (<it>APOE</it>) in a large population of patients with AD compared to the frequencies in a cognitively-normal control group, and estimated the effect of the <it>APOE </it>ε4 allele on the risk and the age at onset of AD in this population.</p> <p>Methods</p> <p>376 patients diagnosed with AD and 561 cognitively-normal control individuals with no known first degree relatives with dementia were genotyped for the <it>APOE </it>alleles. Allele frequencies and genotypes in patients and control individuals were compared. Odds Ratio for developing AD in different genotypes was calculated.</p> <p>Results</p> <p>Odds Ratio (OR) for developing AD was significantly increased in carriers of the <it>APOE </it>ε4 allele compared to individuals with the <it>APOE </it>ε3/ε3 genotype. Individuals carrying <it>APOE </it>ε4/ε4 had OR of 12.9 for developing AD, while carriers of <it>APOE </it>ε2/ε4 and <it>APOE </it>ε3/ε4 had OR of 3.2 and 4.2 respectively. The effect of the <it>APOE </it>ε4 allele was weaker with increasing age. Carrying the <it>APOE </it>ε2 allele showed no significant protective effect against AD and did not influence age at onset of the disease. Onset in LOAD patients was significantly reduced in a dose dependent manner from 78.4 years in patients without the <it>APOE </it>ε4 allele, to 75.3 in carriers of one <it>APOE </it>ε4 allele and 72.9 in carriers of two <it>APOE </it>ε4 alleles. Age at onset in early onset AD (EOAD) was not influenced by <it>APOE </it>ε4 alleles.</p> <p>Conclusion</p> <p><it>APOE </it>ε4 is a very strong risk factor for AD in the population of central Norway, and lowers age at onset of LOAD significantly.</p

    Mammalian Target of Rapamycin (mTOR) Activity Dependent Phospho-Protein Expression in Childhood Acute Lymphoblastic Leukemia (ALL)

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    Modern treatment strategies have improved the prognosis of childhood ALL; however, treatment still fails in 25–30% of patients. Further improvement of treatment may depend on the development of targeted therapies. mTOR kinase, a central mediator of several signaling pathways, has recently attracted remarkable attention as a potential target in pediatric ALL. However, limited data exists about the activity of mTOR. In the present study, the amount of mTOR activity dependent phospho-proteins was characterized by ELISA in human leukemia cell lines and in lymphoblasts from childhood ALL patients (n = 49). Expression was measured before and during chemotherapy and at relapses. Leukemia cell lines exhibited increased mTOR activity, indicated by phospho-S6 ribosomal protein (p-S6) and phosphorylated eukaryotic initiation factor 4E binding protein (p-4EBP1). Elevated p-4EBP1 protein levels were detected in ALL samples at diagnosis; efficacy of chemotherapy was followed by the decrease of mTOR activity dependent protein phosphorylation. Optical density (OD) for p-4EBP1 (ELISA) was significantly higher in patients with poor prognosis at diagnosis, and in the samples of relapsed patients. Our results suggest that measuring mTOR activity related phospho-proteins such as p-4EBP1 by ELISA may help to identify patients with poor prognosis before treatment, and to detect early relapses. Determining mTOR activity in leukemic cells may also be a useful tool for selecting patients who may benefit from future mTOR inhibitor treatments

    Type-1 Collagen differentially alters β-catenin accumulation in primary Dupuytren's Disease cord and adjacent palmar fascia cells

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    <p>Abstract</p> <p>Background</p> <p>Dupuytren's Disease (DD) is a debilitating contractile fibrosis of the palmar fascia characterised by excess collagen deposition, contractile myofibroblast development, increased Transforming Growth Factor-β levels and β-catenin accumulation. The aim of this study was to determine if a collagen-enriched environment, similar to <it>in vivo </it>conditions, altered β-catenin accumulation by primary DD cells in the presence or absence of Transforming Growth Factor-β.</p> <p>Methods</p> <p>Primary DD and patient matched, phenotypically normal palmar fascia (PF) cells were cultured in the presence or absence of type-1 collagen and Transforming Growth Factor-β1. β-catenin and α-smooth muscle actin levels were assessed by western immunoblotting and immunofluorescence microscopy.</p> <p>Results</p> <p>DD cells display a rapid depletion of cellular β-catenin not evident in patient-matched PF cells. This effect was not evident in either cell type when cultured in the absence of type-1 collagen. Exogenous addition of Transforming Growth Factor-β1 to DD cells in collagen culture negates the loss of β-catenin accumulation. Transforming Growth Factor-β1-induced α-smooth muscle actin, a marker of myofibroblast differentiation, is attenuated by the inclusion of type-1 collagen in cultures of DD and PF cells.</p> <p>Conclusion</p> <p>Our findings implicate type-1 collagen as a previously unrecognized regulator of β-catenin accumulation and a modifier of TGF-β1 signaling specifically in primary DD cells. These data have implications for current treatment modalities as well as the design of <it>in vitro </it>models for research into the molecular mechanisms of DD.</p

    The Relevance of Fatalism in the Study of Latinas’ Cancer Screening Behavior: A Systematic Review of the Literature

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    # The Author(s) 2010. This article is published with open access at Springerlink.com Background Fatalism has been identified as a dominant belief among Latinos and is believed to act as a barrier to cancer prevention. However, controversy exists over the utility of the construct in explaining health disparities experienced by disadvantaged populations above the influence of structural barriers such as low socioeconomic status (SES) and limited access to health care. Purpose This paper reviews the empirical research on fatalism and Latinas ’ participation in cancer screening in an attempt to determine whether fatalism predicts participation in cancer screening after accounting for structural barriers

    A comprehensive evaluation of food fortification with folic acid for the primary prevention of neural tube defects

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    BACKGROUND: Periconceptional use of vitamin supplements containing folic acid reduces the risk of a neural tube defect (NTD). In November 1998, food fortification with folic acid was mandated in Canada, as a public health strategy to increase the folic acid intake of all women of childbearing age. We undertook a comprehensive population based study in Newfoundland to assess the benefits and possible adverse effects of this intervention. METHODS: This study was carried out in women aged 19–44 years and in seniors from November 1997 to March 1998, and from November 2000 to March 2001. The evaluation was comprised of four components: I) Determination of rates of NTDs; II) Dietary assessment; III) Blood analysis; IV) Assessment of knowledge and use of folic acid supplements. RESULTS: The annual rates of NTDs in Newfoundland varied greatly between 1976 and 1997, with a mean rate of 3.40 per 1,000 births. There was no significant change in the average rates between 1991–93 and 1994–97 (relative risk [RR] 1.01, 95% confidence interval [CI] 0.76–1.34). The rates of NTDs fell by 78% (95% CI 65%–86%) after the implementation of folic acid fortification, from an average of 4.36 per 1,000 births during 1991–1997 to 0.96 per 1,000 births during 1998–2001 (RR 0.22, 95% CI 0.14–0.35). The average dietary intake of folic acid due to fortification was 70 μg/day in women aged 19–44 years and 74 μg/day in seniors. There were significant increases in serum and RBC folate levels for women and seniors after mandatory fortification. Among seniors, there were no significant changes in indices typical of vitamin B(12 )deficiencies, and no evidence of improved folate status masking haematological manifestations of vitamin B(12 )deficiency. The proportion of women aged 19–44 years taking a vitamin supplement containing folic acid increased from 17% to 28%. CONCLUSIONS: Based on these findings, mandatory food fortification in Canada should continue at the current levels. Public education regarding folic acid supplement use by women of childbearing age should also continue

    Prevalence of plasmodium falciparum in active conflict areas of eastern Burma: a summary of cross-sectional data

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    BACKGROUND: Burma records the highest number of malaria deaths in southeast Asia and may represent a reservoir of infection for its neighbors, but the burden of disease and magnitude of transmission among border populations of Burma remains unknown. METHODS: Plasmodium falciparum (Pf) parasitemia was detected using a HRP-II antigen based rapid test (Paracheck-Pf(R)). Pf prevalence was estimated from screenings conducted in 49 villages participating in a malaria control program, and four retrospective mortality cluster surveys encompassing a sampling frame of more than 220,000. Crude odds ratios were calculated to evaluate Pf prevalence by age, sex, and dry vs. rainy season. RESULTS: 9,796 rapid tests were performed among 28,410 villagers in malaria program areas through four years (2003: 8.4%, 95% CI: 8.3 - 8.6; 2004: 7.1%, 95% CI: 6.9 - 7.3; 2005:10.5%, 95% CI: 9.3 - 11.8 and 2006: 9.3%, 95% CI: 8.2 - 10.6). Children under 5 (OR = 1.99; 95% CI: 1.93 - 2.06) and those 5 to 14 years (OR = 2.24, 95% CI: 2.18 - 2.29) were more likely to be positive than adults. Prevalence was slightly higher among females (OR = 1.04, 95% CI: 1.02 - 1.06) and in the rainy season (OR = 1.48, 95% CI: 1.16 - 1.88). Among 5,538 rapid tests conducted in four cluster surveys, 10.2% were positive (range 6.3%, 95% CI: 3.9 - 8.8; to 12.4%, 95% CI: 9.4 - 15.4). CONCLUSION: Prevalence of plasmodium falciparum in conflict areas of eastern Burma is higher than rates reported among populations in neighboring Thailand, particularly among children. This population serves as a large reservoir of infection that contributes to a high disease burden within Burma and likely constitutes a source of infection for neighboring regions
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