147 research outputs found

    Short-Term Immunosuppression Promotes Engraftment of Embryonic and Induced Pluripotent Stem Cells

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    SummaryEmbryonic stem cells (ESCs) are an attractive source for tissue regeneration and repair therapies because they can be differentiated into virtually any cell type in the adult body. However, for this approach to succeed, the transplanted ESCs must survive long enough to generate a therapeutic benefit. A major obstacle facing the engraftment of ESCs is transplant rejection by the immune system. Here we show that blocking leukocyte costimulatory molecules permits ESC engraftment. We demonstrate the success of this immunosuppressive therapy for mouse ESCs, human ESCs, mouse induced pluripotent stem cells (iPSCs), human induced pluripotent stem cells, and more differentiated ESC/(iPSCs) derivatives. Additionally, we provide evidence describing the mechanism by which inhibition of costimulatory molecules suppresses T cell activation. This report describes a short-term immunosuppressive approach capable of inducing engraftment of transplanted ESCs and iPSCs, providing a significant improvement in our mechanistic understanding of the critical role costimulatory molecules play in leukocyte activation

    Assessment of Serum Proteomics to Detect Large Colon Adenomas

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    A non-invasive blood test that could reliably detect early CRC or large adenomas would provide an important advance in colon cancer screening. The purpose of this study was to determine whether a serum proteomics assay could discriminate among persons with and without a large (≄1cm) colon adenoma. To avoid problems of ‘bias’ that have affected many studies about molecular markers for diagnosis, specimens were obtained from a previously-conducted study of CRC etiology in which bloods had been collected before the presence or absence of neoplasm had been determined by colonoscopy, helping to assure that biases related to differences in sample collection and handling would be avoided. Mass spectra of 65 unblinded serum samples were acquired using a nano-electrospray ionization source on a QSTAR-XL mass spectrometer. Classification patterns were developed using the ProteomeQuestÂź algorithm, performing measurements twice on each specimen, and then applied to a blinded validation set of 70 specimens. After removing 33 specimens that had discordant results, the “test group” comprised 37 specimens that had never been used in training. Although in the primary analysis no discrimination was found, a single post-hoc analysis, done after hemolyzed specimens had been removed, showed sensitivity of 78%, specificity of 53%, and an accuracy of 63% (95% CI: 53% to 72%). The results of this study, although preliminary, suggest that further study of serum proteomics, in a larger number of appropriate specimens, could be useful. They also highlight the importance of understanding sources of ‘noise’ and ‘bias’ in studies of proteomics assays

    In Vitro Pro-apoptotic and Anti-migratory Effects of Ficus deltoidea L. Plant Extracts on the Human Prostate Cancer Cell Lines PC3.

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    This study aims to evaluate the in vitro cytotoxic and anti-migratory effects of Ficus deltoidea L. on prostate cancer cells, identify the active compound/s and characterize their mechanism of actions. Two farmed varieties were studied, var. angustifolia (FD1) and var. deltoidea (FD2). Their crude methanolic extracts were partitioned into n-hexane (FD1h, FD2h) chloroform (FD1c, FD2c) and aqueous extracts (FD1a, FD2a). Antiproliferative fractions (IC50 < 30 ÎŒg/mL, SRB staining of PC3 cells) were further fractionated. Active compound/s were dereplicated using spectroscopic methods. In vitro mechanistic studies on PC3 and/or LNCaP cells included: annexin V-FITC staining, MMP depolarization measurements, activity of caspases 3 and 7, nuclear DNA fragmentation and cell cycle analysis, modulation of Bax, Bcl-2, Smac/Diablo, and Alox-5 mRNA gene expression by RT-PCR. Effects of cytotoxic fractions on 2D migration and 3D invasion were tested by exclusion assays and modified Boyden chamber, respectively. Their mechanisms of action on these tests were further studied by measuring the expression VEGF-A, CXCR4, and CXCL12 in PC3 cells by RT-PCR. FD1c and FD2c extracts induced cell death (P < 0.05) via apoptosis as evidenced by nuclear DNA fragmentation. This was accompanied by an increase in MMP depolarization (P < 0.05), activation of caspases 3 and 7 (P < 0.05) in both PC3 and LNCaP cell lines. All active plant extracts up-regulated Bax and Smac/DIABLO, down-regulated Bcl-2 (P < 0.05). Both FD1c and FD2c were not cytotoxic against normal human fibroblast cells (HDFa) at the tested concentrations. Both plant extracts inhibited both migration and invasion of PC3 cells (P < 0.05). These effects were accompanied by down-regulation of both VEGF-A and CXCL-12 gene expressions (P < 0.001). LC-MS dereplication using taxonomy filters and molecular networking databases identified isovitexin in FD1c; and oleanolic acid, moretenol, betulin, lupenone, and lupeol in FD2c. In conclusion, FD1c and FD2c were able to overcome three main hallmarks of cancer in PC3 cells: (1) apoptosis by activating of the intrinsic pathway, (2) inhibition of both migration and invasion by modulating the CXCL12-CXCR4 axis, and (3) inhibiting angiogenesis by modulating VEGF-A expression. Moreover, isovitexin is here reported for the first time as an antiproliferative principle (IC50 = 43 ÎŒg/mL, SRB staining of PC3 cells)

    A phase III clinical trial of exercise modalities on treatment side-effects in men receiving therapy for prostate cancer

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    Background: Androgen deprivation therapy (ADT) is accompanied by a number of adverse side effects including reduced bone mass and increased risk for fracture, reduced lean mass and muscle strength, mood disturbance and increased fat mass compromising physical functioning, independence, and quality of life. The purpose of this investigation is to examine the effects of long term exercise on reversing musculoskeletal-related side effects, and cardiovascular and diabetes risk factors in men receiving androgen deprivation for their prostate cancer. Specifically, we aim to investigate the effects of a 12-month exercise program designed to load the musculoskeletal system and reduce cardiovascular and diabetes disease progression on the following primary endpoints: 1) bone mineral density; 2) cardiorespiratory function and maximal oxygen capacity; 3) body composition (lean mass and fat mass); 4) blood pressure and cardiovascular function; 5) lipids and glycemic control; and 6) quality of life and psychological distress

    CD36 Participates in PrP106–126-Induced Activation of Microglia

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    Microglial activation is a characteristic feature of the pathogenesis of prion diseases. The molecular mechanisms that underlie prion-induced microglial activation are not very well understood. In the present study, we investigated the role of the class B scavenger receptor CD36 in microglial activation induced by neurotoxic prion protein (PrP) fragment 106–126 (PrP106–126). We first examined the time course of CD36 mRNA expression upon exposure to PrP106–126 in BV2 microglia. We then analyzed different parameters of microglial activation in PrP106–126-treated cells in the presence or not of anti-CD36 monoclonal antibody (mAb). The cells were first incubated for 1 h with CD36 monoclonal antibody to block the CD36 receptor, and were then treated with neurotoxic prion peptides PrP106–126. The results showed that PrP106–126 treatment led to a rapid yet transitory increase in the mRNA expression of CD36, upregulated mRNA and protein levels of proinflammatory cytokines (IL-1ÎČ, IL-6 and TNF-α), increased iNOS expression and nitric oxide (NO) production, stimulated the activation of NF-ÎșB and caspase-1, and elevated Fyn activity. The blockade of CD36 had no effect on PrP106–126-stimulated NF-ÎșB activation and TNF-α protein release, abrogated the PrP106–126-induced iNOS stimulation, downregulated IL-1ÎČ and IL-6 expression at both mRNA and protein levels as well as TNF-α mRNA expression, decreased NO production and Fyn phosphorylation, reduced caspase-1 cleavage induced by moderate PrP106–126 –treatment, but had no effect on caspase-1 activation after treatment with a high concentration of PrP106–126. Together, these results suggest that CD36 is involved in PrP106–126-induced microglial activation and that the participation of CD36 in the interaction between PrP106–126 and microglia may be mediated by Src tyrosine kinases. Our findings provide new insights into the mechanisms underlying the activation of microglia by neurotoxic prion peptides and open perspectives for new therapeutic strategies for prion diseases by modulation of CD36 signaling

    An efficient strategy for evaluating new non-invasive screening tests for colorectal cancer: the guiding principles

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    Objective: New screening tests for colorectal cancer (CRC) are rapidly emerging. Conducting trials with mortality reduction as the end point supporting their adoption is challenging. We re-examined the principles underlying evaluation of new non-invasive tests in view of technological developments and identification of new biomarkers. Design: A formal consensus approach involving a multidisciplinary expert panel revised eight previously established principles. Results: Twelve newly stated principles emerged. Effectiveness of a new test can be evaluated by comparison with a proven comparator non-invasive test. The faecal immunochemical test is now considered the appropriate comparator, while colonoscopy remains the diagnostic standard. For a new test to be able to meet differing screening goals and regulatory requirements, flexibility to adjust its positivity threshold is desirable. A rigorous and efficient four-phased approach is proposed, commencing with small studies assessing the test’s ability to discriminate between CRC and non-cancer states (phase I), followed by prospective estimation of accuracy across the continuum of neoplastic lesions in neoplasia-enriched populations (phase II). If these show promise, a provisional test positivity threshold is set before evaluation in typical screening populations. Phase III prospective studies determine single round intention-to-screen programme outcomes and confirm the test positivity threshold. Phase IV studies involve evaluation over repeated screening rounds with monitoring for missed lesions. Phases III and IV findings will provide the real-world data required to model test impact on CRC mortality and incidence. Conclusion: New non-invasive tests can be efficiently evaluated by a rigorous phased comparative approach, generating data from unbiased populations that inform predictions of their health impact
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