97 research outputs found
Augmenter of liver regeneration: An important intracellular survival factor for hepatocytes
Background/Aims: Augmenter of liver regeneration (ALR), a protein synthesized and stored in hepatocytes, is associated with mitochondria, and possesses sulfhydryl oxidase and cytochrome c reductase activities. We sought to determine the effects of ALR depletion in hepatocytes by antisense oligonucleotide transfection. Methods: Rat hepatocytes in primary culture were transfected with antisense oligonucleotide for ALR mRNA (ALR-AS) or scrambled oligonucleotide. Various analyses were performed at times up to 24 h after transfection. Results: Treatment with ALR-AS caused a decrease in ALR mRNA, cellular depletion of ALR protein primarily from mitochondria, and decreased viability. Flow cytometric analysis of ALR-AS-transfected hepatocytes stained with annexin-Vcy3 and 7-aminoactinomycin D revealed apoptosis as the predominant cause of death up to 6 h; incubation beyond this time resulted in necrosis in addition to apoptosis. ALR-AS-transfection caused release of mitochondrial cytochrome c, activation of caspase-3, profound reduction in the ATP content, and cellular release of LDH. Inhibition of caspase-3 inhibited the early phase of ALR-AS-induced death but not the late phase that included ALR and LDH release. Conclusions: These results suggest that ALR is critically important for the survival of hepatocytes by its association with mitochondria and regulation of ATP synthesis. © 2008 European Association for the Study of the Liver
A standard protocol to report discrete stage-structured demographic information
Stage-based demographic methods, such as matrix population models (MPMs), are powerful tools used to address a broad range of fundamental questions in ecology, evolutionary biology and conservation science. Accordingly, MPMs now exist for over 3000 species worldwide. These data are being digitised as an ongoing process and periodically released into two large open-access online repositories: the COMPADRE Plant Matrix Database and the COMADRE Animal Matrix Database. During the last decade, data archiving and curation of COMPADRE and COMADRE, and subsequent comparative research, have revealed pronounced variation in how MPMs are parameterized and reported.
Here, we summarise current issues related to the parameterisation and reporting of MPMs that arise most frequently and outline how they affect MPM construction, analysis, and interpretation. To quantify variation in how MPMs are reported, we present results from a survey identifying key aspects of MPMs that are frequently unreported in manuscripts. We then screen COMPADRE and COMADRE to quantify how often key pieces of information are omitted from manuscripts using MPMs.
Over 80% of surveyed researchers (n = 60) state a clear benefit to adopting more standardised methodologies for reporting MPMs. Furthermore, over 85% of the 300 MPMs assessed from COMPADRE and COMADRE omitted one or more elements that are key to their accurate interpretation. Based on these insights, we identify fundamental issues that can arise from MPM construction and communication and provide suggestions to improve clarity, reproducibility and future research utilising MPMs and their required metadata. To fortify reproducibility and empower researchers to take full advantage of their demographic data, we introduce a standardised protocol to present MPMs in publications. This standard is linked to www.compa dre-db.org, so that authors wishing to archive their MPMs can do so prior to submission of publications, following examples from other open-access repositories such as DRYAD, Figshare and Zenodo.
Combining and standardising MPMs parameterized from populations around the globe and across the tree of life opens up powerful research opportunities in evolutionary biology, ecology and conservation research. However, this potential can only be fully realised by adopting standardised methods to ensure reproducibility
Predicting effective pro-apoptotic antileukaemic drug combinations using cooperative dynamic BH3 profiling
The BH3-only apoptosis agonists BAD and NOXA target BCL-2 and MCL-1 respectively and co-operate to induce apoptosis. On this basis, therapeutic drugs targeting BCL-2 and MCL-1 might have enhanced activity if used in combination. We identified anti-leukaemic drugs sensitising to BCL-2 antagonism and drugs sensitising to MCL-1 antagonism using the technique of dynamic BH3 profiling, whereby cells were primed with drugs to discover whether this would elicit mitochondrial outer membrane permeabilisation in response to BCL-2-targeting BAD-BH3 peptide or MCL-1-targeting MS1-BH3 peptide. We found that a broad range of anti-leukaemic agents–notably MCL-1 inhibitors, DNA damaging agents and FLT3 inhibitors–sensitise leukaemia cells to BAD-BH3. We further analysed the BCL-2 inhibitors ABT-199 and JQ1, the MCL-1 inhibitors pladienolide B and torin1, the FLT3 inhibitor AC220 and the DNA double-strand break inducer etoposide to correlate priming responses with co-operative induction of apoptosis. ABT-199 in combination with pladienolide B, torin1, etoposide or AC220 strongly induced apoptosis within 4 hours, but the MCL-1 inhibitors did not co-operate with etoposide or AC220. In keeping with the long half-life of BCL-2, the BET domain inhibitor JQ1 was found to downregulate BCL-2 and to prime cells to respond to MS1-BH3 at 48, but not at 4 hours: prolonged priming with JQ1 was then shown to induce rapid cytochrome C release when pladienolide B, torin1, etoposide or AC220 were added. In conclusion, dynamic BH3 profiling is a useful mechanism-based tool for understanding and predicting co-operative lethality between drugs sensitising to BCL-2 antagonism and drugs sensitising to MCL-1 antagonism. A plethora of agents sensitised cells to BAD-BH3-mediated mitochondrial outer membrane permeabilisation in the dynamic BH3 profiling assay and this was associated with effective co-operation with the BCL-2 inhibitory compounds ABT-199 or JQ1
Cancer immunoprevention and public health
The power of cancer immune surveillance has been documented beyond doubt, and the successful exploitation of immune response to cancer has started a new era in the war against cancer. Cancer biologists have recognized immunoevasion as an emerging hallmark in addition to the six hallmarks of cancer. Besides the natural connection between the immune system and cancer development, most established environmental risk factors are now known to interfere with immune surveillance mechanisms. Genetic variations regulating immunity may also modulate cancer susceptibility, but evidence for this is currently limited. Molecular cross talk linking “immune” and “genomic” surveillance pathways has been characterized. It appears that immune mechanisms may contribute to the effects of common cancer risk factors. We provide an updated overview of evidence for cancer immune surveillance, cancer risk factors interfering with it, and interventions to enhance cancer immune surveillance as tools to complement ongoing vaccine development efforts for cancer immunoprevention. Although there is a lot of support for cancer immunoprevention with simple lifestyle modifications from observational studies, there is an urgent need for clinical trials to establish the effectiveness of this approach for public health benefits
Evidence-Based Guidelines for Empirical Therapy of Neutropenic Fever in Korea
Neutrophils play an important role in immunological function. Neutropenic patients are vulnerable to infection, and except fever is present, inflammatory reactions are scarce in many cases. Additionally, because infections can worsen rapidly, early evaluation and treatments are especially important in febrile neutropenic patients. In cases in which febrile neutropenia is anticipated due to anticancer chemotherapy, antibiotic prophylaxis can be used, based on the risk of infection. Antifungal prophylaxis may also be considered if long-term neutropenia or mucosal damage is expected. When fever is observed in patients suspected to have neutropenia, an adequate physical examination and blood and sputum cultures should be performed. Initial antibiotics should be chosen by considering the risk of complications following the infection; if the risk is low, oral antibiotics can be used. For initial intravenous antibiotics, monotherapy with a broad-spectrum antibiotic or combination therapy with two antibiotics is recommended. At 3-5 days after beginning the initial antibiotic therapy, the condition of the patient is assessed again to determine whether the fever has subsided or symptoms have worsened. If the patient's condition has improved, intravenous antibiotics can be replaced with oral antibiotics; if the condition has deteriorated, a change of antibiotics or addition of antifungal agents should be considered. If the causative microorganism is identified, initial antimicrobial or antifungal agents should be changed accordingly. When the cause is not detected, the initial agents should continue to be used until the neutrophil count recovers
GLI1 Confers Profound Phenotypic Changes upon LNCaP Prostate Cancer Cells That Include the Acquisition of a Hormone Independent State
The GLI (GLI1/GLI2) transcription factors have been implicated in the development
and progression of prostate cancer although our understanding of how they
actually contribute to the biology of these common tumours is limited. We
observed that GLI reporter activity was higher in normal (PNT-2) and
tumourigenic (DU145 and PC-3) androgen-independent cells compared to
androgen-dependent LNCaP prostate cancer cells and, accordingly, GLI mRNA levels
were also elevated. Ectopic expression of GLI1 or the constitutively active
ΔNGLI2 mutant induced a distinct cobblestone-like morphology in LNCaP cells
that, regarding the former, correlated with increased GLI2 as well as expression
of the basal/stem-like markers CD44, β1-integrin, ΔNp63 and BMI1, and
decreased expression of the luminal marker AR (androgen receptor). LNCaP-GLI1
cells were viable in the presence of the AR inhibitor bicalutamide and gene
expression profiling revealed that the transcriptome of LNCaP-GLI1 cells was
significantly closer to DU145 and PC-3 cells than to control LNCaP-pBP (empty
vector) cells, as well as identifying LCN2/NGAL as a highly induced transcript
which is associated with hormone independence in breast and prostate cancer.
Functionally, LNCaP-GLI1 cells displayed greater clonal growth and were more
invasive than control cells but they did not form colonies in soft agar or
prostaspheres in suspension suggesting that they do not possess inherent stem
cell properties. Moreover, targeted suppression of GLI1 or GLI2 with siRNA did
not reverse the transformed phenotype of LNCaP-GLI1 cells nor did double
GLI1/GLI2 knockdowns activate AR expression in DU145 or PC-3 cells. As such,
early targeting of the GLI oncoproteins may hinder progression to a hormone
independent state but a more detailed understanding of the mechanisms that
maintain this phenotype is required to determine if their inhibition will
enhance the efficacy of anti-hormonal therapy through the induction of a luminal
phenotype and increased dependency upon AR function
A standard protocol to report discrete stage‐structured demographic information
Stage-based demographic methods, such as matrix population models (MPMs), are powerful tools used to address a broad range of fundamental questions in ecology, evolutionary biology and conservation science. Accordingly, MPMs now exist for over 3000 species worldwide. These data are being digitised as an ongoing process and periodically released into two large open-access online repositories: the COMPADRE Plant Matrix Database and the COMADRE Animal Matrix Database. During the last decade, data archiving and curation of COMPADRE and COMADRE, and subsequent comparative research, have revealed pronounced variation in how MPMs are parameterized and reported.
Here, we summarise current issues related to the parameterisation and reporting of MPMs that arise most frequently and outline how they affect MPM construction, analysis, and interpretation. To quantify variation in how MPMs are reported, we present results from a survey identifying key aspects of MPMs that are frequently unreported in manuscripts. We then screen COMPADRE and COMADRE to quantify how often key pieces of information are omitted from manuscripts using MPMs.
Over 80% of surveyed researchers (n = 60) state a clear benefit to adopting more standardised methodologies for reporting MPMs. Furthermore, over 85% of the 300 MPMs assessed from COMPADRE and COMADRE omitted one or more elements that are key to their accurate interpretation. Based on these insights, we identify fundamental issues that can arise from MPM construction and communication and provide suggestions to improve clarity, reproducibility and future research utilising MPMs and their required metadata. To fortify reproducibility and empower researchers to take full advantage of their demographic data, we introduce a standardised protocol to present MPMs in publications. This standard is linked to www.compadre-db.org, so that authors wishing to archive their MPMs can do so prior to submission of publications, following examples from other open-access repositories such as DRYAD, Figshare and Zenodo.
Combining and standardising MPMs parameterized from populations around the globe and across the tree of life opens up powerful research opportunities in evolutionary biology, ecology and conservation research. However, this potential can only be fully realised by adopting standardised methods to ensure reproducibility
A standard protocol to report discrete stage-structured demographic information
Stage-based demographic methods, such as matrix population models (MPMs), are powerful tools used to address a broad range of fundamental questions in ecology, evolutionary biology and conservation science. Accordingly, MPMs now exist for over 3000 species worldwide. These data are being digitised as an ongoing process and periodically released into two large open-access online repositories: the COMPADRE Plant Matrix Database and the COMADRE Animal Matrix Database. During the last decade, data archiving and curation of COMPADRE and COMADRE, and subsequent comparative research, have revealed pronounced variation in how MPMs are parameterized and reported.
Here, we summarise current issues related to the parameterisation and reporting of MPMs that arise most frequently and outline how they affect MPM construction, analysis, and interpretation. To quantify variation in how MPMs are reported, we present results from a survey identifying key aspects of MPMs that are frequently unreported in manuscripts. We then screen COMPADRE and COMADRE to quantify how often key pieces of information are omitted from manuscripts using MPMs.
Over 80% of surveyed researchers (n = 60) state a clear benefit to adopting more standardised methodologies for reporting MPMs. Furthermore, over 85% of the 300 MPMs assessed from COMPADRE and COMADRE omitted one or more elements that are key to their accurate interpretation. Based on these insights, we identify fundamental issues that can arise from MPM construction and communication and provide suggestions to improve clarity, reproducibility and future research utilising MPMs and their required metadata. To fortify reproducibility and empower researchers to take full advantage of their demographic data, we introduce a standardised protocol to present MPMs in publications. This standard is linked to www.compadre-db.org, so that authors wishing to archive their MPMs can do so prior to submission of publications, following examples from other open-access repositories such as DRYAD, Figshare and Zenodo.
Combining and standardising MPMs parameterized from populations around the globe and across the tree of life opens up powerful research opportunities in evolutionary biology, ecology and conservation research. However, this potential can only be fully realised by adopting standardised methods to ensure reproducibility
Fundulus as the premier teleost model in environmental biology : opportunities for new insights using genomics
Author Posting. © Elsevier B.V., 2007. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Comparative Biochemistry and Physiology Part D: Genomics and Proteomics 2 (2007): 257-286, doi:10.1016/j.cbd.2007.09.001.A strong foundation of basic and applied research documents that the estuarine fish Fundulus heteroclitus and related species are unique laboratory and field models for understanding how individuals and populations interact with their environment. In this paper we summarize an extensive body of work examining the adaptive responses of Fundulus species to environmental conditions, and describe how this research has contributed importantly to our understanding of physiology, gene regulation, toxicology, and ecological and evolutionary genetics of teleosts and other vertebrates. These explorations have reached a critical juncture at which advancement is hindered by the lack of genomic resources for these species. We suggest that a more complete genomics toolbox for F. heteroclitus and related species will permit researchers to exploit the power of this model organism to rapidly advance our understanding of fundamental biological and pathological mechanisms among vertebrates, as well as ecological strategies and evolutionary processes common to all living organisms.This material is based on work supported by grants from the National Science Foundation DBI-0420504 (LJB), OCE 0308777 (DLC, RNW, BBR), BES-0553523 (AW), IBN 0236494 (BBR), IOB-0519579 (DHE), IOB-0543860 (DWT), FSML-0533189 (SC); National Institute of Health NIEHS P42-ES007381(GVC, MEH), P42-ES10356 (RTD), ES011588 (MFO); and NCRR P20 RR-016463 (DWT); Natural Sciences and Engineering Research Council of Canada Discovery (DLM, TDS, WSM) and Collaborative Research and Development Programs (DLM); NOAA/National Sea Grant NA86RG0052 (LJB), NA16RG2273 (SIK, MEH,GVC, JJS); Environmental Protection Agency U91620701 (WSB), R82902201(SC) and EPA’s Office of Research and Development (DEN)
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