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Molecular Responses (molecular + response)
Kinds of Molecular Responses Selected AbstractsDifferent Patterns of Physiological and Molecular Response to Drought in Seedlings of Malt- and Feed-type Barleys (Hordeum vulgare)JOURNAL OF AGRONOMY AND CROP SCIENCE, Issue 1 2010M. Rapacz Abstract A number of physiological and molecular characteristics are proposed as selection criteria for drought tolerance. This study measured the associations between physiological and molecular characteristics of drought response in malting and fodder spring barleys. Plants of 13 malt- and 14 feed-type Polish genotypes were exposed to drought at the four-leaf stage for 7 days. Drought susceptibility indexes (DSI) were calculated for membrane integrity, water status, gas exchange and PSII photochemical activity. Accumulation of HVA1 and SRG6 transcripts in drought was measured with real-time PCR. A wide range of variation in the drought response was observed among studied genotypes. Malting barleys were less sensitive to drought than feed-barleys according to all the traits studied. In both groups, different patterns of relationships between traits were observed. In malting genotypes only, CO2 assimilation rates in drought, as well as PSII efficiency were related to both water content and the accumulation of HVA1 transcript in leaves. On the other hand the SRG6 expression was highly correlated in both groups of barley with the photochemical efficiency of PSII. The results suggest that different physiological, biochemical and molecular characteristics should be applied in the selection towards drought resistance in the case of malting and fodder barleys. [source] Molecular Responses to Stress Induced in Normal Human Caucasian Melanocytes in Culture by Exposure to Simulated Solar UV,PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 2 2005Laurent Marrot ABSTRACT Melanocytes play a central role in the response of skin to sunlight exposure. They are directly involved in UV-induced pigmentation as a defense mechanism. However, their alteration can lead to melanoma, a process where the role of sun overexposure is highly probable. The transformation process whereby UV damage may result in melanoma initiation is poorly understood, especially in terms of UV-induced genotoxicity in pigmented cells, where melanin can act either as a sunscreen or as a photosensitizer. The aim of this study was to analyze the behavior of melanocytes from fair skin under irradiation mimicking environmental sunlight in terms of spectral power distribution. To do this, normal human Caucasian melanocytes in culture were exposed to simulated solar UV (SSUV, 300,400 nm). Even at relatively high doses (until 20 min exposure, corresponding to 12 kJ/m2 UV-B and 110 kJ/m2 UV-A), cell death was limited, as shown by cell viability and low occurrence of apoptosis (caspase-3 activation). Moreover, p53 accumulation was three times lower in melanocytes than in unpigmented cells such as fibroblasts after SSUV exposure. However, an important fraction of melanocyte population was arrested in G2-M phase, and this correlated well with a high induction level of the gene GADD45, 4 h after exposure. Among the genes involved in DNA repair, gene XPC was the most inducible because its expression increased more than two-fold 15 h after a 20 min exposure, whereas expression of P48 was only slightly increased. In addition, an early induction of Heme Oxygenase 1 (HO1) gene, a typical response to oxidative stress, was also observed for the first time in melanocytes. Interestingly, this induction remained significant when melanocytes were exposed to UV-A radiation only (320,400 nm), and stimulation of melanogenesis before irradiation further increased HO1 induction. These results were obtained with normal human cells after exposure to SSUV radiation, which mimicked natural sunlight. They provide new data related to gene expression and suggest that melanin in light skin could contribute to sunlight-induced genotoxicity and maybe to melanocyte transformation. [source] Molecular response to climate change: temperature dependence of UV-induced DNA damage and repair in the freshwater crustacean Daphnia pulicariaGLOBAL CHANGE BIOLOGY, Issue 4 2004Emily J. MacFadyen Abstract In temperate lakes, asynchronous cycles in surface water temperatures and incident ultraviolet (UV) radiation expose aquatic organisms to damaging UV radiation at different temperatures. The enzyme systems that repair UV-induced DNA damage are temperature dependent, and thus potentially less effective at repairing DNA damage at lower temperatures. This hypothesis was tested by examining the levels of UV-induced DNA damage in the freshwater crustacean Daphnia pulicaria in the presence and absence of longer-wavelength photoreactivating radiation (PRR) that induces photoenzymatic repair (PER) of DNA damage. By exposing both live and dead (freeze-killed) Daphnia as well as raw DNA to UV-B in the presence and absence of PRR, we were able to estimate the relative importance and temperature dependence of PER (light repair), nucleotide excision repair (NER, dark repair), and photoprotection (PP). Total DNA damage increased with increasing temperature. However, the even greater increase in DNA repair rates at higher temperatures led net DNA damage (total DNA damage minus repair) to be greater at lower temperatures. Photoprotection accounted for a much greater proportion of the reduction in DNA damage than did repair. Experiments that looked at survival rates following UV exposure demonstrated that PER increased survival rates. The important implication is that aquatic organisms that depend heavily on DNA repair processes may be less able to survive high UV exposure in low temperature environments. Photoprotection may be more effective under the low temperature, high UV conditions such as are found in early spring or at high elevations. [source] Molecular response of nasal mucosa to therapeutic exposure to broad-band ultraviolet radiationJOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 1-2 2010David Mitchell Abstract Ultraviolet radiation (UVR) phototherapy is a promising new treatment for inflammatory airway diseases. However, the potential carcinogenic risks associated with this treatment are not well understood. UV-specific DNA photoproducts were used as biomarkers to address this issue. Radioimmunoassay was used to quantify cyclobutane pyrimidine dimers (CPDs) and (6,4) photoproducts in DNA purified from two milieus: nasal mucosa samples from subjects exposed to intranasal phototherapy and human airway (EpiAirwayÔ) and human skin (EpiDermÔ) tissue models. Immunohistochemistry was used to detect CPD formation and persistence in human nasal biopsies and human tissue models. In subjects exposed to broadband ultraviolet radiation, DNA damage frequencies were determined prior to as well as immediately after treatment and at increasing times post-treatment. We observed significant levels of DNA damage immediately after treatment and efficient removal of the damage within a few days. No residual damage was observed in human subjects exposed to multiple UVB treatments several weeks after the last treatment. To better understand the molecular response of the nasal epithelium to DNA damage, parallel experiments were conducted in EpiAirway and EpiDerm model systems. Repair rates in these two tissues were very similar and comparable to that observed in human skin. The data suggest that the UV-induced DNA damage response of respiratory epithelia is very similar to that of the human epidermis and that nasal mucosa is able to efficiently repair UVB induced DNA damage. [source] Molecular responses of Campylobacter jejuni to cadmium stressFEBS JOURNAL, Issue 20 2008Nadeem O. Kaakoush Cadmium ions are a potent carcinogen in animals, and cadmium is a toxic metal of significant environmental importance for humans. Response curves were used to investigate the effects of cadmium chloride on the growth of Camplyobacter jejuni. In vitro, the bacterium showed reduced growth in the presence of 0.1 mm cadmium chloride, and the metal ions were lethal at 1 mm concentration. Two-dimensional gel electrophoresis combined with tandem mass spectrometry analysis enabled identification of 67 proteins differentially expressed in cells grown without and with 0.1 mm cadmium chloride. Cellular processes and pathways regulated under cadmium stress included fatty acid biosynthesis, protein biosynthesis, chemotaxis and mobility, the tricarboxylic acid cycle, protein modification, redox processes and the heat-shock response. Disulfide reductases and their substrates play many roles in cellular processes, including protection against reactive oxygen species and detoxification of xenobiotics, such as cadmium. The effects of cadmium on thioredoxin reductase and disulfide reductases using glutathione as a substrate were studied in bacterial lysates by spectrophotometry and nuclear magnetic resonance spectroscopy, respectively. The presence of 0.1 mm cadmium ions modulated the activities of both enzymes. The interactions of cadmium ions with oxidized glutathione and reduced glutathione were investigated using nuclear magnetic resonance spectroscopy. The data suggested that, unlike other organisms, C. jejuni downregulates thioredoxin reductase and upregulates other disulfide reductases involved in metal detoxification in the presence of cadmium. [source] Molecular responses to hypoxia: ancient pathways, clinical promisesJOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 9a 2009William Y. Kim No abstract is available for this article. [source] Therapy adapted to molecular response in patients with chronic myelogenous leukaemia in first chronic phase: results of the Duesseldorf study,HEMATOLOGICAL ONCOLOGY, Issue 4 2008Frank Neumann Abstract This study evaluates response-adapted treatment of chronic myelogenous leukaemia (CML) in chronic phase using molecular response criteria. bcr-abl/G6PDH ratios were assessed by Light-Cycler quantitative real-time polymerase chain reaction (PCR( in 277 peripheral blood samples from 33 patients, before and every 3 months during therapy. Sixty-six per cent (22/33) of the patients fulfiled our molecular response criterion of ,1 log decrease in bcr-abl transcript after 6 or ,2 log decrease after 9 and every following 3 months. Dose escalation was necessary for 33% (11/33) of the patients. Of these, 54% (6/11) achieved a reduction of bcr-abl mRNA by ,2 log (n,=,3) or ,3 log (n,=,3) with 800,mg Imatinib. Forty-five per cent (5/11) showed insufficient molecular response with 800,mg Imatinib and received Nilotinib. In conclusion, the assessment of molecular response permits an individual patient-tailored treatment of CML in first chronic phase, resulting in the majority of patients achieving a major molecular response after 2 years of therapy. Copyright © 2008 John Wiley & Sons, Ltd. [source] Proteomics analysis of liver samples from puffer fish Takifugu rubripes exposed to excessive fluoride: An insight into molecular response to fluorosisJOURNAL OF BIOCHEMICAL AND MOLECULAR TOXICOLOGY, Issue 1 2010Jian Lu Abstract Comparative proteomics was performed to identify proteins in the liver of Takifugu rubripes in response to excessive fluoride exposure. Sixteen fish were randomly divided into a control group and an experimental group. The control group was raised in soft water alone (F, = 0.4 mg/L), and the experimental group was raised in the same water with sodium fluoride at a high concentration of 35 mg/L. After 3 days, proteins were extracted from the fish livers and then subjected to two-dimensional polyacrylamide gel electrophoresis analysis. The matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) was applied to identify the proteins that were differentially expressed from the two groups of fish. Among an average of 816 and 918 proteins detected in the control and treated groups, respectively, 16 proteins were upregulated and 35 were downregulated (P < 0.01) in the fluoride-treated group as compared with those in the control group. Twenty-four highly differentially expressed proteins were further analyzed by MALDI-TOF/TOF-MS, and eight were identified by Mascot. These eight proteins include disulfide isomerase ER-60, 4SNc-Tudor domain protein, SMC3 protein, Cyclin D1, and mitogen-activated protein kinase 10, as well as three unknown proteins. Consistent with their previously known functions, these identified proteins seem to be involved in apoptosis and other functions associated with fluorosis. These results will greatly contribute to our understanding of the effects of fluoride exposure on the physiological and biochemical functions of Takifugu and the toxicological mechanism of fluoride causing fluorosis in both fish and human. © 2010 Wiley Periodicals, Inc. J Biochem Mol Toxicol 24:21,28, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20308 [source] Molecular response of nasal mucosa to therapeutic exposure to broad-band ultraviolet radiationJOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 1-2 2010David Mitchell Abstract Ultraviolet radiation (UVR) phototherapy is a promising new treatment for inflammatory airway diseases. However, the potential carcinogenic risks associated with this treatment are not well understood. UV-specific DNA photoproducts were used as biomarkers to address this issue. Radioimmunoassay was used to quantify cyclobutane pyrimidine dimers (CPDs) and (6,4) photoproducts in DNA purified from two milieus: nasal mucosa samples from subjects exposed to intranasal phototherapy and human airway (EpiAirwayÔ) and human skin (EpiDermÔ) tissue models. Immunohistochemistry was used to detect CPD formation and persistence in human nasal biopsies and human tissue models. In subjects exposed to broadband ultraviolet radiation, DNA damage frequencies were determined prior to as well as immediately after treatment and at increasing times post-treatment. We observed significant levels of DNA damage immediately after treatment and efficient removal of the damage within a few days. No residual damage was observed in human subjects exposed to multiple UVB treatments several weeks after the last treatment. To better understand the molecular response of the nasal epithelium to DNA damage, parallel experiments were conducted in EpiAirway and EpiDerm model systems. Repair rates in these two tissues were very similar and comparable to that observed in human skin. The data suggest that the UV-induced DNA damage response of respiratory epithelia is very similar to that of the human epidermis and that nasal mucosa is able to efficiently repair UVB induced DNA damage. [source] Molecular dynamics of detoxification and toxin-tolerance genes in brown planthopper (Nilaparvata lugens Stål., Homoptera: Delphacidae) feeding on resistant rice plantsARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY (ELECTRONIC), Issue 2 2005Zhifan Yang Abstract To investigate the molecular response of brown planthopper, Nilaparvata lugens (BPH) to BPH-resistant rice plants, we isolated cDNA fragments of the genes encoding for carboxylesterase (CAR), trypsin (TRY), cytochrome P450 monooxygenase (P450), NADH-quinone oxidoreductase (NQO), acetylcholinesterase (ACE), and Glutathione S-transferase (GST). Expression profiles of the genes were monitored on fourth instar nymphs feeding on rice varieties with different resistance levels. Northern blot hybridization showed that, compared with BPH reared on susceptible rice TN1, expression of the genes for P450 and CAR was apparently up-regulated and TRY mRNA decreased in BPH feeding on a highly resistant rice line B5 and a moderately resistant rice variety MH63, respectively. Two transcripts of GST increased in BPH feeding on B5; but in BPH feeding on MH63, this gene was inducible and its expression reached a maximum level at 24 h, and then decreased slightly. The expression of NQO gene was enhanced in BPH on B5 plants but showed a constant expression in BPH on MH63 plants. No difference in ACE gene expression among BPH on different rice plants was detected by the RT-PCR method. The results suggest these genes may play important roles in the defense response of BPH to resistant rice. Arch. Insect Biochem. Physiol. 59:59,66, 2005. © 2005 Wiley-Liss, Inc. [source] Time-series integrated "omic" analyses to elucidate short-term stress-induced responses in plant liquid cultures,BIOTECHNOLOGY & BIOENGINEERING, Issue 1 2009Bhaskar Dutta Abstract The research that aims at furthering our understanding of plant primary metabolism has intensified during the last decade. The presented study validated a systems biology methodological framework for the analysis of stress-induced molecular interaction networks in the context of plant primary metabolism, as these are expressed during the first hours of the stress treatment. The framework involves the application of time-series integrated full-genome transcriptomic and polar metabolomic analyses on plant liquid cultures. The latter were selected as the model system for this type of analysis, because they provide a well-controlled growth environment, ensuring that the observed plant response is due only to the applied perturbation. An enhanced gas chromatography,mass spectrometry (GC,MS) metabolomic data correction strategy and a new algorithm for the significance analysis of time-series "omic" data are used to extract information about the plant's transcriptional and metabolic response to the applied stress from the acquired datasets; in this article, it is the first time that these are applied for the analysis of a large biological dataset from a complex eukaryotic system. The case-study involved Arabidopsis thaliana liquid cultures subjected for 30 h to elevated (1%) CO2 stress. The advantages and validity of the methodological framework are discussed in the context of the known A. thaliana or plant, in general, physiology under the particular stress. Of note, the ability of the methodology to capture dynamic aspects of the observed molecular response allowed for 9 and 24 h of treatment to be indicated as corresponding to shifts in both the transcriptional and metabolic activity; analysis of the pathways through which these activity changes are manifested provides insight to regulatory processes. Biotechnol. Bioeng. 2009;102: 264,279. © 2008 Wiley Periodicals, Inc. [source] Prospective monitoring of BCR-ABL1 transcript levels in patients with Philadelphia chromosome-positive acute lymphoblastic leukaemia undergoing imatinib-combined chemotherapyBRITISH JOURNAL OF HAEMATOLOGY, Issue 4 2008Masamitsu Yanada Summary The clinical significance of minimal residual disease (MRD) is uncertain in patients with Philadelphia chromosome-positive acute lymphoblastic leukaemia (Ph+ ALL) treated with imatinib-combined chemotherapy. Here we report the results of prospective MRD monitoring in 100 adult patients. Three hundred and sixty-seven follow-up bone marrow samples, collected at predefined time points during a uniform treatment protocol, were analysed for BCR-ABL1 transcripts by quantitative reverse transcription polymerase chain reaction. Ninety-seven patients (97%) achieved complete remission (CR), and the relapse-free survival (RFS) rate was 46% at 3 years. Negative MRD at the end of induction therapy was not associated with longer RFS or a lower relapse rate (P = 0·800 and P = 0·964 respectively). Twenty-nine patients showed MRD elevation during haematological CR. Of these, 10 of the 16 who had undergone allogeneic haematopoietic stem cell transplantation (HSCT) in first CR were alive without relapse at a median of 2·9 years after transplantation, whereas 12 of the 13 who had not undergone allogeneic HSCT experienced a relapse. These results demonstrate that, in Ph+ ALL patients treated with imatinib-combined chemotherapy, rapid molecular response is not associated with a favourable prognosis, and that a single observation of elevated MRD is predictive of subsequent relapse, but allogeneic HSCT can override its adverse effect. [source] Two novel imatinib-responsive PDGFRA fusion genes in chronic eosinophilic leukaemiaBRITISH JOURNAL OF HAEMATOLOGY, Issue 1 2007Claire E. Curtis Summary We identified two patients with a t(2;4)(p24;q12) and a t(4;12)(q2?3;p1?2), respectively, in association with BCR-ABL and FIP1L1-PDGFRA negative chronic eosinophilic leukaemia. Molecular analysis revealed a novel STRN - PDGFRA fusion for the t(2;4) and ETV6 - PDGFRA for the t(4;12). The fusions were confirmed by specific amplification of the genomic breakpoints, reverse transcription polymerase chain reaction and fluorescence in situ hybridisation. Both patients were treated with imatinib and, following a rapid haematological response, achieved cytogenetic remission and a major molecular response. In conclusion, PDGFRA fuses to diverse partner genes in myeloid disorders. Identification of these fusions is important as they are particularly sensitive to imatinib. [source] Cytogenetic and molecular responses and outcome in chronic myelogenous leukemiaCANCER, Issue 4 2008Need for new response definitions? Abstract BACKGROUND. Response rates in chronic myeloid leukemia (CML) are now reported based on the cumulative incidence of a single-time best response. The study aim was to examine the significance of different response criteria for CML on imatinib therapy. METHODS. In all, 276 patients with chronic phase CML on imatinib therapy were analyzed. Cytogenetic and molecular responses were coded as to single best response and response at specific intervals of treatment. RESULTS. The cumulative incidence of complete cytogenetic response (CGCR) with imatinib was 91%; however, the incidence of CGCR at 48 months into therapy was only 78%. Similarly, the incidence of major molecular responses (best cumulative vs landmark at 48 months) were 74% versus 62%, and of undetectable BCR-ABL transcripts 38% versus 24%. There was a strong association between achievement of major cytogenetic response (Philadelphia chromosome [Ph]-positivity ,35%) at 6 months to 12 months and survival as well as progression-free survival (PFS). Achievement of major molecular response (vs lesser molecular response) in patients in complete cytogenetic response was not associated with significant differences in survival, but showed some association with PFS. Durable CGCR and major molecular responses (documented continuously for ,12 months) were associated with longer PFS duration but not with survival duration differences. Of interest, major molecular responses documented at least twice were noted in 71% of patients on imatinib therapy; undetectable BCR-ABL transcripts documented at least twice were noted in 34%. CONCLUSIONS. Achievement and durability of CGCR and of major and complete molecular responses at landmark times predict outcome in CML, and may help in comparing the efficacy of different treatments. Cancer 2008. © 2007 American Cancer Society. [source] Slower molecular response to treatment predicts poor outcome in patients with TEL/AML1 positive acute lymphoblastic leukemiaCANCER, Issue 1 2003Prospective real-time quantitative reverse transcriptase-polymerase chain reaction study Abstract BACKGROUND The translocation t(12;21)(p13;q22), which produces the TEL/AML1 fusion gene, is the most frequent chromosomal abnormality in patients with childhood acute lymphoblastic leukemia (ALL) and generally is associated with a favorable prognosis. Furthermore, real-time quantitative-polymerase chain reaction (RQ-PCR)-based detection of TEL/AML1 represents an accurate technique for the reproducible assessment of minimal residual disease (MRD). METHODS The authors employed RQ-reverse transcriptase-PCR (RQ-RT-PCR) technology to analyze MRD levels in 57 newly diagnosed patients with TEL/AML1 positive ALL in a prospective study. RESULTS On Day + 33, a particularly important time point in terms of outcome prediction based on MRD monitoring, 75% of patients reached negativity, 13% of patients were positive at very low levels (< 10,4; i.e., 1 or more leukemic cell per 104 normal cells), and another 13% of patients were positive at the level of 10,2 to 10,4 cells. No patient showed MRD levels , 10,2 cells at this time. The data demonstrate that patients with TEL/AML1 positive ALL had a better response to induction chemotherapy on Day + 33 compared with a group of unselected patients with ALL (P = 0.0001). However, four patients with TEL/AML1 positive ALL developed relapse disease. Remarkably, these children were positive for MRD on Day + 33 at a level between 10,2 cells and 10,4 (n = 3 patients) and at < 10,4 (n = 1 patient). Kaplan,Meier analysis of disease free survival showed the statistical significance of this distribution (MRD positive vs. MRD negative; log-rank P = 0.0016). CONCLUSIONS The authors conclude that, although the TEL/AML1 positive leukemias generally are associated with a favorable outcome, MRD positivity assessed by RQ-RT-PCR analysis at the end of induction therapy represents a significantly negative prognostic feature. Cancer 2003;97:105,13. © 2003 American Cancer Society. DOI 10.1002/cncr.11043 [source] A heat labile soluble factor from Bacteroides thetaiotaomicron VPI-5482 specifically increases the galactosylation pattern of HT29-MTX cellsCELLULAR MICROBIOLOGY, Issue 5 2001Miguel Freitas The aim of this work was to set up and validate an in vitro model to study a molecular response of an intestinal host cell line (HT29-MTX), to a non-pathogen microflora component. We found that Bacteroides thetaiotaomicron strain VPI-5482 had the capacity to change a specific glycosylation process in HT29-MTX cells via a mechanism that involved a soluble factor. Differentiated HT29-MTX cells were grown in the presence of 20% of spent culture supernatant from the B. thetaiotaomicron during 10 days. Glycosylation processes were followed using a large panel of lectins and analysed using confocal microscopy, western blotting and flow cytometry techniques. Our results show that a B. thetaiotaomicron soluble factor modified specifically the galactosylation pattern of HT29-MTX cells, whereas other glycosylation steps remained mainly unaffected. Further characterization of this soluble factor indicates that it is a heat labile, low molecular weight compound. Reverse transcript-PCR (RT-PCR) analysis was unable to show any significant change in mRNA expression level of the main galactosyltransferases expressed in HT29-MTX cells. By contrast, galactosyltransferase activities dramatically increased in HT29-MTX cells treated by the soluble extract of B. thetaiotaomicron, suggesting a post-translational regulation of these activities. Our in vitro model allowed us to study the cross-talk between a single bacteria and intestinal cells. The galactosylation process appears to be a target of this communication, thus uncovering a new window to study the functional consequences of co-operative symbiotic bacterial,host interactions. [source] Alterations in gene expression profiles and the DNA-damage response in ionizing radiation-exposed TK6 cells,,ENVIRONMENTAL AND MOLECULAR MUTAGENESIS, Issue 2-3 2005Gregory S. Akerman Abstract Identifying genes that are differentially expressed in response to DNA damage may help elucidate markers for genetic damage and provide insight into the cellular responses to specific genotoxic agents. We utilized cDNA microarrays to develop gene expression profiles for ionizing radiation-exposed human lymphoblastoid TK6 cells. In order to relate changes in the expression profiles to biological responses, the effects of ionizing radiation on cell viability, cloning efficiency, and micronucleus formation were measured. TK6 cells were exposed to 0.5, 1, 5, 10, and 20 Gy ionizing radiation and cultured for 4 or 24 hr. A significant (P < 0.0001) decrease in cloning efficiency was observed at all doses at 4 and 24 hr after exposure. Flow cytometry revealed significant decreases in cell viability at 24 hr in cells exposed to 5 (P < 0.001), 10 (P < 0.0001), and 20 Gy (P < 0.0001). An increase in micronucleus frequency occurred at both 4 and 24 hr at 0.5 and 1 Gy; however, insufficient binucleated cells were present for analysis at the higher doses. Gene expression profiles were developed from mRNA isolated from cells exposed to 5, 10, and 20 Gy using a 350 gene human cDNA array platform. Overall, more genes were differentially expressed at 24-hr than at the 4-hr time point. The genes upregulated (> 1.5-fold) or downregulated (< 0.67-fold) at 4 hr were those primarily involved in the cessation of the cell cycle, cellular detoxification pathways, DNA repair, and apoptosis. At 24 hr, glutathione-associated genes were induced in addition to genes involved in apoptosis. Genes involved in cell cycle progression and mitosis were downregulated at 24 hr. Real-time quantitative PCR was used to confirm the microarray results and to evaluate expression levels of selected genes at the low doses (0.5 and 1.0 Gy). The expression profiles reflect the cellular and molecular responses to ionizing radiation related to the recognition of DNA damage, a halt in progression through the cell cycle, activation of DNA-repair pathways, and the promotion of apoptosis. Environ. Mol. Mutagen., 2005. Published 2005 Wiley-Liss, Inc. [source] Time-Dependent transcriptional profiles of genes of the hypothalamic-pituitary-gonadal axis in medaka (Oryzias latipes) exposed to fadrozole and 17,-trenboloneENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 12 2008Xiaowei Zhang Abstract Both the anabolic androgen 17,-trenbolone (TRB) and the aromatase inhibitor fadrozole (FAD) can cause decreased plasma concentrations of estrogen (E2) and reduce fecundity of fish. However, the underlying mechanisms and the molecular pathways involved are largely unknown. The present study was designed to assess time-dependent effects of FAD and TRB on the transcriptional responses of the hypothalamic-pituitary-gonadal (HPG) axis of Japanese medaka (Oryzias latipes). Fourteen-week-old Japanese medaka were exposed to 50 ,g FAD/L or 2 ,g TRB/L in a 7-d static renewal test, and the expression profiles of 36 HPG axis genes were measured by means of a medaka HPG real-time reverse-transcription polymerase chain reaction array after 8 h, 32 h, or 7 d of exposure. Exposure to TRB or FAD caused lesser fecundity of Japanese medaka and down-regulated transcription of vitellogenin and choriogenin (CHG) gene expression in the liver of females. Exposure to FAD for 8 h resulted in an 8-fold and 71-fold down-regulation of expression of estrogen receptor , and choriogenin L (CHG L), respectively, in female liver. 17,-Trenbolone caused similar down-regulation of these genes, but the effects were not observed until 32 h of exposure. These results support the hypothesis that FAD reduces plasma E2 more quickly by inhibiting aromatase enzyme activity than does TRB, which inhibits the production of the E2 precursor testosterone. Exposure to FAD and TRB resulted in rapid (after 8 h) down-regulation of luteinizing hormone receptor and low-density-lipoprotein receptor in the testis to compensate for excessive androgen levels. Overall, the molecular responses observed in the present study differentiate the mechanisms of the reduced fecundity by TRB and FAD. [source] Alteration of normal cellular profiles in the scleractinian coral (Pocillopora damicornis) following laboratory exposure to fuel oilENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 12 2006Luc Rougée Abstract Petroleum contamination from oil spills is a continuing threat to our ocean's fragile ecosystems. Herein, we explored the effects of the water-soluble fraction of crude oil on a stony coral, Pocillopora damicornis (Linneaeus 1758). We developed methods for exposing corals to various concentrations of crude oil and for assessing the potential molecular responses of the corals. Corals were exposed to water-accommodated fraction solutions, and appropriate cellular biomarkers were quantified. When compared to the "healthy" control specimens, exposed corals exhibited shifts in biomarker concentrations that were indicative of a shift from homeostasis. Significant changes were seen in cytochrome P450 1-class, cytochrome P450 2-class, glutathione- S -transferase-pi, and cnidarian multixenobiotic resistance protein-1 biomarkers, which are involved the cellular response to, and manipulation and excretion of, toxic compounds, including polycyclic aromatic hydrocarbons. A shift in biomarkers necessary for porphyrin production (e.g., protoporphyrinogen oxidase IX and ferrochelatase) and porphyrin destruction (e.g., heme oxygenase-1 and invertebrate neuroglobin homologue) illustrates only one of the cellular protective mechanisms. The response to oxidative stress was evaluated through measurements of copper/zinc superoxide dismutase-1 and DNA glycosylase MutY homologue-1 concentrations. Likewise, changes in heat shock protein 70 and small heat shock proteins indicated an adjustment in the cellular production of proteins. Finally, the results of this laboratory study were nearly identical to what we observed previously among corals of a different species, Porites lobata, exposed to an oil spill in the field after the grounding of the Merchant Vessel Kyowa Violet. [source] Upregulation of genes orchestrating keratinocyte differentiation, including the novel marker gene ID2, by contact sensitizers in human bulge-derived keratinocytesJOURNAL OF BIOCHEMICAL AND MOLECULAR TOXICOLOGY, Issue 1 2010Yoshie Yoshikawa Abstract In the epidermis, keratinocytes are involved in physical and first-line immune protection of the host. In this study, we analyzed the molecular responses to certain contact sensitizers (2,4-dinitrochlorobenzene and NiSO4) and irritants (sodium dodecyl sulfate and benzalkonium chloride) in cultured human keratinocytes from the bulge region of a plucked hair follicle (bulge-derived keratinocytes [BDKs]) and compared these molecular responses to those with the human monocytic leukemia cell line, THP-1. The BDKs, individually established without invasive biopsies, showed high reactivity to these stimulants. As a primary response to the contact sensitizers, the NRF2-mediated signaling pathway was upregulated in BDKs and THP-1. The expression of IL1B and IL8 genes was not induced by the irritants but by the sensitizers in THP-1. However, the expression of the IL1B and IL8 genes was induced at higher levels by the irritants in BDKs than by the sensitizers. Many genes orchestrating keratinocyte differentiation, including ID2, were significantly upregulated in response to the sensitizers in BDKs but not those in THP-1. The use of the ID2 gene to discriminate between sensitizers and irritants might be effective as a novel marker for application during in vitro sensitization with BDKs. © 2010 Wiley Periodicals, Inc. J Biochem Mol Toxicol 24:10,20, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20307 [source] Alterations in Mitochondrial and Apoptosis-regulating Gene Expression in Photodynamic Therapy-resistant Variants of HT29 Colon Carcinoma Cells,PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 2 2005Xiao Yun Shen ABSTRACT Photodynamic therapy (PDT) is a novel cancer therapy inducing irreversible photodamage to tumor tissue via photosensitizer-mediated oxidative cytotoxicity. The cellular and molecular responses associated with PDT are only partially understood. We have reported previously the generation of several photosensitizer-specific PDT-resistant cell variants of HT29 human colon adenocarcinoma cells by selecting cells from sequential PDT treatment using different photosensitizers. In this report, we describe the use of messenger RNA (mRNA) differential display to identify genes that were differentially expressed in the parental HT29 cells compared with their resistant variants. In comparison with parental HT29 cells, mRNA expression was increased in the PDT-resistant cell variants for BNIP3, estrogen receptor-binding fragmentassociated gene 9, Myh-1c, cytoplasmic dynein light chain 1, small membrane protein I and differential dependent protein. In contrast, expression in the PDT-resistant variants was downregulated for NNX3, human HepG2 3,region Mbol complementary DNA, glutamate dehydrogenase, hepatomaderived growth factor and the mitochondrial genes coding for 16S ribosomal RNA (rRNA) and nicotinamide adenine dinucleotide (NADH) dehydrogenase subunit 4. The reduction for mitochondrial 16S rRNA in the PDT-resistant variants was confirmed by Northern blotting, and the elevated expression of the proapoptotic BNIP3 in the PDT-resistant variants was confirmed by Northern and Western blotting analysis. We also examined the expression of some additional apoptosis-regulating genes using Western blotting. We show an increased expression of Bcl-2 and heat shock protein 27 and a downregulation of Bax in the PDT-resistant variants. In addition, the mutant p53 levels in the parental HT29 cells were reduced substantially in the PDT-resistant variants. We suggest that the altered expression in several mitochondria1 and apoptosisregulating genes contributes to PDT resistance. [source] Electromagnetic fields (900 MHz) evoke consistent molecular responses in tomato plantsPHYSIOLOGIA PLANTARUM, Issue 2 2006David Roux First page of article [source] Biochemical and molecular responses to water stress in resurrection plantsPHYSIOLOGIA PLANTARUM, Issue 2 2004Giovanni Bernacchia A small group of angiosperms, known as resurrection plants, can tolerate extreme dehydration. They survive in arid environments because they are able to dehydrate, remain quiescent during long periods of drought, and then resurrect upon rehydration. Dehydration induces the expression of a large number of transcripts in resurrection plants. Gene products with a putative protective function such as LEA proteins have been identified; they are expressed at high levels in the cytoplasm or in chloroplasts upon dehydration and/or ABA treatment of vegetative tissue. An increase in sugar concentration is usually observed at the onset of desiccation in vegetative tissue of resurrection plants. These sugars may be effective in osmotic adjustment or they may stabilize membrane structures and proteins. Regulatory genes such as a protein translation initiation factor, homeodomain-leucine zipper genes and a gene probably working as a regulatory RNA have been isolated and characterized. The knowledge of the biochemical and molecular responses that occur during the onset of drought may help to improve water stress tolerance in plants of agronomic importance. [source] Proteomic analysis of differentially expressed proteins in Penaeus vannamei hemocytes upon Taura syndrome virus infectionPROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 19 2007Phattara-orn Chongsatja Abstract To understand molecular responses of crustacean hemocytes to virus infection, we applied 2-DE proteomics approach to investigate altered proteins in hemocytes of Penaeus vannamei during Taura syndrome virus (TSV) infection. At 24,h postinfection, quantitative intensity analysis and nano-LC-ESI-MS/MS revealed 11 forms of 8 proteins that were significantly up-regulated, whereas 9 forms of 5 proteins were significantly down-regulated in the infected shrimps. These altered proteins play important roles in host defense (hemocyanin, catalase, carboxylesterase, transglutaminase, and glutathione transferase), signal transduction (14-3-3 zeta), carbohydrate metabolism (acetylglucosamine pyrophosphorylase), cellular structure and integrity (beta-tubulin, beta-actin, tropomyosin, and myosin), and ER-stress response (protein disulfide isomerase). Semiquantitative RT-PCR and Western blot analysis confirmed the upregulation of 14-3-3 at both mRNA and protein levels. Interestingly, several altered protein spots were identified as fragments of hemocyanin. Mass spectrometric analysis showed that the hemocyanin spots at acidic and basic regions represented the C- and N-terminal hemocyanin fragments, respectively. As three-quarters of C-terminal fragments were up-regulated, whereas two-thirds of N-terminal hemocyanin fragments were down-regulated, we therefore hypothesize that C- and N-terminal hemocyanin fragments may have differential roles in hemocytes. Further investigation of these data may lead to better understanding of the molecular responses of crustacean hemocytes to TSV infection. [source] A leucine-rich repeat protein is required for growth promotion and enhanced seed production mediated by the endophytic fungus Piriformospora indica in Arabidopsis thalianaTHE PLANT JOURNAL, Issue 1 2007Bationa Shahollari Summary Piriformospora indica, a basidiomycete of the Sebacinaceae family, promotes the growth, development and seed production of a variety of plant species. Arabidopsis plants colonized with the fungus produce 22% more seeds than uncolonized plants. Deactivating the Arabidopsis single-copy gene DMI-1, which encodes an ion carrier required for mycorrihiza formation in legumes, does not affect the beneficial interaction between the two symbiotic partners. We used cellular and molecular responses initiated during the establishment of the interaction between P. indica and Arabidopsis roots to isolate mutants that fail to respond to the fungus. An ethylmethane sulfonate mutant (Piriformospora indica - insensitive-2; pii-2), and a corresponding insertion line, are impaired in a leucine-rich repeat protein (At1g13230). The protein pii-2, which contains a putative endoplasmic reticulum retention signal, is also found in Triton X-100-insoluble plasma membrane microdomains, suggesting that it is present in the endoplasmic reticulum/plasma membrane continuum in Arabidopsis roots. The microdomains also contain an atypical receptor protein (At5g16590) containing leucine-rich repeats, the message of which is transiently upregulated in Arabidopsis roots in response to P. indica. This response is not detectable in At1g13230 mutants, and the protein is not detectable in the At1g13230 mutant microdomains. Partial deactivation of a gene for a sphingosine kinase, which is required for the biosynthesis of sphingolipid found in plasma membrane microdomains, also affects the Arabidopsis/P. indica interaction. Thus, pii-2, and presumably also At5g16590, two proteins present in plasma membrane microdomains, appear to be involved in P. indica -induced growth promotion and enhanced seed production in Arabidopsis thaliana. [source] Progenitor cells in liver regeneration: molecular responses controlling their activation and expansion,APMIS, Issue 11-12 2005ERIC SANTONI-RUGIU Although normally quiescent, the adult mammalian liver possesses a great capacity to regenerate after different types of injuries in order to restore the lost liver mass and ensure maintenance of the multiple liver functions. Major players in the regeneration process are mature residual cells, including hepatocytes, cholangiocytes and stromal cells. However, if the regenerative capacity of mature cells is impaired by liver-damaging agents, hepatic progenitor cells are activated and expand into the liver parenchyma. Upon transit amplification, the progenitor cells may generate new hepatocytes and biliary cells to restore liver homeostasis. In recent years, hepatic progenitor cells have been the subject of increasing interest due to their therapeutic potential in numerous liver diseases as alternative or supportive/complementary tools to liver transplantation. While the first investigations on hepatic progenitor cells have focused on their origin and phenotypic characterization, recent attention has focused on the influence of the hepatic microenvironment on their activation and proliferation. This microenvironment comprises the extracellular matrix, epithelial and non-epithelial resident liver cells, and recruited inflammatory cells as well as the variety of growth-modulating molecules produced and/or harboured by these elements. The cellular and molecular responses to different regenerative stimuli seem to depend on the injury inflicted and consequently on the molecular microenvironment created in the liver by a certain insult. This review will focus on molecular responses controlling activation and expansion of the hepatic progenitor cell niche, emphasizing similarities and differences in the microenvironments orchestrating regeneration by recruitment of progenitor cell populations or by replication of mature cells. [source] Curcumin in Cancer Chemoprevention: Molecular Targets, Pharmacokinetics, Bioavailability, and Clinical TrialsARCHIV DER PHARMAZIE, Issue 9 2010Adeeb Shehzad Abstract Curcumin (diferuloylmethane), a derivative of turmeric is one of the most commonly used and highly researched phytochemicals. Abundant sources provide interesting insights into the multiple mechanisms by which curcumin may mediate chemotherapy and chemopreventive effects on cancer. The pleiotropic role of this dietary compound includes the inhibition of several cell signaling pathways at multiple levels, such as transcription factors (NF-,B and AP-1), enzymes (COX-2, MMPs), cell cycle arrest (cyclin D1), proliferation (EGFR and Akt), survival pathways (,-catenin and adhesion molecules), and TNF. Curcumin up-regulates caspase family proteins and down-regulates anti-apoptotic genes (Bcl-2 and Bcl-XL). In addition, cDNA microarrays analysis adds a new dimension for molecular responses of cancer cells to curcumin at the genomic level. Although, curcumin's poor absorption and low systemic bioavailability limits the access of adequate concentrations for pharmacological effects in certain tissues, active levels in the gastrointestinal tract have been found in animal and human pharmacokinetic studies. Currently, sufficient data has been shown to advocate phase II and phase III clinical trials of curcumin for a variety of cancer conditions including multiple myeloma, pancreatic, and colon cancer. [source] Abiotic stress and plant responses from the whole vine to the genesAUSTRALIAN JOURNAL OF GRAPE AND WINE RESEARCH, Issue 2010G.R. CRAMER Abstract Drought, salinity and extreme temperatures significantly limit the distribution of grapes around the world. In this review, the literature of grape responses to abiotic stress with particular reference to whole plant and molecular responses observed in recent studies is discussed. A number of short-term and long-term studies on grapevine shoots and berries have been conducted using a systems biology approach. Transcripts, proteins and metabolites were profiled. Water deficit, salinity and chilling altered the steady-state abundance of a large number of transcripts. Common responses to these stresses included changes in hormone metabolism, particularly abscisic acid (ABA), photosynthesis, growth, transcription, protein synthesis, signalling and cellular defences. Some of the transcriptional changes induced by stress were confirmed by proteomic and metabolomic analyses. More than 2000 genes were identified whose transcript abundance was altered by both water deficit and ABA. Different gene sets were used to map molecular pathways regulated by ABA, water deficit, salinity and chilling in grapevine. This work supports the hypothesis that ABA is a central regulator of abiotic stress tolerance mechanisms. ABA affects signalling pathways that trigger important molecular activities involving metabolism, transcription, protein synthesis, and cellular defence and also regulates important physiological responses such as stomatal conductance, photoprotection and growth. Systems biology approaches are providing more comprehensive understanding of the complex plant responses to abiotic stress. The molecular sets generated from mapping the ABA-inducible stress responses provide numerous targets for genetic and cultural manipulation for improved plant protection and grape quality. [source] Systematic review of high dose chemotherapy and autologous haematopoietic stem cell transplantation for chronic lymphocytic leukaemia: what is the published evidence?BRITISH JOURNAL OF HAEMATOLOGY, Issue 2 2007Mohamed A. Kharfan-Dabaja Summary Despite improved responses, chronic lymphocytic leukaemia (CLL) remains incurable with conventional chemotherapy. Patients with poor-risk factors or who fail conventional chemoimmunotherapy are offered autografts, preferably after achieving remission. This report presents the totality of evidence through a systematic review that assessed the efficacy of autografts in CLL. A search of MEDLINE databases from 1966,2006 and hand-search of references identified 82 prospective-randomized, non-randomized comparisons or single-arm trials, of which only nine met our inclusion criteria: two trials were funded by public/government, one by private foundations, one jointly by private/public, and was unclear in five. No randomized controlled trials comparing autografts versus conventional chemotherapy (or chemoimmunotherapy) were found. Six studies were single-arm and three were non-randomized with a control-arm (autologous versus allogeneic). Overall, 361 patients were enrolled, but only 292 were transplanted. Transplant-related mortality ranged from 0% to 9%. Complete responses ranged from 74% to 100% and molecular responses ranged from 57% to 88%. Overall survival ranged from 68% at 3 years to 58% at 6 years. It is uncertain whether autograft is superior to conventional therapy. The high incidence of myelodysplastic syndrome (9,12%) is particularly concerning in CLL, where median survival is 9 years. [source] Cytogenetic and molecular responses and outcome in chronic myelogenous leukemiaCANCER, Issue 4 2008Need for new response definitions? Abstract BACKGROUND. Response rates in chronic myeloid leukemia (CML) are now reported based on the cumulative incidence of a single-time best response. The study aim was to examine the significance of different response criteria for CML on imatinib therapy. METHODS. In all, 276 patients with chronic phase CML on imatinib therapy were analyzed. Cytogenetic and molecular responses were coded as to single best response and response at specific intervals of treatment. RESULTS. The cumulative incidence of complete cytogenetic response (CGCR) with imatinib was 91%; however, the incidence of CGCR at 48 months into therapy was only 78%. Similarly, the incidence of major molecular responses (best cumulative vs landmark at 48 months) were 74% versus 62%, and of undetectable BCR-ABL transcripts 38% versus 24%. There was a strong association between achievement of major cytogenetic response (Philadelphia chromosome [Ph]-positivity ,35%) at 6 months to 12 months and survival as well as progression-free survival (PFS). Achievement of major molecular response (vs lesser molecular response) in patients in complete cytogenetic response was not associated with significant differences in survival, but showed some association with PFS. Durable CGCR and major molecular responses (documented continuously for ,12 months) were associated with longer PFS duration but not with survival duration differences. Of interest, major molecular responses documented at least twice were noted in 71% of patients on imatinib therapy; undetectable BCR-ABL transcripts documented at least twice were noted in 34%. CONCLUSIONS. Achievement and durability of CGCR and of major and complete molecular responses at landmark times predict outcome in CML, and may help in comparing the efficacy of different treatments. Cancer 2008. © 2007 American Cancer Society. [source] | ||||||||||||||||||||||||||||