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Wild Type (wild + type)
Terms modified by Wild Type Selected AbstractsHemochromatosis genotypes and risk of 31 disease endpoints: Meta-analyses including 66,000 cases and 226,000 controls,HEPATOLOGY, Issue 4 2007Christina Ellervik Hemochromatosis genotypes have been associated with liver disease, diabetes mellitus, heart disease, arthritis, porphyria cutanea tarda, stroke, neurodegenerative disorders, cancer, and venous disease. We performed meta-analyses including 202 studies with 66,263 cases and 226,515 controls to examine associations between hemochromatosis genotypes C282Y/C282Y, C282Y/H63D, C282Y/wild type, H63D/H63D, and H63D/wild type versus wild type/wild type and 9 overall endpoints and 22 endpoint subgroups. We also explored potential sources of heterogeneity. For liver disease, the odds ratio for C282Y/C282Y versus wild type/wild type was 3.9 (99% confidence interval: 1.9,8.1) overall, 11 (3.7,34) for hepatocellular carcinoma, 4.1 (1.2,14) for hepatitis C, and 10 (2.1,53) for nonalcoholic steatohepatitis. For porphyria cutanea tarda, the odds ratios were 48 (24,95) for C282Y/C282Y, 8.1 (3.9,17) for C282Y/H63D, 3.6 (1.8,7.3) for C282Y/wild type, 3.0 (1.6,5.6) for H63D/H63D, and 1.7 (1.0,3.1) for H63D/wild type versus wild type/wild type. Finally, for amyotrophic lateral sclerosis, the odds ratio was 3.9 (1.2,13) for H63D/H63D versus wild type/wild type. These findings were consistent across individual studies. The hemochromatosis genotypes were not associated with risk for diabetes mellitus, heart disease, arthritis, stroke, cancer, or venous disease in the overall analyses; however, the odds ratio for C282Y/C282Y versus wild type/wild type was 3.4 (1.1,11) for diabetes mellitus among North Europeans. Conclusion: In aggregate, clinically ascertained cases who are homozygous for the C282Y mutation are associated with a 4,11,fold risk of liver disease, whereas all 5 hemochromatosis genotypes are associated with a 2,48,fold risk of porphyria cutanea tarda, and H63D/H63D is associated with a 4-fold risk of amyotrophic lateral sclerosis. These results, mainly from case-control studies, cannot necessarily be extrapolated to the general population. (HEPATOLOGY 2007.) [source] Population-based study of the relationship between mutations in the hemochromatosis (HFE) gene and arthritisJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 3 2006Colin A Sherrington Abstract Background and Aim:, Mutations in the hemochromatosis (HFE) gene are carried by one in three individuals of British Isles descent and may result in increased iron stores. These increased iron stores could potentially induce or exacerbate diseases, such as arthritis, in which iron has a role in pathogenesis. Although arthritis is a well-known association of clinically overt hereditary hemochromatosis, controversy surrounds the role of mutations in the HFE gene as risk factors for arthritis. The aim of the present study was to determine whether mutations in the HFE gene are associated with an increased prevalence of arthritis. Methods:, A population-based study was conducted in Busselton, Western Australia, of the prevalence of arthritis in 1372 individuals of British Isles descent. Participants completed a questionnaire and general physical examination. Analysis for C282Y and H63D HFE mutations was undertaken. Unadjusted and adjusted odds ratios (OR) were calculated for the relationship between HFE mutations and the prevalence of self-reported, doctor-diagnosed arthritis. Results:, There was no association between the presence of HFE mutations and the prevalence of self-reported, doctor-diagnosed arthritis (C282Y/wild type (WT) adjusted OR = 1.041 (95% confidence interval (CI) 0.68,1.61), H63D/WT OR = 0.76 (95% CI 0.53,1.08), C282Y/C282Y OR = 0.39 (95% CI 0.04,3.63), C282Y/H 63D OR = 0.808 (95% CI 0.27,2.42), H63D/H63D OR = 0.419 (95% CI 0.13,1.36)). Overall adjusted OR for arthritis in participants with one or more HFE mutations was 0.81 (95% CI 0.61,1.09). Conclusions:, Mutations of the HFE gene are not risk factors for arthritis in populations of British Isles descent. [source] Hemochromatosis genotypes and risk of 31 disease endpoints: Meta-analyses including 66,000 cases and 226,000 controls,HEPATOLOGY, Issue 4 2007Christina Ellervik Hemochromatosis genotypes have been associated with liver disease, diabetes mellitus, heart disease, arthritis, porphyria cutanea tarda, stroke, neurodegenerative disorders, cancer, and venous disease. We performed meta-analyses including 202 studies with 66,263 cases and 226,515 controls to examine associations between hemochromatosis genotypes C282Y/C282Y, C282Y/H63D, C282Y/wild type, H63D/H63D, and H63D/wild type versus wild type/wild type and 9 overall endpoints and 22 endpoint subgroups. We also explored potential sources of heterogeneity. For liver disease, the odds ratio for C282Y/C282Y versus wild type/wild type was 3.9 (99% confidence interval: 1.9,8.1) overall, 11 (3.7,34) for hepatocellular carcinoma, 4.1 (1.2,14) for hepatitis C, and 10 (2.1,53) for nonalcoholic steatohepatitis. For porphyria cutanea tarda, the odds ratios were 48 (24,95) for C282Y/C282Y, 8.1 (3.9,17) for C282Y/H63D, 3.6 (1.8,7.3) for C282Y/wild type, 3.0 (1.6,5.6) for H63D/H63D, and 1.7 (1.0,3.1) for H63D/wild type versus wild type/wild type. Finally, for amyotrophic lateral sclerosis, the odds ratio was 3.9 (1.2,13) for H63D/H63D versus wild type/wild type. These findings were consistent across individual studies. The hemochromatosis genotypes were not associated with risk for diabetes mellitus, heart disease, arthritis, stroke, cancer, or venous disease in the overall analyses; however, the odds ratio for C282Y/C282Y versus wild type/wild type was 3.4 (1.1,11) for diabetes mellitus among North Europeans. Conclusion: In aggregate, clinically ascertained cases who are homozygous for the C282Y mutation are associated with a 4,11,fold risk of liver disease, whereas all 5 hemochromatosis genotypes are associated with a 2,48,fold risk of porphyria cutanea tarda, and H63D/H63D is associated with a 4-fold risk of amyotrophic lateral sclerosis. These results, mainly from case-control studies, cannot necessarily be extrapolated to the general population. (HEPATOLOGY 2007.) [source] A Study of the Interaction between Auxin and Ethylene in Wild Type and Transgenic Ethylene-Insensitive Tobacco during Adventitious Root Formation Induced by Stagnant Root Zone ConditionsPLANT BIOLOGY, Issue 5 2003M. P. McDonald Abstract: Wild type (Wt) and transgenic plants (etr1-1 gene from Arabidopsis thaliana; encoding for a defective ethylene receptor; Tetr) of Nicotiana tabacum L. were subjected to experiments to resolve the role of the interaction between ethylene and auxin in waterlogging-induced adventitious root formation. Plants were grown in aerated or stagnant deoxygenated nutrient solution and treated with the following plant growth regulators: ethylene, the synthetic auxins 2,4-dichlorophenoxyacetic acid (2,4-D) and 1-naphthaleneacetic acid (1-NAA), and the auxin efflux inhibitor naphthylphthalamic acid (NPA). The superior growth of Wt in stagnant solution suggests that the ability to sense and respond to ethylene partially mediates tolerance to stagnant root zone conditions. Wt produced around 2 - 2.5-fold more adventitious roots than Tetr in aerated and stagnant solution. Treatment with NPA phenocopied the effects of ethylene insensitivity by reducing the number of adventitious roots on Wt to Tetr levels. Additionally, application of 1-NAA to the shoot of Tetr increased the number of adventitious roots on Tetr to similar levels as the untreated Wt. However, this level was only around half the number achieved by 1-NAA-treated Wt. The results suggest an interplay between ethylene and auxin in the process of adventitious root formation in waterlogged tobacco, most likely on the level of polar auxin transport. However, a separate non-auxin-related role as a transcription regulator for genes essential to adventitious root formation cannot be excluded. [source] Heterodimers of Histidine and Amantadine as Inhibitors for Wild Type and Mutant M2 Channels of Influenza ACHINESE JOURNAL OF CHEMISTRY, Issue 8 2010Wenjuan Zhang Abstract Inhibitors bearing the imidazole, adamantane and related structures were synthesized and tested against WT, S31N and S31N-L26I mutant M2 channels. Although amantadine (1) only inhibited WT M2 channel, compound 6 containing the imidazole and adamantane groups showed good inhibitory activity to WT and mutant M2 channels. The stereochemistry and basic pKa of , -amine are important for the activity of inhibitors and our data showed that derivatives of natural histidine are more active for M2 channels than those of unnatural histidine. The significance of our present results is that we have established a prospective strategy of drug discovery of WT and mutant M2 channels against influenza A. [source] The exopolysaccharide of Rhizobium sp.ENVIRONMENTAL MICROBIOLOGY, Issue 8 2008Brassica napus roots but contributes to root colonization, YAS34 is not necessary for biofilm formation on Arabidopsis thaliana Summary Microbial exopolysaccharides (EPSs) play key roles in plant,microbe interactions, such as biofilm formation on plant roots and legume nodulation by rhizobia. Here, we focused on the function of an EPS produced by Rhizobium sp. YAS34 in the colonization and biofilm formation on non-legume plant roots (Arabidopsis thaliana and Brassica napus). Using random transposon mutagenesis, we isolated an EPS-deficient mutant of strain YAS34 impaired in a glycosyltransferase gene (gta). Wild type and mutant strains were tagged with a plasmid-born GFP and, for the first time, the EPS produced by the wild-type strain was seen in the rhizosphere using selective carbohydrate probing with a fluorescent lectin and confocal laser-scanning microscopy. We show for the fist time that Rhizobium forms biofilms on roots of non-legumes, independently of the EPS synthesis. When produced by strain YAS34 wild type, EPS is targeted at specific parts of the plant root system. Nutrient fluctuations, root exudates and bacterial growth phase can account for such a production pattern. The EPS synthesis in Rhizobium sp. YAS34 is not essential for biofilm formation on roots, but is critical to colonization of the basal part of the root system and increasing the stability of root-adhering soil. Thus, in Rhizobium sp. YAS34 and non-legume interactions, microbial EPS is implicated in root,soil interface, root colonization, but not in biofilm formation. [source] Organelle-specific expression of subunit ND5 of human complex I (NADH dehydrogenase) alters cation homeostasis in Saccharomyces cerevisiaeFEMS YEAST RESEARCH, Issue 6 2010Wojtek Steffen Abstract The ND5 component of the respiratory complex I is a large, hydrophobic subunit encoded by the mitochondrial genome. Its bacterial homologue, the NDH-1 subunit NuoL, acts as a cation transporter in the absence of other NDH-1 subunits. Mutations in human ND5 are frequently observed in neurodegenerative diseases. Wild type and mutant variants of ND5 fused to GFP or a FLAG peptide were targeted to the endoplasmatic reticulum (ER) or the inner mitochondrial membrane of Saccharomyces cerevisiae, which lacks an endogenous complex I. The localization of ND5 fusion proteins was confirmed by microscopic analyses of S. cerevisiae cells, followed by cellular fractionation and immunostaining. The impact of the expression of ND5 fusion proteins on the growth of S. cerevisiae in the presence and absence of added salts was studied. ER-resident ND5 conferred Li+ sensitivity to S. cerevisiae, which was lost when the E145V variant of ND5 was expressed. All variants of ND5 tested led to increased resistance of S. cerevisiae at high external concentrations of Na+ or K+. The data seem to indicate that ND5 influences the salt homeostasis of S. cerevisiae independent of other complex I subunits, and paves the way for functional studies of mutations found in mitochondrially encoded complex I genes. [source] Predominant T helper type 2-inflammatory responses promote murine colon cancersINTERNATIONAL JOURNAL OF CANCER, Issue 9 2006Emi Osawa Abstract Colon cancer is one of the most serious complications of inflammatory bowel diseases, especially ulcerative colitis (UC). Previous studies have shown that characteristic immunological event during inflammation in UC is the expression of T helper-type 2 (Th2) cell-derived cytokines. In this study, we investigated the influence of a predominant Th2-type cytokine response in colitis on carcinogen-induced colon tumors. Wild type (WT), interferon gamma (IFN-,) gene deficient (,/,) [Th2 dominant] or interleukin (IL)-4,/, [Th1-dominant] mice of BALB/c background were used in this study. To compare tumor formation, mice were given the carcinogen azoxymethane (AOM) and intrarectal administration of trinitrobenzene sulfonic acid (TNBS), to induce colitis. Thirty-three weeks after initial treatment, the total colon was examined. When IFN-,,/, mice were treated with AOM and TNBS, significantly higher number of tumors were seen (8.4 ± 1.7) than in WT (3.3 ± 2.9) or IL-4,/, (3.1 ± 3.4) mice, which received identical treatments. A separate set of experiment, using less doses of AOM and TNBS also showed the higher frequency of tumor formation in IFN-,,/, mice than in IL-4,/, mice. Histologically, the tumors were well- or moderately-differentiated adenocarcinomas. No invasion into the submucosal or serosal layers of the intestine was seen. In immunohistological staining, some tumors in IFN-,,/, mice showed distinct nuclear expression of ,-catenin, in contrast to the strong membrane staining seen in tumors of IL-4,/, mice. In conclusion, colonic inflammation associated with Th2-donimant cytokine responses enhanced the formation of malignant neoplasms. © 2005 Wiley-Liss, Inc. [source] Cell cycle checkpoints and their impact on anticancer therapeutic strategiesJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 2 2004Alan Eastman Abstract Cells contain numerous pathways designed to protect them from the genomic instability or toxicity that can result when their DNA is damaged. The p53 tumor suppressor is particularly important for regulating passage through G1 phase of the cell cycle, while other checkpoint regulators are important for arrest in S and G2 phase. Tumor cells often exhibit defects in these checkpoint proteins, which can lead to hypersensitivity; proteins in this class include ataxia,telangiectasia mutatated (ATM), Meiotic recanbination 11 (Mre11), Nijmegen breakage syndrome 1 (Nbs 1), breast cancer susceptibility genes 1 and 2 (BRCA1), and (BRCA2). Consequently, tumors should be assessed for these specific defects, and specific therapy prescribed that has high probability of inducing response. Tumors defective in p53 are frequently considered resistant to apoptosis, yet this defect also provides an opportunity for targeted therapy. When their DNA is damaged, p53-defective tumor cells preferentially arrest in S or G2 phase where they are susceptible to checkpoint inhibitors such as caffeine and UCN-01. These inhibitors preferentially abrogate cell cycle arrest in p53-defective cells, driving them through a lethal mitosis. Wild type p53 can prevent abrogation of arrest by elevating levels of p21waf1 and decreasing levels of cyclins A and B. During tumorigenesis, tumor cells frequently loose checkpoint controls and this facilitates the development of the tumor. However, these defects also represent an Achilles heel that can be targeted to improve current therapeutic strategies. © 2003 Wiley-Liss, Inc. [source] Peroxiredoxin I protects gastric mucosa from oxidative injury induced by H. pylori infectionJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 4 2008Daisuke Sato Abstract Background and Aim:, Helicobacter pylori (H. pylori) infection enhances the production of reactive oxygen species and peroxynitrite, thereby resulting in oxidative tissue damage. In this study, we examined the role of peroxiredoxin I (Prx I), a stress-induced antioxidant enzyme, in protecting gastric mucosa from H. pylori -induced gastric mucosal injury. Methods:, Wild type (Prx I+/+) and Prx I-deficient type (Prx I,/,) mice were maintained for 2 to 12 months with or without infection of H. pylori, Sydney strain-1. Gastric mucosal expression of Prx I was assessed by immunoblot analysis and immunohistochemistry. The degree of gastritis was evaluated by the updated Sydney system and by mucosal levels of inflammatory cytokines (MIP-2, IL-1,, and TNF-,). Oxidative DNA injury and apoptosis were analyzed by mucosal level of 8-hydroxy-2,-deoxyguanosine, and the number of apoptotic cells stained with a single-stranded DNA antibody, respectively. Results:,H. pylori infection upregulated gastric mucosal Prx I expression in the Prx I+/+ but not the Prx I,/, mice. H. pylori infection also induced more severe gastritis and a more prominent increase in MIP level, more marked oxidative DNA injury, and apoptosis in the Prx I,/, than the Prx I+/+ mice. In the absence of H. pylori infection, no changes were demonstrated in gastric mucosa in either the Prx I+/+ or the Prx I,/, mice. Conclusion:, These data suggest that H. pylori infection upregulates gastric mucosal Prx I expression, and further, that Prx I plays an important role in gastric mucosal protection against oxidative injury induced by H. pylori infection. [source] In situ assays demonstrate that interferon-gamma suppresses infection-stimulated hepatic fibrin deposition by promoting fibrinolysisJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 7 2006I. K. MULLARKY Summary.,Background:,Inflammatory cytokines potently impact hemostatic pathways during infection, but the tissue-specific regulation of coagulation and fibrinolysis complicates studies of the underlying mechanisms. Methods and Results:,Here, we describe assays that quantitatively measuring prothrombinase (PTase), protein C-ase (PCase) and plasminogen activator (PA) activities in situ, thereby facilitating studies of tissue-specific hemostasis. Using these assays, we investigate the mechanisms regulating hepatic fibrin deposition during murine toxoplasmosis and the means by which interferon-gamma (IFN- ,) suppresses infection-stimulated fibrin deposition. We demonstrate that Toxoplasma infection upregulates hepatic PTase, PCase, and PA activity. Wild type and gene-targeted IFN- , -deficient mice exhibit similar levels of infection-stimulated PTase activity. By contrast, IFN- , -deficiency is associated with increased PCase activity and reduced PA activity during infection. Parallel analyses of hepatic gene expression reveal that IFN- , -deficiency is associated with increased expression of thrombomodulin (TM), a key component of the PCase, increased expression of thrombin-activatable fibrinolysis inhibitor (TAFI), a PC substrate, and reduced expression of urokinase PA (u-PA). Conclusions:,These findings suggest that IFN- , suppresses infection-stimulated hepatic fibrin deposition by suppressing TM-mediated activation of TAFI, thereby destabilizing fibrin deposits, and concomitantly increasing hepatic u-PA activity, thereby promoting fibrinolysis. We anticipate that further application of these in situ assays will improve our understanding of tissue-specific hemostasis, its regulation by cytokines, and its dysregulation during coagulopathy. [source] Lack of O -polysaccharide enhances biofilm formation by Bradyrhizobium japonicumLETTERS IN APPLIED MICROBIOLOGY, Issue 5 2010Y.-W. Lee Abstract Aims:, To reveal the effects of the O -polysaccharide antigen of Bradyrhizobium japonicum LPS on biofilm formation and motility. Methods and Results:, Wild type and O-antigen-deficient mutant strains of B. japonicum were tested for biofilm formation on polyvinyl chloride (PVC) surfaces and motility on semi-solid (0·3%) agar media. After 7 days of incubation, the amount of biofilms formed by the mutant was c. 3·5-fold greater than that of the wild type. Unlike biofilm formation, the motility assay revealed that the mutant strain was less motile than the wild type. Conclusions:, This study shows enhanced biofilm formation and decreased motility by the O-antigen-deficient mutant, suggesting that the lack of the O -polysaccharide of the rhizobial LPS is associated with biofilm-forming ability and movement. Significance and Impact of the Study:, LPS plays an important role in both pathogenic and beneficial bacteria. It has also been reported that LPS deficiency negatively affects biofilm formation. However, our results demonstrate that the O-antigen-deficient mutant enhances biofilm formation, presumably through a significant increase in hydrophobicity. It is notable that the hydrophobicity of cell walls might be a key regulator in controlling biofilm development in B. japonicum. [source] A Study of the Interaction between Auxin and Ethylene in Wild Type and Transgenic Ethylene-Insensitive Tobacco during Adventitious Root Formation Induced by Stagnant Root Zone ConditionsPLANT BIOLOGY, Issue 5 2003M. P. McDonald Abstract: Wild type (Wt) and transgenic plants (etr1-1 gene from Arabidopsis thaliana; encoding for a defective ethylene receptor; Tetr) of Nicotiana tabacum L. were subjected to experiments to resolve the role of the interaction between ethylene and auxin in waterlogging-induced adventitious root formation. Plants were grown in aerated or stagnant deoxygenated nutrient solution and treated with the following plant growth regulators: ethylene, the synthetic auxins 2,4-dichlorophenoxyacetic acid (2,4-D) and 1-naphthaleneacetic acid (1-NAA), and the auxin efflux inhibitor naphthylphthalamic acid (NPA). The superior growth of Wt in stagnant solution suggests that the ability to sense and respond to ethylene partially mediates tolerance to stagnant root zone conditions. Wt produced around 2 - 2.5-fold more adventitious roots than Tetr in aerated and stagnant solution. Treatment with NPA phenocopied the effects of ethylene insensitivity by reducing the number of adventitious roots on Wt to Tetr levels. Additionally, application of 1-NAA to the shoot of Tetr increased the number of adventitious roots on Tetr to similar levels as the untreated Wt. However, this level was only around half the number achieved by 1-NAA-treated Wt. The results suggest an interplay between ethylene and auxin in the process of adventitious root formation in waterlogged tobacco, most likely on the level of polar auxin transport. However, a separate non-auxin-related role as a transcription regulator for genes essential to adventitious root formation cannot be excluded. [source] Hemochromatosis genotypes and risk of 31 disease endpoints: Meta-analyses including 66,000 cases and 226,000 controls,HEPATOLOGY, Issue 4 2007Christina Ellervik Hemochromatosis genotypes have been associated with liver disease, diabetes mellitus, heart disease, arthritis, porphyria cutanea tarda, stroke, neurodegenerative disorders, cancer, and venous disease. We performed meta-analyses including 202 studies with 66,263 cases and 226,515 controls to examine associations between hemochromatosis genotypes C282Y/C282Y, C282Y/H63D, C282Y/wild type, H63D/H63D, and H63D/wild type versus wild type/wild type and 9 overall endpoints and 22 endpoint subgroups. We also explored potential sources of heterogeneity. For liver disease, the odds ratio for C282Y/C282Y versus wild type/wild type was 3.9 (99% confidence interval: 1.9,8.1) overall, 11 (3.7,34) for hepatocellular carcinoma, 4.1 (1.2,14) for hepatitis C, and 10 (2.1,53) for nonalcoholic steatohepatitis. For porphyria cutanea tarda, the odds ratios were 48 (24,95) for C282Y/C282Y, 8.1 (3.9,17) for C282Y/H63D, 3.6 (1.8,7.3) for C282Y/wild type, 3.0 (1.6,5.6) for H63D/H63D, and 1.7 (1.0,3.1) for H63D/wild type versus wild type/wild type. Finally, for amyotrophic lateral sclerosis, the odds ratio was 3.9 (1.2,13) for H63D/H63D versus wild type/wild type. These findings were consistent across individual studies. The hemochromatosis genotypes were not associated with risk for diabetes mellitus, heart disease, arthritis, stroke, cancer, or venous disease in the overall analyses; however, the odds ratio for C282Y/C282Y versus wild type/wild type was 3.4 (1.1,11) for diabetes mellitus among North Europeans. Conclusion: In aggregate, clinically ascertained cases who are homozygous for the C282Y mutation are associated with a 4,11,fold risk of liver disease, whereas all 5 hemochromatosis genotypes are associated with a 2,48,fold risk of porphyria cutanea tarda, and H63D/H63D is associated with a 4-fold risk of amyotrophic lateral sclerosis. These results, mainly from case-control studies, cannot necessarily be extrapolated to the general population. (HEPATOLOGY 2007.) [source] Polymorphisms in the interleukin-1 gene influence the stratum corneum interleukin-1, concentration in uninvolved skin of patients with chronic irritant contact dermatitisCONTACT DERMATITIS, Issue 5 2008Cindy M. DeJongh Background:, Interleukin (IL)-1, and its receptor antagonist IL-1ra play a role in skin inflammation. Several polymorphisms in the IL1 gene cluster, coding for IL-1,, IL-1ra, and IL-1,, influence their protein expression. Within this cluster, strong linkage disequilibrium has been shown. Objective:, We studied the association between the polymorphisms IL1A -889 (C,T) and IL1B -31 (T,C) and the concentration of IL-1, and IL-1ra in the stratum corneum (SC). Method:, In 124 patients with chronic irritant contact dermatitis, we genotyped the IL1A -889 and IL1B -31 polymorphisms and determined the amount of IL-1, and IL-1ra on tape strips obtained from uninvolved skin of the volar forearm. Results:, The SC IL-1, concentration was 23% and 47% lower in subjects with IL1A -889 C/T genotype and T/T genotype, respectively, compared with wild-type genotype. In subjects with IL1B -31 C/C genotype, the IL-1, concentration was 51% lower compared with C/T and T/T genotypes. The ratio IL-1ra/IL-1, increased twofold in IL1A -889 C/T genotype and threefold in T/T genotype compared with wild type. Conclusions:, We have shown a clear effect of IL1 genotype on protein expression in the SC. This altered expression may be responsible for the interindividual differences in the inflammatory response of the skin. [source] Kinesin-5 is not essential for mitotic spindle elongation in DictyosteliumCYTOSKELETON, Issue 11 2008Irina Tikhonenko Abstract The proper assembly and operation of the mitotic spindle is essential to ensure the accurate segregation of chromosomes and to position the cytokinetic furrow during cell division in eukaryotes. Not only are dynamic microtubules required but also the concerted actions of multiple motor proteins are necessary to effect spindle pole separation, chromosome alignment, chromatid segregation, and spindle elongation. Although a number of motor proteins are known to play a role in mitosis, there remains a limited understanding of their full range of functions and the details by which they interact with other spindle components. The kinesin-5 (BimC/Eg5) family of motors is largely considered essential to drive spindle pole separation during the initial and latter stages of mitosis. We have deleted the gene encoding the kinesin-5 member in Dictyostelium, (kif13), and find that, in sharp contrast with results found in vertebrate, fly, and yeast organisms, kif13, cells continue to grow at rates indistinguishable from wild type. Phenotype analysis reveals a slight increase in spindle elongation rates in the absence of Kif13. More importantly, there is a dramatic, premature separation of spindle halves in kif13, cells, suggesting a novel role of this motor in maintaining spindle integrity at the terminal stages of division. Cell Motil. Cytoskeleton 2008. © 2008 Wiley-Liss, Inc. [source] Analysis of force generation during flagellar assembly through optical trapping of free-swimming Chlamydomonas reinhardtiiCYTOSKELETON, Issue 3 2005Rachel Patton McCord Abstract Many studies have used velocity measurements, waveform analyses, and theoretical flagella models to investigate the establishment, maintenance, and function of flagella of the biflagellate green algae Chlamydomonas reinhardtii. We report the first direct measurement of Chlamydomonas flagellar swimming force. Using an optical trap ("optical tweezers") we detect a 75% decrease in swimming force between wild type (CC124) cells and mutants lacking outer flagellar dynein arms (oda1). This difference is consistent with previous estimates and validates the force measurement approach. To examine mechanisms underlying flagella organization and function, we deflagellated cells and examined force generation during flagellar regeneration. As expected, fully regenerated flagella are functionally equivalent to flagella of untreated wild type cells. However, analysis of swimming force vs. flagella length and the increase in force over regeneration time reveals intriguing patterns where increases in force do not always correspond with increases in length. These investigations of flagellar force, therefore, contribute to the understanding of Chlamydomonas motility, describe phenomena surrounding flagella regeneration, and demonstrate the advantages of the optical trapping technique in studies of cell motility. Cell Motil. Cytoskeleton 61:137,144, 2005. © 2005 Wiley-Liss, Inc. [source] High speed sliding of axonemal microtubules produced by outer arm dyneinCYTOSKELETON, Issue 2 2005Raviraja N. Seetharam Abstract To study dynein arm activity at high temporal resolution, axonemal sliding was measured field by field for wild type and dynein arm mutants of Tetrahymena thermophila. For wt SB255 cells, when the rate of data acquisition was 60 fps, about 5× greater than previously published observations, sliding was observed to be discontinuous with very high velocity sliding (average 196 ,m/sec) for a few msec (1 or 2 fields) followed by a pause of several fields. The sliding velocities measured were an order of magnitude greater than rates previously measured by video analysis. However, when the data were analyzed at 12 fps for the same axonemes, consistent with previous observations, sliding was linear as the axonemes extended several times their original length with an average velocity of ,10 ,m/sec. The pauses or stops occurred at approximately 200 and 300% of the initial length, suggesting that dynein arms on one axonemal doublet were initially active to the limit of extension, and then the arms on the next doublet became activated. In contrast, in a mutant where OADs are missing, sliding observed at 60 fps was continuous and slow (5 ,m/sec), as opposed to the discontinuous high-velocity sliding of SB255 and of the mutant at the permissive temperature where OADs are present. High-velocity step-wise sliding was also present in axonemes from an inner arm dynein mutant (KO6). These results indicate that the high-speed discontinuous pattern of sliding is produced by the mechanochemical activity of outer arm dynein. The rate of sliding is consistent with a low duty ratio of the outer arm dynein and with the operation of each arm along a doublet once per beat. Cell Motil. Cytoskeleton 60:96,103, 2005. © 2004 Wiley-Liss, Inc. [source] Morphological irregularities and features of resistance to apoptosis in the dcp-1/pita double mutated egg chambers during Drosophila oogenesisCYTOSKELETON, Issue 1 2005Ioannis P. Nezis Abstract In the present study, we demonstrate the most novel characteristic morphological features of Drosophila egg chambers lacking both dcp-1 and pita functions in the germline cells. Dcp-1 is an effector caspase and it has been previously shown to play an important role during Drosophila oogenesis [McCall and Steller, 1998 : Science 279 : 230,234; Laundrie et al., 2003 : Genetics 165 : 1881,1888; Peterson et al., 2003 : Dev Biol 260 : 113,123]. The completion of sequencing and annotation of the Drosophila genome has revealed that the dcp-1 gene is nested within an intron of another distinct gene, called pita, a member of the C2H2 zinc finger protein family that regulates transcriptional initiation. The dcp-1,/,/pita,/, nurse cells exhibit euchromatic nuclei (delay of apoptosis) during the late stages of oogenesis, as revealed by conventional light and electron microscopy. The phalloidin-FITC staining discloses significant defects in actin cytoskeleton arrangement. The actin bundles fail to organize properly and the distribution of actin filaments in the ring canals is changed compared to the wild type. The oocyte and the chorion structures have been also modified. The oocyte nucleus is out of position and the chorion appears to contain irregular foldings, while the respiratory filaments obtain an altered morphology. The dcp-1,/,/pita,/, egg chambers do not exhibit the rare events of spontaneously induced apoptosis, observed for the wild type flies, during mid-oogenesis. Interestingly, the mutated egg chambers are protected by staurosporine-induced apoptosis in a percentage of 40%, strongly suggesting the essential role of dcp-1 and/or pita during mid-oogenesis. Cell Motil. Cytoskeleton 60:14,23, 2005. © 2004 Wiley-Liss, Inc. [source] Absence of tissue inhibitor of metalloproteinases 3 disrupts alveologenesis in the mouseDEVELOPMENT GROWTH & DIFFERENTIATION, Issue 1 2009Sean E. Gill Tissue inhibitors of metalloproteinases (TIMPs) regulate extracellular matrix (ECM) degradation by matrix metalloproteinases (MMPs) throughout lung development. We examined lungs from TIMP3 null mice and found significant air space enlargement compared with wild type (WT) animals during a time course spanning early alveologenesis (post-partum days 1, 5, 9 and 14). Trichrome staining revealed a similar pattern of collagen distribution in the walls of nascent alveoli; however, the alveolar walls of TIMP3 mutant mice appeared to be thinner than controls. Assessment of MMP2 and MMP9 activities by gelatin zymography demonstrated a significant elevation in the active form of MMP2 at post-partum days 1 and 5. Treatment of null pregnant dams with a broad spectrum synthetic metalloproteinase inhibitor, GM6001, on embryonic day 16.5 enhanced the formation of primitive alveoli during the saccular stage of lung development as evidenced by a partial, but significant, rescue of alveolar size in post-partum day 1 animals. We propose that increased MMP activity in the absence of TIMP3 enhances ECM proteolysis, upsetting proper formation of primitive alveolar septa during the saccular stage of alveologenesis. Therefore, TIMP3 indirectly regulates alveolar formation in the mouse. To our knowledge, ours is the first study to demonstrate that in utero manipulation of the TIMP/MMP proteolytic axis, to specifically inhibit proteolysis, significantly affects lung development. [source] Analysis of Sir2E in the cellular slime mold Dictyostelium discoideum: Cellular localization, spatial expression and overexpressionDEVELOPMENT GROWTH & DIFFERENTIATION, Issue 8 2008Takahiro Katayama It has been reported that Dictyostelium discoideum encodes four silent information regulator 2 (Sir2) proteins (Sir2A,D) showing sequence similarity to human homologues of Sir2 (SIRT1,3). Further screening in a database revealed that D. discoideum encodes an additional Sir2 homologue (Sir2E). The amino acid sequence of Sir2E is not similar to those of SIRTs but is similar to those of proteins encoded by Giardia lamblia, Cryptosporidium hominis and Cryptosporidium parvum. Fluorescence of Sir2E-green fluorescent protein fusion protein was detected in the D. discoideum nucleus, indicating that Sir2E is a nuclear localizing protein. Reverse transcription,polymerase chain reaction and whole-mount in situ hybridization analyses showed that D. discoideum expressed sir2E in amoebae in the growth phase and in prestalk cells in the developmental phase. D. discoideum overexpressing sir2E grew faster than the wild type. These results indicate that Sir2E plays important roles both in the growth phase and developmental phase of D. discoideum. [source] Reelin is essential for neuronal migration but not for radial glial elongation in neonatal ferret cortex,DEVELOPMENTAL NEUROBIOLOGY, Issue 5 2008Alisa Schaefer Abstract Numerous functions related to neuronal migration are linked to the glycoprotein reelin. Reelin also elongates radial glia, which are disrupted in mutant reeler mice. Our lab developed a model of cortical dysplasia in ferrets that shares features with the reeler mouse, including impaired migration of neurons into the cerebral cortex and disrupted radial glia. Explants of normal ferret cortex in coculture with dysplastic ferret cortex restore the deficits in this model. To determine if reelin is integral to the repair, we used explants of P0 mouse cortex either of the wild type (WT) or heterozygous (het) for the reelin gene, as well as P0 reeler cortex (not containing reelin), in coculture with organotypic cultures of dysplastic ferret cortex. This arrangement revealed that all types of mouse cortical explants (WT, het, reeler) elongated radial glia in ferret cortical dysplasia, indicating that reelin is not required for proper radial glial morphology. Migration of cells into ferret neocortex, however, did not improve with explants of reeler cortex, but was almost normal after pairing with WT or het explants. We also placed an exogenous source of reelin in ferret cultures at the pial surface to reveal that migrating cells move toward the reelin source in dysplastic cortex; radial glia in these cultures were also improved toward normal. Our results demonstrate that the normotopic position of reelin is important for proper neuronal positioning, and that reelin is capable of elongating radial glial cells but is not the only radialization factor. © 2008 Wiley Periodicals, Inc. Develop Neurobiol, 2008. [source] Oxidative stress, nitric oxide, and the mechanisms of cell death in Lurcher Purkinje cellsDEVELOPMENTAL NEUROBIOLOGY, Issue 8 2007Rebecca McFarland Abstract Oxidative stress is postulated to play a role in cell death in many neurodegenerative diseases. As a model of neonatal neuronal cell death, we have examined the role of oxidative stress in Purkinje cell death in the heterozygous Lurcher mutant (+/Lc). Lurcher is a gain of function mutation in the ,2 glutamate receptor (GluR,2) that turns the receptor into a leaky membrane channel, resulting in chronic depolarization of +/Lc Purkinje cells starting around the first week of postnatal development. Virtually, all +/Lc Purkinje cells die by the end of the first postnatal month. To investigate the role of oxidative stress in +/Lc Purkinje cell death, we have examined nitric oxide synthase (NOS) activity and the expression of two markers for oxidative stress, nitrotyrosine and manganese super oxide dismutase (MnSOD), in wild type and +/Lc Purkinje cells at P10, P15, and P25. The results show that NOS activity and immunolabeling for nitrotyrosine and MnSOD are increased in +/Lc Purkinje cells. To determine whether peroxynitrite formation is a prerequisite for +/Lc Purkinje cell death, +/Lc mutants were crossed with an ,-nNOS knockout mutant (nNOS,,/,) to reduce the production of NO. Analysis of the double mutants showed that blocking ,-nNOS expression does not rescue +/Lc Purkinje cells. However, we present evidence for sustained NOS activity and nitrotyrosine formation in the GluR,2+/Lc:nNOS,/, double mutant Purkinje cells, which suggests that the failure to rescue GluR,2+/Lc:nNOS,/, Purkinje cells may be explained by the induction of alternative nNOS isoforms. © 2007 Wiley Periodicals, Inc. Develop Neurobiol, 2007. [source] Sex differences in progesterone receptor immunoreactivity in neonatal mouse brain depend on estrogen receptor , expressionDEVELOPMENTAL NEUROBIOLOGY, Issue 3 2001Christine K. Wagner Abstract Around the time of birth, male rats express higher levels of progesterone receptors in the medial preoptic nucleus (MPN) than female rats, suggesting that the MPN may be differentially sensitive to maternal hormones in developing males and females. Preliminary evidence suggests that this sex difference depends on the activation of estrogen receptors around birth. To test whether estrogen receptor alpha (ER,) is involved, we compared progesterone receptor immunoreactivity (PRir) in the brains of male and female neonatal mice that lacked a functional ER, gene or were wild type for the disrupted gene. We demonstrate that males express much higher levels of PRir in the MPN and the ventromedial nucleus of the neonatal mouse brain than females, and that PRir expression is dependent on the expression of ER, in these regions. In contrast, PRir levels in neocortex are not altered by ER, gene disruption. The results of this study suggest that the induction of PR via ER, may render specific regions of the developing male brain more sensitive to progesterone than the developing female brain, and may thereby underlie sexual differentiation of these regions. © 2001 John Wiley & Sons, Inc. J Neurobiol 47: 176,182, 2001 [source] The prevalence of the mitochondrial DNA 16189 variant in non-diabetic Korean adults and its association with higher fasting glucose and body mass indexDIABETIC MEDICINE, Issue 8 2002J. H. Kim Abstract Aims To evaluate the prevalence of the 16189 variant of mitochondrial DNA in Korean adults and its association with insulin resistance. Methods We investigated 160 non-diabetic subjects from a community-based diabetes survey conducted in Yonchon County, Korea in 1993. We extracted the DNA from peripheral blood and examined the 16189 variant by polymerase chain reaction and restrictive enzyme digestion. We compared body mass index (BMI), blood pressure, fasting plasma glucose, 2-h plasma glucose after 75 g glucose load, fasting insulin, cholesterol, and homeostasis model assessment of insulin resistance and ,-cell function between the subjects with 16189 variant and wild type. Results The prevalence of the 16189 variant in Korean adults was 28.8% (46 of 160). Subjects with the 16189 variant had higher fasting glucose and BMI than those with wild type, but fasting insulin, homeostasis model assessment of insulin resistance and ,-cell function, cholesterol, and blood pressure were not different between two groups. Conclusion Our results provide evidence for an association of a frequent mitochondrial polymorphism with higher fasting glucose and the risk factors of diabetes mellitus. [source] Targeting the p53 tumor suppressor gene function in glioblastomas using small chemical moleculesDRUG DEVELOPMENT RESEARCH, Issue 10 2006Roberta Magrini Abstract Glioblastoma multiforme (GBM) is recognized as the most frequent and malignant glioma of which two genetically different subtypes can be distinguished. Primary, de novo glioblastomas show a p53 wild type (wt) status and in 10% of the cases hdm2 overexpression/amplifications occur. In these tumors, the inactivation of the tumor suppressor p53 is elicited by enhanced hdm2-mediated degradation of p53. Secondary glioblastomas, on the other hand, show inactivating p53 mutations (mut) in 40% of the cases. Based on these observations, reactivating the function of p53 might hold promise for treatment of GBM. In wt p53 tumors showing increased hdm2 levels, the therapeutic strategy might be to inhibit the activity of hdm2 by treatment with small molecules like nutlin-3. For mut p53 glioblastomas, p53 function might be restored using small chemical entities such as PRIMA-1. Drug Dev. Res. 67:790,800, 2006. © 2007 Wiley-Liss, Inc. [source] Amperometric Biosensors for Detection of Sugars Based on the Electrical Wiring of Different Pyranose Oxidases and Pyranose Dehydrogenases with Osmium Redox Polymer on Graphite ElectrodesELECTROANALYSIS, Issue 2-3 2007Federico Tasca Abstract Electrical wiring of different types of pyranose oxidase (P2O) (fungal wild type, recombinant wild type with a hexa-histidine tag, mutant form E542K with a hexa-histidine tag) from Trametes multicolor, and recombinant P2O from Coriolus sp. overexpressed in Escherichia coli as well as of pyranose dehydrogenase (PDH) from Agaricus meleagris and Agaricus xanthoderma with an osmium redox polymer (poly(1-vinylimidazole)12 -[Os(4,4,-dimethyl-2,2,-dipyridyl)2Cl2]2+/+) on graphite electrodes was carried out. After optimization studies using glucose as substrate, the biosensors, which showed the best characteristics in terms of linear range, detection limit and sensitivity were selected, viz. wild type P2O from T. multicolor and PDH from A. meleagris. These two enzymes were used and investigated for their selectivity for a number of different sugars. [source] DNA adduct kinetics in reproductive tissues of DNA repair proficient and deficient male mice after oral exposure to benzo(a)pyreneENVIRONMENTAL AND MOLECULAR MUTAGENESIS, Issue 2 2010Nicole Verhofstad Abstract Benzo(a)pyrene (B[a]P) can induce somatic mutations, whereas its potential to induce germ cell mutations is unclear. There is circumstantial evidence that paternal exposure to B[a]P can result in germ cell mutations. Since DNA adducts are thought to be a prerequisite for B[a]P induced mutations, we studied DNA adduct kinetics by 32P-postlabeling in sperm, testes and lung tissues of male mice after a single exposure to B[a]P (13 mg/kg bw, by gavage). To investigate DNA adduct formation at different stages of spermatogenesis, mice were sacrificed at Day 1, 4, 7, 10, 14, 21, 32, and 42 after exposure. In addition, DNA repair deficient (Xpc,/,) mice were used to study the contribution of nucleotide excision repair in DNA damage removal. DNA adducts were detectable with highest levels in lung followed by sperm and testis. Maximum adduct levels in the lung and testis were observed at Day 1 after exposure, while adduct levels in sperm reached maximum levels at ,1 week after exposure. Lung tissue and testis of Xpc,/, mice contained significantly higher DNA adduct levels compared to wild type (Wt) mice over the entire 42 day observation period (P < 0.05). Differences in adduct half-life between Xpc,/, and Wt mice were only observed in testis. In sperm, DNA adduct levels were significantly higher in Xpc,/, mice than in Wt mice only at Day 42 after exposure (P = 0.01). These results indicate that spermatogonia and testes are susceptible for the induction of DNA damage and rely on nucleotide excision repair for maintaining their genetic integrity. Environ. Mol. Mutagen. 2010. © 2009 Wiley-Liss, Inc. [source] The exopolysaccharide of Rhizobium sp.ENVIRONMENTAL MICROBIOLOGY, Issue 8 2008Brassica napus roots but contributes to root colonization, YAS34 is not necessary for biofilm formation on Arabidopsis thaliana Summary Microbial exopolysaccharides (EPSs) play key roles in plant,microbe interactions, such as biofilm formation on plant roots and legume nodulation by rhizobia. Here, we focused on the function of an EPS produced by Rhizobium sp. YAS34 in the colonization and biofilm formation on non-legume plant roots (Arabidopsis thaliana and Brassica napus). Using random transposon mutagenesis, we isolated an EPS-deficient mutant of strain YAS34 impaired in a glycosyltransferase gene (gta). Wild type and mutant strains were tagged with a plasmid-born GFP and, for the first time, the EPS produced by the wild-type strain was seen in the rhizosphere using selective carbohydrate probing with a fluorescent lectin and confocal laser-scanning microscopy. We show for the fist time that Rhizobium forms biofilms on roots of non-legumes, independently of the EPS synthesis. When produced by strain YAS34 wild type, EPS is targeted at specific parts of the plant root system. Nutrient fluctuations, root exudates and bacterial growth phase can account for such a production pattern. The EPS synthesis in Rhizobium sp. YAS34 is not essential for biofilm formation on roots, but is critical to colonization of the basal part of the root system and increasing the stability of root-adhering soil. Thus, in Rhizobium sp. YAS34 and non-legume interactions, microbial EPS is implicated in root,soil interface, root colonization, but not in biofilm formation. [source] d -Alanyl ester depletion of teichoic acids in Lactobacillus reuteri 100-23 results in impaired colonization of the mouse gastrointestinal tractENVIRONMENTAL MICROBIOLOGY, Issue 7 2007Jens Walter Summary The dlt operon of Gram-positive bacteria encodes proteins required for the incorporation of d -alanine esters into cell wall-associated teichoic acids (TA). d -Alanylation of TA has been shown to be important for acid tolerance, resistance to antimicrobial peptides, adhesion, biofilm formation, and virulence of a variety of pathogenic organisms. The aim of this study was to determine the importance of d -alanylation for colonization of the gastrointestinal tract by Lactobacillus reuteri 100-23. Insertional inactivation of the dltA gene resulted in complete depletion of d -alanine substitution of lipoteichoic acids. The dlt mutant had similar growth characteristics as the wild type under standard in vitro conditions, but formed lower population sizes in the gastrointestinal tract of ex- Lactobacillus -free mice, and was almost eliminated from the habitat in competition experiments with the parental strain. In contrast to the wild type, the dlt mutant was unable to form a biofilm on the forestomach epithelium during gut colonization. Transmission electron microscope observations showed evidence of cell wall damage of mutant bacteria present in the forestomach. The dlt mutant had impaired growth under acidic culture conditions and increased susceptibility to the cationic peptide nisin relative to the wild type. Ex vivo adherence of the dlt mutant to the forestomach epithelium was not impaired. This study showed that d -alanylation is an important cell function of L. reuteri that seems to protect this commensal organism against the hostile conditions prevailing in the murine forestomach. [source] | |||||||||||||||||||||||||||||||||||||