109 research outputs found
Regulation of Human Formyl Peptide Receptor 1 Synthesis: Role of Single Nucleotide Polymorphisms, Transcription Factors, and Inflammatory Mediators
The gene encoding the human formyl peptide receptor 1 (FPR1) is heterogeneous, containing numerous single nucleotide polymorphisms (SNPs). Here, we examine the effect of these SNPs on gene transcription and protein translation. We also identify gene promoter sequences and putative FPR1 transcription factors. To test the effect of codon bias and codon pair bias on FPR1 expression, four FPR1 genetic variants were expressed in human myeloid U937 cells fused to a reporter gene encoding firefly luciferase. No significant differences in luciferase activity were detected, suggesting that the translational regulation and protein stability of FPR1 are modulated by factors other than the SNP codon bias and the variant amino acid properties. Deletion and mutagenesis analysis of the FPR1 promoter showed that a CCAAT box is not required for gene transcription. A −88/41 promoter construct resulted in the strongest transcriptional activity, whereas a −72/41 construct showed large reduction in activity. The region between −88 and −72 contains a consensus binding site for the transcription factor PU.1. Mutagenesis of this site caused significant reduction in reporter gene expression. The PU.1 binding was confirmed in vivo by chromatin immunoprecipitation, and the binding to nucleotides −84 to −76 (TTCCTATTT) was confirmed in vitro by an electrophoretic mobility shift assay. Thus, similar to many other myeloid genes, FPR1 promoter activity requires PU.1. Two single nucleotide polymorphisms at −56 and −54 did not significantly affect FPR1 gene expression, despite differences in binding of transcription factor IRF1 in vitro. Inflammatory mediators such as interferon-γ, tumor necrosis factor-α, and lipopolysaccharide did not increase FPR1 promoter activity in myeloid cells, whereas differentiation induced by DMSO and retinoic acid enhanced the activity. This implies that the expression of FPR1 in myeloid cells is developmentally regulated, and that the differentiated cells are equipped for immediate response to microbial infections
Sp1-regulated expression of p11 contributes to motor neuron degeneration by membrane insertion of TASK1
Disruption in membrane excitability contributes to malfunction and differential vulnerability
of specific neuronal subpopulations in a number of neurological diseases. The adaptor protein
p11, and background potassium channel TASK1, have overlapping distributions in the CNS.
Here, we report that the transcription factor Sp1 controls p11 expression, which impacts on
excitability by hampering functional expression of TASK1. In the SOD1-G93A mouse model of
ALS, Sp1-p11-TASK1 dysregulation contributes to increased excitability and vulnerability of
motor neurons. Interference with either Sp1 or p11 is neuroprotective, delaying neuron loss
and prolonging lifespan in this model. Nitrosative stress, a potential factor in human neurodegeneration,
stimulated Sp1 expression and human p11 promoter activity, at least in part,
through a Sp1-binding site. Disruption of Sp1 or p11 also has neuroprotective effects in a
traumatic model of motor neuron degeneration. Together our work suggests the Sp1-p11-
TASK1 pathway is a potential target for treatment of degeneration of motor neurons
Multilocus Genotyping of Human Giardia Isolates Suggests Limited Zoonotic Transmission and Association between Assemblage B and Flatulence in Children
Giardia intestinalis is a protozoan parasite found world-wide and it is a major cause of diarrhea in humans and other mammals. The genetic variability within G. intestinalis is high with eight distinct genotypes or assemblages (A-H). Here we performed sequence-based multilocus genotyping of around 200 human Giardia isolates. We found evidence of limited zoonotic transmission of certain A subtypes and an association between flatulence and assemblage B infection in children. This shows that it is important to investigate different assemblages and sub-assemblages of G. intestinalis in human infections in order to understand the clinical significance, zoonotic potential, sequence divergence, and transmission pathways of this parasite
Severity of Giardia infection associated with post-infectious fatigue and abdominal symptoms two years after
<p>Abstract</p> <p>Background</p> <p>A high rate of post-infectious fatigue and abdominal symptoms two years after a waterborne outbreak of giardiasis in Bergen, Norway in 2004 has previously been reported. The aim of this report was to identify risk factors associated with such manifestations.</p> <p>Methods</p> <p>All laboratory confirmed cases of giardiasis (n = 1262) during the outbreak in Bergen in 2004 received a postal questionnaire two years after. Degree of post-infectious abdominal symptoms and fatigue, as well as previous abdominal problems, was recorded. In the statistical analyses number of treatment courses, treatment refractory infection, delayed education and sick leave were used as indices of protracted and severe <it>Giardia </it>infection. Age, gender, previous abdominal problems and symptoms during infection were also analysed as possible risk factors. Simple and multiple ordinal logistic regression models were used for the analyses.</p> <p>Results</p> <p>The response rate was 81% (1017/1262), 64% were women and median age was 31 years (range 3-93), compared to 61% women and 30 years (range 2-93) among all 1262 cases. Factors in multiple regression analysis significantly associated with abdominal symptoms two years after infection were: More than one treatment course, treatment refractory infection, delayed education, bloating and female gender. Abdominal problems prior to <it>Giardia </it>infection were not associated with post-infectious abdominal symptoms. More than one treatment course, delayed education, sick leave more than 2 weeks, and malaise at the time of infection, were significantly associated with fatigue in the multiple regression analysis, as were increasing age and previous abdominal problems.</p> <p>Conclusion</p> <p>Protracted and severe <it>giardiasis </it>seemed to be a risk factor for post-infectious fatigue and abdominal symptoms two years after clearing the <it>Giardia </it>infection.</p
Surfing the spectrum - what is on the horizon?
Diagnostic imaging techniques have evolved with technological advancements - but how far? The objective of this article was to explore the electromagnetic spectrum to find imaging techniques which may deliver diagnostic information of equal, or improved, standing to conventional radiographs and to explore any developments within radiography which may yield improved diagnostic data. A comprehensive literature search was performed using Medline, Web of Knowledge, Science Direct and PubMed Databases. Boolean Operators were used and key-terms included (not exclusively): terahertz, X-ray, ultraviolet, visible, infra-red, magnetic resonance, dental, diagnostic, caries and periodontal. Radiographic techniques are primarily used for diagnostic imaging in dentistry, and continued developments in X-ray imaging include: phase contrast, darkfield and spectral imaging. Other modalities have potential application, for example, terahertz, laser doppler and optical techniques, but require further development. In particular, infra-red imaging has regenerated interest with caries detection in vitro, due to improved quality and accessibility of cameras. Non-ionising imaging techniques, for example, infra-red, are becoming more commensurate with traditional radiographic techniques for caries detection. Nevertheless, X-rays continue to be the leading diagnostic image for dentists, with improved diagnostic potential for lower radiation dose becoming a reality
Two outer membrane lipoproteins from Histophilus somni are immunogenic in rabbits and sheep and induce protection against bacterial challenge in mice
Histophilus somni is an economically important pathogen of cattle and other ruminants and is considered one of the key components of the bovine respiratory disease (BRD) complex, the leading cause of economic loss in the livestock industry. BRD is a multifactorial syndrome, in which a triad of agents, including bacteria, viruses, and predisposing factors or "stressors," combines to induce disease. Although vaccines against H. somni have been used for many decades, traditional bacterins have failed to demonstrate effective protection in vaccinated animals. Hence, the BRD complex continues to produce strong adverse effects on the health and well-being of stock and feeder cattle. The generation of recombinant proteins may facilitate the development of more effective vaccines against H. somni, which could confer better protection against BRD. In the present study, primers were designed to amplify, clone, express, and purify two recombinant lipoproteins from H. somni, p31 (Plp4) and p40 (LppB), which are structural proteins of the outer bacterial membrane. The results presented here demonstrate, to our knowledge for the first time, that when formulated, an experimental vaccine enriched with these two recombinant lipoproteins generates high antibody titers in rabbits and sheep and exerts a protective effect in mice against septicemia induced by H. somni bacterial challenge. Copyright © 2012, American Society for Microbiology. All Rights Reserved
Tumor necrosis factor ?-308 and -238 polymorphisms in rheumatoid arthritis. Association with messenger RNA expression and sTNF-?
Histophilus somni is an economically important pathogen of cattle and other ruminants and is considered one of the key components of the bovine respiratory disease (BRD) complex, the leading cause of economic loss in the livestock industry. BRD is a multifactorial syndrome, in which a triad of agents, including bacteria, viruses, and predisposing factors or "stressors," combines to induce disease. Although vaccines against H. somni have been used for many decades, traditional bacterins have failed to demonstrate effective protection in vaccinated animals. Hence, the BRD complex continues to produce strong adverse effects on the health and well-being of stock and feeder cattle. The generation of recombinant proteins may facilitate the development of more effective vaccines against H. somni, which could confer better protection against BRD. In the present study, primers were designed to amplify, clone, express, and purify two recombinant lipoproteins from H. somni, p31 (Plp4) and p40 (LppB), which are structural proteins of the outer bacterial membrane. The results presented here demonstrate, to our knowledge for the first time, that when formulated, an experimental vaccine enriched with these two recombinant lipoproteins generates high antibody titers in rabbits and sheep and exerts a protective effect in mice against septicemia induced by H. somni bacterial challenge. Copyright " 2012, American Society for Microbiology. All Rights Reserved.",,,,,,"10.1128/CVI.00451-12",,,"http://hdl.handle.net/20.500.12104/45516","http://www.scopus.com/inward/record.url?eid=2-s2.0-84868245648&partnerID=40&md5=f6b1e1b0296c9ddddd09094747254a4
Regiospecific synthesis of mono-N-substituted indolopyrrolocarbazoles
Two complementary and efficient strategies have been developed for the regiospecific synthesis of unsymmetrical indolopyrrolocarbazoles (IPCs) mono-N-substituted with a pentacycle. A halogen in position 2 of the intermediate bisindolylmaleimides 3a 12e allows a selective Mitsunobu coupling by exploiting the increased acidity of the 2-chloro-substituted indole nitrogen. It also promotes an easier cyclization of bisindolylmaleimides 4a 12e and 7b 12e to IPCs. Alkylation of the 2-unsubstituted indole-3-carboxamides 2a,b and further processing to the corresponding IPCs gives access to the opposite regioisomers
Towards establishing MS prevalence in Latin America and the Caribbean
The Drosophila melanogaster gene diskette (also known as dik or dAda3) encodes a protein 29% identical to human ADA3, a subunit of GCN5-containing histone acetyltransferase (HAT) complexes. The fly dADA3 is a major contributor to oogenesis, and it is also required for somatic cell viability, dADA3 localizes to chromosomes, and it is significantly reduced in dGcn5 and dAda2a, but not in dAda2b, mutant backgrounds. In dAda3 mutants, acetylation at histone H3 K9 and K14, but not K18, and at histone H4 K12, but not K5, K8, and K16, is significantly reduced. Also, phosphorylation at H3 S10 is reduced in dAda3 and dGcn5 mutants. Variegation for white (wm4) and scute (Hwv) genes, caused by rearrangements of X chromosome heterochromatin, is modified in a dAda3+ gene-dosage-dependent manner. The effect is not observed with rearrangements involving Y heterochromatin (bwD), euchromatin (Scutoid), or transvection effects on chromosomal pairing (white and zeste interaction). Activity of scute gene enhancers, targets for Iroquoi transcription factors, is abolished in dAda3 mutants. Also, Iroquoi-associated phenotypes are sensitive to dAda3+ gene dosage. We conclude that dADA3 plays a role in HAT complexes which acetylate H3 and H4 at specific residues. In turn, this acetylation results in chromatin structure effects of certain rearrangements and transcription of specific genes. Copyright " 2008, American Society for Microbiology. All Rights Reserved.",,,,,,"10.1128/MCB.01307-07",,,"http://hdl.handle.net/20.500.12104/45432","http://www.scopus.com/inward/record.url?eid=2-s2.0-37549022286&partnerID=40&md5=1f0a23699f4e9a3f43c8925d5c48c312",,,,,,"1",,"Molecular and Cellular Biology",,"37
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