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排序方式: 共有792条查询结果,搜索用时 15 毫秒
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93.
Jylhävä J Lyytikäinen LP Kähönen M Hutri-Kähönen N Kettunen J Viikari J Raitakari OT Lehtimäki T Hurme M 《PloS one》2012,7(4):e35426
Introduction
Circulating cell-free DNA (cf-DNA) is a useful indicator of cell death, and it can also be used to predict outcomes in various clinical disorders. Several innate immune mechanisms are known to be involved in eliminating DNA and chromatin-related material as part of the inhibition of potentially harmful autoimmune responses. However, the exact molecular mechanism underlying the clearance of circulating cf-DNA is currently unclear.Methods
To examine the mechanisms controlling serum levels of cf-DNA, we carried out a genome-wide association analysis (GWA) in a cohort of young adults (aged 24–39 years; n = 1841; 1018 women and 823 men) participating in the Cardiovascular Risk in Young Finns Study. Genotyping was performed with a custom-built Illumina Human 670 k BeadChip. The Quant-iTTM high sensitivity DNA assay was used to measure cf-DNA directly from serum.Results
The results revealed that 110 single nucleotide polymorphisms (SNPs) were associated with serum cf-DNA with genome-wide significance (p<5×10−8). All of these significant SNPs were localised to chromosome 2q37, near the UDP-glucuronosyltransferase 1 (UGT1) family locus, and the most significant SNPs localised within the UGT1 polypeptide A1 (UGT1A1) gene region.Conclusion
The UGT1A1 enzyme catalyses the detoxification of several drugs and the turnover of many xenobiotic and endogenous compounds by glucuronidating its substrates. These data indicate that UGT1A1-associated processes are also involved in the regulation of serum cf-DNA concentrations. 相似文献94.
M Suorsa S Järvi M Grieco M Nurmi M Pietrzykowska M Rantala S Kangasjärvi V Paakkarinen M Tikkanen S Jansson EM Aro 《The Plant cell》2012,24(7):2934-2948
In nature, plants are challenged by constantly changing light conditions. To reveal the molecular mechanisms behind acclimation to sometimes drastic and frequent changes in light intensity, we grew Arabidopsis thaliana under fluctuating light conditions, in which the low light periods were repeatedly interrupted with high light peaks. Such conditions had only marginal effect on photosystem II but induced damage to photosystem I (PSI), the damage being most severe during the early developmental stages. We showed that PROTON GRADIENT REGULATION5 (PGR5)-dependent regulation of electron transfer and proton motive force is crucial for protection of PSI against photodamage, which occurred particularly during the high light phases of fluctuating light cycles. Contrary to PGR5, the NAD(P)H dehydrogenase complex, which mediates cyclic electron flow around PSI, did not contribute to acclimation of the photosynthetic apparatus, particularly PSI, to rapidly changing light intensities. Likewise, the Arabidopsis pgr5 mutant exhibited a significantly higher mortality rate compared with the wild type under outdoor field conditions. This shows not only that regulation of PSI under natural growth conditions is crucial but also the importance of PGR5 in PSI protection. 相似文献
95.
We report on the analysis of endogenous peptides in cerebrospinal fluid (CSF) by mass spectrometry. A method was developed for preparation of peptide extracts from CSF. Analysis of the extracts by offline LC-MALDI MS resulted in the detection of 3,000-4,000 peptide-like features. Out of these, 730 peptides were identified by MS/MS. The majority of these peptides have not been previously reported in CSF. The identified peptides were found to originate from 104 proteins, of which several have been reported to be involved in different disorders of the central nervous system. These results support the notion that CSF peptidomics may be viable complement to proteomics in the search of biomarkers of CNS disorders. 相似文献
96.
Minna K. Karjalainen Johanna M. Huusko Johanna Ulvila Jenni Sotkasiira Aino Luukkonen Kari Teramo Jevon Plunkett Verneri Anttila Aarno Palotie Ritva Haataja Louis J. Muglia Mikko Hallman 《PloS one》2012,7(12)
Preterm birth is the major cause of neonatal mortality and morbidity. In many cases, it has severe life-long consequences for the health and neurological development of the newborn child. More than 50% of all preterm births are spontaneous, and currently there is no effective prevention. Several studies suggest that genetic factors play a role in spontaneous preterm birth (SPTB). However, its genetic background is insufficiently characterized. The aim of the present study was to perform a linkage analysis of X chromosomal markers in SPTB in large northern Finnish families with recurrent SPTBs. We found a significant linkage signal (HLOD = 3.72) on chromosome locus Xq13.1 when the studied phenotype was being born preterm. There were no significant linkage signals when the studied phenotype was giving preterm deliveries. Two functional candidate genes, those encoding the androgen receptor (AR) and the interleukin-2 receptor gamma subunit (IL2RG), located near this locus were analyzed as candidates for SPTB in subsequent case-control association analyses. Nine single-nucleotide polymorphisms (SNPs) within these genes and an AR exon-1 CAG repeat, which was previously demonstrated to be functionally significant, were analyzed in mothers with preterm delivery (n = 272) and their offspring (n = 269), and in mothers with exclusively term deliveries (n = 201) and their offspring (n = 199), all originating from northern Finland. A replication study population consisting of individuals born preterm (n = 111) and term (n = 197) from southern Finland was also analyzed. Long AR CAG repeats (≥26) were overrepresented and short repeats (≤19) underrepresented in individuals born preterm compared to those born at term. Thus, our linkage and association results emphasize the role of the fetal genome in genetic predisposition to SPTB and implicate AR as a potential novel fetal susceptibility gene for SPTB. 相似文献
97.
Lavoie PM Ladd M Hirschfeld AF Huusko J Mahlman M Speert DP Hallman M Lacaze-Masmonteil T Turvey SE 《PloS one》2012,7(2):e31351
Bronchopulmonary dysplasia (BPD) is a common chronic lung disease and major risk factor for severe respiratory syncytial virus (RSV) infection among preterm infants. The Toll-like receptor 4 (TLR4) is involved in oxidative injury responses in the lungs. Two non-synonymous single nucleotide polymorphisms in the TLR4 gene have been associated with RSV infection in children. However, it is unclear to what extent this association is confounded by BPD or prematurity. In this study, we analyzed two population-based cohorts of preterm infants at risk for BPD as well as ethnicity-matched infants born at term, to test whether the TLR4 polymorphisms Asp299Gly (rs4986790) and Thr399Ile (rs4986791) are independently associated with BPD or premature birth. In a Canadian cohort (n = 269) composed of a majority of Caucasian preterm infants (BPD incidence of 38%), the TLR4-299 heterozygous genotype was significantly under-represented in infants without BPD (1.6% of infants versus 12% in infants with severe BPD) after adjusting for twins, ethnicity, gestational age, birth weight and gender (p = 0.014). This association was not replicated in a Finnish cohort (n = 434) of premature singletons or first-born siblings of Caucasian descent, although the incidence of BPD was substantially lower in this latter population (15%). We did not detect a significant association (>2-fold) between TLR4 genotypes and prematurity (p>0.05). We conclude that these TLR4 genotypes may have, at best, a modest influence on BPD severity in some populations of high-risk preterm infants. Further studies are warranted to clarify how clinical heterogeneity may impact genetic susceptibility to BPD. 相似文献
98.
Fully protected pA2′p5′A2′p5′A trimers 1a and 1b have been prepared as prodrug candidates for a short 2′‐5′ oligoadenylate, 2‐5A, and its 3′‐O‐Me analog, respectively. The kinetics of hog liver carboxyesterase (HLE)‐triggered deprotection in HEPES buffer (pH 7.5) at 37° has been studied. The deprotection of 1a turned out to be very slow, and 2‐5A never appeared in a fully deprotected form. By contrast, a considerable proportion of 1b was converted to the desired 2‐5A trimer, although partial removal of the 3′‐O‐[(acetyloxy)methyl] group prior to exposure of the adjacent phosphodiester linkage resulted in 2′,5′→3′,5′ phosphate migration and release of adenosine as side reactions. 相似文献
99.
M Claesson V Siitonen D Dobritzsch M Metsä-Ketelä G Schneider 《The FEBS journal》2012,279(17):3251-3263
The glycosyltransferase SnogD from Streptomyces?nogalater transfers a nogalamine moiety to the metabolic intermediate 3',4'-demethoxynogalose-1-hydroxynogalamycinone during the final steps of biosynthesis of the aromatic polyketide nogalamycin. The crystal structure of recombinant SnogD, as an apo-enzyme and with a bound nucleotide, 2-deoxyuridine-5'-diphosphate, was determined to 2.6?? resolution. Reductive methylation of SnogD was crucial for reproducible preparation of diffraction quality crystals due to creation of an additional intermolecular salt bridge between methylated lysine residue Lys384 and Glu374* from an adjacent molecule in the crystal lattice. SnogD is a dimer both in solution and in the crystal, and the enzyme subunit displays a fold characteristic of the GT-B family of glycosyltransferases. Binding of the nucleotide is associated with rearrangement of two active-site loops. Site-directed mutagenesis shows that two active-site histidine residues, His25 and His301, are critical for the glycosyltransferase activities of SnogD both in?vivo and in?vitro. The crystal structures and the functional data are consistent with a role for His301 in binding of the diphosphate group of the sugar donor substrate, and a function of His25 as a catalytic base in the glycosyl transfer reaction. Database The atomic coordinates and structure factors have been deposited with the RCSB Protein Data Bank under accession numbers 4AMB, 4AMG and 4AN4 Structured digital abstract ? snogD?and?snogD?bind?by?x-ray crystallography?(View Interaction:?1,?2). 相似文献