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排序方式: 共有137条查询结果,搜索用时 15 毫秒
121.
Kit M Lee Renzo Danuser Jens V Stein Delyth Graham Robert JB Nibbs Gerard J Graham 《The EMBO journal》2014,33(21):2564-2580
Macrophages regulate lymphatic vasculature development; however, the molecular mechanisms regulating their recruitment to developing, and adult, lymphatic vascular sites are not known. Here, we report that resting mice deficient for the inflammatory chemokine‐scavenging receptor, ACKR2, display increased lymphatic vessel density in a range of tissues under resting and regenerating conditions. This appears not to alter dendritic cell migration to draining lymph nodes but is associated with enhanced fluid drainage from peripheral tissues and thus with a hypotensive phenotype. Examination of embryonic skin revealed that this lymphatic vessel density phenotype is developmentally established. Further studies indicated that macrophages and the inflammatory CC‐chemokine CCL2, which is scavenged by ACKR2, are associated with this phenotype. Accordingly, mice deficient for the CCL2 signalling receptor, CCR2, displayed a reciprocal phenotype of reduced lymphatic vessel density. Further examination revealed that proximity of pro‐lymphangiogenic macrophages to developing lymphatic vessel surfaces is increased in ACKR2‐deficient mice and reduced in CCR2‐deficient mice. Therefore, these receptors regulate vessel density by reciprocally modulating pro‐lymphangiogenic macrophage recruitment, and proximity, to developing, resting and regenerating lymphatic vessels. 相似文献
122.
Gezina TML Oei Michal Heger Rowan F van Golen Lindy K Alles Moritz Flick Allard C van der Wal Thomas M van Gulik Markus W Hollmann Benedikt Preckel Nina C Weber 《Molecular medicine (Cambridge, Mass.)》2014,20(1):516-526
Helium, a noble gas, has been used safely in humans. In animal models of regional myocardial ischemia/reperfusion (I/R) it was shown that helium conditioning reduces infarct size. Currently, it is not known how helium exerts its cytoprotective effects and which cell death/survival pathways are affected. The objective of this study, therefore, was to investigate the cell protective effects of helium postconditioning by PCR array analysis of genes involved in necrosis, apoptosis and autophagy. Male rats were subjected to 25 min of ischemia and 5, 15 or 30 min of reperfusion. Semiquantitative histological analysis revealed that 15 min of helium postconditioning reduced the extent of I/R-induced cell damage. This effect was not observed after 5 and 30 min of helium postconditioning. Analysis of the differential expression of genes showed that 15 min of helium postconditioning mainly caused upregulation of genes involved in autophagy and inhibition of apoptosis versus I/R alone. The results suggest that the cytoprotective effects of helium inhalation may be caused by a switch from pro-cell-death signaling to activation of cell survival mechanisms, which appears to affect a wide range of pathways. 相似文献
123.
Matthew W Blair Sharon JB Knewtson Carolina Astudillo Chee-Ming Li Andrea C Fernandez Michael A Grusak 《BMC plant biology》2010,10(1):215
Background
Iron deficiency anemia is a global problem which often affects women and children of developing countries. Strategy I plants, such as common bean (Phaseolus vulgaris L.) take up iron through a process that involves an iron reduction mechanism in their roots; this reduction is required to convert ferric iron to ferrous iron. Root absorbed iron is critical for the iron nutrition of the plant, and for the delivery of iron to the shoot and ultimately the seeds. The objectives of this study were to determine the variability and inheritance for iron reductase activity in a range of genotypes and in a low × high seed iron cross (DOR364 × G19833), to identify quantitative trait loci (QTL) for this trait, and to assess possible associations with seed iron levels. 相似文献124.
Damaged DNA bases are repaired by base excision repair (BER), which can proceed via two pathways: short patch and long patch BER. During the latter, a stretch of several nucleotides is replaced by strand displacement DNA synthesis. We recently demonstrated that the ATP concentration may govern the decision between these BER sub-pathways. Employing a reconstituted BER complex containing among others DNA polymerase beta (Pol beta), DNA ligase III (Lig III) and XRCC1, here we show that Lig III and XRCC1 are essential mediators of this regulation. XRCC1 stimulates Pol beta strand displacement activity and releases inhibition of Pol beta by DNA-bound Lig III if ligation is prevented. XRCC1 is thus able to strongly promote strand displacement and long patch BER under conditions of ATP shortage. If sufficient ATP is available, ligation by Lig III prevents strand displacement, leading to short patch BER. Ligation-inactive mutants of Lig III do not prevent strand displacement by Pol beta under the same conditions. Consequently, the preferred use of short patch BER depends on the ligation competence of Lig III. Accordingly, lowering the levels of the XRCC1/Lig III complex in HeLa cells using siRNA decreases ligation capacity but enhances Pol beta-dependent DNA synthesis. 相似文献
125.
Point mutational analysis of the Xenopus laevis 5S gene promoter. 总被引:11,自引:3,他引:11
126.
127.
The sequences of the linked alpha 2- and alpha 1-globin genes of the equine
BI and BII haplotypes are greater than 99% identical within a 1.2-kb region
extending from approximately 75 bp upstream of the putative cap site to a
point approximately 150 bp 3' to the poly A addition signal. Differences
between the alpha 2 and alpha 1 genes that are common to both haplotypes
indicate that a major gene conversion occurred approximately 12 Myr ago and
that this has been followed by shorter, more localized, conversions.
Interhaplotype (allelic) comparisons at the alpha loci suggest that the BI
and BII haplotypes have probably existed independently greater than or
equal to 0.5 Myr and that the alpha 1 genes may have undergone a recent
interchromosomal gene conversion.
相似文献
128.
Oei Kiem Giok 《Antonie van Leeuwenhoek》1966,32(1):456-456
129.
130.
Affinity chromatography on avidin-Sepharose column was used to bind the biotin-containing car?ylases from rat liver. With a biotin gradient (0–0.3 mM), peaks of activity of pyruvate, propionyl CoA and β-methylcrotonyl CoA car?ylases co-eluted. Subsequent separation of the three car?ylases was attained using DEAE-Sepharose chromatography. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis showed each of the enzymes to be pure, with pyruvate car?ylase giving a single subunit band (Mr 130 000), propionyl-CoA car?ylase giving two bands (Mr 73 000and56500) and β-methylcrotonyl-CoA car?ylase giving two bands (Mr 75 000and60 000. The specific activity of propionyl-CoA car?ylase (15.8 munits/mg) and β-methylcrotonyl-CoA car?ylase (24.2 munits/mg) were comparable with reported activities for these purified enzymes, while that of pyruvate car?ylase (1.25 munits/mg) was low. This is a suitable method for the simultaneous preparation of purified car?ylases for the specific purpose of raising antisera to these enzymes. 相似文献