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991.
Ruther J Fürstenau B 《Zeitschrift für Naturforschung. C, Journal of biosciences》2005,60(9-10):743-756
Green leaf volatiles (GLV), a series of saturated and monounsaturated six-carbon aldehydes, alcohols, and esters are emitted by plants upon mechanical damage. Evidence is increasing that intact plants respond to GLV by activating their own defense mechanisms, thus suggesting that they function in plant-plant communication. The present paper demonstrates that exposure of maize plants to naturally occurring GLV, including (Z)-3-, (E)-2- and saturated derivatives, induce the emission of volatile blends typically associated with herbivory. Position or configuration of a double bond, but not the functional group of the GLV influenced the strength of the emissions. (Z)-3-Configured compounds elicited stronger responses than (E)-2- and saturated derivatives. The response to (Z)-3-hexen-1-ol increased linearly with the dose between 200 and 1000 nmol per plant. Not only the naturally occurring (E)-2-hexenal, but also (E)-2-pentenal and (E)-2-heptenal induced maize plants, although to a lesser extent. Externally applied terpenoids [(3E)-4,8-dimethyl-1,3,7-nonatriene, beta-caryophyllene, and (E)-beta-farnesene] did not significantly increase the total amount of inducible volatiles in maize. Of three tested maize cultivars Delprim and Pactol responded much stronger than Attribut. Recovery experiments in the presence and absence of maize plants demonstrated that large proportions of externally applied GLV were assimilated by the plants, whereas (3E)-4,8-dimethyl-1,3,7-nonatriene was recovered in much higher amounts. The results furthermore suggested that plants converted a part of the assimilated leaf aldehydes and alcohols to the respective acetates. We propose that GLV not only can alert neighboring plants, but may facilitate intra-plant information transfer and can help mediate the systemic defense response in a plant. 相似文献
992.
Allen BL Song JY Izzi L Althaus IW Kang JS Charron F Krauss RS McMahon AP 《Developmental cell》2011,20(6):775-787
Secreted Hedgehog (HH) ligands signal through the canonical receptor Patched (PTCH1). However, recent studies implicate three additional HH-binding, cell-surface proteins, GAS1, CDO, and BOC, as putative coreceptors for HH ligands. A central question is to what degree these coreceptors function similarly and what their collective requirement in HH signal transduction is. Here we provide evidence that GAS1, CDO, and BOC play overlapping and essential roles during HH-mediated ventral neural patterning of the mammalian neural tube. Specifically, we demonstrate two important roles for these molecules: an early role in cell fate specification of multiple neural progenitors and a later role in motor neuron progenitor maintenance. Most strikingly, genetic loss-of-function experiments indicate an obligatory requirement for GAS1, CDO, and BOC in HH pathway activity in multiple tissues. 相似文献
993.
Saher Hamed Benjamin Brenner Anat Aharon Deeb Daoud Ariel Roguin 《Cardiovascular diabetology》2009,8(1):1-12
Background
The renin-angiotensin aldosterone system (RAAS) plays an important role in regulating the blood pressure and the genetic polymorphisms of RAAS genes has been extensively studied in relation to the cardiovascular diseases in various populations with conflicting results. The aim of this study was to determine the association of five genetic polymorphisms (A6G and A20C of angiotensinogen (AGT), MboI of renin, Gly460Trp of aldosterone synthase and Lys173Arg of adducin) of RAAS genes in Malaysian essential hypertensive and type 2 diabetic subjects.Methods
RAAS gene polymorphisms were determined using mutagenically separated PCR and PCR-RFLP method in a total of 270 subjects consisting of 70 hypertensive subjects without type 2 diabetes mellitus (T2DM), 60 T2DM, 65 hypertensive subjects with T2DM and 75 control subjects.Results
There was significant difference found in age, body mass index, systolic/diastolic blood pressure, fasting plasma glucose and high density lipoprotein cholesterol levels between the hypertensive subjects with or without T2DM and control subjects. No statistically significant differences between groups were found in the allele frequency and genotype distribution for A20C variant of AGT gene, MboI of renin, Gly460Trp of aldosterone and Lys173Arg of adducin (p > 0.05). However, the results for A6G of AGT gene revealed significant differences in allele and genotype frequencies in essential hypertension with or without T2DM (p < 0.001).Conclusion
Among the five polymorphisms of RAAS genes only A6G variant of AGT gene was significantly associated in Malaysian essential hypertensive and type 2 diabetic subjects. Therefore, A6G polymorphism of the AGT gene could be a potential genetic marker for increased susceptibility to essential hypertension with or without T2DMin Malaysian subjects. 相似文献994.
Falsone SF Meyer NH Schrank E Leitinger G Pham CL Fodero-Tavoletti MT Holmberg M Dulle M Scicluna B Gesslbauer B Rückert HM Wagner GE Merle DA Nollen EA Kungl AJ Hill AF Cappai R Zangger K 《Cell reports》2012,2(2):358-371
The inherent cytotoxicity of aberrantly folded protein aggregates contributes substantially to the pathogenesis of amyloid diseases. It was recently shown that a class of evolutionary conserved proteins, called MOAG-4/SERF, profoundly alter amyloid toxicity via an autonomous but yet unexplained mode. We show that the biological function of human SERF1a originates from its atypical ability to specifically distinguish between amyloid and nonamyloid aggregation. This inherently unstructured protein directly affected the aggregation kinetics of a broad range of amyloidogenic proteins in vitro, while being inactive against nonamyloid aggregation. A representative biophysical analysis of the SERF1a:α-synuclein (aSyn) complex revealed that the amyloid-promoting activity resulted from an early and transient interaction, which was sufficient to provoke a massive increase of soluble aSyn amyloid nucleation templates. Therefore, the autonomous amyloid-modifying activity of SERF1a observed in living organisms relies on a direct and dedicated manipulation of the early stages in the amyloid aggregation pathway. 相似文献
995.
996.
Oxidative protein folding in eukaryotes: mechanisms and consequences 总被引:29,自引:0,他引:29
The endoplasmic reticulum (ER) provides an environment that is highly optimized for oxidative protein folding. Rather than relying on small molecule oxidants like glutathione, it is now clear that disulfide formation is driven by a protein relay involving Ero1, a novel conserved FAD-dependent enzyme, and protein disulfide isomerase (PDI); Ero1 is oxidized by molecular oxygen and in turn acts as a specific oxidant of PDI, which then directly oxidizes disulfide bonds in folding proteins. While providing a robust driving force for disulfide formation, the use of molecular oxygen as the terminal electron acceptor can lead to oxidative stress through the production of reactive oxygen species and oxidized glutathione. How Ero1p distinguishes between the many different PDI-related proteins and how the cell minimizes the effects of oxidative damage from Ero1 remain important open questions. 相似文献
997.
T J Santoro W R Benjamin J J Oppenheim A D Steinberg 《Journal of immunology (Baltimore, Md. : 1950)》1983,131(1):265-268
Disturbances in immune interferon (IFN gamma) activity have been implicated in the development of human systemic lupus erythematosus (SLE) and the spontaneous disease sustained by autoimmune-prone mice. We therefore investigated the cellular basis for IFN gamma production in MRL-Ipr/Ipr mice and examined the relationship between synthesis of interleukin 2 (IL 2) and IFN gamma. In vitro IL 2 and IFN gamma production in 3 to 6-mo-old, autoimmune MRL-Ipr/Ipr and MRL-+/+ mice was compared with that seen in age- and sex-matched, immunologically normal CBA/J mice. 5 X 10(6) spleen cells were pulsed with 5 micrograms of concanavalin A (Con A), and the cellfree supernatant was assayed for IL 2 and IFN gamma activity at various times up to 72 hr. We found that peak levels of IL 2 in MRL mice were less than 10% of those in the CBA/J. Yet, production of IFN gamma by cells from the autoimmune and normal strains was quite comparable. The addition of murine IL 2 to optimally Con A-stimulated cells from the MRL-Ipr/Ipr or normal mice did not affect the subsequent peak production of IFN gamma. Although the primary producers of IFN gamma in cultures of normal mice bear the Lyt-2+ phenotype, the Lyt-1+2- T-cell subset was found to be the principal source of IFN gamma in the aged MRL-Ipr/Ipr. These data suggest that Lyt-1+ cells from MRL-Ipr/Ipr mice may be differentially responsive to the signal delivered by the same mitogenic lectin with respect to lymphokine production and may indicate a distorted commitment of such cells toward production of IFN gamma and repression of IL 2 synthesis. The relationship between hypoproduction of IL 2, this usual source of IFN gamma, and the autoimmune disease sustained by MRL-Ipr/Ipr mice remains unclear. 相似文献
998.
Akue JP Nkoghe D Padilla C Moussavou G Moukana H Mbou RA Ollomo B Leroy EM 《PLoS neglected tropical diseases》2011,5(10):e1329
Background
The filarial parasites Loa loa and Mansonnella perstans are endemic in the central and western African forest block. Loa loa is pathogenic and represents a major obstacle to the control of co-endemic filariae because its treatment can cause fatal complications such as encephalitis.Methodology/Principal Findings
4392 individuals aged over 15 years were studied both by direct examination and a concentration technique. The overall prevalence rates were 22.4% for Loa loa microfilaremia, 10.2% for M. perstans microfilaremia, and 3.2% for mixed infection. The prevalence of both filariae was higher in the forest ecosystem than in savannah and lakeland (p<0.0001). The intensity of microfilariae (mf) was also higher in the forest ecosystem for both parasites. The prevalence and intensity of microfilaria were both influenced by age and gender. Correlations were found between the prevalence and intensity of Loa loa microfilariae (r = 0.215 p = 0.036), and between the prevalence of Loa loa and the prevalence of individuals with microfilaria >8000 mf/ml (r = 0.624; p<0.0001) and microfilariae >30 000 mf/ml (r = 0.319, p = 0.002). In contrast, the prevalence of pruritis and Calabar swellings correlated negatively with the prevalence of Loa loa microfilaria (r = −0.219, p = 0.032; r = −0.220; p = 0.031, respectively). Pruritis, Calabar swellings and eye worm were not associated with L. loa mf intensity (r = −0.144, p = 0.162; r–0.061, p = 0.558; and r = 0.051, p = 0.624, respectively), or with the prevalence or intensity of M. perstans microfilariae.Conclusions/Significance
This map of the distribution of filariae in Gabon should prove helpful for control programs. Our findings confirm the spatial uniformity of the relationship between parasitological indices. Clinical manifestations point to a relationship between filariae and allergy. 相似文献999.
1000.
Cynthia Chen Nasheen Naidoo Benjamin Er Angela Cheong Ngan Phoon Fong Choo Yian Tay Kin Ming Chan Boon Yeow Tan Edward Menon Chye Hua Ee Kok Keng Lee Yee Sien Ng Yik Ying Teo Gerald C. H. Koh 《PloS one》2013,8(12)