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1.
Reproduction is the highest energy demand period for small mammals, during which both energy intake and expenditure are increased to cope with elevated energy requirements of offspring growth and somatic protection. Oxidative stress life history theory proposed that reactive oxygen species(ROS) were produced in direct proportion to metabolic rate, resulting in oxidative stress and damage to macromolecules. In the present study, several markers of oxidative stress and antioxidants activities were examined in brain, liver, kidneys, skeletal muscle and small intestine in non-lactating(Non-Lac) and lactating(Lac) KM mice. Uncoupling protein(ucps) gene expression was examined in brain, liver and muscle. During peak lactation, gross energy intake was 254% higher in Lac mice than in Non-Lac mice. Levels of H2O2 of Lac mice were 17.7% higher in brain(P<0.05), but 21.1%(P<0.01) and 14.5%(P<0.05) lower in liver and small intestine than that of Non-Lac mice. Malonadialdehyde(MDA) levels of Lac mice were significantly higher in brain, but lower in liver, kidneys, muscle and small intestine than that of Non-Lac mice. Activity of glutathione peroxidase(GSH-PX) was significantly decreased in brain and liver in the Lac group compared with that in the Non-Lac group. Total antioxidant capacity(TAOC) activity of Lac mice was significantly higher in muscle, but lower in kidneys than Non-Lac mice. Ucp4 and ucp5 gene expression of brain was 394% and 577% higher in Lac mice than in Non-Lac mice. These findings suggest that KM mice show tissuedependent changes in both oxidative stress and antioxidants. Activities of antioxidants may be regulated physiologically in response to the elevated ROS production in several tissues during peak lactation. Regulations of brain ucp4 and ucp5 gene expression may be involved in the prevention of oxidative damage to the tissue.  相似文献   

2.
Rasmussen's encephalitis(RE) is a rare pediatric neurological disorder, the etiology of which remains unclear. It has been speculated that the immunopathogenesis of RE involves damage to neurons, which eventually leads to the occurrence of RE. Viral infection may be a critical factor in triggering RE immunopathogenesis. In this study, we analyzed the expression of Epstein-Barr virus(EBV) antigens as well as of Toll-like receptor 3(TLR3), TLR9, and downstream adapter TIRdomain-containing adapter-inducing interferon-β(TRIF) in the brain tissues of 26 patients with RE and 16 control individuals using immunohistochemistry(IHC). In the RE group, EBV antigens were detected in 53% of individuals at various expression levels. In contrast, there was no detectable EBV antigen expression in control brain tissues. Moreover, we found marked increases in the expression of TLR3, TLR9, and TRIF in the brain tissues of RE patients compared with levels in the control group. Furthermore, among RE cases, EBV expression and high TLR3 expression were associated with more severe brain atrophy. Our results suggest that the elevated expression of EBV and TLRs may be involved in RE occurrence through the activation of downstream molecules.  相似文献   

3.
Considering that the involvement of reactive oxygen species (ROS) has been implicated in the toxicity of various pesticides, this study was designed to study the ameliorative effect of Vitamin E (100 mg/kg body weight) on mice (25 -30 mg) treated with diazinon (32.5 or 16.25 mg/kg body weight) organophosphate insecticide for 14 days. Subehronic DZN exposure and the protective effects of vitamins E (vitE) were evaluated for their effects on haematological indices, the enzymes concerning liver damage [plasma alanine aminotransferase ( ALT), aspartate aminotaransferase ( AST), alkaline phosphatise ( ALP), and some parameters of kidney function (urea and creatinine) in mice. Additionally, the histopathological changes in liver and kidney tissue were examined. The high dose of diazinon (DZNH) decreased the body weight significantly at the end of experiment. Additionally, the liver and kidney were examines for histopathological changes. The high dose of diazinon decreased body weight significandy. Moreover, there was a statistically significant decrease in haemoglobin (Hb), red blood cell (RBC) and hematocrit (Hct) in diazinon-treated mice compared to controls. This decrease was partially remedied in the diazinon-treated group that also received vitE. Damage in the liver and kidney tissues was also evident as elevated plasma ALT, AST, ALP, urea and creatinine. VitE partially counteracts the toxic effect of DZN and repairs tissue damage in the liver and kidney, especially when supplemented to 1/4 LD50 intoxicated animals. Histopathological changes in liver and kidney were observed only in 32.5 mg/kg DZN given group. These results suggest that the effects of DZN are dose dependent. No pathological findings were observed in vitE + DZNtreated groups. According to the present study, we conclude that vitE ean reduce the detrimental impacts of diazinon on haematological indicies, as well as liver and kidney function [ Current Zoology 55 (3) : 219 - 226, 2009].  相似文献   

4.
A sex difference in the penetration of selenium into the brain was observed using lipopolysaccharide (LPS)-injected mice. The selenium concentration increased in the brains of sodium selenite-injected LPS-treated female mice, but not males. The selenium concentration peaked when selenite was injected 3 h after the injection of LPS into female mice. In addition, selenium in the brain increased when a dosage of 30 μmol/kg and more of selenite was injected into LPS-treated female mice. Also, the selenium concentration in the brain increased and peaked 2–3 h after selenite injection; 24 h later, the level was similar to the Se-only group. The penetration of selenium into the brain was inhibited by pretreatment with aminoguanidine, an inhibitor of nitric oxide synthetase. From the present results, selenium more easily penetrated into the brains of female mice compared to males after LPS treatment, and nitric oxide may have affected the penetration. However, the sex difference mechanism for selenium penetration needs further investigation.  相似文献   

5.
AIM: To determine the tissue and temporal distribution of human umbilical cord matrix stem (hUCMS) cells in severe combined immunodeficiency (SCID) mice. METHODS: For studying the localization of hUCMS cells, tritiated thymidine-labeled hUCMS cells were injected in SCID mice and tissue distribution was quantitatively determined using a liquid scintillation counter at days 1, 3, 7 and 14. Furthermore, an immunofluorescence detection technique was employed in which anti-human mitochondrial antibody was used to identify hUCMS cells in mouse tissues. In order to visualize the distribution of transplanted hUCMS cells in H&E stained tissue sections, India Black ink 4415 was used to label the hUCMS cells. RESULTS: When tritiated thymidine-labeled hUCMS cells were injected systemically (iv) in female SCID mice, the lung was the major site of accumulation at 24 h after transplantation. With time, the cells migrated to other tissues, and on day three, the spleen, stomach, and small and large intestines were the major accumulation sites. On day seven, a relatively large amount of radioactivity was detected in the adrenal gland, uterus, spleen, lung, and digestive tract. In addition, labeled cells had crossed the blood brain barrier by day 1. CONCLUSION: These results indicate that peripherally injected hUCMS cells distribute quantitatively in a tissue-specific manner throughout the body.  相似文献   

6.
Effects of 2, 4 -D on seedling growth and chromosomal abnormalities were studied in Triticum aestivum and Phalaris minor. Seeds were soaked at different concentrations of 2,4 -D (0.01%, 0.1%, 1.0% ) for 4, 8, 12 and 16 hours. 2,4-D suppressed the germination more severely in P. minor than in T. aestivum. Shoot and root length was retarded with the increase of concentration and time of treatment in both species. Generally radical was more negatively affected than coleoptile and emergence of radical was not observed at 1.0% concentration at 8, 12, and 16 hours of treatment in T. aestivum while in P. minor there was a total lack of radical emergence at 1.0% concentration for all durations of treatment. Stiff and curled roots and undifferentiated callus like scutellar tissues were observed in T. aestivum, while in P. minor the coleoptile obtained was lean, pale green in colour and was lying flat on filter paper. Mitotic index decreased, while chromosomal abnormalities, bridges and laggards were increased with the increase of concentration and soaking time however, laggards were not observed in T. aestivum. Clumping and chain formation of chromosomes at metaphase was also noticed in P. minor.  相似文献   

7.
To study the gene expression profiles between immunologically injured liver cell and normal liver cell of mice and to screen on a large scale the differentially expressed genes associated with the formation of liver injury,the experimental mice were randomly divided into the normal group for controlling and the immunologically liver-injured group induced by BCG and LPS.The liver mRNA of the two groups were extracted respectively and reversely-transcribed to cDNA with the incorpora-tion of different fluorescence(Cy3,Cy5) labeled dUTP as the hybridization probes.The mixed probes were hybridized to the cDNA microarray chips.The fluorescent signal results were acquired by scanner ScanArray 4000 and analyzed with software GenePix Pro 3.0.Among the 14112 target genes,293 genes were found to be significantly differentially expressed,in which 188 genes were up-regulated and 105 genes were down-regulated.Based on the analysis of biological functions of those differentially expressed genes,it was indicated that the occurrence and development of mouse liver damage induced by BCG and LPS were highly correlated with the processes of immune reac-tions,cell synthesis,metabolism,apoptosis and transportation in liver cell,which might be quite im-portant for elucidating the regulatory network of gene expression associated with the liver damage,also important for finally discovering the pathogenic mechanisms of immunological liver damage.  相似文献   

8.
Because caffeine and tissue levels of Zn are closely related, the objectives of this study were to determine the changes in plasma caffeine levels over a period of 5 h when different concentrations of Zn combined with a fixed concentration of caffeine were injected into the femoral vein of rats and to determine the relationship between tissue levels of caffeine and Zn at 5 h postinjection. Rats were divided into three groups: group 1, 220 μg caffeine; group 2,220 μg caffeine + 8 μg Zn/g body weight (BW); group 3, 220 μg caffeine +16 μg Zn/g BW. Blood from groups 1 and 3 was collected at 3 min, 30 min, 1h, 3h, and 5h to determine the pharmacokinetics of caffeine. All groups were killed at 5 h. Caffeine and Zn concentrations of the brain, kidney, heart, and liver of all groups were determined. The plasma-caffeine curve in group 3 showed a lower concentration at 3 min and a slower caffeine-elimination rate during the first 3 h. Brain and kidney caffeine levels remained constant in all groups, whereas caffeine levels were increased in the heart in group 2 and in the liver in group 3. Zn concentrations in the brain and kidney were lower in group 2 compared with groups 1 and 3 and higher in group 3 compared to groups 1 and 2. Zn concentration in the heart was the same among the three groups but was increased in the liver in group 3 compared to groups 1 and 2. Therefore, we concluded that caffeine combined with Zn affects caffeine pharmacokinetics. With caffeine intake, levels of Zn (16 μg/g BW) that are slightly higher than the daily requirements (12 μg/g BW) may prevent a reduction of Zn in tissue. In addition, caffeine’s effects on Zn concentration among organs are different.  相似文献   

9.
To scrutinize the disorders caused by human mutant apoE7/apoE4, human apoE4 and E7 transgenic mice were established with microinjection technique to examine molecular genetic phenomena in vivo. The integration and expression of h-apoE mutant genes in transgenic mice were determined with Southern blot, Northern blot and ELISA. The current studies indicated that the transgenes and the phenotypes regarding expression of transgenes could be transmitted stably in transgenic lines. The levels of serum lipid in transgenic mice showed the characteristics of hyperlipidemia. Besides, behavior tests demonstrated the degeneration of learning and memory in transgenic mice. Short life span was observed in 2 transgenic lines. After fed with high lipid food high serum lipid was found both in normal and transgenic mice, but their mechanism regulating lipid metabolism was different. It was also verified that the human apoE mutants located at either N-terminal or C-terminal had the same pathogenesis regarding disorders of  相似文献   

10.
Selenium has both nutritional function and toxicity according to its concentration and species. To counteract the toxicity of selenium, scutellarin was investigated. Wistar rats were supplemented with 40 μg Se/kg/d as sodium selenite, 40 μg Se/kg/d with 20 mg/kg/d scutellarin, and 20 mg/kg/d scutellarin, respectively, for 15 d. The mRNA levels and activities of glutathione peroxidase (GSH-Px) and thioredoxin reductase (TR), and the malondialdehyde (MDA) contents were measured. Reactive oxygen species (ROS) were detected by chemiluminescence assay, and tissue conformation was investigated by histological study. The results showed significant decreases of mRNA levels and activities of GSH-Px and TR and a significant increase of MDA content in livers of the Se-treated rats (p<0.05, compared with the control). Supplementation of scutellarin to the Se-treated group significantly inhibited the decreases of mRNA levels and activities, and the increase of MDA content (p<0.05, compared with the Setreated group). Meanwhile, scutellarin-scavenged ROS generated in the mixture of sodium selenite, reduced glutathione, and oxygen. Liver injury was displayed in slices exposed to selenium at the present dose. The groups treated with both selenium and scutellarin or only scutellarin did not show significant tissue damage. Thus, scutellarin had an antagonistic effect against the toxicity of selenium.  相似文献   

11.
12.
Exendin-4 (Ex4), a peptide initially found in the saliva of the Gila monster, can activate the signaling pathway of the incre- tin hormone glucagon-like peptide-1 (GLP-1) through the GLP-1 receptor (GLP-1R). We previously reported that a chimera protein consisting of Ex4 and mouse IgG heavy chain constant regions (Ex4/Fc) can exert biological effects of GLP-1, such as improving glycemic control and ameliorating manifestations in diabetic mice. The aim of this study was to determine whether Ex4/Fc is effective in modulating energy homeostasis in mice. Our results showed that in vivo expres- sion of Ex4/Fc by intramuscular injection of the plasmid en- coding Ex4/Fc followed by local electroporation effectively decreased food intake in the mice on high-fat diet (HFD) feeding. In addition, the reduced energy intake was associated with the decreased excrements from the Ex4/Fc-treated HFD mice but not the Fc control mice. Remarkably, the Ex4/Fc- treated HFD mice displayed significantly lower triglyceride (TG) levels when compared with the control mice. Interest- ingly, while the leptin levels were not changed, the circulating ghrelin levels were higher in Ex4/Fc mice than those in the Fc control mice. These results suggested that Ex4/Fc can improve energy metabolism and lipid metabolism through GLP-1R in mice under excessive nutrition conditions.  相似文献   

13.
We compared probability surfaces derived using one set of environmental variables in three Geographic Information Systems (GIS) -based approaches: logistic regression and Akaike's Information Criterion (AIC), Multiple Criteria Evaluation (MCE), and Bayesian Analysis (specifically Dempster-Shafer theory). We used lynx Lynx canadensis as our focal species, and developed our environment relationship model using track data collected in Banff National Park, Alberta, Canada, during winters from 1997 to 2000. The accuracy of the three spatial models were compared using a contingency table method. We determined the percentage of cases in which both presence and absence points were correctly classified (overall accuracy), the failure to predict a species where it occurred (omission error) and the prediction of presence where there was absence (commission error). Our overall accuracy showed the logistic regression approach was the most accurate (74.51%). The multiple criteria evaluation was intermediate (39.22%), while the Dempster-Shafer (D-S) theory model was the poorest (29.90%). However, omission and commission error tell us a different story: logistic regression had the lowest commission error, while D-S theory produced the lowest omission error. Our results provide evidence that habitat modellers should evaluate all three error measures when ascribing confidence in their model. We suggest that for our study area at least, the logistic regression model is optimal. However, where sample size is small or the species is very rare, it may also be useful to explore and/or use a more ecologically cautious modelling approach (e.g. Dempster-Shafer) that would over-predict, protect more sites, and thereby minimize the risk of missing critical habitat in conservation plans .  相似文献   

14.
15.
RxLR effectors produced by Phytophthora pathogens have been proposed to bind to phosphatidylinositol 3-phosphate (Ptdlns(3)P) to mediate their translocation into host cells and/or to increase their stability in planta. Since the levels of Ptdlns(3)P in plants are low, we examined whether Phytophthora species may produce Ptdlns(3)P to pro- mote infection. We observed that Ptdlns(3)P-specific GFP biosensors could bind to P. parasitica and P. sojae hyphae dur- ing infection of Nicotiana benthamiana leaves transiently secreting the biosensors, suggesting that the hyphae exposed Ptdlns(3)P on their plasma membrane and/or secreted Ptdlns(3)R Silencing of the phosphatidylinositol 3-kinases (PI3K) genes, treatment with LY294002, or expression of Ptdlns(3)pobinding proteins by P. sojae reduced the virulence of the pathogen on soybean, indicating that pathogen-synthesized Ptdlns(3)P was required for full virulence. Secretion of Ptdlns(3)P-binding proteins or of a PI3P-5-kinase by N. benthamiana leaves significantly increased the level of resist- ance to infection by P. parasitica and P. capsici. Together, our results support the hypothesis that Phytophthora species produce external Ptdlns(3)P to aid in infection, such as to promote entry of RxLR effectors into host cells. Our results derived from P. sojae RxLR effector Avrlb confirm that both the N-terminus and the C-terminus of this effector can bind Ptdlns(3)P.  相似文献   

16.
A key control point in gene expression is the initiation of protein translation, with a universal stress response being constituted by in- hibitory phosphoryiation of the eukaryotic initiation factor 2α (el F2oL). In humans, four kinases sense diverse physiological stresses to regulate elF2α to control cell differentiation, adaptation, and survival. Here we develop a computational molecular model of elF2α and one of its kinases, the protein kinase R, to simulate the dynamics of their interaction. Predictions generated by coarse-grained dynamics simulations suggest a novel mode of action. Experimentation substantiates these predictions, identifying a previously unrecognized interface in the protein complex, which is constituted by dynamic residues in both elF2α and its kinases that are crucial to regulate protein translation. These findings call for a reinterpretation of the current mechanism of action of the el F2α kinases and demonstrate the value of conducting computational analysis to evaluate protein function.  相似文献   

17.
Mitogen-activated protein kinase (MAPK) pathways regulate signal transduction from different cellular com- partments and from the extracellular environment to the nucleus in all eukaryotes. One of the best-characterized MAPKs in Arabidopsis thaliana is MPK4, which was shown to be a negative regulator of systemic-acquired resistance. The mpk4 mutant accumulates salicylic acid (SA), possesses constitutive expression of pathogenesis-related (PR) genes, and has an extremely dwarf phenotype. We show that suppression of SA and phylloquinone synthesis in chloroplasts by knocking down the IC51 gene (by crossing it with the icsl mutant) in the mpk4 mutant background did not revert mpk4-impaired growth. However, it did cause changes in the photosynthetic apparatus and severely impaired the quantum yield of pho- tosystem Ih Transmission microscopy analysis revealed that the chloroplasts' structure was strongly altered in the mpk4 and mpk4/icsl double mutant. Analysis of reactive oxygen species (ROS)-scavenging enzymes expression showed that suppression of SA and phylloquinone synthesis in the chloroplasts of the mpk4 mutant caused imbalances in ROS homeo- stasis which were more pronounced in mpk4/icsl than in mpk4. Taken together, the presented results strongly suggest that MPK4 is an ROS/hormonal rheostat hub that negatively, in an SA-dependent manner, regulates immune defenses, but at the same time positively regulates photosynthesis, ROS metabolism, and growth. Therefore, we concluded that MPK4 is a complex regulator of chloroplastic retrograde signaling for photosynthesis, growth, and immune defenses in Arabidopsis.  相似文献   

18.
Jasmonate (JA) is an important phytohormone regulating growth, development, and environmental response in plants, particularly defense response against herbivorous insects. Recently, completion of the draft genome of the mulberry (Morus notabilis) in conjunction with genome sequencing of silkworm (Bombyx mori) provides an opportuni-ty to study this unique plant-herbivore interaction. Here, we identified genes involved in JA biosynthetic and signaling pathways in the genome of mulberry for the first time, with the majority of samples showing a tissue-biased expression pattern. The analysis of the representative genes 12-oxophy-todienoic acid reductase (OPRs) and jasmonate ZIM-domain (JAZs) was performed and the results indicated that the mulberry genome contains a relatively smal number of JA biosynthetic and signaling pathway genes. A gene encoding an&amp;nbsp;important repressor, MnNINJA, was identified as an alternative splicing variant lacking an ethylene-responsive element binding factor-associated amphiphilic repression motif. Having this fundamental information wil facilitate future functional study of JA-related genes pertaining to mulberry-silkworm interactions.  相似文献   

19.
In this paper, a highly conservedpiggyBac-like sequence, designated as McrPLE was cloned from a lepidopteran insect, Macdunnoughia crassisigna. It is 2 472 bp long in full length with a single open reading frame and encodes a 595 amino acid transposase. It shares identical terminal and sub-terminal repeats with T. ni IFP2 and is flanked by the typical TTAA target-site duplications. Alignment and phylogenetic analysis revealed that McrPLE had greater than 99.5% identity and appeared to be the closest one in phylogeny to IFP2 among the PLEs so far found in various species. Plasmid-based excision and transposition assay proved it was mobile in cell culture. Otherwise, McrPLE element and all other highly conserved IFP2 sequences reported previously were found to share three common nucleotide substitutions. This suggests that the original IFP2 may be a related variant of a predecessor element that became widespread. The existence of nearly identical piggyBac sequence in reproductively isolated species was thought also a strong indication of horizontal transmission, which raises important considerations for the stability and practical use ofpiggyBac transformation vectors.  相似文献   

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