Geniposide improves insulin resistance through AMPK-mediated Txnip protein degradation in 3T3-L1 adipocytes

Thioredoxin-interacting protein(Txnip)has emerged as a key regulator of insulin resistance.In this study,we investigated the roles of geniposide and Txnip in insulin resistance in differentiated 3T3-L1 adipocytes.Our results revealed that geniposide markedly enhanced glucose uptake,increased the protein levels of insulin receptor substrate(IRS)-1 and GLUT-1,and prevented the phosphorylation of IRS-1 and Akt Thr308 induced by insulin resistance in 3T3-L1 adipocytes.We also observed that geniposide accelerated protein degradation of Txnip through proteasome pathway,and knockdown of Txnip with small interfering RNA attenuated the effect of geniposide on insulin signaling molecules,implying that Txnip played a pivotal role in the regulation of insulin signaling molecules by geniposide in 3T3-L1 adipocytes.Furthermore,geniposide induced the phosphorylation of adenosine monophosphate-activated protein kinase(AMPK)in the presence of high glucose in differentiated 3T3-L1 adipocytes,while compound C,an inhibitor of AMPK,prevented the effect of geniposide on Txnip degradation and the regulation of glucose uptake and insulin signaling molecules including p-IRS-1,IRS-1,and GLUT-1 in differentiated 3T3-L1 adipocytes.Taken together,all these findings suggest that geniposide improves the insulin signaling defect possibly by AMPK-mediated Txnip degradation in 3T3-L1 adipocytes.     

Identification and Validation of a Major Quantitative Trait Locus for Slow-rusting Resistance to Stripe Rust in Wheat

Stripe (yellow) rust,caused by Puccinia striiformis Westend.f.sp.tritici Eriks (Pst),is one of the most important wheat (Triticum aestivum L.) diseases and causes significant yield losses.A recombinant inbred (RI) population derived from a cross between Yanzhan 1 and Xichang 76-9 cultivars was evaluated for resistance to wheat stripe rust strain CYR32 at both the seedling and adult plant stages.Four resistance quantitative trait loci (QTLs) were detected in this population,in which the major one,designated as Yrq1,was mapped on chromosome 2DS.The strategy of using the Brachypodium distachyon genome,wheat expressed sequence tags and a draft DNA sequences (scaffolds) of the D-genome (Aegilops tauschii Coss.) for the development of simple sequence repeat (SSR) markers was successfully used to identify 147 SSRs in hexaploid wheat.Of the 19 polymorphic SSRs in the RI population,17 SSRs were mapped in the homeologous group 2 chromosomes near Yrq1 region and eight SSRs were genetically mapped in the 2.7 cM region of Yrq1,providing abundant DNA markers for fine-mapping of Yrq1 and marker-assisted selection in wheat breeding program.The effectiveness of Yrq1 was validated in an independent population,indicating that this resistance QTL can be successfully transferred into a susceptible cultivar for improvement of stripe rust resistance.     

Evaluation of Seven Function-Known Candidate Genes for their Effects on Improving Drought Resistance of Transgenic Rice under Field Conditions

Many stress responsive genes have been reported with an effect on improving stress resistance in model plants under greenhouse conditions. Towards identification of genes for drought resistance breeding, seven well documented genes （CBF3, SOS2, NCED2, NPK1, LOSS, ZAT10, and NHX1） in stress resistance were selected in this study and transformed into rice cultivar Zhonghua 11 under the control of constitutive promoter Actinl and stress-inducible pro- moter of a rice HVA22 homolog, and transgenic rice were tested for drought resistance under field conditions. A total of 1598 independent transgenic To plants were generated. The percentages of single copy and expression of the transgenes were 36.7% and 57.6%, respectively. For each gene construct, 30 T1 families with expression of transgene were selected for drought resistance testing at the reproductive stage in field, and 10 of them were tested in PVC pipes with a defined stress protocol at the same stage. Relative yield and relative spikelet fertility were used as two major criteria to evaluate drought resistance performance because significantly decreased yield was observed in the T1 generation, Trans- genic families of eight constructs （HVA22P：CBF3, HVA22P：NPK1, Actin 1：LOS5, HVA22P：L OS5, Actin 1：ZA T10, HVA22P：ZA T10, Actinl：NHX1, and HVA22P：NHX1） showed significantly higher RY than wild-type （WT） under both drought stress field and PVC tube conditions. Transgenic families of 9 constructs （HVA22P.SOS2 and CBF3, LOS5, ZAT10, and NHX1 by both promoters） showed significantly higher relative spikelet fertility than WT in the field or PVC pipes. In the field drought resistance testing of T2 families derived from the T1 families with relatively lower yield decrease, transgenic families of seven constructs （HVA22P：CBF3, Actinl：NPK1, HVA22P：NPK1, Actinl：LOS5, HVA22P：LOS5, Actin1：ZAT10, and HVA22P：ZAT10） showed significantly higher yield per plant than WT, and families of nine constructs （Actinl：CBF3, HVA22P：CBF3,     

Research on the Interstitial Fluid Load Support Characteristics and Start-Up Friction Mechanisms of PVA-HA-Silk Composite Hydrogel

Hydrogel has been extensively studied as an articular cartilage repair and replacement material. PVA-HA-Silk composite hydrogel was prepared by freezing-thawing method in this paper. Mechanical properties were determined by experiments and the friction coefficient of PVA-HA-Silk composite hydrogel against steel ball was verified using micro-tribometer. Finite Element Method （FEM） was used to study the lubrication mechanism of PVA-HA-Silk composite hydrogel and the relation between the interstitial fluid load support and the start-up friction resistance. The results show that the elastic modulus and the permeability are 2.07 MPa and 10^-15m^4N^-1s^-1, respectively, and the start-up friction coefficients of PVA-HA-Silk composite hydrogel are in the range of 0.154）.2 at different contact loads, contact time and sliding speeds. The start-up friction resistance of PVA-HA-Silk composite hydrogel increases with the contact load and contact time. With the increase in sliding speed, the start-up friction resistance of PVA-HA-Silk composite hydrogel decreases. There is an inverse relation between the start-up friction resistance and the interstitial fluid load support. The change of fluid flow with the increase in sliding displacement has an important effect on the interstitial fluid load support and friction resistance. The interstitial fluid load support decreases with the increase in contact load and contact time, while the interstitial fluid load support reinforces with the increase in sliding speed. Moreover, PVA-HA-Silk composite hydrogel has mechanical properties of recovery and self-lubricating.     

Hyperhomocysteinemia stimulates hepatic glucose output and PEPCK expression

Homocysteine is an intermediate in the sulfur amino acid metabolism. Recent studies suggested that there might be links between hyperhomocysteinemia and insulin resistance. In the present study, we investigated the effect of homocysteine on glucose metabolism. We demonstrated that the levels of insulin were significantly higher in mice with hyperhomocysteinemia than those in the normal mice after administration of glucose. The effect of insulin on glucose output was significantly blocked in the homocysteine-treated hepatocytes. In addition, the expression of phosphoenolpyruvate carboxykinase （PEPCK） gene was elevated in the liver of mice with hyperhomocysteinemia and primary mouse hepatocytes treated with homocysteine. The action of homocysteine was suppressed by H89, a protein kinase A （PKA） inhibitor. Thus, hyperhomocysteinemia may be considered as a risk factor that contributes to the development of insulin resistance with respect to elev- ated glucose output and upregulation of PEPCK, probably via the PKA pathway. Our study provides a novel mechanistic explanation for the development of insulin resistance in hyperhomocysteinemia.     

Identification and Fine Mapping of rhm1 Locus for Resistance to Southern Corn Leaf Blight in Maize

rhm1 is a major recessive disease resistance locus for Southern corn leaf blight (SCLB).To further narrow down its genetic position,F 2 population and BC 1 F 1 population derived from the cross between resistant (H95 rhm) and susceptible parents (H95) of maize (Zea mays) were constructed.Using newly developed markers,rhm1 was initially delimited within an interval of 2.5 Mb,and then finally mapped to a 8.56 kb interval between InDel marker IDP961-503 and simple sequence repeat (SSR) marker A194149-1.Three polymorphic markers IDP961-504,IDP B2-3 and A194149-2 were shown to be co-segregated with the rhm1 locus.Sequence analysis of the 8.56 kb DNA fragment revealed that it contained only one putative gene with a predicted amino acid sequence identical to lysine histidine transporter 1 (LHT1).Comparative sequence analysis indicated that the LHT1 in H95 rhm harbors a 354 bp insertion in its third exon as compared with that of susceptible alleles in B73,H95 and Mo17.The 354 bp insertion resulted in a truncation of the predicted protein of candidate resistance allele (LHT1-H95 rhm).Our results strongly suggest LHT1 as the candidate gene for rhm1 against SCLB.The tightly linked molecular markers developed in this study can be directly used for molecular breeding of resistance to Southern corn leaf blight in maize.     

Identification of genes contributing to quantitative disease resistance in rice

Despite the importance of quantitative disease resistance during a plant’s life, little is known about the molecular basis of this type of host-pathogen interaction, because most of the genes underlying resistance quantitative trait loci (QTLs) are unknown. To identify genes contributing to resistance QTLs in rice, we analyzed the colocalization of a set of characterized rice defense-responsive genes and resistance QTLs against different pathogens. We also examined the expression patterns of these genes in response to pathogen infection in the parents of the mapping populations, based on the strategy of validation and functional analysis of the QTLs. The results suggest that defense-responsive genes are important resources of resistance QTLs in rice. OsWRKY45-1 is the gene contributing to a major resistance QTL.NRR,OsGH3-1,and OsGLP members on chromosome 8 contribute alone or collectively to different minor resistance QTLs. These genes function in a basal resistance pathway or in major disease resistance gene-mediated race-specific pathways.     

Association of polymorphisms of Nramp1 gene with immune function and production performance of large white pig

The present research was designed to study the association of polymorphism of natural resistance-associated macrophage protein1 (Nramp1) with some immune function and the production performance in Large White pig. The PCR-RFLP technique was applied to analyze the correlation between the polymorphisms of Nramp1 gene and immune function [value of Polymorphonuclear Leukocytes (PMN) obtained by Nitroblue Tetrazolium (NBT) Reduction and effect of Cytotoxin in Monocyte] and production performance in 165 Large White pigs. The results showed that there was one Nde I restriction locus in Large White pig, and both values of PMN by NBT Reduction and effect of Cytotoxin in Monocyte in genotype BB were higher than those in genotype AB (P<0.05). Simultaneously, the weight of 180-day-old pigs with genotype BB was higher than that with genotype AB (P<0.05). The results indicated that there was a significant correlation between different genotypes of Nramp1 gene and Immune function and production performance, and it can be regarded as a candidate gene of disease resistance. All these results provide valuable reference to further studies of pig disease resistance.     

Epidermal growth factor and insulin-like growth factor-1 protect MDA-231 cells from death induced by actinomycin D: The involvement of growth factors in drug resistance

Summary In the present study, we investigated the ability of epidermal growth factor (EGF), insulin-like growth factor-1 (IGF-1), and insulin to protect the human breast cancer cell line MDA-231 from death induced by the antitumor drug actinomycin D (ACT-D). ACT-D is an inhibitor of RNA and protein synthesis, and its cytotoxicity may result due to continuous depletion in some vital protein molecules. Cell death was induced in the MDA-231 cells by either continuous exposure to a low dose of ACT-D (0.2μg/ml), or by a short-time exposure to a high dose of ACT-D (2μg/ml) and further culturing in the absence of the drug. Cell death was evaluated by the trypan blue dye exclusion test, the release of lactic dehydrogenase into the culture medium, and the depletion in the cellular ATP content. EGF and IGF-1, each at an optimal concentration of 20 ng/ml, enhanced substantially survival of cells exposed either to a low or a high dose of ACT-D. The combination of EGF (10 ng/ml) and IGF-1 (10 ng/ml) had an additive survival effect, which proposes that each of the growth factors enhanced survival by a distinct pathway. Insulin up to 40 ng/ml had no effect on cell survival. Pretreatment of the cells for 1 to 5 h with EGF and IGF-1 protected cells from the cytotoxic effect of ACT-D. Exposure of the cells to 2μg/ml of ACT-D for 1 h resulted in a drastic inhibition in uridine incorporation and only in a slight inhibition in leucine incorporation. Further incubation in the absence of ACT-D resulted in a continuous decrease in uridine and in leucine incorporation, either in the absence or presence of the growth factors. However, EGF and IGF-1, but not insulin, attenuated significantly this continuous decrease. We assume that EGF and IGF-1 protect cell viability by a mechanism that maintains a critical level of some vital protein molecule above the critical level at which cells die. Our finding that EGF and IGF-1 induced resistance to ACT-D suggests that growth factors may be involved in the mechanism of drug resistance.     

Influence of Dimensions of UHMW-PE Protuberances on Sliding Resistance and Normal Adhesion of Bangkok Clay Soil to Biomimetic Plates

A number of investigations into application of polymers for macro-morphological modification of tool surface have been carried out. These researches, with extensive stress on convex or domed protuberations as one of the widely used construction units, have tried to harness benefits from using polymers in agriculture. Ultra high molecular weight polyethylene （UHMW-PE） has proved an emerging polymer in its application to reduce soil adhesion. This research was conducted to study the effect of shape （flat, semi-spherical, semi-oblate, semi short-prolate and semi long-prolate） and dimensions （base diameter and dome height） on sliding resistance and normal adhesion of biomimetic plates. To incorporate both shape and size, a dimensionless ratio of height to diameter （HDR） was introduced to characterize the effect of construction unit＇s physique. Experiments were conducted in Bangkok clay soil with dry （ 19.8% d.b.）, sticky （36.9% d.b.） and flooded （60.1% d.b.） soil conditions respectively. Soil at sticky limit exhibited the highest sliding resistance （77.8 N） and normal adhesion （3 kPa to 7 kPa）, whereas these values were 61.7 N and 〈0.2 kPa in dry, and 53.7 N and 0.5 kPa to 1.5 kPa in flooded soil conditions. Protuberances with HDR ≤ 0.5 lowered sliding resistance by 10% - 30% and the same reduced normal adhesion by 10% - 60%. The amount of reduction in both sliding resistance and normal adhesion was higher in flooded soil. Lighter normal loads obviously produced lesser resistance and adhesion.     

Effects of nuclear cross sections at different energies on the radiation hazard from galactic cosmic rays

The radiation hazard for astronauts from galactic cosmic rays (GCR) is a major obstacle to long-duration human space exploration. Space radiation transport codes have been developed to calculate the radiation environment on missions to the Moon, Mars, and beyond. We have studied how uncertainties in fragmentation cross sections at different energies affect the accuracy of predictions from such radiation transport calculations. We find that, in deep space, cross sections at energies between 0.3 and 0.85 GeV/nucleon have the largest effect in solar maximum GCR environments. At the International Space Station, cross sections at higher energies have the largest effect due to the geomagnetic cutoff.     

甘蓝型油菜芥酸含量的主基因＋多基因遗传

应用植物数量性状主基因＋多基因混合遗传模型对甘蓝型油菜无芥酸品种HSTC     

POLLEN INTERFERENCE AND CRYPTIC SELF-FERTILITY IN CAMPSIS RADICANS

The effect of self pollen on the success of cross pollinations was studied in Campsis radicans (L.) Seem., a species previously considered self-sterile. The application of self pollen to stigmas in combination with or preceding the application of cross pollen markedly reduced the likelihood of fruit production. This effect was not due to the dilution of cross pollen nor to physical blocking of the stigmatic surface, since mixtures of talc and cross pollen were as effective as pure cross pollen in causing fruit production. Pollen tubes produced by self pollen grew at rates similar to those from cross pollen, and penetrated the ovary. The interference caused by self pollen appears to take place in the ovary, although it cannot be stated to what degree it is prezygotic or postzygotic. The marked protandry occurring in C. radicans is presumed to be due at least partly to selection for avoidance of these negative effects on female reproductive success. Up to 33% of viable seeds from mixed self + cross pollinations were sired by self pollen. The term “cryptic self-fertility” is coined to describe this phenomenon where pollination with loads of pure self pollen rarely or never yields fruit, but pollination using mixtures of self and cross pollen yields fruit containing considerable numbers of selfed seed. Estimates of selfing frequency that are based on pollination using loads of purely self pollen will be in error for species possessing cryptic self-fertility.     

楱属植物种间杂交花粉直感效应的考测与研究

本文通过对以大连栽培杂交榛为父本（P2）与饶河野生种平榛（Corylus heterophylla Fish)。杂交当代坚果（F0）,母本自然坚果（P1）进行考测与分析发现：（1）由大连引进的栽培杂交种花粉对杂交梁工坚果的开状、色泽、果皮厚度、果皮开裂性、种皮色泽、光滑度等质量性状均有明显的直接影响,即因花粉直效应产生的种子直感现象;（2）对坚果大小、单果重等数量性状也产生了一定花粉直感效应,这种数量性状种子直感遗传现象是在多年来植物杂交试验中较为罕见的。     

上颌固定矫治器联合下颌垫及颏兜矫治恒前牙反

目的:探讨矫治恒前牙反(牙合)的方法。方法:将50例恒前牙反(牙合)患者分为两组,用固定矫治器和活动矫治器矫治,观察解除反(牙合)所需的时间。结果:结果显示固定矫治组疗程明显短于活动矫治组。结论:对于恒前牙反(牙合)患者,可以用固定矫治器联合下颌(牙合)垫、颏兜矫治,缩短疗程,达到理想治疗效果。     

Relative importance of genetic, ontogenetic, induction, and seasonal variation in producing a multivariate defense phenotype in a foundation tree species

Plant adaptations for defense against herbivory vary both among species and among genotypes. Moreover, numerous forms of within-plant variation in defense, including ontogeny, induction, and seasonal gradients, allow plants to avoid expending resources on defense when herbivores are absent. We used an 18-year-old cottonwood common garden composed of Populus fremontii, Populus angustifolia, and their naturally occurring F₁ hybrids (collectively referred to as ??cross types??) to quantify and compare the relative influences of three hierarchical levels of variation (between cross types, among genotypes, and within individual genotypes) on univariate and multivariate phytochemical defense traits. Within genotypes, we evaluated ontogeny, induction (following cottonwood leaf beetle herbivory), and seasonal variation. We compared the effect sizes of each of these sources of variation on the plant defense phenotype. Three major patterns emerged. First, we observed significant differences in concentrations of defense phytochemicals among cross types, and/or among genotypes within cross types. Second, we found significant genetic variation for within-plant differences in phytochemical defenses: (a) based on ontogeny, levels of constitutive phenolic glycosides were nearly three times greater in the mature zone than in the juvenile zone within one cottonwood cross type, but did not significantly differ within another cross type; (b) induced levels of condensed tannins increased up to 65?% following herbivore damage within one cottonwood cross type, but were not significantly altered in another cross type; and (c) concentrations of condensed tannins tended to increase across the season, but did not do so across all cross types. Third, our estimates of effect size demonstrate that the magnitude of within-plant variation in a phytochemical defense can rival the magnitude of differences in defense among genotypes and/or cross types. We conclude that, in cottonwood and likely other plant species, multiple forms of within-individual variation have the potential to substantially influence ecological and evolutionary processes.     

Impact of photon cross section uncertainties on Monte Carlo-determined depth-dose distributions

This work studies the impact of systematic uncertainties associated to interaction cross sections on depth dose curves determined by Monte Carlo simulations. The corresponding sensitivity factors are quantified by changing cross sections by a given amount and determining the variation in the dose. The influence of total and partial photon cross sections is addressed. Partial cross sections for Compton and Rayleigh scattering, photo-electric effect, and pair production have been accounted for. The PENELOPE code was used in all simulations. It was found that photon cross section sensitivity factors depend on depth. In addition, they are positive and negative for depths below and above an equilibrium depth, respectively. At this depth, sensitivity factors are null. The equilibrium depths found in this work agree very well with the mean free path of the corresponding incident photon energy. Using the sensitivity factors reported here, it is possible to estimate the impact of photon cross section uncertainties on the uncertainty of Monte Carlo-determined depth dose curves.     

Impact of biparental mating on correlation coefficients in bread wheat

Summary Phenotypic and genotypic correlation coefficients and path-coefficients were studied in the biparental (BIPs) and F₃ self progenies of the two wheat crosses. A comparison of correlation coefficients in the BIPs and the F₃'s revealed that as many as twelve new significant correlations were noticed in case of the BIPs in cross I although some of them occurred in the undesirable direction. On the other hand, only three new correlations were observed in the BIPs of cross II, although as many as fifteen correlations were not significant. Results suggested that intermating in the F₂ was effective in breaking the linkages. Path-coefficient analysis further revealed that the direct effect of tillers/ plant on grain yield was important and remained unchanged in both populations of cross I. In cross II, the direct effect of tillers/plants on grain yield was also high and it increased in the BIPs. Intermating seemed to have influenced considerably both the direct and indirect effects.     

Role of spectrin in cross bonding of the red cell membrane

Membrane cross bonding--an adhesion between opposing areas of the cytoplasmic face of the red cell membrane--was achieved by treating red cells with heat, diamide, N-ethymaleimide, urea, or by ATP depletion in conjunction with cell shrinking. Membrane cross bonding could be recognized by the shape of the cells upon swelling. Quantitated by the percentage of cross-bonded red cells the effectivity of the treatments decreased in the order given above. Cross bonding was hardly reversible by reducing the diamide-induced S-S bonds with dithioerythritol. The effect of heat and urea treatment as well as ATP depletion was partly reversible. Transmission electron micrographs of the cross-bonded region showed basically parallel membranes. The distance between the respective phospholipid bilayers varied between 40 and 120 nm from cell to cell. Hb-free ghosts prepared from diamide-treated red cells could also be cross bonded. The following conclusions are drawn: spectrin provides the molecular cross link in membrane cross bonding. Aggregation and enrichment of spectrin in the cross-bonded region are probably involved in membrane cross bonding.     

Selective excitation of intense solvent signals in the presence of radiation damping

Summary Selective water excitation schemes are provided which rely on the radiation damping effect in probeheads characterized by high quality factors. The schemes are implemented in homonuclear NOE and ROE experiments, designed for the selective observation of water-protein cross peaks and their assignment using standard probeheads. The one-dimensional NOE and ROE experiments selectively record the cross section through the water signal usually measured in two-dimensional NOESY and ROESY spectra, and the two-dimensional NOE-NOESY and ROE-NOESY experiments selectively measure the cross section through the water line from 3D NOESY-NOESY and ROESY-NOESY spectra, respectively.