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1.
Munoz M  Henderson M  Haber M  Norris M 《IUBMB life》2007,59(12):752-757
Multidrug resistance is a major obstacle to cancer treatment and leads to poor prognosis for the patient. Multidrug resistance-associated protein 1 (MRP1) transports a wide range of therapeutic agents as well as diverse physiological substrates and may play a role in the development of drug resistance in several cancers including those of the lung, breast and prostate, as well as childhood neuroblastoma. The majority of patients with neuroblastoma present with widely disseminated disease at diagnosis and despite intensive treatment, the prognosis for such patients is dismal. There is increasing evidence that MRP1 is a MYCN target gene involved in the development of multidrug resistance in neuroblastoma. Given the importance of MRP1 overexpression in neuroblastoma, MRP1 inhibition may be a clinically relevant approach to improving patient outcome in this disease.  相似文献   

2.
The copines are a newly identified class of calcium-dependent, phospholipid binding proteins that are present in a wide range of organisms, including Paramecium, plants, Caenorhabditis elegans, mouse, and human. However, the biological functions of the copines are unknown. Here, we describe a humidity-sensitive copine mutant in Arabidopsis. Under nonpermissive, low-humidity conditions, the cpn1-1 mutant displayed aberrant regulation of cell death that included a lesion mimic phenotype and an accelerated hypersensitive response (HR). However, the HR in cpn1-1 showed no increase in sensitivity to low pathogen titers. Low-humidity-grown cpn1-1 mutants also exhibited morphological abnormalities, increased resistance to virulent strains of Pseudomonas syringae and Peronospora parasitica, and constitutive expression of pathogenesis-related (PR) genes. Growth of cpn1-1 under permissive, high-humidity conditions abolished the increased disease resistance, lesion mimic, and morphological mutant phenotypes but only partially alleviated the accelerated HR and constitutive PR gene expression phenotypes. The disease resistance phenotype of cpn1-1 suggests that the CPN1 gene regulates defense responses. Alternatively, the primary function of CPN1 may be the regulation of plant responses to low humidity, and the effect of the cpn1-1 mutation on disease resistance may be indirect.  相似文献   

3.
The fungus Cochliobolus victoriae, the causal agent of Victoria blight, produces a compound called victorin that is required for pathogenicity of the fungus. Victorin alone reproduces disease symptoms on sensitive plants. Victorin sensitivity and susceptibility to C. victoriae were originally described on oats but have since been identified on Arabidopsis thaliana. Victorin sensitivity and disease susceptibility in Arabidopsis are conferred by LOV1, a coiled-coil-nucleotide-binding-leucine-rich repeat (CC-NB-LRR) protein. We sequenced the LOV1 gene from 59 victorin-insensitive mutants and found that the spectrum of mutations causing LOV1 loss of function was similar to that found to cause loss of function of RPM1, a CC-NB-LRR resistance protein. Also, many of the mutated residues in LOV1 are in conserved motifs required for resistance protein function. These data indicate that LOV1 may have a mechanism of action similar to resistance proteins. Victorin sensitivity was found to be the prevalent phenotype in a survey of 30 Arabidopsis ecotypes, and we found very little genetic variation among LOV1 alleles. As selection would not be expected to preserve a functional LOV1 gene to confer victorin sensitivity and disease susceptibility, we propose that LOV1 may function as a resistance gene to a naturally-occurring pathogen of Arabidopsis.  相似文献   

4.
5.
Studies have shown that group Therapeutic Patient Education (TPE) may empower patients with type 2 diabetes to better manage their disease. The mechanism of these interventions is not fully understood. A reduction in resistance to treatment may explain the mechanism by which TPE empowers participants to improve self-management. The Objective of this study was to examine the effectiveness of diabetes groups in reducing resistance to treatment and the association between reduced resistance and better management of the disease. In a program evaluation study, we administered validated questionnaires to measure resistance to treatment (RTQ) in 3 time periods: before the intervention (T1), immediately after the intervention (T2) and six months later (T3). Clinical measures (HbA1C, blood pressure, HDL, LDL and total cholesterol, Triglycerides and BMI) were retrieved from Maccabi Healthcare Services computerized systems, for T1;T2 and a year post intervention (T3). Linear mixed models were used adjusting for age, gender, social support and family status. 157; 156 and 106 TPE participants completed the RTQ in T1; T2 and T3 respectively. HbA1C and systolic and diastolic blood pressure were significantly reduced in the group which achieved a reduction in three out of the five RTQ components. For the other clinical measurements no significant changes were observed. Our findings suggest that reducing resistance to treatment, through an educational program for patients with diabetes, is associated with a better disease control. Identifying patients with higher resistance to treatment, and including components that reduce resistance in patient education programs, have the potential to increase the effectiveness of these programs.  相似文献   

6.
We describe the cloning and identification of a rice cDNA, OsTVLP1, encoding a protein with similarity to TGF-beta receptor interacting proteins and vacuolar assembly Vam6p/Vps39p proteins. OsTVLP1 has an open reading frame of 2955 bp, which encodes a 984 amino acid protein, containing a citron homology (CNH) domain at its N-terminal and a clathrin heavy-chain repeat homology (CLH) domain at its C-terminal. The expression of OsTVLP1 was induced by treatments with benzothiadiazole (BTH), a chemical activator of plant disease resistance responses, and by infection of the blast fungus, Magnaporthe grisea. Importantly, the expression of OsTVLP1 was activated specifically in disease resistance response induced by BTH and in an incompatible interaction between rice and the blast fungus. Our observations suggest that OsTVLP1 may play a role in rice disease resistance response against pathogen infection.  相似文献   

7.
丛枝菌根菌诱导植物抗病的内在机制   总被引:15,自引:5,他引:10  
应用菌根真菌诱导植物抗病性是近年化学生态学和病害生物防治研究的热点.研究表明,丛枝菌根真菌(AMF)对土传病原物具有一定拮抗或抑制作用,能提高植物对土传病害的抗/耐病性.在菌根根际,各种菌群不断产生相互作用,AMF在其中起着抑制病原菌、促进有益菌生长的作用,可与其他桔抗菌结合,用做生防菌.AMF提高植物抗病性的机制还有这样几种假设:(1)植物营养得到改善;(2)竞争作用;(3)根系形态结构改变;(4)根际微生物区系变化;(5)诱导抗性及诱导系统抗性,即AMF侵染植物根系后,诱导植物体内酚酸类代谢产物增加,使植物产生局部或系统防御反应.深人研究AMF提高植物抗病性的机制,有助于正确理解菌根的抗病作用,使其能尽快地成为植物病害生物防治中的一种新方法,在生态农业中发挥作用。  相似文献   

8.
Zhang Y  Li X 《The Plant cell》2005,17(4):1306-1316
The Arabidopsis thaliana suppressor of npr1-1, constitutive 1 (snc1) mutant contains a gain-of-function mutation in a Toll Interleukin1 receptor-nucleotide binding-Leu-rich repeat-type resistance gene (R-gene), which leads to constitutive activation of disease resistance response against pathogens. In a screen for suppressors of snc1, a recessive mutation, designated mos3 (for modifier of snc1,3), was found to suppress the constitutive pathogenesis-related gene expression and resistance to virulent Pseudomonas syringae maculicola ES4326 and Peronospora parasitica Noco2 in snc1. In addition, mos3 is also compromised in resistance mediated by Resistance to Peronospora parasitica 4 (RPP4), Resistance to Pseudomonas syringae pv maculicola (RPM1), and Resistance to Pseudomonas syringae 4 (RPS4). Single mutant mos3 plants exhibited enhanced disease susceptibility to P. s. pv maculicola ES4326, suggesting that MOS3 is required for basal resistance to pathogens as well. mos3-1 was identified by map-based cloning, and it encodes a protein with high sequence similarity to human nucleoporin 96. Localization of the MOS3-green fluorescent protein fusion to the nuclear envelope further indicates that MOS3 may encode a nucleoporin, suggesting that nuclear and cytoplasmic trafficking plays an important role in both R-gene-mediated and basal disease resistance.  相似文献   

9.
10.
A new disease resistance locus in Arabidopsis, RPS3 , was identified using a previously cloned avirulence gene from a non- Arabidopsis pathogen. The avrB avirulence gene from the soybean pathogen Pseudomonas syringae pv. glycinea was transferred into a P. syringae pv. tomato strain that is virulent on Arabidopsis , and conversion to avirulence was assayed on Arabidopsis plants. The avrB gene had avirulence activity on most, but not all, Arabidopsis ecotypes. Of 53 ecotypes examined, 45 were resistant to a P. syringae pv. tomato strain carrying avrB , and eight were susceptible. The inheritance of this resistance was examined using crosses between the resistant ecotype Col-0 and the susceptible ecotype Bla-2. In F2 plants from this cross, the ratio of resistant:susceptible plants was approximately 3:1, indicating that resistance to P. syringae expressing avrB is determined by a single dominant locus in ecotype Col-0, which we have designated RPS3 . Using RFLP analysis, RPS3 was mapped to chromosome 3, adjacent to markers M583 and G4523, and ≤ 1 cM from another disease resistance locus, RPM1 . In soybean, resistance to P. syringae strains that carry avrB is controlled by the locus RPG1 . Thus, RPG1 and RPS3 both confer avrB -specific disease resistance, suggesting that these genes may be homologs.  相似文献   

11.
孔海龙  吕敏  祝树德 《昆虫知识》2012,49(6):1572-1576
为了阐明斜纹夜蛾Spodoptera litura Fabricius幼虫密度对其抗病能力的影响,在室内条件下(温度23℃±1℃,相对湿度75%)对不同幼虫密度(1、2、5、10、15头/皿(直径为12cm))饲养的斜纹夜蛾幼虫抵抗斜纹夜蛾核型多角体病毒侵染的能力及其免疫指标进行了研究。结果表明:幼虫密度对斜纹夜蛾幼虫接种核型多角体病毒后的存活率、存活时间及血淋巴酚氧化酶活性影响显著。随着幼虫密度的增加,接种核型多角体病毒后幼虫的存活率降低,存活时间缩短。当幼虫密度达到15头/皿时,幼虫存活率显著低于其它幼虫密度。不同幼虫密度幼虫的存活时间以1头/皿的最高,15头/皿的最低,且二者之间差异显著。幼虫血淋巴中酚氧化酶活性随幼虫密度的增加而明显降低,当幼虫密度达到5头/皿时,幼虫酚氧化酶活性显著低于1头/皿的。另外,幼虫溶菌酶活性和血细胞总数受幼虫密度影响不显著。不同密度幼虫抗病性的变化与其血淋巴中酚氧化酶活性的变化趋势较为一致。所以斜纹夜蛾幼虫抗病能力的降低可能与幼虫酚氧化酶活性的下降有关。因此,幼虫密度是影响斜纹夜蛾幼虫抗病性变化的重要因子。  相似文献   

12.
Bronchial asthma is a disease of multi - factored etiology. Current data show that multiple genes may be involved in the pathogenesis of asthma. Corticosteroids (GCS) are the most effective anti-inflammatory therapy for inflammatory disease such as bronchial asthma. There are 2 major types of GCS-resistant asthma to treatment of high doses of inhaled and oral glucocorticoids. Type I GCS-resistant asthma is cytokine-induced or acquired. Type II GCS resistance involves generalized primary cortisol resistance, which affects all tissues and is likely associated with a mutation in the GCR gene or in genes that modulate GCR function. There are clear examples of glucocorticoid gene h-GCR/NR3C1 polymorphisms that can influence responses and sensitivity to glucocorticosteroids. This article may lead to holistic the development analysis of the factors determining the progress of the glucocorticoid resistance in the severe bronchial asthma with special acknowledgement of the influence of polymorphisms of the glucocorticoid receptor gene h-GCR/NR3C1 to formation GCS resistance.  相似文献   

13.
银杏叶片三种酶活性变化与抗疫霉菌关系的研究   总被引:1,自引:0,他引:1  
林敏敏  廖咏梅  周志权   《广西植物》2007,27(3):513-517,526
将疫霉菌离体接种于银杏叶片,发现不同龄期银杏叶片对疫霉菌的抗病性有差异,叶龄为100d的抗病性较强,叶龄为20d的抗病性较弱。不同银杏品种叶片对疫霉菌的抗性也有差异,潮田1号和大佛手2号较抗病,大佛手1号和桂G86-1较感病。不同龄期叶片接种后,其过氧化物酶(POD)和苯丙氨酸解氨酶(PAL)的酶活性变化与抗病性成正相关,而多酚氧化酶(PPOD)的酶活性变化与抗病性没有相关性;不同银杏品种叶片接种后,品种间的抗病性与PPOD酶活性变化成正相关,而POD和PAL的酶活性变化与品种间的抗病性没有相关性。可见,POD、PPOD和PAL的酶活性变化没有明显规律性,不能作为衡量银杏叶片抗病性的生化指标。  相似文献   

14.
本研究通过对123只陕北白绒山羊DRB1基因外显子2的遗传变异分析,旨在获得陕北白绒山羊DRB1基因的多态性及变异信息,为山羊抗病基因的挖掘研究提供基础资料。本研究共获得6条陕北白绒山羊DRB1基因外显子2序列,其中4条为首次发现。生物信息学分析表明DRB1位点具有较高的多态性,6条等位基因可能起源于2个祖先基因。在长期的进化过程中,DRB1位点受到了明显的选择压力作用,这种选择作用有助于陕北白绒山羊对当地气候的适应。蛋白质结构的预测证实了DRB1*1与其它等位基因间的差异性,说明核苷酸变异可能会引起蛋白质结构的改变,最终可能影响宿主对病原体的免疫应答。本次对陕北白绒山羊DRB1基因多态性的调查与分析有助于筛选疾病抗性和易感性MHC (Major histocompatibility complex)候选基因,进而可加速绒山羊抗病品系的改良与培育进程。  相似文献   

15.
Animal production efficiency, and product volume and quality can be greatly increased by reducing disease losses. Genetic variation, a prerequisite for successful selection, has been found in animals and poultry exposed to a variety of viral, bacterial and parasitic infections. Breeding for disease resistance can play a significant role alone or in combination with other control measures including disease eradication, vaccination and medication. Feasibility of simultaneously improving resistance to specific diseases and production traits has been demonstrated. However, selection for specific resistance to all diseases of animals and poultry is impossible. Development of general disease resistance through indirect selection primarily on immune response traits may be the best long-term strategy but its applicability is presently limited by insufficient understanding of resistance mechanisms. Another hindrance may be negative genetic correlations among various immune response functions: phagocytosis, cell mediated and humoral immunity. To better assess the feasibility of increasing general disease resistance by indirect selection we must obtain estimates of heritability for immune response, disease resistance, and economic production traits, as well as genetic correlations among these traits. The present level of disease resistance in farm animals resulted from natural selection and from correlated responses to selection for production traits while the influence of artificial selection for resistance was minimal. Future research should be directed towards developing and applying breeding techniques that will increase resistance to diseases without compromising production efficiency and product quailty. This will require cooperation of immunogeneticists, veterinarians and animal and poultry breeders. Significant progress in the improvement of resistance to diseases may result from the application of new techniques of molecular genetics and cell manipulation.  相似文献   

16.
Breeding for immune responsiveness and disease resistance   总被引:2,自引:0,他引:2  
Animal production efficiency, and product volume and quality can be greatly increased by reducing disease losses. Genetic variation, a prerequisite for successful selection, has been found in animals and poultry exposed to a variety of viral, bacterial and parasitic infections. Breeding for disease resistance can play a significant role alone or in combination with other control measures including disease eradication, vaccination and medication. Feasibility of simultaneously improving resistance to specific diseases and production traits has been demonstrated. However, selection for specific resistance to all diseases of animals and poultry is impossible. Development of general disease resistance through indirect selection primarily on immune response traits may be the best long-term strategy but its applicability is presently limited by insufficient understanding of resistance mechanisms. Another hindrance may be negative genetic correlations among various immune response functions: phagocytosis, cell mediated and humoral immunity. To better assess the feasibility of increasing general disease resistance by indirect selection we must obtain estimates of heritability for immune response, disease resistance, and economic production traits, as well as genetic correlations among these traits. The present level of disease resistance in farm animals resulted from natural selection and from correlated responses to selection for production traits while the influence of artificial selection for resistance was minimal. Future research should be directed towards developing and applying breeding techniques that will increase resistance to diseases without compromising production efficiency and product quality. This will require cooperation of immunogeneticists, veterinarians and animal and poultry breeders. Significant progress in the improvement of resistance to diseases may result from the application of new techniques of molecular genetics and cell manipulation.  相似文献   

17.
Heat shock protein 90 (HSP90) is involved in plant growth and various stress responses via regulating protein homeostasis. Autophagy keeps cellular homeostasis by recycling the components of cellular cytoplasmic constituents. Although they have similar effects on cellular protein homeostasis, the direct association between HSP90 and autophagy signaling remains unclear in plants, especially in tropical crops. In this study, the correlation between HSP90 and autophagy signaling was systematically analyzed by protein–protein interaction in cassava, one of the most important economy fruit in tropic. In addition, their effects on plant disease response and underlying mechanisms in cassava were investigated by functional genomics and genetic phenotype assay. The potential MeHSP90.9-MeSGT1-MeRAR1 chaperone complex interacts with MeATGs and subsequently triggers autophagy signaling, conferring improved disease resistance to cassava bacterial blight (CBB). On the contrary, HSP90 inhibitor and autophagy inhibitor decreased disease resistance against CBB in cassava, and autophagy may be involved in the potential MeHSP90.9-MeSGT1-MeRAR1 chaperone complex-mediated multiple immune responses. This study highlights the precise modulation of autophagy signaling by potential MeHSP90.9-MeSGT1-MeRAR1 chaperone complex in autophagy-mediated disease resistance to CBB.  相似文献   

18.
研究胰岛素样生长因子-1(IGF-1)与2型糖尿病(T2DM)胰岛素抵抗关系。有研究证实给予IGF-1后,可改善胰岛素抵抗、肝脏脂质代谢,IGF-1基因缺失的动物会产生胰岛素抵抗和高胰岛素血症,低水平的IGF-1还可能与非酒精性脂肪肝病(NAFLD)肝纤维化有关,而T2DM和NAFLD与胰岛素抵抗共存,T2DM合并NAFLD患者IGF-1水平更低。IGF-1与胰岛素抵抗关系密切,IGF-1水平能反映胰岛素抵抗的严重程度,为IGF-l在今后治疗T2DM和NAFLD的提供了潜在的临床应用前景。  相似文献   

19.
An activation-tagged allele of activated disease resistance 1 (ADR1) has previously been shown to convey broad spectrum disease resistance. ADR1 was found to encode a coiled-coil (CC)-nucleotide-binding site (NBS)-leucine-rich repeat (LRR) protein, which possessed domains of homology with serine/threonine protein kinases. Here, we show that either constitutive or conditional enhanced expression of ADR1 conferred significant drought tolerance. This was not a general feature of defence-related mutants because cir (constitutive induced resistance)1, cir2 and cpr (constitutive expressor of PR genes)1, which constitutively express systemic acquired resistance (SAR), failed to exhibit this phenotype. Cross-tolerance was not a characteristic of adr1 plants, rather they showed increased sensitivity to thermal and salinity stress. Hence, adr1-activated signalling may antagonise some stress responses. Northern analysis of abiotic marker genes revealed that dehydration-responsive element (DRE)B2A but not DREB1A, RD (response to dehydration)29A or RD22 was expressed in adr1 plant lines. Furthermore, DREB2A expression was salicylic acid (SA) dependent but NPR (non-expressor of PR genes)1 independent. In adr1/ADR1 nahG (naphthalene hydroxylase G), adr1/ADR1 eds (enhanced disease susceptibility)1 and adr1/ADR1 abi1 double mutants, drought tolerance was significantly reduced. Microarray analyses of plants containing a conditional adr1 allele demonstrated that a significant number of the upregulated genes had been previously implicated in responses to dehydration. Therefore, biotic and abiotic signalling pathways may share multiple nodes and their outputs may have significant functional overlap.  相似文献   

20.
Cytokine levels are elevated in many cardiovascular diseases and seem to be implicated in the associated disturbances in vascular reactivity reported in these diseases. Arterial blood pressure is maintained within a normal range by changes in peripheral resistance and cardiac output. Peripheral resistance is mainly determined by small resistance arteries and arterioles. This review focuses on the effects of cytokines, mainly TNF-alpha, IL-1beta, and IL-6, on the reactivity of resistance arteries. The vascular effects of cytokines depend on the balance between the vasoactive mediators released under their influence in the different vascular beds. Cytokines may induce a vasodilatation and hyporesponsiveness to vasoconstrictors that may be relevant to the pathogenesis of septic shock. Cytokines may also induce vasoconstriction or increase the response to vasoconstrictor agents and impair endothelium-dependent vasodilatation. These effects may help predispose to vessel spasm, thrombosis, and atherogenesis and reinforce the link between inflammation and vascular disease.  相似文献   

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