ABA诱导基因及其与逆境胁迫的关系(综述)

本文介绍 ABA 诱导基因的类型、结构、功能,并对其表达与逆境胁迫的关系进行综述。     

宠物与人类健康的关系

随着人们生活水平的逐渐提高,饲养宠物的家庭在中国越来越多。饲养宠物能改善心血管功能,增强机体免疫力,发出健康预警,增强自信和减少抑郁。但是不科学的饲养宠物也会给人类的健康带来挑战,近年发生的＂非典＂和高致病性禽流感引起了我们对生物安全和人兽共患病的高度重视。只要科学饲养,就可以创造人与动物和谐的幸福生活。     

The Relationship between Salinity and Cadmium Stress in Barley

Distribution of cadmium between roots and shoots of barley was manipulated by the cadmium concentration (0.01 and 0.005 mM Cd²⁺), pH (4.6 and 5.9) as well as treatment duration. The prolongation of treatment increased dry mass and content of cadmium in plants. The cadmium is accumulated mainly in roots. Presence of both, 0.005 mM Cd²⁺ and 100 mM NaCl in medium at pH 5.9 (Cd-NaCl plants) resulted in the most severe growth inhibition of plants, but about one half accumulation of cadmium in roots then in a case of only Cd-treated plants. In the Cd-NaCl plants, the net photosynthetic and transpiration rates were less reduced then in a case of only NaCl-treated plants. The treatments also influenced uptake of Ca, Cd, Cu, K, Mg, Na and Zn predominantly in roots. This revised version was published online in July 2006 with corrections to the Cover Date.     

Analysis of the Relationship between Peak Stress and Proteoglycan Loss following Injurious Compression of Human Post-mortem Knee and Ankle Cartilage

While traumatic joint injuries are known to increase the risk of osteoarthritis (OA), the mechanism is not known. Models for injurious compression of cartilage may identify predictors of injury that suggest a clinical mechanism. We investigated the relationship between peak stress during compression and glycosaminoglycan (GAG) loss after injury for knee and ankle cartilages. Human cartilage explant disks were harvested post-mortem from the knee and ankle of three organ donors with no history of OA and subjected to injurious compression to 65% strain in uniaxial unconfined compression at 2 mm/s (400%/s). The GAG content of the conditioned medium was measured 3 days after injury. After injury of knee cartilage disks, damage was visible in 18 of 39 disks (36%). Three days after injury, the increase in GAG loss to the medium (GAG loss from injured disks minus GAG loss from location-matched uncompressed controls) was 1.5±0.3 μg/disk (mean ± SEM). With final strain and compression velocity held constant, we observed that increasing peak stress during injury was associated with less GAG loss after injury (P<0.001). In contrast, ankle cartilage appeared damaged after injury in only 1 of 16 disks (6%), there was no increase in GAG loss (0.0±0.3 μg/disk), and no relationship between peak stress and increase in GAG loss was detected (P=0.51). By itself, increasing peak stress did not appear to be an important cause of GAG loss from human cartilage in our injurious compression model. However, we observed further evidence for differences in the response of knee and ankle cartilages to injury.     

氧化应激与端粒、端粒酶的关系

端粒是真核生物染色体末端的DNA与特殊蛋白质结合的复合体。端粒酶是一种由蛋白质和RNA组成的核糖核蛋白复合物,具有逆转录酶的活性。除末端复制问题是端粒DNA缩短的原因之外,氧化应激也能加速端粒缩短,而抗氧化剂则能延缓端粒缩短率。氧化应激对端粒酶活性的影响仍不确定。研究表明氧化应激是端粒缩短及其所致细胞衰老的重要调节因子。     

Developmental Biology and Human Concerns

There is a large natural loss of human embryos in early gestation.Most conceptual losses occur before pregnancy has been diagnosedin the woman. It is now acknowledged that chromosomal aberrationsare the major etiologic agents responsible for spontaneous abortions.Fully 50 percent of naturally aborted embryos in the first trimesterhave an abnormal karyotype. Most of the chromosomal errors thathave been identified in abortuses are only rarely seen in livebirths.Natural in utero selection is relentless in eliminating 99 percentof the chromosomally abnormal conceptuses through spontaneousabortion. The birth of affected offspring that escape nature'sscreening mechanism can be averted by the option of prenataldiagnosis. The thrust of prenatal diagnosis is to prevent thetragic impact of debilitating genetic disorders. But notallat-risk parents wish to avail themselves of prenatal diagnosisbecause they are unwilling to accept the choice of therapeuticabortion. Prevention of a genetic disorder before implantationwould obviate the necessity of an abortion at a later stageof pregnancy. With this perspective, the correction of the basicgenetic flaw by replacing the faulty gene with a functioningallele is an attractive alternative. Notwithstanding the imprecisetechnology that presently serves to caution against immediateapplication, gene therapy is a reasonable and natural extensionof efforts to ameliorate the effects of severe inherited disorders.     

Relationship between the Accumulation of Putrescine and the Tolerance to Oxygen-Deficit Stress in Gramineae Seedlings

The accumulation of putrescine under anoxia was studied in seedlingsof 6 Gramineae species showing tolerance to the stress in thefollowing order: rice, barnyard grass>maize>rye, barleyand wheat. The accumulation of putrescine in shoots and rootsduring 6 h of oxygen deprivation was different among the speciesand correlated with their tolerance to anaerobic conditions.In both tissues, rice and barnyard grass accumulated more than0.6 µmol/g fresh weight. The lower increase in the putrescinetiter was observed in wheat tissues with less than 0.1 µmol/gfresh weight. Feeding experiments with [^l4C]arginine showedthat rice tissues have a greater capacity than wheat tissuesto synthesize putrescine under anoxia. The better tolerant speciesto anaerobic conditions showed high arginine decarboxylase activityin shoots and roots than the sensitive species. The presenceof exogenous Put partially increased the survival of wheat rootsafter 7.5 h of oxygen-deficit stress. The role of putrescinein determining differences in the tolerance to anoxia in Gramineaeseedlings is discussed. (Received December 20, 1989; Accepted March 12, 1990)     

人类疱疹病毒6型及其与某些疾病的关系

人类疱疹病毒6型(human herpes virus type 6,HHV-6)是1986年从淋巴增殖异常患者及艾滋病病人外周血单核细胞中,首先分离到的一种具有疱疹病毒形态和嗜淋巴细胞的新病毒。人类感染HHV-6十分普遍,多为隐性感染。可在60%～80%儿童及成人血清中查到HHV-6抗体。HHV-6是婴儿急疹(玫瑰疹)的病原体,并证实与淋巴增殖性疾病、自身免疫病和免疫缺陷病人的感染等有关。随着器官移植的发展和艾滋病病人的增多,HHV-6感染变得日益重要。     

Tadpole Xenopus laevis hemoglobin. Correlation between structure and functional properties

Perutz & Brunori (1982) proposed that the COOH-terminal His and Ser F9 of the beta-chains of fish and amphibian hemoglobins are responsible for their Root effect and part of their alkaline Bohr effect. Analysis of the kinetics of carbon monoxide binding by hemoglobin from the tadpole of Xenopus laevis supports that model and suggests an explanation for the absence of an alkaline Bohr effect in many aquatic Anura and Urodela.     

Protein Antioxidant Response to the Stress and the Relationship between Molecular Structure and Antioxidant Function

Background

Proteins have long been considered a principal target for oxidants as a result of their abundance in biological systems. However, there is increasing evidence about the significant antioxidant activity in proteins such as albumin. It is leading to new concepts that even consider albumin not only as an antioxidant but as the major antioxidant in plasma known to be exposed to continuous oxidative stress. Evidence presented here establishes a previously unrecognized relationship between proteins'' antioxidant capacity and structural stress.

Methodology/Principal Findings

A chemiluminiscence based antioxidant assay was achieved to quantify the antioxidant capacity of albumin and other proteins. The capabilities of proteins as antioxidants were presented, but in addition a new and powerful component of the protein antioxidant capacity was discovered. The intrinsic component, designated as Response Surplus (RS), represents a silent reserve of antioxidant power that awakens when proteins face a structural perturbation (stressor) such as temperature, short wave UV light, the same reactive oxygen species, and more extreme changes like glucose or aldehyde-mediated structural modifications. The work also highlights the importance of structural changes in protein antioxidant properties and the participation of sulfhydryl groups (SHs) in the RS antioxidant component. Based on recent evidence about the SH group chemistry, a possible model for explaining RS is proposed.

Conclusions/Significance

The data presented show the significant antioxidant behavior of proteins and demonstrate the existence of a previously unrecognized antioxidant response to the stress. Several implications, including changes in elementary concepts about antioxidants and protein function, should emerge from here.     

人乳头瘤病毒感染与宫颈癌的研究进展

宫颈癌是一种严重危害女性健康的恶性肿瘤,其发病率较高,位居女性恶性肿瘤的第二位,仅次于乳腺癌.流行病学治疗显示,99％的宫颈癌患者均感染高危型人乳头瘤病毒(Human papillomavirus,HPV),HPV是宫颈癌的首要病因.近年来,HPV分型检测技术的发展十分迅速,在宫颈癌筛查中与细胞学检测联合应用,对子宫颈病变的早期发现和预防有很重要的意义,可以提高诊断的敏感性,预防宫颈癌的发生和改善宫颈癌患者的预后.本文拟对HPV感染的检测方法与宫颈癌的研究进展做一综述.     

Relationship between Measures of Exposure to PCBs/Dioxins and Behavioral Effects in Recent Developmental Studies

This paper does not reflect official EPA policy. Epidemiological studies on the neurodevelopmental effects of exposure to PCBs initiated in the last decade have had the opportunity to take advantage of modern methodologies for the analysis of congeners of PCBs, dioxins, and related orga-nochlorine compounds. Each of these studies is a longitudinal prospective study, in which women were recruited during pregnancy and the children are being followed for at least several years after birth. The study from which the largest body of data has been published to date is being performed in the Netherlands, in which exposure to PCBs and related compounds is through the general food supply. Mother-infant pairs were recruited in two cities. Half of the infants were bottle-fed and half breast-fed in each city. Four PCB congeners (118, 138, 153, 180) were assessed in maternal and cord plasma, breast milk, and plasma of the child at 3.5 years. TEQ in breast milk was calculated based on PCDDs/PCDFs and dioxin-like PCBs. Various measures of in utero exposure were associated with suboptimal neurological status during infancy, whereas maternal plasma PCB concentration was associated with cognitive deficits (Kaufman scores) at 3.5 years of age. The child's concurrent plasma PCB levels and maternal PCB plasma levels independently predicted performance on various aspects of a vigilance task, and maternal and cord plasma levels predicted impairment of complex play behavior. Poor scores on behavioral ratings were associated with concurrent blood PCB concentrations in the child. A study in Oswego in Lake Ontario fish eaters includes mothers who never ate Great Lakes fish and mothers who consumed greater than 40 PCB-equivalent pounds of Lake Ontario fish over their lifetime. Sixty-eight PCB congeners were measured in cord blood. Suboptimal neurological status during infancy was associated with maternal fish consumption and highly chlorinated cord PCB levels, whereas deficits in short-term memory at 6 months and 1 year of age were associated with total chlorinated cord PCB levels. In a study in Germany of 171 mother-infant pairs, PCB congeners 138, 153, and 180 were measured in cord plasma and milk 2 weeks after birth; both measures are considered markers of in utero exposure. Suboptimal neurological status during infancy, decrements in Bayley scores at 30 months and Kaufman scores at 42 months were associated with PCBs in milk but not cord plasma. These studies, combined with data from previous studies, reveal a consistent relationship between PCB exposure and suboptimal neurological status during infancy, and cognitive deficits associated with in utero exposure. Data from the Dutch study revealed effects on other behavioral domains associated with concurrent (postnatal) exposure. Although it is not possible to identify specific congeners or groups of congeners that may be responsible for the neurotoxic effects observed in these studies, the TEQ approach was not particularly predictive for neurotoxic outcomes.     

膜联蛋白A1及其与肿瘤关系的研究进展

膜联蛋白A1 (Annexin A1,ANXA1)是一种来源于脊柱(哺乳)动物的钙依赖性磷脂结合蛋白,是介导细胞内糖皮质激素抗炎作用的效应分子,在组织中广泛表达,参与细胞生长周期的各个阶段.其既可以可溶性形式存在,也可稳定或可逆结合于细胞骨架蛋白,调控细胞与细胞外基质的相互作用.大量的研究发现,AnnexinA1的表达在不同肿瘤组织中有差异,并且同一肿瘤不同类型中表达也不一样,其异常表达及细胞内定位改变可能跟多种恶性肿瘤的分化及转移相关.Annexin A1与肿瘤的密切关系,或许可使其发展为一个新的肿瘤标志物,为肿瘤的早期诊断、治疗及预后提供新的判断标准.因此,探讨Annexin A1与肿瘤的关系极具临床应用前景.     

Developmental Plasticity, Epigenetics and Human Health

The unrelenting rise in global rates of non-communicable disease has necessitated a thorough re-evaluation of the current use of adult- and lifestyle-based strategies to curb the growing epidemic. There is a rapidly emerging set of epidemiological, experimental and clinical data suggesting that developmental factors play a considerable role in determining individual disease risk later in life. This phenomenon is known as the Developmental Origins of Health and Disease (DOHaD). Developmental factors, such as maternal and paternal nutrition, gestational diabetes mellitus, and even the normative range of developmental experiences, may evoke the processes of developmental plasticity which enable an organism to change its developmental trajectory in response to environmental cues. However in the event of a mismatch between the early and mature environment, such anticipatory responses may become maladaptive and lead to elevated risk of disease. The evo-devo and eco-evo-devo framework for DOHaD has more recently been supported by mechanistic insights enabled by rapid advances in epigenetic research. Increasing evidence suggests that developmental plasticity may be effected by epigenetically mediated modulation of the expression of specific genes. These mechanisms include DNA methylation, histone modifications and noncoding RNA activity. A growing number of animal studies also point towards the transgenerational inheritance of epigenetic marks, which may have implications for the perpetuation of ill-health. However early-life epigenotyping may find utility as a prognostic marker of metabolic dysfunction for identification and treatment of at-risk individuals.     

A Non-Stationary Relationship between Global Climate Phenomena and Human Plague Incidence in Madagascar

Background

Plague, a zoonosis caused by Yersinia pestis, is found in Asia and the Americas, but predominantly in Africa, with the island of Madagascar reporting almost one third of human cases worldwide. Plague''s occurrence is affected by local climate factors which in turn are influenced by large-scale climate phenomena such as the El Niño Southern Oscillation (ENSO). The effects of ENSO on regional climate are often enhanced or reduced by a second large-scale climate phenomenon, the Indian Ocean Dipole (IOD). It is known that ENSO and the IOD interact as drivers of disease. Yet the impacts of these phenomena in driving plague dynamics via their effect on regional climate, and specifically contributing to the foci of transmission on Madagascar, are unknown. Here we present the first analysis of the effects of ENSO and IOD on plague in Madagascar.

Methodology/principal findings

We use a forty-eight year monthly time-series of reported human plague cases from 1960 to 2008. Using wavelet analysis, we show that over the last fifty years there have been complex non-stationary associations between ENSO/IOD and the dynamics of plague in Madagascar. We demonstrate that ENSO and IOD influence temperature in Madagascar and that temperature and plague cycles are associated. The effects on plague appear to be mediated more by temperature, but precipitation also undoubtedly influences plague in Madagascar. Our results confirm a relationship between plague anomalies and an increase in the intensity of ENSO events and precipitation.

Conclusions/significance

This work widens the understanding of how climate factors acting over different temporal scales can combine to drive local disease dynamics. Given the association of increasing ENSO strength and plague anomalies in Madagascar it may in future be possible to forecast plague outbreaks in Madagascar. The study gives insight into the complex and changing relationship between climate factors and plague in Madagascar.     

人肺癌细胞抑癌基因PTEN的表达与失巢凋亡的关系

应用Northern印迹、Western印迹和DNA梯形片段方法 ,研究 8株不同细胞类型的人肺癌细胞中抑癌基因PTEN的表达与失巢凋亡 (anoikis)的关系 ,并分析在此过程中蛋白激酶B(proteinkinaseB ,PKB)和粘着斑激酶(focaladhesionkinase ,FAK)的作用。发现 8株人肺癌细胞PTEN均有mRNA表达 ,且mRNA水平比较接近。但PTEN的蛋白质水平不一致 ,其中 95C、95D和A1株的PTEN蛋白未检测到 ;A549、A4、A7和L1株的PTEN蛋白有表达 ,但较低 ;而H460 株的PTEN表达较强。PTEN缺失的 95D和高表达的H460 细胞株中PTENcDNA序列分析均未发生片断缺失或点突变。RNA稳定性分析表明 ,95DmRNA稳定性较H460 明显下降。在无血清且去粘附培养条件下 ,高表达PTEN的细胞株H460 可被诱导发生失巢凋亡现象 ,在 10 %血清培养条件下可保护其免于失巢凋亡 ,而PTEN缺失的 95D等和其他PTEN低表达的细胞株却没有发生诱导失巢凋亡现象。进一步研究发现PTEN表达可降低PKB的磷酸化 ,下调FAK蛋白质的表达。结果提示各种人肺癌细胞株中PTEN蛋白表达存在显著差异。PTEN参与了失巢凋亡的发生。