Production Of Stress Proteins Research Articles

Effect of nanoparticles on Wheat to combat drought and Salinity Stress: Review

A significant obstacle to maintaining global crop productivity and food security is drought stress (DS). With the current rapid climate change and intensifying drought, nanoparticles (NPs) have become a fantastic instrument to increase crop productivity. DS interferes with cellular membranes, nutrient and water uptake, the photosynthetic system, and antioxidant activities, which have a negative impact on plant development and physiological and metabolic processes. When NPs are applied, the membranes are protected, the water relationship is maintained, and the nutrient and water intake is improved, which significantly increases plant development under DS. NPs shield the photosynthetic machinery and enhance photosynthetic efficiency, osmolyte, hormone, and phenolic accumulation, antioxidant activities, and gene expression, giving plants more tolerance to DS. Due to the ability to be applied by both seed soaking and seedling foliar application at various growth stages of the plant, chemical treatment is one of the encouraging methods to improve the drought tolerance of wheat. In this study, the effects of different chemical treatments on wheat physiology and drought production were assessed. Continuous climate change has a negative impact on crop productivity, especially wheat farming. It has been determined that chemical treatment can stabilise the effects of drought on wheat by enhancing the activity of hormones and enzymes that are responsive to drought, as well as by increasing the production of stress proteins and antioxidant enzymes to prevent the generation of reactive oxygen species. In order to maintain wheat's typical physiology in response to changing climates, drought resistance has been improved by the application of various chemicals with pre- and post-emergence treatment. For a successful treatment strategy, it is also important to explore potential priming chemicals and assess molecules with various development phases, chemical combinations, and treatment modalities.

5-Aminolevulinic acid alleviates herbicide-induced physiological and ultrastructural changes in Brassica napus

It is well known that application of 5-aminolevulinic acid (ALA) could promote the plant growth under abiotic stress in oilseed rape (Brassica napus L.). However, the specifics of its physiological and ultrastructural regulation under herbicide stress conditions are poorly understood. In the present study, alleviating role of ALA in B. napus was investigated under four levels of herbicide propyl 4-(2-(4,6-dimethoxypyrimidin-2-yloxy) benzylamino) benzoate (ZJ0273) (0, 100, 200 and 500 mg L−1) with or without 1 mg L−1 ALA treated for 48 or 72 h. Results showed that after 48 h of herbicide stress, the growth of rape seedlings was significantly inhibited with the successive increases of the ZJ0273 concentrations from 0 to 500 mg L−1, but this inhibition was obviously alleviated by exogenous application of ALA. However, when treatment time prolonged to 72 h, the recovery effects of ALA could not be evaluated due to the death of plants treated with the highest concentration of ZJ0273 (500 mg L−1). Further, the root oxidizability and activities of antioxidant enzymes (superoxide dismutase, peroxidase and ascorbate peroxidase) were dramatically enhanced by the application of 1 mg L−1 ALA under herbicide stress. Therefore, plants treated with ALA dynamically modulated their antioxidant defenses to reduce reactive oxygen species (ROS) accumulation and malondialdehyde (MDA) content induced by herbicide stress. Additionally, exogenously applied ALA improved the ultrastructure's of chloroplast, mitochondria and nucleus, and induced the production of stress proteins. Our results suggest that ALA could be considered as a potential plant growth regulator for the improvement of herbicide tolerance through alleviation of the physiological and ultrastructural changes induced by the herbicide in crop production.

High Hydrostatic Treatment of Foods

Heat Treatment (cooking, boiling, roasting, pasteurisation, sterilisation etc.) has always been for centuries the principal method used in Food Preservation. Lately, recent trends in processing are aimed at more healthy, nutritious and convenient food. New food preservation techniques, new concepts (Hurdle Technology) have been developed and are currently being used in the Food Industry. One of the most promising and already applied,tested in the international market, novel techniques is the High Hydrostatic Pressure treatment. Principal usage of High Hydrostatic Pressure treatment (200-600 MPa) is the pasteurization of foods, where the use of heat treatment is not applicable or in cases where maximum retention of the nutritional value of food is needed. In contrast to thermal processing, High Hydrostatic Pressure treatment can inactivate microorganisms and unfavourable enzymes at ambient or low temperatures, without affecting flavour, colour or nutritional constituents within a food system. High Hydrostatic Pressure could also inactivate food parasites, prions viruses and prionsviruses. It is an excellent pasteurisation and in the future it will turn to be even a sterilisation method. High Hydrostatic Pressure treatment affects almost all cellular processes and parts ofthe cell, with more prominent targets the macromolecular synthesis, the proteins and the cellular membrane. The main problem of this method is the occurrence of piezotolerant strains of microorganisms with great deviations regarding their piezotolerance, that could cause problems in the design of the treatment. This phenomenon is mosdy related with the production of stress proteins. The problem could be solved by the use of combined processes of High Hydrostatic Pressure with other methods or with higher pressures achieved by the technological development of the method. Despite the above-mentioned problems, High Hydrostatic Pressure is a method that advances fast and is taking its place in the modern Food Industry, considering that only a decade passed since the first High Hydrostatic Pressure treated products were presented in the market. The Greek Food Industry and Research Sector should take advantage of the developments in HHP, as this method could improve substantially the quality and competitiveness of the Greek agricultural products.

Effects of short‐chain fatty acids on Actinomyces naeslundii biofilm formation

Actinomyces naeslundii is an early colonizer and has important roles in the development of the oral biofilm. Short-chain fatty acids (SCFA) are secreted extracellularly as a product of metabolism by gram-negative anaerobes, e.g. Porphyromonas gingivalis and Fusobacterium nucleatum; and the SCFA may affect biofilm development with interaction between A. naeslundii and gram-negative bacteria. Our aim was to investigate the effects of SCFA on biofilm formation by A. naeslundii and to determine the mechanism. We used the biofilm formation assay in 96-well microtiter plates in tryptic soy broth without dextrose and with 0.25% sucrose using safranin stain of the biofilm monitoring 492 nm absorbance. To determine the mechanism by SCFA, the production of chaperones and stress-response proteins (GrpE and GroEL) in biofilm formation was examined using Western blot fluorescence activity with GrpE and GroEL antibodies. Adding butyric acid (6.25 mm) 0, 6 and 10 h after beginning culture significantly increased biofilm formation by A. naeslundii, and upregulation was observed at 16 h. Upregulation was also observed using appropriate concentrations of other SCFA. In the upregulated biofilm, production of GrpE and GroEL was higher where membrane-damaged or dead cells were also observed. The upregulated biofilm was significantly reduced by addition of anti-GroEL antibody. The data suggest biofilm formation by A. naeslundii was upregulated dependent on the production of stress proteins, and addition of SCFA increased membrane-damaged or dead cells. Production of GroEL may physically play an important role in biofilm development.

Effects of mobile phone radiofrequency waves (RFW) on embryonic stem cells

There is growing concern about the possible effects of radiation associated with mobile phone use on the developing fetus and children. The fetus and children may be more radiosensitive than adults, due to the presence of embryonic stem cells. During the developmental process, embryonic stem cells rapidly proliferate, differentiate, migrate, and undergo apoptosis. Many biological effects of RFW have been reported previously for adult cells. The present study investigated the effects of mobile phone RFW on embryonic stem cells. Fertilized chicken eggs were incubated in a commercial egg incubator and exposed to RFW of a mobile phone (SAR US: 1.10 W/kg head, 0.47 W/kg body) in silent vibration disable mode, for a total of 20 minutes per day. Control embryos were handled identically, but were not exposed to RFW. The embryos were sacrificed at day 10 and 15 post incubation. Embryo wet weight, body dimensions, morphology, and histology were studied. The RFW group at day 10 showed a decrease in wet body weight versus the control. However, at day 15, the RFW group had an increased wet body weight versus control. The same trend was observed for antero‐posterior head‐to‐rump length. Histology revealed cellular necrosis in cardiac muscle and changes in liver tissue of the RFW group. Growth retardation in the RFW group at day 10 could reflect chromosomal aberrations, stress of reactive oxygen species, and apoptosis. The increased weight at day 15 could indicate production of stress proteins and altered calcium influx across cell membranes producing a carcinogenic effect. We conclude that exposure to the RFW associated with mobile phone use has potential cytotoxic and teratogenic effects on embryonic stem cells.

Biotechnological Approaches to Study Plant Responses to Stress

Multiple biotic and abiotic environmental stress factors affect negatively various aspects of plant growth, development, and crop productivity. Plants, as sessile organisms, have developed, in the course of their evolution, efficient strategies of response to avoid, tolerate, or adapt to different types of stress situations. The diverse stress factors that plants have to face often activate similar cell signaling pathways and cellular responses, such as the production of stress proteins, upregulation of the antioxidant machinery, and accumulation of compatible solutes. Over the last few decades advances in plant physiology, genetics, and molecular biology have greatly improved our understanding of plant responses to abiotic stress conditions. In this paper, recent progresses on systematic analyses of plant responses to stress including genomics, proteomics, metabolomics, and transgenic-based approaches are summarized.

A proteome analysis of the response of a Pseudomonas aeruginosa oxyR mutant to iron limitation

In Pseudomonas aeruginosa the response to oxidative stress is orchestrated by the LysR regulator OxyR by activation of the transcription of two catalase genes (katA and katB), of the alkyl-hydroxyperoxidases ahpCF and ahpB. Next to the expected high sensitivity to oxidative stress generated by reactive oxygen species (ROS: H(2)O(2), O(2)(-)), the oxyR mutant shows a defective growth under conditions of iron limitation (Vinckx et al. 2008). Although production and uptake of the siderophore pyoverdine is not affected by the absence of oxyR, the mutant is unable to satisfy its need for iron when grown under iron limiting conditions. In order to get a better insight into the effects caused by iron limitation on the physiological response of the oxyR mutant we decided to compare the proteomes of the wild type and the mutant grown in the iron-poor casamino acids medium (CAA), in CAA plus H(2)O(2), and in CAA plus the strong iron chelator ethylenediamine-N,N'-bis(2-hydroxyphenylacetic acid) (EDDHA). Especially in the presence of hydrogen peroxide the oxyR cells increase the production of stress proteins (Dps and IbpA). The superoxide dismutase SodM is produced in higher amounts in the oxyR mutant grown in CAA plus H(2)O(2). The PchB protein, a isochorismate-pyruvate lyase involved in the siderophore pyochelin biosynthesis is not detectable in the extracts from the oxyR mutant grown in the presence of hydrogen peroxide. When cells were grown in the presence of EDDHA, we observed a reduction of the ferric uptake regulator (Fur), and an increase in the two subunits of the succinyl-CoA synthetase and the fumarase FumC1.

Effects of tungsten on environmental systems

Tungsten is a metal with many industrial and military applications, including manufacturing of commercial and military ammunition. Despite its widespread use, the potential environmental effects of tungsten are essentially unknown. This study addresses environmental effects of particulate and soluble forms of tungsten, and to a minor extent certain tungsten alloy components, present in some munitions formulations. Dissolution of tungsten powder significantly acidifies soils. Tungsten powder mixed with soils at rates higher than 1% on a mass basis, trigger changes in soil microbial communities resulting in the death of a substantial portion of the bacterial component and an increase of the fungal biomass. It also induces the death of red worms and plants. These effects appear to be related with the soil acidification occurring during tungsten dissolution. Dissolved tungsten species significantly decrease microbial yields by as much as 38% for a tungsten media concentration of 89 mg l −1. Soluble tungsten concentrations as low as 10 −5 mg l −1, cause a decrease in biomass production by 8% which is possibly related to production of stress proteins. Plants and worms take up tungsten ions from soil in significant amounts while an enrichment of tungsten in the plant rhizosphere is observed. These results provide an indication that tungsten compounds may be introduced into the food chain and suggest the possibility of development of phytoremediation-based technologies for the cleanup of tungsten contaminated sites.

The role of capsule composition and biologic responses in the function of transplanted microencapsulated islets of Langerhans.

The role of capsule composition and biologic responses in the function of transplanted microencapsulated islets of langerhans

Factors influencing survival of Legionella pneumophila serotype 1 in hot spring water and tap water.

The factors involved in the survival of Legionella pneumophila in the microcosms of both hot spring water and tap water were studied by examining cultivability and metabolic activity. L. pneumophila could survive by maintaining metabolic activity but was noncultivable in all microcosms at 42 degrees C, except for one microcosm with a pH of <2.0. Lower temperatures supported survival without loss of cultivability. The cultivability declined with increasing temperature, although metabolic activity was observed at temperatures of up to 45 degrees C. The optimal range of pH for survival was between 6.0 and 8. The metabolic activity could be maintained for long periods even in microcosms with high concentrations of salt. The cultivability of organisms in the post-exponential phase in a tap water microcosm with a low inoculum size was more rapidly reduced than that of organisms in the exponential phase. In contrast, the loss of cultivability in microcosms of a high inoculum size was significant in the exponential phase. Random(ly) amplified polymorphic DNA analysis of microcosms where cultivability was lost but metabolic activity was retained showed no change compared to cells grown freshly, although an effect on the amplified DNA band pattern by production of stress proteins was expected. Resuscitation by the addition of Acanthamoeba castellanii to the microcosm in which cultivability was completely lost but metabolic activity was maintained was observed only in part of the cell population. Our results suggest that L. pneumophila cell populations can potentially survive as free organisms for long periods by maintaining metabolic activity but temporarily losing cultivability under strict environments and requiring resuscitation by ingestion by amoebas.

PROTEIN PROFILE CHANGES IN ACID ADAPTED LISTERIA MONOCYTOGENES EXHIBITING CROSS-PROTECTION AGAINST AN ACTIVATED LACTOPEROXIDASE SYSTEM IN TRYPTIC SOY BROTH

Foodborne pathogens often tolerate and survive environmental stress conditions including extreme acidity to varying degrees. One possible reason for this survival may be the production of protective stress proteins during acid shock (ASR) and/or tolerance (ATR) responses. The ASR and ATR of Listeria monocytogenes strains V7, V37 and CA in tryptic soy broth without dextrose acidified with lactic acid were studied. Possible cross-protection of acid adapted cells against an activated lactoperoxidase system was also determined. The strains were either directly challenged at pH 4.0 and 3.5 to study their ASR or initially adapted at pH 5.5 for the equivalent of 1 generation before challenging at pH 4. 0 and 3.5 to study their ATR. Adapted and nonadapted cells were challenged at pH 4.5 with or without an activated lactoperoxidase system. In all cases viability was determined by enumeration over a period of 24 or 48 h after challenge and the production of stress proteins analyzed by 2-dimensional gel electrophoresis. While there were some differences in the survival responses for each strain, the acid adapted cells of each strain survived to a greater degree than nonadapted cells at both pH 4.0 (at least 10 fold at 24 h) and pH 3.5 (at least 1000 fold at 6 h) but not at pH 4.5. The acid adapted cells exposed to the lactoperoxidase system survived better (at least 5-fold) than their nonadapted counterparts for all 3 strains at 24 and 48 h. The 2-dimensional gel analysis for all 3 strains showed that the adapted and nonadapted cells underwent a change in their physiology, (at pH 4.0 compared to the control at pH 7.0; at pH 4.5 with the addition of lactoperoxidase system components) in that there was induction as well as repression of several proteins.

Survival of heat-shocked Yersinia enterocolitica after irradiation in ground pork

Earlier studies conducted in our laboratory showed that heat-shocked Yersinia enterocolitica (45°C for 60 min) are more resistant to a subsequent heat treatment of 55 or 60°C in ground pork than cells not previously heat-shocked. The increased thermotolerance was partly attributed to the production of stress proteins. The present study was performed to determine if the stress proteins produced by heating could also afford protection to the cells to irradiation. As part of the study, the effect of air versus vacuum packaging on survival of Yersinia to irradiation was also examined. Irradiating the inoculated pork at 1.0 kGy was sufficient to completely eliminate this pathogen. The irradiation D value for both heat-shocked and non-heat-shocked cells was statistically the same (0.15 kGy). Neither heat-shocking Yersinia nor packaging under vacuum resulted in increased resistance of this organism to irradiation. In addition, no effect was seen in virulence of the cells after these treatments, when compared with controls.

Продукція стресових білків у механізмі формування вторинної радіорезистентності клітин карциноми Герена щурів

Продукція стресових білків у механізмі формування вторинної радіорезистентності клітин карциноми Герена щурів

Biological perspective on "myocardial preconditioning".

There has been an upsurge of research on myocardial preconditioning because of its potential clinical application in areas such as cardiology, cardiac surgery, and transplantation. From a broad biological standpoint, a conceptual framework may help in both promoting understanding and suggesting future research paths. The living organism's tendency toward developing evolutionarily advantageous strategies has led to a fight or flight response, for which the authors consider preconditioning a component. Added to preconditioning, the production of stress proteins and altered myocardial states (especially that of "hibernating myocardium") can be seen as a series of biological strategies developed and maintained during evolution. An increased understanding of the mechanisms involved in the body's self-defense strategies should lead to better approaches, those in which we can help the cells, including those comprising the myocardium, to preserve themselves.

Stress responses to viral infection

Virus infection leads to an increased production of stress proteins in the host. These appear to have two important roles: (1) facilitation of virus replication and assembly and (2) recognition by the immune system when expressed on virus-infected cells and consequent elimination of the infected cells.

Stress Proteins in Development And Disease

Prokaryotes and eukaryotes respond to development cues or cellular challenges by directing their protein synthetic apparatus toward the production of stress proteins. The first expression of these proteins was noted morphologically in the salivary gland polytene chromosomes of Drosophilia melanogaster}1 Ritossa first observed that either shifting the temperature from 20°C to 37°C, or treatments with sodium salicylate or dinitrophenol, produced new chromosome puffing patterns. Tissieres et al., 3 10 years later, showed that heat shock induced the production of a unique set of proteins. Thus, it soon became evident that the puffs observed at the light microscopic level in Drosophila were sites of exuberant RNA transcription, and that the exposure of cells from a wide variety of species to heat challenges produced enhanced synthesis of several unique proteins that were designated heat shock proteins (hsps). In spite of the expression of these proteins following chemical treatment, first described in 1962, this phenomenon has been called the heat shock response. With increased advances in our understanding of the nature of these proteins, including the evidence that they are induced by a wide variety of stresses and that the expression of some of these is refractive to heat shock, there is a trend to refer more appropriately to hsps as stress proteins and the response as the stress response. The heat shock or stress response is probably the most highly conserved genetic system uncovered to date.4 Induction of hsps has been observed in every organism investigated and includes bacteria, soybeans, maize, tobacco, yeast, and many eukaryotes ranging from Drosophila through nematodes, to rat, mouse, and man. The universality of this response and the high level of conservation of these proteins has allowed scientists to investigate the nature and function of hsps in prokaryotes and lower species and then to extrapolate these findings to eukaryotes and higher species. Several advances have expanded our understanding of the stress response and the implications of this phenomenon on the control of normal growth, development, and disease are beginning to emerge. One of the most important advances has been the discovery of mutations of heat shock genes in Saccharomyces cerevisiae and in Escherichia coli. Genetic and molecular analyses of these mutations have permitted investigation of the mechanisms controlling the regulation, expression, and function of stress proteins. Also, polyclonal and monoclonal antibodies directed against hsps have been used to identify the subcellular distribution of these proteins under normal conditions, as well as following incidences of stress, disease, and during development. Finally, many genes of these protein families have been cloned, and promoter sequences necessary for their induction have been discerned in prokaryotes and eukaroytes. In this review we primarily examine some of the hsps that have been studied in mammalian cells. The aim of this review is to begin to draw attention to the role and association between hsps, stress proteins, and their expression during normal development and disease. The reader may also refer to the scholarly reviews of Craig 4 and Lindquist and Craig5 for a comprehensive biochemical and genetic overview of hsps and the heat shock response in prokaryotes and eukaryotes.

Spinal cord injury and the stress protein response.

The heat shock or stress response is a highly conserved primary cellular response to injury. Synthesis of stress proteins (also called "heat shock proteins") is an integral component of this response. Protection from various forms of sublethal stress following increased production of stress proteins has been demonstrated in a number of systems, including the retina. This immunocytochemical study demonstrates the synthesis, accumulation, and redistribution of the 70-kD stress protein following spinal cord injury in rats. The observations confirm that stress protein production is a fundamental feature of the molecular response of the spinal cord to injury, and raise the possibility that augmentation of this response could enhance posttraumatic neuronal survival.