Top PDF Biophoton emission induced by heat shock.

Biophoton emission induced by heat shock.

Biophoton emission induced by heat shock.

The sample azuki bean (Vigna angularis) seeds were purchased from Nakahara Seed Co. Ltd., Japan. To induce germination, about 60 seeds were laid on wet cotton and placed in the incubator (IG-47M, Yamato Science Inc., Japan) for 24 hours under relative humidity (RH) and temperature (T) conditions of 95% and 35 uC, respectively. To promote growth, RH and T were decreased to 82% and 24uC after 24 hours, respectively. To prevent photo- synthesis, these incubation steps were performed in the dark. Pure water (conductivity: 0.10 m S) distilled and filtered by GSH200 Aquarius purifier (Advantec Co., Japan) was used for culture solution. We selected ten germinating seeds with root lengths of 5– 20 mm for one measurement, and the cotton wastes attaching to roots were removed because of their strong fluorescent. In order to investigate the responses of the intact samples which were in the same growth stage and were not heated, we used another samples for each measurement. In the measurements, we placed the sample roots into an inoperculate Petri dish (diameter: 150 mm) and added pure water in the dish until the total weight of seeds and water reached 20g.
Mostrar mais

6 Ler mais

EXPERIMENTALLY INDUCED HEAT- AND COLD-SHOCK TOLERANCE IN ADULT Panstrongylus megistus (BURMEISTER) (HEMIPTERA, REDUVIIDAE)

EXPERIMENTALLY INDUCED HEAT- AND COLD-SHOCK TOLERANCE IN ADULT Panstrongylus megistus (BURMEISTER) (HEMIPTERA, REDUVIIDAE)

According to the World Health Organization, Chagas’ disease affects 20 million people, mostly in Central and South America. In Brazil, Chagas’ disease is the third greatest cause of death by infectious parasitic diseases (Silveira & Rezende, 1994; Dos Reis, 1997), with vectorial transmission being the principal route of infection. Studies of the responses of blood-sucking insects to various stress factors represent an important approach to understanding how to control these species (Rodrigues et al., 1991; Silva & Silva, 1993; Garcia et al., 1999; Schmuñis, 2000).

7 Ler mais

Induction of heat-shock protein 70 expression by geranylgeranylacetone shows cytoprotective effects in cardiomyocytes of mice under humid heat stress.

Induction of heat-shock protein 70 expression by geranylgeranylacetone shows cytoprotective effects in cardiomyocytes of mice under humid heat stress.

that heat stress results in the release of proteins located in the mitochondrial inner-membrane space and triggers the activation of the caspase family proteases [4]. Caspase-3 is one of the key mediators of multiple apoptotic signaling pathways including the death-receptor pathway and the mitochondrial pathway [35,36]. Bcl-2 is an inhibitor of mitochondria-mediated apoptosis [37]. Here, we found that GGA pretreatment significantly decreased cell apoptosis under HHS via increasing Bcl-2 expression and decreasing caspase-3. Previous studies have revealed that GGA induces Hsp70 overexpression and contributed to the inhibition of cell apoptosis under oxidative stress [28,38]. Hsp70 is a well- known member that protects cells and tissues from different pathological conditions [12,13]. It has been reported that almost all types of cell stress can induce Hsp expression [39]. Stress stimuli including environment stress and pathological stress commonly cause protein damage, while Hsp70 is the main chaperone responsible for protein folding and the inhibition of protein aggregation [39,40]. Hsp70 can force target proteins to maintain an adequate structure and retain normal function [41]. It has been reported that Hsp70 overexpression prevents the oxidative-stress- induced decline of mitochondrial permeability transition and the swelling of mitochondria, which may explain the role of Hsp70 in the inhibition of cell apoptosis [42]. Other studies have suggested that Hsp70 suppresses cell apoptosis via blocking JNKs and downstream of JNK activation prior to caspase-3 activation [43,44,45]. In the present study, we have demonstrated that GGA pretreatment significantly enhanced Hsp70 expression, which may account for the apoptosis resistance induced by GGA pretreatment under HHS. However, the mechanism of Hsp induction under various stresses remains poorly understood. One of the mecha- nisms is the activation of heat-shock factor 1 (Hsf-1), which is inactive in the cytoplasm under normal conditions but when activated, binds to Hsps and translocates to the nucleus to enhance Hsp transcription [10,46]. Ikeyama et al. have described that GGA treatment activates Hsf-1 in mouse hepatocytes exposed to ethanol or H 2 O 2 [28]. However, further studies should be
Mostrar mais

7 Ler mais

Frayed at the edges: selective pressure and adaptive response to abiotic stressors are mismatched in low diversity edge populations

Frayed at the edges: selective pressure and adaptive response to abiotic stressors are mismatched in low diversity edge populations

In this study we tested the hypothesis that fitness and adaptive potential are reduced at distributional range edges by investigating the functional differentiation in the heat shock response (HSR) between central and southern (rear) edge populations of F. serratus , as well as the resilience to desiccation, another major emersion stress in the intertidal zone. The congener F. vesiculosus , which has a more southerly distribution limit, provided a ‘non-edge’ control for HSR at the same locations. First, the potential of climate-forcing abiotic factors as selective agents was assessed in the field by comparing the maximum emersion times (upper vertical limits) and summer thermal regimes from in situ temperature profiles experienced by central and southern edge populations. Secondly, in common garden experiments, both photosynthetic indicators and heat shock protein (Hsp) gene expression were used to test the resilience to heat shock (HS), and the relative HSR, respectively, of central and southern edge populations. A second set of common garden experiments compared resilience to desiccation in F. serratus . Our results provide empirical support for the idea that fitness is eroded along with genetic diversity in marginal populations, suggesting that they may be poorly equipped to respond to climate-induced environmental change.
Mostrar mais

13 Ler mais

Effects of hypoxia storage on gene transcript accumulation during tomato fruit ripening

Effects of hypoxia storage on gene transcript accumulation during tomato fruit ripening

Tomato (Solanum lycopersicum L.) is a climacteric fruit, i.e., during ripening an increase in ethylene synthesis and high rate of respiration are observed. Low oxygen levels might inhibit or block ethylene biosynthesis and therefore retard the ripening process. Despite commercial applications of low oxygen treatments, the precise mode of action of low oxygen in fruit tissues and ripening is not well understood. In order to delineate the molecular responses to low oxygen stress in fruits, hypoxia-responsive tomato genes encoding heat shock factors, heat shock proteins, and enzymes involved in fermentation and ethylene synthesis pathways were analyzed. In this study, tomato fruit stored under hypoxia conditions showed that HSP17.7 and HSP21 genes were highly induced by low oxygen level, indicating their primary role in maintaining cellular homeostasis after this stress.
Mostrar mais

8 Ler mais

Aureolib - a proteome signature library: towards an understanding of staphylococcus aureus pathophysiology.

Aureolib - a proteome signature library: towards an understanding of staphylococcus aureus pathophysiology.

diamide, paraquat, NO, fermentation, nitrate respiration, heat shock, puromycin, mupirocin). These expression profiles are stored in an online resource called Aureolib (http://www.aureolib.de). Moreover, information on target genes of 75 regulators and regulatory elements were included in the database. Cross-comparisons of this extensive data collection of protein synthesis profiles using the tools implemented in Aureolib lead to the identification of stress and starvation specific marker proteins. Altogether, 226 protein synthesis profiles showed induction ratios of 2.5-fold or higher under at least one of the tested conditions with 157 protein synthesis profiles specifically induced in response to a single stimulus. The respective proteins might serve as marker proteins for the corresponding stimulus. By contrast, proteins whose synthesis was increased or repressed in response to more than four stimuli are rather exceptional. The only protein that was induced by six stimuli is the universal stress protein SACOL1759. Most strikingly, cluster analyses of synthesis profiles of proteins differentially synthesized under at least one condition revealed only in rare cases a grouping that correlated with known regulon structures. The most prominent examples are the GapR, Rex, and CtsR regulon. In contrast, protein synthesis profiles of proteins belonging to the CodY and s B regulon are widely distributed. In summary, Aureolib is by far the most comprehensive protein expression database for S. aureus and provides an essential tool to decipher more complex adaptation processes in S. aureus during host pathogen interaction.
Mostrar mais

16 Ler mais

Stress-induced PARP activation mediates recruitment of Drosophila Mi-2 to promote heat shock gene expression.

Stress-induced PARP activation mediates recruitment of Drosophila Mi-2 to promote heat shock gene expression.

Despite its well established role in repression, dMi-2 localises to actively transcribed chromosome regions suggesting an unexpect- ed potential function of dMi-2 in transcription [23]. Here we sought to establish how dMi-2 is recruited to actively transcribed chromatin and to clarify its role in transcriptional activation using genetic, biochemical and pharmacological assays. We show that dMi-2 rapidly associates with activated HS loci, covering the entire transcribed region of the hsp70 gene. dMi-2 recruitment is not affected when transcriptional elongation is blocked but is abrogated when PARP is inhibited. Indeed, we find that dMi-2 specifically binds PARP’s oligomeric product PAR in vitro. Significantly, a dMi-2 mutant unable to bind PAR is not recruited to active HS loci in vivo. We have identified several regions of dMi- 2 that bind PAR in vitro. These include the chromodomains and a series of K/R-rich motifs near the N-terminus. Further, dMi-2 depletion or expression of an inactive enzyme greatly decreases transcript levels, suggesting that dMi-2 actively supports efficient HS gene expression. Indeed, dMi-2 associates with nascent hsp70 transcripts in vivo and ablation of dMi-2 function results in inefficient RNA processing. RNA and PAR compete for dMi-2 binding suggesting a two step process of dMi-2 association with HS genes: intial recruitment of dMi-2 is effected by its binding to PAR which is produced prior to the onset of transcription, dMi-2 then switches to interacting with the emerging nascent transcripts. Taken together, our results uncover PAR binding as a novel mechanism for the recruitment of the nucleosome remodeler dMi- 2 to targeted sites of PARP activitation upon environmental stress
Mostrar mais

15 Ler mais

Expression of heat shock protein and trehalose-6-phosphate synthase homologues induced during water deficit in cotton

Expression of heat shock protein and trehalose-6-phosphate synthase homologues induced during water deficit in cotton

Since plants started to emerge 1.5 billion years ago (Lehninger et al., 1993) evolutionary pressure has shaped plant responses to water deficit resulting in a complex web of responses. These responses start with stress perception, which initiates signal transduction pathways, and end in changes at many metabolic, physiological and developmen- tal levels. Therefore, responses to drought will be condi- tioned not only by the nature and intensity of the environ- mental factors involved, but also by the ecological histo- ries of species, ecotypes, cultivars and genotypes. As a consequence, a large range of molecular, biochemical and physiological responses arise when plants are submitted to periods of water deficit. Several genes are likely to be in- volved in each drought tolerance trait. Accordingly, mo- lecular biology and plant physiology together can aid iden- tifying and selecting these genes, and determine their in- fluence in yield (Turner, 1997). Differently expressed genes are usually identified by comparing mRNA abundance (Wan et al., 1996). Therefore, a partial understanding of these developmental events may be obtained by analyzing and comparing mRNAs isolated from well-watered and water- stressed plants.
Mostrar mais

10 Ler mais

Protein kinase A binds and activates heat shock factor 1.

Protein kinase A binds and activates heat shock factor 1.

phosphorylated samples of HSF1, detected by this antibody were then digested in-gel with trypsin and analyzed by mass spectrometry (Fig. 2A). Database analysis of the trypsin fragments indicated the generation of two principal phosphopeptide species, V310-R336 containing a potential site for PKAca at S320 within a consensus PKA motif and K118-K126 containing S121 (Fig. 2A). We have shown that the latter site (S121) is, when phosphorylated, inhibitory for HSF1 under resting conditions. However, the influence of phospho-S121-HSF1 is overridden during heat shock under which conditions it does not influence transcription and becomes dephosphorylated [18]. We therefore concentrated on the novel S320 phosphorylation site. We examined the role of heat shock and PKAca expression on HSF1-S320 phosphorylation using commercial antibodies specific for this phosphorylated form of HSF1 (Fig. 2B, C). Cells apparently contain significant background levels of phospho-S320-HSF1 and phosphorylation increased immediately after heat shock, before decaying back to basal levels by 2 hr recovery at 37 uC, correlating well with the period of increased trans-activation by heat shock (Fig. 2C). We then carried out experiments in which intracellular PKAca levels were reduced by stable knockdown with small hairpin RNA packaged in lentivirus (Fig. 2B). We employed two such shRNA species, PKAkd#1 and PKAkd#2, one of which (PKAkd#1) efficiently reduced PKAca levels in infected cells while the other (PKAkd#2) was relatively less effective (Fig. 2B). Phospho-S320- HSF1 levels were significantly reduced in cells expressing PKAkd#1 compared to cells expressing PKAkd#2 or control cells infected with lentivirus enclosing a scrambled RNA species (PKA scr) (Fig. 2C). As a further control, we investigated HSF1 phosphorylation at the adjacent serine 326 using antibodies specific to this phosphorylated motif. HSF1 phosphorylation at this site was also increased by heat shock, although knockdown of PKAca had minimal effects on S326 phosphorylation (Fig. 2C). Phosphorylation of HSF1 at these two adjacent serine residues, although induced with similar kinetics by heat shock, is evidently regulated independently. It is notable that HSF1 hyperpho- sphorylation was not markedly ablated by PKAca knockdown conditions that led to reduced phospho-S320-HSF1 suggesting that other posttranslational modifications may contribute to the electrophoretic mobility shift seen in HSF1 after heat shock (Fig. 2 C).
Mostrar mais

13 Ler mais

Heat shock-induced accumulation of translation elongation and termination factors precedes assembly of stress granules in S. cerevisiae.

Heat shock-induced accumulation of translation elongation and termination factors precedes assembly of stress granules in S. cerevisiae.

Meanwhile assembly of P-bodies is generally connected with reprogramming of cells to new growth conditions, SGs are formed in response to severe stresses when the translation of housekeeping genes is completely shut down. Although SGs are thought to be sites where mRNA molecules are sorted, selected, and together with translation factors, sheltered from the effects of a stress [15,53], the fate of SGs components after a stress relief is mainly unknown [42]. However, it is conceivable that at least some SGs protein components may also return back to the active translation. In this respect, our observation of accumulation of the key translation initiation factor eIF2a (Sui2p) on dissolving SGs during cell recovery from the heat stress suggests that SGs may help cells to effectively recover after a stress relief. To recover, a fast restart of translation is facilitated by increasing a local concentration of translation initiation and elongation components in SGs, where only the key regulator, eIF2a factor (Sui2p), is missing and recruited after a stress relief only. There is a supporting evidence from mammalian cells where a phospho-variant of the eIF2a factor subunit was found to be recruited to disassembling SGs and considered as important for SGs disassembly [15]. On the contrary, we found that the eIF2a factor (Sui2p) accumulation on SGs does not depend on the phosphorylation status of this factor. It implies that the eIF2a factor is recruited to dissolving SGs also in its unphosphorylated state, thus translation competent. Taken together, it reinforces the hypothesis that SGs serve as sites where translation is effectively initiated at the time of a stress relief. We showed here that a portion of the key translation initiation factor eIF2a (Sui2p) is recruited to dissolving SGs, but some of the Sui2-GFP foci did not co-localize with SGs markers in these cells. We suggest that these particular Sui2-GFP foci may represent the eIF2B bodies [54]. In accordance with our assumption that translation is restored on dissolving SGs, the eIF2B bodies should also be formed under recovery from the stress. The eIF2B bodies most probably serve as sites, where guanine nucleotide exchange of the eIF2a factor takes place and the eIF2a-GDP form is converted to the translation competent eIF2a-GTP form. The eIF2B bodies would then help to regenerate efficiently the translation competent form of the eIF2a factor as suggested previously [55]. The eIF2a-GTP form would then be recruited to sites on dissolving SGs.
Mostrar mais

17 Ler mais

Quantitative analysis of the interplay between hsc70 and its co-chaperone HspBP1

Quantitative analysis of the interplay between hsc70 and its co-chaperone HspBP1

Heat shock shifts the location of hsc70 towards the nucleus in stressed cells (Figs. 1, 3 and 4) and to nucleoli during recovery (Fig. 6). By contrast, no significant global redistribution was observed for HspBP1. Hsc70 relocation and sequestration (Kodiha et al., 2005) will restrict hsc70/HspBP1 interactions in a compartment-specific fashion and could have important physiological consequences. For instance, a HspBP1:chaperone ratio of 4:1 is required to inhibit 50% of the chaperone function (Raynes et al., 2003). The stress-induced nuclear and nucleolar relocation of hsc70 could thus strengthen the inhibitory role of HspBP1 in the cytoplasm. At the same time, liberation from hsc70 may promote other functions of HspBP1 that are unrelated to its chaperone partner. Possible examples of such processes include the inhibition of the ubiquitin ligase CHIP and the stabilization of specific CHIP targets (Alberti et al., 2004; Rogon et al., 2014).
Mostrar mais

22 Ler mais

The membrane-associated transient receptor potential vanilloid channel is the central heat shock receptor controlling the cellular heat shock response in epithelial cells.

The membrane-associated transient receptor potential vanilloid channel is the central heat shock receptor controlling the cellular heat shock response in epithelial cells.

channels are mostly expressed in primary sensory neurons and that they are naturally activated by heat or by capsaicin, protons, and anandamide [38]. We show evidence that TRPV1 acts as a general cellular stress sensor, which in addition of being a thermosensor, elicits a heat-shock-like cellular stress response following heat or other chemical treatments in epithelial cells, such as in the lungs, as well as in various cancerous cells. We demonstrate that treatment of human embryonic kidney cells, alveolar epithelial cells, human breast cancer cells or colon cancer cells with heat, or TRPV1 agonists, capsaicin or RTX, induced the accumulation of Hsp70, Hsp90 and Hsp27, and Hsp70 and Hsp90, respectively, which are hallmarks of the cellular heat-shock response. Thus, in addition to the well-established ability of capsaicin to induce isothermally the activation of an inter-cellular signal resulting in the deceptive sensation of heat [38], TRPV1 agonists can also induce an intracellular signal resulting in the synthesis of HSPs. Further, we show by immunoblots, RT-PCR and Gel-shift assays that capsaicin treatment resulted in the isothermal activation of HSF-1, suggesting that TRPV1, the only known capsaicin target, is directly responsible for the heat or the chemical signal that up-regulates the heat shock genes, and the cellular heat shock response (HSR) in general. In support of these findings, we found that cells devoid of the TRPV1 gene, could not over express Hsp70 in response to heat-shock or capsaicin treatments. Further, we show that in cells harboring TRPV1, Figure 2. TRPV1 mRNA and protein abundances in HEK-293e cells. A. Semi-quantitative RT-PCR for TRPV1. Upper left panel: mRNA levels from PC3 prostate cancer cells: non treated cells, cells treated with 32 mM capsaicin for 1 hr and cells treated with heat shock at 42uC for 3 hrs. Lower right panel: mRNA levels of GAPDH as well as densitometric. Upper right panel: mRNA levels from HEK-293e cells: non treated cells, cells treated with 32 mM capsaicin for 1 hr (Caps), cells treated with heat shock at 42uC for 3 hrs, and cells treated with heat shock at 42uC for 3 hrs with the addition of 32 mM capsaicin. Lower right Panel: mRNA levels of GAPDH as well as densitometry. B. Representative immunoblot analysis of TRPV1 abundance. TRPV1 was detected in HEK-293e cells. Cells in culture were incubated with 0.01% DMSO or treated with 4 mM, 16 mM or 32 mM of capsaicin for 1 hr. C. Representative immunoblot analysis of TRPV1 and Hsp90 abundances in HEK-293e cells. Cells were treated with 32 mM capsaicin for 0 hr, 1 hr, 4 hrs and 6 hrs.
Mostrar mais

12 Ler mais

A cytosolic class II small heat shock protein, PfHSP17.2, confers resistance to heat, cold, and salt stresses in transgenic Arabidopsis

A cytosolic class II small heat shock protein, PfHSP17.2, confers resistance to heat, cold, and salt stresses in transgenic Arabidopsis

Abiotic stresses such as high temperature, drought, salt, cold, and oxidative damage are the main factors im- pacting plant growth (Vermeulen et al., 2012; Nelson et al., 2014; Kumar et al., 2015). In response to these stresses, plants have developed a wide range of physiological and biochemical mechanisms to protect themselves from dam- age (Cabane et al., 1993; Sun et al., 2001; Murakami et al., 2004; Hu et al., 2009; Ahuja et al., 2010, Perez-Clemente et al., 2013; Ruibal et al., 2013). Heat shock proteins (HSPs), which could be induced in almost all organisms by high temperature and other abiotic and biotic stresses, were ac- cumulated in plants as one of the strategies to deal with stressful conditions (Derocher et al., 1991; Lee et al., 1997; Malik et al., 1999; Zhou et al., 2012; Park et al., 2015; Zhai et al., 2016). HSPs are evolutionarily conserved proteins. They are divided into five subfamilies based on their appar- ent molecular weights, viz. HSP100, HSP90, HSP70, HS- P60, and small HSPs (Boston et al., 1996). Among them, small heat shock proteins (sHSPs), which could either pro- tect the plant from damage caused by the stress or help re- pair the damage, were proved to have vital roles in response to abiotic stresses (Chao et al., 2009; Lin et al., 2010; Wang
Mostrar mais

12 Ler mais

Dietary restriction abrogates antibody production induced by a DNA vaccine encoding the mycobacterial 65 kDa heat shock protein

Dietary restriction abrogates antibody production induced by a DNA vaccine encoding the mycobacterial 65 kDa heat shock protein

Background: Protein-calorie malnutrition (PCM) is the most common type of malnutrition. PCM leads to immunodeficiency and consequent increased susceptibility to infectious agents. In addition, responses to prophylactic vaccines depend on nutritional status. This study aims to evaluate the ability of undernourished mice to mount an immune response to a genetic vaccine (pVAXhsp65) against tuberculosis, containing the gene coding for the heat shock protein 65 from mycobacteria. Methods: Young adult female BALB/c mice were fed ad libitum or with 80% of the amount of food consumed by a normal diet group. We initially characterized a mice model of dietary restriction by determining body and spleen weights, hematological parameters and histopathological changes in lymphoid organs. The ability of splenic cells to produce IFN-gamma and IL-4 upon in vitro stimulation with LPS or S. aureus and the serum titer of specific IgG1 and IgG2a anti-hsp65 antibodies after intramuscular immunization with pVAXhsp65 was then tested.
Mostrar mais

8 Ler mais

Systemic analysis of heat shock response induced by heat shock and a proteasome inhibitor MG132.

Systemic analysis of heat shock response induced by heat shock and a proteasome inhibitor MG132.

The molecular basis of heat shock response (HSR), a cellular defense mechanism against various stresses, is not well understood. In this, the first comprehensive analysis of gene expression changes in response to heat shock and MG132 (a proteasome inhibitor), both of which are known to induce heat shock proteins (Hsps), we compared the responses of normal mouse fibrosarcoma cell line, RIF- 1, and its thermotolerant variant cell line, TR-RIF-1 (TR), to the two stresses. The cellular responses we examined included Hsp expressions, cell viability, total protein synthesis patterns, and accumulation of poly-ubiquitinated proteins. We also compared the mRNA expression profiles and kinetics, in the two cell lines exposed to the two stresses, using microarray analysis. In contrast to RIF-1 cells, TR cells resist heat shock caused changes in cell viability and whole-cell protein synthesis. The patterns of total cellular protein synthesis and accumulation of poly- ubiquitinated proteins in the two cell lines were distinct, depending on the stress and the cell line. Microarray analysis revealed that the gene expression pattern of TR cells was faster and more transient than that of RIF-1 cells, in response to heat shock, while both RIF-1 and TR cells showed similar kinetics of mRNA expression in response to MG132. We also found that 2,208 genes were up-regulated more than 2 fold and could sort them into three groups: 1) genes regulated by both heat shock and MG132, (e.g. chaperones); 2) those regulated only by heat shock (e.g. DNA binding proteins including histones); and 3) those regulated only by MG132 (e.g. innate immunity and defense related molecules). This study shows that heat shock and MG132 share some aspects of HSR signaling pathway, at the same time, inducing distinct stress response signaling pathways, triggered by distinct abnormal proteins.
Mostrar mais

15 Ler mais

Specific phosphorylation of histone demethylase KDM3A determines target gene expression in response to heat shock.

Specific phosphorylation of histone demethylase KDM3A determines target gene expression in response to heat shock.

The above results indicate that in untreated Jurkat cells, the ectopic KDM3A S/D mutant occupied the GAS and decreased the H3K9me2 level, but for an unknown reason, hsp90amRNA expression was not induced. Therefore, we transfected wild-type and S/D mutant KDM3A into Jurkat cells to examine the occupancy of the Brg1 chromatin remodeling complex at the GAS before and after HS treatment or after IFNc treatment. The ChIP data indicated that only when KDM3A-S/D was transfected did Brg1 efficiently occupy the GAS following both HS (Fig. 6K) and IFNc treatment (Fig. 6L), but this binding was never constitutive at the GAS. However, transfected KDM3A and its S/A, S/D mutants did not affect Stat1 binding at the GAS (S11 Figure). This result agrees with our previous report that Brg1 is only recruited by p-Stat1 that is induced in response to HS treatment [28]. In IFNc-treated cells, p-Stat1 also occupied the GAS [32], possibly providing a docking site for KDM3A-S/D and activating hsp90a. Therefore, it is conceivable that Stat1-mediated p-KDM3A recruitment is necessary but not sufficient for gene activation (Fig. 7). Our data indicate that the level of gene activation under HS or IFN-c treatment is determined by the potential for an external stimulus to activate MSK1, which phosphorylates KDM3A. The two-step model in Fig. 7 shows that, first, MSK1- transfected as a non-functional control that displays similar effects to transfection with wild-type KDM3A. The HS-induced input percentage of KDM3A was eliminated (F); that of H3K9me2 was retained at a high level (G), and the HS–induced mRNA expression levels were significantly reduced in the KDM3A-S264A mutant-transfected cells under HS (H) but not in the wild-type or S265A KDM3A-transfected control cells. (I) The cells that were transfected with wild-type KDM3A or KDM3A-S264A were treated with HS (filled bars) or not (open bars). DNase I sensitivity analysis showing chromatin remodeling upstream of hsp90a. The annotations are the
Mostrar mais

15 Ler mais

Effect of shock wave reapplication on urinary n-acetyl-beta-glucosaminidase in canine kidney

Effect of shock wave reapplication on urinary n-acetyl-beta-glucosaminidase in canine kidney

The loss of this lysosomal enzyme immedi- ately following ESWL suggests the presence of cor- responding morphologic alterations in the renal tu- bular system, and the intensity of urinary elimination of the enzyme reflects the severity of the tubular dam- age (5). Since NAG is an enzyme with high molecu- lar weight (> 70,000) it is not filtered by the glom- erulus under normal conditions, but when any acute renal damage occurs it reaches the renal tubule’s lu- men and finally the urine.

7 Ler mais

Impact of metal contamination on early life history stages of common cuttlefish (Sepia officinalis)

Impact of metal contamination on early life history stages of common cuttlefish (Sepia officinalis)

31 mechanisms from the high values found in the environment. In contrast, higher concentrations of As were found to be accumulated in the embryos. This association was also observed in the pristine area, Caldeira (Caeiro et al., 2005), suggesting a strong affinity of As to the embryos. In general, higher levels of Cu and, in a less extend, of Zn were also registered in the embryos in the three capture areas. The essentiality of these elements and the presence in several cellular structures may favour the permeability of the eggshells to these elements. However, a different pattern was observed by Miramand et al. (2006), which observed an enhancement of Cu concentrations in the eggshells. The enhancement of Zn concentrations observed in the embryos is in agreement with finding made by Bustamante et al. (2002). Furthermore, Cu and Zn were the elements that presented the lowest coefficients of variation in eggshells and more clearly in embryos. This low variability may result from the metabolic control of these two essential elements as proposed by Villanueva and Bustamante (2006).
Mostrar mais

76 Ler mais

J. Bras. Patol. Med. Lab.  vol.40 número6

J. Bras. Patol. Med. Lab. vol.40 número6

As฀ proteínas฀ de฀ choque฀ térmico฀ ( heat฀ shock฀ protein ฀ –฀ hsp),฀ no฀ passado฀ chamadas฀ de฀ proteínas฀ de฀ estresse,฀ pertencem฀ a฀ um฀ grupo฀ de฀ pelo฀ menos฀ duas฀ dúzias฀ de฀ pr[r]

4 Ler mais

Anticorpos anti-Hsp90 e lúpus eritematoso sistêmico

Anticorpos anti-Hsp90 e lúpus eritematoso sistêmico

Hsp90, our main focus in this study, is an abundant cytoplasm protein representing 1% of the total of non-stimulated proteins. Hsp90 is encoded by two genes (Hsp 90α and Hsp 90β), both heat inducible. 22,23,24 In cell physiology, Hsp90 is known to keep key proteins as steroid receptors or tyrosine kinase Src inactive until converting them to the active form when cells are exposed to their ligands. 25 The cellular expression of Hsp90, Hsp70, and Hsp27 have a negative effect on apoptosis triggered by stimuli such as hyperthermia and oxidative stress. Due to their anti-apoptosis effect, these Hsp confer resistance to anti- cancer drugs and increase survival of tumor cells. 26,27,28 Of note, anti-Hsp antibodies correlate positively to chemotherapy response in patients with osteosarcoma. 29
Mostrar mais

163 Ler mais

Show all 10000 documents...