Stress Response Heat Shock Protein Research Articles

Exploring mitigating role of zinc nanoparticles on arsenic, ammonia and temperature stress using molecular signature in fish

BackgroundThe pollution and climate change in aquatic ecosystems are major problems threatening the aquatic organisms for existence in the recent timeline, which promotes the extinction of the fish species. However, the present study dealt with zinc nanoparticles (Zn-NPs) in mitigating arsenic, ammonia and high temperature stresses in Pangasianodon hypophthalmus. Materials and methodsTo studying different gene expressions, an experiment was conducted to mitigate the multiple stressors using dietary Zn-NPs at 0, 2, 4, and 6 mg kg-1 diets. In the present investigation, the gene expressions studies were performed for growth hormone regulator 1 (GHR1), growth hormone regulator β (GHRβ), growth hormone (GR) in liver and gill tissue as well as myostatin (MYST) and somatostatin (SMT) in the muscle tissue. The anti-oxidative genes CAT, SOD and GPx in liver and gill tissues were also analysed. Expression studies for stress responsive heat shock protein gene (HSP70), DNA damage inducible protein, inducible nitric oxide synthase (iNOS), immune related genes such as interleukin (IL), tumour necrosis factor (TNFα), toll like receptor (TLR) and immunoglobulin were performed. At the end of the experiment the fish were infected with Aeromonas hydrophila to evaluate the immunomodulatory role of Zn-NPs. ResultsIn the present investigation, the growth hormone regulator 1 (GHR1), growth hormone regulator β (GHRβ), growth hormone (GR) in liver and gill as well as myostatin (MYST) and somatostatin (SMT) in muscle were noticeably altered, whereas, Zn-NPs at 4 mg kg-1 diet improved gene expressions. The anti-oxidant gene viz. CAT, SOD and GPx in liver and gill tissues were upregulated by stressors such as As, NH3, NH3+T. As+T and As+NH3+T. Therefore, anti-oxidant genes were noticeably improved with dietary Zn-NPs diet. The stress protein gene (HSP70), DNA damage inducible protein, inducible nitric oxide synthase (iNOS) was significantly upregulated, whereas, Zn-NPs diet was applied to the corrected gene regulation. Similarly, immune related genes such as interleukin (IL), tumour necrosis factor (TNFα), toll like receptor (TLR) and immunoglobulin were highly affected by stressors. Dietary Zn-NPs at 4 mg kg-1 diet was improved all the immune related gene expression and mitigate arsenic, ammonia and high temperature stress in fish. ConclusionThe present investigation revealed that Zn-NPs at 4.0 mg kg-1 diet has enormous potential to modulates arsenic, ammonia and high temperature stress, and protect against pathogenic infections in fish.

Transcriptome profiles of Daphnia magna across to the different water chemistry of surface water of the Korean Demilitarized Zone

The Korean Demilitarized Zone (DMZ) has almost completely protected surface water conditions. Despite the water conditions of DMZ are excellent clear, downstream of river or natural irrigation ponds near the region are recently developed by human activities such as agriculture, ginseng fields or ecotourism. To understand the potential effect of physico-chemical characteristics of the DMZ water, the freshwater model Daphnia magna was exposed to water samples that were collected from four sites near the DMZ. RNA-seq identified some differentially expressed transcripts which are sensitive to small differences of water chemistry. Particularly transcripts coding for the stress responsive heat shock protein (Hsp) superfamily and innate immune system were significantly increased in response to the water samples of irrigation ponds and downstream of Seweol river where are analyzed to have low pH and high levels of chemical fertilizer nutrients such as nitrogen (N) and phosphorus (P). These water samples decreased mRNA expressions of crucial members which are involved in crustacean morphogenesis and reproduction metabolism (e.g. cuticle protein family, ecdysteroid metabolism, vitellogenesis). Evidence on the high transcriptional sensitivity of the aquatic model D. magna against small differences of water chemistry will be a useful strength for further applications in environmental and ecotoxicological genomics.

Marked daily variation in spring temperature induces variation in Caspase-3, Bcl-2 and HSP60 in Asian Short-toed Larks: how do wild birds maintain cellular homeostasis to cope with the ambient temperature variation?

Daily variation in ambient temperature is marked during the spring at middle and high latitudes, when birds have to physiologically prepare for the subsequent breeding period. The ability of birds to maintain homeostasis during this period is important to survival and reproduction. We compared levels of the apoptotic proteins Caspase-3 and B cell lymphoma 2 (Bcl-2) and of the stress response heat shock protein 60 (HSP60) in peripheral blood cell samples of wild Asian Short-toed Larks (Calandrella cheleensis) collected on specific dates in the spring of 2014 and 2015 at different ambient temperatures. We also conducted a controlled temperature experiment to confirm the effect of temperature on the secretion of these proteins. Our results show that levels of Caspase-3, Bcl-2 and HSP60 in the blood of Asian Short-toed Larks varied with daily variations in temperature. Caspase-3 levels were higher but Bcl-2 levels were lower in blood samples collected on days when the mean daily temperature had dramatically increased or decreased, and this trend was confirmed by the results of our laboratory experiment on the effects of temperature on Caspase-3 and Bcl-2 levels. HSP60 levels in the blood of wild-caught Asian Short-toed Larks were higher in samples collected on days with higher temperatures in 2014 and in the high-temperature treatment group in our laboratory experiment. These results indicate that marked daily variation in ambient temperature may increase Caspase-3 levels to initiate apoptosis and that Bcl-2 and HSP60 maintain cellular homeostasis by inhibiting this increase in Caspase-3, suggesting a possible molecular mechanism by which birds cope with the effects of ambient temperature variation at the cellular level.

How tissues can take the heat.

Stress Response Heat shock proteins (HSPs) show a generally conserved stress response, interacting with specific chaperone proteins to maintain cellular homeostasis. However, studies of the heat shock response (HSR) tend to be performed in unicellular organisms or tissue culture. To test whether the HSR is global or tissue-specific, Ma et al. examined HSR and specificity in muscle and intestine in Caenorhabditis elegans. They observed that the tissue specificity of the HSR was determined by the ratio of the specific proteome of each tissue relative to associated HSP chaperone proteins. On the basis of these findings, the authors suggest that some tissue-specific human disease may be explained by similar mechanisms. G3 10.1534/g3.116.038232 (2017).

Comparison of thyroid hormone-dependent gene responses in vivo and in organ culture of the American bullfrog (Rana (Lithobates) catesbeiana) lung

Postembryonic frog development requires a thyroid hormone (TH)-dependent metamorphic transition from an aquatic larva to a terrestrial frog. Such change in environment involves lung maturation in preparation for breathing air. However, little is known regarding the underlying molecular events and the role of THs in this process. Using quantitative real-time polymerase chain reaction, we evaluated Rana (Lithobates) catesbeiana lung mRNA transcripts representing key elements of TH and oxidative stress signaling pathways during natural and TH-induced precocious metamorphosis. TH induction was evaluated in two ways: 1) in vivo through interperitoneal injection of 10pmol/g body weight of 3,3′, 5-triiodothyronine (T3) into premetamorphic tadpoles and analysis after 48h, and 2) in serum-free organ culture in the presence of 10nM T3 after 48h. Abundance of transcripts encoding the transcriptional regulators TH receptors α and β, TH-induced bZip protein, and CCAAT/enhancer binding protein 1 was increased during postembryonic development and following administration of exogenous THs to premetamorphic tadpoles in vivo and culture. In contrast, mRNA representing Krüppel-like factor 9 and cold-inducible RNA binding protein revealed differential effects between natural and precocious metamorphosis. Elevated levels of catalase and Cu/Zn superoxide dismutase mRNA were observed at the end of metamorphosis with transcript levels displaying minimal TH-dependency. No change in stress-responsive heat shock protein 30 mRNA abundance was noted. The results support a role for TH-dependent reprogramming of the lung transcriptome during frog development and reveal a requirement for increased antioxidant capacity following anuran metamorphosis.

Evaluation of the effects of titanium dioxide nanoparticles on cultured Rana catesbeiana tailfin tissue

Nanoparticles (NPs), materials that have one dimension less than 100 nm, are used in manufacturing, health, and food products, and consumer products including cosmetics, clothing, and household appliances. Their utility to industry is derived from their high surface-area-to-volume ratios and physico-chemical properties distinct from their bulk counterparts, but the near-certainty that NPs will be released into the environment raises the possibility that they could present health risks to humans and wildlife. The thyroid hormones (THs), thyroxine, and 3,3′,5-triiodothyronine (T3), are involved in development and metabolism in vertebrates including humans and frogs. Many of the processes of anuran metamorphosis are analogous to human post-embryonic development and disruption of TH action can have drastic effects. These shared features make the metamorphosis of anurans an excellent model for screening for endocrine disrupting chemicals (EDCs). We used the cultured tailfin (C-fin) assay to examine the exposure effects of 0.1–10 nM (~8–800 ng/L) of three types of ~20 nm TiO2 NPs (P25, M212, M262) and micron-sized TiO2 (μ TiO2) ±10 nM T3. The actual Ti levels were 40.9–64.7% of the nominal value. Real-time quantitative polymerase chain reaction (QPCR) was used to measure the relative amounts of mRNA transcripts encoding TH-responsive THs receptors (thra and thrb) and Rana larval keratin type I (rlk1), as well as the cellular stress-responsive heat shock protein 30 kDa (hsp30), superoxide dismutase (sod), and catalase (cat). The levels of the TH-responsive transcripts were largely unaffected by any form of TiO2. Some significant effects on stress-related transcripts were observed upon exposure to micron-sized TiO2, P25, and M212 while no effect was observed with M262 exposure. Therefore, the risk of adversely affecting amphibian tissue by disrupting TH-signaling or inducing cellular stress is low for these compounds relative to other previously-tested NPs.

Inhibitory Effects of Low-Energy Pulsed Ultrasonic Stimulation on Cell Surface Protein Antigen C through Heat Shock Proteins GroEL and DnaK inStreptococcus mutans

This study concerns the use of low-energy pulsed ultrasound as nondestructive photodynamic antimicrobial therapy for controlling dental plaque. We examined the antibacterial and bactericidal effects of low-energy pulsed ultrasound on mutans streptococci and its inhibitory effects on bacterial cell adhesion of Streptococcus mutans. The results indicated weak antibacterial and bactericidal effects. However, ultrasonic stimulation for less than 20 min markedly decreased bacterial cell adhesion. To analyze the mechanism underlying the inhibitory effect, we examined cell surface protein antigen C (PAc) and glucosyltransferase I (GTF-I) expression in S. mutans. The levels of PAc gene and protein expression were markedly decreased by ultrasonic stimulation for 20 min. However, no change in GTF-I expression was observed. The expression of stress response heat shock proteins GroEL and DnaK was also examined. GroEL and DnaK levels were significantly decreased by ultrasonic stimulation, and the expression of the PAc protein was also diminished upon the addition of GroEL or DnaK inhibitors without ultrasonic stimulation. These observations suggest that the expression of the PAc protein in S. mutans may be dependent on heat shock proteins. Thus, low-energy pulsed ultrasound decreases bacterial adhesion by the inhibitory effect on the PAc protein and heat shock protein expression and may be useful as photodynamic antimicrobial chemotherapy in controlling dental plaque.

MAPK-activated Protein Kinase-2 (MK2)-mediated Formation and Phosphorylation-regulated Dissociation of the Signal Complex Consisting of p38, MK2, Akt, and Hsp27

The p38 MAPK and heat shock protein 27 (hsp27) form a signaling complex with serine/threonine kinase Akt and MAPK-activated protein kinase-2 (MK2), which plays an important role in controlling stress-induced apoptosis and reorganizing actin cytoskeleton. However, regulation of the complex is poorly understood. In this study, the interaction between p38 and hsp27 was visualized in single living L929 cells using fluorescence resonance energy transfer technology, while their association with Akt was examined by immunoprecipitation analysis. Under normal growth conditions, p38 kinase constitutively interacts with hsp27. When cells were exposed to H(2)O(2) or stimulated by arachidonic acid, this interaction was disrupted. However, inhibition of the activation of p38 and Akt by selective inhibitors or overexpression of the kinase-dead mutant of p38 diminished such effects. Furthermore, mutation of phosphorylation sites of hsp27 renders the interaction resistant to H(2)O(2) and arachidonic acid. It was interesting to find that the interaction disappeared in the cells from MK2-knock-out mice or the cells treated with lemptomycin B that blocks export of MK2 from nucleus to cytosol. However, MK2 is not required for the association of hsp27 with Akt. This study suggests that MK2 mediates the incorporation of p38 into the pre-existing complex of hsp27 with Akt. Phosphorylation of hsp27 finally breaks the signaling complex.

Pharmacological attenuation of apoptosis in reoxygenated endothelial cells

BRX-235 (Iroxanadine), a novel drug developed by Biorex (Hungary), was previously characterized as a vasculoprotector against atherosclerosis, an activator of p38 kinase, and an enhancer of stress-responsive heat shock protein (Hsp) expression. The present data demonstrate that BRX-235 may improve survival of vascular endothelial cells (ECs) following ischemia/reperfusion stress. ECs cultured from human umbilical veins were exposed to hypoxia/reoxygenation to mimic ischemia/reperfusion. Caspase activation and apoptosis were monitored in the reoxygenated cells. Addition of BRX-235 (0.1-1 microM) to culture medium prior to hypoxia or at start of reoxygenation significantly reduced the caspase-dependent apoptosis. The cytoprotection conferred by the pre-hypoxic drug administration was sensitive to quercetin and seems to be based on enhanced Hsp accumulation in stressed ECs. In the case of post-hypoxic drug administration, the cytoprotection was strongly inhibited by SB202190 and SB203580 and appears to be associated with enhanced p38 kinase activation in reoxygenated ECs.

Growth Hormone (GH), GH Receptor, and Signal Transduction

The pollution and climate change in aquatic ecosystems are major problems threatening the aquatic organisms for existence in the recent timeline, which promotes the extinction of the fish species. However, the present study dealt with zinc nanoparticles (Zn-NPs) in mitigating arsenic, ammonia and high temperature stresses in Pangasianodon hypophthalmus.To studying different gene expressions, an experiment was conducted to mitigate the multiple stressors using dietary Zn-NPs at 0, 2, 4, and 6 mg kg-1 diets. In the present investigation, the gene expressions studies were performed for growth hormone regulator 1 (GHR1), growth hormone regulator β (GHRβ), growth hormone (GR) in liver and gill tissue as well as myostatin (MYST) and somatostatin (SMT) in the muscle tissue. The anti-oxidative genes CAT, SOD and GPx in liver and gill tissues were also analysed. Expression studies for stress responsive heat shock protein gene (HSP70), DNA damage inducible protein, inducible nitric oxide synthase (iNOS), immune related genes such as interleukin (IL), tumour necrosis factor (TNFα), toll like receptor (TLR) and immunoglobulin were performed. At the end of the experiment the fish were infected with Aeromonas hydrophila to evaluate the immunomodulatory role of Zn-NPs.In the present investigation, the growth hormone regulator 1 (GHR1), growth hormone regulator β (GHRβ), growth hormone (GR) in liver and gill as well as myostatin (MYST) and somatostatin (SMT) in muscle were noticeably altered, whereas, Zn-NPs at 4 mg kg-1 diet improved gene expressions. The anti-oxidant gene viz. CAT, SOD and GPx in liver and gill tissues were upregulated by stressors such as As, NH3, NH3+T. As+T and As+NH3+T. Therefore, anti-oxidant genes were noticeably improved with dietary Zn-NPs diet. The stress protein gene (HSP70), DNA damage inducible protein, inducible nitric oxide synthase (iNOS) was significantly upregulated, whereas, Zn-NPs diet was applied to the corrected gene regulation. Similarly, immune related genes such as interleukin (IL), tumour necrosis factor (TNFα), toll like receptor (TLR) and immunoglobulin were highly affected by stressors. Dietary Zn-NPs at 4 mg kg-1 diet was improved all the immune related gene expression and mitigate arsenic, ammonia and high temperature stress in fish.The present investigation revealed that Zn-NPs at 4.0 mg kg-1 diet has enormous potential to modulates arsenic, ammonia and high temperature stress, and protect against pathogenic infections in fish.

Modulation of Heat-Shock Protein 70 (HSP70) Gene Expression by Sodium Butyrate in U-937 Promonocytic Cells: Relationships with Differentiation and Apoptosis

The administration of sodium butyrate at 0.75 mMinduced the functional differentiation of U-937 human promonocytic leukemia cells with negligible cell mortality. However, the drug rapidly caused cell death with characteristics of apoptosis when used at concentrations of 5 mMand above. In addition, butyrate stimulated the expression of the stress-responsive heat-shock protein 70 (HSP70) gene when applied at both differentiation-inducing and apoptosis-inducing concentrations. The induction ofHSP70by butyrate was inhibited by the simultaneous addition of cAMP-increasing agents (dibutyryl cAMP or the combination of forskolin plus theophylline). However, these agents did not prevent differentiation and only partially reduced apoptosis. Moreover, the DNA topoisomerase II inhibitor etoposide, which provoked U-937 cell differentiation and apoptosis with the same or greater efficiency than butyrate, failed to stimulateHSP70expression. Finally, it was observed that cAMP-increasing agents also abrogated the induction ofHSP70and reduced the apoptosis caused by cadmium chloride, a typical inducer of the stress response. Taken together, these results indicate thatHSP70expression is not required for differentiation of promonocytic cells, as earlier proposed, and that butyrate probably triggers the stress response in these cells.