Inducible Hsp70 Research Articles

Hsp70/Bmi1-FoxO1-SOD Signaling Pathway Contributes to the Protective Effect of Sound Conditioning against Acute Acoustic Trauma in a Rat Model.

Sound conditioning (SC) is defined as “toughening” to lower levels of sound over time, which reduces a subsequent noise-induced threshold shift. Although the protective effect of SC in mammals is generally understood, the exact mechanisms involved have not yet been elucidated. To confirm the protective effect of SC against noise exposure (NE) and the stress-related signaling pathway of its rescue, we observed target molecule changes caused by SC of low frequency prior to NE as well as histology analysis in vivo and verified the suggested mechanisms in SGNs in vitro. Further, we investigated the potential role of Hsp70 and Bmi1 in SC by targeting SOD1 and SOD2 which are regulated by the FoxO1 signaling pathway based on mitochondrial function and reactive oxygen species (ROS) levels. Finally, we sought to identify the possible molecular mechanisms associated with the beneficial effects of SC against noise-induced trauma. Data from the rat model were evaluated by western blot, immunofluorescence, and RT-PCR. The results revealed that SC upregulated Hsp70, Bmi1, FoxO1, SOD1, and SOD2 expression in spiral ganglion neurons (SGNs). Moreover, the auditory brainstem responses (ABRs) and electron microscopy revealed that SC could protect against acute acoustic trauma (AAT) based on a significant reduction of hearing impairment and visible reduction in outer hair cell loss as well as ultrastructural changes in OHCs and SGNs. Collectively, these results suggested that the contribution of Bmi1 toward decreased sensitivity to noise-induced trauma following SC was triggered by Hsp70 induction and associated with enhancement of the antioxidant system and decreased mitochondrial superoxide accumulation. This contribution of Bmi1 was achieved by direct targeting of SOD1 and SOD2, which was regulated by FoxO1. Therefore, the Hsp70/Bmi1-FoxO1-SOD signaling pathway might contribute to the protective effect of SC against AAT in a rat model.

Induction of Hsp60, Hsp70, and Hsp90 in formalin exposed white shrimp (Litopenaeus vannamei) stress test

Exposure to formalin was investigated as possible stress tests for evaluating the quality of white shrimp (L. vannamei) PLs. For the formalin stress test, PL10 was stocked in 300 ml cup with seawater of 0 (control), 300, and 600 mg/L formalin for the solution test. The PLs from the same batches were used for seed production to monitor their performance and validate the results of stress tests. Exposure of post larvae to 600 mg/L formalin for 3 hr appeared to be a reliable and practical method for post-larval quality assessment as the survival of larvae in the mass production tanks validated the classification of good and poor qualities batches in the stress tests. On this basis, a hatchery operator can decide which batch should be cultured further. Finally, there appears to be a link between the mortality of PLs and the expression of heat shock proteins. HSP are a highly conserved protein sequence available in the prokaryotic and eukaryotic organism that is known for its rapid response to environmental stresses. During the formalin stress test, the Hsp60 showed the highest expression in comparison with Hsp70 and Hsp90.

Hsp70 and NF-kB Mediated Control of Innate Inflammatory Responses in a Canine Macrophage Cell Line.

The pathogenesis of many inflammatory diseases is associated with the uncontrolled activation of nuclear factor kappa B (NF-κB) in macrophages. Previous studies have shown that in various cell types, heat shock protein 70 (Hsp70) plays a crucial role in controlling NF-κB activity. So far, little is known about the role of Hsp70 in canine inflammatory processes. In this study we investigated the potential anti-inflammatory effects of Hsp70 in canine macrophages as well as the mechanisms underlying these effects. To this end, a canine macrophage cell line was stressed with arsenite, a chemical stressor, which upregulated Hsp70 expression as detected by flow cytometry and qPCR. A gene-edited version of this macrophage cell line lacking inducible Hsp70 was generated using CRISPR-Cas9 technology. To determine the effects of Hsp70 on macrophage inflammatory properties, arsenite-stressed wild-type and Hsp70 knockout macrophages were exposed to lipopolysaccharide (LPS), and the expression of the inflammatory cytokines IL-6, IL-1β and tumor necrosis factor-α (TNF-α) and levels of phosphorylated NF-κB were determined by qPCR and Western Blotting, respectively. Our results show that non-toxic concentrations of arsenite induced Hsp70 expression in canine macrophages; Hsp70 upregulation significantly inhibited the LPS-induced expression of the pro-inflammatory mediators TNF-α and IL-6, as well as NF-κB activation in canine macrophages. Furthermore, the gene editing of inducible Hsp70 by CRISPR-Cas9-mediated gene editing neutralized this inhibitory effect of cell stress on NF-κB activation and pro-inflammatory cytokine expression. Collectively, our study reveals that Hsp70 may regulate inflammatory responses through NF-κB activation and cytokine expression in canine macrophages.

Heat Shock Protein 70 as a Double Agent Acting Inside and Outside the Cell: Insights into Autoimmunity.

Heat shock proteins (Hsp) are a diverse group of constitutive and/or stress-induced molecules that are categorized into several classes on the basis of their molecular weight. Mammalian Hsp have been mostly regarded as intracellular chaperones that mediate a range of essential cellular functions, including proper folding of newly synthesized polypeptides, refolding of denatured proteins, protein transport, and stabilization of native proteins’ structures. The well-characterized and highly evolutionarily conserved, stress-inducible 70-kDa heat shock protein (Hsp70), is a key molecular chaperone that is overexpressed in the cell in response to stress of various origin. Hsp70 exhibits an immunosuppressive activity via, e.g., downregulation of the nuclear factor-kappa B (NF-κB) activation, and pharmacological induction of Hsp70 can ameliorate the autoimmune arthritis development in animal models. Moreover, Hsp70 might be passively or actively released from the necrotic or stressed cells, respectively. Highly immunogenic extracellular Hsp70 has been reported to impact both the innate and adaptive immune responses, and to be implicated in the autoimmune reaction. In addition, preclinical studies revealed that immunization with highly conserved Hsp70 peptides could be regarded as a potential treatment target for autoimmune arthritis, such as the rheumatoid arthritis, via induction of antigen-specific regulatory T helper cells (also called Treg). Here, a dual role of the intra- and extracellular Hsp70 is presented in the context of the autoimmune reaction.

THE 30 YEARS' CLINICAL EXPERIENCE IN DIAGNOSIS AND TREATMENT OF ENDOMETRIAL OVARIAN CYSTS IN PATIENTS OF REPRODUCTIVE AGE

Endometriosis occurs in 50 % of women with infertility. Ovarian endometriosis affects 55 % of women with this disease. Surgical treatment of endometrium is indicated if its size is over 3 cm. After removal of the endometriomas there are used diathermic, bipolar energy, radio wave energy, argon plasma coagulation for hemostasis of ovarian tissue. The use of argon plasma coagulation in ovarian hemostasis causes not only hemostatic but also protective effect, which is mediated by the induction of HSP27, SOD2, VEGF and iNOS, which renders an organ−preserving effect when applied to ovarian tissues. Repeated surgery for ovarian endometrium should be performed taking into account the risk of reduced levels of antimullerian hormone, which may adversely affect the further implementation of reproductive function, including the use of assisted reproductive technologies. The authors comparatively have evaluated the treatment of 900 patients of reproductive age with endometrioid cysts of the ovaries and other concomitant gynecological pathology, which were three clinical groups. The patients received radiowave energy, argonoplasmic coagulation, intraoperative use of various anti−adhesive drugs and combinations of drugs in the postoperative period. It was found that the use of argon plasma coagulation for hemostasis of ovarian tissues after removal of endometrioid cysts, polyethylene oxide gel with carboxymethylcellulose intraoperatively and gonadotropin−releasing hormone agonists, dienogest 2 mg per day for three months contributed to the pregnancy onset in post−srugery period in 56.7 % of patients. It has been noted that in women the presence of adhesions in combination with corpus luteum cysts, endometrial polyps, uterine leiomyoma reduces the onset of pregnancy by 8.0, 12, and 24 times, respectively. Key words: endometrial ovarian cysts, diagnosis, treatment, rehabilitation in the post−surgery period.

Geranylgeranyl acetone prevents glutamate-induced cell death in HT-22 cells by increasing mitochondrial membrane potential

Geranylgeranyl acetone (GGA) protects against various types of cell damages by upregulating heat shock proteins. We investigated whether GGA protects neuronal cells from cell death induced by oxidative stress. Glutamate exposure was lethal to HT-22 cells which comprise a neuronal line derived from mouse hippocampus. This configuration is often used as a model for hippocampus neurodegeneration in vitro. In the present study, GGA protected HT-22 cells from glutamate-induced oxidative stress. GGA pretreatment did not induce heat shock proteins (Hsps). Moreover, reactive oxygen species increased to the same extent in both GGA-pretreated and untreated cells exposed to glutamate. In contrast, glutamate exposure and GGA pretreatment increased mitochondrial membrane potential. However, increases in intracellular Ca2+ concentration were inhibited by GGA pretreatment. In addition, the increase of phosphorylated ERKs by the glutamate exposure was inhibited by GGA pretreatment. These findings suggest that GGA protects HT-22 cells from glutamate-provoked cell death without Hsp induction and that the mitochondrial calcium buffering capacity plays an important role in this protective effect.

Overexpression of HSP70 attenuates sarcopenia by suppressing the expression of miR‐133b

AbstractBackgroundThe aim of the present investigation is to evaluate the effect of the overexpression of inducible 70‐kDa heat shock protein (HSP70) on sarcopenic muscles of aged mice.MethodsTibialis anterior muscles of aged and young transgenic mice overexpressing HSP70 and wild‐type mice were evaluated. Old mice were treated with the HSP inducer O‐[3‐piperidino‐2‐hydroxy‐1‐propyl]‐nicotinic amidoxime (BGP‐15) for 10 days, and their muscles were analysed.ResultsOld HSP70 transgenic mice presented a less pronounced decrease in myofiber size, lower protein levels of Foxo3a, and a spared increase in miRNA‐133b expression when compared with old wild‐type mice. Moreover, in BGP‐15‐treated old mice, the reduction in myofiber size was less intense, and the decline in muscle specific force was attenuated.ConclusionsThese results suggest that HSP70 overexpression attenuates sarcopenia in old mice, and this effect may be mediated by miR‐133b down‐regulation. In addition, BGP‐15 treatment may be a useful strategy to mitigate the effects of sarcopenia in old mice.

S-Glutathionylation of human inducible Hsp70 reveals a regulatory mechanism involving the C-terminal α-helical lid

Heat shock protein 70 (Hsp70) proteins are a family of ancient and conserved chaperones. Cysteine modifications have been widely detected among different Hsp70 family members in vivo, but their effects on Hsp70 structure and function are unclear. Here, we treated HeLa cells with diamide, which typically induces disulfide bond formation except in the presence of excess GSH, when glutathionylated cysteines predominate. We show that in these cells, HspA1A (hHsp70) undergoes reversible cysteine modifications, including glutathionylation, potentially at all five cysteine residues. In vitro experiments revealed that modification of cysteines in the nucleotide-binding domain of hHsp70 is prevented by nucleotide binding but that Cys-574 and Cys-603, located in the C-terminal α-helical lid of the substrate-binding domain, can undergo glutathionylation in both the presence and absence of nucleotide. We found that glutathionylation of these cysteine residues results in unfolding of the α-helical lid structure. The unfolded region mimics substrate by binding to and blocking the substrate-binding site, thereby promoting intrinsic ATPase activity and competing with binding of external substrates, including heat shock transcription factor 1 (Hsf1). Thus, post-translational modification can alter the structure and regulate the function of hHsp70.

Worm-align and Worm_CP, Two Open-Source Pipelines for Straightening and Quantification of Fluorescence Image Data Obtained from Caenorhabditis elegans.

An issue often encountered when acquiring image data from fixed or anesthetized C. elegans is that worms cross and cluster with their neighbors. This problem is aggravated with increasing density of worms and creates challenges for imaging and quantification. We developed a FIJI-based workflow, Worm-align, that can be used to generate single- or multi-channel montages of user-selected, straightened and aligned worms from raw image data of C. elegans. Worm-align is a simple and user-friendly workflow that does not require prior training of either the user or the analysis algorithm. Montages generated with Worm-align can aid the visual inspection of worms, their classification and representation. In addition, the output of Worm-align can be used for subsequent quantification of fluorescence intensity in single worms, either in FIJI directly, or in other image analysis software platforms. We demonstrate this by importing the Worm-align output into Worm_CP, a pipeline that uses the open-source CellProfiler software. CellProfiler's flexibility enables the incorporation of additional modules for high-content screening.As a practical example, we have used the pipeline on two datasets: the first dataset are images of heat shock reporter worms that express green fluorescent protein (GFP) under the control of the promoter of a heat shock inducible gene hsp-70, and the second dataset are images obtained from fixed worms, stained for fat-stores with a fluorescent dye.

Differential expression of HSP70 and SAPK/JNK genes in the cabbage aphid upon salicylic and dilute sulfuric acid treatments in canola

• HSP70 and SAPK/JNK are stress related genes in the cabbage aphid. • Significant up-regulation of HSP70 gene expression occurs in aphids feeding on sulfuric acid-treated plants. • HSP70 gene was not regulated in aphids feeding on salicylic acid-treated plants. • Quantification of SAPK/JNK gene showed a significant effect in aphids feeding on SA-primed plants. Investigating the interaction between insect pests and host plants at molecular level, provides an insight for effective implementation of plant resistance-based strategies in insect pest control programs. Heat shock proteins (HSPs) are found in all living organisms which protect them from biotic and abiotic stresses. Stress-activated protein kinases ( SAPKs ) are members of MPK kinases which also are activated upon cellular stresses. We investigated the effect of seed-primed canola plants with salicylic acid (SA) and the plants treated with dilute sulfuric acid on the regulation of two stress-related genes, HSP70 and SAPK/JNK genes in the cabbage aphid. The results of qRT-PCR revealed a statistically significant up-regulation of HSP70 gene expression in aphids feeding on sulfuric acid-treated plants in comparison with controls (P < 0.01). However, this gene was not regulated in aphids feeding on salicylic acid-treated plants. In addition, quantification of SAPK/JNK gene showed a significant effect in aphids feeding on SA-primed plants (P < 0.05) and a marginally significant effect in sulfuric acid treatment. Further, the expression of both genes were significantly changed in interaction effect between SA and sulfuric acid treatments. Finally, the induction of HSP70 and SAPK/JNK genes in this research might be related to activation of systemic acquired resistance in canola.

Inhibition of HSP90 and Activation of HSF1 Diminish Macrophage NLRP3 Inflammasome Activity in Alcohol-Associated Liver Injury.

Activation of NLRP3 in liver macrophages contributes to alcohol-associated liver disease (ALD). Molecular chaperone heat shock protein (HSP) 90 facilitates NLRP3 inflammasome activity during infections and inflammatory diseases. We previously reported that HSP90 is induced in ALD and regulates proinflammatory cytokines, tumor necrosis factor alpha, and IL-6. Whether HSP90 affects IL-1β and IL-18 regulated by NLRP3 inflammasome in ALD is unknown. Here, we hypothesize that HSP90 modulated NLRP3 inflammasome activity and affects IL-1β and IL-18 secretion in ALD. The expression of HSP90AA1 and NLRP3 inflammasome genes was evaluated in human alcoholic livers and in mouse model of ALD. The importance of HSP90 on NLRP3 inflammasome activation in ALD was evaluated by administering HSP90 inhibitor, 17-dimethylaminoethylamino-17-demethoxygeldanamycin (17-DMAG) to mice subjected to ALD, and in vitro to bone marrow-derived macrophages (BMDM) stimulated with LPS and ATP. The effect of activation of HSF1/HSPA1A axis during HSP90 inhibition or direct activation during heat shock of BMDMs on NLRP3 activity and secretion of downstream cytokines was evaluated. We found positive correlation between induction of HSP90 and NLRP3 inflammasome genes in human alcoholic cirrhotic livers. Administration of 17-DMAG in mouse model of ALD significantly down-regulated NLRP3 inflammasome-mediated caspase-1 (CASP-1) activity and cytokine secretion, with reduction in ALD. 17-DMAG-mediated decrease in NLRP3 was restricted to liver macrophages. Using BMDMs, we show that inhibition of HSP90 prevented CASP-1 activity, and Gasdermin D (GSDMD) cleavage, important in release of active IL-1β and IL-18. Interestingly, activation of the heat shock factor 1 (HSF1)/HSPA1A axis, either during HSP90 inhibition or by heat shock, decreased NLRP3 inflammasome activity and reduced secretion of cytokines. Our studies indicate that inhibition of HSP90 and activation of HSF1/HSPA1A reduce IL-1β and IL-18 via decrease in NLRP3/CASP-1 and GSDMD activity in ALD.

Cell-Specific Transcriptional Responses to Heat Shock in the Mouse Utricle Epithelium.

Sensory epithelia of the inner ear contain mechanosensory hair cells (HCs) and glia-like supporting cells (SCs), both of which are required for hearing and balance functions. Each of these cell types has unique responses to ototoxic and cytoprotective stimuli. Non-lethal heat stress in the mammalian utricle induces heat shock proteins (HSPs) and protects against ototoxic drug-induced hair cell death. Induction of HSPs in the utricle demonstrates cell-type specificity at the protein level, with HSP70 induction occurring primarily in SCs, while HSP32 (also known as heme oxygenase 1, HMOX1) is induced primarily in resident macrophages. Neither of these HSPs are robustly induced in HCs, suggesting that HCs may have little capacity for induction of stress-induced protective responses. To determine the transcriptional responses to heat shock of these different cell types, we performed cell-type-specific transcriptional profiling using the RiboTag method, which allows for immunoprecipitation (IP) of actively translating mRNAs from specific cell types. RNA-Seq differential gene expression analyses demonstrated that the RiboTag method identified known cell type-specific markers as well as new markers for HCs and SCs. Gene expression differences suggest that HCs and SCs exhibit differential transcriptional heat shock responses. The chaperonin family member Cct8 was significantly enriched only in heat-shocked HCs, while Hspa1l (HSP70 family), and Hspb1 and Cryab (HSP27 and HSP20 families, respectively) were enriched only in SCs. Together our data indicate that HCs exhibit a limited but unique heat shock response, and SCs exhibit a broader and more robust transcriptional response to protective heat stress.

Effects of Pro‐Tex® on the expression of Hsp70 gene and immune response parameters in the Persian sturgeon fingerlings, Acipenser persicus, infected with Aeromonas hydrophila

The induction of Hsps (heat shock protein) recognized as a promising approach to limiting disease and improving health in aquaculture. This investigation aimed to study the impacts of Pro‐Tex®, an extract from the prickly pear cactus (Opuntia ficus indica), on the expression of Hsp70 gene and induction of immune response parameters in Acipenser persicus infected with Aeromonas hydrophila ATCC®7966ᵀᴹ. Fish were pretreated with 25, 50 and 100 mg/L of Pro‐Tex and then injected in the intra‐peritoneal cavity with A. hydrophila. The expression level of Hsp70 gene, lysozyme activity (LYZ) and complement C3 (C3), and immunoglobulin M (IgM) levels were assessed in liver, gill, and intestine on the days 3 and 7 post‐infection. Tex‐OE® increased expression of Hsp70 in a dose‐dependent way in A. persicus, but this expression significantly reduced on the 7‐days post‐injection. The Hsp70 expression pattern was variable in each tissue, also, LYZ activity, C3, and IgM increased, depending on the concentration, and showed a decreasing trend in a time‐dependent way. In conclusion, our data indicated that Pro‐Tex as an Hsp70 inducer increases the resistance of sturgeon fry against fish pathogens by induction of different immunity factors.

HSP90 inhibitor 17AAG attenuates sevoflurane-induced neurotoxicity in rats and human neuroglioma cells via induction of HSP70

Background17AAG has been extensively studied for its antitumor effects that protect cells from lethal stress by maintaining protein stability. The role of 17AAG in sevoflurane-induced neuronal injury has never been studied. We aim to investigate the effect of 17AAG on sevoflurane-induced neurotoxicity in vivo and in vitro.MethodsSevoflurane-induced hippocampal neuron injury model was established in aged Sprague–Dawley rats. Pretreatment of vehicle or 17AAG was administered prior to sevoflurane inhalation. H4 neuroglioma cells were pretreated with vehicle or 17AAG and exposed to sevoflurane. Apoptosis, oxidative stress, expression of interleukin-6 (IL-6), and activation of the nuclear factor-κB (NF-κB) signaling pathway in H4 cells were examined by Hoechst assay, flow cytometry, Western blot, and immunofluorescent staining. RNA interference against HSPA1A was performed to test the function of HSP70 in neuroprotection.ResultsExogenous 17AAG reduced sevoflurane-induced apoptosis and oxidative stress in rat hippocampal neurons and in H4 cells. In H4 cells, 17AAG suppressed sevoflurane-induced upregulation of IL-6 and activation of NF-κB signaling. 17AAG enhanced sevoflurane-induced upregulation of HSP70 in rat hippocampal neurons and in H4 cells. Conversely, silencing of HSPA1A in H4 cells blocked the cytoprotective effect of 17AAG against sevoflurane-induced apoptosis and oxidative stress, and prevented upregulation of IL-6 and activation of NF-κB signaling.Conclusions17AAG protects against sevoflurane-induced neurotoxicity in vivo and in vitro via HSP70-dependent inhibition of apoptosis, oxidative stress, and pro-inflammatory signaling pathway.

Age-dependent expression profiles of two adaptogenic systems and thermotolerance in Drosophila melanogaster.

Here, we monitored the expression of three genes (hsp70, hsp22, and hsf1) involved in heat shock response in Drosophila melanogaster in males and females of different age. Also, we investigated age- and sex-dependent expression of three major genes participating in the production of hydrogen sulfide (H2S) (cse, cbs, and mst), implicated in stress resistance and aging. In addition to the control strain, we monitored the expression of all of these genes in a cbs knockout strain (cbs-/-) generated using the CRISPR technique. The tested strains differ in the induction capacities of the studied genes. Relative to the control strain, under normal conditions, the cbs-/- strain expresses all of the studied genes more abundantly, especially hsp22. In the control strain, aging leads to a dramatic increase in hsp22 synthesis, whereas in the cbs-/- strain, hsp22 induction is not pronounced. Furthermore, in 30-day-old cbs-/- flies, the constitutive expression of hsp70 and mst is decreased. Surprisingly, in the cbs-/- strain, we detected an upregulation of hsf1 transcription in the 30-day-old females. After heat shock in the control strain, hsp70 and hsp22 induction decreased with age in males and hsp22 decreased in females, while in the cbs-/- strain, a pronounced drop in the induction capacity of both hsp genes was seen in 30-day-old males and females. However, in most cases, the expression levels of hsf1 and H2S-producing genes do not exhibit pronounced changes depending on sex, age, or heat shock. Flies of control and cbs-/- strain exhibited strong reduction in basal thermotolerance with age. Our data suggest a cross-talk between the two studied ancient and universal adaptive systems.

Reaction of inducible hsp70 form on different environmental conditions in Ommatogammarus flavus

The aim of the research was to estimate heat shock protein expression under the change in ambient temperature and hydrostatic pressure in Baikal deep-water amphipods Ommatogammarus flavus. The expression of the constitutive hsp70 transcript did not change in response to the influence of both environmental factors. The inducible hsp70 form did not differ after the change in hydrostatic pressure in amphipods captured from the depth of 50 and 750 m. High expression of inducible hsp70 transcript was shown during gradual increase in ambient temperature when it reached 22C. The detected increase in hsp70 expression is associated with the cells reaction to protein damage at the high temperature. Thus, the studied hsp70 inducible form is involved in the adaptation to change in ambient temperature in O. flavus despite the fact that this species inhabits the deep-water zone with stable temperature conditions. It is necessary to analyze other isoforms of hsp in the further studies to find those that participate in the adaptation to high hydrostatic pressure.

The Molecular Diversity Scope of Urazole in the Synthesis of Organic Compounds

As a matter of fact, nitrogen as a hetero atom among other atoms has had an important role in active biological compounds. Since heterocyclic molecules with nitrogen are highly demanded due to biological properties, 4-phenylurazole as a compound containing nitrogen might be important in the multicomponent reaction used in agrochemicals, and pharmaceuticals. Considering the case of fused derivatives "pyrazolourazoles" which are highly applicable because of their application for analgesic, antibacterial, anti-inflammatory and antidiabetic activities as HSP-72 induction inhibitors (I and III) and novel microtubule assembly inhibitors. It should be mentioned that spiro-pyrazole also has biological activities like cytotoxic, antimicrobial, anticonvulsant, antifungal, anticancer, anti-inflammatory, and cardiotonic activities. Urazole has been used in many heterocyclic compounds which are valuable in organic syntheses. This review disclosed the advances in the use of urazole as the starting material in the synthesis of various biologically active molecules from 2006 to 2019. Compounds of urazole (1,2,4-triazolidine-3,5-dione) are the most important molecules which are highly active from the biological perspective in the pharmaceuticals as well as polymers. In summary, many protocols for preparations of the urazole derivatives from various substrates in multi-component reactions have been reported from different aromatic and aliphatic groups which have had carbonyl groups in their structures. It is noted that several catalysts have been synthesized to afford applicable molecules with urazole scaffolds. In some papers, being environmentally friendly, short time reactions and high yields are highlighted in the protocols. There is a room to synthesize new catalysts and perform new reactions by manipulating urazole to produce biologically active compounds, even producing chiral urazole component as many groups of chiral urazole compounds are important from biological perspective.

Heat acclimation-induced intracellular HSP70 in humans: a meta-analysis

Heat acclimation (HA) in humans promotes thermoregulatory adaptations that support management of core temperature in hot environments and reduces the likelihood of heat related illness. Another adaptation to HA is thermotolerance through induction of the heat shock protein (HSP) stress system, which provides protection against thermal insult. However, whether or not HA leads to upregulation of the intracellular HSP system, namely intracellular HSP70 (HSP70), is unclear in humans. Therefore, the purposes of this meta-analysis were to determine if HA leads to HSP70 induction among humans and to evaluate how methodological differences among HA studies influence findings regarding HA-induced HSP70 accumulation. Several databases were searched to identify studies that measured HSP70 (protein and mRNA) changes in response to HA among humans. The effect of HA on HSP70 was analyzed. Differences in the effect of HA were assessed between protein and mRNA. The moderating effect of several independent variables (HA frequency, HA duration, core temperature, exercise intensity) on HSP70 was also evaluated. Data were extracted from 12 studies including 118 participants (mean age 24years, 98% male). There was a significant effect of HA on HSP70 expression, g = 0.97 (95% CI, 0.08-1.89). The effect of HA was different between subgroups (protein vs. mRNA), g = 1.51 (95% CI, 0.71-2.31), and g = - 0.39 (95% CI, - 1.36), respectively. The frequency of HA (in days) moderated HSP70 protein expression. There was a significant effect of heat acclimation on HSP70 induction in humans. The only factor among identified studies that may moderate this response was the frequency (number of days) of heat exposure.

Transcriptional regulation of heat shock protein 70 genes by class I histone deacetylases in the red flour beetle, Tribolium castaneum.

The regulatory function of histone acetylation in the expression of genes encoding heat shock proteins (Hsps) has been documented in Drosophila melanogaster; however, knowledge of the role of acetylation in modulating Hsps in other insect pests is limited. In this study, two full-length cDNAs encoding inducible Hsp70 (designated TcHsp70) and heat shock cognate 70 (TcHsc70) were isolated and characterized in the red flour beetle, Tribolium castaneum. TcHsp70 and TcHsc70 cDNAs were 2256 and 2132 bp and encoded 1941- and 1893-bp open reading frames, respectively. The deduced TcHsp70 and TcHsc70 proteins contained 646 and 630 amino acids, respectively, and contained sequences typical of the Hsp70 family, including the EEVD motif for cytoplasmic localization. Expression patterns after heat shock indicated that TcHsp70 was strongly heat-inducible, whereas the expression level of TcHsc70 remained unchanged under heat shock. RNA interference-mediated knock-down of three genes encoding class I histone deacetylases differentially influenced both basal and heat shock inducible expression of TcHsp70 and TcHsc70, suggesting the involvement of histone acetylation in epigenetic regulation of Hsp70 transcription in T. castaneum.

Alpha-Lipoic Acid Protects Cardiomyocytes against Heat Stroke-Induced Apoptosis and Inflammatory Responses Associated with the Induction of Hsp70 and Activation of Autophagy.

Heat stroke (HS) is a life-threatening illness and defined as when body temperature elevates above 40°C accompanied by the systemic inflammatory response syndrome that results in multiple organ dysfunctions. α-Lipoic acid (ALA) acts as a cofactor of mitochondrial enzymes and exerts anti-inflammatory and antioxidant properties in a variety of diseases. This study investigates the beneficial effects of ALA on myocardial injury and organ damage caused by experimental HS and further explores its underlying mechanism. Male Wistar rats were exposed to 42°C until their rectal core temperature reached 42.9°C and ALA was pretreared 40 or 80 mg/kg (i.v.) 1.5 h prior to heat exposure. Results showed that HS-induced lethality and hypothermia were significantly alleviated by ALA treatment that also improved plasma levels of CRE, LDH, and CPK and myocardial injury biomarkers myoglobin and troponin. In addition, ALA reduced cardiac superoxide anion formation and protein expression of cleaved caspase 3 caused by HS. Proinflammatory cytokine TNF-α and NF-κB pathways were significantly reduced by ALA treatment which may be associated with the upregulation of Hsp70. ALA significantly increased the Atg5-12 complex and LC3B II/LC3B I ratio, whereas the p62 and p-mTOR expression was attenuated in HS rats, indicating the activation of autophagy by ALA. In conclusion, ALA ameliorated the deleterious effects of HS by exerting antioxidative and anti-inflammatory capacities. Induction of Hsp70 and activation of autophagy contribute to the protective effects of ALA in HS-induced myocardial injury.