Hsp Synthesis Research Articles

Hsp70 Knockdown in the Brine Shrimp Artemia franciscana: Implication on Reproduction, Immune Response and Embryonic Cuticular Structure.

The potential functional role(s) of heat shock protein 70 (Hsp70) in the brine shrimp, Artemia franciscana, a crucial crustacean species for aquaculture and stress response studies, was investigated in this study. Though we have previously reported that Hsp70 knockdown may have little or no impact on Artemia development, the gestational survival and number of offspring released by adult females were impaired by obscuring Hsp70 synthesis. Transcriptomic analysis revealed that several cuticle and chitin synthetic genes were downregulated, and carbohydrate metabolic genes were differentially expressed in Hsp70-knockdown individuals. A more comprehensive microscopic examination performed in this study revealed exoskeleton structural destruction and abnormal eye lenses featured in Hsp70-deficient adult females 48h after Hsp70 dsRNA injection. Cysts produced by these Hsp70-deficient broods, instead, had a defective shell and were smaller in size, whereas nauplii had shorter first antennae and a rougher body epicuticle surface. Changes in carbohydrate metabolism caused by Hsp70 knockdown affected glycogen levels in adult Artemia females, as well as trehalose in cysts released from these broods, indicating that Hsp70 may play a role in energy storage preservation. Outcomes from this work provided novel insights into the roles of Hsp70 in Artemia reproduction performance, cyst formation, and exoskeleton structure preservation. The findings also support our previous observation that Hsp70 knockdown reduced Artemia nauplius tolerance to bacterial pathogens, which could be explained by the fact that loss of Hsp70 downregulated several Toll receptor genes (NT1 and Spaetzle) and reduced the integrity of the exoskeleton, allowing pathogens to enter and cause infection, ultimately resulting in mortality.

Effect of the HSF1 inhibitor Cl-43 on tumors and non-transformed cells

The occurrence of severe side effects in patients undergoing chemotherapy remains a significant clinical challenge. Therefore, the urgent task is to search for tumor-specific therapies that target opposing responses in non-transformed and tumorigenic cells. HSF1 is known to be an important marker of cancer progression and its transcriptional activity products allow tumor cells to escape the adverse effects of anticancer therapies. Thus, drugs inhibiting HSF1 activity hold promise as a therapeutic strategy. Our study shows that using the cardenolide group’s HSF1 activity inhibitor, CL-43, provides cytoprotective effects on primary, untransformed dermal fibroblast (DF-2) cells, making them less sensitive to etoposide, whereas we observed an increase in sensitivity in the DLD1 tumor cell line. Furthermore, our results show that CL-43 interferes with the intranuclear transport of the active form of HSF1, increasing its activity and consequently the synthesis of HSP70 in human fibroblasts, while suppressing this activity in tumor cells in a dose-dependent manner. Our findings demonstrate the unique potential of CL-43 as a tumor-specific compound with high therapeutic value.

Psammophytes Alyssum desertorum Stapf and Secale sylvestre Host Are Sensitive to Soil Flooding.

While morphological and functional traits enable hydrophytes to survive under waterlogging and partial or complete submergence, the data on responses of psammophytes-sand plants-to flooding are very limited. We analyzed the effect of 5- and 10-day soil flooding on the photosynthetic apparatus and the synthesis of alcohol dehydrogenase (ADH), heat shock proteins 70 (HSP70), and ethylene in seedlings of psammophytes Alyssum desertorum and Secale sylvestre using electron microscopy, chlorophyll a fluorescence induction, and biochemical methods. It was found that seedlings growing under soil flooding differed from those growing in stationary conditions with such traits as chloroplast ultrastructure, pigment content, chlorophyll fluorescence induction, and the dynamics of ADH, HSP, and ethylene synthesis. Although flooding caused no apparent damage to the photosynthetic apparatus in all the variants, a significant decrease in total photosynthesis efficiency was observed in both studied plants, as indicated by decreased values of φR0 and PIABS,total. More noticeable upregulation of ADH in S. sylvestre, as well as increasing HSP70 level and more intensive ethylene emission in A. desertorum, indicate species-specific differences in these traits in response to short-term soil flooding. Meanwhile, the absence of systemic anaerobic metabolic adaptation to prolonged hypoxia causes plant death.

The ribosome quality control factor Asc1 determines the fate of HSP70 mRNA on and off the ribosome.

Cells survive harsh environmental conditions by potently upregulating molecular chaperones such as heat shock proteins (HSPs), particularly the inducible members of the HSP70 family. The life cycle of HSP70 mRNA in the cytoplasm is unique-it is translated during stress when most cellular mRNA translation is repressed and rapidly degraded upon recovery. Contrary to its 5' untranslated region's role in maximizing translation, we discovered that the HSP70 coding sequence (CDS) suppresses its translation via the ribosome quality control (RQC) mechanism. The CDS of the most inducible Saccharomyces cerevisiae HSP70 gene, SSA4, is uniquely enriched with low-frequency codons that promote ribosome stalling during heat stress. Stalled ribosomes are recognized by the RQC components Asc1p and Hel2p and two novel RQC components, the ribosomal proteins Rps28Ap and Rps19Bp. Surprisingly, RQC does not signal SSA4 mRNA degradation via No-Go-Decay. Instead, Asc1p destabilizes SSA4 mRNA during recovery from heat stress by a mechanism independent of ribosome binding and SSA4 codon optimality. Therefore, Asc1p operates in two pathways that converge to regulate the SSA4 mRNA life cycle during stress and recovery. Our research identifies Asc1p as a critical regulator of the stress response and RQC as the mechanism tuning HSP70 synthesis.

Linking Histone Methylation States and hsp Transcriptional Regulation in Thermo-Tolerant and Thermo-Susceptible A. mellifera L. Subspecies in Response to Heat Stress.

Genetic and epigenetic responses to environmental cues of worker honeybees mediate hsp synthesis, a key mechanism to tolerate high ambient temperatures in Apis mellifera. In this study, the chromatin immunoprecipitation assay followed by qPCR were used to determine alterations in histone methylation states (H3K27me2, H3K27me3, H3K4me2, and H3K4me3) associated with hsp/hsc/trx in A. m. jemenetica (thermo-tolerant subspecies) and A. m. carnica (thermo-susceptible subspecies) after heat treatment. The results revealed significant changes in enrichment folds of histone methylation states associated with hsp/hsc/trx. Indeed, the enrichment of H3K27me2 decreased strongly in response to heat stress. Changes in histone methylation states were significantly higher in A. m. carnica samples compared to A. m. jemenitica samples. Our study provides a new perception on linking histone post-translational methylation as an epigenetic mechanism of gene regulation with hsp/hsc/trx in A. mellifera subspecies exposed to heat stress.

Combination of a Chaperone Synthesis Inducer and an Inhibitor of GAPDH Aggregation for Rehabilitation after Traumatic Brain Injury: A Pilot Study

The recovery period after traumatic brain injury (TBI) is often complicated by secondary damage that may last for days or even months after trauma. Two proteins, Hsp70 and glyceraldehyde-3-phosphate dehydrogenase (GAPDH), were recently described as modulating post-traumatic processes, and in this study, we test them as targets for combination therapy using an inhibitor of GAPDH aggregation (derivative of hydrocortisone RX624) and an inducer of Hsp70 synthesis (the pyrrolylazine derivative PQ-29). The protective effect of the combination on C6 rat glioblastoma cells treated with the cerebrospinal fluid of traumatized animals resulted in an increase in the cell index and in a reduced level of apoptosis. Using a rat weight drop model of TBI, we found that the combined use of both drugs prevented memory impairment and motor deficits, as well as a reduction of neurons and accumulation of GAPDH aggregates in brain tissue. In conclusion, we developed and tested a new approach to the treatment of TBI based on influencing distinct molecular mechanisms in brain cells.

Indolylazine Derivative Induces Chaperone Expression in Aged Neural Cells and Prevents the Progression of Alzheimer's Disease.

The risk of progression of most sporadic neurodegenerative diseases, including Alzheimer's disease, increases with age. Traditionally, this is associated with a decrease in the efficiency of cell protection systems, in particular, molecular chaperones. Thus, the development of small molecules able to induce the synthesis of chaperones is a promising therapeutic approach to prevent neural diseases associated with ageing. Here, we describe a new compound IA-50, belonging to the class of indolylazines and featured by a low size of topological polar surface area, the property related to substances with potentially high membrane-penetrating activity. We also estimated the absorption, distribution, metabolism and excretion characteristics of IA-50 and found the substance to fit the effective drug criteria. The new compound was found to induce the synthesis and accumulation of Hsp70 in normal and aged neurons and in the hippocampi of young and old mice. The transgenic model of Alzheimer's disease, based on 5xFAD mice, confirmed that the injection of IA-50 prevented the formation of β-amyloid aggregates, loss of hippocampal neurons and the development of memory impairment. These data indicate that this novel substance may induce the expression of chaperones in neural cells and brain tissues, suggesting its possible application in the therapy of ageing-associated disorders.

MicroRNA-570 targets the HSP chaperone network, increases proteotoxic stress and inhibits mammary tumor cell migration

The dynamic network of chaperone interactions known as the chaperome contributes significantly to the proteotoxic cell response and the malignant phenotype. To bypass the inherent redundancy in the network, we have used a microRNA (mir) approach to target multiple members of the chaperome simultaneously. We identified a potent microRNA, miR-570 that could bind the 3′untranslated regions of multiple HSP mRNAs and inhibit HSP synthesis. Transfection of cells with this miR species reduced expression of multiple HSPs, inhibited the heat shock response and reduced tumor cell growth while acted additively in combination with cytotoxic drugs. As overexpression of miR-570 elicited tumor suppressive effects, we inferred that this miR could play a potential role in inhibiting tumorigenesis and cancer cell growth. In accordance with this hypothesis, we determined a significant role for miR-570 in regulating markers of mammary tumor progression, including cell motility and invasion. Our data provide a proof of the principle that the tumor chaperome can be targeted by microRNAs suggesting a potential therapeutic avenue towards cancer therapy.

Abstract 5426: Down-regulation of cancer metabolism enhances radiosensitivity by impairing the heat shock response

Abstract Therapy (radiation) resistance can, inter alia, be caused by an increased lactate dehydrogenase (LDH) activity, elevated concentrations of the oncometabolite lactate and an overexpression of anti-apoptotic heat shock proteins (HSPs). In this study we aimed to break radioresistance by targeting the cancer metabolism. We could show, for the first time, that the lactate metabolism and heat shock response are co-regulated in two cancer cell systems (murine B16F10 melanoma cells, human LS174T colorectal adenocarcinoma cells). A CRISPR/Cas9 induced double knockout of LDHA/B (LDH−/−) as well as a pharmacological inhibition of LDH by Oxamate or GNE-140 reduces tumor growth, ROS production and synthesis of different HSPs, including Hsp90, Hsp70 and Hsp27. Moreover, the membrane Hsp70 density was significantly reduced on tumor cells after inhibition of the LDH activity as a consequence of a down-regulated lipid metabolism affecting the Hsp70-anchoring, tumor-specific glycosphingolipid Gb3. Our results demonstrate that influencing cancer metabolism increases radiation sensitivity by an impairment of the stress response. Since presently available LDH inhibitors have a low stability and high toxicity in vivo, we are currently investigating more potent LDH inhibitors with a beneficial safety profile. In summary, targeting the lactate metabolism provides a promising strategy to improve radiosensitivity by impairing the stress response. Citation Format: Melissa Schwab, Katharina Thunborg, Omid Azimzadeh, Christine von Toerne, Maxim Shevtsov, Masa Zdralevic, Jacques Pouyssegur, Kathrin Renner, Marina Kreutz, Peter Vaupel, Gabriele Multhoff. Down-regulation of cancer metabolism enhances radiosensitivity by impairing the heat shock response [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5426.

Effects of different protein levels on growth performance and stress parameters in beef calves under heat stress

This study investigated the effects of dietary protein levels under various heat stress (HS) conditions on the growth performance and stress parameters in Korean native beef calves. Male calves (n = 40; initial BW = 202.2 ± 3.31 kg) were randomly assigned to climatic-controlled chambers with 3 × 3 factorial arrangements. Calves were assigned into three dietary protein levels (low protein; LP = 12.5%, medium protein; MP = 15%, and high protein; HP = 17.5%) and three HS levels [mild: temperature-humidity index (THI) = 74 to 76, moderate: THI = 81 to 83, and severe: THI = 89 to 91] with control (threshold: THI = 70 to 73 and dietary protein level 12.5%). The calves were subjected to ambient temperature (22 °C) for 7 days and subsequently to the temperature and humidity corresponding to the target THI level for 21 days. The data were analyzed using the repeated-measures analysis by the GLM procedure of SAS. As a result, average daily gain (ADG) was decreased (P < 0.05) under severe HS level compared to the mild and moderate HS stress levels. However, HP increased ADG (P < 0.05) than moderate levels (LP) and severe levels (LP and MP). Under different HS levels (mild, moderate, and severe), HR, RT, and blood cortisol were increased (P < 0.05) compared to a threshold level, but no differences were observed in the parameters among various protein levels. Varied HS levels decreased the levels of blood glucose, NEFA, and amino acids (AAs) (lysine and glutamic acid) compared to a threshold (P < 0.05). But, the HP group resulted in increased (P < 0.05) levels of blood glucose, NEFA, and AAs (lysine and glutamic acid) compared to LP and MP groups under severe HS stress. The expression level of the HSP70 gene in peripheral blood mononuclear cell (PBMC) and hair follicles was increased (P < 0.05) following an increase in moderate and severe HS levels. Also, HSP70 gene expression in the HP group was decreased (P < 0.05) compared with LP and MP groups under intense HS level. Overall, HS in Korean native beef calves exhibited negative effects on ADG, blood glucose, NEFA, and AA profile. However, 17.5% of dietary protein (HP) could compensate for the growth of heat-exposed Korean native beef calves through the regulation of homeostasis by protein and energy metabolism. Also, it was evident that adequate protein (HP) is used as a major nutrient for HSP70 synthesis in PBMC and hair follicles causing, a boost in the immune system of heat-exposed Korean native beef calves.

Crotalus atrox Induced Cellular Injury Triggers an Oxidative Stress Gene Response in HEK‐293T Cells

Wound and regeneration involves a series of complex processes that can induce oxidative stress by elevating intracellular reactive oxygen species (ROS) levels. In this study, we used RNA‐seq and qPCR to examine the molecular signature of Human Embryonic Kidney cells (HEK 293T) stimulated with Crotalus atrox venom. NGS data was assembled and annotated using BLASTx and UNIPROT. Results showed 243 genes were differentially expressed (106 upregulated, 137 downregulated) between Crotalus atrox stimulated and non‐stimulated cells (p&lt;0.05). HEK 293T stimulated with Crotalus atrox venom for 4 hours showed an increase in the expression of oxidative stress response genes (e.g., TOMM6, EGR (1,2,3), HSP70 (1A, 1B), UPK3BL (1,2)), and protein synthesis (ETV5, EMP1) (fc&gt;2.0). Significantly downregulated (log2(fc)&lt;‐1.20) genes were associated with protein coding (e.g., ABCG1, ABCA1, PPARA, HMGA2, TLCD5). Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses identified 8 significant KEGG pathways, which included an amphetamine addiction pathway (p&lt;0.03). Genes identified in this pathway such as FosB proto‐oncogene (FosB) and activity regulated cytoskeleton protein (ARC) are connected to oxidative stress responses. Quantitative PCR (qPCR) was used to evaluate several genes identified from RNA‐seq data. Cells stimulated with Crotalus atrox venom for 4 hours induced an up‐regulation of HSPA1A (2.49±0.49), HSPA1B (2.04±0.12), and cytochrome P450 1A1 (CYP1A1) (3.24±0.33), matching NGS data trends. Pre‐incubation with the zinc chelator tris(2‐pyridylmethyl) amine (TPA) prior to venom stimulation induced a significant up‐regulation in HSPA1B (13.2±0.04). Extending Crotalus atrox venom stimulation to 8 hours increased the gene expression of metallothionein 1X (MT1X, 4.68±0.26) and peroxiredoxin‐4 (PRDX4, 3.34±0.11) compared to non‐stimulated cells. Interestingly, pre‐incubating cells with polyethylene glycol (PEG) catalase then stimulating cells with Crotalus atrox venom for 8 hours produced PRDX4 and MT1X gene expression values that were not significantly different from the non‐stimulated control. In contrast, glutathione peroxidase‐1 (GPx‐1) was significantly downregulated (0.27±0.16) after an 8 hour stimulation with Crotalus atrox venom, compared to non‐stimulated cells. Our data suggests Crotalus atrox induced cellular injury involves several gene families connected to oxidative stress responses.

A Low Membrane Hsp70 Expression in Tumor Cells With Impaired Lactate Metabolism Mediates Radiosensitization by NVP-AUY922.

As overexpression and membrane localization of stress proteins together with high lactate levels promote radioresistance in tumor cells, we studied the effect of the Hsp90 inhibitor NVP-AUY922 on the cytosolic and membrane expression of heat shock proteins (HSPs) and radiosensitivity in murine melanoma (B16F10) and human colorectal (LS174T) wildtype (WT) and lactate dehydrogenases A/B double knockout (LDH−/−) tumor cells. Double knockout for LDHA/B has been found to reduce cytosolic as well as membrane HSP levels, whereas treatment with NVP-AUY922 stimulates the synthesis of Hsp27 and Hsp70, but does not affect membrane Hsp70 expression. Despite NVP-AUY922-inducing elevated levels of cytosolic HSP, radiosensitivity was significantly increased in WT cells and even more pronounced in LDH−/− cells. An impaired lipid metabolism in LDH−/− cells reduces the Hsp70 membrane-anchoring sphingolipid globotriaosylceramide (Gb3) and thereby results in a decreased Hsp70 cell surface density on tumor cells. Our results demonstrate that the membrane Hsp70 density, but not cytosolic HSP levels determines the radiosensitizing effect of the Hsp90 inhibitor NVP-AUY922 in LDH−/− cells.

Physiological stress responses to nonmimetic model brood parasite eggs: Leukocyte profiles and heat-shock protein Hsp70 levels.

Obligate avian brood parasites lay their eggs in the nest of other bird species, known as hosts. Brood parasitism often imposes severe fitness costs on hosts, selecting for the evolution of effective antiparasitic defences, such as recognition and rejection of brood parasite eggs. Glucocorticoids have been recently found to mediate host physiological and behavioral adjustments in response to brood parasite eggs; however, it remains unclear whether brood parasitism triggers a general response involving multiple physiological elements. In this study, we experimentally investigated whether a salient brood parasitic stimulus (the presence of a nonmimetic model egg in the nest) causes physiological adjustments in adult Eurasian blackbirds (Turdus merula) at immune (leukocyte profiles) and cellular (heat-shock protein Hsp70 synthesis) level. Also, we explored whether these physiological changes are mediated by variations in corticosterone (CORT) levels. We found that experimental brood parasitism caused an increase in heterophils and a decrease in lymphocytes, leading to higher heterophils and lymphocytes ratios in parasitized birds. Nevertheless, we did not find tradeoffs between immune function and CORT levels. Hsp70 synthesis was not affected by our experimental manipulation. Our findings provide evidence that brood parasite eggs trigger a general stress response in egg-rejecter hosts, including changes in cellular immune profiles.

Zinc supplementation prior to heat shock enhances HSP70 synthesis through HSF1 phosphorylation at serine 326 in human peripheral mononuclear cells

Acute alteration of the functional zinc status increases the HSP70 protein level after heat shock in peripheral blood mononuclear cells (PBMC), while zinc deficiency, but not zinc supplementation, further augments heat shock-induced cell death.

Role of a Heat Shock Transcription Factor and the Major Heat Shock Protein Hsp70 in Memory Formation and Neuroprotection.

Heat shock proteins (Hsps) represent the most evolutionarily ancient, conserved, and universal system for protecting cells and the whole body from various types of stress. Among Hsps, the group of proteins with a molecular weight of 70 kDa (Hsp70) plays a particularly important role. These proteins are molecular chaperones that restore the native conformation of partially denatured proteins after exposure to proteotoxic forms of stress and are critical for the folding and intracellular trafficking of de novo synthesized proteins under normal conditions. Hsp70s are expressed at high levels in the central nervous system (CNS) of various animals and protect neurons from various types of stress, including heat shock, hypoxia, and toxins. Numerous molecular and behavioral studies have indicated that Hsp70s expressed in the CNS are important for memory formation. These proteins contribute to the folding and transport of synaptic proteins, modulate signaling cascades associated with synaptic activation, and participate in mechanisms of neurotransmitter release. In addition, HSF1, a transcription factor that is activated under stress conditions and mediates Hsps transcription, is also involved in the transcription of genes encoding many synaptic proteins, whose levels are increased in neurons under stress and during memory formation. Thus, stress activates the molecular mechanisms of memory formation, thereby allowing animals to better remember and later avoid potentially dangerous stimuli. Finally, Hsp70 has significant protective potential in neurodegenerative diseases. Increasing the level of endogenous Hsp70 synthesis or injecting exogenous Hsp70 reduces neurodegeneration, stimulates neurogenesis, and restores memory in animal models of ischemia and Alzheimer’s disease. These findings allow us to consider recombinant Hsp70 and/or Hsp70 pharmacological inducers as potential drugs for use in the treatment of ischemic injury and neurodegenerative disorders.

Inhibition of the Human Hsc70 System by Small Ligands as a Potential Anticancer Approach.

Simple SummaryHigh levels of Heat shock proteins (Hsps) in specific cancers are usually linked to a poor prognosis, tumor progression, invasiveness, and resistance to treatment. Chaperone inhibition could therefore be toxic for cancer cells due to their high dependence on chaperone activity to survive. This study shows the potential to repurpose the small chemical compound pinaverium bromide, currently used to treat functional gastrointestinal disorders, as a possible antitumor drug since it displays a marked toxicity against two melanoma cell lines without affecting the viability of fibroblast and primary melanocytes. This compound interacts with structural regions shared by representatives of the Hsp70 and Hsp110 families, inhibiting the substrate remodeling ability of the Hsp70 system in vitro and in a cellular context.Heat shock protein (Hsp) synthesis is upregulated in a wide range of cancers to provide the appropriate environment for tumor progression. The Hsp110 and Hsp70 families have been associated to cancer cell survival and resistance to chemotherapy. In this study, we explore the strategy of drug repurposing to find new Hsp70 and Hsp110 inhibitors that display toxicity against melanoma cancer cells. We found that the hits discovered using Apg2, a human representative of the Hsp110 family, as the initial target bind also to structural regions present in members of the Hsp70 family, and therefore inhibit the remodeling activity of the Hsp70 system. One of these compounds, the spasmolytic agent pinaverium bromide used for functional gastrointestinal disorders, inhibits the intracellular chaperone activity of the Hsp70 system and elicits its cytotoxic activity specifically in two melanoma cell lines by activating apoptosis. Docking and molecular dynamics simulations indicate that this compound interacts with regions located in the nucleotide-binding domain and the linker of the chaperones, modulating their ATPase activity. Thus, repurposing of pinaverium bromide for cancer treatment appears as a promising novel therapeutic approach.

Тканиноспецифічність експресії гена теплового шоку ATHSP70-10 в проростках Arabidopsis thaliana за нормальних і стресових умов

Mitochondrial heat shock proteins of HSP70 family support protein homeostasis in mitochondria under normal and stress conditions. They provide folding and complex assembly of proteins encoded by mitochondrial genome, as well as import of cytosolic proteins to mitochondria, their folding and protection against aggregation. There are reports about organ-specificity of mitochondrial HSP70 synthesis in plants. However, tissue specificity of their functioning remains incompletely characterized. This problem was studied for mitochondrial AtHSP70-10 in Arabidopsis thaliana seedlings using a transgenic line with uidA signal gene under normal conditions, as well as high temperature and water deficit. Under normal conditions, histochemical GUS-staining revealed the expression of AtHSP70-10 in cotyledon and leaf hydathodes, stipules, central cylinder in root differentiation and mature zones, as well as weak staining in root apex and root-shoot junction zone. RT-PCR analysis of wild-type seedlings exposed to 37°C showed rapid upregulation of AtHSP70-10, which reached the highest level within 2 h. In addition, the gradual development of water deficit for 5 days caused an increase in transcription of this gene, which became more pronounced after 3 days and reached a maximum after 5 days of dehydration. Histochemical analysis showed complete preservation of tissue localization of AtHSP70-10 expression under both abiotic factors. The data obtained indicate the specific functioning of mitochondrial chaperone AtHSP70-10 in certain plant cellular structures.

Indolyl- and Pyrrolylazine Derivatives Cause the Accumulation of Heat Shock Protein Hsp70 in Sh-Sy5Y Human Neuroblastoma Cells.

The heat shock protein Hsp70 is involved in cell defense from various types of stress, including the proteotoxic stress, which occurs during the development of many neurodegenerative diseases. This work presents data on the detection of small molecules, derivatives of indolyl- and pyrrolylazines, which can activate the synthesis of Hsp70 and cause its accumulation in the cell. The toxicity level of the new Hsp70 synthesis inducers was evaluated, and the safety of these compounds was demonstrated in experiments on SH-SY5Y neuroblastoma cell line. Derivatives of indolyl- and pyrrolylazines presented in this work can be potential therapeutic agents in models of neurodegenerative diseases that should be studied in more detail.

Pyrrolylquinoxaline-2-One Derivative as a Potent Therapeutic Factor for Brain Trauma Rehabilitation.

Traumatic brain injury (TBI) often causes massive brain cell death accompanied by the accumulation of toxic factors in interstitial and cerebrospinal fluids. The persistence of the damaged brain area is not transient and may occur within days and weeks. Chaperone Hsp70 is known for its cytoprotective and antiapoptotic activity, and thus, a therapeutic approach based on chemically induced Hsp70 expression may become a promising approach to lower post-traumatic complications. To simulate the processes of secondary damage, we used an animal model of TBI and a cell model based on the cultivation of target cells in the presence of cerebrospinal fluid (CSF) from injured rats. Here we present a novel low molecular weight substance, PQ-29, which induces the synthesis of Hsp70 and empowers the resistance of rat C6 glioma cells to the cytotoxic effect of rat cerebrospinal fluid taken from rats subjected to TBI. In an animal model of TBI, PQ-29 elevated the Hsp70 level in brain cells and significantly slowed the process of the apoptosis in acceptor cells in response to cerebrospinal fluid action. The compound was also shown to rescue the motor function of traumatized rats, thus proving its potential application in rehabilitation therapy after TBI.

The role of dihydroquercetin in the molecular mechanisms of myocardial protection in dust- induced pathology

Introduction. Dust-induced lung pathology in miners is often combined with cardiovascular diseases such as coronary heart disease, hypertension, and atherosclerosis. In this regard, the search for ways to prevent the development of combined pathology with dust effects on the body is an urgent problem in occupational health.The aim of the study was to explore the effect of a complex preparation with dihydroquercetin on the level of protective proteins and myocardial morphostructure in the dynamics of dust-induced pathology development when inhaling coal-rock dust.Materials and methods. The study was conducted on white laboratory male rats weighing 200–250 g. The animals were divided into two groups: rats that inhaled coal-rock dust in the priming dust chamber daily for 4 hours for 1, 3, 6, 9 and 12 weeks; rats that received a daily complex drug with dihydroquercetin. The concentration of IL–6 proinflammatory cytokine and cardiomarkers (B-type brain natriuretic peptide, vascular endothelial growth factor, and fractalkin) was determined in the blood by enzyme immunoassay. In the cytosolic fraction of heart tissue, the level of expression of the hypoxia-induced transcription factor HIF — 1α, the inducible forms of proteins HSP72 and heme-oxygenase–1 was determined.Results. Prolonged dust exposure in the early stages (1–3 weeks) increased the expression of HIF–1α transcription factor and stress-inducible proteins — HSP72 and HOx–1 — in the myocardium. An increase in the dust exposure period of more than 6 weeks was accompanied by a decrease in the level of the HIF–1α transcription factor to control values, but the intensive synthesis of HSP72 and HOx–1 was maintained. In addition, the dynamics of long-term dust exposure to the body changed the level of cardiomarkers in the blood serum: 1) increased vascular endothelial factor; 2) fractalkin and IL–6 decreased in the early stages, as well as brain natriuretic peptide type B — the entire period of the study. By week 12 of dust exposure in the myocardial tissue it was revealed: dystrophic changes of a protein nature, signs of apoptosis, atrophy of some fibers and the development of diff use cardiosclerosis. Daily administration of a complex drug with dihydroquercetin to laboratory animals with prolonged exposure to coal-rock dust for 12 weeks led to the restoration of the level of protective cardiomarkers to control values and reduced the severity of morphological changes in the heart tissue.Conclusions. The administration of a complex drug with dihydroquercetin during prolonged dust exposure on the body has a cardioprotective effect, which is confirmed by the achievement of control levels of cell proliferation factors (B- type brain natriuretic peptide), angiogenesis (vascular endothelial factor), proinflammatory (IL–6) and anti-inflammatory response (CX3CL1), as well as a decrease in the severity of dystrophic changes in myocardial muscle fibers and almost complete disappearance of lymphocytic infiltration in heart vessels.Th e authors declare no confl ict of interests.