The chaperone function of hsp70 is required for protection against stress-induced apoptosis

Altered Levels of Natural Autoantibodies against Heat Shock Proteins in Pregnant Women with Hashimoto's Thyroiditis

The function of natural autoantibodies (nAAbs) in maintaining immunological tolerance has been comprehensively explained; however, their function in pregnant patients dealing with autoimmune diseases has not been thoroughly investigated. As Hashimoto's thyroiditis (HT) is the predominant organ-specific autoimmune condition of women of childbearing age, this study's objective was to evaluate IgM and IgG nAAbs targeting mitochondrial citrate synthase (CS) and heat shock proteins (Hsp60 and Hsp70) in women diagnosed with HT who were pregnant (HTP). Serum samples collected from HTP and healthy pregnant (HP) women in the first and third trimesters were tested using in-house-developed enzyme-linked immunosorbent assays (ELISAs). Our findings indicate the stability of nAAbs against CS and Hsps throughout the pregnancies of both healthy women and those with HT. However, during both trimesters, HTP patients displayed elevated levels of IgM isotype nAAbs against Hsp60 and Hsp70 compared to HP women, suggesting a regulatory role of IgM nAAbs during the pregnancies of patients with HT. Nonetheless, levels of IgG isotype nAAbs against Hsps were lower solely in the third trimester among HTP patients, resulting in a higher IgM/IgG ratio, which indicates their importance in alterations of the nAAb network during pregnancy in patients with HT.

Inhibition of Cell Apoptosis by Apicomplexan Protozoa-Host Interaction in the Early Stage of Infection

Apicomplexan protozoa, which are a group of specialized intracellular parasitic protozoa, infect humans and other animals and cause a variety of diseases. The lack of research on the interaction mechanism between Apicomplexan protozoa and their hosts is a key factor restricting the development of new drugs and vaccines. In the early stages of infection, cell apoptosis is inhibited by Apicomplexan protozoa through their interaction with the host cells; thereby, the survival and reproduction of Apicomplexan protozoa in host cells is promoted. In this review, the key virulence proteins and pathways are introduced regarding the inhibition of cell apoptosis by the interaction between the protozoa and their host during the early stage of Apicomplexan protozoa infection. It provides a theoretical basis for the development of drugs or vaccines for protozoal diseases.

Small Heat Shock Protein (sHsp22.98) from Trialeurodes vaporariorum Plays Important Role in Apple Scar Skin Viroid Transmission

Trialeurodes vaporariorum, commonly known as the greenhouse whitefly, severely infests important crops and serves as a vector for apple scar skin viroid (ASSVd). This vector-mediated transmission may cause the spread of infection to other herbaceous crops. For effective management of ASSVd, it is important to explore the whitefly's proteins, which interact with ASSVd RNA and are thereby involved in its transmission. In this study, it was found that a small heat shock protein (sHsp) from T. vaporariorum, which is expressed under stress, binds to ASSVd RNA. The sHsp gene is 606 bp in length and encodes for 202 amino acids, with a molecular weight of 22.98 kDa and an isoelectric point of 8.95. Intermolecular interaction was confirmed through in silico analysis, using electrophoretic mobility shift assays (EMSAs) and northwestern assays. The sHsp22.98 protein was found to exist in both monomeric and dimeric forms, and both forms showed strong binding to ASSVd RNA. To investigate the role of sHsp22.98 during ASSVd infection, transient silencing of sHsp22.98 was conducted, using a tobacco rattle virus (TRV)-based virus-induced gene silencing system. The sHsp22.98-silenced whiteflies showed an approximate 50% decrease in ASSVd transmission. These results suggest that sHsp22.98 from T. vaporariorum is associated with viroid RNA and plays a significant role in transmission.

Integrative profiling of metabolome and transcriptome of skeletal muscle after acute exercise intervention in mice

This study aims to explore the molecular regulatory mechanisms of acute exercise in the skeletal muscle of mice. Male C57BL/6 mice were randomly assigned to the control group, and the exercise group, which were sacrificed immediately after an acute bout of exercise. The study was conducted to investigate the metabolic and transcriptional profiling in the quadriceps muscles of mice. The results demonstrated the identification of 34 differentially expressed metabolites (DEMs), with 28 upregulated and 6 downregulated, between the two groups. Metabolic pathway analysis revealed that these DEMs were primarily enriched in several, including the citrate cycle, propanoate metabolism, and lysine degradation pathways. In addition, the results showed a total of 245 differentially expressed genes (DEGs), with 155 genes upregulated and 90 genes downregulated. KEGG analysis indicated that these DEGs were mainly enriched in various pathways such as ubiquitin mediated proteolysis and FoxO signaling pathway. Furthermore, the analysis revealed significant enrichment of DEMs and DEGs in signaling pathways such as protein digestion and absorption, ferroptosis signaling pathway. In summary, the identified multiple metabolic pathways and signaling pathways were involved in the exercise-induced physiological regulation of skeletal muscle, such as the TCA cycle, oxidative phosphorylation, protein digestion and absorption, the FoxO signaling pathway, ubiquitin mediated proteolysis, ferroptosis signaling pathway, and the upregulation of KLF-15, FoxO1, MAFbx, and MuRF1 expression could play a critical role in enhancing skeletal muscle proteolysis.

From sleep to cancer to neurodegenerative disease: the crucial role of Hsp70 in maintaining cellular homeostasis and potential therapeutic implications

Sleep is a fundamental process essential for reparatory and restorative mechanisms in all organisms. Recent research has linked sleep to various pathological conditions, including cancer and neurodegeneration, which are associated with various molecular changes in different cellular environments. Despite the potential significance of various molecules, the HSPA1A or Hsp70 protein, which has possible connections with sleep and different neuropsychological and pathological disorders, has been explored the least. This paper explores the potential for manipulating and discovering drugs related to the Hsp70 protein to alleviate sleep problems and improve the prognosis for various other health issues. This paper discusses the critical role of Hsp70 in cancer, neurodegeneration, apoptosis, sleep, and its regulation at the structural level through allosteric mechanisms and different substrates. The significant impact of Hsp70's connection to various conditions suggests that existing sleep medicine could be used to improve such conditions, leading to improved outcomes, minimized research costs, and a new direction for current research. Overall, this paper highlights the potential of Hsp70 protein as a key therapeutic target for developing new drugs for the treatment of sleep disorders, cancer, neurodegeneration, and other related pathological conditions. Further research into the molecular mechanisms of Hsp70 regulation and its interactions with other cellular pathways is necessary to develop targeted treatments for these conditions.Communicated by Ramaswamy H. Sarma.

Cellular protection from H2O2 toxicity by Fv-Hsp70: protection via catalase and gamma-glutamyl-cysteine synthase

Heat shock proteins (HSPs), especially Hsp70 (HSPA1), have been associated with cellular protection from various cellular stresses including heat, hypoxia-ischemia, neurodegeneration, toxins, and trauma. Endogenous HSPs are often synthesized in direct response to these stresses but in many situations are inadequate in protecting cells. The present study addresses the transduction of Hsp70 into cells providing protection from acute oxidative stress by H2O2. The recombinant Fv-Hsp70 protein and two mutant Fv-Hsp70 proteins minus the ATPase domain and minus the ATPase and terminal lid domains were tested at 0.5 and 1.0 μM concentrations after two different concentrations of H2O2 treatment. All three recombinant proteins protected SH-SY5Y cells from acute H2O2 toxicity. This data indicated that the protein binding domain was responsible for cellular protection. In addition, experiments pretreating cells with inhibitors of antioxidant proteins catalase and gamma-glutamylcysteine synthase (GGCS) before H2O2 resulted in cell death despite treatment with Fv-Hsp70, implying that both enzymes were protected from acute oxidative stress after treatment with Fv-Hsp70. This study demonstrates that Fv-Hsp70 is protective in our experiments primarily by the protein-binding domain. The Hsp70 terminal lid domain was also not necessary for protection.

ZNF330/NOA36 interacts with HSPA1 and HSPA8 and modulates cell cycle and proliferation in response to heat shock in HEK293 cells

BACKGROUND

The human genome contains nearly 20.000 protein-coding genes, but there are still more than 6,000 proteins poorly characterized. Among them, ZNF330/NOA36 stand out because it is a highly evolutionarily conserved nucleolar zinc-finger protein found in the genome of ancient animal phyla like sponges or cnidarians, up to humans. Firstly described as a human autoantigen, NOA36 is expressed in all tissues and human cell lines, and it has been related to apoptosis in human cells as well as in muscle morphogenesis and hematopoiesis in Drosophila. Nevertheless, further research is required to better understand the roles of this highly conserved protein.

RESULTS

Here, we have investigated possible interactors of human ZNF330/NOA36 through affinity-purification mass spectrometry (AP-MS). Among them, NOA36 interaction with HSPA1 and HSPA8 heat shock proteins was disclosed and further validated by co-immunoprecipitation. Also, "Enhancer of Rudimentary Homolog" (ERH), a protein involved in cell cycle regulation, was detected in the AP-MS approach. Furthermore, we developed a NOA36 knockout cell line using CRISPR/Cas9n in HEK293, and we found that the cell cycle profile was modified, and proliferation decreased after heat shock in the knocked-out cells. These differences were not due to a different expression of the HSPs genes detected in the AP-MS after inducing stress.

CONCLUSIONS

Our results indicate that NOA36 is necessary for proliferation recovery in response to thermal stress to achieve a regular cell cycle profile, likely by interaction with HSPA1 and HSPA8. Further studies would be required to disclose the relevance of NOA36-EHR interaction in this context.

Acquired heat acclimation in rats subjected to physical exercise under environmental heat stress alleviates brain injury caused by exertional heat stroke

BACKGROUND

Exertional heatstroke (EHS) is an emergency with a high mortality rate, characterized by central nervous system dysfunctions. This study aims to establish a Heat acclimation/acclimatization (HA) rat model in locomotion to recapitulate the physical state of human in severe environment of high temperature and humidity, and investigate the mechanism of organism protection in HA. (2) Methods: Wistar rats were exposed to 36°C and ran 2 h/d for 21 days, acquired thermal tolerance test was conducted to assess the thermotolerance and exercise ability. Core temperature and consumption of water and food were observed. Expression of HSP70 and HSP90 of different tissues were determined by WB. Pathological structure of brain tissue was detected with HE staining. Proteomics was used to identify the differently expressed proteins in cerebral cortex of different groups. And key molecules were identified by RT-PCR and WB. (3) Results: HA rats displayed stronger thermotolerance and exercised ability on acquired thermal tolerance test. Brain water content of HA+EHS group reduced compared with EHS group. HE staining revealed slighter brain injuries of HA+EHS group than that of EHS. Proteomics focused on cell death-related pathways and key molecules Aquaporin 4 (AQP4) related to cell edema. Identification results showed HA increased AQP4, Bcl-xl, ratio of p-Akt/AKT and Bcl-xl/Bax, down-regulated Cleaved Caspase-3. (4) Conclusions: This HA model can ameliorate brain injury of EHS by reducing cerebral edema and cell apoptosis, offering experimental evidence for EHS prophylaxis.

Effects of heat stress exposure on porcine muscle satellite cells

Heat stress (HS) affects cell culture as well as animal production. Although there have been many reports on the disparate effects of heat stress, its effects on mammalian muscle stem cells are still unclear. In this study, we isolated porcine muscle satellite cells (PMSCs) from the femurs of 1-day-old piglets, and cultured them under three temperature conditions: 37 °C, 39 °C, and 41 °C. Exposure to HS not only decreased the viability and proliferation rates of PMSCs, but also regulated the cell cycle and induced apoptosis. High-temperature culture conditions decreased both protein and gene expression of Pax7, a proliferation and maintenance marker of muscle satellite cells, whereas it increased both protein and gene expression of MyoG, a differentiation marker, and promoted myotube formation in the early stage of differentiation induction. In addition, the protein and gene expression of several heat shock proteins (HSPs) in PMSCs increased due to heat treatment. In conclusion, HS induced the cell cycle arrest of PMSCs, thereby reducing the proliferation rate. In addition, high-temperature culture conditions promoted the formation of myotubes at the early stage of differentiation of PMSCs without additives.

Transcriptomics provides insights into toxicological effects and molecular mechanisms associated with the exposure of Chinese mitten crab, Eriocheir sinensis, to dioxin

Dioxins are stable, ubiquitous, persistent, and halogenated environmental pollutants that have recently garnered increasing attention. This study constructed a microcosmic system to simulate the real breeding conditions of the Chinese mitten crab (Eriocheir sinensis) to evaluate the impact of environmental dioxins on these aquaculture animals. Histological observation and detection of antioxidant enzyme activities revealed that dioxin exposure for different durations substantially damaged the hepatopancreas of Chinese mitten crabs, increasing the enzymatic activities of total superoxide dismutase (T-SOD) and catalase (CAT) but decreasing that of malondialdehyde (MDA). We also obtained the gene expression profiles of the hepatopancreas corresponding to different periods of dioxin exposure using RNA-seq technology. Compared with the control group, 2999 and 941 differentially expressed genes (DEGs) corresponding to different periods of dioxin exposure were identified in the hepatopancreas. Enrichment analysis indicated that some pathways, such as those governing carbohydrate metabolism, fatty acid metabolism, and immune disease, also responded to dioxin exposure. Subsequently, we selectively analyzed DEGs involved in oxidoreductase activity, carbohydrate metabolic processes, and other processes, identifying that increased expression of Hsp70, Ldh, and Trx1 and decreased expression of Lgbp, Bgal1, and Acsbg2 were potentially caused by sensitivity to environmental dioxin exposure. Therefore, we contend that, although crabs exposed to unfavorable environmental pollutants, such as dioxin, may adapt via antioxidant and immune response modulation. However, continued dioxin exposure would disrupt such homeostatic restorative capabilities. Thus, this study may provide new insights into the toxicological effects exerted by dioxin on aquatic organisms, such as E. sinensis, as well as the mechanisms underlying such toxicity.

Glutamine alleviated heat stress-induced damage of porcine intestinal epithelium associated with the mitochondrial apoptosis pathway mediated by heat shock protein 70

The present study aimed to investigate the effect of glutamine (Gln) addition on the damage of porcine intestinal epithelial cells (IPEC-J2) induced by heat stress (HS). IPEC-J2 cultured in logarithmic growth period in vitro were firstly exposed to 42 °C for 0.5, 1, 2, 4, 6, 8, 10, 12, and 24 h for cell viability and cultured with 1, 2, 4, 6, 8, or 10 mmol Gln per L of culture media for heat shock protein 70 (HSP70) expression to determine the optimal disposal strategy (HS, 42 °C for 12 h and HSP70 expression, 6 mmol/L Gln treatment for 24 h). Then IPEC-J2 cells were divided into three groups: control group (Con, cultured at 37 °C), HS group (HS, cultured at 42 °C for 12 h), and glutamine group (Gln+HS, cultured at 42 °C for 12 h combined with 6 mmol/L Gln treatment for 24 h). The results showed that HS treatment for 12 h significantly decreased the cell viability of IPEC-J2 (P < 0.05) and 6 mmol/L Gln treatment for 12 h increased HSP70 expression (P < 0.05). HS treatment increased the permeability of IPEC-J2, evidenced by the increased fluorescent yellow flux rates (P < 0.05) and the decreased transepithelial electrical resistance (P < 0.05). Moreover, the downregulated protein expression of occludin, claudin-1, and zonula occludens-1 was observed in HS group (P < 0.05), but Gln addition alleviated the negative effects on permeability and the integrity of intestinal mucosal barrier induced by HS (P < 0.05). In addition, HS resulted in the elevations in HSP70 expression, cell apoptosis, cytoplasmic cytochrome c potential expression, and the protein expressions of apoptosis-related factors (apoptotic protease-activating factor-1, cysteinyl aspartate-specific proteinase-3, and cysteinyl aspartate-specific proteinase-9) (P < 0.05); however, the reductions in mitochondrial membrane potential expression and B-cell lymphoma-2 expression were induced by HS (P < 0.05). But Gln treatment attenuated HS-induced adverse effects mentioned above (P < 0.05). Taken together, Gln treatment exhibited protective effects in protecting IPEC-J2 from cell apoptosis and the damaged integrity of epithelial mucosal barrier induced by HS, which may be associated with the mitochondrial apoptosis pathway mediated by HSP70.

The effects of low pH and high water temperature on oxidative stress and cell damage in juvenile olive flounder Paralichthys olivaceus: comparison of single and combined environmental conditions

The use of fossil fuels by anthropogenic activities causes ocean acidification and warming, and these changes in the marine environment can negatively affect the metabolism, growth, and survival of fish. In the present study, we evaluated the ability of olive flounder Paralichthys olivaceus to cope with future marine environmental changes by investigating the oxidative stress (cortisol, HSP70), antioxidant enzyme (superoxide dismutase; SOD, catalase; CAT) activity, and apoptosis (caspase-3) after exposure to control conditions (20 °C and pH 8.1), warming (30 °C) and acidification (pH 7.5) conditions, and a combined environment (30 °C and pH 7.5) for 28 days. Under warming conditions, increased oxidative stress, activity of antioxidant enzymes, and apoptosis were observed. Acidifying conditions showed negative effects at the beginning of exposure, but these effects were offset over time. Even in a combined environment of acidification and warming, negative effects were seen only at the beginning of exposure and were not sustained. In conclusion, the effects of acidification on oxidative stress, antioxidant response, and apoptosis in P. olivaceus did not exceed the effects of warming. These results suggest that P. olivaceus can cope with the predicted future acidifying environment.

Leveraging the Structure of DNAJA1 to Discover Novel Potential Pancreatic Cancer Therapies

Pancreatic cancer remains one of the deadliest forms of cancer with a 5-year survival rate of only 11%. Difficult diagnosis and limited treatment options are the major causes of the poor outcome for pancreatic cancer. The human protein DNAJA1 has been proposed as a potential therapeutic target for pancreatic cancer, but its cellular and biological functions remain unclear. Previous studies have suggested that DNAJA1's cellular activity may be dependent upon its protein binding partners. To further investigate this assertion, the first 107 amino acid structures of DNAJA1 were solved by NMR, which includes the classical J-domain and its associated linker region that is proposed to be vital to DNAJA1 functionality. The DNAJA1 NMR structure was then used to identify both protein and ligand binding sites and potential binding partners that may suggest the intracellular roles of DNAJA1. Virtual drug screenings followed by NMR and isothermal titration calorimetry identified 5 drug-like compounds that bind to two different sites on DNAJA1. A pull-down assay identified 8 potentially novel protein binding partners of DNAJA1. These proteins in conjunction with our previously published metabolomics study support a vital role for DNAJA1 in cellular oncogenesis and pancreatic cancer.

Involvement of heat shock proteins and parkin/α-synuclein axis in Parkinson's disease

Parkinson's disease (PD) is one of the most common neurological diseases, next only to Alzheimer's disease (AD) in terms of prevalence. It afflicts about 2-3% of individuals over 65 years old. The etiology of PD is unknown and several environmental and genetic factors are involved. From a pathological point of view, PD is characterized by the loss of dopaminergic neurons in the substantia nigra, which causes the abnormal accumulation of α-synuclein (α-syn) (a component of Lewy bodies), which subsequently interact with heat shock proteins (HSPs), leading to apoptosis. Apoptosis is a vital pathway for establishing homeostasis in body tissues, which is regulated by pro-apoptotic and anti-apoptotic factors. Recent findings have shown that HSPs, especially HSP27 and HSP70, play a pivotal role in regulating apoptosis by influencing the factors involved in the apoptosis pathway. Moreover, it has been reported that the expression of these HSPs in the nervous system is high. Apart from this finding, investigations have suggested that HSP27 and HSP70 (related to parkin) show a potent protective and anti-apoptotic impact against the damaging outcomes of mutant α-syn toxicity to nerve cells. Therefore, in this study, we aimed to investigate the relationship between these HSPs and apoptosis in patients with PD.

Procyanidin B2 Alleviates Heat-Induced Oxidative Stress through the Nrf2 Pathway in Bovine Mammary Epithelial Cells

The objective of this study was to investigate the protective effects and potential molecular mechanisms of procyanidin B2 (PB2) in MAC-T (mammary alveolar cells-large T antigen) cells during heat stress (HS). The MAC-T cells were divided into three treatment groups: control (37 °C), HS (42 °C), and PB2 + HS (42 °C). Compared with MAC-T cells that were consistently cultured at 37 °C, acute HS treatment remarkably decreased cell viability, reduced activities of catalase (CAT), superoxide dismutase (SOD), and total antioxidant capacity (T-AOC), and elevated intracellular levels of malondialdehyde (MDA) and reactive oxygen species (ROS). Additionally, nuclear factor erythroid 2-related factor 2 (Nrf2) was activated and translocated to the nucleus, in accompaniment with upregulation of Nrf2, heme oxygenase 1 (HO-1), thioredoxin reductase 1 (Txnrd1), and heat shock protein 70 (HSP70). In parallel, both mRNA transcript and actual protein secretion of pro-inflammatory cytokines, including tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β), were increased by heat stress. Pretreatment of MAC-T cells with 0~25 μM PB2 alleviated the decline of cell viability by HS in a dose-dependent fashion and protected cells against HS-induced oxidative stress, as evidenced by significantly improved CAT, SOD, and T-AOC activity, as well as with decreased MDA and ROS generation. Furthermore, PB2 further activated the Nrf2 signaling pathway and reversed the inflammatory response induced by HS. Silencing of Nrf2 by si-Nrf2 transfection not only exacerbated HS-induced cell death and provoked oxidative stress and the inflammatory response, but also greatly abolished the cytoprotective effects under HS of PB2. In summary, PB2 protected MAC-T cells against HS-induced cell death, oxidative stress, and inflammatory response, partially by operating at the Nrf2 signal pathway.

The APE2 Exonuclease Is a Client of the Hsp70–Hsp90 Axis in Yeast and Mammalian Cells

Molecular chaperones such as Hsp70 and Hsp90 help fold and activate proteins in important signal transduction pathways that include DNA damage response (DDR). Previous studies have suggested that the levels of the mammalian APE2 exonuclease, a protein critical for DNA repair, may be dependent on chaperone activity. In this study, we demonstrate that the budding yeast Apn2 exonuclease interacts with molecular chaperones Ssa1 and Hsp82 and the co-chaperone Ydj1. Although Apn2 does not display a binding preference for any specific cytosolic Hsp70 or Hsp90 paralog, Ssa1 is unable to support Apn2 stability when present as the sole Ssa in the cell. Demonstrating conservation of this mechanism, the exonuclease APE2 also binds to Hsp70 and Hsp90 in mammalian cells. Inhibition of chaperone function via specific small molecule inhibitors results in a rapid loss of APE2 in a range of cancer cell lines. Taken together, these data identify APE2 and Apn2 as clients of the chaperone system in yeast and mammalian cells and suggest that chaperone inhibition may form the basis of novel anticancer therapies that target APE2-mediated processes.

Multiple-stressor effects of ocean acidification, warming and predation risk cues on the early ontogeny of a rocky-shore keystone gastropod

To understand how climate change stressors might affect marine organisms and support adequate projections it is important to know how multiple stressors may be modulated by the presence of other species. We evaluated the direct effects of ocean warming (OW) and ocean acidification (OA) together with non-consumptive effects (NCEs) of the predatory crab Acanthocyclus hassleri on early ontogeny fitness-related traits of the commercially important rocky-shore keystone gastropod Concholepas concholepas. We measured the response of nine traits to these stressors at either the organismal level (survival, growth, feeding rates, tenacity, metabolic rate, calcification rate) or sub-organismal level (nutritional status, ATP-supplying capacity, stress condition). C. concholepas survival was not affected by any of the stressors. Feeding rates were not affected by OW or OA; however, they were reduced in the presence of crab NCEs compared with control conditions. Horizontal tenacity was affected by the OA × NCEs interaction; in the presence of NCEs, OA reduced tenacity. The routine metabolic rate, measured by oxygen consumption, increased significantly with OW. Nutritional status assessment determined that carbohydrate content was not affected by any of the stressors. However, protein content was affected by the OA × NCEs interaction; in the absence of NCEs, OA reduced protein levels. ATP-supplying capacity, measured by citrate synthase (CS) activity, and cellular stress condition (HSP70 expression) were reduced by OA, with reduction in CS activity found particularly at the high temperature. Our results indicate C. concholepas traits are affected by OA and OW and the effects are modulated by predator risk (NCEs). We conclude that some C. concholepas traits are resilient to climate stressors (survival, growth, horizontal tenacity and nutritional status) but others are affected by OW (metabolic rate), OA (ATP-supplying capacity, stress condition), and NCEs (feeding rate). The results suggest that these negative effects can adversely affect the associated community.

LINC00963: A potential cancer diagnostic and therapeutic target

Long intergenic noncoding RNA 00963 (LINC00963) is located on human chromosome 9q34.11. Aberrantly expressed LINC00963 often exerts oncogenic effects by regulating various cellular processes including proliferation, migration, invasion, EMT, and apoptosis. Overexpressed LINC00963 is associated with cancer clinicopathological features and poor cancer prognosis, and can be used in the diagnosis of hepatocellular carcinoma. LINC00963 can build a complex ceRNA network by competitively binding to 22 miRNAs in 14 cancers. LINC00963 can also directly regulate four downstream protein-coding genes. Specifically, LINC00963 promotes the transition of prostate cancer from an androgen-dependent mode to an androgen-independent mode by participating in the transactivation of EGFR. LINC00963 can bind EZH2 and inhibit p21 expression, thereby promoting glioma cell proliferation and invasion. In non-small cell lung cancer, LINC00963 can recruit NONO and CRTC, forming a positive feedback loop of LINC00963/NONO/CRTC/CREB/LINC00963, thereby promoting cancer cell metastasis. LINC00963 is involved in the PI3K/AKT signaling pathway, Wnt signaling pathway, AMPK signaling pathway, and MAPK signaling pathway. Furthermore, LINC00963 is associated with drug resistance in oral squamous cell carcinoma (cisplatin and 5-fluorouracil) and gastric cancer (oxaliplatin) and predicts neoadjuvant efficacy of taxane-anthracyclines in breast cancer. This work systematically reviewed the clinical value of abnormal expression of LINC00963 in various tumors, demonstrated the complex molecular mechanism of LINC00963, and provided directions for future related research.

Effects of Nitrite Exposure on the Hematological Properties, Antioxidant and Stress Responses of Juvenile Hybrid Groupers, Epinephelus lanceolatus ♂ × Epinephelus fuscoguttatus ♀

Nitrite concentrations can reach high levels in indoor aquaculture systems, thus it is vital to determine the nitrite tolerance of aquaculture fish species. Here, juvenile hybrid groupers (Epinephelus lanceolatus ♂ × Epinephelus fuscoguttatus ♀, Family: Serranidae) were exposed to waterborne nitrite at 0, 10, 20, 40, and 80 mg NO₂⁻/L for 2 weeks. Nitrite exposure caused significant reductions in hematocrit and hemoglobin levels, significant increases in plasma calcium and plasma ALP levels, but had no significant effects on magnesium and total protein levels. Of the antioxidant responses investigated, SOD activity increased significantly in the liver and gills, but GST activity and GSH levels were significantly inhibited by nitrite exposure. Stress indicators, such as plasma cortisol and HSP 70 levels, were significantly stimulated by nitrite exposure. In brief, nitrite exposure over 20 mg NO₂⁻/L had toxic effects and affected the hematological properties, antioxidant responses, and stress indicators of juvenile hybrid groupers.

Expression of pro-apoptotic and anti-apoptotic proteins in granulosa cells of women with diminished ovarian reserve

PURPOSE

To evaluate the expressions of caspase-3 and cytochrome c and heat shock protein 70 (Hsp70) in granulosa cells (GCs) from women with normal ovarian reserve (NOR) and diminished ovarian reserve (DOR) undergoing intracytoplasmic sperm injection (ICSI).

METHODS

GCs were collected from 117 infertile women during oocyte retrieval. Patients were classified into four groups as follows: DOR-COC score of 0, DOR-COC score of I, NOR-COC score of 0, and NOR-COC score of I. The caspase-3, cytochrome c, and Hsp70 analyses were performed immunohistochemically in GCs. The ICSI outcomes were evaluated prospectively.

RESULTS

The clinical pregnancy and live birth rates were higher in DOR-COC score of I (15, 30.6%; 14, 38.9%) and NOR-COC score of I (19, 38.77%; 19, 52.7%) groups, compared with DOR-COC score of 0 (12, 24.4%; 3, 6.1%) and NOR-COC score of 0 (3, 6.1%; 0%) groups (p = 0.0001; 0.00002), respectively. Caspase-3 and cytochrome c expression levels were higher in DOR-COC score of 0 (23, 65.7%; 25, 71.4%) and NOR-COC score of 0 groups (19, 61.3%; 20, 64.5%), compared with DOR-COC score of I (8, 32%; 9, 36%) and NOR-COC score of I groups (7, 26.9%; 8, 30.8%) (p = 0.00297; p = 0.002), respectively. Lower expression levels of Hsp70 were found in DOR-COC score of 0 (11, 31.4%) and NOR-COC score of 0 groups (10, 32.3%), compared with DOR-COC score of I (16, 64%) and NOR-COC score of I groups (20, 76.9%) (p = 0.001), respectively. Hsp70 expression levels were positively correlated with the number of day 3 good-quality embryo and negatively correlated with estradiol levels in the DOR group.

CONCLUSION

Our data suggest that COC score of 0 is associated with increased expression levels of apoptotic proteins, decreased expression levels of anti-apoptotic protein, and poor ICSI clinical outcomes in women with and without DOR.

BH3-Only Proteins Noxa and Puma Are Key Regulators of Induced Apoptosis

Apoptosis is an evolutionarily conserved and tightly regulated cell death pathway. Physiological cell death is important for maintaining homeostasis and optimal biological conditions by continuous elimination of undesired or superfluous cells. The BH3-only pro-apoptotic members are strong inducers of apoptosis. The pro-apoptotic BH3-only protein Noxa activates multiple death pathways by inhibiting the anti-apoptotic Bcl-2 family protein, Mcl-1, and other protein members leading to Bax and Bak activation and MOMP. On the other hand, Puma is induced by p53-dependent and p53-independent apoptotic stimuli in several cancer cell lines. Moreover, this protein is involved in several physiological and pathological processes, such as immunity, cancer, and neurodegenerative diseases. Future heat shock research could disclose the effect of hyperthermia on both Noxa and BH3-only proteins. This suggests post-transcriptional mechanisms controlling the translation of both Puma and Noxa mRNA in heat-shocked cells. This study was also the chance to recapitulate the different reactional mechanisms investigated for caspases.

Caspase-mediated cleavage of miRNA processing proteins Drosha, DGCR8, Dicer, and TRBP2 in heat-shocked cells and its inhibition by HSP70 overexpression

Cells respond to stress through adaptive mechanisms that limit cellular damage and prevent cell death. MicroRNAs act as regulators of stress responses and stress can impact the functioning of miRNA biogenesis pathways. We were interested in the effect that severe proteotoxic stress capable of inducing apoptosis may have on miRNA biogenesis and the impact of the molecular chaperone protein HSP70 under these conditions. We found that the miRNA processing enzymes Drosha and Dicer and their accessory proteins DGCR8 and TRBP2 are cleaved by caspases in apoptotic cells. Overexpression of HSP70 prevented caspase activation and the degradation of these processing proteins. Caspase cleavage of TRBP2 was mapped to amino acid 234 which separates the two dsRNA-binding domains from the C-terminal Dicer interacting domain. Overexpression of TRBP2 was found to increase miRNA maturation, while expression of either of the fragments generated by caspase cleavage impaired maturation. These results indicate that inactivation of miRNA biogenesis is a critical feature of apoptosis and that cleavage of TRBP2, rather than simply a loss of function, serves to create positive acting inhibitors of pre-miRNA maturation.

The Role of p53 Protein in the Realization of the Exogenous Heat Shock Protein 70 Anti-Apoptotic Effect during Axotomy

The search for effective neuroprotective agents for the treatment of neurotrauma has always been of great interest to researchers around the world. Extracellular heat shock protein 70 (eHsp70) is considered a promising agent to study, as it has been demonstrated to exert a significant neuroprotective activity against various neurodegenerative diseases. We showed that eHsp70 can penetrate neurons and glial cells when added to the incubation medium, and can accumulate in the nuclei of neurons and satellite glial cells after axotomy. eHsp70 reduces apoptosis and necrosis of the glial cells, but not the neurons. At the same time, co-localization of eHsp70 with p53 protein, one of the key regulators of apoptosis, was noted. eHsp70 reduces the level of the p53 protein apoptosis promoter both in glial cells and in the nuclei and cytoplasm of neurons, which indicates its neuroprotective effect. The ability of eHsp70 to reverse the proapoptotic effect of the p53 activator WR1065 may indicate its ability to regulate p53 activity or its proteosome-dependent degradation.

The alleviative effect of thyroid hormone on cold stress-induced apotosis via HSP70 and mitochondrial apoptosis signal pathway in bovine Sertoli cells

Thyroid hormone was involved in gene expression and functional regulation in various signal pathways. Cold stress can increase triiodothyronine (T₃) level in the blood. The aim of this study was to investigate the effect of T₃ on HSP70 expression and apoptosis in Sertoli cells (SCs) under cold stress in vitro culture at 26 °C, and provide a theoretical and practical basis for improving the reproductive efficiency of bulls in cold areas. SCs were treated with different cold stress duration and different T₃ concentrations for pre-screening. HSP70 inhibitor was added later, and the apoptotic rate was measured using flow cytometry. The expression of HSP70 and the main genes of mitochondrial apoptosis pathway were determined by means of real-time PCR and western-blot, respectively. The localization of HSP70 was assessed by immunofluorescence. The results showed that cold stress (26 °C, 6 h) played an inductive role in SCs apoptotic rate (P < 0.01) and the transfer of HSP70 into the nucleus. 100 nM T₃ further promoted HSP70 expression and its transfer into the nucleus, which significantly inhibited the expression of vital genes (cyt-c, Caspase-9 and Caspase-3) in mitochondrial pathway (P < 0.05). Subsequently, higher survival and lower apoptotic rates of SCs (P < 0.01) were observed. When T₃ and HSP70 inhibitor were added together, the expression of cyt-c, Caspase-9 and Caspase-3 were inhibited (P < 0.05), and then the declining apoptotic rate increased again (P < 0.01). In conclusion, T₃ can regulate HSP70 expression and translocation to mediate mitochondrial apoptosis pathway to inhibit SCs apoptosis induced by cold stress.

Sex steroid dynamics and mRNA transcript profiles of growth- and development-related genes during embryogenesis following induced follicular maturation in European eel

Hormones and mRNA transcripts of maternal origin deposited in the egg may affect early embryonic development in oviparous species. These hormones include steroids, such as estradiol-17β (E2), testosterone (T), 11-ketotestosterone (11-kt), 17α,20ß-dihydroxy-4-pregnen-3-one (DHP), and cortisol, which also play an important role in fish reproduction. In European eel, Anguilla anguilla, which does not reproduce naturally in captivity, vitellogenesis in female broodstock is commonly induced by administration of salmon or carp pituitary extract (PE) as an exogenous source of gonadotropins, while follicular maturation is stimulated by a priming dose of PE followed by provision of DHP as a maturation inducing hormone. In this regard, the main purpose of the present study was to evaluate effects of induced follicular maturation on reproductive success in European eel, focusing on maternal transfer and dynamics of steroids and mRNA transcripts of growth- and development-related genes throughout embryogenesis. The results showed that maternal blood plasma concentrations of E2, T and DHP were reflected in the unfertilized eggs. Moreover, a negative relationship between concentrations of E2 and DHP in eggs and embryos and quality parameters measured as fertilization success, cleavage abnormalities, embryonic survival, and hatch success was found. Concomitant mRNA transcript abundance analysis including genes involved in stress response (hsp70, hsp90), somatotropic axis (gh, igf1, igf2a, igf2b), lipid (cpt1a, cpt1b, pigf5) and thyroid metabolism (dio1, dio2, dio3, thrαb, thrβa, thrβb) varied among unfertilized egg batches. For the majority of genes, mRNA abundance increased during the maternal-to-zygotic transition in connection to activation of the transcription of the embryos own genome. mRNA abundance of dio1, cpt1a and cpt1b throughout embryogenesis was related to embryonic developmental competence. Notably, mRNA abundance of dio3 was positively associated with E2 concentrations, while the mRNA abundance of thrαb was negatively related to T concentrations in the unfertilized eggs, which may suggest an interaction between the thyroid and steroid hormone systems. Altogether, maternal plasma concentrations of E2 and DHP were reflected in the eggs, with high concentrations of these steroids in the eggs being negatively associated with embryonic developmental competence. Additionally, high transcript levels of two of the investigated genes (dio1, cpt1b) were positively associated with embryonic developmental competence. This study reveals maternal transfer of steroids and mRNA transcripts to the eggs, which may be significant contributors to the variability in embryonic survival observed in European eel captive reproduction.

Role of Heat Shock Proteins (HSP70 and HSP90) in Viral Infection

Heat shock proteins (HSPs) are a large group of chaperones found in most eukaryotes and bacteria. They are responsible for the correct protein folding, protection of the cell against stressors, presenting immune and inflammatory cytokines; furthermore, they are important factors in regulating cell differentiation, survival and death. Although the biological function of HSPs is to maintain cell homeostasis, some of them can be used by viruses both to fold their proteins and increase the chances of survival in unfavorable host conditions. Folding viral proteins as well as replicating many different viruses are carried out by, among others, proteins from the HSP70 and HSP90 families. In some cases, the HSP70 family proteins directly interact with viral polymerase to enhance viral replication or they can facilitate the formation of a viral replication complex and/or maintain the stability of complex proteins. It is known that HSP90 is important for the expression of viral genes at both the transcriptional and the translational levels. Both of these HSPs can form a complex with HSP90 and, consequently, facilitate the entry of the virus into the cell. Current studies have shown the biological significance of HSPs in the course of infection SARS-CoV-2. A comprehensive understanding of chaperone use during viral infection will provide new insight into viral replication mechanisms and therapeutic potential. The aim of this study is to describe the molecular basis of HSP70 and HSP90 participation in some viral infections and the potential use of these proteins in antiviral therapy.

Mangiferin mitigates di-(2-ethylhexyl) phthalate-induced testicular injury in rats by modulating oxidative stress-mediated signals, inflammatory cascades, apoptotic pathways, and steroidogenesis

Di-(2-ethylhexyl) phthalate (DEHP) is an endocrine disruptor that causes reproductive defects in male animal models. This study was conducted to explore the plausible modulatory effects of mangiferin (MF) against DEHP-induced testicular injury in rats. Thirty-two adult male albino rats were allocated into four groups. Two groups were given DEHP (2 g/kg/day, p.o) for 14 days. One of these groups was treated with MF (20 mg/kg/day, i.p) for 7 days before and 14 days after DEHP administration. A vehicle-treated control was included, and another group of rats was given MF only. Results revealed that MF treatment suppressed oxidative testicular injury by amplifying the mRNA expression of nuclear factor-erythroid 2 related factor-2 (Nrf2) and increasing hemoxygenase-1 (HO-1), glutathione, and total antioxidant capacity (TAC) levels. This treatment also enhanced superoxide dismutase activity, but it decreased malondialdehyde and nitric oxide levels. MF had an anti-inflammatory characteristic, as demonstrated by the downregulation of the mRNA of the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB). The content of tumor necrosis factor-alpha also decreased. MF modulated the apoptotic pathway by suppressing the mRNA of cytochrome c (Cyt c), Fas ligand content, Bax IHC expression, caspase-3 activity and cleaved caspase-3 IHC expression. It also upregulated the expression levels of heat-shock protein 70 (HSP70) and B-cell lymphoma 2. Moreover, MF upregulated the mRNA expression levels of HSP70 and c-kit and enriched the content of steroidogenic acute regulatory (StAR) protein, which were reflected in serum testosterone levels. This result indicated that MF played crucial roles in steroidogenesis and spermatogenesis. Besides, the activities of testicular marker enzymes, namely, acid and alkaline phosphatases, and lactate dehydrogenase, significantly increased. Histopathological observations provided evidence supporting the biochemical and molecular measurements. In conclusion, MF provided protective mechanisms against the DEHP-mediated deterioration of testicular functions partially through its antioxidant, anti-inflammatory, and anti-apoptotic properties. It also involved the restoration of steroidogenesis and spermatogenesis through the modulation of Nrf2/HO-1, NF-κB/Cyt c/HSP70, and c-Kit signaling cascades.

Profiling Transcriptional Response of Dengue-2 Virus Infection in Midgut Tissue of Aedes aegypti

Understanding the mosquito antiviral response could reveal target pathways or genes of interest that could form the basis of new disease control applications. However, there is a paucity of data in the current literature in understanding antiviral response during the replication period. To illuminate the gene expression patterns in the replication stage, we collected gene expression data at 2.5 days after Dengue-2 virus (DENV-2) infection. We sequenced the whole transcriptome of the midgut tissue and compared gene expression levels between the control and virus-infected group. We identified 31 differentially expressed genes. Based on their function, we identified that those genes fell into two major functional categories - (1) nucleic acid/protein process and (2) immunity/oxidative stress response. Our study has identified candidate genes that can be followed up for gene overexpression/inhibition experiments to examine if the perturbed gene interaction may impact the mosquito’s immune response against DENV. This is an important step to understanding how mosquitoes eliminate the virus and provides an important foundation for further research in developing novel dengue control strategies.

Domestication affected stress and immune response markers in Perca fluviatilis in the early larval stage

It is already known that domestication modifies stress and immune responses in juveniles and adults of several fish species. However, there is a lack of information on whether these modulations result from adaptability along the life cycle or if they are pre-determined in very early developmental stages. To shed light on mechanisms that help to explain the process of domestication, a study was conducted to analyze comparatively Eurasian perch larval performance, stress, and immune status between wild and domesticated specimens. Eurasian perch larvae obtained from wild and domesticated (generation F5 reared in recirculating aquaculture systems) spawners were reared in the same conditions during the main rearing trial (MRT) and also subjected to a thermal challenge (TC). During the study, larval performance (including survival, growth performance, swim bladder inflation effectiveness, deformity rate), the expression of genes involved in immune and stress response, and the specific activity of oxidative stress enzymes (during MRT only) were analyzed. No significant differences in hatching rate, deformity rate, or swim bladder inflation effectiveness between wild and domesticated larvae were found, whereas specific growth rate, final total length, and wet body weight were significantly lower in wild larvae. Higher mortality was also observed in wild larvae during both MRT and TC. The data obtained in this study clearly indicated that during domestication, significant modifications in stress and immune response, such as complement component c3, were noted as early as just after hatching. Generally, domesticated fish were characterized by a lower stress response and improved immune response in comparison to the wild fish. This probably resulted from the domesticated larvae being better adapted to the conditions of artificial aquaculture. The data obtained provided information on how domestication affects fish in aquaculture, and they contribute to the development of efficient selective breeding programs of Eurasian perch and other freshwater teleosts.

Bio-indicators in cadmium toxicity: Role of HSP27 and HSP70

Heat shock proteins (HSPs) are a family of proteins that are expressed by cells in reply to stressors. The changes in concentration of HSPs could be utilized as a bio-indicator of oxidative stress caused by heavy metal. Exposure to the different heavy metals may induce or reduce the expression of different HSPs. The exposure to cadmium ion (Cd²⁺) could increase HSP70 and HSP27 over 2- to 10-fold or even more. The in vitro and in vivo models indicate that the HSP70 family is more sensitive to Cd intoxication than other HSPs. The analyses of other HSPs along with HSP70, especially HSP27, could also be useful to obtain more accurate results. In this regard, this review focuses on examining the literature to bold the futuristic uses of HSPs as bio-indicators in the initial assessment of Cd exposure risks in defined environments.

The HSP70 gene predicts prognosis and response to chemotherapy in epithelial ovarian cancer

Background

Chemotherapy resistance is an intractable problem in treating patients with epithelial ovarian cancer (EOC). Heat shock proteins (HSPs) act as apoptosis inhibitors and are highly conserved genetically. Most HSPs have strong cytoprotective effects, and their overexpression inhibits apoptosis. This has been demonstrated for HSP70. Heat shock protein 70 (HSP70) expression is abnormally upregulated in malignant cells. Furthermore, HSP70 can inhibit cell death and promote chemotherapeutic resistance. In our study, the relationship between the HSP70 gene and primary chemotherapy resistance and clinical outcome in patients with EOC was explored.

Methods

Quantitative real-time polymerase chain (qRT-PCR) was applied to determine HSP70 messenger RNA (mRNA) levels, and immunohistochemistry assay was conducted to determine HSP70 protein level. HSP70 overexpression was assessed to clarify its role on chemotherapy resistance to cisplatin in SKOV3 cell lines.

Results

RT-qPCR assay indicated a strong relationship between HSP70 expression and chemotherapy resistance in patients with EOC. In cultured SKOV3 cells, overexpression of HSP70 inhibited cell sensitivity to cisplatin. Kaplan-Meier analysis demonstrated high HSP70 expression was associated with poor outcome of EOC patients. In multivariate models, high HSP70 expression independently predicted this poor outcome.

Conclusions

HSP70 predicts the prognosis and response to chemotherapy in EOC patients.

Heat shock response enhanced by cell culture treatment in mouse embryonic stem cell-derived proliferating neural stem cells

Cells have a regulatory mechanism known as heat shock (HS) response, which induces the expression of HS genes and proteins in response to heat and other cellular stresses. Exposure to moderate HS results in beneficial effects, such as thermotolerance and promotes survival, whereas excessive HS causes cell death. The effect of HS on cells depends on both exogenous factors, including the temperature and duration of heat application, and endogenous factors, such as the degree of cell differentiation. Neural stem cells (NSCs) can self-renew and differentiate into neurons and glial cells, but the changes in the HS response of symmetrically proliferating NSCs in culture are unclear. We evaluated the HS response of homogeneous proliferating NSCs derived from mouse embryonic stem cells during the proliferative phase and its effect on survival and cell death in vitro. The number of adherent cells and the expression ratios of HS protein (Hsp)40 and Hsp70 genes after exposure to HS for 20 min at temperatures above 43°C significantly increased with the extension of the culture period before exposure to HS. In contrast, caspase activity was significantly decreased by extension of the culture period before exposure to HS and suppressed the decrease in cell viability. These results suggest that the culture period before HS remarkably affects the HS response, influencing the expression of HS genes and cell survival of proliferating NSCs in culture.

Heat stress on cattle embryo: gene regulation and adaptation

Global warming has been affecting animal husbandry and farming production worldwide via changes in organisms and their habitats. In the tropics, these conditions are adverse for agriculture and animal production in some areas, due to high temperatures and relative humidity, affecting competitiveness related to economic activities. These environments have deteriorated livestock production, due to periods of drought, reduction in forage quality and heat stress, eliciting negative effects on reproduction, weight gain, and reduced meat and milk production. However, the use of animals adapted to tropics such as breeds derived from subspecies Bos primigenius indicus and native breeds from tropical countries or their crossings, is an alternative to improve production under high-temperature conditions. Therefore, physiological adaptation including gene expression induced by heat stress have been studied to understand the response of animals and to improve cross-breeding between cattle breeds to maintain high productivity in adverse weather conditions. Heat stress has been associated with lower reproductive performance in cows, due to the impact on blastocyst production, decreased implantation and increased embryonic death. Thus, for decades, in vitro fertilization and embryo transfer techniques have focused on studying the optimal conditions for production of high-quality embryos to transfer. The aim of this review is to discuss the effects of heat stress in bovine embryos, and their physiological and genetic modulation, focusing on the genes that are related with major adaptability to heat stress conditions and their relationship with different embryonic stages.

β-Alanine Supplementation Attenuates the Neurophysiological Response in Animals Exposed to an Acute Heat Stress

The effect of 30 days of β-alanine supplementation on neurophysiological responses of animals exposed to an acute heat stress (HS) was examined. Animals were randomized to one of three groups; exposed to HS (120 min at 40-41 °C) and fed a normal diet (EXP; n = 12); EXP and supplemented with β-alanine (EXP + BA; n = 10); or not exposed (CTL; n = 10). Hippocampal (CA1, CA3 and DG) and hypothalamic (PVN) immunoreactive (ir) cell numbers of COX2, IBA-1, BDNF, NPY and HSP70 were analyzed. Three animals in EXP and one in EXP-BA did not survive the HS, however no significant difference (p = 0.146) was noted in survival rate in EXP + BA. The % change in rectal temperature was significantly lower (p = 0.04) in EXP + BA than EXP. Elevations (p's < 0.05) in COX-2, IBA-1 and HSP70 ir-cell numbers were noted in animals exposed to HS in all subregions. COX-2 ir-cell numbers were attenuated for EXP + BA in CA1 (p = 0.02) and PVN (p = 0.015) compared to EXP. No difference in COX-2 ir-cell numbers was noted between CTL and EXP + BA at CA1. BDNF-ir cell numbers in CA1, DG and PVN were reduced (p's < 0.05) during HS compared to CTL. No difference in BDNF-ir cell numbers was noted between EXP + BA and CTL in CA3 and PVN. NPY-ir density was reduced in exposed animals in all subregions, but NPY-ir density for EXP-BA was greater than EXP in CA3 (p < 0.001) and PVN (p = 0.04). β-Alanine supplementation attenuated the thermoregulatory and inflammatory responses and maintained neurotrophin and neuropeptide levels during acute HS. Further research is necessary to determine whether β-alanine supplementation can increase survival rate during a heat stress.

Prognostic Significance of the Hsp70 Gene Family in Colorectal Cancer

Background

Colorectal cancer (CRC) is a deadly form of cancer worldwide. Heat shock protein 70 (Hsp70) belongs to the family of human HSPs and plays an essential role in multiple cellular developments and in responding to environmental changes. However, studies on the relationship between CRC and the Hsp70 family are rare.

Material/Methods

Data pertaining to 438 patients with CRC was downloaded from The Cancer Genome Atlas database. To investigate the prognostic significance of the Hsp70 genes, survival and joint-effect analyses were conducted. The correlation between prognosis-related Hsp70 genes and clinical factors in CRC was analyzed using a nomogram. Gene set enrichment analysis (GSEA) was performed to explore the complex enrichment pathway in CRC with the prognosis-related Hsp70 genes.

Results

According to multivariate Cox regression survival analysis, low expression levels of HSPA1A, HSPA1B, and HSPA1L were correlated with improved overall survival (OS). According to the joint-effects survival analysis, the joint low expression levels of HSPA1A, HSPA1B, and HSPA1L were related to improved OS. The 1-, 3-, 5-, and 10-year survival rates of patients with CRC were predicted by constructing a nomogram model based on HSPA1A, HSPA1B, HSPA1L, and tumor stage. The GSEA results indicated the biological roles of HSPA1A, HSPA1B, and HSPA1L in CRC.

Conclusions

Low expression levels of HSPA1A, HSPA1B, and HSPA1L were strongly correlated with improved prognosis in CRC and might serve as latent prognostic biomarkers in CRC.

An aptamer interacting with heat shock protein 70 shows therapeutic effects and prognostic ability in serous ovarian cancer

Ovarian cancer (OvCa) is the most lethal gynecologic malignancy owing to its high chemoresistance and late diagnosis, which lead to a poor prognosis. Hence, developing new therapeutic modalities is important for OvCa patient treatment. Our previous results indicated that a novel aptamer, Tx-01, can specifically recognize serous carcinoma cells and tissues. Here, we aim to clarify the clinical role and possible molecular mechanisms of Tx-01 in OvCa. Immunostaining and statistical analysis were performed to detect the interaction of Tx-01 and heat shock protein 70/Notch1 intracellular domain (HSP70/NICD) in OvCa. The in vitro and in vivo experiments were carried out to demonstrate the potential mechanisms of Tx-01. Results show that Tx-01 reduced serous OvCa OVCAR3 cell migration and invasion and inhibited HSP70 nuclear translocation by interrupting the intracellular HSP70/NICD interaction. Furthermore, Tx-01 suppressed serous-type OVCAR3 cell tumor growth in vivo. Tx-01 acts as a prognostic factor through its interaction with membrane-bound HSP70 (mHSP70 that locates on the cell surface without direct interaction to NICD) on ascitic circulating tumor cells (CTCs) and is reported to be involved in natural killer (NK) cell recognition and activation. Our data demonstrated that Tx-01 interacted with HSP70 and showed therapeutic and prognostic effects in serous OvCa. Tx-01 might be a potential inhibitor for use in serous OvCa treatment.

Exogenous recombinant Hsp70 mediates neuroprotection after photothrombotic stroke

Ischaemic stroke is an acute interruption of the blood supply to the brain, which leads to rapid irreversible damage to nerve tissue. Ischaemic stroke is accompanied by the development of neuroinflammation and neurodegeneration observed around the affected brain area. Heat shock protein 70 (Hsp70) facilitates cell survival under a variety of different stress conditions. Hsp70 may be secreted from cells and exhibits cytoprotective activity. This activity most likely occurs by decreasing the levels of several proinflammatory cytokines through interaction with a few receptors specific to the innate immune system. Herein, we demonstrated that intranasal administration of recombinant human Hsp70 shows a significant twofold decrease in the volume of local ischaemia induced by photothrombosis in the mouse prefrontal brain cortex. Our results revealed that intranasal injections of recombinant Hsp70 decreased the apoptosis level in the ischaemic penumbra, stimulated axonogenesis and increased the number of neurons producing synaptophysin. Similarly, in the isolated crayfish stretch receptor, consisting of a single sensory neuron surrounded by the glial envelope, exogenous Hsp70 significantly decreased photoinduced apoptosis and necrosis of glial cells. The obtained data enable one to consider human recombinant Hsp70 as a promising compound that could be translated from the bench into clinical therapies.

Silent effect of the fungicide pyraclostrobin on the larval exposure of the non-target organism Africanized Apis mellifera and its interaction with the pathogen Nosema ceranae in adulthood

The frequent exposure of bees to a wide variety of fungicides, on crops where they forage, can be considered a stressor factor for these pollinators. The organisms are exposed both to the fungicide active ingredients and to the adjuvants of commercial formulations. All these ingredients are brought to the hive by bee foragers through contaminated pollen and nectar, thus exposing also immature individuals during larval phase. This work aimed to compare the effects of larval exposure to the fungicide pyraclostrobin (active ingredient and commercial formulation) and its influence on the cytotoxicity to midguts in adults, which were inoculated with the Nosema ceranae spores in the post-emergence stage. Under laboratory conditions, Apis mellifera larvae received an artificial diet containing fungicide solution from the third to the sixth day of the feeding phase. One-day-old adult workers ingested 100,000 infectious N. ceranae spores mixed in sucrose solution. Effects on midgut were evaluated through cellular biomarkers of stress and cell death. The exposure to the fungicide (active ingredient and commercial formulation) did not affect the larval post-embryonic development and survival of adult bees. However, this exposure induced cytotoxicity in the cells of the midgut, showed by the increase in DNA fragmentation and alteration in the HSP70 immunolabeling pattern. Without the pathogen, the midgut cytotoxic effects and HSP70 immunolabeling of the organisms exposed to the commercial formulation were lower when compared to the exposure to its active ingredient. However, in the presence of the pathogen, the cytotoxic effects of the commercial formulation to the adult bees' midgut were potentialized. The pathogen N. ceranae increased the damage to the intestinal epithelium of adult bees. Thus, realistic doses of pyraclostrobin present in beebread consumed by larvae can affect the health and induce physiological implications to the midgut functions of the adult bees.

Thermal cycling protects SH-SY5Y cells against hydrogen peroxide and β-amyloid-induced cell injury through stress response mechanisms involving Akt pathway

Neurodegenerative diseases (NDDs) are becoming a major threat to public health, according to the World Health Organization (WHO). The most common form of NDDs is Alzheimer’s disease (AD), boasting 60–70% share. Although some debates still exist, excessive aggregation of β-amyloid protein (Aβ) and neurofibrillary tangles has been deemed one of the major causes for the pathogenesis of AD. A growing number of evidences from studies, however, have suggested that reactive oxygen species (ROS) also play a key role in the onset and progression of AD. Although scientists have had some understanding of the pathogenesis of AD, the disease still cannot be cured, with existing treatment only capable of providing a temporary relief at best, partly due to the obstacle of blood-brain barrier (BBB). The study was aimed to ascertain the neuroprotective effect of thermal cycle hyperthermia (TC-HT) against hydrogen peroxide (H₂O₂) and Aβ-induced cytotoxicity in SH-SY5Y cells. Treating cells with this physical stimulation beforehand significantly improved the cell viability and decreased the ROS content. The underlying mechanisms may be due to the activation of Akt pathway and the downstream antioxidant and prosurvival proteins. The findings manifest significant potential of TC-HT in neuroprotection, via inhibition of oxidative stress and cell apoptosis. It is believed that coupled with the use of drugs or natural compounds, this methodology can be even more effective in treating NDDs.

Transcriptome analysis reveals the potential mechanism of dietary carotenoids improving antioxidative capability and immunity of juvenile Chinese mitten crabs Eriocheir sinensis

Carotenoids are known to be involved in the regulation of the antioxidative capability, immune response and stress resistance in crustacean species; however, very limited information is available on their underlying molecular mechanisms. This study performed transcriptome sequencing of hemolymph and hepatopancreas of juvenile Chinese mitten crabs (Eriocheir sinensis) that fed with three diets, i.e. diet A containing 90 mg kg^-1 dry weight of astaxanthin, diet B containing 200 mg kg^-1 dry weight of β-carotene and control diet without supplementation of dietary carotenoids. The results showed that there were 2955 and 497 differentially expressed genes (DEGs) in the hemolymph between the astaxanthin treatment and control groups, and between the β-carotene treatment and control groups, respectively. Moreover, compared with the control group, 833 and 1886 DEGs were obtained in the hepatopancreas of the astaxanthin treatment and the β-carotene treatment groups, respectively. The DEGs in the three groups were enriched in 255 specific KEGG metabolic pathways according to KEGG enrichment analysis. Through this study, a series of key genes involved in Nrf2 signalling, ROS production, intracellular antioxidant enzymes and chaperones were significantly affected by dietary carotenoids. Dietary carotenoids also significantly altered the expression levels of immune-related molecules associated with signal transduction, prophenoloxidase cascade, apoptosis, pattern recognition proteins/receptors and antimicrobial peptides. In conclusion, this transcriptomic study provides valuable information for understanding the molecular mechanism and potential pathway of dietary carotenoids improved the antioxidative capability and immunity of juvenile E. sinensis.

Identification of a Novel Gene, Osbht, in Response to High Temperature Tolerance at Booting Stage in Rice

Rice is one of the world’s leading food crops, and over 90% of the world’s rice production stems from Asia. In particular, an increase of 1 °C in the minimum temperature reduces the quantity of rice by 10%. Therefore, the development of rice varieties that can stably maintain the yield and quality of the rice even under these rapid climate changes is indispensable. In this study, we performed quantitative trait loci (QTL) mapping after treatment with heat stress during the booting stage in rice. We performed a QTL analysis using the Cheongcheong/Nagdong double haploid (CNDH) line and identified 19 QTLs during the 2 year analysis. Of these QTL regions, the 2.2 cM region of RM3709–RM11694 on chromosome 1 was shared among the six traits (heading date; culm length; panicle length; number of tiller; 1000 grain weight; and content of chlorophyll) examined. Rice Microsatellite (RM) 3709–RM11694 contained 27 high-temperature-tolerance candidate genes. Among the candidate genes, OsBHT showed a different gene expression level between CNDH75, which is a high-temperature tolerant line, and CNDH11 which is a susceptible line. Although some existing high-temperature-tolerant genes have been reported, OsBHT can be used more effectively for the development of heat tolerance in rice.

Cellular and functional adaptation to thermal stress in ovarian granulosa cells in mammals

Climate change represents a significant environmental challenge to human welfare. One of many negative impacts may be on animal reproduction. Elevated ambient temperature unfavourably influences reproductive processes in mammals. High temperature can affect reproductive processes such as follicle development and may alter follicular fluid concentrations of amino acids, fatty acids, minerals, enzymes, antioxidants defence and growth factors. These impacts may lead to inferior oocyte competence and abnormal granulosa cell (GCs) function. Mammalian oocytes are enclosed by GCs that secret hormones and signalling molecules to promote oocyte competence. GCs are essential for proper follicular development, oocyte maturation, ovulation, and luteinization. Many environmental stressors, including thermal stress, affect GC function and alter oocyte development and growth. Several studies documented a link between elevated ambient temperature and increased generation of cellular reactive oxygen species (ROS). ROS can damage DNA, reduce cell proliferation, and induce apoptosis in GCs, thus altering oocyte development. Additionally, thermal stress induces upregulation of thermal shock proteins, such as HSP70 and HSP90. This review provides an update on the influence of thermal stress on GCs of mammals. Discussions include impacts to steroidogenesis (estradiol and progesterone), proliferation and cell cycle transition, apoptosis, oxidative stress (ROS), antioxidants related genes, heat shock proteins (HSPs) and endoplasmic reticulum responses.

Molecular Chaperone HSP70 and Key Regulators of Apoptosis - A Review

Identified as a molecular chaperone constitutively being synthesized due to enhanced elevated temperature change, this heat shock protein HSP70 has shown to be intimately involved in many protein biogenesis, facilitating the synthesis and folding of proteins and trafficking of nascent peptides during cell growth. HSP70 also plays a vital role in protein assembly, regulation and interaction with a wide variety of proteins. Stress-induced cell death is under the control of the Bcl-2 family of apoptotic regulators and display either pro-apoptotic or anti-apoptotic activities. Subjected to stress conditions such as heat shock, cells have been reported to express elevated expressions of HSP70. Moreover, this molecular chaperon has shown to act at multiple levels to suppress stressed-induced apoptotic signals of some Bcl-2 members by repairing, re-synthesizing damaged proteins, and stabilizing unfolded proteins. Therefore, HSP70 synthesis can act as an essential recovery mode for cellular survival and adaptation during lethal conditions.

RNAi-Mediated Silencing of Catalase Gene Promotes Apoptosis and Impairs Proliferation of Bovine Granulosa Cells under Heat Stress

Heat stress in dairy cattle is recognized to compromise fertility by altering the functions of ovarian follicle-enclosed cells, e.g., oocyte and granulosa cells (GCs). Catalase is an antioxidant enzyme that plays a significant role in cellular protection against oxidative damage by the degradation of hydrogen peroxide to oxygen and water. In this study, the role and mechanism of CAT on the heat stress (HS)-induced apoptosis and altered proliferation of bovine GCs were studied. The catalase gene was knocked-down successfully in bovine GCs at both the transcriptional and translational levels. After a successful knockdown using siRNA, GCs were divided into HS (40 °C + NC and 40 °C + CAT siRNA) and 38 °C + NC (NC) groups. The GCs were then examined for ROS, viability, mitochondrial membrane potential (MMP), cell cycle, and biosynthesis of progesterone (P4) and estrogen (E2) hormones. The results indicated that CAT silencing promoted ROS production and apoptosis by up-regulating the Bcl-2-associated X protein (BAX) and Caspase-3 genes both at the transcriptional and translational levels. Furthermore, the knockdown of CAT markedly disrupted the MMP, impaired the production of P4 and E2, altered the progression of the G1 phase of the cell cycle, and decreased the number of cells in the S phase. This was further verified by the down-regulation of proliferating cell nuclear antigen (PCNA), CyclinB1, steroidogenic acute regulatory protein (STAR), and cytochrome P450 family 11 subfamily A member 1 (Cyp11A1) genes. Our study presented a novel strategy to characterize how CAT can regulate cell proliferation and apoptosis in GCs under HS. We concluded that CAT is a broad regulatory marker in GCs by regulating apoptosis, cellular progression, and simultaneously by vital fluctuations in hormonal signaling. Our findings infer a crucial evidence of how to boost the fertility of heat-stressed cows.

Genomic innovation of ATD alleviates mistranslation associated with multicellularity in Animalia

The emergence of multicellularity in Animalia is associated with increase in ROS and expansion of tRNA-isodecoders. tRNA expansion leads to misselection resulting in a critical error of L-Ala mischarged onto tRNA^Thr, which is proofread by Animalia-specific-tRNA Deacylase (ATD) in vitro. Here we show that in addition to ATD, threonyl-tRNA synthetase (ThrRS) can clear the error in cellular scenario. This two-tier functional redundancy for translation quality control breaks down during oxidative stress, wherein ThrRS is rendered inactive. Therefore, ATD knockout cells display pronounced sensitivity through increased mistranslation of threonine codons leading to cell death. Strikingly, we identify the emergence of ATD along with the error inducing tRNA species starting from Choanoflagellates thus uncovering an important genomic innovation required for multicellularity that occurred in unicellular ancestors of animals. The study further provides a plausible regulatory mechanism wherein the cellular fate of tRNAs can be switched from protein biosynthesis to non-canonical functions.

The first animals evolved around 750 million years ago from single-celled ancestors that were most similar to modern-day organisms called the Choanoflagellates. As animals evolved they developed more complex body plans consisting of multiple cells organized into larger structures known as tissues and organs. Over time cells also evolved increased levels of molecules called reactive oxygen species, which are involved in many essential cell processes but are toxic at high levels.

Animal cells also contain more types of molecules known as transfer ribonucleic acids, or tRNAs for short, than Choanoflagellate cells and other single-celled organisms. These molecules deliver building blocks known as amino acids to the machinery that produces new proteins. To ensure the proteins are made correctly, it is important that tRNAs deliver specific amino acids to the protein-building machinery in the right order.

Each type of tRNA usually only pairs with a specific type of amino acid, but sometimes the enzymes involved in this process can make mistakes. Therefore, cells contain proofreading enzymes that help remove incorrect amino acids on tRNAs. One such enzyme – called ATD – is only found in animals. Experiments in test tubes reported that ATD removes an amino acid called alanine from tRNAs that are supposed to carry threonine, but its precise role in living cells remained unclear.

To address this question, Kuncha et al. studied proofreading enzymes in human kidney cells. The experiments showed that, in addition to ATD, a second enzyme known as ThrRS was also able to correct alanine substitutions for threonines on tRNAs. However, reactive oxygen species inactivated the proofreading ability of ThrRS, suggesting ATD plays an essential role in correcting errors in cells containing high levels of reactive oxygen species.

These findings suggest that as organisms evolved multiple cells and the levels of tRNA and oxidative stress increased, this led to the appearance of a new proofreading enzyme. Further studies found that ATD originated around 900 million years ago, before Choanoflagellates and animals diverged, indicating these enzymes might have helped to shape the evolution of animals.

The next step following on from this work will be to understand the role of ATD in the cells of organs that are known to have particularly high levels of reactive oxygen species, such as testis and ovaries.

Immune response to acute heat stress in the intestine of the red swamp crayfish, Procambarus clarkii

High temperature is an important environmental factor that affects the survival and immunity of aquatic animals. The intestine of crustaceans is their first line of defense, and the physiological homeostasis of this organ can be influenced by high temperature stress. The red swamp crayfish Procambarus clarkii is an important commercial aquaculture species in China, but little is known about its intestinal immune response to acute heat stress. In this study, we investigated the intestinal immune response of P. clarkii individuals that were assigned to the control (25 °C) and heat stress (35 °C) groups. Biochemical assays were conducted for the oxidative stress parameters ·O₂^- generation capacity, lipid peroxide content, and malondialdehyde content; the activities of the antioxidant enzymes superoxide dismutase, catalase, and glutathione peroxidase; and the activities of the immunity-related enzymes alkaline phosphatase, acid phosphatase, and lysozyme. The relative expression level of the antioxidant genes heat shock protein 70 (hsp70), ferritin (fer), and metallothione (met) was examined by RT-PCR. Based on the data obtained, all the parameters tended to increase, peak and then decrease with time, and were significantly different between the two groups (P < 0.05). These findings reveal that acute heat stress adversely affects the antioxidant status and immune function in the P. clarkii intestine. They lay the groundwork for future studies on the effect of rising water temperatures on immune function and survival of this species.