Induction Of Heat Shock Proteins Research Articles

HSF1/HSP25 system protects mitochondria function from heat stress and assists steroidogenesis in MA-10 Leydig cells

Heat shock response is characterized by the induction of heat shock proteins (HSPs) or molecular chaperones that maintain protein homeostasis. Heat shock transcription factor 1 (HSF1) plays a central role in heat shock response in mammalian cells. To investigate the impact of the heat shock response mechanism on steroidogenesis, we generated MA-10 mouse Leydig tumor cells deficient in HSF1 using CRISPR-Cas9 genome editing. Under heat stress conditions, the levels of StAR protein, but not its mRNA, decreased more in HSF1-knockout cells than in wild-type cells, confirming that HSF1 stabilizes StAR protein. Simultaneously, HSP110, HSP70, and HSP25 were markedly upregulated in an manner dependent on HSF1. Mitochondrial membrane potential (MMP) and ATP synthesis were decreased in HSF1-knockout cells under heat stress conditions, and mitochondrial fragmentation was enhanced. Furthermore, treatment with carbonyl cyanide 3-chlorophenylhydrazone (CCCP), a disruptor of MMP, reduced the levels of StAR protein to a greater extent in HSF1-knockout cells than in wild-type cells, which was associated with decreased MMP and ATP synthesis. Unexpectedly, HSP25 expression was markedly increased in wild-type cells following CCCP treatment. HSP25 knockdown reduces MMP under heat stress conditions and decreases StAR protein levels and progesterone synthesis. HSP25 overexpression in HSF1KO cells restored StAR protein levels. These results show that the HSF1/HSP25 pathway protects mitochondrial function and maintains StAR synthesis.

Copper homeostasis and cuproptosis in gynecological cancers.

Copper (Cu) is an essential trace element involved in a variety of biological processes, such as antioxidant defense, mitochondrial respiration, and bio-compound synthesis. In recent years, a novel theory called cuproptosis has emerged to explain how Cu induces programmed cell death. Cu targets lipoylated enzymes in the tricarboxylic acid cycle and subsequently triggers the oligomerization of lipoylated dihydrolipoamide S-acetyltransferase, leading to the loss of Fe-S clusters and induction of heat shock protein 70. Gynecological malignancies including cervical cancer, ovarian cancer and uterine corpus endometrial carcinoma significantly impact women's quality of life and even pose a threat to their lives. Excessive Cu can promote cancer progression by enhancing tumor growth, proliferation, angiogenesis and metastasis through multiple signaling pathways. However, there are few studies investigating gynecological cancers in relation to cuproptosis. Therefore, this review discusses Cu homeostasis and cuproptosis while exploring the potential use of cuproptosis for prognosis prediction as well as its implications in the progression and treatment of gynecological cancers. Additionally, we explore the application of Cu ionophore therapy in treating gynecological malignancies.

The role of dietary fibre in intestinal heat shock protein regulation

SummaryThe gastrointestinal tract serves as a pivotal physical barrier that prevents the translocation of exogenous substances from the intestinal lumen into the systemic circulation. Dysfunction of intestinal barrier function has been implicated in the pathogenesis of several diseases, such as metabolic disorders. Heat shock proteins (HSPs) play a critical role in maintaining the resilience and viability of epithelial cells when exposed to stressors. Evidence suggests that dietary fibre (DF), a known inducer of HSP production, may be a promising candidate for strengthening the intestinal barrier. Understanding the regulation of intestinal HSPs and the protective effect of DF is critical to defending against environmental threats and preserving human health. To date, six DFs—pectin, chicory, psyllium, guar gum, partially hydrolysed guar gum, and xylooligosaccharide—have been reported to have promotive effects on intestinal HSP induction. DF promotes intestinal HSP induction through gut microbiota‐dependent and independent mechanisms. DF is fermented by gut microbiota to produce short‐chain fatty acids, specifically butyrate and propionate, to promote HSP production. Meanwhile, DF also promotes intestinal HSP induction through direct interaction with intestinal epithelial cells, independent of gut microbiota activity, although the precise mechanism is still unclear. Regulation of intestinal HSP occurs by transcriptional modulation through activation of heat shock transcription factors, primarily heat shock factor 1, or at the post‐transcriptional level by modulation of the translation process. This review highlights recent advances in understanding the role of DF in improving intestinal barrier function, with particular emphasis on the regulatory mechanisms of intestinal HSPs.

HSF1 is required for cellular adaptation to daily temperature fluctuations.

The heat shock response (HSR) is a universal mechanism of cellular adaptation to elevated temperatures and is regulated by heat shock transcription factor 1 (HSF1) or HSF3 in vertebrate endotherms, such as humans, mice, and chickens. We here showed that HSF1 and HSF3 from egg-laying mammals (monotremes), with a low homeothermic capacity, equally possess a potential to maximally induce the HSR, whereas either HSF1 or HSF3 from birds have this potential. Therefore, we focused on cellular adaptation to daily temperature fluctuations and found that HSF1 was required for the proliferation and survival of human cells under daily temperature fluctuations. The ectopic expression of vertebrate HSF1 proteins, but not HSF3 proteins, restored the resistance in HSF1-null cells, regardless of the induction of heat shock proteins. This function was associated with the up-regulation of specific HSF1-target genes. These results indicate the distinct role of HSF1 in adaptation to thermally fluctuating environments and suggest association of homeothermic capacity with functional diversification of vertebrate HSF genes.

Vanadium Toxicity Is Altered by Global Warming Conditions in Sea Urchin Embryos: Metal Bioaccumulation, Cell Stress Response and Apoptosis.

In recent decades, the global vanadium (V) industry has been steadily growing, together with interest in the potential use of V compounds as therapeutics, leading to V release in the marine environment and making it an emerging pollutant. Since climate change can amplify the sensitivity of marine organisms already facing chemical contamination in coastal areas, here, for the first time, we investigated the combined impact of V and global warming conditions on the development of Paracentrotus lividus sea urchin embryos. Embryo-larval bioassays were carried out in embryos exposed for 24 and 48 h to sodium orthovanadate (Na3VO4) under conditions of near-future ocean warming projections (+3 °C, 21 °C) and of extreme warming at present-day marine heatwave conditions (+6 °C, 24 °C), compared to the control temperature (18 °C). We found that the concomitant exposure to V and higher temperature caused an increased percentage of malformations, impaired skeleton growth, the induction of heat shock protein (HSP)-mediated cell stress response and the activation of apoptosis. We also found a time- and temperature-dependent increase in V bioaccumulation, with a concomitant reduction in intracellular calcium ions (Ca2+). This work demonstrates that embryos' sensitivity to V pollution is increased under global warming conditions, highlighting the need for studies on multiple stressors.

Febrile Temperature Acts through HSP70-Toll4 Signaling to Improve Shrimp Resistance to White Spot Syndrome Virus.

In aquatic ectotherms, temperature plays a pivotal role in biological processes and the prevalence of viral diseases; however, the molecular mechanisms underlying these effects are not fully elucidated. In this study, we investigate the impact of elevated temperatures (32°C) on the immune response against white spot syndrome virus (WSSV) in shrimp (Litopenaeus vannamei). Our findings reveal that higher water temperatures, specifically 32°C, significantly inhibit WSSV replication and pathogenicity, thereby enhancing the survival rates of infected shrimp. Through transcriptome analysis and invivo experiments, we identified heat shock protein 70 (HSP70) as a key factor in this thermal regulation of immunity. Shrimp maintained at 32°C, with silenced HSP70 expression, exhibited increased viral loads and reduced survival, underscoring the crucial protective role of HSP70 against WSSV at elevated temperatures. Our results further uncover the HSP70-Toll4-Dorsal-antimicrobial peptide (AMP) pathway as a key mediator of WSSV resistance at elevated temperatures. This pathway involves the interaction of HSP70 with the Toll4 receptor, resulting in the phosphorylation of Dorsal and the consequent modulation of expression of AMPs such as the anti-LPS factor (ALF) and lysozyme (LYZ) families. Taken together, these findings advance our understanding of temperature's role in disease dynamics in aquatic ectotherms, especially the unexpected roles of HSP70 in shrimp in facilitating the innate immune system's response to thermal stress, and suggest new approaches to managing WSSV in shrimp farming, such as environmental temperature control or HSP70 induction.

Oxysterol Induces Expression of 60 kDa Chaperone Protein on Cell Surface of Microglia.

Microglia, essential immune cells in the brain, play crucial roles in neuroinflammation by performing various functions such as neurogenesis, synaptic pruning, and pathogen defense. These cells are activated by inflammatory factors like β-amyloid (Aβ) and oxysterols, leading to morphological and functional changes, including the secretion of inflammatory cytokines and the upregulation of MHC class II molecules. This study focused on identifying specific markers for microglial activation, with a particular emphasis on the roles of oxysterols in this process. We used the HMC3 human microglial cell line to investigate the induction of heat shock protein 60 (HSP60), a chaperonin protein by oxysterols, specifically in the presence of 25-hydroxycholesterol (25OHChol) and 27-hydroxycholesterol (27OHChol). Our findings obtained by the proteomics approach revealed that these oxysterols significantly increased HSP60 expression on microglial cells. This induction was further confirmed using Western blot analysis and immunofluorescence microscopy. Additionally, Aβ1-42 also promoted HSP60 expression, indicating its role as a microglial activator. HSP60 involved in protein folding and immune modulation was identified as a potential marker for microglial activation. This study underscores the importance of HSP60 in the inflammatory response of microglia, suggesting its utility as a target for new therapeutic approaches in neuroinflammatory diseases such as Alzheimer's disease (AD).

Phototactic/Photosynthetic/Magnetic-Powered Chlamydomonas Reinhardtii-Metal-Organic Frameworks Micro/Nanomotors for Intelligent Thrombolytic Management and Ischemia Alleviation.

Thrombosis presents a critical health threat globally, with high mortality and incidence rates. Clinical treatment faces challenges such as low thrombolytic agent bioavailability, thrombosis recurrence, ischemic hypoxia damage, and neural degeneration. This study developed biocompatible Chlamydomonas Reinhardtii micromotors (CHL) with photo/magnetic capabilities to address these needs. These CHL micromotors, equipped with phototaxis and photosynthesis abilities, offer promising solutions. A core aspect of this innovation involves incorporating polysaccharides (glycol chitosan (GCS) and fucoidan (F)) into ferric Metal-organic frameworks (MOFs), loaded with urokinase (UK), and subsequently self-assembled onto the multimodal CHL, forming a core-shell microstructure (CHL@GCS/F-UK-MOF). Under light-navigation, CHL@GCS/F-UK-MOF is shown to penetrate thrombi, enhancing thrombolytic biodistribution. Combining CHL@GCS/F-UK-MOF with the magnetic hyperthermia technique achieves stimuli-responsive multiple-release, accelerating thrombolysis and rapidly restoring blocked blood vessels. Moreover, this approach attenuates thrombi-induced ischemic hypoxia disorder and tissue damage. The photosynthetic and magnetotherapeutic properties of CHL@GCS/F-UK-MOF, along with their protective effects, including reduced apoptosis, enhanced behavioral function, induced Heat Shock Protein (HSP), polarized M2 macrophages, and mitigated hypoxia, are confirmed through biochemical, microscopic, and behavioral assessments. This multifunctional biomimetic platform, integrating photo-magnetic techniques, offers a comprehensive approach to cardiovascular management, advancing related technologies.

The influence of HSP inducers on salinity stress in sterlet sturgeon (Acipenser ruthenus): In vitro study on HSP expression, immune responses, and antioxidant capacity.

Heat shock proteins (HSPs) play a crucial role in antioxidant systems, immune responses, and enzyme activation during stress conditions. Salinity changes can cause stress and energy expenditure in fish, resulting in mortality, especially in fingerlings. The purpose of this study was to examine the relationship between salinity and HSPs in stressed fish by assessing the effects of various HSP inducers (HSPis), including Pro-Tex® (800mM), amygdalin (80mM), and a novel synthetic compound derived from pirano piranazole (80µM), on isolated cells from Sterlet Sturgeon (Acipenser ruthenus) exposed to 13‰ salinity (S13). After liver, kidney, and gill cells were cultured, the HSPi compounds were treated in vitro in the presence and absence of salinity. The expression patterns of HSP27, HSP70, and HSP90 were assessed by Western blotting. Biochemical enzymes (aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, and lactate dehydrogenase), cortisol levels, and immune parameters (component 3, immunoglobulin M, and lysozyme) were measured before and after treatment with HSPis and HSPi+S13. According to these findings, HSPis positively modulate HSP expression, immune responses, and antioxidant levels. Furthermore, they increased in vitro cell survival by maintaining cortisol levels and biochemical enzyme activities in A. ruthenus under saline conditions (P<0.0001). In conclusion, HSPis can increase A. ruthenus resistance to salinity stress. However, the results also indicated that these compounds can reverse the adverse effects of salinity. The effectiveness of this approach depends on further research into the effects of these ecological factors on the health status of the species, especially in vivo and in combination with other stresses.

Impact of histone deacetylase inhibition and arimoclomol on heat shock protein expression and disease biomarkers in primary culture models of familial ALS.

Protein misfolding and mislocalization are common themes in neurodegenerative disorders, including motor neuron disease, and amyotrophic lateral sclerosis (ALS). Maintaining proteostasis is a crosscutting therapeutic target, including the upregulation of heat shock proteins (HSP) to increase chaperoning capacity. Motor neurons have a high threshold for upregulating stress-inducible HSPA1A, but constitutively express high levels of HSPA8. This study compared the expression of these HSPs in cultured motor neurons expressing three variants linked to familial ALS: TAR DNA binding protein 43kDa (TDP-43)G348C, fused in sarcoma (FUS)R521G, or superoxide dismutase I (SOD1)G93A. All variants were poor inducers of Hspa1a, and reduced levels of Hspa8 mRNA and protein, indicating multiple compromises in chaperoning capacity. To promote HSP expression, cultures were treated with the putative HSP coinducer, arimoclomol, andclass I histone deacetylase inhibitors, to promote active chromatin for transcription, and with the combination. Treatments had variable, often different effects on the expression of Hspa1a and Hspa8, depending on the ALS variant expressed, mRNA distribution (somata and dendrites), and biomarker of toxicity measured (histone acetylation, maintaining nuclear TDP-43 and the neuronal Brm/Brg-associated factor chromatin remodeling complex component Brg1, mitochondrial transport, FUS aggregation). Overall, histone deacetylase inhibition alone was effective on more measures than arimoclomol. As in the FUS model, arimoclomol failed to induce HSPA1A or preserve Hspa8 mRNA in the TDP-43 model, despite preserving nuclear TDP-43 and Brg1, indicating neuroprotective properties other than HSP induction. The data speak to the complexity of drug mechanisms against multiple biomarkers of ALS pathogenesis, as well as to the importance of HSPA8 for neuronal proteostasis in both somata and dendrites.

A transcriptional enhancer regulates cardiac maturation.

Cardiomyocyte maturation is crucial for generating adult cardiomyocytes and the application of human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs). However, regulation at the cis-regulatory element level and its role in heart disease remain unclear. Alpha-actinin 2 (ACTN2) levels increase during CM maturation. In this study, we investigated a clinically relevant, conserved ACTN2 enhancer's effects on CM maturation using hPSC and mouse models. Heterozygous ACTN2 enhancer deletion led to abnormal CM morphology, reduced function and mitochondrial respiration. Transcriptomic analyses in vitro and in vivo showed disrupted CM maturation and upregulated anabolic mammalian target for rapamycin (mTOR) signaling, promoting senescence and hindering maturation. As confirmation, ACTN2 enhancer deletion induced heat shock protein 90A expression, a chaperone mediating mTOR activation. Conversely, targeting the ACTN2 enhancer via enhancer CRISPR activation (enCRISPRa) promoted hPSC-CM maturation. Our studies reveal the transcriptional enhancer's role in cardiac maturation and disease, offering insights into potentially fine-tuning gene expression to modulate cardiomyocyte physiology.

Induction of heat shock protein expression in SP2/0 transgenic cells and its effect on the production of monoclonal antibodies.

The objective of the current investigation was to evaluate the induction of heat shock proteins (HSPs) in SP2/0 transgenic cells and the effect of these proteins on the production of monoclonal antibodies (mAbs). The SP2/0 cell line expressing the PSG-026 antibody, a biosimilar candidate of golimumab, the culture parameters, and the target protein expression were not justified for industrial production and were used for the experiments. Paracetamol and heat shock were used as chemical and physical inducers of HSPs, respectively. The results showed that paracetamol and heat shock increased the expression of HSP70 and HSP27 at the mRNA and protein levels. The expression of HSPs was greater in paracetamol-treated cells than in heat shock-treated cells. Paracetamol treatment at concentrations above 0.5 mM significantly reduced cell viability and mAb expression. However, treatment with 0.25 mM paracetamol results in delayed cell death and increased mAb production. Heat shock treatment at 45°C for 30 minutes after enhanced mAb expression was applied after pre-treatment with paracetamol. In bioreactor cultures, pretreatment of cells with paracetamol improved cell viability and shortened the lag phase, resulting in increased cell density. The production of mAbs in paracetamol-treated cultures was markedly greater than that in the control. Analysis of protein quality and charge variants revealed no significant differences between paracetamol-treated and control cultures, indicating that the induction of HSPs did not affect protein aggregation or charge variants. These findings suggest that inducing and manipulating HSP expression can be a valuable strategy for improving recombinant protein production in biopharmaceutical processes.

The analysis of inducible family members in the water flea Daphnia magna led to the identification of an uncharacterized lineage of heat shock protein 70

To explore the function and evolutionary relationships of inducible heat shock protein 70 (Hsp70) in Daphnia magna, cDNAs of four Hsp70 family members (DmaHsp70, DmaHsp70-2, DmaHsp70-12, DmaHsp70-14) were cloned. While all DmaHsp70s possess three function domains, it is noteworthy that only DmaHsp70 ends with a “EEVD” motif. Phylogenetic analysis indicates that the Hsp70-12 lineage is distanced from the rest, and therefore it is an uncharacterized lineage of Hsp70. The differences in isoelectric point and 3-dimensional (3D) conformation of the N-terminal nucleotide binding domain (NBD) of DmaHsp70s further support the theory. DmaHsp70s exhibit varied motif distribution patterns and the logo sequences of motifs have diverse signature characteristics, indicating that different mechanisms are involved in the regulation of ATP binding and hydrolysis for the DmaHsp70s. Protein-protein network together with the predicted subcellular locations of DmaHsp70s suggest that they likely fulfill distinct roles in cells. The transcription of four DmaHsp70s were changed during the recovery stage after thermal stress or oxidative stress. But the expression pattern of them were dissimilar. Collectively, these results collectively elucidated the identification of a previously uncharacterizedHsp70 lineage in animal and extended our understanding of the Hsp70 family.

Short-term dietary teprenone improved thermal tolerance and mitigated liver damage caused by heat stress in juvenile largemouth bass (Micropterus salmoides)

Heat stress seriously threatens fish survival and health, demanding immediate attention. Teprenone is a gastric mucosal protective agent that can induce heat shock protein expression. This research investigated the effects of teprenone on largemouth bass (Micropterus salmoides) subjected to heat stress. Juvenile fish were assigned to different groups: group C (control group, 0 mg teprenone/kg diet), T0, T200, T400, and T800 (0, 200, 400, and 800 mg teprenone/kg diet, respectively), which were fed for 3 days, followed by a day without the diet. All groups except group C were subjected to acute heat stress (from 24 °C to 35 °C at 1 °C per hour and then maintained at 35 °C for 3 h). The results were as follows: The critical thermal maxima were significantly higher in the T200, T400, and T800 groups compared with the T0 group (P < 0.05). Heat stress caused severe damage to the tissue morphology of the liver, while teprenone significantly reduced this injury (P < 0.05). Serum cortisol concentration decreased gradually as teprenone concentration increased, and the lowest concentration was observed in the T800 group (P < 0.05). Compared with the T0 group, the serum activities of aspartate aminotransferase, alanine aminotransferase, and gamma-glutamyl transferase were significantly lower in the T200, T400, and T800 groups (P < 0.05). The liver activities of catalase, total superoxide dismutase, and peroxidase were significantly higher in the T200 group than in the T0 group (P < 0.05). Transcript levels of the heat shock proteins (hsp90, hsp70, hspa5, and hsf1) and caspase family (caspase3 and caspase9) in the liver of the T200 group were significantly higher than those of the T0 group (P < 0.05). Western blot results showed that HSP70 and HSPA5 in the liver were significantly upregulated in the T200 group compared with the T0 group (P < 0.05). In summary, dietary teprenone improved thermal tolerance, alleviated heat stress damage in the liver, enhanced antioxidant capacity, and upregulated heat shock proteins in juvenile largemouth bass. This study offers theoretical support for applying teprenone in aquaculture to reduce financial losses caused by abiotic factors.

Effects of HSP inducers on the gene expression of Heat Shock Proteins (HSPs) in cells extracted from sterlet sturgeon under temperature stress with antioxidant and immunity responses.

Global warming has profound effects on the living conditions and metabolism of organisms, including fish. The metabolic rate of fish increases as the temperature increases within its thermal tolerance range. Temperature changes can trigger a range of physiological reactions, including the activation of the stress axis and the production of HSPs. Under stress conditions, HSPs play a crucial role in antioxidant systems, immune responses, and enzyme activation. This study examined the effects of heat shock products (HSPs) on fish under temperature stress. Various HSP inducers (HSPis), including Pro-Tex®, amygdalin, and novel synthetic compounds derived from pirano piranazole (SZ, MZ, HN-P1, and HN-P2), were evaluated in isolated cells of sterlet sturgeon (Acipenser ruthenus) treated with temperature changes (18, 22, and 26°C). Cells from the liver, kidney, and gills were cultured in vitro in the presence and absence of temperature stress and treated with HSPi compounds. To assess HSP27, HSP70, and HSP90 expression patterns, Western blotting was used. The HSPis and HSPi + temperature stress treatments affected the antioxidant capacity and immune parameters, among other enzyme activities. The results showed that HSPi compounds increase cell survival in vitro, positively modulate HSP expression and antioxidant levels, and decrease immune parameters. HSPi can increase A. ruthenus tolerance to temperature stress. In addition, the results indicate that these compounds can reverse adverse temperature effects. Further research is needed to determine how these ecological factors affect fish species' health in vivo and in combination with other stressors.

Distinct induction pathways of heat shock protein 27 in human keratinocytes: Heat stimulation or capsaicin through phosphorylation of heat shock factor 1 at serine 326 and/or suppression of ΔNp63

Epidermal keratinocytes, forming the outermost layer of the human body, serve as a crucial barrier against diverse external stressors such as ultraviolet radiation. Proper keratinocyte differentiation and effective responses to external stimuli are pivotal for maintaining barrier integrity. Heat is one such stimulus that triggers the synthesis of heat shock proteins (HSPs) when cells are exposed to temperatures above 42 °C. Additionally, activation of the transient receptor potential cation channel subfamily V member 1 (TRPV1) occurs at 42 °C. Here, we explore the interplay between TRPV1 signaling and HSP induction in human keratinocytes. Both heat and capsaicin, a TRPV1 agonist, induce expression of HSP27, HSP70, and HSP90 in keratinocytes. Interestingly, pharmacological inhibition of TRPV1 attenuates heat-induced HSP27 expression, but not that of HSP70 or HSP90. Furthermore, both heat and capsaicin stimulation result in distinct phosphorylation patterns of heat shock factor 1 (HSF1), with phosphorylation at serine 326 being a common feature. Notably, genetic manipulation to mimic dephosphorylation of HSF1 at serine 326 reduces HSP27 levels. Additionally, ΔNp63, a key regulator of epidermal differentiation, negatively modulates HSP27 expression independently of HSF1 phosphorylation status. While heat stimulation has no effect on ΔNp63 expression, capsaicin reduces its levels. The precise role of TRPV1 signaling in keratinocytes warrants further investigation for a comprehensive understanding of its impact on barrier function.

A histone deacetylase, FaSRT1-2, plays multiple roles in regulating fruit ripening, plant growth and stresses resistance of cultivated strawberry.

Sirtuins (SRTs) are a group of nicotinamide adenine dinucleotide (NAD+)-dependent deacetylase that target both histone and nonhistone proteins. The biological function of SRT in horticultural plants has been rarely studied. In this study, FaSRT1-2 was identified as a key member of the 8 FaSRTs encoded in cultivated strawberry genome. Transient overexpression of FaSRT1-2 in strawberry fruit accelerated ripening, increased the content of anthocyanins and sugars, enhanced ripening-related gene expression. Moreover, stable transformation of FaSRT1-2 in strawberry plants resulted in enhanced vegetative growth, increased sensitivity to heat stress and increased susceptibility to Botrytis cinerea infection. Interestingly, knocking out the homologous gene in woodland strawberry had the opposite effects. Additionally, we found the content of stress-related hormone abscisic acid (ABA) was decreased, while the growth-related gibberellin (GA) concentration was increased in FaSRT1-2 overexpression lines. Gene expression analysis revealed induction of heat shock proteins, transcription factors, stress-related and antioxidant genes in the FaSRT1-2-overexpressed plants while knocked-out of the gene had the opposite impact. In conclusion, our findings demonstrated that FaSRT1-2 could positively promote strawberry plant vegetative growth and fruit ripening by affecting ABA and GA pathways. However, it negatively regulates the resistance to heat stress and B. cinerea infection by influencing the related gene expression.

Pre-exercise hot water immersion increased circulatory heat shock proteins but did not alter muscle damage markers or endurance capacity after eccentric exercise

ABSTRACT Pre-exercise passive heating attenuates muscle damage caused by eccentric exercise in rats where the induction of heat shock proteins (HSPs) confers a myoprotective effect. We investigated whether pre-exercise hot water immersion (HWI) confers similar benefits in humans. Eleven recreational male athletes were immersed in 41°C water up to 60 min or until rectal temperatures reached 39.5°C. After a 6 h rest, the participants performed an eccentric downhill run for 1 h at −4% gradient to induce muscle damage. An endurance capacity test at 75% VO2max was conducted 18 h later. The control trial was similar except that participants were immersed at 34°C. Blood samples were collected to assess HSPs levels, creatine kinase, and lactate dehydrogenase activities. Plasma eHSP70 was higher post-immersion in HWI trials (1.3 ± 0.4 vs 1.1 ± 0.4; p = 0.005). Plasma eHSP27 was higher before (p = 0.049) and after (p = 0.015) endurance test in HWI. Leukocytic p-HSP27 was increased 18 h after HWI (0.97 ± 0.14 vs 0.67 ± 0.11; p = 0.04). Creatine kinase and lactate dehydrogenase activities were increased by 3-fold and 1.5-fold, respectively, after endurance test in HWI but did not differ across trials (p > 0.05). Mean heart rates were higher during eccentric run and endurance test in HWI as compared to control (p < 0.05). Endurance capacity was similar between trials (57.3 ± 11.5 min vs 55.0 ± 13.5 min; p = 0.564). Pre-exercise heating increased the expression of plasma eHSPs and leukocytic p-HSP27 but did not reduce muscle damage nor enhance endurance capacity.

Metalloproteomic analysis of liver proteins isolated from broilers fed with different sources and levels of copper and manganese

Supplementing minerals beyond dietary requirements can increase the risk of toxicity and mineral excretion, making the selection of more bioavailable sources crucial. Thus, this work aimed to use metalloproteomics tools to investigate possible alterations in the hepatic proteome of broilers fed with diets containing two sources (sulfate and hydroxychloride) and two levels of copper (15 and 150 ppm) and manganese (80 and 120 ppm), totaling four treatments: low Cu/Mn SO4, high Cu/Mn SO4, low Cu/Mn (OH)Cl and high Cu/Mn (OH)Cl. The difference in abundance of protein spots and copper and manganese concentrations in liver and protein pellets were analyzed by analysis of variance with significance level of 5%. The Cu and Mn concentrations determined in liver and protein pellets suggested greater bioavailability of hydroxychloride sources. We identified 19 Cu-associated proteins spots, 10 Mn-associated protein spots, and 5 Cu and/or Mn-associated protein spots simultaneously. The analysis also indicated the induction of heat shock proteins and detoxification proteins in broilers fed with high levels of copper and manganese, suggesting the involvement of these proteins in metal tolerance and stress.

The major inducible small heat shock protein HSP20-3 in the tardigrade Ramazzottius varieornatus forms filament-like structures and is an active chaperone.

The tardigrade Ramazzottius varieornatus has remarkable resilience to a range of environmental stresses. In this study, we have characterised two members of the small heat shock protein (sHSP) family in R. varieornatus, HSP20-3 and HSP20-6. These are the most highly upregulated sHSPs in response to a 24h heat shock at 35 0C of adult tardigrades with HSP20-3 being one of the most highly upregulatedgene in the whole transcriptome. Both R. varieornatus sHSPs and the human sHSP, CRYAB (HSPB5), were produced recombinantly for comparative structure-function studies. HSP20-3 exhibited a superior chaperone activity than human CRYAB in a heat-induced protein aggregation assay. Both tardigrade sHSPs also formed larger oligomers than CRYAB as assessed by size exclusion chromatography and transmission electron microscopy of negatively stained samples. Whilst both HSP20-3 and HSP20-6 formed particles that were variable in size and larger than the particles formed by CRYAB, only HSP20-3 formed filament-like structures. The particles and filament-like structures formed by HSP20-3 appear inter-related as the filament-like structures often had particles located at their ends. Sequence analyses identified two unique features; an insertion in the middle region of the N-terminal domain (NTD) and preceding the critical-sequence identified in CRYAB, as well as a repeated QNTN-motif located in the C-terminal domain of HSP20-3. The NTD insertion is expected to affect protein-protein interactions and subunit oligomerisation. Removal of the repeated QNTN-motif abolished HSP20-3 chaperone activity and also affected the assembly of the filament-like structures. We discuss the potential contribution of HSP20-3 to protein condensate formation.