Search Results (2,833)

Thermal stimulation represents an effective method for enhancing reservoir permeability, thereby improving geothermal energy recovery in Enhanced Geothermal Systems (EGS). The phase-field method (PFM) has been widely adopted for its proven capability in modeling the fracture behavior of brittle solids. Consequently, a coupled thermo-mechanical phase-field model (TM-PFM) was developed in COMSOL 6.2 Multiphysics to probe thermal fracturing mechanisms in reservoir rocks. The TM-PFM was validated against the analytical solutions for the temperature and stress fields under steady-state heat conduction in a thin-walled cylinder, three-point bending tests, and thermal shock tests. Subsequently, two distinct thermal fracturing modes in reservoir rock under high-temperature conditions were investigated: (i) fracture initiation driven by sharp temperature gradients during instantaneous thermal shocks, and (ii) crack propagation resulting from heterogeneous thermal expansion of constituent minerals. The proposed TM-PFM has been validated through systematic comparison between the simulation results and the corresponding experimental data, thereby demonstrating its capability to accurately simulate thermal fracturing. These findings provide mechanistic insights for optimizing geothermal energy extraction in EGS. Full article

Cardiopulmonary bypass (CPB) is associated with significant neurological complications, yet the mechanisms underlying brain injury remain unclear. This study investigated the role of interleukin-17A (IL-17A) in exacerbating CPB-induced neuronal apoptosis and identified vulnerable brain regions. Utilizing a rat CPB model and an oxygen–glucose deprivation/reoxygenation (OGD/R) cellular model, we demonstrated that IL-17A levels were markedly elevated in the hippocampus post-CPB, correlating with endoplasmic reticulum stress (ERS)-mediated apoptosis. Transcriptomic analysis revealed the enrichment of IL-17 signaling and apoptosis-related pathways. IL-17A-Neutralizing monoclonal antibody (mAb) and the ERS inhibitor 4-phenylbutyric acid (4-PBA) significantly attenuated neurological deficits and hippocampal neuronal damage. Mechanistically, IL-17A activated the Act1-IRE1-JNK1 axis, wherein heat shock protein 90 (Hsp90) competitively regulated Act1-IRE1 interactions. Co-immunoprecipitation confirmed the enhanced Hsp90-Act1 binding post-CPB, promoting IRE1 phosphorylation and downstream caspase-12 activation. In vitro, IL-17A exacerbated OGD/R-induced apoptosis via IRE1-JNK1 signaling, reversible by IRE1 inhibition. These findings identify the hippocampus as a key vulnerable region and delineate a novel IL-17A/Act1-IRE1-JNK1 pathway driving ERS-dependent apoptosis. Targeting IL-17A or Hsp90-mediated chaperone switching represents a promising therapeutic strategy for CPB-associated neuroprotection. This study provides critical insights into the molecular crosstalk between systemic inflammation and neuronal stress responses during cardiac surgery. Full article

(1) Background: Polyploid fish are highly important in increasing fish production, improving fish quality, and breeding new varieties. The loach (Misgurnus anguillicaudatus), as a naturally polyploid fish, serves as an ideal biological model for investigating the mechanisms of chromosome doubling; (2) Methods: In this study, tetraploidization in diploid loach was induced by heat shock treatment, and, for the first time, the role of the key cell cycle gene cdk1 (cyclin-dependent kinase 1) in chromosome doubling was investigated; (3) Results: The experimental results show that when eggs are fertilized for 20 min and then subjected to a 4 min heat shock treatment at 39–40 °C, this represents the optimal induction condition, resulting in a tetraploid rate of 44%. Meanwhile, the results of the cdk1 knockout model (2n cdk1^−/−) constructed using CRISPR/Cas9 showed that the absence of cdk1 significantly increased the chromosome doubling efficiency of the loach. The qPCR analysis revealed that knockout of cdk1 significantly upregulated cyclin genes (ccnb3,ccnc, and ccne1), while inhibiting expression of the separase gene espl1 (p < 0.05); (4) Conclusions: During chromosome doubling in diploid loaches induced by heat shock, knocking out the cdk1 gene can increase the tetraploid induction rate. This effect may occur through downregulation of the espl1 gene. This study offers novel insights into optimizing the induced breeding technology of polyploid fish and deciphering its molecular mechanism, while highlighting the potential application of integrating gene editing with physical induction. Full article

Members of the heat shock protein 20 (HSP20) family of proteins play an important role in responding to various forms of stress. Here, the expression of ClaHSP17.4 was induced by heat stress in watermelon. Then, a floral dipping approach was used to introduce the pCAMBIA1391b-GFP overexpression vector encoding the heat tolerance-related gene ClaHSP17.4 from watermelon into Arabidopsis thaliana, and we obtained ClaHSP17.4-overexpressing Arabidopsis plants. Under normal conditions, the phenotypes of transgenic and wild-type (WT) Arabidopsis plants were largely similar. Following exposure to heat stress, however, the germination rates (96%) of transgenic Arabidopsis plants at the germination stages were significantly higher than those of wild-type idopsis (17%). Specifically, the malondialdehyde (MDA) content of transgenic Arabidopsis was half that of the control group, while the activities of peroxidase (POD) and superoxide dismutase (SOD) were 1.25 times those of the control group after exposure to high temperatures for 12 h at the seedling stages. The proline content in ClaHSP17.4-overexpressing transgenic Arabidopsis increased by 17% compared to WT plants (* p < 0.05), while the soluble sugar content rose by 37% (* p < 0.05). These results suggest that ClaHSP17.4 overexpression indirectly improves the antioxidant capacity and osmotic regulatory capacity of Arabidopsis seedlings, leading to improved survival and greater heat tolerance. Meanwhile, the results of this study provide a reference for further research on the function of the ClHSP17.4 gene and lay a foundation for breeding heat-tolerant watermelon varieties and advancing our understanding of plant adaptation to environmental stress. Full article

Global warming has resulted in an increase in the frequency of extreme high-temperature events. High temperatures can increase cell membrane permeability, elevate levels of osmotic adjustment substances, reduce photosynthetic capacity, impair plant growth and development, and even result in plant death. Under high-temperature stress, plants mitigate damage through physiological and biochemical adjustments, heat signal transduction, the regulation of transcription factors, and the synthesis of heat shock proteins. However, different plants exhibit varying regulatory abilities and temperature tolerances. Investigating the heat-resistance and regulatory mechanisms of plants can facilitate the development of heat-resistant varieties for plant genetic breeding and landscaping applications. This paper presents a systematic review of plant physiological and biochemical responses, regulatory substances, signal transduction pathways, molecular mechanisms—including the regulation of heat shock transcription factors and heat shock proteins—and the role of plant hormones under high-temperature stress. The study constructed a molecular regulatory network encompassing Ca²⁺ signaling, plant hormone pathways, and heat shock transcription factors, and it systematically elucidated the mechanisms underlying the enhancement of plant thermotolerance, thereby providing a scientific foundation for the development of heat-resistant plant varieties. Full article

Molecular chaperones, especially heat shock proteins (HSPs) have vital functions in cells’ responses to stress. Here, we cloned and sequenced the complete complementary DNA encoding HSP90 (MjHSP90) from the shrimp Marsupenaeus japonicus. The MjHSP90 cDNA comprised 3162 bp, including a 2172 bp coding region encoding a 724 amino acid-protein (predicted molecular mass = 83.12 kDa). Homology and phylogenetic analyses showed that MjHSP90 was highly conserved and most homologous to Litopenaeus vannamei HSP90. MjHSP90 is expressed in all tested tissues, with high expression in gill tissue and the hepatopancreas. Cold stress significantly upregulated MjHSP90 expression in the gill and hepatopancreas (p < 0.05). Following RNA interference knockdown of MjHSP90, the cold stress-related death rate of the shrimp increased significantly, accompanied by significantly upregulated expression of apoptosis-related genes Mjcaspase-3 and Mjbcl-2 (p < 0.05) and an increase in the number of apoptotic cells. The results indicated that MjHSP90 might play a pivotal role in the shrimp’s immune response to cold stress. Full article

Anthropogenic vibrational disturbances in the marine environment can affect benthic organisms, but these effects on marine animals remain poorly understood. To examine whether anthropogenic substrate-borne vibrations induce physiological stress in the white-clawed fiddler crab (Austruca lactea), individuals were exposed to vibrations at 120 Hz and 250 Hz (~100 dB re 1 µm/s²), and physiological indicators were measured. Lactate and ATP concentrations in the leg muscle were measured, and heat shock protein 70 kDa (HSP70) gene expression in the hepatopancreas was analyzed using RT-PCR with newly designed primers. At 120 Hz, ATP and lactate levels in the leg muscle did not differ significantly between the exposure and control groups. However, at 250 Hz, ATP levels were lower and lactate levels were higher in the exposure group compared to the control. HSP70 gene expression in the hepatopancreas did not differ significantly between the exposure and control groups at either frequency, although one individual exposed to 250 Hz exhibited markedly elevated expression, inducing higher expression variability in the exposed group. These results suggest that anthropogenic vibrational pollution may induce physiological stress in A. lactea, and that such physiological indices could serve as biomarkers for assessing vibroacoustic pollution on marine animals. Full article

Pain following orthodontic treatment is the chief complaint of patients undergoing this form of treatment. Although the use of diode lasers has been suggested for pain reduction, the mechanism of laser-induced analgesic effects remains unclear. Neuropeptides, such as substance P (SP) and calcitonin gene-related peptide (CGRP), contribute to the transmission and maintenance of inflammatory pain. Heat shock protein (HSP) 70 plays a protective role against various stresses, including orthodontic forces. This study aimed to examine the effects of diode laser irradiation on neuropeptides and HSP 70 expression in periodontal tissues induced by experimental tooth movement (ETM). For inducing ETM for 24 h, 50 g of orthodontic force was applied using a nickel–titanium closed-coil spring to the upper left first molar and the incisors of 20 male Sprague Dawley rats (7 weeks old). The right side without ETM treatment was considered the untreated control group. In 10 rats, diode laser irradiation was performed on the buccal and palatal sides of the first molar for 90 s with a total energy of 100.8 J/cm². A near-infrared (NIR) laser with a 808 nm wavelength, 7 W peak power, 560 W average power, and 20 ms pulse width was used for the experiment. We measured the number of facial groomings and vacuous chewing movements (VCMs) in the ETM and ETM + laser groups. Immunohistochemical staining of the periodontal tissue with SP, CGRP, and HSP 70 was performed. The number of facial grooming and VCM periods significantly decreased in the ETM + laser group compared to the ETM group. Moreover, the ETM + laser group demonstrated significant suppression of SP, CGRP, and HSP 70 expression. These results suggest that the diode laser demonstrated analgesic effects on ETM-induced pain by inhibiting SP and CGRP expression, and decreased HSP 70 expression shows alleviation of cell damage. Thus, although further validation is warranted for human applications, an NIR diode laser can be used for reducing pain and neuropeptide markers during orthodontic tooth movement. Full article

Extracellular vesicles (EVs), nanoscale membrane-enclosed particles, are natural carriers of proteins and nucleic acids. Microalgae are widely used as a source of bioactive substances in the food and cosmetic industries and definitely have a potential to be used as the producers of EVs for biomedical applications. In this study, the extracellular vesicles isolated from the culture medium of two unicellular microalgae, Chlamydomonas reinhardtii (Chlamy-EVs) and Parachlorella kessleri (Chlore-EVs), were characterized by atomic force microscopy (AFM), cryo-electronic microscopy (cryo-EM), and nanoparticle tracking analysis (NTA). The biocompatibility with human cells in vitro (HEK-293T, DF-2 and A172) and biodistribution in mouse organs and tissues in vivo were tested for both microalgal EVs. An exogenous therapeutic protein, human heat shock protein 70 (HSP70), was successfully loaded to Chlamy- and Chlore-EVs, and its efficient delivery to human glioma and colon carcinoma cell lines has been confirmed. Additionally, in order to search for potential therapeutic biomolecules within the EVs, their proteomes have been characterized. A total of 105 proteins were identified for Chlamy-EVs and 33 for Chlore-EVs. The presence of superoxide dismutase and catalase in the Chlamy-EV constituents allows for considering them as antioxidant agents. The effective delivery of exogenous cargo to human cells and the possibility of the particle yield optimization by varying the microalgae growth conditions make them favorable producers of EVs for biotechnology and biomedical application. Full article

Soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), is a major pest of soybean fields. While high-temperature stress induced by global warming can initially suppress aphid populations, these pests may eventually adapt, leading to more severe infestations and crop damage. Heat shock proteins (HSPs), which are upregulated in response to heat stress to protect aphid development, also confer tolerance to other abiotic stressors, including insecticides. To investigate the role of HSPs in insecticide resistance in A. glycines, we analyzed the expression profiles of three AgHsp90 genes (AgHsp75, AgHsp83, and AgGrp94) following exposure to high temperatures and insecticides. Functional validation was performed using RNA interference (RNAi) to silence AgHsp90 genes. Our results demonstrated that AgHsp90 genes were significantly upregulated under both heat and insecticide stress conditions. Furthermore, after feeding on dsRNA of AgHsp90 genes, mortality rates of A. glycines significantly increased when exposed to imidacloprid and lambda-cyhalothrin. This study provides evidence that AgHsp90 genes play a crucial role in mediating thermal tolerance and insecticide resistance in A. glycines. Full article

An analytical study of the interaction of an ideal gas flow with a detonation wave was performed with account for the activation energy of chemical processes. Based on the modified Rankine-Hugoniot conditions, the effect of heat release on the limiting characteristics of detonation was analyzed. A dependence of the limiting value of the exponent Arrhenius number on the Mach number before the shock wave has been obtained. As the Mach number increases, the limiting value of the Arrhenius number decreases. An equation has been derived for determining the limiting value of the compression ratio in the shock wave. The effect of heat release intensity on the limiting compression ratio in a shock wave was elucidated. Also studied were effects of the Mach number and the Arrhenius number on the limiting compression ratio in a detonation wave. A condition for determining the critical value of the Arrhenius number necessary for the onset of detonation was obtained. Effects of the Mach number and the exponent of the Arrhenius number ${\mathrm{Ar}}_E$ on the critical value of the amplitude Arrhenius number ${\mathrm{Ar}}_A$ were discussed. The symmetry analysis of the gas flow parameters when passing through a detonation wave was performed. Full article

The seasonal patterns of viral diseases in farm animals present significant challenges to global livestock productivity, with cold stress emerging as a potential modulator of host–pathogen interactions. This review synthesizes current knowledge on the expression dynamics of heat shock protein 70 (HSP70) in farm animals under cold-stress conditions and its potential roles as (1) a viral replication facilitator and (2) an immune response regulator. This review highlights cold-induced HSP70 overexpression in essential organs, as well as its effects on significant virus life cycles, such as porcine epidemic diarrhea virus (PEDV), porcine reproductive and respiratory syndrome virus (PRRSV), and bovine viral diarrhea virus (BVDV), through processes like viral protein chaperoning, replication complex stabilization, and host defense modulation. By integrating insights from thermophysiology, virology, and immunology, we suggest that HSP70 serves as a crucial link between environmental stress and viral disease seasonality. We also discuss translational opportunities targeting HSP70 pathways to break the cycle of seasonal outbreaks, while addressing key knowledge gaps requiring further investigation. This article provides a framework for understanding climate-driven disease patterns and developing seasonally adjusted intervention strategies. Full article

Myeloid-derived growth factor (MYDGF), named in reference to its secretion from myeloid cells in bone marrow, is a novel protein with anti-apoptotic and tissue-repairing properties. MYDGF is found in various human tissues affected by different diseases. To date, however, MYDGF expression has yet to be reported in the nervous system. Herein, we demonstrate for the first time that MYDGF mRNA levels increased in the zebrafish retina 1 h after optic nerve injury (ONI). MYDGF-producing cells were located in the photoreceptors and infiltrating leukocytic cells. We prepared the retina for MYDGF gene knockdown by performing intraocular injections using either MYDGF-specific morpholino or the CRISPR/Cas9 system. Under these MYDGF-knockdown retinal conditions, anti-apoptotic Bcl-2 mRNA was suppressed; in comparison, apoptotic caspase-3 and inflammatory TNFα mRNA were significantly upregulated in the zebrafish retina after ONI compared to the control. Furthermore, heat shock factor 1 (HSF1) was evidently suppressed under these conditions, leading to a significant number of apoptotic neurons. These findings indicate that MYDGF is a key molecule in the stimulation of neuronal regeneration in the central nervous system. Full article

Protein degradation plays a fundamental role in maintaining protein homeostasis and ensures proper cellular function by regulating protein quality and quantity. Heat shock protein 100 (Hsp100), found in bacteria, plants, and fungi, is a unique chaperone family responsible for rescuing misfolded proteins from aggregated states in an ATP-dependent manner. To date, they are primarily known to mediate heat stress adaptation and enhance cellular survival under extreme conditions in higher plants and algae. Resting cyst formation in dinoflagellates is widely recognized as a response to adverse conditions, which offers an adaptive advantage to endure harsh environmental extremes that are unsuitable for vegetative cell growth and survival. In this study, based on a full-length cDNA sequence, we characterized an Hsp100 gene (SaHsp100) from the cosmopolitan bloom-forming dinoflagellate Scrippsiella acuminata, aiming to examine its life stage-specific expression patterns and preliminarily explore its potential functions. The qPCR results revealed that Hsp100 transcript levels were significantly elevated in newly formed resting cysts compared to vegetative cells and continued to increase during storage under simulated marine sediment conditions (darkness, low temperature, and anoxia). Parallel reaction monitoring (PRM)-based quantification further confirmed that Hsp100 protein levels were significantly higher in resting cysts than in vegetative cells and increased after three months of storage. These findings collectively highlighted the fundamental role of Hsp100 in the alteration of the life cycle and dormancy maintenance of S. acuminata, likely by enhancing stress adaptation and promoting cell survival through participation in proteostasis maintenance, particularly under natural sediment-like conditions that trigger severe abiotic stress. Our work deepens the current understanding of Hsp family members in dinoflagellates, paving the way for future investigations into their ecological relevance within this ecologically significant group. Full article

Enterotoxigenic Escherichia coli (ETEC) leads to severe diarrhea in piglets. Naringenin (Nar), a natural flavonoid compound, is known for its antibacterial and anti-antioxidant properties. However, the protective effects of Nar against ETEC-induced diarrhea have not been reported yet. This study investigated the protective mechanisms of Nar against ETEC infection in porcine intestinal epithelial cells (IPEC-J2). ETEC infection induced oxidative stress and ferroptosis in IPEC-J2 cells by elevating intracellular iron content and ROS accumulation, increasing MDA levels, downregulating SOD activity and GPX4 expression, and upregulating the transcription of CHAC1 and SLC7A11. In contrast, Nar suppressed ETEC-induced ferroptosis of IPEC-J2 cells by inhibiting the SLC7A11/GPX4 pathway. Specifically, Nar mitigated mitochondrial damage, reduced intracellular iron levels and ROS accumulation, and ultimately reversed the oxidative stress. Network pharmacology and molecular docking identified heat-shock protein 90 (HSP90) as a potential target of Nar. Overexpression and knockdown experiments revealed that ETEC-induced ferroptosis was mediated by upregulation of HSP90, while the protective effects of Nar against ETEC-induced ferroptosis were dependent on the downregulation of HSP90. In conclusion, Nar targets host HSP90 to protect IPEC-J2 cells from ferroptosis caused by ETEC infection. This study demonstrates that Nar is a potent antioxidant natural compound with potential for preventing ETEC-induced intestinal damage. Full article