Search Results (474)

Sodium regulation is a potentially major driver of cancer metastasis. Voltage-gated sodium channels (VGSCs) and Na,K-ATPase are sodium transporters that are upregulated in many advanced carcinomas and are implicated as metastatic drivers. However, little is known about what drives this overexpression, how these proteins influence metastatic behavior, or whether these complementary sodium transporters are co-regulated in cancer. Using sodium transporter regulation in healthy neurons as a model, the present study demonstrated that the inflammatory mediator tumor necrosis factor alpha (TNFα) affects the expression of VGSCs and Na,K-ATPase in an in vitro model of metastatic breast cancer. Acute TNFα challenge increased RNA for sodium transporter subtypes by 20–100%, TNFα reduced the overall expression of VGSCs by 20–30% at all time-points examined, and long-term administration increased nuclear localization of the α1 subtype of Na,K-ATPase while increasing the overall expression of the α3 subtype. This study established that VGSCs and Na,K-ATPase are co-regulated by TNFα at the RNA level, and it was demonstrated that both TNFα and sodium transport-blocking drugs can significantly impact cellular metastasis-like behavior. Together these data are evidence that inflammation in metastatic breast cancer co-regulates the expression of VGSCs and Na,K-ATPase, and this regulatory system may contribute to carcinogenesis. Full article

Global freshwater scarcity necessitates the exploitation of alternative water resources for aquaculture. Chloride-type saline-alkaline water, characterized by high salinity but moderate pH, is widely distributed in arid regions worldwide and represents a vast, underutilized resource. This study comprehensively evaluated the potential of the endemic Ili perch (Perca schrenkii) for aquaculture in such environments. Through acute stress experiments, we determined its 96 h median lethal salinity (LC₅₀) to be 12.396 ppt, with a safe concentration of 3.72 ppt. Physiological analysis revealed a critical salinity threshold of 13 ppt, beyond which osmoregulatory collapse (indicated by plasma Na⁺/K⁺ dysregulation and Na⁺-K⁺-ATPase suppression), oxidative damage (elevated malondialdehyde), and immune suppression occurred. In contrast, chronic 60-day exposure to salinities up to 7 ppt demonstrated successful long-term acclimation. Acclimated fish re-established ion homeostasis, as plasma ion levels normalized, and exhibited sustained antioxidant enzyme (SOD, CAT) and immune parameter (AKP, ACP, IgM) activities without signs of damage. Our findings establish P. schrenkii as a highly promising species for chloride-type saline-alkaline aquaculture. The study provides a physiological framework for its adaptation and offers evidence-based salinity guidelines for its sustainable cultivation, thereby contributing to the expansion of aquaculture into non-traditional water resources. Full article

Traumatic brain injury (TBI) causes cortical dysfunction by increasing oxidative stress, neuroinflammation, apoptosis, and mitochondrial dysregulation, and impairing neurotrophic signaling and neurogenesis. This systematic review aimed to evaluate the effectiveness of exercise training on cortical molecular dysregulation and motor function in post-TBI. Following PRISMA 2020 guidelines, PubMed, EMBASE, and Web of Science were searched up to August 2025. Of 1173 records, 35 studies involving exercise training in post-TBI animal models were included. Exercise training protocols included voluntary wheel running, treadmill running, and swimming, with durations ranging from 7 to 63 days. Study quality was assessed using the CAMARADES checklist. Exercise training increased cortical glutathione and Na⁺/K⁺-ATPase activity and reduced oxidative stress in post-TBI. It reduced microglial, astrocytic reactivity, and pro-inflammatory markers, including IL-1β and TNF-α expression in post-TBI. It also reduced caspase activity while increasing heat shock protein 20 (HSP20), thereby downregulating cortical apoptosis in post-TBI. It enhanced motor function, cortical neurogenesis, and neurotrophic factors signaling, including BDNF, in post-TBI. Exercise training improved motor function and cortical neuroprotection by reducing oxidative stress, neuroinflammation, and apoptosis, while enhancing neurotrophic signaling and neurogenesis in post-TBI rodents, but the regulation of let-7c, IL-6, and mitochondrial function remained unclear. (PROSPERO: CRD420251073725) Full article

Vacuolar H⁺-ATPases play crucial roles in plant ion homeostasis and stress adaptation, yet the functional characterization of their subunit genes in purslane remains limited. In this study, PoVHA-a3, encoding a tonoplast-localized V-ATPase a3 subunit, was identified as a key salt-responsive gene through transcriptomic analysis. Integrated bioinformatic analysis and molecular docking simulations predicted specific binding of NAC3, MYB1, and bHLH62 to the PoVHA-a3 promoter, suggesting their synergistic role in regulating PoVHA-a3 expression. Under salt stress, PoVHA-a3 transgenic Arabidopsis lines exhibited elevated endogenous abscisic acid levels and upregulation of signaling genes (AtNCED3, AtRD29A, AtCOR15A), while the brassinosteroid signaling pathway was suppressed, as indicated by the reduced expression of AtBZR1 and AtEXPA8. Meanwhile, the transgenic lines demonstrated enhanced ATP levels, respiratory rate, and V-ATPase activity. In addition, PoVHA-a3 expression led to greater accumulation of osmoprotectants (proline, soluble sugars and proteins), higher activities of antioxidant enzymes, and reduced levels of oxidative stress indices. Furthermore, a significantly lower shoot Na⁺/K⁺ ratio was observed in transgenic plants, indicating improved ion homeostasis. In conclusion, this study demonstrates that PoVHA-a3 acts as a pivotal positive regulator of salt tolerance in purslane, providing a valuable genetic resource for enhancing salt tolerance in crops through genetic engineering. Full article

Cardenolides are an important group of steroidal natural products and have been used successfully for the treatment of cardiovascular diseases by targeting Na⁺/K⁺-ATPase (NKA) and found more recently to show potential anticancer activity. Biological investigations indicate that both the C-17 lactone unit and the C-3 saccharide moiety of these compounds play an important role in their interaction with NKA and in manifesting the resultant bioactivities. Interestingly, the crystal structures of several cardenolides show various conformations, due to a rotation of the C-3 saccharide moiety or the C-17 lactone unit. These rotation conformations could affect their binding to NKA and the resultant bioactivities, and thus docking profiles with NKA for several cardenolides, including cryptanoside A, digoxin and its aglycone, digoxigenin, and gitoxin, have been investigated in the present investigation. The results indicate that the binding poses of the rotation conformations of the cardenolides selected are different when they bind to NKA, as indicated by their docking scores calculated. For each compound, the rotation conformations observed could be in a dynamic equilibrium, of which each conformer may interact with NKA differentially, and these rotation conformers could act on NKA cooperatively to lead to a specific bioactivity. Full article

Background: The Na⁺/K⁺-ATPase (NKA) maintains electrochemical gradients by exporting Na+ and importing K⁺ at the expense of ATP hydrolysis. Although NKA inhibition is a well-established strategy for increasing cardiac contractility, existing inhibitors such as cardiotonic steroids (CTS) are limited by serious adverse effects. N106 is a small molecule previously shown to enhance cardiac lusitropy by promoting SERCA2a SUMOylation and, intriguingly, also exerts positive inotropic effects, suggesting additional mechanisms of action. Methods: To test whether N106 directly modulates NKA, we combined ATPase activity assays with molecular docking and microsecond-scale molecular dynamics simulations. Results: Biochemical measurements showed that N106 partially inhibits NKA, achieving ~80% maximal inhibition with an IC50 of 7 ± 1 µM, while leaving the pump’s apparent affinity for Na⁺, K⁺, and ATP unchanged. Computational analyses suggest that N106 binds within the canonical CTS-binding pocket but undergoes intermittent unbinding events, consistent with the partial inhibition observed experimentally. Conclusions: These findings identify N106 as a first-in-class dual modulator of cardiac ion pumps, partially inhibiting NKA while previously shown to activate SERCA2a through enhanced SUMOylation. This combined mechanism likely underlies its positive inotropic and lusitropic effects and positions the N106 scaffold as a promising lead for developing next-generation dual-target therapeutics for heart failure. Full article

Background: Small-cell lung cancer (SCLC) is an aggressive malignancy marked by rapid progression, early metastasis, and frequent relapse despite chemotherapy. Due to its genetic complexity, targeted therapies have limited success. Autophagy, a lysosome-dependent cellular degradation process, plays a key role in SCLC, yet effective autophagy-targeting strategies are lacking. This study evaluates Tat-SP4, an autophagy-targeting stapled peptide, for its anti-proliferative effects in SCLC. Method: We assessed Tat-SP4′s impact on autophagy in SCLC cells by measuring p62 and LC3 levels. Mitochondrial function was evaluated via mitochondrial membrane potential (Δψm) and oxygen consumption rate (OCR). Anti-proliferative effects were determined using cell viability assays in vitro and xenograft models in vivo. Cellular uptake mechanisms were investigated using Ca²⁺ imaging and pharmacological inhibitors. Result: Tat-SP4 induced a strong autophagic response and triggered autosis, a form of autophagy-dependent necrotic cell death, impairing SCLC cell proliferation. It also caused mitochondrial dysfunction with impaired oxidative phosphorylation (OXPHOS). Tat-SP4 entered cells predominantly via macropinocytosis, triggering extracellular Ca²⁺ influx measurable by live-cell imaging. Digoxin, an Na⁺, K⁺-ATPase inhibitor, partially reversed the effect of Tat-SP4 on Ca²⁺ influx, cell death, and OXPHOS activity. Lastly, Tat-SP4 inhibited tumor growth in a xenograft-based animal model for SCLC. Conclusions: The autophagy-targeting stapled peptide Tat-SP4 inhibited the proliferation of SCLC cells in vitro and inhibited the growth of the SCLC tumor in vivo. Macropinocytosis facilitates cell entry for Tat-SP4, which can be monitored by influx of extracellular Ca²⁺. By exploiting macropinocytosis for cell entry and converting the pro-survival autophagy process into a death pathway, Tat-SP4 represents a novel therapeutic strategy against SCLC. Full article

The assessment of donor corneas is currently based solely on central endothelial cell (EC) density, which potentially overlooks the transition zone (TZ) regenerative potential. Therefore, the present study characterizes TZ using multimodal imaging techniques to understand its regenerative potential and refine the assessment of donor tissue. Ex vivo donor corneas (n = 41) were examined using phase-contrast microscopy for EC counting and reflectance confocal microscopy (HRTII/RCM) for non-invasive visualization of the TZ. A subset of eight of these corneas underwent ultrastructural analysis using field-emission scanning electron microscopy (SEM) and immunostaining analysis using confocal microscopy. We observed a significant decrease in central EC density (p < 0.001) with increasing storage duration and donor age, while TZ width and TZ surface cell count remained stable. HRTII/RCM and SEM revealed distinct morphological differences (small, polygonal cells, irregular arrangement) in the TZ compared to the peripheral endothelium (PE). Immunostaining revealed elevated expression of progenitor markers (Nestin, ABCG2, SOX2, Lgr5, Vimentin) and reduced expression of endothelial markers (ZO1 and Na/K-ATPase) in the TZ compared to the PE, indicating the presence of a stem cell-like population. These findings suggest that TZ may contribute to endothelial cell regeneration, and HRTII/RCM could serve as a novel tool for TZ evaluation in low EC count donor corneas. Full article

Salinity is one of the most critical environmental factors for fish, influencing their reproduction, growth, and physiological and metabolic activities. Lateolabrax japonicus is a major commercially important marine fish that has been widely cultured in China. However, there are few reports on the growth tolerance of fish juveniles of different species under various salinity conditions. In this study, we investigated the effects of acute low-salt stress on the survival, plasma osmolality, blood ion concentration, and Na⁺/K⁺-ATPase (NKA) activity in L. japonicus juveniles of two size groups. Our findings revealed no significant difference in survival rates between 5 cm and 10 cm juveniles at salinities of 0.2, 1, 3, 5, 10, 15, and 25. Plasma osmolality and blood ions exhibited a “decrease-increase-stabilization” pattern; 5 cm juveniles stabilized at 6 h at all salinities, whereas 10 cm juveniles required 48 h to stabilize at a salinity of 1, with isosmotic points of 10.91 and 11.00, respectively. Gill and kidney NKA activity followed an “increase-decrease-stabilization” pattern, with 5 cm juveniles achieving stability 12–24 h earlier than 10 cm individuals under low salinities (1, 3, 5). In conclusion, 5 cm L. japonicus juveniles exhibited superior low-salinity tolerance, accelerated osmoregulatory responses, and enhanced adaptation compared to 10 cm juveniles. These findings strongly support the prioritizing of smaller-sized L. japonicus for low-salinity aquaculture practices. Full article

This study addressed the optimal magnesium (Mg) requirement for juvenile largemouth bass (Micropterus salmoides) and assessed the effects of dietary Mg supplementation on growth performance, nutrient metabolism, and alleviation of heat stress in it. In this study, six diets with varying Mg levels (1.01, 1.26, 1.78, 2.24, 2.35, and 2.51 g/kg), designated as MG1, MG2, MG3, MG4, MG5, and MG6, respectively, were formulated using MgSO₄·7H₂O as the Mg source. These diets were fed to juvenile M. salmoides (initial body weight 2.27 ± 0.02 g) for 8 weeks. The growth performance of the MG4 group was significantly improved. In addition, Plasma GLU, LDL-C, and TG levels were significantly reduced in the MG4 group, while plasma HDL-C levels were increased. In terms of gene expression, glut2, g6pdh, ppar-γ, fas, elovl2, acc, and igf-1 were significantly upregulated in the MG4 and MG5 groups, while g6pase and ppar-α were significantly downregulated in the MG5 group. In the heat stress test, MG4 group exhibited enhanced antioxidant capacity, as evidenced by decreased plasma MDA levels and increased CAT activity, coupled with enhanced gill Na⁺/K⁺-ATPase activity. Gene expression results also showed that il-10 and bcl-2 were significantly upregulated in the MG4 group, while nf-κb, ifn-γ, il-8, tnf-α, casp3, casp8, bax, jnk2 and ask1 were significantly downregulated. Furthermore, the results of TUNEL immunofluorescence labeling analysis showed that the apoptotic index was significantly decreased in the MG2-MG6 groups. Overall, appropriate dietary Mg levels promoted growth performance, improved glucose metabolism, and induced lipid deposition in juvenile M. salmoides. Notably, Mg reduced oxidative damage by enhancing antioxidant enzyme activity, thereby modulating heat stress-induced Antioxidant–Inflammatory–Apoptotic of juvenile M. salmoides. Based on quadratic regression analysis of SGR and FCR, the optimal Mg requirement for juvenile M. salmoides was 2.04, and 2.15 g/kg, respectively. Full article

Panulirus ornatus, the ornate spiny lobster, is a stenohaline weak hyper-osmoregulator, yet its osmoregulatory response to salinity stress remains poorly understood. This study investigated six osmoregulatory genes—Na⁺/K⁺-ATPase (nka), V-type H⁺-ATPase (vhe), Na⁺/HCO₃⁻ exchanger (nbc), Na⁺/K⁺/2Cl⁻ co-transporter (nkcc), Na⁺/H⁺ exchanger (nhe), and carbonic anhydrase (ca)—in juvenile gills exposed to 25 ppt, 34 ppt (control), and 40 ppt salinities during acute (48 h) and chronic (>38 d) phases. Transcriptome analysis revealed that all genes were unresponsive following either 25 ppt or 40 ppt salinity acute exposure. However, nkcc showed a tendency toward for upregulation under 25 ppt salinity during acute exposure. Additionally, glutathione S-transferase and putative ferrous reductase 1 were upregulated under 25 ppt salinity, suggesting increased metabolic demand. In contrast, glutathione peroxidase and an ammonia transporter were upregulated in 40 ppt salinity, indicating protein catabolism. Quantitative PCR confirmed nkcc- and nka upregulation under chronic 25 ppt salinity. Vhe, nbc, nhe and ca showed no response, and 40 ppt salinity did not affect the six target genes. These findings suggest P. ornatus relies on nkcc- and nka-mediated ion transport and lacks mechanisms to tolerate high salinity, resulting in reduced growth and survival. These findings define optimal salinity range for aquaculture (25–34 ppt), highlighting the need to avoid high-salinity stress in lobster water quality management Full article

Bufadienolides exert broad-spectrum pharmacological activities relevant to cardiology and novel cancer treatments. Their efficacy, toxicity, and pharmacokinetic profiles are significantly affected by modifications at carbon-3 (C3) of the steroid core. We have applied molecular dynamics simulations to characterize the consequences of (i) variations in size of the substituent at C3, (ii) the type of linker at C3 (ether vs. N-methoxy), and (iii) stereochemistry (C3β vs. C3α) for derivatives’ interactions with Na⁺,K⁺-ATPase. The model compounds included bufalin, bufalin-N-glucose, bufalin-O-glucose as well as digoxigenin, digoxigenin monodigitoxoside and digoxin. It was shown that the optimal size of the substituent is a trade-off between the ability to form stabilizing interactions and steric and entropic interferences. The former is strongly affected by the nature of the linker due to its impact on the spatial position of the ligand: N-methoxy linker imposes rotational restrictions and places the core into a less favorable position compared to an ether bond. Similarly, the change from β- to α-anomer delocalizes the substituent precluding contacts with amino acid residues of the binding site. The presented mechanistic model of bufadienolide interactions with Na⁺,K⁺-ATPase helps to anticipate the consequences of modifications while designing derivatives with high anticancer activity but reduced cardiotoxicity. Full article

The RTgill-W1 cell line serves as an alternative for acute fish toxicity testing. This study aims to study the reliability of the RTgill-W1 cell line in copper cytotoxicity using transcriptomic analysis followed by comparison with existing literature. As a result, the study found that the average EC50 (375 μg/L ± 181 μg/L) in cell viability was similar to previous literature results (0.093–530 μg/L), suggesting the system’s reliability as an alternative. The transcriptome changes of the RTgill-W1 cell line caused by copper exposure are supported by the existing literature on individual fish. For example, osmoregulatory disturbances, regulation of Na⁺/K⁺-ATPase activity, oxidative stress, apoptosis, energy metabolism alterations, metal detoxification, and chaperone protein expression were found in the RTgill-W1 cell line in response to copper exposure, indicating the utility of this cell line for transcriptome analysis. Finally, through RT-PCR confirmation and literature analysis, this study suggests that sirtuin 1, sirtuin 4, Na⁺/K⁺-ATPase, aifm4, bcl2, carbonic anhydrase, hsp70, hsp30, and other biomarkers could be used for detecting copper stress in aquatic organisms. This study is helpful for understanding the toxicity mechanism of copper and can be referred to as scientific data for regulating copper release into the aquatic environment. Full article

Mancozeb is a broad-spectrum fungicide used extensively in agriculture to protect crops against a wide range of plant diseases. Although its capacity to induce oxidative stress is well documented, the cytotoxic effects of mancozeb on red blood cells (RBCs) remain poorly characterized. The present study aimed to investigate the cytotoxic effects of mancozeb on isolated RBCs, with particular focus on oxidative stress-induced cellular and molecular alterations. Human RBCs were exposed to mancozeb (0.5–100 µM) for 24 h. No hemolytic activity was observed across the tested concentrations. However, 10 and 100 µM mancozeb induced a significant increase in intracellular reactive oxygen species (ROS), leading to lipid and protein oxidation and impaired Na⁺/K⁺-ATPase and anion exchanger 1 (AE1) function. These changes resulted in altered RBC morphology, reduced deformability, and increased methemoglobin levels. Alterations in glycophorin A distribution, anion exchanger 1 (AE1) clustering and phosphorylation, and α/β-spectrin and band 4.1 re-arrangement indicated disrupted membrane–cytoskeleton interactions. A release of extracellular vesicles (EVs) positive for glycophorin A and annexin-V was also observed, consistent with plasma membrane remodeling. Despite increased intracellular calcium, eryptosis remained minimal, possibly due to activation of protective estrogen receptor (ER)-mediated pathways involving ERK1/2 and AKT signaling. Activation of the cellular antioxidant system and the glutathione redox system (GSH/GSSG) occurred, with catalase (CAT) playing a predominant role, while superoxide dismutase (SOD) activity remained largely unchanged. These findings offer mechanistic insights regarding the potential health impact of oxidative stress induced by pesticide exposure. Full article