Search Results (205)

M8OI is a cytotoxic methylimidazolium ionic liquid solvent through its binding to the ubiquinone binding site on complex I of the mitochondrial electron transport chain. Given the overlap in terms of toxic mechanism of action with the pesticide rotenone, the potential neurotoxic effects of M8OI were examined. In vitro, cytotoxicity and mitochondrial function were assessed in SH-SY5Y cells by measuring MTT reduction and oxygen consumption/extracellular acidification using a Seahorse analyser. SH-SY5Y cells were sensitised to M8OI toxicity by replacing medium glucose with galactose. Glucose protected the cells from M8OI toxicity, whereas galactose showed no clear dose–response protection. M8OI induced a dose-dependent reduction in oxygen consumption rate with a compensatory increase in extracellular acidification rate, consistent with inhibition of mitochondrial oxidative phosphorylation and a shift toward glycolysis. In vivo, rats were orally exposed via drinking water for 20 weeks and assessed using behavioural tests. In addition, the concentrations of M8OI and its metabolites were quantified by LC–MS in rat brain and other tissues. In rats, M8OI concentrations were ~30-fold higher in kidney than brain, and brain levels were at least 100-fold lower than the concentrations that affected SH-SY5Y cell viability in vitro. However, based on open field tests, M8OI exposure suppressed motor activity without any anxious behaviours. The cytotoxicity of M8OI in SH-SY5Y neuroblastoma cells was associated with metabolic mitochondrial dysfunction. However, the neurobehavioural changes observed in orally exposed rats occurred at significantly lower brain concentrations than would be predicted to lead to neural cell death. Nevertheless, direct comparisons between acute in vitro exposures and chronic in vivo outcomes should be interpreted cautiously. Full article

The proton-activated chloride channel PAC/TMEM206 is broadly expressed in mammalian tissues and contributes to acid-induced cell injury in pathological settings such as ischemia, inflammation, and tumor acidosis. In addition to its established proton sensitivity, PAC is strongly modulated by temperature: heating potentiates proton-evoked currents and shifts activation toward less acidic pH yet does not open the channel at neutral pH. How proton and thermal inputs are structurally integrated remains unclear. Here, we combined site-specific incorporation of the environmentally sensitive fluorescent amino acid ANAP with automated patch-clamp electrophysiology and molecular dynamics simulations to identify structural elements underlying PAC thermal modulation. ANAP reporters introduced across the extracellular domain and vestibule–pore coupling region revealed residue-specific thermal- and proton-dependent spectral shifts, showing that heating and acidification remodel overlapping but non-identical local environments. The strongest ANAP-reported temperature-dependent changes were observed at R93, Y111, F196, R237, and F282, whereas proton-dependent changes prominently involved R93, Y111, H130, and R237. Several temperature-sensitive ANAP reporters mapped to an intersubunit region also highlighted by dynamic correlation analysis. Together, our results identify structural correlates of PAC thermal modulation consistent with a model in which protonation creates an activation-permissive landscape while heating reweights coupling across an intersubunit scaffold; this model generates testable predictions that should be addressed by targeted mutagenesis and thermodynamic characterization. Full article

Albic soils are a typical problematic soil type distributed worldwide. These soils are characterized by a thin humus layer, low organic matter content, nutrient insufficiency, and weak microbial activity. Therefore, microbial-based approaches hold great potential for the amelioration of Albic soils. This review synthesizes microbial characteristics, influencing factors, amelioration mechanisms, and related technical efficacy of Albic soils. Microbial communities of Albic soils exhibit distinct regional characteristics, with Acidobacteriota and Proteobacteria dominating the bacterial community. Reasonable agricultural management practices—including deep plowing and subsoil mixing, combined organic fertilization and straw return—can increase microbial biomass by 62–248% and enhance enzyme activities by 12–303%, ultimately increasing crop yield by 1.5–13%. Such practices drive fertility enhancement and ecological functional improvement in Albic soils. Inoculation with functional microbes (e.g., Arbuscular Mycorrhizal Fungi, Trichoderma) alleviates Albic soil acidification by 1.1–3.8%, activates recalcitrant nutrients, and accelerates Soil Organic Matter (SOM) decomposition. Through extracellular polymeric substance secretion, such inoculation promotes aggregate formation, improving soil permeability and structural stability. However, challenges remain for current research, including difficult microbial agent colonization, unstable amelioration effects, and a lack of long-term field studies. Future research should utilize bio-omics technologies, artificial intelligence, and big data technologies to analyze microbial functions and regulate soil quality for cultivated land improvement and sustainable agriculture development. Full article

Macrophage migration inhibitory factor (MIF) has been shown to induce M1 macrophage polarization with oxidative stress and associated metabolic reprogramming. Several tautomerase inhibitors were shown to selectively inhibit either MIF’s ketonase or enolase sub-activities. In this study, we aimed to investigate the role of enolase sub-activity in M1 polarization using the selective enolase inhibitor TE-91. We performed in silico molecular docking analysis and physicochemical characterization of TE-91. LPS + IFN-γ-induced RAW264.7 cells were applied as a model for M1 macrophage activation. We performed ROS and nitrite determinations, ELISA, qPCR, and immunoblot analysis, and measured mitochondrial oxygen consumption rate and extracellular acidification rate. Here, we reveal that TE-91 might directly bind to the MIF tautomerase active site. Furthermore, TE-91 reduces M1 activation by enhancing oxidative phosphorylation and reducing the glycolytic activity in LPS + IFN-γ-induced macrophage cells. In the same model, TE-91 reduces TNF-α, IL-6, CCL2, and iNOS mRNA transcription yet fails to modulate PARP1 and SOD2 mRNA transcription. It also decreases ROS, nitrite, and IL-6 production without influencing TNF-α and CCL2 protein production. TE-91 was unable to reduce either HIF-1α mRNA transcription or its protein expression. Finally, TE-91 reduced IL-1β cleavage, without affecting IL-1β protein expression. These results may highlight the importance of tautomerase sub-activities in M1 polarization. Full article

Vasculogenic mimicry (VM) is the ability of cancer stem cells (CSCs) to express an endothelial-like phenotype and participate in tumor neovascularization via the formation of a blood-conducting, matrix-rich network. We previously reported that pancreatic ductal adenocarcinoma (PDAC) CSCs develop their VM phenotype via two interacting and coordinated factors that support the formation of the VM network: (i) the overexpression of genes for endothelial factors and vascular receptors and (ii) the very high secretion of numerous pro-angiogenic/growth factors. While microenvironmental acidosis (low pHe) is an important driver of tumor metastasis, especially in PDAC, and is a component of the CSC niche, its role in VM and the ion transporters involved remains unknown. As normal stem cell differentiation is regulated by Na⁺/H⁺ exchanger 1 (NHE1)-driven pH, we investigated the role of NHE1 and the intracellular signaling involved in the acidosis-induced VM using a platform of 3D organotypic cultures composed of Matrigel with increasing concentrations of Collagen I. VM was highest on 90% Matrigel:10% Collagen I, representative of an early tumor ECM, and it decreased with increasing concentrations of Collagen I, representative of advanced tumors. In all ECM compositions, VM capacity increased stepwise with pHe acidification, and both basal and acid-stimulated VM were dependent on NHE1 activity. Acidification also decreased resting pHi and increased NHE1 proton extrusion activity, NHE1/ß1 integrin co-expression, and intracellular Ca²⁺. The stimulation of VM by extracellular acidosis depended on the transport of extracellular Ca²⁺ into the cell and the consequent increase in intracellular Ca²⁺. Altogether, these data demonstrate that extracellular acidification triggers cellular mechanisms that upregulate VM to overcome the constraints imposed by ECM composition, thereby permitting VM in ECMs where this phenotype is not expressed and extending the VM phenotype towards the tumor center to further drive metastasis. Full article

Metabolic heterogeneity within the cell microenvironment is a key driver of cancer progression and resistance to therapy. However, current approaches lack the spatial and temporal resolution required to capture its dynamics in living systems. While recent advances in 3D cell culture models and metabolomic profiling have improved our understanding of the tumor niche, their integration with real-time optical sensing remains underdeveloped. Here, we present an integrated platform combining a 3D-printed microreactor culture chamber with Raman spectroscopy to enable non-invasive, spatially resolved metabolic monitoring of living cell cultures. Our microreactor platform generates controlled oxygen and nutrient cues while simultaneously acquiring label-free Raman spectra, revealing extracellular metabolic fingerprints linked to cell catabolism (e.g., glucose and lactate shifts) and acidification. Analysis across four cell lines uncovered temporal evolution as the dominant source of metabolic variance, while spatial heterogeneity along oxygen gradients is a secondary factor. In particular, diffusion-limited regions exhibited localized acidification and accumulation of stress biomarkers—such as the release of nucleotides—features that cannot be detected using conventional bulk assays. By providing a versatile platform for real-time mapping, this work enables the mechanistic dissection of cell adaptation to microenvironmental stress and supports the prediction of metabolic signatures underlying drug response and treatment outcomes. Full article

Background: Carbonic Anhydrases (CAs) represent regulators of cell adaptation to hypoxia, pH regulation, and metabolic fitness. Among cancers, multiple myeloma (MM) is a plasma cell malignancy sustained by hypoxia-driven metabolic adaptation, extracellular acidification, and redox imbalance. Tight regulation of tumor extracellular pH, mediated by Carbonic Anhydrases IX and XII, is crucial for myeloma survival, progression, and stemness, making these isoforms attractive therapeutic targets. Methods: We designed and synthesized a library of terpenoid-based hybrids by derivatizing chlorothymol and 4-isopropyl-3-methylphenol with either the natural coumarin umbelliferon or the 2,2′-dipicolylamine (DPA) scaffold. This chemical strategy aimed to selectively inhibit tumor-associated CAs IX/XII through coumarin- or DPA-mediated recognition, while terpenoid fragments were introduced to enhance lipophilicity, membrane permeability, and potential redox-modulating properties. The compounds were tested by a Stopped-Flow assay for CA inhibition, in cell-based assays for antiproliferative properties and by means of several antioxidant assays. Results: The most active compounds, connecting the coumarin core to a terpenoid tail, inhibited the targeted CAs in the nanomolar range, showing up higher selectivity over off-target isoforms (I and II). In studies performed on MM cell lines, selected derivatives reduced viability (IC₅₀ = 15.8–85.4 µM) and displayed favorable selectivity over normal cells. In silico investigations suggested that the compounds were able to interact selectively with the target enzymes. Conclusions: Collectively, these results support a dual-targeting strategy in which selective inhibition of tumor-associated CAs, combined with redox modulation, interferes with adaptive mechanisms of MM cells, providing a rational framework for the development of multifunctional agents against metabolically resilient hematological malignancies. Full article

Mitochondrial dysfunction is a hallmark of aging and age-related physical decline in people living with HIV (PLWH) who experience accelerated aging. This pilot study investigated the relationships between platelet mitochondrial function, physical performance, and body composition in older, sedentary PLWH compared with older, sedentary HIV-negative controls. Platelets have the potential to act as minimally invasive and easily accessible biomarkers for systemic mitochondrial bioenergetics and may serve as a practical biomarker in aging-related research. We analyzed correlations between mitochondrial parameters, protein levels, and measures of physical performance and body composition in a cohort of predominantly African American men (n = 7 PLWH, n = 7 controls). Body composition was assessed using dual-energy X-ray absorptiometry (DXA), and exercise capacity through VO₂ peak and strength tests. Platelet mitochondrial bioenergetic parameters were measured by oxygen consumption rates (OCR) and extracellular acidification rates (ECAR). Key mitochondrial proteins SIRT3, COXII, DRP1, and OPA1 were evaluated by Western blotting. The PLWH and HIV-negative control groups were similar in age and cardiorespiratory fitness. In PLWH, basal OCR and ATP-linked respiration showed strong positive correlations with VO₂ peak (r = 0.874, p < 0.05 and r = 0.862, p < 0.05, respectively) and negative correlations with BMI (r = −0.856, p < 0.05 and r = −0.849, p < 0.05, respectively). SIRT3 emerged as a potential key player, demonstrating strong positive correlations with basal OCR (r = 0.804, p < 0.05), ATP-linked respiration (r = 0.787, p < 0.05), and VO₂ peak (r = 0.970, p < 0.001), and negative correlations with BMI (r = −0.830, p < 0.05) and fat mass (r = −0.827, p < 0.05) in PLWH. Analyses focused on within-group associations in PLWH because bioenergetic measures were obtained using different Seahorse platforms in PLWH and controls, precluding valid direct quantitative comparisons between groups. Our findings provide evidence for significant associations between platelet mitochondrial bioenergetics, specific mitochondrial proteins (particularly SIRT3), and key physical attributes in older, sedentary PLWH. These preliminary findings suggest that platelets may serve as minimally invasive biomarkers of systemic mitochondrial health, contribute to our understanding of mitochondrial function in HIV-associated accelerated aging, and inform future interventions to enhance mitochondrial function and improve health outcomes in this vulnerable population. However, results should be interpreted cautiously given the small sample size and exploratory design and should be considered hypothesis-generating rather than definitive. Larger, demographically more diverse studies that include HIV-negative controls are needed to validate these associations and determine their clinical relevance. Full article

The tumor microenvironment, including extracellular pH (pHe), has emerged as a key regulator of tumor cellular function. Although extracellular acidification sensing and function are well established, the effect of extracellular alkalinization on cellular functioning remains unclear. Here, we report that transient receptor potential ankyrin 1 (TRPA1) functions as an alkaline sensor and mediator of cell death in melanoma cells. Exposure to alkaline pHe (8.1) or allyl isothiocyanate (AITC), a TRPA1 agonist, significantly reduced melanoma cell viability. We found that cell death was propidium iodide-positive and annexin V-negative, suggesting that pHe or AITC treatment induced necrosis rather than apoptosis. TRPA1 activation induced sustained Ca²⁺ influx, which was suppressed by either extracellular Ca²⁺ removal or treatment with the TRPA1 inhibitor, HC-030031, both of which attenuated cell death. Pharmacological screening has identified phosphatidylcholine-specific phospholipase D1 (PLD1) as a positive regulator of cell death. We confirmed that transfection with PLD1 siRNA significantly reduced AITC-induced cell death, whereas PLD2, PLD3, and NAPE-PLD siRNAs had no effect. These observations suggest that the vulnerability of melanoma cells to alkaline pHe is mediated by activation of the TRPA1-PLD1 axis. Thus, TRPA1 and PLD1 are potential targets for therapeutic intervention in melanoma. Full article

Head and neck squamous cell carcinoma (HNSCC) develops within a chronically inflamed and metabolically constrained tumor microenvironment that profoundly shapes innate immune function. Tumor-associated macrophages (TAMs) are abundant in HNSCC and display marked plasticity, yet predominantly acquire immunosuppressive states that promote tumor progression and therapeutic resistance. Traditional M1/M2 polarization models fail to capture this dynamic behavior. Emerging evidence instead identifies metabolic reprogramming as a central regulator of macrophage function in cancer. Hypoxia, nutrient limitation, extracellular acidification, and tumor-derived metabolites such as lactate and lipids rewire macrophage metabolism, directly influencing inflammatory signaling and immune suppression. This review integrates recent advances in immunometabolism to examine how metabolic adaptations govern macrophage innate functions in HNSCC and highlights therapeutic opportunities targeting macrophage metabolism to overcome immune resistance. Full article

Alzheimer’s disease (AD) is the most prevalent cause of dementia and can be conceptualized as a tauopathy initiated by the accumulation of amyloid-β (Aβ) in the brain. The clinical introduction of anti-Aβ antibody therapies has marked the beginning of a new era in disease-modifying treatment for dementia. While the deleterious effects of Aβ on postsynaptic spines and axonal microtubules have been increasingly clarified, recent studies have shifted attention beyond extracellular Aβ deposition as senile plaques to the pathogenic significance of intracellular Aβ. In particular, accumulating evidence highlights lysosomes as critical sites of intracellular Aβ toxicity. Interactions between Aβ and gangliosides, v-ATPase-dependent lysosomal acidification, and lysosomal membrane integrity are the key determinants of disease progression. In parallel, additional molecular players, including components of the complement cascade and asparaginyl endopeptidase, have been implicated in linking Aβ pathology to tau dysregulation and neurodegeneration. As therapeutic strategies targeting Aβ enter clinical practice, these emerging pathways represent promising targets for the next generation of AD treatment. Here, we summarize current insights and ongoing therapeutic developments centered on these mechanisms. Full article

Cholangiocarcinoma (CCA) is a rare malignancy of the biliary tree with increasing global incidence and mortality and limited therapeutic options. Intrahepatic cholangiocarcinoma (iCCA) metabolism exhibits enhanced glycolysis, oxidative phosphorylation, and glutamine utilization. In this study, we investigated the therapeutic potential of targeting glutaminolysis in iCCA, identifying glutamate dehydrogenase (GDH)—which converts glutamate to α-ketoglutarate—as a key metabolic hub. We evaluated the effects of pomegranate waste extract (PWE), a by-product of industrial pomegranate juice production, on cell viability, proliferation, migration, ATP production, and extracellular acidification in CCLP1 cells, an established iCCA model. Our results are consistent with an altered cellular energy metabolism. We further assessed GDH enzymatic activity, expression, and transcriptional regulation in the presence or absence of PWE and its major components, punicalagin and ellagic acid. GDH expression was downregulated by PWE in a dose-dependent manner through inhibition of NF-κB signaling, revealing a new mechanistic link between NF-κB and GDH. In addition, GDH enzymatic activity was dose-dependently inhibited by PWE, as well as punicalagin and ellagic acid. Notably, punicalagin was identified as a novel competitive inhibitor of GDH. Overall, these findings provide the first evidence that modulation of glutaminolysis through GDH targeting impairs iCCA cell growth and metabolism, supporting GDH as a promising metabolic target. This study highlights pomegranate-derived compounds as potential leads for the development of adjunctive or preventive strategies in intrahepatic cholangiocarcinoma. Full article

Fungal transformation is increasingly recognized as an important process influencing metal solubilization and immobilization in soil environments. In this study, a fungal strain (PTW4) isolated from mining-contaminated soil was molecularly identified as Aspergillus aculeatus. The strain was evaluated for its ability to solubilize and transform several heavy metal oxides, including ZnO, Pb₃O₄, Cu₂O, and MoO₃. PTW4 produced consistent halo formation across all tested oxides, accompanied by progressive acidification of the culture medium, suggesting organic acid-mediated solubilization. Characterization of extracellular precipitates by SEM-EDS and XRD indicated mineral phases consistent with oxalate-associated biominerals, including zinc oxalate dihydrate (ZnC₂O₄·2H₂O), lead oxalate (PbC₂O₄), and copper oxalate hydrate (CuC₂O₄·xH₂O). These minerals represent low-solubility phases that may reduce metal mobility in the surrounding environment. In contrast, molybdenum did not precipitate under the experimental conditions, suggesting metal-specific constraints in fungal biomineralization processes. Although organic acid production was not directly quantified, identification of oxalate mineral phases supports an oxalate-associated mineralization mechanism. Overall, the results provide evidence for heavy metal solubilization and selective extracellular precipitation consistent with oxalate biomineral formation by A. aculeatus PTW4, highlighting its potential relevance to fungal-mediated bioremediation and selective bioleaching processes. Full article

This study compared the bioenergetic profiles of immature and in vitro–matured bovine cumulus–oocyte complexes (COCs) using Seahorse extracellular flux technology, with the aim of establishing standardized conditions for real-time metabolic assessment during in vitro maturation (IVM). Groups of five COCs were analysed prior to maturation and after 22 h of IVM using the Seahorse XFp Analyzer to measure oxygen consumption rate (OCR, pmoL/min) and extracellular acidification rate (ECAR, mpH/min), providing dynamic readouts of oxidative phosphorylation and glycolysis that extend beyond conventional endpoint assays. To optimize assay performance, three media were first evaluated: TCM199, DMEM/F12, and HEPES-buffered synthetic oviductal fluid (HSOF). HSOF yielded the most reliable readings for immature COCs, whereas TCM199 provided superior conditions for mature COCs. Adhesion strategies were then tested by comparing uncoated wells with wells coated with fibronectin, concanavalin A, or Matrigel^®. Sequential injections of oligomycin and rotenone plus antimycin A enabled partitioning of mitochondrial and glycolytic contributions to ATP production. COC maturation was associated with a clear metabolic shift from glycolysis toward oxidative metabolism. Immature COCs displayed a predominantly glycolytic phenotype, while mature COCs showed increased active mitochondrial ATP production. Adhesion conditions markedly affected the detected metabolic profile: concanavalin A and fibronectin supported effective attachment and were associated with robust energy metabolism, whereas Matrigel^® and poor adhesion were linked to quiescent profiles with low OCR and ECAR signals. Together, these data define practical assay parameters for extracellular flux analysis of COCs and highlight the increasing reliance on mitochondrial function as a hallmark of oocyte maturation, supporting improved metabolic phenotyping for IVM optimization. Full article

Microalgal amendments can improve soil structure by regulating extracellular polymeric substances (EPSs). However, the mechanisms underlying this process in red soils (characterized by high clay content and susceptibility to acidification) under different farming practices remain unclear. This study examined how Chlorella vulgaris (C. vulgaris) amendment influences EPS composition to enhance soil aggregate stability under arable land and rice paddy farming. A five-month pot experiment using a completely randomized design was conducted to investigate the effects of Chlorella vulgaris amendment on soils cultivated with Pennisetum × sinese and rice, two economically important crops commonly grown in South China. At the end of the experiment, Chlorella vulgaris amendment substantially increased both the mean weight diameter (MWD) and geometric mean diameter (GMD) of soil aggregates under both farming systems. Excitation–emission matrix (EEM) fluorescence spectroscopy revealed distinct changes in soil EPS components between the two farming types. Under arable land farming, humic-like and protein-like EPSs were dominant in Chlorella vulgaris-amended treatments, with fluorescence intensities more than doubling compared to the control. Conversely, under rice paddy farming, soil fulvic acid was the main component and showed a moderate increase. Partial least squares path modeling (PLS-PM) demonstrated that protein-like and humic-like EPSs had the strongest direct effects on aggregate stability in arable land red soil, while fulvic acid was the key factor in rice paddy red soil. The present study demonstrates that Chlorella vulgaris amendment improves aggregate stability in red soils through farming-specific, EPS-mediated pathways, providing a quantitative framework for researchers and land managers seeking to apply microalgal amendments for red soil enhancement and sustainable land management. Full article