Search Results (1,308)

Garrya flavescens S. Wats. (GF) has been traditionally used to treat gastrointestinal spasms, yet its bioactivity within the central nervous system remains unexplored. This study aimed to characterize the bioactive constituents of GF and evaluate its anti-inflammatory and metabolic regulatory effects in lipopolysaccharide-activated microglia. Phytochemical profiling using LC-HRMS and HPLC identified rutin as a primary bioactive component, present at an exceptionally high concentration (9309 μg/g). In BV-2 microglial and RAW 264.7 cells, GF treatment significantly suppressed the expression of pro-inflammatory cytokines and mediators in a dose-dependent manner. Mechanistic studies revealed that GF specifically modulated the ERK signaling pathway. Furthermore, Seahorse XF analysis demonstrated that GF restored mitochondrial homeostasis by reducing basal respiration and proton leak while significantly enhancing spare respiratory capacity. Finally, conditioned medium from GF-treated microglia improved the viability of N2A neuronal cells. These findings highlight GF as a potent botanical source with significant neuroprotective potential, offering a promising candidate for functional food or nutraceutical applications targeting neuroinflammatory disorders. Full article

Cytochrome c (Cytc) tyrosine 48 (Y48) has been previously shown to be phosphorylated in bovine liver, and phosphomimetic substitution (Y48E) inhibits key functions of Cytc in vitro, including respiration and apoptosis. In this study, we investigated the effect of Y48 modification in a double-knockout cell culture model that stably expressed either unphosphorylated wild-type (WT) Cytc, control Y48F Cytc, or phosphomimetic Y48E Cytc. Our findings revealed that Y48E Cytc caused partial inhibition of mitochondrial respiration in intact cells, which corresponded with lower mitochondrial membrane potentials (ΔΨ_m) and reduced reactive oxygen species (ROS) production. When subjected to an oxygen–glucose deprivation/reoxygenation (OGD/R) model, which simulates ischemia/reperfusion injury, the Y48E phosphomimetic cell line showed lower ROS production compared to the unphosphorylated WT and Y48F Cytc cell lines, the latter of which generated higher levels of ROS upon reoxygenation. As a result, the Y48E Cytc cell line had significantly lower cell death rates when exposed to OGD/R, confirming the cytoprotective role of Y48 phosphorylation of Cytc. In summary, our research indicates that the loss of Y48 phosphorylation in Cytc during ischemia leads to reperfusion injury by driving maximum electron transport chain flow, hyperpolarization of ΔΨ_m, bursts of ROS, and death of cells through apoptosis. Full article

Cutaneous melanoma is the most lethal form of skin cancer because of its aggressiveness, rapid metastasis, and high therapeutic resistance. The 2018 World Health Organization (WHO) classification emphasized that melanoma comprises distinct subtypes defined by cumulative sun damage, site of origin, and molecular characteristics, which explain differences in mutational burden, immunogenicity, and treatment response. Immunotherapy with anti-PD-1 therapy such as nivolumab and pembrolizumab changed the therapeutic landscape by restoring CD8+ T-cell activity and improving survival. Still, many patients show primary or acquired resistance influenced by low PD-L1 expression, loss of antigen presentation, tumor metabolic plasticity, and an immunosuppressive microenvironment. Mitochondria are central to this process. They regulate ATP generation through oxidative phosphorylation (OXPHOS), redox control, apoptosis, and the metabolic programming needed for T-cell activation. In the tumor microenvironment (TME), hypoxia, nutrient restriction, and PD-1 signaling reduce mitochondrial biogenesis, increase fission and reactive oxygen species (ROS) accumulation, and lead to exhaustion and impaired effector function. Moreover, tumor cells outcompete immune cells for key nutrients such as glucose and glutamine, while increased lactate production and extracellular acidosis further suppress mitochondrial respiration in T cells. Strategies to overcome resistance include restoring oxidative metabolism, activating PGC-1α, supplying metabolic substrates, and combining checkpoint blockade with inhibitors of glycolysis or glutaminolysis to enhance the immune response. Full article

Neuroblastoma remains a formidable pediatric malignancy characterized by profound metabolic plasticity and limited therapeutic responsiveness in high-risk disease. Emerging evidence positions the interplay between Reactive Oxygen Species (ROS) and the metabolic sentinel AMP-activated protein kinase (AMPK) as a critical regulator of tumor metabolic stress and apoptotic susceptibility, with additional implications in the systemic pathology of Cancer Cachexia. Building on our previous work demonstrating that 1,1-Diethoxyethane (1,1-DEE; Biosacetalin), a volatile aroma compound inhibits mitochondrial complex I, induces ROS production, and activates AMPK-PGC1α-mediated mitochondrial biogenesis accompanying enhancement of aerobic respiration, leading to anti-Warburg effect. We identify 1,1-DEE as a previously unrecognized metabolic modulator with potent antitumor activity. 1,1-DEE triggers ROS-induced AMPK activation, leading to apoptotic elimination of neuroblastoma cells (SH-SY5Y), robust suppression of tumor growth, and significant prolongation of survival (median survival 77 days) in tumor-bearing NSG mice. Strikingly, 1,1-DEE simultaneously alleviates cancer-associated cachexia by preserving body weight. Mechanistically, our findings reveal a ROS–AMPK–centered signaling axis through which 1,1-DEE integrates tumor-selective cytotoxicity with systemic metabolic protection, highlighting a unified therapeutic strategy for targeting both tumor progression and cachexia in neuroblastoma. Full article

Copper is a crucial cofactor that sustains multiple cellular electron-transfer reactions, making it an essential element for life. However, cytotoxic levels of copper can cause structural damage and cell death through the production of reactive oxygen species (ROS) and nonspecific attacks on proteins. Moreover, immune cells, including neutrophils and macrophages, accumulate copper to induce oxidative bursts that kill engulfed pathogens. Therefore, a well-regulated copper homeostasis system is required for the human commensal fungus Candida albicans to thrive in extreme host environments. Remarkably, C. albicans exhibits higher copper tolerance than the nonpathogenic model yeast Saccharomyces cerevisiae, suggesting the presence of a specific copper tolerance mechanism that supports its adaptability to copper stress. Ndt80 is a versatile transcription factor that regulates several biological processes in C. albicans, ranging from morphological control to drug resistance. This study further reveals that Ndt80 may contribute to copper tolerance by regulating copper transporters and copper-dependent superoxide dismutases (Sods). Additionally, RNA sequencing and complementary approaches uncovered the involvement of Ndt80 in plasma membrane integrity and mitochondrial respiration under copper stress, further linking Ndt80 to copper tolerance. Together, these results broaden our understanding of Ndt80 functions and provide new insights into copper tolerance in C. albicans. Full article

(1) Background: Mild traumatic brain injury (mTBI), the most prevalent form of traumatic brain injury, often results from repetitive impacts to the head and is associated with long-term neurological impairment. The pathophysiology of mTBI is multifactorial and involves alterations in mitochondrial bioenergetics, a key determinant of neuronal function and survival. Although mitochondrial dysfunction is recognized as a hallmark of mTBI, its long-term effects on bioenergetics and the roles of regulatory cytosolic and mitochondrial proteins remain poorly understood. We hypothesized that repeated mTBI (rmTBI) induces sustained deficits in mitochondrial bioenergetics that are associated with long-term changes in key bioenergetic and other regulatory proteins. (2) Methods: Using the repeated CHIMERA injury model in adult male rats, randomly assigned to sham or rmTBI groups, we assessed mitochondrial respiration in isolated mitochondria and whole cerebral cortex homogenates using a Clark O₂ electrode and an Oroboros O₂k respirometer at time points ranging from 1 day to 2 months post-injury. Western blotting was performed for expression of regulatory proteins HKI, DRP1, MFN2, VDAC1, and ANT2. (3) Results: At 2 months post-rmTBI, respiration was faster and uncoupled, while ATP synthesis was significantly slowed compared with sham rats. This was accompanied by decreased expression of mitochondrial MFN2 and ANT2, by increased mitochondrial expression of DRP1, and by decreased translocation of HKI to mitochondria. There was no significant difference in VDAC1 expression. Earlier time points showed no significant differences in bioenergetics or protein expression, but neuro-inflammatory markers (GFAP and Iba1) were significantly elevated at these earlier time points of post-injury. (4) Conclusions: These findings indicate that rmTBI leads to a delayed long-term impairment of mitochondrial bioenergetics associated with alterations in proteins critical for bioenergetic regulation and mitochondrial control. This suggests a pathophysiologic mechanism for the persistent cognitive and behavioral deficits observed following rmTBI. Full article

Oxidative stress occurs when there is an excess of reactive oxygen species (ROS) in the cell, primarily produced by mitochondria. Excess ROS trigger membrane lipid peroxidation (LPO), cause mitochondrial swelling, and release proapoptotic proteins into the cytoplasm, which can lead to apoptosis. It is assumed that antioxidants that reduce excessive ROS formation by mitochondria can increase the body’s resistance to stress factors. We investigated the effects of hypoxia and the antioxidant Ambiol (2-methyl-4-dimethylaminomethylbenzimidazole-5-ol dihydrochloride) on the functional characteristics of mitochondria, which were assessed by measuring lipid peroxidation intensity using spectrofluorimetry, mitochondrial membranes fatty acid composition using chromatography, mitochondrial morphology using atomic force microscopy, and respiration rate using polarography. Injecting mice with Ambiol at a dose of 10⁻⁶ mol/kg for 5 days prevented the stress-induced activation of lipid peroxidation, a decrease in the unsaturation index of C₁₈ and C₂₀ fatty acids in mitochondrial membranes, and swelling of these organelles. The drug also increased the efficiency of oxidative phosphorylation during the oxidation of NAD-dependent substrates. Furthermore, Ambiol increased the lifespan of mice by 3.0–4.0 times under various types of hypoxia. Ambiol’s ability to maintain initial (control) levels of C₁₈ and C₂₀ unsaturated fatty acids appears to protect against stress-induced mitochondrial dysfunction. Full article

A549 cells are widely used as an in vitro model of alveolar type II (ATII) epithelial cells; however, their phenotype and metabolic state are highly sensitive to culture conditions, cell density, and the duration of static, non-passaged cultivation. Here, we examined how prolonged static culture affects lipid metabolism, mitochondrial bioenergetics, and viability in A549 cells. A549 cultures were maintained without passaging for up to 25 days in DMEM or Ham’s F-12 and analyzed using lipid secretion assays, targeted lipidomics, [¹⁴C]-acetate incorporation, Seahorse bioenergetic profiling, and transcriptional analysis of stress-associated markers. Several surfactant-associated readouts were highest during early culture, peaking on day 7, as evidenced by elevated expression of ABCA3 and SP-A and maximal secretion of surfactant-associated phospholipids. With prolonged cultivation and increasing culture density, cellular phosphatidylglycerol levels declined progressively and became nearly undetectable by day 25, accompanied by reduced anabolic lipid metabolism, lower oxygen consumption, and impaired glycolytic activity. These changes coincided with increased reactive oxygen species, elevated intracellular Ca²⁺ levels, and increased expression of stress-associated transcripts, including CASP1, IL1B, and C3. Later stages were also associated with reduced mitochondrial respiration and decreased viability. Collectively, our findings show that prolonged static culture is associated with metabolic remodeling and reduced bioenergetic capacity in A549 cells. Full article

Objective: This study aims to investigate the protective effect of Shengmai San (SMS) against high-glucose (HG)-induced injury in neonatal rat ventricular myocytes (NRVMs) and to elucidate the underlying pharmacological molecular mechanisms. We hypothesize that SMS ameliorates HG-induced calcium homeostasis imbalance in NRVMs by improving mitochondrial energy metabolism disorder, and this protective effect is associated with the downregulation of oxidized and phosphorylated CaMKII expression to inhibit CaMKII signaling pathway overactivation. Herein, we verify this hypothesis by assessing mitochondrial function, calcium transients, sarcoplasmic reticulum (SR) calcium handling and CaMKII phosphorylation levels in NRVMs. Methods: First, ultra-high performance liquid chromatography–high resolution mass spectrometry was used to identify the chemical components of SMS to clarify its material basis. Primary NRVMs were then cultured under low-glucose (LG) or HG conditions, with 2% SMS-medicated serum (SMS-MS) as the experimental intervention, and NAC (ROS scavenger) and KN93 (CaMKII inhibitor) as positive controls. Following intervention, we sequentially detected key indicators corresponding to the proposed pathological pathway: intracellular reactive oxygen species (ROS) levels (oxidative stress), mitochondrial ROS, mitochondrial function indices including oxygen consumption rate (OCR) (energy metabolism), calcium transients and diastolic intracellular free calcium concentration (global calcium homeostasis), sarcoplasmic reticulum (SR) calcium leak (calcium handling disorder), and, finally, the phosphorylation, oxidation levels of CaMKII and RyR2 phosphorylation (Ser2814) (p-RyR2) (key regulatory pathway) via Western blot to systematically elucidate the mechanistic link between SMS intervention and HG-induced NRVM injury. Results: Quantitative analysis revealed that high-glucose (HG) induction significantly reduced calcium transient amplitude and prolonged the decay time constant (tau) in NRVMs at 72 h (p < 0.01 vs. LG), with these parameters normalizing by 120 h—an effect indicative of a compensatory adaptive response. The 2%SMS-MS markedly ameliorated HG-induced calcium transient abnormalities at 72 h (p < 0.01 vs. HG). Additionally, 2%SMS-MS significantly enhanced mitochondrial basal oxygen consumption rate, spare respiratory capacity, ATP production, and maximal respiration in HG-exposed NRVMs (p < 0.01 vs. HG). SMS also significantly reduced intracellular reactive oxygen species (ROS) levels (p < 0.01 vs. HG), mitochondrial ROS levels (p < 0.01 vs. HG), diastolic intracellular free calcium concentration (p < 0.01 vs. HG), and SR calcium leak (p < 0.05 vs. HG). Western blot analysis revealed that 2%SMS-MS intervention effectively downregulated the expression of oxidized CaMKII (Ox-CaMKII) (p < 0.01 vs. HG), phosphorylated CaMKII (p-CaMKII) (p < 0.01 vs. HG), and RyR2 phosphorylation (Ser2814) (p < 0.05 vs. HG), which may be the potential mechanism in maintaining calcium homeostasis in HG-induced NRVMs. Conclusions: This study suggests that SMS enhances mitochondrial energy metabolism and exerts a protective effect against high-glucose-induced calcium homeostasis imbalance in NRVMs, which supports our proposed hypothesis. Its potential mechanism indicates that the protective effects of SMS are associated with its ability to downregulate the expression of oxidized and phosphorylated CaMKII. These findings highlight SMS as a potential therapeutic candidate for alleviating HG-related myocardial injury and provide evidence for its application in the prevention of early diabetic cardiomyopathy. Full article

Congenital heart diseases (CHDs) are characterized by profound metabolic remodeling of mitochondrial pathways. However, data regarding mitochondrial respiration, oxidative phosphorylation (OXPHOS), and fatty acid oxidation (FAO) in patients with Ebstein anomaly (EA) are currently unavailable. This study evaluated 14 EA patients and 18 healthy volunteers. In accordance with the 2020 ESC guidelines, patients were stratified into two cohorts: EA-0 (patients currently without an indication for intervention) and EA-1 (patients meeting Class Ia or IIb indications for surgical intervention). Platelet OXPHOS and FAO parameters were determined simultaneously via high-resolution respirometry. CI-linked LEAK respiration (substrates: pyruvate and malate) and FAO-linked LEAK respiration (substrates: octanoylcarnitine and malate) were significantly elevated in EA patients. Furthemore, the EA-1 group showed significantly lower coenzyme Q₁₀ (CoQ₁₀) and γ-tocopherol levels than EA-0. Differences in the measured parameters between groups suggest a state of myocardial adaptation and transient metabolic reprogramming in EA-0 patients, whereas in EA-1 patients, a significant change in mitochondrial metabolism and bioenergetics was found. We hypothesize that increased platelet LEAK mitochondrial respiration and CoQ₁₀ deficiency could be key signals of mitochondrial reprogramming and serve as potential biomarkers for right ventricular dysfunction. The analysis of platelet mitochondrial bioenergetics represents a novel area of translational mitochondrial cardiology, contributing to personalized diagnostics, risk stratification and optimal surgical timing in EA patients. Full article

Background: Hypothermic machine perfusion (HMP) has been associated with reduced delayed graft function compared with static cold storage (SCS). However, the molecular mechanisms underlying these differences during cold preservation remain incompletely understood. This study compared cold-storage-related biochemical and histological changes in kidneys preserved by HMP versus SCS using a Lewis rat model prior to transplantation. Methods: Following isolation, rat kidneys were flushed with cold saline (4 °C). Left kidneys were preserved by HMP at constant flow using Belzer’s machine perfusion solution (MPS) at 4 °C, while right kidneys were stored using SCS in University of Wisconsin solution at 4 °C. After four hours of preservation, kidneys were processed for biochemical and histological analysis. Fresh biopsies were evaluated for mitochondrial complex respiration. Western blotting was performed to assess expression of NDUFS3, a complex I subunit. Histological staining for nitrotyrosine and kidney injury markers was compared across groups. Results: Mitochondrial complex respiration did not differ significantly between the SCS and HMP groups. Western blot analysis demonstrated significantly increased NDUFS3 expression in HMP-preserved kidneys compared with SCS and control kidneys. Histological evaluation revealed elevated tubular staining of nitrotyrosine and kidney injury markers in SCS kidneys relative to controls, whereas HMP preservation markedly attenuated these increases. Conclusions: HMP mitigates cold-storage-induced oxidative stress and reduces expression of kidney injury markers after four hours of preservation. These molecular findings suggest a protective effect of HMP during cold preservation. Future studies with longer preservation times and transplantation models are needed to determine whether these improvements translate into enhanced post-transplant kidney function. Full article

Ubiquitin-specific protease 2 (USP2) is a deubiquitinase that controls various cellular events, including cell cycle progression and tumorigenesis. Along with cell culture models, mouse models induced using chemical blockers and gene engineering have substantially contributed to our knowledge of the crucial roles of USP2 in energy metabolism and metabolic disorders. This review summarizes the evidence of the role of USP2 in regulating energy metabolism in mice and cells under physiological and pathological conditions. In hepatocytes, a short isoform of USP2, USP2b, aggravates type 2 diabetes and metabolic dysfunction-associated steatotic liver disease. Meanwhile, a long isoform of USP2 in adipose tissue macrophages, USP2a, attenuates the onset of diabetes. USP2a mitigates insulin resistance and subsequent muscle atrophy. In ventromedial hypothalamic neurons, USP2b inhibits an increase in blood glucose by repressing hepatic glycogenolysis. In addition to regulating diabetes, USP2 isoforms potentially regulate the progression of atherosclerosis by modulating macrophages and hepatocytes. In brown adipose tissue, USP2a regulates thermogenesis, thus influencing systemic energy control. Meanwhile, in testicular macrophages, USP2 protects the mitochondrial respiration of sperm and consequently contributes to maintaining the quality of frozen sperm for use in the treatment of male infertility. As USP2 is distributed to multiple cellular components, it mediates the polyubiquitination of various molecules. For instance, USP2 modulates the stability of various transcription regulators, including C/EBP-α, PPARγ, EBF2, and PGC1α. The accumulating evidence indicates that USP2 functions as a modulatory molecule for energy metabolism across organs. Full article

Natural deep eutectic solvents (NADES) offer sustainable alternatives to conventional solvents for plant extraction, yet their influence on extract composition and bioactivity preservation requires further study. Here, choline chloride-based NADES with lactic acid or propylene glycol were evaluated for ultrasound-assisted extraction (60 °C, 30 min, 1:20 w/v) of polyphenol-rich fractions from Sanguisorba officinalis and Symphytum officinale. Spectrophotometric analysis yielded total phenolic contents of 6.49–9.67 mg GAE g⁻¹ and total flavonoids of 0.08–0.52 mg g⁻¹, with values dependent on the plant matrix and the NADES formulation. Targeted HPLC-MS/MS enabled identification of representative phenolic acids (chlorogenic, caffeic, ferulic, rosmarinic) and flavonoid markers (rutin, quercetin derivatives), showing qualitative differences in the detected marker profiles between solvents and matrices. Functional assays demonstrated pronounced antioxidant-related effects, including DPPH radical scavenging at 0.5–25 µg mL⁻¹ (polyphenols), inhibition of lipid peroxidation in rat erythrocytes at 0.25–1.20 µg mL⁻¹, and modulation of mitochondrial respiration and permeability transition in isolated rat liver mitochondria. Overall, the results indicate that choline chloride-based NADES can be used to obtain polyphenol-rich plant extracts compatible with the applied analytical workflow while preserving redox-active fractions, supporting their utility in green analytical sample preparation. Full article

Introduction: Ubiquinol–cytochrome c reductase core protein II (UQCRC2) encodes a core subunit of the mitochondrial electron transport chain (ETC) complex III (CIII). Biallelic pathogenic variants in UQCRC2 have been associated with mitochondrial disease characterized by lactic acidosis, developmental delay, hepatopathy, and episodic metabolic decompensation. Methods: We reviewed the biochemical phenotypes of 14 individuals possessing UQCRC2 variants, including two novel cases. We performed biochemical studies of mitochondrial respiration and oxidative phosphorylation (OXPHOS) complex measurements in patient-derived fibroblasts. Results: We report reduced CIII activity in a majority of individuals possessing variants in UQCRC2, as well as biochemical findings consistent with impaired mitochondrial energy metabolism, though impairments in mitochondrial respiration were variable. The two previously unreported, unrelated patients possessing the likely pathogenic missense variant c.361T>C, p.Tyr121His in UQCRC2 in trans with a 16p12.2 microdeletion encompassing UQCRC2 showed milder phenotypes, less severe metabolic decompensations, and no long-term neurological impairments. Both individuals display reduced CIII activity and mitochondrial respiratory dysfunction. Discussion: These data expand the current understanding of genotypes associated with UQCRC2-associated mitochondrial disease to include the novel 16p12.2 microdeletion. These data also highlight the consistent biochemical phenotype associated with UQCRC2-associated mitochondrial disease, and the need for consistent biochemical and respiratory assessment of individuals possessing UQCRC2 variants to further our understanding of this phenotype. Full article

Background: The pathophysiological mechanisms of Abdominal Aortic Aneurysm (AAA) are not elucidated. Alterations in mitochondrial function, such as a reduction in oxidative phosphorylation (OXPHOS), have been observed at genome level and functionally in vascular smooth muscle cells. Metformin reduces AAA development and growth in diabetic patients, but the precise mechanisms are not known. In this paper we aim to demonstrate the feasibility of measuring mitochondrial functional capacity ex vivo in intact murine aneurysmal tissue and confirm a decrease in OXPHOS, and to determine if the protective effect of metformin on AAA is mediated by mitochondrial function. Methods: AAA was induced in ApoE KO mice by administration of angII (1000 ng/kg/min) through osmotic minipumps. Metformin was administered in drinking water at a dose of 100 mg/kg/day. The abdominal aorta was isolated in situ and mitochondrial functional capacity was analyzed ex vivo in whole permeabilized tissue by high-resolution respirometry. Results: Mitochondrial respiration was successfully measured ex vivo in whole aneurysmal tissue. Mitochondrial function was impaired in angII-treated mice, with decreased fold change in Complex I and Complex I+II oxygen consumption, relative to basal levels. Complex II oxygen consumption was also decreased in angII-treated mice. Rescue treatment of mice with metformin did not affect or restore mitochondrial function. Conclusions: Mitochondrial function can be evaluated in murine whole aneurysmal tissue, providing a method for a physiological approach to the study of mitochondrial function in AAA. Mitochondrial function is impaired in AAA. However, rescue treatment with metformin is not sufficient to recover mitochondrial function and seems not to be the mechanism behind prevention of aneurysm. Full article