Search Results (892)

Leishmaniasis is a neglected tropical disease caused by parasites of the genus Leishmania. Curcumin (CUR) is a polyphenol with several biological properties, including antimicrobial effects. However, its low bioavailability remains a challenge, and nanoencapsulation may represent a useful strategy to overcome this limitation. This study aimed to evaluate, in vitro, the antipromastigote activity of free CUR and the antiamastigote effect of CUR nanoparticles and their association with antimoniate, as well as to elucidate possible mechanisms of action. Free CUR directly inhibited promastigote proliferation, with an IC₅₀ of 25 µM at 24 h. CUR induced mitochondrial hyperpolarization, increased the production of reactive oxygen species (ROS) and nitric oxide (NO), and enhanced lipid peroxidation and the accumulation of lipid droplets in promastigotes. These alterations were associated with autophagic and apoptotic processes, morphological and ultrastructural changes, DNA fragmentation, and cell cycle arrest. Free CUR also reduced the viability of BALB/c peritoneal macrophages, and this effect was attenuated after nanoencapsulation. Free CUR, CUR nanoparticles, and their association with antimoniate (AM) reduced both the percentage of infected macrophages and the number of intracellular amastigotes at all tested concentrations, with increased NO production observed at the highest concentrations of free CUR. Altogether, our findings suggest that CUR exerts leishmanicidal activity against promastigotes by disrupting oxidative metabolism and triggering autophagic and apoptotic pathways, while amastigote elimination appears to occur through mechanisms independent of oxidative stress. Full article

Heat stress severely constrains wheat productivity, yet the mechanisms underlying thermotolerance remain incompletely understood. This study integrated physiological, biochemical, molecular, and ultrastructural analyses to characterize heat-stress responses in four bread wheat (Triticum aestivum L.) genotypes contrasting in heat tolerance. Membrane injury was assessed by membrane damage rate, lipid peroxidation by malondialdehyde accumulation, antioxidant defense by SOD, CAT, GPX, and BPX activities, and stress-responsive regulation by qRT-PCR analysis of DREB, HSP16.9, and SOD isoforms. HSP16.9 protein accumulation was further evaluated by Western blotting. Heat stress increased membrane damage and MDA accumulation in all genotypes; however, tolerant Murov 2 and Zirva 85 showed lower oxidative membrane injury than sensitive Aran and Gyzyl bugda. Thermotolerance was associated with stronger antioxidant activation, enhanced DREB and HSP16.9 induction, and more coordinated FeSOD and MnSOD expression. The HSP16.9 protein accumulated after heat treatment, supporting its role as a stress-responsive molecular chaperone. Separate correlation analyses of tolerant and sensitive genotypes revealed stronger coordination among transcriptional, chaperone-related, and antioxidant markers in tolerant genotypes, whereas sensitive genotypes showed a more fragmented response. Microscopy further showed better preservation of chloroplast, mitochondrial, and mesophyll organization in the tolerant genotype relative to the sensitive counterpart, indicating integrated cellular protection. Together, these responses define a coordinated tolerance strategy that may guide the selection of heat-resilient wheat genotypes. Full article

Melanoma exhibits pronounced metabolic plasticity and mitochondrial dependency, contributing to therapeutic resistance and tumor progression. Targeting mitochondrial function therefore represents a promising anticancer strategy. 2-Aminoethyl dihydrogen phosphate (2-AEH₂P), a bioactive phosphomonoester, has demonstrated antiproliferative potential, while metformin, a clinically established antidiabetic drug, acts as a mitochondrial complex I inhibitor and metabolic modulator. This study investigated the cytotoxic and mechanistic effects of 2-AEH₂P and metformin hydrochloride, individually and in combination, in human (SK-MEL-28) and murine (B16-F10) melanoma models, using non-tumorigenic fibroblasts (FN1 and L929) as controls. Cell viability, proliferation dynamics, cell-cycle distribution, mitochondrial membrane potential (ΔΨm), and apoptosis-associated markers were evaluated by flow cytometry. 2-AEH₂P reduced melanoma cell viability and proliferation while inducing G2/M accumulation, DNA fragmentation, mitochondrial depolarization, increased cytochrome c release, caspase-3 and caspase-8 activation, upregulation of p53 and Bad, and downregulation of Bcl-2. Metformin alone exerted moderate cytotoxic and pro-apoptotic effects. Notably, combined treatment markedly potentiated mitochondrial depolarization and intrinsic apoptotic signaling in melanoma cells, significantly lowering IC₅₀ values and enhancing caspase activation and cytochrome c release. Bliss independence analysis demonstrated synergistic interaction in SK-MEL-28 and B16-F10 cells. Although interaction scores indicated synergy in one fibroblast model, absolute cytotoxicity remained lower than in melanoma cells. These findings demonstrate that metabolic co-targeting with metformin enhances mitochondrial dysfunction-associated apoptotic signaling in melanoma cells, supporting a drug repositioning strategy aimed at exploiting mitochondrial vulnerability in metabolically adaptable tumors. Full article

Metabolic dysfunction and proteinopathy are hallmarks of neurodegenerative disease, yet their mechanistic interplay remains poorly understood. Here, we show that loss of the neuronal NAD⁺-synthesizing enzyme Nicotinamide mononucleotide adenylyltransferase 2 (NMNAT2) disrupts amyloid precursor protein (APP) processing in cortical neurons, leading to accumulation of APP C-terminal fragments (APP-CTFs). NMNAT2 deficiency lowers the NAD⁺/NADH redox ratio coincident with APP-CTF buildup. Temporal profiling reveals a biphasic increase in APP-CTFs, with an initial gradual rise followed by rapid accumulation, paralleling the expansion of differentially expressed proteins. Pathway analysis indicates early activation of JNK/MAPK signaling, followed by late-stage suppression of mitochondrial pathways and induction of endoplasmic reticulum stress and unfolded protein response programs. Seahorse analyses reveal early glycolytic impairment followed by deficits in mitochondrial respiration. Knockdown of the NAD⁺ hydrolase sterile alpha and TIR motif-containing protein 1 (SARM1) restores mitochondrial function and normalizes APP-CTF levels in NMNAT2 knockout neurons, whereas NAD⁺ supplementation provides only modest rescue. Together, these data demonstrate that neuronal NAD⁺ depletion drives progressive, SARM1-dependent disruption of glucose metabolism and proteostasis, impairing APP processing. The NMNAT2–SARM1 axis thus links metabolic stress to proteinopathy and highlights SARM1 as a central mediator of neurodegenerative dysfunction. Full article

Introduction: The Catalan chub (Squalius laietanus) is a freshwater cyprinid endemic to Catalonia, from the lower course of the Ebro River to the Tech, Tet, Agly, and Massane rivers in France. Classified as Vulnerable in the IUCN Red List (2024), its populations face significant threats due to anthropogenic pressures and the potential hybridization with the European chub (Squalius cephalus). Objective: This study aimed to characterize the genetic variation of the mitochondrial control region (CR) of S. laietanus across the main Catalan river basins to determine the population genetic structure of this species in the core of its distribution range. Methodology: A 789 bp fragment of the CR was sequenced in 334 chubs from 24 sampling sites collected by electrofishing between 2021 and 2025. The S. laietanus specific matrilineage of all these specimens had been previously detected by sequencing the Cytochrome c oxidase subunit I (COI) but this marker did not detect clear genetic structuring among basins. Results: In contrast to the low diversity within and among locations reported by COI, the CR showed a population structure distinguishing between northern (Muga, Fluvià, Daró, Ter, and Tordera rivers) and southern basins (Besòs, Llobregat, Gaià, Francolí, and Ebro rivers). In the southern rivers, a single haplotype, (H1), was present. This haplotype declined in abundance towards the north, being replaced with H2. In the Muga River, native Catalan chub populations showed the fixed H3 haplotype, suggesting strong isolation, while populations from the Daró River contained a private haplotype (H4). In contrast, the presence of a common and single haplotype in southern basins possibly resulted from genetic drift under strong summer droughts. Conclusions: Overall, these results reveal population structuring in S. laietanus and highlight the importance of considering regional differentiation in conservation and management strategies. Full article

Dynamin-related protein 1 (Drp1) is essential for mitochondrial dynamics in skeletal muscle, particularly in regulating fission, mitophagy, and maintaining mitochondrial function. Exercise is crucial for sustaining muscle function, promoting mitochondrial adaptations that enhance energy metabolism and oxidative capacity in skeletal muscle. In this Review, we discuss the role of Drp1 in exercise-induced mitochondrial adaptations and its potential implications for skeletal muscle health. We first address the evidence that Drp1 activity must be maintained within a narrow physiological range. Both Drp1 deficiency and overabundance provoke muscle atrophy and dysfunction, establishing a Goldilocks principle for mitochondrial fission. We then examine the multi-layered post-translational modification code that governs Drp1 activity, including canonical phosphorylation, redox-sensing modifications, and the receptor selectivity model that may specify distinct fission programs. A three-stage model of exercise-induced mitochondrial adaptation is presented, describing how Drp1 activity is temporally orchestrated from acute fragmentation through short-term remodeling to long-term network optimization, and how these morphological transitions govern substrate metabolism and determine exercise performance. The pathological consequences of Drp1 dysregulation are examined in metabolic disease, where Drp1 is chronically hyperactivated, and in aging, where Drp1 activity is deficient. Finally, we analyze the ROS-Drp1 signaling axis as the mechanistic basis for the bidirectional regulation of Drp1 by exercise. Moderate exercise-induced ROS production activates Nrf2 and AMPK signaling, which suppress excessive fission in metabolic disease while restoring insufficient fission in aging, thereby moving Drp1 activity toward the physiological Goldilocks zone in both contexts. This context-dependent, bidirectional regulation distinguishes exercise from pharmacological inhibitors and identifies the ROS-Drp1 axis as a therapeutic target for conditions at opposite ends of the Drp1 activity continuum, such as sarcopenia and type 2 diabetes. Full article

Background: Early endolysosomal and autophagic defects are among the earliest cellular alterations observed in Alzheimer’s disease (AD). However, the molecular mechanisms linking amyloid precursor protein (APP) metabolism to vesicle trafficking dysfunction remain incompletely understood. The APP-derived fragment C99 has emerged as a potential upstream mediator of intracellular toxicity, but its impact on organelle homeostasis and its modulation by metabolic interventions remain unclear. Methods: To investigate these mechanisms, we expressed human C99 in Drosophila neurons and examined intracellular pathology using ultrastructural analysis, fluorescent reporters of autophagy and mitochondrial turnover, and proteomic interactome mapping. The effects of the ketone body β-hydroxybutyrate (BHB) were evaluated to assess the impact of metabolic intervention. Results: Neuronal C99 expression induced pronounced vesicular abnormalities, impaired autophagic turnover, and disrupted mitochondrial quality control. Transmission electron microscopy revealed extensive accumulation of enlarged vesicular compartments, accompanied by reduced mitochondrial turnover and accumulation of aged mitochondria. BHB treatment restored autophagic cargo clearance, improved mitochondrial turnover, and normalized vesicular ultrastructure. These protective effects required neuronal ketone transport, indicating a neuron-intrinsic metabolic mechanism. Proteomic analysis of the C99-associated interactome revealed that ketone treatment remodels networks enriched for vesicle trafficking and proteostasis pathways. Network prioritization identified the retromer component VPS35 as a candidate regulatory hub. Functional analyses demonstrated that depletion of VPS35 abolished the BHB-dependent restoration of autophagy, mitochondrial turnover, and vesicle morphology. Conclusions: Ketone treatment restores mitochondrial quality control and autophagic homeostasis through a VPS35-dependent mechanism in C99-induced neurodegeneration. These findings provide mechanistic insight into how metabolic interventions may restore intracellular homeostasis in Alzheimer’s disease. Full article

Corydalis ophiocarpa is a medicinally valuable plant, noted for its abundant alkaloid content. Despite its significance, the mitochondrial (mt) genome of this plant has not been characterized, which impedes both the phylogenetic understanding within the Corydalis genus and the comprehension of its full genetic potential. In this research, we successfully assembled the complete mitogenome of C. ophiocarpa by employing a hybrid method that integrates Oxford Nanopore long reads with Illumina short reads. The assembled genome forms a circular structure of 600,064 bp, with a GC content of 46.49%, and includes 63 genes, comprising 40 unique protein-coding genes (PCGs), 20 tRNAs, and three rRNAs. Through assembly and coverage analysis, we identified a 6383 bp forward repeat associated with a contig having approximately double the depth, indicating a repeat-mediated multipartite structure where the main circle may coexist with two smaller subgenomic forms. We discovered 775 C-to-U RNA editing sites across the 40 PCGs, with 95.4% being non-synonymous and favoring hydrophobic amino acid substitutions, particularly in Complex I subunits. Furthermore, we identified sixteen mt plastid DNA fragments constituting 2.43% of the mitogenome, a proportion more than double that found in the closely related C. saxicola. Phylogenetic analysis confirms that C. ophiocarpa is most closely related to C. saxicola, with C. pauciovulata as another close relative. This study presents the first complete mitogenome of C. ophiocarpa, providing a genomic basis for investigating the relationships between mt genome structure, post-transcriptional regulation, and specialized metabolism in the Corydalis genus. Full article

Cephalopod products are widely distributed as frozen raw materials or cut portions, making morphology-based species identification difficult during commercial handling and inspection. In this study, we developed a conventional multiplex PCR assay for the simultaneous identification of six commercially important cephalopod species, Octopus vulgaris, O. ocellatus, O. minor, Enteroctopus dofleini, Dosidicus gigas, and Todarodes pacificus. Species-specific forward primers and a shared reverse primer were designed from the mitochondrial cytochrome c oxidase subunit I (COI) region to generate distinct diagnostic amplicons within a single reaction. The assay successfully produced species-resolved bands of 459, 365, 248, 194, 141, and 82 bp for O. vulgaris, E. dofleini, O. ocellatus, O. minor, D. gigas, and T. pacificus, respectively, with no ambiguous overlap among diagnostic fragments. Clear and reproducible amplification was obtained at annealing temperatures of 51–54 °C, with 52 °C selected as the standard condition, indicating useful operational tolerance for routine application. The assay also retained consistent diagnostic performance down to 1 ng of template DNA per reaction. These results demonstrate that the developed multiplex PCR assay provides a simple, rapid, and gel-based method for the preliminary identification of selected cephalopod species in frozen commercial materials and may be useful for seafood inspection and market surveillance. Full article

Fatty liver disease represents a major metabolic disorder affecting domestic animals worldwide, with significant implications for animal health, welfare, and agricultural productivity. Disrupted communication between mitochondria and other organelles—particularly the endoplasmic reticulum, lipid droplets, and lysosomes—plays a critical role in disease pathogenesis. This review synthesizes knowledge on inter-organellar communication across domestic animals, with emphasis on species-specific adaptations. We address the “Dairy Cow Paradox”—periparturient dairy cows develop severe hepatic steatosis (>30% liver fat), yet under sterile conditions, they have a higher threshold for progressing to sterile steatohepatitis compared to rodents and humans. However, it is critical to note that severe fatty liver in dairy cows is indeed associated with impaired autophagy, inflammation, and liver damage, particularly when accompanied by ketosis or concurrent infections, and 39% of transition cows exhibit moderate to severe lymphocytic hepatitis. We propose that the tolerance to severe steatosis in dairy cows arises from three adaptations: (1) attenuated innate immune sensing via the cGAS-STING pathway; (2) enhanced lipid buffering from perilipin 5 (PLIN5) with a hypothesized ruminant-specific Val152 substitution that may stabilize lipid droplet–mitochondria contacts; and (3) dampened calcium signaling due to ER–mitochondria membrane lipid raft rigidity, elevated inositol 1,4,5-trisphosphate receptor 2 (IP₃R2) expression, and reduced mitochondrial calcium uniporter (MCU) conductance. We contrast this with the inflammatory steatohepatitis common in rodent models driven by calcium overload and mitochondrial DNA (mtDNA) release, and glucocorticoid-mediated mitofusin 1 (MFN1) suppression, causing mitochondrial fragmentation in poultry. We identify critical knowledge gaps, including the need to define bovine and avian mitochondria-associated endoplasmic reticulum membrane (MAM) proteomes and spatially resolve hepatic zonal communication patterns. Targeting organellar communication hubs with nutraceuticals or pharmacological agents offers promising therapeutic strategies. Full article

While amyloid precursor protein (APP) overexpression in adipose tissue is a recognized consequence of high-fat diet (HFD) feeding, its role in metabolically active organs and the mechanisms linking it to systematic dysfunction remain unclear. In particular, the potential for diet-induced APP dysregulation in the other tissues and the contribution of its βC-terminal fragment (βCTF) are poorly characterized. Using a high-fat diet (HFD) mouse model to induce systematic metabolic stress, we assessed APP and βCTF levels across multiple tissues. HFD triggered a tissue-specific response, with APP levels increasing >2-fold in visceral and subcutaneous white adipose tissue (WAT) and in the kidney but remained unchanged in the liver and brain. βCTF levels were significantly elevated in the visceral WAT (3-fold) and kidney. In these responsive tissues, APP and βCTF accumulated within mitochondria, which coincided with significantly reduced complex I and IV activities. Complementary in vitro studies confirmed that APP levels can dictate mitochondrial function. Furthermore, we identified that cytokines–IL-4, IL-13, TNF-α, and IL-1β–induced APP transcription, providing a mechanistic link between diet-induced inflammation and APP dysregulation. Collectively, our findings demonstrate that APP is overexpressed in response to HFD in select peripheral tissues, which coincides with reduced mitochondrial complex enzyme activities and increased cytokine levels. Full article

Regulation of the endothelial stress response is important for blood vessel homeostasis and angiogenesis, processes disrupted in common vascular diseases and ageing. Here, we discovered that the Y-box factor ZONAB (ZO-1-associated nucleic acid binding protein; YBX3), a gene associated with risk loci for severe vascular disorders, regulates endothelial homeostasis and angiogenesis. By combining cell-based assays with primary endothelial cells and genome-wide expression and methylation measurements, we found that ZONAB depletion results in mitochondrial deregulation, increased reactive oxygen species, and a defective oxidative stress response, which correlates with increased promoter methylation of cell cycle genes. ZONAB depletion triggered cellular senescence via a phosphatidylinositol 3-kinase (PI3K)/Akt-dependent pathway, which was attenuated by PIK3 inhibitors, an antioxidant, or by drugs targeting mitochondrial function or fragmentation. Thus, our results reveal that ZONAB repression in endothelial cells leads to genome-wide changes in gene expression and DNA methylation, regulating endothelial proliferation and inflammation, as well as mitochondrial deregulation to promote cellular senescence. Hence, ZONAB supports endothelial homeostasis and may play a role in vascular health. Full article

Hypoxia-induced radioresistance remains a major obstacle in non-small cell lung cancer (NSCLC) radiotherapy. This study investigates whether artificially activating mitochondrial reverse electron transfer (RET) can enhance radiosensitivity in NSCLC by triggering oxidative stress. An in vitro hypoxia/reoxygenation (H/R) model was established in A549 cells to assess reactive oxygen species (ROS) levels, mitochondrial function, and metabolic alterations using fluorescence probes, flow cytometry, confocal microscopy, and targeted metabolomics. Mitochondrial complex inhibitors and dimethyl succinate (DM-S) were employed to validate the RET mechanism, and radiosensitivity was evaluated through clonogenic survival, apoptosis assays, and γ-H2AX staining. In vivo, A549 tumor-bearing mice received high oxygen (95% O₂) combined with DM-S and localized irradiation (4 Gy); tumor growth, histopathology, and immunohistochemistry were examined. H/R triggered substantial mitochondrial ROS production via complex I-mediated RET, dependent on a high mitochondrial membrane potential and electron transport chain imbalance, with succinate accumulation serving as a key metabolic switch. Exogenous DM-S exacerbated H/R-induced oxidative damage, DNA fragmentation (8-OHdG elevation, mtDNA integrity loss), and mitochondrial network disruption. H/R combined with DM-S significantly enhanced in vitro radiosensitivity, reducing clonogenic survival and increasing apoptosis to 53.4% ± 1.9% versus 10.3% ± 1.2% with irradiation alone. In vivo, the combination therapy markedly suppressed tumor growth, induced apoptosis and oxidative lipid damage (4-HNE), alleviated hypoxia (reduced HIF-1α), and showed no overt toxicity. These findings demonstrate that activating mitochondrial RET effectively enhances radiosensitivity in NSCLC. Succinate metabolism is a critical therapeutic target, and combining high oxygen with a succinate analog represents a promising radiosensitization strategy for hypoxic tumors. Full article

Brain aging is a complex biological process characterised by progressive neuronal and synaptic decline, in which disruption of mitochondrial quality control plays a central role. This system encompasses multiple synergistic components, including mitochondrial biogenesis, dynamic equilibrium, autophagic clearance, and energy metabolism. Aging induces dysfunction across these processes, precipitating mitochondrial fragmentation, functional decline, and energy crises, ultimately driving cognitive deterioration. Exercise is a promising non-pharmacological intervention for preserving brain health during aging, and its benefits may be mediated, at least in part, through modulation of mitochondrial quality control. Specifically, exercise has been shown to activate key signaling pathways such as AMPK/SIRT1/PGC-1α, thereby promoting mitochondrial biogenesis and metabolic adaptation. It may also regulate mitochondrial dynamics and mitophagy via pathways including cAMP/PKA/Drp1 and AMPK/mTOR. In addition, emerging evidence indicates that exercise may influence brain mitochondrial function through activity-dependent regulation of mitochondrial gene expression and systemic signaling factors. Furthermore, this review discusses potential differences between exercise modalities and highlights future directions for personalised intervention strategies, providing a theoretical basis for the application of exercise in delaying brain aging and preventing neurodegenerative diseases. Full article

Mitochondrial DNA (mtDNA) analysis is a fundamental tool in forensic genetics, particularly when biological samples exhibit severe degradation or low nuclear DNA content. Its unique biological characteristics, such as a high copy number per cell, strict matrilineal inheritance, and lack of recombination, enable human identification and reconstruction of maternal lineages in complex contexts, including disaster victim identification, historical cases, and missing persons investigations. This narrative review examines contemporary methodological approaches for investigating the human mitogenome. We discuss recent advancements in extraction and enrichment techniques, emphasizing their efficacy in reducing the interference of nuclear mitochondrial DNA sequences (NUMTs) and enhancing the recovery of informative fragments. Moreover, the shift from traditional Sanger sequencing to Massive Parallel Sequencing (MPS) is examined, as MPS has markedly enhanced the sensitivity and capability of contemporary methods to detect low-frequency heteroplasmies. Additionally, the advent of Third-Generation Sequencing (TGS), exemplified by nanopore platforms, is evaluated, which facilitates the reading of full-length native molecules without the biases introduced by PCR amplification. Despite the interpretive challenges posed by heteroplasmy, contamination, and limitations in population databases, ongoing methodological advances in mitochondrial DNA analysis continue to strengthen its reliability and expand its potential in forensic genetics. Full article