Search Results (204)

Today, microfluidics has become a revolutionary field of engineering due to its wide range of applications, including lab-on-a-chip devices, microscale biochemical reactors, drug delivery systems, and disease diagnostics. Efficient fluid mixing has been a significant challenge in these systems due to the dominance of laminar flow and low-Reynolds number conditions, where mixing relies primarily on slow molecular diffusion. It is very difficult to achieve rapid mixing and homogeneous mixing within a limited length. In this study, a bioinspired passive micromixer is developed based on the cristae architecture of mitochondria, which is known for maximizing surface area and transport efficiency in biological systems. The micromixer incorporates cristae-like microstructures within a straight microchannel to produce continuous flow deflection, stretching, and folding, thereby promoting chaotic advection without relying on external energy sources. It also includes mitochondrial granules, such as micropillars, within the channel to disrupt streamline flow. Thus, a numerical investigation was conducted to design four different micromixer geometries: conventional T-channel, and T-channels with a single, double and triple matrix of cristae. The analysis was performed in COMSOL Multiphysics, in which “Laminar flow” and “Transport of diluted species” physics were used, and a stationary study was executed. Simulations were conducted at different Reynolds numbers (Re = 0.1–100) to observe the feasibility of the proposed designs. For analysis, the mixing index and concentration profiles at the outlet and along the length were also examined. The results showed that the high cristae density channel performed well, achieving a mixing index of 95.85% at Re = 0.1 and 85.84% at Re = 100, proving that the proposed mitochondria-inspired cristae Mito-mixer delivers efficient mixing over a broad Reynolds-number range while maintaining a compact, length-efficient design. Full article

The diversity of mitochondria ultrastructure in human aging striated muscles is presented in relation to the complexity and variability of the cristae architecture and in relation to the environment of mitochondrial occurrence in the muscle fiber on the example of the orbicularis oculi. Ultrastructure analysis of mitochondria in muscles was performed using a transmission electron microscope. The studies revealed the presence of mitochondria of various sizes and unexpected shapes, and also modifications of the cristae architecture which included the occurrence of different configurations of membranes. In some mitochondria, instead of cristae, crystalline inclusion bodies and granules resembling calcium deposits were found. The range of diversity of the studied morphotypes of mitochondria exceeds the algorithms for the morphology of these organelles presented in the literature to date. This diversity of mitochondria should probably be viewed as a manifestation of evolution from the classical cristae architecture to a wide range of forms of mitochondria corresponding to the current environmental conditions of the muscle fiber. Full article

Bovine mastitis is a multifactorial inflammatory disease primarily characterized by inflammatory cell infiltration and the destruction of mammary alveoli. It is a major cause of reduced milk yield and quality. The imbalance between antioxidant defenses and the generation of reactive oxygen species (ROS), which occurs due to the high metabolic activity of the mammary gland during the periparturient period, increases the incidence of mastitis. During early lactation, especially in high-yielding dairy cows, the massive synthesis and secretion of milk increase the energy demand of mammary tissue, leading to excessive ROS accumulation. This results in cell membrane disruption and, ultimately, antioxidant dysfunction in the mammary tissue. This study established an in vitro oxidative stress model by treating bovine mammary epithelial cells (BMECs) with 2,2′-azobis(2-amidinopropane) dihydrochloride (AAPH). The optimal concentration of 1000 μmol/L AAPH was determined using the CCK-8 assay. Model validation showed that, compared to the control group, ROS levels were significantly elevated (p < 0.001) and mitochondrial membrane potential was significantly decreased (p < 0.001) in the AAPH-treated group. Transmission electron microscopy (TEM) analysis revealed that AAPH treatment caused ultrastructural damage, including reduced microvilli, mitochondrial swelling, disappearance of cristae, and vacuolization. Mechanistic studies demonstrated that AAPH treatment significantly upregulated the mRNA and protein expression of AMPK, HMOX-1, mTOR, NOS, and SOD (p < 0.001), while significantly downregulating CYP1A1 expression (p < 0.001). Pretreatment with N-acetylcysteine (NAC) effectively alleviated the oxidative stress damage caused by AAPH. This study successfully established an in vitro AAPH-induced oxidative stress model in BMECs and revealed its molecular mechanism of cellular damage. The damage occurs through modulation of the AMPK/mTOR signaling pathway and the regulation of antioxidant-related gene expression. Full article

This study investigated breed- and sex-related variation in two adjacent regions of the sheep cranial base on the endocranial surface, namely the ethmoidal region (fossa ethmoidalis–crista galli complex) and the prechiasmatic region centered on the sulcus chiasmatis. We hypothesized that breed-related morphometric differences would be detectable in this cranial base region and that the ethmoidal and prechiasmatic regions would show modular separation despite substantial covariation. Three-dimensional landmark data from 113 adult Akkaraman, Morkaraman, and Zom sheep were analyzed. Whole-configuration size differed by breed and sex, ethmoidal size mainly by sex, and prechiasmatic size mainly by breed. Shape analyses showed significant breed effects in the whole configuration and in both regional modules, whereas sex effects were weaker and limited to the whole configuration and prechiasmatic region. Allometry was significant at all levels and was strongest in the two regional modules, especially the prechiasmatic region. Modularity analysis supported the separation of the ethmoidal and prechiasmatic landmarks into two modules, whereas integration analysis indicated a high degree of covariation between them (r-PLS = 0.933), with most shared covariance concentrated on the first PLS axis. These findings indicate that variation in this endocranial cranial base region is detectable in both size and shape, with shape differences identified more consistently across the whole configuration and the two regional modules, although the associated effect sizes were modest. Overall, the results highlight that variation between adjacent cranial base regions is primarily expressed through shape and covariation rather than size alone, providing a morphometric framework for future studies of cranial structure. Full article

Adenine nucleotide translocase (ANT) has traditionally been defined as the ADP/ATP exchanger of the inner mitochondrial membrane. However, accumulating mechanistic evidence reveals a substantially broader functional spectrum that extends beyond nucleotide transport. In this review, we integrate these advances into a unified conceptual framework that positions ANT isoforms as modulators of mitochondrial bioenergetics, quality control, and cellular communication. Beyond its canonical exchange activity, ANT influences permeability transition thresholds and membrane potential stability, participates in regulated uncoupling and redox control, and contributes to inner membrane organization and cristae integrity. ANT further modulates TIMM23-dependent protein import and PINK1–Parkin-mediated mitophagy, thereby shaping mitochondrial quality control decisions. In addition, ANT regulates mitochondrial nucleic acid release and inflammasome activation, linking bioenergetic imbalance to innate immune signaling. Emerging evidence for alternative subcellular localizations suggests that ANT-dependent signaling extends mitochondrial state information to extracellular and intercellular contexts. Collectively, these findings support an expanded view of ANT as a multifunctional modulator linking mitochondrial energetic state to stress adaptation, inflammatory signaling, and tissue-level communication. Full article

Leptin receptor-deficient WBN/Kob-Lepr fa/fa (WKF) rats spontaneously developed chronic pancreatitis and severe diabetes with obesity. Here, we evaluated the protective effects of diet restriction and chronic exercise against fatty and inflammation-induced disorders in the vulnerable pancreas of WKF rats. Six-week-old male WKF rats were divided into obese control (Obese), diet restriction (DR), and diet restriction + exercise (DR + Ex) groups. WBN/Kob (WK) rats were used as lean control (Lean). Lean and Obese rats had free access to food, whereas food intake for DR and DR + Ex rats was restricted to 69% and 70% of the Obese level, respectively. The DR + Ex rats exercised voluntarily on a wheel ergometer daily. After six weeks, the rats were euthanized with isoflurane after overnight fasting. Obese rats exhibited diabetes, early stages of pancreatitis, diffuse pancreatic islets, and ultrastructural deteriorations in the pancreatic acinar cells, such as lipid droplet accumulation and swollen mitochondria with destroyed cristae, whereas Lean rats did not. DR rats exhibited improved glucose metabolism and serum triglyceride levels, effectively preventing inflammatory processes in the pancreas. However, DR rats exhibited no amelioration in the serum free fatty acids (FFAs) level, and limited improvements in ultrastructural deterioration in pancreatic cells. Chronic exercise combined with diet restriction (DR + Ex) improved serum FFA levels, the boundary of pancreatic islets, and the ultrastructure of subcellular organelles. These results demonstrate that diet restriction suppresses pancreatic inflammation, and further additional exercise effectively improves fatty pancreas-related deterioration by skeletal muscle activity linked through the circulatory network in WKF rats. Full article

Background: Glucocorticoids (GCs) are a key pathogenic factor in steroid-induced avascular necrosis of the femoral head (SANFH). GCs can directly damage bone microvascular endothelial cells (BMECs), leading to impaired intraosseous blood supply. Recent studies suggest the Hippo signaling pathway may be involved in the pathogenesis of SANFH; however, its role in vascular endothelial repair and angiogenesis remains unclear. This study aims to investigate the therapeutic effects of human umbilical cord mesenchymal stem cells (hUC-MSCs) on SANFH, with a particular focus on their protective or reparative mechanisms on BMECs. Methods: In vivo, a SANFH mouse model is established and divided into NC, MPS, and hUC-MSCs groups, followed by Micro-CT imagin, hematoxylin and eosin (HE) staining and immunohistochemistry (IHC) (n = 8 per group). In vitro, BMECs are divided into NC, dexamethasone (Dex), hUC-MSCs, and Fer-1 groups to analyze cellular biological behaviors. Target protein expression is assessed using Western blotting and immunofluorescence microscopy. Ferroptosis-related markers are detected via biochemical assays. Mitochondrial ultrastructural changes are observed using transmission electron microscopy. Results: In vivo, the MPS group exhibited significant bone cavitation, sparse trabeculae, and disrupted trabecular architecture in the femoral head. The hUC-MSCs group showed marked improvement in bone microstructure, HE staining showed a significant decrease in the empty lacunae rate in the femoral head, and IHC results revealed markedly increased expression of cluster of differentiation 31 (CD31) and vascular endothelial growth factor (VEGF). In vitro, Dex stimulation suppressed BMECs proliferation. In Dex-treated cells, levels of intracellular reactive oxygen species (ROS), lipid peroxides, ferrous ion (Fe²⁺), malondialdehyde (MDA), acyl-CoA synthetase long chain family member 4 (ACSL4) and nicotinamide adenine dinucleotide phosphate oxidase 4 (NOX4) were all increased, while expression of glutathione (GSH) and glutathione Peroxidase 4 (GPX4) was reduced. Transmission electron microscopy revealed plasma membrane rupture and reduction or loss of mitochondrial cristae. Furthermore, Dex promoted Hippo-mediated phosphorylation of Yes-associated protein (YAP)/Transcriptional coactivator with PDZ-binding motif (TAZ), upregulated NOX4 expression, and suppressed CD31 and VEGF expression. Following hUC-MSCs treatment, BMECs demonstrated enhanced proliferation, migration, and tube-forming capacity. Cellular GSH and GPX4 levels increased, antioxidant capacity was restored, peroxide accumulation decreased, and cells were protected from ferroptosis-effects comparable to those in the Fer-1 group. Additionally, hUC-MSCs inhibited YAP/TAZ phosphorylation and promoted elevated expression of CD31 and VEGF. Conclusions: These findings suggest that hUC-MSCs may attenuate Dex-induced ferroptosis in BMECs, enhance BMEC migration and angiogenesis, and improve femoral head microstructure in SANFH through modulation of the Hippo-YAP/TAZ signaling pathway. This study provides novel insights into the therapeutic potential of hUC-MSCs for SANFH. Full article

Background/Objectives: Endometrial cancer frequently develops resistance to therapy, partly due to the ability of tumor cells to adapt to cellular stress through non-apoptotic mechanisms. Mitochondrial dysfunction and cytoskeletal remodeling are increasingly recognized as key components of stress adaptation; however, their structural relationship under pharmacological stress in three-dimensional (3D) tumor models remains poorly characterized. The present study aimed to investigate the ultrastructural and phenotypic effects of lithium chloride (LiCl)-induced stress in 3D endometrial cancer spheroids, with a particular focus on mitochondrial alterations and intermediate filament organization. Methods: Three-dimensional spheroids generated from Ishikawa endometrial cancer cells were exposed to lithium chloride at concentrations of 1, 10, or 50 mM for defined time periods. Cell viability, proliferative activity, and clonogenic capacity were assessed using Trypan Blue exclusion, BrdU incorporation, and soft agar assays. Ultrastructural changes were examined by transmission electron microscopy to evaluate mitochondrial morphology, cytoplasmic organization, and intermediate filament distribution. Results: LiCl exposure resulted in a dose- and time-dependent reduction in cell viability, proliferation, and clonogenic potential in 3D spheroids. Ultrastructural analysis revealed pronounced mitochondrial swelling, cristae disorganization, and membrane-associated mitochondrial alterations. These changes were consistently accompanied by conspicuous accumulation and reorganization of intermediate filaments in close spatial proximity to damaged mitochondria, suggesting a structural association between cytoskeletal remodeling and mitochondrial injury. Across all experimental conditions, classical apoptotic ultrastructural features, including chromatin condensation and apoptotic body formation, were not observed. Conclusions: Together, these observations indicate that lithium chloride elicits a stress phenotype in 3D endometrial cancer spheroids that primarily manifests at the organelle and cytoskeletal levels, rather than through classical apoptotic execution. Although descriptive in nature, the present study highlights intermediate filament accumulation as a prominent structural feature of lithium-induced mitochondrial stress and establishes a structural reference point for future studies aimed at further investigating mitochondrial–cytoskeletal relationships during pharmacological stress in endometrial cancer. Full article

Mitochondria comprise ~1/3rd of the volume of an adult ventricular cardiomyocyte. The gene Immt encodes the Mic60/Mitofilin protein that is hypothesized to organize the mitochondrial contact site and cristae organization system (MICOS) complex that generates mitochondrial cristae junctions between the inner and outer membranes. To investigate the function of the Immt gene in the mouse heart, we generated and characterized mice in which this gene was specifically deleted in the mouse heart using a loxP-targeted allele (Immt^fl/fl) and either the constitutive heart-specific Myh6-Cre transgene or the conditional Myh6-MerCreMer transgene, each of which showed lethality in several weeks. Hearts from these mice showed progressive hypertrophic cardiomyopathy and failure with lost contractility and lung edema. At the ultrastructural level, hearts from these mice showed extreme abnormalities in mitochondrial architecture characterized by lost cristae junctions, stacking of the inner mitochondrial membranes, mitophagy and areas with complete absence of mitochondria. Analysis of mitochondria showed loss of the MICOS complex of proteins as well as loss of mitochondrial membrane potential (Δψ) and increased expression of mitophagy proteins and mitochondrial biogenesis transcription factors. Hearts from these mice also showed widespread cardiomyocyte necrosis and induction of the universal mitochondrial stress response at the mRNA level, as well as major alterations in cardiac metabolites, suggesting greater use of glucose, ketones and amino acids. We conclude that the Immt gene is required for cardiac mitochondrial structure and function, although the ensuing mitochondrial stress response provides molecular clues as to how the heart can compensate metabolically and maintain viability for weeks after mitochondria are absent or unfunctional. Full article

Multiple sclerosis (MS) is a highly disabling chronic autoimmune disease of the central nervous system with neuroinflammatory and neurodegenerative alterations found in the white and grey matter of the brain. The pathogenesis of MS is complex and not fully understood. Mitochondrial dysfunctions are suspected to play an important role. The visual system is often affected in MS. Optic neuritis is a frequent symptom, but also the retina itself, including retinal synapses appear compromised in MS independent from demyelination of the optic nerve. A previous study demonstrated synapse-specific alterations of mitochondria in photoreceptor synapses in the Experimental Autoimmune Encephalomyelitis (EAE) mouse model of MS at day 9 after injection, an early time point in pre-clinical EAE. In the present study, we analysed even earlier stages of pre-clinical EAE for possible alterations of synaptic mitochondria. For this purpose, we performed qualitative and quantitative immunolabelling analyses of the mitochondrial cristae organising protein MIC60 at retinal synapses and functional analyses by measuring synaptic mitochondrial membrane potential (during rest and depolarisation-induced exocytosis) and visually guided behaviour (optometry analyses). At day 3 after injection, morphological and functional data were indistinguishable between MOG/CFA-injected EAE mice and CFA-injected control mice. But already on day 5 after injection, we observed a decreased expression of the mitochondrial MIC60 protein at synaptic mitochondria, a decreased synaptic mitochondrial membrane potential at rest, an enhanced drop of mitochondrial membrane potential during stimulated exocytosis and a decreased visual performance of the respective EAE mice. These data argue that synaptic pathology in the EAE retina begins as early as day 5 after injection. Our data propose that dysfunctions of mitochondria play an important role already at the very early stages of synaptic pathology in EAE. Full article

Boron compounds, classified as prohibited food additives due to their high toxicity, persist in pesticides and fertilisers, industrial processes, food supply chains, and consumer goods, perpetuating multisource exposure risks. Chronic ingestion may induce fatal hepatorenal injury; however, mechanistic insights and epidemiological surveillance remain critically lacking amidst sector-wide regulatory gaps. This study employed integrated cellular and organismal models to elucidate the relationship between boron-induced hepatotoxicity and ferroptosis. We demonstrate that dietary boron accumulation in chicken livers is associated with histopathological damage, mitochondrial cristae dissolution and atrophy (a hallmark of ferroptosis), and elevated serum biomarkers AST and ALT. Boron exacerbates oxidative damage in hepatocytes by elevating malondialdehyde (MDA) production while modulating the Nrf2/ARE antioxidant signaling pathway—specifically downregulating key genes (Nrf2, HO-1, GCLM, CAT). Concurrently, it inhibits critical antioxidant enzymes (SOD, T-AOC), thereby depleting cellular antioxidant defenses. Crucially, boron disrupts iron homeostasis and induces ferroptosis by dysregulating the SLC7A11-GPX4 pathway: upregulating pro-ferroptotic genes (ACSL4, TF, TFR) and downregulating cytoprotective genes (SLC7A11, GPX4, FTH1). Co-treatment with the ferroptosis inhibitor ferrostatin-1 (Fer-1) attenuated boron-induced oxidative damage, whereas the ferroptosis inducer Erastin potentiated toxicity. Collectively, we pioneer the dual-pathogenic mechanism of boron hepatotoxicity—oxidative stress and ferroptotic cell death—establishing the SLC7A11/GPX4 axis as a novel therapeutic target against boron toxicity. Full article

This study investigated the mechanisms by which ZEA induces oxidative stress and apoptosis in the jejunum of piglets and explored the roles of the tumor suppressor gene p53 and nuclear factor E2-related factor 2 (Nrf2) signaling pathways. Twelve weaned piglets were randomized into Control (basal diet) and ZEA groups (basal diet + 1.0 mg/kg ZEA; 6 piglets/group). No differences were observed between the control and ZEA groups for all production performance indicators. Compared with the jejunum of the control group, the ZEA group exhibited reduced levels of total superoxide dismutase, glutathione peroxidase activity, and total antioxidant capacity, along with elevated malondialdehyde content. Morphological examination revealed increased crypt depth and decreased villus height and villus-to-crypt ratio, as well as swollen, vacuolated spherical mitochondria with disrupted cristae. Immunohistochemistry showed enhanced p53 and Nrf2 immunoreactivity. The relative mRNA levels of Nrf2, Ho1, Gpx1, Cytc1, p53, Caspase1, and Bax increased. The Bax/Bcl-2 ratio increased, and Keap1 and Bcl-2 mRNA levels decreased. The relative protein levels of Nrf2, p53, Bax, Caspase1, and Gpx1 increased, whereas that of Bcl-2 decreased. All differences were significant at p < 0.05. Dietary supplementation with ZEA altered the morphological structure of intestinal tissues and mitochondria. By affecting the expression of genes related to the p53 and Nrf2 signaling pathways, it induces intestinal oxidative stress and apoptosis, thereby impairing intestinal health in weaned piglets. Full article

Bovine mastitis threatens the dairy industry with limited effective therapies. The selenoprotein family offers potential anti-inflammatory interventions, yet the role of Selenoprotein F (SELENOF) remains unclear. This study investigated SELENOF in mitochondrial damage and pyroptosis using clinical mammary biopsies and a Staphylococcus aureus-induced Mammary alveolar cell-type T (MAC-T) cell model. Histology, TEM, immunofluorescence, Western blot, qPCR, RNA-seq, and mitochondrial staining (MitoTracker Red and JC-1) were employed. Mastitic mammary tissue exhibited severe architectural disruption, including focal necrosis with coalescing vacuoles of variable size, extensive epithelial denudation, and interstitial thickening with dense inflammatory infiltrates. At the ultrastructural level, mitochondrial swelling, cristae loss, and plasma membrane rupture were evident. Additionally, these tissue specimens exhibited marked upregulation of inflammatory mediator transcripts, notably IL-1β, IL-6, and TNF-α, alongside heightened abundance of pyroptosis-associated proteins including NOD-like receptor family pyrin domain containing 3 (NLRP3), cleaved caspase-1, and GSDMD-N (Gasdermin D N-terminal domain). RNA-seq identified SELENOF as significantly downregulated. The MAC-T model recapitulated the mitochondrial dysfunction, inflammatory response, and pyroptosis observed in mastitic tissue. SELENOF overexpression restored mitochondrial membrane potential, dampened the output of inflammatory signaling molecules, and suppressed NLRP3-mediated pyroptosis via attenuation of caspase-1/GSDMD-N pathway activation. These findings establish SELENOF as a novel target that mitigates bovine mastitis by preserving mitochondrial homeostasis and suppressing NLRP3-mediated pyroptosis. Full article

Parkinson’s disease (PD) is the second most prevalent neurodegenerative disorder, yet its pathogenic mechanisms remain incompletely understood, highlighting the need for reliable experimental models. We previously developed a murine model based on inhalation of a manganese mixture (MnCl₂ and Mn(OAc)₃), which reproduces dopaminergic neuron loss in the substantia nigra pars compacta (SNc) and motor impairment. However, its capacity to mimic mitochondrial dysfunction, a key mechanism in PD, had not been explored. This study evaluated mitochondrial ultrastructure, fission and fusion proteins, and the activity of electron transport chain complexes I and IV, alongside fine motor performance. Forty male CD1 mice were divided into control (deionized water) and manganese-exposed groups (0.04 M MnCl₂ + 0.02 M Mn(OAc)₃), inhaled for 1 h twice weekly over five months. Manganese inhalation induced significant fine motor deficits, increased mitochondrial number with reduced area and circularity, and disorganized cristae. Drp1 and Fis1 levels were elevated, accompanied by decreased activity of complexes I and IV, predominantly in the SNc. These findings demonstrate that this progressive, bilateral model reproduces mitochondrial and motor alterations resembling those observed in PD, supporting its utility for testing mitochondria-targeted therapeutic strategies. Full article

In the last decades, ozone (O₃)-based medical treatments have become a widely applied complementary therapy for several pathological conditions. O₃ is administered at low dosages since the induction of a mild oxidative stress does not cause damage but stimulates the antioxidant cell response through the nuclear factor erythroid 2-related factor 2 (Nrf2). Mitochondria are sensitive to even mild oxidative stress, thus being a responsive target for O₃. This study aimed to evaluate the mitochondrial response to low O₃ doses used for medical treatments. As the skeletal muscle represents a primary target in local O₃ treatments, a murine non-tumoral muscle cell line was selected as an appropriate in vitro model. Transmission electron microscopy, biochemistry, and flow cytometry provided original information on the O₃ dose-dependent modifications of mitochondrial structural and molecular features. Low O₃ doses promoted an increase in mitochondrial area and in cristae extension, as well as an enhancement of the electron transport chain complexes and of antioxidant catalase and manganese-dependent superoxide dismutase. Nrf2 maintained its association with the outer mitochondrial membrane, thus exerting its protective role. All mitochondrial modifications were observed 24 h after treatment and disappeared after 48 h, demonstrating that cells promptly respond to the O₃-driven oxidative stress, effectively restoring homeostasis. Full article