Search Results (1,158)

Associated with high morbidity and mortality, cisplatin-induced acute kidney injury (AKI) is a common clinical complication characterized by oxidative stress, inflammation, and mitochondria-associated signaling. Although multiple signaling pathways have been implicated in AKI progression, effective interventions targeting these complex mechanisms are still lacking. As a medicinal fungus with antioxidant and anti-inflammatory properties, Schizophyllum commune (SC) has shown potential biological activities; however, its renoprotective effects in cisplatin-induced AKI remain unclear. Therefore, this study aimed to investigate SC’s protective effects and underlying mechanisms in a cisplatin-induced AKI mouse model. SC treatment improved renal function and attenuated histopathological damage. It reduced oxidative stress and inflammatory responses, as evidenced by the modulation of malondialdehyde (MDA), glutathione (GSH), nitric oxide (NO), and pro-inflammatory cytokines. Mechanistically, SC regulated multiple signaling pathways, including mitogen-activated protein kinase (MAPK), toll-like receptor 4/nuclear factor kappa B (TLR4/ NF-κB), PI3K/AKT, nuclear factor erythroid 2–related factor 2/heme oxygenase-1 (Nrf2/HO-1), and the calcium/calmodulin-dependent protein kinase kinase–AMP-activated protein kinase–sirtuin 1 (CaMKK–AMPK–Sirt1) axis. In addition, SC modulated apoptosis, autophagy, and PTEN-induced kinase 1 (PINK1)/Parkin-mediated mitophagy, suggesting improved mitochondrial homeostasis. These findings indicate that SC exerts renoprotective effects and may contribute to cisplatin-induced nephrotoxicity mitigation strategies. Full article

Sudden cardiac death (SCD) in athletes often represents the first manifestation of an underlying inherited cardiovascular disorder exposed by adrenergic stress, altered calcium cycling, mechanical loading, and metabolic demand during intense exercise. This review focuses on the molecular architecture that links genotype to arrhythmogenic phenotype in athletes, emphasizing sarcomeric force generation and energetic inefficiency in hypertrophic cardiomyopathy, desmosomal failure and Hippo/Wnt/transforming growth factor-beta (TGF-β) signaling in arrhythmogenic cardiomyopathy, and ion-channel and calcium/calmodulin-dependent protein kinase II (CaMKII)calcium handling abnormalities in inherited channelopathies. This review further examines how exercise-induced physiological remodeling intersects with these pathways through insulin-like growth factor-1 (IGF-1)/phosphoinositide 3-kinase (PI3K)/ protein kinase B (AKT) signaling, mitochondrial biogenesis, oxidative stress, inflammatory signaling, and epigenetic regulation. Attention is given to the molecular basis of genotype-positive/phenotype-negative states, variable penetrance, and exercise-mediated disease expression. Finally, the integration of molecular biology with genomic data, polygenic risk, and emerging digital phenotyping is discussed to refine mechanism-based risk stratification and identify future therapeutic targets for prevention of SCD in athletes. Full article

Heart failure (HF) remains a major cause of morbidity and mortality despite substantial therapeutic progress, and important phenotype-specific treatment gaps persist. Protein S-nitrosylation (SNO) is a reversible cysteine-centered post-translational modification (PTM) whose reported associations with selected HF-relevant contexts, including vascular–endothelial dysfunction, mitochondrial–energetic remodeling, Ca²⁺-handling abnormalities, and selected receptor- or stress-related signaling observations, are supported to varying degrees. In this review, we evaluate reported mechanisms that may regulate cardiac SNO and define the evidentiary boundaries that constrain interpretation across HF-relevant settings. Available studies suggest that altered SNO homeostasis is associated with selected HF-related processes, but the strength of support varies substantially across targets, phenotypes, and disease contexts. Many mechanistic observations derive from animal models, cultured systems, donor-based perturbations, or non-HF settings. These should, therefore, be interpreted as hypothesis-generating rather than as established mechanisms in human HF. We accordingly distinguish findings supported by human HF tissue or HF-relevant in vivo evidence from more preliminary observations and highlight the need for human, site-resolved, and, where feasible, quantitatively grounded datasets. Future studies should prioritize stronger tissue anchoring, better integration of circulating and myocardial readouts, and closer alignment between mechanistic claims and the strength of the supporting evidence. Full article

Alzheimer’s disease (AD) is characterized by the accumulation of amyloid-β (Aβ) and chronic neuroinflammation, with microglia playing a central role in its pathogenesis. Alterations in microglial metabolism have been proposed to contribute to AD-related inflammatory responses and reduced Aβ clearance, suggesting that thiamine-dependent pathways may be relevant in this context. Thiamine pyrophosphate (TPP), the active form of vitamin B1, is essential for glucose metabolism and mitochondrial function; however, its association with microglial changes in AD remains unclear. In this study, 9-month-old female triple-transgenic AD (3xTg-AD) mice and non-transgenic controls (NoTg) received TPP (2.0 mg/mL) or saline as a vehicle for six weeks via osmotic pumps. Nesting, a hippocampus-dependent behavioral test, as well analyses of Aβ burden, microglial morphology, and the expression of genes related to metabolic and immune pathways were evaluated. Differences in nesting behavior between experimental groups were observed, but TPP treatment was not associated with an evident change in 3xTg-AD mice. In the subiculum and CA1 regions of the hippocampus of female 3xTg-AD mice exposed to TPP, a lower Aβ burden was observed, and morphological variations in microglia were detected in both groups (3xTg-AD and NoTg). Additionally, in the brain of the TPP-treated group, some changes in mRNA gene expression were recorded. Together, these findings describe hippocampal microglial and amyloid profiles following TPP treatment in 3xTg-AD mice and provide a basis for further investigation of thiamine-dependent pathways in AD-related neuroinflammatory contexts. Full article

Background: Glucagon-like peptide-1 receptor (GLP1R) agonists, particularly semaglutide, show neuroprotective effects in genetic models of Alzheimer’s disease (AD). However, their delayed and long-term effects in sporadic AD, such as the intracerebroventricular streptozotocin (STZ) injection, remain insufficient. It is unclear how long the effects of GLP1R agonists persist after discontinuation and whether a single course can suppress progressive neurodegeneration. This study aimed to evaluate the delayed effects of semaglutide administration on morphological changes in neurons and glial cells in the hippocampus associated with cognitive impairment in an STZ-induced rat model of AD. Methods: Rats received bilateral intracerebroventricular STZ injections (3 mg/kg) followed by a 5-week course of intraperitoneal administration of semaglutide (0.1 mg/kg, every other day), and were euthanized 60 days after discontinuation of semaglutide administration. Immunomorphological methods were used to detect neuronal, astrocytic and microglial alterations. A novel object recognition test was performed to assess behavioral effects. Results: STZ-treated animals demonstrated cognitive impairments, ventriculomegaly, a significant increase in p-tau protein fluorescence intensity (p = 0.02), a decrease in CA1–CA3 field area (by 23%, p = 0.008), and reduced hippocampal neuronal density. Decreases in TOMM20 (mitochondrial marker) and synaptophysin levels were accompanied by significant glial activation in the hippocampal CA3 field. Semaglutide administration significantly reduced the enlarged ventricular lumen (by 43.5%), decreased p-tau fluorescence intensity, reduced vimentin-positive reactive astrocytes (by 68.4%), and increased synaptophysin fluorescence intensity. Furthermore, it reduced microglial activation (decreasing IBA1 cell density and elongation) and alleviated the disrupted AQP4 distribution. However, semaglutide did not completely halt the neurodegenerative process and showed no effect on the number of doublecortin-positive cells in the dentate gyrus. Conclusions: Hippocampal changes assessment revealed that course administration of semaglutide exerts prolonged effects, attenuating the severity of pathomorphological alterations and behavioral changes in a sporadic AD model after drug discontinuation. Full article

Background/objectives: Epithelial ovarian cancer (EOC) is the deadliest gynaecologic malignancy, largely due to late-stage diagnosis and ineffective therapy. EOC commonly spreads through the peritoneal cavity as multicellular spheroids, which are metastatic structures that enhance survival under detachment stress, promote dissemination, and contribute to therapeutic resistance. We previously showed that ULK1, a serine/threonine kinase classically linked to macroautophagy initiation, supports EOC progression, suggesting non-canonical roles in spheroid biology and pathogenesis. Methods: CRISPR/Cas9 ULK1 knockout (ULK1KO) models were generated in OVCAR8, HEYA8, and ES2 cells. Mitochondrial degradation phenotypes were assessed in spheroids by immunoblotting and fluorescence microscopy. Label-free proteomics with bioinformatic pathway analysis identified ULK1-associated programs in EOC spheroids. Bioenergetic consequences were quantified using Seahorse ATP-Rate assays. Therapeutic interactions were evaluated using multi-dose combination matrices testing the ULK1 inhibitor DCC-3116 with metformin. Results: ULK1 modulated mitochondrial degradation in a cell-line-specific manner, either promoting or protecting against mitochondrial loss through mechanisms that were uncoupled from canonical autophagy machinery. Proteomic and bioinformatic analyses revealed significant alterations in mitochondria-related processes, aligning with emerging ULK1 functions in mitochondrial homeostasis. ULK1 loss broadly reduced OXPHOS complex proteins in EOC spheroids and consistently decreased hexokinase 2 (HK2), indicating coordinated metabolic remodeling. Seahorse profiling mirrored these shifts: OVCAR8 ULK1KO spheroids showed reduced OCR and ATP production, whereas HEYA8 and ES2 ULK1KO spheroids exhibited increased mitochondrial ATP production. Combination matrices showed potential synergy between DCC-3116 and metformin. Conclusions: These data show that ULK1 differentially regulates mitochondrial degradation across EOC spheroid models through potential mechanisms alternative to canonical autophagy machinery, while reshaping spheroid metabolism and revealing potential therapeutic vulnerabilities in advanced EOC. Full article

Epidermal lipid homeostasis is crucial for skin barrier integrity. This study investigated the effects of an aqueous extract from Beta vulgaris subsp. vulgaris Beetroot Group (BvE) on stress responses and lipid metabolism in HaCaT keratinocytes. BvE, obtained from leaves grown in SETIS^® bioreactors as a standardized biomass source, was chemically characterized by ¹H NMR and ¹³C NMR. HaCaT cells were treated with BvE (1 µg/mL), H₂O₂, or palmitic/oleic acids (PA/OA) to evaluate its protective effects against oxidative damage and lipotoxic stress. Under these conditions, BvE exhibited a distinctive dual action as a reactive oxygen species (ROS) scavenger and triacylglycerol (TAG)-lowering agent. On the one hand, BvE was associated with decreased intracellular ROS levels and changes in NRF2 protein expression, suggesting involvement of redox-regulatory pathways. On the other hand, it was associated with attenuation of lipotoxicity, as evidenced by reduced lipid droplet (LD) formation and decreased expression of DGAT1 and PLIN2. Furthermore, these effects were accompanied by a reduction in Unfolded Protein Response (UPR) markers, modulation of AMPK-associated signaling, attenuation of mitochondrial disfunction, and decreased p53 phosphorylation, findings collectively consistent with a coordinated cytoprotective response. In conclusion, BvE shows potential to protect keratinocytes against lipotoxicity and oxidative stress through mechanisms that may involve both chemical and biological antioxidant activity and metabolic reprogramming, supporting its further investigation for dermatological applications. Full article

The root bark of Morus alba L. is commonly used as a natural antioxidant; however, its active constituents and underlying molecular mechanisms remain unclear. In this study, a bioactivity-guided isolation approach was employed to identify antioxidant substances from the root bark of Morus alba L. and to investigate their protective effects against oxidative damage in HaCaT cells. Using techniques such as silica gel column chromatography and semi-preparative HPLC, combined with NMR and HR-ESI-MS analysis, 22 compounds were isolated and identified from the dichloromethane extract of Morus alba L. root bark, including Diels–Alder adducts, flavonoids, and benzofurans. Among them, compounds 1 and 2 are new compounds, while compounds 12 and 16 were isolated from this plant for the first time. Bioactivity screening revealed that Kuwanon A (compound 17) exhibited significant cytoprotective effects in an H₂O₂-induced HaCaT cell injury model, effectively scavenging intracellular reactive oxygen species (ROS), restoring mitochondrial function, and enhancing the activities of antioxidant enzymes such as SOD and GSH. Further studies indicated that H₂O₂ induced ferroptosis in HaCaT cells, characterized by abnormal Fe²⁺ levels, lipid peroxidation, and elevated levels of pro-inflammatory cytokines (IL-1β, IL-6, TNF-α). Kuwanon A significantly ameliorated these pathological changes. Consistently, ELISA and Astral DIA quantitative proteomics analyses demonstrated that Kuwanon A specifically upregulates the expression of the sulfurtransferase NFS1, thereby promoting the expression of the core antioxidant enzyme GPX4 and the iron storage protein ferritin-H, collectively inhibiting ferroptosis. This study elucidates that Kuwanon A is a key active component responsible for the antioxidant and anti-inflammatory effects of Morus alba L. root bark, and its mechanism is closely associated with regulating the NFS1-mediated ferroptosis defense pathway. Full article

Retinal neurovascular unit (RNVU) dysfunction underlies major blinding and neurodegenerative conditions including glaucoma, diabetic retinopathy (DR), age-related macular degeneration (AMD), retinal ischemia–reperfusion (RIR) injury, and Alzheimer’s disease (AD)-associated retinopathy. Within the RNVU, calcium ions coordinate neurotransmission, glial activation, vascular tone, and blood–retinal barrier maintenance, and calcium dysregulation is emerging as a unifying pathogenic hub across these conditions. Although upstream triggers differ, including mechanical stress in glaucoma, hyperglycemia in DR, oxidative damage in AMD, ischemic energy failure in RIR, and amyloid-β–driven endoplasmic reticulum stress in AD, all converge on disruption of intracellular calcium homeostasis, producing shared downstream consequences including excitotoxic injury of retinal ganglion cells (RGCs), Müller cell reactive gliosis, and pericyte hypercontraction. Broad-spectrum calcium channel blockade has shown limited clinical success, underscoring the need for cell-type-specific and pathway-selective approaches. This review therefore catalogs key interventional nodes, including transient receptor potential (TRP) channel antagonists, T-type calcium channel inhibitors, calcium/calmodulin-dependent protein kinase II (CaMKII) suppressors, and mitochondrial permeability transition pore (mPTP) inhibitors, and discusses how precision targeting of these pathways may restore RNVU homeostasis and open a therapeutic window into central nervous system (CNS) degenerative disorders. Full article

Excitotoxicity is one of the factors that participates in neurodegeneration, impairing neuronal and glial cells’ function, and leading to the development of chronic neurodegenerative diseases. The main mechanism of action lies in the overstimulation of excitatory receptors, especially the NMDA (N-methyl-D-aspartic acid) receptor, by glutamate, which promotes a massive influx of Ca²⁺ that is not sufficiently buffered by the intracellular machinery, or not released by mechanisms such as Ca²⁺ ATPase and plasma membrane Ca²⁺/Na⁺ exchanger promoting, among other toxic effects, mitochondrial damage and an increase in reactive oxygen species (ROS). Notably, many cases reported of long COVID-19 describe significant brain alterations and neuropsychiatric disorders, including delirium, depression, etc., and patients required increased use of antidepressant or anxiolytic drugs, for example. In addition, emerging evidence links neurodegeneration as a potential long-term sequelae associated with an increased number of patients with cognitive disorders. This review analyzes data from the literature regarding brain alterations associated with post-COVID-19 syndrome and explores a potential link to the excitotoxicity pathways, due to its participation in neurodegeneration by homeostatic failure, and it is clearly present in various brain conditions, such as Alzheimer’s and Parkinson’s diseases. Full article

The family of Nek kinases has 11 human members that are conserved in their kinase domains but diverse in their regulatory domains. Functionally, they can be associated with diverse aspects of cell cycle regulation, from mitosis and primary cilia function to centrosome disjunction in the G2 phase and checkpoints of the DNA damage response. However, novel functional contexts have emerged in recent years, including regulatory roles of Neks 1, 4, 5, and 10 in mitochondrial metabolic and morphological homeostasis. We recently generated, by CRISPR-Cas9 technology, a DU-145 prostate cancer cell line, with an NEK6 gene knockout. Here, we focus on a detailed characterization of changes in this cell line, in mitochondrial respiration function and morphology. DU-145 NEK6 knockout cells exhibited reduced mitochondrial respiration and a fragmented phenotype in electron microscopy, with reduced mitochondrial cristae numbers. Alterations in mitochondrial architecture and respiration were correlated with increased expression of anaerobic glycolytic proteins (HK2, PFKP, and LDHA) and decreased expression of PDH, an enzyme of aerobic glycolysis. Molecular analysis by Western blot revealed decreased levels of mitochondrial mass and biogenesis protein markers (TOM20, TFAM), without alterations in other markers such as VDAC1/3 or mtDNA copy number in the NEK6 knockout cells. Furthermore, the regulators of mitochondrial fusion/fission are altered in the knockout cells (decrease in the Long-OPA1:Short-OPA1 ratio and DRP1 total level), which is associated with an increase in endoplasmic reticulum–mitochondria contact at ≤20 nm observed in transmission electron microscopy (TEM) image analysis. Using analysis of TEM micrographs, we found an increase in the autophagic structures (autophagosome, amphisome, and autolysosome), with mitochondria as cargo in some structures, which was correlated with a decrease in LC3A/B and an increase in the BECLIN1 total level, and with an increase in acidic vesicles approximation, suggesting that reduction in TOM20 and TFAM without alterations in VDAC1/3 and mtDNA copy number might be related to mitochondrial degradation through autophagy. Together, our data suggest a new role for NEK6 in regulating mitochondrial homeostasis, where its loss alters mitochondrial morphology and respiration, and could be associated with an increase in the degradation of the dysfunctional mitochondria through autophagy. Full article

Tumour necrosis factor-alpha (TNF-α) disrupts bioenergetic homeostasis in skeletal muscle cells through the suppression of ion-dependent ATPase activities, mitochondrial depolarisation, and impairment of antioxidant defences. Carvacrol, a phenolic monoterpenoid constituent of thyme and oregano essential oil, has been shown to exert cytoprotective effects in TNF-α-challenged L6 rat myoblasts. The mechanistic basis of these effects, specifically the relationship between membrane-associated ATPase function, mitochondrial polarisation status, and transcriptional regulation of metabolic stress-response genes, has not been formally characterised. L6 rat myoblasts were exposed to TNF-α (10 ng/mL, 1 h), then treated with carvacrol (6.25 µg/mL, 24 h) in a post-inflammatory rescue paradigm. Cell viability (MTT), membrane integrity (LDH), ion-dependent ATPase activities (Na⁺/K⁺, Ca²⁺, Mg²⁺), antioxidant enzyme activities (catalase, SOD), mitochondrial membrane potential (Muse™ MitoPotential flow cytometry), and SIRT1/AMPK mRNA expression were quantified. TNF-α significantly suppressed Na⁺/K⁺, Ca²⁺, and Mg²⁺-dependent ATPase activities (all p < 0.001), consistent with impaired membrane-associated bioenergetic function. Post-TNF-α carvacrol treatment partially restored all three ATPase activities (p < 0.05) and reduced the proportion of mitochondrially depolarised cells from 31.65 ± 4.25% to 19.0 ± 2.6% (p < 0.05). LDH release, catalase activity, and SOD activity were also significantly modulated. At the transcriptional level, carvacrol increased SIRT1 mRNA by 1.6-fold and AMPK mRNA by 2.0-fold relative to TNF-α-treated cells. An integrative bioenergetic model is proposed in which carvacrol’s membrane-intercalating properties restore the phospholipid environment required for ATPase conformational cycling, attenuating the Ca²⁺ overload that drives mitochondrial permeability transition, and thereby partially preserving Δψm. Transcriptional upregulation of SIRT1 and AMPKα may represent an adaptive response to residual energetic stress. The mechanistic relationships among these endpoints and the causal contribution of SIRT1 and AMPK to observed bioenergetic changes require protein-level and pathway-specific experimental validation. Full article

Mitochondria–endoplasmic reticulum contact sites (MERCs) are known as the specialized areas that are involved in a large number of intracellular signaling pathways that regulate Ca²⁺ homeostasis, lipid transport, mitochondrial dynamics, cell death, and autophagy. Understanding MERC dynamics has important therapeutic implications in cancer, as these contacts regulate fundamental cellular processes and MERCs represent promising targets for therapeutic interventions aimed at improving cancer treatment outcomes. Despite the accumulated data, the role of MERCs in carcinogenesis still remains unknown; thus, it seems promising to search for new tools facilitating the study of MERCs in tumor cells. The structure of MERCs can be examined in great detail using transmission electron microscopy (TEM). Currently, several hundred TEM images are required to obtain reliable data on these contacts. The speed of data processing can be significantly improved by using fast and accurate image analysis techniques based on deep learning models. In this study, five U-Net models with a ResNet34 encoder network were evaluated, including the basic U-Net-Vanilla architecture as well as models incorporating various attention blocks and blocks capturing multilevel image structure, for the segmentation of mitochondria and the endoplasmic reticulum (ER). The best performance on the test dataset was demonstrated by the U-Net-scSE network, with F1 scores of 0.872 for mitochondria and 0.744 for the ER being achieved. Two models were tested for their ability to leverage pre-training on external datasets (Lucchi++, Kasthuri++, and DeepPi-EM). Additionally, models pre-trained on the CEM500K dataset were evaluated after the parameters had been tuned on the data. It was demonstrated by the results that pre-training or the use of pre-trained networks did not lead to an improvement in the IoU and F1 metrics on the test dataset. Subsequent image analysis was conducted to assess two types of MERCs in the segmented images. Finally, the free and user-friendly UltraNet web server was developed for automated analysis of mitochondria, ER, and MERCs using TEM images. Full article

Green seeds of Coffea arabica represent a rich source of bioactive compounds. This study aimed to compare the butanol-soluble (CA-BU) and the ethyl acetate-soluble (CA-EtAc) fractions in terms of their phytochemical composition and biological activity. As a first step, the fractions were analyzed by Fourier-transform infrared spectroscopy (FT-IR) and high-performance liquid chromatography coupled with mass spectrometry (HPLC–MS) in order to investigate the major constituents. Subsequently, CA-BU and CA-EtAc were evaluated for antioxidant effect, antimicrobial activity, antiproliferative properties, effects on the mitochondrial function, and on the chorioallantoic membrane. The CA-EtAc fraction was enriched in chlorogenic acids and catechins and showed superior antioxidant activity, whereas CA-BU displayed a broader profile of semi-polar polyphenols, conferring moderate antimicrobial effects and stronger antiproliferative activity in MCF-7 human breast adenocarcinoma cells, although with limited selectivity compared with HaCaT non-tumorigenic cells. Respirometric analysis demonstrated that CA-BU selectively inhibited mitochondrial oxidative phosphorylation Complex I (OXPHOS CI), without affecting Complex II (CII) or basal respiration, indicating a specific mitochondria-targeted mechanism. Both fractions were non-irritant and well tolerated in the chorioallantoic membrane (CAM) assay; CA-BU reduced vascular density. These findings demonstrate a clear mechanistic differentiation between the fractions, highlighting the decisive role of solvent polarity in obtaining extracts with distinct and targeted biological effects. Full article

Periodontitis is a chronic inflammatory disease remaining elusive with its pathogenesis. Mitochondrial dysfunction and aberrant immune activation are implicated, but the underlying mechanisms remain incompletely understood. Given the essential role of Ca²⁺ homeostasis in maintaining normal mitochondrial function, we investigated the role of mitochondrial calcium (mtCa²⁺) dysregulation in periodontitis. Gingival tissues from periodontitis patients and healthy controls, as well as cultured gingival fibroblasts stimulated with Porphyromonas gingivalis lipopolysaccharide, were examined using transmission electron microscopy, confocal imaging, flow cytometry, qPCR, and western blotting. Notably, mtCa²⁺ was overloaded under inflammatory conditions, accompanied by disruption of whole-cell Ca²⁺ homeostasis. We also observed marked mitochondrial ultrastructural damage, mitochondrial DNA (mtDNA) leakage, and activation of the cyclic GMP-AMP synthase (cGAS)- stimulator of interferon genes (STING) pathway. The mitochondrial Ca²⁺ channel proteins, voltage dependent anion channel 1 (VDAC1) and mitochondrial calcium uniporter (MCU), were significantly upregulated in periodontitis gingiva, and their expression positively correlated with probing depth. Pharmacological inhibition of VDAC1 or MCU attenuated mtCa²⁺ overload, reduced mtDNA release and downregulated pro-inflammatory cytokines. These findings link mtCa²⁺ overload to mtDNA leakage and innate immune activation in periodontitis, and identify VDAC1 and MCU as promising therapeutic targets to restore mtCa²⁺ homeostasis and control host immune responses. Full article