Search Results (1,235)

Alzheimer’s disease (AD) is increasingly recognized as a multifactorial disorder driven by a combination of disruptions in proteostasis and organelle communication. The 2020 Lancet commission reported that approximately 10 million people worldwide were affected by AD in the mid-20th century. AD is the most prevalent cause of dementia. By early 2030, the global cost of dementia is projected to rise by USD 2 trillion per year, with up to 85% of that cost attributed to daily patient care. Several factors have been implicated in the progression of neurodegeneration, including increased oxidative stress, the accumulation of misfolded proteins, the formation of amyloid plaques and aggregates, the unfolded protein response (UPR), and mitochondrial–endoplasmic reticulum (ER) calcium homeostasis. However, the exact triggers that initiate these pathological processes remain unclear, in part because clinical symptoms often emerge gradually and subtly, complicating early diagnosis. Among the early hallmarks of neurodegeneration, elevated levels of reactive oxygen species (ROS) and the buildup of misfolded proteins are believed to play pivotal roles in disrupting proteostasis, leading to cognitive deficits and neuronal cell death. The accumulation of amyloid-β (Aβ) plaques and tau neurofibrillary tangles is a characteristic feature of AD. These features contribute to chronic neuroinflammation, which is marked by the release of pro-inflammatory cytokines and chemokines that exacerbate oxidative stress. Given these interconnected mechanisms, targeting stress-related signaling pathways, such as oxidative stress (ROS) generated in the mitochondria and ER, ER stress, UPR, and cytosolic chaperones, represents a promising strategy for therapeutic intervention. This review focuses on the relationship between stress chaperone responses and organelle function, particularly the interaction between mitochondria and the ER, in the development of new therapies for AD and related neurodegenerative disorders. Full article

Background/Objectives: An important new consideration when studying autism spectrum disorder (ASD) is the bioenergetic mechanisms underlying the relatively recent rapid evolutionary expansion of the human brain, which pose fundamental risks for mitochondrial dysfunction and calcium signaling abnormalities and their potential role in ASD, as recently highlighted by insights from the BTBR mouse model of ASD. The rapid brain expansion taking place as Homo sapiens evolved, particularly in the parietal lobe, led to increased energy demands, making the brain vulnerable to such metabolic disruptions as are seen in ASD. Methods: Mitochondrial dysfunction in ASD is characterized by impaired oxidative phosphorylation, elevated lactate and alanine levels, carnitine deficiency, abnormal reactive oxygen species (ROS), and altered calcium homeostasis. These dysfunctions are primarily functional, rather than being due to mitochondrial DNA mutations. Calcium signaling plays a crucial role in neuronal ATP production, with disruptions in inositol 1,4,5-trisphosphate receptor (ITPR)-mediated endoplasmic reticulum (ER) calcium release being observed in ASD patient-derived cells. Results: This impaired signaling affects the ER–mitochondrial calcium axis, leading to mitochondrial energy deficiency, particularly in high-energy regions of the developing brain. The BTBR mouse model, with its unique Itpr3 gene mutation, exhibits core autism-like behaviors and metabolic syndromes, providing valuable insights into ASD pathophysiology. Conclusions: Various interventions have been tested in BTBR mice, as in ASD, but none have directly targeted the Itpr3 mutation or its calcium signaling pathway. This review presents current genetic, biochemical, and neurological findings in ASD and its model systems, highlighting the need for further research into metabolic resilience and calcium signaling as potential diagnostic and therapeutic targets for ASD. Full article

T cells play a vital role in resisting pathogen invasion and maintaining immune homeostasis. However, T cells gradually become exhausted under chronic antigenic stimulation, and this exhaustion is closely related to mitochondrial dysfunction in T cells. Mitochondria play a crucial role in the metabolic reprogramming of T cells to achieve the desired immune response. Here, we compiled the latest research on how mitochondrial metabolism determines T cell function and differentiation, with the mechanisms mainly including mitochondrial biogenesis, fission, fusion, mitophagy, and mitochondrial transfer. In addition, the alterations in mitochondrial metabolism in T-cell exhaustion were also reviewed. Furthermore, we discussed intervention strategies targeting mitochondrial metabolism to reverse T cell exhaustion in detail, including inducing PGC-1α expression, alleviating reactive oxygen species (ROS) production or hypoxia, enhancing ATP production, and utilizing mitochondrial transfer. Targeting mitochondrial metabolism in exhausted T cells may achieve the goal of reversing and preventing T cell exhaustion. Full article

The enzyme γ-glutamyl transpeptidase (GGT), located on the surface of cellular membranes, hydrolyzes extracellular glutathione (GSH) to guarantee the recycling of cysteine and maintain intracellular redox homeostasis. High expression levels of GGT on tumor cells are associated with increased cell proliferation and resistance against chemotherapy. Therefore, GGT inhibitors have potential as adjuvants in treating GGT-positive tumors; however, most have been abandoned during clinical trials due to toxicity. Recent studies indicate marine-derived ovothiols as more potent non-competitive GGT inhibitors, inducing a mixed cell-death phenotype of apoptosis and autophagy in GGT-overexpressing cell lines, such as the chronic B leukemic cell HG-3, while displaying no toxicity towards non-proliferative cells. In this work, we characterize the activity of two synthetic ovothiol analogs, L-5-sulfanylhistidine and iso-ovothiol A, in GGT-positive cells, such as HG-3 and HL-60 cells derived from acute promyelocytic leukemia. The two compounds inhibit the activity of membrane-bound GGT, without altering cell vitality nor inducing cytotoxic autophagy in HG-3 cells. We provide evidence that a portion of L-5-sulfanylhistidine enters HG-3 cells and acts as a redox regulator, contributing to the increase in intracellular GSH. On the other hand, ovothiol A, which is mostly sequestered by external membrane-bound GGT, induces intracellular ROS increase and the consequent autophagic pathways. These findings provide the basis for developing ovothiol derivatives as adjuvants in treating GGT-positive tumors’ chemoresistance. Full article

Background: Short-chain fatty acids (SCFAs), microbial metabolites also known as postbiotics, are essential for maintaining gut health. However, their antiproliferative effects on gastric cancer cells and potential interactions with conventional therapies remain underexplored. This study aimed to investigate the effects of three SCFA salts—magnesium acetate (A), sodium propionate (P), and sodium butyrate (B)—individually and in combination (APB), as well as in combination with dexamethasone (Dex), on AGS gastric adenocarcinoma cells. Methods: AGS cells were treated with PB, AP, AB, APB, Dex, and APB+Dex. Cell viability was assessed to determine antiproliferative effects, and the IC₅₀ of APB was calculated. Flow cytometry was used to evaluate apoptosis and necrosis. Reactive oxygen species (ROS) levels were measured to assess oxidative stress. Proteomic analysis via LC-MS was performed to identify differential protein expression and related pathways impacted by the treatments. Results: SCFA salts showed significant antiproliferative effects on AGS cells, with APB exhibiting a combined IC₅₀ of 568.33 μg/mL. The APB+Dex combination demonstrated strong synergy (combination index = 0.76) and significantly enhanced growth inhibition. Both APB and APB+Dex induced substantial apoptosis (p < 0.0001) with minimal necrosis. APB alone significantly increased ROS levels (p < 0.0001), while Dex moderated this effect in the combination group APB+Dex (p < 0.0001). Notably, the APB+Dex treatment synergistically targeted multiple tumour-promoting mechanisms, including the impairment of redox homeostasis through SLC7A11 suppression, and inhibition of the haemostasis, platelet activation network and NF-κB signalling pathway via downregulation of NFKB1 (−1.34), exemplified by increased expression of SERPINE1 (1.99) within the “Response to elevated platelet cytosolic Ca²⁺” pathway. Conclusions: These findings showed a multifaceted anticancer mechanism by APB+Dex that may collectively impair cell proliferation, survival signalling, immune modulation, and tumour microenvironment support in gastric cancer. Full article

Background: Rehmannia glutinosa, a traditional Chinese herb, is commonly used to treat vascular-related disorders. Sepsis-associated vascular endothelial dysfunction is closely associated with mitochondrial damage. This study investigated the protective effects of secondary metabolites from R. glutinosa against LPS-induced mitochondrial dysfunction in endothelial cells, providing potential therapeutic insights into sepsis-related vascular complications. Methods: Phytochemical profiling of fresh R. glutinosa roots was conducted, and the structures of new secondary metabolites (1 and 2) were elucidated through comprehensive spectroscopic analysis and ECD calculations. UPLC-Q-TOF-MS/MS characterized phenylethanoid glycosides. Mitochondrial function was assessed by measuring the membrane potential, ROS levels, and TOM20/DRP1 expression in LPS-injured HUVECs. Results: Two novel eremophilane-type sesquiterpenes, remophilanetriols J (1) and K (2), along with five known phenylethanoid glycosides (3–7), were isolated from the fresh roots of R. glutinosa. UPLC-Q-TOF-MS/MS analysis revealed unique fragmentation pathways for phenylethanoid glycosides (3–7). In LPS-injured HUVECs, all compounds collectively restored the mitochondrial membrane potential, attenuated ROS accumulation, and modulated TOM20/DRP1 expression. In particular, remophilanetriol K (2) exhibited potent protective effects at a low concentration (1.5625 μM). Conclusions: This study identifies R. glutinosa metabolites as potential therapeutics for sepsis-associated vascular dysfunction by preserving mitochondrial homeostasis. This study provides a mechanistic basis for the traditional use of R. glutinosa and offers valuable insights into the development of novel therapeutics targeting mitochondrial dysfunction in sepsis. Full article

Cadmium (Cd)-induced pulmonary toxicity is closely associated with ferroptosis, a regulated form of cell death characterized by iron-dependent lipid peroxidation (LPO). Luteolin (Lut) is a natural flavonoid compound that exists in many plants. In this study, we used human bronchial epithelial BEAS-2B cells to explore the impact of ferroptosis in the inhibition of Cd-induced BEAS-2B cells proliferation. BEAS-2B cells were exposed to Cd (5 μM) with/without Lut (10 μM), ferroptosis modulators (Ferrostatin-1 (Fer-1)/Erastin), or nuclear factor erythroid 2-related factor 2 (Nrf2) regulators (tert-butylhydroquinone (TBHQ)/ML385). Viability, iron content, reactive oxygen species (ROS), LPO, mitochondrial membrane potential (MMP), and glutathione peroxidase (GSH-PX) activity were assessed. Exposure to Cd significantly decreased cell viability, increased intracellular iron levels, ROS production, and LPO activity, while simultaneously reducing MMP and GSH-PX activity. Fer-1 mitigated Cd-induced cytotoxicity, but Erastin intensified these effects. Mechanistically, Cd exposure suppressed the Nrf2/Solute Carrier Family 7 Member 11 (SLC7A11)/glutathione peroxidase 4 (GPX4) signaling pathway, which plays a crucial role in maintaining redox homeostasis. Activation of Nrf2 using TBHQ mitigated oxidative stress and upregulated the expression of key proteins within this pathway, while inhibition of Nrf2 with ML385 exacerbated cellular damage. Notably, Lut treatment could significantly alleviate Cd-induced cytotoxicity, oxidative stress, and downregulation of Nrf2/SLC7A11/GPX4 proteins. These findings demonstrate that ferroptosis is a critical mechanism underlying Cd-mediated lung epithelial injury and identify Lut as a promising therapeutic candidate via its activation of Nrf2-driven antioxidant defense mechanisms. This study provides novel insights into molecular targets for the prevention and treatment of Cd-associated pulmonary disorders. Full article

The functional role of MAPKK genes in potato (Solanum tuberosum L.) under high-temperature stress remains unexplored, despite their critical importance in stress signaling and yield protection. We characterized StMAPKK1, a novel group D MAPKK localized to plasma membrane/cytoplasm. Quantitative real-time polymerase chain reaction (qRT-PCR) revealed cultivar-specific upregulation in potato (‘Atlantic’ and ‘Desiree’) leaves under heat stress (25 °C, 30 °C, and 35 °C). Transgenic lines overexpressing (OE) StMAPKK1 exhibited elevated antioxidant enzyme activity, including ascorbate peroxidase (APX), catalase (CAT), superoxide dismutase (SOD), and peroxidase (POD), mitigating oxidative damage. Increased proline and chlorophyll accumulation and reduced oxidative stress markers, hydrogen peroxide (H₂O₂) and malondialdehyde (MDA), indicate improved cellular redox homeostasis. The upregulation of key antioxidant and heat stress-responsive genes (StAPX, StCAT1/2, StPOD12/47, StFeSOD2/3, StMnSOD, StCuZnSOD1/2, StHSFA3 and StHSP20/70/90) strengthened the enzymatic defense system, enhanced thermotolerance, and improved photosynthetic efficiency, with significant improvements in net photosynthetic rate (Pn), transpiration rate (E), and stomatal conductance (Gs) under heat stress (35 °C) in StMAPKK1-OE plants. Superior growth and biomass (plant height, plant and its root fresh and dry weights, and tuber yield) accumulation, confirming the positive role of StMAPKK1 in thermotolerance. Conversely, RNA interference (RNAi)-mediated suppression of StMAPKK1 led to a reduction in enzymatic activity, proline content, and chlorophyll levels, exacerbating oxidative stress. Downregulation of antioxidant-related genes impaired ROS scavenging capacity and declines in photosynthetic efficiency, growth, and biomass, accompanied by elevated H₂O₂ and MDA accumulation, highlighting the essential role of StMAPKK1 in heat stress adaptation. These findings highlight StMAPKK1’s potential as a key genetic target for breeding heat-tolerant potato varieties, offering a foundation for improving crop resilience in warming climates. Full article

Air pollution acts as a pervasive oxidative stressor, disrupting global crop production and ecosystem health through the overproduction of reactive oxygen species (ROS). Hazardous pollutants impair critical physiological processes—photosynthesis, respiration, and nutrient uptake—triggering oxidative damage and yield losses. This review synthesizes current knowledge on plant defense mechanisms, emphasizing the integration of enzymatic (SOD, POD, CAT, APX, GPX, GR) and non-enzymatic (polyphenols, glutathione, ascorbate, phytochelatins) antioxidant systems to scavenge ROS and maintain redox homeostasis. We highlight the pivotal roles of transcription factors (MYB, WRKY, NAC) in orchestrating stress-responsive gene networks, alongside MAPK and phytohormone signaling (salicylic acid, jasmonic acid, ethylene), in mitigating oxidative stress. Secondary metabolites (flavonoids, lignin, terpenoids) are examined as biochemical shields against ROS and pollutant toxicity, with evidence from transcriptomic and metabolomic studies revealing their biosynthetic regulation. Furthermore, we explore biotechnological strategies to enhance antioxidant capacity, including overexpression of ROS-scavenging genes (e.g., TaCAT3) and engineering of phenolic pathways. By addressing gaps in understanding combined stress responses, this review provides a roadmap for developing resilient crops through antioxidant-focused interventions, ensuring sustainability in polluted environments. Full article

Inflammatory Bowel Disease (IBD), which includes ulcerative colitis (UC) and Crohn’s disease (CD), results from dysregulated immune responses that drive chronic intestinal inflammation. Neutrophils, as key effectors of the innate immune system, contribute to IBD through multiple mechanisms, including the release of reactive oxygen species (ROS), pro-inflammatory cytokines, and neutrophil extracellular traps (NETs). NETs are web-like structures composed of DNA, histones, and associated proteins including proteolytic enzymes and antimicrobial peptides. NET formation is increased in IBD and has a context-dependent role; under controlled conditions, NETs support antimicrobial defense and tissue repair, whereas excessive or dysregulated NETosis contributes to epithelial injury, barrier disruption, microbial imbalance, and thrombotic risk. This review examines the roles of neutrophils and NETs in IBD. We summarize recent single-cell and spatial-omics studies that reveal extensive neutrophil heterogeneity in the inflamed gut. We then address the dual role of neutrophils in promoting tissue damage—through cytokine release, immune cell recruitment, ROS production, and NET formation—and in supporting microbial clearance and mucosal healing. We also analyze the molecular mechanisms regulating NETosis, as well as the pathways involved in NET degradation and clearance. Focus is given to the ways in which NETs disrupt the epithelial barrier, remodel the extracellular matrix, contribute to thrombosis, and influence the gut microbiota. Finally, we discuss emerging therapeutic strategies aimed at restoring NET homeostasis—such as PAD4 inhibitors, NADPH oxidase and ROS pathway modulators, and DNase I—while emphasizing the need to preserve antimicrobial host defenses. Understanding neutrophil heterogeneity and NET-related functions may facilitate the development of new therapies and biomarkers for IBD, requiring improved detection tools and integrated multi-omics and clinical data. Full article

Background/Objectives: Oxidative stress constitutes a principal pathophysiological mechanism driving neurodegeneration and brain aging. α-Ketoglutarate (AKG), a key intermediate of the tricarboxylic acid (TCA) cycle, has shown potential in longevity and oxidative stress resistance. However, the role of AKG in oxidative stress-induced neuronal senescence and its interaction with the mTOR signaling pathway during neuronal aging remain poorly understood, posing a key challenge for developing senescence-targeted therapies. Methods: We investigated the neuroprotective effects of AKG using H₂O₂-induced senescence in HT22 cells and a D-galactose-induced brain aging mouse model. Assessments encompassed SA-β-gal staining, EdU incorporation, mitochondrial membrane potential (JC-1), and ROS measurement. Antioxidant markers, ATP levels, and the NAD⁺/NADH ratio were also analyzed. Proteomic profiling (DIA-MS) and KEGG/GSEA enrichment analyses were employed to identify AKG-responsive signaling pathways, and Western blotting validated changes in mTOR signaling and downstream effectors. Results: AKG significantly alleviated H₂O₂-induced senescence in HT22 cells, evidenced by enhanced cell viability, reduced ROS level, restored mitochondrial function, and downregulated p53/p21 expression. In vivo, AKG administration improved cognitive deficits and vestibulomotor dysfunction while ameliorating brain oxidative damage in aging mice. Proteomics revealed mTOR signaling pathways as key targets for AKG’s anti-aging activity. Mechanistically, AKG suppressed mTOR phosphorylation and activated ULK1, suggesting modulation of autophagy and metabolic homeostasis. These effects were accompanied by enhanced antioxidant enzyme activities and improved redox homeostasis. Conclusions: Our study demonstrates that AKG mitigates oxidative stress-induced neuronal senescence through suppression of the mTOR pathway and enhancement of mitochondrial and antioxidant function. These findings highlight AKG as a metabolic intervention candidate for age-related neurodegenerative diseases. Full article

Male infertility is a pathological condition that affects many subjects and for which a progressive increase in cases has been observed in recent years. The mechanisms underlying male reproductive system dysfunction are not fully understood and the specific drugs use has not produced optimal results. Therefore, the focus on developing new therapeutic options to prevent or treat this dysfunction is continuously growing. Defective sperm function has been associated with oxidative stress (OS) due to reactive oxygen species (ROS) excessive production. OS is related to mitochondrial dysfunction, lipid peroxidation, DNA damage and fragmentation, and ultimately sperm cell death. Many defense mechanisms to protect from ROS injuries have been developed; natural antioxidants, such as vitamin C and E are able to interact with oxidizing radicals, neutralizing them. Interestingly, resveratrol (RSV), a natural polyphenol with proven health-promoting actions, has been found to be an effective free radical scavenger in several in vitro and in vivo models, providing protection against OS. In this review, we discussed mechanisms related to the modulation of redox homeostasis in the testis and how the alteration of these processes can determine a damage in testicular function; particularly, we focused on the antioxidant properties of RSV that could give beneficial effects in preserving male fertility. Full article

The rapid evolution of pathogens and the limited genetic diversity of hosts are two major factors contributing to the plant pathogenic phenomenon known as the loss of disease resistance in maize (Zea mays L.). It has emerged as a significant biological stressor threatening the global food supplies and security. Based on previous cross-species homologous gene screening assays conducted in the laboratory, this study identified the maize disease-resistance candidate gene ZmNLR-7 to investigate the maize immune regulation mechanism against Bipolaris maydis. Subcellular localization assays confirmed that the ZmNLR-7 protein is localized in the plasma membrane and nucleus, and phylogenetic analysis revealed that it contains a conserved NB-ARC domain. Analysis of tissue expression patterns revealed that ZmNLR-7 was expressed in all maize tissues, with the highest expression level (5.11 times) exhibited in the leaves, and that its transcription level peaked at 11.92 times 48 h post Bipolaris maydis infection. Upon inoculating the ZmNLR-7 EMS mutants with Bipolaris maydis, the disease index was increased to 33.89 and 43.33, respectively, and the lesion expansion rate was higher than that in the wild type, indicating enhanced susceptibility to southern corn leaf blight. Physiological index measurements revealed a disturbance of ROS metabolism in ZmNLR-7 EMS mutants, with SOD activity decreased by approximately 30% and 55%, and POD activity decreased by 18% and 22%. Moreover, H₂O₂ content decreased, while lipid peroxide MDA accumulation increased. Transcriptomic analysis revealed a significant inhibition of the expression of the key genes NPR1 and ACS6 in the SA/ET signaling pathway and a decrease in the expression of disease-related genes ERF1 and PR1. This study established a new paradigm for the study of NLR protein-mediated plant immune mechanisms and provided target genes for molecular breeding of disease resistance in maize. Overall, these findings provide the first evidence that ZmNLR-7 confers resistance to southern corn leaf blight in maize by synergistically regulating ROS homeostasis, SA/ET signal transduction, and downstream defense gene expression networks. Full article

The accumulation of nanoparticles (NPs) in the female body has raised global concerns regarding potential effects on the reproductive system. This study aimed to investigate the toxic effects of nano-titanium dioxide (nano-TiO₂) exposure on the ovaries and the underlying mechanisms. By establishing a nano-TiO₂ accumulation model in mice, our research systematically evaluated the effects of different concentrations of nano-TiO₂ exposure on the development and reproductive endocrine functions of mice. The results showed that nano-TiO₂ exposure significantly reduced the littering rate, sex hormone levels, and ovarian index of mice, and the effects were dose-dependent. Studies on the mechanisms involved revealed that nano-TiO₂ induces an excessive production of reactive oxygen species (ROS), leading to the potential collapse of the mitochondrial membrane and an increase in the apoptosis rate of granulosa cells, thereby triggering oxidative stress and inhibiting the expression of ovarian-specific genes and granulosa-cell function genes. This study reveals the “dual blow” mechanism of nano-TiO₂-mediated ovarian morphology and function through oxidative stress in granulosa cells, namely directly disrupting cellular homeostasis and interfering with the reproductive-related gene network, ultimately leading to decreased ovarian function. This provides experimental evidence for assessing the reproductive risks of nanomaterials in women. Full article

Idiopathic pulmonary fibrosis (IPF) is a progressive and fatal lung disorder characterized by excessive scarring of lung tissue, predominantly affecting middle-aged and elderly populations. Oxidative stress plays a pivotal role in the pathogenesis of pulmonary fibrosis, disrupting redox homeostasis and driving fibrotic progression. Glutathione reductase (GSR), a key antioxidant enzyme, is essential for maintaining cellular glutathione (GSH) levels and mitigating oxidative damage. However, the specific involvement of GSR in IPF remains poorly understood. This study found that GSR levels were downregulated in IPF patients and mice treated with bleomycin (BLM). GSR knockdown enhanced epithelial-to-mesenchymal transition (EMT) in A549 cells and promoted the activation of MRC5 cells. Additionally, GSR depletion promoted cellular migration and senescence in both A549 and MRC5 cells. Mechanistically, silencing GSR in A549 and MRC5 cells led to a marked reduction in intracellular GSH levels, resulting in elevated reactive oxygen species (ROS) accumulation, thereby promoting the activation of the TGF-β/Smad2 signaling pathway. In conclusion, our findings demonstrate that GSR deficiency aggravates pulmonary fibrosis by impairing antioxidant defense mechanisms, promoting EMT, and activating fibroblasts through the TGF-β/Smad2 signaling. These findings suggest that GSR may be essential in reducing the fibrotic progression of IPF. Full article