Search Results (9,262)

Global plastic production has led to widespread contamination by micro- and nanoplastics, with polystyrene nanoplastics (PSNPs) increasingly being detected in human biological samples, including blood and cardiac tissue. Given the critical role of mitochondria in cardiac energy metabolism, this study investigated whether 100 nm PSNPs interact with mitochondria and affect mitochondrial function in H9c2 cardiomyoblasts. Cellular uptake and intracellular distribution were examined, followed by an evaluation of mitochondrial ultrastructure, intracellular and mitochondrial reactive oxygen species (ROS) production, mitochondrial membrane potential, mitochondrial dynamics and mitophagy-related gene expression, mitochondrial DNA copy number, and metabolic function. PSNPs were internalized but did not directly localize to mitochondria within 24 h. No significant cytotoxicity, increase in intracellular or mitochondrial ROS production, or alteration in basal metabolic activity was observed. However, PSNP exposure resulted in intracellular accumulation, an altered mitochondrial ultrastructure characterized by crista loosening and vacuole-like structural changes. These changes were accompanied by reduced mitochondrial membrane potential; the upregulation of mitochondrial dynamics-related genes, including optic atrophy 1 (Opa1) and dynamin-related protein 1 (Drp1); the suppression of PTEN-induced kinase 1 (PINK1)/Parkin RBR E3 ubiquitin protein ligase (Parkin)-mediated mitophagy-related genes; and decreased maximal respiratory capacity. Lactate production and the extracellular acidification rate remained unchanged, suggesting that compensatory glycolysis was not activated. These findings indicate that PSNP exposure induces early mitochondrial structural and functional alterations without substantial cell damage, suggesting a potential reduction in cardiac adaptive capacity under PSNP-induced stress conditions. Full article

Radiation therapy is a fundamental pillar in cancer treatment, yet its clinical efficacy is frequently compromised by the development of intrinsic and acquired tumor radioresistance. This review provides a comprehensive analysis of the molecular mechanisms underlying radioresistance, with a specific focus on the Epithelial–Mesenchymal Transition (EMT) and its regulation by microRNAs (miRNAs). EMT is recognized as a key driver of therapeutic resistance, enabling cancer cells to acquire enhanced migratory capacity, stem-like characteristics, and resistance to apoptosis. Importantly, ionizing radiation can itself function as a cellular stressor that induces EMT through major signaling pathways, including TGF-β, Wnt, and Notch, thereby establishing a self-reinforcing loop that promotes resistance. In addition, this review highlights the pivotal role of miRNAs as post-transcriptional regulators within this network. Dysregulated miRNAs, acting as either tumor suppressors or oncogenes, modulate EMT-transcription factors and DNA damage repair pathways to influence cellular radiosensitivity. The complex interplay between these factors and the tumor microenvironment is also explored. Finally, emerging therapeutic strategies designed to break this resistance loop, such as EMT inhibitors, miRNA mimics, and antagomirs, as well as combination therapies, are evaluated. Collectively, these approaches hold significant promise for restoring radiosensitivity and improving clinical outcomes in precision oncology. Full article

Oral mucosal repair is a redox-regulated process that may be impaired by diabetes, chronic inflammation, infection, and chemotherapy- or radiotherapy-induced oral mucositis. Reactive oxygen species (ROS) support host defense, epithelial migration, angiogenesis, extracellular matrix remodeling, and adaptive repair when their production is transient and compartmentalized. In contrast, persistent ROS promote lipid, protein, and DNA oxidation, mitochondrial dysfunction, and extracellular matrix damage. Photobiomodulation (PBM) is increasingly used to support oral tissue repair, but its effects should be interpreted as dose- and context-dependent redox modulation rather than as simple antioxidant activity. This narrative review synthesizes oxidative stress biomarkers and redox-sensitive pathways relevant to oral mucosal repair and PBM, including oxidant–antioxidant balance, lipid and protein oxidation, oxidative DNA damage, antioxidant defense, thiol/disulfide homeostasis, mitochondrial and NADPH oxidase-derived ROS, Nrf2/HO-1, NF-κB, HIF-1α/VEGF, MAPK/ERK, PI3K/Akt, and MMP/TIMP signaling. The review emphasizes the distinction between transient mitochondrial ROS/nitric oxide signaling and sustained NADPH oxidase-driven oxi-inflammatory stress. It proposes a practical redox-guided framework for biomarker selection, PBM response interpretation, and future study design, while noting that this framework remains conceptual and is not yet a validated clinical decision algorithm. Full article

Cellular senescence is a biological process involved in aging and neurodegenerative disease progression, characterized by cell-cycle arrest, oxidative stress, persistent DNA damage, and development of a pro-inflammatory senescence-associated secretory phenotype (SASP). While replicative senescence results from exhaustion of cellular proliferative capacity, stress-induced premature senescence (SIPS) can be induced by multiple triggers, contributing to various pathological conditions. Among compounds reported to modulate cellular senescence, quercetin (QUE), a dietary flavonoid with antioxidant and anti-inflammatory properties, has emerged as a promising modulator of senescence-related pathways. This study investigated the protective effects of QUE against oxidative stress-induced senescence in SH-SY5Y neuronal-like cells. Cells were exposed to H₂O₂ (25 μM) to trigger early SIPS and subsequently treated with QUE (2.5 and 5 μM) for 24 h. H₂O₂ induced a senescence-like phenotype characterized by increased senescence-associated β-galactosidase (SA-β-gal) activity, lamin-B1 depletion, activation of p53/p21 pathway, modulation of Bcl-2/Bax ratio, and upregulation of SASP mediators, including NF-κB, MCP-1 and PAI-1. QUE treatment significantly attenuated these markers in a dose-dependent manner. These effects were associated with the enhancement of Nrf2-linked antioxidant responses, indicating a potential contribution to QUE senescence-modulating properties. These findings support the potential of QUE as a senescence-modulating compound against oxidative stress-induced neuronal senescence through the modulation of key molecular pathways, along with the enhancement of Nrf2-associated antioxidant defenses. Full article

Background/Objectives: Cardiovascular disease increases with ageing and remains the leading cause of death worldwide. Cellular senescence contributes to cardiac dysfunction in the older population by secreting the senescence-associated secretory phenotype (SASP). Cardiac injury models induced by surgery have been shown to induce senescence in young adult rodents. However, surgical models are complex and associated with high mortality. Methods: We established a rat model of injury and senescence using isoproterenol (ISO). Male SD rats received ISO (100 mg/kg) for five days, then hearts were collected on days 10 and 28 after the first ISO dose. Results: ISO administration caused cardiac injury, manifested by inflammatory infiltration, fibrosis, and increased cardiomyocyte cross-sectional area. Cardiac injury was accompanied by an increase in the senescence markers SA-β-gal, p16 and p21, and DNA damage marker γH2AX. Moreover, the mRNA levels of p21 increased on day 10, along with several SASP factors, whereas the mRNA levels of p16 increased on day 28. Fibrosis, hypertrophy, and senescence persisted until day 28, indicating long-lasting cardiac remodeling and senescent cell accumulation. Conclusions: These findings suggest that ISO can provide a simple, cost-effective platform for studying senescence and cardiac injury. This model facilitates the study of timing, dosage, mechanisms and efficacy of senolytic interventions and may contribute to the development of senescence-targeted therapies. Full article

Reactive oxygen species (ROS) and reactive nitrogen species (RNS) are critical modulators of male reproductive health, influencing sperm function, hormonal regulation, and overall fertility. While physiological levels of ROS and RNS are essential for processes such as sperm capacitation and acrosome reaction, their overproduction leads to oxidative and nitrosative stress, contributing to male infertility. Excessive ROS and RNS can damage sperm DNA, proteins, and lipids, impairing motility, viability, and fertilizing capacity. Moreover, these reactive species disrupt the hypothalamic-pituitary-gonadal (HPG) axis, leading to hormonal imbalances that further compromise reproductive function. Environmental factors, lifestyle choices, and underlying health conditions exacerbate the production of ROS and RNS, highlighting the need for preventive and therapeutic strategies. Clinically, ROS- and RNS-mediated redox imbalance has been implicated in several male reproductive disorders, including varicocele, genital tract infection and inflammation, obesity, diabetes and other metabolic disorders, and toxicant-related reproductive dysfunction. Antioxidant supplementation has shown promise in mitigating oxidative stress; however, its efficacy varies, and further research is necessary to establish standardized treatment protocols. These findings underscore the clinical relevance of integrating oxidative stress assessment with conventional semen analysis to improve risk stratification and guide targeted interventions in male infertility. This review synthesizes current knowledge on the molecular mechanisms by which ROS and RNS affect male reproduction and discusses potential clinical interventions to address oxidative and nitrosative stress in male infertility. Full article

Ring finger protein 126 (RNF126) is a RING-type E3 ubiquitin ligase that has recently emerged as a multifaceted regulator of cellular homeostasis, stress adaptation, and disease progression. Through its structurally distinct zinc-finger and catalytic RING domains, RNF126 orchestrates substrate recognition and ubiquitin transfer, generating diverse ubiquitin linkages with both proteolytic and nonproteolytic functions. Initially characterized as a component of the protein quality control (PQC) machinery, RNF126 cooperates with chaperones such as BAG6 and UBQLN1 to eliminate mislocalized and misfolded proteins, thereby maintaining proteostasis. Beyond PQC, RNF126 plays pivotal roles in DNA damage response pathways by regulating homologous recombination, non-homologous end joining, checkpoint signaling, and genome stability through substrates, including MRE11, Ku80, RNF168, and 14-3-3σ. Genetic studies have further demonstrated its importance in embryogenesis and male fertility, and accumulating evidence has identified RNF126 as a critical driver of malignancy in multiple cancers. RNF126 promotes tumor progression by degrading or modulating key regulators, such as p21, PTEN, p53, PDKs, and LKB1, thereby enhancing proliferation, metabolic reprogramming, anoikis resistance, metastasis, and chemo/radioresistance. Intriguingly, RNF126 exhibits context-dependent functions, acting as an oncogene or tumor suppressor depending on the tissue type and substrate selection. In addition to cancer, RNF126 has been implicated in neurodegeneration, cardiac pathology, antiviral immunity and adaptive immune regulation. This review summarizes the current knowledge of RNF126 structure, ubiquitin signaling mechanisms, physiological functions, and pathological roles, while discussing emerging therapeutic strategies and future challenges for targeting RNF126 in precision medicine. Full article

Mitochondrial Lon peptidase 1 (LONP1) is an ATP-dependent AAA⁺ (ATPases associated with diverse cellular activities) protease that has emerged as a key regulator of mitochondrial proteostasis, with functions extending beyond protein quality control. In addition to degrading misfolded and oxidized proteins, LONP1 coordinates mitochondrial DNA maintenance, metabolic remodeling, and stress-responsive signaling. Recent structural and functional advances have expanded the biological significance of LONP1 beyond protein quality control, highlighting its roles in mitochondrial metabolism, genome maintenance, and stress responses. LONP1 dysregulation is increasingly implicated in cancer, metabolic disorders, neurodegeneration, and aging, where it exerts context-dependent effects on cell survival and disease progression. In cancer, LONP1 supports metabolic plasticity, redox adaptation, and therapeutic resistance, whereas in degenerative conditions, its decline contributes to mitochondrial dysfunction and tissue damage. Here, we synthesize recent insights into the structure, mechanisms, and biological functions of LONP1 and discuss their implications for human disease. We further discuss emerging therapeutic strategies and key challenges for targeting LONP1 in human disease. Full article

p53 tumor suppressor evolved as a critical player in navigating the response to environmental stresses such as DNA or oxidative damage and drives cell fate by governing life and death decisions. The p53 protein is encoded by the most commonly mutated gene in human cancers. TP53 gene mutations are associated with worse prognosis and refractory and relapsed disease. The most prevalent mutations are of the missense type and often result in disruption of the DNA-binding capacity and transcription activity. In healthy cells, p53 protein is tightly regulated by its E3 ubiquitin ligase, MDM2 (HDM2), its own transcription target. Mutant p53, therefore, escapes the regulation by the negative feedback loop and is often found upregulated in cancer cells. The efforts to exploit wild-type and mutant p53 for precision oncology have been ongoing in the last two decades yet have not been successful. A recently reported strategy to target TP53-mutant cancers leverages induced proximity, utilizing the high cellular abundance of mutant p53 as a scaffold to concentrate a small-molecule inhibitor against an essential survival protein. This strategy relies on the Regulated Induced Proximity TArgeting Chimera (RIPTAC). Given the recent FDA approval of the first chimeric drug, vepdegestrant, killing by proximity might turn out to be a promising medical advancement for precision oncology. Full article

Background/Aims: While pathogenic germline variants play a critical role in pediatric cancer susceptibility, traditional clinical genetics primarily focuses on single-gene interpretations. Transitioning to a systems-level analysis of inherited variation can uncover shared biological vulnerabilities, informing genetic counseling, surveillance, and targeted therapeutics. This study aims to implement an unsupervised machine learning framework to identify and characterize Germline Mutation Signatures (GMS) across diverse pediatric malignancies, elucidating latent genomic patterns that reveal shared oncogenic mechanisms. Methods: We analyzed germline whole-exome and whole-genome sequencing (WES/WGS) data from a retrospective cohort of 420 pediatric cancer patients and matched non-cancer controls. Variants were deeply annotated to capture multi-dimensional features, including predicted pathogenicity, splice-site disruption, regulatory impact, population frequency, and sequence context. To enable robust modeling, we integrated an augmented feature set encompassing evolutionary constraint, loss-of-function intolerance, and compositionally normalized substitution spectra. These high-dimensional annotations were processed using a deep autoencoder for non-linear representation learning, followed by Gaussian Mixture Modeling (GMM) of the latent space. Results: The framework delineated 13 signatures (GMS1–GMS13), yielding an optimal Davies–Bouldin index of 1.051. These signatures map to fundamental biological processes, including DNA repair deficiencies, transcription-coupled damage, replication stress, and aberrant RNA regulation. Crucially, these GMSs transcend traditional tissue-of-origin classifications, manifesting across multiple distinct cancer types. This observation indicates convergent germline etiologies and suggests potential shared susceptibilities to pathway-directed therapies. Conclusions: The discovery of these cross-cancer signatures provides a scalable, biologically interpretable framework for decoding inherited pediatric cancer risk. While the therapeutic mapping networks identified are currently exploratory and serve as a hypothesis-generating foundation, this deep learning-driven paradigm establishes a robust basis for stratified precision medicine. Pending prospective clinical validation, this approach holds significant translational potential to move beyond single-gene paradigms toward unified, systems-level precision oncology strategies. Full article

Spinocerebellar ataxia type 7 (SCA7) is a hereditary disorder characterized by degeneration of the cerebellum and retina. SCA7 is caused by the expansion of a polyQ tract in the ATXN7 gene, leading to protein misfolding, transcriptional dysregulation, and neuronal/glial degeneration. Recently, altered DNA damage response (DDR) was revealed in SCA7, which may contribute to disease pathogenesis. Impaired DDR causes DNA damage, which in turn triggers cellular senescence. Consistently, senescent cells were identified in the cerebellum Purkinje layer of an SCA7 mouse model. In this study a Müller glial model (MIO-M1) expressing normal (10Q) or expanded (64Q) ataxin-7 was utilized to ascertain whether mutant protein induces genomic instability and consequently the emergence of senescence. PolyQ ataxin-7 elicits nuclear lamina disorganization, γH2AX foci (DDR marker), micronuclei and telomere shortening, which indicate genomic instability. Furthermore, 64Q cells expressing polyQ ataxin-7 exhibited senescence hallmarks, including heterochromatin loss and increased senescence-associated β-galactosidase activity, but not p21 nor p53 expression. Instead of the senescence-associated enlargement of nucleoli, these cells exhibited nucleolar disaggregation. Together, these findings indicate that the expression of polyQ ataxin-7 disrupts the nuclear architecture, thereby inducing genomic instability. This, in turn, results in a senescence-like phenotype, a phenomenon that may contribute to glial pathogenesis. Full article

Chronic obstructive pulmonary disease (COPD) is characterized by systemic inflammation, immune dysregulation, and increased susceptibility to infections. Obesity may influence these processes and has been proposed as a potential contributor to the so-called “obesity paradox”, although its effects on immune competence, viral burden, and survival are not yet fully understood. Seventy patients with severe to very severe COPD (GOLD stage 3–4) were stratified according to BMI (<30 vs. ≥30 kg/m²). Clinical and functional parameters were assessed together with biomarkers of oxidative stress, DNA damage, systemic inflammation, and T-cell subsets. A comprehensive viral panel, including Torque Teno virus (TTV), was also analyzed. Five-year survival was evaluated using Kaplan–Meier curves and Cox regression models. Patients with BMI ≥ 30 showed higher lymphocyte counts and increased CD4⁺ and CD8⁺ T-cell levels, accompanied by lower systemic inflammatory indices. No significant differences were observed in oxidative stress or DNA damage markers. In addition, TTV viremia (≥4 log₁₀ copies/mL) was more frequently observed among patients with lower BMI. Despite these differences, five-year survival did not significantly differ between the two groups. These findings suggest that BMI alone may have limited value as a predictor of outcomes in patients with advanced COPD. Conversely, immune-inflammatory indices and viral burden, particularly TTV viremia, could provide complementary information for risk assessment and may deserve further investigation as potential tools for personalized patient stratification. Full article

Colorectal cancer (CRC) is driven by oxidative stress, chronic inflammation, and disruption of cytoprotective signaling pathways. This study aimed to evaluate whether poly(lactic-co-glycolic acid) (PLGA)-based nanoparticle delivery enhances the chemoprotective efficacy of paeonol against 1,2-dimethylhydrazine (DMH)-induced colorectal carcinogenesis, with a focus on modulation of the NRF2/HO-1 pathway. Sixty male Wistar rats were randomly assigned to six groups: control, paeonol (PNL), PNL-PLGA, DMH, DMH + PNL, and DMH + PNL-PLGA. CRC was induced using DMH over 10 weeks. Serum tumor biomarkers (AFP, CEA, CA19-9, CA125, CA15-3), oxidative stress markers (ROS, MDA, antioxidant enzymes), inflammatory cytokines, DNA damage, apoptosis- and autophagy-related gene expression, and hepatic and renal function were assessed. Histopathological and ultrastructural analyses of colonic tissues were performed. DMH exposure was markedly associated with increased tumor biomarkers, oxidative stress, and inflammatory mediators, DNA damage, and impaired liver and kidney function. It was also associated with the restoration of NRF2/HO-1 signaling, improved redox balance, suppression of inflammation, reduction in DNA damage, and preservation of regulated NRF2/HO-1 signaling, antioxidant defenses, autophagy markers, and apoptotic proteins, as well as severe histological and ultrastructural alterations. Free paeonol partially attenuated these changes. In contrast, PNL-PLGA was significantly associated with restoring NRF2/HO-1 signaling, improving redox balance, suppressing inflammation, reducing DNA damage, and preserving colonic architecture and ultrastructure. These findings demonstrate that a PLGA-based nanoformulation of paeonol markedly improves its chemopreventive efficacy against DMH-induced CRC, primarily by activating NRF2/HO-1 signaling and modulating oxidative stress, inflammation, apoptosis, and autophagy, highlighting its potential as a promising nanotherapeutic strategy for colorectal cancer. Full article

Background/Objectives: Autophagy is a key degradative pathway involved in orthodontic tooth movement. DNA damage-regulated autophagy modulator 1 (DRAM1), a protein that plays a central role in the degradation of autophagic cargo, exhibits differential regulation in human periodontal ligament (hPDL) fibroblasts under compressive force. Single-nucleotide polymorphisms (SNPs) may influence force-induced gene expression. Therefore, this study investigated the impact of DRAM1 SNPs on its expression in hPDL fibroblasts under compression force. Methods: The hPDL sample comprised cells of 59 patients. A physiological compressive strain of 2 g/cm³ was used to simulate orthodontic tooth movement. Total RNA from hPDL fibroblasts was isolated to determine DRAM1 relative gene expression under loaded conditions and in a physiological control. Furthermore, a genotyping analysis of six SNPs within the DRAM1 gene (rs756534 (G/T), rs2138257 (C/T), rs2176092 (C/T), rs4622329 (A/G), rs10860812 (A/G), and rs4764657 (A/G)) was performed using real-time polymerase chain reaction. DRAM1 expression was com-pared among genotypes of each SNP using an alpha of 5%. Linear regression analysis was then employed to evaluate SNP-SNP interaction. Results: The relative DRAM1 gene expression was not statistically significantly different (p > 0.05) according to the geno-types. The SNP-SNP interaction did not demonstrate any statistically significant associ-ation either. Conclusions: DRAM1 gene expression in hPDL fibroblasts under orthodontic compression may not be regulated by the studied intronic SNPs in the gene encoding DRAM1. Full article

N-nitrosamines and acrylamide are food mutagens classified as “probably carcinogenic to humans (Group 2A)” by the International Agency for Research on Cancer (IARC) from evidence of carcinogenicity. One of the main objectives of food safety is to reduce the presence of these substances in food. Therefore, the present study aimed to evaluate the effect of the addition of propolis, royal jelly or a combination of both bee products (2–10%) to chestnut and thyme honey on their protective properties against food mutagen-induced genotoxicity. DNA damage was evaluated by the alkaline comet assay. N-nitrosamines (N-nitrosodimethylamine (NDMA) and N-nitrosopyrrolidine (NPYR)) and acrylamide (AA) induced genotoxicity in human hepatoma HepG2 cells. All tested samples at all concentrations used (0.1–10 µg/mL) decreased genotoxic effects of the three food mutagens. The protective effects of honey samples and mixtures towards DNA damage induced by food mutagens were in the following order: NDMA > AA > NPYR, being more effective against NDMA compared to AA and NPYR. The mixtures of chestnut honey with 10% propolis, or 10% royal jelly, and 10% propolis showed a greater protective effect against NDMA, NPYR and AA compared to the honey sample alone. This protective activity may be attributable to the phenolic compound content and antioxidant capacity exhibited by the analyzed samples. Overall, the results suggest that thyme and chestnut honey supplemented with bee-derived products could represent potential natural chemopreventive candidates against food-borne mutagens. Full article