Search Results (5,624)

Quercetin, a naturally occurring flavonoid, exhibits antiproliferative and pro-apoptotic effects across various cancer models. Topotecan, a topoisomerase I inhibitor, is used in the treatment of retinoblastoma; however, its clinical utility is limited by dose-dependent toxicity. This study aimed to investigate whether quercetin is associated with enhanced topotecan-induced cytotoxicity in retinoblastoma and to explore the underlying mechanisms under both two-dimensional (2D) and three-dimensional (3D) conditions. Cell viability was assessed using the MTT assay, and drug interactions were evaluated using the combination index (CI) based on the Chou–Talalay method. Apoptosis was analyzed by Annexin V-FITC/PI staining and flow cytometry. Reactive oxygen species (ROS) levels and mitochondrial membrane potential were evaluated using fluorometric methods, and N-acetyl-L-cysteine (NAC) was used for functional modulation of oxidative stress. Three-dimensional tumor spheroid models were used to assess treatment effects under conditions that partially recapitulate tumor architecture. Gene expression levels of apoptosis-related markers and PI3K/Akt/mTOR pathway components were analyzed by quantitative real-time polymerase chain reaction (qRT-PCR). The combination of quercetin and topotecan was associated with synergistic cytotoxic effects in Y79 cells (CI < 1), accompanied by increased ROS levels, mitochondrial membrane depolarization, and elevated apoptotic cell death. NAC co-treatment partially attenuated ROS levels and restored cell viability. In 3D spheroid models, combination treatment induced structural disruption, reduced viability, and increased cell death, effects that were partially reversed by NAC. Gene expression analysis revealed upregulation of pro-apoptotic genes and downregulation of survival-related genes, along with increased PTEN expression. Quercetin is associated with enhanced topotecan-induced cytotoxicity in retinoblastoma cells under both 2D and 3D conditions. These effects were associated with ROS-associated cellular stress, mitochondrial dysfunction, and modulation of apoptotic and survival-related pathways. The partial rescue by NAC supports a contributory, but not exclusive, role of oxidative stress. These findings should be interpreted within a preclinical context and suggest that quercetin may represent a potential adjunct strategy warranting further validation in translational and in vivo models. Full article

Oral mucosal ulcers sustain a persistent inflammatory and oxidative microenvironment that interferes with epithelial repair and delays healing. Although hyaluronic acid (HA) is used in oral wound management due to its biocompatibility and hydrating properties, its biological activity is highly context-dependent and can be compromised under inflammatory conditions. In contrast, N-acetyl-L-cysteine (NAC) is a well-established antioxidant with documented anti-inflammatory effects, yet its rapid clearance limits its effectiveness when applied locally. In this study, the effects of HA and NAC, individually and in combination, on metabolic activity and inflammatory responses of TNF-α–stimulated human gingival keratinocytes were evaluated. In parallel, the individual immobilization of HA or NAC onto plasma-activated decellularized extracellular matrix (dECM) films was investigated as a materials-oriented approach for potential localized intraoral applications. NAC significantly attenuated TNF-α-induced IL-6 and IL-8 secretion, reducing both cytokines by approximately 99%, while preserving keratinocyte metabolic activity. HA displayed limited immunomodulatory effects. The combined HA + NAC condition did not improve the response compared with NAC alone. Plasma treatment enabled stable individual grafting of HA and NAC onto dECM films, and both functionalized surfaces retained chemical stability under saliva-like conditions. Collectively, these findings identify NAC as the most effective anti-inflammatory candidate under the tested cellular conditions and support plasma-functionalized dECM films as a feasible platform for future biological evaluation in intraoral applications. Full article

Background: To evaluate the effects of a preservative-free artificial tear formulation containing trehalose, sodium hyaluronate, and N-acetyl-aspartyl-glutamate (NAAGA) on ocular surface parameters and quality of life in patients with primary open-angle glaucoma (POAG) treated with preserved versus preservative-free prostaglandin analogues. Methods: For this prospective, observational clinical study, thirty-eight patients (76 eyes) with POAG receiving stable topical prostaglandin therapy were enrolled and divided into two groups: preserved prostaglandins (Group 1, n = 44) and preservative-free prostaglandins (Group 2, n = 32). All patients received adjunctive preservative-free artificial tears (trehalose, sodium hyaluronate, NAAGA) three times daily for one month. Assessments at baseline (T0) and 1 month (T1) included best-corrected visual acuity (BCVA), intraocular pressure (IOP), contrast sensitivity, Schirmer test, tear break-up time (BUT), Efron grading scale, Ocular Surface Disease Index (OSDI), visual field (VF) indices (Mean Deviation (MD), Pattern Standard Deviation (PSD), Visual Field Index (VFI)), and quality of life (QoL) measured using Visual Analogue Scales (VAS). Results: After 1 month, both groups demonstrated significant improvement in ocular surface parameters. Schirmer test increased by approximately 4–5 mm (p = 0.001 in both groups), and BUT improved by 5 s (p = 0.001 in both groups). OSDI scores significantly decreased (Group 1: –18.5; Group 2: –23; p = 0.001 for both), and Efron grading significantly improved (p = 0.001 in both groups). Artificial tears-related QoL markedly increased in both groups (p = 0.001), while pathology-related QoL remained unchanged. IOP showed a modest but significant reduction in both groups (Group 1 p = 0.011; Group 2 p = 0.003), without intergroup differences. VFI significantly improved in both groups from T0 to T1 (Group 1 p = 0.013; Group 2 p = 0.04). Group 1 also showed an improvement in terms of PSD (p = 0.025). Conclusions: Adjunctive treatment with preservative-free artificial tears containing trehalose, sodium hyaluronate, and NAAGA significantly improved tear film stability VF indexes, ocular surface signs and symptoms, and patient-reported QoL in POAG patients treated with prostaglandins, regardless of preservative status. Routine ocular surface optimization should be considered an integral component of comprehensive glaucoma management. Full article

In this study, a hydrogel was developed based on a chondroitin sulfate–iron complex (CSFe) incorporated into a sodium alginate matrix. The CSFe complex was first prepared through the interaction of chondroitin sulfate (CS) with Fe³⁺ ions, achieving an iron content of 2.06%. Structural characterization confirmed that Fe³⁺ coordinated with the carboxyl, sulfate, and N-acetyl groups of CS, resulting in increased molecular weight and altered physicochemical properties. The CSFe complex exhibited significant antibacterial activity against Escherichia coli and Staphylococcus aureus (S. aureus), and was further incorporated into a sodium alginate matrix to form an injectable hydrogel with favorable physicochemical properties such as spreadability, shear-thinning behavior, and a compact porous microstructure. In a mouse model of S. aureus-infected wounds, the CSFe hydrogel significantly accelerated wound closure, reduced the levels of pro-inflammatory cytokines (TNF-α and IL-6), and increased the anti-inflammatory cytokine IL-10, indicating potent anti-infective and immunomodulatory functions. Overall, this work presents a multifunctional CSFe-incorporated hydrogel system that integrates antibacterial, anti-inflammatory, and tissue-regenerative properties, offering a promising strategy for infected wound healing and highlighting the potential of trivalent iron–polysaccharide coordination complexes in the development of advanced biomedical materials. Full article

Objectives: This study aims to identify the reactive metabolite of acetaminophen (AAP) and the cyanopyrrolidine metabolite of saxagliptin in human induced pluripotent stem cell-derived hepatic organoids (HHOs) and to compare them with human liver microsomes (HLMs) and plateable cryopreserved human hepatocytes (CHHs) to evaluate the feasibility of HHOs for reactive metabolite screening and metabolite profiling. Methods: AAP (50 μM) or sax-agliptin (50 μM) was incubated for 1 h at 37 °C in HLMs with or without NADPH-generating solution and 0.5 mM reduced glutathione (GSH). AAP (50 μM) was incubated for 24 h in HHOs and CHHs at 37 °C in a CO₂ incubator. AAP and saxagliptin metabolites in the reaction mixtures were analyzed using ultra-performance liquid chromatography coupled with tandem mass spectrometry. Results: N-acetyl-p-benzoquinone imine (NAPQI) was identified in the incubation mixture of HLMs with AAP, and its levels were reduced in the presence of GSH, accompanied by increased formation of AAP–GSH adduct. Incubation of AAP with HHOs for 24 h resulted in the formation of NAPQI, AAP–GSH, AAP–glucuronide, and AAP–sulfate. Moreover, CYP1A2 induction using omeprazole treatment increased the formation of AAP and AAP–GSH conjugate from phenacetin, reflecting enhanced CYP1A2 activity in both CHHs and HHOs. The findings indicate that HHOs are a suitable platform for reactive metabolites, such as NAPQI and AAP–GSH adducts, under chronic exposure and metabolic modulator intervention. Additionally, CHHs and HHOs exhibited similar saxagliptin metabolite profiles after incubation with saxagliptin and generated cysteine conjugates of saxagliptin and its hydroxylated metabolite. Conclusions: HHOs system can be used as an in vitro model for screening reactive metabolites, comparable to those obtained with CHHs. Full article

Parkinson’s disease (PD) is a common neurodegenerative disorder marked by progressive loss of dopaminergic neurons in the substantia nigra pars compacta and the accumulation of Lewy bodies, intracellular inclusions enriched in α-synuclein. Synphilin-1 interacts with α-synuclein, localizes to Lewy bodies, and has been implicated in inclusion formation and neuroprotection in cellular and animal models; however, its physiological function in vivo remains poorly defined. Here, we generated and characterized a synphilin-1 knockout (Sph-1 KO) mouse by targeted genetic deletion of the Sph-1 locus and performed a comprehensive phenotyping battery including behavioral testing as well as biochemical, histological, structural, and ultrastructural analyses. Sph-1 KO mice survived to nearly two years of age and showed normal body weight, lifespan, motor performance, learning and memory, anxiety-like behavior, attention, and gross brain morphology. Western blot analyses indicated that levels of α-synuclein and synaptic proteins were largely unchanged. While outer mitochondrial membrane proteins were unaffected, the mitochondrial matrix protein HSP60 was reduced, consistent with altered mitochondrial proteostasis in the absence of synphilin-1. Strikingly, histochemical analyses, magnetic resonance imaging, and electron microscopy revealed early-onset hydrocephalus in Sph-1 KO mice associated with severe loss and disorganization of motile ependymal cilia in the ventricular lining, a cell type that normally expresses high levels of synphilin-1. Ultrastructural and immunohistochemical analyses revealed disrupted ependymal architecture, mislocalization of acetylated α-tubulin to the cytoplasm, cellular swelling, and enlarged, aberrant mitochondria, whereas cortical neurons appeared largely structurally unaffected. Together, these findings identify synphilin-1 as a key regulator of microtubule organization and cytoskeletal/organelle homeostasis in ependymal cells, required to maintain motile ciliogenesis, cerebrospinal fluid flow, and ventricular integrity. This unexpected role for synphilin-1 in ciliated brain epithelia, along with a reduction in the critical mitochondrial chaperone HSP60, broadens our understanding of synphilin-1 biology and provides a new framework for its potential relevance to PD-associated pathology. Full article

Cysteine is a sulfur-containing amino acid that plays a central role in skin physiology through thiol-mediated redox regulation and glutathione (GSH) synthesis. It critically influences melanogenesis, collagen homeostasis, and wound healing. However, its clinical application is limited by poor stability and bioavailability. In this review, we provide a mechanistic and comparative analysis of cysteine and its derivatives, including N-acetylcysteine (NAC), cysteinamide (C-NH₂), GSH, and related compounds. These derivatives regulate melanogenesis by modulating dopaquinone pathways and tyrosinase activity, maintain collagen balance by preserving redox-sensitive enzymatic processes, and enhance wound healing through antioxidant and anti-inflammatory mechanisms. Importantly, chemical modifications such as acetylation, amidation, and esterification improve pharmacokinetic properties, enabling more effective intracellular delivery. Furthermore, different derivatives exhibit distinct advantages depending on biological context, highlighting the importance of compound selection. Overall, cysteine derivatives emerge as promising therapeutic candidates for dermatological applications, particularly in pigmentation disorders and impaired wound healing. Future studies should focus on in vivo validation and clinical translation. Full article

High ammonia nitrogen stress significantly compromises the survival of Litopenaeus vannamei under low-salinity conditions. However, existing studies predominantly focus on ammonia nitrogen responses under single stressors or normal seawater salinity. The molecular regulatory mechanisms, metabolic remodeling patterns, and key pathway interactions in shrimp subjected to high ammonia nitrogen stress under low-salinity environment remain unclear. In this study, we employed integrated transcriptomic and metabolomic analyses to unveil the underlying molecular responses and metabolic biomarkers in the gills of L. vannamei to ammonia stress under low-salinity conditions. First, L. vannamei underwent low-salinity acclimation from 30‰ to 5‰ salinity and was then reared for one week to acclimate to the experimental environment. Subsequently, shrimp were treated with 42.32 mg/L ammonia nitrogen for a consecutive 96 h period. Integrated transcriptomic and metabolomic analyses elucidated the stress response patterns in the gills of L. vannamei under low-salinity ammonia nitrogen exposure. Specifically, 352, 802, and 140 differentially expressed genes (DEGs) were identified at 12 h, 48 h, and 96 h post-exposure, respectively. GO and KEGG enrichment analyses revealed that the significant DEGs were primarily enriched in six major pathways: autophagy, immune-related pathway, ABC transporter, fatty acid degradation and metabolism, metabolic pathway, and PPAR signaling pathway. Metabolomic profiling identified numerous differentially accumulated metabolites (DAMs) in both positive and negative ion modes, with significantly altered DAMs mainly consisting of organic acids and their derivatives, phospholipids, and other related metabolites. Key DAMs included taurine, guanosine, 1-palmitoyl-sn-glycero-3-phosphocholine, pseudouridine, and betaine. Integrative multi-omics analysis revealed that L. vannamei mediates stress responses by modulating five core pathways under low-salinity/high-ammonia-nitrogen dual stress: fatty acid degradation and metabolism (e.g., acyl-CoA dehydrogenase short chain (Acads), acetyl-CoA acetyltransferase 2 (ACAT2)), autophagy (e.g., autophagy-related protein 101-like (atg101)), immune regulation pathway (e.g., V-type proton ATPase subunit H-like (VhaSFD), actin-5C-like (Act5C)), metabolic pathway (e.g., molybdopterin synthase catalytic subunit-like (Mocs2B), cytochrome P450 2U1-like (Cyp2b1)), and ABC transporter (e.g., ATP-binding cassette sub-family D member 3-like (ABCD3), ATP-binding cassette sub-family B member 10 (ABCB10)). Through characterization of these core pathways, this study reveals the fundamental mechanisms by which L. vannamei responds to high ammonia nitrogen stress following low-salinity acclimation, providing a theoretical foundation for estuarine shrimp farming. Full article

Precise control of mitochondrial electron transport is essential to maintain mitochondrial coupling and efficiency in ATP production. Furthermore, disruptions to ETC complex function can drive increased oxidant production, resulting in oxidative damage to the mitochondrion and bioenergetic inefficiency. This is highly relevant in the aging heart, as increased cardiac oxidative stress and mitochondrial dysfunction are hallmarks of age-related cardiovascular disease. Lysine acetylation has recently been characterized as a novel regulator of mitochondrial metabolic and bioenergetic function in the aging heart. In the present study, we investigated how lysine acetylation regulates oxidant production and redox milieu through mitochondrial acetyltransferase GCN5L1. Using a cardiac-specific GCN5L1 knockout mouse model, we observed that age-associated lipid peroxidation and semiquinone radicals were decreased with GCN5L1 KO. RNA sequencing analysis identified mitochondrial bioenergetic and respiratory pathways revolving around the respiratory chain to be enriched in the old KO group. Further, we showed the old KO group to exhibit reduced acetylation of ETC complex and antioxidant proteins, improved ETC complex and antioxidant protein activity. Overall, GCN5L1 regulates redox homeostasis in the aged heart by regulating mitochondrial ETC complex activity, oxidative stress, and mitochondrial bioenergetics. These findings identify GCN5L1 and acetylation as potential therapeutic targets in aging and age-related diseases. Full article

Background: Nymphaea atrans exhibits a gradual flower color transition from nearly white to rose-red during anthesis, yet the molecular mechanisms of this phenomenon remain unclear. In the present study, transcriptomic and metabolomic analyses were performed to systematically investigate anthocyanin accumulation patterns and regulatory mechanisms during the color transition of N. atrans. Methods: Petals were collected at three flowering stages: day 1 (D1), day 3 (D3), and day 5 (D5). Targeted metabolomics was performed using UPLC-ESI-MS/MS to profile anthocyanin and other flavonoid metabolites. Transcriptome analysis was conducted via RNA-seq. Differentially accumulated metabolites (DAMs) and differentially expressed genes (DEGs) were identified, followed by functional enrichment and integration analysis. Results: The results revealed significant accumulation of seven anthocyanins, including cyanidin-3-O-arabinoside, cyanidin-3-O-glucoside, cyanidin-3-O-galactoside, cyanidin-3-O-(6″-O-acetyl)-glucoside, at stages D3 (day 3 after flowering, light pink petals) and D5 (day 5 after flowering, deep pink petals), accompanied by the upregulation of key enzyme-encoding genes, chalcone synthase, chalcone isomerase, flavanone 3-hydroxylase, di-hydroflavonol 4-reductase, and anthocyanidin synthase in the anthocyanin biosynthetic pathway. Genes involved in JA biosynthesis and key regulatory genes in the JA signaling pathway were significantly up-regulated, indicating that the JA signaling pathway may play an important regulatory role in the synthesis of anthocyanins in N. atrans. Conclusions: This study unravels the metabolic and molecular underpinnings of flower color transition in N. atrans, thereby establishing a theoretical basis for the targeted regulation of floral pigmentation and molecular breeding of ornamental water lilies. Full article

Antimicrobial peptides (AMPs) have re-emerged as promising anti-infective agents, particularly against multidrug-resistant bacteria; however, their therapeutic development remains constrained by proteolytic degradation, host cell toxicity, and rapid systemic clearance. Rather than focusing solely on sequence discovery, recent efforts have shifted toward structural and supramolecular modification strategies aimed at improving stability, selectivity, and pharmacological performance. This review critically analyzes intramolecular modifications—including phosphorylation, glycosylation, acetylation, methylation, and backbone cyclization—that modulate peptide conformation and resistance to enzymatic degradation. In parallel, extramolecular approaches such as PEGylation, lipidation, and conjugation to antibiotics, siderophores, or antibodies are examined in the context of enhanced targeting and prolonged bioavailability. Particular emphasis is placed on localized delivery systems, including hydrogels, polymeric films, and nanofibrous scaffolds, which enable spatially controlled administration and mitigate systemic exposure. By integrating evidence from ex vivo and in vivo infection models, this work delineates the translational potential and remaining bottlenecks of chemically engineered AMP platforms for skin and soft tissue infections. Full article

Background: Gut microbiome-derived metabolites, particularly short-chain fatty acids (SCFA) and tryptophan derivatives, are central mediators of the gut–brain axis. This ex vivo study assessed how nutritional interventions impact such metabolites during early life, a critical period for neurodevelopment. Methods: The effects of galacto-oligosaccharides (GOS), nutrient blends (vitamins, minerals and amino acids) and their combinations were evaluated in the gut microbiomes of infants (2–4 months, n = 6) and young children (2–3 years old, n = 6) using the ex vivo SIFR^® technology. Results: Baseline microbiome composition was age-dependent, with infants displaying lower α-diversity and greater interpersonal variability. After ex vivo incubation, nutrient blends increased the propionate/butyrate ratio and branched-chain fatty acids in young children and elevated several B-vitamins and amino acid-derived metabolites, including indole-3-carboxaldehyde, imidazoleacetic acid and pipecolinic acid. Combining nutrient blends with GOS exhibited potential synergistic effects on propionate (infants) and 2-hydroxyisocaproic acid (HICA, both age groups). GOS strongly stimulated Bifidobacteriaceae and increased metabolites linked to bifidobacterial metabolism like acetate, HICA, N-acetylated amino acids, aromatic lactic acids and acetylagmatine; in young children, butyrate and γ-aminobutyric acid (GABA) also increased. Conclusions: Combinations of GOS with nutrient blends impacted microbiome-derived metabolites associated with the gut–brain axis, with potential synergistic increases of metabolites with emerging roles in neurodevelopment, including GABA, acetylagmatine and HICA. Despite shared bifidogenic effects, differences between age groups indicate that microbiome maturity may influence responses to nutritional intervention. Future clinical studies are needed to determine whether these metabolite changes translate into neurodevelopmental benefits in vivo. Full article

Hydralazine is widely used to treat hypertension during pregnancy and has epigenetic effects in cancer therapy. Cryoplatable human hepatocytes showed concentration-dependent increase in DNA damage response (linear trend p = 0.0069) following 24 h hydralazine treatment. DNA repair-deficient UV5 Chinese hamster ovary (CHO) cell lines expressing human CYP1A2 and either NAT2*4 (reference allele) or NAT2*5 (variant allele) were treated with hydralazine for 24 h. CHO cells expressing NAT2*4 showed a higher acetylation rate than those with NAT2*5 (p < 0.001), whereas CHO cell viability did not differ significantly following hydralazine treatment (p > 0.05). Hydralazine caused a concentration-dependent increase in DNA damage response in the un-transfected UV5 CHO cell line, as well as in each of the UV5 CHO cell lines transfected with human CYP1A2 and/or NAT2 alleles. CHO cells with CYP1A2 only showed higher DNA damage response from hydralazine compared to cells with CYP1A2/NAT2*4 or CYP1A2/NAT2*5 (p < 0.05 and p < 0.0001, respectively), and higher in CYP1A2/NAT2*4 versus CYP1A2/NAT2*5 cells (p = 0.0011). Apurinic/apyrimidinic (AP) sites in CHO cells expressing only CYP1A2 were significantly higher than in the un-transfected UV5 CHO cell line (p < 0.01) and higher in CHO cells expressing CYP1A2/NAT2*4 compared to CYP1A2/NAT2*5, but the difference was not significant (p > 0.05). In contrast, ROS levels were reduced following hydralazine treatment in CHO cells with CYP1A2/NAT2*4 and CYP1A2/NAT2*5 (p < 0.001 and p < 0.05, respectively). The results of the current study document DNA damage responses associated with hydralazine in human hepatocytes and CHO cells. The DNA damage response was increased following N-hydroxylation by CYP1A2, which competes with N-acetylation by NAT2. Full article

Global climate change poses a significant threat to viticulture, primarily due to high temperatures. This study examined temperature-induced changes in phenolic profiles in berries of three wine grape cultivars under 25, 35, and 45 °C for 0–48 h using HPLC-ESI-MS/MS. To investigate the molecular response to severe heat stress, transcriptomic analysis was conducted in Cabernet Sauvignon berries subjected to a 45 °C treatment. Results showed that the 45 °C treatment decreased the levels of anthocyanins (particularly delphinidin-3-O-glucoside and cyanidin-3-O-glucoside) in grape berries. Acylated anthocyanins, such as malvidin-3-O-(6-acetyl)-glucoside, exhibited enhanced stability at elevated temperatures. Additionally, high temperatures increased the levels of protocatechuic and gentisic acids and decreased those of rutin, ferulic acid, and p-coumaric acid. Transcriptomic and qRT-PCR analyses revealed that the expression of OMT, LDOX, GST, F3′5′H, and 3AT was positively correlated with changes in anthocyanin levels under high temperatures, suggesting their roles in the observed phenolic alterations. These findings highlight the molecular responses of winegrapes to heat stress, providing a foundation for future viticulture strategies under changing climatic conditions. Full article

Mitotic catastrophe refers to a complicated mechanism of cell death characterized by failure to complete the processes of mitosis correctly due to aberrant chromosome segregation and abnormal tubulin polymerization. Post-translational modifications (PTMs) play a crucial role in the functional diversity of the proteome by mediating the covalent attachment of functional groups to proteins, which regulates the proteolytic cleavage of subunits, facilitating the degradation of entire proteins. Recent studies suggest that PTMs of key proteins are closely implicated in the occurrence, regulation and potential therapeutic targets of mitotic catastrophe. Here, we summarize how multiple PTMs, including phosphorylation, ubiquitination, acetylation, methylation and other types of PTMs, regulate mitotic catastrophe. In addition, potential therapeutic approaches targeting mitotic catastrophe were also discussed. It is anticipated that the inducement of mitotic catastrophe can serve as a promising new therapeutic approach for various diseases in the future. Full article