Search Results (286)

Iron overload significantly contributes to chronic kidney disease progression by triggering oxidative stress and mitochondrial impairment via the Fenton reaction. This study investigates the protective role of aldehyde dehydrogenase 1a3 (ALDH1a3), an enzyme that detoxifies reactive aldehydes, in renal iron overload. C57BL/6N mice were fed a 2.25% ferric citrate diet for 24 weeks to establish a chronic model, followed by treatment with the chelator Dimercaprol (DP). In vitro, TCMK−1 cells were subjected to iron intervention with ALDH1a3 overexpression or inhibition. Chronic iron overload induced significant renal iron deposition, lipid peroxidation (elevated MDA, depleted GSH), and mitochondrial structural damage. ALDH1a3 was endogenously upregulated in renal tubular epithelial cells under iron stress. Overexpressing ALDH1a3 significantly enhanced cell viability, suppressed reactive oxygen species and MDA levels, and preserved mitochondrial membrane potential, whereas its inhibition exacerbated cellular damage. Furthermore, DP treatment reduced iron deposition and was associated with increased ALDH1a3 expression. In conclusion, ALDH1a3 acts as a critical endogenous protective factor against iron−induced nephrotoxicity by mitigating oxidative damage and maintaining mitochondrial stability. These findings indicate that ALDH1a3 is a promising potential therapeutic target for the treatment of iron overload−related kidney diseases. Full article

The World Health Organization (WHO) defines infertility as the inability of a couple to conceive after at least 12 months of regular, unprotected sexual intercourse. The male factor appears to be contributing, solely or in combination with other causes, to approximately 50% of all infertility cases. Several etiological factors of male infertility have been identified; however, the exact molecular mechanisms underlying sperm dysfunction are not yet fully understood. Aldehyde dehydrogenases (ALDHs) are multifaceted metabolic enzymes that catalyze the detoxification of several aldehydes, thus acting as antioxidants, while they regulate additional homeostatic functions by contributing to retinoic acid (RA) synthesis. Consequently, they have been identified as crucial factors in various pathogenetic mechanisms. ALDHs hold physiological roles in the testis through supporting the Sertoli cell function, the steroidogenesis in Leydig cells, and the maintenance of sperm integrity. Current evidence supports that dysregulation of specific ALDHs isoforms could be associated with disrupted testicular cell function, including oxidative imbalance and altered RA synthesis. These irregularities could interfere with germ cell development and, subsequently, contribute to decline in reproductive function. In this paper, we are reviewing the role of ALDHs in male reproduction and how their dysregulation could be implicated in male infertility. Unraveling the mechanisms underlying the association of ALDHs with male reproductive function could hold clinical interest regarding the development of novel approaches for enhancing male fertility. Full article

Purpose: To study the time course of the differentiation process and its regulatory networks in primary limbal epithelial cells (pLECs) using serum-free, low calcium Keratocyte growth medium 3 (KGM3) and CnT-2D differentiation medium. Methods: pLECs were isolated from corneoscleral rims from healthy donors and cultured in serum-free low calcium (0.06 mM Ca²⁺) KGM3. Differentiation was induced by supplementation with CnT-2D differentiation medium, while control cells were maintained in low-calcium KGM3 medium. Gene and protein expression analyses were performed using qPCR and Western blotting, respectively, at 72 h and at 5, 7, 10, and 14 days post-supplementation to determine the optimal time course of differentiation induction. Results: CnT-2D differentiation medium supplementation resulted in a significant upregulation of differentiation-associated markers, including desmoglein 1 (DSG1), paired box domain 6 (PAX6), keratin 3 (KRT3), fatty acid binding protein 5 (FABP5), cellular retinoic acid binding protein 2 (CRABP2), alcohol dehydrogenase 7 (ADH7), aldehyde dehydrogenase 1A1 (ALDH1A1), with the most pronounced changes observed at day 10 post-supplementation (p ≤ 0.05). Conclusions: CnT-2D differentiation medium effectively initiates differentiation of limbal epithelial cells in vitro. The gradual increase in the expression of key differentiation markers, including DSG1, KRT3, and PAX6, indicates that CnT-2D medium successfully induces differentiation in 2D cultured primary limbal epithelial cells. However, subcellular localization of these markers, epithelial barrier function, and differentiation in 3D models were not assessed and remain to be investigated. Full article

Excessive alcohol consumption causes millions of deaths annually, yet current pharmacological treatments for alcohol use disorders show limited efficacy and poor adherence, creating an urgent need for new therapeutic alternatives. Aldehyde dehydrogenase 2 (ALDH2) metabolizes acetaldehyde, a key mediator of the rewarding effects of alcohol in the brain, making ALDH2 activation a promising therapeutic target. This study investigated whether flurbiprofen, an FDA-approved nonsteroidal anti-inflammatory drug that activates ALDH2, reduces alcohol intake compared to the experimental ALDH2 activator Alda-1 and the structurally similar NSAID ibuprofen. Male alcohol-preferring UChB rats received oral flurbiprofen (2.5–10 mg/kg), Alda-1 (5 mg/kg), or ibuprofen (5 mg/kg) during acquisition and chronic phases of voluntary alcohol consumption under a two-bottle free-choice paradigm. Both flurbiprofen and Alda-1 reduced alcohol intake by approximately 60% and similarly increased ALDH2 activity 3–4-fold in brain and liver tissues. Ibuprofen showed modest effects (25% alcohol intake reduction). In vitro assays confirmed that flurbiprofen and Alda-1, but not ibuprofen, activated ALDH2 in PC-12 cells. Enzymatic assays and molecular docking revealed that Alda-1 lacks cyclooxygenase-inhibitory activity, unlike flurbiprofen, suggesting that ALDH2 activation is the primary mechanism underlying reduced alcohol consumption. These findings identify flurbiprofen as a clinically available ALDH2 activator with significant translational potential for treating alcohol use disorders. Full article

Salivary aldehyde dehydrogenases (ALDHs), particularly ALDH3A1 and ALDH1A1, serve as frontline enzymatic defenses in the oral cavity, detoxifying reactive aldehydes generated through metabolic activity, microbial fermentation, and environmental exposures. These enzymes are essential for maintaining redox homeostasis, mucosal integrity, and immune modulation. However, under chronic metabolic stress, such as in diabetes, oral inflammation, and cancer, salivary ALDHs become vulnerable to non-enzymatic glycation by reactive carbonyl species like methylglyoxal. This modification impairs cofactor binding, catalytic activity, and structural stability, thereby compromising detoxification capacity at a time of heightened aldehyde burden. This review provides the first insights into ALDH glycation and particularly that of salivary ALDH, examining its structural mechanisms, disease-specific consequences, and emerging protective strategies. Special focus is given to natural compounds, including curcumin, thymoquinone, resveratrol, carnosine, and EGCG, that prevent glycation or restore ALDH function via carbonyl scavenging, antioxidant activation, and NAD⁺/SIRT1 pathway modulation. We also highlight critical research gaps, such as the absence of site-specific glycation maps, lack of salivary gland-based models, and limited availability of ALDH3A1-specific activators. Importantly, we propose that the glycation status of salivary ALDHs may serve as a non-invasive biomarker of oxidative stress and therapeutic response in metabolic and inflammatory disorders. By bridging biochemical insights with translational potential, this review establishes ALDH glycation as a mechanistic and clinically actionable axis in oral and systemic health. Full article

Ovarian cancer is the most lethal gynecologic malignancy, with chemoresistance and recurrence driven by cancer stem cells (CSCs). Mesenchymal stem cell-derived extracellular vesicles (MSC-EVs) mediate tumor–stroma communication, but their role in ovarian cancer progression and therapy remains unclear. Here, we investigated bone marrow (BM)-MSC-EVs, their effects on ovarian cancer cells, and the underlying molecular mechanisms. BM-MSCs were isolated, confirmed using flow cytometry and trilineage differentiation, and their EVs characterized using nanoparticle tracking analysis, transmission electron microscopy, and Western blotting. Kuramochi cells were treated with BM-MSC-EVs and assessed for proliferation, colony formation, migration, invasion, apoptosis, and chemosensitivity. Aldehyde dehydrogenase (ALDH⁺) Kuramochi cells, with or without EV exposure, were transplanted into non-obese diabetic severe combined immunodeficiency mice for xenograft studies, followed by histology, immunohistochemistry, Western blotting, and EV miRNA profiling. BM-MSC-EVs increased cancer cell proliferation but reduced colony formation, migration, and invasion in vitro. They sensitized ALDH⁺ CSC-like cells to carboplatin, while paclitaxel response remained unchanged. In vivo, EVs accelerated tumor growth and activated prosurvival (p-AKT, BCL-2), angiogenic (VEGFA, CD31), and epithelial–mesenchymal transition-associated (vimentin) pathways. EVs were found to be enriched in hsa-miR-100-5p, hsa-miR-122-5p, and hsa-let-7i-5p based on miRNA array analysis, and these findings were further validated by qRT-PCR. These findings reveal the dual roles of BM-MSC-EVs: enhancing carboplatin sensitivity while promoting tumor progression and angiogenesis. Full article

Background: Neuroblastoma (NB) progression is influenced by metabolic and redox adaptations. The polyol pathway, driven by aldose reductase (AKR1B1) and sorbitol dehydrogenase (SORD), is activated in hyperglycemic conditions, while detoxification of lipid peroxidation products such as 4-hydroxynonenal (4-HNE) involves carbonyl reductase 1 (CBR1) and AKR1B1. A systematic characterization of these enzymes under distinct metabolic and oxidative challenges in NB is currently lacking. Methods: Human neuroblastoma LAN-5 and SH-SY5Y cells were exposed to hyperglycemic medium to assess polyol pathway regulation, and to exogenous 4-HNE to model aldehyde-induced oxidative stress. Protein expression and enzyme activities were quantified. Cells were treated with Sorbinil or rutin during stress exposure, and viability was analyzed in 2D and 3D models. Results: Hyperglycemia increased AKR1B1 activity and sorbitol accumulation, indicating polyol pathway activation in NB cells. Both NB cell lines displayed an incomplete HNE-detoxifying enzyme profile, with absence of ALDH1A1 and AKR1C3 expression. Exposure to 4-HNE reduced NB cell viability both in 2D and 3D models. Pharmacological inhibition of AKR1B1, but not of CBR1, exacerbated 4-HNE-mediated cytotoxicity. Conclusions: While hyperglycemia stimulates the polyol pathway, aldehyde detoxification by AKR1B1 supports resistance to 4-HNE toxicity, demonstrating that AKR1B1 activity is essential to counteract HNE toxicity, and its impairment may increase the susceptibility of NB cells to oxidative damage. Full article

Oxidative alcohol metabolism in the liver relies on sequential enzymatic reactions involving alcohol dehydrogenase (ADH), cytochrome P450 2E1 (CYP2E1), and aldehyde dehydrogenase (ALDH) isozymes. However, the circadian regulation of these enzymes, their susceptibility to genetic, environmental, and metabolic disruption, and their functional implications toward alcohol-mediated tissue injury remain incompletely defined. To address this gap, we performed a comprehensive integrative analysis of the publicly available circadian transcriptome datasets spanning genetic clock disruption, acute sleep deprivation, chronic high-fat diet feeding, and occupational shift work to systematically characterize the temporal regulation and disruption vulnerability of the major alcohol-metabolizing enzymes. Mouse tissue-cycling analyses revealed pronounced gene- and tissue-specific diurnal regulation, with Adh1 oscillating primarily in adipose tissues; Cyp2e1 and mitochondrial Aldh2 cycling broadly across kidney, aorta, lung, adrenal gland, and liver; and cytosolic Aldh1b1 being uniformly arrhythmic. In the liver, Cyp2e1 and Aldh2 exhibited robust ~24 h oscillations that peaked during the light/resting phase, while Adh1 showed inconsistent rhythmicity and Aldh1b1 remained arrhythmic. Notably, Cyp2e1 and Aldh2 rhythms persisted in Bmal1 knockout and Clock mutant livers under light–dark conditions, despite complete loss of core clock gene oscillations, yet were abolished in constant darkness, revealing that systemic zeitgeber cues can mask the loss of intrinsic clock function to maintain apparent rhythmicity in these metabolic genes. Systematic cross-paradigm comparison established a novel gene-specific vulnerability hierarchy. Aldh2 was found to be most disrupted by environmental and metabolic perturbations, with acute sleep deprivation eliminating its rhythmicity and temporal expression pattern and a Western-style high-fat diet inducing pronounced phase delays and rhythm loss relative to low-fat diet controls. Both disruptions paralleled alterations in hepatocyte nuclear factor 4α (Hnf4a), newly implicating HNF4α as a potential mediator of ALDH2 circadian instability. In humans, ALDH2 and CYP2E1 exhibited conserved but phase-inverted circadian rhythms across multiple tissues relative to mice, and, importantly, night-shift workers showed markedly dampened and phase-shifted ALDH2 rhythms in peripheral blood mononuclear cells, providing the molecular link between occupational circadian misalignment and impaired acetaldehyde detoxification. Collectively, our detailed and innovative analytical approach reveals gene- and tissue-specific circadian regulation of alcohol-metabolizing enzymes, identifies ALDH2 as uniquely vulnerable to circadian misalignment, underscores the importance of circadian timing for optimal hepatic detoxification and resistance to tissue injury, and suggests that monitoring circadian rhythms could help tailor individualized advice on alcohol consumption for shift workers and populations with irregular sleep schedules, informing precision medicine approaches for alcohol-related disorders. Full article

Disulfiram (DSF) is a well-established inhibitor of aldehyde dehydrogenases (ALDHs) and an FDA-approved drug for chronic alcoholism. DSF has gained attention as a versatile scaffold for drug repurposing. Its metabolite, diethyldithiocarbamate (DDTC), mediates multiple biological effects via metal chelation and covalent modification of key cysteine residues. Beyond its established anticancer properties, DSF modulates cancer stem cells, reactive oxygen species, proteasome function, and drug-resistance pathways. It also shows promise in metabolic disorders, including type 2 diabetes and obesity, by targeting enzymes such as fructose-1,6-bisphosphatase and α-glucosidase, and influences energy expenditure and autophagy. DSF exhibits antimicrobial and antiparasitic activity, enhances antibiotic efficacy against multidrug-resistant bacteria, and demonstrates antischistosomal and anti-Trichomonas effects, while also providing radioprotective benefits. The clinical translation of DSF is limited by poor solubility, rapid metabolism, and off-target effects; consequently, the development of DSF analogs has become a major focus. Structural optimization has yielded derivatives with improved selectivity, stability, solubility, and target specificity, enabling precise modulation of key enzymes while reducing adverse effects. A key structure-based strategy involves introducing bulkier substituents to exploit differences in ALDH active-site architecture and achieve target selectivity. This concept is exemplified by compounds (1) and (2), in which bulky substituents confer selective inhibition of ALDH1A1 while sparing ALDH2. This review provides a comprehensive overview of DSF analogs, their molecular mechanisms, and therapeutic potential, highlighting their promise as multifunctional agents for cancer, metabolic disorders, infectious diseases, and radioprotection. Full article

Slugs are significant agricultural pests and act as vectors for zoonotic parasites. However, current molluscicide options are limited and associated with substantial environmental risks. This study investigates the role of aldehyde dehydrogenase (ALDH) in the biosynthesis of farnesoic acid (FA), a key intermediate in the sesquiterpenoid hormone pathway, in two slug species: Philomycus bilineatus and Laevicaulis alte. Transcriptomic analysis revealed that both species possess conserved sesquiterpenoid biosynthetic pathways, yet they exhibit distinct levels of ALDH gene expression and differences in FA content. RNA interference (RNAi)-mediated gene silencing was employed to validate the potential of these candidate genes as targets for molluscicide development. Structural modeling of ALDH proteins using AlphaFold2 demonstrated notable divergence in the architecture of their active sites, suggesting species-specific enzymatic properties. Citral, a known inhibitor of ALDH, significantly reduced FA production in vivo and exhibited contact toxicity against both slug species. The lethal concentration 50 (LC₅₀) values were determined to be 378.2 g/L for P. bilineatus and 85.2 g/L for L. alte, respectively. Molecular docking analyses indicated that citral binds within the conserved substrate-binding tunnel of ALDH, potentially inhibiting the oxidation of farnesal. These findings establish ALDH as a critical enzymatic target for disrupting endogenous hormone biosynthesis in slugs and support the development of novel, eco-friendly molluscicides targeting the sesquiterpenoid pathway. Full article

Cyclin-dependent kinase 4/6 inhibitors (CDK4/6i) have transformed the treatment landscape for estrogen receptor-positive (ER+) breast cancer, yet resistance remains a major clinical challenge. Although CDK4/6i induce G₁ arrest and therapy-induced senescence (TIS), the exact nature of this senescent state and its contribution to resistance are not well understood. To explore this, we developed palbociclib- (2PR, 9PR, TPR) and abemaciclib- (2AR, 9AR, TAR) resistant ER+ breast cancer sublines through prolonged drug exposure over six months. Resistant cells demonstrated distinct phenotypic alterations, including cellular senescence, reduced mitochondrial membrane potential, and impaired glycolytic activity. Cytokine profiling and enzyme-linked immunosorbent assay (ELISA) validation revealed a non-canonical senescence-associated secretory phenotype (SASP) characterized by elevated growth/differentiation factor 15 (GDF-15) and serpin E1 (plasminogen activator inhibitor-1, PAI-1) and absence of classical pro-inflammatory interleukins, including IL-1α and IL-6. IL-8 levels were significantly elevated, but no association with epithelial–mesenchymal transition (EMT) was observed. Resistant cells preserved their epithelial morphology, showed no upregulation of EMT markers, and lacked aldehyde dehydrogenase 1-positive (ALDH1+) stem-like populations. Additionally, Regulated upon Activation, Normal T-cell Expressed, and Secreted (RANTES) was strongly upregulated in palbociclib-resistant cells. Together, these findings identify a distinct, non-canonical senescence phenotype associated with CDK4/6i resistance and may provide a foundation for identifying new vulnerabilities in resistant ER+ breast cancers through targeting SASP-related signaling. Full article

Background/Objectives: Oral potentially malignant disorders (OPMDs), including oral leukoplakia (OLK), oral lichen planus (OLP), and actinic cheilitis (AC), have varying risks of progression to oral squamous cell carcinoma (OSCC). Biomarkers such as aldehyde dehydrogenase 1 (ALDH1) and mammary serine protease inhibitor (Maspin) have shown potential for diagnostic and prognostic use in oral cancer. The present study aimed to evaluate the immunoexpression of aldehyde dehydrogenase 1, a cancer stem cell marker associated with aggressiveness, and the mammary serine protease inhibitor, a potential tumor suppressor, in OPMD and OSCC tissues. Methods: A retrospective analysis was performed on 145 biopsy specimens collected from January 2015 to January 2023, including normal epithelium, OPMDs (OLK, OLP, AC), and OSCC. ALDH1 and Maspin expression levels were evaluated using immunohistochemistry, considering both the percentage of positive cells and staining intensity. Statistical analyses were carried out using the Statistical Package for the Social Sciences (SPSS, version 29.0; IBM Corp., Chicago, IL, USA). Results: Normal oral epithelium showed no expression of ALDH1, whereas 40.6% of OPMDs and 44.4% of OSCC samples exhibited high cytoplasmic ALDH1 expression. Nuclear ALDH1 expression was elevated in 29.7% of OPMDs and 38.9% of OSCCs (p < 0.001). Nuclear Maspin expression was high in 95.2% of normal tissues, in 67.2% of OPMDs and in 55.6% of OSCCs (p < 0.001). Maspin showed strong nuclear and cytoplasmic expression in normal tissue, but its expression decreased in OPMDs and OSCCs, with statistically significant reductions in both compartments (p < 0.001). Conclusions: The results indicate that ALDH1 upregulation and Maspin downregulation are hallmark events in oral carcinogenesis. Their combined evaluation provides a powerful tool for assessing dysplastic severity and malignant transformation risk in OPMDs. Future studies on larger cohorts are needed to confirm the prognostic utility of this dual-marker model. Full article

The spoilage bacterium Acetobacter aceti poses a major threat to wine quality by causing acetification, driving the need for effective control methods. This study investigated the inactivation of A. aceti using pulsed electric field (PEF) and elucidated the multi-target mechanisms. The results demonstrated that PEF efficacy was highly dependent on the electric field intensity. PEF treatment at 30 kV/cm achieved a >3-log reduction in viable cell counts, with a Weibull model analysis indicating a critical inactivation threshold of 21.64 kV/cm. Mechanistic investigations revealed that PEF induced irreversible damage to the cell membrane, evidenced by morphological rupture (SEM) and a 4-fold increased permeability (flow cytometry), which led to a massive leakage of intracellular contents. Critically, this physical damage was correlated with profound physiological disruption, including the inactivation of key spoilage enzymes alcohol dehydrogenase (ADH, 80.0% relative activity loss) and aldehyde dehydrogenase (ALDH, 93.1% relative activity loss). Furthermore, PEF induced severe oxidative stress (4.25-fold increase in ROS and 3.30-fold increase in MDA) and a collapse in energy metabolism. Collectively, these findings reveal a synergistic inactivation mechanism, which establishes a strong theoretical foundation for the potential development of PEF as a non-thermal strategy to control acetic spoilage in winemaking. Full article

High temperatures induce oxidative stress and the production of a large amount of malondialdehyde (MDA) in the Pacific oyster Crassostrea gigas, and they can even lead to mass mortality. Aldehyde dehydrogenase (ALDH) degrades MDA and is attracting increasing attention for its role in enhancing antioxidant defense capacity. This study identified 14 ALDH family members in the oyster genome. Among them, CgALDH6A1 harbored a conserved ALDH_F6_MMSDH domain (known to catalyze the oxidation of aliphatic and aromatic aldehydes) and was likely involved in the high-temperature stress response through the detoxification of accumulated toxic aldehydes. In the gills, CgALDH6A1 had significantly higher mRNA expression than other tissues, with a significant increase at 12 h under 28 °C high-temperature stress. During the outdoor aquaculture period, the mRNA transcripts of CgALDH6A1 in the gills exhibited a significant increase from June to October. After the expression of CgALDH6A1 was inhibited by RNAi, the MDA content in the gills increased significantly (1.31-fold, p < 0.01), while the activities of superoxide dismutase (SOD) (0.93-fold, p < 0.05) and catalase (CAT) (0.45-fold, p < 0.001) and total antioxidant capacity (T-AOC) (0.54-fold, p < 0.01) decreased significantly under high-temperature stress. Meanwhile, the gill tissue was observed to be disorganized with obvious filament swelling. After the oysters were treated with CgALDH6A1 agonist (Alda-1), the MDA content (0.59-fold, p < 0.001) in the gills decreased significantly, while the activities of SOD (1.33-fold, p < 0.001), CAT (1.81-fold, p < 0.001), and T-AOC (1.79-fold, p < 0.01) all increased significantly 48 h after high-temperature stress. However, no obvious morphological changes were observed in the gills. These results demonstrate that CgALDH6A1 plays a key role in regulating the oxidative stress response by degrading MDA under high-temperature stress and plays a cooperative role with the antioxidant system in alleviating oxidative stress under high-temperature stress. Full article

Salivary gland carcinomas (SGCs) are aggressive malignancies with limited treatment options, primarily due to the complexity of the tumor microenvironment (TME). Cancer-associated fibroblasts (CAFs) remodel the extracellular matrix (ECM), enhance cancer cell stemness, and drive drug resistance. This study introduces a decellularized CAF-derived spheroid system as a biomimetic platform to study tumor–stromal interactions in SGC. Multicellular spheroids were generated by co-culturing Medical Research Council cell strain 5 (MRC-5) fibroblasts (fetal lung-derived) with A253 salivary gland cancer cells, producing distinct spatial architecture, with fibroblasts at the core and cancer cells at the periphery. Compared with A253-only spheroids, A253/MRC-5 spheroids exhibited enhanced proliferation and elevated expression of stemness markers (aldehyde dehydrogenase 1 [ALDH1], CD133, cytokeratin 19 [CK19]). MRC-5 spheroids displayed robust ECM and growth factor expression that persisted after decellularization. Decellularized spheroids retained biological activity, enabling A253 cells to develop invasive phenotypes, metabolic reprogramming, and stemness-associated signatures. Transcriptomic analysis revealed a transition from proliferative pathways to stress-adaptive survival programs, mirroring in vivo tumor behavior. Moreover, A253 cells cultured with decellularized fibroblast spheroids exhibited altered cisplatin sensitivity, highlighting the critical role of stromal ECM in therapeutic response. In conclusion, this study establishes decellularized CAF spheroids as a simplified yet biologically relevant TME-mimetic platform. By recapitulating tumor–stromal crosstalk without live co-culture, this system provides a powerful tool for mechanistic studies of salivary gland cancer, preclinical drug screening, and development of stroma-targeted therapies. Full article