Search Results (271)

The discovery of bioactive natural compounds from microbes holds promise for regenerative medicine. In this study, we identified and characterized a steroid-like compound, 3,12-dioxochola-4,6-dien-24-oic acid (DOCDA), from a crude extract of Rhodococcus sp. DOCDA significantly promoted wound healing by enhancing HaCaT cell invasion and migration. It upregulated key growth factors (EGF, VEGF-A, IGF, TGF-β, and HGF), indicating the activation of regenerative signaling. Additionally, DOCDA increased the expression of genes related to focal adhesion and cytoskeletal regulation (ITGB1, ITGA4, FAK, SRC, RHOA, CDC42, RAC1, and paxillin), supporting enhanced cellular motility and remodeling. Notably, DOCDA promoted stem-like properties in HaCaT cells, as shown by increased spheroid formation and elevated levels of the stemness markers ALDH1 and CD44. Target prediction and molecular docking identified the glucocorticoid receptor (GR) as the primary target of DOCDA, with a docking score of −7.7 kcal/mol. Network and pathway enrichment analysis revealed that GR-linked pathways were significantly associated with wound healing, including steroid hormone signaling, inflammation, immune responses, and cell migration. In vivo, the topical application of DOCDA led to over 70% wound closure in mice by day 5. These findings suggest that DOCDA is a steroid-like compound that accelerates wound healing and may serve as a potential agent in regenerative therapy. Full article

Background: Alcohol-associated liver disease (ALD) is characterized by gut–liver axis dysfunction and metabolic dysregulation, yet the therapeutic potential of probiotics remains underexplored. This study aimed to investigate the protective effects and mechanisms of Lacticaseibacillus paracasei 36 (LP36) against ethanol-induced ALD in mice. Methods: Mice were pretreated with LP36 prior to ethanol exposure. Liver injury was assessed through serum ALT/AST levels, hepatic steatosis (TC/TG content), and ethanol detoxification capacity (ADH/ALDH activity). Intestinal barrier integrity was evaluated via Mucin2 and ZO-1 expression, and gut microbiota alterations were analyzed by 16S rRNA sequencing. Hepatic transcriptomics (RNA-seq) was performed to identify key regulatory pathways. Results: LP36 significantly attenuated ethanol-induced liver injury, evidenced by reduced ALT/AST, improved hepatic steatosis (lower TC/TG), and enhanced ADH/ALDH activity. Mechanistically, LP36 restored intestinal barrier function (upregulated Mucin2 and ZO-1), modulated gut microbiota (suppressed Parasutterella, Romboutsia, and Christensenellaceae_R-7_group; enriched Faecalibaculum and Tuzzerella), and reduced systemic inflammation. Transcriptomics revealed LP36-mediated rescue of AMPK signaling, involving regulation of Stk11, Prkag3, lipid synthesis genes (Fasn, Acaca), and metabolic modulators (Creb3l3, G6pc3, mTOR, Rps6kb2).Conclusions: LP36 ameliorates ethanol-induced ALD by enhancing intestinal barrier integrity, reshaping gut microbiota, and restoring AMPK-dependent metabolic homeostasis. These findings highlight LP36 as a promising probiotic candidate for ALD prevention. Full article

Heart failure (HF) has become an epidemic, with a prevalence of ~7 million cases in the USA. Despite accounting for nearly 50% of all HF cases, heart failure with a preserved ejection fraction (HFpEF) remains challenging to treat. Common pathophysiological mechanisms in HFpEF include oxidative stress, microvascular dysfunction, and chronic unresolved inflammation. Our lab focuses on oxidative stress-mediated cellular dysfunction, particularly the toxic effects of lipid peroxidation products like 4-hydroxy-2-nonenal (4HNE). Aldehyde dehydrogenase 2 (ALDH2), a mitochondrial enzyme, plays a vital role in detoxifying 4HNE and thereby protecting the heart against pathological stress. ALDH2 activity is reduced in various metabolic stress-mediated cardiac pathologies. The dysfunction of coronary vascular endothelial cells (CVECs) is critical in initiating HFpEF development. Thus, we hypothesized that ectopic overexpression of ALDH2 in CVECs could mitigate metabolic stress-induced HFpEF pathogenesis. In this study, we tested the efficacy of intracardiac injections of the ALDH2 gene into CVECs in db/db mice—a model of obesity-induced type 2 diabetes mellitus (T2DM)—and their controls, db/m mice, by injection with ALDH2 constructs (AAV9-VE-cadherin-hALDH2-HA tag-P2A) or control constructs (AAV9-VE-cadherin-HA tag-P2A-eGFP). We found that intracardiac ALDH2 gene transfer increased ALDH2 levels specifically in CVECs compared to other myocardial cells. Additionally, we observed increased ALDH2 levels and activity, along with decreased 4HNE adducts, in the hearts of mice receiving ALDH2 gene transfer compared to control GFP transfer. Furthermore, ALDH2 gene transfer to CVECs improved diastolic function compared to GFP control alone. In conclusion, ectopic ALDH2 expression in CVECs can contribute, at least partially, to the amelioration of HFpEF. Full article

Stroke poses a serious threat to human health, while there are very few drugs that can directly alleviate ischemia/reperfusion injury and improve the prognosis. Studies have shown that small-molecule activators of aldehyde dehydrogenase 2 (ALDH2) have the potential to become novel therapeutic drugs for ischemic stroke. In this study, through the systematic structural optimization of novel N-benzylaniline-based ALDH2 activators obtained from our previous virtual screening, ALDH2 activators with improved water solubility and activity were obtained. Among them, compound D10 exhibits the best activity, with a maximum activation fold reaching 114% relative to Alda-1. And the water solubility of its hydrochloride salt D27 was increased by more than 200-fold. The intravenous injection of this compound can significantly reduce the infarct area in the rat model of cerebral infarction compared with the model group. This study lays a good foundation for the future research on ALDH2 activators used in the treatment of stroke. Full article

Background: Modulating ethanol metabolism and attenuating alcohol-induced oxidative stress are promising therapeutic strategies for reducing the severity of hangovers and alleviating their associated physiological burden. Methods: A randomized, double-blind, placebo-controlled, crossover study was conducted to evaluate the effects of the probiotic strain Leuconostoc mesenteroides VITA-PB2 on ethanol metabolism, oxidative stress, and hangover-related symptoms in 28 healthy adults. The participants consumed either VITA-PB2 or a placebo before standardized alcohol intake, with a 7-day washout period and subsequent crossover. Primary outcomes included blood ethanol, acetaldehyde levels, and aldehyde dehydrogenase (ALDH) activity. Secondary outcomes measured hangover severity assessed by the Acute Hangover Scale (AHS), liver enzymes including aspartate aminotransferase (AST), alanine aminotransferase (ALT), and gamma-glutamyl transferase (GGT), oxidative stress indicators reactive oxygen species (ROS) and nitric oxide (NO), and antioxidant responses measured by glutathione peroxidase (GPx), catalase, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging capacity. Results: VITA-PB2 supplementation led to a sustained reduction in blood ethanol concentrations beginning at 0.5 h post-ingestion compared with the placebo group, indicating more efficient ethanol clearance. Additionally, VITA-PB2 significantly reduced acetaldehyde levels at 1 h post-ingestion (p < 0.05) and increased ALDH activity by 42.15% at 30 min (p < 0.05). It also markedly reduced ROS levels at 1 h (p < 0.05), enhanced glutathione peroxidase (GPx) activity at 2 h (p < 0.01), and significantly improved the subjective hangover symptoms, particularly thirst (p < 0.05). Conclusions: No adverse effects were reported during the trial, indicating that Leuconostoc mesenteroides VITA-PB2 is a safe probiotic. These findings suggest its efficacy in mitigating alcohol-induced oxidative stress and alleviating hangover-related symptoms. Full article

In acute myeloid leukemia (AML) it is important to elucidate the biological events that lead from remission to relapse, which have a high probability of leading to an adverse disease outcome. The cancer stem cell marker aldehyde dehydrogenase 1 (ALDH1A1) is underexpressed in AML cells when compared to healthy cells, both at the RNA level and at the protein level, and at least in the former, both in the bone marrow and in peripheral blood. Nonetheless, ALDH1A1/ALDH1A2 activity increases in AML cells during disease relapse and is higher in adverse prognosis AML in comparison with favorable prognosis AML. Furthermore, especially in relapsed AML and in unfavorable AML, AML cells rich in ALDH1A1 can contain high levels of reactive oxygen species (ROS), in parallel with high ALDH1A1/2 activity. This metabolic feature is clearly incompatible with normal stem cells. The term “stem-like” therefore is useful to coin malignant cells with a variety of genetic makeups, metabolic programming and biomarkers that converge in the function of survival of clones sufficient to sustain, spread and re-establish neoplastic disease. Therefore, AML “stem-like” cells survive cancer treatment that eradicates other malignant cell clones. This fact differentiates AML “stem-like” cells from normal stem and progenitor cells that function in tissue regeneration as part of a distinct hierarchical order of cell phenotypes. The ODYSSEY clinical trial is a Phase I/II study designed to evaluate the safety, tolerability, pharmacokinetics, and pharmacodynamics of ABD-3001, a novel therapeutic agent, in patients with AML who have relapsed or are refractory to standard treatments. In this context, ABD-3001 is used as an inhibitor of cytosolic ALDH1 enzymes, such as ALDH1A1 and ALDH1A2. Full article

Background: Metabolic-associated fatty liver disease (MAFLD) is characterized by metabolic syndrome and immune infiltration, with glycolysis pathway activation emerging as a pivotal contributor. This study aims to identify glycolysis-associated key genes driving MAFLD progression and elucidate their crosstalk with immune infiltration through bioinformatics analysis and experimental validation. Methods: Integrative multi-omics analysis was performed on bulk RNA-seq, single-cell RNA-seq, and spatial transcriptomic datasets from MAFLD patients and controls. Differential expression analysis and WGCNA were employed to pinpoint glycolysis-correlated key genes. The relationship with immune infiltration was analyzed using single-cell and spatial transcriptomics technologies. Machine learning was applied to identify feature genes for matching shared TFs and miRNAs. External cohort validation and in vivo experiments (methionine choline-deficient diet murine models) were conducted for biological confirmation. Results: Five glycolysis-associated key genes (ALDH3A1, CDK1, DEPDC1, HKDC1, SOX9) were identified and validated as MAFLD discriminators. Single-cell analysis revealed that the hepatocyte–fibroblast–macrophage axis constitutes the predominant glycolysis-active niche. Spatial transcriptomics showed that CDK1, SOX9, and HKDC1 were colocalized with the monocyte-derived macrophage marker CCR2. Using four machine learning models, four feature genes were identified, along with their common transcription factors YY1 and FOXC1, and the miRNA “hsa-miR-590-3p”. External datasets and experimental validation confirmed that the key genes were upregulated in MAFLD samples. Conclusions: In this study, we identified five glycolysis-related key genes in MAFLD and explored their relationship with immune infiltration, providing new insights for diagnosis and metabolism-directed immunomodulation strategies in MAFLD. Full article

Background: Cancer stem cells (CSCs) are a subpopulation of cancer cells known for their self-renewal capacity, tumorigenicity, and resistance to treatment. Toll-like receptor 3 (TLR3) plays a complex role in cancer, exhibiting both pro-apoptotic and pro-tumorigenic effects. This study investigates the pro-tumorigenic role of TLR3, specifically its impact on CSCs in head and neck cancer. Methods: We have investigated Detroit 562, FaDu and SQ20B cell lines, the latter being stably transfected with a plasmid containing inducible shRNA for TLR3, by cultivating them to form tumor spheres in order to study CSCs. Results: Our findings demonstrate that TLR3 activation promotes stemness in head and neck cancer cell lines. This is evidenced by increased tumor sphere formation, promotion of epithelial-to-mesenchymal transition (EMT), upregulated stemness gene expression, and elevated aldehyde dehydrogenase (ALDH) activity. Conditional TLR3 knockdown abolished tumor sphere formation, confirming its important role. Furthermore, TLR3 activation triggers the secretion of damage-associated molecular patterns (DAMPs) into the tumor microenvironment, leading to increased cancer cell migration. This was inhibited by DAMP inhibitors. In patient tissue samples, we observed co-localization of TLR3 with stemness markers CD133 and ALDH1, as well as with heat shock protein 70 (HSP70) and receptor for advanced glycation end products (RAGE). We then explored potential CSC-targeted therapies, initially combining the apoptosis inducer poly (I:C) with DAMP inhibitors and γ-irradiation. While this combination proved effective in adherent cells, it failed to eliminate tumor spheres. Nevertheless, we discovered that proton radiotherapy, particularly when combined with aspirin (HMGB1 inhibitor) and poly (I:C), effectively eliminates CSCs. Conclusions: This novel combination holds promise for the development of new therapeutic strategies for head and neck cancers, particularly given the promising results of proton therapy in treating this disease. Full article

Aldehyde dehydrogenase 2 (ALDH2) is a crucial detoxifying enzyme that eliminates toxic aldehydes. ALDH2 deficiency has been linked to various human diseases, including certain cancers. We have previously reported ALDH2 downregulation in human melanoma tissues. Here, we further investigated the biological significance of ALDH2 downregulation in this malignancy. Analysis of TCGA dataset revealed that low ALDH2 expression correlates with poorer survival in metastatic melanoma. Examination of human metastatic melanoma cell lines confirmed that most had ALDH2 downregulation (ALDH2-low) compared to primary melanocytes. In contrast, a small subset of metastatic melanoma cell lines exhibited normal ALDH2 levels (ALDH2-normal). CRISPR/Cas9-mediated ALDH2 knockout in ALDH2-normal A375 cells promoted tumor growth and MAPK/ERK activation. Given the pivotal role of MAPK/ERK signaling in melanoma and cellular response to acetaldehyde, we compared A375 with ALDH2-low SK-MEL-28 and 1205Lu cells. ALDH2-low cells were intrinsically resistant to BRAF and MEK inhibitors, whereas A375 cells were not. However, A375 cells acquired resistance upon ALDH2 knockout. Furthermore, melanoma cells with acquired resistance to these inhibitors displayed further ALDH2 downregulation. Our findings indicate that ALDH2 downregulation contributes to melanoma progression and therapy resistance in BRAF-mutated human metastatic melanoma cells, highlighting ALDH2 as a potential prognostic marker and therapeutic target in metastatic melanoma. Full article

Diabetic cardiomyopathy (DCM) is a significant complication of diabetes, particularly affecting East Asian populations with a high prevalence of the ALDH2*2 (Glu504Lys) genetic variant. This variant impairs aldehyde detoxification, leading to increased oxidative stress, mitochondrial dysfunction, and chronic inflammation, exacerbating cardiac damage and fibrosis. This review aimed to systematically delineate the pathological role of ALDH2 enzyme deficiency in DCM by integrating clinical observations with mechanistic insights from experimental models and evaluating emerging therapies for genetically susceptible populations. In vitro and in vivo studies demonstrate that ALDH2*2 amplifies oxidative stress and disrupts mitochondrial homeostasis under hyperglycemic conditions, leading to enhanced cardiac fibrosis and functional decline. Additionally, ALDH2*2 carriers show heightened susceptibility to metabolic stress, further aggravating DCM. Given the high prevalence of ALDH2*2 in East Asian populations, targeted therapeutic strategies are urgently needed. Promising approaches include ALDH2 activators (e.g., Alda-1) that enhance detoxification of reactive aldehydes, and SGLT2 inhibitors (e.g., empagliflozin) that improve mitochondrial function and reduce oxidative damage. These therapies can mitigate oxidative stress and preserve cardiac function in ALDH2*2 carriers, thereby potentially reducing DCM burden, especially in high-risk East Asian populations. Further clinical investigations are warranted to validate these therapeutic approaches and optimize management for ALDH2-deficient individuals. Full article

Excessive drinking or even alcoholism poses noticeable health risks to society, and investigating ways to improve alcohol metabolism may be a potential strategy to address this public health issue. The aim of this study was to explore the efficacy of freshwater clam aqueous extract (CE) in promoting alcohol metabolism and to further elucidate its potential mechanism. Male Wistar rats were divided into four groups: (1) control group (C); (2) vehicle group (V), which was given a single dose of 2 g/kg bw ethanol; (3) low-dose CE group (CEL), which was given ethanol and 128 mg/kg bw CE; and (4) high-dose CE group (CEH), which was given ethanol and 256 mg/kg bw CE. Blood was drawn from the tails of the rats at 0, 1, 2, 3, and 4 h after alcohol administration, and serum samples were collected. The results showed that compared with the V group, oral administration of CE reduced the ethanol concentration in the serum of the rats, with the area under the serum ethanol curve (AUC) of the CEH group decreased by 32.6%, exhibiting a significant difference (p < 0.05). Moreover, the high-dose CE (CEH) treatment significantly increased the activities of alcohol dehydrogenase (ADH), acetaldehyde dehydrogenase (ALDH), catalase (CAT), and superoxide dismutase (SOD) in the liver of the rats by 41.5%, 42.4%, 40.6%, and 34.6%, respectively, compared with those in group V (p < 0.05). The Western blot results indicated that CE reduced the expression of ethanol-induced inflammation-related proteins COX-2, iNOS, and TNF-α in the liver by 66.4%, 90.6%, and 41.4%, respectively. In conclusion, it can be inferred that CE can help reduce the ethanol concentration in the serum of rats fed with alcohol, and its possible mechanism is to promote the metabolism of ethanol by increasing the activities of ADH and ALDH and the antioxidant capacity in the liver. Full article

Emergent cancer drug resistance and further metastasis can mainly be attributed to altered expression levels and functional activities of multiple genes of cancer cells under chemotherapy. In response to challenge with anticancer drugs, enhanced ceramide glycosylation catalyzed by glucosylceramide synthase (GCS) confers drug resistance and enrichment with cancer stem cells. p53 mutations, which gain function in tumor progression, are prevalently extant in ovarian cancers. Via integrated gene expression assessments, we characterized GCS-responsive genes in ovarian cancer cells treated with dactinomycin. NCI/ADR-RES cells dominantly expressed a p53 mutant (7 aa deleted in exon-5) and displayed anti-apoptosis; however, silencing GCS expression rendered these cells sensitive to dactinomycin-induced apoptosis. Microarray analyses of NCI/ADR-RES and its GCS transfected sublines found that elevated GCS expression or ceramide glycosylation was associated with altered expression of 41 genes, notably coding for ABCB1, FGF2, ALDH1A3, apolipoprotein E, laminin 2, chemokine ligands, and IL6, with cellular resistance to induced apoptosis and enrichment with cancer stem cells, promoting cancer progression. These findings were further corroborated through integrated genomic analyses of ovarian cancer from The Cancer Genome Atlas (TCGA) and cancer resistance to platinum-based chemotherapy. Altogether, our present study indicates that altered ceramide glycosylation can modulate expression of these GCS-responsive genes and alter cancer cell attributes under chemotherapy. Full article

Background/Objectives: Hexaraphane, also known as 6-methylsulfinylhexyl isothiocyanate, derived from wasabi (Eutrema japonicum), increases heme oxygenase-1 (HO-1) and aldehyde dehydrogenase 2 (ALDH2) mRNA expression by activating nuclear factor erythroid 2-related factor 2 (Nrf2) in both HepG2 cells and the mouse liver. Given the presence of a peroxisome proliferator-activated receptor (PPAR) response element (PPRE) in the HO-1 and ALDH2 promoters, the present study aimed to determine the effects of hexaraphane on PPARα-associated genes, age-related weight gain, plasma triglyceride levels, and hepatic senescence. Methods: HepG2 cells were treated with hexaraphane to evaluate PPARα target gene expression and PPRE transcriptional activity. Male C57BL/6J young control, aged control, and aged mice administered with hexaraphane for 16 weeks were assessed for food and water intake, body and tissue weights, plasma parameters, and hepatic PPARα-related gene expression. Results: Hexaraphane increased HO-1 mRNA expression levels in HepG2 cells, which was inhibited by GW6471, a PPARα antagonist. It elevated PPRE transcriptional activity and increased carnitine palmitoyltransferase 1A (CPT1A) mRNA expression levels, indicating PPARα activation. In aged mice, hexaraphane intake reduced body weight gain by decreasing the adipose tissue weight. Increased CPT1A expression levels and a tendency toward increased acyl-CoA oxidase 1 (ACOX1) expression levels in the liver of aged mice administered hexaraphane were associated with reduced plasma triglyceride levels and body weight gain. Increased hepatic Sirt1 expression levels in aged mice administered hexaraphane was associated with lower plasma triglyceride levels. Increased hepatic PPARα mRNA expression levels in aged mice administered hexaraphane suggest a positive feedback loop between PPARα and Sirt1. The expression levels of hepatic p21 mRNA, a senescence marker regulated by Sirt1, were upregulated in aged mice but suppressed by hexaraphane intake. Conclusions: Hexaraphane may prevent age-related body weight gain, elevated plasma triglyceride levels, and hepatic senescence by activating PPARα, potentially contributing to longevity. Full article

Lignocellulosic biomass is widely recognized as a renewable resource for bioconversion. However, the presence of inhibitors such as furfural, 5-HMF, and acetic acid can inhibit cell growth, thereby affecting the overall efficiency of the bioconversion process. The studies on the degradation of lignocellulosic hydrolysate inhibitors by Saccharomyces cerevisiae have been limited. In this research, a yeast strain Kodamaea ohmeri can degrade inhibitors furfural, 5-HMF, and acetic acid, and the genome sequence of the strain was analyzed. Furthermore, the molecular detoxification mechanism of K. ohmeri SSK against lignocellulosic hydrolysate inhibitors was predicted using whole genome sequencing. Annotation based on the COG/KEGG databases identified 57 key detoxification genes, including the alcohol dehydrogenase (ADH) gene, aldo-keto/aldehyde reductase (AKR/ARI) gene, and aldehyde dehydrogenase (ALDH) gene. Stress tolerance experiments revealed that the maximum tolerance concentration for the strain was 5.2 g/L of furfural, 2.5 g/L of 5-HMF, and 5.9 g/L of acetic acid, respectively. A NAD(P)⁺-dependent bifunctional enzyme with possible ADH and ARI activities was found by conserved domain analysis. Phylogenetic analysis indicated that this enzyme shared 99% homology with the detoxification enzyme from S. cerevisiae S288C (GenBank: Q04894.1). This study represents the first comprehensive analysis of the inhibitor detoxification network in K. ohmeri SSK from a genome perspective, providing theoretical targets and design strategies for developing highly efficient biorefinery strains. Full article

Cysteine, a semi-essential amino acid, is found in the active site of a number of vital enzymes of the bacterium Mycobacterium tuberculosis (Mtb) and in particular those that relate to its survival, adaptability and pathogenicity. Mtb is the causative agent of tuberculosis, an infectious disease that affects millions of people globally. Common anti-tuberculosis targets are focused on immobilizing a vital cysteine amino acid residue in enzymes that plays critical roles in redox and non-redox catalysis, the modulation of the protein, enzyme activity, protein structure and folding, metal coordination, and posttranslational modifications of newly synthesized proteins. This review examines five Mtb enzymes that contain an active site cysteine residue and are considered as key targets for anti-tuberculosis drugs, namely alkyl hydroperoxide reductase (AhpC), dihydrolipoamide dehydrogenase (Lpd), aldehyde dehydrogenase (ALDH), methionine aminopeptidase (MetAP) and cytochromes P450. AhpC and Lpd protect Mtb against oxidative and nitrosative stress, whereas AhpC neutralizes peroxide/peroxynitrite substrates with two active site cysteine residues. Mtb ALDH detoxifies aldehydes, using a nucleophilic active site cysteine to form an oxyanion thiohemiacetal intermediate, whereas MtMetAP’s active site cysteine is essential for substrate recognition. The P450s metabolize various endogenous and exogenous compounds. Targeting these critical active site cysteine residues could disrupt enzyme functions, presenting a promising avenue for developing anti-mycobacterial agents. Full article