Search Results (260)

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: 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

Insulin resistance (IR) is a key mechanism underlying type 2 diabetes mellitus and is closely associated with obesity. Although numerous genome-wide association studies (GWASs) have identified variants that influence IR-related traits, it remains unclear whether the genetic architecture of IR differs according to obesity status. We conducted a stratified GWAS of the Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) in 8906 Korean individuals from the Korean Genome and Epidemiology Study. Participants were categorized into a normal-weight group (Body Mass Index (BMI) ≤ 23 kg/m²) and an overweight or obese group (BMI > 23 kg/m²), and the GWAS was performed separately within each group. No significant genome-wide variants were identified in the normal-weight group; however, seven loci showed suggestive associations. In contrast, in the overweight and obese group, two loci, rs662799 in Apolipoprotein A5 (APOA5) and rs671 in Aldehyde Dehydrogenase 2 (ALDH2), showed genome-wide significance, with seven loci showing suggestive associations. The risk allele of rs662799 was associated with increased HOMA-IR values, with a stronger effect observed in the overweight and obese group. This finding aligns with the known role of APOA5 in triglyceride metabolism, suggesting that a higher BMI may exacerbate its effect on IR. These results highlight obesity-specific genetic susceptibility to IR and the need to consider obesity status in genetic studies of metabolic traits. 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

Background/Objectives: Abiotic stresses severely constrain the yield of Brassica juncea, and aldehyde dehydrogenases (ALDHs) play a pivotal role in plant stress resistance. This study aims to systematically identify the ALDH gene family members in B. juncea and elucidate their expression patterns under salt and drought stress. Methods: Using the Arabidopsis thaliana AtALDH proteins as seed sequences, BLASTp alignment was performed against the B. juncea whole-protein sequence database, combined with the conserved domain PF00171 of the ALDH proteins. A total of 39 BjALDH gene family members were identified, and their physicochemical properties, structures, phylogenetic relationships, interspecies collinearity, and intraspecies collinearity were analyzed. The qRT-PCR method was employed to quantify the relative expression levels of the BjALDH genes potentially associated with stress resistance under various treatments, and their effects on drought and salt stress tolerance were evaluated. Results: The results demonstrated that BjALDH were universally significantly upregulated under salt stress, while exhibiting predominantly upregulated trends under drought stress. These findings suggest that BjALDH may enhance plant resistance to both salt and drought stress by modulating the aldehyde metabolic pathways. Conclusions: This study provides a theoretical basis for elucidating the functional roles and molecular genetic mechanisms of the BjALDH gene family in B. juncea under salt and drought stress. 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

Previously, we reported that mating induces an early transcriptional response in the oviductal mucosa of rats. The functional category ‘cell-to-cell signaling and interaction’ was overrepresented in this gene list. Therefore, in the present study, we describe the role of one of these genes, carbohydrate sulfotransferase 10 (Chst10), in the oviductal mucosa. CHST10 participates in the synthesis of the carbohydrate moiety human natural killer-1 (HNK-1), which mediates cell-to-cell interactions. When using one-dimensional Western blot and sulfotransferase analyses, we found that mating increased the protein level and activity of CHST10 in the oviductal mucosa at 3 h after stimulation. A two-dimensional Western blot analysis and mass spectrometry were used to identify the novel HNK-1 glycoproteins aldehyde dehydrogenase 9 family, member A1 (ALDH9A1), fructose bisphosphate aldolase A (ALDOA), and four and a half LIM domains protein 1 (FHL1) in the oviductal mucosa, and we found that mating induces the synthesis of their acidic variants. Interestingly, in the utero-tubal junction (UTJ), acrosome-reacted sperm apparently were interacting with regions in which ALDH9A1 and HNK-1 signals overlap. Furthermore, vaginocervical stimulation applied to unmated rats increased the mRNA level of Chst10 in the oviductal mucosa. In conclusion, mating increases the activity of CHST10 in the oviductal mucosa, which in turn induces the synthesis of acidic variants of ALDH9A1 and FHL1 via HNK-1 glycosylation. ALDH9A1, HNK-1-ALDH9A1, and/or other HNK-1 glycoproteins could participate in the negative selection of sperm in the UTJ, since we detected acrosome-reacted sperm apparently interacting with regions where these proteins are located. Finally, the sensorial component of mating could regulate early events (e.g., sperm transport and selection) occurring in the oviductal mucosa after mating. Full article

Since ancient times, plants have been used in folk medicine to treat different diseases. Plants offer exceptional chemical diversity with a wide range of biological activities, and have therefore been the most promising sources for the discovery and development of drugs, including antimicrobial agents. This study reports the antibacterial effect of geraniol (GER), alone and in combination with biogenic silver nanoparticles (bioAgNPs), produced using the aqueous extract of Trichilia catigua bark, against planktonic and sessile cells of methicillin-resistant Staphylococcus aureus (MRSA), one of the main opportunistic and potentially fatal human pathogens. GER had a time-dependent bactericidal effect on planktonic cells, impairing the cell membrane integrity. In addition, GER inhibited the staphyloxanthin production, and molecular docking analyses supported the in silico affinity of GER to dehydrosqualene synthase (CrtM) and 4,4′-diaponeurosporen-aldehyde dehydrogenase (AldH), which are key enzymes within the pigment biosynthesis pathway in S. aureus. GER treatment increased the sensitivity of MRSA to hydrogen peroxide killing. GER displayed synergism with bioAgNPs against planktonic and sessile cells, inhibiting bacterial adhesion and the viability of biofilms formed on abiotic surfaces. MRSA planktonic and sessile cells treated with GER or GER/bioAgNPs displayed severe morphological and ultrastructural alterations. Notably, neither GER nor its combination caused in vitro and in vivo toxicity in mammalian cells and Galleria mellonella larvae, respectively. These findings suggest that the combination of GER/bioAgNPs may be a promising strategy to control MRSA infections. Full article

Amino acid metabolism constitutes a major metabolic pathway in plants, playing an important role in the modulation of plant responses to stress. In this study, we investigated the amino acid metabolism responses of M. sativa (Medicago sativa L.) and M. truncatula (Medicago truncatula L.) plants under salt stress using transcriptomic and proteomic approaches to elucidate their salt stress tolerance mechanisms in relation to the regulation of amino acid homeostasis. Transcriptome and proteome sequencing followed by Kyoto Gene and Genome Encyclopedia enrichment analysis revealed 34 differentially expressed genes and 45 differentially expressed proteins involved in valine, leucine, and isoleucine degradation, tyrosine metabolism, and glutathione metabolism. Significant differences were observed in the expression of glutathione S-transferase (GST) within the glutathione metabolic pathway between M. sativa and M. truncatula. The induction of valine, leucine, and isoleucine metabolism, aldehyde dehydrogenases (ALDHs), and alanine-glyoxylate aminotransferases (AGXTs), involved in intracellular reactive oxygen species scavenging, also significantly differed under salt stress. Significant differences were identified in the expression of tyrosine decarboxylases (TDCs) involved in tyrosine metabolism, which are responsible for tyramine biosynthesis and can enhance plant tolerance to salt stress. This study delved into the effects of amino acid metabolism on the salt tolerance mechanisms of M. sativa and M. truncatula, which is crucial in guiding the future breeding of salt-tolerant alfalfa varieties. Full article

Scleroglucan is the extracellular polysaccharide (EPS) produced by Sclerotium rolfsii (S. rolfsii). The low EPS titer and limited substrate utilization of S. rolfsii present significant challenges in the fermentation process, restricting industrial applications of scleroglucan. In this study, we performed a transcriptomic analysis on the mycelium of S. rolfsii fermented with different carbon sources. The key genes involved in polysaccharide biosynthesis (6-phosphofructokinase 1 (PFK1), pyruvate decarboxylase (PDC), aldehyde dehydrogenase (NAD (P)+) (ALDH3), and acetyl-CoA synthase (ACS)) were identified and their roles in the process were investigated. The supplementation of specific precursors—fructose-6-phosphate, pyruvate, aldehydes, and acetate—was shown to enhance both the polysaccharide titer and substrate utilization. By adding precursors, the titer of SEPS produced in a 5 L fermentation tank reached 48.69 ± 3.8 g/L. Notably, the addition of these precursors increased the titer of EPS fermented with sucrose (SEPS) by 65.63% and substrate utilization by 119.3%, while the titer of EPS fermented with lactose (LEPS) rose by 80.29% and substrate utilization rose by 47.08%. These findings suggest that precursor supplementation can effectively improve polysaccharide production and substrate efficiency, thereby minimizing resource waste and environmental impact. Full article