Aldehyde Dehydrogenase Activity Research Articles

Pharmacological activation of aldehyde dehydrogenase 2 inhibits ferroptosis via SLC7A11/GPX4 axis to reduce kidney stone formation.

Calcium oxalate (CaOx) kidney stones pose a global health challenge due to their high prevalence and recurrence rates. While cell death mechanisms such as ferroptosis are known to play a crucial role in stone formation, the precise underlying mechanisms remain enigmatic. Aldehyde dehydrogenase 2 (ALDH2) is a metabolic enzyme of the ferroptosis product 4-hydroxy-2-nonenal (4-HNE). However, the function of ALDH2 in kidney stones is poorly understood. In this study, we observed a downregulation of aldehyde dehydrogenase 2 (ALDH2) in the stone group. Significantly, the administration of Alda-1, an ALDH2 agonist, notably reduced crystal deposition in the kidneys and hindered crystal adhesion to cells. Furthermore, Alda-1 induced upregulation of SLC7A11 expression, promoting glutathione synthesis, reducing lipid peroxidation accumulation, and lowering Fe2+ levels. These collective effects attenuated crystal-induced ferroptosis. However, the renoprotective effects of Alda-1 were inhibited by SLC7A11 siRNA. In conclusion, our study explores the applications of Alda-1 and highlights the potential of targeting ALDH2 as a promising therapeutical strategy for urolithiasis.

Investigation of Bottleneck Enzyme Through Flux Balance Analysis to Improve Glycolic Acid Production in Escherichia coli.

Amid rising environmental concerns, attempts have been made to produce glycolic acid (GA) using microbial processes with renewable carbon resources instead of using chemicals. The Dahms pathway for GA production uses xylose as a substrate and consists of relatively simple enzymatic steps. However, employing it leads to a decrease in cell growth and GA productivity. Systematically identifying and addressing metabolic bottlenecks in the Dahms pathway are essential for efficient glycolic acid (GA) production have not yet been performed. Through metabolic flux balance analysis, we found that insufficient aldehyde dehydrogenase (AldA) activity lowers GA production and negatively affects cell growth due to reduced energy production. Thus, we discovered a novel AldA isolated from Buttiauxella agrestis (BaAldA) demonstrated a 1.69-fold lower KM and a 1.49-fold higher turnover rate (kcat/KM) than AldA from Escherichia coli (EcAldA). GA production in E. coli harboring BaAldA was 1.59 times higher than in the original strain. Fed-batch fermentation of E. coli harboring BaAldA produced 22.70g/L GA with a yield of 0.497g/gxylose (98.2% of the theoretical maximum yield in the Dahms pathway), showing a higher final yield for GA than previously reported in E. coli. Our novel BaAldA enzyme shows great potential for the production of GA using microorganisms or enzymes. Furthermore, our approach to identifying metabolic bottlenecks using flux balance analysis could be utilized to enhance the microbial production of various desirable products in future studies.

Targeting Retinaldehyde Dehydrogenases to Enhance Temozolomide Therapy in Glioblastoma.

Glioblastoma (GB) is an aggressive malignant central nervous system tumor that is currently incurable. One of the main pitfalls of GB treatment is resistance to the chemotherapeutic standard of care, temozolomide (TMZ). The role of aldehyde dehydrogenases (ALDHs) in the glioma stem cell (GSC) subpopulation has been related to chemoresistance. ALDHs take part in processes such as cell proliferation, differentiation, invasiveness or metastasis and have been studied as pharmacological targets in cancer treatment. In the present work, three novel α,β-acetylenic amino thiolester compounds, with demonstrated efficacy as ALDH inhibitors, were tested in vitro on a panel of six human GB cell lines and one murine GB cell line. Firstly, the expression of the ALDH1A isoforms was assessed, and then inhibitors were tested for their cytotoxicity and their ability to inhibit cellular ALDH activity. Drug combination assays with TMZ were performed, as well as an assessment of the cell death mechanism and generation of ROS. A knockout of several ALDH genes was carried out in one of the human GB cell lines, allowing us to discuss their role in cell proliferation, migration capacity and resistance to treatment. Our results strongly suggest that ALDH inhibitors could be an interesting approach in the treatment of GB, with EC50 values in the order of micromolar, decreasing ALDH activity in GB cell lines to 40-50%.

ALDH2 mediates the effects of sodium-glucose cotransporter 2 inhibitors (SGLT2i) on improving cardiac remodeling

BackgroundSodium-glucose cotransporter-2 inhibitors (SGLT2i) are now recommended for patients with heart failure, but the mechanisms that underlie the protective role of SGLT2i in cardiac remodeling remain unclear. Aldehyde dehydrogenase 2 (ALDH2) effectively prevents cardiac remodeling. Here, the key role of ALDH2 in the efficacy of SGLT2i on cardiac remodeling was studied.MethodsAnalysis of multiple transcriptomic datasets and two-sample Mendelian randomization were performed to find out the differentially expressed genes between pathological cardiac hypertrophy models (patients) and controls. A pathological cardiac hypertrophy mouse model was established via transverse aortic constriction (TAC) or isoproterenol (ISO). Cardiomyocyte-specific ALDH2 knockout mice (ALDH2CMKO) and littermate control mice (ALDH2flox/flox) were generated to determine the critical role of ALDH2 in the preventive effects of dapagliflozin (DAPA) on cardiac remodeling. RNA sequencing, gene knockdown or overexpression, bisulfite sequencing PCR, and luciferase reporter assays were performed to explore the underlying molecular mechanisms involved.ResultsOnly ALDH2 was differentially expressed when the differentially expressed genes obtained via Mendelian analysis and the differentially expressed genes obtained from the multiple transcriptome datasets were combined. Mendelian analysis revealed that ALDH2 was negatively related to the severity of myocardial hypertrophy in patients. DAPA alleviated cardiac remodeling in mouse hearts subjected to TAC or ISO. ALDH2 expression was reduced, whereas ALDH2 expression was restored by DAPA in hypertrophic hearts. Cardiomyocyte specific ALDH2 knockout abolished the protective role of DAPA in preventing cardiac remodeling. ALDH2 expression and activity were increased in DAPA-treated neonatal rat primary cardiomyocytes (NRCMs), H9C2 cells and AC16 cells. Moreover, DAPA upregulated ALDH2 in peripheral blood mononuclear cells (PBMCs) from patients with type 2 diabetes. Sodium/proton exchanger 1 (NHE1) inhibition contributed to the regulation of ALDH2 by DAPA. DAPA suppressed the production of reactive oxygen species (ROS), downregulated DNA methyltransferase 1 (DNMT1) and subsequently reduced the ALDH2 promoter methylation level. Further studies revealed that DAPA enhanced the binding of nuclear transcription factor Y, subunit A (NFYA) to the promoter region of ALDH2, which was due to the decreased promoter methylation level of ALDH2.ConclusionsThe upregulation of ALDH2 plays a critical role in the protection of DAPA against cardiac remodeling. DAPA enhances the binding of NFYA to the ALDH2 promoter by reducing the ALDH2 promoter methylation level through NHE1/ROS/DNMT1 pathway.Graphical abstract

Tumor Heterogeneity Shapes Survival Dynamics in Drug-Treated Cells, Revealing Size-Drifting Subpopulations.

The goal of this project was to demonstrate that subpopulations of cells in tumors can uniquely fluctuate in size in response to environmental conditions created during drug treatment, thereby acting as a dynamic "rheostat" to create a favorable tumor environment for growth. The cancer modeling used for these studies was subpopulations of melanoma cells existing in cultured and tumor systems that differed in aldehyde dehydrogenase (ALDH) activity. However, similar observations were found in other cancer types in addition to melanoma, making them applicable broadly across cancer. The approach was designed to show that either ALDHhigh and ALDHlow subpopulations rapidly epigenetically transition between stem-cell-like high into nonstem-like low production states to create an environment during drug treatment that would enable optimal cellular proliferation and tumor expansion to facilitate drug resistance. The controlled experiments showed proportional changes in each cell population to reach an evolutionarily stable equilibrium mediated by the needed levels of ALDH enzyme activity. Mechanistically, cell population size changes served to functionally move the aldehyde and the resulting reactive oxygen species (ROS) levels to those compatible with optimal cellular proliferation with population fluctuations dependent on the levels of drug induced tumor stress. This is the first report documenting fluctuations in the sizes of cell populations in tumors to cooperatively assist in drug resistance development.

Glycolysis-mTORC1 crosstalk drives proliferation of patient-derived endometrial cancer spheroid cells with ALDH activity

Cancer stem cells are associated with aggressive phenotypes of malignant tumors. A prominent feature of uterine endometrial cancer is the activation of the PI3K–Akt–mTOR pathway. In this study, we present variations in sensitivities to a PI3K–Akt–mTORC1 inhibitor among in vitro endometrial cancer stem cell-enriched spheroid cells from clinical specimens. The in vitro sensitivity was consistent with the effects observed in in vivo spheroid-derived xenograft tumor models. Our findings revealed a complementary suppressive effect on endometrial cancer spheroid cell growth with the combined use of aldehyde dehydrogenase (ALDH) and PI3K–Akt inhibitors. In the PI3K–Akt–mTORC1 signaling cascade, the influence of ALDH on mTORC1 was partially channeled through retinoic acid-induced lactate dehydrogenase A (LDHA) activation. LDHA inhibition was found to reduce endometrial cancer cell growth, aligning with the effects of mTORC1 inhibition. Building upon our previous findings highlighting ALDH-driven glycolysis through GLUT1 in uterine endometrial cancer spheroid cells, curbing mTORC1 enhanced glucose transport via GLUT1 activation. Notably, elevated LDHA expression correlated with adverse clinical survival and escalated tumor grade, especially in advanced stages. Collectively, our findings emphasize the pivotal role of ALDH–LDHA–mTORC1 cascade in the proliferation of endometrial cancer. Targeting the interaction between mTORC1 and ALDH-influenced glycolysis holds promise for developing novel strategies to combat this aggressive cancer.

Advances in Factors Affecting ALDH2 Activity and its Mechanisms.

Aldehyde dehydrogenase 2 (ALDH2) is a mitochondrial enzyme primarily involved in the detoxification of alcohol-derived aldehyde and endogenous toxic aldehydes. It exhibits widespread expression across various organs and exerts a broad and significant impact on diverse acute cardiovascular diseases, including acute coronary syndrome, acute aortic dissection, hypoxic pulmonary hypertension, and heart failure. The ALDH2 rs671 variant represents the most prevalent genetic variant in East Asian populations, with carriage rates ranging from 30 to 50% among the Chinese population. Given its widespread presence in the body, the wide range of diseases it affects, and its high rate of variation, it can serve as a crucial tool for the precise prevention and treatment of acute cardiovascular diseases, while offering individualized medication guidance. This review aims to provide a comprehensive overview of the latest advancements in factors affecting ALDH2 activity, encompassing post-transcriptional modifications, modulators of ALDH2, and relevant clinical drugs.

Electrochemical characterization of carbon black in different redox probes and their application in electrochemical sensing

Carbon black - materials rich in carbon nanostructures - have been successfully applied as modifiers of electrochemical transducers, rivalling other carbon nanomaterials for cost and ease-of-use. Despite the remarkable promise of this nanomaterial, no study has yet comparatively characterised a wide range of different grades of carbon black for their utility in electrochemical sensors. Here, we explore several commonly-studied carbon black grades (N220, N234, N326, N330, N339, N375, N550, N660 and Lamp Black-101), alongside relatively newer grades (Printex®-200, Printex® G, Printex® XE-2B, and Printex® Zeta) for their application in electrochemical sensors. The effects of coating glassy carbon electrodes with carbon black on electrode performance were studied by cyclic voltammetry using three redox probes: ferri-/ferrocyanide (anionic probe molecules), ferrocenemethanol (neutral) and hexaammineruthenium (cationic). Raman Spectroscopy characterisation of the different grades associated a lower degree of graphitisation with superior electrode modifiers. Generally, modification increased the anodic peak current for ferri-/ferrocyanide probes; and lowered anodic potential for ferri-/ferrocyanide and hexaammineruthenium probes. Increases in peak current and potential observed at ferrocenemethanol are consistent with the increased tendency for this probe to adsorb to the surface of modified electrodes. N330 and Printex® XE-2B displayed the best electrocatalytic properties in terms of enhanced peak currents and lowered anodic overpotentials for the redox probes. CB grades were used to modify screen-printed carbon electrodes and the obtained sensors examined for anodic detection of reduced nicotinamide adenine dinucleotide (NADH) cofactor by cyclic voltammetry. Printex® XE-2B significantly improved the detection of NADH and was further used for chronoamperometric detection of NADH at low overpotentials. Grades N220, N375, N550 and P-G showed their suitability as enzyme scaffolds for sensor fabrication, as determined by their preservation of the activity of a NAD-dependent aldehyde dehydrogenase.

Self-Nanoemulsifying Drug Delivery System of Morin: A New Approach for Combating Acute Alcohol Intoxication.

Acute alcohol intoxication (AAI) is a life-threatening medical condition resulting from excessive alcohol consumption. Our research revealed the potential of morin (MOR) in treating AAI. However, MOR's effectiveness against AAI was hindered by its poor solubility in water and low bioavailability. In this study, our aim was to develop a self-nanoemulsifying drug delivery system (SNEDDS) to enhance MOR's solubility and bioavailability, evaluate its anti-AAI effects, and investigate the underlying mechanism. The composition of MOR-loaded self-nanoemulsifying drug delivery system (MOR-SNEDDS) was determined by constructing pseudo-ternary phase diagrams, and its formulation proportion was optimized using the Box-Behnken design. Following characterization of MOR-SNEDDS, we investigated its pharmacokinetics and biodistribution in healthy animals. Additionally, we assessed the anti-AAI effects and gastric mucosal protection of MOR-SNEDDS in an AAI mice model, exploring potential mechanisms. After breaking down into tiny droplets, the optimized mixture of MOR-SNEDDS showed small droplet size on average, even distribution, strong stability, and permeability. Pharmacokinetic studies indicated that MOR-SNEDDS, compared to a MOR suspension, increased the area under the plasma concentration-time curve (AUC0-t) by 10.43 times. Additionally, studies on how drugs move and are distributed in the body showed that MOR-SNEDDS had an advantage in passively targeting the liver. Moreover, in a mouse model for alcohol addiction, MOR not only decreased alcohol levels by boosting the activity of alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) in the stomach and liver, which counteracted the loss of righting reflex (LORR), but also reduced alcohol-induced damage to the stomach lining by lowering malondialdehyde (MDA) levels and increasing superoxide dismutase (SOD) levels. Furthermore, MOR-SNEDDS notably amplified these effects. MOR exhibits significant potential as a new medication for treating AAI, and utilizing MOR-SNEDDS with high oral bioavailability represents a promising new strategy in combating AAI.

Improving the alcohol respiratory chain and energy metabolism by enhancing PQQ synthesis in Acetobacter pasteurianus.

Pyrroquinoline quinone (PQQ) is one of the important coenzymes in living organisms. In acetic acid bacteria (AAB) it plays a crucial role in alcohol respiratory chain, as a coenzyme of alcohol dehydrogenase. In this work, the PQQ biosynthetic genes were overexpressed in Acetobacter pasteurianus CGMCC 3089 to improve the fermentation performance. The result shows that the intracellular and extracellular PQQ contents in the recombinant strain A. pasteurianus (pBBR1-p264-pqq) were 152.53% and 141.08% higher than those of the control A. pasteurianus (pBBR1-p264), respectively. The catalytic activity of alcohol dehydrogenase and aldehyde dehydrogenase increased by 52.92% and 67.04%, respectively. The results indicated that the energy charge and intracellular ATP were also improved in the recombinant strain. The acetic acid fermentation was carried out using a 5 L self-aspirating fermenter, and the acetic acid production rate of the recombinant strain was 23.20% higher compared with the control. Furthermore, the relationship between the PQQ and acetic acid tolerance of cells was analyzed. The biomass of recombinant strain was 180.2%, 44.3%, and 38.6% higher than those of control under 2%, 3%, and 4% acetic acid stress, respectively. After treated with 6% acetic acid for 40 min, the survival rate of the recombinant strain was increased by 76.20% compared with the control. Those result demonstrated that overexpression of PQQ biosynthetic genes increased the content of PQQ, therefore improving the acetic acid fermentation and the cell tolerance against acetic acid by improving the alcohol respiratory chain and energy metabolism.

Sex-related differences in efficacy of bone marrow-derived high aldehyde dehydrogenase activity cells against pulmonary fibrosis

BackgroundAlthough bone marrow-derived cells with high aldehyde dehydrogenase activity (ALDHbr) have shown therapeutic potential against various diseases in animal studies, clinical trials have failed to show concurrent findings. We aimed to clarify the optimal conditions for the efficacy of ALDHbr cells by using a murine bleomycin-induced pulmonary fibrosis model.MethodsWe intravenously transferred male or female donor C57BL/6 mice-derived ALDHbr cells into recipient C57BL/6 mice under various conditions, and used mCherry-expressing mice as a donor to trace the transferred ALDHbr cells.ResultsPulmonary fibrosis improved significantly when (1) female-derived, not male-derived, and (2) lineage (Lin)-negative, not lineage-positive, ALDHbr cells were transferred during the (3) fibrotic, not inflammatory, phase. Consistent with the RNA-sequencing results, female-derived Lin−/ALDHbr cells were more resistant to oxidative stress than male-derived cells in vitro, and transferred female-derived Lin−/ALDHbr cells were more viable than male-derived cells in the fibrotic lung. The mechanism underlying the antifibrotic effects of Lin−/ALDHbr cells was strongly associated with reduction of oxidative stress.ConclusionsOur results indicated that Lin−/ALDHbr cell therapy could ameliorate pulmonary fibrosis by reducing oxidative stress and suggested that their efficacy was mediated by sex-related differences. Thus, sex-awareness strategies may be important for clinical application of bone marrow ALDHbr cells as a therapeutic tool.

Targeting ALDH2 to Augment Platinum-Based Chemosensitivity through Ferroptosis in Lung Adenocarcinoma

Ferroptosis is a regulated cell death driven by iron-dependent lipid peroxidation and associated with drug resistance in lung adenocarcinoma (LUAD). It’s found that aldehyde dehydrogenase 2 (ALDH2), which is highly mutated in East Asian populations, is correlated with response to chemotherapy in LUAD patients. The rs671 variant knock-in, downregulation, and pharmacological inhibition of ALDH2 render LUAD cells more vulnerable to ferroptosis inducers and platinum-based chemotherapy. ALDH2 inhibits ferroptosis through the detoxification of 4-hydroxynonenal and malondialdehyde, the product of lipid peroxidation, as well as the production of NADH at the same time. Besides, ALDH2 deficiency leads to elevated intracellular pH (pHi), thus inhibiting the ERK/CREB1/GPX4 axis. Interestingly, ALDH2 is also regulated by CREB1, and the ALDH2 enzyme activity was decreased with elevated pHi. What’s more, the elevated pHi caused by impaired ALDH2 activity promotes the biosynthesis of lipid droplets to counteract ferroptosis. At last, the effect of ALDH2 on ferroptosis and chemosensitivity is confirmed in patient-derived organoids and xenograft models. Collectively, this study demonstrates that ALDH2 deficiency confers sensitivity to platinum through ferroptosis in LUAD, and targeting ALDH2 is a promising new strategy to enhance the sensitivity of platinum-based chemotherapy for the treatment of LUAD patients.

Trapped in Cells: A Selective Accumulation Approach for Type-I Photodynamic Ablation of Cancer Stem-like Cells.

Aldehyde dehydrogenase (ALDH) is an enzyme responsible for converting aldehyde functional groups into carboxylate metabolites. Elevated ALDH activity is a characteristic feature of cancer stem-like cells (CSCs). As a novel approach to target the CSC trait of overexpressing ALDH, we aimed to utilize ALDH activity for the selective accumulation of a photosensitizer in ALDHHigh CSCs. A novel ALDH substrate photosensitizer, SCHO, with thionylated coumarin and N-ethyl-4-(aminomethyl)benzaldehyde was developed to achieve this goal. Our study demonstrated the efficient metabolism of the aldehyde unit of SCHO into carboxylate, leading to its accumulation in ALDHHigh MDA-MB-231 cells. Importantly, we established the selectivity of SCHO as an ALDHHigh cell photosensitizer as it is not a substrate for ABC transporters. SCHO-based photodynamic therapy triggers apoptosis and pyroptosis in MDA-MB-231 cells and further reduces the characteristics of CSCs. Our study presents a novel strategy to target CSCs by exploiting their cellular metabolism to enhance photosensitizer accumulation, highlighting the potential of photodynamic therapy as a powerful tool for eliminating ALDHHigh CSCs.

Molecular mechanisms of high aldehyde dehydrogenase production for improved beany flavour regulated by the LuxS/AI-2 quorum sensing system in Limosilactobacillus fermentum A119

Aldehydes cause beany flavor, which is one of the factors limiting the further development of plant-based fermented milks. Limosilactobacillus fermentum (L. fermentum) A119, which has the LuxS/AI-2 quorum sensing (QS) system and producing aldehyde dehydrogenase (ALDH), improves the beany flavor of soy protein-based fermented milk. However, the precise mechanism underlying the production of ALDH and its improvement on the beany flavor remains unclear. The test results indicate that cell density content and ALDH activity were up-regulated with increasing autoinducer-2 (AI-2) signaling molecule. This suggests that ALDH synthesis in L. fermentum A119 may be regulated by the LuxS/AI-2 QS system. Subsequently, the 4D-data-independent acquisition (DIA) proteomics results revealed a total of 378 differentially expressed proteins (DEPs) after 24 h of incubation compared to 2 h incubation. Among them, 236 DEPs were up-regulated, including s-ribosylhomocysteinase (LuxS) and ALDH. Additionally, Western blot analysis confirmed that LuxS/AI-2 QS system successfully mediates the expression of ALDH. Finally, under the catalysis of ALDH, the beany flavor-metabolites benzaldehyde was converted to benzoic acid, which improved the flavor of soy protein-based fermented milk. This study reveals the mechanism of ALDH regulation through the LuxS/AI-2 QS system, provide new insights for reducing beany flavor in soy protein-based fermented milk.

Effects of Several Tea-like Plants on Liver Injury Induced by Alcohol via Their Antioxidation, Anti-Inflammation, and Regulation of Gut Microbiota.

Liver injury induced by alcohol is a serious global health problem. Several tea-like plants are widely used as beverages, which are drunk like tea. In this study, the hepatoprotective effects of eight tea-like plant extracts with the intake of 200 mg/kg.bw/day were investigated and compared using a C57BL/6J mouse model of acute alcohol exposure, including sweet tea, vine tea, Rabdosia serra kudo, broadleaf holly leaf, mulberry leaf, bamboo leaf, Camellia nitidissima, and Akebia trifoliata peels. The results showed that the eight tea-like plants had hepatoprotective effects to different degrees against acute alcohol exposure via enhancing the activities of alcoholic metabolism enzymes, ameliorating oxidative stress and inflammation in the liver, as well as regulating gut microbiota. In particular, sweet tea, bamboo leaf, mulberry leaf, and Camellia nitidissima increased the activities of alcohol dehydrogenase or aldehyde dehydrogenase. Among these tea-like plants, sweet tea and Camellia nitidissima had the greatest hepatoprotective effects, and their bioactive compounds were determined by high-performance liquid chromatography. Chlorogenic acid, rutin, and ellagic acid were identified in sweet tea, and epicatechin, rutin, and ellagic acid were identified in Camellia nitidissima, which could contribute to their hepatoprotective action. These tea-like plants could be drunk or developed into functional food against alcoholic liver injury, especially sweet tea and Camellia nitidissima. In the future, the effects of sweet tea and Camellia nitidissima on chronic alcoholic liver diseases should be further investigated.

Gas Phase Aldehydes Detection in Exhaled Breath in Screening of Barrett's Esophagus

Aldehydes, e.g., acetaldehyde, have been classified as toxic and carcinogenic volatile organic compounds (VOCs) and are recognized as one determinant of upper aerodigestive tract cancer like Barrett's esophagus. Measuring aldehyde levels in breath provides information about the aldehydes released by abnormal cells, the level of aldehyde dehydrogenase (ALDH2) activity, and risks and diseases associated with high levels of acetaldehyde, which include liver disease and lung and upper digestive cancers. Devices currently available for breath analysis are state-of-the-art, high-resolution mass spectrometry instruments. These instruments have some drawbacks such as size, initial cost, and operational expense. Electrochemical sensors are capable of miniaturization and are available as portable and handheld breathalyzers. The non-invasive nature of breath analysis and its easy sampling makes smaller devices a more attractive alternative, particularly for continuous monitoring and point-of-care (POC) testing.1 However, the lack of an exchangeable/disposable sensing element, the resulting memory effect, and the need for frequent recalibration is the main drawback of currently available electrochemical breathalyzers.Herein we examine the feasibility of a POC testing device for aldehyde in exhaled breath to assess the medical application of such a device in noninvasive diagnostic testing for Barrett’s esophagus. To improve the selectivity of the method we harness the unique catalytic activity of the aminoxyl radical/oxoammonium redox couple toward aldehyde oxidation. The highly selective/sensitive device offers the capability for use in the detection of Barrett's esophagus, ideally at early stages, without the need for a high-cost screening test. Our functional sensing element consists of a screen-printed electrode (SPE) in which the graphene oxide-based is the working electrode. Exposing this electrode to simulated breath that contains aldehyde, while applying the required potential for oxidation of the aminoxyl radical (4-acetamido-TEMPO known as ACT), generates an electrocatalytic current proportional to the aldehyde concentration in the breath. These simple, sensitive, durable, and inexpensive electrodes may contribute to the development of a single-use reliable aldehyde sensor for personal or law enforcement applications.1. M. Mayer, M. Rafiee, Electrocatalytic Detection of Ethanol and Acetaldehyde by Aminoxyl Radicals: Utilizing Molecular Catalysis for Breath Analysis. Analyst 147, 2022, 3420 – 3423.

ATG10-dependent autophagy is required for DDX10 to regulate cell proliferation, apoptosis and stemness in colorectal cancer

Colorectal cancer (CRC) remains a highly prevalent gastrointestinal neoplasm, presenting significant prevalence and lethality rate. DEAD/H box RNA helicase 10 (DDX10) has been proposed as a potential oncogene in CRC, the specific action mechanism by which DDX10 modulates the aggressive biological cellular events in CRC remains implicitly elucidated, however. During this study, DDX10 expression was detected via RT-qPCR and Western blotting. Cell proliferation was estimated via EDU staining. TUNEL staining and Western blotting appraised cell apoptosis. Cell stemness was evaluated by sphere formation assay, RT-qPCR, Western blotting as well as immunofluorescence staining. Relevant assay kit examined aldehyde dehydrogenase (ALDH) activity. Western blotting and immunofluorescence staining also detected autophagy. DDX10 was hyper-expressed in CRC cells. Down-regulation of DDX10 hampered cell proliferation, aggravated the apoptosis while eliminated the ability to form spheroid cells in CRC. In addition, DDX10 deletion improved ATG10 expression and therefore activated autophagy in CRC cells. Consequently, ATG10 depletion or treatment with autophagy inhibitor 3-Methyladenine (3-MA) partially compensated the influences of DDX10 silencing on the proliferation, apoptosis and stemness of CRC cells. Accordingly, DDX10 deficiency may aggravate autophagy mediated by ATG10 to impede cell proliferation, stemness and facilitate cell apoptosis, hence blocking the progression of CRC.

GLP-1RA therapy increases circulating vascular regenerative cell content in people living with type 2 diabetes.

Glucagon-like peptide-1 receptor agonists (GLP-1RAs) and sodium-glucose cotransporter-2 (SGLT2) inhibitors are guideline-recommended therapies for the management of type 2 diabetes (T2D), atherosclerotic cardiovascular disease, heart failure, and chronic kidney disease. We previously observed in people living with T2D and coronary artery disease that circulating vascular regenerative (VR) progenitor cell content increased following 6-mo use of the SGLT2 inhibitor empagliflozin. In this post hoc subanalysis of the ORIGINS-RCE CardioLink-13 study (ClinicalTrials.gov Identifier NCT05253521), we analyzed the circulating VR progenitor cell content of 92 individuals living with T2D, among whom 20 were on a GLP-1RA, 42 were on an SGLT2 inhibitor but not a GLP-1RA, and 30 were on neither of these vascular protective therapies. In the GLP-1RA group, the mean absolute count of circulating VR progenitor cells defined by high aldehyde dehydrogenase (ALDH) activity (ALDHhiSSClow) and VR progenitor cells further characterized by surface expression of the proangiogenic marker CD133 (ALDHhiSSClowCD133+) was higher than the group receiving neither a GLP-1RA nor an SGLT2 inhibitor (P = 0.02) and comparable with that in the SGLT2 inhibitor group (P = 0.25). The absolute count of proinflammatory, granulocyte-restricted precursor cells (ALDHhiSSChi) was significantly lower in the GLP-1RA group compared with the group on neither therapy (P = 0.031). Augmented vessel repair initiated by VR cells with previously documented proangiogenic activity, alongside a reduction in systemic, granulocyte precursor-driven inflammation, may represent novel mechanisms responsible for the cardiovascular-metabolic benefits of GLP-1RA therapy. Prospective, randomized clinical trials are now warranted to establish the value of recovering circulating VR progenitor cell content with blood vessel regenerative functions.NEW & NOTEWORTHY In this post hoc subanalysis of 92 individuals living with T2D and at high cardiovascular risk, the authors summarize the differences in circulating vascular regenerative (VR) progenitor cell content between those on GLP-1RA therapy, on SGLT2 inhibitor without GLP-1RA therapy, and on neither therapy. Those on GLP-1RA therapy demonstrated greater circulating VR progenitor cell content and reduced proinflammatory granulocyte precursor content. These results offer novel mechanistic insights into the cardiometabolic benefits associated with GLP-1RA therapy.

Retraction Note: 9-O-acetylated sialic acids differentiating normal haematopoietic precursors from leukemic stem cells with high aldehyde dehydrogenase activity in children with acute lymphoblastic leukaemia.

Retraction Note: 9-O-acetylated sialic acids differentiating normal haematopoietic precursors from leukemic stem cells with high aldehyde dehydrogenase activity in children with acute lymphoblastic leukaemia.

Evaluation of quercetin as a potential cytoprotector against acetaldehyde using the cultured hepatocyte model with aldehyde dehydrogenase isozyme deficiency.

Protective effect of quercetin against acetaldehyde was evaluated using the cultured hepatocyte models with aldehyde dehydrogenase (ALDH) isozyme deficiency (aldh2-kd and aldh1a1-kd). The quercetin-induced cytoprotection against acetaldehyde in the ALDH1A1-deficient mutant (aldh1a1-kd) was weaker than that in wild type. Furthermore, quercetin did not enhance the ALDH activity in aldh1a1-kd cells, suggesting that ALDH1A1 is involved in the quercetin-induced cytoprotection.