Common Mitochondrial Targets of Curcumin and Cinnamic Acid, the Membrane-Active Natural Phenolic Compounds.

Background: Research has shown the multiple actions of curcumin on different cell systems, including enzymes and mitochondria. The detected effects of curcumin on mitochondria are diverse, ranging from protective to toxic. Objectives: In this present work, the influence of curcumin, as well as cinnamic acid, which is a microbial metabolite and a possible product of the microbial breakdown of curcumin, on isolated mitochondria, was investigated. Methods: Membrane potential, swelling, respiration, and calcium retention capacity were studied using selective electrodes, fluorescence and spectral methods. Results: It was found that curcumin at low concentrations (10-20 µM) activated the opening of the calcium-dependent permeability transition pore (mPTP) and decreased the calcium retention capacity and threshold concentrations necessary for the mPTP opening. Moreover, curcumin caused a concentration-dependent stepwise decrease in the membrane potential, accompanied by the activation of respiration and a decrease in oxidative phosphorylation, which indicates that curcumin is a typical mitochondrial uncoupler. The uncoupling effect strongly depended on the concentration of curcumin, which also increased, stepwise, from weak uncoupling at 25 µM to complete uncoupling at 75-100 µM. Cinnamic acid had similar effects, with the exception of the depolarizing effect, at concentrations that were an order of magnitude higher. Conclusions: Presumably, the uncoupling action of curcumin is a priming event that modulates any energy- and redox-dependent mitochondrial functions, from positive stimulation to toxic disorder. This effect can also underlie the curcumin-induced changes in different cellular processes and be achieved by targeted delivery of curcumin to certain cells, bypassing the microbiota.

Association between Liver Damage and Disease Progression Markers with Mortality Risk and Mechanical Ventilation in Hospitalized COVID-19 Patients: A Nationwide Retrospective SARSTer Study.

(1) Background: Liver damage is an important component of acute COVID-19, and the advancement of preexisting liver disease is associated with a worse prognosis; (2) Methods: A nationwide retrospective study including 7444 patients aimed to evaluate levels of selected markers of liver damage and disease advancement and their association with mortality and mechanical ventilation (MV); (3) Results: Elevation of the following markers in multivariate models were associated with increased odds of mortality: Alanine transaminase (ALT), aspartate transaminase (AST), gamma-glutamyltransferase (GGT), lactate dehydrogenase (LDH), fibrosis-4 score (FIB-4), AST-to-platelet ratio index (APRI), and decreased levels of platelet count (PLT). Elevated levels of AST, LDH, APRI, FIB-4, and the AST/ALT ratio and decreased levels of PLT were associated with increased odds of MV in multivariate models. The best predictive accuracy against mortality was achieved with FIB-4 with AUC = 0.733 (95% CI, 0.718-0.749) at the optimal cut-off point of 2.764, while against MV was achieved with LDH with AUC = 0.753 (95% CI, 0.727-0.778) at the optimal cut-off point of 449.5 IU/L. (4) Conclusions: Our study confirms that the advancement of liver damage contributes to a worse prognosis in COVID-19 patients. Markers for liver damage and the advancement of liver disease can provide predictive value in clinical practice among COVID-19 patients.

Determination of Serum Myeloperoxidase (MPO) and lactate dehydrogenase (LDH) as a tumour Marker in Chronic Myeloid Leukaemia (CML).

OBJECTIVE: To evaluate the efficacy of serum myeloperoxidase and lactate dehydrogenase levels as tumour markers in chronic myeloid leukaemia patients after one-year treatment with tyrosine kinase inhibitors. METHODS: The case-control study was conducted at the College of Medicine, Mustansiriyah University, Baghdad, Iraq, in collaboration with the National Centre of Haematology, Baghdad, from December 2019 to April 2020. The cases comprised chronic myeloid leukaemia patients aged ≥18 years who had completed one-year treatment with tyrosine kinase inhibitor. They were divided into two groups on the basis of major molecular response. Group 1 patients had major molecular response >0.1%, while group 2 patients had major molecular response <0.1%. Group 3 had healthy controls matched for age and gender. Serum myeloperoxidase and lactate dehydrogenase concentrations were measured using enzyme-linked immunosorbent assay. Data was analysed using SPSS 25. RESULTS: Of the 88 subjects, 32(36.4%) were in group A with mean age 44.9±12.6 years, 26(29.5%) were in group B with mean age 48.23±10.6 years, and 30(34%) were in group C with mean age 43.1±9.3 years. There was a significant increase in myeloperoxidase and lactate dehydrogenase levels in patient groups compared group 3 controls (p<0.05). Between the patient groups 1 and 2, the difference was significant for myeloperoxidase (p<0.05), but not for lactate dehydrogenase (p>0.05). CONCLUSIONS: There was higher oxidative stress in chronic myeloid leukaemia patients.

Evaluation the effects of Omega-3 and vitamin C alone or in combination on Methotrexate-Induced hepatotoxicity (in mice).

OBJECTIVE: To assess the effect of pretreatment with omega-3 alone or in combination with vitamin C on hepatotoxicity raised by methotrexate. Method: The experimental study was conducted at the animal house of the Iraqi Centre of Cancer Research and Medical Genetics and the Department of Pharmacology, College of Medicine, Al-Mustansiriyah University, Baghdad, Iraq, from November 2020 to July 2021, and comprised Swiss albino mice who were divided into 5 groups. Group A was treated with normal saline, group B was injected with methotrexate 20mg/kg intraperitoneally, group C was pretreated with omega 3 100mg/kg, group D was pretreated with vitamin C 100mg/kg, and group E was pretreated with concomitant vitamin C and omega 3 100mg/kg. The intervention lasted 9 days in each group, and were injected with methotrexate on day 10. The mice were sacrificed under chloroform anaesthesia after 48 hours. Blood sample was taken for biochemical examination. One part of liver was preserved in formalin 10% for histopathological study. Results: Of the 35 mice, there were 7(20%) in each of the 5 groups. There was a significant increase in malondialdehyde and lactate dehydrogenase levels and a decrease in the superoxide dismutase and glutathione (p<0.05). CONCLUSIONS: Pretreatment with omega-3 and vitamin C ameliorated the hepatotoxicity induced by methotrexate due to strong antioxidant, anti-inflammatory and anti-apoptotic effects.

Evaluation of the hepatoprotective effect of curcumin alone or in combination with vitamin C in methotrexate-induced hepatotoxicity in mice.

OBJECTIVE: To assess the hepatoprotective effect of curcumin and/or vitamin C in methotrexate-induced hepatotoxicity. METHODS: The experimental study was conducted at the Department of Pharmacology, College of Medicine, and the Iraqi Centre for Cancer and Medical Genetic Research, Mustansiriya University, Baghdad, Iraq, from Nov 12, 2020, to June 1, 2021, and comprised Swiss albino female mice aged 3-4 months and weighing 30-40g each. The mice were divided into 5 groups and treated for 10 days. Group 1 received distilled water, group 2 received single-dose methotrexate on the 10th day of the trial, group 3 was treated with curcumin plus methotrexate, group 4 was treated with vitamin C plus methotrexate, and group 5 was treated with curcumin and vitamin C plus methotrexate. Parameters measured were serum alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase and lactate dehydrogenase, as well as hepatic tissue malondialdehyde, superoxide dismutase and glutathione. Data was analysed using SPSS 16. RESULTS: There were 35 mice; 7(20%) in each of the 5 groups. Hepatoprotection produced by curcumin as reflected by a decrease in lactate dehydrogenase and malondialdehyde levels was significant (p<0.05). Vitamin C also produced a significant hepatoprotection, demonstrated by a decrease in alanine aminotransferase, alkaline phosphatase, lactate dehydrogenase and malondialdehyde levels. The combination of curcumin and vitamin C reflected an additive effect demonstrated by a significant decrease in malondialdehyde (p<0.05). CONCLUSIONS: Curcumin and/or vitamin C provided hepatoprotection against methotrexate-induced hepatotoxicity through modulation of oxidative stress biomarkers.

Characterization of a Drought-Induced Betaine Aldehyde Dehydrogenase Gene SgBADH from Suaeda glauca.

Betaine aldehyde dehydrogenases (BADHs) are key enzymes in the biosynthesis of glycine betaine, which is an important organic osmolyte that maintains cell structure and improves plant tolerance to abiotic stresses, especially in halotolerant plants. Improving the drought tolerance of crops will greatly increase their yield. In this study, a novel BADH gene named SgBADH from Suaeda glauca was induced by drought stress or abscisic acid. To explore the biological function of SgBADH, the SgBADH gene was transformed into Arabidopsis. Then, we found SgBADH-overexpressing Arabidopsis seedlings showed enhanced tolerance to drought stress. SgBADH transgenic Arabidopsis seedlings also had longer roots compared with controls under drought stress, while SgBADH-overexpressing Arabidopsis exhibited increased glycine betaine accumulation and decreased malondialdehyde (MDA) under drought stress. Our results suggest that SgBADH might be a positive regulator in plants during the response to drought.

Estimation of Periodontal Inflamed Surface Area by Salivary Lactate Dehydrogenase Level Using a Test Kit.

Background: Salivary lactate dehydrogenase (LD) levels are a feasible and useful parameter for screening periodontal diseases. The periodontal inflamed surface area (PISA) is useful to clinically assess periodontal diseases. However, PISA is difficult to calculate and PISA-compatible screening kits are required. We aimed to investigate the association between salivary LD levels, using a test kit, and PISA and PISA-Japanese and determine the feasibility and reliability of the salivary LD test kit for evaluation of periodontal status. Methods: This study included 110 patients (66.4% female, median and 25-75 percentiles of age were 66.5 and 53.0-75.0 years, respectively) who visited the Dental University Clinic in Japan. Resting saliva samples were collected from each participant and LD levels were evaluated in real time using a kit featuring an integer scale ranging from 1 to 10. PISA and PISA-Japanese were calculated using periodontal parameters. Results: The median salivary LD level was 4.0. The medians of PISA and PISA-Japanese were 46.9 and 61.0, respectively. Salivary LD levels were positively correlated with the bleeding on probing rate (r = 0.626, p < 0.001), PISA (r = 0.560, p < 0.001), and PISA-Japanese (r = 0.581, p < 0.001). Conclusions: Our results suggest that salivary LD levels assessed using the salivary LD kit showed a significantly positive correlation with PISA and PISA-Japanese. In addition, we developed the PISA estimation formula using salivary LD levels measured with a test kit, sex, and age.

Exploring the Role and Pathophysiological Significance of Aldehyde Dehydrogenase 1B1 (ALDH1B1) in Human Lung Adenocarcinoma.

Aldehyde dehydrogenases (ALDHs) constitute a diverse superfamily of NAD(P)+-dependent enzymes pivotal in oxidizing endogenous and exogenous aldehydes to carboxylic acids. Beyond metabolic roles, ALDHs participate in essential biological processes, including differentiation, embryogenesis and the DNA damage response, while also serving as markers for cancer stem cells (CSCs). Aldehyde dehydrogenase 1B1 (ALDH1B1) is a mitochondrial enzyme involved in the detoxification of lipid peroxidation by-products and metabolism of various aldehyde substrates. This study examines the potential role of ALDH1B1 in human lung adenocarcinoma and its association with the CSC phenotype. To this end, we utilized the lung adenocarcinoma cell line A549, engineered to stably express the human ALDH1B1 protein tagged with green fluorescent protein (GFP). Overexpression of ALDH1B1 led to notable changes in cell morphology, proliferation rate and clonogenic efficiency. Furthermore, ALDH1B1-overexpressing A549 cells exhibited enhanced resistance to the chemotherapeutic agents etoposide and cisplatin. Additionally, ALDH1B1 overexpression correlated with increased migratory potential and epithelial-mesenchymal transition (EMT), mediated by the upregulation of transcription factors such as SNAI2, ZEB2 and TWIST1, alongside the downregulation of E-cadherin. Moreover, Spearman's rank correlation coefficient analysis using data from 507 publicly available lung adenocarcinoma clinical samples revealed a significant correlation between ALDH1B1 and various molecules implicated in CSC-related signaling pathways, including Wnt, Notch, hypoxia, Hedgehog, retinoic acid, Hippo, NF-κΒ, TGF-ß, PI3K/PTEN-AKT and glycolysis/gluconeogenesis. These findings provide insights into the role of ALDH1B1 in lung tumor progression and its relation to the lung CSC phenotype, thereby offering potential therapeutic targets in the clinical management of lung adenocarcinoma.

Disruption of HSD17B12 in mouse hepatocytes leads to reduced body weight and defect in the lipid droplet expansion associated with microvesicular steatosis.

The function of hydroxysteroid dehydrogenase 12 (HSD17B12) in lipid metabolism is poorly understood. To study this further, we created mice with hepatocyte-specific knockout of HSD17B12 (LiB12cKO). From 2 months on, these mice showed significant fat accumulation in their liver. As they aged, they also had a reduced whole-body fat percentage. Interestingly, the liver fat accumulation did not result in the typical formation of large lipid droplets (LD); instead, small droplets were more prevalent. Thus, LiB12KO liver did not show increased macrovesicular steatosis with the increasing fat content, while microvesicular steatosis was the predominant feature in the liver. This indicates a failure in the LD expansion. This was associated with liver damage, presumably due to lipotoxicity. Notably, the lipidomics data did not support an essential role of HSD17B12 in fatty acid (FA) elongation. However, we did observe a decrease in the quantity of specific lipid species that contain FAs with carbon chain lengths of 18 and 20 atoms, including oleic acid. Of these, phosphatidylcholine and phosphatidylethanolamine have been shown to play a key role in LD formation, and a limited amount of these lipids could be part of the mechanism leading to the dysfunction in LD expansion. The increase in the Cidec expression further supported the deficiency in LD expansion in the LiB12cKO liver. This protein is crucial for the fusion and growth of LDs, along with the downregulation of several members of the major urinary protein family of proteins, which have recently been shown to be altered during endoplasmic reticulum stress.

Clinical analysis of 163 pediatric patients with infectious mononucleosis: a single-center retrospective analysis.

OBJECTIVE: This study aims to enhance the management of Epstein-Barr Virus (EBV) infections by analyzing the correlation between laboratory indicators and clinical manifestations in children, thereby proposing more precise diagnostic and treatment strategies. METHODS: In this retrospective study included 163 pediatric patients with EBV infections treated at the Children's Hospital of Soochow University from December 2017 to December 2019. Data collected through retrospective analysis included gender, age, clinical symptoms, signs, liver function tests, T-cell subset distribution, EBV-DNA copy numbers in plasma, and treatment outcomes. Patients were grouped based on EBV-DNA copy numbers in plasma and hospital stay duration to compare clinical indicators across different groups. RESULTS: The dichotomous results of EBV-DNA copy numbers in plasma showed that the two groups of children were significantly different in the number of days of fever (p = .0022), platelet count (p = .0212), ALT (p = .001), immunoglobulin IgM (p = .0039), IgG (p = .0195), TBiL (p = .025), LDH (p = 0.0001), and length of hospital stay (p < .001) were significantly different, indicating that EBV-DNA copy numbers in plasma may be correlated with these characteristic variables. The dichotomous results of the length of hospital stay showed that the two groups were significantly increased in tonsil enlargement (p = .0024), platelet count (p = .0059), LDH (p = .0394), and ferritin (p = .0106) and EBV-DNA copy numbers in plasma (p = 0.0361) were significantly different, This suggests a potential correlation between EBV-DNA copy numbers in plasma and these clinical indicators. CONCLUSION: Variations in platelet counts and lactate dehydrogenase (LDH) levels in children with EBV infections may serve as indicators of clinical outcomes.

Hydrogen sulfide antagonizes cytokinin to change root system architecture through persulfidation of CKX2 in Arabidopsis.

Hydrogen sulfide (H2S) is an endogenous gaseous signaling molecule, which has been shown to play an important role in plant growth and development by coupling with various phytohormones. However, the relationship between H2S and cytokinin (CTK) and the mechanisms by which H2S and CTK affect root growth remain poorly understood. Endogenous CTK was analyzed by UHPLC-ESI-MS/MS. Persulfidation of cytokinin oxidase/dehydrogenases (CKXs) was analyzed by mass spectrometry (MS). ckx2/CKX2wild-type (WT), OE CKX2 and ckx2/CKX2Cys(C)62alanine(A) transgenic lines were isolated with the ckx2 background. H2S is linked to CTK content by CKX2, which regulates root system architecture (RSA). Persulfidation at cysteine (Cys)62 residue of CKX2 enhances CKX2 activity, resulting in reduced CTK content. We utilized 35S-LCD/oasa1 transgenic lines to investigate the effect of endogenous H2S on RSA, indicating that H2S reduces the gravitropic set-point angle (GSA), shortens root hairs, and increases the number of lateral roots (LRs). The persulfidation of CKX2Cys62 changes the elongation of cells on the upper and lower flanks of LR elongation zone, confirming that Cys62 of CKX2 is the specificity target of H2S to regulate RSA in vivo. In conclusion, this study demonstrated that H2S negatively regulates CTK content and affects RSA by persulfidation of CKX2Cys62 in Arabidopsis thaliana.

Isocitrate dehydrogenases 2-mediated dysfunctional metabolic reprogramming promotes intestinal cancer progression via regulating HIF-1A signaling pathway.

Changes in isocitrate dehydrogenases (IDH) lead to the production of the cancer-causing metabolite 2-hydroxyglutarate, making them a cause of cancer. However, the specific role of IDH in the progression of colon cancer is still not well understood. Our current study provides evidence that IDH2 is significantly increased in colorectal cancer (CRC) cells and actively promotes cell growth in vitro and the development of tumors in vivo. Inhibiting the activity of IDH2, either through genetic silencing or pharmacological inhibition, results in a significant increase in α-ketoglutarate (α-KG), indicating a decrease in the reductive citric acid cycle. The excessive accumulation of α-KG caused by the inactivation of IDH2 obstructs the generation of ATP in mitochondria and promotes the downregulation of HIF-1A, eventually inhibiting glycolysis. This dual metabolic impact results in a reduction in ATP levels and the suppression of tumor growth. Our study reveals a metabolic trait of colorectal cancer cells, which involves the active utilization of glutamine through reductive citric acid cycle metabolism. The data suggests that IDH2 plays a crucial role in this metabolic process and has the potential to be a valuable target for the advancement of treatments for colorectal cancer.

Rational design of deep eutectic solvents for the stabilization of dehydrogenases: an artificial neural network prediction approach.

Stabilized enzymes are crucial for the industrial application of biocatalysis due to their enhanced operational stability, which leads to prolonged enzyme activity, cost-efficiency and consequently scalability of biocatalytic processes. Over the past decade, numerous studies have demonstrated that deep eutectic solvents (DES) are excellent enzyme stabilizers. However, the search for an optimal DES has primarily relied on trial-and-error methods, lacking systematic exploration of DES structure-activity relationships. Therefore, this study aims to rationally design DES to stabilize various dehydrogenases through extensive experimental screening, followed by the development of a straightforward and reliable mathematical model to predict the efficacy of DES in enzyme stabilization. A total of 28 DES were tested for their ability to stabilize three dehydrogenases at 30°C: (S)-alcohol dehydrogenase from Rhodococcus ruber (ADH-A), (R)-alcohol dehydrogenase from Lactobacillus kefir (Lk-ADH) and glucose dehydrogenase from Bacillus megaterium (GDH). The residual activity of these enzymes in the presence of DES was quantified using first-order kinetic models. The screening revealed that DES based on polyols serve as promising stabilizing environments for the three tested dehydrogenases, particularly for the enzymes Lk-ADH and GDH, which are intrinsically unstable in aqueous environments. In glycerol-based DES, increases in enzyme half-life of up to 175-fold for Lk-ADH and 60-fold for GDH were observed compared to reference buffers. Furthermore, to establish the relationship between the enzyme inactivation rate constants and DES descriptors generated by the Conductor-like Screening Model for Real Solvents, artificial neural network models were developed. The models for ADH-A and GDH showed high efficiency and reliability (R2 > 0.75) for in silico screening of the enzyme inactivation rate constants based on DES descriptors. In conclusion, these results highlight the significant potential of the integrated experimental and in silico approach for the rational design of DES tailored to stabilize enzymes.

Influence of deep eutectic solvents on redox biocatalysis involving alcohol dehydrogenases.

Redox biocatalysis plays an increasingly important role in modern organic synthesis. The recent integration of novel media such as deep eutectic solvents (DESs) has significantly impacted this field of chemical biology. Alcohol dehydrogenases (ADHs) are important biocatalysts where their unique specificity is used for enantioselective synthesis. This review explores aspects of redox biocatalysis in the presence of DES both with whole cells and with isolated ADHs. In both cases, the presence of DES has a significant influence on the outcome of reactions albeit via different mechanisms. For whole cells, DES was shown to be a useful tool to direct product formation or configuration - a process of solvent engineering. Whole cells can tolerate DES as media components for the solubilization of hydrophobic substrates. In some cases, DES in the growth medium altered the enantioselectivity of whole cell transformations by solvent control. For isolated enzymes, on the other hand, the presence of DES promotes substrate solubility as well as enhancing enzyme stability and activity. DES can be employed as a smart solvent or smart cosubstrate particularly for cofactor regeneration purposes. From the literatures examined, it is suggested that DES based on choline chloride (ChCl) such as ChCl:Glycerol (Gly), ChCl:Glucose (Glu), and ChCl:1,4-butanediol (1,4-BD) are useful starting points for ADH-based redox biocatalysis. However, each specific reaction will require optimisation due to the influence of several factors on biocatalysis in DES. These include solvent composition, enzyme source, temperature, pH and ionic strength as well as the substrates and products under investigation.

Exploring the therapeutic potential of garlic in alcoholic liver disease: a network pharmacology and experimental validation study.

OBJECTIVE: Employing network pharmacology and molecular docking, the study predicts the active compounds in garlic and elucidates their mechanism in inhibiting the development of alcoholic liver disease (ALD). ALD is a global chronic liver disease with potential for hepatocellular carcinoma progression. METHODS: The main active ingredients and targets of garlic were identified through screening the TCMSP, TCM-ID, and ETCM databases. ALD disease targets were sourced from DisGeNET, GeneCards, and DiGSeE databases, and intervention targets for garlic were determined through intersections. Protein interaction networks were constructed using the STRING platform, and GO and KEGG pathway enrichment analyses were performed with R software. The garlic component-disease-target network was established using Cytoscape software. Validation of active ingredients against core targets was conducted through molecular docking simulations using AutoDock Vina software. Expression validation of core targets was carried out using human sequencing data of ALD obtained from the GEO database. RESULTS: Integration of garlic drug targets with ALD disease targets identified 83 target genes. Validation through an alcohol-induced ALD mouse model supported certain network pharmacology findings, suggesting that garlic may impede disease progression by mitigating the inflammatory response and promoting ethanol metabolism. CONCLUSION: This study provides insights into the potential therapeutic mechanisms of garlic in inhibiting ALD development. The identified active ingredients offer promising avenues for further investigation and development of treatments for ALD, emphasizing the importance of botanical remedies in liver disease management.

Co-immobilization of amine dehydrogenase and glucose dehydrogenase for the biosynthesis of (S)-2-aminobutan-1-ol in continuous flow.

Reductive amination by amine dehydrogenases is a green and sustainable process that produces only water as the by-product. In this study, a continuous flow process was designed utilizing a packed bed reactor filled with co-immobilized amine dehydrogenase wh84 and glucose dehydrogenase for the highly efficient biocatalytic synthesis of chiral amino alcohols. The immobilized amine dehydrogenase wh84 exhibited better thermo-, pH and solvent stability with high activity recovery. (S)-2-aminobutan-1-ol was produced in up to 99% conversion and 99% ee in the continuous flow processes, and the space-time yields were up to 124.5 g L-1 d-1. The continuous reactions were also extended to 48 h affording up to 91.8% average conversions. This study showcased the important potential to sustainable production of chiral amino alcohols in continuous flow processes.

Identification of Novel Isatin Derivative Bearing a Nitrofuran Moiety as Potent Multi-Isoform Aldehyde Dehydrogenase Inhibitor.

Aldehyde dehydrogenases (ALDHs) are a family of enzymes that aid in detoxification and are overexpressed in several different malignancies. There is a correlation between increased expression of ALDH and a poor prognosis, stemness, and resistance to several drugs. Several ALDH inhibitors have been generated due to the crucial role that ALDH plays in cancer stem cells. All of these inhibitors, however, are either ineffective, very toxic, or have yet to be subjected to rigorous testing on their effectiveness. Although various drug-like compounds targeting ALDH have been reported in the literature, none have made it to routine use in the oncology clinic. As a result, new potent, non-toxic, bioavailable, and therapeutically effective ALDH inhibitors are still needed. In this study, we designed and synthesized potent multi-ALDH isoform inhibitors based on the isatin and indazole pharmacophore. Molecular docking studies and enzymatic tests revealed that among all of the synthesized analogs, compound 3 is the most potent inhibitor of ALDH1A1, ALDH3A1, and ALDH1A3, exhibiting 51.32%, 51.87%, and 36.65% inhibition, respectively. The ALDEFLUOR assay further revealed that compound 3 acts as an ALDH broad spectrum inhibitor at 500 nM. Compound 3 was also the most cytotoxic to cancer cells, with an IC50 in the range of 2.1 to 3.8 µM for ovarian, colon, and pancreatic cancer cells, compared to normal and embryonic kidney cells (IC50 7.1 to 8.7 µM). Mechanistically, compound 3 increased ROS activity due to potent multi-ALDH isoform inhibition, which increased apoptosis. Taken together, this study identified a potent multi-isoform ALDH inhibitor that could be further developed as a cancer therapeutic.

Structure modeling-based characterization of ChnD, the 6-hydroxyhexanoate dehydrogenase from Acinetobacter sp. strain NCIMB 9871.

α,ω-Dicarboxylic acids, ω-aminoalkanoic acids, and α,ω-diaminoalkanes are valuable building blocks for the production of biopolyesters and biopolyamides. One of the key steps in producing these chemicals is the oxidation of ω-hydroxycarboxylic acids using alcohol dehydrogenases (e.g., ChnD of Acinetobacter sp. NCIMB 9871). However, the reaction and structural features of these enzymes remain mostly undiscovered. Thereby, we have investigated characteristics of ChnD based on enzyme kinetics, substrate-docking simulations, and mutation studies. Kinetic analysis revealed a distinct preference of ChnD for medium chain ω-hydroxycarboxylic acids, with the highest catalytic efficiency of 18.0 mM-1s-1 for 12-hydroxydodecanoic acid among C6 to C12 ω-hydroxycarboxylic acids. The high catalytic efficiency was attributed to the positive interactions between the carboxyl group of the substrates and the guanidino group of two arginine residues (i.e., Arg62 and Arg266) in the substrate binding site. The ChnD_R62L variant showed the increased efficiency and affinity, particularly for fatty alcohols (i.e., C6-C10) and branched-chain fatty alcohols, such as 3-methyl-2-buten-1-ol. Overall, this study contributes to the deeper understanding of medium-chain primary aliphatic alcohol dehydrogenases and their applications for the production of industrially relevant chemicals such as α,ω-dicarboxylic acids, ω-aminoalkanoic acids, and α,ω-diaminoalkanes from renewable biomass.

Discovery of novel natural-product-derived mutant isocitrate dehydrogenases 1 inhibitors: Structure-based virtual screening, biological evaluation and structure-activity relationship study.

Mutations in IDH1 are commonly observed across various cancers, causing the conversion of α-KG to 2-HG. Elevated levels of 2-HG disrupt histone and DNA demethylation processes, promoting tumor development. Consequently, there is substantial interest in developing small molecule inhibitors targeting the mutant enzymes. Herein, we report a structure-based high-throughput virtual screening strategy using a natural products library, followed by hit-to-lead optimization. Through this process, we discover a potent compound, named 11s, which exhibited significant inhibition to IDH1 R132H and IDH1 R132C with IC50 values of 124.4 and 95.7 nM, respectively. Furthermore, 11s effectively reduced 2-HG formation, with EC50 values of 182 nM in U87 R132H cell, and 84 nM in HT-1080 cell. In addition, 11s significantly reduced U87 R132H and HT-1080 cell proliferation with GC50 values of 3.48 and 1.38 µM, respectively. PK-PD experiments further confirmed that compound 11s significantly decreased 2-HG formation in an HT-1080 xenograft mouse model, resulting in notable suppression of tumor growth without apparent loss in body weight.

Structural and biochemical characterization of the M405S variant of Desulfovibrio vulgaris formate dehydrogenase.

Molybdenum- or tungsten-dependent formate dehydrogenases have emerged as significant catalysts for the chemical reduction of CO2 to formate, with biotechnological applications envisaged in climate-change mitigation. The role of Met405 in the active site of Desulfovibrio vulgaris formate dehydrogenase AB (DvFdhAB) has remained elusive. However, its proximity to the metal site and the conformational change that it undergoes between the resting and active forms suggests a functional role. In this work, the M405S variant was engineered, which allowed the active-site geometry in the absence of methionine Sδ interactions with the metal site to be revealed and the role of Met405 in catalysis to be probed. This variant displayed reduced activity in both formate oxidation and CO2 reduction, together with an increased sensitivity to oxygen inactivation.