Aldo-keto Reductase Research Articles

Aldo-keto reductase family 1 member A1 (AKR1A1) exerts a protective function in alcohol-associated liver disease by reducing 4-HNE accumulation and p53 activation

BackgroundThe development of alcohol-associated liver disease (ALD) is influenced by the amount and duration of alcohol consumption. The resulting liver damage can range from reversible stages, such as steatosis, steatohepatitis and alcoholic fibrosis, to the advanced and irreversible stage of cirrhosis. Aldo-keto reductase family 1 member A1 (AKR1A1) is a member of the aldo-keto reductase family that catalyzes the reduction of aldehyde groups to their corresponding alcohols in an NADPH-dependent manner. AKR1A1 was found to be downregulated in patients diagnosed with ALD. This study aims to interpret the protective effects of AKR1A1 on the development of ALD.MethodsA 5% alcohol-fed (AF) Akr1a1 knockout (Akr1a1−/−) mouse model and an AML12 hepatocyte model were used. The effects of AKR1A1 on liver function, inflammation, oxidative stress, lipid accumulation, and fibrosis were assessed by ELISA, western blotting, RT‒PCR, and a variety of histological staining methods in AF-induced wild-type (WT) and Akr1a1−/− mice compared to control liquid diet-fed (PF) WT and Akr1a1−/− mice.ResultsThe results demonstrated that AF-WT mice expressed higher levels of AKR1A1 than WT mice fed a control diet, and they did not show any noticeable liver steatosis. However, AF-Akr1a1−/− mice displayed a lower survival rate and more severe liver injury than AF-WT mice, as demonstrated by increased proinflammatory cytokines, oxidative stress, lipid accumulation, fibrosis, and reduced antioxidant enzymes in their livers. Additionally, elevated levels of 4-HNE and p53 phosphorylation were observed in AF-Akr1a1−/− mice, suggesting that the loss of AKR1A1 led to increased 4-HNE accumulation and subsequent activation of p53, which contributed to the progression of ALD. Furthermore, in AML12 hepatocytes, Akr1a1 knockdown aggravated oxidative stress and steatosis induced by palmitic acid/oleic acid (P/O) inflammation induced by lipopolysaccharide (LPS), and fibrosis induced by TGF-β1.ConclusionsThis loss-of-function study suggests that AKR1A1 plays a liver-protective role during chronic alcohol consumption by reducing the accumulation of 4-HNE and inhibiting 4-HNE-mediated p53 activation.

A Composite Blood Biomarker Including AKR1B10 and Cytokeratin 18 for Progressive Types of Nonalcoholic Fatty Liver Disease.

We aimed to evaluate whether composite blood biomarkers including aldo-keto reductase family 1 member B10 (AKR1B10) and cytokeratin 18 (CK-18; a nonalcoholic steatohepatitis [NASH] marker) have clinically applicable performance for the diagnosis of NASH, advanced liver fibrosis, and high-risk NASH (NASH+significant fibrosis). A total of 116 subjects including healthy control subjects and patients with biopsy-proven nonalcoholic fatty liver disease (NAFLD) were analyzed to assess composite blood-based and imaging-based biomarkers either singly or in combination. A composite blood biomarker comprised of AKR1B10, CK-18, aspartate aminotransferase (AST), and alanine aminotransferase (ALT) showed excellent performance for the diagnosis of, NASH, advanced fibrosis, and high-risk NASH, with area under the receiver operating characteristic curve values of 0.934 (95% confidence interval [CI], 0.888 to 0.981), 0.902 (95% CI, 0.832 to 0.971), and 0.918 (95% CI, 0.862 to 0.974), respectively. However, the performance of this blood composite biomarker was inferior to that various magnetic resonance (MR)-based composite biomarkers, such as proton density fat fraction/MR elastography- liver stiffness measurement (MRE-LSM)/ALT/AST for NASH, MRE-LSM+fibrosis-4 index for advanced fibrosis, and the known MR imaging-AST (MAST) score for high-risk NASH. Our blood composite biomarker can be useful to distinguish progressive forms of NAFLD as an initial noninvasive test when MR-based tools are not available.

Structure-activity relationship and target investigation of 2-aryl quinolines with nematocidal activity

Within the context of our anthelmintic discovery program, we recently identified and evaluated a quinoline derivative, called ABX464 or obefazimod, as a nematocidal candidate; synthesised a series of analogues which were assessed for activity against the free-living nematode Caenorhabditis elegans; and predicted compound-target relationships by thermal proteome profiling (TPP) and in silico docking. Here, we logically extended this work and critically evaluated the anthelmintic activity of ABX464 analogues on Haemonchus contortus (barber's pole worm) – a highly pathogenic nematode of ruminant livestock. First, we tested a series of 44 analogues on H. contortus (larvae and adults) to investigate the nematocidal pharmacophore of ABX464, and identified one compound with greater potency than the parent compound and showed moderate activity against a select number of other parasitic nematodes (including Ancylostoma, Heligmosomoides and Strongyloides species). Using TPP and in silico modelling studies, we predicted protein HCON_00074590 (a predicted aldo-keto reductase) as a target candidate for ABX464 in H. contortus. Future work aims to optimise this compound as a nematocidal candidate and investigate its pharmacokinetic properties. Overall, this study presents a first step toward the development of a new nematocide.

Self-cascade deoxynivalenol detoxification by an artificial enzyme with bifunctions of dehydrogenase and aldo/keto reductase from genome mining

Due to the severe health risks for human and animal caused by the intake of toxic deoxynivalenol (DON) derived from Fusarium species, elimination DON in food and feed has been initiated as a critical issue. Enzymatic cascade catalysis by dehydrogenase and aldo-keto reductase represents a fascinating strategy for DON detoxification. Here, one quinone-dpendent alcohol dehydrogenase DADH oxidized DON into less-toxic 3-keto-DON and NADPH-dependent aldo-keto reductase AKR13B3 reduced 3-keto-DON into relatively non-toxic 3-epi-DON were identified from Devosia strain A6-243, indicating that degradation of DON on C3 are two-step sequential cascade processes. To establish the bifunctions, fusion enzyme linking DADH and AKR13B3 was successfully assembled to promote one-step DON degradations with accelerated specific activity and efficiency, resulting 93.29 % of DON removal rate in wheat sample. Three-dimensional simulation analysis revealed that the bifunctional enzyme forms an artificial intramolecular channel to minimize the distance of intermediate from DADH to AKR13B3 for two-step enzymatic reactions, and thereby accelerates this enzymatic process. As the first report of directing single step DON detoxification by an interesting bifunctional artificial enzyme, this work revealed a facile and eco-friendly approach to detoxify DON with application potential and gave valuable insights into execute other mycotoxin detoxification for ensuring food safety.

Angular dihydropyranocoumarins from the flowers of Peucedanum japonicum and their aldo-keto reductase inhibitory activities

Twenty-one angular dihydropyranocoumarins and a linear furanocoumarin, including four previously undescribed compounds (1–4), were isolated from the flowers of Peucedanum japonicum (Umbelliferae). The structures of 1–4, along with their absolute stereochemistry, were determined to be (3′S,4′S)-3′-O-propanoyl-4′-O-(3‴-methyl-2‴-butenoyl)khellactone (1), (3′S,4′S)-3′-O-propanoyl-4′-O-(2‴-methyl-2‴Z-butenoyl)khellactone (2), (3′S,4′S)-3′-O-propanoyl-4′-O-(2‴-methylbutanoyl)khellactone (3), and (3′S,4′S)-3′-O-(2″-methylpropanoyl)-4′-O-(3‴-methyl-2‴-butenoyl)khellactone (4) using one- and two-dimensional nuclear magnetic resonance, high-resolution electrospray ionization mass spectroscopy, and electronic circular dichroism spectroscopy. In addition, the absolute configuration of the three angular dihydropyranocoumarins (5–7) was determined for the first time in this study. Among the previously reported compounds isolated in this study, 8 and 9 were isolated for the first time from the genus Peucedanum, whereas 10 and 11 were previously unreported and had not been isolated from P. japonicum to date. Furthermore, all isolated compounds were evaluated for their aldo–keto reductase 1C1 inhibitory activities on A549 human non-small-cell lung cancer cells. Compounds 10 and 12 exhibited substantial AKR1C1 inhibitory activities with IC50 values of 35.8 ± 0.9 and 44.2 ± 1.5 μM, respectively.

In vitro evaluation of the reductive carbonyl idarubicin metabolism to evaluate inhibitors of the formation of cardiotoxic idarubicinol via carbonyl and aldo–keto reductases

The most important dose-limiting factor of the anthracycline idarubicin is the high risk of cardiotoxicity, in which the secondary alcohol metabolite idarubicinol plays an important role. It is not yet clear which enzymes are most important for the formation of idarubicinol and which inhibitors might be suitable to suppress this metabolic step and thus would be promising concomitant drugs to reduce idarubicin-associated cardiotoxicity. We, therefore, established and validated a mass spectrometry method for intracellular quantification of idarubicin and idarubicinol and investigated idarubicinol formation in different cell lines and its inhibition by known inhibitors of the aldo–keto reductases AKR1A1, AKR1B1, and AKR1C3 and the carbonyl reductases CBR1/3. The enzyme expression pattern differed among the cell lines with dominant expression of CBR1/3 in HEK293 and MCF-7 and very high expression of AKR1C3 in HepG2 cells. In HEK293 and MCF-7 cells, menadione was the most potent inhibitor (IC50 = 1.6 and 9.8 µM), while in HepG2 cells, ranirestat was most potent (IC50 = 0.4 µM), suggesting that ranirestat is not a selective AKR1B1 inhibitor, but also an AKR1C3 inhibitor. Over-expression of AKR1C3 verified the importance of AKR1C3 for idarubicinol formation and showed that ranirestat is also a potent inhibitor of this enzyme. Taken together, our study underlines the importance of AKR1C3 and CBR1 for the reduction of idarubicin and identifies potent inhibitors of metabolic formation of the cardiotoxic idarubicinol, which should now be tested in vivo to evaluate whether such combinations can increase the cardiac safety of idarubicin therapies while preserving its efficacy.

Aldo-keto reductases: Role in cancer development and theranostics.

Aldo-keto reductases (AKRs) are a superfamily of enzymes that play crucial roles in various cellular processes, including the metabolism of xenobiotics, steroids, and carbohydrates. A growing body of evidence has unveiled the involvement of AKRs in the development and progression of various cancers. AKRs are aberrantly expressed in a wide range of malignant tumors. Dysregulated expression of AKRs enables the acquisition of hallmark traits of cancer by activating oncogenic signaling pathways and contributing to chemoresistance. AKRs have emerged as promising oncotherapeutic targets given their pivotal role in cancer development and progression. Inhibition of aldose reductase (AR), either alone or in combination with chemotherapeutic drugs, has evolved as a pragmatic therapeutic option for cancer. Several classes of synthetic aldo-keto reductase (AKR) inhibitors have been developed as potential anticancer agents, some of which have shown promise in clinical trials. Many AKR inhibitors from natural sources also exhibit anticancer effects. Small molecule inhibitors targeting specific AKR isoforms have shown promise in preclinical studies. These inhibitors disrupt the activation of oncogenic signaling by modulating transcription factors and kinases and sensitizing cancer cells to chemotherapy. In this review, we discuss the physiological functions of human AKRs, the aberrant expression of AKRs in malignancies, the involvement of AKRs in the acquisition of cancer hallmarks, and the role of AKRs in oncogenic signaling, and drug resistance. Finally, the potential of aldose reductase inhibitors (ARIs) as anticancer drugs is summarized.

Computational Insight and Anticancer Effect of Cinnamic Acid-Derivative Amide Compounds

In this research, a meticulous screening process was conducted using four servers: Drug Target Explorer, Swiss Target Predictor, SEA Predictor, and Target Hunter. The primary objective was to identify a series of potential biological targets related to the regulation of cell growth and apoptosis in cancer cells using cinnamic acid derivatives. This study focused on five specific targets, matrix metallopeptidase 9 (MMP9), apoptosis inducing factor (AIF), aldo-keto reductase family 1 member C3 (AKR1C3), aldo-keto reductase family 1 member B10 (AKR1B10), mitogenactivated protein kinase 14 (MAPK14), all of which are well known to play a significant role in cancer cell dynamics. To explore both molecular recognition and molecular dynamics, a series of in silico investigations (docking and molecular dynamics) were carried out using a collection of 14 cinnamic acid derivatives, including cinnamic acid phenethyl ester (CAPE) as a notable reference molecule due to its widely recognized anticancer effects. Furthermore, preliminary in vitro data revealed a potentially promising cytotoxic effect of (E)-N-[(3,4-dichlorophenyl)methyl]- 3-(4-phenoxyphenyl)-2-propenamide (LQM755) on a human gastric adenocarcinoma cell-line (AGS cells), which are characterized by the overexpression of the MMP9 protein. Therefore, the chemical compound LQM755 provides an initial perspective in the field of cancer therapy.

Decoding selectivity: computational insights into AKR1B1 and AKR1B10 inhibition.

Understanding selectivity mechanisms of inhibitors towards highly homologous proteins is of paramount importance in the design of selective candidates. Human aldo-keto reductases (AKRs) pertain to a superfamily of monomeric oxidoreductases, which serve as NADPH-dependent cytosolic enzymes to catalyze the reduction of carbonyl groups to primary and secondary alcohols using electrons from NADPH. Among AKRs, AKR1B1 is emerging as a promising target for cancer treatment and diabetes, despite its high structural similarity with AKR1B10, which leads to severe adverse events. Therefore, it is crucial to understand the selectivity mechanisms of AKR1B1 and AKR1B10 to discover safe anticancer candidates with optimal therapeutic efficacy. In this study, multiple computational strategies, including sequence alignment, structural comparison, Protein Contacts Atlas analysis, molecular docking, molecular dynamics simulation, MM-GBSA calculation, alanine scanning mutagenesis and pharmacophore modeling analysis were employed to comprehensively understand the selectivity mechanisms of AKR1B1/10 inhibition based on selective inhibitor lidorestat and HAHE. This study would provide substantial evidence in the design of potent and highly selective AKR1B1/10 inhibitors in future.

Serum Aldo-Keto Reductase Family 1 Member B10 (AKR1B10) as a Potential Biomarker for Diagnosis of Hepatocellular Carcinoma.

To evaluate the diagnostic performance of aldo-keto reductase family 1 member B10 (AKR1B10) in a Beijing cohort with hepatocellular carcinoma (HCC). This study included 521 subjects who visited Peking Union Medical College Hospital from June 2017 to May 2023, including 109 cases of HCC, 165 cases of healthy controls, 106 cases of benign liver diseases, and 141 cases of other cancers. Serum AKR1B10 levels were measured and compared across various groups. Diagnostic performances of serum AKR1B10 and other tumor markers were assessed using receiver operator characteristic (ROC) curves. In addition, a subset of HCC patients who underwent surgical resection were recruited for clinical follow-up study. We found that serum AKR1B10 expression was higher in patients with HCC relative to other control groups. The association between serum AKR1B10 and clinical features of HCC was not observed. Serum AKR1B10 showed a high diagnostic performance for HCC, and when combined with AFP, the diagnostic effectiveness was significantly improved. Specifically, serum AKR1B10 showed superior diagnostic effectiveness for AFP-negative HCC. The clinical follow-up study indicated a gradual decrease in serum AKR1B10 after surgery. Our study demonstrated that serum AKR1B10 is a promising biomarker for HCC, and when used in combination with AFP can significantly improve the detection rate of HCC.

EPS15-AS1 Inhibits AKR1B1 Expression to Enhance Ferroptosis in Hepatocellular Carcinoma Cells.

Epidermal growth factor receptor substrate 15 (EPS15) is part of the EGFR pathway and has been implicated in various tumorigenesis. Increasing evidence suggests that long noncoding RNA (lncRNA) plays an essential role in liver hepatocellular carcinoma (LIHC) by regulating the expression of proteins and genes. Through analysis of the cancer genome atlas (TCGA) database, we found that EPS15 is highly expressed in LIHC tissue, and lncRNA EPS15-antisense1 (EPS15-AS1) decreased in LIHC cell lines. However, the function of EPS15-AS1 in LIHC is still unknown. When EPS15-AS1 was overexpressed in HepG2 cell lines, the expression of EPS15 was reduced and cell activity and invasiveness were inhibited. In addition, we observed an increase in Fe2+ ion and lipid peroxidation after overexpression of EPS15-AS1, and further analysis showed that the susceptibility to ferroptosis increased. Aldo-keto reductase family 1 member B 1 (AKR1B1) belongs to the aldo/keto reductase superfamily and is involved in maintaining the cellular redox balance. Survival analysis revealed that patients with a higher level of AKR1B1 have a lower survival rate in the TCGA database. We also found that EPS15 enhanced the AKR1B1 expression in LIHC, and AKR1B1 had the ability to promote cell invasiveness. Moreover, overexpression of AKR1B1 alleviated the promoting effect of EPS15-AS1 on ferroptosis. Therefore, EPS15-AS1 can induce ferroptosis in hepatocellular carcinoma cells by inhibiting the expression of EPS15 and AKR1B1 and disrupting the redox balance. EPS15 and AKR1B1 may serve as biomarkers for diagnosis and lncRNA EPS15-AS1 potential drug for LIHC.

Aldo-keto reductase family member C3 (AKR1C3) promotes hepatocellular carcinoma cell growth by producing prostaglandin F2α.

Hepatocellular carcinoma (HCC) is a leading cause of death worldwide. Current therapies are effective for HCC patients with early disease, but many patients suffer recurrence after surgery and have a poor response to chemotherapy. Therefore, new therapeutic targets are needed. We analyzed gene expression profiles between HCC tissues and normal adjacent tissues from public databases and found that the expression of genes involved in lipid metabolism was significantly different. The analysis showed that AKR1C3 was upregulated in tumors, and high AKR1C3 expression was associated with a poorer prognosis in HCC patients. In vitro, assays demonstrated that the knockdown of AKR1C3 or the addition of the AKR1C3 inhibitor indomethacin suppressed the growth and colony formation of HCC cell lines. Knockdown of AKR1C3 in Huh7 cells reduced tumor growth in vivo. To explore the mechanism, we performed pathway enrichment analysis, and the results linked the expression of AKR1C3 with prostaglandin F2 alpha (PGF2α) downstream target genes. Suppression of AKR1C3 activity reduced the production of PGF2α, and supplementation with PGF2α restored the growth of indomethacin-treated Huh7 cells. Knockdown of the PGF receptor (PTGFR) and treatment with a PTGFR inhibitor significantly reduced HCC growth. We showed that indomethacin potentiated the sensitivity of Huh7 cells to sorafenib. In summary, our results indicate that AKR1C3 upregulation may promote HCC growth by promoting the production of PGF2α, and suppression of PTGFR limited HCC growth. Therefore, targeting the AKR1C3-PGF2α-PTGFR axis may be a new strategy for the treatment of HCC.

Mechanistic study of the Aldo-keto reductase family 1 member A1 in regulating mesenchymal stem cell fate decision toward adipogenesis and osteogenesis

AimsAkr1A1 is a glycolytic enzyme catalyzing the reduction of aldehyde to alcohol. This study aims to delineate the role of Akr1A1 in regulating the adipo-osteogenic lineage differentiation of mesenchymal stem cells (MSCs). Main methodsMSCs derived from human bone marrow and Wharton Jelly together with gain- and loss-of-function analysis as well as supplementation with the S-Nitrosoglutathione reductase (GSNOR) inhibitor N6022 were used to study the function of Akr1A1 in controlling MSC lineage differentiation into osteoblasts and adipocytes. Key findingsAkr1A1 expression, PKM2 activity, and lactate production were found to be decreased in osteoblast-committed MSCs, but PGC-1α increased to induce mitochondrial oxidative phosphorylation. Increased Akr1A1 inhibited the SIRT1-dependent pathway for decreasing the expressions of PGC-1α and TAZ but increasing PPAR γ in adipocyte-committed MSCs, hence promoting glycolysis in adipogenesis. In contrast, Akr1A1 expression, PKM2 activity and lactate production were all increased in adipocyte-differentiated cells with decreased PGC-1α for switching energy utilization to glycolytic metabolism. Reduced Akr1A1 expression in osteoblast-committed cells relieves its inhibition of SIRT1-mediated activation of PGC-1α and TAZ for facilitating osteogenesis and mitochondrial metabolism. SignificanceSeveral metabolism-involved regulators including Akr1A1, SIRT1, PPARγ, PGC-1α and TAZ were differentially expressed in osteoblast- and adipocyte-committed MSCs. More importantly, Akr1A1 was identified as a new key regulator for controlling the MSC lineage commitment in favor of adipogenesis but detrimental to osteogenesis. Such information should be useful to develop perspective new therapeutic agents to reverse the adipo-osteogenic differentiation of BMSCs, in a way to increase in osteogenesis but decrease in adipogenesis.

Potential Role of AKR1B1 Gene Methylation in Diagnosis of Patients With Breast Cancer.

In addition to the great challenge of early diagnosis and prognosis in breast cancer (BC), the role of gene promoters in BC remains largely unexplored. This study aimed to evaluate aldo-keto reductase family 1 member B1 (AKR1B1) methylation as noninvasive biomarker for early BC diagnosis. A total of 200 (120 with BC, 40 with benign breast diseases, 40 healthy) Egyptian women were enrolled. AKR1B1 methylation level was determined using EpiTect Methyl II QPCR assay quantitative polymerase chain reaction. Findings revealed that hypermethylation AKR1B1 was reported to be associated (P < .0001) with BC cases (93.2 [75.4-98.6]) compared with benign (23.9 [22.6-48.3]) or healthy (15.5 [10.6-16]) controls. It had a great diagnostic power (area under the curve [AUC] = 0.909) that was superior to cancer antigen (CA) 15-3 (AUC = 0.681) and carcinoembryonic antigen (CEA) (AUC = 0.539). Interestingly, AKR1B1 hypermethylation was reported to be significant in identifying BC early stages (AUC = 0.899) and grades (AUC = 0.903). Independent to hormonal status and HER2neu expression, AKR1B1 hypermethylation was related to some tumor severity features, including advanced stages, high histological grades, and lymph node invasion. Also, AKR1B1 high degrees of methylation were significantly correlated with the increase in CEA (r = .195; P = .027), CA-15.3 (r = .351; P = .0001) and tumor stages (r = .274; P = .014), grades (r = .253; P = .024), and lymph node invasion (r = .275; P = .014). This study revealed that aberrant AKR1B1 methylation could facilitate early BC detection from benign br0east disorders. Hypermethylated AKR1B1 was related to BC aggressiveness suggesting its potential role as diagnostic and prognostic BC biomarker.

Aldo-keto reductase 1B10 as a Carcinogenic but Not a Prognostic Factor in Colorectal Cancer

Aldo-keto reductase 1B10 as a Carcinogenic but Not a Prognostic Factor in Colorectal Cancer

QSAR modeling of isoquinoline derivatives having AKR1C3 inhibitory activity: Lead optimization

Aldo-keto reductase 1C3 is a promising drug target for castration-resistant prostate cancer. In the present study, quantitative structure-activity relationship studies were carried out by QSARINS software on 3-(3, 4-dihydroisoquinolin-2(1H)-yl sulfonyl) benzoic acid derivatives having AKR1C3 inhibitory activity. The developed Quantitative Structure-activity relationship (QSAR) model suggests that the descriptors play key roles and are extremely helpful in predicting bioactivity. The best model shows validated statistical values, and residual information predicts the obtained model is robust, stable, and can be utilized to the extent of a novel series of isoquinoline derivatives.

Synthesis and biological evaluation of novel D-ring fused steroidal N(2)-substituted-1,2,3-triazoles.

In this study, a series of 13 new D-ring fused steroidal N(2)-substituted-1,2,3-triazoles were synthesized, characterized and evaluated for their biological activities. The relative binding affinities of the synthesized compounds for the ligand-binding domains of estrogen receptors α and β, androgen receptor and glucocorticoid receptor demonstrated that androstane derivatives 3a and 3h and estratriene derivative 4e showed highly specific and strong binding affinity for estrogen receptor β, while 3b, 3e, 4a and 4b displayed high binding affinity for the glucocorticoid receptor. The synthesized compounds were tested for their ability to inhibit aldo-keto reductases 1C3 and 1C4 in vitro by monitoring NADPH consumption using fluorescence spectroscopy. The most potent aldo-keto reductase 1C3 inhibitors were compounds 3h (71.17%) and 3f (69.9%). Moreover, a molecular docking study was carried out for compounds 3f and 3h against aldo-keto reductase 1C3 and results showed that compounds 3h and 3f could bind in the same site and orientation as EM1404. However, polar atoms in the triazole group enable additional hydrogen bonding deeper in SP1 with Tyr319, Tyr216 and the NADP+ cofactor, which are not visible in the AKR1C3-EM1404 crystal structure. The synthesized compounds were screened for their anticancer activity against four cancer cell lines. Compound 3f demonstrated moderate toxic effects across various cancer types, while displaying lower toxicity towards the healthy cell line. In summary, our findings indicate that N(2)-substituted-1,2,3-triazoles are high-affinity ligands for estrogen receptor β and glucocorticoid receptor, inhibitors of aldo-keto reductase 1C3 enzyme, and exhibit antiproliferative effects against cancer cells, suggesting that they could serve as scaffolds for anticancer drug development.

Structure-Guided Steric Hindrance Engineering of Devosia Strain A6-243 Quinone-Dependent Dehydrogenase to Enhance Its Catalytic Efficiency.

Deoxynivalenol (DON), the most widely distributed mycotoxin worldwide, causes severe health risks for humans and animals. Quinone-dependent dehydrogenase derived from Devosia strain A6-243 (DADH) can degrade DON into less toxic 3-keto-DON and then aldo-keto reductase AKR13B3 can reduce 3-keto-DON into relatively nontoxic 3-epi-DON. However, the poor catalytic efficiency of DADH made it unsuitable for practical applications, and it has become the rate-limiting step of the two-step enzymatic cascade catalysis. Here, structure-guided steric hindrance engineering was employed to enhance the catalytic efficiency of DADH. After the steric hindrance engineering, the best mutant, V429G/N431V/T432V/L434V/F537A (M5-1), showed an 18.17-fold increase in specific activity and an 11.04-fold increase in catalytic efficiency (kcat/Km) compared with that of wild-type DADH. Structure-based computational analysis provided information on the increased catalytic efficiency in the directions that attenuated steric hindrance, which was attributed to the reshaped substrate-binding pocket with an expanded catalytic binding cavity and a favorable attack distance. Tunnel analysis suggested that reshaping the active cavity by mutation might alter the shape and size of the enzyme tunnels or form one new enzyme tunnel, which might contribute to the improved catalytic efficiency of M5-1. These findings provide a promising strategy to enhance the catalytic efficiency by steric hindrance engineering.

Genome-wide identification of the BmAKR gene family in the silkworm (Bombyx mori) and their expression analysis in diapause eggs and nondiapause eggs

The aldo-keto reductase super family (AKRs) has a wide range of substrate specificity. However, the systematic identification of insect AKR gene family members has not been reported. In this study, bioinformatics methods were used to predict the phylogenetic evolution, physical and chemical properties, chromosome location, conserved motifs, and gene structure of AKR family members in Bombyx mori (BmAKR). Transcriptome data or quantitative real time polymerase chain reaction (qRT-PCR) were used to analyze the expression level of BmAKR genes during different organizational periods and silkworm eggs in different developmental states. Moreover, Western blotting was used to detect the expression level of the BmAKR in silkworm eggs. The results showed that 11 BmAKR genes were identified. These genes were distributed on 4 chromosomes of the silkworm genome, all of which had the (α/β) 8-barrel motif, and their physical and chemical characteristics were relatively similar. Phylogenetic analysis showed that the BmAKR genes could be divided into 2 subgroups (AKR1 and AKR2). Transcriptome data analysis showed that the expression of BmAKR genes were quite different in different tissues and periods. Moreover, the expression analysis of BmAKR genes in silkworm eggs showed that some genes were expressed significantly higher in nondiapause eggs than in diapause eggs; but another gene, BmAKR1-1, was expressed significantly higher in diapause eggs than in nondiapause eggs. The detection of protein level found that the difference trend of BmAKR1-1 in diapause eggs and non-diapause eggs was consistent with the results of qRT-PCR. In conclusion, BmAKR1-1 was screened out as candidates through the identification and analysis of the BmAKR genes in silkworm, which may regulate silkworm egg development is worthy of further investigation.

Endogenous reductase activities for the generation of ribitol-phosphate, a CDP-ribitol precursor, in mammals.

The core M3 O-mannosyl glycan on α-dystroglycan serves as the binding epitope for extracellular matrix molecules. Defects in core M3 glycans cause congenital muscular dystrophies that are collectively known as dystroglycanopathies. The core M3 glycan contains a tandem D-ribitol-5-phosphate (Rbo5P) structure, which is synthesized by the Rbo5P-transferases fukutin and fukutin-related protein using CDP-ribitol (CDP-Rbo) as a donor substrate. CDP-Rbo is synthesized from CTP and Rbo5P by CDP-Rbo pyrophosphorylase A. However, the Rbo5P biosynthesis pathway has yet to be elucidated in mammals. Here, we investigated the reductase activities toward four substrates, including ribose, ribulose, ribose-phosphate and ribulose-phosphate, to identify the intracellular Rbo5P production pathway and elucidated the role of the aldo-keto reductases AKR1A1, AKR1B1 and AKR1C1 in those pathways. It was shown that the ribose reduction pathway is the endogenous pathway that contributes most to Rbo5P production in HEK293T cells and that AKR1B1 is the major reductase in this pathway.