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International Ophthalmology Oct 2023The aim is to evaluate the aldose reductase (AR) and glutathione (GSH) activity in the nucleus of senile cataract in type 2 diabetes and non-diabetic group of patients.
PURPOSE
The aim is to evaluate the aldose reductase (AR) and glutathione (GSH) activity in the nucleus of senile cataract in type 2 diabetes and non-diabetic group of patients.
METHODS
A total of 62 patients including 31 diabetics and 31 non- diabetics who were undergoing cataract surgery were included. Nucleus extracted was sent for analysis of AR and GSH activity while blood sample was taken for glycated haemoglobin (HbA1c) levels.
STATISTICAL ANALYSIS
Data were analysed using IBM SPSS 25. Comparison was carried out by unpaired T-test and correlations were established by Pearson's correlation. The p value less than 0.05 was considered significant for all analyses.
STUDY DESIGN
This is a prospective cross-sectional comparative study.
RESULTS
In this study, diabetic group patients showed earlier progression of cataract as compared to the non-diabetic group (p-value 0.0310). Mean HbA1c in the diabetic group was 7.34% compared to the non-diabetic group of 5.7% (p value < 0.001). AR in the diabetic patients was 2.07 mU/mg while the non-diabetic group was 0.22 mU/mg (p-value < 0.001). GSH in the diabetic group was 3.38 μMol/g and the non-diabetic group was 7.47 μMol/g (p value < 0.001). HbA1c showed positive correlation with AR among the diabetic group (p-value 0.028).
CONCLUSION
Elevated oxidative stress can be strongly attributed to high AR and low GSH activity among the diabetic group as compared to the non-diabetic group and can lead to early cataract formation.
Topics: Humans; Diabetes Mellitus, Type 2; Glycated Hemoglobin; Aldehyde Reductase; Cross-Sectional Studies; Prospective Studies; Cataract; Lens, Crystalline; Glutathione
PubMed: 37395905
DOI: 10.1007/s10792-023-02776-1 -
Journal of Translational Medicine Oct 2023Nonalcoholic steatohepatitis (NASH) is a progressive and inflammatory subtype of nonalcoholic fatty liver disease (NAFLD) characterized by hepatocellular injury,...
BACKGROUND
Nonalcoholic steatohepatitis (NASH) is a progressive and inflammatory subtype of nonalcoholic fatty liver disease (NAFLD) characterized by hepatocellular injury, inflammation, and fibrosis in various stages. More than 20% of patients with NASH will progress to cirrhosis. Currently, there is a lack of clinically effective drugs for treating NASH, as improving liver histology in NASH is difficult to achieve and maintain through weight loss alone. Hence, the present study aimed to investigate potential therapeutic drugs for NASH.
METHODS
BMDMs and THP1 cells were used to construct an inflammasome activation model, and then we evaluated the effect of epalrestat on the NLRP3 inflammasome activation. Western blot, real-time qPCR, flow cytometry, and ELISA were used to evaluate the mechanism of epalrestat on NLRP3 inflammasome activation. Next, MCD-induced NASH models were used to evaluate the therapeutic effects of epalrestat in vivo. In addition, to evaluate the safety of epalrestat in vivo, mice were gavaged with epalrestat daily for 14 days.
RESULTS
Epalrestat, a clinically effective and safe drug, inhibits NLRP3 inflammasome activation by acting upstream of caspase-1 and inducing ASC oligomerization. Importantly, epalrestat exerts its inhibitory effect on NLRP3 inflammasome activation by inhibiting the activation of aldose reductase. Further investigation revealed that the administration of epalrestat inhibited NLRP3 inflammasome activation in vivo, alleviating liver inflammation and improving NASH pathology.
CONCLUSIONS
Our study indicated that epalrestat, an aldose reductase inhibitor, effectively suppressed NLRP3 inflammasome activation in vivo and in vitro and might be a new therapeutic approach for NASH.
Topics: Humans; Mice; Animals; Non-alcoholic Fatty Liver Disease; Inflammasomes; NLR Family, Pyrin Domain-Containing 3 Protein; Aldehyde Reductase; Inflammation; Fibrosis; Mice, Inbred C57BL
PubMed: 37805545
DOI: 10.1186/s12967-023-04380-4 -
Nature Communications Nov 2023Methyl jasmonate (MeJA) is a known elicitor of plant specialized metabolism, including triterpenoid saponins. Saponaria vaccaria is an annual herb used in traditional...
Methyl jasmonate (MeJA) is a known elicitor of plant specialized metabolism, including triterpenoid saponins. Saponaria vaccaria is an annual herb used in traditional Chinese medicine, containing large quantities of oleanane-type triterpenoid saponins with anticancer properties and structural similarities to the vaccine adjuvant QS-21. Leveraging the MeJA-elicited saponin biosynthesis, we identify multiple enzymes catalyzing the oxidation and glycosylation of triterpenoids in S. vaccaria. This exploration is aided by Pacbio full-length transcriptome sequencing and gene expression analysis. A cellulose synthase-like enzyme can not only glucuronidate triterpenoid aglycones but also alter the product profile of a cytochrome P450 monooxygenase via preference for the aldehyde intermediate. Furthermore, the discovery of a UDP-glucose 4,6-dehydratase and a UDP-4-keto-6-deoxy-glucose reductase reveals the biosynthetic pathway for the rare nucleotide sugar UDP-D-fucose, a likely sugar donor for fucosylation of plant natural products. Our work enables the production and optimization of high-value saponins in microorganisms and plants through synthetic biology approaches.
Topics: Triterpenes; Transcriptome; Saponaria; Vaccaria; Plants; Saponins; Uridine Diphosphate; Glucose; Sugars
PubMed: 37925486
DOI: 10.1038/s41467-023-42877-0 -
Biomolecules Mar 2022Aldose reductase, classified within the aldo-keto reductase family as AKR1B1, is an NADPH dependent enzyme that catalyzes the reduction of hydrophilic as well as... (Review)
Review
Aldose reductase, classified within the aldo-keto reductase family as AKR1B1, is an NADPH dependent enzyme that catalyzes the reduction of hydrophilic as well as hydrophobic aldehydes. AKR1B1 is the first enzyme of the so-called polyol pathway that allows the conversion of glucose into sorbitol, which in turn is oxidized to fructose by sorbitol dehydrogenase. The activation of the polyol pathway in hyperglycemic conditions is generally accepted as the event that is responsible for a series of long-term complications of diabetes such as retinopathy, cataract, nephropathy and neuropathy. The role of AKR1B1 in the onset of diabetic complications has made this enzyme the target for the development of molecules capable of inhibiting its activity. Virtually all synthesized compounds have so far failed as drugs for the treatment of diabetic complications. This failure may be partly due to the ability of AKR1B1 to reduce alkenals and alkanals, produced in oxidative stress conditions, thus acting as a detoxifying agent. In recent years we have proposed an alternative approach to the inhibition of AKR1B1, suggesting the possibility of a differential inhibition of the enzyme through molecules able to preferentially inhibit the reduction of either hydrophilic or hydrophobic substrates. The rationale and examples of this new generation of aldose reductase differential inhibitors (ARDIs) are presented.
Topics: Aldehyde Reductase; Diabetes Complications; Diabetes Mellitus; Enzyme Inhibitors; Glucose; Humans
PubMed: 35454074
DOI: 10.3390/biom12040485 -
Microorganisms Apr 2022Furfural and hydroxy-methyl-furfural (HMF) are produced by lignocellulosic biomass during heat or acid pretreatment and are toxic to yeast. Aldehyde reductase is the...
Furfural and hydroxy-methyl-furfural (HMF) are produced by lignocellulosic biomass during heat or acid pretreatment and are toxic to yeast. Aldehyde reductase is the main enzyme to reduce furfural and HMF. To improve the conversion efficiency of lignocellulosic biomass into ethanol, we constructed with overexpression of aldehyde reductase (encoded by ). The gene of aldehyde reductase (encoded by ) was cloned via polymerase chain reaction (PCR) and ligated with the expression vector pGAPZαC. Western blot coupled with anti-His tag confirmed overexpression of the gene. The growth curves of the wild and -overexpressed strain in the YPD medium were found to be almost identical. Compare to the -overexpressed strain, the wild strain showed a longer doubling time and lag phase in the presence of 20 mM furfural and 60 mM HMF, respectively. The real-time PCR results showed that furfural was much more potent than HMF in stimulating expression, but the cell growth patterns showed that 60 mM HMF was more toxic to yeast than 20 mM furfural. with overexpression appeared to confer higher tolerance to aldehyde inhibitors, thereby increasing the growth rate and ethanol production capacity of in an aldehyde-containing environment.
PubMed: 35630298
DOI: 10.3390/microorganisms10050850 -
Microorganisms Jun 2023Molybdenum (Mo) is vital for the activity of a small but essential group of enzymes called molybdoenzymes. So far, specifically five molybdoenzymes have been discovered... (Review)
Review
Molybdenum (Mo) is vital for the activity of a small but essential group of enzymes called molybdoenzymes. So far, specifically five molybdoenzymes have been discovered in eukaryotes: nitrate reductase, sulfite oxidase, xanthine dehydrogenase, aldehyde oxidase, and mARC. In order to become biologically active, Mo must be chelated to a pterin, forming the so-called Mo cofactor (Moco). Deficiency or mutation in any of the genes involved in Moco biosynthesis results in the simultaneous loss of activity of all molybdoenzymes, fully or partially preventing the normal development of the affected organism. To prevent this, the different mechanisms involved in Mo homeostasis must be finely regulated. is a unicellular, photosynthetic, eukaryotic microalga that has produced fundamental advances in key steps of Mo homeostasis over the last 30 years, which have been extrapolated to higher organisms, both plants and animals. These advances include the identification of the first two molybdate transporters in eukaryotes (MOT1 and MOT2), the characterization of key genes in Moco biosynthesis, the identification of the first enzyme that protects and transfers Moco (MCP1), the first characterization of mARC in plants, and the discovery of the crucial role of the nitrate reductase-mARC complex in plant nitric oxide production. This review aims to provide a comprehensive summary of the progress achieved in using as a model organism in Mo homeostasis and to propose how this microalga can continue improving with the advancements in this field in the future.
PubMed: 37512844
DOI: 10.3390/microorganisms11071671 -
Journal of Enzyme Inhibition and... Dec 2020The ability to catalyse a reaction acting on different substrates, known as "broad-specificity" or "multi-specificity", and to catalyse different reactions at the same... (Review)
Review
The ability to catalyse a reaction acting on different substrates, known as "broad-specificity" or "multi-specificity", and to catalyse different reactions at the same active site ("promiscuity") are common features among the enzymes. These properties appear to go against the concept of extreme specificity of the catalytic action of enzymes and have been re-evaluated in terms of evolution and metabolic adaptation. This paper examines the potential usefulness of a differential inhibitory action in the study of the susceptibility to inhibition of multi-specific or promiscuous enzymes acting on different substrates. Aldose reductase is a multi-specific enzyme that catalyses the reduction of both aldoses and hydrophobic cytotoxic aldehydes and is used here as a concrete case to deal with the differential inhibition approach.
Topics: Aldehyde Reductase; Aldehydes; Biocatalysis; Enzyme Inhibitors; Humans
PubMed: 32208768
DOI: 10.1080/14756366.2020.1743988 -
Cell Reports Jan 2023Nitric oxide (NO) production in the tumor microenvironment is a common element in cancer. S-nitrosylation, the post-translational modification of cysteines by NO, is...
Nitric oxide (NO) production in the tumor microenvironment is a common element in cancer. S-nitrosylation, the post-translational modification of cysteines by NO, is emerging as a key transduction mechanism sustaining tumorigenesis. However, most oncoproteins that are regulated by S-nitrosylation are still unknown. Here we show that S-nitrosoglutathione reductase (GSNOR), the enzyme that deactivates S-nitrosylation, is hypo-expressed in several human malignancies. Using multiple tumor models, we demonstrate that GSNOR deficiency induces S-nitrosylation of focal adhesion kinase 1 (FAK1) at C658. This event enhances FAK1 autophosphorylation and sustains tumorigenicity by providing cancer cells with the ability to survive in suspension (evade anoikis). In line with these results, GSNOR-deficient tumor models are highly susceptible to treatment with FAK1 inhibitors. Altogether, our findings advance our understanding of the oncogenic role of S-nitrosylation, define GSNOR as a tumor suppressor, and point to GSNOR hypo-expression as a therapeutically exploitable vulnerability in cancer.
Topics: Humans; Aldehyde Oxidoreductases; Focal Adhesion Kinase 1; Neoplasms; Nitric Oxide; Phosphorylation; Protein Processing, Post-Translational; Tumor Microenvironment; Alcohol Dehydrogenase
PubMed: 36656716
DOI: 10.1016/j.celrep.2023.111997 -
Journal of Translational Medicine Dec 2022Epithelial ovarian cancer is the most lethal gynaecological cancer worldwide. Chemotherapy resistance represents a significant clinical challenge and is the main reason...
BACKGROUND
Epithelial ovarian cancer is the most lethal gynaecological cancer worldwide. Chemotherapy resistance represents a significant clinical challenge and is the main reason for poor ovarian cancer prognosis. We identified novel expression of markers related to epithelial mesenchymal transitions (EMT) in a carboplatin resistant ovarian cancer cell line by proteomics. This was validated in the platinum resistant versus sensitive parental cell lines, as well as platinum resistant versus sensitive human ovarian cancer patient samples. The prognostic significance of the different proteomics-identified marker proteins in prognosis prediction on survival as well as their correlative association and influence on immune cell infiltration was determined by public domain data bases.
METHODS
We explored the proteomic differences between carboplatin-sensitive OVCAR5 cells (parental) and their carboplatin-resistant counterpart, OVCAR5 CBPR cells. qPCR and western blots were performed to validate differentially expressed proteins at the mRNA and protein levels, respectively. Association of the identified proteins with epithelial-mesenchymal transition (EMT) prompted the investigation of cell motility. Cellular bioenergetics and proliferation were studied to delineate any biological adaptations that facilitate cancer progression. Expression of differentially expressed proteins was assessed in ovarian tumors obtained from platinum-sensitive (n = 15) versus platinum-resistant patients (n = 10), as well as matching tumors from patients at initial diagnosis and following relapse (n = 4). Kaplan-Meier plotter and Tumor Immune Estimation Resource (TIMER) databases were used to determine the prognostic significance and influence of the different proteomics-identified proteins on immune cell infiltration in the tumor microenvironment (TME).
RESULTS
Our proteomics study identified 2422 proteins in both cell lines. Of these, 18 proteins were upregulated and 14 were downregulated by ≥ twofold (p < 0.05) in OVCAR5 CBPR cells. Gene ontology enrichment analysis amongst upregulated proteins revealed an overrepresentation of biological processes consistent with EMT in the resistant cell line. Enhanced mRNA and/or protein expression of the identified EMT modulators including ITGA2, TGFBI, AKR1B1, ITGAV, ITGA1, GFPT2, FLNA and G6PD were confirmed in OVCAR5 CBPR cells compared to parental OVCAR5 cell line. Consistent with the altered EMT profile, the OVCAR5 CBPR cells demonstrated enhanced migration and reduced proliferation, glycolysis, and oxidative phosphorylation. The upregulation of G6PD, AKR1B1, ITGAV, and TGFβ1 in OVCAR5 CBPR cells was also identified in the tumors of platinum-resistant compared to platinum-sensitive high grade serous ovarian cancer (HGSOC) patients. Matching tumors of relapsed versus newly diagnosed HGSOC patients also showed enhanced expression of AKR1B1, ITGAV, TGFβ1 and G6PD protein in relapsed tumors. Among the identified proteins, significant enhanced expression of GFPT2, FLNA, TGFBI (CDGG1), ITGA2 predicted unfavorable prognosis in ovarian cancer patients. Further analysis suggested that the expression of TGFBI to correlate positively with the expression of identified and validated proteins such as GFPT2, FLNA, G6PD, ITGAV, ITGA1 and ITGA2; and with the infiltration of CD8 T cells, macrophages, neutrophils, and dendritic cells in the TME.
CONCLUSIONS
Our research demonstrates proteomic-based discovery of novel EMT-related markers with an altered metabolic profile in platinum-resistant versus sensitive ovarian cancer cell lines. The study also confirms the expression of selected identified markers in the tumors of platinum-resistant versus sensitive, and in matching relapsed versus newly diagnosed HGSOC patients. The study provides insights into the metabolic adaptation of EMT-induced carboplatin resistant cells that confers on them reduced proliferation to provide effective migratory advantage; and the role of some of these identified proteins in ovarian cancer prognosis. These observations warrant further investigation of these novel target proteins in platinum-resistant patients.
Topics: Female; Humans; Aldehyde Reductase; Carboplatin; Carcinoma, Ovarian Epithelial; CD8-Positive T-Lymphocytes; Epithelial-Mesenchymal Transition; Ovarian Neoplasms; Platinum; Proteomics; RNA, Messenger; Tumor Microenvironment; Drug Resistance, Neoplasm
PubMed: 36463238
DOI: 10.1186/s12967-022-03776-y -
Brain Research May 2021Traumatic spinal cord injury (SCI) enhances the activity of S-nitrosoglutathione reductase (GSNOR) and inhibits the mitochondrial aldehyde dehydrogenase 2 (ALDH2)...
Traumatic spinal cord injury (SCI) enhances the activity of S-nitrosoglutathione reductase (GSNOR) and inhibits the mitochondrial aldehyde dehydrogenase 2 (ALDH2) activity, resulting in prolonged and sustained pain and functional deficits. This study's objective was to test the hypotheses that GSNOR's specific inhibitor N6022 mitigates pain and improves functional recovery in a mouse model of SCI. Furthermore, the degree of recovery is enhanced and the rate of recovery is accelerated by an ALDH2 activator Alda-1. Using both wild-type and GSNOR/ mice, the SCI model deployed for groups was contusion at the T9-T10 vertebral level. The enzymatic activity of GSNOR and ALDH2 was measured, and the expression of GSNOR and ALDH2 was determined by western blot analysis. Functional improvements in experimental animals were assessed with locomotor, sensorimotor, and pain-like behavior tests. Wild-type SCI animals had enhanced GSNOR activity and decreased ALDH2 activity, leading to neurovascular dysfunction, edema, and worsened functional outcomes, including locomotor deficits and pain. Compared to wild-type SCI mice, GSNOR/ mice had better functional outcomes. Monotherapy with either GSNOR inhibition by N6022 or enhanced ALDH2 activity by Alda-1 correlated well with functional recovery and lessened pain. However, combination therapy provided synergistic pain-relieving effects and more significant functional recovery compared with monotherapy. Conclusively, dysregulations in GSNOR and ALDH2 are among the causative mechanisms of SCI injury. Either inhibiting GSNOR or activating ALDH2 ameliorates SCI. Combining the specific inhibitor of GSNOR (N6022) with the selective activator of ALDH2 (Alda-1) provides greater protection to the neurovascular unit and confers greater functional recovery. The study is novel, and the combination therapy (N6022 + Alda-1) possesses translational potential.
Topics: Alcohol Dehydrogenase; Aldehyde Dehydrogenase, Mitochondrial; Animals; Benzamides; Benzodioxoles; Enzyme Inhibitors; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Pyrroles; Recovery of Function; Spinal Cord Injuries
PubMed: 33545099
DOI: 10.1016/j.brainres.2021.147335