The Experts below are selected from a list of 3555 Experts worldwide ranked by ideXlab platform
Paul J. Thornalley - One of the best experts on this subject based on the ideXlab platform.
-
Glyoxalase Centennial: 100 Years of Glyoxalase Research and Emergence of Dicarbonyl Stress 419 Activity, regulation, copy number and function in the Glyoxalase system
2016Co-Authors: Naila Rabbani, Mingzhan Xue, Paul J. ThornalleyAbstract:Molecular, catalytic and structural properties of Glyoxalase pathway enzymes of many species are now known. Current research has focused on the regulation of activity and expression of Glo1 (Glyoxalase I) and Glo2 (Glyoxalase II) and their role in health and disease. Human GLO1 has MRE (metal-response element), IRE (insulin-response element), E2F4 (early gene 2 factor isoform 4), AP-2α (activating enhancer-binding protein 2α) and ARE (antioxidant response-element) regulatory elements and is a hotspot for copy number variation. The human Glo2 gene, HAGH (hydroxyacylglutathione hydrolase), has a regulatory p53-response element. Glo1 is linked to healthy aging, obesity, diabetes and diabetic complications, chronic renal disease, cardiovascular disease, other disorders and multidrug resistance in cancer chemotherapy. Mathematical modelling of the Glyoxalase pathway predicts that pharmacological levels of increased Glo1 activity markedly decrease cellular methylglyoxal and related glycation, and pharmacological Glo1 inhibition markedly increases cellular methylglyoxal and related glycation. Glo1 inducers are in development to sustain healthy aging and for treatment of vascular complications of diabetes and other disorders, and cell-permeant Glo1 inhibitors are in development for treatment of multidrug-resistant tumours, malaria and potentially pathogenic bacteria and fungi
-
methylglyoxal induced dicarbonyl stress in aging and disease first steps towards Glyoxalase 1 based treatments
Clinical Science, 2016Co-Authors: Naila Rabbani, Paul J. Thornalley, Mingzhan XueAbstract:Dicarbonyl stress is the abnormal accumulation of dicarbonyl metabolites leading to increased protein and DNA modification contributing to cell and tissue dysfunction in aging and disease. It is produced by increased formation and/or decreased metabolism of dicarbonyl metabolites. MG (methylglyoxal) is a dicarbonyl metabolite of relatively high flux of formation and precursor of the most quantitatively and functionally important spontaneous modifications of protein and DNA clinically. Major MG-derived adducts are arginine-derived hydroimidazolones of protein and deoxyguanosine-derived imidazopurinones of DNA. These are formed non-oxidatively. The Glyoxalase system provides an efficient and essential basal and stress-response-inducible enzymatic defence against dicarbonyl stress by the reduced glutathione-dependent metabolism of methylglyoxal by Glyoxalase 1. The GLO1 gene encoding Glyoxalase 1 has low prevalence duplication and high prevalence amplification in some tumours. Dicarbonyl stress contributes to aging, disease and activity of cytotoxic chemotherapeutic agents. It is found at a low, moderate and severe level in obesity, diabetes and renal failure respectively, where it contributes to the development of metabolic and vascular complications. Increased Glyoxalase 1 expression confers multidrug resistance to cancer chemotherapy and has relatively high prevalence in liver, lung and breast cancers. Studies of dicarbonyl stress are providing improved understanding of aging and disease and the basis for rational design of novel pharmaceuticals: Glyoxalase 1 inducers for obesity, diabetes and cardiovascular disease and Glyoxalase 1 inhibitors for multidrug-resistant tumours. The first clinical trial of a Glyoxalase 1 inducer in overweight and obese subjects showed improved glycaemic control, insulin resistance and vascular function.
-
activity regulation copy number and function in the Glyoxalase system
Biochemical Society Transactions, 2014Co-Authors: Naila Rabbani, Paul J. ThornalleyAbstract:Molecular, catalytic and structural properties of Glyoxalase pathway enzymes of many species are now known. Current research has focused on the regulation of activity and expression of Glo1 (Glyoxalase I) and Glo2 (Glyoxalase II) and their role in health and disease. Human GLO1 has MRE (metal-response element), IRE (insulin-response element), E2F4 (early gene 2 factor isoform 4), AP-2α (activating enhancer-binding protein 2α) and ARE (antioxidant response-element) regulatory elements and is a hotspot for copy number variation. The human Glo2 gene, HAGH (hydroxyacylglutathione hydrolase), has a regulatory p53-response element. Glo1 is linked to healthy aging, obesity, diabetes and diabetic complications, chronic renal disease, cardiovascular disease, other disorders and multidrug resistance in cancer chemotherapy. Mathematical modelling of the Glyoxalase pathway predicts that pharmacological levels of increased Glo1 activity markedly decrease cellular methylglyoxal and related glycation, and pharmacological Glo1 inhibition markedly increases cellular methylglyoxal and related glycation. Glo1 inducers are in development to sustain healthy aging and for treatment of vascular complications of diabetes and other disorders, and cell-permeant Glo1 inhibitors are in development for treatment of multidrug-resistant tumours, malaria and potentially pathogenic bacteria and fungi.
-
Glyoxalase centennial conference introduction history of research on the Glyoxalase system and future prospects
Biochemical Society Transactions, 2014Co-Authors: Naila Rabbani, Paul J. ThornalleyAbstract:On 27–29 November 2013, researchers gathered at the University of Warwick, Coventry, U.K., to celebrate the centennial of the discovery of the Glyoxalase pathway. The Glyoxalase system was discovered and reported in papers by Carl Neuberg and by Henry Drysdale Dakin and Harold Ward Dudley in 1913. All three were leading extraordinary investigators in the pioneering years of biochemistry. Neuberg proposed Glyoxalase as the pathway of mainstream glycolysis and Gustav Embden correctly discounted this, later confirmed by Otto Meyerhof. Albert Szent-Gyorgyi proposed Glyoxalase I as the regulator of cell growth and others discounted this. In the meantime, molecular, structural and mechanistic properties of the enzymatic components of the system, Glyoxalase I and Glyoxalase II, have been characterized. The physiological function of the Glyoxalase pathway of enzymatic defence against dicarbonyl glycation, particularly by endogenous methylglyoxal, now seems secure. We are now in an era of investigation of the regulation of the Glyoxalase system where a role in aging and disease, physiological stress and drug resistance and development of healthier foods and new pharmaceuticals is emerging. The history of Glyoxalase research illustrates the scientific process of hypothesis proposal, testing and rejection or acceptance with further investigation, standing testament to the need for intuition guided by experience and expertise, as well as indefatigable experimentation. Abbreviations: DHAP, dihydroxyacetone phosphate; F-1,6-BP, fructose 1,6-bisphosphate; GA3P, glyceraldehyde 3-phosphate; Glo, Glyoxalase; MDR, multidrug resistance
-
measurement of Glyoxalase activities
Biochemical Society Transactions, 2014Co-Authors: Makoto Arai, Naila Rabbani, Naomi Nihonmatsukikuchi, Masanari Itokawa, Paul J. ThornalleyAbstract:Glyoxalase I catalyses the isomerization of the hemithioacetal formed non-enzymatically from methylglyoxal and glutathione to S-D-lactoylglutathione. The activity of Glyoxalase I is conventionally measured spectrophotometrically by following the increase in A240 for which the change in molar absorption coefficient Δe240=2.86 mM⁻¹·cm⁻¹. The hemithioacetal is pre-formed in situ by incubation of methylglyoxal and glutathione in 50 mM sodium phosphate buffer (pH 6.6) at 37°C for 10 min. The cell extract is then added, the A240 is monitored over 5 min, and the initial rate of increase in A240 and hence Glyoxalase I activity deduced with correction for blank. Glyoxalase I activity is given in units per mg of protein or cell number where one unit is the amount of enzyme that catalyses the formation of 1 μmol of S-D-lactoylglutathione per min under assay conditions. Glyoxalase II catalyses the hydrolysis of S-D-lactoylglutathione to D-lactate and glutathione. Glyoxalase II activity is also measured spectrophotometrically by following the decrease in A240 for which the change in molar absorption coefficient Δe240=-3.10 mM⁻¹·cm⁻¹. It is given in units per mg of protein or cell number where one unit is the amount of enzyme that catalyses the hydrolysis of 1 μmol of S-D-lactoylglutathione per min under assay conditions. Glyoxalase I and Glyoxalase II activity measurements have been modified for use with a UV-transparent microplate for higher sample throughput.
Naila Rabbani - One of the best experts on this subject based on the ideXlab platform.
-
Glyoxalase Centennial: 100 Years of Glyoxalase Research and Emergence of Dicarbonyl Stress 419 Activity, regulation, copy number and function in the Glyoxalase system
2016Co-Authors: Naila Rabbani, Mingzhan Xue, Paul J. ThornalleyAbstract:Molecular, catalytic and structural properties of Glyoxalase pathway enzymes of many species are now known. Current research has focused on the regulation of activity and expression of Glo1 (Glyoxalase I) and Glo2 (Glyoxalase II) and their role in health and disease. Human GLO1 has MRE (metal-response element), IRE (insulin-response element), E2F4 (early gene 2 factor isoform 4), AP-2α (activating enhancer-binding protein 2α) and ARE (antioxidant response-element) regulatory elements and is a hotspot for copy number variation. The human Glo2 gene, HAGH (hydroxyacylglutathione hydrolase), has a regulatory p53-response element. Glo1 is linked to healthy aging, obesity, diabetes and diabetic complications, chronic renal disease, cardiovascular disease, other disorders and multidrug resistance in cancer chemotherapy. Mathematical modelling of the Glyoxalase pathway predicts that pharmacological levels of increased Glo1 activity markedly decrease cellular methylglyoxal and related glycation, and pharmacological Glo1 inhibition markedly increases cellular methylglyoxal and related glycation. Glo1 inducers are in development to sustain healthy aging and for treatment of vascular complications of diabetes and other disorders, and cell-permeant Glo1 inhibitors are in development for treatment of multidrug-resistant tumours, malaria and potentially pathogenic bacteria and fungi
-
methylglyoxal induced dicarbonyl stress in aging and disease first steps towards Glyoxalase 1 based treatments
Clinical Science, 2016Co-Authors: Naila Rabbani, Paul J. Thornalley, Mingzhan XueAbstract:Dicarbonyl stress is the abnormal accumulation of dicarbonyl metabolites leading to increased protein and DNA modification contributing to cell and tissue dysfunction in aging and disease. It is produced by increased formation and/or decreased metabolism of dicarbonyl metabolites. MG (methylglyoxal) is a dicarbonyl metabolite of relatively high flux of formation and precursor of the most quantitatively and functionally important spontaneous modifications of protein and DNA clinically. Major MG-derived adducts are arginine-derived hydroimidazolones of protein and deoxyguanosine-derived imidazopurinones of DNA. These are formed non-oxidatively. The Glyoxalase system provides an efficient and essential basal and stress-response-inducible enzymatic defence against dicarbonyl stress by the reduced glutathione-dependent metabolism of methylglyoxal by Glyoxalase 1. The GLO1 gene encoding Glyoxalase 1 has low prevalence duplication and high prevalence amplification in some tumours. Dicarbonyl stress contributes to aging, disease and activity of cytotoxic chemotherapeutic agents. It is found at a low, moderate and severe level in obesity, diabetes and renal failure respectively, where it contributes to the development of metabolic and vascular complications. Increased Glyoxalase 1 expression confers multidrug resistance to cancer chemotherapy and has relatively high prevalence in liver, lung and breast cancers. Studies of dicarbonyl stress are providing improved understanding of aging and disease and the basis for rational design of novel pharmaceuticals: Glyoxalase 1 inducers for obesity, diabetes and cardiovascular disease and Glyoxalase 1 inhibitors for multidrug-resistant tumours. The first clinical trial of a Glyoxalase 1 inducer in overweight and obese subjects showed improved glycaemic control, insulin resistance and vascular function.
-
Glyoxalase centennial conference introduction history of research on the Glyoxalase system and future prospects
Biochemical Society Transactions, 2014Co-Authors: Naila Rabbani, Paul J. ThornalleyAbstract:On 27–29 November 2013, researchers gathered at the University of Warwick, Coventry, U.K., to celebrate the centennial of the discovery of the Glyoxalase pathway. The Glyoxalase system was discovered and reported in papers by Carl Neuberg and by Henry Drysdale Dakin and Harold Ward Dudley in 1913. All three were leading extraordinary investigators in the pioneering years of biochemistry. Neuberg proposed Glyoxalase as the pathway of mainstream glycolysis and Gustav Embden correctly discounted this, later confirmed by Otto Meyerhof. Albert Szent-Gyorgyi proposed Glyoxalase I as the regulator of cell growth and others discounted this. In the meantime, molecular, structural and mechanistic properties of the enzymatic components of the system, Glyoxalase I and Glyoxalase II, have been characterized. The physiological function of the Glyoxalase pathway of enzymatic defence against dicarbonyl glycation, particularly by endogenous methylglyoxal, now seems secure. We are now in an era of investigation of the regulation of the Glyoxalase system where a role in aging and disease, physiological stress and drug resistance and development of healthier foods and new pharmaceuticals is emerging. The history of Glyoxalase research illustrates the scientific process of hypothesis proposal, testing and rejection or acceptance with further investigation, standing testament to the need for intuition guided by experience and expertise, as well as indefatigable experimentation. Abbreviations: DHAP, dihydroxyacetone phosphate; F-1,6-BP, fructose 1,6-bisphosphate; GA3P, glyceraldehyde 3-phosphate; Glo, Glyoxalase; MDR, multidrug resistance
-
activity regulation copy number and function in the Glyoxalase system
Biochemical Society Transactions, 2014Co-Authors: Naila Rabbani, Paul J. ThornalleyAbstract:Molecular, catalytic and structural properties of Glyoxalase pathway enzymes of many species are now known. Current research has focused on the regulation of activity and expression of Glo1 (Glyoxalase I) and Glo2 (Glyoxalase II) and their role in health and disease. Human GLO1 has MRE (metal-response element), IRE (insulin-response element), E2F4 (early gene 2 factor isoform 4), AP-2α (activating enhancer-binding protein 2α) and ARE (antioxidant response-element) regulatory elements and is a hotspot for copy number variation. The human Glo2 gene, HAGH (hydroxyacylglutathione hydrolase), has a regulatory p53-response element. Glo1 is linked to healthy aging, obesity, diabetes and diabetic complications, chronic renal disease, cardiovascular disease, other disorders and multidrug resistance in cancer chemotherapy. Mathematical modelling of the Glyoxalase pathway predicts that pharmacological levels of increased Glo1 activity markedly decrease cellular methylglyoxal and related glycation, and pharmacological Glo1 inhibition markedly increases cellular methylglyoxal and related glycation. Glo1 inducers are in development to sustain healthy aging and for treatment of vascular complications of diabetes and other disorders, and cell-permeant Glo1 inhibitors are in development for treatment of multidrug-resistant tumours, malaria and potentially pathogenic bacteria and fungi.
-
measurement of Glyoxalase activities
Biochemical Society Transactions, 2014Co-Authors: Makoto Arai, Naila Rabbani, Naomi Nihonmatsukikuchi, Masanari Itokawa, Paul J. ThornalleyAbstract:Glyoxalase I catalyses the isomerization of the hemithioacetal formed non-enzymatically from methylglyoxal and glutathione to S-D-lactoylglutathione. The activity of Glyoxalase I is conventionally measured spectrophotometrically by following the increase in A240 for which the change in molar absorption coefficient Δe240=2.86 mM⁻¹·cm⁻¹. The hemithioacetal is pre-formed in situ by incubation of methylglyoxal and glutathione in 50 mM sodium phosphate buffer (pH 6.6) at 37°C for 10 min. The cell extract is then added, the A240 is monitored over 5 min, and the initial rate of increase in A240 and hence Glyoxalase I activity deduced with correction for blank. Glyoxalase I activity is given in units per mg of protein or cell number where one unit is the amount of enzyme that catalyses the formation of 1 μmol of S-D-lactoylglutathione per min under assay conditions. Glyoxalase II catalyses the hydrolysis of S-D-lactoylglutathione to D-lactate and glutathione. Glyoxalase II activity is also measured spectrophotometrically by following the decrease in A240 for which the change in molar absorption coefficient Δe240=-3.10 mM⁻¹·cm⁻¹. It is given in units per mg of protein or cell number where one unit is the amount of enzyme that catalyses the hydrolysis of 1 μmol of S-D-lactoylglutathione per min under assay conditions. Glyoxalase I and Glyoxalase II activity measurements have been modified for use with a UV-transparent microplate for higher sample throughput.
S. K. Sopory - One of the best experts on this subject based on the ideXlab platform.
-
Methylglyoxal, Triose Phosphate Isomerase, and Glyoxalase Pathway: Implications in Abiotic Stress and Signaling in Plants
Elucidation of Abiotic Stress Signaling in Plants, 2015Co-Authors: Charanpreet Kaur, Sneh L. Singla-pareek, Shweta Sharma, S. K. SoporyAbstract:Methylglyoxal (MG) is a cytotoxic metabolite inevitably produced as a side product of primary metabolic pathways via both enzymatic and non-enzymatic reactions. In plants, spontaneous generation of MG through breakdown of triose sugars (dihydroxyacetone phosphate and glyceraldehyde 3-phosphate) is believed to be the major route for MG formation. MG is maintained at basal levels in plants under normal conditions that accumulate to higher concentrations under various stresses, probably as a general consequence of all abiotic stresses. The toxic effects of MG is due to its ability to induce oxidative stress in cells, either directly through increased generation of reactive oxygen species (ROS) or indirectly via advanced glycation end product (AGE) formation. Thus, elevated MG levels have implications in inhibition of growth and development in plants. To keep MG levels in check, the two-step Glyoxalase pathway comprising Glyoxalase I (GLYI) and Glyoxalase II (GLYII) enzymes has evolved as the major MG-scavenging detoxification system that converts MG to d-lactate using glutathione as a cofactor in this process. Over-expression of Glyoxalase pathway has been shown to confer tolerance to multiple stresses that works by controlling MG levels and maintaining glutathione homeostasis in plants. Moreover, increased activity of triose phosphate isomerase under different stresses that use up triose sugars via glycolysis further prevents MG levels from accumulating in the system along with increasing the energy status of plants. Considering the fact that MG levels are maintained at a threshold concentration in plants even under physiological conditions and also observed MG-dependent induction in expression of triose phosphate isomerase, a role for MG in signaling pathways is suggested. Here, we provide an insight to the role of MG and Glyoxalases in plant stress response with special mention about the possible involvement of MG in signaling pathway.
-
Glyoxalase and methylglyoxal as biomarkers for plant stress tolerance
Critical Reviews in Plant Sciences, 2014Co-Authors: Charanpreet Kaur, Sneh L Singlapareek, S. K. SoporyAbstract:Glyoxalases are known to play a very important role in abiotic stress tolerance. This two-step pathway detoxifies ubiquitously present cytotoxic metabolite methylglyoxal, which otherwise increases to lethal concentrations under various stress conditions. Methylglyoxal initiates stress-induced signaling cascade via reactive oxygen species, resulting in the modifications of proteins involved in various signal transduction pathways, that eventually culminates in cell death or growth arrest. The associated mechanism of tolerance conferred by over-expression of methylglyoxal-detoxifying Glyoxalase pathway mainly involves lowering of methylglyoxal levels, thereby reducing subsequently induced cellular toxicity. Apart from abiotic stresses, expression of Glyoxalases is affected by a wide variety of other stimuli such as biotic, chemical and hormonal treatments. Additionally, alterations in cellular milieu during plant growth and development also affect expression of Glyoxalases. The multiple stress-inducible nat...
-
Enhancing salt tolerance in a crop plant by overexpression of Glyoxalase II
Transgenic Research, 2008Co-Authors: Sneh L. Singla-pareek, Sudesh Kumar Yadav, Ashwani Pareek, M. K. Reddy, S. K. SoporyAbstract:Earlier we have shown the role of Glyoxalase overexpression in conferring salinity tolerance in transgenic tobacco. We now demonstrate the feasibility of same in a crop like rice through overproduction of Glyoxalase II. The rice Glyoxalase II was cloned in pCAMBIA1304 and transformed into rice ( Oryza sativa cv PB1) via Agrobacterium. The transgenic plants showed higher constitutive activity of Glyoxalase II that increased further upon salt stress, reflecting the upregulation of endogenous Glyoxalase II. The transgenic rice showed higher tolerance to toxic concentrations of methylglyoxal (MG) and NaCl. Compared with non-transgenics, transgenic plants at the T1 generation exhibited sustained growth and more favorable ion balance under salt stress conditions.
-
transgenic tobacco overexpressing Glyoxalase pathway enzymes grow and set viable seeds in zinc spiked soils
Plant Physiology, 2006Co-Authors: Sneh L Singlapareek, Sudesh Kumar Yadav, Ashwani Pareek, Malireddy K Reddy, S. K. SoporyAbstract:We reported earlier that engineering of the Glyoxalase pathway (a two-step reaction mediated through Glyoxalase I and II enzymes) enhances salinity tolerance. Here we report the extended suitability of this engineering strategy for improved heavy-metal tolerance in transgenic tobacco (Nicotiana tabacum). The Glyoxalase transgenics were able to grow, flower, and set normal viable seeds in the presence of 5 mm ZnCl2 without any yield penalty. The endogenous ion content measurements revealed roots to be the major sink for excess zinc accumulation, with negligible amounts in seeds in transgenic plants. Preliminary observations suggest that Glyoxalase overexpression could confer tolerance to other heavy metals, such as cadmium or lead. Comparison of relative tolerance capacities of transgenic plants, overexpressing either Glyoxalase I or II individually or together in double transgenics, evaluated in terms of various critical parameters such as survival, growth, and yield, reflected double transgenics to perform better than either of the single-gene transformants. Biochemical investigations indicated restricted methylglyoxal accumulation and less lipid peroxidation under high zinc conditions in transgenic plants. Studies employing the glutathione biosynthetic inhibitor, buthionine sulfoximine, suggested an increase in the level of phytochelatins and maintenance of glutathione homeostasis in transgenic plants during exposure to excess zinc as the possible mechanism behind this tolerance. Together, these findings presents a novel strategy to develop multiple stress tolerance via Glyoxalase pathway engineering, thus implicating its potential use in engineering agriculturally important crop plants to grow on rapidly deteriorating lands with multiple unfavorable edaphic factors.
-
methylglyoxal levels in plants under salinity stress are dependent on Glyoxalase i and glutathione
Biochemical and Biophysical Research Communications, 2005Co-Authors: Sudesh Kumar Yadav, Sneh L Singlapareek, Malireddy K Reddy, Manju Ray, S. K. SoporyAbstract:Methylglyoxal (MG), a cytotoxic by-product produced mainly from triose phosphates, is used as a substrate by Glyoxalase I. In this paper, we report on the estimation of MG level in plants which has not been reported earlier. We show that MG concentration varies in the range of 30-75 microM in various plant species and it increases 2- to 6-fold in response to salinity, drought, and cold stress conditions. Transgenic tobacco underexpressing Glyoxalase I showed enhanced accumulation of MG which resulted in the inhibition of seed germination. In the Glyoxalase I overexpressing transgenic tobacco, MG levels did not increase in response to stress compared to the untransformed plants, however, with the addition of exogenous GSH there was a decrease in MG levels in both untransformed and transgenic plants. The exogenous application of GSH reduced MG levels in WT to 50% whereas in the transgenic plants a 5-fold decrease was observed. These studies demonstrate an important role of Glyoxalase I along with GSH concentration in maintaining MG levels in plants under normal and abiotic stress conditions.
Masayuki Fujita - One of the best experts on this subject based on the ideXlab platform.
-
exogenous silicon attenuates cadmium induced oxidative stress in brassica napus l by modulating asa gsh pathway and Glyoxalase system
Frontiers in Plant Science, 2017Co-Authors: Mirza Hasanuzzaman, Taufika Islam Anee, Kamrun Nahar, Masayuki FujitaAbstract:Cadmium (Cd) brings a devastating health hazard to human being as a serious consequence of agricultural and environmental contamination. We demonstrated the protective effect of silicon (Si) on cadmium (Cd)-stressed rapeseed (Brassica napus L. cv. BINA Sharisha 3) plants through regulation of antioxidant defense and Glyoxalase systems. Twelve-d-old seedlings were exposed to Cd stress (0.5 and 1.0 mM CdCl2) separately and in combination with Si (SiO2, 1.0 mM) for two days. Cadmium toxicity was evident by an obvious oxidative stress through sharp increases in H2O2 content and lipid peroxidation (malondialdehyde, MDA content), and visible sign of superoxide and H2O2. Cadmium stress also decreased the content of ascorbate (AsA) and glutathione (GSH) as well as their redox pool. The activities of monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR) and catalase (CAT) were decreased by Cd while ascorbate peroxidase (APX) and glutathione S-transferase (GST) activities were increased. The enzymes of Glyoxalase system (Glyoxalase I, Gly I and Glyoxalase II, Gly II) were also inefficient under Cd stress. However, exogenous application of Si in Cd treated seedlings reduced H2O2 and MDA contents and improved antioxidant defense mechanism through increasing the AsA and GSH pools and activities of AsA-GSH cycle (APX, MDHAR, DHAR and GR) and Glyoxalase system (Gly I and Gly II) enzymes and CAT. Thus Si reduced oxidative damage in plants to make more tolerant under Cd stress through augmentation of different antioxidant components and methylglyoxal detoxification system.
-
Hydrogen Peroxide Pretreatment Mitigates Cadmium-Induced Oxidative Stress in Brassica napus L.: An Intrinsic Study on Antioxidant Defense and Glyoxalase Systems
Frontiers in Plant Science, 2017Co-Authors: Mirza Hasanuzzaman, Kamrun Nahar, Sarvajeet Singh Gill, Hesham F. Alharby, Bam H. N. Razafindrabe, Masayuki FujitaAbstract:Cadmium is considered as one of the most toxic metals for plant growth and development. In the present study, we investigated the role of externally applied hydrogen peroxide (H2O2) in regulating the antioxidant defense and Glyoxalase systems in conferring cadmium (Cd)-induced oxidative stress tolerance in rapeseed (Brassica napus L.). Seedlings were pretreated with 50 μM H2O2 for 24 h. These pretreated seedlings as well as non-pretreated seedlings were grown for another 48 h at two concentrations of CdCl2 (0.5 and 1.0 mM). Both the levels of Cd increased MDA and H2O2 levels and LOX (lipoxygenase) activity while ascorbate (AsA) declined significantly. However, reduced glutathione (GSH) content showed an increase at 0.5 mM CdCl2, but glutathione disulfide (GSSG) increased at any level of Cd with a decrease in GSH/GSSG ratio. The activities of ascorbate peroxidase (APX) and glutathione S-transferase (GST) upregulated due to Cd treatment in dose-dependent manners, while glutathione reductase (GR) and glutathione peroxidase (GPX) increased only at 0.5 mM CdCl2 and decreased at higher dose. The activity of monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), catalase (CAT), Glyoxalase I (Gly I) and Glyoxalase II (Gly II) decreased under Cd stress. On the other hand, H2O2 pretreated seedlings, when exposed to Cd, AsA and GSH contents and GSH/GSSG ratio increased noticeably. H2O2 pretreatment increased the activities of APX, MDHAR, DHAR, GR, GST, GPX and CAT of Cd affected seedlings. Thus enhancement of both the non-enzymatic and enzymatic antioxidants helped to decrease the oxidative damage as indicated by decreased levels of H2O2 and MDA. The seedlings which were pretreated with H2O2 also showed enhanced Glyoxalase system. The activities of Gly I, and Gly II and the content of GSH increased significantly due to H2O2 pretreatment in Cd affected seedlings, compared to the Cd-stressed plants without H2O2 pretreatment which were vital for methylglyoxal detoxification. So, the major roles of H2O2 were improvement of antioxidant defense system and glyoxalse system which protected plants from the damage effects of ROS and MG. The mechanism of H2O2 to induce antioxidant defense and glyoxalse system and improving physiology under stress condition is not known clearly which should
-
Exogenous calcium alleviates cadmium-induced oxidative stress in rice (Oryza sativa L.) seedlings by regulating the antioxidant defense and Glyoxalase systems
Brazilian Journal of Botany, 2016Co-Authors: Anisur Rahman, Mohammad Golam Mostofa, Mirza Hasanuzzaman, Kamrun Nahar, Masayuki FujitaAbstract:The present study was undertaken to investigate the regulatory role of exogenous application of calcium (Ca) in enhancing the antioxidant defense and Glyoxalase systems in mitigating cadmium (Cd) stress in rice. Hydroponically grown 14-day-old rice ( Oryza sativa L. cv. BRRI dhan29) seedlings were exposed to 0.25 and 0.5 mM CdCl_2 alone and in combination with 2.5 mM CaCl_2 for 3 days. Exposure to Cd caused chlorosis, leaf rolling symptoms, and growth inhibition. A higher concentration of Cd in the growth medium resulted in higher Cd accumulation, which induced oxidative stress through overproduction of reactive oxygen species (ROS) by disrupting the antioxidant defense system. Cadmium treatment increased the methylglyoxal (MG) level. Calcium supplementation in the Cd-treated growth medium reduced Cd uptake. Application of Ca also significantly increased the (ascorbate) AsA content, increased the activities of superoxide dismutase (SOD), catalase (CAT), glutathione S -transferase (GST), monodehydroascorbate reductase (MDHAR), and dehydroascorbate reductase (DHAR) in the antioxidant system, and increased the Glyoxalase I (Gly I) and Glyoxalase II (Gly II) activities in the Glyoxalase system in rice seedlings exposed to both levels of Cd. Exogenous Ca application regulated the antioxidant defense and Glyoxalase systems, which reversed overproduced ROS and detoxified MG, which in turn reduced Cd toxicity.
-
Calcium Mitigates Arsenic Toxicity in Rice Seedlings by Reducing Arsenic Uptake and Modulating the Antioxidant Defense and Glyoxalase Systems and Stress Markers.
BioMed Research International, 2015Co-Authors: Anisur Rahman, Mohammad Golam Mostofa, Mirza Hasanuzzaman, Kamrun Nahar, Mahabub Alam, Masayuki FujitaAbstract:The effect of exogenous calcium (Ca) on hydroponically grown rice seedlings was studied under arsenic (As) stress by investigating the antioxidant and Glyoxalase systems. Fourteen-day-old rice (Oryza sativa L. cv. BRRI dhan29) seedlings were exposed to 0.5 and 1 mM Na2HAsO4 alone and in combination with 10 mM CaCl2 (Ca) for 5 days. Both levels of As caused growth inhibition, chlorosis, reduced leaf RWC, and increased As accumulation in the rice seedlings. Both doses of As in growth medium induced oxidative stress through overproduction of reactive oxygen species (ROS) by disrupting the antioxidant defense and Glyoxalase systems. Exogenous application of Ca along with both levels of As significantly decreased As accumulation and restored plant growth and water loss. Calcium supplementation in the As-exposed rice seedlings reduced ROS production, increased ascorbate (AsA) content, and increased the activities of monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), catalase (CAT), glutathione peroxidase (GPX), superoxide dismutase (SOD), and the Glyoxalase I (Gly I) and Glyoxalase II (Gly II) enzymes compared with seedlings exposed to As only. These results suggest that Ca supplementation improves rice seedlings tolerance to As-induced oxidative stress by reducing As uptake, enhancing their antioxidant defense and Glyoxalase systems, and also improving growth and physiological condition.
-
physiological and biochemical mechanisms associated with trehalose induced copper stress tolerance in rice
Scientific Reports, 2015Co-Authors: Mohammad Golam Mostofa, Mohammad Anwar Hossain, Masayuki Fujita, Lamson Phan TranAbstract:In this study, we examined the possible mechanisms of trehalose (Tre) in improving copper-stress (Cu-stress) tolerance in rice seedlings. Our findings indicated that pretreatment of rice seedlings with Tre enhanced the endogenous Tre level and significantly mitigated the toxic effects of excessive Cu on photosynthesis- and plant growth-related parameters. The improved tolerance induced by Tre could be attributed to its ability to reduce Cu uptake and decrease Cu-induced oxidative damage by lowering the accumulation of reactive oxygen species (ROS) and malondialdehyde in Cu-stressed plants. Tre counteracted the Cu-induced increase in proline and glutathione content, but significantly improved ascorbic acid content and redox status. The activities of major antioxidant enzymes were largely stimulated by Tre pretreatment in rice plants exposed to excessive Cu. Additionally, increased activities of Glyoxalases I and II correlated with reduced levels of methylglyoxal in Tre-pretreated Cu-stressed rice plants. These results indicate that modifying the endogenous Tre content by Tre pretreatment improved Cu tolerance in rice plants by inhibiting Cu uptake and regulating the antioxidant and Glyoxalase systems, and thereby demonstrated the important role of Tre in mitigating heavy metal toxicity. Our findings provide a solid foundation for developing metal toxicity-tolerant crops by genetic engineering of Tre biosynthesis.
Mirza Hasanuzzaman - One of the best experts on this subject based on the ideXlab platform.
-
exogenous silicon attenuates cadmium induced oxidative stress in brassica napus l by modulating asa gsh pathway and Glyoxalase system
Frontiers in Plant Science, 2017Co-Authors: Mirza Hasanuzzaman, Taufika Islam Anee, Kamrun Nahar, Masayuki FujitaAbstract:Cadmium (Cd) brings a devastating health hazard to human being as a serious consequence of agricultural and environmental contamination. We demonstrated the protective effect of silicon (Si) on cadmium (Cd)-stressed rapeseed (Brassica napus L. cv. BINA Sharisha 3) plants through regulation of antioxidant defense and Glyoxalase systems. Twelve-d-old seedlings were exposed to Cd stress (0.5 and 1.0 mM CdCl2) separately and in combination with Si (SiO2, 1.0 mM) for two days. Cadmium toxicity was evident by an obvious oxidative stress through sharp increases in H2O2 content and lipid peroxidation (malondialdehyde, MDA content), and visible sign of superoxide and H2O2. Cadmium stress also decreased the content of ascorbate (AsA) and glutathione (GSH) as well as their redox pool. The activities of monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR) and catalase (CAT) were decreased by Cd while ascorbate peroxidase (APX) and glutathione S-transferase (GST) activities were increased. The enzymes of Glyoxalase system (Glyoxalase I, Gly I and Glyoxalase II, Gly II) were also inefficient under Cd stress. However, exogenous application of Si in Cd treated seedlings reduced H2O2 and MDA contents and improved antioxidant defense mechanism through increasing the AsA and GSH pools and activities of AsA-GSH cycle (APX, MDHAR, DHAR and GR) and Glyoxalase system (Gly I and Gly II) enzymes and CAT. Thus Si reduced oxidative damage in plants to make more tolerant under Cd stress through augmentation of different antioxidant components and methylglyoxal detoxification system.
-
Hydrogen Peroxide Pretreatment Mitigates Cadmium-Induced Oxidative Stress in Brassica napus L.: An Intrinsic Study on Antioxidant Defense and Glyoxalase Systems
Frontiers in Plant Science, 2017Co-Authors: Mirza Hasanuzzaman, Kamrun Nahar, Sarvajeet Singh Gill, Hesham F. Alharby, Bam H. N. Razafindrabe, Masayuki FujitaAbstract:Cadmium is considered as one of the most toxic metals for plant growth and development. In the present study, we investigated the role of externally applied hydrogen peroxide (H2O2) in regulating the antioxidant defense and Glyoxalase systems in conferring cadmium (Cd)-induced oxidative stress tolerance in rapeseed (Brassica napus L.). Seedlings were pretreated with 50 μM H2O2 for 24 h. These pretreated seedlings as well as non-pretreated seedlings were grown for another 48 h at two concentrations of CdCl2 (0.5 and 1.0 mM). Both the levels of Cd increased MDA and H2O2 levels and LOX (lipoxygenase) activity while ascorbate (AsA) declined significantly. However, reduced glutathione (GSH) content showed an increase at 0.5 mM CdCl2, but glutathione disulfide (GSSG) increased at any level of Cd with a decrease in GSH/GSSG ratio. The activities of ascorbate peroxidase (APX) and glutathione S-transferase (GST) upregulated due to Cd treatment in dose-dependent manners, while glutathione reductase (GR) and glutathione peroxidase (GPX) increased only at 0.5 mM CdCl2 and decreased at higher dose. The activity of monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), catalase (CAT), Glyoxalase I (Gly I) and Glyoxalase II (Gly II) decreased under Cd stress. On the other hand, H2O2 pretreated seedlings, when exposed to Cd, AsA and GSH contents and GSH/GSSG ratio increased noticeably. H2O2 pretreatment increased the activities of APX, MDHAR, DHAR, GR, GST, GPX and CAT of Cd affected seedlings. Thus enhancement of both the non-enzymatic and enzymatic antioxidants helped to decrease the oxidative damage as indicated by decreased levels of H2O2 and MDA. The seedlings which were pretreated with H2O2 also showed enhanced Glyoxalase system. The activities of Gly I, and Gly II and the content of GSH increased significantly due to H2O2 pretreatment in Cd affected seedlings, compared to the Cd-stressed plants without H2O2 pretreatment which were vital for methylglyoxal detoxification. So, the major roles of H2O2 were improvement of antioxidant defense system and glyoxalse system which protected plants from the damage effects of ROS and MG. The mechanism of H2O2 to induce antioxidant defense and glyoxalse system and improving physiology under stress condition is not known clearly which should
-
coordinated actions of Glyoxalase and antioxidant defense systems in conferring abiotic stress tolerance in plants
International Journal of Molecular Sciences, 2017Co-Authors: Mirza Hasanuzzaman, Kamrun Nahar, Anisur Rahman, Md Shahadat Hossain, Jubayer Al Mahmud, Masashi InafukuAbstract:Being sessile organisms, plants are frequently exposed to various environmental stresses that cause several physiological disorders and even death. Oxidative stress is one of the common consequences of abiotic stress in plants, which is caused by excess generation of reactive oxygen species (ROS). Sometimes ROS production exceeds the capacity of antioxidant defense systems, which leads to oxidative stress. In line with ROS, plants also produce a high amount of methylglyoxal (MG), which is an α-oxoaldehyde compound, highly reactive, cytotoxic, and produced via different enzymatic and non-enzymatic reactions. This MG can impair cells or cell components and can even destroy DNA or cause mutation. Under stress conditions, MG concentration in plants can be increased 2- to 6-fold compared with normal conditions depending on the plant species. However, plants have a system developed to detoxify this MG consisting of two major enzymes: Glyoxalase I (Gly I) and Glyoxalase II (Gly II), and hence known as the Glyoxalase system. Recently, a novel Glyoxalase enzyme, named Glyoxalase III (Gly III), has been detected in plants, providing a shorter pathway for MG detoxification, which is also a signpost in the research of abiotic stress tolerance. Glutathione (GSH) acts as a co-factor for this system. Therefore, this system not only detoxifies MG but also plays a role in maintaining GSH homeostasis and subsequent ROS detoxification. Upregulation of both Gly I and Gly II as well as their overexpression in plant species showed enhanced tolerance to various abiotic stresses including salinity, drought, metal toxicity, and extreme temperature. In the past few decades, a considerable amount of reports have indicated that both antioxidant defense and Glyoxalase systems have strong interactions in conferring abiotic stress tolerance in plants through the detoxification of ROS and MG. In this review, we will focus on the mechanisms of these interactions and the coordinated action of these systems towards stress tolerance.
-
Exogenous calcium alleviates cadmium-induced oxidative stress in rice (Oryza sativa L.) seedlings by regulating the antioxidant defense and Glyoxalase systems
Brazilian Journal of Botany, 2016Co-Authors: Anisur Rahman, Mohammad Golam Mostofa, Mirza Hasanuzzaman, Kamrun Nahar, Masayuki FujitaAbstract:The present study was undertaken to investigate the regulatory role of exogenous application of calcium (Ca) in enhancing the antioxidant defense and Glyoxalase systems in mitigating cadmium (Cd) stress in rice. Hydroponically grown 14-day-old rice ( Oryza sativa L. cv. BRRI dhan29) seedlings were exposed to 0.25 and 0.5 mM CdCl_2 alone and in combination with 2.5 mM CaCl_2 for 3 days. Exposure to Cd caused chlorosis, leaf rolling symptoms, and growth inhibition. A higher concentration of Cd in the growth medium resulted in higher Cd accumulation, which induced oxidative stress through overproduction of reactive oxygen species (ROS) by disrupting the antioxidant defense system. Cadmium treatment increased the methylglyoxal (MG) level. Calcium supplementation in the Cd-treated growth medium reduced Cd uptake. Application of Ca also significantly increased the (ascorbate) AsA content, increased the activities of superoxide dismutase (SOD), catalase (CAT), glutathione S -transferase (GST), monodehydroascorbate reductase (MDHAR), and dehydroascorbate reductase (DHAR) in the antioxidant system, and increased the Glyoxalase I (Gly I) and Glyoxalase II (Gly II) activities in the Glyoxalase system in rice seedlings exposed to both levels of Cd. Exogenous Ca application regulated the antioxidant defense and Glyoxalase systems, which reversed overproduced ROS and detoxified MG, which in turn reduced Cd toxicity.
-
Calcium Mitigates Arsenic Toxicity in Rice Seedlings by Reducing Arsenic Uptake and Modulating the Antioxidant Defense and Glyoxalase Systems and Stress Markers.
BioMed Research International, 2015Co-Authors: Anisur Rahman, Mohammad Golam Mostofa, Mirza Hasanuzzaman, Kamrun Nahar, Mahabub Alam, Masayuki FujitaAbstract:The effect of exogenous calcium (Ca) on hydroponically grown rice seedlings was studied under arsenic (As) stress by investigating the antioxidant and Glyoxalase systems. Fourteen-day-old rice (Oryza sativa L. cv. BRRI dhan29) seedlings were exposed to 0.5 and 1 mM Na2HAsO4 alone and in combination with 10 mM CaCl2 (Ca) for 5 days. Both levels of As caused growth inhibition, chlorosis, reduced leaf RWC, and increased As accumulation in the rice seedlings. Both doses of As in growth medium induced oxidative stress through overproduction of reactive oxygen species (ROS) by disrupting the antioxidant defense and Glyoxalase systems. Exogenous application of Ca along with both levels of As significantly decreased As accumulation and restored plant growth and water loss. Calcium supplementation in the As-exposed rice seedlings reduced ROS production, increased ascorbate (AsA) content, and increased the activities of monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), catalase (CAT), glutathione peroxidase (GPX), superoxide dismutase (SOD), and the Glyoxalase I (Gly I) and Glyoxalase II (Gly II) enzymes compared with seedlings exposed to As only. These results suggest that Ca supplementation improves rice seedlings tolerance to As-induced oxidative stress by reducing As uptake, enhancing their antioxidant defense and Glyoxalase systems, and also improving growth and physiological condition.