1.
Genome-Wide Analysis of ROS Antioxidant Genes in Resurrection Species Suggest an Involvement of Distinct ROS Detoxification Systems during Desiccation.
Gupta, S, Dong, Y, Dijkwel, PP, Mueller-Roeber, B, Gechev, TS
International journal of molecular sciences. 2019;(12)
Abstract
Abiotic stress is one of the major threats to plant crop yield and productivity. When plants are exposed to stress, production of reactive oxygen species (ROS) increases, which could lead to extensive cellular damage and hence crop loss. During evolution, plants have acquired antioxidant defense systems which can not only detoxify ROS but also adjust ROS levels required for proper cell signaling. Ascorbate peroxidase (APX), glutathione peroxidase (GPX), catalase (CAT) and superoxide dismutase (SOD) are crucial enzymes involved in ROS detoxification. In this study, 40 putative APX, 28 GPX, 16 CAT, and 41 SOD genes were identified from genomes of the resurrection species Boea hygrometrica, Selaginella lepidophylla, Xerophyta viscosa, and Oropetium thomaeum, and the mesophile Selaginella moellendorffii. Phylogenetic analyses classified the APX, GPX, and SOD proteins into five clades each, and CAT proteins into three clades. Using co-expression network analysis, various regulatory modules were discovered, mainly involving glutathione, that likely work together to maintain ROS homeostasis upon desiccation stress in resurrection species. These regulatory modules also support the existence of species-specific ROS detoxification systems. The results suggest molecular pathways that regulate ROS in resurrection species and the role of APX, GPX, CAT and SOD genes in resurrection species during stress.
2.
Effect of topical application of methylsulfonylmethane (MSM), EDTA on pitting edema and oxidative stress in a double blind, placebo-controlled study.
Tripathi, R, Gupta, S, Rai, S, Mittal, PC
Cellular and molecular biology (Noisy-le-Grand, France). 2011;(1):62-9
Abstract
No pharmacological treatment exists for lower extremity pitting edema, characterized by inflammation, found in chronic venous insufficiency. Treatment with EDTA, an effective metal chelator, was explored because it can modulate free calcium and iron and prevent further free radical production. However, EDTA may not effectively penetrate the cell membrane, hence methylsulfonylmethane(MSM), reported to facilitate transmembrane transport, was added. The effect of topical application of a lotion containing MSM+EDTA was assessed in two phases of a double blind, placebo controlled clinical trial. In phase 1, patients having swelling in the lower extremities were randomly distributed to receive the MSM+EDTA lotion or a placebo (vehicle) alone. In the second phase, patients were given MSM as placebo followed by MSM+EDTA lotion for 2 weeks. The circumference of calf, ankle and foot for both legs were found to decline significantly after 2 weeks of application of the lotion/ but not placebo, and total antioxidant capacity (FRAP) and lipid peroxidation products (MDA), assayed in blood, showed decline in oxidative stress. Application of MSM alone increased the swelling. Thus EDTA+MSM offers an efficacious treatment for lower extremity pitting edema, through reduction in oxidative stress.
3.
Vitamin E supplementation may ameliorate oxidative stress in type 1 diabetes mellitus patients.
Gupta, S, Sharma, TK, Kaushik, GG, Shekhawat, VP
Clinical laboratory. 2011;(5-6):379-86
Abstract
BACKGROUND Increasing evidence in both experimental and clinical studies suggests that free radical mediated oxidative stress plays a major role in the pathogenesis of both types of diabetes mellitus. Proteins and lipids are among the prime targets for oxidative stress. In this study we evaluated oxidative stress in Type 1 Diabetes Mellitus (insulin dependent diabetes mellitus, IDDM) patients by estimating lipid peroxidation and the effect of vitamin E on oxidative stress and metabolic parameters. METHODS A total of 40 children (20 Type 1 Diabetes Mellitus patients + 20 healthy controls) were examined in the study. Oxidative stress parameters malondialdehyde (MDA), antioxidants, reduced glutathione (GSH), vitamin E and metabolic parameters were studied. All the type 1 Diabetes Mellitus patients were supplemented with 600 mg/daily vitamin E for three months. After three months of supplementation all the parameters mentioned above were studied again. RESULTS Reduced glutathione and vitamin E levels were lower and malondialdehyde levels were higher in Type 1 Diabetes Mellitus patients compared to healthy controls (p < 0.05). After supplementation with vitamin E in diabetic patients a significant decrease (p < 0.05) in MDA levels and significant increase in GSH (p < 0.05) and vitamin E (p < 0.05) levels were found. A negative correlation between MDA and vitamin E, between MDA and GSH and a positive correlation between vitamin E and GSH was found. Significant changes were not observed in metabolic parameters in Type 1 Diabetes Mellitus patients after vitamin E supplementation (p > 0.05). CONCLUSIONS Vitamin E ameliorates oxidative stress in Type 1 Diabetes Mellitus patients and improves antioxidant defense system. However, vitamin E does not have any advantage for metabolic parameters.
4.
Stress responses in mycobacteria.
Gupta, S, Chatterji, D
IUBMB life. 2005;(3):149-59
Abstract
Mycobacterium tuberculosis is a successful pathogen that overcomes numerous challenges presented by the immune system of the host. This bacterium usually establishes a chronic infection in the host where it may silently persist inside a granuloma until, a failure in host defenses, leads to manifestation of the disease. None of the conventional anti-tuberculosis drugs are able to target these persisting bacilli. Development of drugs against such persisting bacilli is a constant challenge since the physiology of these dormant bacteria is still not understood at the molecular level. Some evidence suggests that the in vivo environment encountered by the persisting bacteria is anoxic and nutritionally starved. Based on these assumptions, anaerobic and starved cultures are used as models to study the molecular basis of dormancy. This review outlines the problem of persistence of M. tuberculosis and the various in vitro models used to study mycobacterial latency. The basis of selecting the nutritional starvation model has been outlined here. Also, the choice of M. smegmatis as a model suitable for studying mycobacterial latency is discussed. Lastly, general issues related to oxidative stress and bacterial responses to it have been elaborated. We have also discussed general control of OxyR-mediated regulation and emphasized the processes which manifest in the absence of functional OxyR in the bacteria. Lastly, a new class of protein called Dps has been reviewed for its important role in protecting DNA under stress.