scholarly journals NAD(P)H Drives the Ascorbate–Glutathione Cycle and Abundance of Catalase in Developing Beech Seeds Differently in Embryonic Axes and Cotyledons

Antioxidants ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 2021
Author(s):  
Ewa Marzena Kalemba ◽  
Shirin Alipour ◽  
Natalia Wojciechowska
Keyword(s):  
Seed Quality ◽  
Redox Homeostasis ◽  
Reducing Power ◽  
European Beech ◽  
Embryonic Axes ◽  
Lowland Forests ◽  
Glutathione Cycle ◽  
Glutathione Enzymes ◽  
Redox Forms

European beech is an important component of European lowland forests in terms of ecology, and produces irregular seeds categorized as intermediate due to their limited longevity. Removal of the excess of reactive oxygen species is crucial for redox homeostasis in growing plant tissues. Hydrogen peroxide (H2O2) is detoxified via the plant-specific ascorbate-glutathione cycle, and enzymatically, mainly by catalase (CAT). The reduced and oxidized (redox) forms of ascorbate (AsA, DHA) and glutathione (GSH, GSSG) decreased during maturation as the content of redox forms of nicotinamide adenine dinucleotide (NADH, NAD+) phosphate (NADPH, NADP+), cofactors of ascorbate–glutathione enzymes, declined and limited this cycle. The degree of oxidation of glutathione peaked at approximately 80%, at the exact time when the NADP content was the lowest and the NADPH/NADP+ ratio reached the highest values. The glutathione pool was reflected in changes in the NADP pool, both in embryonic axes (R2 = 0.61) and in cotyledons (R2 = 0.98). A large excess of NADPH was reported in embryonic axes, whereas cotyledons displayed more unified levels of NADP redox forms. As a result, anabolic redox charge and reducing power were higher in embryonic axes. CAT was recognized as two proteins, and the abundance of the 55 kDa protein was correlated with all redox forms of ascorbate, glutathione, NAD, and NADP, whereas the 37 kDa protein was oppositely regulated in embryonic axes and cotyledons. Here, we discuss the role of NAD(P) in the regulation of the ascorbate–glutathione cycle, catalase, and seed longevity concerning a putative role of NAD(P)H as a redox biomarker involved in predefining seed quality, because NAD(P)H-derived redox homeostasis was found to be better controlled in embryonic axes than cotyledons.

Cloning and characterization of a thermostable glutathione reductase from a psychrophilic Arctic bacterium Sphingomonas sp.

2019 ◽  
Author(s):  
Hai VuThi ◽  
Sei-Heon Jang ◽  
ChangWoo Lee
Keyword(s):  
Thermal Stability ◽  
Glutathione Reductase ◽  
Redox Homeostasis ◽  
Residual Activity ◽  
Reducing Power ◽  
Composition Analysis ◽  
Psychrophilic Bacterium ◽  
Tertiary Structures

Abstract Glutathione reductase is an important oxidoreductase that helps maintain redox homeostasis by catalyzing the conversion of glutathione disulfide to glutathione using NADPH as a cofactor. In this study, we cloned and characterized a glutathione reductase (referred hereafter to as SpGR) from Sphingomonas sp. PAMC 26621, an Arctic bacterium. SpGR comprises 449 amino acids, and functions as a dimer. Surprisingly, SpGR exhibits characteristics of thermophilic enzymes, showing optimum activity at 60°C and thermal stability up to 70 °C with approximately 50% residual activity at 70 °C for 2 h. The amino acid composition analysis of SpGR showed a 1.9-fold higher Arg content (6%) and a 2.7-fold lower Lys/Arg ratio (0.75) compared to the Arg content (3.15%) and the Lys/Arg ratio (2.01) of known psychrophilic glutathione reductases. SpGR also exhibits its activity at 4°C, and circular dichroism and fluorescence spectroscopy results indicate that SpGR maintains its secondary and tertiary structures within the temperature range 4–70°C. Taken together, the results of this study indicate that despite its origin from a psychrophilic bacterium, SpGR has high thermal stability. Our study provides an insight into the role of glutathione reductase in maintaining the reducing power of an Arctic bacterium in a broad range of temperatures.

Involvement of Heme Oxygenase-1 in Neuropsychiatric and Neurodegenerative Diseases

2018 ◽  
Vol 24 (20) ◽  
pp. 2283-2302 ◽  
Author(s):  
Vivian B. Neis ◽  
Priscila B. Rosa ◽  
Morgana Moretti ◽  
Ana Lucia S. Rodrigues
Keyword(s):  
Neurodegenerative Diseases ◽  
Heme Oxygenase ◽  
Therapeutic Potential ◽  
Redox Homeostasis ◽  
Antioxidant Defenses ◽  
Heme Oxygenase 1 ◽  
Physiological Conditions ◽  
And Oxidative Stress ◽  
Defensive Mechanism

Heme oxygenase (HO) family catalyzes the conversion of heme into free iron, carbon monoxide and biliverdin. It possesses two well-characterized isoforms: HO-1 and HO-2. Under brain physiological conditions, the expression of HO-2 is constitutive, abundant and ubiquitous, whereas HO-1 mRNA and protein are restricted to small populations of neurons and neuroglia. HO-1 is an inducible enzyme that has been shown to participate as an essential defensive mechanism for neurons exposed to oxidant challenges, being related to antioxidant defenses in certain neuropathological conditions. Considering that neurodegenerative diseases (Alzheimer’s Disease (AD), Parkinson’s Disease (PD) and Multiple Sclerosis (MS)) and neuropsychiatric disorders (depression, anxiety, Bipolar Disorder (BD) and schizophrenia) are associated with increased inflammatory markers, impaired redox homeostasis and oxidative stress, conditions that may be associated with alterations in HO-levels/activity, the purpose of this review is to present evidence on the possible role of HO-1 in these Central Nervous System (CNS) diseases. In addition, the possible therapeutic potential of targeting brain HO-1 is explored in this review.

scholarly journals Using Regulatory Flexibility to Address Market Informality in Seed Systems: A Global Study

Agronomy ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 377
Author(s):  
Katrin Kuhlmann ◽  
Bhramar Dey
Keyword(s):  
Seed Quality ◽  
Regulatory Environment ◽  
Control Mechanisms ◽  
Seed Systems ◽  
High Quality ◽  
Design And Implementation ◽  
Key Dimensions ◽  
Regulatory Flexibility

Seed rules and regulations determine who can produce and sell seeds, which varieties will be available in the market, the quality of seed for sale, and where seed can be bought and sold. The legal and regulatory environment for seed impacts all stakeholders, including those in the informal sector, through shaping who can participate in the market and the quality and diversity of seed available. This paper addresses a gap in the current literature regarding the role of law and regulation in linking the informal and formal seed sectors and creating more inclusive and better governed seed systems. Drawing upon insights from the literature, global case studies, key expert consultations, and a methodology on the design and implementation of law and regulation, we present a framework that evaluates how regulatory flexibility can be built into seed systems to address farmers’ needs and engage stakeholders of all sizes. Our study focuses on two key dimensions: extending market frontiers and liberalizing seed quality control mechanisms. We find that flexible regulatory approaches and practices play a central role in building bridges between formal and informal seed systems, guaranteeing quality seed in the market, and encouraging market entry for high-quality traditional and farmer-preferred varieties.

scholarly journals Antioxidants for the Treatment of Breast Cancer: Are We There Yet?

Antioxidants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 205
Author(s):  
Carmen Griñan-Lison ◽  
Jose L. Blaya-Cánovas ◽  
Araceli López-Tejada ◽  
Marta Ávalos-Moreno ◽  
Alba Navarro-Ocón ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Oxidative Stress ◽  
Cancer Progression ◽  
Redox Homeostasis ◽  
Breast Carcinogenesis ◽  
Breast Cancer Patients ◽  
Chemopreventive Agents ◽  
Low Degree ◽  
Potential Use

Breast cancer is the most frequent cancer and the leading cause of cancer death in women. Oxidative stress and the generation of reactive oxygen species (ROS) have been related to cancer progression. Compared to their normal counterparts, tumor cells show higher ROS levels and tight regulation of REDOX homeostasis to maintain a low degree of oxidative stress. Traditionally antioxidants have been extensively investigated to counteract breast carcinogenesis and tumor progression as chemopreventive agents; however, there is growing evidence indicating their potential as adjuvants for the treatment of breast cancer. Aimed to elucidate whether antioxidants could be a reality in the management of breast cancer patients, this review focuses on the latest investigations regarding the ambivalent role of antioxidants in the development of breast cancer, with special attention to the results derived from clinical trials, as well as their potential use as plausible agents in combination therapy and their power to ameliorate the side effects attributed to standard therapeutics. Data retrieved herein suggest that antioxidants play an important role in breast cancer prevention and the improvement of therapeutic efficacy; nevertheless, appropriate patient stratification based on “redoxidomics” or tumor subtype is mandatory in order to define the dosage for future standardized and personalized treatments of patients.

Ozone risk assessment for plants: Central role of metabolism-dependent changes in reducing power

2008 ◽  
Vol 156 (1) ◽  
pp. 11-15 ◽  
Author(s):  
Pierre Dizengremel ◽  
Didier Le Thiec ◽  
Matthieu Bagard ◽  
Yves Jolivet
Keyword(s):  
Risk Assessment ◽  
Reducing Power ◽  
Ozone Risk Assessment

scholarly journals Glutathione “Redox Homeostasis” and Its Relation to Cardiovascular Disease

2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Vladan P. Bajic ◽  
Christophe Van Neste ◽  
Milan Obradovic ◽  
Sonja Zafirovic ◽  
Djordje Radak ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cardiac Dysfunction ◽  
Redox Homeostasis ◽  
Cardiovascular Complications ◽  
Homeostatic Mechanism ◽  
Redox Mechanism ◽  
Signaling Mechanisms ◽  
Research Findings ◽  
Glutathione Redox

More people die from cardiovascular diseases (CVD) than from any other cause. Cardiovascular complications are thought to arise from enhanced levels of free radicals causing impaired “redox homeostasis,” which represents the interplay between oxidative stress (OS) and reductive stress (RS). In this review, we compile several experimental research findings that show sustained shifts towards OS will alter the homeostatic redox mechanism to cause cardiovascular complications, as well as findings that show a prolonged antioxidant state or RS can similarly lead to such cardiovascular complications. This experimental evidence is specifically focused on the role of glutathione, the most abundant antioxidant in the heart, in a redox homeostatic mechanism that has been shifted towards OS or RS. This may lead to impairment of cellular signaling mechanisms and elevated pools of proteotoxicity associated with cardiac dysfunction.

scholarly journals Possible Role of Myoglobin in Regulating Calpain-1 Activity in Postmortem Beef Muscle

2019 ◽  
Vol 3 (2) ◽  
Author(s):  
J. V. Cooper ◽  
S. Suman ◽  
Z. D. Callahan ◽  
K. C. Kerns ◽  
M. Zigo ◽  
...  
Keyword(s):  
Shear Force ◽  
Beef Tenderness ◽  
Beef Carcasses ◽  
Muscle Ph ◽  
Reducing Activity ◽  
The Right ◽  
Beef Color ◽  
Moderate Relationship ◽  
Redox Forms

ObjectivesPrevious research revealed a relationship between meat color and beef tenderness and indicated that myoglobin can inhibit calpain-1 in solution. The objective of this study was to determine the extent to which myoglobin and beef color are associated with calpain activity and beef tenderness.Materials and MethodsBeef Longissimus dorsi samples from the left side of Holstein beef carcasses (n = 21) were collected immediately post exsanguination on the processing floor for 0 h analyses. Muscle temperature and pH was measured at 0, 24, and 48 h postmortem. After USDA quality and yield grade determination, steaks (n = 6) were removed from the right side of each carcass (n = 21) at 48 h for analyses at 48 and 336 h postmortem. Color (L*, a*, and b* values), surface myoglobin redox forms, metmyoglobin reducing activity (MRA), total myoglobin concentrations, slice shear force (SSF), Warner-Bratzler shear force (WBSF) were measured. Calpain-1 concentrations and autolysis were determined via Western blot at 0, 48, and 336 h.ResultsDecline in muscle pH was 6.4, 5.8, and 5.6 at 0, 24, and 48 h, respectively. Shear force values at 48 h were 73.19 N for WBSF and 384.21 N for SSF and at 336 h were 48.75 N for WBSF and 260.47 N for SSF. Myoglobin reducing activity at 336 h was positively correlated to WBSF at 48 h and negatively correlated to calpain-1 concentration at 0 h (P < 0.05; Table 9). Color measurements of L* and b* at 48 h were moderately correlated with WBSF at 336 h (P < 0.05; Table 9). The b* measurement at 336 h showed a moderate relationship to calpain-1 concentration at 0 h (P < 0.05; Table 9).ConclusionModerate correlations between color and tenderness measurements taken at 48 h with those taken at 336 h were discovered indicating that myoglobin may impact calpain-1 in vivo.Table 9Correlations (P-values) between selected color and tenderness measurements (n = 21)

scholarly journals Glutathione S - transferases class Pi and Mi and their significance in oncology

2017 ◽  
Vol 71 (1) ◽  
pp. 0-0 ◽  
Author(s):  
Zofia Marchewka ◽  
Agnieszka Piwowar ◽  
Sylwia Ruzik ◽  
Anna Długosz
Keyword(s):  
Redox Homeostasis ◽  
Current Data ◽  
Altered Expression ◽  
Potential Marker ◽  
Inflammatory Processes ◽  
Glutathione S Transferases ◽  
Endogenous Substrates ◽  
Cancer Tissues ◽  
Serum And Urine

In this article the current data, which shows that glutathione S-transferases (GST) class Pi and Mi are interesting and promising biomarkers in acute and chronic inflammatory processes as well as in the oncology, were presented based on the review of the latest experimental and clinical studies. The article shows their characteristics, functions and participation (direct - GST Pi, indirect - GST Mi) in the regulation of signaling pathways of JNK kinases, which are involved in cell differentiation. Overexpression of glutathione S-transferases class Pi and Mi in many cancer cells plays a key role in cancer treatment, making them resistant to chemotherapy. GST isoenzymes are involved in the metabolism of various types of xenobiotics and endogenous substrates, so their altered expression in cancer tissues as well as in serum and urine could be an important potential marker of the cancer and an indicator of oxidative stress. The study shows the role of glutathione S-transferases in redox homeostasis of tumor cells and in the mechanism of resistance to anticancer drugs.

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