scholarly journals Methyl viologen can affect mitochondrial function in Arabidopsis

2018 ◽  
Author(s):  
Fuqiang Cui ◽  
Mikael Brosché ◽  
Alexey Shapiguzov ◽  
Xin-Qiang He ◽  
Julia P. Vainonen ◽  
...  
Keyword(s):  
Stress Responses ◽  
Methyl Viologen ◽  
Stress Hormones ◽  
Ros Generation ◽  
Photosynthetic Organisms ◽  
Cell Compartments ◽  
Ros Signalling ◽  
Ros Tolerance ◽  
Exogenous Sugar

AbstractReactive oxygen species (ROS) are key signalling intermediates in plant metabolism, defence, and stress adaptation. The chloroplast and mitochondria are centres of metabolic control and ROS production, which coordinate stress responses in other cell compartments. The herbicide and experimental tool, methyl viologen (MV) induces ROS generation in the chloroplast under illumination, but is also toxic in non-photosynthetic organisms. We used MV to probe plant ROS signalling in compartments other than the chloroplast. Taking a genetic approach in Arabidopsis thaliana, we used natural variation, QTL mapping, and mutant studies with MV in the light, but also under dark conditions, when the chloroplast electron transport is inactive. These studies revealed a light-independent MV-induced ROS-signalling pathway, suggesting mitochondrial involvement. Mitochondrial Mn SUPEROXIDE DISMUTASE was required for ROS-tolerance and the effect of MV was enhanced by exogenous sugar, providing further evidence for the role of mitochondria. Mutant and hormone feeding assays revealed roles for stress hormones in organellar ROS-responses. The radical-induced cell death1 mutant, which is tolerant to MV-induced ROS and exhibits altered mitochondrial signalling, was used to probe interactions between organelles. Our studies implicate mitochondria in the response to ROS induced by MV.

scholarly journals Signalling crosstalk in light stress and immune reactions in plants

2014 ◽  
Vol 369 (1640) ◽  
pp. 20130235 ◽  
Author(s):  
Andrea Trotta ◽  
Moona Rahikainen ◽  
Grzegorz Konert ◽  
Giovanni Finazzi ◽  
Saijaliisa Kangasjärvi
Keyword(s):  
Stress Responses ◽  
Stress Hormones ◽  
Light Stress ◽  
Microbial Pathogens ◽  
Immune Reactions ◽  
Plasma Membrane Receptor ◽  
History Of ◽  
Key Steps ◽  
Plant Pathogen Interactions

The evolutionary history of plants is tightly connected with the evolution of microbial pathogens and herbivores, which use photosynthetic end products as a source of life. In these interactions, plants, as the stationary party, have evolved sophisticated mechanisms to sense, signal and respond to the presence of external stress agents. Chloroplasts are metabolically versatile organelles that carry out fundamental functions in determining appropriate immune reactions in plants. Besides photosynthesis, chloroplasts host key steps in the biosynthesis of amino acids, stress hormones and secondary metabolites, which have a great impact on resistance against pathogens and insect herbivores. Changes in chloroplast redox signalling pathways and reactive oxygen species metabolism also mediate local and systemic signals, which modulate plant resistance to light stress and disease. Moreover, interplay among chloroplastic signalling networks and plasma membrane receptor kinases is emerging as a key mechanism that modulates stress responses in plants. This review highlights the central role of chloroplasts in the signalling crosstalk that essentially determines the outcome of plant–pathogen interactions in plants.

scholarly journals Analysis of the Streptococcus mutans proteome during acid and oxidative stress reveals modules of co-expression and an expanded role for the TreR transcriptional regulator

2021 ◽  
Author(s):  
Elizabeth L Tinder ◽  
Roberta C. Faustoferri ◽  
Andrew A Buckley ◽  
Robert G Quivey ◽  
Jonathon L Baker
Keyword(s):  
Oxidative Stress ◽  
Streptococcus Mutans ◽  
Stress Responses ◽  
Acid Stress ◽  
Oral Microbiota ◽  
Oxidative Stresses ◽  
Ros Tolerance ◽  
And Oxidative Stress ◽  
Better Than

Streptococcus mutans promotes a tooth-damaging dysbiosis in the oral microbiota because it can form biofilms and survive acid stress better than most of its health-associated, ecological competitors. Many of these commensals produce hydrogen peroxide, therefore S. mutans must manage both oxidative stress and acid stress with coordinated and complex physiological responses. In this study, the proteome of S. mutans was examined during regulated growth in acid and oxidative stresses, as well as in deletion mutants with impaired oxidative stress phenotypes, Δnox and ΔtreR. 607 proteins exhibited significantly different abundance levels across the conditions tested, and correlation network analysis identified several modules of co-expressed proteins that were responsive to the deletion of nox and/or treR, as well as acid and oxidative stress. The data provided evidence explaining the ROS-sensitive and mutacin-deficient phenotypes exhibited by the ΔtreR strain. SMU.1069-1070, a poorly understood LytTR system, had elevated abundance in the ΔtreR strain. S. mutans LytTR systems regulate mutacin production and competence, which may explain how TreR affects mutacin production. Furthermore, the gene cluster that produces mutanobactin, important in ROS tolerance, displayed reduced abundance in the ΔtreR strain. The role of Nox as a keystone in the oxidative stress response was also emphasized. This dataset illustrates, at high resolution, how the paradigm cariogenic species activates the stress responses which enable it to cause disease, and it provides oral microbiota researchers with a resource to both reexamine previous hypotheses regarding proteins of interest and explore newly identified co-expression modules and pathways.

scholarly journals Putative role of the malate valve enzyme NADP–malate dehydrogenase in H 2 O 2 signalling in Arabidopsis

2014 ◽  
Vol 369 (1640) ◽  
pp. 20130228 ◽  
Author(s):  
Eiri Heyno ◽  
Gilles Innocenti ◽  
Stéphane D. Lemaire ◽  
Emmanuelle Issakidis-Bourguet ◽  
Anja Krieger-Liszkay
Keyword(s):  
Malate Dehydrogenase ◽  
Catalase Activity ◽  
Redox State ◽  
Electron Flow ◽  
Light Stress ◽  
Reversible Inactivation ◽  
Photosynthetic Organisms ◽  
Cell Compartments ◽  
Malate Valve

In photosynthetic organisms, sudden changes in light intensity perturb the photosynthetic electron flow and lead to an increased production of reactive oxygen species. At the same time, thioredoxins can sense the redox state of the chloroplast. According to our hypothesis, thioredoxins and related thiol reactive molecules downregulate the activity of H 2 O 2 -detoxifying enzymes, and thereby allow a transient oxidative burst that triggers the expression of H 2 O 2 responsive genes. It has been shown recently that upon light stress, catalase activity was reversibly inhibited in Chlamydomonas reinhardtii in correlation with a transient increase in the level of H 2 O 2 . Here, it is shown that Arabidopsis thaliana mutants lacking the NADP–malate dehydrogenase have lost the reversible inactivation of catalase activity and the increase in H 2 O 2 levels when exposed to high light. The mutants were slightly affected in growth and accumulated higher levels of NADPH in the chloroplast than the wild-type. We propose that the malate valve plays an essential role in the regulation of catalase activity and the accumulation of a H 2 O 2 signal by transmitting the redox state of the chloroplast to other cell compartments.

scholarly journals Attachment to Caregivers and Type 1 Diabetes in Children / Navezanost Na Starše in Sladkorna Bolezen Tipa 1 Pri Otrocih

2015 ◽  
Vol 54 (2) ◽  
pp. 126-130
Author(s):  
Maja Drobnič Radobuljac ◽  
Yael Shmueli-Goetz
Keyword(s):  
Type 1 Diabetes ◽  
Stress Responses ◽  
Stress Reactivity ◽  
Prolonged Exposure ◽  
Attachment Security ◽  
Pancreatic Beta Cell ◽  
Stress Hormones ◽  
Individual Response

Abstract Attachment is a behavioral and physiological system, which enables individual’s dynamic adaptation to its environment. Attachment develops in close interaction between an infant and his/her mother, plays an important role in the development of the infant’s brain, and influences the quality of interpersonal relationships throughout life. Security of attachment is believed to influence individual response to stress, exposing insecurely organized individuals to deregulated autonomic nervous system and exaggerated hypothalamic-pituitary-adrenal activity, which, in turn, produces increased and prolonged exposure to stress-hormones. Such stress responses may have considerable implications for the development of diverse health-risk conditions, such as insulin resistance and hyperlipidemia, shown by numerous studies. Although the mechanisms are not yet fully understood, there is compelling evidence highlighting the role of psychological stress in the development of type 1 diabetes (T1D). One of the possible contributing factors for the development of T1D may be the influence of attachment security on individual stress reactivity. Thus, the suggestion is that insecurely attached individuals are more prone to experience increased and prolonged influence of stress hormones and other mechanisms causing pancreatic beta-cell destruction. The present paper opens with a short overview of the field of attachment in children, the principal attachment classifications and their historic development, describes the influence of attachment security on individual stress-reactivity and the role of the latter in the development of T1D. Following is a review of recent literature on the attachment in patients with T1D with a conclusion of a proposed role of attachment organization in the etiology of T1D.

Ionic homeostasis and subcellular element compartmentation

1990 ◽  
Vol 48 (2) ◽  
pp. 150-151
Author(s):  
Ann LeFurgey ◽  
Peter Ingram ◽  
J.J. Blum ◽  
M.C. Carney ◽  
L.A. Hawkey ◽  
...  
Keyword(s):  
Leishmania Major ◽  
Ionic Homeostasis ◽  
X Ray ◽  
Functional Studies ◽  
Cell Compartments ◽  
X Ray Imaging ◽  
Resolution Electron ◽  
Multiple Cell ◽  
Role Of Zn

Subcellular compartments commonly identified and analyzed by high resolution electron probe x-ray microanalysis (EPXMA) include mitochondria, cytoplasm and endoplasmic or sarcoplasmic reticulum. These organelles and cell regions are of primary importance in regulation of cell ionic homeostasis. Correlative structural-functional studies, based on the static probe method of EPXMA combined with biochemical and electrophysiological techniques, have focused on the role of these organelles, for example, in maintaining cell calcium homeostasis or in control of excitation-contraction coupling. New methods of real time quantitative x-ray imaging permit simultaneous examination of multiple cell compartments, especially those areas for which both membrane transport properties and element content are less well defined, e.g. nuclei including euchromatin and heterochromatin, lysosomes, mucous granules, storage vacuoles, microvilli. Investigations currently in progress have examined the role of Zn-containing polyphosphate vacuoles in the metabolism of Leishmania major, the distribution of Na, K, S and other elements during anoxia in kidney cell nuclel and lysosomes; the content and distribution of S and Ca in mucous granules of cystic fibrosis (CF) nasal epithelia; the uptake of cationic probes by mltochondria in cultured heart ceils; and the junctional sarcoplasmic retlculum (JSR) in frog skeletal muscle.

scholarly journals Flavonoids: Potential Candidates for the Treatment of Neurodegenerative Disorders

Biomedicines ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 99
Author(s):  
Shweta Devi ◽  
Vijay Kumar ◽  
Sandeep Kumar Singh ◽  
Ashish Kant Dubey ◽  
Jong-Joo Kim
Keyword(s):  
Stress Response ◽  
Stress Responses ◽  
Neurodegenerative Disorders ◽  
Cell Damage ◽  
Cellular Stress ◽  
Clinical Manifestations ◽  
Cellular Stress Response ◽  
Dramatic Rise ◽  
Cellular Stress Responses

Neurodegenerative disorders, such as Parkinson’s disease (PD), Alzheimer’s disease (AD), Amyotrophic lateral sclerosis (ALS), and Huntington’s disease (HD), are the most concerning disorders due to the lack of effective therapy and dramatic rise in affected cases. Although these disorders have diverse clinical manifestations, they all share a common cellular stress response. These cellular stress responses including neuroinflammation, oxidative stress, proteotoxicity, and endoplasmic reticulum (ER)-stress, which combats with stress conditions. Environmental stress/toxicity weakened the cellular stress response which results in cell damage. Small molecules, such as flavonoids, could reduce cellular stress and have gained much attention in recent years. Evidence has shown the potential use of flavonoids in several ways, such as antioxidants, anti-inflammatory, and anti-apoptotic, yet their mechanism is still elusive. This review provides an insight into the potential role of flavonoids against cellular stress response that prevent the pathogenesis of neurodegenerative disorders.

scholarly journals Mitochondrial Sirtuins in Reproduction

Antioxidants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1047
Author(s):  
Giovanna Di Emidio ◽  
Stefano Falone ◽  
Paolo Giovanni Artini ◽  
Fernanda Amicarelli ◽  
Anna Maria D’Alessandro ◽  
...  
Keyword(s):  
Stress Responses ◽  
Metabolic Pathways ◽  
Redox Balance ◽  
Antioxidant Defenses ◽  
Metabolic Abnormalities ◽  
Female Reproduction ◽  
Mitochondrial Dysfunctions ◽  
Early Embryos ◽  
The Relationship

Mitochondria act as hubs of numerous metabolic pathways. Mitochondrial dysfunctions contribute to altering the redox balance and predispose to aging and metabolic alterations. The sirtuin family is composed of seven members and three of them, SIRT3-5, are housed in mitochondria. They catalyze NAD+-dependent deacylation and the ADP-ribosylation of mitochondrial proteins, thereby modulating gene expression and activities of enzymes involved in oxidative metabolism and stress responses. In this context, mitochondrial sirtuins (mtSIRTs) act in synergistic or antagonistic manners to protect from aging and aging-related metabolic abnormalities. In this review, we focus on the role of mtSIRTs in the biological competence of reproductive cells, organs, and embryos. Most studies are focused on SIRT3 in female reproduction, providing evidence that SIRT3 improves the competence of oocytes in humans and animal models. Moreover, SIRT3 protects oocytes, early embryos, and ovaries against stress conditions. The relationship between derangement of SIRT3 signaling and the imbalance of ROS and antioxidant defenses in testes has also been demonstrated. Very little is known about SIRT4 and SIRT5 functions in the reproductive system. The final goal of this work is to understand whether sirtuin-based signaling may be taken into account as potential targets for therapeutic applications in female and male infertility.

scholarly journals Loss of mGluR5 in D1 Receptor-Expressing Neurons Improves Stress Coping

2021 ◽  
Vol 22 (15) ◽  
pp. 7826
Author(s):  
Luca Zangrandi ◽  
Claudia Schmuckermair ◽  
Hussein Ghareh ◽  
Federico Castaldi ◽  
Regine Heilbronn ◽  
...  
Keyword(s):  
Stress Responses ◽  
Metabotropic Glutamate Receptor ◽  
Forced Swim Test ◽  
Functional Integration ◽  
D1 Receptor ◽  
Conditional Knockout ◽  
Stress Coping ◽  
Metabotropic Glutamate ◽  
Internal States

The metabotropic glutamate receptor type 5 (mGluR5) has been proposed to play a crucial role in the selection and regulation of cognitive, affective, and emotional behaviors. However, the mechanisms by which these receptors mediate these effects remain largely unexplored. Here, we studied the role of mGluR5 located in D1 receptor-expressing (D1) neurons in the manifestation of different behavioral expressions. Mice with conditional knockout (cKO) of mGluR5 in D1 neurons (mGluR5D1 cKO) and littermate controls displayed similar phenotypical profiles in relation to memory expression, anxiety, and social behaviors. However, mGluR5D1 cKO mice presented different coping mechanisms in response to acute escapable or inescapable stress. mGluR5D1 cKO mice adopted an enhanced active stress coping strategy upon exposure to escapable stress in the two-way active avoidance (TWA) task and a greater passive strategy upon exposure to inescapable stress in the forced swim test (FST). In summary, this work provides evidence for a functional integration of the dopaminergic and glutamatergic system to mediate control over internal states upon stress exposure and directly implicates D1 neurons and mGluR5 as crucial mediators of behavioral stress responses.

Ozone-induced acute phase response in lung versus liver: the role of adrenal-derived stress hormones

2020 ◽  
pp. 1-14
Author(s):  
Devin I. Alewel ◽  
Andres R. Henriquez ◽  
Catherine H. Colonna ◽  
Samantha J. Snow ◽  
Mette C. Schladweiler ◽  
...  
Keyword(s):  
Acute Phase ◽  
Acute Phase Response ◽  
Stress Hormones ◽  
Phase Response

scholarly journals Stoichiometric Analysis of Shifting in Subcellular Compartmentalization of HSP70 within Ischemic Penumbra

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3578
Author(s):  
Federica Mastroiacovo ◽  
Francesca Biagioni ◽  
Paola Lenzi ◽  
Larisa Ryskalin ◽  
Stefano Puglisi-Allegra ◽  
...  
Keyword(s):  
Direct Evidence ◽  
Neuronal Survival ◽  
Hsp 70 ◽  
Preclinical Models ◽  
Brain Areas ◽  
Cell Compartments ◽  
Control Brain ◽  
Disease Modifier ◽  
Subcellular Compartmentalization

The heat shock protein (HSP) 70 is considered the main hallmark in preclinical studies to stain the peri-infarct region defined area penumbra in preclinical models of brain ischemia. This protein is also considered as a potential disease modifier, which may improve the outcome of ischemic damage. In fact, the molecule HSP70 acts as a chaperonine being able to impact at several level the homeostasis of neurons. Despite being used routinely to stain area penumbra in light microscopy, the subcellular placement of this protein within area penumbra neurons, to our knowledge, remains undefined. This is key mostly when considering studies aimed at deciphering the functional role of this protein as a determinant of neuronal survival. The general subcellular placement of HSP70 was grossly reported in studies using confocal microscopy, although no direct visualization of this molecule at electron microscopy was carried out. The present study aims to provide a direct evidence of HSP70 within various subcellular compartments. In detail, by using ultrastructural morphometry to quantify HSP70 stoichiometrically detected by immuno-gold within specific organelles we could compare the compartmentalization of the molecule within area penumbra compared with control brain areas. The study indicates that two cell compartments in control conditions own a high density of HSP70, cytosolic vacuoles and mitochondria. In these organelles, HSP70 is present in amount exceeding several-fold the presence in the cytosol. Remarkably, within area penumbra a loss of such a specific polarization is documented. This leads to the depletion of HSP70 from mitochondria and mostly cell vacuoles. Such an effect is expected to lead to significant variations in the ability of HSP70 to exert its physiological roles. The present findings, beyond defining the neuronal compartmentalization of HSP70 within area penumbra may lead to a better comprehension of its beneficial/detrimental role in promoting neuronal survival.

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