scholarly journals A Spatiotemporal Characterisation of Redox Molecules in Planarians, with a Focus on the Role of Glutathione during Regeneration

Biomolecules ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 714
Author(s):  
Karolien Bijnens ◽  
Vincent Jaenen ◽  
Annelies Wouters ◽  
Nathalie Leynen ◽  
Nicky Pirotte ◽  
...  
Keyword(s):  
Normal Animal ◽  
Redox System ◽  
Redox Balance ◽  
Central Component ◽  
Antioxidant Genes ◽  
Animal Physiology ◽  
Exact Function ◽  
Cell Alterations ◽  
Redox Molecules

A strict coordination between pro- and antioxidative molecules is needed for normal animal physiology, although their exact function and dynamics during regeneration and development remains largely unknown. Via in vivo imaging, we were able to locate and discriminate between reactive oxygen species (ROS) in real-time during different physiological stages of the highly regenerative planarian Schmidtea mediterranea. All ROS signals were strong enough to overcome the detected autofluorescence. Combined with an in situ characterisation and quantification of the transcription of several antioxidant genes, our data showed that the planarian gut and epidermis have a well-equipped redox system. Pharmacological inhibition or RNA interference of either side of the redox balance resulted in alterations in the regeneration process, characterised by decreased blastema sizes and delayed neurodevelopment, thereby affecting tails more than heads. Focusing on glutathione, a central component in the redox balance, we found that it is highly present in planarians and that a significant reduction in glutathione content led to regenerative failure with tissue lesions, characterised by underlying stem cell alterations. This exploratory study indicates that ROS and antioxidants are tightly intertwined and should be studied as a whole to fully comprehend the function of the redox balance in animal physiology.

scholarly journals Nrf1 Is Critical for Redox Balance and Survival of Liver Cells during Development

2003 ◽  
Vol 23 (13) ◽  
pp. 4673-4686 ◽  
Author(s):  
Linyun Chen ◽  
Mandy Kwong ◽  
Ronghua Lu ◽  
David Ginzinger ◽  
Candy Lee ◽  
...  
Keyword(s):  
Leucine Zipper ◽  
Primary Cultures ◽  
Embryonic Stem ◽  
Cell Types ◽  
Redox Balance ◽  
Liver Cells ◽  
Late Gestation ◽  
Basic Leucine Zipper ◽  
Antioxidant Genes

ABSTRACT The Nrf1 transcription factor belongs to the CNC subfamily of basic leucine zipper proteins. Knockout of Nrf1 is lethal in mouse embryos, but nothing is known about the cell types that absolutely require its function during development. We show by chimera analysis that Nrf1 is essential for the hepatocyte lineage. Mouse embryonic stem cells lacking Nrf1 developed normally and contributed to most tissues in adult chimeras where Nrf1 is normally expressed. Nrf1-deficient cells contributed to fetal, but not adult, liver cells. Loss of Nrf1 function resulted in liver cell apoptosis in late-gestation chimeric fetuses. Fetal livers from mutant embryos exhibited increased oxidative stress and impaired expression of antioxidant genes, and primary cultures of nrf1−/− fetal hepatocytes were sensitive to tert-butyl hydroperoxide-induced cell death, suggesting that impaired antioxidant defense may be responsible for the apoptosis observed in the livers of chimeric mice. In addition, cells deficient in Nrf1 were sensitized to the cytotoxic effects of tumor necrosis factor (TNF). Our results provide in vivo evidence demonstrating an essential role of Nrf1 in the survival of hepatocytes during development. Our results also suggest that Nrf1 may promote cell survival by maintaining redox balance and protecting embryonic hepatocytes from TNF-mediated apoptosis during development.

scholarly journals Overexpression of DUF538 from Wild Arachis Enhances Plant Resistance to Meloidogyne spp.

Agronomy ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 559
Author(s):  
Ana Claudia Guerra Araujo ◽  
Patricia Messenberg Guimaraes ◽  
Ana Paula Zotta Mota ◽  
Larissa Arrais Guimaraes ◽  
Bruna Medeiros Pereira ◽  
...  
Keyword(s):  
Transgenic Plants ◽  
Redox System ◽  
Redox Balance ◽  
Uncharacterized Protein ◽  
Chlorophyll Breakdown ◽  
Domain Of Unknown Function ◽  
Expression Behavior ◽  
Meloidogyne Spp ◽  
Wild Peanut ◽  
First Time

DUF538 proteins belong to a large group of uncharacterized protein families sharing the highly conserved Domain of Unknown Function (DUF). Attention has been given to DUF538 domain-containing proteins due to changes in their gene expression behavior and protein abundance during plant development and responses to stress. Putative roles attributed to DUF538 in plants under abiotic and biotic constraints include involvement in cell redox balance, chlorophyll breakdown and pectin degradation. Our previous transcriptome studies suggested that DUF538 is also involved in the resistance responses of wild Arachis species against the highly hazardous root-knot nematodes (RKNs). To clarify the role of the AsDUF538 gene from the wild peanut relative Arachis stenosperma in this interaction, we analyzed the effect of its overexpression on RKN infection in peanut and soybean hairy roots and Arabidopsis transgenic plants. AsDUF538 overexpression significantly reduced the infection in all three heterologous plant systems against their respective RKN counterparts. The distribution of AsDUF538 transcripts in RKN-infected Arachis roots and the effects of AsDUF538 overexpression on hormonal pathways and redox system in transgenic Arabidopsis were also evaluated. This is the first time that a DUF538 gene is functionally validated in transgenic plants and the earliest report on its role in plant defense against RKNs.

scholarly journals High Glucose and Lipopolysaccharide Prime NLRP3 Inflammasome via ROS/TXNIP Pathway in Mesangial Cells

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Hong Feng ◽  
Junling Gu ◽  
Fang Gou ◽  
Wei Huang ◽  
Chenlin Gao ◽  
...  
Keyword(s):  
Diabetic Nephropathy ◽  
Nlrp3 Inflammasome ◽  
High Glucose ◽  
Mesangial Cells ◽  
Central Component ◽  
Dependent Manner ◽  
Glomerular Mesangial Cells ◽  
Interacting Protein

While inflammation is considered a central component in the development in diabetic nephropathy, the mechanism remains unclear. The NLRP3 inflammasome acts as both a sensor and a regulator of the inflammatory response. The NLRP3 inflammasome responds to exogenous and endogenous danger signals, resulting in cleavage of procaspase-1 and activation of cytokines IL-1β, IL-18, and IL-33, ultimately triggering an inflammatory cascade reaction. This study observed the expression of NLRP3 inflammasome signaling stimulated by high glucose, lipopolysaccharide, and reactive oxygen species (ROS) inhibitor N-acetyl-L-cysteine in glomerular mesangial cells, aiming to elucidate the mechanism by which the NLRP3 inflammasome signaling pathway may contribute to diabetic nephropathy. We found that the expression of thioredoxin-interacting protein (TXNIP), NLRP3, and IL-1βwas observed by immunohistochemistry in vivo. Simultaneously, the mRNA and protein levels of TXNIP, NLRP3, procaspase-1, and IL-1βwere significantly induced by high glucose concentration and lipopolysaccharide in a dose-dependent and time-dependent manner in vitro. This induction by both high glucose and lipopolysaccharide was significantly inhibited by N-acetyl-L-cysteine. Our results firstly reveal that high glucose and lipopolysaccharide activate ROS/TXNIP/ NLRP3/IL-1βinflammasome signaling in glomerular mesangial cells, suggesting a mechanism by which inflammation may contribute to the development of diabetic nephropathy.

Mice overexpressing placenta growth factor exhibit increased vascularization and vessel permeability

2002 ◽  
Vol 115 (12) ◽  
pp. 2559-2567 ◽  
Author(s):  
Teresa Odorisio ◽  
Cataldo Schietroma ◽  
M. Letizia Zaccaria ◽  
Francesca Cianfarani ◽  
Cecilia Tiveron ◽  
...  
Keyword(s):  
Vascular Endothelial Growth Factor ◽  
Growth Factor ◽  
Adult Life ◽  
Growth Factor Receptor ◽  
Vascular Endothelial ◽  
Placenta Growth Factor ◽  
Vessel Permeability ◽  
Exact Function ◽  
Endothelial Growth Factor

Placenta growth factor (PlGF) is a member of the vascular endothelial growth factor (VEGF) family, comprising at least five cytokines specifically involved in the regulation of vascular and/or lymphatic endothelium differentiation. Several lines of evidence indicate a role for PlGF in monocyte chemotaxis and in potentiating the activity of VEGF, but the exact function of this cytokine is not fully understood. To define the biological role of PlGF in vivo, we have produced a transgenic mouse model overexpressing this factor in the skin by using a keratin 14 promoter cassette. Our data indicate that PlGF has strong angiogenic properties in both fetal and adult life. PlGF overexpression results in a substantial increase in the number,branching and size of dermal blood vessels as well as in enhanced vascular permeability. Indeed, intradermally injected recombinant PlGF was able to induce vessel permeability in wild-type mice. The analysis of vascular endothelial growth factor receptor 1/flt-1 and vascular endothelial growth factor receptor 2/flk-1 indicates that the two receptors are induced in the skin endothelium of transgenic mice suggesting that both are involved in mediating the effect of overexpressed PlGF.

Dimerization of TOC receptor GTPases and its implementation for the control of protein import into chloroplasts

2011 ◽  
Vol 436 (2) ◽  
pp. e1-e2 ◽  
Author(s):  
Henrik Aronsson ◽  
Paul Jarvis
Keyword(s):  
Protein Import ◽  
Control Point ◽  
Nucleotide Exchange ◽  
Biochemical Journal ◽  
Exact Function ◽  
Translocation Mechanism ◽  
Loaded State ◽  
Outer Envelope Membrane ◽  
And Function

Pre-protein import into chloroplasts is facilitated by multiprotein translocon complexes in the envelope membranes. Major components of the TOC (translocon at the outer envelope membrane of chloroplasts) complex are the receptor proteins Toc33 and Toc159. These two receptors are related GTPases, and they are predicted to engage in homodimerization and/or heterodimerization. Although such dimerization has been studied extensively, its exact function in vivo remains elusive. In this issue of the Biochemical Journal, Oreb et al. present evidence that homodimerization of Toc33 prevents nucleotide exchange, thereby locking the receptor in the GDP-loaded state and preventing further activity. Pre-protein arrival is proposed to release this lock, through disruption of the dimer and subsequent nucleotide exchange. The Toc33-bound pre-protein is then able to progress to downstream steps in the translocation mechanism, with GTP hydrolysis defining another important control point as well as preparing the receptor for the next pre-protein client. These new results are discussed in the context of previous findings pertaining to TOC receptor dimerization and function.

scholarly journals PIWIL1 Drives Chemoresistance in Multiple Myeloma by Modulating Mitophagy and the Myeloma Stem Cell Population

2022 ◽  
Vol 11 ◽  
Author(s):  
Yajun Wang ◽  
Lan Yao ◽  
Yao Teng ◽  
Hua Yin ◽  
Qiuling Wu
Keyword(s):  
Multiple Myeloma ◽  
Drug Resistance ◽  
Stem Cell ◽  
Cell Population ◽  
Side Population ◽  
Chemotherapeutic Agents ◽  
Stem Cell Population ◽  
Exact Function

As an important member of the Argonaute protein family, PIWI-like protein 1 (PIWIL1) plays a key role in tumor cell viability. However, the exact function of PIWIL1 in multiple myeloma (MM) and the underlying mechanism remain unclear. Here, we revealed that PIWIL1 was highly expressed in myeloma cell lines and newly diagnosed MM patients, and that its expression was notably higher in refractory/relapsed MM patients. PIWIL1 promoted the proliferation of MM cells and conferred resistance to chemotherapeutic agents both in vitro and in vivo. More importantly, PIWIL1 enhanced the formation of autophagosomes, especially mitophagosomes, by disrupting mitochondrial calcium signaling and modulating mitophagy-related canonical PINK1/Parkin pathway protein components. Mitophagy/autophagy inhibitors overcome PIWIL1-induced chemoresistance. In addition, PIWIL1 overexpression increased the proportion of side population (SP) cells and upregulated the expression of the stem cell-associated genes Nanog, OCT4, and SOX2, while its inhibition resulted in opposite effects. Taken together, our findings demonstrated that PIWIL1 induced drug resistance by activating mitophagy and regulating the MM stem cell population. PIWIL1 depletion significantly overcame drug resistance and could be used as a novel therapeutic target for reversing resistance in MM patients.

scholarly journals Oxidative stress promotes liver cancer metastasis via a PKA-activated RNF25/ECAD/YAP circuit

2022 ◽  
Author(s):  
Zhao Huang ◽  
Li Zhou ◽  
Jiufei Duan ◽  
Siyuan Qin ◽  
Yu Wang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cancer Metastasis ◽  
Anoikis Resistance ◽  
Antioxidant Genes ◽  
Redox Sensor ◽  
Stress Signals ◽  
Hcc Cells

Abstract Loss of E-cadherin (ECAD), often caused by epigenetic inactivation, is closely associated with tumor metastasis. However, how ECAD is regulated in response to oxidative stress during tumorigenesis is largely unknown. Here we identify RNF25 as a new E3 ligase of ECAD, whose activation by oxidative stress leads to ECAD protein degradation in hepatocellular carcinoma (HCC). Loss of ECAD activates YAP, which in turn promotes the transcription of RNF25, thus forming a positive feedback loop to sustain the ECAD downregulation. YAP activation mitigates oxidative stress in detached HCC cells by upregulating antioxidant genes, protecting detached HCC cells from ferroptosis, resulting in anoikis resistance. Mechanistically, we found that protein kinase A (PKA) senses oxidative stress by redox modification in its β catalytic subunit (PRKACB) at Cys200 and Cys344, which increases its kinase activity towards RNF25 phosphorylation at Ser450, facilitating RNF25-mediated degradation of ECAD. Moreover, RNF25 expression is associated with HCC metastasis and depletion of RNF25 is sufficient to diminish HCC invasion and metastasis in vitro and in vivo. Together, these results identify a dual role of RNF25 as a critical regulator of ECAD protein turnover, promoting both anoikis resistance and metastasis, and PKA is a necessary redox sensor to enable this process. Our study provides mechanistic insight into how tumor cells sense oxidative stress signals to spread while escaping cell death.

scholarly journals Schizophrenia Increases Variability of the Central Antioxidant System: A Meta-Analysis of Variance From MRS Studies of Glutathione

2021 ◽  
Vol 12 ◽  
Author(s):  
Lena Palaniyappan ◽  
Priyadharshini Sabesan ◽  
Xuan Li ◽  
Qiang Luo
Keyword(s):  
Meta Analysis ◽  
Redox System ◽  
Antioxidant Response ◽  
Anterior Cingulate ◽  
System Stability ◽  
Careful Examination ◽  
Resonance Spectroscopy ◽  
1H Mrs ◽  
System A

Patients with schizophrenia diverge in their clinical trajectories. Such diverge outcomes may result from the resilience provided by antioxidant response system centered on glutathione (GSH). Proton Magnetic Resonance Spectroscopy (1H-MRS) has enabled the precise in vivo measurement of intracortical GSH; but individual studies report highly variable results even when GSH levels are measured from the same brain region. This inconsistency could be due to the presence of distinct subgroups of schizophrenia with varying GSH-levels. At present, we do not know if schizophrenia increases the interindividual variability of intracortical GSH relative to matched healthy individuals. We reviewed all 1H-MRS GSH studies in schizophrenia focused on the Anterior Cingulate Cortex published until August 2021. We estimated the relative variability of ACC GSH levels in patients compared to control groups using the variability ratio (VR) and coefficient of variation ratio (CVR). The presence of schizophrenia significantly increases the variability of intracortical GSH in the ACC (logVR = 0.12; 95% CI: 0.03–0.21; log CVR = 0.15; 95% CI = 0.06–0.23). Insofar as increased within-group variability (heterogeneity) could result from the existence of subtypes, our results call for a careful examination of intracortical GSH distribution in schizophrenia to seek redox-deficient and redox-sufficient subgroups. An increase in GSH variability among patients also indicate that the within-group predictability of adaptive response to oxidative stress may be lower in schizophrenia. Uncovering the origins of this illness-related reduction in the redox system stability may provide novel treatment targets in schizophrenia.

scholarly journals Transcriptional role of p53 in interferon-mediated antiviral immunity

2008 ◽  
Vol 205 (8) ◽  
pp. 1929-1938 ◽  
Author(s):  
César Muñoz-Fontela ◽  
Salvador Macip ◽  
Luis Martínez-Sobrido ◽  
Lauren Brown ◽  
Joseph Ashour ◽  
...  
Keyword(s):  
Tumor Suppressor ◽  
Viral Replication ◽  
Viral Infections ◽  
Suppressor Gene ◽  
Central Component ◽  
Type I ◽  
Infected Cells

Tumor suppressor p53 is activated by several stimuli, including DNA damage and oncogenic stress. Previous studies (Takaoka, A., S. Hayakawa, H. Yanai, D. Stoiber, H. Negishi, H. Kikuchi, S. Sasaki, K. Imai, T. Shibue, K. Honda, and T. Taniguchi. 2003. Nature. 424:516–523) have shown that p53 is also induced in response to viral infections as a downstream transcriptional target of type I interferon (IFN) signaling. Moreover, many viruses, including SV40, human papillomavirus, Kaposi's sarcoma herpesvirus, adenoviruses, and even RNA viruses such as polioviruses, have evolved mechanisms designated to abrogate p53 responses. We describe a novel p53 function in the activation of the IFN pathway. We observed that infected mouse and human cells with functional p53 exhibited markedly decreased viral replication early after infection. This early inhibition of viral replication was mediated both in vitro and in vivo by a p53-dependent enhancement of IFN signaling, specifically the induction of genes containing IFN-stimulated response elements. Of note, p53 also contributed to an increase in IFN release from infected cells. We established that this p53-dependent enhancement of IFN signaling is dependent to a great extent on the ability of p53 to activate the transcription of IFN regulatory factor 9, a central component of the IFN-stimulated gene factor 3 complex. Our results demonstrate that p53 contributes to innate immunity by enhancing IFN-dependent antiviral activity independent of its functions as a proapoptotic and tumor suppressor gene.

scholarly journals Antioxidant and Pro-Oxidant Activities of Melatonin in the Presence of Copper and Polyphenols In Vitro and In Vivo

Cells ◽  
2019 ◽  
Vol 8 (8) ◽  
pp. 903 ◽  
Author(s):  
Jiajia Wang ◽  
Xiaoxiao Wang ◽  
Yufeng He ◽  
Lijie Jia ◽  
Chung S. Yang ◽  
...  
Keyword(s):  
Dna Damage ◽  
Hydroxyl Radical ◽  
Density Functional ◽  
Antioxidant Activities ◽  
Chelating Agent ◽  
Redox System ◽  
Radical Scavenger ◽  
Dual Function ◽  
High Concentrations

Melatonin is a well-documented antioxidant. Physicochemical analysis using the density functional theory suggests that melatonin is a copper chelating agent; however, experimental evidence is still in demand. The present study investigated the influence of melatonin on reactive oxygen species (ROS) generated from polyphenol autoxidation in the presence of copper. Surprisingly, we found that melatonin paradoxically enhanced ROS formation in a redox system containing low concentrations of copper and quercetin (Que) or (−)-epigallocatechin-3-gallate (EGCG), due to reduction of cupric to cuprous ion by melatonin. Addition of DNA to this system inhibited ROS production, because DNA bound to copper and inhibited copper reduction by melatonin. When melatonin was added to a system containing high concentrations of copper and Que or EGCG, it diminished hydroxyl radical formation as expected. Upon addition of DNA to high concentrations of copper and Que, this pro-oxidative system generated ROS and caused DNA damage. The DNA damage was not prevented by typical scavengers of hydroxyl radical DMSO or mannitol. Under these conditions, melatonin or bathocuproine disulfonate (a copper chelator) protected the DNA from damage by chelating copper. When melatonin was administered intraperitoneally to mice, it inhibited hepatotoxicity and DNA damage evoked by EGCG plus diethyldithiocarbamate (a copper ionophore). Overall, the present study demonstrates the pro-oxidant and antioxidant activities of melatonin in the redox system of copper and polyphenols. The pro-oxidant effect is inhibited by the presence of DNA, which prevents copper reduction by melatonin. Interestingly, in-vivo melatonin protects against copper/polyphenol-induced DNA damage probably via acting as a copper-chelating agent rather than a hydroxyl radical scavenger. Melatonin with a dual function of scavenging hydroxyl radical and chelating copper is a more reliable DNA guardian than antioxidants that only have a single function of scavenging hydroxyl radical.

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