scholarly journals Zebrafish Oxr1a Knockout Reveals Its Role in Regulating Antioxidant Defenses and Aging

Genes ◽  
2020 ◽  
Vol 11 (10) ◽  
pp. 1118 ◽  
Author(s):  
Hao Xu ◽  
Yu Jiang ◽  
Sheng Li ◽  
Lang Xie ◽  
Yi-Xi Tao ◽  
...  

Oxidation resistance gene 1 (OXR1) is essential for protection against oxidative stress in mammals, but its functions in non-mammalian vertebrates, especially in fish, remain uncertain. Here, we created a homozygous oxr1a-knockout zebrafish via the CRISPR/Cas9 (Clustered Regularly Interspaced Short Palindromic Repeats/CRISPR associated protein 9) system. Compared with wild-type (WT) zebrafish, oxr1a−/− mutants exhibited higher mortality and more apoptotic cells under oxidative stress, and multiple antioxidant genes (i.e., gpx1b, gpx4a, gpx7 and sod3a) involved in detoxifying cellular reactive oxygen species were downregulated significantly. Based on these observations, we conducted a comparative transcriptome analysis of early oxidative stress response. The results show that oxr1a mutation caused more extensive changes in transcriptional networks compared to WT zebrafish, and several stress response and pro-inflammatory pathways in oxr1a−/− mutant zebrafish were strongly induced. More importantly, we only observed the activation of the p53 signaling and apoptosis pathway in oxr1a−/− mutant zebrafish, revealing an important role of oxr1a in regulating apoptosis via the p53 signaling pathway. Additionally, we found that oxr1a mutation displayed a shortened lifespan and premature ovarian failure in prolonged observation, which may be caused by the loss of oxr1a impaired antioxidant defenses, thereby increasing pro-apoptotic events. Altogether, our findings demonstrate that oxr1a is vital for antioxidant defenses and anti-aging in zebrafish.

2021 ◽  
Author(s):  
Liang Xiong ◽  
Jinyu Huang ◽  
Ying Gao ◽  
Yanfang Gao ◽  
Chunmei Wu ◽  
...  

Abstract Arsenic (As) is a ubiquitous environmental and industrial toxin with known correlates of oxidative stress and cognitive deficits in the brain. Nuclear factor erythroid 2-related factor 2 (Nrf2) is a transcriptional factor that represents a central cellular antioxidant defense mechanism and transcribes many antioxidant genes. Peroxisome proliferator-activated receptor-gamma (PPARγ) is a well-known nuclear receptor to regulate lipid metabolism in many tissues, and it has been also associated with the control of oxidative stress, neuronal death, neurogenesis and differentiation. The role of Nrf2 and PPARγ in As-induced neurotoxicity is still debated. The present study was designed to investigate the neurobehavioral toxic effect of sub-chronic and middle-dose sodium arsenite exposure in mice hippocampus, as well as the response of Nrf2/PPARγ expression and influence on protein expression levels of their downstream antioxidant genes. Our results showed that mice treated with intraperitoneal injection of sodium arsenite (50 mg/kg body wt.) twice a week for 7 weeks resulted in increased generation of reactive oxygen species and impairment of spatial cognitive function. The present study also found a positive association between Nrf2/PPARγ expression in hippocampus of mice, and activation of antioxidant defenses by the evidently upregulated expression of their downstream genes, including superoxide dismutase, heme oxygenase-1 and glutathione peroxidase-3. Therefore, our findings were helpful for further understanding the role of Nrf2/PPARγ feedback loop in As-induced neurobehavioral toxicity.


2014 ◽  
Vol 2014 ◽  
pp. 1-16 ◽  
Author(s):  
Shanshan Zhou ◽  
Wanqing Sun ◽  
Zhiguo Zhang ◽  
Yang Zheng

Heart failure (HF) is frequently the consequence of sustained, abnormal neurohormonal, and mechanical stress and remains a leading cause of death worldwide. The key pathophysiological process leading to HF is cardiac remodeling, a term referring to maladaptation to cardiac stress at the molecular, cellular, tissue, and organ levels. HF and many of the conditions that predispose one to HF are associated with oxidative stress. Increased generation of reactive oxygen species (ROS) in the heart can directly lead to increased necrosis and apoptosis of cardiomyocytes which subsequently induce cardiac remodeling and dysfunction. Nuclear factor-erythroid-2- (NF-E2-) related factor 2 (Nrf2) is a transcription factor that controls the basal and inducible expression of a battery of antioxidant genes and other cytoprotective phase II detoxifying enzymes that are ubiquitously expressed in the cardiovascular system. Emerging evidence has revealed that Nrf2 and its target genes are critical regulators of cardiovascular homeostasis via the suppression of oxidative stress, which is the key player in the development and progression of HF. The purpose of this review is to summarize evidence that activation of Nrf2 enhances endogenous antioxidant defenses and counteracts oxidative stress-associated cardiac remodeling and HF.


Microbiology ◽  
2009 ◽  
Vol 155 (6) ◽  
pp. 1912-1922 ◽  
Author(s):  
Kiyonobu Honma ◽  
Elina Mishima ◽  
Satoru Inagaki ◽  
Ashu Sharma

Tannerella forsythia is an anaerobic periodontal pathogen that encounters constant oxidative stress in the human oral cavity due to exposure to air and reactive oxidative species from coexisting dental plaque bacteria as well as leukocytes. In this study, we sought to characterize a T. forsythia ORF with close similarity to bacterial oxidative stress response sensor protein OxyR. To analyse the role of this OxyR homologue, a gene deletion mutant was constructed and characterized. Aerotolerance, survival after hydrogen peroxide challenge and transcription levels of known bacterial antioxidant genes were then determined. Since an association between oxidative stress and biofilm formation has been observed in bacterial systems, we also investigated the role of the OxyR protein in biofilm development by T. forsythia. Our results showed that aerotolerance, sensitivity to peroxide challenge and the expression of oxidative stress response genes were significantly reduced in the mutant as compared with the wild-type strain. Moreover, the results of biofilm analyses showed that, as compared with the wild-type strain, the oxyR mutant showed significantly less autoaggregation and a reduced ability to form mixed biofilms with Fusobacterium nucleatum. In conclusion, a gene annotated in the T. forsythia genome as an oxyR homologue was characterized. Our studies showed that the oxyR homologue in T. forsythia constitutively activates antioxidant genes involved in resistance to peroxides as well as oxygen stress (aerotolerance). In addition, the oxyR deletion attenuates biofilm formation in T. forsythia.


2022 ◽  
Author(s):  
Zhao Huang ◽  
Li Zhou ◽  
Jiufei Duan ◽  
Siyuan Qin ◽  
Yu Wang ◽  
...  

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.


2021 ◽  
Author(s):  
Anindita Dutta ◽  
Apurba Das ◽  
Deep Bisht ◽  
Vijendra Arya ◽  
Rohini Muthuswami

Cells respond to oxidative stress by elevating the levels of antioxidants, signaling, and transcriptional regulation often implemented by chromatin remodeling proteins.  The study presented in this paper shows that the expression of PICH, an ATP-dependent chromatin remodeler, is upregulated during oxidative stress in HeLa cells. We also show that PICH regulates the expression of Nrf2, a transcription factor regulating antioxidant response, both in the absence and presence of oxidative stress. In turn, Nrf2 regulates the expression of PICH in the presence of oxidative stress. Both PICH and Nrf2 together regulate the expression of antioxidant genes and this transcriptional regulation is dependent on the ATPase activity of PICH. In addition, H3K27ac modification also plays a role in activating transcription in the presence of oxidative stress. Co-immunoprecipitation experiments show that PICH and Nrf2 interact with H3K27ac in the presence of oxidative stress. Mechanistically, PICH recognizes ARE sequences present on its target genes and introduces a conformational change to the DNA sequences leading us to hypothesize that PICH regulates transcription by remodeling DNA. PICH ablation leads to reduced expression of Nrf2 and impaired antioxidant response leading to increased ROS content, thus, showing PICH is essential for the cell to respond to oxidative stress.


PLoS ONE ◽  
2015 ◽  
Vol 10 (4) ◽  
pp. e0124582 ◽  
Author(s):  
Ramona Jühlen ◽  
Jan Idkowiak ◽  
Angela E. Taylor ◽  
Barbara Kind ◽  
Wiebke Arlt ◽  
...  

2021 ◽  
Author(s):  
Dina Marghani ◽  
Zhuo Ma ◽  
Anthony J. Centone ◽  
Weihua Huang ◽  
Meenakshi Malik ◽  
...  

Francisella tularensis is a Gram-negative bacterium that causes a fatal human disease known as tularemia. The Centers for Disease Control have classified F. tularensis as Category A Tier-1 Select Agent. The virulence mechanisms of Francisella are not entirely understood. Francisella possesses very few transcription regulators, and most of these regulate the expression of genes involved in intracellular survival and virulence. The F. tularensis genome sequence analysis reveals an AraC ( FTL_ 0689) transcriptional regulator homologous to the AraC/XylS family of transcriptional regulators. In Gram-negative bacteria, AraC activates genes required for L-arabinose utilization and catabolism. The role of the FTL_ 0689 regulator in F. tularensis is not known. In this study, we characterized the role of FTL_ 0689 in gene regulation of F. tularensis and investigated its contribution to intracellular survival and virulence. The results demonstrate that FTL_0689 in Francisella is not required for L-arabinose utilization. Instead, FTL_ 0689 specifically regulates the expression of the oxidative and global stress response, virulence, metabolism, and other key pathways genes required by Francisella when exposed to oxidative stress. The FTL_0689 mutant is attenuated for intramacrophage growth and virulence in mice. Based on the deletion mutant phenotype, FTL_0689 was termed osrR ( o xidative s tress r esponse r egulator). Altogether, this study elucidates the role of the osrR transcriptional regulator in tularemia pathogenesis. IMPORTANCE: The virulence mechanisms of category A select agent Francisella tularensis , the causative agent of a fatal human disease known as tularemia, remain largely undefined. The present study investigated the role of a transcriptional regulator and its overall contribution to the oxidative stress resistance of F. tularensis . The results provide an insight into a novel gene regulatory mechanism, especially when Francisella is exposed to oxidative stress conditions. Understanding such Francisella - specific regulatory mechanisms will identify potential targets for developing effective therapies and vaccines to prevent tularemia.


Biomolecules ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 703 ◽  
Author(s):  
Ahlam Alhusaini ◽  
Laila Fadda ◽  
Iman H. Hasan ◽  
Enas Zakaria ◽  
Abeer M. Alenazi ◽  
...  

Lead (Pb) is a toxic heavy metal pollutant with adverse effects on the liver and other body organs. Curcumin (CUR) is the principal curcuminoid of turmeric and possesses strong antioxidant and anti-inflammatory activities. This study explored the protective effect of CUR on Pb hepatotoxicity with an emphasis on oxidative stress, inflammation and Akt/GSK-3β signaling. Rats received lead acetate and CUR and/or ascorbic acid (AA) for seven days and samples were collected for analyses. Pb(II) induced liver injury manifested by elevated serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and lactate dehydrogenase (LDH), as well as histopathological alterations, including massive hepatocyte degeneration and increased collagen deposition. Lipid peroxidation, nitric oxide, TNF-α and DNA fragmentation were increased, whereas antioxidant defenses were diminished in the liver of Pb(II)-intoxicated rats. Pb(II) increased hepatic NF-κB and JNK phosphorylation and caspase-3 cleavage, whereas Akt and GSK-3β phosphorylation was decreased. CUR and/or AA ameliorated liver function, prevented tissue injury, and suppressed oxidative stress, DNA damage, NF-κB, JNK and caspase-3. In addition, CUR and/or AA activated Akt and inhibited GSK-3β in Pb(II)-induced rats. In conclusion, CUR prevents Pb(II) hepatotoxicity via attenuation of oxidative injury and inflammation, activation of Akt and inhibition of GSK-3β. However, further studies scrutinizing the exact role of Akt/GSK-3β signaling are recommended.


2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Vittoria Cenni ◽  
Snezana Kojic ◽  
Cristina Capanni ◽  
Georgine Faulkner ◽  
Giovanna Lattanzi

Ankrd2 (ankyrin repeats containing domain 2) or Arpp (ankyrin repeat, PEST sequence, and proline-rich region) is a member of the muscle ankyrin repeat protein family. Ankrd2 is mostly expressed in skeletal muscle, where it plays an intriguing role in the transcriptional response to stress induced by mechanical stimulation as well as by cellular reactive oxygen species. Our studies in myoblasts from Emery-Dreifuss muscular dystrophy 2, a LMNA-linked disease affecting skeletal and cardiac muscles, demonstrated that Ankrd2 is a lamin A-binding protein and that mutated lamins found in Emery-Dreifuss muscular dystrophy change the dynamics of Ankrd2 nuclear import, thus affecting oxidative stress response. In this review, besides describing the latest advances related to Ankrd2 studies, including novel discoveries on Ankrd2 isoform-specific functions, we report the main findings on the relationship of Ankrd2 with A-type lamins and discuss known and potential mechanisms involving defective Ankrd2-lamin A interplay in the pathogenesis of muscular laminopathies.


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