scholarly journals Gene bb0318 Is Critical for the Oxidative Stress Response and Infectivity of Borrelia burgdorferi

2016 ◽  
Vol 84 (11) ◽  
pp. 3141-3151 ◽  
Author(s):  
Adrienne C. Showman ◽  
George Aranjuez ◽  
Philip P. Adams ◽  
Mollie W. Jewett
Keyword(s):  
Oxidative Stress ◽  
Stress Response ◽  
Borrelia Burgdorferi ◽  
Molecular Mechanisms ◽  
De Novo ◽  
Oxidative Stress Response ◽  
Growth Defect ◽  
Content Type

A greater understanding of the molecular mechanisms that Borrelia burgdorferi uses to survive during mammalian infection is critical for the development of novel diagnostic and therapeutic tools to improve the clinical management of Lyme disease. By use of an in vivo expression technology (IVET)-based approach to identify B. burgdorferi genes expressed in vivo , we discovered the bb0318 gene, which is thought to encode the ATPase component of a putative riboflavin ABC transport system. Riboflavin is a critical metabolite enabling all organisms to maintain redox homeostasis. B. burgdorferi appears to lack the metabolic capacity for de novo synthesis of riboflavin and so likely relies on scavenging riboflavin from the host environment. In this study, we sought to investigate the role of bb0318 in B. burgdorferi pathogenesis. No in vitro growth defect was observed for the Δ bb0318 clone. However, the mutant spirochetes displayed reduced levels of survival when exposed to exogenous hydrogen peroxide or murine macrophages. Spirochetes lacking bb0318 were found to have a 100-fold-higher 50% infectious dose than spirochetes containing bb0318 . In addition, at a high inoculum dose, bb0318 was found to be important for effective spirochete dissemination to deep tissues for as long as 3 weeks postinoculation and to be critical for B. burgdorferi infection of mouse hearts. Together, these data implicate bb0318 in the oxidative stress response of B. burgdorferi and indicate the contribution of bb0318 to B. burgdorferi mammalian infectivity.

scholarly journals Dps and DpsL Mediate SurvivalIn VitroandIn Vivoduring the Prolonged Oxidative Stress Response in Bacteroides fragilis

2015 ◽  
Vol 197 (20) ◽  
pp. 3329-3338 ◽  
Author(s):  
Michael I. Betteken ◽  
Edson R. Rocha ◽  
C. Jeffrey Smith
Keyword(s):  
Oxidative Stress ◽  
Stress Response ◽  
Peritoneal Cavity ◽  
Bacteroides Fragilis ◽  
Oxidative Stress Response ◽  
Iron Storage ◽  
Content Type ◽  
Iron Storage Proteins

ABSTRACTBacteroides fragilisis a Gram-negative anaerobe and member of the human intestinal tract microbiome, where it plays many beneficial roles. However, translocation of the organism to the peritoneal cavity can lead to peritonitis, intra-abdominal abscess formation, bacteremia, and sepsis. During translocation,B. fragilisis exposed to increased oxidative stress from the oxygenated tissues of the peritoneal cavity and the immune response. In order to survive,B. fragilismounts a robust oxidative stress response consisting of an acute and a prolonged oxidative stress (POST) response. This report demonstrates that the ability to induce high levels of resistance totert-butyl hydroperoxide (tBOOH) after extended exposure to air can be linked to the POST response. Disk diffusion assays comparing the wild type to a Δdpsmutant and a ΔdpsΔbfrmutant showed greater sensitivity of the mutants to tBOOH after exposure to air, suggesting that Dps and DpsL play a role in the resistance phenotype. Complementation studies withdpsorbfr(encoding DpsL) restored tBOOH resistance, suggesting a role for both of these ferritin-family proteins in the response. Additionally, cultures treated with the iron chelator dipyridyl were not killed by tBOOH, indicating Dps and DpsL function by sequestering iron to prevent cellular damage. Anin vivoanimal model showed that the ΔdpsΔbfrmutant was attenuated, indicating that management of iron is important for survival within the abscess. Together, these data demonstrate a role for Dps and DpsL in the POST response which mediates survivalin vitroandin vivo.IMPORTANCEB. fragilisis the anaerobe most frequently isolated from extraintestinal opportunistic infections, but there is a paucity of information about the factors that allow this organism to survive outside its normal intestinal environment. This report demonstrates that the iron storage proteins Dps and DpsL protect against oxidative stress and that they contribute to survival bothin vitroandin vivo. Additionally, this work demonstrates an important role for the POST response inB. fragilissurvival and provides insight into the complex regulation of this response.

scholarly journals 4-PHENYLBUTYRATE: MOLECULAR MECHANISMS AND AGING INTERVENTION POTENTIAL

2019 ◽  
Vol 3 (Supplement_1) ◽  
pp. S101-S101
Author(s):  
Michael R Bene ◽  
Kevin Thyne ◽  
Jonathan Dorigatti ◽  
Adam B Salmon
Keyword(s):  
Oxidative Stress ◽  
Stress Response ◽  
Molecular Mechanisms ◽  
Oxidative Stress Response ◽  
Chemical Chaperone ◽  
Mouse Muscle ◽  
Age Related ◽  
Primary Mouse ◽  
Wide Range

Abstract 4-Phenylbutyrate (PBA) is a FDA approved drug for treating patients with urea cycle disorders. Additionally, PBA acts upon several pathways thought of as important modifiers of aging including: histone deacetylation, proteostasis as a chemical chaperone, and stress resistance by regulating expression of oxidative stress response proteins. PBA has also been shown to extend lifespan and improve markers of age-related health in Drosophila. Due to its wide range of effects PBA has been investigated for use in numerous age-related disorders including neurodegenerative and cardiovascular diseases. To better understand the effects of PBA on the molecular level, we used both in cellulo and in vivo studies. Treatment of primary mouse fibroblasts, C2C12 mouse muscle cells, and NCTC 1469 mouse liver cells with PBA demonstrated differential responses among cell lines to upregulation of oxidative stress response and histone acetylation. Specifically, upregulation of the oxidative stress response protein DJ-1 by PBA was found to have a corresponding dose response curve to histone H3 acetylation in primary fibroblasts. To study effects of PBA in vivo, four cohorts of HET3 mice were treated with PBA at different doses in drinking water for 4 weeks. PBA was well tolerated and led to different effects on body composition dependent on the sex of mice. We are currently investigating the molecular effects of PBA treatment in multiple tissues samples from these mice. The potential of PBA to alter many fundamental pathways, and specifically those related to stress responses, make it an attractive prospect for treatment of many age-related disorders.

scholarly journals Evidence for a Role of Oxidative Stress in the Carcinogenicity of Ochratoxin A

2011 ◽  
Vol 2011 ◽  
pp. 1-15 ◽  
Author(s):  
M. Marin-Kuan ◽  
V. Ehrlich ◽  
T. Delatour ◽  
C. Cavin ◽  
B. Schilter
Keyword(s):  
Oxidative Stress ◽  
Stress Response ◽  
Oxidative Stress Response ◽  
Renal Tumors ◽  
Safe Level ◽  
Reduction Mechanisms ◽  
Indirect Source

Thein vitroandin vivoevidence compatible with a role for oxidative stress in OTA carcinogenicity has been collected and described. Several potential oxido-reduction mechanisms have been identified in the past. More recently, the possibility of a reduction of cellular antioxidant defense has been raised as an indirect source of oxidative stress. Consequences resulting from the production of oxidative stress are observed at different levels. First, OTA exposure has been associated with increased levels of oxidative DNA, lipid, and protein damage. Second, various biological processes known to be mobilized under oxidative stress were shown to be altered by OTA. These effects have been observed in bothin vitroandin vivotest systems.In vivo, active doses were often within doses documented to induce renal tumors in rats. In conclusion, the evidence for the induction of an oxidative stress response resulting from OTA exposure can be considered strong. Because the contribution of the oxidative stress response in the development of cancers is well established, a role in OTA carcinogenicity is plausible. Altogether, the data reviewed above support the application of a threshold-based approach to establish safe level of dietary human exposure to OTA.

scholarly journals Lignans Extracted from Eucommia Ulmoides Oliv. Protects Against AGEs-Induced Retinal Endothelial Cell Injury

2016 ◽  
Vol 39 (5) ◽  
pp. 2044-2054 ◽  
Author(s):  
Ban Liu ◽  
Chao-Peng Li ◽  
Wen-Qi Wang ◽  
Shu-Guang Song ◽  
Xiu-Ming Liu
Keyword(s):  
Oxidative Stress ◽  
Endothelial Cell ◽  
Stress Response ◽  
Oxidative Stress Response ◽  
Eucommia Ulmoides ◽  
Endothelial Cell Function ◽  
Retinal Endothelial Cell ◽  
Endothelium Damage

Background/Aims: Advanced glycation end products (AGEs) could elicit oxidative stress, trigger and aggravate endothelium damage in several ischemic retinopathies including diabetic retinopathy (DR). The leaves of Eucommia ulmoides O., also referred to as Tu-chung or Du-zhong, have been used for the treatment of hypertension and diabetes, showing great antioxidant activity and anti-glycation activity. Lignans is one of the main bioactive components of Eucommia ulmoides. This study mainly investigated the effect of lignans treatment on AGEs-induced endothelium damage. Methods: MTT assay, Hoechst staining, and calcein-AM/ propidium iodide (PI) staining was conducted to determine the effect of lignans treatment on endothelial cell function in vitro. Retinal trypsin digestion, Evans blue assay, isolectin staining, and western blots were conducted to determine the effect of lignans treatment on retinal microvascular function in vivo. Western blot, protein immunoprecipitation (IP), MTT assays, and enzyme activity assay was conducted to detect the effect of ligans treatment on oxidative stress response. Results: Lignans protected retinal endothelial cell against AGEs-induced injury in vitro and diabetes-induced vascular dysfunction in vivo. Lignans treatment could regulate oxidative stress response in retinal endothelial cell line, retina, and liver. Moreover, we showed that NRF2/HO-1 signaling was critical for lignans-mediated oxidative stress regulation. Conclusion: Lignans treatment could protect against endothelial dysfunction in vivo and in vitro via regulating Nrf2/HO-1 signaling. Lignans might be developed as a promising drug for the treatment of diabetes-induced microvascular dysfunction.

scholarly journals Novel lncRNA AL033381.2 Promotes Hepatocellular Carcinoma Progression by Upregulating PRKRA Expression

2022 ◽  
Vol 2022 ◽  
pp. 1-24
Author(s):  
Feiran Wang ◽  
Lirong Zhu ◽  
Qiang Xue ◽  
Chong Tang ◽  
Weidong Tang ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Hepatocellular Carcinoma ◽  
Stress Response ◽  
Stress Responses ◽  
Molecular Mechanisms ◽  
Oxidative Stress Response ◽  
Migration And Invasion ◽  
Pcr Analysis ◽  
Therapeutic Effects

Hepatocellular carcinoma (HCC) is a common malignant tumor that is characterized by aggressiveness and poor prognosis. Accumulating evidence indicates that oxidative stress plays a crucial role in carcinogenesis, whereas the potential mechanism between oxidative stress and carcinogenic effects remains elusive. In recent years, long noncoding RNAs (lncRNAs) in cancers have attracted extensive attention and have been shown to be involved in oxidative stress response and carcinogenesis. Nevertheless, the roles of lncRNA AL033381.2 in regulating the development and progression of HCC still remain unclear. The purpose of our study was to evaluate the potential effects and molecular mechanisms of AL033381.2 that may be involved in oxidative stress response in HCC. Using bioinformatics analyses based on the TCGA database, we screened and identified a novel lncRNA AL033381.2 in HCC, which may be involved in oxidative stress responses. qRT-PCR analysis revealed that AL033381.2 is upregulated in HCC tissues. Through in vitro and in vivo experiments, we found that AL033381.2 dramatically facilitates the growth and metastasis of HCC. Mechanistically, RNA pull-down experiments, mass spectrometry, PathArray™, and RIP were used to determine that AL033381.2 binds to PRKRA and may be involved in AL033381.2-mediated oncogenic functions in HCC cells. Moreover, rescue experiments demonstrated that PRKRA overexpression rescues the abilities of HCC cell proliferation, migration, and invasion that were affected by AL033381.2 knockdown. Furthermore, we produced a nanoparticle-based siRNA delivery system and tested its therapeutic effects in vivo. The results showed that the in vivo growth rate of the tumors treated with the nanoparticle/AL033381.2 siRNA complexes was dramatically lower than those treated with the nanoparticle/scramble siRNA complexes. Taken together, our results suggest that the novel lncRNA AL033381.2 may be involved in oxidative stress response by targeting oxidative stress-related genes in HCC. AL033381.2 plays vital oncogenic roles in HCC progression and may be a novel therapeutic marker for HCC diagnosis and treatment.

scholarly journals Multiple Myeloma Cells Depend on the DDI2/NRF1-mediated Proteasome Stress Response for Survival

2021 ◽  
Author(s):  
Tianzeng Chen ◽  
Matthew Ho ◽  
Jenna Briere ◽  
Maria Moscvin ◽  
Peter G Czarnecki ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Stress Response ◽  
Molecular Mechanisms ◽  
Nuclear Translocation ◽  
De Novo ◽  
Proteasome Inhibitors ◽  
Proteasome Inhibition ◽  
Knock Out

Multiple myeloma (MM) cells suffer from baseline proteotoxicity due to an imbalance between the load of misfolded proteins awaiting proteolysis and the capacity of the ubiquitin-proteasome system to degrade them. This intrinsic vulnerability is at the base of MM sensitivity to agents that perturb proteostasis such as proteasome inhibitors (PIs), the mainstay of modern-day myeloma therapy. De-novo and acquired PI resistance are important clinical limitations, adversely affecting prognosis. The molecular mechanisms underpinning PI resistance are only partially understood, limiting the development of drugs that can overcome it. The transcription factor NRF1 is activated by the aspartic protease DDI2 upon proteasome insufficiency and governs proteasome biogenesis. In this work, we show that MM cells exhibit baseline NRF1 activation and are dependent upon DDI2 for survival. DDI2 knock out (KO) is cytotoxic for MM cells, both in vitro and in vivo. Protein structure-function studies show that DDI2 KO blocks NRF1 cleavage and nuclear translocation, causing impaired proteasome activity recovery upon irreversible proteasome inhibition, thereby increasing sensitivity to PI. Add-back of wild-type, but not of catalytically-dead DDI2, fully rescues these phenotypes. We propose that DDI2 is an unexplored, promising molecular target in MM by disrupting the proteasome stress response and exacerbating proteotoxicity.

scholarly journals Mitochondrial Sirtuin TcSir2rp3 Affects TcSODA Activity and Oxidative Stress Response in Trypanosoma cruzi

2021 ◽  
Vol 11 ◽  
Author(s):  
Leila dos Santos Moura ◽  
Vinícius Santana Nunes ◽  
Antoniel A. S. Gomes ◽  
Ana Caroline de Castro Nascimento Sousa ◽  
Marcos R. M. Fontes ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Superoxide Dismutase ◽  
Stress Response ◽  
Trypanosoma Cruzi ◽  
Conformational Changes ◽  
Manganese Superoxide Dismutase ◽  
Oxidative Stress Response ◽  
Lysine Acetylation

Trypanosoma cruzi faces a variety of environmental scenarios during its life cycle, which include changes in the redox environment that requires a fine regulation of a complex antioxidant arsenal of enzymes. Reversible posttranslational modifications, as lysine acetylation, are a fast and economical way for cells to react to environmental conditions. Recently, we found that the main antioxidant enzymes, including the mitochondrial superoxide dismutase A (TcSODA) are acetylated in T. cruzi, suggesting that protein acetylation could participate in the oxidative stress response in T. cruzi. Therefore, we investigated whether mitochondrial lysine deacetylase TcSir2rp3 was involved in the activity control of TcSODA. We observed an increased resistance to hydrogen peroxide and menadione in parasites overexpressing TcSir2rp3. Increased resistance was also found for benznidazole and nifurtimox, known to induce reactive oxidative and nitrosactive species in the parasite, associated to that a reduction in the ROS levels was observed. To better understand the way TcSir2rp3 could contributes to oxidative stress response, we analyzed the expression of TcSODA in the TcSir2rp3 overexpressing parasites and did not detect any increase in protein levels of this enzyme. However, we found that these parasites presented higher levels of superoxide dismutase activity, and also that TcSir2rp3 and TcSODA interacts in vivo. Knowing that TcSODA is acetylated at lysine residues K44 and K97, and that K97 is located at a similar region in the protein structure as K68 in human manganese superoxide dismutase (MnSOD), responsible for regulating MnSOD activity, we generated mutated versions of TcSODA at K44 and K97 and found that replacing K97 by glutamine, which mimics an acetylated lysine, negatively affects the enzyme activity in vitro. By using molecular dynamics approaches, we revealed that acetylation of K97 induces specific conformational changes in TcSODA with respect to hydrogen-bonding pattern to neighbor residues, suggesting a key participation of this residue to modulate the affinity to O2−. Taken together, our results showed for the first time the involvement of lysine acetylation in the maintenance of homeostatic redox state in trypanosomatids, contributing to the understanding of mechanisms used by T. cruzi to progress during the infection.

Targeting PPARalpha in Alzheimer's Disease

2018 ◽  
Vol 15 (4) ◽  
pp. 345-354 ◽  
Author(s):  
Barbara D'Orio ◽  
Anna Fracassi ◽  
Maria Paola Cerù ◽  
Sandra Moreno
Keyword(s):  
Oxidative Stress ◽  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Molecular Mechanisms ◽  
Redox Homeostasis ◽  
Antioxidant Response ◽  
Peroxisome Proliferator ◽  
Prevailing Paradigm

Background: The molecular mechanisms underlying Alzheimer's disease (AD) are yet to be fully elucidated. The so-called “amyloid cascade hypothesis” has long been the prevailing paradigm for causation of disease, and is today being revisited in relation to other pathogenic pathways, such as oxidative stress, neuroinflammation and energy dysmetabolism. The peroxisome proliferator-activated receptors (PPARs) are expressed in the central nervous system (CNS) and regulate many physiological processes, such as energy metabolism, neurotransmission, redox homeostasis, autophagy and cell cycle. Among the three isotypes (α, β/δ, γ), PPARγ role is the most extensively studied, while information on α and β/δ are still scanty. However, recent in vitro and in vivo evidence point to PPARα as a promising therapeutic target in AD. Conclusion: This review provides an update on this topic, focussing on the effects of natural or synthetic agonists in modulating pathogenetic mechanisms at AD onset and during its progression. Ligandactivated PPARα inihibits amyloidogenic pathway, Tau hyperphosphorylation and neuroinflammation. Concomitantly, the receptor elicits an enzymatic antioxidant response to oxidative stress, ameliorates glucose and lipid dysmetabolism, and stimulates autophagy.

scholarly journals Proanthocyanidins against Oxidative Stress: From Molecular Mechanisms to Clinical Applications

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Lingyu Yang ◽  
Dehai Xian ◽  
Xia Xiong ◽  
Rui Lai ◽  
Jing Song ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Signaling Pathways ◽  
Molecular Mechanisms ◽  
Metabolic Diseases ◽  
Low Cost ◽  
Natural Agents ◽  
Molecular Damage ◽  
And Control

Proanthocyanidins (PCs) are naturally occurring polyphenolic compounds abundant in many vegetables, plant skins (rind/bark), seeds, flowers, fruits, and nuts. Numerousin vitroandin vivostudies have demonstrated myriad effects potentially beneficial to human health, such as antioxidation, anti-inflammation, immunomodulation, DNA repair, and antitumor activity. Accumulation of prooxidants such as reactive oxygen species (ROS) exceeding cellular antioxidant capacity results in oxidative stress (OS), which can damage macromolecules (DNA, lipids, and proteins), organelles (membranes and mitochondria), and whole tissues. OS is implicated in the pathogenesis and exacerbation of many cardiovascular, neurodegenerative, dermatological, and metabolic diseases, both through direct molecular damage and secondary activation of stress-associated signaling pathways. PCs are promising natural agents to safely prevent acute damage and control chronic diseases at relatively low cost. In this review, we summarize the molecules and signaling pathways involved in OS and the corresponding therapeutic mechanisms of PCs.

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