scholarly journals POS0005 THE EFFECT OF LKB1 INHIBITION IN RA PATHOGENESIS

2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 204.3-204
Author(s):  
H. R. Lee ◽  
J. Kim ◽  
S. J. Yoo ◽  
J. A. Park ◽  
S. W. Kang
Keyword(s):  
Rheumatoid Arthritis ◽  
Reactive Oxygen Species ◽  
Mrna Expression ◽  
Proinflammatory Cytokines ◽  
Critical Role ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Reactive Oxygen ◽  
Migration And Invasion ◽  
Oxygen Species ◽  
Fibroblast Like Synoviocytes

Background:Liver kinase B1 (LKB1) is known as a tumor suppressor gene and also inhibits reactive oxygen species (ROS) levels. Intracellular ROS are catalyzed by the enzyme complex nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX). We previously reported that NOX4 induced the migration and invasion of fibroblast-like synoviocytes (FLS) in rheumatoid arthritis (RA). Although LKB1 is expected to alleviate synovial inflammation through ROS regulation, the role of LKB1 in RA has not been examined.Objectives:To explore whether LKB1 affects RA inflammation, we transfected LKB1 siRNA and analyzed related gene expressions in RA FLS.Methods:Synovial tissues were obtained from RA patients who were undergoing synovectomy or joint replacement. The isolated cells were cultured in Dulbecco’s modified Eagle’s medium (DMEM) supplemented with 10% fetal bovine serum, 100 U/ml penicillin and 100 mg/ml streptomycin and maintained in a 5% CO2 incubator at 37 °C. FLS were used for experiments after four to six passages. Cells were transfected with lipofectamine transfection reagent and LKB1 siRNA duplex targeting constructs. After incubation for 24 h, downregulation of target expression was evaluated by real-time PCR and western blot analysis.Results:RA FLS was transfected with LKB1 siRNA and 90% of LKB1 mRNA expression was decreased. LKB1 knock-down also caused the decreased expression of mechanistic target of rapamycin (mTOR; 0.38 fold) and serine/threonine kinase (AKT) 2 (0.40 fold), which are downstream targets of LKB1. NOX4 was significantly increased (4.94 fold) by LKB1 inhibition. On the other side, the down regulated NOX4 induced significantly elevated LKB1 mRNA expression in RA FLS. When the expressions of proinflammatory cytokines were examined, IL-1β, IL-6, TNF-α were highly increased by LKB1 deficiency. FLS migration-related chemokines, IL-8 and MMP-3 were also enhanced compared to control.Conclusion:There was a negative correlation between NOX4 and LKB1 in RA FLS. As LKB1 deficiency induced the expression of proinflammatory cytokines and migration related chemokines, LKB1 could play a critical role in RA pathogenesis.References:[1]Bartok B, Firestein GS. Fibroblast-like synoviocytes: key effector cells in rheumatoid arthritis. Immunol Rev. 2010;233(1):233–55.[2]Mateen S, Moin S, Khan AQ, Zafar A, Fatima N. Increased reactive oxygen species formation and oxidative stress in rheumatoid arthritis. PLoS One. 2016;11(4):e0152925.Disclosure of Interests:None declared.

scholarly journals Evaluation of apocynin in vitro on high glucose-induced oxidative stress on tenocytes

2020 ◽  
Vol 9 (1) ◽  
pp. 23-28
Author(s):  
Takashi Kurosawa ◽  
Yutaka Mifune ◽  
Atsuyuki Inui ◽  
Hanak Nishimoto ◽  
Yasuhiro Ueda ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Cell Proliferation ◽  
Mrna Expression ◽  
High Glucose ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Reactive Oxygen ◽  
Control Group ◽  
Oxygen Species

Aims The purpose of this study was to evaluate the in vitro effects of apocynin, an inhibitor of nicotinamide adenine dinucleotide phosphate oxidase (NOX) and a downregulator of intracellular reactive oxygen species (ROS), on high glucose-induced oxidative stress on tenocytes. Methods Tenocytes from normal Sprague-Dawley rats were cultured in both control and high-glucose conditions. Apocynin was added at cell seeding, dividing the tenocytes into four groups: the control group; regular glucose with apocynin (RG apo+); high glucose with apocynin (HG apo+); and high glucose without apocynin (HG apo–). Reactive oxygen species production, cell proliferation, apoptosis and messenger RNA (mRNA) expression of NOX1 and 4, and interleukin-6 (IL-6) were determined in vitro. Results Expression of NOX1, NOX4, and IL-6 mRNA in the HG groups was significantly higher compared with that in the RG groups, and NOX1, NOX4, and IL-6 mRNA expression in the HG apo+ group was significantly lower compared with that in the HG apo– group. Cell proliferation in the RG apo+ group was significantly higher than in the control group and was also significantly higher in the HG apo+ group than in the HG apo– group. Both the ROS accumulation and the amounts of apoptotic cells in the HG groups were greater than those in the RG groups and were significantly less in the HG apo+ group than in the HG apo– group. Conclusion Apocynin reduced ROS production and cell death via NOX inhibition in high-glucose conditions. Apocynin is therefore a potential prodrug in the treatment of diabetic tendinopathy. Cite this article: Bone Joint Res 2020;9(1):23–28.

Abstract P192: Both Mineralocorticoid Receptor and Angiotensin II type 1 Receptors in the Subfornical Organ Mediate Angiotensin II Induced Reactive Oxygen Species (ROS) in Brain Angiotensinergic Pathways

Hypertension ◽  
2015 ◽  
Vol 66 (suppl_1) ◽  
Author(s):  
Hong-Wei Wang ◽  
Roselyn White ◽  
Bing S Huang ◽  
Aidong Chen ◽  
Monir Ahmad ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Angiotensin Ii ◽  
Mrna Expression ◽  
Sympathetic Neurons ◽  
Critical Role ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Ang Ii ◽  
Endogenous Ouabain

Activation of angiotensinergic pathways and central aldosterone (aldo)-MR-ENaC-endogenous ouabain (EO)-AT 1 R pathway play a critical role in Ang II associated hypertension. The SFO contains both MR and AT 1 R and can relay the signals of circulating Ang II to downstream nuclei such as the PVN, SON and RVLM. We evaluated the effect of knockdown of MR and AT 1 R specific in the SFO on reactive oxygen species (ROS) production in downstream nuclei. Wistar rats were intra SFO infused with AAV-MR- or AT 1a R-siRNA and after 7 days received a sc infusion of Ang II at 500 ng/min/kg for 2 weeks. MR and AT 1 R expression were measured by real-time qPCR and western blotting. ROS was assessed by DHE staining. Ang II increased AT 1 R mRNA expression in the SFO. Both MR- and AT 1 R-siRNA in the SFO prevented this increase. Ang II decreased MR mRNA but increased protein expression in the SFO. Both MR- and AT 1 R-siRNA further decreased MR mRNA expression. Ang II significantly increased ROS in the SFO, magno- and parvocellular parts of the PVN, SON and RVLM. Both MR- and AT 1 R-siRNA in the SFO prevented ROS increases in the PVN and RVLM. In contrast, MR- but not AT 1 R-siRNA in the SFO prevented the Ang II-induced ROS in the SON. Both MR- and AT 1 R-siRNA in the SFO prevented most of the Ang II-induced hypertension. These results suggest that aldo-MR signaling in the SFO is needed for the activation of Ang II-AT 1 R signaling from the SFO to the PVN and RVLM. Considering that only MR-siRNA in the SFO prevents circulating Ang II induced ROS in the SON, activation of aldo-MR signaling from the SFO to the SON may via EO enhance AT 1 R dependent activation of pre-sympathetic neurons in the PVN, and thereby to Ang II-hypertension.

scholarly journals Reactive Oxygen Species: Beyond Their Reactive Behavior

2021 ◽  
Vol 46 (1) ◽  
pp. 77-87
Author(s):  
Arnaud Tauffenberger ◽  
Pierre J. Magistretti
Keyword(s):  
Reactive Oxygen Species ◽  
Second Messengers ◽  
Critical Role ◽  
Complex Function ◽  
Reactive Oxygen ◽  
High Reactivity ◽  
Oxygen Species ◽  
Health And Disease ◽  
Cellular Dysfunction ◽  
The Brain

AbstractCellular homeostasis plays a critical role in how an organism will develop and age. Disruption of this fragile equilibrium is often associated with health degradation and ultimately, death. Reactive oxygen species (ROS) have been closely associated with health decline and neurological disorders, such as Alzheimer’s disease or Parkinson’s disease. ROS were first identified as by-products of the cellular activity, mainly mitochondrial respiration, and their high reactivity is linked to a disruption of macromolecules such as proteins, lipids and DNA. More recent research suggests more complex function of ROS, reaching far beyond the cellular dysfunction. ROS are active actors in most of the signaling cascades involved in cell development, proliferation and survival, constituting important second messengers. In the brain, their impact on neurons and astrocytes has been associated with synaptic plasticity and neuron survival. This review provides an overview of ROS function in cell signaling in the context of aging and degeneration in the brain and guarding the fragile balance between health and disease.

scholarly journals CYP450 Mediates Reactive Oxygen Species Production in a Mouse Model of β-Thalassemia through an Increase in 20-HETE Activity

2021 ◽  
Vol 22 (3) ◽  
pp. 1106
Author(s):  
Rayan Bou-Fakhredin ◽  
Batoul Dia ◽  
Hilda E. Ghadieh ◽  
Stefano Rivella ◽  
Maria Domenica Cappellini ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Mouse Model ◽  
Cell Injury ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Reactive Oxygen ◽  
Ros Generation ◽  
Oxygen Species ◽  
Species Production ◽  
Different Sources ◽  
Dependent Pathway

Oxidative damage by reactive oxygen species (ROS) is one of the main contributors to cell injury and tissue damage in thalassemia patients. Recent studies suggest that ROS generation in non-transfusion-dependent (NTDT) patients occurs as a result of iron overload. Among the different sources of ROS, the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase family of enzymes and cytochrome P450 (CYP450) have been proposed to be major contributors for oxidative stress in several diseases. However, the sources of ROS in patients with NTDT remain poorly understood. In this study, Hbbth3/+ mice, a mouse model for β-thalassemia, were used. These mice exhibit an unchanged or decreased expression of the major NOX isoforms, NOX1, NOX2 and NOX4, when compared to their C57BL/6 control littermates. However, a significant increase in the protein synthesis of CYP4A and CYP4F was observed in the Hbbth3/+ mice when compared to the C57BL/6 control mice. These changes were paralleled by an increased production of 20-hydroxyeicosatetraenoic acid (20-HETE), a CYP4A and CYP4F metabolite. Furthermore, these changes corroborate with onset of ROS production concomitant with liver injury. To our knowledge, this is the first report indicating that CYP450 4A and 4F-induced 20-HETE production mediates reactive oxygen species overgeneration in Hbbth3/+ mice through an NADPH-dependent pathway.

Methotrexate suppresses the interleukin-6 induced generation of reactive oxygen species in the synoviocytes of rheumatoid arthritis

2000 ◽  
Vol 47 (1) ◽  
pp. 35-44 ◽  
Author(s):  
Ji-Yeon Sung ◽  
Jang-Hee Hong ◽  
Hyung-Sik Kang ◽  
Inpyo Choi ◽  
Sang-Deok Lim ◽  
...  
Keyword(s):  
Rheumatoid Arthritis ◽  
Reactive Oxygen Species ◽  
Interleukin 6 ◽  
Reactive Oxygen ◽  
Oxygen Species
Sign in / Sign up

Export Citation Format

Share Document