The glycoprotein GPNMB attenuates astrocyte inflammatory responses through the CD44 receptor.
Female; Humans; Male; Animals; Mice; Reactive Oxygen Species/metabolism; Astrocyte; CD44; GPNMB; *Neuroinflammation; *Parkinson's disease; Case-Control Studies; Analysis of Variance; Signal Transduction/drug effects; Hyaluronan Receptors/*metabolism; Glial Fibrillary Acidic Protein/metabolism; Nitric Oxide/metabolism; Cells; Cultured; RNA; Messenger/metabolism; Chemical; 3; Databases; 1-Methyl-4-phenyl-1; 2; 6-tetrahydropyridine/pharmacology; Anti-Inflammatory Agents/*therapeutic use; Astrocytes/*drug effects; Cytokines/genetics/metabolism; Inflammation/*drug therapy/etiology; Membrane Glycoproteins/*therapeutic use; Neurotoxins/toxicity; Parkinson Disease/complications/*pathology
BACKGROUND: Neuroinflammation is one of the hallmarks of neurodegenerative diseases, such as Parkinson's disease (PD). Activation of glial cells, including microglia and astrocytes, is a characteristic of the inflammatory response. Glycoprotein non-metastatic melanoma protein B (GPNMB) is a transmembrane glycoprotein that releases a soluble signaling peptide when cleaved by ADAM10 or other extracellular proteases. GPNMB has demonstrated a neuroprotective role in animal models of ALS and ischemia. However, the mechanism of this protection has not been well established. CD44 is a receptor expressed on astrocytes that can bind GPNMB, and CD44 activation has been demonstrated to reduce NFkappaB activation and subsequent inflammatory responses in macrophages. GPNMB signaling has not been investigated in models of PD or specifically in astrocytes. More recently, genetic studies have linked polymorphisms in GPNMB with risk for PD. Therefore, it is important to understand the role this signaling protein plays in PD. METHODS: We used data mining techniques to evaluate mRNA expression of GPNMB and its receptor CD44 in the substantia nigra of PD and control brains. Immunofluorescence and qPCR techniques were used to assess GPNMB and CD44 levels in mice treated with MPTP. In vitro experiments utilized the immortalized mouse astrocyte cell line IMA2.1 and purified primary mouse astrocytes. The effects of recombinant GPNMB on cytokine-induced astrocyte activation was determined by qPCR, immunofluorescence, and measurement of nitric oxide and reactive oxygen production. RESULTS: Increased GPNMB and CD44 expression was observed in the substantia nigra of human PD brains and in GFAP-positive astrocytes in an animal model of PD. GPNMB treatment attenuated cytokine-induced levels of inducible nitric oxide synthase, nitric oxide, reactive oxygen species, and the inflammatory cytokine IL-6 in an astrocyte cell line and primary mouse astrocytes. Using primary mouse astrocytes from CD44 knockout mice, we found that the anti-inflammatory effects of GPNMB are CD44-mediated. CONCLUSIONS: These results demonstrate that GPNMB may exert its neuroprotective effect through reducing astrocyte-mediated neuroinflammation in a CD44-dependent manner, providing novel mechanistic insight into the neuroprotective properties of GPNMB.
Neal Matthew L; Boyle Alexa M; Budge Kevin M; Safadi Fayez F; Richardson Jason R
Journal of neuroinflammation
2018
2018-03
<a href="http://doi.org/10.1186/s12974-018-1100-1" target="_blank" rel="noreferrer noopener">10.1186/s12974-018-1100-1</a>
Quinone and nitrofurantoin redox cycling by recombinant cytochrome b5 reductase.
Humans; Reactive Oxygen Species/metabolism; Oxidation-Reduction; Liver; *Reactive oxygen species; Kinetics; Recombinant Proteins/metabolism; Oxygen Consumption; Free Radicals/metabolism; Microsomes; *Cytochrome b5; *Free radicals; *Redox cycling; Benzoquinones/*metabolism; Cytochrome-B(5) Reductase/*metabolism; NADP/metabolism; Nitrofurantoin/*metabolism
NADH cytochrome b5 reductase mediates electron transfer from NADH to cytochrome b5 utilizing flavin adenine dinucleotide as a redox cofactor. Reduced cytochrome b5 is an important cofactor in many metabolic reactions including cytochrome
Szilagyi John T; Fussell Karma C; Wang Yun; Jan Yi-Hua; Mishin Vladimir; Richardson Jason R; Heck Diane E; Yang Shaojun; Aleksunes Lauren M; Laskin Debra L; Laskin Jeffrey D
Toxicology and applied pharmacology
2018
2018-11
<a href="http://doi.org/10.1016/j.taap.2018.09.011" target="_blank" rel="noreferrer noopener">10.1016/j.taap.2018.09.011</a>
Acute exposure to a glyphosate-containing herbicide formulation inhibits Complex II and increases hydrogen peroxide in the model organism Caenorhabditis elegans.
C. elegans; Glyphosate; *hydrogen peroxide; Mitochondrial inhibition; Oxygen Consumption; *Reactive oxygen species; Animals; Reactive Oxygen Species/metabolism; Adenosine Triphosphate/metabolism; Herbicides/*toxicity; Caenorhabditis elegans/*drug effects/metabolism; Electron Transport Complex II/*antagonists & inhibitors/metabolism; Glycine/*analogs & derivatives/toxicity
Glyphosate-based herbicides, such as Touchdown (TD) and Roundup, are among the most heavily-used herbicides in the world. While the active ingredient is generally considered non-toxic, the toxicity resulting from exposure to commercially-sold formulations is less clear. In many cases, cell cultures or various model organisms exposed to glyphosate formulations show toxicity and, in some cases, lethality. Using Caenorhabditis elegans, we assessed potential toxic mechanisms through which a highly-concentrated commercial formulation of TD promotes neurodegeneration. Following a 30-min treatment, we assayed mitochondrial electron transport chain function and reactive oxygen species (ROS) production. Initial oxygen consumption studies indicated general mitochondrial inhibition compared to controls ((*)p < 0.05). When Complex II activity was further assessed, inhibition was observed in all TD-treated groups ((*)p < 0.05). Complex IV activity, however, was not adversely affected by TD. This electron transport chain inhibition also resulted in reduced ATP levels ((*)p < 0.05). Furthermore, hydrogen peroxide levels, but not other ROS, were increased ((*)p < 0.05). Taken together, these data indicate that commercially-available formulations of TD may exert neurotoxicity through Complex II (succinate dehydrogenase) inhibition, decreased ATP levels, and increased hydrogen peroxide production.
Burchfield Shelbie L; Bailey Denise C; Todt Callie E; Denney Rachel D; Negga Rekek; Fitsanakis Vanessa A
Environmental toxicology and pharmacology
2019
2019-02
<a href="http://doi.org/10.1016/j.etap.2018.12.019" target="_blank" rel="noreferrer noopener">10.1016/j.etap.2018.12.019</a>
Biocompatibility, efficacy and biodistribution of Gelucire-stabilized nanoparticles engineered for docetaxel delivery.
*Biocompatible Materials; *Nanoparticles; Animals; Antineoplastic Agents/*administration & dosage/pharmacokinetics/pharmacology; Docetaxel; Macrophage Activation/drug effects; Platelet Aggregation/drug effects; Rats; Reactive Oxygen Species/metabolism; Taxoids/*administration & dosage/pharmacokinetics/pharmacology; Tissue Distribution
Docetaxel is a potent anticancer agent that will benefit greatly from alternative delivery systems that can overcome several reported adverse effects due to the drug itself and/or the solvent system in the current clinical formulation. In this regard, a new nanoparticle delivery system for docetaxel was prepared from Gelucire-based nanoemulsions by using binary mixtures of Gelucire 44/14 and cetyl alcohol as NP matrix materials. Various amounts of docetaxel (50-1000 microg/ml) were added to the oil phase of the nanoemulsions prior to obtaining solid nanoparticles. The nanoparticles (100-140 nm) achieved high entrapment efficiency (\textgreater or = 89%) of docetaxel which was maintained upon storage at 4 degrees C and 25 degrees C. Additional data indicated the Gelucire component in NP played influential roles in drug release possibly by facilitating diffusion from NPs and/or accelerating erosion of NP matrix. Docetaxel-loaded nanoparticles did not cause any significant red blood cell lysis or platelet aggregation nor activate macrophages. Also in-vitro antitumor efficacy in human lung adenocarcinoma cells was demonstrated based on cell cytotoxicity, production of reactive oxygen species and reduction of mitochondrial potential. Enhancement of in-vitro antitumor effects of docetaxel with Gelucire-based NPs could be ascribed to improved particle dispersion and efficient cell permeability. Studies in BALB/c mice demonstrated the stability/retention of NPs in blood circulation and the potential in facilitating docetaxel absorption across the peritoneal cavity. The nanoparticles reported herein may be effective as novel biocompatible and effective delivery systems for docetaxel.
Wehrung Daniel; Geldenhuys Werner J; Bi Lipeng; Oyewumi Moses O
Journal of nanoscience and nanotechnology
2012
2012-03
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1166/jnn.2012.5789" target="_blank" rel="noreferrer noopener">10.1166/jnn.2012.5789</a>
Antitumor effect of novel gallium compounds and efficacy of nanoparticle-mediated gallium delivery in lung cancer.
Antineoplastic Agents/*administration & dosage/chemistry/pharmacokinetics; Biocompatible Materials/administration & dosage/chemistry/pharmacokinetics; Cell Line; Cell Survival/drug effects; Coordination Complexes/*administration & dosage/chemistry/pharmacokinetics; Drug Carriers/administration & dosage/chemistry; Drug Stability; Endocytosis/drug effects; Gallium/*administration & dosage/chemistry/pharmacokinetics; Hemolysis/drug effects; Humans; Lung Neoplasms/*drug therapy/metabolism; Materials Testing; Membrane Potential; Mitochondrial/drug effects; Nanoparticles/*administration & dosage/chemistry; Particle Size; Platelet Aggregation/drug effects; Reactive Oxygen Species/metabolism; Transferrin/chemistry/pharmacology; Tumor
The widespread application of gallium (Ga) in cancer therapy has been greatly hampered by lack of specificity resulting in poor tumor accumulation and retention. To address the challenge, two lipophilic gallium (III) compounds (gallium hexanedione; GaH and gallium acetylacetonate; GaAcAc) were synthesized and antitumor studies were conducted in human lung adenocarcinoma (A549) cells. Nanoparticles (NPs) containing various concentrations of the Ga compounds were prepared using a binary mixture of Gelucire 44/14 and cetyl alcohol as matrix materials. NPs were characterized based on size, morphology, stability and biocompatibility. Antitumor effects of free or NP-loaded Ga compounds were investigated based on cell viability, production of reactive oxygen species and reduction of mitochondrial potential. Compared to free Ga compounds, cytotoxicity of NP-loaded Ga (5-150 microg/ml) was less dependent on concentration and incubation time (exposure) with A549 cells. NP-mediated delivery (5-150 microg Ga/ml) enhanced antitumor effects of Ga compounds and the effect was pronounced at: (i) shorter incubation times; and (ii) at low concentrations of gallium (approximately 50 microg/ml) (p \textless 0.0006). Additional studies showed that
Wehrung Daniel; Oyewumi Moses O
Journal of biomedical nanotechnology
2012
2012-02
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1166/jbn.2012.1361" target="_blank" rel="noreferrer noopener">10.1166/jbn.2012.1361</a>
Resolution of mitochondrial oxidative stress rescues coronary collateral growth in Zucker obese fatty rats.
Animal; Animals; Antioxidants/*pharmacology; Collateral Circulation/*drug effects/physiology; Coronary Vessels/drug effects/*growth & development; Disease Models; Heart/*drug effects/physiology; Lipid Peroxidation/drug effects/physiology; Lipid Peroxides/metabolism; Male; Metabolic Syndrome/*metabolism/physiopathology; Mitochondria; Mitochondrial Proteins/metabolism; Obesity/*metabolism/physiopathology; Organophosphorus Compounds/pharmacology; Oxidative Stress/*drug effects/physiology; Piperidines/pharmacology; Rats; Reactive Oxygen Species/metabolism; Ubiquinone/pharmacology; Zucker
OBJECTIVE: We have previously found abrogated ischemia-induced coronary collateral growth in Zucker obese fatty (ZOF) rats compared with Zucker lean (ZLN) rats. Because ZOF rats have structural abnormalities in their mitochondria suggesting dysfunction and also show increased production of O(2), we hypothesized that mitochondrial dysfunction caused by oxidative stress impairs coronary collateral growth in ZOF. METHODS AND RESULTS: Increased levels of reactive oxygen species were observed in aortic endothelium and smooth muscle cells in ZOF rats compared with ZLN rats. Reactive oxygen species levels were decreased by the mitochondria-targeted antioxidants MitoQuinone (MQ) and MitoTempol (MT) as assessed by MitoSox Red and dihydroethidine staining. Lipid peroxides (a marker of oxidized lipids) were increased in ZOF by approximately 47% compared with ZLN rats. The elevation in oxidative stress was accompanied by increased antioxidant enzymes, except glutathione peroxidase-1, and by increased uncoupling protein-2 in ZOF versus ZLN rats. In addition, elevated respiration rates were also observed in the obese compared with lean rats. Administration of MQ significantly normalized the metabolic profiles and reduced lipid peroxides in ZOF rats to the same level observed in lean rats. The protective effect of MQ also suppressed the induction of uncoupling protein-2 in the obese rats. Resolution of mitochondrial oxidative stress by MQ or MT restored coronary collateral growth to the same magnitude observed in ZLN rats in response to repetitive ischemia. CONCLUSIONS: We conclude that mitochondrial oxidative stress and dysfunction play a key role in disrupting coronary collateral growth in obesity and the metabolic syndrome, and elimination of the mitochondrial oxidative stress with MQ or MT rescues collateral growth.
Pung Yuh Fen; Rocic Petra; Murphy Michael P; Smith Robin A J; Hafemeister Jennifer; Ohanyan Vahagn; Guarini Giacinta; Yin Liya; Chilian William M
Arteriosclerosis, thrombosis, and vascular biology
2012
2012-02
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1161/ATVBAHA.111.241802" target="_blank" rel="noreferrer noopener">10.1161/ATVBAHA.111.241802</a>
Butein Activates Autophagy Through AMPK/TSC2/ULK1/mTOR Pathway to Inhibit IL-6 Expression in IL-1beta Stimulated Human Chondrocytes.
AMP-Activated Protein Kinases/metabolism; AMPK; Articular/cytology/pathology; Autophagy; Autophagy-Related Protein 5/antagonists & inhibitors/genetics/metabolism; Autophagy-Related Protein-1 Homolog/metabolism; Autophagy/*drug effects; Butein; Cartilage; Cell Survival/drug effects; Cells; Chalcones/*pharmacology; Chondrocytes/cytology/drug effects/metabolism; Cultured; Humans; Inflammation; Interleukin-1beta/*pharmacology; Interleukin-6/genetics/*metabolism; Intracellular Signaling Peptides and Proteins/metabolism; mTOR; Osteoarthritis; Osteoarthritis/metabolism/pathology; Phosphorylation/drug effects; Reactive Oxygen Species/metabolism; RNA; RNA Interference; Signal Transduction/*drug effects; Small Interfering/metabolism; TOR Serine-Threonine Kinases/metabolism; TSC2; Tuberous Sclerosis Complex 2 Protein; Tumor Suppressor Proteins/metabolism; ULK1
BACKGROUND/AIMS: Butein (2',3,4,4'-Tetrahydroxychalcone), a polyphenol produced by several plants including Butea monoserpma, has been reported to exert potent anti-inflammatory activity but the mechanism remains unknown. In the present work we investigated the mechanism of Butein-mediated suppression of IL-6 expression in normal and human osteoarthritis (OA) chondrocytes under pathological conditions. METHODS: Expression level of interleukin-6 (IL-6) protein in OA cartilage was analyzed by immunohistochemistry using a validated antibody. Chondrocytes derived from normal or OA cartilage by enzymatic digestion were pretreated with Butein followed by stimulation with interleukin-1beta (IL-1beta) and the levels of IL-6 mRNA were quantified by TaqMan assay and the protein levels were measured by Western immunoblotting. Autophagy activation was determined by Western blotting and confocal microscopy. Autophagy was inhibited by siRNA mediated knockdown of ATG5. RESULTS: Expression of IL-6 protein was high in the OA cartilage compared to smooth cartilage from the same patient. OA chondrocytes and cartilage explants stimulated with IL-1beta showed high level expression of IL-6 mRNA and protein. Butein increased the phosphorylation of AMPKalphaThr-172, TSC2Ser-1387 and ULK1Ser-317 and inhibited the phosphorylation of mTORSer-2448 and its downstream target p70S6K and increased autophagy flux that correlated with the suppression of the IL-1beta mediated expression of IL-6 in normal and OA chondrocytes. In OA chondrocytes with siRNA-mediated knockdown of ATG5 expression, treatment with Butein failed to activate autophagy and abrogated the suppression of IL-1beta induced IL-6 expression. CONCLUSION: Our findings demonstrate for the first time that Butein activate autophagy in OA chondrocytes via AMPK/TSC2/ULK1/mTOR pathway. Additionally, activation of autophagy was essential to block the IL-1beta-induced expression of IL-6 in OA chondrocytes. These data support further studies to evaluate the use of Butein or compounds derived from it for the management of OA.
Ansari Mohammad Y; Ahmad Nashrah; Haqqi Tariq M
Cellular physiology and biochemistry : international journal of experimental cellular physiology, biochemistry, and pharmacology
2018
2018
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1159/000493225" target="_blank" rel="noreferrer noopener">10.1159/000493225</a>
Trivalent chromium inhibits TSP-1 expression, proliferation, and O-GlcNAc signaling in vascular smooth muscle cells in response to high glucose in vitro.
Aorta/drug effects/metabolism; Cell Proliferation/*drug effects/genetics; Cells; Chromium/*pharmacology; Cultured; Fructosephosphates/metabolism; Genetic/drug effects/genetics; Glucose/*metabolism; Glutamine/genetics; Glycosylation/drug effects; Hexosamines/metabolism; Humans; Hyperglycemia/metabolism; Muscle; Myocytes; N-Acetylglucosaminyltransferases/genetics; O-glycosylation; Promoter Regions; reactive oxygen species; Reactive Oxygen Species/metabolism; Signal Transduction/*drug effects/genetics; Smooth; Smooth Muscle/*drug effects/metabolism; Thrombospondin 1/*antagonists & inhibitors/genetics; thrombospondin-1; Transcription; trivalent chromium; vascular smooth muscle cells; Vascular/*drug effects/metabolism
Trivalent chromium (Cr(3+)) is a mineral nutrient reported to have beneficial effects in glycemic and cardiovascular health. In vitro and in vivo studies suggest that Cr(3+) supplementation reduces the atherogenic potential and lowers the risk of vascular inflammation in diabetes. However, effects of Cr(3+) in vascular cells under conditions of hyperglycemia, characteristic of diabetes, remain unknown. In the present study we show that a therapeutically relevant concentration of Cr(3+) (100 nM) significantly downregulates a potent proatherogenic matricellular protein, thrombospondin-1 (TSP-1), in human aortic smooth muscle cells (HASMC) stimulated with high glucose in vitro. Promoter-reporter assays reveal that this downregulation of TSP-1 expression by Cr(3+) occurs at the level of transcription. The inhibitory effects of Cr(3+) on
Ganguly Rituparna; Sahu Soumyadip; Chavez Ronaldo J; Raman Priya
American journal of physiology. Cell physiology
2015
2015-01
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1152/ajpcell.00256.2014" target="_blank" rel="noreferrer noopener">10.1152/ajpcell.00256.2014</a>
MicroRNA-223 ameliorates alcoholic liver injury by inhibiting the
*CYTOKINES; *ETHANOL; *FATTY LIVER; *INFLAMMATION; *LEUKOCYTES; Adult; Alanine Transaminase/blood; Alcoholic/genetics/*metabolism/pathology; Alcoholism/*blood/complications; Animals; Aspartate Aminotransferases/blood; Bilirubin/blood; Binge Drinking/*blood/complications; Case-Control Studies; Central Nervous System Depressants/administration & dosage; Down-Regulation; Ethanol/administration & dosage; Female; Humans; Inbred C57BL; Interleukin-6/genetics/metabolism; Liver Diseases; Male; Mice; MicroRNAs/*blood/*genetics; Middle Aged; NADPH Oxidases/genetics/metabolism; Neutrophils/*metabolism; Reactive Oxygen Species/metabolism; Up-Regulation; Young Adult
OBJECTIVES: Chronic-plus-binge ethanol feeding activates neutrophils and exacerbates liver injury in mice. This study investigates how recent excessive drinking affects peripheral neutrophils and liver injury in alcoholics, and how miR-223, one of the most abundant microRNAs (miRNAs) in neutrophils, modulates neutrophil function and liver injury in ethanol-fed mice. DESIGNS: Three hundred alcoholics with (n=140) or without (n=160) recent excessive drinking and 45 healthy controls were enrolled. Mice were fed an ethanol diet for 10 days followed by a single binge of ethanol. RESULTS: Compared with healthy controls or alcoholics without recent drinking, alcoholics with recent excessive drinking had higher levels of circulating neutrophils, which correlated with serum levels of alanine transaminase (ALT) and aspartate transaminase (AST). miRNA array analysis revealed that alcoholics had elevated serum miR-223 levels compared with healthy controls. In chronic-plus-binge ethanol feeding mouse model, the levels of miR-223 were increased in both serum and neutrophils. Genetic deletion of the miR-223 gene exacerbated ethanol-induced hepatic injury, neutrophil infiltration, reactive oxygen species (ROS) and upregulated hepatic expression of interleukin (IL)-6 and phagocytic oxidase (phox) p47(phox). Mechanistic studies revealed that miR-223 directly inhibited IL-6 expression and subsequently inhibited p47(phox) expression in neutrophils. Deletion of the p47(phox) gene ameliorated ethanol-induced liver injury and ROS production by neutrophils. Finally, miR-223 expression was downregulated, while IL-6 and p47(phox) expression were upregulated in peripheral blood neutrophils from alcoholics compared with healthy controls. CONCLUSIONS: miR-223 is an important regulator to block neutrophil infiltration in alcoholic liver disease and could be a novel therapeutic target for the treatment of this malady.
Li Man; He Yong; Zhou Zhou; Ramirez Teresa; Gao Yueqiu; Gao Yanhang; Ross Ruth A; Cao Haixia; Cai Yan; Xu Ming-Jiang; Feng Dechun; Zhang Ping; Liangpunsakul Suthat; Gao Bin
Gut
2017
2017-04
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1136/gutjnl-2016-311861" target="_blank" rel="noreferrer noopener">10.1136/gutjnl-2016-311861</a>
Hyperammonaemia-induced skeletal muscle mitochondrial dysfunction results in cataplerosis and oxidative stress.
*ammonia; *ATP; *cellular respiration; *cirrhosis; *mitochondria; *Oxidative Stress; *portacaval anastamosis; *reactive oxygen species; *skeletal muscle; Adenosine Triphosphate/metabolism; Aged; Animals; Cell Line; Cell Respiration; Creatine Kinase/metabolism; Female; Humans; Hyperammonemia/*metabolism; Liver Cirrhosis/metabolism; Male; Middle Aged; Mitochondria; Muscle; Muscle/*metabolism; Myosin Heavy Chains/metabolism; NAD/metabolism; Rats; Reactive Oxygen Species/metabolism; Skeletal/*metabolism; Sprague-Dawley; Thiobarbituric Acid Reactive Substances/metabolism
KEY POINTS: Hyperammonaemia occurs in hepatic, cardiac and pulmonary diseases with increased muscle concentration of ammonia. We found that ammonia results in reduced skeletal muscle mitochondrial respiration, electron transport chain complex I dysfunction, as well as lower NAD(+) /NADH ratio and ATP content. During hyperammonaemia, leak of electrons from complex III results in oxidative modification of proteins and lipids. Tricarboxylic acid cycle intermediates are decreased during hyperammonaemia, and providing a cell-permeable ester of alphaKG reversed the lower TCA cycle intermediate concentrations and increased ATP content. Our observations have high clinical relevance given the potential for novel approaches to reverse skeletal muscle ammonia toxicity by targeting the TCA cycle intermediates and mitochondrial ROS. ABSTRACT: Ammonia is a cytotoxic metabolite that is removed primarily by hepatic ureagenesis in humans. Hyperammonaemia occurs in advanced hepatic, cardiac and pulmonary disease, and in urea cycle enzyme deficiencies. Increased skeletal muscle ammonia uptake and metabolism are the major mechanism of non-hepatic ammonia disposal. Non-hepatic ammonia disposal occurs in the mitochondria via glutamate synthesis from alpha-ketoglutarate resulting in cataplerosis. We show skeletal muscle mitochondrial dysfunction during hyperammonaemia in a comprehensive array of human, rodent and cellular models. ATP synthesis, oxygen consumption, generation of reactive oxygen species with oxidative stress, and tricarboxylic acid (TCA) cycle intermediates were quantified. ATP content was lower in the skeletal muscle from cirrhotic patients, hyperammonaemic portacaval anastomosis rat, and C2C12 myotubes compared to appropriate controls. Hyperammonaemia in C2C12 myotubes resulted in impaired intact cell respiration, reduced complex I/NADH oxidase activity and electron leak occurring at complex III of the electron transport chain. Consistently, lower NAD(+) /NADH ratio was observed during hyperammonaemia with reduced TCA cycle intermediates compared to controls. Generation of reactive oxygen species resulted in increased content of skeletal muscle carbonylated proteins and thiobarbituric acid reactive substances during hyperammonaemia. A cell-permeable ester of alpha-ketoglutarate reversed the low TCA cycle intermediates and ATP content in myotubes during hyperammonaemia. However, the mitochondrial antioxidant MitoTEMPO did not reverse the lower ATP content during hyperammonaemia. We provide for the first time evidence that skeletal muscle hyperammonaemia results in mitochondrial dysfunction and oxidative stress. Use of anaplerotic substrates to reverse ammonia-induced mitochondrial dysfunction is a novel therapeutic approach.
Davuluri Gangarao; Allawy Allawy; Thapaliya Samjhana; Rennison Julie H; Singh Dharmvir; Kumar Avinash; Sandlers Yana; Van Wagoner David R; Flask Chris A; Hoppel Charles; Kasumov Takhar; Dasarathy Srinivasan
The Journal of physiology
2016
2016-12
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1113/JP272796" target="_blank" rel="noreferrer noopener">10.1113/JP272796</a>
Coronary microvascular Kv1 channels as regulatory sensors of intracellular pyridine nucleotide redox potential.
* NADH; *endothelium; *ion channels; *vascular smooth muscle; *vasodilation; Animals; Coronary Vessels/chemistry; Humans; Microcirculation; Oxidation-Reduction; Potassium Channels; Pyrimidine Nucleotides/*metabolism; Reactive Nitrogen Species/metabolism; Reactive Oxygen Species/metabolism; Voltage-Gated/*physiology
Smooth muscle voltage-gated potassium (Kv) channels are important regulators of microvascular tone and tissue perfusion. Recent studies indicate that Kv1 channels represent a key component of the physiological coupling between coronary blood flow and myocardial oxygen demand. While the mechanisms by which metabolic changes in the heart are transduced to alter coronary Kv1 channel gating and promote vasodilation are unclear, a growing body of evidence underscores a pivotal role of Kv1 channels in sensing the cellular redox status. Here, we discuss current knowledge of mechanisms of Kv channel redox regulation with respect to pyridine nucleotide modulation of Kv1 function via ancillary Kvbeta proteins as well as direct modulation of channel activity via reactive oxygen and nitrogen species. We identify areas of additional research to address the integration of regulatory processes under altered physiological and pathophysiological conditions that may reveal insights into novel treatment strategies for conditions in which the matching of coronary blood supply and myocardial oxygen demand is compromised.
Dwenger Marc M; Ohanyan Vahagn; Navedo Manuel F; Nystoriak Matthew A
Microcirculation (New York, N.Y. : 1994)
2018
2018-01
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1111/micc.12426" target="_blank" rel="noreferrer noopener">10.1111/micc.12426</a>
Redox-dependent mechanisms in coronary collateral growth: the "redox window" hypothesis.
Angiotensin II/physiology; Animals; Coronary Vessels/*growth & development/metabolism; Humans; Oxidation-Reduction; Reactive Oxygen Species/metabolism
This review addresses the complexity of coronary collateral growth from the aspect of redox signaling and introduces the concept of a "redox window" in the context of collateral growth. In essence, the redox window constitutes a range in the redox state of cells, which not only is permissive for the actions of growth factors but also amplifies their actions. The interactions of redox-dependent signaling with growth factors are well established through the actions of many redox-dependent kinases (e.g., Akt and p38 mitogen-activated protein kinase). The initial changes in cellular redox can be induced by a variety of events, from the oxidative burst during reperfusion after ischemia, to recruitment of various types of inflammatory cells capable of producing reactive oxygen species. Any event that "upsets" the normal redox equilibrium is capable of amplifying growth. However, extremes of the redox window, oxidative and reductive stresses, are associated with diminished growth-factor signaling and reduced activation of redox-dependent kinases. This concept of a redox window helps to explain why the clinical trials aimed at stimulating coronary collateral growth, the "therapeutic angiogenesis trials," failed. However, understanding of redox signaling in the context of coronary collateral growth could provide new paradigms for stimulating collateral growth in patients.
Yun June; Rocic Petra; Pung Yuh Fen; Belmadani Souad; Carrao Ana Catarina Ribeiro; Ohanyan Vahagn; Chilian William M
Antioxidants & redox signaling
2009
2009-08
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1089/ars.2009.2476" target="_blank" rel="noreferrer noopener">10.1089/ars.2009.2476</a>
A wogonin-rich-fraction of Scutellaria baicalensis root extract exerts chondroprotective effects by suppressing IL-1beta-induced activation of AP-1 in human OA chondrocytes.
Cells; Chemical Fractionation/methods; Chondrocytes/*drug effects/metabolism; Cultured; Cyclooxygenase 2/genetics/metabolism; Flavanones/*pharmacology; Gene Expression Regulation/drug effects; Humans; Interleukin-1beta/pharmacology; Interleukin-6/genetics/metabolism; Osteoarthritis/pathology; Plant Extracts/*pharmacology; Plant Roots/*chemistry; Protective Agents/pharmacology; Reactive Oxygen Species/metabolism; Scutellaria baicalensis/*chemistry; Transcription Factor AP-1/genetics/*metabolism
Osteoarthritis (OA) is a common joint disorder with varying degrees of inflammation and sustained oxidative stress. The root extract of Scutellaria baicalensis (SBE) has been used for the treatment of inflammatory and other diseases. Here, we performed activity-guided HPLC-fractionation of SBE, identified the active ingredient(s) and investigated its chondroprotective potential. We found that the Wogonin containing fraction-4 (F4) was the most potent fraction based on its ability to inhibit ROS production and the suppression of catabolic markers including IL-6, COX-2, iNOS, MMP-3, MMP-9,
Khan Nazir M; Haseeb Abdul; Ansari Mohammad Y; Haqqi Tariq M
Scientific reports
2017
2017-03
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1038/srep43789" target="_blank" rel="noreferrer noopener">10.1038/srep43789</a>
Differential protein acetylation assists import of excess SOD2 into mitochondria and mediates SOD2 aggregation associated with cardiac hypertrophy in the murine
*Cardiac-specific transgenic mouse; *Mitochondria; *Mitochondrial translocation; *Protein acetylation; *Protein aggregation; *SOD2; Acetylation; Animals; Cardiomegaly/*metabolism; Cytosol/*metabolism; Heart/*physiology; Mice; Mitochondria/*metabolism; Pathological; Post-Translational; Protein Aggregation; Protein Folding; Protein Processing; Protein Transport; Reactive Oxygen Species/metabolism; Sirtuin 3/metabolism; Superoxide Dismutase/genetics/*metabolism; Transgenic
SOD2 is the primary antioxidant enzyme neutralizing (*)O2(-) in mitochondria. Cardiac-specific SOD2 overexpression (SOD2-tg) induces supernormal function and cardiac hypertrophy in the mouse heart. However, the reductive stress imposed by SOD2 overexpression results in protein aggregation of SOD2 pentamers and differential hyperacetylation of SOD2 in the mitochondria and cytosol. Here, we studied SOD2 acetylation in SOD2-tg and wild-type mouse hearts. LC-MS/MS analysis indicated the presence of four acetylated lysines in matrix SOD2 and nine acetylated lysines in cytosolic SOD2 from the SOD2-tg heart. However, only one specific acetylated lysine residue was detected in the mitochondria of the wild-type heart, which was consistent with Sirt3 downregulation in the SOD2-tg heart. LC-MS/MS further detected hyperacetylated SOD2 with a signaling peptide in the mitochondrial inner membrane and matrix of the SOD2-tg heart, indicating partial arrest of the SOD2 precursor in the membrane during translocation into the mitochondria. Upregulation of HSP 70 and cytosolic HSP 60 enabled the translocation of excess SOD2 into mitochondria. In vitro acetylation of matrix SOD2 with Ac2O deaggregated pentameric SOD2, restored the profile of cytosolic SOD2 hyperacetylation, and decreased matrix SOD2 activity. As revealed by 3D structure, acetylation of K89, K134, and K154 of cytosolic SOD2 induces unfolding of the tertiary structure and breaking of the salt bridges that are important for the quaternary structure, suggesting that hyperacetylation and HSP 70 upregulation maintain the unfolded status of SOD2 in the cytosol and mediate the import of SOD2 across the membrane. Downregulation of Sirt3, HSP 60, and presequence protease in the mitochondria of the SOD2-tg heart promoted protein misfolding that led to pentameric aggregation.
Zhang Liwen; Chen Chwen-Lih; Kang Patrick T; Jin Zhicheng; Chen Yeong-Renn
Free radical biology & medicine
2017
2017-07
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1016/j.freeradbiomed.2017.04.022" target="_blank" rel="noreferrer noopener">10.1016/j.freeradbiomed.2017.04.022</a>
Wogonin, a plant derived small molecule, exerts potent anti-inflammatory and chondroprotective effects through the activation of ROS/ERK/Nrf2 signaling pathways in human Osteoarthritis chondrocytes.
*ERK1/2; *Nrf2; *Osteoarthritis; *Redox; *Wogonin; Anti-Inflammatory Agents/administration & dosage; Chondrocytes/drug effects/pathology; Flavanones/*administration & dosage; Gene Expression Regulation/drug effects; Humans; Inflammation/*drug therapy/metabolism/pathology; Kelch-Like ECH-Associated Protein 1/chemistry/*genetics/metabolism; MAP Kinase Signaling System/drug effects; Molecular Docking Simulation; NF-E2-Related Factor 2/antagonists & inhibitors/chemistry/*genetics/metabolism; Osteoarthritis/*drug therapy/metabolism/pathology; Protein Binding; Reactive Oxygen Species/metabolism; Signal Transduction/drug effects
Osteoarthritis (OA), characterized by progressive destruction of articular cartilage, is the most common form of human arthritis. Here, we evaluated the potential chondroprotective and anti-inflammatory effects of Wogonin, a naturally occurring flavonoid, in IL-1beta-stimulated human OA chondrocytes and cartilage explants. Wogonin completely suppressed the expression and production of inflammatory mediators including IL-6, COX-2, PGE2, iNOS and NO in
Khan Nazir M; Haseeb Abdul; Ansari Mohammad Y; Devarapalli Pratap; Haynie Sara; Haqqi Tariq M
Free radical biology & medicine
2017
2017-05
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1016/j.freeradbiomed.2017.02.041" target="_blank" rel="noreferrer noopener">10.1016/j.freeradbiomed.2017.02.041</a>
Effects of gelucire content on stability, macrophage interaction and blood circulation of nanoparticles engineered from nanoemulsions.
Animals; ATP Binding Cassette Transporter; Calorimetry; Differential Scanning; Drug Carriers/*chemical synthesis/pharmacokinetics; Drug Stability; Emulsions/chemistry; Fatty Alcohols/*chemistry; Fourier Transform Infrared; Humans; Inbred BALB C; Macrophages/*drug effects/metabolism; Member 1/metabolism; Mice; Nanoparticles/*chemistry/ultrastructure; Oils/chemistry; Paclitaxel/pharmacokinetics; Particle Size; Polyethylene Glycols/*chemistry; Reactive Oxygen Species/metabolism; Rhodamine 123/metabolism; Spectroscopy; Subfamily B; Water/chemistry
The main objective of the study is to investigate the efficacy of Gelucire 44/14 (gelucire) in facilitating formation of cetyl alcohol (CA)-based nanoparticle (NP) and to assess the effects on key NP properties and functions. NPs from oil-in-water nanoemulsion precursors were prepared using binary mixtures of CA and gelucire (CA/gelucire) containing gelucire at 0, 25, 50 and 75% (w/w). The sizes of gelucire-based NPs (128-183 nm) were five times lower than control NPs (made without gelucire). All the NPs (with or without gelucire component) did not activate macrophages as monitored by reactive oxygen species production. Results from differential scanning calorimetry, FT-IR and multimodal light scattering measurements demonstrated the involvement of gelucire component in achieving homogeneous CA/gelucire particle populations that were stable on storage. The
Wehrung Daniel; Geldenhuys Werner J; Oyewumi Moses O
Colloids and surfaces. B, Biointerfaces
2012
2012-06
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1016/j.colsurfb.2012.02.005" target="_blank" rel="noreferrer noopener">10.1016/j.colsurfb.2012.02.005</a>
Wogonin, a natural flavonoid, intercalates with genomic DNA and exhibits protective effects in IL-1beta stimulated osteoarthritis chondrocytes.
Apoptosis/drug effects; Binding Sites; Cells; Chondrocytes/cytology/*drug effects/metabolism; Chondroprotective effects; Cultured; Denaturation; DNA binding; DNA/chemistry/*metabolism; Flavanones/chemistry/metabolism/*pharmacology; Flavonoids/chemistry/pharmacology; Fluorescence Resonance Energy Transfer; Humans; Intercalating Agents/chemistry/metabolism/*pharmacology; Interleukin-1beta/*pharmacology; Molecular Docking Simulation; Nucleic Acid Conformation; Osteoarthritis; Osteoarthritis/metabolism/pathology; Protective Agents/chemistry/metabolism/*pharmacology; Reactive Oxygen Species/metabolism; Up-Regulation/drug effects; Wogonin
Wogonin has recently been shown to possess anti-inflammatory and chondroprotective properties and is of considerable interest due to its broad pharmacological activities. The present study highlights that Wogonin binds DNA and exerts chondroprotective effects in vitro. Wogonin showed strong binding with chondrocytes genomic DNA in vitro. The mode of binding of Wogonin to genomic-DNA was assessed by competing Wogonin with EtBr or DAPI, known DNA intercalator and a minor groove binder, respectively. EtBr fluorescence reduced significantly with increase in Wogonin concentration suggesting possible DNA intercalation of Wogonin. Further, in silico molecular docking of Wogonin on mammalian DNA also indicated possible intercalation of Wogonin with DNA. The denaturation and FRET studies revealed that Wogonin prevents denaturation of DNA strands and provide stability to genomic DNA against a variety of chemical denaturants. The cellular uptake study showed that Wogonin enters osteoarthritis chondrocytes and was mainly localized in the nucleus. Wogonin treatment to OA chondrocytes protects the fragmentation of genomic DNA in response to IL-1beta as evaluated by DNA ladder and TUNEL assay. Treatment of chondrocytes with Wogonin resulted in significant suppression of IL-1beta-mediated induction of ROS. Further, Wogonin exhibited protective potential through potent suppression of extrinsic and intrinsic apoptotic pathways and induction of anti-apoptotic proteins in
Khan Nazir M; Ahmad Imran; Ansari Mohammad Y; Haqqi Tariq M
Chemico-biological interactions
2017
2017-08
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1016/j.cbi.2017.06.025" target="_blank" rel="noreferrer noopener">10.1016/j.cbi.2017.06.025</a>
Impaired coronary metabolic dilation in the metabolic syndrome is linked to mitochondrial dysfunction and mitochondrial DNA damage.
Animal; Animals; Coronary circulation; Coronary microcirculation; Coronary Vessels/metabolism/*physiopathology; Diabetes; Disease Models; DNA; DNA Damage/physiology; DNA Fragmentation; Metabolic Syndrome/metabolism/*physiopathology; Mitochondria; Mitochondria/*metabolism; Mitochondrial/*metabolism; Obesity; Oxidative Stress/physiology; Rats; Reactive Oxygen Species/metabolism; Vasodilation/physiology; Zucker
Mitochondrial dysfunction in obesity and diabetes can be caused by excessive production of free radicals, which can damage mitochondrial DNA. Because mitochondrial DNA plays a key role in the production of ATP necessary for cardiac work, we hypothesized that mitochondrial dysfunction, induced by mitochondrial DNA damage, uncouples coronary blood flow from cardiac work. Myocardial blood flow (contrast echocardiography) was measured in Zucker lean (ZLN) and obese fatty (ZOF) rats during increased cardiac metabolism (product of heart rate and arterial pressure, i.v. norepinephrine). In ZLN increased metabolism augmented coronary blood flow, but in ZOF metabolic hyperemia was attenuated. Mitochondrial respiration was impaired and ROS production was greater in ZOF than ZLN. These were associated with mitochondrial DNA (mtDNA) damage in ZOF. To determine if coronary metabolic dilation, the hyperemic response induced by heightened cardiac metabolism, is linked to mitochondrial function we introduced recombinant proteins (intravenously or intraperitoneally) in ZLN and ZOF to fragment or repair mtDNA, respectively. Repair of mtDNA damage restored mitochondrial function and metabolic dilation, and reduced ROS production in ZOF; whereas induction of mtDNA damage in ZLN reduced mitochondrial function, increased ROS production, and attenuated metabolic dilation. Adequate metabolic dilation was also associated with the extracellular release of ADP, ATP, and H2O2 by cardiac myocytes; whereas myocytes from rats with impaired dilation released only H2O2. In conclusion, our results suggest that mitochondrial function plays a seminal role in connecting myocardial blood flow to metabolism, and integrity of mtDNA is central to this process.
Guarini Giacinta; Kiyooka Takahiko; Ohanyan Vahagn; Pung Yuh Fen; Marzilli Mario; Chen Yeong-Renn; Chen Chwen-Lih; Kang Patrick T; Hardwick James P; Kolz Christopher L; Yin Liya; Wilson Glenn L; Shokolenko Inna; Dobson James G Jr; Fenton Richard; Chilian William M
Basic research in cardiology
2016
2016-05
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1007/s00395-016-0547-4" target="_blank" rel="noreferrer noopener">10.1007/s00395-016-0547-4</a>
Demethyleneberberine alleviates inflammatory bowel disease in mice through regulating NF-kappaB signaling and T-helper cell homeostasis.
Animals; Anti-Inflammatory Agents/*pharmacology/therapeutic use; Berberine/*analogs & derivatives/pharmacology/therapeutic use; Colitis; Colon/drug effects/immunology/pathology; Cytokines/immunology; Dextran Sulfate; DMB; Female; Helper-Inducer/*drug effects/immunology; Homeostasis/drug effects; Immunoglobulin G/blood; Inbred C57BL; Inflammatory Bowel Diseases/blood/chemically induced/drug therapy/*immunology; Mice; NF-kappa B/*antagonists & inhibitors/immunology; NF-kappaB; RAW 264.7 Cells; Reactive Oxygen Species/metabolism; Signal Transduction/drug effects; Spleen/cytology; T-Lymphocytes; Th cell
OBJECTIVE: The activation of NF-kappaB signaling and unbalance of T-helper (Th) cells have been reported to play a key role in the pathogenesis of colitis. Cortex Phellodendri Chinensis (CPC) is commonly used to treat inflammation and diarrhea. Demethyleneberberine (DMB), a component of CPC, was reported to treat alcoholic liver disease as a novel natural mitochondria-targeted antioxidant in our previous study. In this study, we investigated whether DMB could protect against dextran sulfate sodium (DSS)-induced inflammatory colitis in mice by regulation of NF-kappaB pathway and Th cells homeostatis. METHODS: Inflammatory colitis mice were induced by 3% DSS, and DMB were orally administered on the doses of 150 and 300 mg/kg. In vitro, DMB (10, 20, 40 muM) and N-acetyl cysteine (NAC, 5 mM) were co-cultured with RAW264.7 for 2 h prior to lipopolysaccharide (LPS) stimulation, and splenocytes from the mice were cultured ex vivo for 48 h for immune response test. RESULTS: In vivo, DMB significantly alleviated the weight loss and diminished myeloperoxidase (MPO) activity, while significantly reduced the production of pro-inflammatory cytokines, such as interleukin (IL)-6 and tumor necrosis factor-alpha (TNF-alpha), and inhibited the activation of
Chen Yingying; Li Rui-Yan; Shi Mei-Jing; Zhao Ya-Xing; Yan Yan; Xu Xin-Xin; Zhang Miao; Zhao Xiao-Tong; Zhang Yu-Bin
Inflammation research : official journal of the European Histamine Research Society ... [et al.]
2017
2017-02
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1007/s00011-016-1005-3" target="_blank" rel="noreferrer noopener">10.1007/s00011-016-1005-3</a>
Harpagoside suppresses IL-6 expression in primary human osteoarthritis chondrocytes.
*c-FOS/AP-1; *harpagoside; *IL-6; *MMP-13; *osteoarthritis; CCAAT-Enhancer-Binding Protein-beta/metabolism; Chemokines/metabolism; Chondrocytes/*drug effects/metabolism; Drug Evaluation; Glycosides/pharmacology/*therapeutic use; Harpagophytum; Humans; Interleukin-1beta; Interleukin-6/antagonists & inhibitors/*metabolism; Matrix Metalloproteinase 13/metabolism; NF-kappa B/metabolism; Osteoarthritis/*drug therapy/metabolism; Phytotherapy; Plant Extracts/pharmacology/therapeutic use; Preclinical; Primary Cell Culture; Proto-Oncogene Proteins c-fos/metabolism; Pyrans/pharmacology/*therapeutic use; Reactive Oxygen Species/metabolism; Transcription Factor AP-1/metabolism
There is growing evidence in support of the involvement of inflammatory response in the pathogenesis of osteoarthritis (OA). Harpagoside, one of the bioactive components of Harpagophytum procumbens (Hp), has been shown to possess anti-inflammatory properties. Here we used an in vitro model of inflammation in OA to investigate the potential of harpagoside to suppress the production of inflammatory cytokines/chemokines such as IL-6 and matrix degrading proteases. We further investigated the likely targets of harpagoside in primary human OA chondrocytes. OA chondrocytes were pre-treated with harpagoside before stimulation with IL-1beta. mRNA expression profile of 92 cytokines/chemokines was determined using TaqMan Human Chemokine PCR Array. Expression levels of selected mRNAs were confirmed using TaqMan assays. Protein levels of IL-6 and MMP-13 were assayed by ELISA and immunoblotting. Total protein levels and phosphorylation of signaling proteins were determined by immunoblotting. Cellular localization of
Haseeb Abdul; Ansari Mohammad Yunus; Haqqi Tariq M
Journal of orthopaedic research : official publication of the Orthopaedic Research Society
2017
2017-02
Article information provided for research and reference use only. All rights are retained by the journal listed under publisher and/or the creator(s).
<a href="http://doi.org/10.1002/jor.23262" target="_blank" rel="noreferrer noopener">10.1002/jor.23262</a>