المؤلفون: Hong Soon Kang, Anton M. Jetten, Kevin Gerrish, Amir Aghajanian, Ju Youn Beak, Brian C. Jensen, Seok Jae Hong, Wei Huang, Rishi Deshmukh, Nishi Kadakia

المصدر: The Journal of Biological Chemistry

مصطلحات موضوعية: HIF-1α, hypoxia-inducible factor-1α, Caveolin 3, PINK1, PTEN-induced putative kinase 1, LC3B-II, microtubule-associated protein light chain beta 3-II, Mitochondrion, Biochemistry, CMKO, cardiomyocyte-specific RORα KO, JC-1, 5, 5′, 6, 6′-tetrachloro-1, 1′, 3, 3′-tetraethylbenzimidazolylcarbocyanine iodide, Mitochondria, Heart, Mice, Mitophagy, OCR, oxygen consumption rate, Myocytes, Cardiac, Cav-3, caveolin-3, mt-Keima, mitochondrial-targeted Keima, shCtrl, scrambled shRNA, Cardioprotection, Gene knockdown, LDH, lactate dehydrogenase, Bnip3, BCL2 interacting protein 3, HRP, horseradish peroxidase, Nuclear Receptor Subfamily 1, Group F, Member 1, shRORα, shRNA against RORα, Cell biology, ChIP, chromatin immunoprecipitation, BFA1, bafilomycin A1, SDH, succinate dehydrogenase, NRVMs, neonatal rat ventricular myocytes, qRT-PCR, quantitative RT-PCR, Research Article, caveolin-3, mPTP, mitochondrial permeability transition pore, cardiomyocyte mitochondrial physiology, Biology, ROS, reactive oxygen species, Downregulation and upregulation, Animals, TEM, transmission electron microscopy, Molecular Biology, ROR, retinoic acid–related orphan nuclear receptor, Ang II, angiotensin II, hypoxia, Autophagy, Cell Biology, RAR-related orphan receptor alpha (ROR-alpha), Nuclear receptor, Hsp60, heat shock protein 60, PFA, paraformaldehyde

الوصف: Preserving optimal mitochondrial function is critical in the heart, which is the most ATP-avid organ in the body. Recently, we showed that global deficiency of the nuclear receptor RORα in the "staggerer" mouse exacerbates angiotensin II-induced cardiac hypertrophy and compromises cardiomyocyte mitochondrial function. However, the mechanisms underlying these observations have not been defined previously. Here, we used pharmacological and genetic gain- and loss-of-function tools to demonstrate that RORα regulates cardiomyocyte mitophagy to preserve mitochondrial abundance and function. We found that cardiomyocyte mitochondria in staggerer mice with lack of functional RORα were less numerous and exhibited fewer mitophagy events than those in WT controls. The hearts of our novel cardiomyocyte-specific RORα KO mouse line demonstrated impaired contractile function, enhanced oxidative stress, increased apoptosis, and reduced autophagic flux relative to Cre(-) littermates. We found that cardiomyocyte mitochondria in "staggerer" mice with lack of functional RORα were upregulated by hypoxia, a classical inducer of mitophagy. The loss of RORα blunted mitophagy and broadly compromised mitochondrial function in normoxic and hypoxic conditions in vivo and in vitro. We also show that RORα is a direct transcriptional regulator of the mitophagy mediator caveolin-3 in cardiomyocytes and that enhanced expression of RORα increases caveolin-3 abundance and enhances mitophagy. Finally, knockdown of RORα impairs cardiomyocyte mitophagy, compromises mitochondrial function, and induces apoptosis, but these defects could be rescued by caveolin-3 overexpression. Collectively, these findings reveal a novel role for RORα in regulating mitophagy through caveolin-3 and expand our currently limited understanding of the mechanisms underlying RORα-mediated cardioprotection.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::47cc243bde3123b1ebf3e9dc15c170f2Test
http://europepmc.org/articles/PMC8626585Test

المؤلفون: Richard L. Gallo, Tatsuya Dokoshi, Alan M. O’Neill, Elizabeth Wei Chia Luo, Nikhil Nitin Kulkarni, Gerard C. L. Wong

المصدر: The Journal of Biological Chemistry
The Journal of biological chemistry, vol 297, iss 1

مصطلحات موضوعية: 0301 basic medicine, Transcription, Genetic, medicine.medical_treatment, Inbred C57BL, Biochemistry, Medical and Health Sciences, Cathelicidin, Mice, Double-Stranded, antimicrobial peptides, SR, scavenger receptor, Receptors, cathelicidin, Innate, Receptor, GAS, group A Streptococcus, Receptors, Scavenger, Alanine, LDH, lactate dehydrogenase, Chemistry, LL-37, 37-amino acid peptide, UCSD, University of California, San Diego, SAXS, small-angle X-ray scattering, interferon, Alanine scanning, Biological Sciences, Cell biology, IL-6, interleukin 6, Infectious Diseases, LL-34, 34-amino acid peptide, Interferon Type I, qRT-PCR, quantitative RT-PCR, Female, NHEK, normal human epidermal keratinocyte, Transcription, RIGI, retinoic acid–inducible gene I, Research Article, Protein Binding, Signal Transduction, Biochemistry & Molecular Biology, skin, HDMEC, human dermal microvascular endothelial cell, MIC, minimum inhibitory concentration, Antimicrobial peptides, I20P, proline at isoleucine position 20, IRF7, interferon regulatory factor 7, Biophysical Phenomena, Scavenger, MAVS, mitochondrial antiviral signaling, Cell Line, 03 medical and health sciences, Structure-Activity Relationship, Genetic, Cathelicidins, GO, Gene Ontology, medicine, Genetics, Animals, Humans, Amino Acid Sequence, Molecular Biology, RNA, Double-Stranded, Inflammation, Innate immune system, 030102 biochemistry & molecular biology, Cell Membrane, Immunity, RNA, Cell Biology, cytokines, Immunity, Innate, Toll-Like Receptor 3, Mice, Inbred C57BL, 030104 developmental biology, Emerging Infectious Diseases, Gene Expression Regulation, Chemical Sciences, TBK1, TANK-binding kinase 1, Mutation, Nucleic acid, Antimicrobial Cationic Peptides

الوصف: Cathelicidins such as the human 37-amino acid peptide (LL-37) are peptides that not only potently kill microbes but also trigger inflammation by enabling immune recognition of endogenous nucleic acids. Here, a detailed structure-function analysis of LL-37 was performed to understand the details of this process. Alanine scanning of 34-amino acid peptide (LL-34) showed that some variants displayed increased antimicrobial activity against Staphylococcus aureus and group A Streptococcus. In contrast, different substitutions clustered on the hydrophobic face of the LL-34 alpha helix inhibited the ability of those variants to promote type 1 interferon expression in response to U1 RNA or to present U1 to the scavenger receptor (SR) B1 on the keratinocyte cell surface. Small-angle X-ray scattering experiments of the LL-34 variants LL-34, F5A, I24A, and L31A demonstrated that these peptides form cognate supramolecular structures with U1 characterized by inter-dsRNA spacings of approximately 3.5nm, a range that has been previously shown to activate toll-like receptor 3 by the parent peptide LL-37. Therefore, while alanine substitutions on the hydrophobic face of LL-34 led to loss of binding to SRs and the complete loss of autoinflammatory responses in epithelial and endothelial cells, they did not inhibit the ability to organize with U1 RNA in solution to associate with toll-like receptor 3. These observations advance our understanding of how cathelicidin mediates the process of innate immune self-recognition to enable inert nucleic acids to trigger inflammation. We introduce the term "innate immune vetting" to describe the capacity of peptides such as LL-37 to enable certain nucleic acids to become an inflammatory stimulus through SR binding prior to cell internalization.

وصف الملف: application/pdf

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::7653124affc7f3c4f58a75aed7ae4eb7Test
http://europepmc.org/articles/PMC8214221Test

المؤلفون: Yoshitake Cho, Anne N. Murphy, Alex Liang, Shamim Khosrowjerdi, Oliver R. Zhang, Robert S. Ross, Aleksander Andreyev, Kayla Lam, Ruixia Li, Shizuko Tachibana, Yoh Arita

المصدر: The Journal of Biological Chemistry
The Journal of biological chemistry, vol 297, iss 1

مصطلحات موضوعية: 0301 basic medicine, mitochondrial biogenesis, ATP5B, Messenger, NCM, neonatal cardiomyocytes, Muscle Proteins, cardiomyocytes, Mitochondrion, PGC-1, PPARgamma coactivator 1, SDHb, succinate dehydrogenase complex iron–sulfur subunit B, Inbred C57BL, Cardiovascular, Biochemistry, Medical and Health Sciences, OxPhos, oxidative phosphorylation, Oxidative Phosphorylation, Mice, Cox, cytochrome c oxidase, oxidative metabolism, Receptors, Myocyte, Protein Isoforms, 2.1 Biological and endogenous factors, OCR, oxygen consumption rate, Perm1, peroxisome proliferator-activated receptor coactivator 1 (PGC-1)- and estrogen-related receptor (ERR)-induced regulator, muscle 1, Aetiology, Organelle Biogenesis, Heart development, LDH, lactate dehydrogenase, Intracellular Signaling Peptides and Proteins, Heart, Biological Sciences, Cell Hypoxia, Cell biology, Mitochondria, Mitochondrial, Heart Disease, 5.1 Pharmaceuticals, medicine.symptom, Development of treatments and therapeutic interventions, Mito, mitochondrial, Cardiac, Transcription, Oxidation-Reduction, Perm1, NDUFS3, NADH dehydrogenase [ubiquinone] iron–sulfur protein 3, Research Article, Programmed cell death, Biochemistry & Molecular Biology, Heart Ventricles, Down-Regulation, ATP5b, ATP synthase F1 subunit beta, Biology, TUNEL, terminal deoxynucleotidyl transferase dUTP nick end labeling, Promoter Regions, 03 medical and health sciences, H/R, hypoxia-reoxygenation, UQCRC2, ubiquinol-cytochrome C reductase core protein 2, Genetic, Coactivator, medicine, Genetics, COXIV, cytochrome c oxidase subunit IV, Animals, Humans, Molecular Biology, Heart Failure, Myocytes, 030102 biochemistry & molecular biology, Cell Biology, DNA, Hypoxia (medical), Estrogen, Oxygen, ERR, estrogen-related receptor, 030104 developmental biology, Mitochondrial biogenesis, SERCA, Sarco/endoplasmic reticulum Ca2+-ATPase, Protein Biosynthesis, Musculoskeletal, Chemical Sciences, RNA, Transcription Factors

الوصف: Normal contractile function of the heart depends on a constant and reliable production of ATP by cardiomyocytes. Dysregulation of cardiac energy metabolism can result in immature heart development and disrupt the ability of the adult myocardium to adapt to stress, potentially leading to heart failure. Further, restoration of abnormal mitochondrial function can have beneficial effects on cardiac dysfunction. Previously, we identified a novel protein termed Perm1 (PGC-1 and estrogen-related receptor (ERR)-induced regulator, muscle 1) that is enriched in skeletal and cardiac-muscle mitochondria and transcriptionally regulated by PGC-1 (peroxisome proliferator-activated receptor gamma coactivator 1) and ERR. The role of Perm1 in the heart is poorly understood and is studied here. We utilized cell culture, mouse models, and human tissue, to study its expression and transcriptional control, as well as its role in transcription of other factors. Critically, we tested Perm1's role in cardiomyocyte mitochondrial function and its ability to protect myocytes from stress-induced damage. Our studies show that Perm1 expression increases throughout mouse cardiogenesis, demonstrate that Perm1 interacts with PGC-1α and enhances activation of PGC-1 and ERR, increases mitochondrial DNA copy number, and augments oxidative capacity in cultured neonatal mouse cardiomyocytes. Moreover, we found that Perm1 reduced cellular damage produced as a result of hypoxia and reoxygenation-induced stress and mitigated cell death of cardiomyocytes. Taken together, our results show that Perm1 promotes mitochondrial biogenesis in mouse cardiomyocytes. Future studies can assess the potential of Perm1 to be used as a novel therapeutic to restore cardiac dysfunction induced by ischemic injury.

وصف الملف: application/pdf

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::352ef9a79b8dfcd8924d67bb08dbe283Test
http://europepmc.org/articles/PMC8214196Test

المؤلفون: Yan Wang, Yalin Wu, Zuguo Liu, Jingmeng Chen, Chao Chen

المصدر: The Journal of Biological Chemistry

مصطلحات موضوعية: 0301 basic medicine, Retinal degeneration, STEAP3, six-transmembrane epithelial antigen of prostate 3, genetic structures, STGD1, autosomal recessive Stargardt disease, TFRC, transferrin receptor, ONL, outer nuclear layer, Mitochondrion, medicine.disease_cause, Biochemistry, Photoreceptor cell, Mice, DMT1, Divalent metal transporter 1, GSH, glutathione, Stargardt Disease, oxidative stress, iron metabolism, AMD, age-related macular degeneration, IREB2, Iron-responsive element binding protein 2, POS, photoreceptor outer segments, chemistry.chemical_classification, Deferoxamine mesylate, LDH, lactate dehydrogenase, Chemistry, TEM, transmission electron microscope, lipid peroxidation, LED, light emitting diode, Cell biology, medicine.anatomical_structure, cell death, Retinaldehyde, Photoreceptor Cells, Vertebrate, Research Article, Programmed cell death, macular degeneration, 03 medical and health sciences, ROS, reactive oxygen species, medicine, Animals, Ferroptosis, Molecular Biology, Reactive oxygen species, Retina, 030102 biochemistry & molecular biology, Cell Biology, medicine.disease, all-trans-retinal, photoreceptor, eye diseases, TF, transferrin, Mice, Inbred C57BL, 030104 developmental biology, CP, ceruloplasmin, atRAL, all-trans-retinal, H&E, hematoxylin and eosin, sense organs, FPN, Ferroportin, Reactive Oxygen Species, Oxidative stress

الوصف: The death of photoreceptor cells in dry age-related macular degeneration (AMD) and autosomal recessive Stargardt disease (STGD1) is closely associated with disruption in all-trans-retinal (atRAL) clearance in neural retina. In this study, we reveal that the overload of atRAL leads to photoreceptor degeneration through activating ferroptosis, a nonapoptotic form of cell death. Ferroptosis of photoreceptor cells induced by atRAL resulted from increased ferrous ion (Fe2+), elevated ACSL4 expression, system Xc- inhibition, and mitochondrial destruction. Fe2+ overload, tripeptide glutathione (GSH) depletion, and damaged mitochondria in photoreceptor cells exposed to atRAL provoked reactive oxygen species (ROS) production, which, together with ACSL4 activation, promoted lipid peroxidation and thereby evoked ferroptotic cell death. Moreover, exposure of photoreceptor cells to atRAL activated COX2, a well-accepted biomarker for ferroptosis onset. In addition to GSH supplement, inhibiting either Fe2+ by deferoxamine mesylate salt (DFO) or lipid peroxidation with ferrostatin-1 (Fer-1) protected photoreceptor cells from ferroptosis caused by atRAL. Abca4-/-Rdh8-/- mice exhibiting defects in atRAL clearance is an animal model for dry AMD and STGD1. We observed that ferroptosis was indeed present in neural retina of Abca4-/-Rdh8-/- mice after light exposure. More importantly, photoreceptor atrophy and ferroptosis in light-exposed Abca4-/-Rdh8-/- mice were effectively alleviated by intraperitoneally injected Fer-1, a selective inhibitor of ferroptosis. Our study suggests that ferroptosis is one of the important pathways of photoreceptor cell death in retinopathies arising from excess atRAL accumulation and should be pursued as a novel target for protection against dry AMD and STGD1.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::e528672cccb4554ebf9c4e807e79212aTest
https://pubmed.ncbi.nlm.nih.gov/33334878Test

المؤلفون: Xenia Schafer, Sergiy M. Nadtochiy, Paul S. Brookes, Joshua Munger, Keith Nehrke, James H. Miller, Dragony Fu

المصدر: The Journal of biological chemistry. 291(38)

مصطلحات موضوعية: 0301 basic medicine, Male, Mutant, Dehydrogenase, Biology, Biochemistry, Malate dehydrogenase, Glutarates, 03 medical and health sciences, chemistry.chemical_compound, Mice, 0302 clinical medicine, Malate Dehydrogenase, Lactate dehydrogenase, medicine, Animals, Molecular Biology, 030304 developmental biology, Acidosis, chemistry.chemical_classification, 0303 health sciences, L-Lactate Dehydrogenase, Cell Biology, Metabolism, Hydrogen-Ion Concentration, Isoenzymes, Cytosol, Alcohol Oxidoreductases, 030104 developmental biology, Isocitrate dehydrogenase, Enzyme, chemistry, 030220 oncology & carcinogenesis, Hypoxia-Inducible Factor 1, medicine.symptom, Signal Transduction

الوصف: 2-hydroxyglutarate (2-HG) is an important epigenetic regulator, with potential roles in cancer and stem cell biology. The D (R) enantiomer (D-2-HG) is anoncometabolitegenerated from αketoglutarate (α-KG) by mutant isocitrate dehydrogenase (ICDH), while L (S) 2-HG is generated by lactate dehydrogenase (LDH) and malate dehydrogenase (MDH) in response to hypoxia. Since acidic pH is a common feature of hypoxia, as well as tumor and stem cell microenvironments, we hypothesized that pH may regulate cellular 2-HG levels. Herein we report that cytosolic acidification under normoxia moderately elevated 2-HG in cells, and boosting endogenous substrate α-KG levels further stimulated this elevation. Studies with isolated LDH-1 and MDH-2 revealed that generation of 2-HG by both enzymes was stimulated several-fold at acidic pH, relative to normal physiologic pH. In addition, acidic pH was found to inhibit the activity of the mitochondrial L-2-HG removal enzyme L-2-HG dehydrogenase, and to stimulate the reverse reaction of ICDH (carboxylation of αKG to isocitrate). Furthermore, since acidic pH is known to stabilize hypoxia-inducible factor (HIF), and 2-HG is a known inhibitor of HIF prolyl hydroxylases, we hypothesized that 2-HG may be required for acid-induced HIF stabilization. Accordingly, cells stably over-expressing L-2HGDH exhibited a blunted HIF response to acid. Together these results suggest that acidosis is an important and previously overlooked regulator of 2-HG accumulation and other oncometabolic events, with implications for HIF signaling.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::a369b15b0d271f7a50d09e61fc0124b8Test
https://pubmed.ncbi.nlm.nih.gov/27510037Test

المؤلفون: Chiara Riganti, Manuela Polimeni, Amalia Bosia, Dario Ghigo, Costanzo Costamagna, Elena Gazzano

المصدر: The Journal of biological chemistry. 279(46)

مصطلحات موضوعية: animal diseases, Citric Acid Cycle, pentose phosphate pathway, Dehydrogenase, Pentose phosphate pathway, Glucosephosphate Dehydrogenase, medicine.disease_cause, Biochemistry, Cell Line, chemistry.chemical_compound, Mice, dehydroepiandrosterone, Onium Compounds, Lactate dehydrogenase, diphenyleneiodonium, diphenyliodonium, glucose 6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, reactive oxygen species, malonyldialdehyde, lactate dehydrogenase, glyceraldehyde 3-phosphate dehydrogenase, medicine, Animals, Enzyme Inhibitors, Molecular Biology, L-Lactate Dehydrogenase, Phosphogluconate Dehydrogenase, Biphenyl Compounds, Glyceraldehyde-3-Phosphate Dehydrogenases, Cell Biology, Glutathione, Molecular biology, Citric acid cycle, Oxidative Stress, Glucose, chemistry, Glutathione disulfide, NAD+ kinase, Neuroglia, Oxidation-Reduction, Oxidative stress

الوصف: Diphenyleneiodonium (DPI) and the structurally related compound diphenyliodonium (DIP) are widely used as inhibitors of flavoenzymes, particularly NADPH oxidase. Here we report further evidence that DPI and DIP are not specific flavin binders. A 3-h incubation of N11 glial cells with DPI significantly inhibited in a dose-dependent way both the pentose phosphate pathway and the tricarboxylic acid cycle. In parallel, we observed a dose-dependent increase of reactive oxygen species generation and lipoperoxidation and increased leakage of lactate dehydrogenase activity in the extracellular medium. The glutathione/glutathione disulfide ratio decreased, whereas the efflux of glutathione out of the cells increased. This suggests that DPI causes an augmented oxidative stress and exerts a cytotoxic effect in N11 cells. Indeed, the cells were protected from these events when loaded with glutathione. Similar results were observed using DIP instead of DPI and also in other cell types. We suggest that the DPI-elicited inhibition of the pentose phosphate pathway and tricarboxylic acid cycle may be mediated by the blockade of several NAD(P)-dependent enzymes, such as glucose 6-phosphate dehydrogenase, glyceraldehyde 3-phosphate dehydrogenase, and lactate dehydrogenase. In light of these results, we think that some effects of DPI or DIP in in vitro and in vivo experimental models should be interpreted with caution.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::56fe07c5c147e53e0fb82421a17077e4Test
https://pubmed.ncbi.nlm.nih.gov/15358777Test

المؤلفون: Syeda Maham Mahmood, Shunqian Jin, Vijay P. Singh, Dong Wang, Meena Ananthanaravanan, John F. Eisses, George Perides, Yuhuan Luo, Tanveer A. Javed, Sohail Z. Husain, John A. Williams, Kamaldeen A. Muili, Abrahim I. Orabi, Sheharyar Sarwar, Jeffery D. Molkentin

المصدر: The Journal of biological chemistry. 288(1)

مصطلحات موضوعية: medicine.medical_specialty, Time Factors, medicine.drug_class, Acinar Cells, Biology, Biochemistry, digestive system, Tacrolimus, Bile Acids and Salts, chemistry.chemical_compound, Mice, Cytosol, Internal medicine, Acinar cell, medicine, Animals, Chymotrypsin, Protein Isoforms, Molecular Biology, Egtazic Acid, Pancreas, Pancreatic duct, Bile acid, L-Lactate Dehydrogenase, NFATC Transcription Factors, Calcineurin, NF-kappa B, NFAT, Cell Biology, Taurocholic acid, medicine.anatomical_structure, Endocrinology, chemistry, Pancreatitis, Calcium, Taurolithocholic acid, Taurolithocholic Acid, Signal Transduction

الوصف: Biliary pancreatitis is the leading cause of acute pancreatitis in both children and adults. A proposed mechanism is the reflux of bile into the pancreatic duct. Bile acid exposure causes pancreatic acinar cell injury through a sustained rise in cytosolic Ca(2+). Thus, it would be clinically relevant to know the targets of this aberrant Ca(2+) signal. We hypothesized that the Ca(2+)-activated phosphatase calcineurin is such a Ca(2+) target. To examine calcineurin activation, we infected primary acinar cells from mice with an adenovirus expressing the promoter for a downstream calcineurin effector, nuclear factor of activated T-cells (NFAT). The bile acid taurolithocholic acid-3-sulfate (TLCS) was primarily used to examine bile acid responses. TLCS caused calcineurin activation only at concentrations that cause acinar cell injury. The activation of calcineurin by TLCS was abolished by chelating intracellular Ca(2+). Pretreatment with 1,2-bis(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (acetoxymethyl ester) (BAPTA-AM) or the three specific calcineurin inhibitors FK506, cyclosporine A, or calcineurin inhibitory peptide prevented bile acid-induced acinar cell injury as measured by lactate dehydrogenase leakage and propidium iodide uptake. The calcineurin inhibitors reduced the intra-acinar activation of chymotrypsinogen within 30 min of TLCS administration, and they also prevented NF-κB activation. In vivo, mice that received FK506 or were deficient in the calcineurin isoform Aβ (CnAβ) subunit had reduced pancreatitis severity after infusion of TLCS or taurocholic acid into the pancreatic duct. In summary, we demonstrate that acinar cell calcineurin is activated in response to Ca(2+) generated by bile acid exposure, bile acid-induced pancreatic injury is dependent on calcineurin activation, and calcineurin inhibitors may provide an adjunctive therapy for biliary pancreatitis.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::a613772fe026a7527e6fdda5ff429bcaTest
https://pubmed.ncbi.nlm.nih.gov/23148215Test

المؤلفون: Rong Meng, Leobaldo Solorzano, Charles P. Scott, Andrew A. Quong, Je-Wook Yu, Christine Juliana, Emad S. Alnemri, Jianghong Wu, Teresa Fernandes-Alnemri, Eicke Latz, Pinaki Datta

المصدر: The Journal of biological chemistry. 285(13)

مصطلحات موضوعية: medicine.drug_class, Immunoblotting, Caspase 1, Anti-Inflammatory Agents, Inflammation, Bone Marrow Cells, IκB kinase, Pharmacology, Biology, Biochemistry, Anti-inflammatory, chemistry.chemical_compound, Mice, Nitriles, medicine, Animals, Humans, Protease inhibitor (pharmacology), Parthenolide, Sulfones, Molecular Biology, Cell Death, L-Lactate Dehydrogenase, Macrophages, NF-kappa B, Inflammasome, Cell Biology, chemistry, medicine.symptom, Signal transduction, Sesquiterpenes, medicine.drug, Signal Transduction

الوصف: Activation of the inflammasome generates the pro-inflammatory cytokines interleukin-1 beta and -18, which are important mediators of inflammation. Abnormal activation of the inflammasome leads to many inflammatory diseases, including gout, silicosis, neurodegeneration, and genetically inherited periodic fever syndromes. Therefore, identification of small molecule inhibitors that target the inflammasome is an important step toward developing effective therapeutics for the treatment of inflammation. Here, we show that the herbal NF-kappaB inhibitory compound parthenolide inhibits the activity of multiple inflammasomes in macrophages by directly inhibiting the protease activity of caspase-1. Additional investigations of other NF-kappaB inhibitors revealed that the synthetic I kappaB kinase-beta inhibitor Bay 11-7082 and structurally related vinyl sulfone compounds selectively inhibit NLRP3 inflammasome activity in macrophages independent of their inhibitory effect on NF-kappaB activity. In vitro assays of the effect of parthenolide and Bay 11-7082 on the ATPase activity of NLRP3 demonstrated that both compounds inhibit the ATPase activity of NLRP3, suggesting that the inhibitory effect of these compounds on inflammasome activity could be mediated in part through their effect on the ATPase activity of NLRP3. Our results thus elucidate the molecular mechanism for the therapeutic anti-inflammatory activity of parthenolide and identify vinyl sulfones as a new class of potential therapeutics that target the NLRP3 inflammasome.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::d1fce605e79687f0d0a2f84fc6c63533Test
https://pubmed.ncbi.nlm.nih.gov/20093358Test

المؤلفون: Tatsuhide Tanaka, Masaki Ueno, Toshihide Yamashita

المصدر: The Journal of biological chemistry. 284(32)

مصطلحات موضوعية: MAPK/ERK pathway, Nervous system, Central Nervous System, Wallerian degeneration, Neurite, Central nervous system, Biology, Biochemistry, Models, Biological, p38 Mitogen-Activated Protein Kinases, Cell Line, Myelin, Mice, Molecular Basis of Cell and Developmental Biology, Phagocytosis, medicine, Animals, Axon, Rats, Wistar, Molecular Biology, Microglia, L-Lactate Dehydrogenase, Brain, Cell Biology, medicine.disease, Axons, Cell biology, Rats, Mice, Inbred C57BL, medicine.anatomical_structure, nervous system, Immunology, Spleen

الوصف: The clearance of debris after injuries to the nervous system is a critical step for restoration of the injured neural network. Microglia are thought to be involved in elimination of degenerating neurons and axons in the central nervous system (CNS), presumably restoring a favorable environment after CNS injuries. However, the mechanism underlying debris clearance remains elusive. Here, we establish an in vitro assay system to estimate phagocytosis of axon debris. We employed a Wallerian degeneration model by cutting axons of the cortical explants. The cortical explants were co-cultured with primary microglia or the MG5 microglial cell line. The cortical neurites were then transected. MG5 cells efficiently phagocytosed the debris, whereas primary microglia showed phagocytic activity only when they were activated by lipopolysaccharide or interferon-beta. When MG5 cells or primary microglia were co-cultured with degenerated axons, p38 mitogen-activated protein kinase (MAPK) was activated in these cells. Engulfment of axon debris was blocked by the p38 MAPK inhibitor SB203580, indicating that p38 MAPK is required for phagocytic activity. Receptors that recognize dying cells appeared not to be involved in the process of phagocytosis of the axon debris. In addition, the axons undergoing Wallerian degeneration did not release lactate dehydrogenase, suggesting that degeneration of the severed axons and apoptosis may represent two distinct self-destruction programs. We observed regrowth of the severed neurites after axon debris was removed. This finding suggests that axon debris, in addition to myelin debris, is an inhibitory factor for axon regeneration.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::52c6a9e7ed1b9a07a31f27b2a2ac7b4bTest
https://pubmed.ncbi.nlm.nih.gov/19531468Test

المؤلفون: Anindita, Das, Lei, Xi, Rakesh C, Kukreja

المصدر: The Journal of biological chemistry. 280(13)

مصطلحات موضوعية: Male, DNA, Complementary, Time Factors, Nitric Oxide Synthase Type III, Transcription, Genetic, Cell Survival, Phosphodiesterase Inhibitors, Blotting, Western, bcl-X Protein, Nitric Oxide Synthase Type II, Apoptosis, Nitric Oxide, Piperazines, Sildenafil Citrate, Membrane Potentials, Mice, Necrosis, 3',5'-Cyclic-GMP Phosphodiesterases, In Situ Nick-End Labeling, Animals, Myocytes, Cardiac, Sulfones, Enzyme Inhibitors, Cells, Cultured, DNA Primers, Cyclic Nucleotide Phosphodiesterases, Type 5, Mice, Knockout, Mice, Inbred ICR, Muscle Cells, L-Lactate Dehydrogenase, Caspase 3, Phosphoric Diester Hydrolases, Reverse Transcriptase Polymerase Chain Reaction, Trypan Blue, Carbocyanines, Immunohistochemistry, Mitochondria, Enzyme Activation, Mice, Inbred C57BL, Oxygen, NG-Nitroarginine Methyl Ester, Proto-Oncogene Proteins c-bcl-2, Purines, Caspases, Benzimidazoles, Nitric Oxide Synthase, Signal Transduction

الوصف: We investigated the effect of sildenafil in protection against necrosis or apoptosis in cardiomyocytes. Adult mouse ventricular myocytes were treated with sildenafil (1 or 10 microM) for 1 h before 40 min of simulated ischemia (SI). Necrosis was determined by trypan blue exclusion and lactate dehydrogenase release following SI alone or plus 1 or 18 h of reoxygenation (RO). Apoptosis was assessed by terminal deoxynucleotidyl transferase-mediated nick end labeling assay and mitochondrial membrane potential measured using a fluorescent probe 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimidazolyl-carbocyanine iodide (JC-1). Sildenafil reduced necrosis as indicated by decrease in trypan blue-positive myocytes and leakage of lactate dehydrogenase compared with untreated cells after either SI or SI-RO. The number of terminal deoxynucleotidyl transferase-mediated nick end labeling-positive myocytes or loss of JC-1 fluorescence following SI and 18 h of RO was attenuated in the sildenafil-treated group with concomitant inhibition of caspase 3 activity. An early increase in Bcl-2 to Bax ratio with sildenafil treatment was also observed in myocytes after SI-RO. The increase of Bcl-2 expression by sildenafil was inhibited by nitric-oxide synthase (NOS) inhibitor, L-nitro-amino-methyl-ester. The drug also enhanced mRNA and protein content of inducible NOS (iNOS) and endothelial NOS (eNOS) in the myocytes. Sildenafil-induced protection against necrosis and apoptosis was absent in the myocytes derived from iNOS knock-out mice and was attenuated in eNOS knock-out myocytes. The up-regulation of Bcl-2 expression by sildenafil was also absent in iNOS-deficient myocytes. Reverse transcription-PCR, Western blots, and immunohistochemical assay confirmed the expression of phosphodiesterase-5 in mouse cardiomyocytes. These data provide strong evidence for a direct protective effect of sildenafil against necrosis and apoptosis through NO signaling pathway. The results may have possible therapeutic potential in preventing myocyte cell death following ischemia/reperfusion.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=pmid________::4d1a6a0ddb956c78eb41ec3e4d9ad7c5Test
https://pubmed.ncbi.nlm.nih.gov/15668244Test