25 results on '"Maddipati, K."'
Search Results
2. LSEA Evaluation of Lipid Mediators of Inflammation in Lung and Cortex of Mice Exposed to Diesel Air Pollution
- Author
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Massimino, L, Bulbarelli, A, Corsetto, P, Milani, C, Botto, L, Farina, F, Lamparelli, L, Lonati, E, Ungaro, F, Maddipati, K, Palestini, P, Rizzo, A, Corsetto, PA, Lamparelli, LA, Maddipati, KR, Rizzo, AM, Massimino, L, Bulbarelli, A, Corsetto, P, Milani, C, Botto, L, Farina, F, Lamparelli, L, Lonati, E, Ungaro, F, Maddipati, K, Palestini, P, Rizzo, A, Corsetto, PA, Lamparelli, LA, Maddipati, KR, and Rizzo, AM
- Abstract
Airborne ultrafine particle (UFP) exposure is a great concern as they have been correlated to increased cardiovascular mortality, neurodegenerative diseases and morbidity in occupational and environmental settings. The ultrafine components of diesel exhaust particles (DEPs) represent about 25% of the emission mass; these particles have a great surface area and consequently high capacity to adsorb toxic molecules, then transported throughout the body. Previous in-vivo studies indicated that DEP exposure increases pro- and antioxidant protein levels and activates inflammatory response both in respiratory and cardiovascular systems. In cells, DEPs can cause additional reactive oxygen species (ROS) production, which attacks surrounding molecules, such as lipids. The cell membrane provides lipid mediators (LMs) that modulate cell-cell communication, inflammation, and resolution processes, suggesting the importance of understanding lipid modifications induced by DEPs. In this study, with a lipidomic approach, we evaluated in the mouse lung and cortex how DEP acute and subacute treatments impact polyunsaturated fatty acid-derived LMs. To analyze the data, we designed an ad hoc bioinformatic pipeline to evaluate the functional enrichment of lipid sets belonging to the specific biological processes (Lipid Set Enrichment Analysis-LSEA). Moreover, the data obtained correlate tissue LMs and proteins associated with inflammatory process (COX-2, MPO), oxidative stress (HO-1, iNOS, and Hsp70), involved in the activation of many xenobiotics as well as PAH metabolism (Cyp1B1), suggesting a crucial role of lipids in the process of DEP-induced tissue damage.
- Published
- 2022
3. Characterization of the major hydroperoxide-reducing activity of human plasma. Purification and properties of a selenium-dependent glutathione peroxidase.
- Author
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Maddipati, K R and Marnett, L J
- Abstract
We have recently characterized the major hydroperoxide-reducing enzyme of human plasma as a glutathione peroxidase (Maddipati, K. R., Gasparski, C., and Marnett, L. J. (1987) Arch. Biochem. Biophys. 254, 9-17). We now report the purification and kinetic characterization of this enzyme. The purification steps involved ammonium sulfate precipitation, hydrophobic interaction chromatography on phenyl-Sepharose, anion exchange chromatography, and gel filtration. The purified peroxidase has a specific activity of 26-29 mumol/min/mg with hydrogen peroxide as substrate. The human plasma glutathione peroxidase is a tetramer of identical subunits of 21.5 kDa molecular mass as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and is different from human erythrocyte glutathione peroxidase. The plasma peroxidase is a selenoprotein containing one selenium per subunit. Unlike several other glutathione peroxidases this enzyme exhibits saturation kinetics with respect to glutathione (Km for glutathione = 4.3 mM). The peroxidase exhibits high affinity for hydroperoxides with Km values ranging from 2.3 microM for 13-hydroperoxy-9,11-octadecadienoic acid to 13.3 microM for hydrogen peroxide at saturating glutathione concentration. These kinetic parameters are suggestive of the potential of human plasma glutathione peroxidase as an important regulator of plasma hydroperoxide levels.
- Published
- 1987
- Full Text
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4. Functional differentiation of cyclooxygenase and peroxidase activities of prostaglandin synthase by trypsin treatment. Possible location of a prosthetic heme binding site.
- Author
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Marnett, L J, Chen, Y N, Maddipati, K R, Plé, P, and Labèque, R
- Abstract
Treatment of prostaglandin (PG)H synthase purified from ram seminal vesicle microsomes with trypsin cleaves the 70-kDa subunits into 33- and 38-kDa fragments (Chen, Y.-N. P., Bienkowski, M. J., and Marnett, L. J. (1987) J. Biol. Chem. 262, 16892-16899). In contrast to a minimal decrease in cyclooxygenase activity, peroxidase activity declines rapidly following trypsin treatment. The time course for loss of guaiacol peroxidase activity corresponds closely to the time course for protein cleavage. The ability of trypsin-treated enzyme to support catalytic reduction of 5-phenyl-4-pentenyl-1-hydroperoxide in the presence of reducing substrates is significantly reduced. The products of metabolism of 10-hydroperoxy-8,12-octadecadienoic acid indicate that trypsin-treated enzyme catalyzes homolytic scission of the hydroperoxide bond in contrast to the heterolytic scission catalyzed by intact enzyme. Spectrophotometric titrations of hematin addition to trypsin-treated PGH synthase indicate approximately a 50% reduction in heme binding. These observations suggest that trypsin treatment of PGH synthase decreases the ability of the protein to bind prosthetic heme at a site that controls peroxidase activity. Comparison of the N-terminal sequence of the 38-kDa fragment of trypsin-treated PGH synthase to the amino acid sequence of the intact protein indicates that cleavage occurs between Arg253 and Gly254. Based on literature precedents and the results of the present investigations, we propose that the heme prosthetic group that controls the peroxidase activity of PGH synthase binds to the His residue of the sequence His250-Tyr251-Pro252-Arg253 located immediately adjacent to the trypsin cleavage site.
- Published
- 1988
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5. Stimulation of the omega-3 docosahexaenoic acid metabolism via MFSD2A as a novel therapy for inflammatory bowel disease
- Author
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Ungaro, F., Correale, C., Corsetto, P., Massimino, L., Fonteyne, P., Tacconi, C., Maddipati, K. R., ANGELA MARIA RIZZO, D Alessio, S., and Danese, S.
6. LSEA Evaluation of Lipid Mediators of Inflammation in Lung and Cortex of Mice Exposed to Diesel Air Pollution
- Author
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Luca, Massimino, Alessandra, Bulbarelli, Paola Antonia, Corsetto, Chiara, Milani, Laura, Botto, Francesca, Farina, Luigi Antonio, Lamparelli, Elena, Lonati, Federica, Ungaro, Krishna Rao, Maddipati, Paola, Palestini, Angela Maria, Rizzo, Massimino, L, Bulbarelli, A, Corsetto, P, Milani, C, Botto, L, Farina, F, Lamparelli, L, Lonati, E, Ungaro, F, Maddipati, K, Palestini, P, and Rizzo, A
- Subjects
inflammation ,air pollution ,diesel exhaust particle ,LSEA ,lipid mediator ,BIO/10 - BIOCHIMICA - Abstract
Airborne ultrafine particle (UFP) exposure is a great concern as they have been correlated to increased cardiovascular mortality, neurodegenerative diseases and morbidity in occupational and environmental settings. The ultrafine components of diesel exhaust particles (DEPs) represent about 25% of the emission mass; these particles have a great surface area and consequently high capacity to adsorb toxic molecules, then transported throughout the body. Previous in-vivo studies indicated that DEP exposure increases pro- and antioxidant protein levels and activates inflammatory response both in respiratory and cardiovascular systems. In cells, DEPs can cause additional reactive oxygen species (ROS) production, which attacks surrounding molecules, such as lipids. The cell membrane provides lipid mediators (LMs) that modulate cell-cell communication, inflammation, and resolution processes, suggesting the importance of understanding lipid modifications induced by DEPs. In this study, with a lipidomic approach, we evaluated in the mouse lung and cortex how DEP acute and subacute treatments impact polyunsaturated fatty acid-derived LMs. To analyze the data, we designed an ad hoc bioinformatic pipeline to evaluate the functional enrichment of lipid sets belonging to the specific biological processes (Lipid Set Enrichment Analysis-LSEA). Moreover, the data obtained correlate tissue LMs and proteins associated with inflammatory process (COX-2, MPO), oxidative stress (HO-1, iNOS, and Hsp70), involved in the activation of many xenobiotics as well as PAH metabolism (Cyp1B1), suggesting a crucial role of lipids in the process of DEP-induced tissue damage.
- Published
- 2022
7. Stimulation of CYP450-mediated ω-3 docosahexaenoic acid metabolism via MFSD2A as a novel therapy for inflammatory bowel disease
- Author
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F. Ungaro, C. Tacconi, C. Correale, L. Massimino, P. A. Corsetto, A. Piontini, P. Fonteyne, F. Calcaterra, S. Della Bella, A. Spinelli, M. Carvello, A. M. Rizzo, S. Vetrano, G. Fiorino, F. Furfaro, K. R. Maddipati, S. D'Alessio, S. Danese, Ungaro, F., Tacconi, C., Correale, C., Massimino, L., Corsetto, P. A., Piontini, A., Fonteyne, P., Calcaterra, F., Della Bella, S., Spinelli, A., Carvello, M., Rizzo, A. M., Vetrano, S., Fiorino, G., Furfaro, F., Maddipati, K. R., D'Alessio, S., and Danese, S.
- Published
- 2017
8. MFSD2A Promotes Endothelial Generation of Inflammation-resolving Lipid Mediators and Reduces Colitis in Mice
- Author
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Alberto Malesci, Silvio Danese, Antonino Spinelli, Federica Furfaro, Stefania Vetrano, Paola Antonia Corsetto, Luciana Petti, Luca Massimino, Angela Maria Rizzo, Silvia D'Alessio, Laurent Peyrin-Biroulet, Gionata Fiorino, Carlotta Tacconi, Domenico Mavilio, Philippe Fonteyne, Federica Ungaro, F. Calcaterra, Andrea Piontini, Valeria Garzarelli, Silvia Della Bella, Carmen Correale, Krishna Rao Maddipati, Michele Carvello, Ungaro, F., Tacconi, C., Massimino, L., Corsetto, P., Correale, C., Fonteyne, P., Piontini, A., Garzarelli, V., Calcaterra, F., Della Bella, S., Spinelli, A., Carvello, M., Rizzo, A., Vetrano, S., Petti, L., Fiorino, G., Furfaro, F., Mavilio, D., Maddipati, K., Malesci, A., Peyrin-Biroulet, L., D’Alessio, S., and Danese, S.
- Subjects
0301 basic medicine ,Endothelium ,Docosahexaenoic Acids ,Angiogenesis ,Colon ,IBD ,Mice, Nude ,Inflammation ,Biology ,gut vasculature ,Transfection ,Inflammatory bowel disease ,03 medical and health sciences ,angiogenesis ,Cytochrome P-450 Enzyme System ,inflammatory bowel disease ,medicine ,Animals ,Humans ,Oxylipins ,Progenitor cell ,Colitis ,Cells, Cultured ,Endothelial Progenitor Cells ,Hepatology ,Symporters ,Tumor Necrosis Factor-alpha ,Tumor Suppressor Proteins ,Dextran Sulfate ,Gastroenterology ,Membrane Transport Proteins ,Lipid metabolism ,medicine.disease ,Ulcerative colitis ,Disease Models, Animal ,030104 developmental biology ,medicine.anatomical_structure ,Immunology ,Cancer research ,Epoxy Compounds ,RNA Interference ,medicine.symptom ,Signal Transduction - Abstract
Background & Aims Alterations in signaling pathways that regulate resolution of inflammation (resolving pathways) contribute to pathogenesis of ulcerative colitis (UC). The resolution process is regulated by lipid mediators, such as those derived from the ω-3 docosahexaenoic acid (DHA), whose esterified form is transported by the major facilitator superfamily domain containing 2A (MFSD2A) through the endothelium of brain, retina, and placenta. We investigated if and how MFSD2A regulates lipid metabolism of gut endothelial cells to promote resolution of intestinal inflammation. Methods We performed lipidomic and functional analyses of MFSD2A in mucosal biopsies and primary human intestinal microvascular endothelial cells (HIMECs) isolated from surgical specimens from patients with active, resolving UC and healthy individuals without UC (controls). MFSD2A was knocked down in HIMECs with small hairpin RNAs or overexpressed from a lentiviral vector. Human circulating endothelial progenitor cells that overexpress MFSD2A were transferred to CD1 nude mice with dextran sodium sulfate–induced colitis, with or without oral administration of DHA. Results Colonic biopsies from patients with UC had reduced levels of inflammation-resolving DHA-derived epoxy metabolites compared to healthy colon tissues or tissues with resolution of inflammation. Production of these metabolites by HIMECs required MFSD2A, which is required for DHA retention and metabolism in the gut vasculature. In mice with colitis, transplanted endothelial progenitor cells that overexpressed MFSD2A not only localized to the inflamed mucosa but also restored the ability of the endothelium to resolve intestinal inflammation, compared with mice with colitis that did not receive MFSD2A-overexpressing endothelial progenitors. Conclusions Levels of DHA-derived epoxides are lower in colon tissues from patients with UC than healthy and resolving mucosa. Production of these metabolites by gut endothelium requires MFSD2A; endothelial progenitor cells that overexpress MFSD2A reduce colitis in mice. This pathway might be induced to resolve intestinal inflammation in patients with colitis.
- Published
- 2017
9. Loss of flavin-containing monooxygenase 3 modulates dioxin-like polychlorinated biphenyl 126-induced oxidative stress and hepatotoxicity.
- Author
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Agarwal M, Roth K, Yang Z, Sharma R, Maddipati K, Westrick J, and Petriello MC
- Subjects
- Animals, Mice, Male, Liver drug effects, Liver metabolism, Environmental Pollutants toxicity, Oxygenases genetics, Oxygenases metabolism, Polychlorinated Biphenyls toxicity, Oxidative Stress drug effects, Mice, Inbred C57BL, Mice, Knockout
- Abstract
Dioxin-like pollutants (DLPs), such as polychlorinated biphenyl 126 (PCB 126), are synthetic chemicals classified as persistent organic pollutants. They accumulate in adipose tissue and have been linked to cardiometabolic disorders, including fatty liver disease. The toxicity of these compounds is associated with activation of the aryl hydrocarbon receptor (Ahr), leading to the induction of phase I metabolizing enzyme cytochrome P4501a1 (Cyp1a1) and the subsequent production of reactive oxygen species (ROS). Recent research has shown that DLPs can also induce the xenobiotic detoxification enzyme flavin-containing monooxygenase 3 (FMO3), which plays a role in metabolic homeostasis. We hypothesized whether genetic deletion of Fmo3 could protect mice, particularly in the liver, where Fmo3 is most inducible, against PCB 126 toxicity. To test this hypothesis, male C57BL/6 wild-type (WT) mice and Fmo3 knockout (Fmo3 KO) mice were exposed to PCB 126 or vehicle (safflower oil) during a 12-week study, at weeks 2 and 4. Various analyses were performed, including hepatic histology, RNA-sequencing, and quantitation of PCB 126 and F2-isoprostane concentrations. The results showed that PCB 126 exposure caused macro and microvesicular fat deposition in WT mice, but this macrovesicular fatty change was absent in Fmo3 KO mice. Moreover, at the pathway level, the hepatic oxidative stress response was significantly different between the two genotypes, with the induction of specific genes observed only in WT mice. Notably, the most abundant F2-isoprostane, 8-iso-15-keto PGE2, increased in WT mice in response to PCB 126 exposure. The study's findings also demonstrated that hepatic tissue concentrations of PCB 126 were higher in WT mice compared to Fmo3 KO mice. In summary, the absence of FMO3 in mice led to a distinctive response to dioxin-like pollutant exposure in the liver, likely due to alterations in lipid metabolism and storage, underscoring the complex interplay of genetic factors in the response to environmental toxins., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests:Michael Petriello reports financial support was provided by National Institute of Environmental Health Sciences. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)
- Published
- 2024
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10. Associations of Plasma Omega-3 Fatty Acids With Progression and Survival in Pulmonary Fibrosis.
- Author
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Kim JS, Ma SF, Ma JZ, Huang Y, Bonham CA, Oldham JM, Adegunsoye A, Strek ME, Flaherty KR, Strickland E, Udofia I, Mooney JJ, Ghosh S, Maddipati K, and Noth I
- Subjects
- Humans, Male, Eicosapentaenoic Acid, Carbon Monoxide, Disease Progression, Fatty Acids, Omega-3, Idiopathic Pulmonary Fibrosis
- Abstract
Background: Preclinical experiments suggest protective effects of omega-3 fatty acids and their metabolites in lung injury and fibrosis. Whether higher intake of omega-3 fatty acids is associated with disease progression and survival in humans with pulmonary fibrosis is unknown., Research Question: What are the associations of plasma omega-3 fatty acid levels (a validated marker of omega-3 nutritional intake) with disease progression and transplant-free survival in pulmonary fibrosis?, Study Design and Methods: Omega-3 fatty acid levels were measured from plasma samples of patients with clinically diagnosed pulmonary fibrosis from the Pulmonary Fibrosis Foundation Patient Registry (n = 150), University of Virginia (n = 58), and University of Chicago (n = 101) cohorts. The N-3 index (docosahexaenoic acid + eicosapentaenoic acid) was the primary exposure variable of interest. Linear-mixed effects models with random intercept and slope were used to examine associations of plasma omega-3 fatty acid levels with changes in FVC and diffusing capacity for carbon monoxide over a period of 12 months. Cox proportional hazards models were used to examine transplant-free survival. Stratified analyses by telomere length were performed in the University of Chicago cohort., Results: Most of the cohort were patients with idiopathic pulmonary fibrosis (88%) and male patients (74%). One-unit increment in log-transformed N-3 index plasma level was associated with a change in diffusing capacity for carbon monoxide of 1.43 mL/min/mm Hg per 12 months (95% CI, 0.46-2.41) and a hazard ratio for transplant-free survival of 0.44 (95% CI, 0.24-0.83). Cardiovascular disease history, smoking, and antifibrotic usage did not significantly modify associations. Omega-3 fatty acid levels were not significantly associated with changes in FVC. Higher eicosapentaenoic acid plasma levels were associated with longer transplant-free survival among University of Chicago participants with shorter telomere length (P value for interaction = .02)., Interpretation: Further research is needed to investigate underlying biological mechanisms and whether omega-3 fatty acids are a potential disease-modifying therapy., Competing Interests: Financial/Nonfinancial Disclosures The authors have reported to CHEST the following: J. M. O. reports fees and support from BI, Roche, Lupin and Gatehouse Bio and DMC for Genentech, Endeavor BioMedicines and Novartis. A. A. has received research grants from the Pulmonary Fibrosis Foundation, the American College of Chest Physicians, and the National Institutes of Health for the conduct of studies in pulmonary fibrosis and served on a pulmonary fibrosis educational forum for Boehringer Ingelheim, as well as consultancy for Roche Pharmaceuticals, Boehringer Ingelheim, Inogen, and Medscape. M. E. S. reports grant support from Galapagos and personal fees from Fibrogen. Reports grant, personal fees, and non-financial support from Boehringer-Ingelheim. All of these are outside the scope of submitted work. I. N. reports personal fees from Boehringer Ingelheim, Genentech, and Confo. All of these are outside the submitted work. In addition, Dr. Noth has a patent transcriptomic prognostics in IPF pending. None declared (J. S. K., S.-F. M., J. Z. M., Y. H., C. A. B., K. R. F., E. S., I. U., J. J. M., S. G., K. M.)., (Copyright © 2023 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.)
- Published
- 2024
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11. Disrupted intercellular bridges and spermatogenesis in fatty acyl-CoA reductase 1 knockout mice: A new model of ether lipid deficiency.
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Pan B, Yuan S, Mayernik L, Yap YT, Moin K, Chung CS, Maddipati K, Krawetz SA, Zhang Z, Hess RA, and Chen X
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- Mice, Animals, Male, Humans, Mice, Knockout, Spermatogenesis genetics, Spermatids, Ethers, Ethyl Ethers, Lipids, RNA, Transcription Factors genetics, Ether, Azoospermia
- Abstract
Peroxisomal fatty acyl-CoA reductase 1 (FAR1) is a rate-limiting enzyme for ether lipid (EL) synthesis. Gene mutations in FAR1 cause a rare human disease. Furthermore, altered EL homeostasis has also been associated with various prevalent human diseases. Despite their importance in human health, the exact cellular functions of FAR1 and EL are not well-understood. Here, we report the generation and initial characterization of the first Far1 knockout (KO) mouse model. Far1 KO mice were subviable and displayed growth retardation. The adult KO male mice had smaller testes and were infertile. H&E and immunofluorescent staining showed fewer germ cells in seminiferous tubules. Round spermatids were present but no elongated spermatids or spermatozoa were observed, suggesting a spermatogenesis arrest at this stage. Large multi-nucleated giant cells (MGC) were found lining the lumen of seminiferous tubules with many of them undergoing apoptosis. The immunofluorescent signal of TEX14, an essential component of intercellular bridges (ICB) between developing germ cells, was greatly reduced and mislocalized in KO testis, suggesting the disrupted ICBs as an underlying cause of MGC formation. Integrative analysis of our total testis RNA-sequencing results and published single-cell RNA-sequencing data unveiled cell type-specific molecular alterations underlying the spermatogenesis arrest. Many genes essential for late germ cell development showed dramatic downregulation, whereas genes essential for extracellular matrix dynamics and cell-cell interactions were among the most upregulated genes. Together, this work identified the cell type-specific requirement of ELs in spermatogenesis and suggested a critical role of Far1/ELs in the formation/maintenance of ICB during meiosis., (© 2023 Federation of American Societies for Experimental Biology.)
- Published
- 2023
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12. Lipidomic Profiling of Bronchoalveolar Lavage Fluid Extracellular Vesicles Indicates Their Involvement in Lipopolysaccharide-Induced Acute Lung Injury.
- Author
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Nirujogi TS, Kotha SR, Chung S, Reader BF, Yenigalla A, Zhang L, Shapiro JP, Wisler J, Christman JW, Maddipati K, Parinandi NL, and Karpurapu M
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- Animals, Bronchoalveolar Lavage Fluid, Lipidomics, Lipopolysaccharides pharmacology, Lung metabolism, Mice, Mice, Inbred C57BL, Toll-Like Receptor 4 metabolism, Acute Lung Injury chemically induced, Acute Lung Injury metabolism, Extracellular Vesicles metabolism
- Abstract
Emerging data support the pivotal role of extracellular vesicles (EVs) in normal cellular physiology and disease conditions. However, despite their abundance, there is much less information about the lipid mediators carried in EVs, especially in the context of acute lung injury (ALI). Our data demonstrate that C57BL/6 mice subjected to intranasal Escherichia coli lipopolysaccharide (LPS)-induced ALI release, a higher number of EVs into the alveolar space, compared to saline-treated controls. EVs released during ALI originated from alveolar epithelial cells, macrophages, and neutrophils and carry a diverse array of lipid mediators derived from ω-3 and ω-6 polyunsaturated fatty acids (PUFA). The eicosanoids in EVs correlated with cellular levels of arachidonic acid, expression of cytosolic phospholipase A2, cyclooxygenase (COX), lipoxygenase (LOX), and cytochrome epoxygenase p450 proteins in pulmonary macrophages. Furthermore, EVs from LPS-toll-like receptor 4 knockout (TLR4-/-) mice contained significantly lower amounts of COX and LOX catalyzed eicosanoids and ω-3 PUFA metabolites. More importantly, EVs from LPS-treated wild-type mice increased TNF-α release by macrophages and reduced alveolar epithelial monolayer barrier integrity compared to EVs from LPS-treated TLR4-/- mice. In summary, our study demonstrates for the first time that the EV carried PUFA metabolite profile in part depends on the inflammatory status of the lung macrophages and modulates pulmonary macrophage and alveolar epithelial cell function during LPS-induced ALI., (© 2022 The Author(s). Published by S. Karger AG, Basel.)
- Published
- 2022
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13. Linoleic Acid-Derived Oxylipins Differentiate Early Stage Alcoholic Hepatitis From Mild Alcohol-Associated Liver Injury.
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Warner D, Vatsalya V, Zirnheld KH, Warner JB, Hardesty JE, Umhau JC, McClain CJ, Maddipati K, and Kirpich IA
- Abstract
Alcohol-associated liver disease (ALD) is a spectrum of liver disorders ranging from steatosis to steatohepatitis, fibrosis, and cirrhosis. Alcohol-associated hepatitis (AH) is an acute and often severe form of ALD with substantial morbidity and mortality. The mechanisms and mediators of ALD progression and severity are not well understood, and effective therapeutic options are limited. Various bioactive lipid mediators have recently emerged as important factors in ALD pathogenesis. The current study aimed to examine alterations in linoleic acid (LA)-derived lipid metabolites in the plasma of individuals who are heavy drinkers and to evaluate associations between these molecules and markers of liver injury and systemic inflammation. Analysis of plasma LA-derived metabolites was performed on 66 individuals who were heavy drinkers and 29 socially drinking but otherwise healthy volunteers. Based on plasma alanine aminotransferase (ALT) levels, 15 patients had no liver injury (ALT ≤ 40 U/L), 33 patients had mild liver injury (ALT > 40 U/L), and 18 were diagnosed with moderate AH (mAH) (Model for End-Stage Liver Disease score <20). Lipoxygenase-derived LA metabolites (13-hydroxy-octadecadienoic acid [13-HODE] and 13-oxo-octadecadienoic acid) were markedly elevated only in patients with mAH. The cytochrome P450-derived LA epoxides 9,10-epoxy-octadecenoic acid (9,10-EpOME) and 12,13-EpOME were decreased in all patients regardless of the presence or absence of liver injury. LA-derived diols 9,10-dihydroxy-octadecenoic acid (9,10-DiHOME) and 12,13-DiHOME as well as the corresponding diol/epoxide ratio were elevated in the mAH group, specifically compared to patients with mild liver injury. We found that 13-HODE and 12,13-EpOME (elevated and decreased, respectively) in combination with elevated interleukin-1β as independent predictors can effectively predict altered liver function as defined by elevated bilirubin levels. Conclusion: Specific changes in LA metabolites in individuals who are heavy drinkers can distinguish individuals with mAH from those with mild ALD., (© 2021 The Authors. Hepatology Communications published by Wiley Periodicals LLC on behalf of the American Association for the Study of Liver Diseases.)
- Published
- 2021
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14. Maresin 1 attenuates neuroinflammation in a mouse model of perioperative neurocognitive disorders.
- Author
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Yang T, Xu G, Newton PT, Chagin AS, Mkrtchian S, Carlström M, Zhang XM, Harris RA, Cooter M, Berger M, Maddipati KR, Akassoglou K, and Terrando N
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- Aged, Aged, 80 and over, Animals, Disease Models, Animal, Female, Humans, Male, Mice, Mice, Inbred C57BL, Middle Aged, Perioperative Period, Brain Diseases prevention & control, Docosahexaenoic Acids pharmacology, Fractures, Bone surgery, Inflammation prevention & control, Neurocognitive Disorders prevention & control
- Abstract
Background: Resolution of inflammation is an active and dynamic process after surgery. Maresin 1 (MaR1) is one of a growing number of specialised pro-resolving lipids biosynthesised by macrophages that regulates acute inflammation. We investigated the effects of MaR1 on postoperative neuroinflammation, macrophage activity, and cognitive function in mice., Methods: Adult male C57BL/6 (n=111) and Ccr2
RFP/+ Cx3cr1GFP/+ (n=54) mice were treated with MaR1 before undergoing anaesthesia and orthopaedic surgery. Systemic inflammatory changes, bone healing, neuroinflammation, and cognition were assessed at different time points. MaR1 protective effects were also evaluated using bone marrow derived macrophage cultures., Results: MaR1 exerted potent systemic anti-inflammatory effects without impairing fracture healing. Prophylaxis with MaR1 prevented surgery-induced glial activation and opening of the blood-brain barrier. In Ccr2RFP/+ Cx3cr1GFP/+ mice, fewer infiltrating macrophages were detected in the hippocampus after surgery with MaR1 prophylaxis, which resulted in improved memory function. MaR1 treatment also reduced expression of pro-inflammatory cell surface markers and cytokines by in vitro cultured macrophages. MaR1 was detectable in the cerebrospinal fluid of older adults before and after surgery., Conclusions: MaR1 exerts distinct anti-inflammatory and pro-resolving effects through regulation of macrophage infiltration, NF-κB signalling, and cytokine release after surgery. Future studies on the use of pro-resolving lipid mediators may inform novel approaches to treat neuroinflammation and postoperative neurocognitive disorders., (Copyright © 2018 The Author(s). Published by Elsevier Ltd.. All rights reserved.)- Published
- 2019
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15. Ocimum gratissimum retards breast cancer growth and progression and is a natural inhibitor of matrix metalloproteases.
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Nangia-Makker P, Raz T, Tait L, Shekhar MP, Li H, Balan V, Makker H, Fridman R, Maddipati K, and Raz A
- Subjects
- Animals, Breast Neoplasms enzymology, Breast Neoplasms pathology, Carcinoma, Ductal, Breast drug therapy, Carcinoma, Ductal, Breast enzymology, Carcinoma, Ductal, Breast pathology, Cell Growth Processes drug effects, Cell Line, Tumor, Disease Progression, Female, Humans, Immunohistochemistry, Matrix Metalloproteinase Inhibitors chemistry, Mice, Mice, Nude, Random Allocation, Xenograft Model Antitumor Assays, Breast Neoplasms drug therapy, Matrix Metalloproteinase 2 metabolism, Matrix Metalloproteinase 9 metabolism, Matrix Metalloproteinase Inhibitors pharmacology, Ocimum chemistry, Plant Extracts pharmacology
- Abstract
Ocimum genus (a.k.a holy basil or tulsi) is a dietary herb used for its multiple beneficial pharmacologic properties including anti-cancer activity. Here we show that crude extract of Ocimum gratissimum (OG) and its hydrophobic and hydrophilic fractions (HB and HL) differentially inhibit breast cancer cell chemotaxis and chemoinvasion in vitro and retard tumor growth and temporal progression of MCF10ADCIS.com xenografts, a model of human breast comedo-ductal carcinoma in situ (comedo-DCIS). OG-induced inhibition of tumor growth was associated with decreases in basement membrane disintegration, angiogenesis and MMP-2 and MMP-9 activities as confirmed by in situ gelatin zymography and cleavage of galectin-3. There was also decrease in MMP-2 and MMP-9 activities in the conditioned media of OG-treated MCF10AT1 and MCF10AT1-EIII8 premalignant human breast cancer cells as compared with control. The MMP-2 and MMP-9 inhibitory activities of OG were verified in vitro using gelatin, a synthetic fluorogenic peptide and recombinant galectin-3 as MMP substrates. Mice fed on OG-supplemented drinking water showed no adverse effects compared with control. These data suggest that OG is non-toxic and that the anti-cancer therapeutic activity of OG may in part be contributed by its MMP inhibitory activity.
- Published
- 2013
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16. Paradoxical effects of resveratrol on the two prostaglandin H synthases.
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Johnson JL and Maddipati KR
- Subjects
- Animals, Arachidonic Acid metabolism, Chromatography, High Pressure Liquid, Enzyme Activation drug effects, Female, Indomethacin pharmacology, Male, Oxidation-Reduction, Phenol pharmacology, Prostaglandin H2, Prostaglandins G biosynthesis, Prostaglandins H biosynthesis, Resveratrol, Sheep, Cyclooxygenase Inhibitors pharmacology, Isoenzymes antagonists & inhibitors, Prostaglandin-Endoperoxide Synthases metabolism, Stilbenes pharmacology
- Abstract
Prostaglandin H synthase (PGHS) is the primary enzyme responsible for the biosynthesis of prostaglandins and thromboxanes. Of the two isoenzymes of PGHS, PGHS-1 is constitutively expressed and PGHS-2 is inducible by mitogens or other inflammatory stimuli. Constitutive expression of PGHS-2 in neoplastic tissues has been implicated in carcinogenesis. Resveratrol, a lignan, was recently shown to be an anticarcinogen that selectively inhibits PGHS-1. In vitro experiments to resolve these seemingly paradoxical observations revealed that resveratrol is not only an inhibitor of PGHS-1 but also is an activator of PGHS-2. Resveratrol non-competitively inhibited PGHS-1 with a K1 of 26 +/- 2 microM but enhanced the PGHS-2 activity nearly twofold. Additionally, resveratrol did not serve as a reducing co-substrate for the peroxidase activities of either enzyme despite being an easily oxidizable phenolic compound. Resveratrol inhibited the peroxidase activity of PGHS-1 (IC50 = 15 microM) better than that of PGHS-2 (IC50 = > 200 microM). Inhibition of the perxidase activity but not the cyclooxygenase activity of PGHS-2 resulted in the production of PGG2 from arachidonic acid. A plausible relationship between these observation and the anticarcinogenic activity of resveratrol is discussed.
- Published
- 1998
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- View/download PDF
17. Purification and characterization of prostaglandin H synthase-2 from sheep placental cotyledons.
- Author
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Johnson JL, Wimsatt J, Buckel SD, Dyer RD, and Maddipati KR
- Subjects
- Amino Acid Sequence, Animals, Anti-Inflammatory Agents, Non-Steroidal pharmacology, Female, Humans, Immunoblotting, Isoenzymes chemistry, Isoenzymes immunology, Isoenzymes metabolism, Male, Molecular Sequence Data, Pregnancy, Prostaglandin-Endoperoxide Synthases chemistry, Prostaglandin-Endoperoxide Synthases immunology, Prostaglandin-Endoperoxide Synthases metabolism, Recombinant Proteins drug effects, Seminal Vesicles enzymology, Sequence Analysis, Sequence Homology, Amino Acid, Sex Characteristics, Sheep, Isoenzymes isolation & purification, Placenta enzymology, Prostaglandin-Endoperoxide Synthases isolation & purification
- Abstract
Recent identification of a second, inducible form of prostaglandin H synthase (PGHS-2) led to the hypothesis that constitutively expressed PGHS (PGHS-1) is involved in the homeostatic role of eicosanoids, whereas the inducible enzyme is responsible for their inflammatory actions. We report here the purification of PGHS-2 from near-term sheep placental cotyledons. The PGHS-2 from this tissue was purified in multimilligram quantities by a combination of anion-exchange, size-exclusion, and affinity chromatography. This enzyme is different from ovine seminal vesicle PGHS-1 and was characterized as PGHS-2 based on (a) chromatographic properties, (b) immunochemical reactivities with isoenzyme-specific antibodies, (c) amino acid microsequencing, (d) kinetics of reaction with arachidonic acid (Km = 2.1 +/- 0.2 microM vs 8.3 +/- 0.2 microM for ovine PGHS-1), and (e) different sensitivities for several non-steroidal antiinflammatory drugs. Since the first identification of PGHS, ram seminal vesicles served as a rich source of the enzyme (PGHS-1). Our studies establish the sheep placental cotyledons as a rich natural source of PGHS-2.
- Published
- 1995
- Full Text
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18. Free radical oxidation of (E)-retinoic acid by prostaglandin H synthase.
- Author
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Samokyszyn VM, Chen T, Maddipati KR, Franz TJ, Lehman PA, and Lloyd RV
- Subjects
- Animals, Chromatography, High Pressure Liquid, Electron Spin Resonance Spectroscopy, Free Radicals, Male, Mass Spectrometry, Microsomes enzymology, Oxidation-Reduction, Seminal Vesicles enzymology, Sheep, Prostaglandin-Endoperoxide Synthases metabolism, Tretinoin metabolism
- Abstract
Cooxidative metabolism of all-trans (E)-retinoic acid (RA) by prostaglandin H synthase was investigated employing ram seminal vesicle microsomes (RSVM) or purified, RSVM-derived enzyme. RA was shown to undergo hydroperoxide [H2O2 or 5-phenyl-4-penten-1-yl hydroperoxide (PPHP)]- or arachidonic acid-dependent cooxidation by microsomal prostaglandin H (PGH) synthase as evidenced by UV spectroscopic analysis of reaction mixtures. Cooxidation of RA by microsomal or purified PGH synthase, using PPHP as substrate, was characterized by uptake of dioxygen which was first order with respect to enzyme concentration. Dioxygen uptake was inhibited by the peroxidase reducing substrate 2-methoxyphenol. In addition, O2 uptake was inhibited by the spin trap nitrosobenzene. ESR spin trapping studies, using alpha-phenyl-N-tert-butylnitrone (PBN) as the spin trap, demonstrated the formation of RA-PBN adducts, characterized by hyperfine coupling constants of alpha H = 3.2 G and alpha N = 15.8 G. Reverse phase HPLC analysis of reaction mixtures demonstrated the formation of 4-hydroxy-RA, 5,6-epoxy-RA, 4-oxo-RA, (13Z)-retinoic acid, and other geometric isomers which were identified on the basis of cochromatography with synthetic standards, UV spectroscopy, and/or mass spectrometry. Mechanisms are proposed for the hydroperoxide-dependent, PGH synthase-catalyzed oxidation of RA that are consistent with these results.
- Published
- 1995
- Full Text
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19. Peroxidase-catalyzed oxidation of pentachlorophenol.
- Author
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Samokyszyn VM, Freeman JP, Maddipati KR, and Lloyd RV
- Subjects
- Catalysis, Oxidation-Reduction, Substrate Specificity, Environmental Pollutants metabolism, Horseradish Peroxidase pharmacology, Pentachlorophenol metabolism
- Abstract
Pentachlorophenol (PCP) was shown to function as a reducing substrate for horseradish peroxidase (HRP) and to stimulate the HRP-catalyzed reduction of 5-phenyl-4-penten-1-yl hydroperoxide (PPHP) to 5-phenyl-4-penten-1-ol. HRP catalyzed the hydroperoxide-dependent oxidation of PCP, using H2O2, PPHP, or ethyl hydroperoxide as substrates, as evidenced by UV spectroscopic and reverse phase HPLC analysis of reaction mixtures. The major oxidation product was tetrachloro-1,4-benzoquinone which was identified on the basis of electronic absorption spectroscopy, mass spectrometry, and cochromatography with authentic standard. HRP-catalyzed oxidation of PCP yielded relatively stable, ESR-detectable pentachlorophenoxyl radical intermediates whose ESR spectra consisted of a symmetrical single line without hyperfine structure. Substitution of natural abundance isotopically-labeled PCP with 13C-labeled PCP resulted in broadening of the ESR signal line width from 6.1 G to 13.5 G. ESR spin trapping studies, with alpha-(1-oxy-4-pyridyl)-N tert-butylnitrone (4-POBN) as the spin trap demonstrated identical spectra using natural abundance isotopically-labeled PCP versus 13C-labeled PCP, suggesting oxyl addition, rather than carbon-centered radical addition to 4-POBN. The computer simulation of the observed spectra is consistent with two distinct 4-POBN adducts, with relative abundances of approximately 3:1, and hyperfine coupling constants of alpha N = (14.61 G)/alpha H = 1.83 G and alpha N = (14.76 G)/alpha H = 5.21 G, respectively. Mechanisms for the hydroperoxide-dependent, HRP-catalyzed oxidation of PCP are presented that are consistent with these results.
- Published
- 1995
- Full Text
- View/download PDF
20. Purification of class I medullipins from the venous effluent of isolated normal kidneys perfused under high pressure with saline.
- Author
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Brooks B, Byers LW, Muirhead EE, Muirhead M, Pitcock JA, Maddipati KR, and Maxey KM
- Subjects
- Animals, Chromatography, High Pressure Liquid, Chromatography, Thin Layer, Kidney blood supply, Lipids isolation & purification, Male, Perfusion, Pressure, Rabbits, Rats, Rats, Inbred SHR, Rats, Wistar, Sodium Chloride, Kidney metabolism, Lipids blood, Renal Veins
- Abstract
Medullipin I (Med I) is a vasodepressor prohormone which is continuously elaborated into the renal venous effluent (RVE) of isolated rat kidneys perfused under high pressure. We have improved the yield of Med I by substituting saline for the albumin perfusate previously reported; and considerably improved refinement by directly fractionating the crude lipid extract of the RVE with high pressure liquid chromatography. The results show that Med I, as defined by previous physiologic and pharmacologic criteria, is not a single molecule. The 3 Class I medullipins described here are distinguished by subtle or overt differences in polarity and biologic activity.
- Published
- 1994
- Full Text
- View/download PDF
21. Detection of a higher oxidation state of manganese-prostaglandin endoperoxide synthase.
- Author
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Odenwaller R, Maddipati KR, and Marnett LJ
- Subjects
- Alkenes metabolism, Animals, Apoenzymes metabolism, Arachidonic Acid metabolism, Glutathione pharmacology, Kinetics, Male, Microsomes enzymology, Oxidation-Reduction, Peroxides metabolism, Prostaglandin-Endoperoxide Synthases chemistry, Prostaglandin-Endoperoxide Synthases isolation & purification, Protein Binding, Seminal Vesicles enzymology, Sheep, Spectrophotometry, Manganese metabolism, Peroxidase metabolism, Prostaglandin-Endoperoxide Synthases metabolism
- Abstract
Addition of arachidonic acid or 5-phenyl-4-pentenylhydroperoxide to manganese-prostaglandin endoperoxide synthase (Mn-PGH synthase) produced a species with an absorbance maximum at 418 nm. This maximum is distinct from those of resting enzyme (372 and 468 nm) or reduced enzyme (434 nm). The formation of the 418 nm-absorbing species was observed immediately after the addition of hydroperoxide to enzyme but only after a 10-s lag period following addition of arachidonate. Mn-PGH synthase exhibited a peroxidase activity that was 0.8% that of Fe-PGH synthase. Addition of peroxidase reducing substrates to the oxidized form of Mn-PGH synthase diminished the absorbance at 418 nm. In the case of N,N,N',N'-tetramethylphenylenediamine, reduction of the 418 nm-absorbing species was accompanied by an increase in absorbance at 610 nm due to the oxidized form of the amine. Thus, the spectral and chemical properties of the 418 nm-absorbing species are consistent with its existence as a higher oxidation state of Mn-PGH synthase. Kinetic analysis indicated that formation of the higher oxidation state preceded or was coincident with oxygenation of the fatty acid substrate, eicosa-11,14-dienoic acid. The cyclooxygenase activity of Mn-PGH synthase was inhibited by the combination of glutathione and human plasma glutathione peroxidase at a glutathione peroxidase concentration 227-fold lower than the concentration that inhibited Fe-PGH synthase. The results suggest that Mn-PGH synthase forms a higher oxidation state following reaction with hydroperoxides added exogenously or generated endogenously from polyunsaturated fatty acid substrates. This higher oxidation state functions in the peroxidase catalytic cycle of Mn-PGH synthase, and its formation appears to be essential for activation of the cyclooxygenase catalytic cycle.
- Published
- 1992
22. Purification of arachidonate 5-lipoxygenase from potato tubers.
- Author
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Reddanna P, Whelan J, Maddipati KR, and Reddy CC
- Subjects
- Arachidonate 5-Lipoxygenase metabolism, Chromatography, DEAE-Cellulose methods, Chromatography, High Pressure Liquid methods, Chromatography, Ion Exchange methods, Enzyme Stability, Indicators and Reagents, Kinetics, Arachidonate 5-Lipoxygenase isolation & purification, Solanum tuberosum enzymology
- Published
- 1990
- Full Text
- View/download PDF
23. Characterization of the hydroperoxide-reducing activity of human plasma.
- Author
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Maddipati KR, Gasparski C, and Marnett LJ
- Subjects
- Alkenes, Erythrocytes enzymology, Humans, Kinetics, Peroxides, Plasma enzymology, Substrate Specificity, Glutathione Peroxidase blood
- Abstract
A peroxidase was identified in human plasma using a novel peroxidase assay. In this assay both the substrate 5-phenyl-4-pentenyl hydroperoxide (PPHP) and its reduction product, 5-phenyl-4-pentenyl alcohol (PPA) are quantitated by HPLC. Substrate specificity studies indicated that the peroxidase requires glutathione as reducing substrate. No reduction was detected using the classical heme peroxidase reducing substrates, phenol and hydroquinone. Peroxidase activity was not due to glutathione transferases. Failure to saturate the peroxidase activity with reduced glutathione and inhibition by Cd+2 indicated that it is probably selenium dependent. The enzyme appears to be different from erythrocyte glutathione peroxidase based on kinetic and immunological experiments. The apparent Km values for PPHP are 25 microM for erythrocyte peroxidase and 54 microM for plasma peroxidase at 0.5 mM reduced glutathione. Anti-peroxidase prepared against bovine erythrocyte glutathione peroxidase partially inhibited human erythrocyte peroxidase but did not inhibit human plasma peroxidase.
- Published
- 1987
- Full Text
- View/download PDF
24. A sensitive electrochemical method for quantitative hydroperoxide determination.
- Author
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O'Gara CY, Maddipati KR, and Marnett LJ
- Subjects
- Borohydrides chemistry, Chromatography, High Pressure Liquid, Electrochemistry, Glutathione analysis, Glutathione Peroxidase metabolism, Glutathione Reductase metabolism, Humans, Hydrogen Peroxide metabolism, Indicators and Reagents, Lipid Peroxidation, NADP metabolism, Oxidation-Reduction, Phospholipases A metabolism, Phospholipases A2, Tin chemistry, Hydrogen Peroxide analysis, Tin Compounds
- Abstract
We report a general assay for hydroperoxides that is simple, selective, and sensitive. The assay is based on the reduction of hydroperoxides by glutathione (GSH) catalyzed by GSH peroxidase. Stoichiometric amounts of oxidized glutathione (GSSG) are produced that are separated from GSH by HPLC. GSSG eluting from the column is quantitated with a coulometric detector operating in the oxidizing mode (E = 0.82 V vs Pd). Picomole amounts of GSSG can be measured and related to the hydroperoxide concentration in the incubation mixture. GSH peroxidase has broad substrate specificity to many different hydroperoxides. Therefore, this method allows the determination of the total hydroperoxide concentration in the reaction mixture. For analysis of peroxidized phospholipids, phospholipase A2 is included in the reaction to release fatty acid hydroperoxides from the 2-position of the glycerol moiety. The presence of hydroperoxide is verified by addition of sodium borohydride or stannous chloride to sample extracts of biological fluids before analysis. The applicability of this method was tested by examination of human plasma from normal individuals for hydroperoxide levels.
- Published
- 1989
- Full Text
- View/download PDF
25. Localization of the peroxidase active site of PGH synthase.
- Author
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Marnett LJ, Chen YN, Maddipati KR, Labeque R, and Ple P
- Subjects
- Binding Sites, Heme metabolism, Kinetics, Peptide Mapping, Trypsin, Peroxidases, Prostaglandin-Endoperoxide Synthases metabolism
- Published
- 1989
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