A kinetic model of superoxide production from single pulmonary alveolar macrophages

A kinetic model was developed to describe the production of superoxide (O2-) by single pulmonary alveolar macrophages (PAM). Model predictions were compared with experimental results obtained from single rat PAM. The O2- was quantified by measuring the reduction of nitro blue tetrazolium (NBT) to a diformazan precipitate (NBTH2) from video-recorded images of individual cells. The kinetic model considered three reactions: 1) the production of extracellular O2- from the reduction of oxygen by NADPH oxidase using intracellular NADPH as the substrate, 2) the subsequent dismutation of O2- to form H2O2, and 3) the reaction of O2- and NBT to form diformazan. NBT specificity for O2- was analyzed by comparing results in the presence and absence of superoxide dismutase (SOD) that catalyzes the dismutation of O2- to H2O2. Measured PAM heterogeneity was accounted for by varying the concentration of intracellular NADPH, its rate of depletion, and the concentration of intracellular NADPH oxidase in the kinetic model. Model predictions compared favorably with experimental results except when SOD was present. This discrepancy may be due to diffusional limitations because NBT is a relatively small molecule (818 mol wt) compared with SOD (34,000 mol wt). In addition, the cell surface is both ruffled and negatively charged, which may introduce steric hindrances and/or electrostatic effects, since SOD is also negatively charged, whereas NBT is positively charged.

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Development of an Activity Based Kinetic Model for an Esterification Process with Indion 180 Catalyst

International Journal of Chemical Reactor Engineering ◽

10.1515/ijcre-2018-0285 ◽

2019 ◽

Vol 17 (9) ◽

Author(s):

Mekala Mallaiah ◽

Chimmiri Venkateswarlu

Keyword(s):

Kinetic Model ◽

Reaction Rate ◽

Experimental Results ◽

Catalyst Loading ◽

Esterification Reaction ◽

Order Kinetic ◽

Kinetic Rate ◽

Model Predictions ◽

Effects Of Temperature ◽

Kinetics Of

Abstract The kinetics of esterification reaction between acetic acid and methanol was studied with the Indion 180 catalyst in the temperature range between 323.15 and 353.15K, and the catalyst loading between 0.01 g/cc to0.05 g/cc. The effects of temperature, catalyst loading, size of the catalyst and agitation speed on the reaction rate were investigated. The experimental results have shown the negligible effect of mass transfer resistances on the reaction rate. A second order kinetic rate expression was used to correlate the experimental data. An activity based kinetic model was also developed for the esterification process, which was validated against experimental results. The activity based model is found advantageous as it involves only two reaction rate parameters which were determined based on the kinetic rate parameters of the concentration based model. The comparison of the model predictions with the experimental results for different temperature and catalyst loading conditions has shown the better suitability of the activity based kinetic model for the esterification process with Indion 180 catalyst.

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Faculty Opinions recommendation of Amelioration of emphysema in mice through lentiviral transduction of long-lived pulmonary alveolar macrophages.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1760957.2713054 ◽

2010 ◽

Author(s):

Caroline Owen ◽

Martin Knolle

Keyword(s):

Alveolar Macrophages ◽

Lentiviral Transduction ◽

Pulmonary Alveolar Macrophages

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Nitrate and chloride formation in chloramination

Water Science & Technology ◽

10.2166/wst.1994.0453 ◽

1994 ◽

Vol 30 (9) ◽

pp. 101-110

Author(s):

V. Diyamandoglu

Keyword(s):

Kinetic Model ◽

Analytical Method ◽

Kinetic Data ◽

Experimental Results ◽

Mass Balances ◽

Time Profiles ◽

Slow Decay ◽

Concentration Time ◽

End Products ◽

Chlorine Residuals

The formation of nitrate and chloride as end-products of chloramination (combined chlorination) was investigated at pH ranging between 6.9 and 9.6 at 25°C. The experimental results comprised concentration-time profiles of combined chlorine residuals along with nitrate and chloride. Nitrite, if present, was always below the detectibility limit of the analytical method used (25 ppb). Mass balances on chlorine species depicted that chloride formed during the slow decay of combined chlorine residuals does not account for all the chlorine lost. This substantiates the formation of other reaction end-products which are yet to be identified. A kinetic model for chloramination is proposed based on the kinetic data obtained in this study.

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New Insights on NETosis Induced by Entamoeba histolytica: Dependence on ROS from Amoebas and Extracellular MPO Activity

Antioxidants ◽

10.3390/antiox10060974 ◽

2021 ◽

Vol 10 (6) ◽

pp. 974

Author(s):

César Díaz-Godínez ◽

Joshue Fabián Jorge-Rosas ◽

Mario Néquiz ◽

Santiago Martínez-Calvillo ◽

Juan P. Laclette ◽

...

Keyword(s):

Cell Surface ◽

Nadph Oxidase ◽

Entamoeba Histolytica ◽

Pathogen Detection ◽

Dependent Manner ◽

Antimicrobial Proteins ◽

Nadph Oxidase Activity ◽

Mitochondrial Ros ◽

Pre Treatment ◽

Dose Dependent

NETosis is a neutrophil process involving sequential steps from pathogen detection to the release of DNA harboring antimicrobial proteins, including the central generation of NADPH oxidase dependent or independent ROS. Previously, we reported that NETosis triggered by Entamoeba histolytica trophozoites is independent of NADPH oxidase activity in neutrophils, but dependent on the viability of the parasites and no ROS source was identified. Here, we explored the possibility that E. histolytica trophozoites serve as the ROS source for NETosis. NET quantitation was performed using SYTOX® Green assay in the presence of selective inhibitors and scavengers. We observed that respiratory burst in neutrophils was inhibited by trophozoites in a dose dependent manner. Mitochondrial ROS was not also necessary, as the mitochondrial scavenger mitoTEMPO did not affect the process. Surprisingly, ROS-deficient amoebas obtained by pre-treatment with pyrocatechol were less likely to induce NETs. Additionally, we detected the presence of MPO on the cell surface of trophozoites after the interaction with neutrophils and found that luminol and isoluminol, intracellular and extracellular scavengers for MPO derived ROS reduced the amount of NET triggered by amoebas. These data suggest that ROS generated by trophozoites and processed by the extracellular MPO during the contact with neutrophils are required for E. histolytica induced NETosis.

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Are there excess fetal deaths attributable to waterborne lead exposure during the Flint Water Crisis? Evidence from bio-kinetic model predictions and Vital Records

Journal of Exposure Science & Environmental Epidemiology ◽

10.1038/s41370-021-00363-z ◽

2021 ◽

Author(s):

Siddhartha Roy ◽

Marc A. Edwards

Keyword(s):

Kinetic Model ◽

Lead Exposure ◽

Water Crisis ◽

Vital Records ◽

Model Predictions

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LPS-induced expression of CD14 in the TRIF pathway is epigenetically regulated by sulforaphane in porcine pulmonary alveolar macrophages

Innate Immunity ◽

10.1177/1753425916669418 ◽

2016 ◽

Vol 22 (8) ◽

pp. 682-695 ◽

Cited By ~ 12

Author(s):

Qin Yang ◽

Maren J Pröll ◽

Dessie Salilew-Wondim ◽

Rui Zhang ◽

Dawit Tesfaye ◽

...

Keyword(s):

Gene Expression ◽

Alveolar Macrophages ◽

Methylation Status ◽

Gene Body ◽

Gene Body Methylation ◽

Tnf Α ◽

Pulmonary Alveolar Macrophages ◽

Cluster Of Differentiation ◽

Cd14 Gene

Pulmonary alveolar macrophages (AMs) are important in defense against bacterial lung inflammation. Cluster of differentiation 14 (CD14) is involved in recognizing bacterial lipopolysaccharide (LPS) through MyD88-dependent and TRIF pathways of innate immunity. Sulforaphane (SFN) shows anti-inflammatory activity and suppresses DNA methylation. To identify CD14 epigenetic changes by SFN in the LPS-induced TRIF pathway, an AMs model was investigated in vitro. CD14 gene expression was induced by 5 µg/ml LPS at the time point of 12 h and suppressed by 5 µM SFN. After 12 h of LPS stimulation, gene expression was significantly up-regulated, including TRIF, TRAF6, NF-κB, TRAF3, IRF7, TNF-α, IL-1β, IL-6, and IFN-β. LPS-induced TRAM, TRIF, RIPK1, TRAF3, TNF-α, IL-1β and IFN-β were suppressed by 5 µM SFN. Similarly, DNMT3a expression was increased by LPS but significantly down-regulated by 5 µM SFN. It showed positive correlation of CD14 gene body methylation with in LPS-stimulated AMs, and this methylation status was inhibited by SFN. This study suggests that SFN suppresses CD14 activation in bacterial inflammation through epigenetic regulation of CD14 gene body methylation associated with DNMT3a. The results provide insights into SFN-mediated epigenetic down-regulation of CD14 in LPS-induced TRIF pathway inflammation and may lead to new methods for controlling LPS-induced inflammation in pigs.

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The Proliferation Kinetics of Pulmonary Alveolar Macrophages

Journal of Leukocyte Biology ◽

10.1002/jlb.35.3.317 ◽

1984 ◽

Vol 35 (3) ◽

pp. 317-327 ◽

Cited By ~ 39

Author(s):

J.E. Coggle ◽

J.D. Tarling

Keyword(s):

Alveolar Macrophages ◽

Proliferation Kinetics ◽

Pulmonary Alveolar Macrophages ◽

Kinetics Of

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Attenuation of renal excretory responses to ANG II during inhibition of superoxide dismutase in anesthetized rats

AJP Renal Physiology ◽

10.1152/ajprenal.00511.2009 ◽

2010 ◽

Vol 298 (2) ◽

pp. F401-F407 ◽

Cited By ~ 2

Author(s):

Md. Abdul Hye Khan ◽

Mohammed Toriqul Islam ◽

Alexander Castillo ◽

Dewan Syed Abdul Majid

Keyword(s):

Superoxide Dismutase ◽

Nadph Oxidase ◽

Oxidase Activity ◽

Ang Ii ◽

Sod Activity ◽

Doppler Flowmetry ◽

Nadph Oxidase Activity ◽

Blood Flows ◽

Renal Responses

To examine the functional interaction between superoxide dismutase (SOD) and NADPH oxidase activity, we assessed renal responses to acute intra-arterial infusion of ANG II (0.5 ng·kg−1·min−1) before and during administration of a SOD inhibitor, diethyldithiocarbamate (DETC, 0.5 mg·kg−1·min−1), in enalaprilat-pretreated (33 μg·kg−1·min−1) rats ( n = 11). Total (RBF) and regional (cortical, CBF; medullary; MBF) renal blood flows were determined by Transonic and laser-Doppler flowmetry, respectively. Renal cortical and medullary tissue NADPH oxidase activity in vitro was determined using the lucigenin-chemiluminescence method. DETC treatment alone resulted in decreases in RBF, CBF, MBF, glomerular filtration rate (GFR), urine flow (V), and sodium excretion (UNaV) as reported previously. Before DETC, ANG II infusion decreased RBF (−18 ± 3%), CBF (−16 ± 3%), MBF [−5 ± 6%; P = not significant (NS)], GFR (−31 ± 4%), V (−34 ± 2%), and UNaV (−53 ± 3%). During DETC infusion, ANG II also caused similar reductions in RBF (−20 ± 4%), CBF (−19 ± 3%), MBF (−2 ± 2; P = NS), and in GFR (−22 ± 7%), whereas renal excretory responses (V; −12 ± 2%; UNaV; −24 ± 4%) were significantly attenuated compared with those before DETC. In in vitro experiments, ANG II (100 μM) enhanced NADPH oxidase activity both in cortical [13,194 ± 1,651 vs. 20,914 ± 2,769 relative light units (RLU)/mg protein] and in medullary (21,296 ± 2,244 vs. 30,597 ± 4,250 RLU/mg protein) tissue. Application of DETC (1 mM) reduced the basal levels and prevented ANG II-induced increases in NADPH oxidase activity in both tissues. These results demonstrate that renal excretory responses to acute ANG II administration are attenuated during SOD inhibition, which seems related to a downregulation of NADPH oxidase in the deficient condition of SOD activity.

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