scholarly journals Nickel-deficient carbon monoxide dehydrogenase from Rhodospirillum rubrum: in vivo and in vitro activation by exogenous nickel.

1988 ◽  
Vol 85 (1) ◽  
pp. 31-35 ◽  
Author(s):  
D. Bonam ◽  
M. C. McKenna ◽  
P. J. Stephens ◽  
P. W. Ludden
Keyword(s):  
Carbon Monoxide ◽  
Rhodospirillum Rubrum ◽  
Carbon Monoxide Dehydrogenase ◽  
In Vitro Activation

Vitamin D modulates the expression of HLA-DR and CD38 after in vitro activation of T-cells

2017 ◽  
Vol 29 (3) ◽  
Author(s):  
Simon Villegas-Ospina ◽  
Wbeimar Aguilar-Jimenez ◽  
Sandra M. Gonzalez ◽  
María T. Rugeles
Keyword(s):  
Vitamin D ◽  
Flow Cytometry ◽  
Healthy Subjects ◽  
Mononuclear Cells ◽  
Activation Markers ◽  
Hla Dr ◽  
In Vitro Activation ◽  
Cells Cultured

AbstractObjective:Vitamin D (VitD) is an anti-inflammatory hormone; however, some evidence shows that VitD may induce the expression of activation markers, such as CD38 and HLA-DR. We explored its effect on the expression of these markers on CD4Materials and methods:CD38 and HLA-DR expression was measured by flow cytometry in PHA/IL-2-activated mononuclear cells cultured under VitD precursors: three cholecalciferol (10Results:Cholecalciferol at 10Conclusion:Although no significant correlations were observed in vivo in healthy subjects, VitD treatment in vitro modulated immune activation by increasing the expression of CD38 and decreasing the proliferation of HLA-DR

scholarly journals Carbon Monoxide Inhibits Tenascin-C Mediated Inflammation via IL-10 Expression in a Septic Mouse Model

2015 ◽  
Vol 2015 ◽  
pp. 1-14 ◽  
Author(s):  
Md. Jamal Uddin ◽  
Chun-shi Li ◽  
Yeonsoo Joe ◽  
Yingqing Chen ◽  
Qinggao Zhang ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Proinflammatory Cytokines ◽  
Tissue Injury ◽  
Inflammatory Diseases ◽  
Septic Mouse ◽  
Induced Expression ◽  
Tenascin C ◽  
Co Gas

Tenascin-C (TN-C), an extracellular matrix (ECM) glycoprotein, is specifically induced upon tissue injury and infection and during septic conditions. Carbon monoxide (CO) gas is known to exert various anti-inflammatory effects in various inflammatory diseases. However, the mechanisms underlying the effect of CO on TN-C-mediated inflammation are unknown. In the present study, we found that treatment with LPS significantly enhanced TN-C expression in macrophages. CO gas, or treatment with the CO-donor compound, CORM-2, dramatically reduced LPS-induced expression of TN-C and proinflammatory cytokines while significantly increased the expression of IL-10. Treatment with TN-C siRNA significantly suppressed the effects of LPS on proinflammatory cytokines production. TN-C siRNA did not affect the CORM-2-dependent increase of IL-10 expression. In cells transfected with IL-10 siRNA, CORM-2 had no effect on the LPS-induced expression of TN-C and its downstream cytokines. These data suggest that IL-10 mediates the inhibitory effect of CO on TN-C and the downstream production of proinflammatory cytokines. Additionally, administration of CORM-2 dramatically reduced LPS-induced TN-C and proinflammatory cytokines production while expression of IL-10 was significantly increased. In conclusion, CO regulated IL-10 expression and thus inhibited TN-C-mediated inflammationin vitroandin vivo.

Neutrophil kinetics in rabbits during infusion of zymosan-activated plasma

1989 ◽  
Vol 67 (1) ◽  
pp. 88-95 ◽  
Author(s):  
C. M. Doerschuk ◽  
M. F. Allard ◽  
J. C. Hogg
Keyword(s):  
Relative Size ◽  
Pulmonary Sequestration ◽  
Blood Velocity ◽  
Pulmonary Capillaries ◽  
In Vitro Activation ◽  
The Complement System ◽  
Kinetics In Vivo ◽  
Neutrophil Kinetics

Complement activation in vivo produces neutropenia and pulmonary sequestration of neutrophils (PMNs) whereas in vitro activation increases PMN adherence and decreases PMN deformability. The present study examined PMN kinetics in vivo to determine if this sequestration was specific to the lung. Venous or arterial injections of radiolabeled PMNs were given to animals receiving infusions of zymosan-activated plasma (ZAP) or saline, and the PMN distribution was evaluated 10 min later. In control animals, the relative size of the marginated and circulating PMN pools was similar after venous or arterial injection and regional PMN retention increased as blood velocity slowed. ZAP infusion produced threefold increases in PMNs within pulmonary capillaries after venous injection and PMN retention was independent of blood velocity. After arterial injection, ZAP infusion produced PMN sequestration in all organs. Rigid (glutaraldehyde-fixed) PMNs injected into control rabbits showed increased lung recoveries similar to those of fresh PMNs injected into ZAP-treated rabbits. We conclude that activation of the complement system causes PMN sequestration in both the pulmonary and the systemic microvasculature and that the decrease in PMN deformability that occurs with activation of the PMN may be important in the genesis of PMN sequestration.

Bioconversion of Carbon Monoxide to Formate Using Artificially Designed Carbon Monoxide:Formate Oxidoreductase in Hyperthermophilic Archaea

2021 ◽  
Author(s):  
Jae Kyu Lim ◽  
Ji-In Yang ◽  
Yun Jae Kim ◽  
Yeong-Jun Park ◽  
Yong Hwan Kim
Keyword(s):  
Carbon Monoxide ◽  
Electron Transfer ◽  
Fusion Protein ◽  
Direct Electron Transfer ◽  
Co2 Reduction ◽  
Hyperthermophilic Archaea ◽  
Production Activity ◽  
Formate Production

Abstract Ferredoxin-dependent metabolic engineering of electron transfer circuits has been developed to enhance redox efficiency in the field of synthetic biology, e.g., for hydrogen production and for reduction of flavoproteins or NAD(P)+. Here, we present the bioconversion of carbon monoxide (CO) gas to formate via a synthetic CO:formate oxidoreductase (CFOR), designed as an enzyme complex for direct electron transfer between noninteracting CO dehydrogenase and formate dehydrogenase using an electron-transferring Fe-S fusion protein. The CFOR-introduced Thermococcus onnurineus mutant strains showed CO-dependent formate production in vivo and in vitro. The formate production rate from purified CFOR complex and specific formate productivity from the bioreactor were 348 ± 34 μmol/mg/min and 90.2 ± 20.4 mmol/g-cells/h, respectively. The CO-dependent CO2 reduction/formate production activity of synthetic CFOR was confirmed, indicating that direct electron transfer between two unrelated dehydrogenases was feasible via mediation of the FeS-FeS fusion protein.

scholarly journals Ruthenium, Not Carbon Monoxide, Inhibits the Procoagulant Activity of Atheris, Echis, and Pseudonaja Venoms

2020 ◽  
Vol 21 (8) ◽  
pp. 2970 ◽  
Author(s):  
Vance G. Nielsen
Keyword(s):  
Carbon Monoxide ◽  
Phospholipase A2 ◽  
Procoagulant Activity ◽  
Inhibitory Effects ◽  
Snake Venoms ◽  
Radical Intermediate ◽  
Experimental Systems ◽  
Phospholipase A2 Activity

The demonstration that carbon monoxide releasing molecules (CORMs) affect experimental systems by the release of carbon monoxide, and not via the interaction of the inactivated CORM, has been an accepted paradigm for decades. However, it has recently been documented that a radical intermediate formed during carbon monoxide release from ruthenium (Ru)-based CORM (CORM-2) interacts with histidine and can inactivate bee phospholipase A2 activity. Using a thrombelastographic based paradigm to assess procoagulant activity in human plasma, this study tested the hypothesis that a Ru-based radical and not carbon monoxide was responsible for CORM-2 mediated inhibition of Atheris, Echis, and Pseudonaja species snake venoms. Assessment of the inhibitory effects of ruthenium chloride (RuCl3) on snake venom activity was also determined. CORM-2 mediated inhibition of the three venoms was found to be independent of carbon monoxide release, as the presence of histidine-rich albumin abrogated CORM-2 inhibition. Exposure to RuCl3 had little effect on Atheris venom activity, but Echis and Pseudonaja venom had procoagulant activity significantly reduced. In conclusion, a Ru-based radical and ion inhibited procoagulant snake venoms, not carbon monoxide. These data continue to add to our mechanistic understanding of how Ru-based molecules can modulate hemotoxic venoms, and these results can serve as a rationale to focus on perhaps other, complementary compounds containing Ru as antivenom agents in vitro and, ultimately, in vivo.

DETECTION OF INACTIVATED α2-MACROGLOBULIN (α2M) IN HUMAN PLASMA USING MONOCLONAL ANTIBODIES

1987 ◽  
Author(s):  
J Abbink ◽  
J Nuijens ◽  
C Huijbregts ◽  
E Hack
Keyword(s):  
Monoclonal Antibodies ◽  
Longitudinal Studies ◽  
Human Plasma ◽  
Dextran Sulfate ◽  
Optimal Conditions ◽  
Α2 Macroglobulin ◽  
In Vitro Activation

Monoclonal antibodies (mAbs) were raised against human a2M. Five mAbs that bound to α2M in ELISA were further analyzed by a radioimmunoassay (RIA) for their reaction with three types of α2M: native α2M, chemically inactivated α2M (iα2M) (methylamine treated), and proteolytically iα2M. One mAb reacted with all forms of α2M, while four mAbs bound both forms of ia2M but not native α2M. One of these latter mAbs (Ml) was used to develop a RIA (the Ml-assay) for the detection of iα2M in plasma: Ml coupled to Sepharose is incubated with the plasma to be tested, and bound iα2M is detected by a subsequent incubation with polyclonal 125I-anti-α2M antibodies. As little as 5 ng of iα2M can be detected with this assay in the presence of an excess of native α2M. This assay was then applied to measure inactivation of α2M in vitro and in vivo. In vitro activation of the contact system in plasma by dextran sulfate results in the inactivation of ca 10% of α2M. When blood from normal donors was collected under optimal conditions, about 0.5% of the total α2M content appeared to be iα2M. Longitudinal studies in patients (a.o. with septicaemie, during cardiopulmunary bypass) revealed that increased levels of iα2M occurred sporadically. The Ml-assay appears to be useful to monitor the role of α2M in human diseases.

scholarly journals A neuroglobin-based high-affinity ligand trap reverses carbon monoxide–induced mitochondrial poisoning

2020 ◽  
Vol 295 (19) ◽  
pp. 6357-6371 ◽  
Author(s):  
Jason J. Rose ◽  
Kaitlin A. Bocian ◽  
Qinzi Xu ◽  
Ling Wang ◽  
Anthony W. DeMartino ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Mitochondrial Respiration ◽  
Oxygen Delivery ◽  
Oxygen Electrode ◽  
Heart Tissue ◽  
Tissue Respiration ◽  
Co Poisoning ◽  
Affinity Ligand

Carbon monoxide (CO) remains the most common cause of human poisoning. The consequences of CO poisoning include cardiac dysfunction, brain injury, and death. CO causes toxicity by binding to hemoglobin and by inhibiting mitochondrial cytochrome c oxidase (CcO), thereby decreasing oxygen delivery and inhibiting oxidative phosphorylation. We have recently developed a CO antidote based on human neuroglobin (Ngb-H64Q-CCC). This molecule enhances clearance of CO from red blood cells in vitro and in vivo. Herein, we tested whether Ngb-H64Q-CCC can also scavenge CO from CcO and attenuate CO-induced inhibition of mitochondrial respiration. Heart tissue from mice exposed to 3% CO exhibited a 42 ± 19% reduction in tissue respiration rate and a 33 ± 38% reduction in CcO activity compared with unexposed mice. Intravenous infusion of Ngb-H64Q-CCC restored respiration rates to that of control mice correlating with higher electron transport chain CcO activity in Ngb-H64Q-CCC–treated compared with PBS-treated, CO-poisoned mice. Further, using a Clark-type oxygen electrode, we measured isolated rat liver mitochondrial respiration in the presence and absence of saturating solutions of CO (160 μm) and nitric oxide (100 μm). Both CO and NO inhibited respiration, and treatment with Ngb-H64Q-CCC (100 and 50 μm, respectively) significantly reversed this inhibition. These results suggest that Ngb-H64Q-CCC mitigates CO toxicity by scavenging CO from carboxyhemoglobin, improving systemic oxygen delivery and reversing the inhibitory effects of CO on mitochondria. We conclude that Ngb-H64Q-CCC or other CO scavengers demonstrate potential as antidotes that reverse the clinical and molecular effects of CO poisoning.

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