| 1. |
- Abdalla, Hana, et al.
(författare)
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Effects of CNI-1493 on human granulocyte functions
- 2006
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Ingår i: Immunobiology. - : Elsevier BV. - 0171-2985 .- 1878-3279. ; 211:3, s. 191-197
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Tidskriftsartikel (refereegranskat)abstract
- During acute bacterial infections such as sepsis and meningitis, activation of inflammatory mediators such as nitric oxide (NO) plays a crucial role in both pathogenesis and host defense. We have previously reported that CNI-1493, a macrophage deactivator, reduced mortality in infant rats infected with Haemophilus influenzae type b (Hib) with associated decrease in the number of granulocytes in the infected tissue. The aim of the present study was to investigate how CNI-1493 affects granulocytes and macrophages in vitro. Murine macrophages (RAW 264.7) pre-incubated with CNI-1493 prior to activation with lipopolysaccharide (LPS)/interferon gamma (IFNγ) had decreased NO production measured as NO2−/NO3− levels and reduction in inducible NO-synthase (iNOS) expression. Reactive oxygen species (ROS) production was increased in formylmethionyl-leucyl-phenylalanine (FMLP)-stimulated granulocytes following CNI-1493 treatment, whereas F-actin content, motility and chemotaxis were decreased under the same conditions. The effects of CNI-1493 on both NO production in LPS/IFNγ-activated macrophages and ROS production, F-actin content, motility and chemotaxis in granulocytes, may contribute to the reduced inflammatory response and increased survival in Hib-infected animals treated with CNI-1493.
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| 2. |
- Abdalla, Hana, et al.
(författare)
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Expression of inducible nitric oxide synthases and nitrotyrosine during the course of Haemophilus influenzae type b meningitis in rat
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Bacterial meningitis continues to be a major health problem and despite great advances in antimicrobial therapy the fatality rate remains high. There is increasing evidence that leukocyte-endothelial interactions are involved in CNS damage during bacterial meningitis. Once leukocytes have entered the CSF they cause injury by releasing toxic molecules such as nitric oxide (NO) and reactive oxygen species (ROS). The induction of iNOS was examined by assessing intracerebral mRNA expression and protein production during the course of Haemophilus influenzae type b (Hib) meningitis in the rat. Induction of iNOS mRNA was detected 12h postinoculation (pi), followed by a gradual reduction. The increased number of intracerebral iN OS expressing cells was detected at 12h pi. followed by further elevation to peak expression at 72h pi. The iNOS positive tissue also bound antibodies specific for nitrotyrosine. The expression of iNOS and NO production, as shown by nitrotyrosine expression, correlated with disease severity, suggesting that activation of iNOS may play an important role in Haemophilus irifluenzae type b meningitis.
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| 3. |
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| 4. |
- Andersson, Henrik, et al.
(författare)
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Orexin A Phosphorylates the gamma-Aminobutyric Acid Type A Receptor beta(2) Subunit on a Serine Residue and Changes the Surface Expression of the Receptor in SH-SY5Y Cells Exposed to Propofol
- 2015
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Ingår i: Journal of Neuroscience Research. - : WILEY-BLACKWELL. - 0360-4012 .- 1097-4547. ; 93:11, s. 1748-1755
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Tidskriftsartikel (refereegranskat)abstract
- Propofol activates the gamma-aminobutyric acid type A receptor (GABA(A)R) and causes a reversible neurite retraction, leaving a thin, thread-like structure behind; it also reverses the transport of vesicles in rat cortical neurons. The awakening peptide orexin A (OA) inhibits this retraction via phospholipase D (PLD) and protein kinase CE (PKCE). The human SH-SY5Y cells express both GABA(A)Rs and orexin 1 and 2 receptors. These cells are used to examine the interaction between OA and the GABAAR. The effects of OA are studied with flow cytometry and immunoblotting. This study shows that OA stimulates phosphorylation on the serine residues of the GABA(A)R beta(2) subunit and that the phosphorylation is caused by the activation of PLD and PKCE. OA administration followed by propofol reduces the cell surface expression of the GABA(A)R, whereas propofol stimulation before OA increases the surface expression. The GABA(A)R beta(2) subunit is important for receptor recirculation, and the effect of OA on propofol-stimulated cells may be due to a disturbed recirculation of the GABA(A)R. (C) 2015 Wiley Periodicals, Inc.
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| 5. |
- Björnsson, Bergthor, et al.
(författare)
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Conventional, but not remote ischemic preconditioning, reduces iNOS transcription in liver ischemia/reperfusion
- 2014
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Ingår i: World Journal of Gastroenterology. - : Baishideng Publishing Group Co. Limited. - 1007-9327 .- 2219-2840. ; 20:28, s. 9506-9512
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Tidskriftsartikel (refereegranskat)abstract
- AIM: To study the effects of preconditioning on inducible nitric oxide synthase (iNOS) and interleukin 1 (IL-1) receptor transcription in rat liver ischemia/reperfusion injury (IRI). METHODS: Seventy-two male rats were randomized into 3 groups: the one-hour segmental ischemia (IRI, n = 24) group, the ischemic preconditioning (IPC, n = 24) group or the remote ischemic preconditioning (R-IPC, n = 24) group. The IPC and R-IPC were performed as 10 min of ischemia and 10 min of reperfusion. The iNOS and the IL-1 receptor mRNA in the liver tissue was analyzed with real time PCR. The total Nitrite and Nitrate (NOx) in continuously sampled microdialysate (MD) from the liver was analyzed. In addition, the NOx levels in the serum were analyzed. RESULTS: After 4 h of reperfusion, the iNOS mRNA was significantly higher in the R-IPC (Delta Ct: 3.44 +/- 0.57) group than in the IPC (Delta Ct: 5.86 +/- 0.82) group (P = 0.025). The IL-1 receptor transcription activity was reduced in the IPC group (Delta Ct: 1.88 +/- 0.53 to 4.81 +/- 0.21), but not in the R-IPC group, during reperfusion (P = 0.027). In the MD, a significant drop in the NOx levels was noted in the R-IPC group (12.3 +/- 2.2 to 4.7 +/- 1.2 mu mol/L) at the end of ischemia compared with the levels in early ischemia (P = 0.008). A similar trend was observed in the IPC group (11.8 +/- 2.1 to 6.4 +/- 1.5 mu mol/L), although this difference was not statistically significant. The levels of NOx rose quickly during reperfusion in both groups. CONCLUSION: IPC, but not R-IPC, reduces iNOS and IL-1 receptor transcription during early reperfusion, indicating a lower inflammatory reaction. NOx is consumed in the ischemic liver lobe.
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| 6. |
- Björnsson, Bergthor, et al.
(författare)
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Nitrite, a novel method to decrease ischemia/reperfusion injury in the rat liver
- 2015
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Ingår i: World Journal of Gastroenterology. - : Baishideng Publishing Group Co. Limited. - 1007-9327 .- 2219-2840. ; 21:6, s. 1775-1783
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Tidskriftsartikel (refereegranskat)abstract
- AIM: To investigate whether nitrite administered prior to ischemia/reperfusion (I/R) reduces liver injury.METHODS: Thirty-six male Sprague-Dawley rats were randomized to 3 groups, including sham operated (n = 8), 45-min segmental ischemia of the left liver lobe (IR, n = 14) and ischemia/reperfusion (I/R) preceded by the administration of 480 nmol of nitrite (n = 14). Serum transaminases were measured after 4 h of reperfusion. Liver microdialysate (MD) was sampled in 30-min intervals and analyzed for glucose, lactate, pyruvate and glycerol as well as the total nitrite and nitrate (NOx). The NOx was measured in serum.RESULTS: Aspartate aminotransferase (AST) at the end of reperfusion was higher in the IR group than in the nitrite group (40 ± 6.8 μkat/L vs 22 ± 2.6 μkat/L, P = 0.022). Similarly, alanine aminotransferase (ALT) was also higher in the I/R group than in the nitrite group (34 ± 6 μkat vs 14 ± 1.5 μkat, P = 0.0045). The NOx in MD was significantly higher in the nitrite group than in the I/R group (10.1 ± 2.9 μM vs 3.2 ± 0.9 μM, P = 0.031) after the administration of nitrite. During ischemia, the levels decreased in both groups and then increased again during reperfusion. At the end of reperfusion, there was a tendency towards a higher NOx in the I/R group than in the nitrite group (11.6 ± 0.7 μM vs 9.2 ± 1.1 μM, P = 0.067). Lactate in MD was significantly higher in the IR group than in the nitrite group (3.37 ± 0.18 mM vs 2.8 ± 0.12 mM, P = 0.01) during ischemia and the first 30 min of reperfusion. During the same period, glycerol was also higher in the IRI group than in the nitrite group (464 ± 38 μM vs 367 ± 31 μM, P = 0.049). With respect to histology, there were more signs of tissue damage in the I/R group than in the nitrite group, and 29% of the animals in the I/R group exhibited necrosis compared with none in the nitrite group. Inducible nitric oxide synthase (iNOS) transcription increased between early ischemia (t = 15) and the end of reperfusion in both groups.CONCLUSION: Nitrite administered before liver ischemia in the rat liver reduces anaerobic metabolism and cell necrosis, which could be important in the clinical setting.
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| 7. |
- Björnsson, Bergthor, et al.
(författare)
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Remote or Conventional Ischemic Preconditioning -Local Liver Metabolism in Rats Studied with Microdialysis
- 2012
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Ingår i: Journal of Surgical Research. - : Elsevier. - 0022-4804 .- 1095-8673. ; 176:1, s. 55-62
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Tidskriftsartikel (refereegranskat)abstract
- Background. Ischemic preconditioning (IPC) of the liver decreases liver injury secondary to ischemia and reperfusion. An attractive alternative to IPC is remote ischemic preconditioning (R-IPC), but these two methods have not previously been compared. Material and Methods. Eighty-seven rats were randomized into four groups: sham operated (n = 15), 1 h segmental ischemia (IRI, n = 24), preceeded by IPC (n = 24), or R-IPC (n = 24) (to the left hindleg). IPC and R-IPC were performed with 10 min ischemia and 10 min of reperfusion. Analyses of liver microdialysate (MD), serum transaminase levels, and liver histology were made. Results. Rats treated with IPC and R-IPC had significantly lower AST, 71.5 (19.6) IU/L respective 96.6 (12.4) at 4 h reperfusion than those subjected to IRI alone, 155 (20.9), P = 0.0004 and P = 0.04 respectively. IPC also had lower ALT levels, 41.6 (11.3) IU/L than had IRI 107.4 (15.5), P = 0.003. The MD glycerol was significantly higher during ischemia in the R-IPC = 759 (84) mu M] and the IRI = 732 (67)] groups than in the IPC 514 (70) group, P = 0.022 and P = 0.046 respectively. The MD glucose after ischemia was lower in the IPC group 7.1 (1.2) than in the IRI group 12.7 (1.6), P = 0.005. Preconditioning to the liver caused an direct increase in lactate, glucose and glycerol in the ischemic segment compared with the control segment an effect not seen in the R-IPC and IRI groups. Conclusions. IPC affects glucose metabolism in the rat liver, observed with MD. IPC reduces liver cell injury during ischemic and reperfusion in rats. R-IPC performed over the same length of time as IPC does not have the same effect as the latter on ALT levels and MD glycerol; this may suggest that R-IPC does not offer the same protection as IPC in this setting of rat liver IRI.
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| 8. |
- Björnström-Karlsson, Karin, et al.
(författare)
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Orexin A Inhibits Propofol-Induced Neurite Retraction by a Phospholipase D/Protein Kinase C-epsilon-Dependent Mechanism in Neurons
- 2014
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Ingår i: PLOS ONE. - : Public Library of Science. - 1932-6203. ; 9:5, s. e0097129-
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Tidskriftsartikel (refereegranskat)abstract
- Background: The intravenous anaesthetic propofol retracts neurites and reverses the transport of vesicles in rat cortical neurons. Orexin A (OA) is an endogenous neuropeptide regulating wakefulness and may counterbalance anaesthesia. We aim to investigate if OA interacts with anaesthetics by inhibition of the propofol-induced neurite retraction. Methods: In primary cortical cell cultures from newborn rats brains, live cell light microscopy was used to measure neurite retraction after propofol (2 mu M) treatment with or without OA (10 nM) application. The intracellular signalling involved was tested using a protein kinase C (PKC) activator [phorbol 12-myristate 13-acetate (PMA)] and inhibitors of Rho-kinase (HA-1077), phospholipase D (PLD) [5-fluoro-2-indolyl des-chlorohalopemide (FIPI)], PKC (staurosporine), and a PKC epsilon translocation inhibitor peptide. Changes in PKC epsilon Ser(729) phosphorylation were detected with Western blot. Results: The neurite retraction induced by propofol is blocked by Rho-kinase and PMA. OA blocks neurite retraction induced by propofol, and this inhibitory effect could be prevented by FIPI, staurosporine and PKC epsilon translocation inhibitor peptide. OA increases via PLD and propofol decreases PKC epsilon Ser(729) phosphorylation, a crucial step in the activation of PKC epsilon. Conclusions: Rho-kinase is essential for propofol-induced neurite retraction in cortical neuronal cells. Activation of PKC inhibits neurite retraction caused by propofol. OA blocks propofol-induced neurite retraction by a PLD/PKC epsilon-mediated pathway, and PKC epsilon maybe the key enzyme where the wakefulness and anaesthesia signal pathways converge.
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| 9. |
- Cedergren, Jan, et al.
(författare)
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Inducible nitric oxide synthase is expressed in synovial fluid granulocytes
- 2002
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Ingår i: Clinical Experimental Immunology. - : Oxford University Press (OUP). - 0009-9104 .- 1365-2249. ; 130, s. 150-155
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Tidskriftsartikel (refereegranskat)abstract
- The objective of the study was to evaluate the NO-producing potential of synovial fluid (SF) cells. SF from 15 patients with arthritis was compared with blood from the same individuals and with blood from 10 healthy controls. Cellular expression of inducible nitric oxide synthase (iNOS) was analysed by flow cytometry. High-performance liquid chromatography was used to measure L-arginine and L-citrulline. Nitrite and nitrate were measured colourimetrically utilizing the Griess' reaction. Compared to whole blood granulocytes in patients with chronic arthritis, a prominent iNOS expression was observed in SF granulocytes (P < 0.001). A slight, but statistically significant, increase in iNOS expression was also recorded in lymphocytes and monocytes from SF. L-arginine was elevated in SF compared to serum (257 ± 78 versus 176 ± 65 µmol/l, P = 0.008), whereas a slight increase in L-citrulline (33 ± 11 versus 26 ± 9 µmol/l), did not reach statistical significance. Great variations but no significant differences were observed comparing serum and SF levels of nitrite and nitrate, respectively, although the sum of nitrite and nitrate tended to be elevated in SF (19.2 ± 20.7 versus 8,6 ± 6.5 µmol/l,P = 0.054). Synovial fluid leucocytes, in particular granulocytes, express iNOS and may thus contribute to intra-articular NO production in arthritis.
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| 10. |
- Cedergren, Jan, et al.
(författare)
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Inducible nitric oxide synthase (NOS II) is constitutive in human neutrophils
- 2003
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Ingår i: APMIS. - : Wiley. - 0903-4641 .- 1600-0463. ; 111:10, s. 963-968
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Tidskriftsartikel (refereegranskat)abstract
- The objective was to study the expression of inducible nitric oxide synthase (NOS II) in and NO production by human blood neutrophils and in in vivo exudated neutrophils. Cellular expression of NOS II was evaluated by flow cytometry in whole blood, in isolated blood neutrophils, and in neutrophils obtained by exudation in vivo into skin chambers. Neutrophil NOS II was also demonstrated by Western blotting. Uptake of 3H-labelled L-arginine was studied in vitro and NOS activity measured in a whole cell assay by the conversion of 3H-arginine to 3H-citrulline. In contrast to unseparated blood cells, NOS II was demonstrable both in isolated blood neutrophils and exudated cells. The failure to detect NOS II by flow cytometry in whole blood cells thus proved to be due to the quenching effect of hemoglobin. Western blotting revealed a 130 kD band corresponding to NOS II in isolated blood neutrophils, but detection was dependent on diisopropylfluorophosphate for proteinase inhibition. L-arginine was taken up by neutrophils, but enzymatic activity could not be demonstrated. We conclude that human neutrophils constitutively express NOS II, but that its demonstration by FITC-labelling is inhibited by hemoglobin-mediated quenching in whole blood samples.
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