@article{eckert_neuder_park_adler_jones_2010, title={Myristoylated Alanine-Rich C-Kinase Substrate (MARCKS) Protein Regulation of Human Neutrophil Migration}, volume={42}, ISSN={["1535-4989"]}, url={http://europepmc.org/abstract/med/19574534}, DOI={10.1165/rcmb.2008-0394oc}, abstractNote={Neutrophil migration into infected tissues is essential for host defense, but products of activated neutrophils can be quite damaging to host cells. Neutrophil influx into the lung and airways and resultant inflammation characterizes diseases such as chronic obstructive pulmonary disease, bronchiectasis, and cystic fibrosis. To migrate, neutrophils must reorganize the actin cytoskeleton to establish a leading edge pseudopod and a trailing edge uropod. The actin-binding protein myristoylated alanine-rich C-kinase substrate (MARCKS) has been shown to bind and cross-link actin in a variety of cell types and to co-localize with F-actin in the leading edge lamellipodium of migrating fibroblasts. The hypothesis that MARCKS has a role in the regulation of neutrophil migration was tested using a cell-permeant peptide derived from the MARCKS myristoylated aminoterminus (MANS peptide). Treatment of isolated human neutrophils with MANS significantly inhibited both their migration and beta2 integrin-dependent adhesion in response to N-formyl-methionyl-leucyl-phenylalanine (fMLF), IL-8, or leukotriene (LT)B(4). The IC(50) for fMLF-induced migration and adhesion was 17.1 microM and 12.5 microM, respectively. MANS significantly reduced the F-actin content in neutrophils 30 seconds after fMLF stimulation, although the peptide did not alter the ability of cells to polarize or spread. MANS did not alter fMLF-induced increases in surface beta2 integrin expression. These results suggest that MARCKS, via its myristoylated aminoterminus, is a key regulator of neutrophil migration and adhesion.}, number={5}, journal={AMERICAN JOURNAL OF RESPIRATORY CELL AND MOLECULAR BIOLOGY}, author={Eckert, Rachael E. and Neuder, Laura E. and Park, Joungjoa and Adler, Kenneth B. and Jones, Samuel L.}, year={2010}, month={May}, pages={586–594} }
 @article{neuder_keener_eckert_trujillo_jones_2009, title={Role of p38 MAPK in LPS induced pro-inflammatory cytokine and chemokine gene expression in equine leukocytes}, volume={129}, ISSN={["1873-2534"]}, url={http://europepmc.org/abstract/med/19070370}, DOI={10.1016/j.vetimm.2008.11.006}, abstractNote={Endotoxemia occurs when bacterial lipopolysaccharide (LPS) in the blood induces a dysregulated inflammatory response, resulting in circulatory shock and multi-organ failure. Laminitis is a common complication in endotoxemic horses and is frequently the reason for humane euthanasia of these cases. Blood leukocytes are a principal target of LPS in endotoxemia leading to activation of multiple signal transduction pathways involved in the induction of a number of pro-inflammatory genes. In other animal models, the p38 mitogen activated protein kinase (MAPK) pathway has been associated with induced expression of tumor necrosis factor-α (TNFα), interleukin (IL)-1β, IL-6 and IL-8. The goal of this study was to determine the role of the p38 MAPK pathway in the induction of these pro-inflammatory cytokine and chemokine genes in LPS-stimulated equine leukocytes. Stimulation of equine peripheral blood leukocytes resulted in an increase in TNFα, IL-1β, IL-6 and IL-8 mRNA levels. Pharmacological inhibition of p38 MAPK activity with SB203580 or SB202190 reduced the ability of LPS stimulation to increase mRNA concentrations for all four genes. However, only SB203580 pretreatment significantly reduced LPS-stimulated IL-1β and IL-8 mRNA expression and only pretreatment with SB202190 significantly reduced LPS-stimulated TNFα and IL-6 mRNA expression. From this study we conclude TNFα, IL-1β, IL-6 and IL-8 are induced upon LPS stimulation of equine leukocytes and that this induction of gene expression is dependent on the p38 MAPK pathway. However, there are differences in the efficacy of the p38 inhibitors tested here that may be explained by differences in specificity or potency. This study provides evidence for the use of selective p38 MAPK inhibitors as potential therapeutics for the treatment of equine endotoxemia.}, number={3-4}, journal={VETERINARY IMMUNOLOGY AND IMMUNOPATHOLOGY}, author={Neuder, Laura E. and Keener, Jamie M. and Eckert, Rachael E. and Trujillo, Jennifer C. and Jones, Samuel L.}, year={2009}, month={Jun}, pages={192–199} }
 @article{cook_neuder_blikslager_jones_2009, title={The effect of lidocaine on in vitro adhesion and migration of equine neutrophils}, volume={129}, ISSN={0165-2427}, url={http://dx.doi.org/10.1016/j.vetimm.2008.12.017}, DOI={10.1016/j.vetimm.2008.12.017}, abstractNote={The effect of lidocaine on in vitro migration and adhesion of equine neutrophils was evaluated. Neutrophils were isolated from equine whole blood using a Percoll-gradient centrifugation protocol. Purified neutrophils were incubated with lidocaine at concentrations from 0.1 to 1000 microg/ml for 30 min at 37 degrees C, after calcein loading. Neutrophil integrin-mediated adhesion in response to stimulation with 100 nM LTB(4), 100 nM PAF, or 100 ng/ml IL-8, or integrin-mediated migration in response to stimulation with 100 nM LTB(4), 150 nM PAF, or 100 ng/ml IL-8 was assessed. Statistical significance was set at P<0.05. Neutrophil adhesion was significantly increased in response to all three stimulants. IL-8-stimulated adhesion was significantly increased when neutrophils were incubated with 1mg/ml lidocaine, compared to lower lidocaine concentrations. LTB(4)-stimulated adhesion was significantly increased when neutrophils were incubated with 1mg/ml lidocaine compared to that at 5 microg/ml lidocaine. Migration was significantly increased in response to IL-8. IL-8 and LTB(4) stimulated migration was significantly increased when neutrophils were incubated with 1mg/ml lidocaine, compared to lower lidocaine concentrations. In conclusion, lidocaine did not inhibit neutrophil migration or adhesion in vitro at therapeutic concentrations, and increased migration and adhesion at higher concentrations.}, number={1-2}, journal={Veterinary Immunology and Immunopathology}, publisher={Elsevier BV}, author={Cook, Vanessa L. and Neuder, Laura E. and Blikslager, Anthony T. and Jones, Samuel L.}, year={2009}, month={May}, pages={137–142} }
 @article{eckert_neuder_bell_trujillo_jones_2007, title={The role of p38 mitogen-activated kinase (MAPK) in the mechanism regulating cyclooxygenase gene expression in equine leukocytes}, volume={118}, ISSN={["1873-2534"]}, url={http://europepmc.org/abstract/med/17614138}, DOI={10.1016/j.vetimm.2007.06.001}, abstractNote={The goal of this study was to define the role for p38 mitogen-activated kinase (MAPK) in the signaling mechanism regulating pro-inflammatory cyclooxygenase (COX) gene expression in lipopolysaccharide (LPS)-activated equine leukocytes for the purposes of identifying novel targets for anti-inflammatory therapy in endotoxemic horses. The p38 MAPK has been shown to positively regulate inflammatory gene expression in human leukocytes and can be activated by a variety of stimuli including LPS, TNF-α, and IL-1. Activation-associated phosphorylated p38 MAPK has been implicated in the up-regulation of several inflammatory genes, including COX-2 which ultimately results in the production of prostanoids that are responsible for the pathophysiology associated with endotoxemia. Our hypothesis is that activation of p38 MAPK is essential for LPS-induced COX-2 expression in equine peripheral blood leukocytes. We tested our hypothesis by investigating the effects of the specific p38 MAPK inhibitors SB203580 and SB202190 on LPS-induced COX-2 protein expression and PGE2 production in equine leukocytes. LPS stimulation activated p38 MAPK and increased COX-2 expression in a dose-dependent manner with maximal activation observed after 30 min and 4 h, respectively, at a concentration of 10 ng/ml LPS. In contrast, LPS stimulation did not affect COX-1 protein expression. Pretreatment with SB203580 or SB202190 significantly inhibited LPS-induced activation-associated p38 MAPK phosphorylation, COX-2 mRNA and protein levels, and PGE2 production in equine leukocytes. Maximal inhibition of LPS-induced COX-2 protein expression was achieved at a concentration of 10 μM SB203580. We concluded that p38 MAPK is essential for LPS-induced COX-2 expression suggesting that p38 MAPK is a potential target for anti-inflammatory therapy during equine endotoxemia.}, number={3-4}, journal={VETERINARY IMMUNOLOGY AND IMMUNOPATHOLOGY}, author={Eckert, Rachael E. and Neuder, Laura E. and Bell, Jennifer L. and Trujillo, Jennifer C. and Jones, Samuel L.}, year={2007}, month={Aug}, pages={294–303} }