FRINK Linked Data Fragments server

Matches in SemOpenAlex for { <https://semopenalex.org/work/W1992092413> ?p ?o ?g. }

• W1992092413 endingPage "43740" @default.
• W1992092413 startingPage "43730" @default.
• W1992092413 abstract "The plasma lipoprotein-associated apolipoproteins (apo) A-I and apoE have well described anti-inflammatory actions in the cardiovascular system, and mimetic peptides that retain these properties have been designed as therapeutics. The anti-inflammatory mechanisms of apolipoprotein mimetics, however, are incompletely defined. Whether circulating apolipoproteins and their mimetics regulate innate immune responses at mucosal surfaces, sites where transvascular emigration of leukocytes is required during inflammation, remains unclear. Herein, we report that Apoai−/− and Apoe−/− mice display enhanced recruitment of neutrophils to the airspace in response to both inhaled lipopolysaccharide and direct airway inoculation with CXCL1. Conversely, treatment with apoA-I (L-4F) or apoE (COG1410) mimetic peptides reduces airway neutrophilia. We identify suppression of CXCR2-directed chemotaxis as a mechanism underlying the apolipoprotein effect. Pursuing the possibility that L-4F might suppress chemotaxis through heterologous desensitization, we confirmed that L-4F itself induces chemotaxis of human PMNs and monocytes. L-4F, however, fails to induce a calcium flux. Further exploring structure-function relationships, we studied the alternate apoA-I mimetic L-37pA, a bihelical analog of L-4F with two Leu-Phe substitutions. We find that L-37pA induces calcium and chemotaxis through formyl peptide receptor (FPR)2/ALX, whereas its D-stereoisomer (i.e. D-37pA) blocks L-37pA signaling and induces chemotaxis but not calcium flux through an unidentified receptor. Taken together, apolipoprotein mimetic peptides are novel chemotactic agents that possess complex structure-activity relationships to multiple receptors, displaying anti-inflammatory efficacy against innate immune responses in the airway. The plasma lipoprotein-associated apolipoproteins (apo) A-I and apoE have well described anti-inflammatory actions in the cardiovascular system, and mimetic peptides that retain these properties have been designed as therapeutics. The anti-inflammatory mechanisms of apolipoprotein mimetics, however, are incompletely defined. Whether circulating apolipoproteins and their mimetics regulate innate immune responses at mucosal surfaces, sites where transvascular emigration of leukocytes is required during inflammation, remains unclear. Herein, we report that Apoai−/− and Apoe−/− mice display enhanced recruitment of neutrophils to the airspace in response to both inhaled lipopolysaccharide and direct airway inoculation with CXCL1. Conversely, treatment with apoA-I (L-4F) or apoE (COG1410) mimetic peptides reduces airway neutrophilia. We identify suppression of CXCR2-directed chemotaxis as a mechanism underlying the apolipoprotein effect. Pursuing the possibility that L-4F might suppress chemotaxis through heterologous desensitization, we confirmed that L-4F itself induces chemotaxis of human PMNs and monocytes. L-4F, however, fails to induce a calcium flux. Further exploring structure-function relationships, we studied the alternate apoA-I mimetic L-37pA, a bihelical analog of L-4F with two Leu-Phe substitutions. We find that L-37pA induces calcium and chemotaxis through formyl peptide receptor (FPR)2/ALX, whereas its D-stereoisomer (i.e. D-37pA) blocks L-37pA signaling and induces chemotaxis but not calcium flux through an unidentified receptor. Taken together, apolipoprotein mimetic peptides are novel chemotactic agents that possess complex structure-activity relationships to multiple receptors, displaying anti-inflammatory efficacy against innate immune responses in the airway. In recent years, it has been increasingly recognized that high density lipoprotein (HDL), a multimolecular particle composed of apolipoproteins (e.g. apolipoprotein (apo) A-I and apoE), lipids, and other cargo, has potent and wide ranging anti-inflammatory properties in addition to its well known function as a vehicle for cholesterol transport in the serum. HDL down-regulates adhesion molecules on endothelium and leukocytes, sequesters and reduces oxidized lipids, suppresses myeloid cell production in the bone marrow, and attenuates pro-inflammatory signaling by Toll-like receptors (1.Murphy A.J. Woollard K.J. High-density lipoprotein. A potent inhibitor of inflammation.Clin. Exp. Pharmacol. Physiol. 2010; 37: 710-718Crossref PubMed Scopus (83) Google Scholar, 2.Yvan-Charvet L. Wang N. Tall A.R. Role of HDL, ABCA1, and ABCG1 transporters in cholesterol efflux and immune responses.Arterioscler. Thromb. Vasc. Biol. 2010; 30: 139-143Crossref PubMed Scopus (477) Google Scholar). Many of these anti-inflammatory effects of HDL have been attributed to apoA-I, and in particular, to the 10 tandem amphipathic α-helices of apoA-I, a lipid-binding motif it shares with apoE and other apolipoproteins. Exploiting this discovery, several anti-inflammatory α-helical apoA-I mimetic peptides (e.g. the 18-amino acid peptide L-4F (3.Navab M. Shechter I. Anantharamaiah G.M. Reddy S.T. Van Lenten B.J. Fogelman A.M. Structure and function of HDL mimetics.Arterioscler. Thromb. Vasc. Biol. 2010; 30: 164-168Crossref PubMed Scopus (94) Google Scholar, 4.Dai L. Datta G. Zhang Z. Gupta H. Patel R. Honavar J. Modi S. Wyss J.M. Palgunachari M. Anantharamaiah G.M. White C.R. The apolipoprotein A-I mimetic peptide 4F prevents defects in vascular function in endotoxemic rats.J. Lipid Res. 2010; 51: 2695-2705Abstract Full Text Full Text PDF PubMed Scopus (46) Google Scholar, 5.Getz G.S. Wool G.D. Reardon C.A. Biological properties of apolipoprotein A-I mimetic peptides.Curr. Atheroscler. Rep. 2010; 12: 96-104Crossref PubMed Scopus (29) Google Scholar)) have now been designed, and some are under development for atherosclerotic cardiovascular disease and/or other inflammatory disorders. Amphipathic α-helical apoE mimetic peptides (e.g. the 12-amino acid peptide COG1410 (6.Laskowitz D.T. Fillit H. Yeung N. Toku K. Vitek M.P. Apolipoprotein E-derived peptides reduce CNS inflammation. Implications for therapy of neurological disease.Acta Neurol. Scand Suppl. 2006; 185: 15-20Crossref PubMed Scopus (62) Google Scholar)) have similarly been developed that display anti-inflammatory activity not only in the cardiovascular system, but also in the brain and other organs (6.Laskowitz D.T. Fillit H. Yeung N. Toku K. Vitek M.P. Apolipoprotein E-derived peptides reduce CNS inflammation. Implications for therapy of neurological disease.Acta Neurol. Scand Suppl. 2006; 185: 15-20Crossref PubMed Scopus (62) Google Scholar). ApoA-I and apoE are expressed in the lung by structural (i.e. alveolar epithelial) and hematopoietic (e.g. alveolar macrophages) cells, and they and their mimetic peptides have recently been shown to regulate physiology and adaptive immunity of the airway. Thus, Apoai−/− mice have increased lung inflammation and airway hyperresponsiveness, whereas treatment with two apoA-I mimetics (L-4F or 5A) reduces inflammation and airway hyperresponsiveness in mouse models of asthma (7.Yao X. Dai C. Fredriksson K. Dagur P.K. McCoy J.P. Qu X. Yu Z.X. Keeran K.J. Zywicke G.J. Amar M.J. Remaley A.T. Levine S.J. 5A, an apolipoprotein A-I mimetic peptide, attenuates the induction of house dust mite-induced asthma.J. Immunol. 2011; 186: 576-583Crossref PubMed Scopus (63) Google Scholar, 8.Wang W. Xu H. Shi Y. Nandedkar S. Zhang H. Gao H. Feroah T. Weihrauch D. Schulte M.L. Jones D.W. Jarzembowski J. Sorci-Thomas M. Pritchard Jr., K.A. Genetic deletion of apolipoprotein A-I increases airway hyperresponsiveness, inflammation, and collagen deposition in the lung.J. Lipid Res. 2010; 51: 2560-2570Abstract Full Text Full Text PDF PubMed Scopus (63) Google Scholar). Apoe−/− mice similarly develop exaggerated airway disease in an asthma model, and an apoE mimetic peptide rescues this response (9.Yao X. Fredriksson K. Yu Z.X. Xu X. Raghavachari N. Keeran K.J. Zywicke G.J. Kwak M. Amar M.J. Remaley A.T. Levine S.J. Apolipoprotein E negatively regulates house dust mite-induced asthma via a low-density lipoprotein receptor-mediated pathway.Am. J. Respir Crit. Care Med. 2010; 182: 1228-1238Crossref PubMed Scopus (69) Google Scholar). Studies on lung and other disease models have generally defined the anti-inflammatory effects of apolipoproteins on tissue-resident cells in various organs, as well as on effector functions of leukocytes. Whether apolipoproteins and their mimetics attenuate end-organ inflammation through the unifying mechanism of modulating leukocyte migration to tissues has not been defined. Herein, we report that Apoai−/− and Apoe−/− mice have enhanced recruitment of neutrophils (PMNs) 3The abbreviations used are: PMNneutrophilapoapolipoproteinfMLFformyl-Met-Leu-PheFPRformyl peptide receptorGPCRG protein-coupled receptorHDLhigh density lipoproteinAibamino isobutyric acidMIP-2macrophage inflammatory protein-2. and monocytes to the airspace in response to inhaled lipopolysaccharide (LPS), as well as enhanced airway neutrophilia in response to direct airway inoculation with CXCL1. Conversely, treatment with apoA-I (L-4F) and apoE (COG1410) mimetics reduces PMN/monocyte recruitment to the airway under these conditions. We identify suppression of chemokine-directed chemotaxis as a mechanism underlying the apolipoprotein effect. ApoA-I protein and L-4F suppress chemotaxis of murine PMNs to CXCL2; this is associated with reduced PMN surface display of CXCR2 in the case of L-4F. Pursuing the possibility that L-4F might suppress chemotaxis through heterologous desensitization (i.e. through itself acting as a chemoattractant), we confirmed that L-4F indeed induces chemotaxis of human PMNs and monocytes. L-4F, however, neither induces a calcium flux in PMNs or monocytes, nor induces chemotaxis through CXCR2, CCR2, formyl peptide receptor (FPR) 1, or FPR2/ALX in transfected HEK293 cells, making the identity of its receptor uncertain. Further exploring structure-function relationships, we studied an alternate apoA-I mimetic peptide, L-37pA, a bihelical version of L-4F with two Leu-Phe substitutions (10.Bocharov A.V. Baranova I.N. Vishnyakova T.G. Remaley A.T. Csako G. Thomas F. Patterson A.P. Eggerman T.L. Targeting of scavenger receptor class B type I by synthetic amphipathic alpha-helical-containing peptides blocks lipopolysaccharide (LPS) uptake and LPS-induced pro-inflammatory cytokine responses in THP-1 monocyte cells.J. Biol. Chem. 2004; 279: 36072-36082Abstract Full Text Full Text PDF PubMed Scopus (53) Google Scholar). We find that L-37pA induces chemotaxis through the multi-recognition receptor FPR2/ALX, whereas its D-stereoisomer (D-37pA) (11.Remaley A.T. Thomas F. Stonik J.A. Demosky S.J. Bark S.E. Neufeld E.B. Bocharov A.V. Vishnyakova T.G. Patterson A.P. Eggerman T.L. Santamarina-Fojo S. Brewer H.B. Synthetic amphipathic helical peptides promote lipid efflux from cells by an ABCA1-dependent and an ABCA1-independent pathway.J. Lipid Res. 2003; 44: 828-836Abstract Full Text Full Text PDF PubMed Scopus (174) Google Scholar) blocks L-37pA signaling and induces chemotaxis through a different, yet unidentified receptor. Taken together, we report that apolipoprotein mimetic peptides are novel PMN and monocyte chemotactic agents that possess complex structure-function activity relationships to multiple receptors. neutrophil apolipoprotein formyl-Met-Leu-Phe formyl peptide receptor G protein-coupled receptor high density lipoprotein amino isobutyric acid macrophage inflammatory protein-2. Escherichia coli 0111:B4 LPS and formyl-Met-Leu-Phe (fMLF) were from Sigma. CXCL1/KC and CXCL2/MIP-2 were from R&D Systems (Minneapolis, MN). ApoA-I was purified as previously described (12.Brewer Jr., H.B. Ronan R. Meng M. Bishop C. Isolation and characterization of apolipoproteins A-I, A-II, and A-IV.Methods Enzymol. 1986; 128: 223-246Crossref PubMed Scopus (129) Google Scholar). WKYMVm (designated W peptide) and MMK-1 were synthesized and purified by the Department of Biochemistry, Colorado State University (Fort Collins, CO). IL-8 (CXCL8) was from PeproTech (Rocky Hill, NJ). Fura-2 was from Invitrogen. COG1410 (Ac-AS(Aib)LRKL(Aib)-KRLL-NH2), a peptide derived from apoE residues 138–149 with Aib (aminoisobutyric acid) substitutions at positions 140 and 145 (6.Laskowitz D.T. Fillit H. Yeung N. Toku K. Vitek M.P. Apolipoprotein E-derived peptides reduce CNS inflammation. Implications for therapy of neurological disease.Acta Neurol. Scand Suppl. 2006; 185: 15-20Crossref PubMed Scopus (62) Google Scholar, 13.Gao J. Wang H. Sheng H. Lynch J.R. Warner D.S. Durham L. Vitek M.P. Laskowitz D.T. A novel apoE-derived therapeutic reduces vasospasm and improves outcome in a murine model of subarachnoid hemorrhage.Neurocrit. Care. 2006; 4: 25-31Crossref PubMed Google Scholar) was synthesized by the Peptide Synthesis Laboratory at the University of North Carolina (Chapel Hill, NC) to a purity of >95%. Peptide 264 (Ac-AS(Aib)LRKL(Aib)KR-NH2), a negative control for COG1410 that displays reduced anti-inflammatory activity in attenuating the LPS response (14.Laskowitz D.T. McKenna S.E. Song P. Wang H. Durham L. Yeung N. Christensen D. Vitek M.P. COG1410, a novel apolipoprotein E-based peptide, improves functional recovery in a murine model of traumatic brain injury.J. Neurotrauma. 2007; 24: 1093-1107Crossref PubMed Scopus (85) Google Scholar), was synthesized to similar specifications at the University of North Carolina. L-4F (Ac-DWFKAFYDKVAEKFKEAF-NH2) and its scrambled version, sc-4F (Ac-DWFAKDYF-KKAFVEEFAK-NH2) (4.Dai L. Datta G. Zhang Z. Gupta H. Patel R. Honavar J. Modi S. Wyss J.M. Palgunachari M. Anantharamaiah G.M. White C.R. The apolipoprotein A-I mimetic peptide 4F prevents defects in vascular function in endotoxemic rats.J. Lipid Res. 2010; 51: 2695-2705Abstract Full Text Full Text PDF PubMed Scopus (46) Google Scholar), were also synthesized to >95% purity at the University of North Carolina. L-37pA (DWLKAFYDKVAEKLKEAF-P-DWLKAFYDKVAEKLKEAF) and D-37pA (i.e. D-amino acid version of 37pA) were synthesized by a solid-phase procedure as previously reported (10.Bocharov A.V. Baranova I.N. Vishnyakova T.G. Remaley A.T. Csako G. Thomas F. Patterson A.P. Eggerman T.L. Targeting of scavenger receptor class B type I by synthetic amphipathic alpha-helical-containing peptides blocks lipopolysaccharide (LPS) uptake and LPS-induced pro-inflammatory cytokine responses in THP-1 monocyte cells.J. Biol. Chem. 2004; 279: 36072-36082Abstract Full Text Full Text PDF PubMed Scopus (53) Google Scholar). A scrambled version of L-37pA, sc-37pA, was synthesized (FWFDAYFEVVDKALLAYKPALDKEKKAEFKEKLDWKA). Female mice (8–12 weeks old, weighing 15–22 g) were used in all experiments. Apoai−/− (B6.129P2-Apoa1tm1Unc/J), Apoe−/− (B6.129P2-Apoetm1Unc/J) (both backcrossed 10 generations onto C57BL/6), and wild type C57BL/6 mice were all from Jackson Laboratories (Bar Harbor, ME). All experiments were performed in accordance with the Animal Welfare Act and the United States Public Health Service Policy on Humane Care and Use of Laboratory Animals after review by the Animal Care and Use Committee of the NIEHS, National Institutes of Health. Mice were injected intravenously (150 μl in saline) with 20 mg/kg of L-4F or sc-4F peptide (control for L-4F), or with 1.2 mg/kg of COG1410 or 264 peptide (control for COG1410) 2 h prior to pulmonary exposures, similar to past reports (4.Dai L. Datta G. Zhang Z. Gupta H. Patel R. Honavar J. Modi S. Wyss J.M. Palgunachari M. Anantharamaiah G.M. White C.R. The apolipoprotein A-I mimetic peptide 4F prevents defects in vascular function in endotoxemic rats.J. Lipid Res. 2010; 51: 2695-2705Abstract Full Text Full Text PDF PubMed Scopus (46) Google Scholar, 13.Gao J. Wang H. Sheng H. Lynch J.R. Warner D.S. Durham L. Vitek M.P. Laskowitz D.T. A novel apoE-derived therapeutic reduces vasospasm and improves outcome in a murine model of subarachnoid hemorrhage.Neurocrit. Care. 2006; 4: 25-31Crossref PubMed Google Scholar). LPS exposure was by aerosol (300 μg/ml, 20 min) and KC exposure by intratracheal delivery (0.25 or 0.5 μg/60 μl by oropharyngeal aspiration), both as previously described (15.Smoak K. Madenspacher J. Jeyaseelan S. Williams B. Dixon D. Poch K.R. Nick J.A. Worthen G.S. Fessler M.B. Effects of liver X receptor agonist treatment on pulmonary inflammation and host defense.J. Immunol. 2008; 180: 3305-3312Crossref PubMed Scopus (69) Google Scholar). L-37pA or scrambled L-37pA (100 μg/60 μl) were also delivered intratracheally. Bronchoalveolar lavage fluid was collected immediately following sacrifice, and total leukocyte and differential counts were performed, as previously described (15.Smoak K. Madenspacher J. Jeyaseelan S. Williams B. Dixon D. Poch K.R. Nick J.A. Worthen G.S. Fessler M.B. Effects of liver X receptor agonist treatment on pulmonary inflammation and host defense.J. Immunol. 2008; 180: 3305-3312Crossref PubMed Scopus (69) Google Scholar). Cytokines were quantified by a multiplex assay (Bio-Plex, Bio-Rad) per the manufacturer's instructions. Mature murine bone marrow PMNs were isolated from mouse femurs and tibias by discontinuous Percoll gradient centrifugation, as previously described (15.Smoak K. Madenspacher J. Jeyaseelan S. Williams B. Dixon D. Poch K.R. Nick J.A. Worthen G.S. Fessler M.B. Effects of liver X receptor agonist treatment on pulmonary inflammation and host defense.J. Immunol. 2008; 180: 3305-3312Crossref PubMed Scopus (69) Google Scholar). This preparation yields >95% PMNs (data not shown). Human peripheral blood monocytes were isolated from buffy coats (NIH Clinical Center, Transfusion Medicine Department, Bethesda, MD) enriched for mononuclear cells by using an iso-osmotic Percoll gradient, and neutrophils by dextran sedimentation of the buffy coat, both as previously described (16.Deng X. Ueda H. Su S.B. Gong W. Dunlop N.M. Gao J.L. Murphy P.M. Wang J.M. A synthetic peptide derived from human immunodeficiency virus type 1 gp120 down-regulates the expression and function of chemokine receptors CCR5 and CXCR4 in monocytes by activating the 7-transmembrane G-protein-coupled receptor FPRL1/LXA4R.Blood. 1999; 94: 1165-1173Crossref PubMed Google Scholar). The purity of the cell preparations was confirmed by morphology to be >90% for monocytes and >98% for neutrophils. Parental HEK293 cells were stably transfected with FPR1, FPR2/ALX, CCR2, or CXCR2 as previously described (16.Deng X. Ueda H. Su S.B. Gong W. Dunlop N.M. Gao J.L. Murphy P.M. Wang J.M. A synthetic peptide derived from human immunodeficiency virus type 1 gp120 down-regulates the expression and function of chemokine receptors CCR5 and CXCR4 in monocytes by activating the 7-transmembrane G-protein-coupled receptor FPRL1/LXA4R.Blood. 1999; 94: 1165-1173Crossref PubMed Google Scholar). All cell lines were maintained in DMEM supplemented with 10% FBS (Hyclone, Logan, UT), 1 mm glutamine (Invitrogen), and 800 μg/ml of geneticin (G418; Invitrogen). Bone marrow-isolated murine PMNs (1 × 106, 0.1 ml of RPMI, 1% FBS) were seeded into the upper chamber of a 96-well transwell system (polycarbonate membrane, 3.0 μm pore) (Corning, Corning, NY) after pretreatment (apoA-I, peptide (L-4F or sc-4F), or buffer control for 30 min), staining (2 μm calcein-AM, 30 min), and then washing in 1× in Hanks' balanced salt solution. Media (0.1 ml) with or without MIP-2 (50 ng/ml) was added to the lower chamber. Fluorescence was monitored in the lower chamber every 2 min in triplicate over a time course (34 min, 37 °C), using Gen5 software on a Synergy 2 plate reader (BioTek Instruments, Inc., Winooski, VT), as previously described (15.Smoak K. Madenspacher J. Jeyaseelan S. Williams B. Dixon D. Poch K.R. Nick J.A. Worthen G.S. Fessler M.B. Effects of liver X receptor agonist treatment on pulmonary inflammation and host defense.J. Immunol. 2008; 180: 3305-3312Crossref PubMed Scopus (69) Google Scholar). Directional migration (i.e. chemotaxis) was derived at each time point by subtracting the fluorescence signal of nondirectionally migrating cells in control wells with no chemoattractant, and then normalizing this as a % of total cellular fluorescence by indexing it to labeled cells plated directly into the lower chamber (15.Smoak K. Madenspacher J. Jeyaseelan S. Williams B. Dixon D. Poch K.R. Nick J.A. Worthen G.S. Fessler M.B. Effects of liver X receptor agonist treatment on pulmonary inflammation and host defense.J. Immunol. 2008; 180: 3305-3312Crossref PubMed Scopus (69) Google Scholar). Chemotaxis of human neutrophils, human monocytes, and transfected HEK293 cells in response to peptides, IL-8, and/or fMLF was measured using a 48-well microchemotaxis chamber technique (Neuroprobe, Cabin John, MD) system with 5-μm pore-sized polycarbonate membranes for the former two cell types, and 10-μm pore-sized membranes for receptor-transfected HEK293 cells, as previously described (17.Su S.B. Gong W. Gao J.L. Shen W. Murphy P.M. Oppenheim J.J. Wang J.M. A seven-transmembrane, G protein-coupled receptor, FPRL1, mediates the chemotactic activity of serum amyloid A for human phagocytic cells.J. Exp. Med. 1999; 189: 395-402Crossref PubMed Scopus (373) Google Scholar). A 25-μl aliquot of chemoattractant diluted in chemotaxis medium (RPMI 1640, 1% BSA, 25 mm HEPES) was placed in the lower compartment, and 50 μl of cell suspension (106 cells/ml in chemotaxis medium) was placed in the upper compartment. The chamber was incubated (37 °C, humidified air with 5% CO2; 90 min for monocytes, 60 min for neutrophils, 240 min for HEK293 cells), after which the filter was removed, fixed, and stained with Diff-Quik (Harlew, Gibbstown, NJ). The number of migrated cells in three high-powered fields (×400) was counted by light microscopy after coding the samples. Results are obtained from triplicate samples and are representative of at least 5 experiments. Results are expressed as the chemotaxis index (mean ± S.D.), which represents the fold-increase in the number of migrated cells in response to chemoattractants over spontaneous cell migration (to control medium). Calcium mobilization of monocytes, neutrophils, and HEK293 cells was assayed by measuring fluorescence (LS-50B spectrometer, PerkinElmer Life Sciences) of Fura-2-loaded cells, and calculating the ratio of fluorescence at 340 and 380 nm (FL WinLab, PerkinElmer Life Sciences), as previously reported (17.Su S.B. Gong W. Gao J.L. Shen W. Murphy P.M. Oppenheim J.J. Wang J.M. A seven-transmembrane, G protein-coupled receptor, FPRL1, mediates the chemotactic activity of serum amyloid A for human phagocytic cells.J. Exp. Med. 1999; 189: 395-402Crossref PubMed Scopus (373) Google Scholar). The assays were performed at least five times and results from representative experiments are shown. Murine blood samples were analyzed using the HEMAVET 1700 hematology analyzer (Drew Scientific, Inc.). Manual WBC differential counts were reported and smear estimates were used to confirm values. Anti-CXCR2 (PerCP/Cy5.5), -Gr-1 (FITC), and isotype control antibodies were from Biolegend (San Diego, CA). Cells (peripheral blood or isolated bone marrow neutrophils) were stained and flow cytometry was performed using an LSR II (BD Biosciences) and analyzed using FlowJo (Tree Star, Inc., Ashland, OR) and FCS Express (De Novo Software, Los Angeles, CA) software. Analysis was performed using GraphPad Prism statistical software (San Diego, CA). Data are represented as mean ± S.E. Two-tailed Student's t test was applied for comparisons of two groups, and analysis of variance for analyses of three or more groups. For all tests, p < 0.05 was considered significant. ApoE and ApoA-I, major protein components of circulating HDL particles, have anti-inflammatory effects on several cell types in the cardiovascular system. Moreover, by binding LPS in the bloodstream and dampening systemic inflammation, intravenous apoA-I supplementation attenuates secondary injury in the lung and other peripheral organs during endotoxemia (4.Dai L. Datta G. Zhang Z. Gupta H. Patel R. Honavar J. Modi S. Wyss J.M. Palgunachari M. Anantharamaiah G.M. White C.R. The apolipoprotein A-I mimetic peptide 4F prevents defects in vascular function in endotoxemic rats.J. Lipid Res. 2010; 51: 2695-2705Abstract Full Text Full Text PDF PubMed Scopus (46) Google Scholar, 18.Yan Y.J. Li Y. Lou B. Wu M.P. Beneficial effects of ApoA-I on LPS-induced acute lung injury and endotoxemia in mice.Life Sci. 2006; 79: 210-215Crossref PubMed Scopus (59) Google Scholar). ApoA-I and apoE are also expressed by airway-resident cells (19.Kim T.H. Lee Y.H. Kim K.H. Lee S.H. Cha J.Y. Shin E.K. Jung S. Jang A.S. Park S.W. Uh S.T. Kim Y.H. Park J.S. Sin H.G. Youm W. Koh E.S. Cho S.Y. Paik Y.K. Rhim T.Y. Park C.S. Role of lung apolipoprotein A-I in idiopathic pulmonary fibrosis. Anti-inflammatory and antifibrotic effect on experimental lung injury and fibrosis.Am. J. Respir. Crit. Care Med. 2010; 182: 633-642Crossref PubMed Scopus (80) Google Scholar, 20.Lin C.T. Xu Y.F. Wu J.Y. Chan L. Immunoreactive apolipoprotein E is a widely distributed cellular protein. Immunohistochemical localization of apolipoprotein E in baboon tissues.J. Clin. Invest. 1986; 78: 947-958Crossref PubMed Google Scholar). However, the role of apolipoproteins in innate immunity of the airway and other mucosal surfaces, sites at which inflammatory responses to environmental stimuli require both local cellular responses and trans-tissue migration of circulating leukocytes, remains undefined. In an effort to define possible regulatory roles for apoA-I and apoE in the pulmonary innate immune response, we exposed Apoai−/− and Apoe−/− mice (and wild type controls) to inhaled LPS and then quantified PMN influx into the airspace, a well established, disease-relevant summary measure of the response to LPS in the lung (15.Smoak K. Madenspacher J. Jeyaseelan S. Williams B. Dixon D. Poch K.R. Nick J.A. Worthen G.S. Fessler M.B. Effects of liver X receptor agonist treatment on pulmonary inflammation and host defense.J. Immunol. 2008; 180: 3305-3312Crossref PubMed Scopus (69) Google Scholar). As shown in panels A, C, and E of Figs. 1 and 2, both apolipoprotein-deficient strains recruited higher numbers of leukocytes to the airspace than WT controls. In addition to an increase in recruited PMNs, increased macrophage numbers were also observed in the airway 24 h post-LPS, consistent with increased recruitment of macrophage precursors (i.e. monocytes) to the alveolus.FIGURE 2.ApoA-I deficiency and supplementation with peptide have reciprocal effects on leukocyte trafficking to inflamed lung. A, C, and E, Apoai+/+ and Apoai−/− mice were exposed to inhaled LPS, and then bronchoalveolar lavage (BAL) total leukocytes (WBC) (A), neutrophils (PMNs) (C), and macrophages (MΦ) (E) were quantified at the indicated post-exposure time points. B, D, and F, Apoai+/+ (C57BL/6) mice were pretreated intravenously with 20 mg/kg of L-4F or scrambled control peptide (sc-4F) 2 h before LPS inhalation. BAL WBCs (B), PMNs (D), and MΦ (F) were then quantified at the indicated post-LPS time points. Data are mean ± S.E. n = 9–10 mice per condition/time point (B, D, and F) (*, p < 0.01; **, p < 0.001; ***, p < 0.0001).View Large Image Figure ViewerDownload Hi-res image Download (PPT) Synthetic peptides have been designed that mimic the class A amphipathic α-helical domains of apoA-I (i.e. peptide l-4F (4.Dai L. Datta G. Zhang Z. Gupta H. Patel R. Honavar J. Modi S. Wyss J.M. Palgunachari M. Anantharamaiah G.M. White C.R. The apolipoprotein A-I mimetic peptide 4F prevents defects in vascular function in endotoxemic rats.J. Lipid Res. 2010; 51: 2695-2705Abstract Full Text Full Text PDF PubMed Scopus (46) Google Scholar)) and apoE (i.e. peptide COG1410 (6.Laskowitz D.T. Fillit H. Yeung N. Toku K. Vitek M.P. Apolipoprotein E-derived peptides reduce CNS inflammation. Implications for therapy of neurological disease.Acta Neurol. Scand Suppl. 2006; 185: 15-20Crossref PubMed Scopus (62) Google Scholar)) and that retain the anti-inflammatory activity, including in the context of LPS exposure, of their parental holoproteins (Table 1). Notably, as shown in Fig. 1 (panels B, D, and F), WT mice pretreated intravenously with COG1410 2 h before LPS inhalation recruited fewer PMNs and macrophages to the airspace than WT counterparts pretreated with 264, a truncated control peptide that has reduced anti-inflammatory activity against LPS (14.Laskowitz D.T. McKenna S.E. Song P. Wang H. Durham L. Yeung N. Christensen D. Vitek M.P. COG1410, a novel apolipoprotein E-based peptide, improves functional recovery in a murine model of traumatic brain injury.J. Neurotrauma. 2007; 24: 1093-1107Crossref PubMed Scopus (85) Google Scholar). Similarly, L-4F-pretreated WT mice recruited fewer airway PMNs and macrophages 24 h post-LPS inhalation than counterparts pretreated with a scrambled, non-helical version of L-4F (i.e. sc-4F (4.Dai L. Datta G. Zhang Z. Gupta H. Patel R. Honavar J. Modi S. Wyss J.M. Palgunachari M. Anantharamaiah G.M. White C.R. The apolipoprotein A-I mimetic peptide 4F prevents defects in vascular function in endotoxemic rats.J. Lipid Res. 2010; 51: 2695-2705Abstract Full Text Full Text PDF PubMed Scopus (46) Google Scholar)) (Fig. 2, B, D, and F). Taken together, these data suggest that deficiency of apoE and apoA-I is associated with enhanced trafficking of PMNs and monocytes to the LPS-exposed airspace, whereas supplementation of both using mimetic peptides conversely suppresses influx of phagocytes to the airspace.TABLE 1Apolipoprotein mimetic and control peptidesPeptidesSequenceMrL-4FAc-DWFKAFYDKVAEKFKEAF-NH22310.64Sc-4FaScrambled versions of L-4F and L-37pA, respectively.Ac-DWFAKDYFKKAFVEEFAK-NH22310.6437pAbThis peptide was synthesized with either L- or" @default.
• W1992092413 created "2016-06-24" @default.
• W1992092413 creator A5000594249 @default.
• W1992092413 creator A5000716419 @default.
• W1992092413 creator A5006672267 @default.
• W1992092413 creator A5047235136 @default.
• W1992092413 creator A5055586787 @default.
• W1992092413 creator A5068951391 @default.
• W1992092413 creator A5075003658 @default.
• W1992092413 creator A5078129198 @default.
• W1992092413 creator A5085604291 @default.
• W1992092413 date "2012-12-01" @default.
• W1992092413 modified "2023-10-16" @default.
• W1992092413 title "Apolipoproteins and Apolipoprotein Mimetic Peptides Modulate Phagocyte Trafficking through Chemotactic Activity" @default.
• W1992092413 cites W121664585 @default.
• W1992092413 cites W1498425904 @default.
• W1992092413 cites W1506943947 @default.
• W1992092413 cites W1517227660 @default.
• W1992092413 cites W1521327967 @default.
• W1992092413 cites W1541841154 @default.
• W1992092413 cites W1592678705 @default.
• W1992092413 cites W1876581925 @default.
• W1992092413 cites W1893626841 @default.
• W1992092413 cites W1902057567 @default.
• W1992092413 cites W1909650171 @default.
• W1992092413 cites W1968283484 @default.
• W1992092413 cites W1974455553 @default.
• W1992092413 cites W1979751791 @default.
• W1992092413 cites W1982092413 @default.
• W1992092413 cites W1987647341 @default.
• W1992092413 cites W1993947882 @default.
• W1992092413 cites W2003732215 @default.
• W1992092413 cites W2008233106 @default.
• W1992092413 cites W2010239869 @default.
• W1992092413 cites W2010841339 @default.
• W1992092413 cites W2011988398 @default.
• W1992092413 cites W2025504145 @default.
• W1992092413 cites W2026625700 @default.
• W1992092413 cites W2029430072 @default.
• W1992092413 cites W2038774571 @default.
• W1992092413 cites W2039210373 @default.
• W1992092413 cites W2039551737 @default.
• W1992092413 cites W2053202566 @default.
• W1992092413 cites W2054895562 @default.
• W1992092413 cites W2060168245 @default.
• W1992092413 cites W2098159175 @default.
• W1992092413 cites W2099816162 @default.
• W1992092413 cites W2100607138 @default.
• W1992092413 cites W2106792443 @default.
• W1992092413 cites W2111790202 @default.
• W1992092413 cites W2112863190 @default.
• W1992092413 cites W2122062568 @default.
• W1992092413 cites W2122154529 @default.
• W1992092413 cites W2131896212 @default.
• W1992092413 cites W2132342511 @default.
• W1992092413 cites W2137513062 @default.
• W1992092413 cites W2152561082 @default.
• W1992092413 cites W2153285971 @default.
• W1992092413 cites W2154843786 @default.
• W1992092413 cites W2185709413 @default.
• W1992092413 cites W2254553501 @default.
• W1992092413 cites W2398701972 @default.
• W1992092413 doi "https://doi.org/10.1074/jbc.m112.377192" @default.
• W1992092413 hasPubMedCentralId "https://www.ncbi.nlm.nih.gov/pmc/articles/3527958" @default.
• W1992092413 hasPubMedId "https://pubmed.ncbi.nlm.nih.gov/23118226" @default.
• W1992092413 hasPublicationYear "2012" @default.
• W1992092413 type Work @default.
• W1992092413 sameAs 1992092413 @default.
• W1992092413 citedByCount "35" @default.
• W1992092413 countsByYear W19920924132013 @default.
• W1992092413 countsByYear W19920924132014 @default.
• W1992092413 countsByYear W19920924132015 @default.
• W1992092413 countsByYear W19920924132016 @default.
• W1992092413 countsByYear W19920924132017 @default.
• W1992092413 countsByYear W19920924132018 @default.
• W1992092413 countsByYear W19920924132019 @default.
• W1992092413 countsByYear W19920924132020 @default.
• W1992092413 countsByYear W19920924132021 @default.
• W1992092413 countsByYear W19920924132022 @default.
• W1992092413 crossrefType "journal-article" @default.
• W1992092413 hasAuthorship W1992092413A5000594249 @default.
• W1992092413 hasAuthorship W1992092413A5000716419 @default.
• W1992092413 hasAuthorship W1992092413A5006672267 @default.
• W1992092413 hasAuthorship W1992092413A5047235136 @default.
• W1992092413 hasAuthorship W1992092413A5055586787 @default.
• W1992092413 hasAuthorship W1992092413A5068951391 @default.
• W1992092413 hasAuthorship W1992092413A5075003658 @default.
• W1992092413 hasAuthorship W1992092413A5078129198 @default.
• W1992092413 hasAuthorship W1992092413A5085604291 @default.
• W1992092413 hasBestOaLocation W19920924131 @default.
• W1992092413 hasConcept C160448771 @default.
• W1992092413 hasConcept C170493617 @default.
• W1992092413 hasConcept C185592680 @default.
• W1992092413 hasConcept C19702531 @default.
• W1992092413 hasConcept C202751555 @default.
• W1992092413 hasConcept C203014093 @default.
• W1992092413 hasConcept C2777700362 @default.
• W1992092413 hasConcept C2778163477 @default.

• next