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Jay A Nadel - One of the best experts on this subject based on the ideXlab platform.
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fmlp causes degranulation followed by Regranulation in rat nasal glands
Laryngoscope, 2010Co-Authors: Seontae Kim, Takashi Nakanaga, Iris F Ueki, Jay A NadelAbstract:OBJECTIVE To determine the mechanism of mucus production by nasal glands. STUDY DESIGN Because neutrophilic inflammation is associated with mucus hypersecretion in disease states, here we examine the role of neutrophil recruitment in mucous cell degranulation and Regranulation in rat nasal glands. METHODS N-formyl-methionyl-leucyl-phenylalanine (fMLP) was aerosolized intranasally in rats (n = 5), and its effects on degranulation and Regranulation of submucosal glands were evaluated by Alcian blue/periodic acid-Schiff (AB/PAS) staining and by immunolocalization of neutrophils and epidermal growth factor receptor (EGF-R). RESULTS In control subjects, glands were filled with mucin. After fMLP inhalation, degranulation, 31.7 +/- 0.8% (P <.01), was maximal at 2 to 4 hours. By 24 to 48 hours after fMLP inhalation, degranulation had decreased to 10.3 +/- 0.6% (P <.05), indicating that Regranulation of mucous glycoconjugates was occurring. After fMLP inhalation, neutrophils around submucosal glands increased within 0.5 hours from 1.4 +/- 0.1 to 9.5 +/- 0.3 per 0.0032 mm2 (P <.05). In control subjects, EGF-R protein was expressed near acinar ducts, 16.4 +/- 0.7% of gland area, and increased to 30.9 +/- 0.9% (P <.05) 24 to 48 hours after fMLP inhalation. Nasal pretreatment with a selective EGF-R tyrosine kinase inhibitor (BIBX1522, 15 mg/kg bid) prevented Regranulation at 24 hours after fMLP inhalation (degranulation 27.8 +/- 0.3%, P <.05, compared to 24 hours after fMLP alone), indicating that inhibition of EGF-R activation had prevented Regranulation after fMLP inhalation. CONCLUSIONS Degranulation of rat nasal glands by fMLP is followed by Regranulation; Regranulation depends on a neutrophil-associated EGF-R cascade.
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epidermal growth factor receptor signaling mediates Regranulation of rat nasal goblet cells
The Journal of Allergy and Clinical Immunology, 2001Co-Authors: Heungman Lee, Iris F Ueki, Lars Malm, Karim Dabbagh, Trang Daopick, Suil Kim, Jae Jeong Shim, Jay A NadelAbstract:Abstract Background: Mucus hypersecretion is a common response to inflammation in the lower airways and is a hallmark of chronic rhinitis. Objective: The purpose of this study was to elucidate the mechanisms of Regranulation (mucus production) of goblet cells in nasal epithelium. Methods: Because neutrophils induce an epidermal growth factor (EGFR) cascade, we induced degranulation of goblet cells in rat nasal respiratory epithelium by means of intranasal inhalation of N-formyl-methionyl-leucyl-phenylalanine (fMLP), and we examined Regranulation of the goblet cells and the role of EGFR inhibitors and neutrophils in the Regranulation process. Results: In the control state Alcian blue/periodic acid–Schiff and mucin MUC5AC staining was present. Degranulation was induced in the nasal septal epithelium 4 hours after intranasal inhalation of fMLP (10 –7 mol/L); 48 hours later, goblet-cell Regranulation was complete. In the control state EGFR protein staining was absent in the epithelium, but after fMLP-induced degranulation, EGFR protein was expressed. After pretreatment with BIBX1522, a selective EGFR tyrosine kinase inhibitor, fMLP-induced degranulation was unaffected, but goblet-cell Regranulation was prevented completely. Conclusion: These data suggest a role for the EGFR cascade in neutrophil-dependent production of goblet-cell mucins. Proving this theory will require the use of selective EGFR inhibitors in clinical studies of nasal hypersecretory states. (J Allergy Clin Immunol 2001;107:1046-50.)
M B Farnell - One of the best experts on this subject based on the ideXlab platform.
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the use of selective pharmacological inhibitors to delineate signal transduction pathways activated during complement receptor mediated degranulation in chicken heterophils
International Immunopharmacology, 2003Co-Authors: Michael H. Kogut, Virginia K Lowry, M B FarnellAbstract:Abstract Complement receptors (CRs), along with Fc receptors, play a primary role in the removal of bacterial pathogens in poultry. The binding of serum-opsonized bacteria to CR results in the secretion of both toxic oxygen metabolites and antibacterial granules. We have previously shown that the stimulation of chicken heterophils with serum-opsonized Salmonella enteritidis induced tyrosine kinase-dependent phosphorylation regulated degranulation. In the present studies, we used selective pharmacological inhibitors to investigate the roles of protein tyrosine kinases, phospholipases C and D (PLC and PLD), phosphatidylinositol 3′-kinase (PI3-K), and the super family of mitogen-activated protein kinases (MAPKs) on CR-mediated heterophil degranulation. Inhibitors of receptor-linked tyrosine kinases (the tryphostins AG1478 and AG1296) had no attenuating effects on CR-mediated degranulation. However, PP2, a selective inhibitor of the src family of protein tyrosine kinases, and piceatannol, an inhibitor of Syk tyrosine kinases, both significantly attenuated the CR-mediated degranulation. Additionally, the specific inhibitors of PLC, U73122, and PI3-K, LY294002, significantly decreased CR-mediated heterophil degranulation. Two inhibitors of PLD-mediated signaling, 2,3-diphosphoglycerate (2,3-DPG) and 1-butanol, hindered degranulation. Addition of purified PLD restored control levels of degranulation in heterophils in which PLD was inhibited. Lastly, SP600125, a selective inhibitor of c-Jun N-terminal kinase (JNK), inhibited degranulation; whereas neither PD98059, the inhibitor of p38 MAPK, nor SB203580, the inhibitor of extracellular signal-regulated kinase, had any effect on CR-mediated heterophil degranulation. These studies demonstrate that CRs on chicken heterophils lack intrinsic tyrosine kinase activity, but that binding of serum-opsonized bacteria activates both proximal tyrosine kinases ( src and Syk kinases), but differentially activates downstream tyrosine kinases (JNK, but not p38 nor ERK). Activation of src and Syk kinases plays a significant role in signal transduction of heterophil degranulation probably by stimulating downstream phosphorylation of PLC, PLD, and PI3-K. PI3-K has also been recently shown to be an upstream mediator of JNK activation, suggesting that this enzyme can induce signaling as both a lipid kinase and protein kinase. Engaging CRs on chicken heterophils activates a proximal tyrosine kinase ( src and Syk kinases)→PLC (PLD)→PI3-K→JNK signal transduction pathway that induces degranulation.
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selective pharmacological inhibitors reveal the role of syk tyrosine kinase phospholipase c phosphatidylinositol 3 kinase and p38 mitogen activated protein kinase in fc receptor mediated signaling of chicken heterophil degranulation
International Immunopharmacology, 2002Co-Authors: Michael H. Kogut, Virginia K Lowry, M B FarnellAbstract:Abstract Fc receptors of avian heterophils play a primary role in the elimination of bacterial pathogens in poultry. The cross-linking of Fc receptors with IgG-bacteria complexes results in the secretion of toxic oxygen metabolites and anti-bacterial granules. We have been investigating the upstream signaling events that precede degranulation following crosslinkage of Fc receptors on heterophils. Previously when using the non-selective pharmacological inhibitors genistein, chelerythrine, verapamil, and pertussis toxin, we found no significant inhibitory effects on Fc-mediated heterophil degranulation. In the present studies, we used more selective pharmacological inhibitors to investigate the roles of protein tyrosine kinases, phospholipase C (PLC), phosphatidylinositol 3′-kinase, and the family of mitogen-activated protein kinases (MAPK) on Fc-mediated heterophil degranulation. Inhibitors of the receptor-linked tyrosine kinases (the tryphostins AG 1478 and AG 1296) had no attenuating effects on the Fc receptor-mediated degranulation of chicken heterophils. Likewise, PP2, a selective inhibitor of the Src family of protein tyrosine kinases, had no inhibitory effects on degranulation. However, piceatannol, a selective inhibitor of Syk tyrosine kinase, significantly attenuated the effect of Fc receptor-mediated degranulation. Additionally, Fc-mediated degranulation was significantly attenuated by SB 203580, an inhibitor of p38 MAPK, but not by PD98059, an inhibitor of the extracellular signal-regulated kinase (ERK). An inhibitor of phospholipase C, U73122 and LY294002, an inhibitor of phosphoinositol-3 kinase significantly decreased heterophil degranulation. These results suggest that the Fc receptors on chicken heterophils, like their counterparts on mammalian neutrophils, have no intrinsic tyrosine kinase activity, but probably mediate downstream events through activation of tyrosine-based activation motifs (ITAM). Activation of the Syk tyrosine kinase stimulates downstream phosphorylation of p38 MAPK, phospholipase C, and phosphatidylinositol-3 kinase as signaling pathways that regulate Fc-receptor-mediated degranulation of chicken heterophils. Engaging Fc receptors on chicken heterophils activates a Syk →PLC→PI3-K→p38 MAPK signal transduction pathway that induces degranulation.
Iris F Ueki - One of the best experts on this subject based on the ideXlab platform.
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fmlp causes degranulation followed by Regranulation in rat nasal glands
Laryngoscope, 2010Co-Authors: Seontae Kim, Takashi Nakanaga, Iris F Ueki, Jay A NadelAbstract:OBJECTIVE To determine the mechanism of mucus production by nasal glands. STUDY DESIGN Because neutrophilic inflammation is associated with mucus hypersecretion in disease states, here we examine the role of neutrophil recruitment in mucous cell degranulation and Regranulation in rat nasal glands. METHODS N-formyl-methionyl-leucyl-phenylalanine (fMLP) was aerosolized intranasally in rats (n = 5), and its effects on degranulation and Regranulation of submucosal glands were evaluated by Alcian blue/periodic acid-Schiff (AB/PAS) staining and by immunolocalization of neutrophils and epidermal growth factor receptor (EGF-R). RESULTS In control subjects, glands were filled with mucin. After fMLP inhalation, degranulation, 31.7 +/- 0.8% (P <.01), was maximal at 2 to 4 hours. By 24 to 48 hours after fMLP inhalation, degranulation had decreased to 10.3 +/- 0.6% (P <.05), indicating that Regranulation of mucous glycoconjugates was occurring. After fMLP inhalation, neutrophils around submucosal glands increased within 0.5 hours from 1.4 +/- 0.1 to 9.5 +/- 0.3 per 0.0032 mm2 (P <.05). In control subjects, EGF-R protein was expressed near acinar ducts, 16.4 +/- 0.7% of gland area, and increased to 30.9 +/- 0.9% (P <.05) 24 to 48 hours after fMLP inhalation. Nasal pretreatment with a selective EGF-R tyrosine kinase inhibitor (BIBX1522, 15 mg/kg bid) prevented Regranulation at 24 hours after fMLP inhalation (degranulation 27.8 +/- 0.3%, P <.05, compared to 24 hours after fMLP alone), indicating that inhibition of EGF-R activation had prevented Regranulation after fMLP inhalation. CONCLUSIONS Degranulation of rat nasal glands by fMLP is followed by Regranulation; Regranulation depends on a neutrophil-associated EGF-R cascade.
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epidermal growth factor receptor signaling mediates Regranulation of rat nasal goblet cells
The Journal of Allergy and Clinical Immunology, 2001Co-Authors: Heungman Lee, Iris F Ueki, Lars Malm, Karim Dabbagh, Trang Daopick, Suil Kim, Jae Jeong Shim, Jay A NadelAbstract:Abstract Background: Mucus hypersecretion is a common response to inflammation in the lower airways and is a hallmark of chronic rhinitis. Objective: The purpose of this study was to elucidate the mechanisms of Regranulation (mucus production) of goblet cells in nasal epithelium. Methods: Because neutrophils induce an epidermal growth factor (EGFR) cascade, we induced degranulation of goblet cells in rat nasal respiratory epithelium by means of intranasal inhalation of N-formyl-methionyl-leucyl-phenylalanine (fMLP), and we examined Regranulation of the goblet cells and the role of EGFR inhibitors and neutrophils in the Regranulation process. Results: In the control state Alcian blue/periodic acid–Schiff and mucin MUC5AC staining was present. Degranulation was induced in the nasal septal epithelium 4 hours after intranasal inhalation of fMLP (10 –7 mol/L); 48 hours later, goblet-cell Regranulation was complete. In the control state EGFR protein staining was absent in the epithelium, but after fMLP-induced degranulation, EGFR protein was expressed. After pretreatment with BIBX1522, a selective EGFR tyrosine kinase inhibitor, fMLP-induced degranulation was unaffected, but goblet-cell Regranulation was prevented completely. Conclusion: These data suggest a role for the EGFR cascade in neutrophil-dependent production of goblet-cell mucins. Proving this theory will require the use of selective EGFR inhibitors in clinical studies of nasal hypersecretory states. (J Allergy Clin Immunol 2001;107:1046-50.)
Michael H. Kogut - One of the best experts on this subject based on the ideXlab platform.
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the use of selective pharmacological inhibitors to delineate signal transduction pathways activated during complement receptor mediated degranulation in chicken heterophils
International Immunopharmacology, 2003Co-Authors: Michael H. Kogut, Virginia K Lowry, M B FarnellAbstract:Abstract Complement receptors (CRs), along with Fc receptors, play a primary role in the removal of bacterial pathogens in poultry. The binding of serum-opsonized bacteria to CR results in the secretion of both toxic oxygen metabolites and antibacterial granules. We have previously shown that the stimulation of chicken heterophils with serum-opsonized Salmonella enteritidis induced tyrosine kinase-dependent phosphorylation regulated degranulation. In the present studies, we used selective pharmacological inhibitors to investigate the roles of protein tyrosine kinases, phospholipases C and D (PLC and PLD), phosphatidylinositol 3′-kinase (PI3-K), and the super family of mitogen-activated protein kinases (MAPKs) on CR-mediated heterophil degranulation. Inhibitors of receptor-linked tyrosine kinases (the tryphostins AG1478 and AG1296) had no attenuating effects on CR-mediated degranulation. However, PP2, a selective inhibitor of the src family of protein tyrosine kinases, and piceatannol, an inhibitor of Syk tyrosine kinases, both significantly attenuated the CR-mediated degranulation. Additionally, the specific inhibitors of PLC, U73122, and PI3-K, LY294002, significantly decreased CR-mediated heterophil degranulation. Two inhibitors of PLD-mediated signaling, 2,3-diphosphoglycerate (2,3-DPG) and 1-butanol, hindered degranulation. Addition of purified PLD restored control levels of degranulation in heterophils in which PLD was inhibited. Lastly, SP600125, a selective inhibitor of c-Jun N-terminal kinase (JNK), inhibited degranulation; whereas neither PD98059, the inhibitor of p38 MAPK, nor SB203580, the inhibitor of extracellular signal-regulated kinase, had any effect on CR-mediated heterophil degranulation. These studies demonstrate that CRs on chicken heterophils lack intrinsic tyrosine kinase activity, but that binding of serum-opsonized bacteria activates both proximal tyrosine kinases ( src and Syk kinases), but differentially activates downstream tyrosine kinases (JNK, but not p38 nor ERK). Activation of src and Syk kinases plays a significant role in signal transduction of heterophil degranulation probably by stimulating downstream phosphorylation of PLC, PLD, and PI3-K. PI3-K has also been recently shown to be an upstream mediator of JNK activation, suggesting that this enzyme can induce signaling as both a lipid kinase and protein kinase. Engaging CRs on chicken heterophils activates a proximal tyrosine kinase ( src and Syk kinases)→PLC (PLD)→PI3-K→JNK signal transduction pathway that induces degranulation.
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selective pharmacological inhibitors reveal the role of syk tyrosine kinase phospholipase c phosphatidylinositol 3 kinase and p38 mitogen activated protein kinase in fc receptor mediated signaling of chicken heterophil degranulation
International Immunopharmacology, 2002Co-Authors: Michael H. Kogut, Virginia K Lowry, M B FarnellAbstract:Abstract Fc receptors of avian heterophils play a primary role in the elimination of bacterial pathogens in poultry. The cross-linking of Fc receptors with IgG-bacteria complexes results in the secretion of toxic oxygen metabolites and anti-bacterial granules. We have been investigating the upstream signaling events that precede degranulation following crosslinkage of Fc receptors on heterophils. Previously when using the non-selective pharmacological inhibitors genistein, chelerythrine, verapamil, and pertussis toxin, we found no significant inhibitory effects on Fc-mediated heterophil degranulation. In the present studies, we used more selective pharmacological inhibitors to investigate the roles of protein tyrosine kinases, phospholipase C (PLC), phosphatidylinositol 3′-kinase, and the family of mitogen-activated protein kinases (MAPK) on Fc-mediated heterophil degranulation. Inhibitors of the receptor-linked tyrosine kinases (the tryphostins AG 1478 and AG 1296) had no attenuating effects on the Fc receptor-mediated degranulation of chicken heterophils. Likewise, PP2, a selective inhibitor of the Src family of protein tyrosine kinases, had no inhibitory effects on degranulation. However, piceatannol, a selective inhibitor of Syk tyrosine kinase, significantly attenuated the effect of Fc receptor-mediated degranulation. Additionally, Fc-mediated degranulation was significantly attenuated by SB 203580, an inhibitor of p38 MAPK, but not by PD98059, an inhibitor of the extracellular signal-regulated kinase (ERK). An inhibitor of phospholipase C, U73122 and LY294002, an inhibitor of phosphoinositol-3 kinase significantly decreased heterophil degranulation. These results suggest that the Fc receptors on chicken heterophils, like their counterparts on mammalian neutrophils, have no intrinsic tyrosine kinase activity, but probably mediate downstream events through activation of tyrosine-based activation motifs (ITAM). Activation of the Syk tyrosine kinase stimulates downstream phosphorylation of p38 MAPK, phospholipase C, and phosphatidylinositol-3 kinase as signaling pathways that regulate Fc-receptor-mediated degranulation of chicken heterophils. Engaging Fc receptors on chicken heterophils activates a Syk →PLC→PI3-K→p38 MAPK signal transduction pathway that induces degranulation.
Ulrich Blank - One of the best experts on this subject based on the ideXlab platform.
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loss of trpc1 mediated ca2 influx contributes to impaired degranulation in fyn deficient mouse bone marrow derived mast cells
Journal of Leukocyte Biology, 2010Co-Authors: Ryo Suzuki, Xibao Liu, Ana Olivera, Lizath Aguiniga, Yumi Yamashita, Ulrich Blank, Indu S Ambudkar, Juan A RiveraAbstract:MC degranulation requires the influx of calcium from the extracellular environment. Orai1/STIM1 is essential to MC SOCE, as shown in rat peritoneal MCs, the rat MC lines (RBL-2H3), or in Orai1 null embryo liver-derived, cultured MCs. However, minimal information exists about the role of other calcium channels expressed on these cells. Here, we demonstrate that the nonselective TRPC1 participates in FceRI-mediated calcium entry in mouse BMMCs. We found that Fyn null MCs, which have an impaired degranulation response, expressed reduced levels of TRPC1, had normal depletion of intracellular calcium stores but an impaired calcium influx, and failed to depolymerize cortical F-actin (a key step for granule-plasma membrane fusion). Partial RNAi silencing of TRPC1 expression in WT MCs (to the level of Fyn null MCs) mimicked the Fyn null defect in calcium influx, cortical F-actin depolymerization, and MC degranulation. Ectopic expression of Fyn or TRPC1 in Fyn null MCs restored calcium responses and cortical F-actin depolymerization and increased MC degranulation. Together with our findings that expression of Orai1 is not altered in Fyn null MCs, our findings suggest that TRPC1 participates in calcium influx and other key events required for MC degranulation. This demonstrates that in addition to a role described previously for Orai1 in promoting MC degranulation, nonselective cation channels participate in promoting the exocytotic response.
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human serum ige mediated mast cell degranulation shows poor correlation to allergen specific ige content
Allergy, 2003Co-Authors: F Marchand, Ulrich Blank, Salaheddine Mecheri, L Guilloux, B Iannascoli, A WeyerAbstract:Background: Although allergen-specific IgE content in serum can be determined immunochemically, little is known about the relationship between this parameter and the strength of the degranulation response upon allergen triggering. Objectives: Analyse the degranulation capacity of immunochemically defined purified and serum IgE after challenge with anti-IgE or allergen using a rat mast cell line (RBL) transfected with the α-chain of the human high-affinity IgE receptor (FcɛRI). Methods: Purified IgE specific for 4-hydroxy-3nitrophenylacetyl, purified IgE of unknown specificity, and sera from allergic patients sensitive to Dermatophagoides pteronyssinus and Dactylis glomerata were assessed. Degranulation was measured by a β-hexosaminidase release assay after anti-IgE or allergen-specific challenge. Results: For purified monoclonal IgE a significant correlation (r = 0.97) was found between the proportion of bound allergen-specific IgE and the strength of the degranulation response. In contrast, no correlation (r = 0.27) was detected after sensitization with serum IgE. Conclusion: Our studies demonstrate that mast cell activation mediated through IgE from allergic patients is a result of complex relationships that are not only dependent on allergen-specific IgE content but also relate to the capacity to efficiently sensitize and trigger the signalling responses that lead to degranulation.