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1.
Article in English | MEDLINE | ID: mdl-29763661

ABSTRACT

The profile of activation of lipid mediator (LM) pathways in asthmatic airway inflammation remains unclear. This experimental study quantified metabolite levels of ω3-, ω6- and ω9-derived polyunsaturated fatty acids in bronchoalveolar lavage fluid (BALF) after 4-weeks of repeated house dust mite (HDM) exposure in a murine (C57BL/6) asthma model. The challenge induced airway hyperresponsiveness, pulmonary eosinophil infiltration, but with low and unchanged mast cell numbers. Of the 112 screened LMs, 26 were increased between 2 to >25-fold in BALF with HDM treatment (p < 0.05, false discovery rate = 5%). While cysteinyl-leukotrienes were the most abundant metabolites at baseline, their levels did not increase after HDM treatment, whereas elevation of PGD2, LTB4 and multiple 12/15-lipoxygenase products, such as 5,15-DiHETE, 15-HEDE and 15-HEPE were observed. We conclude that this model has identified a global lipoxygenase activation signature, not linked to mast cells, but with aspects that mimic chronic allergic airway inflammation in asthma.


Subject(s)
Arachidonate 12-Lipoxygenase/immunology , Arachidonate 15-Lipoxygenase/immunology , Arachidonate 5-Lipoxygenase/immunology , Asthma/immunology , Inflammation Mediators/immunology , Prostaglandins/immunology , Pyroglyphidae/immunology , Animals , Asthma/pathology , Bronchoalveolar Lavage , Disease Models, Animal , Mice , Mice, Transgenic
2.
Pulm Pharmacol Ther ; 48: 203-210, 2018 02.
Article in English | MEDLINE | ID: mdl-29247703

ABSTRACT

INTRODUCTION: Acute exposure to organic dust (OD) in pig barns induces intense airway inflammation with neutrophilia and hyperresponsiveness. This reaction is likely associated with increased cholinergic activity. Therefore, the involvement of cholinergic mechanisms in the reaction to acute exposure of OD was investigated in mice using the long-acting muscarinic antagonist tiotropium. METHODS: BALB/c mice received tiotropium (2-200 ng) intranasally on day 1 of the study. On days 2-4, mice received vehicle or OD (25 µg) intranasally. Airway hyperresponsiveness to methacholine was assessed 24 h following the last OD exposure. Bronchoalveolar lavage (BAL) fluid, lung tissue and blood were collected for analyses. RESULTS: Organic dust elevated airway responsiveness to methacholine compared with controls (PBS) assessed as Newtonian resistance (1.5 ±â€¯0.1 vs 0.9 ±â€¯0.1 cm H2O x s/mL), tissue damping (12.4 ±â€¯1.4 vs 8.9 ±â€¯0.9 cm H2O∙s/mL) and tissue elastance (41.1 ±â€¯5.3 vs 27.2 ±â€¯2.5 cm H2O∙s/mL). Tiotropium (200 ng) decreased the Newtonian resistance and tissue damping after exposure to PBS or OD. Organic dust exposure increased inflammatory cells in BAL fluid by almost 400%, mainly due to neutrophil influx, which was unaffected by tiotropium. Organic dust increased levels of mainly Th1 mediators. Tiotropium treatment attenuated OD-induced release of IL-2, IL-4 and IL-6. CONCLUSIONS: Tiotropium decreased the OD-induced increase of specific cytokines without influencing the OD-induced increase of airway responsiveness and neutrophil infiltration into the lungs. We conclude that the cholinergic pathway contributes to the pro-inflammatory effects caused by inhalation of OD from pig barns.


Subject(s)
Cholinergic Antagonists/pharmacology , Inflammation/drug therapy , Respiratory Hypersensitivity/drug therapy , Tiotropium Bromide/pharmacology , Animals , Bronchoalveolar Lavage Fluid , Cholinergic Antagonists/administration & dosage , Cytokines/metabolism , Dose-Response Relationship, Drug , Dust , Female , Inflammation/etiology , Lung/drug effects , Lung/metabolism , Methacholine Chloride/pharmacology , Mice , Mice, Inbred BALB C , Neutrophil Infiltration/drug effects , Respiratory Hypersensitivity/etiology , Swine , Tiotropium Bromide/administration & dosage
3.
PLoS One ; 12(12): e0188909, 2017.
Article in English | MEDLINE | ID: mdl-29206862

ABSTRACT

Interleukin (IL)-26 is released in response to bacterial endotoxin (LPS) in the bronchoalveolar space of humans in vivo and it may potentiate neutrophil chemotaxis by enhanced IL-26 receptor stimulation. However, the effects of extracellular IL-26 protein on the innate immune response in the lungs in vivo remain unknown. Here, we characterized these effects of IL-26 on a wide range of aspects of the innate immune response to LPS in different compartments of the lungs in vivo over time. We administrated recombinant human (rh) IL-26 protein in the bronchoalveolar space using intranasal instillation in a mouse in vivo model, with and without prior instillation of LPS. We verified gene expression of the IL-26 receptor complex in mouse lungs and observed that, after instillation of LPS, rhIL-26 increases the phosphorylation of STAT3, a signaling molecule of the IL-26 receptor complex. We also observed that rhIL-26 exerted additional stimulatory and inhibitory actions that are compartment- and time-dependent, resulting in alterations of cytokines, proteinases, tissue inflammation and the accumulation of innate effector cells. Without the prior instillation of LPS, rhIL-26 exerted time-dependent effects on total gelatinase activity but few other effects. Most important, after instillation of LPS, rhIL-26 cleared inflammatory cells from local tissue and increased the accumulation of innate effector cells in the bronchoalveolar space. Tentatively, rhIL-26 may facilitate the innate immune response towards the bronchoalveolar space in vivo and represents a potential target for therapy in lung disorders involving the innate immune response.


Subject(s)
Bronchi/drug effects , Immunity, Innate/drug effects , Interleukins/pharmacology , Lipopolysaccharides/pharmacology , Pulmonary Alveoli/drug effects , Animals , Bronchi/immunology , Bronchoalveolar Lavage Fluid , Cytokines/biosynthesis , Humans , Mice , Mice, Inbred BALB C , Peroxidase/metabolism , Phosphorylation , Pulmonary Alveoli/immunology , RNA, Messenger/genetics , Recombinant Proteins/pharmacology
4.
PLoS One ; 12(12): e0190159, 2017.
Article in English | MEDLINE | ID: mdl-29272313

ABSTRACT

Asthma is a chronic inflammatory disease characterized by bronchial hyperresponsiveness, mucus overproduction and airway remodeling. Notably, we have recently demonstrated that insulin-like growth factor 1 receptor (IGF1R) deficiency in mice attenuates airway hyperresponsiveness and mucus secretion after chronic house dust mite (HDM) exposure. On this basis, inbred C57BL/6 and Igf1r-deficient mice were given HDM extract to study the acute inflammatory profile and implication of Igf1r in acute asthma pathobiology. Additionally, Igf1r-deficiency was therapeutically induced in mice to evaluate the resolution of HDM-induced inflammation. Acute HDM exposure in inbred C57BL/6 mice led to a progressive increase in inflammation, airway remodeling and associated molecular indicators. Preventively-induced Igf1r-deficiency showed reduced neutrophil and eosinophil numbers in BALF and bone marrow, a significant reduction of airway remodeling and decreased levels of related markers. In addition, therapeutic targeting of Igf1r promoted the resolution of HDM-induced-inflammation. Our results demonstrate for the first time that Igf1r is important in acute asthma pathobiology and resolution of HDM-induced inflammation. Thus, IGF1R is suggested to be a promising candidate for future therapeutic approaches for the treatment and prevention of asthma.


Subject(s)
Asthma/therapy , Disease Models, Animal , Gene Targeting , Inflammation/therapy , Receptor, IGF Type 1/genetics , Acute Disease , Animals , Bone Marrow Cells , Bronchoalveolar Lavage Fluid , Mice , Mice, Inbred C57BL
5.
Neurosci Res ; 109: 9-15, 2016 Aug.
Article in English | MEDLINE | ID: mdl-26907521

ABSTRACT

BACE1-mediated cleavage of APP is a pivotal step in the production of the Alzheimer related Aß peptide and inhibitors of BACE1 are currently in clinical development for the treatment of Alzheimer disease (AD). While processing and trafficking of APP has been extensively studied in non-neuronal cells, the fate of APP at neuronal synapses and in response to reduced BACE1 activity has not been fully elucidated. Here we examined the consequence of reduced BACE1 activity on endogenous synaptic APP by monitoring N- and C-terminal APP epitopes by immunocytochemistry. In control rodent primary hippocampal neuron cultures, labeling with antibodies directed to N-terminal APP epitopes showed a significant overlap with synaptic vesicle markers (SV2 or synaptotagmin). In contrast, labeling with antibodies directed to C-terminal epitopes of APP showed only a limited overlap with these proteins. In neurons derived from BACE1-deficient mice, and in control neurons treated with a BACE1 inhibitor, both the N-terminal and the C-terminal APP labeling overlapped significantly with synaptic vesicle markers. Moreover, BACE1 inhibition increased the proximity between the APP C-terminus and SV2 as shown by a proximity ligation assay. These results, together with biochemical observations, indicate that BACE1 can regulate the levels of full-length APP at neuronal synapses.


Subject(s)
Amyloid Precursor Protein Secretases/antagonists & inhibitors , Amyloid beta-Protein Precursor/metabolism , Aspartic Acid Endopeptidases/antagonists & inhibitors , Neurons/drug effects , Synapses/drug effects , Amyloid Precursor Protein Secretases/genetics , Animals , Aspartic Acid Endopeptidases/genetics , Cells, Cultured , Mice, Inbred C57BL , Mice, Knockout , Morpholines/pharmacology , Neurons/metabolism , Pyrimidines/pharmacology , Rats, Sprague-Dawley , Synapses/metabolism
6.
Int Arch Allergy Immunol ; 165(3): 195-205, 2014.
Article in English | MEDLINE | ID: mdl-25531229

ABSTRACT

BACKGROUND: Allergic asthma is a chronic inflammatory airway disease caused by exposure to airborne allergens. In order to develop novel therapies for allergic asthma, models that are relevant to human disease are needed. METHODS: Female BALB/c mice were presensitised subcutaneously with alum-adsorbed recombinant cat allergen Fel d 1, followed by intranasal challenges with cat dander extract spiked with recombinant Fel d 1 for 7 weeks. For reference, mice were presensitised and challenged with ovalbumin following the same protocol. Airway hyperresponsiveness, serum antibodies, airway inflammation and cell infiltration, and cytokines in lung tissue and bronchoalveolar lavage were measured. RESULTS: Mice presensitised with recombinant Fel d 1 and challenged with cat dander extract or presensitised and challenged with ovalbumin showed airway hyperresponsiveness in response to metacholine. Mice of the cat allergen model showed influx of neutrophils, eosinophils and lymphocytes in bronchoalveolar lavage, combined with increased levels of IL-17a and increased IL-4 mRNA expression in lung tissue. In contrast, mice sensitised and challenged with ovalbumin showed a predominant influx of eosinophils in bronchoalveolar lavage and had an increased expression of IL-5 in lung tissue. Both protocols induced features of lung tissue remodelling and allergen-specific antibody responses. CONCLUSIONS: The presented mouse model for cat allergen-induced asthma exhibits hallmarks of chronic allergic asthma, like airway hyperresponsiveness, a mixed neutrophilic/eosinophilic infiltration in bronchoalveolar lavage, expression of IL-17a and signs of remodelling in lung tissue. The model will provide a relevant platform for the development of novel treatment strategies.


Subject(s)
Asthma/immunology , Disease Models, Animal , Eosinophils/immunology , Lymphocytes/immunology , Neutrophils/immunology , Airway Remodeling , Animals , Antibodies/blood , Bronchial Hyperreactivity , Cats , Cells, Cultured , Cytokines/metabolism , Dander/immunology , Female , Glycoproteins/immunology , Humans , Immunization , Mice , Mice, Inbred BALB C , Recombinant Proteins/immunology
7.
Pulm Pharmacol Ther ; 26(5): 532-9, 2013 Oct.
Article in English | MEDLINE | ID: mdl-23583635

ABSTRACT

Therapeutics targeting specific mechanisms of asthma have shown promising results in mouse models of asthma. However, these successes have not transferred well to the clinic or to the treatment of asthma sufferers. We suggest a reason for this incongruity is that mast cell-dependent responses, which may play an important role in the pathogenesis of both atopic and non-atopic asthma, are not a key component in most of the current asthma mouse models. Two reasons for this are that wild type mice have, in contrast to humans, a negligible number of mast cells localized in the smaller airways and in the parenchyma, and that only specific protocols show mast cell-dependent reactions. The development of mast cell-deficient mice and the reconstitution of mast cells within these mice have opened up the possibility to generate mouse models of asthma with a marked role of mast cells. In addition, mast cell-deficient mice engrafted with mast cells have a distribution of mast cells more similar to humans. In this article we review and highlight the mast cell-dependent and -independent responses with respect to airway hyperresponsiveness and inflammation in asthma models using mast cell-deficient and mast cell-engrafted mice.


Subject(s)
Asthma/physiopathology , Disease Models, Animal , Mast Cells/metabolism , Animals , Bronchial Hyperreactivity/physiopathology , Humans , Inflammation/physiopathology , Mice , Species Specificity
8.
Acta Neuropathol ; 124(4): 561-73, 2012 Oct.
Article in English | MEDLINE | ID: mdl-22791295

ABSTRACT

Diabetic neuropathy includes damage to neurons, Schwann cells and blood vessels. Rodent models of diabetes do not adequately replicate all pathological features of diabetic neuropathy, particularly Schwann cell damage. We, therefore, tested the hypothesis that combining hypertension, a risk factor for neuropathy in diabetic patients, with insulin-deficient diabetes produces a more pertinent model of peripheral neuropathy. Behavioral, physiological and structural indices of neuropathy were measured for up to 6 months in spontaneously hypertensive and age-matched normotensive rats with or without concurrent streptozotocin-induced diabetes. Hypertensive rats developed nerve ischemia, thermal hyperalgesia, nerve conduction slowing and axonal atrophy. Thinly myelinated fibers with supernumerary Schwann cells indicative of cycles of demyelination and remyelination were also identified along with reduced nerve levels of myelin basic protein. Similar disorders were noted in streptozotocin-diabetic rats, except that thinly myelinated fibers were not observed and expression of myelin basic protein was normal. Superimposing diabetes on hypertension compounded disorders of nerve blood flow, conduction slowing and axonal atrophy and increased the incidence of thinly myelinated fibers. Rats with combined insulinopenia, hyperglycemia and hypertension provide a model for diabetic neuropathy that offers an opportunity to study mechanisms of Schwann cell pathology and suggests that hypertension may contribute to the etiology of diabetic neuropathy.


Subject(s)
Diabetes Complications/complications , Diabetes Mellitus, Experimental/complications , Hypertension/complications , Peripheral Nervous System Diseases/complications , Animals , Diabetes Complications/pathology , Diabetes Complications/physiopathology , Diabetes Mellitus, Experimental/pathology , Diabetes Mellitus, Experimental/physiopathology , Enzyme-Linked Immunosorbent Assay , Hypertension/pathology , Hypertension/physiopathology , Immunohistochemistry , Nerve Fibers, Myelinated/pathology , Peripheral Nervous System Diseases/pathology , Peripheral Nervous System Diseases/physiopathology , Rats , Rats, Inbred SHR , Rats, Wistar
10.
Metabolism ; 57(7): 873-81, 2008 Jul.
Article in English | MEDLINE | ID: mdl-18555826

ABSTRACT

We investigated the effect of treatment with an aldose reductase inhibitor, insulin, or select neurotrophic factors on the generation of oxidative damage in peripheral nerve. Rats were either treated with streptozotocin to induce insulin-deficient diabetes or fed with a diet containing 40% d-galactose to promote hexose metabolism by aldose reductase. Initial time course studies showed that lipid peroxidation and DNA oxidation were significantly elevated in sciatic nerve after 1 week or 2 weeks of streptozotocin-induced diabetes, respectively, and that both remained elevated after 12 weeks of diabetes. The increase in nerve lipid peroxidation was completely prevented or reversed by treatment with the aldose reductase inhibitor, ICI 222155, or by insulin, but not by the neurotrophic factors, prosaptide TX14(A) or neurotrophin-3. The increase in nerve DNA oxidation was significantly prevented by insulin treatment. In contrast, up to 16 weeks of galactose feeding did not alter nerve lipid peroxidation or protein oxidation, despite evidence of ongoing nerve conduction deficits. These observations demonstrate that nerve oxidative damage develops early after the onset of insulin-deficient diabetes and that it is not induced by increased hexose metabolism by aldose reductase per se, but rather is a downstream consequence of flux through this enzyme. Furthermore, the beneficial effect of prosaptide TX14(A) and neurotrophin-3 on nerve function and structure in diabetic rats is not due to amelioration of increased lipid peroxidation.


Subject(s)
Aldehyde Reductase/antagonists & inhibitors , DNA/metabolism , Diabetes Mellitus, Experimental/metabolism , Diabetic Neuropathies/metabolism , Enzyme Inhibitors/pharmacology , Hypoglycemic Agents/pharmacology , Insulin/pharmacology , Lipid Peroxidation/drug effects , Nerve Growth Factors/pharmacology , Neurons/metabolism , Animals , Blood Glucose/metabolism , Body Weight/drug effects , DNA/drug effects , Female , Galactitol/pharmacology , Galactose/metabolism , Galactose/toxicity , Hydrazones/pharmacology , Malondialdehyde/metabolism , Neurons/drug effects , Nitroparaffins/pharmacology , Oxidation-Reduction , Rats , Rats, Sprague-Dawley , Sulfones/pharmacology
11.
Article in English | MEDLINE | ID: mdl-15275655

ABSTRACT

Sturgeons are primitive bony fishes and their hearts have structural features found in other primitive fishes. Sturgeons have a pericardioperitoneal canal (PPC), a one-way conduit into the peritoneum. A PPC also occurs in elasmobranchs (sharks and rays) and studies with that group demonstrate that pericardial pressure and pericardial fluid loss via the PPC affect stroke volume. A study of white sturgeon (Acipenser transmontanus) heart function was conducted to test for a comparable PPC and pericardial effects. White sturgeon-elasmobranch heart-function similarities include biphasic ventricular filling, a comparable operational pericardial pressure (-0.03 kPa), and a strongly negative pressure (-0.2 to -0.6 kPa) with complete pericardial fluid withdrawal. Differences include the white sturgeon's relatively smaller atrium and ventricle but a larger conus arteriosus. Although white sturgeon heart size is also smaller, its pericardial volume is disproportionately less (2.4 to 2.7 vs. 3.5 to 5.4 ml kg(-1) in elasmobranchs), meaning it has less scope for increasing stroke volume upon PPC fluid release. These differences may reflect the phylogenetic progression from the less complex operation of the elasmobranch heart, which lacks sympathetic innervation and has a mechanically mediated (PPC) stroke volume, to the condition in the more derived bony fishes which have sympathetic and parasympathetic regulation of both stroke volume and heart rate.


Subject(s)
Heart/physiology , Pericardium/physiology , Peritoneum/physiology , Animals , Blood Pressure , Blood Volume , Body Fluids/physiology , Echocardiography , Fishes , Heart Function Tests
12.
J Pharmacol Exp Ther ; 311(1): 356-63, 2004 Oct.
Article in English | MEDLINE | ID: mdl-15175421

ABSTRACT

Activation of protease-activated receptors (PARs) in non-neural tissue results in prostaglandin production. Because PARs are found in the spinal cord and increased prostaglandin release in the spinal cord causes thermal hyperalgesia, we hypothesized that activation of these spinal PARs would stimulate prostaglandin production and cause a cyclooxygenase-dependent thermal hyperalgesia. PARs were activated using either thrombin or peptide agonists derived from the four PAR subtypes, delivered to the lumbar spinal cord. Dialysis experiments were conducted in conscious, unrestrained rats using loop microdialysis probes placed in the lumbar intrathecal space. Intrathecal thrombin stimulated release of prostaglandin E (PGE)(2) but not aspartate or glutamate. Intrathecal delivery of the PAR 1-derived peptide SFLLRN-NH(2) and the PAR 2-derived peptide SLIGRL both stimulated PGE(2) release; PAR 3-derived TFRGAP and PAR 4-derived GYPGQV were inactive. Intrathecal thrombin had no effect upon formalin-induced flinching or tactile sensitivity but resulted in a thermal hyperalgesia. Intrathecal SFLLRN-NH(2) and SLIGRL both produced thermal hyperalgesia. Consistent with their effects on spinal PGE(2), hyperalgesia from these peptides was blocked by pretreatment with the cyclooxygenase inhibitor ibuprofen. SLIGRL-induced hyperalgesia was also blocked by the selective inhibitors SC 58,560 [5-(4-fluorophenyl)-1-[4-(methylsulfonyl)phenyl]-3-(trifluoromethyl)-1H-pyrazole; cyclooxygenase (COX) 1] and SC 58,125 [5-(4-chlorophenyl)-1-(4-methoxyphenyl)-3-(trifluoromethyl)-1H-pyrazole; COX 2]. These data indicate that activation of spinal PAR 2 and possibly PAR 1 results in the stimulation of the spinal cyclooxygenase cascade and a prostaglandin-dependent thermal hyperalgesia.


Subject(s)
Hyperalgesia/enzymology , Prostaglandin-Endoperoxide Synthases/metabolism , Receptors, Proteinase-Activated/metabolism , Animals , Behavior, Animal/drug effects , Cyclooxygenase 1 , Cyclooxygenase 2 , Dinoprostone/metabolism , Hyperalgesia/metabolism , Isoenzymes/metabolism , Male , Membrane Proteins , Microdialysis , Peptides/pharmacology , Rats , Rats, Sprague-Dawley , Receptors, Proteinase-Activated/physiology , Spinal Cord/enzymology , Thrombin/pharmacology
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