ovalbumin and fasudil

Airway mucus hypersecretion is a key pathophysiological feature in asthma. Fasudil, a selective Rho-A/Rho kinase inhibitor, has been used in clinical trials to treat pulmonary hypertension. However, its function in modulating airway mucus hypersecretion in asthma remains undefined.. We examined whether fasudil, a selective Rho-A/Rho kinase inhibitor, affects the mucus hypersecretion by suppressing MUC5AC via signal transducer and activator of transcription factor 6 (STAT6) and nuclear factor-kappa B (NFκB) in mice and cells.. We measured mucus secretion and the expression of Rho-kinase in the airway tissue of patients with asthma. BALB/c mice were sensitized and challenged with ovalbumin (OVA) followed with fasudil treatment. The lung tissues were assessed for airway inflammation and mucus secretion. Cytokine levels and airway responsiveness were determined. STAT6 and NFκB were quantified by Western blot. 16HBE cells were stimulated with house dust mite (HDM) extracts. MUC5AC and muc5ac promoter activities were measured. Using siRNA to knockdown STAT6 in epithelial cells, we determined the impact of STAT6 on muc5ac promoter activity. NFκB nuclear translocation was observed with immunostaining.. Fasudil administration significantly decreased the number of inflammatory cells, inflammation index in the lung and airway responsiveness. Fasudil also reduced mucous secretion and MUC5AC expression in OVA-challenged mice. Fasudil down-regulated the levels of IL-17, IL-4 and IL-13 in the lung tissue of OVA-challenged mice. Fasudil also decreased the expression and phosphorylation of NFκB and STAT6 as well as the nuclear translocation of NFκB. In addition, human airway epithelial cells (16HBE) were challenged with HDM extracts and then treated with fasudil. Fasudil inhibited HDM extract-induced MUC5AC expression, which is associated with a reduction in STAT6 and NFκB in epithelial cells.. These findings indicate that the Rho-A/Rho kinase inhibitor, fasudil, plays a negative regulatory role in allergen-induced mucus secretion and MUC5AC expression by regulating STAT6 and NFκB.

Topics: 1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; Allergens; Animals; Asthma; Case-Control Studies; Cell Line; Cytokines; Disease Models, Animal; Down-Regulation; Female; Gene Expression; Humans; Hypersensitivity; Male; Mice; Mucin 5AC; Mucus; NF-kappa B; Ovalbumin; Protein Kinase Inhibitors; Pyroglyphidae; Respiratory Mucosa; rho-Associated Kinases; Signal Transduction; STAT6 Transcription Factor

The exact mechanisms underlying the weak bronchodilator effect of K(ATP) channel openers on cholinergic stimulations is unknown. The present study was designed to examine the relaxant efect of pinacidil in guinea-pig trachea stimulated with carbachol by the presence of calcium sensitizer inhibitors; HA 1077, a rhoA kinase inhibitor, and chelerythrine, a protein kinase C inhibitor. Adenosine (10 microM) was used as other contractile agent for comparison. Tracheal tissues were isolated from ovalbumin sensitized guineapigs and changes in tension were recorded isometrically. Pinacidil (1-100 muM, cumulatively) and HA 1077 (0.01-30 microM, cumulatively) produced concentration-dependent relaxations in unstimulated tisues. The relaxant response to pinacidil decreased in carbachol contracted tissues, but increased in adenosine-stimulated tissues. Pretreatment of the tissues with HA 1077 (0.1 microM) and chelerythrine (10 microM) increased the pinacidil-induced relaxations by approximately %100 and %40, respectively. Glibenclamide, a KATP channel blocker, partially antagonized the pinacidil response in contracted tissues. Glibenclamide also inhibited the carbachol and adenosine induced contractions. These results suggest that diminish effect of pinacidil may have related to the enhanced calcium sensitization by cholinergic stimulation. Rho kinase inhibitors appear more effective than PKC inhibitors to achieve of this failure.

Topics: 1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; Adenosine; Animals; Benzophenanthridines; Bronchodilator Agents; Carbachol; Dose-Response Relationship, Drug; Guinea Pigs; In Vitro Techniques; KATP Channels; Muscle Contraction; Muscle Relaxation; Muscle, Smooth; Ovalbumin; Pinacidil; Protein Kinase C; rhoA GTP-Binding Protein; Trachea

A small GTPase, Rho, and its target molecule, Rho-kinase, play an important role in the cell functions, including contractility, chemotaxis, adhesion, and migration. It is generally considered that eosinophilic inflammation and hyper-reactivity to methacholine in airways are fundamental to the pathophysiology of bronchial asthma.. This study was designed to determine whether the Rho/Rho-kinase pathways are involved in the eosinophil recruitment and airway hyper-reactivity. We investigated inhibitory effects of fasudil, a specific inhibitor of Rho-kinase, on acute allergic inflammation in mice.. BALB/c mice were sensitized and challenged with ovalbumin (OVA). OVA-challenged mice were treated orally with fasudil (3, 10, 30 mg/kg) or saline before each OVA challenge. Total cell counts, differential cell counts, cytokines, and chemokines levels were measured in bronchoalveolar lavage (BAL), and lungs were examined histologically. Moreover, respiratory resistance in response to methacholine was measured.. When fasudil was administrated to OVA-challenged mice, increased cell numbers of total cells and eosinophils were significantly attenuated in a dose-dependent manner. However, inflammatory cells other than eosinophils were not affected by fasudil. Fasudil caused a dose-dependent inhibition in increased levels of IL-5, IL-13, and eotaxin in BAL fluid by OVA challenges. Histological analysis of the airways revealed that both infiltration of inflammatory cells and goblet cell hyperplasia were significantly suppressed in fasudil treatment. Furthermore, fasudil significantly suppressed the augmented responsiveness to methacholine induced by OVA challenges.. Oral administration of fasudil inhibits eosinophil recruitment, goblet cell hyperplasia and airway hyper-reactivity by allergen challenges. These effects of this agent may be mediated by suppressing a chemokine and cytokines related to the pathophysiology of bronchial asthma such as eotaxin, IL-5, and IL-13. Our findings provide evidence that inhibition of the Rho/Rho-kinase pathway may be beneficial for bronchial asthma.

Topics: 1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; Allergens; Animals; Bronchial Hyperreactivity; Bronchial Provocation Tests; Bronchoalveolar Lavage Fluid; Chemokine CCL11; Chemokines, CC; Dose-Response Relationship, Drug; Drug Evaluation, Preclinical; Eosinophilia; Female; Interleukins; Intracellular Signaling Peptides and Proteins; Mice; Mice, Inbred BALB C; Mucus; Ovalbumin; Protein Kinase Inhibitors; Protein Serine-Threonine Kinases; rho-Associated Kinases