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1.
Am J Physiol Lung Cell Mol Physiol ; 316(3): L537-L546, 2019 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-30628486

RESUMO

The direct relationship between pulmonary structural changes and airway hyperresponsiveness (AHR) in chronic obstructive pulmonary disease (COPD) is unclear. We investigated AHR in relation to airway and parenchymal structural changes in a guinea pig model of COPD and in COPD patients. Precision-cut lung slices (PCLS) were prepared from guinea pigs challenged with lipopolysaccharide or saline two times weekly for 12 wk. Peripheral PCLS were obtained from patients with mild to moderate COPD and non-COPD controls. AHR to methacholine was measured in large and small airways using video-assisted microscopy. Airway smooth muscle mass and alveolar airspace size were determined in the same slices. A mathematical model was used to identify potential changes in biomechanical properties underlying AHR. In guinea pigs, lipopolysaccharide increased the sensitivity of large (>150 µm) airways toward methacholine by 4.4-fold and the maximal constriction of small airways (<150 µm) by 1.5-fold. Similarly increased small airway responsiveness was found in COPD patients. In both lipopolysaccharide-challenged guinea pigs and patients, airway smooth muscle mass was unaltered, whereas increased alveolar airspace correlated with small airway hyperresponsiveness in guinea pigs. Fitting the parameters of the model indicated that COPD weakens matrix mechanical properties and enhances stiffness differences between the airway and the parenchyma, in both species. In conclusion, this study demonstrates small airway hyperresponsiveness in PCLS from COPD patients. These changes may be related to reduced parenchymal retraction forces and biomechanical changes in the airway wall. PCLS from lipopolysaccharide-exposed guinea pigs may be useful to study mechanisms of small airway hyperresponsiveness in COPD.


Assuntos
Remodelação das Vias Aéreas/fisiologia , Músculo Liso/efeitos dos fármacos , Doença Pulmonar Obstrutiva Crônica/patologia , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Adulto , Idoso , Animais , Asma/patologia , Asma/fisiopatologia , Modelos Animais de Doenças , Feminino , Cobaias , Humanos , Lipopolissacarídeos/farmacologia , Pulmão/patologia , Pulmão/fisiopatologia , Masculino , Pessoa de Meia-Idade , Músculo Liso/fisiopatologia , Doença Pulmonar Obstrutiva Crônica/induzido quimicamente , Hipersensibilidade Respiratória/induzido quimicamente , Hipersensibilidade Respiratória/patologia , Hipersensibilidade Respiratória/fisiopatologia
2.
Respir Res ; 17: 13, 2016 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-26846267

RESUMO

BACKGROUND: The long-acting anticholinergic tiotropium has recently been registered for the treatment of asthma, and its use is associated with a reduction in exacerbation frequency. Anti-inflammatory and anti-remodeling effects of tiotropium have been demonstrated in in vitro and in vivo models. Because tiotropium treatment is used in combination with inhaled corticosteroids, potential additive effects between the two would be clinically relevant. Therefore, the aim of this study was to investigate additive effects between tiotropium and ciclesonide on airway inflammation and remodeling in guinea pig models of asthma. METHODS: Guinea pigs (n = 3-8/group) were sensitized and challenged with ovalbumin in an acute (single challenge) and a chronic model (12 weekly challenges) of allergic asthma. Animals were treated with vehicle, nebulized tiotropium (0.01-0.3 mM) and/or intranasally instilled ciclesonide (0.001-1 mg/kg) before each challenge. Bronchoalveolar lavage fluid and lungs were collected for analysis of airway inflammation and remodeling. RESULTS: Tiotropium and ciclesonide treatment, alone or in combination, did not inhibit airway inflammation in the acute asthma model. In a dose-finding study, low doses of tiotropium and ciclesonide inhibited airway eosinophilia and airway smooth muscle thickening in the chronic asthma model. Threshold doses of 0.01 mM tiotropium (nebulizer concentration) and 0.01 mg/kg ciclesonide were selected to investigate potential additive effects between both drugs. At these doses, tiotropium and ciclesonide did not inhibit airway eosinophilia or airway smooth muscle thickening when administered alone, but significantly inhibited these allergen-induced responses when administered in combination. CONCLUSIONS: Combined treatment with low doses of tiotropium and ciclesonide inhibits airway inflammation and remodeling in a guinea pig model of chronic asthma, suggesting that combined treatment with anticholinergics and corticosteroids may have anti-inflammatory and anti-remodeling activity in allergic airway diseases. Since tiotropium is registered as a therapy for asthma added on to corticosteroid treatment, these beneficial effects of the combination therapy may be clinically relevant.


Assuntos
Remodelação das Vias Aéreas/efeitos dos fármacos , Asma/imunologia , Asma/prevenção & controle , Modelos Animais de Doenças , Pregnenodionas/administração & dosagem , Brometo de Tiotrópio/administração & dosagem , Administração por Inalação , Animais , Antialérgicos/administração & dosagem , Asma/induzido quimicamente , Broncodilatadores/administração & dosagem , Doença Crônica , Relação Dose-Resposta a Droga , Quimioterapia Combinada/métodos , Cobaias , Masculino , Ovalbumina , Resultado do Tratamento
3.
Pharmacol Rev ; 65(2): 670-709, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23447132

RESUMO

Since the discovery nearly 60 years ago, cAMP is envisioned as one of the most universal and versatile second messengers. The tremendous feature of cAMP to tightly control highly diverse physiologic processes, including calcium homeostasis, metabolism, secretion, muscle contraction, cell fate, and gene transcription, is reflected by the award of five Nobel prizes. The discovery of Epac (exchange protein directly activated by cAMP) has ignited a new surge of cAMP-related research and has depicted novel cAMP properties independent of protein kinase A and cyclic nucleotide-gated channels. The multidomain architecture of Epac determines its activity state and allows cell-type specific protein-protein and protein-lipid interactions that control fine-tuning of pivotal biologic responses through the "old" second messenger cAMP. Compartmentalization of cAMP in space and time, maintained by A-kinase anchoring proteins, phosphodiesterases, and ß-arrestins, contributes to the Epac signalosome of small GTPases, phospholipases, mitogen- and lipid-activated kinases, and transcription factors. These novel cAMP sensors seem to implement certain unexpected signaling properties of cAMP and thereby to permit delicate adaptations of biologic responses. Agonists and antagonists selective for Epac are developed and will support further studies on the biologic net outcome of the activation of Epac. This will increase our current knowledge on the pathophysiology of devastating diseases, such as diabetes, cognitive impairment, renal and heart failure, (pulmonary) hypertension, asthma, and chronic obstructive pulmonary disease. Further insights into the cAMP dynamics executed by the Epac signalosome will help to optimize the pharmacological treatment of these diseases.


Assuntos
AMP Cíclico/fisiologia , Fatores de Troca do Nucleotídeo Guanina/fisiologia , Sistemas do Segundo Mensageiro/fisiologia , Animais , Descoberta de Drogas , Fatores de Troca do Nucleotídeo Guanina/agonistas , Fatores de Troca do Nucleotídeo Guanina/antagonistas & inibidores , Humanos , Estrutura Molecular , Especificidade de Órgãos , Preparações Farmacêuticas/química , Sistemas do Segundo Mensageiro/efeitos dos fármacos , Sistemas do Segundo Mensageiro/genética
4.
Am J Physiol Lung Cell Mol Physiol ; 308(8): L766-75, 2015 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-25637608

RESUMO

ß2-Agonist inhibitors can relieve chronic obstructive pulmonary disease (COPD) symptoms by stimulating cyclic AMP (cAMP) signaling. A-kinase-anchoring proteins (AKAPs) compartmentalize cAMP signaling by establishing protein complexes. We previously reported that the ß2-agonist fenoterol, direct activation of protein kinase A (PKA), and exchange factor directly activated by cAMP decrease cigarette smoke extract (CSE)-induced release of neutrophil attractant interleukin-8 (IL-8) from human airway smooth muscle (ASM) cells. In the present study, we tested the role of AKAPs in CSE-induced IL-8 release from ASM cells and assessed the effect of CSE on the expression levels of different AKAPs. We also studied mRNA and protein expression of AKAPs in lung tissue from patients with COPD. Our data show that CSE exposure of ASM cells decreases AKAP5 and AKAP12, both capable of interacting with ß2-adrenoceptors. In lung tissue of patients with COPD, mRNA levels of AKAP5 and AKAP12 were decreased compared with lung tissue from controls. Using immunohistochemistry, we detected less AKAP5 protein in ASM of patients with COPD Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage II compared with control subjects. St-Ht31, which disrupts AKAP-PKA interactions, augmented CSE-induced IL-8 release from ASM cells and diminished its suppression by fenoterol, an effect mediated by disturbed ERK signaling. The modulatory role of AKAP-PKA interactions in the anti-inflammatory effects of fenoterol in ASM cells and the decrease in expression of AKAP5 and AKAP12 in response to cigarette smoke and in lungs of patients with COPD suggest that cigarette smoke-induced changes in AKAP5 and AKAP12 in patients with COPD may affect efficacy of pharmacotherapy.


Assuntos
Proteínas de Ancoragem à Quinase A/metabolismo , Proteínas de Ciclo Celular/metabolismo , Miócitos de Músculo Liso/metabolismo , Fumar/efeitos adversos , Proteínas de Ancoragem à Quinase A/genética , Idoso , Idoso de 80 Anos ou mais , Proteínas de Ciclo Celular/genética , Células Cultivadas , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Feminino , Expressão Gênica , Humanos , Interleucina-8/metabolismo , Masculino , Pessoa de Meia-Idade , Doença Pulmonar Obstrutiva Crônica/etiologia , Doença Pulmonar Obstrutiva Crônica/metabolismo
6.
FASEB J ; 28(11): 4617-28, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25103224

RESUMO

Cigarette smoke (CS) induces inflammatory responses characterized by increase of immune cells and cytokine release. Remodeling processes, such as mucus hypersecretion and extracellular matrix protein production, are also directly or indirectly induced by CS. Recently, we showed that activation of the exchange protein directly activated by cAMP (Epac) attenuates CS extract-induced interleukin (IL)-8 release from cultured airway smooth muscle cells. Using an acute, short-term model of CS exposure, we now studied the role of Epac1, Epac2, and the Epac effector phospholipase-Cε (PLCε) in airway inflammation and remodeling in vivo. Compared to wild-type mice exposed to CS, the number of total inflammatory cells, macrophages, and neutrophils and total IL-6 release was lower in Epac2(-/-) mice, which was also the case for neutrophils and IL-6 in PLCε(-/-) mice. Taken together, Epac2, acting partly via PLCε, but not Epac1, enhances CS-induced airway inflammation in vivo. In total lung homogenates of Epac1(-/-) mice, MUC5AC and matrix remodeling parameters (transforming growth factor-ß1, collagen I, and fibronectin) were increased at baseline. Our findings suggest that Epac1 primarily is capable of inhibiting remodeling processes, whereas Epac2 primarily increases inflammatory processes in vivo.


Assuntos
Remodelação das Vias Aéreas/fisiologia , Fatores de Troca do Nucleotídeo Guanina/metabolismo , Fumaça/efeitos adversos , Remodelação das Vias Aéreas/genética , Animais , Linhagem Celular , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Citocinas/metabolismo , Feminino , Fatores de Troca do Nucleotídeo Guanina/genética , Inflamação/metabolismo , Pulmão/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Knockout
7.
Am J Physiol Cell Physiol ; 306(6): C585-97, 2014 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-24452374

RESUMO

Airway epithelium, which forms the first barrier towards environmental insults, is disturbed by cigarette smoking, a major risk factor for developing chronic obstructive pulmonary disease (COPD). A-kinase anchoring proteins (AKAP) maintain endothelial barrier function and coordinate subcellular localization of protein kinase A (PKA). However, the role of AKAPs in epithelial barrier function is unknown. We studied the role of AKAPs in regulating human bronchial epithelial (Hogg JC, Timens W. Annu Rev Pathol 4: 435-459, 2009; HBE) barrier. Cigarette smoke extract (CSE) reduced barrier function in 16HBE cells and the expression of the adhesion molecule E-cadherin specifically at the cell membrane. In addition, CSE reduced the protein expression of the AKAP family member AKAP9 at the cell membrane. The expression of AKAP5 and AKAP12 was unaffected by CSE. AKAP9 interacted and colocalized with E-cadherin at the cell membrane, suggesting that the reduction of both proteins may be related. Interestingly, disruption of AKAP-PKA interactions by st-Ht31 prevented the CSE-induced reduction of E-cadherin and AKAP9 protein expression and subsequent loss of barrier function. Silencing of AKAP9 reduced the functional epithelial barrier and prevented the ability of st-Ht31 to restore membrane localization of E-cadherin. Our data suggest the possibility of a specific role for AKAP9 in the maintenance of the epithelial barrier. E-cadherin, but not AKAP9, protein expression was reduced in lung tissue from COPD patients compared with controls. However, AKAP9 mRNA expression was decreased in primary bronchial epithelial cells from current smokers compared with non/ex-smokers. In conclusion, our results indicate that AKAP proteins, most likely AKAP9, maintain the bronchial epithelial barrier by regulating the E-cadherin expression at the cell membrane.


Assuntos
Proteínas de Ancoragem à Quinase A/metabolismo , Caderinas/metabolismo , Proteínas do Citoesqueleto/metabolismo , Nicotiana/efeitos adversos , Mucosa Respiratória/metabolismo , Fumaça/efeitos adversos , Fumar/metabolismo , Proteínas de Ancoragem à Quinase A/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Brônquios/efeitos dos fármacos , Brônquios/metabolismo , Caderinas/genética , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular , Membrana Celular/metabolismo , Proteínas do Citoesqueleto/genética , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Antígenos de Histocompatibilidade Menor , Proteínas Proto-Oncogênicas/metabolismo , Doença Pulmonar Obstrutiva Crônica/metabolismo , Interferência de RNA , RNA Interferente Pequeno , Mucosa Respiratória/efeitos dos fármacos
8.
J Pharmacol Exp Ther ; 348(2): 303-10, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24307202

RESUMO

The novel once-daily ß2-agonist bronchodilator drug olodaterol has recently been shown to be effective in patients with allergic asthma for >24 hours. An increased cholinergic tone common to these patients may decrease the effectiveness of ß2-agonists. This could provide a rationale for combination therapy with olodaterol and the long-acting anticholinergic tiotropium to aim for a once-daily treatment regimen. In guinea pigs, we evaluated the protective effects of olodaterol, alone and in combination with tiotropium, on airway responsiveness to histamine, which is partially mediated by a cholinergic reflex mechanism. In addition, using a guinea pig model of acute allergic asthma, we examined the cooperative effects of these bronchodilators on allergen-induced early (EAR) and late (LAR) asthmatic reactions, airway hyper-responsiveness (AHR) to histamine, and airway inflammation. It was demonstrated that the protective effect of olodaterol against histamine-induced bronchoconstriction was synergistically enhanced and prolonged in the presence of tiotropium. In addition, tiotropium synergistically augmented both the reversal of and the protection against the allergen-induced AHR after the EAR by olodaterol. Olodaterol and tiotropium were highly effective in inhibiting the magnitude of the allergen-induced EAR and LAR, and both reactions were fully inhibited by the combination of these drugs. It is remarkable that these effects were not associated with an effect on inflammatory cell infiltration in the airways. In conclusion, the results indicate that combination therapy with olodaterol and tiotropium may be highly effective in the treatment of allergen-induced asthmatic reactions and AHR.


Assuntos
Agonistas de Receptores Adrenérgicos beta 2/uso terapêutico , Antialérgicos/uso terapêutico , Benzoxazinas/uso terapêutico , Brônquios/efeitos dos fármacos , Modelos Animais de Doenças , Hipersensibilidade Respiratória/tratamento farmacológico , Derivados da Escopolamina/uso terapêutico , Administração por Inalação , Agonistas de Receptores Adrenérgicos beta 2/administração & dosagem , Animais , Animais não Endogâmicos , Antialérgicos/administração & dosagem , Benzoxazinas/administração & dosagem , Brônquios/imunologia , Brônquios/metabolismo , Brônquios/patologia , Broncoconstrição/efeitos dos fármacos , Broncodilatadores/administração & dosagem , Broncodilatadores/uso terapêutico , Antagonistas Colinérgicos/administração & dosagem , Antagonistas Colinérgicos/uso terapêutico , Relação Dose-Resposta a Droga , Esquema de Medicação , Sinergismo Farmacológico , Quimioterapia Combinada , Cobaias , Histamina/administração & dosagem , Histamina/metabolismo , Masculino , Substâncias Protetoras/administração & dosagem , Substâncias Protetoras/uso terapêutico , Hipersensibilidade Respiratória/imunologia , Hipersensibilidade Respiratória/metabolismo , Hipersensibilidade Respiratória/patologia , Mucosa Respiratória/efeitos dos fármacos , Mucosa Respiratória/imunologia , Mucosa Respiratória/metabolismo , Mucosa Respiratória/patologia , Derivados da Escopolamina/administração & dosagem , Brometo de Tiotrópio
10.
Pulm Pharmacol Ther ; 29(2): 121-8, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24747433

RESUMO

Chronic obstructive pulmonary disease (COPD) is currently the fourth leading cause of death worldwide and, in contrast to the trend for cardiovascular diseases, mortality rates still continue to climb. This increase is in part due to an aging population, being expanded by the "Baby boomer" generation who grew up when smoking rates were at their peak and by people in developing countries living longer. Sadly, there has been a disheartening lack of new therapeutic approaches to counteract the progressive decline in lung function associated with the disease that leads to disability and death. COPD is characterized by irreversible chronic airflow limitation that is caused by emphysematous destruction of lung elastic tissue and/or obstruction in the small airways due to occlusion of their lumen by inflammatory mucus exudates, narrowing and obliteration. These lesions are mainly produced by the response of the tissue to the repetitive inhalational injury inflicted by noxious gases, including cigarette smoke, which involves interaction between infiltrating inflammatory immune cells, resident cells (e.g. epithelial cells and fibroblasts) and the extra cellular matrix. This interaction leads to tissue destruction and airway remodeling with changes in elastin and collagen, such that the epithelial-mesenchymal trophic unit is dysregulated in both the disease pathologies. This review focuses on: 1--novel inflammatory and remodeling factors that are altered in COPD; 2--in vitro and in vivo models to understand the mechanism whereby the extra cellular matrix environment in altered in COPD; and 3--COPD in the context of wound-repair tissue responses, with a focus on the regulation of mesenchymal cell fate and phenotype.


Assuntos
Pulmão/patologia , Células-Tronco Mesenquimais/fisiologia , Doença Pulmonar Obstrutiva Crônica/patologia , Animais , Transição Epitelial-Mesenquimal/fisiologia , Humanos , Inflamação/patologia , Inflamação/fisiopatologia , Pulmão/citologia , Pulmão/fisiopatologia , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Transdução de Sinais/fisiologia
12.
Pulm Pharmacol Ther ; 26(1): 145-55, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22842340

RESUMO

Since ancient times, anticholinergics have been used as a bronchodilator therapy for obstructive lung diseases. Targets of these drugs are G-protein-coupled muscarinic M(1), M(2) and M(3) receptors in the airways, which have long been recognized to regulate vagally-induced airway smooth muscle contraction and mucus secretion. However, recent studies have revealed that acetylcholine also exerts pro-inflammatory, pro-proliferative and pro-fibrotic actions in the airways, which may involve muscarinic receptor stimulation on mesenchymal, epithelial and inflammatory cells. Moreover, acetylcholine in the airways may not only be derived from vagal nerves, but also from non-neuronal cells, including epithelial and inflammatory cells. Airway smooth muscle cells seem to play a major role in the effects of acetylcholine on airway function. It has become apparent that these cells are multipotent cells that may reversibly adopt (hyper)contractile, proliferative and synthetic phenotypes, which are all under control of muscarinic receptors and differentially involved in bronchoconstriction, airway remodeling and inflammation. Cholinergic contractile tone is increased by airway inflammation associated with asthma and COPD, resulting from exaggerated acetylcholine release as well as increased expression of contraction related proteins in airway smooth muscle. Moreover, muscarinic receptor stimulation promotes proliferation of airway smooth muscle cells as well as fibroblasts, and regulates cytokine, chemokine and extracellular matrix production by these cells, which may contribute to airway smooth muscle growth, airway fibrosis and inflammation. In line, animal models of chronic allergic asthma and COPD have recently demonstrated that tiotropium may potently inhibit airway inflammation and remodeling. These observations indicate that muscarinic receptors have a much larger role in the pathophysiology of obstructive airway diseases than previously thought, which may have important therapeutic implications.


Assuntos
Asma/tratamento farmacológico , Doença Pulmonar Obstrutiva Crônica/tratamento farmacológico , Receptores Muscarínicos/metabolismo , Acetilcolina/metabolismo , Remodelação das Vias Aéreas , Animais , Asma/fisiopatologia , Modelos Animais de Doenças , Fibroblastos/metabolismo , Humanos , Inflamação/tratamento farmacológico , Inflamação/patologia , Terapia de Alvo Molecular , Contração Muscular , Miócitos de Músculo Liso/metabolismo , Doença Pulmonar Obstrutiva Crônica/fisiopatologia
13.
Pulm Pharmacol Ther ; 26(1): 3-12, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22989721

RESUMO

Respiratory symptoms are largely caused by obstruction of the airways. In asthma, airway narrowing mediated by airway smooth muscle (ASM) contraction contributes significantly to obstruction. The spasmogens produced following exposure to environmental triggers, such as viruses or allergens, are initially responsible for ASM activation. However, the extent of narrowing of the airway lumen due to ASM shortening can be influenced by many factors and it remains a real challenge to decipher the exact role of ASM in causing asthmatic symptoms. Innovative tools, such as the forced oscillation technique, continue to develop and have been proven useful to assess some features of ASM function in vivo. Despite these technologic advances, it is still not clear whether excessive narrowing in asthma is driven by ASM abnormalities, by other alterations in non-muscle factors or simply because of the overexpression of spasmogens. This is because a multitude of forces are acting on the airway wall, and because not only are these forces constantly changing but they are also intricately interconnected. To counteract these limitations, investigators have utilized in vitro and ex vivo systems to assess and compare asthmatic and non-asthmatic ASM contractility. This review describes: 1- some muscle and non-muscle factors that are altered in asthma that may lead to airway narrowing and asthma symptoms; 2- some technologies such as the forced oscillation technique that have the potential to unveil the role of ASM in airway narrowing in vivo; and 3- some data from ex vivo and in vitro methods that probe the possibility that airway hyperresponsiveness is due to the altered environment surrounding the ASM or, alternatively, to a hypercontractile ASM phenotype that can be either innate or acquired.


Assuntos
Remodelação das Vias Aéreas/fisiologia , Asma/fisiopatologia , Músculo Liso/metabolismo , Obstrução das Vias Respiratórias/fisiopatologia , Animais , Hiper-Reatividade Brônquica/fisiopatologia , Humanos , Testes de Função Respiratória
14.
Pulm Pharmacol Ther ; 26(1): 24-36, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22967819

RESUMO

Asthma is a chronic obstructive airway disease characterised by airway hyperresponsiveness (AHR) and airway wall remodelling. The effector of airway narrowing is the contraction of airway smooth muscle (ASM), yet the question of whether an inherent or acquired dysfunction in ASM contractile function plays a significant role in the disease pathophysiology remains contentious. The difficulty in determining the role of ASM lies in limitations with the models used to assess contraction. In vivo models provide a fully integrated physiological response but ASM contraction cannot be directly measured. Ex vivo and in vitro models can provide more direct assessment of ASM contraction but the loss of factors that may modulate ASM responsiveness and AHR, including interaction between multiple cell types and disruption of the mechanical environment, precludes a complete understanding of the disease process. In this review we detail key advantages of common in vivo, ex vivo and in vitro models of ASM contraction, as well as emerging tissue engineered models of ASM and whole airways. We also highlight important findings from each model with respect to the pathophysiology of asthma.


Assuntos
Asma/fisiopatologia , Modelos Biológicos , Músculo Liso/metabolismo , Animais , Hiper-Reatividade Brônquica/fisiopatologia , Modelos Animais de Doenças , Humanos , Contração Muscular/fisiologia , Engenharia Tecidual
15.
Sr Care Pharm ; 38(11): 472-485, 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37885097

RESUMO

Background Advances in antiretroviral therapy (ART) enable people with HIV to live longer, healthier lives. However, older people with HIV (OPWH) are more susceptible to long-term toxicity and drug interactions associated with ART. Racial and ethnic minorities have specific social determinants of health, which increase their risks of negative outcomes. Objective To determine if there were differences in the safety and effectiveness of ART in White, Black, and Hispanic OPWH. Methods A retrospective observational study was conducted on patients receiving care between January 1, 2017, and December 31, 2022, at two affiliated HIV clinics in South Florida. The primary effectiveness endpoint was the percentage of OPWH with undetectable viral load (< 50 copies/mL) throughout the study. Secondary safety endpoints were changes in median metabolic, hepatic, and renal parameters. A two-way analysis of variance or the Chi-square test was used to determine differences between groups. Results A total of 116 White, 42 Black, and 40 Hispanic OPWH were included. Upon enrollment, most patients (90.7%) were receiving ART. Of these, the percentage with undetectable viral load was lower among Black (61.8%) compared with White (85.8%; P < 0.01) or Hispanic (83.3%; P < 0.05) patients. Similarly, throughout the study after the first visit, the percentage with undetectable viral load was lower among Black (61.6%) compared with White (84.7%; P < 0.05) or Hispanic (83.3%; P = 0.12) patients. However, there were no significant differences in the percentage of virally suppressed (< 200 copies/mL) participants throughout the study after the first visit between Black (88.5%), White (94.9%), and Hispanic (96.7%) patients. Additionally, no significant changes in safety endpoints were observed among the groups throughout the study. Conclusion Fewer Black OPWH had undetectable viral load upon enrollment and throughout the study compared with White or Hispanic OPWH, suggesting the need to provide more targeted interventions for Black patients.


Assuntos
Antirretrovirais , Infecções por HIV , Idoso , Humanos , Hispânico ou Latino , HIV , Infecções por HIV/tratamento farmacológico , Infecções por HIV/epidemiologia , Grupos Raciais , Estudos Retrospectivos , Brancos , Negro ou Afro-Americano , Antirretrovirais/uso terapêutico
16.
J Clin Invest ; 133(18)2023 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-37432742

RESUMO

Asthma is a chronic inflammatory disease associated with episodic airway narrowing. Inhaled ß2-adrenergic receptor (ß2AR) agonists (ß2-agonists) promote - with limited efficacy - bronchodilation in asthma. All ß2-agonists are canonical orthosteric ligands that bind the same site as endogenous epinephrine. We recently isolated a ß2AR-selective positive allosteric modulator (PAM), compound-6 (Cmpd-6), which binds outside of the orthosteric site and modulates orthosteric ligand functions. With the emerging therapeutic potential of G-protein coupled receptor allosteric ligands, we investigated the impact of Cmpd-6 on ß2AR-mediated bronchoprotection. Consistent with our findings using human ß2ARs, Cmpd-6 allosterically potentiated ß2-agonist binding to guinea pig ß2ARs and downstream signaling of ß2ARs. In contrast, Cmpd-6 had no such effect on murine ß2ARs, which lack a crucial amino acid in the Cmpd-6 allosteric binding site. Importantly, Cmpd-6 enhanced ß2 agonist-mediated bronchoprotection against methacholine-induced bronchoconstriction in guinea pig lung slices, but - in line with the binding studies - not in mice. Moreover, Cmpd-6 robustly potentiated ß2 agonist-mediated bronchoprotection against allergen-induced airway constriction in lung slices obtained from a guinea pig model of allergic asthma. Cmpd-6 similarly enhanced ß2 agonist-mediated bronchoprotection against methacholine-induced bronchoconstriction in human lung slices. Our results highlight the potential of ß2AR-selective PAMs in the treatment of airway narrowing in asthma and other obstructive respiratory diseases.


Assuntos
Asma , Humanos , Camundongos , Animais , Cobaias , Cloreto de Metacolina/farmacologia , Cloreto de Metacolina/uso terapêutico , Ligantes , Asma/tratamento farmacológico , Asma/genética , Asma/complicações , Pulmão/metabolismo , Sítios de Ligação , Receptores Adrenérgicos beta 2/genética , Receptores Adrenérgicos beta 2/metabolismo
17.
Front Health Serv ; 2: 960427, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36925860

RESUMO

Background: The efficiency of the patient care process of short-term medical service trips is often not assessed. The Gregory School of Pharmacy has organized annual medical camps in rural Uganda, however, the paper health records used for documentation and communication between stations have shown several limitations that hinder an optimal patient care process. Therefore, our objective was to implement an electronic health record system in these medical camps to improve the workflow and optimize the patient care process. Methods: An electronic health record system that functioned over a battery-operated local area network was developed and implemented. Patient health information was entered and reviewed at the different stations using mobile devices. The impact of electronic health records (used in 2019) on the patient care process was assessed using the number of patients served per physician per hour and the number of prescriptions filled per hour and comparing these to paper records (used in 2017). Results: Electronic health records were successfully implemented and communication across stations was fluid, thus improving transitions. Importantly, 45% more patients were served per physician per hour and 38% more prescriptions were dispensed per hour when using electronic (2019) compared to paper records (2017), despite having a smaller team in 2019. Conclusion: Implementation of electronic health records in rural Uganda improved the patient care process and the efficiency of the medical camp.

18.
J Cell Mol Med ; 15(7): 1551-63, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20716113

RESUMO

Dysfunctional regulation of airway smooth muscle tone is a feature of obstructive airway diseases such as asthma and chronic obstructive pulmonary disease. Airway smooth muscle contraction is directly associated with changes in the phosphorylation of myosin light chain (MLC), which is increased by Rho and decreased by Rac. Although cyclic adenosine monophosphate (cAMP)-elevating agents are believed to relieve bronchoconstriction mainly via activation of protein kinase A (PKA), here we addressed the role of the novel cAMP-mediated exchange protein Epac in the regulation of airway smooth muscle tone. Isometric tension measurements showed that specific activation of Epac led to relaxation of guinea pig tracheal preparations pre-contracted with methacholine, independently of PKA. In airway smooth muscle cells, Epac activation reduced methacholine-induced MLC phosphorylation. Moreover, when Epac was stimulated, we observed a decreased methacholine-induced RhoA activation, measured by both stress fibre formation and pull-down assay whereas the same Epac activation prevented methacholine-induced Rac1 inhibition measured by pull-down assay. Epac-driven inhibition of both methacholine-induced muscle contraction by Toxin B-1470, and MLC phosphorylation by the Rac1-inhibitor NSC23766, were significantly attenuated, confirming the importance of Rac1 in Epac-mediated relaxation. Importantly, human airway smooth muscle tissue also expresses Epac, and Epac activation both relaxed pre-contracted human tracheal preparations and decreased MLC phosphorylation. Collectively, we show that activation of Epac relaxes airway smooth muscle by decreasing MLC phosphorylation by skewing the balance of RhoA/Rac1 activation towards Rac1. Therefore, activation of Epac may have therapeutical potential in the treatment of obstructive airway diseases.


Assuntos
Fatores de Troca do Nucleotídeo Guanina/metabolismo , Relaxamento Muscular/fisiologia , Músculo Liso/fisiologia , Traqueia/anatomia & histologia , Animais , Moléculas de Adesão Celular/metabolismo , Células Cultivadas , AMP Cíclico/análogos & derivados , AMP Cíclico/metabolismo , Fatores de Troca do Nucleotídeo Guanina/genética , Cobaias , Humanos , Isoproterenol/farmacologia , Masculino , Proteínas dos Microfilamentos/metabolismo , Músculo Liso/citologia , Músculo Liso/efeitos dos fármacos , Miócitos de Músculo Liso/efeitos dos fármacos , Miócitos de Músculo Liso/fisiologia , Cadeias Leves de Miosina/metabolismo , Fosfoproteínas/metabolismo , Proteínas rac1 de Ligação ao GTP/metabolismo , Proteína rhoA de Ligação ao GTP/metabolismo
19.
Org Biomol Chem ; 9(6): 1817-22, 2011 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-21267493

RESUMO

Isothiazolones and 5-chloroisothiazolones react chemoselectively with thiols by cleavage of the weak nitrogen-sulfur bond to form disulfides. They show selectivity for inhibition of the thiol-dependent cysteine protease cathepsin B and the histone acetyltransferase p300/CBP associated factor (PCAF) based on their substitution pattern. Furthermore, enzyme kinetics and mass spectroscopy indicate covalent binding of a 5-chloroisothiazolone to cathepsin B, which demonstrates their potential utility as probes for activity-based protein profiling.


Assuntos
Catepsina B/antagonistas & inibidores , Inibidores Enzimáticos/síntese química , Inibidores de Proteases/síntese química , Compostos de Sulfidrila/química , Tiazóis/síntese química , Fatores de Transcrição de p300-CBP/antagonistas & inibidores , Inibidores Enzimáticos/farmacologia , Concentração Inibidora 50 , Cinética , Modelos Moleculares , Estrutura Molecular , Inibidores de Proteases/farmacologia , Tiazóis/farmacologia
20.
Curr Pharm Teach Learn ; 13(9): 1160-1167, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34330394

RESUMO

INTRODUCTION: Pharmacy programs employ a variety of remediation methods intended to bring underperforming students to a level of competency. Our objective was to evaluate pharmacy students' perceptions of eligibility criteria and academic outcomes of remediation and potential predictors for lack of success in the original and remediated course. METHODS: Palm Beach Atlantic University School of Pharmacy revised its remediation policy in fall 2017, shifting from a course-centric to student-centric policy. Pharmacy students (N = 265) were surveyed in spring 2019 regarding eligibility criteria and academic outcomes of remediation. Enrolled students who remediated under the revised policy were surveyed on the lack of success in the original course and the remediation process. RESULTS: Students viewed remediation as an opportunity to prevent delayed graduation. They agreed with the revised, student-centric eligibility criteria and with the new approach allowing all courses to be remediated. First-year students provided lower scores, whereas students who never failed a course gave higher scores. Students agreed that remediation produces proficient students who are as competent as those who passed the original course. The main reason for failing the original course was lack of study time. Students who failed remediation tended to spend more time on external activities and used less remediation resources. CONCLUSIONS: A student-centric approach to remediation with active involvement from students and faculty support was successful in producing students who are viewed just as proficient and competent as students who passed the original course. Predictors for success were study time and the use of remediation resources.


Assuntos
Educação em Farmácia , Estudantes de Farmácia , Logro , Avaliação Educacional , Humanos , Percepção
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