Lipopolysaccharide-induced pulmonary endothelial barrier disruption and lung edema: critical role for bicarbonate stimulation of AC10
| Autor: | Kevin Putinta, Jordan Nickols, Sarah Sayner, Sarah Schilling, K. C. Ramila, Boniface Obiako |
|---|---|
| Rok vydání: | 2015 |
| Předmět: |
Pulmonary and Respiratory Medicine
Lipopolysaccharides Male medicine.medical_specialty Lipopolysaccharide Physiology Bicarbonate Vascular permeability Pulmonary Edema Biology Capillary Permeability Rats Sprague-Dawley chemistry.chemical_compound Cytosol Physiology (medical) Internal medicine Sepsis medicine Extracellular Cyclic AMP Animals Protein Isoforms education Lung education.field_of_study Respiratory Distress Syndrome Cell Membrane Endothelial Cells Cell Biology Soluble adenylyl cyclase Pulmonary edema medicine.disease Bicarbonates Endocrinology medicine.anatomical_structure Biochemistry chemistry Call for Papers Endothelium Vascular Intracellular Adenylyl Cyclases |
| Zdroj: | American journal of physiology. Lung cellular and molecular physiology. 309(12) |
| ISSN: | 1522-1504 |
| Popis: | Bacteria-induced sepsis is a common cause of pulmonary endothelial barrier dysfunction and can progress toward acute respiratory distress syndrome. Elevations in intracellular cAMP tightly regulate pulmonary endothelial barrier integrity; however, cAMP signals are highly compartmentalized: whether cAMP is barrier-protective or -disruptive depends on the compartment (plasma membrane or cytosol, respectively) in which the signal is generated. The mammalian soluble adenylyl cyclase isoform 10 (AC10) is uniquely stimulated by bicarbonate and is expressed in pulmonary microvascular endothelial cells (PMVECs). Elevated extracellular bicarbonate increases cAMP in PMVECs to disrupt the endothelial barrier and increase the filtration coefficient ( Kf) in the isolated lung. We tested the hypothesis that sepsis-induced endothelial barrier disruption and increased permeability are dependent on extracellular bicarbonate and activation of AC10. Our findings reveal that LPS-induced endothelial barrier disruption is dependent on extracellular bicarbonate: LPS-induced barrier failure and increased permeability are exacerbated in elevated bicarbonate compared with low extracellular bicarbonate. The AC10 inhibitor KH7 attenuated the bicarbonate-dependent LPS-induced barrier disruption. In the isolated lung, LPS failed to increase Kf in the presence of minimal perfusate bicarbonate. An increase in perfusate bicarbonate to the physiological range (24 mM) revealed the LPS-induced increase in Kf, which was attenuated by KH7. Furthermore, in PMVECs treated with LPS for 6 h, there was a dose-dependent increase in AC10 expression. Thus these findings reveal that LPS-induced pulmonary endothelial barrier failure requires bicarbonate activation of AC10. |
| Databáze: | OpenAIRE |
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