title: Reorganization of cytoskeleton during surfactant secretion in lung type II cells: a role of annexin II.
abstract: The secretion of lung surfactant requires the movement of lamellar bodies to the plasma membrane through cytoskeletal barrier at the cell cortex. We hypothesized that the cortical cytoskeleton undergoes a transient disassembly/reassembly in the stimulated type II cells, therefore allowing lamellar bodies access to the plasma membrane. Stabilization of cytoskeleton with Jasplakinolinde (JAS), a cell permeable actin microfilament stabilizer, caused a dose-dependent inhibition of lung surfactant secretion stimulated by terbutaline. This inhibition was also observed in ATP-, phorbol 12-myristate 13-acetate (PMA)- or Ca(2+) ionophore A23187-stimulated surfactant secretion. Stimulation of type II cells with terbutaline exhibited a transient disassembly of filamentous actin (F-actin) as determined by staining with Oregon Green 488 Phalloidin. The protein kinase A inhibitor, H89, abolished the terbutaline-induced F-actin disassembly. Western blot analysis using anti-actin and anti-annexin II antibodies showed a transient increase of G-actin and annexin II in the Triton X-100 soluble fraction of terbutaline-stimulated type II cells. Furthermore, introduction of exogenous annexin II tetramer (AIIt) into permeabilized type II cells caused a disruption in the cortical actin. Treatment of type II cells with N-ethylmaleimide (NEM) resulted in a disruption of the cortical actin. NEM also inhibited annexin II's abilities to bundle F-actin. The results suggest that cytoskeleton undergoes reorganization in the stimulated type II cells, and annexin II tetramer plays a role in this process.
authors: Department of Physiological Sciences, Oklahoma State University, Stillwater, OK 74078, USA.
authors: Taran K
authors: TK
authors: Singh
authors: Barack
authors: B
authors: Abonyo
authors: Telugu A
authors: TA
authors: Narasaraju
authors: Lin
authors: L
authors: Liu
mesh_terms: D000199:Actins / Q000187:drug effects / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism / Q000494:pharmacology; D000818:Animals; D017306:Annexin A2 / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D002478:Cells, Cultured; D054746:Cyclic AMP-Dependent Protein Kinase Type II; D017868:Cyclic AMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D003599:Cytoskeleton / Q000187:drug effects / Q000378:metabolism*; D047630:Depsipeptides; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005089:Exocytosis / Q000187:drug effects / Q000502:physiology*; D007476:Ionophores / Q000494:pharmacology; D008168:Lung / Q000166:cytology / Q000378:metabolism*; D008297:Male; D015388:Organelles / Q000187:drug effects / Q000378:metabolism; D010456:Peptides, Cyclic / Q000494:pharmacology; D011663:Pulmonary Surfactants / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D020545:Respiratory Mucosa / Q000187:drug effects / Q000378:metabolism*; D013726:Terbutaline / Q000494:pharmacology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
chemical_list: D000199:Actins; D017306:Annexin A2; D047630:Depsipeptides; D004791:Enzyme Inhibitors; D007476:Ionophores; D010456:Peptides, Cyclic; D011663:Pulmonary Surfactants; C057531:jasplakinolide; D000255:Adenosine Triphosphate; D054746:Cyclic AMP-Dependent Protein Kinase Type II; D017868:Cyclic AMP-Dependent Protein Kinases; D013726:Terbutaline; D013755:Tetradecanoylphorbol Acetate