Pharmacological modulation of cGMP levels by phosphodiesterase 5 inhibitors as a therapeutic strategy for treatment of respiratory pathology in cystic fibrosis

JF Poschet, GS Timmins… - … of Physiology-Lung …, 2007 - journals.physiology.org
JF Poschet, GS Timmins, JL Taylor-Cousar, W Ornatowski, J Fazio, E Perkett, KR Wilson…
American Journal of Physiology-Lung Cellular and Molecular …, 2007journals.physiology.org
The CFTR gene encodes a chloride channel with pleiotropic effects on cell physiology and
metabolism. Here, we show that increasing cGMP levels to inhibit epithelial Na+ channel in
cystic fibrosis (CF) respiratory epithelial cells corrects several aspects of the downstream
pathology in CF. Cell culture models, using a range of CF cell lines and primary cells,
showed that complementary pharmacological approaches to increasing intracellular cGMP,
by elevating guanyl cyclase activity though reduced nitric oxide, addition of cell-permeable …
The CFTR gene encodes a chloride channel with pleiotropic effects on cell physiology and metabolism. Here, we show that increasing cGMP levels to inhibit epithelial Na+ channel in cystic fibrosis (CF) respiratory epithelial cells corrects several aspects of the downstream pathology in CF. Cell culture models, using a range of CF cell lines and primary cells, showed that complementary pharmacological approaches to increasing intracellular cGMP, by elevating guanyl cyclase activity though reduced nitric oxide, addition of cell-permeable cGMP analogs, or inhibition of phosphodiesterase 5 corrected multiple aspects of the CF pathological cascade. These included correction of defective protein glycosylation, bacterial adherence, and proinflammatory responses. Furthermore, pharmacological inhibition of phosphodiesterase 5 in tissues ex vivo or in animal models improved transepithelial currents across nasal mucosae from transgenic F508del Cftrtm1Eur mice and reduced neutrophil infiltration on bacterial aerosol challenge in Pseudomonas aeruginosa-susceptible DBA/2 mice. Our findings define phosphodiesterase 5 as a specific target for correcting a number of previously disconnected defects in the CF respiratory tract, now linked through this study. Our study suggests that phosphodiesterase 5 inhibition provides an opportunity for simultaneous and concerted correction of seemingly disparate complications in CF.
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