Adenoviral gene transfer of a mutant surfactant enzyme ameliorates pseudomonas-induced lung injury.
Surfactant deficiency is an important contributor to the acute respiratory distress syndrome, a disorder that commonly occurs after bacterial sepsis. CTP:phosphocholine cytidylyltransferase (CCTalpha) is the rate-limiting enzyme required for the biosynthesis of dipalmitoylphosphatidylcholine (DPPC), the major phospholipid of surfactant. In this study, a cDNA encoding a novel, calpain-resistant mutant CCTalpha enzyme was delivered intratracheally in mice using a replication-deficient adenovirus 5 CTP:phosphocholine cytidylyltransferase construct (Ad5-CCT(Penta)) in models of bacterial sepsis. Ad5-CCT(Penta) gene transfer produced high-level CCTalpha gene expression, increased alveolar surfactant (DPPC) levels and improved lung surface tension and pressure-volume relationships relative to control mice. Pseudomonas aeruginosa (PA103) decreased DPPC synthesis, in part, via calpain-mediated degradation of CCTalpha. Deleterious effects of Pseudomonas on surfactant were lessened after infection with a mutant strain lacking the type III exotoxin, Exo U. Replication-deficient adenovirus 5 CTP:phosphocholine cytidylyltransferase gene delivery improved lung biophysical properties by optimizing surface activity in this Pseudomonas model of proteinase-mediated lung injury. The studies are the first demonstration of in vivo gene transfer of a lipogenic enzyme resulting in improved lung mechanics. The studies suggest that augmentation of DPPC synthesis via gene delivery of CCTalpha can attenuate impaired lung function in surfactant-deficient states such as bacterial sepsis.
Zhou
J
J
Department of Internal Medicine, Pulmonary and Critical Care Division, Roy J and Lucille A Carver College of Medicine, The University of Iowa, Iowa City, IA 52242, USA.
Wu
Y
Y
Henderson
F
F
McCoy
D M
DM
Salome
R G
RG
McGowan
S E
SE
Mallampalli
R K
RK
D015060:1,2-Dipalmitoylphosphatidylcholine / Q000378:metabolism; D000208:Acute Disease; D000256:Adenoviridae / Q000235:genetics; D000818:Animals; D002135:Calcium-Binding Proteins / Q000235:genetics / Q000378:metabolism; D019916:Choline-Phosphate Cytidylyltransferase / Q000008:administration & dosage / Q000235:genetics*; D015316:Genetic Therapy / Q000379:methods*; D005822:Genetic Vectors / Q000008:administration & dosage / Q000235:genetics; D008168:Lung / Q000201:enzymology; D008171:Lung Diseases / Q000201:enzymology / Q000628:therapy*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D011552:Pseudomonas Infections / Q000201:enzymology / Q000628:therapy*; D011663:Pulmonary Surfactants / Q000008:administration & dosage*; D014161:Transduction, Genetic / Q000379:methods
D002135:Calcium-Binding Proteins; D011663:Pulmonary Surfactants; D015060:1,2-Dipalmitoylphosphatidylcholine; C033668:calpastatin; D019916:Choline-Phosphate Cytidylyltransferase