Pretreatment with cationic lipid-mediated transfer of the Na+K+-ATPase pump in a mouse model in vivo augments resolution of high permeability pulmonary oedema.
Resolution of pulmonary oedema is mediated by active absorption of liquid across the alveolar epithelium. A key component of this process is the sodium-potassium ATPase (Na+K+-ATPase) enzyme located on the basolateral surface of epithelial cells and up-regulated during oedema resolution. We hypothesised that lung liquid clearance could be further up-regulated by lipid-mediated transfer and expression of exogenous Na+K+-ATPase cDNA. We demonstrate proof of this principle in a model of high permeability pulmonary oedema induced by intraperitoneal injection of thiourea (2.5 mg/kg) in C57/BL6 mice. Pretreatment of mice (24 h before thiourea) by nasal sniffing of cationic liposome (lipid #67)-DNA complexes encoding the alpha and beta subunits of Na+K+-ATPase (160 microg per mouse), significantly (P<0.01) decreased the wet:dry weight ratios measured 2 h after thiourea injection compared with control animals, pretreated with an equivalent dose of an irrelevant gene. Whole lung Na+K+-ATPase activity was significantly (P<0.05) increased in mice pretreated with Na+K+-ATPase cDNA compared both with untreated control animals as well as animals pretreated with the irrelevant gene. Nested RT-PCR on whole lung homogenates confirmed gene transfer by detection of vector-specific mRNA in three of four mice studied 24 h after gene transfer. This demonstration of a significant reduction in pulmonary oedema following in vivo gene transfer raises the possibility of gene therapy as a novel, localised approach for pulmonary oedema in clinical settings such as ARDS and lung transplantation.
Stern
M
M
Department of Gene Therapy, Imperial College at the National Heart and Lung Institute, London, UK.
Ulrich
K
K
Robinson
C
C
Copeland
J
J
Griesenbach
U
U
Masse
C
C
Cheng
S
S
Munkonge
F
F
Geddes
D
D
Berthiaume
Y
Y
Alton
E
E
D000818:Animals; D002412:Cations; D015870:Gene Expression; D015316:Genetic Therapy / Q000379:methods*; D008081:Liposomes; D008168:Lung / Q000201:enzymology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D011654:Pulmonary Edema / Q000201:enzymology / Q000628:therapy*; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D000254:Sodium-Potassium-Exchanging ATPase / Q000235:genetics*; D014162:Transfection / Q000379:methods*
D002412:Cations; D008081:Liposomes; D000254:Sodium-Potassium-Exchanging ATPase