Paxillin-associated focal adhesion involvement in perinatal pulmonary arterial remodelling.
Birth is followed by remodelling of the actin cytoskeleton of pulmonary arterial smooth muscle cells, then by extracellular matrix deposition. Hypothesising that the cell/matrix adhesions would also be remodelled, we investigated the expression, localisation and biochemical characteristics of the focal adhesion protein paxillin in vivo, in vessels from normal and pulmonary hypertensive neonatal piglets. Initially we showed that in intact porcine pulmonary arteries exposed to cytochalasin D there was a reduction filamentous actin accompanied by a reduction in paxillin-associated focal adhesions, similar to that seen in cultured pulmonary arterial smooth muscle cells. Vessels from normal and hypoxic animals were found to have two isoforms of paxillin, of 60 and 66 kDa with pI values of 6.7-4.2. Transient changes occurred during the first 14 days of life. Between birth and 6 days there was a reduction in the amount of both paxillin isoforms, a shift to more acidic pI values and an increase in paxillin phosphorylation. Simultaneously, immunostaining showed a transient reduction in paxillin expression, a change temporally and spatially associated with a previously demonstrated reduction in actin. Findings are consistent with an immediate postnatal spatial reorganisation of paxillin-associated focal adhesions. Paxillin content and remodelling was abnormal in pulmonary hypertensive arteries, the response varying according to postnatal age.
Diagne
Ibrahima
I
Vascular Biology & Pharmacology Unit, Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK.
Hall
Susan M
SM
Kogaki
Shigetoyo
S
Kielty
Cay M
CM
Haworth
Sheila G
SG
D000199:Actins / Q000502:physiology; D000375:Aging / Q000378:metabolism; D000818:Animals; D000831:Animals, Newborn / Q000378:metabolism*; D002478:Cells, Cultured; D002908:Chronic Disease; D003598:Cytoskeletal Proteins / Q000235:genetics / Q000378:metabolism*; D003599:Cytoskeleton / Q000502:physiology; D005333:Fetus / Q000378:metabolism*; D005455:Fluorescent Antibody Technique; D022001:Focal Adhesions / Q000502:physiology*; D000860:Hypoxia / Q000378:metabolism; D007150:Immunohistochemistry / Q000379:methods; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000378:metabolism / Q000502:physiology*; D032389:Myocytes, Smooth Muscle / Q000378:metabolism; D051419:Paxillin; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation; D011651:Pulmonary Artery / Q000166:cytology / Q000254:growth & development / Q000502:physiology*; D012333:RNA, Messenger / Q000378:metabolism; D013194:Staining and Labeling; D013552:Swine
D000199:Actins; D003598:Cytoskeletal Proteins; D051419:Paxillin; D010750:Phosphoproteins; D012333:RNA, Messenger