TY - JOUR
T1 - Lamellar bodies of cultured human fetal lung
T2 - Content of surfactant protein A (SP-A), surface film formation and structural transformation in vitro
AU - Froh, Deborah
AU - Ballard, Philip L.
AU - Williams, Mary C.
AU - Gonzales, John
AU - Goerke, Jon
AU - Odom, Michael W.
AU - Gonzales, Linda W.
N1 - Funding Information:
The authors thank Robert Ertsey, Madeleine Huey, and Lennell Allen for their technical assistance, and Patricia Weinmann and Jan Alfstad for their assistance in manuscript preparation. This work was supported by NIH grants HL07842 (D.F.), HL24075, and HL27356. M.W.O. was supported by a grant from the California Lung Association.
PY - 1990/4/9
Y1 - 1990/4/9
N2 - Lamellar bodies were isolated from dexamethasone and T3-treated explant cultures of human fetal lung, using sucrose density-gradient centrifugation. We examined their content of surfactant apoprotein A (SP-A), and their ability to form surface films and to undergo structural transformation in vitro. SP-A measured by ELISA composed less than 2% of total protein within lamellar bodies; this represented, as a minimum estimate, a 2-12-food enrichment over homogenate. One- and two-dimensional gel electrophoresis also suggested that SP-A was a minor protein component of lamellar bodies. Adsorption of lamellar bodies to an air/water interface was moderately rapid, but accelerated dramatically upon addition of exogenous SP-A in ratios of 1:2-16 (SP-A: phospholipid, w/w). Similar adsorption patterns were seen for lamellar bodies from fresh adult rat and rabbit lung. Lamellar bodies incubated under conditions that promote formation of tubular myelin underwent structural rearrangement only in the presence of exogenous SP-A, with extensive formation of multiamellate whorls of lipid bilayers (but no classical tubular myelin lattices). We conclude that lamellar bodies are enriched in SP-A, but have insufficient content of SP-A for structural transformation to tubular myelin and rapid surface film formation in vitro.
AB - Lamellar bodies were isolated from dexamethasone and T3-treated explant cultures of human fetal lung, using sucrose density-gradient centrifugation. We examined their content of surfactant apoprotein A (SP-A), and their ability to form surface films and to undergo structural transformation in vitro. SP-A measured by ELISA composed less than 2% of total protein within lamellar bodies; this represented, as a minimum estimate, a 2-12-food enrichment over homogenate. One- and two-dimensional gel electrophoresis also suggested that SP-A was a minor protein component of lamellar bodies. Adsorption of lamellar bodies to an air/water interface was moderately rapid, but accelerated dramatically upon addition of exogenous SP-A in ratios of 1:2-16 (SP-A: phospholipid, w/w). Similar adsorption patterns were seen for lamellar bodies from fresh adult rat and rabbit lung. Lamellar bodies incubated under conditions that promote formation of tubular myelin underwent structural rearrangement only in the presence of exogenous SP-A, with extensive formation of multiamellate whorls of lipid bilayers (but no classical tubular myelin lattices). We conclude that lamellar bodies are enriched in SP-A, but have insufficient content of SP-A for structural transformation to tubular myelin and rapid surface film formation in vitro.
KW - (Human fetal lung)
KW - Lamellar body
KW - Pulmonary surfactant
KW - Tubular myelin
UR - http://www.scopus.com/inward/record.url?scp=0025267692&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0025267692&partnerID=8YFLogxK
U2 - 10.1016/0167-4889(90)90060-Q
DO - 10.1016/0167-4889(90)90060-Q
M3 - Article
C2 - 2322594
AN - SCOPUS:0025267692
VL - 1052
SP - 78
EP - 89
JO - Biochimica et Biophysica Acta - Molecular Cell Research
JF - Biochimica et Biophysica Acta - Molecular Cell Research
SN - 0167-4889
IS - 1
ER -