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Dipalmitoyl‐Phosphatidylcholine Biosynthesis is Induced by Non‐Injurious Mechanical Stretch in a Model of Alveolar Type II Cells
Author(s) -
Pantazi Despoina,
Kitsiouli Eirini,
Karkabounas Athanasios,
Trangas Theoni,
Nakos George,
Lekka Marilena E.
Publication year - 2013
Publication title -
lipids
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.601
H-Index - 120
eISSN - 1558-9307
pISSN - 0024-4201
DOI - 10.1007/s11745-013-3800-8
Subject(s) - phosphatidylcholine , dipalmitoylphosphatidylcholine , phospholipid , chemistry , biosynthesis , biochemistry , sphingomyelin , a549 cell , phospholipase a2 , microbiology and biotechnology , biophysics , biology , enzyme , cell , membrane
Dipalmitoylphosphatidylcholine, (DP‐PtdCho), the major phospholipid component of lung surfactant is biosynthesized via a de novo pathway, the last step of which is catalyzed by CDP‐choline:cholinephosphotransferase (CPT) and two remodeling steps: a deacylation and a reacylation one, catalyzed by an acidic, Ca 2+ ‐independent phospholipase A 2 ( ai PLA 2 ) and a lyso‐phosphatidylcholine acyltransferase (LPCAT), respectively. The aim of our study was to investigate whether a low magnitude, non‐injurious static mode of mechanical stretch can induce phosphatidylcholine (PtdCho) biosynthesis and its remodeling to DP‐PtdCho in the A549 cell‐line, a model of alveolar type II cells. The deformation of A549 cells did not cause any release of lactate dehydrogenase, or phospholipids into the cell culture supernatants. An increase in PtdCho levels was observed after 1 h of static stretching, especially among the DP‐PtdCho molecular species, as indicated by targeted lipidomics approach and site‐directed fatty acyl‐chain analysis. Moreover, although sphingomyelin (CerPCho) levels were unaffected, the DP‐PtdCho/CerPCho ratio increased. Induction was observed in CPT, LPCAT and ai PLA 2 enzymatic activities and gene expression. Finally, incubation of the cells with MJ33 suppressed ai PLA 2 activity and DP‐PtdCho production. Our data suggest that mild static mechanical stretch can promote the biosynthesis of PtdCho and its remodeling to DP‐PtdCho in lung epithelial cells. Thus, low magnitude stretch could contribute to protective mechanisms rather than to injurious ones.