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Role of SphK1/S1P/Spns2/S1P 1 signaling in HGF‐mediated lamellipodia formation and migration of human lung endothelial cells
Author(s) -
Fu Panfeng,
Usatyuk Peter,
Ebenezer David,
Natarajan Viswanathan
Publication year - 2015
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.29.1_supplement.863.6
Subject(s) - lamellipodium , sphingosine kinase 1 , microbiology and biotechnology , chemistry , cell migration , cortactin , phosphorylation , sphingosine , biology , sphingosine 1 phosphate , cell , receptor , biochemistry , cytoskeleton
We have demonstrated earlier that HGF‐induced lamellipodia formation in human lung microvascular endothelial cells (HLMVECs) was through c‐Met receptor tyrosine kinase and PI3 kinase/Akt signal transduction. Here, we show that HGF‐mediated lamellipodia formation is dependent on intracellular S1P generation via sphingosine kinase 1 (SphK1) and transport of S1P to outside the cell by S1P transporter, Spns2. HGF stimulated phosphorylation of SphK1, and its localization in lamellipodia of HLMVECs. Down‐regulation of SphK1, but not SphK2, with siRNA or inhibition of SphK1 with PF‐543 attenuated HGF‐induced lamellipodia formation in HLMVECs. The HGF‐mediated phosphorylation of SphK1 and its localization in lamellipodia was dependent on ERK1/2 activation. HGF increased S1P levels in HLMVECs, which was blocked by inhibition of SphK1. Further, the HGF‐induced lamellipodia formation in HLMVECs was blocked by down‐regulation of Spns2, suggesting extracellular action of S1P in lamellipodia formation. Down‐regulation of S1P 1, but not S1P 2 or S1P 3, with siRNA attenuated HGF‐induced lamellipodia formation. HGF stimulation enhanced association of Spns2 with S1P 1 and blocking SphK1 activty with PF‐543 reduced the association between S1P 1 and Spns2. Additionally, HGF‐induced migration of HLMVECs was attenuated by down‐regulation of SphK1, Spns2 and S1P 1. These results suggest that HGF/c‐Met mediated lamellipodia formation and motility is dependent on intracellular generation of S1P via activation and localization of SphK1 to cell periphery and Spns2 mediated transport of S1P to signal via S1P 1 . This work was supported by NIH/HLBI P01 HL98050 to VN.