Lysophosphatidic acid modulates c-Met redistribution and hepatocyte growth factor/c-Met signaling in human bronchial epithelial cells through PKC delta and E-cadherin

Cell Signal. 2007 Nov;19(11):2329-38. doi: 10.1016/j.cellsig.2007.07.005. Epub 2007 Jul 13.

Abstract

Previously we demonstrated that ligation of lysophosphatidic acid (LPA) to G protein-coupled LPA receptors induces transactivation of receptor tyrosine kinases (RTKs), such as platelet-derived growth factor receptor beta (PDGF-Rbeta) and epidermal growth factor receptor (EGF-R), in primary cultures of human bronchial epithelial cells (HBEpCs). Here we examined the role of LPA on c-Met redistribution and modulation of hepatocyte growth factor (HGF)/c-Met pathways in HBEpCs. Treatment of HBEpCs with LPA-induced c-Met serine phosphorylation and redistribution to plasma membrane, while treatment with HGF-induced c-Met internalization. Pretreatment with LPA reversed HGF-induced c-Met internalization. Overexpression of dominant negative (Dn)-PKC delta or pretreatment with Rottlerin or Pertussis toxin (PTx) attenuated LPA-induced c-Met serine phosphorylation and redistribution. Co-immnuoprecipitation and immunocytochemistry showed that E-cadherin interacted with c-Met in HBEpCs. LPA treatment induced E-cadherin and c-Met complex redistribution to plasma membranes. Overexpression of Dn-PKC delta attenuated LPA-induced E-cadherin redistribution and E-cadherin siRNA attenuated LPA-induced c-Met redistribution to plasma membrane. Furthermore, pretreatment of LPA attenuated HGF-induced c-Met tyrosine phosphorylation and downstream signaling, such as Akt kinase phosphorylation and cell motility. These results demonstrate that LPA regulates c-Met function through PKC delta and E-cadherin in HBEpCs, suggesting an alternate function of the cross-talk between G-protein-coupled receptors (GPCRs) and RTKs in HBEpCs.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetophenones / pharmacology
  • Benzopyrans / pharmacology
  • Bronchi / cytology
  • Bronchi / drug effects
  • Bronchi / enzymology
  • Cadherins / metabolism*
  • Cell Movement / drug effects
  • Cells, Cultured
  • Endocytosis / drug effects
  • Epithelial Cells / cytology
  • Epithelial Cells / drug effects
  • Epithelial Cells / enzymology*
  • GTP-Binding Protein alpha Subunits, Gi-Go / metabolism
  • Hepatocyte Growth Factor / pharmacology*
  • Humans
  • Lysophospholipids / pharmacology*
  • Models, Biological
  • Phosphoserine / metabolism
  • Phosphotyrosine / metabolism
  • Protein Binding / drug effects
  • Protein Kinase C-delta / metabolism*
  • Protein Transport / drug effects
  • Proto-Oncogene Proteins c-met / metabolism*
  • RNA, Small Interfering / metabolism
  • Signal Transduction / drug effects*

Substances

  • Acetophenones
  • Benzopyrans
  • Cadherins
  • Lysophospholipids
  • RNA, Small Interfering
  • Phosphoserine
  • Phosphotyrosine
  • Hepatocyte Growth Factor
  • rottlerin
  • Proto-Oncogene Proteins c-met
  • Protein Kinase C-delta
  • GTP-Binding Protein alpha Subunits, Gi-Go
  • lysophosphatidic acid