Schwann cell survival mediated by the signaling phospholipid lysophosphatidic acid

JA Weiner, J Chun - … of the National Academy of Sciences, 1999 - National Acad Sciences
Proceedings of the National Academy of Sciences, 1999National Acad Sciences
Lysophosphatidic acid (LPA) is a bioactive phospholipid with properties of an extracellular
growth factor for many cell lines, including those derived from neuroblastomas. However, the
relevance of LPA signaling to the normal, developing nervous system is unknown, in part
reflecting the previous unavailability of cloned receptor genes. Recent studies of the first
such gene, encoding the G protein-coupled receptor LPA1/VZG-1 (lysophospholipid
receptor A1/ventricular zone gene-1), revealed a major locus of expression in …
Lysophosphatidic acid (LPA) is a bioactive phospholipid with properties of an extracellular growth factor for many cell lines, including those derived from neuroblastomas. However, the relevance of LPA signaling to the normal, developing nervous system is unknown, in part reflecting the previous unavailability of cloned receptor genes. Recent studies of the first such gene, encoding the G protein-coupled receptor LPA1/VZG-1 (lysophospholipid receptor A1/ventricular zone gene-1), revealed a major locus of expression in oligodendrocytes and Schwann cells (SCs) during development, suggesting an influence of LPA on these myelinating cells. Here we report that LPA (≥10 nM) is a potent survival factor for cultured neonatal SCs, with survival activity equaling the maximal effect of neuregulin, the major peptide SC survival factor. LPA activates a pharmacologically defined signaling pathway in SCs, involving Gi and phosphoinositide 3-kinase. Moreover, LPA’s effect depends on Akt, a downstream kinase that can mediate phosphoinositide 3-kinase-dependent survival, as demonstrated by both Western blot and transfection analyses. Overexpression of functional epitope-tagged LPA1/VZG-1 protein decreases SC apoptosis in response to serum withdrawal. These data demonstrate a role for extracellular LPA and its receptor LPA1/VZG-1 in SC survival and, more broadly, implicate G protein-coupled receptor-mediated lysophospholipid signaling as a significant mechanism in neural development.
National Acad Sciences