Lysophosphatidic acid stimulates astrocyte proliferation through LPA1.
Lysophosphatidic acid (LPA) is an extracellular lipid mediator that regulates nervous system development and functions through multiple types of LPA receptors. Here we explore the role of LPA receptor subtypes in cortical astrocyte functions. Astrocytes cultured under serum-free conditions were found to express the genes of five LPA receptor subtypes, lpa1 to lpa5. When astrocytes were treated with dibutyryl cyclic adenosine monophosphate, a reagent inducing astrocyte differentiation or activation, lpa1 expression levels remained unchanged, but those of other LPA receptor subtypes were relatively reduced. LPA stimulated DNA synthesis in both undifferentiated and differentiated astrocytes, but failed to do so in astrocytes prepared from mice lacking lpa1 gene. LPA also inhibited [3H]-glutamate uptake in both undifferentiated and differentiated astrocytes; and LPA-induced inhibition of glutamate uptake was still observed in lpa1-deficient astrocytes. Taken together, these observations demonstrate that LPA1 mediates LPA-induced stimulation of cell proliferation but not inhibition of glutamate uptake in astrocytes.
Shano
Shinya
S
Division of Molecular Neurobiology, Department of Life Sciences, School of Science and Engineering, Kinki University, Kowakae 3-4-1, Higashiosaka 577-8502, Japan.
Moriyama
Ryutaro
R
Chun
Jerold
J
Fukushima
Nobuyuki
N
D000818:Animals; D001253:Astrocytes / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D001483:Base Sequence; D049109:Cell Proliferation / Q000187:drug effects*; D017931:DNA Primers; D005260:Female; D018698:Glutamic Acid / Q000378:metabolism; D006801:Humans; D008246:Lysophospholipids / Q000494:pharmacology*; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D020133:Reverse Transcriptase Polymerase Chain Reaction
D017931:DNA Primers; D008246:Lysophospholipids; D018698:Glutamic Acid; C032881:lysophosphatidic acid
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