Lysophospholipid Receptors Are Differentially Expressed in Rat Terminal Schwann Cells, As Revealed by a Single Cell RT-PCR and In Situ Hybridization

Terminal Schwann cells (TSCs) that cover motor neuron terminals, are known to play an important role in maintaining neuromuscular junctions, as well as in the repair process after nerve injury. However, the molecular characteristics of TSCs remain unknown, because of the difficulties in analyzing them due to their paucity. By using our previously reported method of selectively and efficiently collecting TSCs, we have analyzed the difference in expression patterns of lysophospholipid (LPL) receptor genes (LPA(1), LPA(2), LPA(3), S1P(1), S1P(2), S1P(3), S1P(4), and S1P(5)) between TSCs and myelinating Schwann cells (MSCs). LPL, which includes lysophosphatidic acid (LPA) and sphingosine 1-phosphate (S1P), is the bioactive lipid that induces a myriad of cellular responses through specific members of G-protein coupled receptors for LPA. It turned out that LPA(3) was expressed only in TSCs, whereas S1P(1) was expressed in TSCs and skeletal muscle, but not in MSCs. Other types of LPL receptor genes, including LPA(1), S1P(2), S1P(3), S1P(4), were expressed in both types of Schwann cells. None of the LPL receptor gene family showed MSCs-specific expression.