Regulation of kappa-opioid receptor mRNA level by cyclic AMP and growth factors in cultured rat glial cells.
The mRNA of the kappa-opioid receptor (KOR) has been found recently in cultured astrocytes and in microglia. By using RT-PCR and Southern hybridization, we confirmed these observations and, in addition, we observed that KOR mRNA was expressed in oligodendrocytes and in the precursors of astrocytes and oligodendrocytes. KOR mRNA level was the highest in the immature astrocytes and decreased with their maturation. Very few data are available on the regulation of KOR level by extracellular signals. Therefore, we examined the effect of three growth factors known to be present in the adult brain, basic fibroblast growth factor (bFGF), platelet-derived growth factor (PDGF-BB) and leukemia inhibitory factor (LIF) and of two cyclic AMP (cAMP) generating systems, the cAMP analog, 8-(4-chlorophenylthio)-cAMP and forskolin, on this level. It was found that in astrocytes, KOR mRNA level decreased dramatically under the effect of cAMP and less under the effect of bFGF while it did not change significantly after LIF treatment. In oligodendrocytes, it also decreased with cAMP, but increased under the effect of bFGF and PDGF-BB. In microglia, a decrease was observed with cAMP and lipopolysaccharides (LPS), the most used activators of macrophages. These results shed new evidence on the expression of opioid receptor mRNA in the glial cells of the rat CNS. The regulation of KOR mRNA level under the effect of extracellular signals suggests that opioids take part in dynamic processes in glial cells, possibly related to glial-neuron communication.
Tryoen-Toth
P
P
Laboratoire de neurobiologie du Développement et de la Régénération, UPR 132 CNRS, Strasbourg, France.
Gavériaux-Ruff
C
C
Maderspach
K
K
Labourdette
G
G
D000818:Animals; D000831:Animals, Newborn; D001253:Astrocytes / Q000187:drug effects / Q000378:metabolism; D000077214:Becaplermin; D015139:Blotting, Southern; D001921:Brain / Q000166:cytology; D002450:Cell Communication; D002478:Cells, Cultured; D005576:Colforsin / Q000494:pharmacology; D000242:Cyclic AMP / Q000031:analogs & derivatives / Q000494:pharmacology / Q000502:physiology*; D016222:Fibroblast Growth Factor 2 / Q000494:pharmacology*; D005786:Gene Expression Regulation / Q000187:drug effects*; D006131:Growth Inhibitors / Q000494:pharmacology*; D015850:Interleukin-6; D053605:Leukemia Inhibitory Factor; D008070:Lipopolysaccharides / Q000494:pharmacology; D008222:Lymphokines / Q000494:pharmacology*; D017628:Microglia / Q000187:drug effects / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000096:biosynthesis / Q000235:genetics*; D009457:Neuroglia / Q000187:drug effects* / Q000378:metabolism; D009836:Oligodendroglia / Q000187:drug effects / Q000378:metabolism; D018847:Opioid Peptides / Q000502:physiology; D010982:Platelet-Derived Growth Factor / Q000494:pharmacology*; D016133:Polymerase Chain Reaction; D020574:Proto-Oncogene Proteins c-sis; D012333:RNA, Messenger / Q000096:biosynthesis* / Q000235:genetics; D051381:Rats; D017208:Rats, Wistar; D017473:Receptors, Opioid, kappa / Q000096:biosynthesis / Q000235:genetics*; D013234:Stem Cells / Q000187:drug effects / Q000378:metabolism; D013873:Thionucleotides / Q000494:pharmacology
D006131:Growth Inhibitors; D015850:Interleukin-6; D053605:Leukemia Inhibitory Factor; D008070:Lipopolysaccharides; D008222:Lymphokines; D009419:Nerve Tissue Proteins; D018847:Opioid Peptides; D010982:Platelet-Derived Growth Factor; D020574:Proto-Oncogene Proteins c-sis; D012333:RNA, Messenger; D017473:Receptors, Opioid, kappa; D013873:Thionucleotides; D016222:Fibroblast Growth Factor 2; D000077214:Becaplermin; D005576:Colforsin; C015929:8-((4-chlorophenyl)thio)cyclic-3',5'-AMP; D000242:Cyclic AMP