Effects of c-fos antisense oligodeoxynucleotide on 5-HT-induced upregulation of preprodynorphin, preproenkephalin, and glutamic acid decarboxylase mRNA expression in cultured rat spinal dorsal horn neurons.
Effects of c-fos antisense oligodeoxynucleotide (ASO) on serotonin (5-HT)-induced upregulation of preprodynorphin (ppDyn), preproenkephalin (ppEnk), and glutamic acid decarboxylase (GAD), a special chemical marker for gamma-aminobutyric acid (GABA) neurons, mRNAs in cultured spinal dorsal horn neurons were investigated in order to extend our understanding of expressions of opioid peptides and GABA in spinal cord regulated by the descending serotonergic efferents. Reverse transcription-polymerase chain reaction analysis revealed a time-course increase in the expression of mRNAs encoding c-fos, ppDyn, ppEnk, and GAD after administration of 5-HT (100 nM). Administration of c-fos ASO (0.02 nM) 30 min prior to 5-HT application markedly blocked the expression of c-fos gene. Moreover, c-fos ASO pretreatment significantly decreased the 5-HT-induced upregulation of ppDyn and ppEnk mRNAs, but failed to affect the expression level of GAD mRNA. These results suggest that the serotoningic raphe-spinal efferents might play an important role in regulating the synthesis of enkephalin, dynorphin, and GABA in the spinal dorsal horn neurons. The immediate early oncogene c-fos might be involved in the 5-HT-induced increase in ppDyn and ppEnk expression. However, under the present experimental conditions, c-fos does not seem to be associated with the upregulation of GAD mRNA induced by 5-HT.
Wang
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Department of Anatomy and K.K. Leung Brain Research Centre, The Fourth Military Medical University, Xi'an 710032, People's Republic of China.
Wu
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SX
Liu
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XY
Wang
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W
Li
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YQ
D000818:Animals; D002478:Cells, Cultured; D004399:Dynorphins / Q000096:biosynthesis* / Q000235:genetics; D004745:Enkephalins / Q000096:biosynthesis* / Q000235:genetics; D005786:Gene Expression Regulation; D005968:Glutamate Decarboxylase / Q000096:biosynthesis* / Q000235:genetics; D020319:Oligodeoxyribonucleotides, Antisense / Q000494:pharmacology*; D020671:Posterior Horn Cells / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D011498:Protein Precursors / Q000096:biosynthesis* / Q000235:genetics; D016760:Proto-Oncogene Proteins c-fos / Q000037:antagonists & inhibitors* / Q000096:biosynthesis / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D017208:Rats, Wistar; D012701:Serotonin / Q000494:pharmacology*; D012702:Serotonin Antagonists / Q000494:pharmacology; D015854:Up-Regulation
D004745:Enkephalins; D020319:Oligodeoxyribonucleotides, Antisense; D011498:Protein Precursors; D016760:Proto-Oncogene Proteins c-fos; D012333:RNA, Messenger; D012702:Serotonin Antagonists; C036448:pre-prodynorphin; D012701:Serotonin; D004399:Dynorphins; C033660:preproenkephalin; D005968:Glutamate Decarboxylase