Cloning of rat interleukin-3 receptor beta-subunit from cultured microglia and its mRNA expression in vivo.
The high-affinity receptors for interleukin-3 (IL-3), GM-CSF, and IL-5 are composed of a ligand binding (alpha-) and a transducing (beta-) subunit. Two distinct transducing subunits (clones AIC2A and AIC2B) have been cloned from mouse, whereas in humans, only one (common) beta-subunit (beta c) has been found. A PCR-based cloning strategy was used to obtain a full-length cDNA sequence from rat microglia including 5'-untranslated regions. Sequence analysis revealed a number of features indicative of the presence of only one beta-subunit in the rat. Most likely, the new rIL-3R beta cDNA is the rat equivalent of human respective murine (AIC2B) beta c subunits. Regulation of rIL-3R beta mRNA expression was investigated in cultured microglia and in vivo. Purified microglia expressed significant amounts of rIL-3R beta mRNA. Addition of lipopolysaccharide (LPS) resulted in a marked upregulation of rIL-3R beta mRNA within approximately 4 hr. No downregulation was observed within 1 week's treatment. No rIL-3R beta mRNA was detectable in normal rat brain. However, 3 hr after a single injection of LPS into the tail vein of a rat, a marked induction of receptor mRNA occurred in a variety of brain regions. Transcriptional rates subsided significantly after 24 hr. rIL-3R beta mRNA was visualized by in situ hybridizations with cRNA antisense probes in ramified cells formerly characterized as microglial cells. rIL-3R beta mRNA was also induced in rat brain after occlusion of middle cerebral artery (MCAO).(ABSTRACT TRUNCATED AT 250 WORDS)
Appel
K
K
Department of Psychiatry, University of Freiburg Medical School, Germany.
Buttini
M
M
Sauter
A
A
Gebicke-Haerter
P J
PJ
D000595:Amino Acid Sequence; D000818:Animals; D001157:Arterial Occlusive Diseases / Q000378:metabolism; D001483:Base Sequence; D001921:Brain / Q000166:cytology / Q000378:metabolism; D002478:Cells, Cultured; D002536:Cerebral Arteries; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D008297:Male; D017628:Microglia / Q000378:metabolism*; D008969:Molecular Sequence Data; D015345:Oligonucleotide Probes / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism*; D051381:Rats; D011918:Rats, Inbred SHR; D017207:Rats, Sprague-Dawley; D016185:Receptors, Interleukin-3 / Q000235:genetics*; D011994:Recombinant Proteins
D018076:DNA, Complementary; D015345:Oligonucleotide Probes; D012333:RNA, Messenger; D016185:Receptors, Interleukin-3; D011994:Recombinant Proteins