Regulation of alpha 2-macroglobulin gene expression by interleukin-6 (BSF-2/HSF).
In rat hepatocyte primary cultures recombinant human interleukin-6 (rhIL-6) induced alpha 2-macroglobulin (alpha 2M) synthesis 54-fold. Half-maximal induction was achieved at a rhIL-6 concentration of 30 pM. RhIL-1 beta led only to a 2-fold increase in alpha 2M synthesis, but strongly impaired the action of IL-6. Intraperitoneal injection of rhIL-6 into male rats resulted in a 19.7-fold increase of alpha 2M mRNA already after 4h. In contrast, alpha 2M mRNA levels (50-fold increase) were reached between 16 and 24 h after intramuscular injection of turpentine. Whereas turpentine-induced inflammation resulted in an increased alpha 2M synthesis in male and female rats, rhIL-6 injection had no effect in female rats. The increases after rhIL-6 administration in mRNA concentrations were followed by corresponding changes in alpha 2M levels in serum. By Northern analysis it was demonstrated that LPS-stimulated human monocytes synthesize IL-6 mRNA. The 5'-end of the rat alpha 2M gene has been isolated and the first 3 exons and 166 base pairs of the 5'-flanking region were identified by a combination of oligonucleotide hybridization and DNA sequencing. The transcriptional start site was determined by RNase protection as well as by primer extension experiments. 5'-CATAAAG-3' and 5'-TCAAAA-3' were found as TATA- and CAAT-box equivalent sequences, respectively. Furthermore, a potential glucocorticoid binding site (5'-TGTTCT-3') was localized on the antisense strand of the alpha 2M gene.
Andus
T
T
Biochemisches Institut, Universität Freiburg, F.R.G.
Geiger
T
T
Klapproth
J
J
Kunz
D
D
Heisig
M
M
Castell
J
J
Heinrich
P C
PC
D000818:Animals; D001483:Base Sequence; D002478:Cells, Cultured; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D066298:In Vitro Techniques; D015850:Interleukin-6 / Q000494:pharmacology*; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D008297:Male; D008969:Molecular Sequence Data; D009000:Monocytes / Q000187:drug effects / Q000378:metabolism; D012333:RNA, Messenger / Q000096:biosynthesis; D015183:Restriction Mapping; D000511:alpha-Macroglobulins / Q000096:biosynthesis / Q000235:genetics*
D015850:Interleukin-6; D012333:RNA, Messenger; D000511:alpha-Macroglobulins