Cell cycle-dependent interleukin 1 gene expression by cultured glomerular mesangial cells.
Glomerular mesangial cell (MC)--derived IL-1 may be an important factor in the development of the hypercellularity and sclerosis characteristic of many forms of glomerulonephritis. To define the regulation of IL-1 synthesis by human MC, Northern blot analyses were performed using specific probes for monocytic IL-1 alpha and beta mRNA. Proliferating MC expressed mRNA for both IL-1 alpha and beta, whereas nonproliferating MC contained no detectable IL-1 mRNA. Synchronized MC expressed IL-1 alpha and beta mRNA within 2 h of stimulation with serum. This serum effect could be reproduced with platelet-derived growth factor and epidermal growth factor. Immune precipitations of 35S-methionine-labeled cells indicate that the mesangial IL-1 is synthesized as a 33-kD precursor protein with a pI of 7.2. Extracellular mesangial IL-1 has a pI of 7.0 and molecular weight of 17 kD, consistent with its identification as IL-1 beta. Cellular proliferation in glomerular disease may be driven in part by peptide growth factor-mediated induction of mesangial IL-1 gene expression and protein synthesis.
Lovett
D H
DH
Medical Service, Veterans Administration Medical Center, San Francisco, CA 94121.
Larsen
A
A
D002453:Cell Cycle / Q000187:drug effects; D002478:Cells, Cultured; D005109:Extracellular Matrix / Q000648:ultrastructure; D005786:Gene Expression Regulation / Q000187:drug effects; D005920:Glomerular Mesangium / Q000378:metabolism* / Q000648:ultrastructure; D006133:Growth Substances / Q000494:pharmacology; D006801:Humans; D007375:Interleukin-1 / Q000096:biosynthesis / Q000235:genetics* / Q000502:physiology; D007399:Interphase / Q000187:drug effects; D007700:Kinetics; D012333:RNA, Messenger / Q000378:metabolism
D006133:Growth Substances; D007375:Interleukin-1; D012333:RNA, Messenger