Gene expression in regenerating liver in relation to cell proliferation and stress.
When hepatocyte proliferation is stimulated in the liver by partial hepatectomy, messenger RNAs coding for fibrinogen, actin, c-myc and topoisomerase I are rapidly accumulated. We distinguish an early phase of accumulation (0-3 h after partial hepatectomy) which is also observed after a sham operation for the four genes, and during inflammation produced by Freund's adjuvant in the case of fibrinogen and c-myc genes. The hepatic response to inflammation appears therefore to mimic events characteristic of the G0/G1 transition, such as the accumulation of the c-myc mRNA. The late phase of mRNA accumulation (beyond 3 h after partial hepatectomy) is typical of liver regeneration. The level of c-myc mRNA is transiently increased (20-fold over normal) 20 h after partial hepatectomy, that is, at the time of DNA synthesis. Topoisomerase-I mRNA level increases between 3 and 24 h after partial hepatectomy (5-10-fold over normal). These results suggest that accumulation of c-myc and topoisomerase-I mRNAs is associated with DNA replication in regenerating liver.
Sobczak
J
J
Laboratoire d'enzymologie des acides nucléiques, Unité associée 554 du Centre National de la Recherche Scientifique, Université Paris VI, France.
Tournier
M F
MF
Lotti
A M
AM
Duguet
M
M
D000199:Actins / Q000096:biosynthesis / Q000235:genetics; D000210:Acute-Phase Reaction / Q000378:metabolism*; D000418:Albumins / Q000096:biosynthesis / Q000235:genetics; D000818:Animals; D002455:Cell Division; D015342:DNA Probes; D004261:DNA Replication; D004264:DNA Topoisomerases, Type I / Q000235:genetics / Q000378:metabolism*; D005340:Fibrinogen / Q000096:biosynthesis / Q000235:genetics; D006498:Hepatectomy; D007249:Inflammation / Q000378:metabolism*; D008099:Liver / Q000201:enzymology / Q000378:metabolism*; D008115:Liver Regeneration; D008297:Male; D012333:RNA, Messenger / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D014158:Transcription, Genetic
D000199:Actins; D000418:Albumins; D015342:DNA Probes; D012333:RNA, Messenger; D005340:Fibrinogen; D004264:DNA Topoisomerases, Type I