Glucocorticoid and developmental regulation of amylase mRNAs in mouse liver cells.
We characterized alpha-amylase expression in the hepatoma cell line Hepa 1-6 and in normal mouse liver. Both Amy-1 and Amy-2 were expressed in Hepa 1-6 and were regulated by glucocorticoids. Transcription in the hepatoma cells was initiated at the same start sites as in mouse tissues. Glucocorticoid treatment increased the abundance of Amy-1 and Amy-2 transcripts by 10 to 20-fold. This increase was detected within 4 h and was maximal by 24 h. The pattern of amylase expression in this hepatoma cell line accurately reflects amylase expression in the liver in vivo. During liver development, we observed a large increase in the abundance of Amy-1 transcripts just before birth, at a time when circulating glucocorticoids are also elevated. Adult mouse liver expressed Amy-1 and Amy-2 at levels comparable to those of fully induced hepatoma cells. Liver is thus a likely source of both amylase isozymes in mouse serum. These studies demonstrate that Amy-2 expression is not limited to the pancreas but also occurs at a low level in liver cells.
Samuelson
L C
LC
Department of Human Genetics, University of Michigan Medical School, Ann Arbor, 48109-0618.
Keller
P R
PR
Darlington
G J
GJ
Meisler
M H
MH
D000681:Amylases / Q000096:biosynthesis / Q000235:genetics*; D000818:Animals; D002478:Cells, Cultured; D003907:Dexamethasone / Q000494:pharmacology*; D005786:Gene Expression Regulation; D005796:Genes; D007527:Isoenzymes / Q000096:biosynthesis / Q000235:genetics; D008099:Liver / Q000201:enzymology*; D008114:Liver Neoplasms, Experimental / Q000201:enzymology / Q000235:genetics*; D051379:Mice; D009928:Organ Specificity; D010179:Pancreas / Q000201:enzymology; D012333:RNA, Messenger / Q000187:drug effects / Q000235:genetics*; D012016:Reference Values; D014158:Transcription, Genetic / Q000187:drug effects*
D007527:Isoenzymes; D012333:RNA, Messenger; D003907:Dexamethasone; D000681:Amylases