Activation of nucleolar DNA expression in hepatocytes by glucocorticoids and high density lipoproteins.
A novel mechanism of protein biosynthesis regulation in liver under the action of reduced forms of steroid hormones (tetrahydrocortisol) and apolipoprotein A-I (apoA-I) is presented. Kupffer cells play an important role in uptake of the cortisol and high density lipoproteins (HDL) as well as in formation of the active complex, tetrahydrocortisol+apolipoprotein A-I (THC-apoA-I). If macrophages are stimulated by lipopolysaccharides (LPS), these processes enhance dramatically, thus causing parallel activation of nucleolar DNA expression and ribosome formation in hepatocytes. THC-apoA-I complex accelerates protein biosynthesis in primary cultures of hepatocytes, but not in macrophages and endotheliocytes.
Siberian Division of the Russian Academy of Medical Sciences, Institute of Biochemistry, Novosibirsk, Russia. ibch@cyber.ma.nsc.ru
Lev E
LE
Panin
Valery F
VF
Maksimov
Ivan F
IF
Usynin
Irina M
IM
Korostyshevskaya
D000818:Animals; D002466:Cell Nucleolus / Q000187:drug effects* / Q000235:genetics; D004247:DNA / Q000235:genetics*; D005938:Glucocorticoids / Q000494:pharmacology*; D022781:Hepatocytes / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure; D008075:Lipoproteins, HDL / Q000494:pharmacology*; D008854:Microscopy, Electron; D051381:Rats; D017208:Rats, Wistar
D005938:Glucocorticoids; D008075:Lipoproteins, HDL; D004247:DNA