RNAse L and genome expression during early period of the rat liver regeneration

Abstract

Partial hepatectomy (PHE) stimulates an intact part of the liver to exchange the existing «quiescence» program for the proliferative one. Several changes between 0.5 and 3 h after PHE are considered as manifestations of the abolishment of «quiescence» program' a temporal decrease of either RNA synthesis or accumulation of the newly formed RNA; a restricted variability of RNA transcripts; a partial retention of newly synthesized RNA within the nuclei thereby providing less RNA for the cytoplasm; previously obtained data about transient dissociation of ribosomes from endoplasmic reticulum. An involvement of the 2' ,5'-oligo(A Synthetase-RNAse L system in the process is suggested by up-and down-regulation of 2',5'-oligo(A)synthetase activity in the cytoplasm and in the nucleus, respectively, and by up-regulation of RNAse L content in regenerating liver. The production of IFN alp, an inducer of the 2',5'-oligo(A Synthetase-RNAse L system, is also increased during transition period. A specific role of sinusoidal cells, the main producers of IFN alp in the liver, in the abolishment of the old program is strongly suggested.