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Gene expression of N ‐acetylglucosaminyltransferases III and V: A possible implication for liver regeneration
Author(s) -
Miyoshi Elji,
Ihara Yoshito,
Nishikawa Atsushi,
Saito Hiroyuki,
Uozumi Naofumi,
Hayashi Norio,
Fusamoto Hideyuki,
Kamada Takenobu,
Taniguchi Naoyuki
Publication year - 1995
Publication title -
hepatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.488
H-Index - 361
eISSN - 1527-3350
pISSN - 0270-9139
DOI - 10.1002/hep.1840220634
Subject(s) - liver regeneration , hepatocyte , collagenase , biology , regeneration (biology) , gene expression , glycosyltransferase , messenger rna , microbiology and biotechnology , gene , enzyme , biochemistry , in vitro
Abstract N ‐acetylglucosaminyltransferases III and V (GnT‐III and ‐V) are key enzymes in the synthesis of the branches of asparagine‐linked oligosaccharides. Although their messenger RNAs (mRNAs) are expressed in various rat tissues, they are not detected in normal rat liver. Expression of the GnT‐III and ‐V mRNAs, however, increased in regenerating liver after two‐thirds partial hepatectomy compared with sham‐operated rats. The enzymatic activities of GnT‐III and ‐V increased in proportion to mRNA expression. To determine which type of cells in the liver have high activities of these glycosyltransfersses, hepatocytes and nonparenchymal cells were separated by means of a two‐step collagenase perfusion technique. GnT‐III activity was only detected in nonparenchymal cells of normal rat liver. However, during liver regeneration, GnT‐III activity increased and thus was also detectable in hepatocytes. GnT‐V activity was detected in both types of cells. These data were supported by reverse transcription–polymerase chain reaction results. Although the mechanism underlying the induction of these glycosyltransferases is unknown, lectin blot analysis showed that oligosaccharides in many glycoproteins, including hepatocyte growth factor, a major growth factor associated with liver regeneration, were newly synthesized during liver regeneration. This is the first report on the expression of glycosyltransferases during liver regeneration and suggests that there are different mechanisms involved in regulation of the genes of GnT‐III and‐V during liver regeneration. (Hepatology 1995; 22:1847‐1855).