The elongated PAP II/Reg III mRNA is upregulated in rat pancreas during acute experimental pancreatitis.

Abstract

The pathogenesis and the mechanism of the development of severe acute pancreatitis are not clearly understood. We performed differential display analysis to find genes that show transcriptional changes in the pancreas during the development of severe acute pancreatitis in the rat. Twenty candidate pancreatitis-associated complementary DNA (cDNA) fragments were isolated. cDNA sequencing and subsequent database analysis revealed that one fragment (C18-2) among the 20 cDNA fragments showed no significant sequence similarity to previously reported genes, suggesting that it represented a novel gene. The rapid and high expression of C18-2 during the acute phase of pancreatitis suggested that the gene was involved in the development of acute pancreatitis. Therefore, we used rapid amplification of cDNA ends and identified the full-length cDNA. Analysis of the open reading frame of the cDNA indicated that the deduced protein from the messenger RNA (mRNA) was a polypeptide of 174 amino acids, unexpectedly similar to that of a known gene, rat pancreatitis-associated protein II/regenerating gene III (PAP II/Reg III). However, the length of the identified mRNA (1,467 base pairs) was longer than that of rat PAP II mRNA (885 base pairs), because the elongated mRNA was generated through the different polyadenylation site in the same gene. The elongated mRNA after acute pancreatitis was strongly induced in the restricted early phase, in comparison with the original mRNA. It is considered that the elongated mRNA affects the function of PAP II/Reg III protein because the elongated mRNA with long 3; untranslated regions is known to be involved in the translation efficiency. The identified mRNA may play an important role in the progression of pancreatitis.