Transcriptome Analysis of the Duodenum, Pancreas, Liver, and Muscle from Diabetic Goto-Kakizaki Rats Fed a Trypsin Inhibitor Derived from Squid Viscera

Trypsin inhibitors (TIs) have various nutritional effects.
However,
a detailed mechanism for their effects, especially on the gene expression
patterns in various tissues, remains unknown. Here, we used transcriptome
techniques and gene ontology (GO) analysis to examine the effects
of squid TI (sqTI), a biochemically stable peptide, on diabetic Goto-Kakizaki
rats after feeding for 10 weeks. We demonstrated that downregulation
of SREBP1c in the liver via duodenal/pancreatic hormones suppresses
the blood cholesterol level. Consistently, in GO analysis, the term
“cholesterol biosynthetic process” was enriched among
downregulated genes. No hypoglycemic or insulinotropic effects were
observed, in contrast to the results from our previous studies (single
stimulation with the same dose of TI), which can be partly ascribed
to the inactive responses of the duodenum and pancreas in this condition.