The findings, in the November issue of Cell Metabolism, a Cell Press publication, suggest a new target for the treatment of insulin resistance and type 2 diabetes, the researchers say.
"The current study sheds light on a previously underexplored function of the liver; the liver participates in the pathogenesis of insulin resistance through hormone secretion," said Hirofumi Misu of Kanazawa University Graduate School of Medical Science in Japan.
The researchers had discovered earlier that genes encoding secretory proteins are abundantly expressed in the livers of people with type 2 diabetes. On the basis of those findings, Misu and colleagues began to suspect that, similar to the role of fat tissue, the liver might contribute to the development of type 2 diabetes and insulin resistance via secretory proteins they call "hepatokines."
Now, the researchers report the results of comprehensive gene expression analyses, revealing that the liver expresses higher levels of the gene encoding selenoprotein P (SeP) in people with type 2 diabetes who are more insulin resistant. Blood levels of SeP are also increased in people with diabetes compared to healthy people.