The researchers were able to show for the first time how the protein molecule Wingless-type signaling pathway protein-1 (WISP1) directly impairs the insulin effect in muscle cells and in the liver and thus leads to insulin insensitivity.
The study shows that WISP1 cancels insulin-induced inhibition of glucose production (gluconeogesis) in murine hepatocytes and glycogen synthesis in human muscle cells. The synthesis quantity of the WISP1 protein correlates with the blood glucose levels in the oral glucose tolerance test (OGTT) and with the circulating level of heme oxygenase-1 (HO-1), an enzyme that promotes systemic inflammation, especially in obesity.
The researchers suspect that an increased production of WISP1 from the abdominal fat could be one of the reasons why overweight people often have a disturbed glucose metabolism.
Hörbelt, T., Tacke, C., Markova, M. et al. (2018): The novel adipokine WISP1 associates with insulin resistance and impairs insulin action in myotubes and hepatocytes. Diabetologia https://doi.org/10.1007/s00125-018-4636-9