GDF15
Growth/differentiation factor 15 was first identified as Macrophage inhibitory cytokine-1 or MIC-1.
It is a protein belonging to the transforming growth factor beta superfamily. Under normal conditions, GDF-15 is expressed in low concentrations in most organs and upregulated because of injury of organs such as such as liver, kidney, heart and lung.
The function of GDF-15 is not fully cleared but it seems to have a role in regulating inflammatory pathways and to be involved in regulating apoptosis, cell repair and cell growth, which are biological processes observed in cardiovascular and neoplastic disorders. GDF-15 has shown to be a strong prognostic protein in patients with different diseases such as heart diseases and cancer.
Metformin was shown to cause increased levels of GDF-15. This increase mediates the effect of body weight loss by metformin.