Endothelial Cell-Specific Molecule-1 Inhibits Albuminuria in Diabetic Mice

Diabetic kidney disease (DKD) is the most common cause of kidney failure in the world, and novel predictive biomarkers and molecular mechanisms of disease are needed. Endothelial cell-specific molecule-1 (Esm-1) is a secreted proteoglycan that attenuates inflammation. We previously identified that a glomerular deficiency of Esm-1 associates with more pronounced albuminuria and glomerular inflammation in DKD-susceptible relative to DKD-resistant mice, but its contribution to DKD remains unexplored. In this study, we show that lower circulating Esm-1 predicts progressive stages of albuminuria in patients with diabetes. In DKD-susceptible mice, Esm-1 inversely correlates with albuminuria and glomerular leukocyte infiltration. Using hydrodynamic tail-vein injection, we show that over-expression of either mouse or human Esm-1 reduces diabetes-induced albuminuria relative to saline-injected controls independent of leukocyte infiltration. Using a complementary approach, we find that constitutive deletion of Esm-1 in DKD-resistant mice increases the degree of diabetes-induced albuminuria versus wild-type controls. Mechanistically, over-expression of Esm-1 attenuates diabetes-induced podocyte injury. By glomerular RNAseq, we identify that Esm-1 attenuates diabetes-induced up-regulation of interferon-stimulated genes, and Esm-1 inhibits expression of kidney disease-promoting and interferon-related genes, including Ackr2 and Cxcl11. In conclusion, we demonstrate that Esm-1 protects against diabetes-induced albuminuria, and podocytopathy, possibly through select interferon signaling.