Endocan removal during continuous renal replacement therapy: does it affect the reliability of this biomarker?

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

Background

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.

Methods

Using hydrodynamic tail-vein injection, we overexpress Esm-1 in DKD-susceptible DBA/2 mice and delete Esm-1 in DKD-resistant C57BL/6 mice to study the contribution of Esm-1 to DKD. We analyze clinical indices of DKD, leukocyte infiltration, podocytopenia, and extracellular matrix production. We also study transcriptomic changes to assess potential mechanisms of Esm-1 in glomeruli.

Results

In DKD-susceptible mice, Esm-1 inversely correlates with albuminuria and glomerular leukocyte infiltration. We show that overexpression of Esm-1 reduces albuminuria and diabetes-induced podocyte injury, independent of changes in leukocyte infiltration. Using a complementary approach, we find that constitutive deletion of Esm-1 in DKD-resistant mice modestly increases the degree of diabetes-induced albuminuria versus wild-type controls. By glomerular RNAseq, we identify that Esm-1 attenuates expression of kidney disease-promoting and interferon (IFN)-related genes, including Ackr2 and Cxcl11.

Conclusions

We demonstrate that, in DKD-susceptible mice, Esm-1 protects against diabetes-induced albuminuria and podocytopathy, possibly through select IFN signaling. Companion studies in patients with diabetes suggest a role of Esm-1 in human DKD.