Heparanase: another renal player controlled by vitamin D.

Vitamin D deficiency is inevitable in chronic kidney diseases. Clinical and experimental therapies with vitamin D supplements or analogues have demonstrated nephroprotective effects, which vitamin D exerts partly by controlling the renin-angiotensin-aldosterone system, but also by modulating other signalling pathways. In recent work published in the Journal of Pathology, Garsen and colleagues identified heparanase as a novel target of vitamin D and its antiproteinuric activity. Heparanase is an endoglycosidase with a role in remodelling the extracellular matrix through its ability to degrade heparan sulphate, and is involved in the pathogenesis of several proteinuric and fibrotic renal diseases. The new evidence that vitamin D inhibits heparanase expression sets the stage for a better understanding of the vitamin's kidney-protecting effects and its possible application to proteinuric and non-proteinuric chronic kidney diseases.