Low molecular weight heparin promotes the PPAR pathway by protecting the glycocalyx of cells to delay the progression of diabetic nephropathy

Abstract

Diabetic nephropathy (DN) is one of the most important comorbidities for diabetic patients, which is the main factor leading to end-stage renal disease. Heparin analogues can delay the progression of DN, but the mechanism is not fully understood. In this study, we found that low molecular weight heparin (LMWH) therapy significantly upregulated some downstream proteins of the peroxisome proliferator-activated receptor (PPAR) signaling pathway by label-free quantification of the mouse kidney proteome. Through cell model verification, LMWH can protect the heparan sulfate (HS) of renal tubular epithelial cells from being degraded by heparanase that is highly expressed in a high-glucose environment, enhance the endocytic recruitment of fatty acid-binding protein 1 (FABP1), a coactivator of the PPAR pathway, and then regulate the activation level of intracellular PPAR. In addition, we have elucidated for the first time the molecular mechanism of HS and FABP1 interaction. These findings provide new insights into understanding the role of heparin in the pathogenesis of DN and developing corresponding treatments.