Abstract 16951: Polycystic Kidney Disease Aortic Endothelial Cells Show an Abnormal Angiogenic Response to the Hedgehog Ligand
Introduction: Polycystic Kidney Disease (PKD), a common renal ciliopathy, is characterized by impaired vascular structure and function, prior to changes in blood pressure or renal function. The canonical Hedgehog (Hh) pathway is mainly ligand-activated at the primary cilium to regulate vascular development. In this study, we hypothesized that endothelial cells in autosomal recessive PKD (ARPKD) have an abnormal response to the activation of the Hh pathway, leading to impaired angiogenesis.
Methods: We isolated Aortic Endothelial Cells (AECs, n=4) from young (4-week old) wild type and Polycystic Kidney (PCK) rats carrying ARPKD. Using protein and mRNA expression analysis of known markers of angiogenic activity, we characterized the angiogenic function of these cells in starving conditions (1% FBS). Then, to study their ability to respond to Hh angiogenic stimuli, the cells were exposed to Sonic Hh (SHH) and the angiogenic markers were examined 24 hours post-treatment.
Results: Protein expression analysis of PCK-AECs revealed a significant endothelial dysfunction with reduced levels of the endothelial marker CD31 and the angiogenic receptor Neuropilin1 (Fig. 1A). Moreover, an increase in Angiopoietin1 mRNA expression (6.5 fold) with unchanged vascular endothelial growth factor (VEGF) further suggests a decompensation in vascular stability in PCK-AECs. In response to SHH, PCK-AECs, as opposed to wild type, displayed a significantly higher upregulation of the transcription factor Gli1, a known marker of Hh activity (Fig. 1B), with no activation of VEGFA and VEGF Receptor 2 (Fig. 1C).
Conclusions: Here we provide evidence that PKD-derived AECs exposed to SHH show an impaired expression of genes involved in angiogenic response. Understanding the biology of endothelial cells in PKD may provide insights on the involvement of Hh in PKD and allow optimization of therapies aimed at the reduction of vascular dysfunction in PKD.
Author Disclosures: F. Franchi: None. K.M. Peterson: None. E.J. Tolosa: None. P.C. Harris: None. M.E. Fernandez-Zapico: None. M.G. Rodriguez-Porcel: None.
- © 2016 by American Heart Association, Inc.