Abstract: TH-PO1065
Pharmacologically Stimulating Nitric Oxide-Soluble Guanylate Cyclase Signalling to Prevent Podocyte Injury
Session Information
- Glomerular Diseases: Podocyte Biology - I
November 07, 2019 | Location: Exhibit Hall, Walter E. Washington Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Glomerular Diseases
- 1204 Podocyte Biology
Authors
- 't Hart, Daan C., RIMLS, Radboud University Medical Centre,, Nijmegen, Netherlands
- Van der vlag, Johan, RIMLS, Radboud University Medical Centre,, Nijmegen, Netherlands
- Nijenhuis, Tom, RIMLS, Radboud University Medical Centre,, Nijmegen, Netherlands
Background
The effects of nitric oxide (NO) on podocytes are not known. We hypothesize that NO production by glomerular endothelial cells (GEnC) acts on podocytes as a protective paracrine factor in the glomerulus, thereby preventing podocyte injury. We propose a mechanism in which NO-mediated soluble guanylyl cyclase (sGC) activation results in enhanced cGMP synthesis and reduced expression/activity of the Ca2+-permeable Transient Receptor Potential Channel 6 (TRPC6), thereby inhibiting deleterious podocyte signalling processes. Several market approved drugs for non-renal disorders act on sGC. We aim to investigate glomerular NO-sGC signalling and the potential of repurposing sGC activators to prevent podocyte injury.
Methods
In vitro experiments were performed using conditionally immortalized GEnC and podocytes. NO production was visualized using the NO sensitive dye DAF-FM diacetate. Podocyte injury was induced with 0.25µg/mL adriamycin for 24hrs, with or without co-exposure of NO-donor SNAP (200µM) or sGC activators Cinaciguat (2µM) and Riociguat (20µM).
Results
Two forms of nitric oxide synthases (NOS; i.e. iNOS and eNOS) were expressed by GEnC and podocytes, whereas both cell types produced NO. GEnC particularly produced NO under (physiological) flow conditions. Interestingly, neuronal NOS (nNOS) was solely expressed by podocytes when injury was induced. All sGC subunits were expressed by podocytes. Stimulation of sGC via either SNAP or Riociguat elevated cGMP production in podocytes. Importantly, SNAP, Cinaciguat and Riociguat all reduced adriamycin-induced TRPC6 overexpression in human podocytes. No additional reduction of adriamycin-induced TRPC6 overexpression was observed when SNAP was co-administered with either Riociguat or Cinaciguat.
Conclusion
Our data supports the hypothesis of a paracrine NOS-NO-sGC axis between GEnC and podocytes. Moreover, sGC stimulation via SNAP or through repurposing drugs that activate sGC exert a protective effect on podocytes. Glomerular NO production might therefore play an important role in preserving the integrity of the glomerular filtration barrier. When experimental animal models for glomerular disease will confirm our in vitro findings, we will design clinical studies to evaluate the therapeutic effect of sGC activators to treat glomerular diseases.
Funding
- Government Support - Non-U.S.