(484.11) A Novel Approach to Assess Podocyte Damage at Single Cell Level

Poster Board Number: A23

He Chen (CECAD, University of Cologne), Tsimafei Padvitski (CECAD, University of Cologne), Cem Özel (CECAD, University of Cologne), Paul Brinkkötter (CECAD, University of Cologne), Thomas Benzing (CECAD, University of Cologne), Andreas Beyer (CECAD, University of Cologne), Martin Kann (CECAD, University of Cologne)

Diseases affecting podocytes in kidney glomeruli are heterogeneous with respect to triggers, molecular mechanisms, and speed of progression. Frequently, healthy and diseased podocytes are present in parallel. Single cell technology is ideally suited to capture such heterogeneity including temporal resolution, which can be achieved by trajectory analysis. However, trajectories require large numbers of cells, which are difficult to obtain for rare cell populations such as podocytes. Here, we propose a novel analysis approach for single-cell data in rare cell types, which relies on a podocyte disease score (PDS) to monitor the health status of individual cells. PDS is based on integrative meta-analysis of published and our own bulk and single-cell transcriptomic data of glomeruli and primary podocytes obtained from a multitude (n=37) of mouse models featuring podocyte damage. Among others, podocyte damage triggers integrated in the analysis include diabetes, ageing, mutations in slit diaphragm proteins, alterations of transcription factors, and adriamycin-induced podocytopathy. In a rank-based approach, a geneset was derived, whose expression quantitatively predicts podocyte damage irrespective of the trigger and at single-cell resolution. Our PDS is robust, correlates with albuminuria in mice and humans, and allows for aligning disease states across independent and novel datasets. Applying PDS to published and novel glomerular single-nucleus RNAseq data from mouse models recapitulated established molecular pathways relevant to the models, and identified common and model-specific pathways related to podocyte damage. As such, Eph-ephrin signaling was identified as a pathway that is universally altered upon podocyte damage at transcriptional level, and was confirmed by STED microscopy on the protein level in two mouse models. In conclusion, PDS is a valid and versatile method to assess podocyte damage at single-cell level and allows to characterize cellular processes in podocytes in mice and humans.

This study was supported by the German Research Foundation: clinical research unit (KFO 329, KA3217/5-2 to MK, BE2603/10-2 to AB, BR2955/8-1 to PB)