Abstract: TH-PO1121
Exosome-Based LNA-Anti-miR-21 Delivery Enables Functional miR-21 Inhibition in Podocytes
Session Information
- Bioengineering: Emerging Research
October 22, 2026 | Location: Exhibit Hall A, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Bioengineering
- 400 Bioengineering
Authors
- Lange, Tim, University Medicine Greifswald, Institute of Anatomy and Cell Biology, Greifswald, Mecklenburg-Vorpommern, Germany
- Soh, Joanne Ern Chi, University Medicine Greifswald, Institute of Anatomy and Cell Biology, Greifswald, Mecklenburg-Vorpommern, Germany
- Friedrich, Lea-Katharina, University Medicine Greifswald, Institute of Anatomy and Cell Biology, Greifswald, Mecklenburg-Vorpommern, Germany
- Götsch, Paul Luca, University Medicine Greifswald, Institute of Anatomy and Cell Biology, Greifswald, Mecklenburg-Vorpommern, Germany
- Weber, Claudia, University Medicine Greifswald, Institute of Anatomy and Cell Biology, Greifswald, Mecklenburg-Vorpommern, Germany
- Biedenweg, Doreen, University of Greifswald, Institute for Physics, Greifswald, Mecklenburg-Vorpommern, Germany
- Schlueter, Rabea, University of Greifswald, Imaging Center of the Department of Biology, Greifswald, Mecklenburg-Vorpommern, Germany
- Janke, Una, University of Greifswald, Institute of Biochemistry, Greifswald, Mecklenburg Vorpommern, Germany
- Delcea, Mihaela, University of Greifswald, Institute of Biochemistry, Greifswald, Mecklenburg Vorpommern, Germany
- Endlich, Nicole, University Medicine Greifswald, Institute of Anatomy and Cell Biology, Greifswald, Mecklenburg-Vorpommern, Germany
Background
Podocyte injury and loss are central drivers of chronic kidney disease (CKD) and involved in the majority of glomerular diseases. MicroRNA-21 (miR-21) is consistently upregulated during glomerular injury and suppresses protective targets including PTEN. Although anti-miR-21 approaches show high preclinical efficacy, clinical translation remains challenging, potentially due to limited podocyte target engagement. We investigated whether exosome-mediated delivery of miR-21 inhibitors improves intracellular uptake and functional miR-21 inhibition in podocytes.
Methods
Exosomes were isolated from immortalized murine podocytes and directly loaded with fluorescently-labeled LNA-anti-miR-21 and anti-miR-Ctrl. Exosome integrity was assessed by transmission electron microscopy, dynamic light scattering, and Western blot for CD9 and TSG101. Uptake efficiency and intracellular delivery were analyzed by confocal laser-scanning microscopy, time-series imaging and flow cytometry. Functional efficacy was evaluated by RT-qPCR and PTEN protein expression in differentiated SVI podocytes, primary murine podocytes and PAN-injured primary glomeruli.
Results
Exosome number, morphology and marker expression remained unchanged after direct LNA-anti-miR-21 and anti-miR-Ctrl loading. Time-series imaging demonstrated progressive intracellular accumulation of exosome-delivered LNA-anti-miR-21 and anti-miR-Ctrl cargo from 2 to 48 h, whereas free LNA showed no detectable uptake. Flow cytometry confirmed efficient intracellular delivery (76.6%) exclusively via exosomes. Exosomal LNA delivery induced robust, sequence-specific miR-21 suppression: 804-fold in immortalized podocytes, 33-fold in primary podocytes, and 36-fold in PAN-injured glomeruli. In contrast, free LNA achieved no significant suppression in any model. Restoration of PTEN protein expression was observed only after exosomal LNA delivery and was confirmed by Western blot and immunofluorescence. Scrambled controls confirmed sequence specificity throughout.
Conclusion
Taken together, these findings demonstrate that exosome-mediated LNA delivery overcomes the limited uptake of free inhibitor oligonucleotides in podocytes and enables functional inhibition of miR-21 across multiple experimental systems. These data provide mechanistic proof-of-principle for exosome-based LNA-anti-miR delivery as a potential strategy to improve podocyte-targeted therapies in CKD.
Funding
- Government Support – Non-U.S.