Abstract 929 Circulating microRNA-122-5p is associated with a lack of improvement in left-ventricular function after TAVR and regulates viability of cardiomyocytes via extracellular vesicles

Background: Transcatheter aortic valve replacement (TAVR) is a well-established treatment option for high- and intermediate-risk patients with severe symptomatic aortic valve stenosis (AVS). A majority of patients exhibit improvements in left ventricular ejection fraction following TAVR in response to TAVR-associated afterload reduction. However, a specific role for circulating microRNAs in the improvement of cardiac function for patients after TAVR has not yet been investigated. Herein, we profiled the differential expression of miRNAs in circulating extracellular vesicles in patients after TAVR and, in particular, the novel role of circulating miR-122-5p in cardiomyocytes.

Methods: Circulating EV-associated miRNAs were investigated by using an unbiased Taqman-based human miR array. Several EV-miRNAs (miR-122-5p, miR-26a, miR-192, miR-483-5p, miR-720, miR-885-5p, and miR-1274) were significantly deregulated in AVS patients at day seven after TAVR in comparison to the pre-procedural levels in patients without LVEF-improvement. The higher levels of miR-122-5p were negatively correlated with LVEF improvement at both day seven (r=-0.264 and p=0.015) and at six months (r=-0.328 and p=0.0018) after TAVR.

Results: By utilization of patient-derived samples and a murine AVS model, we observed that the expression of miR-122-5p correlates negatively with cardiac function, which is associated with LVEF. Graded wire-injury-induced AVS mice demonstrated a higher level of miR-122-5p, which was related to cardiomyocytes dysfunction. Murine ex vivo experiments revealed that miR-122-5p is highly enriched in endothelial cells in comparison to cardiomyocytes. Co-culture experiments, copy-number analysis, fluorescence microscopy with Cy3-labeled miR-122-5p demonstrated that miR-122-5p can be shuttled via large EVs from endothelial cells into cardiomyocytes. Gain- and loss-of-function experiments suggested that EV-mediated shuttling of miR-122-5p increases the level of miR-122-5p in recipient cardiomyocytes. Mechanistically, mass spectrometry, miR-pull down, EMSA, and RNA-IP experiments confirmed that miR-122-5p interacts with the RBP, hnRNPU, in a sequence-specific manner to encapsulate miR-122-5p into large EVs. Upon shuttling, miR-122-5p reduces the expression of the anti-apoptotic gene BCL2, by binding to its 3' untranslated region to inhibit its translation, and thereby decreasing the viability of target cardiomyocytes.

Conclusion: Increased levels of circulating pro-apoptotic EV-incorporated miR-122-5p are associated with reduced LVEF after TAVR. Extracellular vesicular shuttling of miR-122-5p regulates the viability and apoptosis of cardiomyocytes in a BCL2-dependent manner.

Keywords: Transcatheter aortic valve replacement, extracellular vesicles, cardiomyocytes, endothelial cells, microRNAs, cardiovascular disease.

Clin Res Cardiol (2023). https://doi.org/10.1007/s00392-023-02180-w
Circulating microRNA-122-5p is associated with a lack of improvement in left-ventricular function after TAVR and regulates viability of cardiomyocytes via extracellular vesicles
M. R. Hosen¹, P. R. Goody¹, A. Zietzer¹, S. T. Niepmann¹, A. Sedaghat¹, V. Tiyerili², J.-M. Sinning³, S. Zimmer¹, S. Uchida⁴, J. B. Moore IV⁵, R. Boon⁶, R. Chennupati⁷, E. Latz⁸, N. Werner⁹, F. Jansen¹, G. Nickenig¹
¹Medizinische Klinik und Poliklinik II, Universitätsklinikum Bonn, Bonn; ²Klinik für Innere Medizin I, Kath. St. Paulus Gesellschaft, Dortmund; ³Innere Medizin III - Kardiologie, St. Vinzenz-Hospital, Köln; ⁴Department of Clinical Medicine, Center for RNA Medicine, Copenhagen, DK; ⁵Diabetes and Obesity Center, University of Louisville, Louisville, US; ⁶Department of Physiology, VU University Medical Cente, Amsterdam, NL; ⁷Pulmonology and Vascular Medicine, Medical Faculty, University Hospital Düsseldorf, Division of Cardiology, Düsseldorf; ⁸Institute of Innate Immunity, University Hospital Bonn, University of Bonn, Bonn; ⁹Innere Medizin III, Krankenhaus der Barmherzigen Brüder Trier, Trier;
Background: Transcatheter aortic valve replacement (TAVR) is a well-established treatment option for high- and intermediate-risk patients with severe symptomatic aortic valve stenosis (AVS). A majority of patients exhibit improvements in left ventricular ejection fraction following TAVR in response to TAVR-associated afterload reduction. However, a specific role for circulating microRNAs in the improvement of cardiac function for patients after TAVR has not yet been investigated. Herein, we profiled the differential expression of miRNAs in circulating extracellular vesicles in patients after TAVR and, in particular, the novel role of circulating miR-122-5p in cardiomyocytes. Methods: Circulating EV-associated miRNAs were investigated by using an unbiased Taqman-based human miR array. Several EV-miRNAs (miR-122-5p, miR-26a, miR-192, miR-483-5p, miR-720, miR-885-5p, and miR-1274) were significantly deregulated in AVS patients at day seven after TAVR in comparison to the pre-procedural levels in patients without LVEF-improvement. The higher levels of miR-122-5p were negatively correlated with LVEF improvement at both day seven (r=-0.264 and p=0.015) and at six months (r=-0.328 and p=0.0018) after TAVR. Results: By utilization of patient-derived samples and a murine AVS model, we observed that the expression of miR-122-5p correlates negatively with cardiac function, which is associated with LVEF. Graded wire-injury-induced AVS mice demonstrated a higher level of miR-122-5p, which was related to cardiomyocytes dysfunction. Murine ex vivo experiments revealed that miR-122-5p is highly enriched in endothelial cells in comparison to cardiomyocytes. Co-culture experiments, copy-number analysis, fluorescence microscopy with Cy3-labeled miR-122-5p demonstrated that miR-122-5p can be shuttled via large EVs from endothelial cells into cardiomyocytes. Gain- and loss-of-function experiments suggested that EV-mediated shuttling of miR-122-5p increases the level of miR-122-5p in recipient cardiomyocytes. Mechanistically, mass spectrometry, miR-pull down, EMSA, and RNA-IP experiments confirmed that miR-122-5p interacts with the RBP, hnRNPU, in a sequence-specific manner to encapsulate miR-122-5p into large EVs. Upon shuttling, miR-122-5p reduces the expression of the anti-apoptotic gene BCL2, by binding to its 3' untranslated region to inhibit its translation, and thereby decreasing the viability of target cardiomyocytes. Conclusion: Increased levels of circulating pro-apoptotic EV-incorporated miR-122-5p are associated with reduced LVEF after TAVR. Extracellular vesicular shuttling of miR-122-5p regulates the viability and apoptosis of cardiomyocytes in a BCL2-dependent manner. Keywords: Transcatheter aortic valve replacement, extracellular vesicles, cardiomyocytes, endothelial cells, microRNAs, cardiovascular disease.
https://dgk.org/kongress_programme/jt2023/aP1321.html