PhD Scientific Days 2025

Pathological and Oncological Sciences I.

ECFC-Derived Extracellular Vesicles Attenuate Immune and Cardiac Impairment in a Model of Sepsis

Name of the presenter

Menna Luigi

Institute/workplace of the presenter

Semmelweis University

Authors

Luigi Menna¹, Nóra Fekete¹, Boglárka Nagy¹, Kristóf Csont¹, Zsófia Szász¹, Edit I. Buzás¹, Hargita Hegyesi¹

1: Semmelweis University

Text of the abstract

Introduction: Sepsis is a life-threatening condition that disrupts immune balance and impairs cardiac function, demanding therapies that target both systems. Endothelial colony-forming cells (ECFCs), a subset of progenitor cells with vascular regenerative potential, act through paracrine mechanisms—most notably by releasing extracellular vesicles (EVs) enriched with bioactive molecules involved in immune modulation and tissue repair.

Aims: We examined the impact of ECFC-derived sEVs on sepsis models both in vitro, using lipopolysaccharide-challenged neonatal cardiomyocytes, and in vivo, by evaluating immune responses in a murine model of sepsis.

Methods: ECFCs were isolated from the bone marrow of CDH5 Cre/mTmG mice and cultured to confluence. Large and small EVs were obtained from conditioned media and isolated by differential ultracentrifugation. ECFCs and EVs were characterized by flow cytometry, while sEVs were further analyzed using nanoparticle tracking analysis and transmission electron microscopy. For the in vitro model, neonatal cardiomyocytes were exposed to LPS and treated with ECFC-sEVs; after 24 hours, inflammatory gene expression (qPCR tests) and TNFα/troponin I levels (ELISA assays) were assessed. For the in vivo model, LPS-treated mice received ECFC-sEVs after 4 hours; blood samples collected at 6 and 24 hours were analysed for immune cell populations and endothelial EVs by flow cytometry.

Results: ECFCs expressed endothelial markers (CD31, CD34, VCAM), and their EVs carried CD31 and CD63. LPS induced strong inflammatory responses, with increased inflammatory gene and protein expression. ECFC-sEV treatment significantly reduced pro-inflammatory mediators, including CCL-2, and decreased Troponin I levels. In vivo, LPS caused a marked drop in circulating immune cells, which was partially or fully reversed by ECFC-sEV administration.

Conclusions: Our findings highlight the potential of ECFC-derived sEVs as multifunctional modulators of inflammation, capable of alleviating both immune and cardiac impairments associated with sepsis.

Funding: NVKP_16-1-2016-0004 NKFIH, VEKOP-2.3.2-162016-00002, VEKOP-2.3.3-15-2017-00016, the TTP TKP2021-EGA-23, RRF-2.3.121-2022-00003 (NCLP), 2019-2.1.7-ERA-NET-2021-00015, and the EU’s Horizon 2020 R&IP No. 739593.

e-mail: menna.luigi@semmelweis.hu
University: Semmelweis University
Supervisor: Hargita Hegyesi