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Characterization of Immune Cell-derived Extracellular Vesicles and Studying Functional Impact on Cell Environment
Published on: June 2, 2020
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Extracellular vesicles derived from endothelial cells modulate macrophage phenotype in vitro
Zhizhen He1, Johannes Greven1,2, Yulong Shi3,4
1Department of Orthopedics, Trauma and Reconstructive Surgery, RWTH Aachen University Hospital, Pauwelsstraße 30, 52074, Aachen, Germany.
European Journal of Medical Research
|November 10, 2023
Summary
Lipopolysaccharide (LPS)-induced endothelial cell-derived extracellular vesicles (E-EVs) promote macrophage activation. These E-EVs enhance macrophage viability and induce a proinflammatory M1-like phenotype via the toll-like receptor 4 (TLR4)-nuclear factor kappa B (NFκB) pathway.
Area of Science:
- Cell Biology
- Immunology
- Biochemistry
Background:
- Extracellular vesicles (EVs) mediate intercellular communication by transferring biomaterials.
- Endothelial cells release EVs (E-EVs) upon pathogen exposure, influencing recipient cells.
- Macrophage polarization is critical in innate immunity, often involving the TLR4-NFκB pathway.
Purpose of the Study:
- To investigate the function of LPS-induced E-EVs (ELPS-EVs) in modulating macrophage phenotype and activation.
- To compare the effects of ELPS-EVs with EVs from quiescent cells (ENor-EVs).
- To elucidate the role of the TLR4-NFκB pathway in ELPS-EVs-mediated macrophage modulation.
Main Methods:
- Characterization of ELPS-EVs and ENor-EVs using TEM, Western blot, and NTA.
- Stimulation of NR8383 macrophages with isolated EVs or PBS.
- Assessment of EV uptake, cell viability (MTT assay), macrophage phenotype (flow cytometry, immunofluorescence), and TLR4-NFκB pathway activation (Western blot).
Main Results:
- Endothelial cells secreted significantly more ELPS-EVs than ENor-EVs upon LPS exposure.
- ELPS-EVs were more readily internalized by macrophages compared to ENor-EVs.
- ELPS-EVs increased macrophage viability and promoted a proinflammatory M1-like phenotype, evidenced by upregulated CD86 and iNOS expression.
- Activation of the TLR4-NFκB pathway was observed in macrophages treated with ELPS-EVs, indicated by elevated TLR4 and p-NFκBp65 levels.
Conclusions:
- LPS-induced E-EVs play a significant role in modulating macrophage phenotype and activation.
- E-EVs contribute to the inflammatory response by promoting macrophage polarization towards an M1-like state.
- The TLR4-NFκB signaling pathway is implicated in the effects of ELPS-EVs on macrophages.
