MoS2 Quantum Dots Alter Macrophage Plasticity and Induce Mitophagy to Attenuate Endothelial Barrier Dysfunctions

Molybdenum disulfide (MoS2), as a member of transition metal dichalcogenides (TMDs), presents enormous potential in biomedical applications due to its unique chemical–physical properties, photo-electronic properties, and biocompatibility. MoS2 nanostructures have recently been shown to be multifunctional nanotheranostic agents for neuroprotection and maintenance of endothelial homeostasis. However, whether ultrasmall MoS2 quantum dots (QD) participate in preventing the impairment of the endothelial barrier elicited by pro-inflammatory stimuli and the associated underlying mechanisms remain elusive yet. Herein, we set out to explore the protective effects of MoS2 QD on inflammatory endothelial barrier dysfunction and macrophage plasticity. We revealed an inhibitory effect of MoS2 QD on endothelial barrier impairment and monocyte–endothelial cell interactions, including monocyte adhesion and transmigration, and this might be associated with a reduced activation of focal adhesion kinase (FAK). Importantly, using an in vitro macrophage polarization system, we revealed that MoS2 QD altered macrophage plasticity via inhibiting M1-macrophage polarization, and the reduction in nuclear factor-κB (NF-κB) activation and promotion of mitophagy by MoS2 QD was involved in preventing M1 macrophage polarization. Taken together, these findings suggested potential therapeutic applications of MoS2-based bioactive nanoagents to attenuate inflammatory endothelial barrier dysfunctions that are provoked by macrophage-mediated endothelial activation.