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M2 Macrophage-Derived Exosomes Inhibit Apoptosis of HUVEC Cell through Regulating miR-221-3p Expression
Xiandong Cheng1, Hong Zhou1, Ying Zhou1
1Department of Pulmonary and Critical Care Medicine, The Central Hospital of Wuhan, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430014, China.
Insights
Macrophage exosomes, specifically M2-Exo, promote human umbilical vein endothelial cell (HUVEC) proliferation and reduce inflammation and apoptosis. The microRNA miR-221-3p plays a key role in these protective effects against atherosclerosis development.
Area of Science:
- Molecular Biology
- Cell Biology
- Cardiovascular Research
Background:
- Atherosclerosis (AS) poses significant health risks with limited effective treatments.
- Endothelial cell dysfunction, inflammation, and apoptosis are key processes in AS pathogenesis.
- The role of macrophage-derived exosomes in endothelial cell injury remains incompletely understood.
Purpose of the Study:
- To investigate the therapeutic potential of macrophage exosomes in mitigating HUVEC injury.
- To elucidate the involvement of miR-221-3p in the protective effects of macrophage exosomes.
- To understand the impact of macrophage exosomes on inflammation and apoptosis in HUVECs.
Main Methods:
- Established HUVEC injury models using oxidized low-density lipoprotein (ox-LDL) and tumor necrosis factor-α (TNF-α).
- Assessed cell proliferation (CCK8), inflammatory cytokine expression (qRT-PCR), apoptosis rates (TUNEL), and protein levels (Western blotting).
- Utilized miR-221-3p mimics and inhibitors via liposome transfection to explore molecular mechanisms.
Main Results:
- HUVEC injury models showed increased inflammatory markers (IL-6, IL-1β, TNF-α), decreased IL-10, and elevated apoptosis.
- Treatment with M2 macrophage exosomes (M2-Exo) reduced inflammation, decreased apoptosis, and increased IL-10 levels.
- Overexpression of miR-221-3p enhanced the protective effects of M2-Exo, while inhibition worsened HUVEC injury.
Conclusions:
- M2 macrophage exosomes exert protective effects by promoting HUVEC proliferation and inhibiting inflammation and apoptosis.
- miR-221-3p is a critical mediator in the anti-inflammatory and anti-apoptotic actions of M2-Exo.
- Macrophage exosomes represent a promising therapeutic strategy for atherosclerosis.
Abstract:
Atherosclerosis (AS) is associated with high morbidity and mortality rates and currently has no effective treatment. This study was aimed at investigating the role of macrophage exosomes in the inflammation and apoptosis after HUVEC injury. We established the HUVEC injury model using 100 mg/L oxidized low-density lipoprotein (ox-LDL) or 50 ng/mL tumor necrosis factor-α (TNF-α). Cell proliferation was assessed using cell counting kit-8 (CCK8) assays, and the expression of miR-221, TNF-α, and IL-6, IL-10, and IL-1β was detected using quantitative real-time PCR (qRT-PCR). The apoptotic rate was analyzed by the TUNEL method, and the expressions of apoptosis-related proteins Bcl2, Caspase-3, and c-myc were detected by western blotting. Finally, miR-221-3p mimics and miR-221-3p inhibitors were constructed by liposome transfection to determine the mechanism of action of macrophage exosomes on HUVEC injury. The expression levels of IL-6, IL-1β, and TNF-α in the injury groups were higher than those in the normal group, but the expression of IL-10 in the injury groups was lower than that in the normal group. Meanwhile, the apoptotic rate of the HUVEC cell injury group was higher than that of the normal group. In contrast, the expression levels of IL-6, IL-1β, and TNF-α were lower in the M2 macrophage exosome (M2-Exo) group, but the expression of IL-10 was higher compared with the control group. The apoptosis rate was reduced in the M2-Exo group, and the expression of the proapoptotic gene Caspase-3 was reduced, while the expression of the antiapoptotic gene Bcl2 was increased. Liposome transfection of miR-221-3p mimics was able to enhance the effect of M2 macrophage exosomes. Thus, M2-Exo promotes HUVEC cell proliferation and inhibits HUVEC cell inflammation and apoptosis. miR-221-3p overexpression attenuates HUVEC cell injury-induced inflammatory response and apoptosis, while miR-221-3p gene inhibition enhances this inflammatory response and apoptosis.
