Preeclampsia (PE) continues to be a significant cause of maternal and neonatal morbidity and mortality. Angiotensin II type I receptor autoantibody (AT1-AA) has been reported accompanied by PE women in numerous studies. Therefore, detecting the mechanism of AT1-AA production is the key breakthrough in understanding PE. Deficiency in MFG-E8 has been verified can lead to autoimmune diseases due to dysfunction in macrophage phagocytosis and the production of autoantibodies. In the present study, we examined the expression of MFG-E8 in PE patients. Compared with the control, PE patients had a lower expression of placental MFG-E8 and a higher expression of placental AT1R. Then, we tested the effect of MFG-E8 on AT1-AA production and macrophage phagocytosis of trophoblast apoptosis in PE rats induced by low-dose endotoxin(LPS) and trophoblast model. In vivo, experiments results showed that systolic blood pressure, 24h urinary protein, serum TNF-α,sLFt-1 and AT1-AA levels, and placental trophoblast apoptosis caused by LPS were all significantly alleviated by MFG-E8. Moreover, administrated with MFG-E8 has shown decreased trophoblast apoptosis and AT1R exposure in vitro, and enhanced the phagocytosis of dead trophoblasts by macrophages. That supports the idea that MFG-E8 could be a potential therapeutic target for attenuating AT1-AA and protecting patients from AT1-AA and PE.

Extracellular vesicles (EVs) effectively suppress neuroinflammation and induce neuroprotective effects in different disease models. However, the mechanisms by which EVs regulate neuroinflammatory response of microglia remain largely unexplored. Here, we addressed this issue by testing the action of EVs derived from human exfoliated deciduous teeth stem cells (SHEDs) on immortalized human microglial cells. We found that EVs induced a rapid increase in intracellular Ca2+ and promoted a significant ATP release in microglial after 20 min of treatment. Boyden chamber assays revealed that EVs promoted microglial migration by 20 %. Pharmacological inhibition of different subtypes of purinergic receptors demonstrated that EVs activated microglial migration preferentially through the P2X4R pathway. Proximity ligation and co-immunoprecipitation assays revealed that EVs promote association between milk fat globule-epidermal growth factor-factor VIII (MFG-E8) and P2X4 receptor proteins. Furthermore, pharmacological inhibition of αVβ3/αVβ5 integrin suppressed EV -induced cell migration and formation of lipid rafts in microglia. These results demonstrate that EVs promote microglial motility through P2X4 R/ MFG-E8 – dependent mechanisms. Our findings provide novel insights into the molecular mechanisms through which EVs target human microglia that may be exploited for the development of new therapeutic strategies targeting disease associated neuroinflammation.