Related Experiment Video
Updated: Aug 5, 2026
Assessing Retinal Microglial Phagocytic Function In Vivo Using a Flow Cytometry-based Assay
Published on: October 18, 2016
Propofol suppresses microglial phagocytosis through the downregulation of MFG-E8
Xiaoying Cai1, Ying Li1, Xiaoyang Zheng1
1Department of Anesthesiology, The First Affiliated Hospital, Sun Yat-sen University, No. 58 Zhongshan 2nd Road, Guangzhou, 510080, Guangdong, People's Republic of China.
Background:
Microglia are highly motile phagocytic cells in the healthy brain with surveillance and clearance functions. Although microglia have been shown to engulf cellular debris following brain insult, less is known about their phagocytic function in the absence of injury. Propofol can inhibit microglial activity, including phagocytosis. Milk fat globule epidermal growth factor 8 (MFG-E8), as a regulator of microglia, plays an essential role in the phagocytic process. However, whether MFG-E8 affects the alteration of phagocytosis by propofol remains unknown.
Methods:
Microglial BV2 cells were treated with propofol, with or without MFG-E8. Phagocytosis of latex beads was evaluated by flow cytometry and immunofluorescence. MFG-E8, p-AMPK, AMPK, p-Src, and Src levels were assessed by western blot analysis. Compound C (AMPK inhibitor) and dasatinib (Src inhibitor) were applied to determine the roles of AMPK and Src in microglial phagocytosis under propofol treatment.
Results:
The phagocytic ability of microglia was significantly decreased after propofol treatment for 4 h (P < 0.05). MFG-E8 production was inhibited by propofol in a concentration- and time-dependent manner (P < 0.05). Preadministration of MFG-E8 dose-dependently (from 10 to 100 ng/ml) reversed the suppression of phagocytosis by propofol (P < 0.05). Furthermore, the decline in p-AMPK and p-Src levels induced by propofol intervention was reversed by MFG-E8 activation (P < 0.05). Administration of compound C (AMPK inhibitor) and dasatinib (Src inhibitor) to microglia blocked the trend of enhanced phagocytosis induced by MFG-E8 (P < 0.05).
Conclusions:
These findings reveal the intermediate role of MFG-E8 between propofol and microglial phagocytic activity. Moreover, MFG-E8 may reverse the suppression of phagocytosis induced by propofol through the regulation of the AMPK and Src signaling pathways.
Insights
Propofol reduces microglial phagocytosis, but Milk fat globule epidermal growth factor 8 (MFG-E8) can reverse this effect. MFG-E8 modulates phagocytosis via AMPK and Src pathways, offering a potential therapeutic target.
Area of Science:
- Neuroscience
- Cell Biology
- Immunology
Background:
- Microglia are crucial phagocytic cells in the brain, involved in surveillance and clearance.
- Propofol is known to inhibit microglial phagocytosis.
- Milk fat globule epidermal growth factor 8 (MFG-E8) regulates microglial phagocytosis, but its interaction with propofol is unclear.
Purpose of the Study:
- To investigate the role of MFG-E8 in propofol-induced microglial phagocytosis inhibition.
- To elucidate the signaling pathways involved in MFG-E8's effect on microglial function.
Main Methods:
- BV2 microglial cells were treated with propofol and/or MFG-E8.
- Phagocytosis was assessed using latex beads via flow cytometry and immunofluorescence.
- Western blot analysis measured MFG-E8, p-AMPK, AMPK, p-Src, and Src levels.
- AMPK and Src inhibitors (Compound C, dasatinib) were used to explore pathway involvement.
Main Results:
- Propofol significantly decreased microglial phagocytosis and MFG-E8 production.
- MFG-E8 pre-administration dose-dependently reversed propofol's inhibitory effect on phagocytosis.
- Propofol-induced decreases in p-AMPK and p-Src were reversed by MFG-E8.
- AMPK and Src inhibitors blocked MFG-E8's enhancement of phagocytosis.
Conclusions:
- MFG-E8 acts as an intermediate in the interaction between propofol and microglial phagocytic activity.
- MFG-E8 may counteract propofol's suppression of phagocytosis by regulating AMPK and Src signaling pathways.
