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Microglial Immunoregulation by Apoptotic Cellular Membrane Mimetic Polymeric Particles
Yasuhiro Nakagawa1,2,3,4,5, Jeonggyu Lee4,5, Yihua Liu4
1School of Materials and Chemical Technology, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8550, Japan.
Abstract:
Phosphatidylserine (PtdSer), one of the phospholipids that the apoptotic cell exposes, has emerged for anti-inflammatory therapy via polarizing inflammatory microglia (Mi1) to anti-inflammatory phenotype (Mi2). In this study, we report microglia polarization effect of PtdSer-exposing polymeric particles (PSPs). PSPs upregulated Mi2 microglia and suppressed Mi1 microglia through peroxisome proliferator-activated receptor gamma upregulation in vitro and in vivo. This study highlights the potential of PSPs for anti-inflammatory therapy.
Insights
Phosphatidylserine-exposing polymeric particles (PSPs) effectively polarize microglia from an inflammatory (Mi1) to an anti-inflammatory (Mi2) state. This suggests PSPs hold promise for novel anti-inflammatory therapies.
Area of Science:
- Immunology
- Biomaterials Science
- Neuroinflammation
Background:
- Phosphatidylserine (PtdSer) is a phospholipid exposed on apoptotic cells, known to modulate immune responses.
- Microglia, the resident immune cells of the central nervous system, exist in different activation states, including inflammatory (Mi1) and anti-inflammatory (Mi2) phenotypes.
- Targeting microglia polarization is a key strategy for developing anti-inflammatory therapies.
Purpose of the Study:
- To investigate the microglia polarization effects of PtdSer-exposing polymeric particles (PSPs).
- To evaluate the therapeutic potential of PSPs in modulating neuroinflammation.
Main Methods:
- In vitro cell culture experiments using microglia.
- In vivo animal models to assess therapeutic efficacy.
- Analysis of microglia polarization markers (Mi1 and Mi2).
- Investigation of the underlying molecular mechanisms, including peroxisome proliferator-activated receptor gamma (PPARγ) signaling.
Main Results:
- PSPs successfully induced a shift in microglia polarization.
- Upregulation of the anti-inflammatory Mi2 microglia phenotype was observed.
- Suppression of the inflammatory Mi1 microglia phenotype was achieved.
- PPARγ upregulation was identified as a key mechanism mediating PSP effects both in vitro and in vivo.
Conclusions:
- PSPs effectively polarize microglia towards an anti-inflammatory phenotype.
- The mechanism involves the upregulation of PPARγ.
- PSPs demonstrate significant potential for developing novel anti-inflammatory therapies, particularly for neuroinflammatory conditions.
