Plasmalogens Inhibit Endocytosis of Toll-like Receptor 4 to Attenuate the Inflammatory Signal in Microglial Cells.

Microglial activation is a pathological feature of many neurodegenerative diseases and the role of cellular lipids in these diseases is mostly unknown. It was known that the special ether lipid plasmalogens (Pls) were reduced in the brain and blood samples of Alzheimer's disease (AD) patients. It has recently been reported that the oral ingestion of scallop-derived Pls (sPls) improved cognition among mild AD patients, which led us to investigate the role of sPls in the microglial activation.

Scallop-derived plasmalogens attenuate the activation of PKCδ associated with the brain inflammation.

Activation of protein kinase C delta (PKCδ) has been linked to the neuroinflammation but the relationship with the various neurodegenerative diseases including the Alzheimer's disease (AD) was mostly elusive. In the AD brains, the special phospholipids, ethanolamine plasmalogens (Pls), were found to be reduced and our previous study showed that these lipids possess neuroprotective and anti-inflammatory functions. In the present study, we could find that these lipids can significantly attenuate the microglial expression of PKCδ in the neuroinflammation model and in the AD model mice brains.