Japanese researchers find new mechanism of Lypd8 protein preventing inflammation

Japanese researchers discovered a mechanism - a protein called Lypd8 defends the body against inflammation - it is attached to the tail of the bacteria to stop its process. The findings were published in journal Nature.

Dysfunction of intestinal barrier is usually considered to be the main cause of inflammatory bowel disease. In mice with intestinal mucosal barrier injury caused by genetic changes, the bacteria invade the colonic mucosa and lead to a high susceptibility of intestinal inflammation. It has been clear that this mucosal barrier layer provides protection, but the mechanism of inhibition of bacterial invasion is not yet clear.

The research team, led by Dr. Ryu Okumura and Professor Kiyoshi Takeda from the Institute of Medicine, Osaka University, was specialized in Ly6/Plaur domain containing 8 (Lypd8), a highly glycosylated glycosyl phosphatidylinositol immobilized protein, which specific expresses and embeds into intestine in colonic epithelial cells.

Ulcers in patients with type colitis colonic epithelial cells have lower Lypd8 expression. In mice withLypd8 missing, flagellated bacteria such as Proteus mirabilis and Escherichia coli can frequently invade the intestinal mucosa. When exposed to dextran sulfate sodium (DSS), a compound that stimulates infectious inflammation, mice with Lypd8 deletion showed more severe DSS- excitation enteritis compared with those wild-type mice.

In laboratory studies with recombinant mouse proteins and recombinant rat proteins, Lypd8 protein bonds to bacterial flagellum which grows in semi-solid agar dish. This mechanism is about how Lypd8 inhibit bacterial movement and how the bacteria invade colonic epithelial cells of human host.