Akkermansia muciniphila outer membrane protein Amuc_0904 modulates intestinal homeostasis by promoting goblet cell differentiation.

A. muciniphila abundance was dramatically increased during colitis recovery in mice.

• A. muciniphila colonization significantly increased goblet cell numbers to protect the intestinal barrier.
• The increase in A. muciniphila during recovery from colitis suggested a protective role in intestinal homeostasis.
• This observation motivated investigation into the mechanisms by which A. muciniphila promotes intestinal recovery.

Amuc_0904 is a previously uncharacterized outer membrane protein of A. muciniphila that induces goblet cell differentiation.

• Amuc_0904 was identified through screening of A. muciniphila outer membrane proteins for effects on intestinal epithelial cells.
• Treatment with Amuc_0904 promoted goblet cell differentiation in intestinal epithelial cell models.
• This was the first characterization of Amuc_0904 as a bioactive molecule affecting intestinal homeostasis.

Amuc_0904 directly interacted with the MET receptor and decreased its phosphorylation in intestinal epithelia.

• Direct binding between Amuc_0904 and MET (hepatocyte growth factor receptor) was demonstrated.
• Amuc_0904 binding led to decreased MET phosphorylation, indicating inhibition of MET signaling activity.
• This interaction represents the mechanistic link between the bacterial protein and host epithelial signaling.

Amuc_0904-mediated MET inhibition led to decreased Wnt/β-catenin signaling and enhanced oxidative phosphorylation and mitochondrial function.

• Decreased MET phosphorylation downstream resulted in reduced Wnt/β-catenin pathway activity.
• Reduced Wnt/β-catenin signaling was associated with promotion of goblet cell differentiation over stem/progenitor cell proliferation.
• Amuc_0904 treatment enhanced oxidative phosphorylation and improved mitochondrial function in intestinal epithelial cells.
• These metabolic changes were linked mechanistically to the goblet cell differentiation phenotype.

Amuc_0904 protected mice from colitis and colitis-associated colorectal cancer.

• Administration of Amuc_0904 protein reduced disease severity in mouse models of colitis.
• Amuc_0904 treatment also provided protection in a colitis-associated colorectal cancer mouse model.
• Protection was associated with increased goblet cell numbers and improved intestinal barrier integrity.

Engineered Escherichia coli Nissle 1917 expressing Amuc_0904 protected mice from colitis and colitis-associated colorectal cancer.

• E. coli Nissle 1917 was engineered to express and deliver Amuc_0904 in vivo.
• The engineered probiotic recapitulated the protective effects of the purified Amuc_0904 protein in colitis models.
• The engineered probiotic also demonstrated efficacy in the colitis-associated colorectal cancer model.
• This approach demonstrates a translational strategy for delivering Amuc_0904 as a therapeutic.