Inflammation is increasingly regarded as a key process underlying metabolic diseases in obese individuals where obese adipose tissue shows features characteristic of active local inflammation. Metformin is a biguanide derivative used in the treatment of T2D and one of the world's most widely prescribed drugs and have been suggested that metformin has anti-inflammatory properties. Here we show that metformin efficiently attenuates the metabolic disorder in DIO mice and suppresses MHC-restricted antigen presentation in dendritic cells. This study was to investigate the therapeutic effect of metformin on diabetic symptoms in DIO mice. Metformin decreased aipogenesis related gene, FAS, SCD-1, GPAT, SREBP1a, but also suppressed gene expression of innate cytokines than control mice. Metformin decreased both class I- and class II-restricted presentation of exogenous OVA in dendritic cells. Metformin also decreased expression of the co-stimulatory molecules, ICAM-1 and B7-1/-2, and MHC class I and II molecules but not phagocytic activity of DCs. Metformin decreased MHC class II-restricted exogenous antigen presentation in peritoneal macrophages in vivo. These results show that metformin attenuates immune responses followed by decreases MHC-restricted presentation of exogenous antigen in DCs via intracellular processing events. Theses finding suggest that modulation of the antigen presentation pathway could provide a novel means for regulating T cell responses in metabolic diseases.
- Copyright © 2013 by The American Association of Immunologists, Inc.