ABSTRACT: CD44 expression has been shown to be enhanced in the liver and white adipose tissue (WAT) during obesity, suggesting a possible regulatory role for CD44 in metabolic syndrome. To study this hypothesis, we compared the gene expression profiles in liver and in WAT between WT and CD44 knockout (CD44KO) mice fed a high-fat diet (HFD) for 21 weeks. This analysis demonstrated that several genes associated with triglyceride synthesis and accumulation, including Mogat2, Cidea, Cidea, Apoa4, and Elovl7, were decreased in the livers of CD44KO mice compared to WT mice. Many genes encoding pro-inflammatory chemokines and chemokine receptors also were decreased in the livers of CD44KO mice. Analysis with WAT showed that genes associated with triglyceride accumulation, including Fasn, Elovl6 and Mogat2, were increased in WAT of CD44KO(HFD) mice compared to WT(HFD) mice. Moreover, many genes associated with inflammation, including cytokines (Cxcl14, Cxcl12, Il33, and Il2), cytokine receptors (Ccr1, Il6ra, Il10rb), trypases (Tpsb2, Tpsab1, Tpsg1), and cellular matrix proteins (Integrin α4 (Itga4), ItgaM, Itgb2), were decreased in WAT of CD44(HFD) compared to WT(HFD) mice. This study indicates that CD44 plays a critical role in regulating several aspects of metabolic syndrome.
