CD36 deficiency causes intestinal extracellular matrix disruption and chronic neutrophil

ABSTRACT: BACKGROUND & AIMS: The scavenger receptor CD36 has versatile immuno-metabolic actions. CD36 is abundantly expressed in the small intestinal epithelium but its impact on gut homeostasis is unknown. METHODS: Wild type (WT) and CD36-null (CD36KO) mice were fed a chow diet and small intestinal morphology assessed by immunohistochemistry and electron microscopy (EM). Inflammation was evaluated from neutrophil infiltration, expression of cytokines and toll-like receptors. Barrier integrity was determined using FITC-dextran and circulating lipopolysaccharide (LPS). Enterocyte (Ent-CD36KO) and endothelial (EC-CD36KO) CD36 null mice were generated to test contribution of epithelial versus endothelial CD36 to the intestinal phenotype. RESULTS: The small intestine of CD36KO mice fed a chow diet showed abnormal remodeling of the extracellular matrix (ECM) with altered expression of ECM and junction proteins. Hypertrophy of cell junctions and basement membranes was observed by EM. The CD36KO intestines displayed neutrophil infiltration, inflammation and compromised barrier function. Systemic leukocytosis and neutrophilia were present in CD36KO mice and there was 80% reduction of anti-inflammatory Ly6Clow monocytes important for ECM regulation and tissue repair. Bone marrow transplants supported primary contribution of tissue injury in initiation of inflammation. Studies with Ent-CD36KO mice did not support a major contribution of enterocyte CD36 while endothelial CD36 deficiency associated with neutrophil infiltration, aberrant expression of tight junctions and inflammation in the small intestine. CONCLUSION: CD36 is important for maintenance of barrier function in the small intestine. CD36 deletion causes ECM remodeling with collagen accumulation, depletion of the Ly6Clow monocyte subset and chronic inflammation. Endothelial but not enterocyte CD36 loss is a significant contributor to the spontaneous inflammation.

ORGANISM(S): Mus musculus

PROVIDER: GSE73569 | GEO | 2016/10/01

SECONDARY ACCESSION(S): PRJNA297353

REPOSITORIES: GEO