AMPK a 1 subunit is required for proper intestinal epithelial differentiation

Abstract

Intestinal epithelial cells renew every 2-4 days, which involves rapid proliferation and differentiation. AMP-activated protein Kinase (AMPK) is a key sensor and regulator of energy catabolism, and recent studies suggest that it is also an important regulator of cell differentiation. We hypothesized that AMPKa1 subunit is required for the differentiation of intestinal epithelial cells and the formation of epithelial tight junctions. To test, AMPKa1flox/flox – CreER conditional knock out (KO) mice were used, and the deletion of AMPK was induced by 4-hydrotamoxifen. Fetal intestines were sampled from WT and AMPKa1 KO E13.4 embryos, which were cultured in vitro to establish a “mini-gut” system. The differentiation was monitored by immunofluoresent staining of intestinal differentiation markers. The mini-gut from WT forms a clearly defined, well-organized epithelial layer, which was absent in that from AMPK KO. In addition, the formation of enterocytes were also decreased and disorganized in KO mini-guts compared to WT, accompanied by the disordered formation of epithelial tight junctions. In addition to impaired epithelial differentiation, the supporting mesenchymal cells, including smooth muscle cells, were also disarranged in mini-guts from KO. Taken together, these data clearly show that AMPKa1 is required for proper differentiation and development of gut epithelium (NIH R15HD073864).