title: Glycosphingolipids are essential for intestinal endocytic function.
abstract: Glycosphingolipids (GSLs) constitute major components of enterocytes and were hypothesized to be potentially important for intestinal epithelial polarization. The enzyme UDP-glucose ceramide glucosyltransferase (Ugcg) catalyzes the initial step of GSL biosynthesis. Newborn and adult mice with enterocyte-specific genetic deletion of the gene Ugcg were generated. In newborn mutants lacking GSLs at day P0, intestinal epithelia were indistinguishable from those in control littermates displaying an intact polarization with regular brush border. However, those mice were not consistently able to absorb nutritional lipids from milk. Between postnatal days 5 and 7, severe defects in intestinal epithelial differentiation occurred accompanied by impaired intestinal uptake of nutrients. Villi of mutant mice became stunted, and enterocytes lacked brush border. The defects observed in mutant mice caused diarrhea, malabsorption, and early death. In this study, we show that GSLs are essential for enterocyte resorptive function but are primarily not for polarization; GSLs are required for intracellular vesicular transport in resorption-active intestine.
authors.affiliation: Department of Cellular and Molecular Pathology, German Cancer Research Center, 69120 Heidelberg, Germany. r.jennemann@dkfz.de
authors.forename: Richard
authors.initials: R
authors.lastname: Jennemann
authors.forename: Sylvia
authors.initials: S
authors.lastname: Kaden
authors.forename: Roger
authors.initials: R
authors.lastname: Sandhoff
authors.forename: Viola
authors.initials: V
authors.lastname: Nordström
authors.forename: Shijun
authors.initials: S
authors.lastname: Wang
authors.forename: Martina
authors.initials: M
authors.lastname: Volz
authors.forename: Sylvie
authors.initials: S
authors.lastname: Robine
authors.forename: Nicole
authors.initials: N
authors.lastname: Amen
authors.forename: Ulrike
authors.initials: U
authors.lastname: Rothermel
authors.forename: Herbert
authors.initials: H
authors.lastname: Wiegandt
authors.forename: Hermann-Josef
authors.initials: HJ
authors.lastname: Gröne
mesh_terms: D000818:Animals; D016764:Cell Polarity / Q000502:physiology*; D020895:Enterocytes / Q000378:metabolism*; D018397:Equidae; D017353:Gene Deletion; D005964:Glucosyltransferases / Q000235:genetics / Q000378:metabolism*; D006028:Glycosphingolipids / Q000096:biosynthesis* / Q000235:genetics; D006041:Goats; D007408:Intestinal Absorption / Q000502:physiology*; D051379:Mice; D008817:Mice, Mutant Strains; D011817:Rabbits
chemical_list: D006028:Glycosphingolipids; D005964:Glucosyltransferases; C023246:ceramide glucosyltransferase