title: Human fetal intestinal epithelial cells metabolize and incorporate branched chain fatty acids in a structure specific manner.
abstract: Branched chain fatty acids (BCFA) are constituents of gastrointestinal (GI) tract in healthy newborn human infants, reduce the incidence of necrotizing enterocolitis (NEC) in a neonatal rat model, and are incorporated into small intestine cellular lipids in vivo. We hypothesize that BCFA are taken up, metabolized and incorporated into human fetal cells in vitro.
  
  
  
  Human H4 cells, a fetal non-transformed primary small intestine cell line, were incubated with albumin-bound non-esterified anteiso-17:0, iso-16:0, iso-18:0 and/or iso-20:0, and FA profiles in lipid fractions were analyzed.
  
  
  
  All BCFA were readily incorporated as major constituents of cellular lipids. Anteiso-17:0 was preferentially taken up, and was most effective among BCFA tested in displacing normal (n-) FA. The iso BCFA were preferred in reverse order of chain length, with iso-20:0 appearing at lowest level. BCFA incorporation in phospholipids (PL) followed the same order of preference, accumulating 42% of FA as BCFA with no overt morphological signs of cell death. Though cholesterol esters (CE) are at low cellular concentration among lipid classes examined, CE had the greatest affinity for BCFA, accumulating 65% of FA as BCFA. BCFA most effectively displaced lower saturated FA. Iso-16:0, iso-18:0 and anteiso-17:0 were both elongated and chain shortened by ±C2. Iso-20:0 was chain shortened to iso-18:0 and iso-16:0 but not elongated.
  
  
  
  Nontransformed human fetal intestinal epithelial cells incorporate high levels of BCFA when they are available and metabolize them in a structure specific manner. These findings imply that specific pathways for handling BCFA are present in the lumen-facing cells of the human fetal GI tract that is exposed to vernix-derived BCFA in late gestation.
authors.affiliation: College of Veterinary Medicine, Hunan Agricultural University, Changsha, Hunan 410128, China; Division of Nutritional Sciences, Cornell University, Ithaca, NY 14853, USA.
authors.forename: Lei
authors.initials: L
authors.lastname: Liu
authors.affiliation: Division of Nutritional Sciences, Cornell University, Ithaca, NY 14853, USA.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Division of Nutritional Sciences, Cornell University, Ithaca, NY 14853, USA.
authors.forename: Hui Gyu
authors.initials: HG
authors.lastname: Park
authors.affiliation: Division of Nutritional Sciences, Cornell University, Ithaca, NY 14853, USA; College of Animal Science and Technology, Heilongjiang Bayi Agricultural University, Daqing, Heilongjiang 163319, China.
authors.forename: Chuang
authors.initials: C
authors.lastname: Xu
authors.affiliation: Division of Nutritional Sciences, Cornell University, Ithaca, NY 14853, USA.
authors.forename: Peter
authors.initials: P
authors.lastname: Lawrence
authors.affiliation: Division of Nutritional Sciences, Cornell University, Ithaca, NY 14853, USA; Jingchu University of Technology, Jingmen, Hubei 448000, China.
authors.forename: Xueli
authors.initials: X
authors.lastname: Su
authors.affiliation: Mucosal Immunology and Biology Research Center, Massachusetts General Hospital for Children, Charlestow, MA, USA.
authors.forename: Vasuki
authors.initials: V
authors.lastname: Wijendran
authors.affiliation: Mucosal Immunology and Biology Research Center, Massachusetts General Hospital for Children, Charlestow, MA, USA.
authors.forename: W Allan
authors.initials: WA
authors.lastname: Walker
authors.affiliation: Division of Nutritional Sciences, Cornell University, Ithaca, NY 14853, USA. Electronic address: ksk25@cornell.edu.
authors.forename: Kumar S D
authors.initials: KS
authors.lastname: Kothapalli
authors.affiliation: Division of Nutritional Sciences, Cornell University, Ithaca, NY 14853, USA. Electronic address: jtb4@cornell.edu.
authors.forename: J Thomas
authors.initials: JT
authors.lastname: Brenna
mesh_terms: D002478:Cells, Cultured; D002788:Cholesterol Esters / Q000032:analysis; D004847:Epithelial Cells / Q000166:cytology / Q000378:metabolism; D005227:Fatty Acids / Q000032:analysis* / Q000378:metabolism; D006801:Humans; D007421:Intestine, Small / Q000166:cytology / Q000196:embryology* / Q000378:metabolism
chemical_list: D002788:Cholesterol Esters; D005227:Fatty Acids
keywords: Cholesterol esters; Diacylglycerol; Free fatty acids; Intestine; Lipids; Metabolism; Phospholipids; Triglycerides