title: Effects of zinc on epithelial barrier properties and viability in a human and a porcine intestinal cell culture model.
abstract: Zinc is an essential trace element with a variety of physiological and biochemical functions. Piglets are commonly supplemented, during the weaning period, with doses of zinc above dietary requirements with positive effects on health and performance that might be attributed to anti-secretory and barrier-enhancing effects in the intestine. For a better understanding of these observations increasing zinc sulfate (ZnSO4; 0-200μM) concentrations were used in an in vitro culture model of porcine (IPEC-J2) and human (Caco-2) intestinal epithelial cells and effects on barrier function, viability, and the mRNA expression of one selected heat shock protein (Hsp) were assessed. When treated apically with zinc sulfate, the transepithelial electrical resistance (TEER) did not change significantly. In contrast, cell viability measured by lactate dehydrogenase (LDH) leakage, by ATP and by WST-1 conversion in postconfluent IPEC-J2 monolayers was affected after a 24-h treatment with 200μM ZnSO4. Caco-2 cells were more resistant to Zn. ZnSO4 did not induce any effect on viability, except when it was used at the highest concentration (200μM), and only in preconfluent cells. Furthermore, ZnSO4 induced Hsp70 mRNA expression at 200μM and was more pronounced in preconfluent cells. The observed dose-related effects of zinc are cell-line specific and depended on the differentiation status of the cells. The IPEC-J2 cell line appears to be a suitable in vitro model to characterize specific effects on porcine intestinal cells.
authors.affiliation: Institute of Veterinary Physiology, Department of Veterinary Medicine, Freie Universität Berlin, Oertzenweg 19b, 14163 Berlin, Germany. lodemann@zedat.fu-berlin.de
authors.forename: U
authors.initials: U
authors.lastname: Lodemann
authors.forename: R
authors.initials: R
authors.lastname: Einspanier
authors.forename: F
authors.initials: F
authors.lastname: Scharfen
authors.forename: H
authors.initials: H
authors.lastname: Martens
authors.forename: A
authors.initials: A
authors.lastname: Bondzio
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D018938:Caco-2 Cells; D018929:Cell Culture Techniques; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D004847:Epithelial Cells / Q000187:drug effects* / Q000378:metabolism; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics; D006801:Humans; D007422:Intestines / Q000166:cytology; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D013552:Swine; D015032:Zinc / Q000633:toxicity*
chemical_list: D018840:HSP70 Heat-Shock Proteins; D012333:RNA, Messenger; D000255:Adenosine Triphosphate; D007770:L-Lactate Dehydrogenase; D015032:Zinc