Abstract
Cell lines matching the source epithelium are indispensable for investigating porcine intestinal transport and barrier properties on a subcellular or molecular level and furthermore help to reduce animal usage. The porcine jejunal cell line IPEC-J2 is established as an in vitro model for porcine infection studies but exhibits atypically high transepithelial resistances (TER) and only low active transport rates so that the effect of nutritional factors cannot be reliably investigated. This study aimed to properly remodel IPEC-J2 and then to re-characterize these cells regarding epithelial architecture, expression of barrier-relevant tight junction (TJ) proteins, adequate TER and transport function, and reaction to secretagogues. For this, IPEC-J2 monolayers were cultured on permeable supports, either under conventional (fetal bovine serum, FBS) or species-specific (porcine serum, PS) conditions. Porcine jejunal mucosa was analyzed for comparison. Main results were that under PS conditions (IPEC-J2/PS), compared to conventional FBS culture (IPEC-J2/FBS), the cell height increased 6-fold while the cell diameter was reduced by 50%. The apical cell membrane of IPEC-J2/PS exhibited typical microvilli. Most importantly, PS caused a one order of magnitude reduction of TER and of trans- and paracellular resistance, and a 2-fold increase in secretory response to forskolin when compared to FBS condition. TJ ultrastructure and appearance of TJ proteins changed dramatically in IPEC-J2/PS. Most parameters measured under PS conditions were much closer to those of typical pig jejunocytes than ever reported since the cell line’s initial establishment in 1989. In conclusion, IPEC-J2, if cultured under defined species-specific conditions, forms a suitable model for investigating porcine paracellular intestinal barrier function.
Highlights
In intensive pig farming, a significant fraction of piglets die after weaning, in many cases due to infectious diarrhea [1]
In order to compare transepithelial resistance (TER) values of IPEC-J2 with values from pig jejunal epithelia, the jejunal surface enlargement by villi and crypts has to be taken into account
Under pig serum (PS) condition TER developed a maximum around day 7 post seeding and reached a lower plateau level (200–400 V?cm2) at around day 14 post seeding which was maintained for several days
Summary
A significant fraction of piglets die after weaning, in many cases due to infectious diarrhea [1]. For molecular studies on mechanisms and signaling pathways between germ exposure and diarrheal effect, porcine cell cultures are highly desirable These cultures are only suitable if they closely match the properties of pig small intestinal epithelium. For research on intestinal barrier function, cell models have to meet specific physiological requirements: reflecting epithelial architecture, displaying adequate transepithelial resistance (TER) and transport properties, reacting to secretagogues, and expressing bowel-relevant tight junction (TJ) proteins. If these prerequisites have been achieved, the model system will be potentially suitable for studying effects of e.g. nutritional factors
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
