X/XO or H2O2 induced IPEC-J2 cell as a new in vitro model for studying apoptosis in post-weaning piglets.

We previously demonstrated that intestinal epithelial cell apoptosis in weaned piglets is much more serious than that observed in sucking piglets and is related to oxidative stress during weaning. It is difficult to study the apoptosis mechanisms only using in vivo methods because of the limit of existing research technology. An in vitro cellular system is required for piglet intestinal epithelial cell apoptosis research. In this study, a non-tumorigenic epithelial cell line, IPEC-J2 cells, was employed as a cell model. Hydrogen peroxide and xanthine/xanthine oxidase (X/XO) were both used and compared for apoptosis modeling. The concentrations of hydrogen peroxide and XO were selected and verified using cell viability analysis, the comet assay and flow cytometry. Intracellular ROS were measured using fluorescent probes. Additionally, the expression levels of the apoptosis-related genes Fas, Bcl-2, P53, Caspase 3, Caspase 8, and Caspase 9 were analyzed using quantitative RT-PCR. The results indicated the optimal modeling method is a final concentration of 0.5 mM H2O2 incubated with IPEC-J2 cells for 1 h at 37 °C in 5 % CO2 for hydrogen peroxide-induced apoptosis modeling, and a final concentration of 250 µM X/50 U/L XO incubated with IPEC-J2 cells for 6 h at 37 °C in 5 % CO2 for X/XO-induced apoptosis modeling. For the apoptotic pathway, the X/XO modeling method is more similar to 21 days weaning piglets. Therefore, we suggest that X/XO modeling with IPEC-J2 cells be used as an in vitro cell culture model for weaning piglet intestinal epithelial cell apoptosis.

Regulation of an antioxidant blend on intestinal redox status and major microbiota in early weaned piglets.

OBJECTIVE: According to the "antioxidants network" theory, the present study was conducted to evaluate the regulation of an antioxidant blend on intestinal redox status and major microbiota of early-weaned piglets. METHODS: Piglets from 15 litters were randomly allocated by litter to the control group (suckling normally, fed the basal diet, n = 5), the weaning group (weaned at age 21 d, fed the basal diet, n = 5), and the repair group (weaned at age 21 d, fed the basal diet supplemented with an antioxidant blend, n = 5). The redox status and major microbiota in jejunum and colon tracts of 24-d-old piglets were detected, respectively. RESULTS: Early weaning resulted in significant decreases in jejunum and colon antioxidant capacities, Lactobacillus and Bifidobacterium counts, and significant increases in levels of jejunum malondialdehyde, colon hydroxyl radicals, jejunum and colon H2O2, and Escherichia coli counts in piglets. The observed imbalance of the intestinal redox status and microbiota was significantly restored by the antioxidant blend. Interestingly, intestinal selected antioxidative items presented a positive correlation with potential beneficial bacteria and a negative correlation with E. coli. Nevertheless, selected oxidative items and the bacteria presented an inverse relationship in piglets. CONCLUSION: Supplementation of the antioxidant blend effectively restored intestinal redox status and microbiota balance in the porcine intestine in response to early weaning stress, enhancing intestinal health and function of piglets.