Parenteral Nutrition–Associated Liver Injury and Increased GRP94 Expression Prevented by ω-3 Fish Oil–Based Lipid Emulsion Supplementation

OBJECTIVE Parenteral nutrition in infants with gastrointestinal disorders can be lifesaving, but it is also associated with parenteral nutrition-associated liver disease. We investigated the effects of incorporating ω-3 fish oil in a parenteral nutrition mixture on signs of parenteral nutrition-associated liver disease and explored the mechanism involved in this process. METHODS Seven-day-old New Zealand rabbits were divided into 3 groups of 8, and for 1 week they were infused via the right jugular vein with standard total parenteral nutrition with soybean oil (TPN-soy) or TPN with ω-3 fish oil-based lipid emulsion (TPN-FO), or naturally nursed with rabbit milk (control). Serum and liver tissues were analyzed for serological indicators and pathology, respectively. Reverse-transcriptase polymerase chain reaction was used to evaluate the messenger RNA levels of the endoplasmic reticulum stress chaperone protein glucose-regulated protein 94 (GRP94) in liver tissues and GRP94 protein levels were compared through immunohistochemistry and Western blot assays. RESULTS TPN-soy animals had significantly higher serum total bilirubin, direct bilirubin, and γ-glutamyl transpeptidase and lower serum albumin than the controls (P < 0.01, each) or the TPN-FO group, which were similar to the controls (P < 0.01 cf. TPN). Damage to liver tissues of the TPN-FO group was much less than that of the TPN-soy group. GRP94 messenger RNA and protein levels in liver tissues of TPN-soy animals were significantly higher than that of the controls or TPN-FO rabbits, which were similar to the controls. CONCLUSIONS Incorporating ω-3 fish oil in parenteral nutrition emulsion greatly prevented liver dysfunction and liver tissue damage in week-old rabbit kits, possibly by preventing endoplasmic reticulum stress.