VARIATIONS IN THE EXPRESSION OF TRIGLYCERIDE SYNTHESIS GENES IN PIGS PROVIDED ENTEROBACTER CLOACAE
Enteric infections are leading causes of morbidity and mortality among livestock. Weanling pigs are particularly susceptible to infections, primarily due to reduced amounts of adipose tissue. Limited stores of adipose tissue can lead to an insufficient supply of energy during times of nutritional restriction that would be available to mount an effective immune response. Previously, two novel probiotics (Enterobacter cloacae JD6301 and JD8715, a genetically altered form that produces extracellular lipids) were found to increase circulating triglycerides in pigs. In this current study, thirty-six weanling pigs were supplemented with Enterobacter cloacae JD6301 or JD8715 for 7 d prior and 3 d afterwards relative to an orally inoculated Salmonella typhimurium (1x109 CFU) challenge. To determine if either probiotic altered the production of triglycerides in response to the infection, adipose tissues were collected from 4 pigs every 24 h in relation to the challenge to evaluate potential differences in lipogenesis. Total RNA was isolated post challenge and analyzed for variations in the expression of genes involved in triglyceride synthesis and compared to control pigs only provided phosphate buffered saline. The data indicate that pigs provided JD8715 had an increase in lipoprotein lipase (P = 0.027), and a decrease in the insulin-induced gene 1 (P = 0.02), apolipoprotein A1 (P = 0.04), and DGAT2 (P = 0.009) 1 d post-challenge in comparison to controls. A 16-fold increase (P = 0.001) in the insulin-induced gene 1 was also observed on d 3 in pigs provided JD8715 compared to control pigs. Together, these data suggest that providing Enterobacter cloacae JD8715 increased the amount of triglycerides available to the pigs, thus potentially improving the availability of energy. Further research is needed to determine how this increase modulates the immune response.
pigs, lipids, adipose tissue