Late-gestation Maternal Chitosan-oligosaccharide Feeding Affects Hepatic Lipid Metabolism In The Suckling Offsprings

The aim of this study was to investigate whether dietary supplementation of chitosan-oligosaccharide(COS)in sows during late-gestation and lactation would affect hepatic lipid metabolism in the neonatal and suckling piglets.From day 85 of gestation,40 pregnant sows were divided into 2 dietary treatments and fed two diets with 0 or 30 mg COS/kg feed.After farrowing,a piglet from 8 litters in each treatment was bled and euthanized to collect liver tissue on d 0 and d 14 of age.Samples were used to measure serum lipid,hepatic lipid and expression of genes and protein for circadian clock and lipid metabolism in the liver.The results showed that:(1)COS supplementation increased the serum and hepatic HDL-C(P < 0.05),T-CHO,LDL-C and HDL-C/ LDL-C(P < 0.01)in piglet on d 14 of age.However,there is no significantly effected on the serum and hepatic HDL-C,T-CHO,LDL-C,TG and HDL-C/ LDL-C(P> 0.05)in piglet on d 0 of age.(2)COS supplementation down regulated(P<0.05)expression of circadian clock genesPer1,Per2,Cry2 and Rev-erba1 in piglets on d 0 of age.And on d 14 of lactation,COS supplementation increased(P < 0.01)expression of circadian clock genes Per1.(3)COS supplementation in sow diets reduced(P< 0.05)de novo lipid synthesis capacity in the liver by down-regulating gene expression of HMGCR,FAS and ACC in piglets on d 14 of age.And on d 14 of age,COS supplementation increased(P < 0.05)expression of hepatic lipid metabolism genes Cyp7?1 and LCAT.(4)COS supplementation reduced(P < 0.05)protein expression of CLOCK,BMAL1,T-mTOR and p-mTOR in piglets' liver on d 14 of age.However,COS supplementation increased(P < 0.05)protein expression of T-AMPK?1/2 and pAMPK?1/2 in piglets' liver on d 14 of age.The results showed that COS supplementation in sow diets could affect the hepatic lipid metabolism by pathways:(1)Affected the AMPK pathway and mTOR pathway,inhibited the de novo synthesis of fatty acids and cholesterol.Increased the secretion of cholesterol to maintain the cholesterol homeostasis.(2)Stimulated heptic circadian negativeelement Per1,suppressed the protein expression of CLOCK and BMAL1,and increased the cholesterol accumulation in the serum and liver.Cholesterol can inhibition of lipid metabolic gene by negative feedback.Collectively,our study suggested that dietary supplementation of Chitosan-oligosaccharide in a sow's during gestation and lactation significantly affected hepatic lipid metabolism inthe neonatal and suckling offsprings.Collectively,it can be concluded that COS supplemented in sow diets were delivered in utero and postnatal affecting hepatic circadian clock and lipid metabolism of offspring.