The Changes Of Genes Expression Related To Lipid Metabolism In Liver Injury Induced By Lipopolysaccharide

The liver detoxification function of ruminant animal immunity relates to cow health.Ithas attracted scientists attention.The research shows that LPS can induce mastitis and hepaticgene expression profiling changed significantly (Jiang et al.2008; Vels et al.2009). Show thatThe ruminant animal liver microorganisms (LPS) into the digestive tract effect on geneexpression in hepatocytes, which has become a frontier reserach field to liver.In this paper, from two aspects of in vivo and in vitro, two aspects of LPS for differentdoses and different time of liver induced test, the expression changes of cytokines and lipidmetabolism related inflammation related genes to study the changes of lipid metabolismrelated gene expression of LPS induced liver injury in the mechanism. This topic researchcontents and results are as follows:1Isolation and culture of calf hepatocytes. The results show that the average per calfseparation hepatocytes were1.37±0.51×108, primary hepatocytes viability was95.31±2.3%,the best period of primary hepatocytes culture for7d.2LPS different doses was0,50ng/ml,75ng/ml,100ng/ml,250ng/ml,500ng/ml(labeledD0, D50, D75, D100, D250, D500) primary stimulation of calf liver cell24h at different time;a standard dose of100ng/ml LPS effect on primary hepatocytes respectively:0,1,3,6,9,12,24h (labeled T0, T1, T3, T6, T9, T12, T24). To study the effect of LPS on the expression ofliver TLR4, MyD88, NF-κB, IRAK4, IL-10, TNFα and other inflammatory gene.2.1LPS induced primary hepatic a dose effect on inflammatory cytokine gene expression:LPS can upregulate the expression of MyD88, IRAK4, NF-κB, IL-10, but the expression ofTLR4and TNFα little effect.2.2LPS induced primary hepatic time effect of inflammatory cytokine gene expression:LPS can promote the expression in primary hepatocytes MyD88, NF-κB, IRAK4, TNFα,IL-10, expression and inhibition of TLR4, the best time at T6-T9.3By add different doses of LPS (0,50ng/ml,75ng/ml,100ng/ml,250ng/ml,500ng/ml)primary stimulation of primary hepatocytes24h, the LPS standard dose is100ng/mL indifferent time (0,1,3,6,9,12,24h), generation of grease detecting primary hepatocyteswas ACC, CD36, SCD, FAS, LXRβ, LXRα expression changes, the results are as follows: 3.1LPS induced lipid metabolism primary hepatocytes related gene expression time effect:the expression of LPS can significantly inhibit SCD, CD36, upregulate the expression ofLXRα, LXRβ, FAS, ACC.3.2Dose effect of LPS induced expression of lipid metabolism in primary hepatocytes:effect of related genes in both time and dose of LPS on liver lipid metabolism gene changesare obvious, time, LPS can upregulate the expression of LXRα, LXRβ, FAS, ACC, and dose,LPS was down regulated expression LXRβ, FAS, ACC.4Lactating Saanen dairy goat as research object, by intravenous injection of differentdoses of LPS (0,1,3,5,7,10mg/kg B.W, D0, D1, respectively, marked D3, D5, D7, D10)continuous stimulation of hepatic24h dose effect experiment，intravenous injection of LPSstandard dose3mg/kg B.W, stimulated respectively different time (0,1,3,6,9,12,24h,markT0, T1, T3, T6, T9, T12, T24) test time effect of LPS, and then was measured in bloodand dirty enzymes (GPT, GOT) content changes and the expression of TLR4, MyD88, NF-κB, IRAK4, IL-10, TNFα.,the degree of liver damage by LPS. The results are as follows:4.1With the increase of LPS dosage and time, damage of liver tissue to gradualincrease，GPT and GOT content showed a trend of increase in blood and liver tissue4.2LPS stimulation liver inflammatory factor (TLR4, MyD88, NF-κB, IRAK4, IL-10,TNFα) expression: time effect has little effect on the expression of LPS TLR4in liver, but itcan improve the expression of NF-κB,IRAK4, MyD88, and associated with the time, the besttime is T6-T9. The expression of TNF α was not obvious, but it can significantly increase theexpression of IL-10.4.3LPS stimulation of liver inflammatory factor (TLR4, MyD88, NF-κB, IRAK4, IL-10,TNFα) dose effect expression: the expression of the TLR4almost has no effect, but couldenhance MyD88, expression of NF-κB, IRAK4, and the optimum dosage of3mg/kg. Theexpression of TNF α and IL-10showed the increase trend of the whole.5Lactating Saanendairy goat as research object, by intravenous injection different dosesof LPS (0,1,3,5,7,10mg/kg B.W,) for (24h) and intravenous injection LPS standard dose(3mg/kg B.W) at different time (0,1,3,6,9,12,24h) in the liver lipid metabolism relatedgenes to study LPS induced liver injury (SCD, ACC, CD36, FAS, LXRβ, LXRα) expressionchanges, the results are as follows:5.1With the duration of LPS effect, the expression of LXRα is-up-down-up trend;LXRβ expression showed first increased and then decreased, the expression of ACC isincreased, FAS is showed increased expression，and SCD, CD36overall declining changestrend.5.2Dose of LPS effect on expression related to lipid metabolism genes in liver: with the dose of LPS increased, the expression of LXRα, LXRβ overall showed a downward trend;the expression of ACC, FAS presents an overall upward trend, the expression of SCD, CD36overall change is not obvious. The expression of ACC, FAS, CD36, SCD by LPS treatmentdose effect.Conclusion: In this paper, the calf primary hepatocytes and lactating Saanen dairygoats as the carrier, the test dose effect and time effect by LPS from in vitro and in vivo to acton the liver, the expression of LPS on inflammatory factor and liver lipid metabolism relatedgenes. The results showed that LPS can up regulate the expression of liver injury inducedinflammatory signaling molecules, the dose and time of LPS to the degree of injury is related;The inhibition of expression of LPS and its target gene by down-regulation of ACC, LXRα toreduce the ability of synthesis and transport of fatty acids. The research for ruminant animalrumen metabolism product LPS influence on milk fat synthesis and improve milk qualityprovide a theoretical basis.