Effect Of Milk Fat Precursor On Lipid Metabolism In LPS Induced Hepatic Cell Injury

Subacute ruminal acidosis(SARA) is a common metabolic disorder. Ruminal free lipopolysaccharide(LPS) increases during SARA and translocates into the blood circulation activating an inflammatory response,inducing liver injury and leading to a decline in milk production, especially milk fat decreased.Acetic acid and β-hydroxybutyric acid are the main precursors of butterfat can also act as signaling molecules to regulate expression of lipid metabolism genes in the liver.There is several report about the precursors of butterfat effect on the fatty acid metabolism in LPS-induced degeneration of liver cell.In this study, Acetic acid and β-hydroxybutyric acid are treated to LPS-induced degeneration of liver cell,then the relative m RNA expression of apoptosis,mastitis and hepatic gene expression were detected by realtime fluorescence quantitative PCR. In this paper,we illustrates the influence of the precursors of butterfat effect on the fatty acid metabolism in LPS-induced degeneration of liver cell, to provide a theoretical basis for the early reveal SARA caused decrease of milk fat.LPS promotes liver cell injury and apoptosis through activating the TLR4 signaling pathway and apoptosis signal transduction pathway.LPS can increase lipid oxidation and transport, decrease lipid synthesis in liver cell.By upregulating the genes expression of PPAR α 、 CPT 、 LPL 、 CD36 、VLDLR,reducing the expression and transcriptional activity of PPAR γ、SREBP-1c、Ch REBP、FAS、ACC、SCD genes.Acetic acid can activates the AMPK signaling pathway to promote lipid oxidation and inhibition of lipid synthesis in hepatocytes. Acetic acid can increases the expression and transcriptional activity of PPAR α、PPAR γ、Ch REBP and they downstream genes,inhibits the expression and transcriptional activity of SREBP-1c、FAS、ACC.Furthermore,acetic acid can weaken the inhibitory effect of LPS on the related genes of lipid synthesis and transport.β-hydroxybutyric activates the AMPK signaling pathway to increase lipid oxidation and transport, decrease lipid synthesis in hepatocytes, thereby reducing liver fat accumulation in the liver.The effect of BHBA on the transcriptional activity of PPAR α、PPAR γ、Ch REBP are decreased in LPS-induced liver cells than only BHBA treatment.Moreover,BHBA can affect the ability of LPS regulating fatty acid transport in a certain extent.