Pro-inflammatory remodeling of high density lipoprotein (HDL) precedes development of dyslipidemia and hepatic steatosis upon exposure to four weeks of high fat diet

ABSTRACT: Long-term high fat feeding leads to hepatic steatosis, dyslipidemia, and a pro-inflammatory state. In a previous study, we observed this dysregulated metabolic phenotype when C57BL/6 mice were fed a high fat diet (HFD) for sixteen weeks. Additionally, a five-fold increase in liver gene expression of serum amyloid A-1 (SAA-1), an acute phase response protein that associates with high density lipoprotein (HDL), was observed. Inflammation induced changes composition may alter HDL functions, including anti-oxidant, anti-inflammatory and reverse cholesterol transport properties. Diet-induced onset and progression of HDL dysfunction is poorly understood. To examine the relationship between high fat diet and HDL dysfunction, we performed a short-term diet study. Four-week high fat feeding caused an increase in total plasma cholesterol compared with mice fed normal control diet (ND). No change in plasma triglycerides or development of hepatic steatosis was observed. These mice did however show evidence for increase in acute phase reactants, with a 3.25-fold increase in SAA-1 expression in liver. Heavy water labelling was used to determine the turnover rates of proteins associated with HDL. High fat diet resulted in increased fractional catabolic rate (HFD vs ND) of several acute phase response proteins involved ininnate immunity , including – Complement C3 (7.06 ± 0.99 vs 5.20 ± 0.56 %/h, p < 0.005), complement factor B (6.17 ± 0.59 vs 5.09 ± 0.87 %/h, p < 0.05), complement Factor H (4.16 ± 0.41 vs 3.56 ± 0.36 %/h, p < 0.05), and Complement factor I (3.50 ± 0.26 vs 2.75 ± 0.14 %/h, p < 0.005). Our findings suggest that early immune response-induced inflammatory remodeling of HDL precedes the diet-induced steatosis and dyslipidemia. Early HDL dysfunction reflected on impaired reverse cholesterol transport likely results in increase in plasma cholesterol in the absence of other lipid abnormalities.

INSTRUMENT(S): Q Exactive

ORGANISM(S): Mus Musculus (mouse)

TISSUE(S): Blood Plasma

DISEASE(S): Fatty Liver Disease

SUBMITTER: Serguei Ilchenko  

LAB HEAD: Takhar Kasumov

PROVIDER: PXD010272 | Pride | 2021-09-08

REPOSITORIES: Pride