Objective To investigate whether inflammatory stress exacerbates lipid accumulation and the mechanism of up - regulation of sterol regulatory element binding protein 2 (SREBP2) expression in the aorta of scavenger receptor double knockout (SR DKO) mice.  Methods Male SR DKO mice fed with high lipid diet were randomly divided into the control group (

n

=7) and the inflammation group induced by 10% (w/v) 0 . 5 ml casein injection (

n

=6). After 14 weeks

the mice were sacrificed

and the blood

sample of right atrium was collected and the aorta was taken. Inflammatory cytokines

such as serum amyloid A (SAA)

IL - 6 and TNF - α was determined by ELISA. Serum levels of total cholesterol (TC) and low - density lipid cholesterol (LDL - C) were detected by enzymatic assay. Frozen sections of aorta were stained with Red Oil O to visualize lipid accumulation. Both the mRNA and protein expressions of SREBP2

SREBP cleavage - activating protein (SCAP) and low density lipoprotein receptor (LDLr) in the aorta were measured by real - time polymerase chain reaction and immunohistochemical staining respectively.  Results Increased of serum SAA was observed in inflammatory mice (10.32 ± 2.88

vs

5.50 ± 2.67 ng/ml

P

0 . 05). In the inflammatory mice

a increase in SREBP2

SCAP and LDLr mRNA level of the aorta

as well as mature SREBP2

SCAP and LDLr proteins abundance were found

when compared with control animals (

P

0 . 05).  Conclusion Inflammatory SR DKO mice are associated with increased SREBP2 gene expression of aortas. This is probably the cause for enhanced SCAP gene expression and

consequently

for increase cholesterol uptake through LDLr pathway and for promoting lipid accumulation in aortas of the mice with absence of uptake of modified LDL.