Deficiency in sPLA2 does not affect HDL levels or atherosclerosis in mice

Secretory non-pancreatic phospholipase A2 (sPLA2) has been implicated in inflammation and has been found in human atherosclerotic lesions. To test the effect of sPLA2 deficiency on atherosclerosis, C57BL/Ks mice (apoE+/+ and sPLA2+/+) were bred with C57BL/6 apoE knockout mice which are sPLA2−/− due to a spontaneous mutation. Sibling pairs of mice (apoE−/−/sPLA2+/+ and apoE−/−/sPLA2−/−) on high fat Western diets were dissected at 22 weeks. In vitro enzyme assays confirmed higher serum sPLA2 activity in the sPLA2+/+ compared to sPLA2−/− for both sexes, while sPLA2−/− males had slightly higher serum cholesterol and phospholipids. Analysis of lipoprotein profiles by FPLC showed no effect of sPLA2 genotype on any measured parameters. Atherosclerosis was quantitated by assaying cholesterol in aortic extracts. Male sPLA2−/− trended slightly higher than sPLA2+/+ with no statistical significance. Female sPLA2+/+ and sPLA2−/− mice showed no significant differences in any of the measured parameters. These results suggest that the endogenous mouse sPLA2 gene does not significantly affect HDL or atherosclerosis in mice.