RT Journal Article
SR Electronic
T1 YIA2 11β-HSD1 deficiency attenuates atherosclerosis in ApoE−/− mice: role of both glucocorticoid and non-glucocorticoid (oxysterol) factors
JF Heart
JO Heart
FD BMJ Publishing Group Ltd and British Cardiovascular Society
SP e9
OP e9
DO 10.1136/hrt.2010.205781.2
VO 96
IS 17
A1 T Mitic
A1 P W F Hadoke
A1 S Chuaiphichai
A1 T Y Man
A1 E Miller
A1 R Andrew
A1 B R Walker
A1 K E Chapman
A1 J R Seckl
YR 2010
UL http://heart.bmj.com/content/96/17/e9.2.abstract
AB 11β-Hydroxysteroid dehydrogenase type 1 (11β-HSD1) regenerates active glucocorticoids, amplifying intracellular actions.1 11β-HSD1 deficiency or inhibition improves metabolic syndrome and attenuates atherosclerosis in vulnerable rodent strains and is a target for drug development.2–4 However, 11β-HSD1 also catalyses conversion of 7-ketocholesterol,5 which accumulates in fatty tissues,6 to potentially more atherogenic 7β-hydroxycholesterol. Whether atheroprotection with 11β-HSD1 deficiency is dependent on glucocorticoid or oxysterol effects is unknown. Male atherosclerosis-prone ApoE−/− and ApoE−/−.11β-HSD1−/− double knockout (DKO) mice underwent adrenalectomy or sham surgery (n=8/group), then received a high (0.2%) cholesterol Western diet for 12 weeks. The aorta and branches were perfusion-fixed. Lesion volume and extracellular lipids were determined by 3D optical projection tomography. Data are mean±SE of the means. Adrenalectomy had no effect on body/organ weights in either genotype. Removal of endogenous glucocorticoids by adrenalectomy in ApoE−/− mice did not reduce lesion volume (232±24 vs 235±34 μm3 sham control). DKO mice had reduced lesion volumes (139±17 μm3) compared with ApoE−/−(p<0.05). Adrenalectomy reversed this effect (263±52 μm3).Adrenalectomised DKO mice had increased extracellular lipids (73.6±2.6 μm3) within the lesion compared with either ApoE−/− adrenalectomised (37.4±5.2 μm3), ApoE−/− sham (42.9±5.5 μm3) or DKO sham (44.2±12 μm3) group. Thus circulating glucocorticoids are necessary for 11β-HSD1 deficiency to attenuate atherosclerosis. However, 11β-HSD1 deficiency increases the lipid content of plaques in the absence of glucocorticoids, perhaps owing to accumulation of 7-ketocholesterol? Consequently, both reactions of 11β-HSD1 may be involved in the effects of the enzyme on atherogenesis.