Hormone-sensitive lipase deficiency in mice causes lipid storage in the adrenal cortex and impaired corticosterone response to corticotropin stimulation.
Hormone-sensitive lipase (HSL, E.C.3.1.1.3, gene designation Lipe) is reportedly the major cholesteryl esterase of adrenal cortex. Because of the potential importance of cholesteryl ester hydrolysis in steroidogenesis, gene-targeted HSL-deficient mice were assessed for adrenal cortical morphology and function. Compared with control animals, HSL deficiency results in a marked accumulation of lipid droplets both in zona glomerulosa and zona fasciculata. In the zona fasciculata, lipid accumulation was observed progressively from the outer to the inner regions, culminating near the corticomedullary junction with the formation of syncytial-lipoid structures having the appearance of degenerative cells. These morphological changes did not significantly alter the basal levels of circulating corticosterone, but following ACTH stimulation, corticosterone levels were decreased (P < 0.001). The observation of normal basal corticosterone and aldosterone levels demonstrates that some free cholesterol for steroid synthesis can be produced independently of HSL. Taken together, these results indicate that HSL-deficient mice accumulate lipid droplets in such a way as to impair acute ACTH stimulation of corticosterone secretion. Such observations are also found in some forms of congenital adrenal hyperplasia. By extension, HSL deficiency may be a cause of hereditary adrenocortical hypofunction in humans.
Service de Génétique Médicale, Hôpital Ste-Justine, Montréal, Canada H3T 1C5.
Hong
H
Li
Michèle
M
Brochu
Shu Pei
SP
Wang
Leila
L
Rochdi
Mylène
M
Côté
Grant
G
Mitchell
Nicole
N
Gallo-Payet
D000302:Adrenal Cortex / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D000312:Adrenal Hyperplasia, Congenital / Q000378:metabolism; D000313:Adrenal Medulla / Q000378:metabolism; D000324:Adrenocorticotropic Hormone / Q000494:pharmacology*; D000450:Aldosterone / Q000097:blood; D000818:Animals; D002788:Cholesterol Esters / Q000378:metabolism; D003345:Corticosterone / Q000097:blood / Q000494:pharmacology*; D018390:Gene Targeting; D006868:Hydrolysis; D050356:Lipid Metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008854:Microscopy, Electron; D008928:Mitochondria / Q000648:ultrastructure; D002787:Sterol Esterase / Q000172:deficiency*; D015383:Zona Fasciculata / Q000378:metabolism / Q000648:ultrastructure; D015384:Zona Glomerulosa / Q000378:metabolism / Q000648:ultrastructure
D002788:Cholesterol Esters; D000450:Aldosterone; D000324:Adrenocorticotropic Hormone; D002787:Sterol Esterase; D003345:Corticosterone