Age-related changes in bile acid synthesis and hepatic nuclear receptor expression.
Eur J Clin Invest
; 37(6): 501-8, 2007 Jun.
Article
en En
| MEDLINE
| ID: mdl-17537158
ABSTRACT
BACKGROUND:
Recent data highlighted the role of nuclear receptors in the transcriptional regulation of the limiting enzyme of bile acid synthesis, cholesterol 7alpha-hydroxylase, in cellular and animal models. This study was designed to analyze the effects of age on cholesterol 7alpha-hydroxylase and related nuclear receptor expression in human livers.DESIGN:
Surgical liver biopsies were obtained in 23 patients requiring operation on the gastrointestinal tract. mRNA levels of cholesterol 7alpha-hydroxylase and related nuclear receptors and co-activators were assayed by quantitative real-time RT-PCR. Serum levels of 7alpha-hydroxy-4-cholesten-3-one, a marker of bile acid synthesis, were assayed by gas-liquid chromatographymass spectrometry.RESULTS:
Ageing was inversely correlated with serum 7alpha-hydroxy-4-cholesten-3-one and with cholesterol 7alpha-hydroxylase mRNA levels (r = -0.44 and r = -0.45 on a semi-log scale, respectively, P < 0.05). Among different nuclear factors, cholesterol 7alpha-hydroxylase mRNA best correlated with hepatocyte nuclear factor-4 (r = 0.55 on a log scale, P < 0.05); hepatocyte nuclear factor-4 levels were also inversely correlated with age (r = -0.64 on a semi-log scale, P < 0.05). Age was inversely correlated with serum insulin-like growth factor-I levels, which were directly correlated with hepatocyte nuclear factor-4 and cholesterol 7alpha-hydroxylase expression. No suppressive effect of short heterodimer partner expression on cholesterol 7alpha-hydroxylase was observed.CONCLUSIONS:
Ageing associates with reduced bile acid synthesis, possibly related to decreased hepatic expression of hepatocyte nuclear factor-4 and consequently of cholesterol 7alpha-hydroxylase. Age-related modifications of the growth hormone/insulin-like growth factor axis might play a role. These findings may help to elucidate the pathophysiology of age-related modifications of cholesterol metabolism.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Envejecimiento
/
Ácidos y Sales Biliares
/
Colesterol 7-alfa-Hidroxilasa
/
Factor Nuclear 4 del Hepatocito
/
Hígado
Tipo de estudio:
Prognostic_studies
Límite:
Adolescent
/
Adult
/
Aged
/
Aged80
/
Female
/
Humans
/
Male
/
Middle aged
Idioma:
En
Revista:
Eur J Clin Invest
Año:
2007
Tipo del documento:
Article
País de afiliación:
Italia