Increased expression of transthyretin in leptin-deficient ob/ob mice is not causative for their major phenotypic abnormalities.
J Neuroendocrinol
; 25(1): 14-22, 2013 Jan.
Article
en En
| MEDLINE
| ID: mdl-22849972
ABSTRACT
The hormone leptin is a critical regulator of adipogenesis and energy metabolism. Similarly, leptin-deficient ob/ob mice display various metabolic abnormalities, including not only obesity and insulin resistance, but also hypogonadism and high bone mass. By genome-wide expression analysis using hypothalamus RNA from wild-type and ob/ob mice, we observed the increased expression of the gene for transthyretin (Ttr) in the latter, as confirmed by quantitative real-time-polymerase chain reaction. Because Ttr encodes a carrier protein for retinol transport, and because we further found increased retinol levels in the serum of ob/ob mice, we investigated whether the additional absence of Ttr would influence the ob/ob phenotype. It was found that Ttr-deficient ob/ob mice were indistinguishable from ob/ob littermates in terms of body weight, as well as serum glucose, insulin and cholesterol levels. Although all of these parameters were identical to wild-type controls in Ttr-deficient mice, we found that the sole deletion of Ttr caused a significant increase of trabecular bone mass, bone marrow adiposity and mean adipocyte area in white adipose tissue. Interestingly, all these latter parameters were highest in Ttr-deficient ob/ob mice, and only in these mice did we observe a full penetrance of liver steatosis at 24 weeks of age. Taken together, our data demonstrate that the increased expression of Ttr in ob/ob mice does not cause (but rather attenuates) their phenotypic abnormalities.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Fenotipo
/
Prealbúmina
/
Leptina
/
Hipotálamo
/
Obesidad
Límite:
Animals
Idioma:
En
Revista:
J Neuroendocrinol
Asunto de la revista:
ENDOCRINOLOGIA
/
NEUROLOGIA
Año:
2013
Tipo del documento:
Article
País de afiliación:
Alemania