Glucose and insulin modify thrombospondin 1 expression and secretion in primary adipocytes from diet-induced obese rats

Garcia-Diaz, Diego F.; Arellano, Arianna V.; Milagro, Fermin I.; Jesus Moreno-Aliaga, Maria; Puy Portillo, Maria; Alfredo Martinez, J.; Campion, Javier

Abstract

Thrombospondin 1 (TSP-1), an antiangiogenic factor and transforming growth factor (TGF)-beta activity regulator, has been recently recognized as an adipokine that correlates with obesity, inflammation and insulin resistance processes. In the present study, epididymal adipocytes of rats that were fed a chow or a high-fat diet (HFD) for 50 days were isolated and incubated (24-72 h) in low (5.6 mM) or high (HG; 25 mM) glucose, in the presence or absence of 1.6 nM insulin. Rats fed the HF diet showed an established obesity state. Serum TSP-1 levels and TSP-1 mRNA basal expression of adipocytes from HFD rats were higher than those from controls. Adipocytes from HFD animals presented an insulin resistance state, as suggested by the lower insulin-stimulated glucose uptake as compared to controls. TSP-1 expression in culture was higher in adipocytes from obese animals at 24 h, but when the adipocytes were treated with HG, these expression levels dropped dramatically. Later at 72 h, TSP-1 expression was lower in adipocytes from HFD rats, and no effects of the other treatments were observed. Surprisingly, the secretion levels of this protein at 72 h were increased significantly by the HG treatment in both types of adipocytes, although they were even higher in adipocytes from obese animals. Finally, cell viability was significantly reduced by HG treatment in both types of adipocytes. In summary, TSP-1 expression/secretion was modulated in an in vitro model of insulin-resistant adipocytes. The difference between expression and secretion patterns suggests a posttranscriptional regulation. The present study confirms that TPS-1 is closely associated with obesity-related mechanisms.

Más información

Título según WOS: ID WOS:000293774100017 Not found in local WOS DB
Título de la Revista: JOURNAL OF PHYSIOLOGY AND BIOCHEMISTRY
Volumen: 67
Número: 3
Editorial: SERVICIO PUBLICACIONES UNIVERSIDAD NAVARRA
Fecha de publicación: 2011
Página de inicio: 453
Página final: 461
DOI:

10.1007/s13105-011-0081-7

Notas: ISI