Characterisation of insulin-resistant phenotype of cultured XXXX primary adipose cells.

@entity844 @entity70840 @entity35 @entity1792 @entity209 @entity413 @entity2388
AIMS/HYPOTHESIS: We characterised insulin resistance, @entity209 and endocrine dysfunction in cultured adipose cells and examined the autocrine or paracrine roles of cytokines/adipokines in the progression of insulin resistance. MATERIALS AND METHODS: @entity35 primary adipose cells were prepared and cultured for 24 and 48 h. Insulin resistance and gene expression were examined by @entity413 uptake assay, cDNA microarray and real-time RT-PCR. RESULTS: After 24 h in culture, the fold increase of insulin-stimulated @entity413 uptake in adipose cells was markedly reduced; after 48 h the response of the cells to insulin decreased. cDNA microarray analysis showed that the expression of 514 genes was altered in adipose cells after 24 h in culture. The dysregulated genes included those involved in the @entity1792 cycle and in @entity844 and @entity2388 @entity209 . Specifically, the following genes were all downregulated: genes encoding lipolytic and lipogenic enzymes; uncoupling protein 1 and 2 genes; @entity70840 gene. This indicates that lipolytic and lipogenic activity, as well as mitochondria capacity decline in adipose cells cultured for 24 h. The mRNAs encoding 40 adipokines were also dysregulated in cultured cells. Strikingly, the dysregulated adipokines in cultured cells and in freshly isolated adipose cells from insulin-resistant Zucker fa/fa @entity35 displayed a similar pattern with regard to protein functions. Also striking was the fact that progression of insulin resistance was promoted by the adipokines secreted from insulin-resistant adipose tissue or cells. CONCLUSIONS/INTERPRETATION: Our data demonstrate that the impairment of @entity209 and endocrine dysfunction in cultured adipose cells mimics the insulin resistance occurring in vivo. Cytokines and adipokines appear to play a critical role in the progression of insulin resistance in adipose cells.
