@entity6170 prevents the impairment of XXXX islet function induced by @entity1718 : evidence for a role of PPARgamma2 in the modulation of insulin secretion.

@entity1 @entity844 @entity2365 @entity13149 @entity5601 @entity1718 @entity6170 @entity413 @entity6864 @entity11589
Peroxisome proliferator-activated receptors (PPARs) are a subgroup of the superfamily of nuclear receptors, with three distinct main types: alpha, beta and gamma (subdivided into gamma(1) and gamma(2)). Recently, the presence of @entity6864 has been reported in @entity1 islets. Whether other @entity5601 types can be found in @entity1 islets, how islet @entity6864 mRNA expression is regulated by the metabolic milieu, their role in insulin secretion, and the effects of a @entity6864 agonist are not known. In this study, @entity1 pancreatic islets were prepared by collagenase digestion and density gradient purification from nonobese adult donors. The presence of @entity5601 mRNAs was assessed by RT-PCR, and the effect was evaluated of exposure for up to 24 h to either 22.2 mmol/l @entity413 and/or 0.25, 0.5, or 1.0 mmol/l long-chain @entity844 mixture (oleate to @entity2365 , 2:1). @entity11589 and, to a greater extent, total @entity6864 and @entity6864 (2) mRNAs were expressed in @entity1 islets, whereas @entity5601 mRNA was not detected. Compared with @entity1 adipose tissue, @entity6864 mRNA was expressed at lower levels in the islets, and @entity11589 at similar levels. The expression of @entity6864 (2) mRNA was not affected by exposure to 22.2 mmol/l @entity413 , whereas it decreased markedly and time-dependently after exposure to progressively higher free @entity1718 (FFA). This latter effect was not affected by the concomitant presence of high @entity413 . Exposure to FFA caused inhibition of insulin mRNA expression, @entity413 -stimulated insulin release, and reduction of islet insulin content. The @entity6864 agonists @entity6170 and @entity13149 prevented the cytostatic effect of FFA as well as the FFA-induced changes of @entity5601 and insulin mRNA expression. In conclusion, this study shows that @entity6864 mRNA is expressed in @entity1 pancreatic islets, with predominance of @entity6864 (2); exposure to FFA downregulates @entity6864 (2) and insulin mRNA expression and inhibits @entity413 -stimulated insulin secretion; exposure to @entity6864 agonists can prevent these effects.
