GPR109A (HM74A), a G-protein-coupled receptor, is hypothesized to mediate lipid and lipoprotein changes and dermal flushing associated with niacin administration. GSK256073 (8-chloro-3-pentyl-1H-purine-2,6[3H,7H]-dione) is a selective GPR109A agonist shown to suppress fatty acid levels and produce mild flushing in short-term clinical studies. This study evaluated the effects of GSK256073 on lipids in subjects with low high-density lipoprotein cholesterol (HDLc).
View Article and Find Full Text PDFUsing microarray technology, we analyzed 12,000 genes for regulation by TNF-alpha and the synthetic glucocorticoid, dexamethasone, in the human lung epithelial cell line, A549. Only one gene was induced by both agents, the cellular inhibitor of apoptosis 2 (c-IAP2), which was induced 17-fold and 5-fold by TNF-alpha at 2 h and 24 h, respectively, and increased 14-fold and 9-fold by dexamethasone at 2 h and 24 h, respectively. The combination of the two agents together led to an additive increase (34-fold) at 2 h and a more than additive effect (36-fold) at 24 h.
View Article and Find Full Text PDFBile acid biosynthesis is regulated by both feed-forward and feedback mechanisms involving a cascade of nuclear hormone receptors. Feed-forward regulation of the rate limiting enzyme in bile acid biosynthesis is provided by oxysterols through liver-X-receptor alpha (NR1H3), while feedback regulation is provided by bile acids through farnesoid-X-receptor (FXR) (NR1H4). The Syrian golden hamster provides a useful model for studying lipid metabolism.
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