ABSTRACT
Diacylglycerol acyltransferase (DGAT) enzymes are involved in triglyceride (TG) biosynthesis. GSK3008356 is a potent and selective DGAT1 inhibitor that was administered orally in a 2-part study as double-blind, randomized, placebo-controlled single doses (SDs) and repeat doses (RDs) in healthy subjects to investigate its pharmacokinetics, pharmacodynamics, and safety/tolerability. Gastrointestinal adverse events were considered drug related and increased with dose and when given as multiple doses. In the SD part (n = 80), GSK3008356 was dosed from 5 to 200 mg as single or multiple doses per day. In the RD part (n = 24), GSK3008356 was dosed twice daily at 1, 3, and 10 mg for 14 days. GSK3008356 was generally well tolerated in the SD and RD parts. With single doses, absorption was rapid (median tmax , 0.5-1.5 hours), whereas single-day divided dosing resulted in higher tmax . Following 14-day RD oral administration, GSK3008356 was also rapidly absorbed, with median tmax ranging from 0.5 to 0.75 hours on days 1 and 14. Estimated mean half-life ranged from 1.5 to 4.6 hours with SDs and 1.3 to 2.1 hours with RDs. Exposure of GSK3008356 was largely dose proportional after RDs. At higher doses, there was a trend toward lower absolute postprandial TG level in some subjects.
Subject(s)
Diacylglycerol O-Acyltransferase/antagonists & inhibitors , Drug-Related Side Effects and Adverse Reactions/etiology , Enzyme Inhibitors/adverse effects , Enzyme Inhibitors/pharmacokinetics , Gastrointestinal Tract/drug effects , Indoles/adverse effects , Pyrimidines/adverse effects , Administration, Oral , Adolescent , Adult , Area Under Curve , Biomarkers/blood , Dose-Response Relationship, Drug , Double-Blind Method , Drug-Related Side Effects and Adverse Reactions/epidemiology , Enzyme Inhibitors/blood , Enzyme Inhibitors/urine , Female , Healthy Volunteers , Humans , Indoles/pharmacokinetics , Indoles/urine , Male , Middle Aged , Pyrimidines/pharmacokinetics , Pyrimidines/urine , Triglycerides/blood , Young AdultABSTRACT
In our continuing efforts to identify small molecule vitronectin receptor antagonists, we have discovered a series of phenylbutyrate derivatives, exemplified by 16, which have good potency and excellent oral bioavailability (approximately 100% in rats). This new series is derived conceptually from opening of the seven-membered ring of SB-265123.
Subject(s)
Integrin alphaVbeta3/antagonists & inhibitors , Phenylbutyrates/pharmacology , Phenylbutyrates/pharmacokinetics , Acetates/chemistry , Administration, Oral , Aminopyridines/chemistry , Animals , Biological Availability , Cell Adhesion/drug effects , Cell Line , Half-Life , Humans , Phenylbutyrates/chemistry , RatsABSTRACT
We have recently reported the identification of four novel members of the interleukin-1 (IL-1) family which we designated as IL-1 homologue 1-4 (IL-1H1-4). These proteins exhibit significant sequence homology to other members of the IL-1 family. Of these homologues, only IL-1H4 (renamed IL-1F7b) was predicted to contain a propeptide domain and a caspase cleavage site. We now report that caspase-1 cleaves IL-1F7b at the predicted site to generate mature IL-1F7b. Caspase-4 was also able to process IL-1F7b, albeit inefficiently. Other caspases and Granzyme-B did not cleave IL-1F7b. Furthermore, adenovirus-mediated expression of IL-1F7b in HEK 293 cells led to in situ processing and secretion of mature IL-1F7b. In a screen to identify a potential receptor, both pro and mature IL-1F7b bound to the soluble IL-18 receptor alpha-Fc (IL-18Ralpha-Fc) but not to the soluble IL-1R-Fc or ST2R-Fc fusion proteins. Mature IL-1F7b bound to the IL-18Ralpha-Fc protein with higher affinity than the pro form, although the affinities for both proteins were significantly lower than that observed for IL-18. Consistent with this observation, only IL-18 and not IL-1F7b induced IFN-gamma production by KG1a cells. We also report that pro and mature IL-1F7b form homodimers with association constants of 4 microM and 5 nM, respectively, suggesting biological relevance to IL-1F7b processing. Finally, we have localized the expression of IL-1F7b protein in discrete cell populations including plasma cells and tumor cells. These data suggest that IL-1F7b may be involved in immune response, inflammatory diseases and/or cancer.
