Search

Cortisol and the glucocorticoid receptor signaling pathway have been implicated in the development of diabetes and obesity. The reduction of cortisone to cortisol is catalyzed by 11beta-hydroxysteroid dehydrogenase type I (11beta-HSD1). 2,4-Disubsituted benzenesulfonamides were identified as potent inhibitors of both the human and mouse enzymes. The lead compounds displayed good pharmacokinetics and ex vivo inhibition of the target in mice. Cocrystal structures of compounds 1 and 20 bound to human 11beta-HSD1 were obtained. Compound 20 was found to achieve high concentrations in target tissues, resulting in 95% inhibition in the ex vivo assay when dosed with a food mix (0.5 mg of drug per g of food) after 4 days. Compound 20 was efficacious in a mouse diet-induced obesity model and significantly reduced fed glucose and fasted insulin levels. Our findings suggest that 11beta-HSD1 inhibition may be a valid target for the treatment of diabetes.

11beta-Hydroxysteroid dehydrogenase type 1 (11beta-HSD1) is the enzyme that converts cortisone to cortisol. Evidence suggests that selective inhibition of 11beta-HSD1 could treat diabetes and metabolic syndrome. Presented herein are the synthesis, structure-activity relationship, and in vivo evaluation of piperazine sulfonamides as 11beta-HSD1 inhibitors. Through modification of our initial lead 5a, we have identified potent and selective 11beta-HSD1 inhibitors such as 13q and 13u with good pharmacokinetic properties.

The design, synthesis, and biological evaluation of arylsulfonamidooxazoles as 11beta-HSD1 inhibitors and the serendipitous discovery of beta-keto sulfones as potent 11beta-HSD1 inhibitors are described here. These two classes of compounds are not active against 11beta-HSD2 and therefore may have significant therapeutic potential for metabolic syndrome, type 2 diabetes and related metabolic dysfunctions.

Antagonists of the B7 family of co-stimulatory molecules have the potential for altering immune responses therapeutically. To better define the requirements for such inhibitors, we have mapped the binding of an entire panel of blocking antibodies specific for human B7.1. By mutagenesis, each of the residues critical for blocking antibody binding appeared to fall entirely within the N-terminal V-set domain of B7.1. Thus, although antibody-antigen interacting surfaces can be quite large, these results indicate that a relatively small portion of the GFCC'C" face of this domain is crucial for further antagonist development.

The in vivo actions of insulin-like growth factor-I (IGF-I) on cerebellum development have been investigated in transgenic (Tg) mice (IGF-II/I Tg mice) in whom an IGF-II promoter-driven IGF-I transgene is highly expressed in cerebellum. Compared to normal littermates, the brains of IGF-II/I Tg mice exhibited overgrowth beginning from the second week of postnatal life. Among the brain regions examined, cerebellum exhibited the greatest increase in size, such that by 50 days of age cerebellar weight and DNA content were increased by 90% and 143%, respectively, compared to littermate controls. Morphological studies of adult IGF-II/I Tg mice showed that the total number of granule and Purkinje cells was increased by 82% and 20%, respectively, findings consistent with the increased cerebellar DNA content and indicating that the increased cerebellar weight was due in part to an increase in cell number. The thickness of the molecular layer also was increased in IGF-II/I Tg mice. During early postnatal development the number of external granular layer cells, as well as the number of BrdU labeled external granular cells, was increased. These data strongly indicate that IGF-I increases granule cell number by a mechanism that involves the stimulation of granule cell progenitor proliferation. Our findings also indicate that IGF-I influences the growth of Purkinje cells and possibly of other cell types in the cerebellum.

Three hemizygous transgenic (Tg) mouse lines were generated with a fusion gene composed of the mouse metallothionein promoter (mMT-I) and a full-length human insulin-like growth factor binding protein-1 (hIGFBP-1) complementary DNA that was truncated in its 3'-untranslated region. Despite high serum hIGFBP-1 levels (120-2570 micrograms/liter) before puberty in two of these lines, no significant alterations were observed in somatic growth, nor were marked alterations noted in fasting or random serum glucose or in the response of young adult Tg mice to ip glucose. The transgene was expressed in a number of tissues from each line, but liver was a significant site of transgene expression in only one line. Unexpectedly, liver hIGFBP-1 messenger RNA (mRNA) expression in this line was regulated in fashion similar to the native liver IGFBP-1 mRNA: 1) its abundance waned with advancing postnatal age and became minimal in early adult life, despite continuous zinc supplementation to stimulate its transcription; and 2) fasting increased its abundance 3- to 4.3-fold. The decline in transgene expression with aging was not due to a deletion, rearrangement, or a change in the methylation of liver transgene DNA. Transcriptional mechanisms also were not likely to account for the observed regulation of the transgene mRNA, because liver expression of the mMT-I gene, which shares identical genomic 5'-regulatory elements with the transgene, was not similarly altered by aging or fasting. Because cycloheximide (CHX) treatment of cultured rat H4IIE cells has been shown to prolong IGFBP-1 mRNA half-life while decreasing its transcription, Tg mice were treated with CHX to test the possibility that instability of the liver transgene mRNA influenced its abundance. After CHX and under conditions of chronic zinc supplementation, liver transgene mRNA abundance increased in parallel with that of the native IGFBP-1 mRNA. Although CHX is known to activate mMT-I transcription by mechanisms involving the 5'-regulatory regions contained in the transgene, CHX-induced transcription only in part accounted for the increase in liver transgene mRNA, because CHX induced an earlier and greater increase in liver transgene mRNA than in mMT-I mRNA. Taken together, these data indicate that both transgene and native IGFBP-1 liver mRNA are regulated by factors that alter mRNA stability. The finding that native liver IGFBP-1 mRNA abundance is influenced by transgene expression further supports the concept that both mRNAs share some common mechanisms of regulation.(ABSTRACT TRUNCATED AT 400 WORDS)

The design, synthesis, and biological evaluation of beta-keto sulfones as 11beta-HSD1 inhibitors and the mechanism of inhibition are described here. This class of compounds is not active against 11beta-HSD2 and therefore may have therapeutic potential for metabolic syndrome and type 2 diabetes.

Ertiprotafib belongs to a novel class of insulin sensitizers developed for treatment of type 2 diabetes. In insulin-resistant rodent models, ertiprotafib and a close analog lowered both fasting blood glucose and insulin levels and improved glycemic excursion during an oral glucose tolerance test. In addition, treatment of rodents improved lipid profiles, with significantly lowered triglyceride and free fatty acid levels. These results suggested that this therapeutic activity might involve mechanisms in addition to PTP1b inhibition. In this study, we demonstrate that ertiprotafib activates peroxisome proliferator-activated receptor (PPAR)alpha and PPARgamma at concentrations comparable with those of known agonists of these regulators. Furthermore, it is able to drive adipocyte differentiation of C3H10T(1/2) cells, a hallmark of PPARgamma activation. Livers from ertiprotafib-treated animals showed significant induction of acyl-CoA oxidase activity, probably caused by PPARalpha engagement in these animals. We also show that ertiprotafib inhibits PTP1b in vitro with nonclassic kinetics at concentrations above its EC(50) for PPAR agonism. Thus, the complete mechanism of action for ertiprotafib and related compounds in vivo may involve multiple independent mechanisms, including (but not necessarily limited to) PTP1b inhibition and dual PPARalpha/PPARgamma agonism. Ertiprotafib pharmacology and interpretation of clinical results must be seen in light of this complexity.

The interaction of co-stimulatory molecules on T cells with B7 molecules on antigen presenting cells plays an important role in the activation of naive T cells. Consequently, agents that disrupt these interactions should have applications in treatment of transplant rejection as well as autoimmune diseases. To this end, specific small molecule inhibitors of human B7.1 were identified and characterized. These compounds inhibit the binding of B7.1 to both CD28 and CTLA4. Both classes of compounds appear to bind the same site, a relatively small portion of the GFCC'C" face of the N-terminal V-set domain of human B7.1, not present in the homologous B7.2 or even mouse B7.1. This site may represent a rare hot spot for small molecule antagonist design of inhibitors of cell-cell interactions, whose ligands may yield leads for the development of novel immunomodulatory medicines.