Milana Maletic

11β-HSD1 inhibition reduces atherosclerosis in mice by altering proinflammatory gene expression in the vasculature

11β-Hydroxysteroid dehydrogenase type 1 (11β-HSD1) is implicated in the etiology of metabolic syndrome. We previously showed that pharmacological inhibition of 11β-HSD1 ameliorated multiple facets of metabolic syndrome and attenuated atherosclerosis in ApoE-/- mice. However, the molecular mechanism underlying the atheroprotective effect was not clear. In this study, we tested whether and how 11β-HSD1 inhibition affects vascular inflammation, a major culprit for atherosclerosis and its associated complications. ApoE-/- mice were treated with an 11β-HSD1 inhibitor for various periods of time. Plasma lipids and aortic cholesterol accumulation were quantified. Several microarray studies were carried out to examine the effect of 11β-HSD1 inhibition on gene expression in atherosclerotic tissues. Our data suggest 11β-HSD1 inhibition can directly modulate atherosclerotic plaques and attenuate atherosclerosis independently of lipid lowering effects. We identified immune response genes as the category of mRNA most significantly suppressed by 11β-HSD1 inhibition. This anti-inflammatory effect was further confirmed in plaque macrophages and smooth muscle cells procured by laser capture microdissection. These findings in the vascular wall were corroborated by reduction in circulating MCP1 levels after 11β-HSD1 inhibition. Taken together, our data suggest 11β-HSD1 inhibition regulates proinflammatory gene expression in atherosclerotic tissues of ApoE-/- mice, and this effect may contribute to the attenuation of atherosclerosis in these animals.

Fluorogenic substrates for high-throughput measurements of endothelial lipase activity

Endothelial lipase (EL) has been shown to be a critical determinant for high density lipoprotein cholesterol levels in vivo; therefore, assays that measure EL activity have become important for the discovery of small molecule inhibitors that specifically target EL. Here, we describe fluorescent Bodipy-labeled substrates that can be used in homogeneous, ultra-high-throughput kinetic assays that measure EL phospholipase or triglyceride lipase activities. Triton X-100 detergent micelles and synthetic HDL particles containing Bodipy-labeled phospholipid or Bodipy-labeled triglyceride substrates were shown to be catalytic substrates for EL, LPL, and HL. More importantly, only synthetic HDL particles containing Bodipy-labeled triglyceride were ideal substrates for EL, LPL, and HL in the presence of high concentrations of human or mouse serum. These data suggest that substrate presentation is a critical factor when determining EL activity in the presence of serum.

Substituted phenyl triazoles as selective inhibitors of 11β-Hydroxysteroid Dehydrogenase Type 1.

3-(Phenylcyclobutyl)-1,2,4-triazoles were identified as inhibitors of 11β-Hydroxysteroid Dehydrogenase Type 1 (HSD1). They were shown to be active in the mouse in vivo pharmacodynamic model (PD) for HSD1 but exhibited a potent off-target activation of the Pregnane X Receptor (PXR). SAR studies and synthesis of analogs that led to the discovery of a selective HSD1 inhibitor are described in detail.

Preparation of Potential Inhibitors of the Mur-Pathway Enzymes on Solid Support Using an Acetal Linker

Here, we report a novel strategy for the combinatorial or parallel solid-phase synthesis of potential inhibitors of the mur-pathway enzymes. The strategy involves the efficient use of p-alkoxybenzylidene acetal linker for reversible immobilization of sugar scaffolds to solid phase. This methodology was used to synthesize several glycopeptides on solid phase in good yields.