Impact of Minor Structural Modifications on Properties of a Series of mTOR Inhibitors.

Minor structural modifications-sometimes single atom changes-can have a dramatic impact on the properties of compounds. This is illustrated here on structures related to known mTOR inhibitor Sapanisertib. Subtle changes in the hinge binder lead to strikingly different overall profiles with changes in physical properties, metabolism, and kinase selectivity.

Sulfoximines as potent RORγ inverse agonists.

Progress in the identification of suitable RORγ inverse agonists as clinical candidates has been hampered by the high lipophilicity that seems required for high potency on this nuclear receptor. In this context, we decided to focus on the replacement of the hydroxymethyl group found on known modulators to determine if more polarity could be tolerated in this position. SAR of the replacement of this moiety is presented in this article leading to the identification of sulfoximine derivatives as potent modulators with pharmacological activity in the in vivo mouse Imiquimod psoriasis model.

Discovery and Characterization of CD12681, a Potent RORγ Inverse Agonist, Preclinical Candidate for the Topical Treatment of Psoriasis.

With possible implications in multiple autoimmune diseases, the retinoic acid receptor-related orphan receptor RORγ has become a sought-after target in the pharmaceutical industry. Herein are described the efforts to identify a potent RORγ inverse agonist compatible with topical application for the treatment of skin diseases. These efforts culminated in the discovery of N-(2,4-dimethylphenyl)-N-isobutyl-2-oxo-1-[(tetrahydro-2H-pyran-4-yl)methyl]-2,3-dihydro-1H-benzo[d]imidazole-5-sulfonamide (CD12681), a potent inverse agonist with in vivo activity in an IL-23-induced mouse skin inflammation model.

Discovery and process development of a novel TACE inhibitor for the topical treatment of psoriasis.

Targeting the TNFα pathway is a validated approach to the treatment of psoriasis. In this pathway, TACE stands out as a druggable target and has been the focus of in-house research programs. In this article, we present the discovery of clinical candidate 26a. Starting from hits plagued with poor solubility or genotoxicity, 26a was identified through thorough multiparameter optimisation. Showing robust in vivo activity in an oxazolone-mediated inflammation model, the compound was selected for development. Following a polymorph screen, the hydrochloride salt was selected and the synthesis was efficiently developed to yield the API in 47% overall yield.

Identification of novel TACE inhibitors compatible with topical application.

Targeting the Tumor Necrosis Factor α signalling with antibodies has led to a revolution in the treatment of psoriasis. Locally inhibiting Tumor Necrosis Factor α Converting Enzyme (TACE or ADAM17) could potentially mimic those effects and help treat mild to moderate psoriasis, without the reported side effect of systemic TACE inhibitors. Efforts to identify new TACE inhibitors are presented here. Enzymatic SAR as well as ADME and physico-chemistry data are presented. This study culminated in the identification of potent enzymatic inhibitors. Suboptimal cellular activity of this series is discussed in the context of previously published results.

Discovery of phenoxyindazoles and phenylthioindazoles as RORγ inverse agonists.

Targeting the IL17 pathway and more specifically the nuclear receptor RORγ is thought to be beneficial in multiple skin disorders. The Letter describes the discovery of phenoxyindazoles and thiophenoxy indazoles as potent RORγ inverse agonists. Optimization of the potency and efforts to mitigate the phototoxic liability of the series are presented. Finally, crystallization of the lead compound revealed that the series bound to an allosteric site of the nuclear receptor. Such compounds could be useful as tool compounds for understanding the impact of topical treatment on skin disease models.

An insect-specific P450 oxidative decarbonylase for cuticular hydrocarbon biosynthesis.

Insects use hydrocarbons as cuticular waterproofing agents and as contact pheromones. Although their biosynthesis from fatty acyl precursors is well established, the last step of hydrocarbon biosynthesis from long-chain fatty aldehydes has remained mysterious. We show here that insects use a P450 enzyme of the CYP4G family to oxidatively produce hydrocarbons from aldehydes. Oenocyte-directed RNAi knock-down of Drosophila CYP4G1 or NADPH-cytochrome P450 reductase results in flies deficient in cuticular hydrocarbons, highly susceptible to desiccation, and with reduced viability upon adult emergence. The heterologously expressed enzyme converts C(18)-trideuterated octadecanal to C(17)-trideuterated heptadecane, showing that the insect enzyme is an oxidative decarbonylase that catalyzes the cleavage of long-chain aldehydes to hydrocarbons with the release of carbon dioxide. This process is unlike cyanobacteria that use a nonheme diiron decarbonylase to make alkanes from aldehydes with the release of formate. The unique and highly conserved insect CYP4G enzymes are a key evolutionary innovation that allowed their colonization of land.

Effects of hormone agonists on Sf9 cells, proliferation and cell cycle arrest.

Methoxyfenozide and methoprene are two insecticides that mimic the action of the main hormones involved in the control of insect growth and development, 20-hydroxyecdysone and juvenile hormone. We investigated their effect on the Spodoptera frugiperda Sf9 cell line. Methoxyfenozide was more toxic than methoprene in cell viability tests and more potent in the inhibition of cellular proliferation. Cell growth arrest occurred in the G2/M phase after a methoprene treatment and more modestly in G1 after methoxyfenozide treatment. Microarray experiments and real-time quantitative PCR to follow the expression of nuclear receptors ultraspiracle and ecdysone receptor were performed to understand the molecular action of these hormone agonists. Twenty-six genes were differentially expressed after methoxyfenozide treatment and 55 genes after methoprene treatment with no gene in common between the two treatments. Our results suggest two different signalling pathways in Sf9 cells.

Transcriptional interactions between the pannier isoforms and the cofactor U-shaped during neural development in Drosophila.

The pannier (pnr) gene of Drosophila melanogaster encodes two isoforms that belong to the family of GATA transcription factors. The isoforms share an expression domain in the wing discs where they exhibit distinct functions during regulation of the proneural achaete/scute (ac/sc) genes. We previously identified two regions in the pnr locus that drive reporter expression in transgenic lines in patterns that recapitulate the essential features of expression of the two isoforms. Here, we identify promoter regions driving isoform expression, showing that pnr-α regulatory sequences are close to the transcription start site while pnr-ß expression requires functional interactions between proximal and distal regulatory elements. We find that the promoter domains necessary for reporter expression also mediate autoregulation of Pnr-ß and repression of pnr-α by Pnr-ß. The cofactor U-shaped (Ush), which is known to down-regulate the function of Pnr during thorax patterning postranscriptionally, in addition represses pnr-ß required for ac/sc activation. Moreover, Ush negatively regulates its own expression, while the pnr isoforms positively regulate ush. Our study uncovers complex transcriptional interactions between the pnr isoforms and the cofactor Ush that may be important for regulation of proneural expression and thorax patterning.

Differential between protein and mRNA expression of CCR7 and SSTR5 receptors in Crohn's disease patients.

Crohn's disease (CD) is a multifactorial chronic inflammatory bowel disease of unknown cause. The aim of the present study was to explore if mRNA over-expression of SSTR5 and CCR7 found in CD patients could be correlated to respective protein expression. When compared to healthy donors, SSTR5 was over-expressed 417 +/- 71 times in CD peripheral blood mononuclear cells (PBMCs). Flow cytometry experiments showed no correlation between mRNA and protein expression for SSTR5 in PBMCs. In an attempt to find a reason of such a high mRNA expression, SSTR5 present on CD PBMCs were tested and found as biologically active as on healthy cells. In biopsies of CD intestinal tissue, SSTR5 was not over-expressed but CCR7, unchanged in PBMCs, was over-expressed by 10 +/- 3 times in the lamina propria. Confocal microscopy showed a good correlation of CCR7 mRNA and protein expression in CD intestinal biopsies. Our data emphasize flow and image cytometry as impossible to circumvent in complement to molecular biology so to avoid false interpretation on receptor expressions. Once confirmed by further large-scale studies, our preliminary results suggest a role for SSTR5 and CCR7 in CD pathogenesis.

Celastrol inhibits pro-inflammatory cytokine secretion in Crohn's disease biopsies.

Crohn's disease is a chronic intestinal inflammatory process. In modern therapy, TNF-alpha inhibition is the main goal. The aim here is to characterize the effects of Celastrol, a pentacyclic-triterpene, on the secretion of inflammatory cytokines by LPS-activated human cells. Celastrol dose-dependently inhibited the secretion of all tested pro-inflammatory cytokines with IC(50) in the nanomolar range. Effect not related to glucocorticoid receptor activity is shown by competition experiments with the steroid antagonist RU486. Celastrol inhibited the pro-inflammatory cytokine secretion from mucosal inflammatory biopsies from Crohn's disease patients. Cytometry emphasized that for all tested pro-inflammatory cytokines, CD33(+) cells are the most sensitive. Quantitative-PCR and confocal analysis on a human monocytic cell line indicated that Celastrol acts at the transcriptional level by inhibiting LPS-induced NF-kappaB translocation. Celastrol might be a putative anti-inflammatory drug in the treatment of inflammatory diseases, given its inhibition of cytokine production by intestinal biopsies from Crohn's disease patients.