Recent advances in the development of novel glucocorticoid receptor modulators

Divergent Chemo- and Biocatalytic Route to 16β-Methylcorticoids: Asymmetric Synthesis of Betamethasone Dipropionate, Clobetasol Propionate, and Beclomethasone Dipropionate

16β-Methylcorticoids are among the most important glucocorticoid steroids for the treatment of various dermatological disorders, respiratory infections, and other allergic reactions elicited during inflammatory responses of the human body. Betamethasone dipropionate, clobetasol propionate, and beclomethasone dipropionate are particularly noteworthy for their synthetic intractability. Despite five decades of research, these 16β-methylcorticoids have remained challenging synthetic targets owing to insurmountable issues of reactivity, selectivity, and cost efficiency associated with all previously explored strategies. We herein report our practicability-oriented strategy toward the unified stereoselective synthesis of 16β-methylcorticoids in 12.6-14.0 % overall yield from commercially available 9α-hydroxyandrost-4-ene-3,17-dione (9α-OH-AD). In this approach, the chiral C16β-Me and C17α-OH groups of the corticosteroid D ring were installed via a substrate-controlled diastereo- and enantioselective Mn-catalyzed oxidation-reduction hydration of Δ4,9(11),16 -triene-3,20-dione. The C1-C2 double bond of the corticosteroid A ring was constructed using an unprecedented engineered 3-ketosteroid-Δ1 -dehydrogenase (MK4-KstD)-catalyzed regioselective Δ1 -dehydrogenation of Δ4,9(11) -diene-3,21-dione. This strategy provides a general method and a key precursor for the divergent synthesis of a variety of glucocorticoids and related steroidal drugs.

Withaferin A: A potential selective glucocorticoid receptor modulator with anti-inflammatory effect

Glucocorticoids have been widely applied to various clinical treatment, however some serious side effects may occur during the treatment. It is widely known that glucocorticoids produce a marked effect through binding to glucocorticoid receptor (GR). As withaferin A can provide multiple health benefits, this work aims to confirm withaferin A as a potential selective GR modulator with anti-inflammatory effect. Fluorescence polarization assay confirmed that withaferin A could steadily bind to GR with an IC50 value of 203.80 ± 0.36 μM. Meanwhile, glucocorticoid receptor translocation of withaferin A was measured by nuclear fractionation assay. Dual luciferase reporter assay showed that withaferin A did not activate GR transcription. Furthermore, withaferin A decreased the GR-related protein expression with less side effects. The result of molecular docking showed that hydrogen-bonding and hydrophobic interactions contributed to the binding of withaferin A with GR. In addition, the GR-withaferin A complex maintained a stable binding throughout the dynamics simulation process. Enzyme-linked immunosorbent assay showed that withaferin A inhibited the production of cytokines, confirming its anti-inflammatory effect. These findings indicate that withaferin A is a potential selective GR modulator and this work may provide a research basis for developing dietary supplements and nutraceuticals against inflammation.

Development of Novel Glucocorticoids for Use in Antibody-Drug Conjugates for the Treatment of Inflammatory Diseases

Glucocorticoids (GCs) are widely used to treat a variety of autoimmune and inflammatory diseases; however, systemic delivery of GCs is associated with side effects that affect essentially every organ system, reflecting the nearly ubiquitous expression of the glucocorticoid receptor (GR). Targeted delivery of GCs to diseased tissues using antibody-glucocorticoid conjugates (GC-ADCs) offers a therapeutic alternative to overcome these adverse effects. Herein, we describe novel classes of GCs that exhibited greater potency than dexamethasone and budesonide, a 100-fold selectivity toward the GR over other nuclear receptors, and no in vitro safety liability in pharmacology assays (hERG, AMES) and that demonstrated a substantial reduction in tumor necrosis factor-α (TNF-α) release in mice challenged with lipopolysaccharide (LPS). The site-specific conjugated GC-ADCs via cathepsin-cleavable linkers were highly stable in plasma and specifically released GCs in antigen-positive cells, suggesting that these novel GCs can serve as ADC payloads to treat autoimmune and inflammatory diseases.

Computational and Biological Comparisons of Plant Steroids as Modulators of Inflammation through Interacting with Glucocorticoid Receptor

Despite the usefulness of glucocorticoids, they may cause hazardous side effects that limit their use. Searching for compounds that are as equally efficient as glucocorticoids, but with less side effects, the current study compared plant steroids, namely, glycyrrhetinic acid, guggulsterone, boswellic acid, withaferin A, and diosgenin with the classical glucocorticoid, fluticasone. This was approached both in silico using molecular docking against glucocorticoid receptor (GR) and in vivo in two different animal models. All tested compounds interacted with GR, but only boswellic acid and withaferin A showed docking results comparable to fluticasone, as well as similar in vivo anti-inflammatory effects, by significantly decreasing serum levels of interleukin-6 and tumor necrosis factor-α in cotton pellet-induced granuloma in rats. In addition, both compounds significantly decreased the percent of change in ear weight in croton oil-induced ear edema in mice and the granuloma weight in cotton pellet-induced granuloma in rats, to levels comparable to that of fluticasone. Both boswellic acid and withaferin A had no effect on adrenal index, but only withaferin A significantly increased the thymus index. In conclusion, boswellic acid may have comparable anti-inflammatory effects to fluticasone with fewer side effects.

Glucocorticoid signaling and osteoarthritis

Glucocorticoids are steroid hormones synthesized and released by the adrenal cortex. Their main function is to maintain cell homeostasis through a variety of signaling pathways, responding to changes in an organism's environment or developmental status. Mimicking the actions of natural glucocorticoids, synthetic glucocorticoids have been recruited to treat many diseases that implicate glucocorticoid receptor signaling such as osteoarthritis. In osteoarthritis, synthetic glucocorticoids aim to alleviate inflammation and pain. The variation of patients' response and the possibility of complications associated with their long-term use have led to a need for a better understanding of glucocorticoid receptor signaling in osteoarthritis. In this review, we performed a literature search in the molecular pathways that link the osteoarthritic joint to the glucocorticoid receptor signaling. We hope that this information will advance research in the field and propose new molecular targets for the development of more optimized therapies for osteoarthritis.

Development of nonsteroidal glucocorticoid receptor modulators based on N-benzyl-N-(4-phenoxyphenyl)benzenesulfonamide scaffold

N-Benzyl-N-(4-phenoxyphenyl)benzenesulfonamide derivatives were developed as a novel class of nonsteroidal glucocorticoid receptor (GR) modulators, which are promising drug candidates for treating immune-related disorders. Focusing on the similarity of the GR and progesterone receptor (PR) ligand-binding domain (LBD) structures, we adopted our recently developed PR antagonist 10 as a lead compound and synthesized a series of derivatives. We found that the N-(4-phenoxyphenyl)benzenesulfonamide skeleton serves as a versatile scaffold for GR antagonists. Among them, 4-cyano derivative 14m was the most potent, with an IC₅₀ value of 1.43μM for GR. This compound showed good selectivity for GR; it retained relatively weak antagonistic activity toward PR (IC₅₀ for PR: 8.00μM; 250-fold less potent than 10), but showed no activity toward AR, ERα or ERβ. Interestingly, the 4-amino derivative 15a exhibited transrepression activity toward NF-κB in addition to GR-antagonistic activity, whereas 14m did not. The structure-activity relationship for transrepression was different from that for GR-antagonistic activity. Computational docking simulations suggested that 15a might bind to the ligand-binding pocket of GR in a different manner from 14m. These findings open up new possibilities for developing novel nonsteroidal GR modulators with distinctive activity profiles.

Safety and pharmacodynamic dose response of short-term prednisone in healthy adult subjects: a dose ranging, randomized, placebo-controlled, crossover study

Background

Glucocorticoids (GCs), such as prednisone, are the standard of care for several inflammatory and immunologically mediated diseases, but their chronic systemic administration is severely limited by serious adverse effects that are both dose and time dependent. Short-term treatment (7–14 days) with oral prednisone is used for many acute inflammatory and allergic conditions. This study was conducted to characterize the safety and pharmacodynamic (PD) dose–response of a 7-day course of oral prednisone on biomarkers of GC receptor agonism.

Methods

In this randomized, single-blind, placebo-controlled, crossover study (A9001309), 37 healthy subjects received placebo or a prednisone dose from 2.5–60 mg daily over 7 days in each of three treatment periods. White blood cell counts and plasma samples for measuring cortisol, osteocalcin and procollagen type 1 N-propeptide (P1NP) were obtained at 2, 4, 8, and 12 h post-dose on Day 1, immediately prior to dosing on Days 1, 2, and 4, and at nominal dosing time on Days 0 and 8. Urine samples for urinary N-terminal cross-linked telopeptide of type 1 collagen (uNTX) were collected on Days 0, 1, 2, 4, and 8. Serum samples for adiponectin were obtained prior to dosing on days 0, 1, 4 and 8.

Results

Daily doses of prednisone up to 60 mg resulted in dose- and time-dependent decreases in plasma osteocalcin, plasma P1NP, serum cortisol, and absolute blood eosinophil counts. Absolute blood neutrophil counts increased, while blood lymphocyte counts rebounded to an increased level following an initial rapid decrease after dosing. An increase was observed for uNTX and adiponectin. The incidence of adverse effects with prednisone was not dose related, and nervous system disorders, mainly headache, were the most frequently reported adverse effects.

Conclusions

This characterization provides important and relevant information on safety and PD responses of short-term prednisone dosing over the commonly-used clinical dose range, and also provides a reference for early clinical development of dissociated agents targeting a differentiated PD profile.

Trial registration number

NCT02767089 (retrospectively registered: 21 April 2016).

Computational prediction of formulation strategies for beyond-rule-of-5 compounds

The physicochemical properties of some contemporary drug candidates are moving towards higher molecular weight, and coincidentally also higher lipophilicity in the quest for biological selectivity and specificity. These physicochemical properties move the compounds towards beyond rule-of-5 (B-r-o-5) chemical space and often result in lower water solubility. For such B-r-o-5 compounds non-traditional delivery strategies (i.e. those other than conventional tablet and capsule formulations) typically are required to achieve adequate exposure after oral administration. In this review, we present the current status of computational tools for prediction of intestinal drug absorption, models for prediction of the most suitable formulation strategies for B-r-o-5 compounds and models to obtain an enhanced understanding of the interplay between drug, formulation and physiological environment. In silico models are able to identify the likely molecular basis for low solubility in physiologically relevant fluids such as gastric and intestinal fluids. With this baseline information, a formulation scientist can, at an early stage, evaluate different orally administered, enabling formulation strategies. Recent computational models have emerged that predict glass-forming ability and crystallisation tendency and therefore the potential utility of amorphous solid dispersion formulations. Further, computational models of loading capacity in lipids, and therefore the potential for formulation as a lipid-based formulation, are now available. Whilst such tools are useful for rapid identification of suitable formulation strategies, they do not reveal drug localisation and molecular interaction patterns between drug and excipients. For the latter, Molecular Dynamics simulations provide an insight into the interplay between drug, formulation and intestinal fluid. These different computational approaches are reviewed. Additionally, we analyse the molecular requirements of different targets, since these can provide an early signal that enabling formulation strategies will be required. Based on the analysis we conclude that computational biopharmaceutical profiling can be used to identify where non-conventional gateways, such as prediction of 'formulate-ability' during lead optimisation and early development stages, are important and may ultimately increase the number of orally tractable contemporary targets.

Synthesis of two potent glucocorticoid receptor agonists labeled with carbon-14 and stable isotopes

Two potent glucocorticoid receptor agonists were prepared labeled with carbon-14 and with stable isotopes to perform drug metabolism, pharmacokinetics, and bioanalytical studies. Carbon-14 labeled (1) was obtained from an enantiopure alkyne (5) via a Sonogashira coupling to a previously reported 5-amino-4-iodo-[2-(14)C]pyrimidine [(14)C]-(6), followed by a base-mediated cyclization (1) in 72% overall radiochemical yield. Carbon-14 labeled (2) was prepared in five steps employing a key benzoic acid intermediate [(14)C]-(13), which was synthesized in one pot from enolization of trifluoromethylketone (12), followed by bromine-magnesium exchange and then electrophile trapping reaction with [(14)C]-carbon dioxide. A chiral auxiliary (S)-1-(4-methoxyphenyl)ethylamine was then coupled to this acid to give [(14)C]-(15). Propargylation and separation of diastereoisomers by crystallizations gave the desired diastereomer [(14)C]-(17) in 34% yield. Sonogashira coupling to iodopyridine (10) followed by cyclization to the azaindole [(14)C]-(18) and finally removal of the chiral auxiliary gave [(14)C]-(2) in 7% overall yield. For stable isotope syntheses, [(13)C6]-(1) was obtained in three steps using [(13)C4]-(6) and trimethylsilylacetylene-[(13)C2] in 26% yield, while [(2)H5]-(2) was obtained by first preparing the iodopyridine [(2)H5]-(10) in five steps. Then, Sonogashira coupling to chiral alkyne (24) and cyclization gave [(2)H5]-(2) in 42% overall yield.

Optimization of drug-like properties of nonsteroidal glucocorticoid mimetics and identification of a clinical candidate

A series of nonsteroidal "dissociated" glucocorticoid receptor agonists was optimized for drug-like properties such as cytochrome P450 inhibition, metabolic stability, aqueous solubility, and hERG ion channel inhibition. This effort culminated in the identification of the clinical candidate compound ( R )-39.

C7-derivatization of C3-alkylindoles including tryptophans and tryptamines

A versatile strategy for C7-selective boronation of tryptophans, tryptamines, and 3-alkylindoles by way of a single-pot C2/C7-diboronation-C2-protodeboronation sequence is described. The combination of a mild iridium-catalyzed C2/C7-diboronation followed by an in situ palladium-catalyzed C2-protodeboronation allows efficient entry to valuable C7-boroindoles that enable further C7-derivatization. The versatility of the chemistry is highlighted by the gram-scale synthesis of C7-boronated N-Boc-L-tryptophan methyl ester and the rapid synthesis of C7-halo, C7-hydroxy, and C7-aryl tryptophan derivatives.

Evaluation of the selective glucocorticoid receptor agonist compound A for ototoxic effects

OBJECTIVES/HYPOTHESIS

To evaluate the selective glucocorticoid receptor agonist (SEGRA) compound A, a potential novel therapeutic for inner ear disorders, for ototoxic effects.

STUDY DESIGN

Laboratory animal study.

METHODS

Experimental guinea pigs were grouped as follows: Systemic application of compound A (1.5 mg/kg and 4.5 mg/kg; n = 6/group) and intratympanic application of compound A (1 mM and 10 mM; n = 6/group). Contralateral ears in topically treated animals served as controls. Hearing thresholds were determined by auditory brainstem response before and directly after the application of compound A, as well as on days 3, 7, 14, 21, and 28. At the end of the experiments, temporal bones were harvested for histological evaluation.

RESULTS

Systemic administration of compound A (1.5 mg/kg and 4.5 mg/kg) did not cause hearing threshold shifts, whereas the intratympanic injection (1 mM and 10 mM) resulted in a hearing loss. Histological analysis of the middle and inner ears after topical compound A application showed alterations in the tympanic membranes, the auditory ossicles, and the round window membranes, whereas spiral ganglion cells and hair cells were not affected.

CONCLUSION

SEGRAs such as compound A could provide novel therapeutic options for the treatment of inner ear disorders and reduce metabolic side effects. Whereas the intratympanic application of compound A resulted in a hearing loss, the systemic application of compound A merits evaluation for otoprotective effects in trauma models.

The preclinical efficacy, selectivity and pharmacologic profile of MK-5932, an insulin-sparing selective glucocorticoid receptor modulator

Glucocorticoids are used widely in the treatment of inflammatory diseases, but use is accompanied by a significant burden of adverse effects. It has been hypothesized that gene- and cell-specific regulation of the glucocorticoid receptor by small molecule ligands could be translated into a therapeutic with an improved risk-benefit profile. MK-5932 is a highly selective glucocorticoid receptor modulator that is anti-inflammatory in vivo with an improved profile on glucose metabolism: Bungard et al. (2011). Bioorg. Med. Chem. 19, 7374-7386. Here we describe the full biological profile of MK-5932. Cytokine production following lipopolysaccharide (LPS) challenge was blocked by MK-5932 in both rat and human whole blood. Oral administration reduced inflammatory cytokine levels in the serum of rats challenged with LPS. MK-5932 was anti-inflammatory in a rat contact dermatitis model, but was differentiated from 6-methylprednisolone by a lack of elevation of fasting insulin or glucose levels after 7 days of dosing, even at high exposure levels. In fact, animals in the vehicle group were consistently hyperglycemic at the end of the study, and MK-5932 normalized glucose levels in a dose-dependent manner. MK-5932 was also anti-inflammatory in the rat collagen-induced arthritis and adjuvant-induced arthritis models. In healthy dogs, oral administration of MK-5932 exerted acute pharmacodynamic effects with potency comparable to prednisone, but with important differences on neutrophil counts, again suggestive of a dissociated profile. Important gaps in our understanding of mechanism of action remain, but MK-5932 will be a useful tool in dissecting the mechanisms of glucose dysregulation by therapeutic glucocortiocids.

Creation of lung-targeted dexamethasone immunoliposome and its therapeutic effect on bleomycin-induced lung injury in rats

OBJECTIVE

Acute lung injury (ALI), is a major cause of morbidity and mortality, which is routinely treated with the administration of systemic glucocorticoids. The current study investigated the distribution and therapeutic effect of a dexamethasone(DXM)-loaded immunoliposome (NLP) functionalized with pulmonary surfactant protein A (SP-A) antibody (SPA-DXM-NLP) in an animal model.

METHODS

DXM-NLP was prepared using film dispersion combined with extrusion techniques. SP-A antibody was used as the lung targeting agent. Tissue distribution of SPA-DXM-NLP was investigated in liver, spleen, kidney and lung tissue. The efficacy of SPA-DXM-NLP against lung injury was assessed in a rat model of bleomycin-induced acute lung injury.

RESULTS

The SPA-DXM-NLP complex was successfully synthesized and the particles were stable at 4°C. Pulmonary dexamethasone levels were 40 times higher with SPA-DXM-NLP than conventional dexamethasone injection. Administration of SPA-DXM-NLP significantly attenuated lung injury and inflammation, decreased incidence of infection, and increased survival in animal models.

CONCLUSIONS

The administration of SPA-DXM-NLP to animal models resulted in increased levels of DXM in the lungs, indicating active targeting. The efficacy against ALI of the immunoliposomes was shown to be superior to conventional dexamethasone administration. These results demonstrate the potential of actively targeted glucocorticoid therapy in the treatment of lung disease in clinical practice.

Therapeutic targeting of eosinophil adhesion and accumulation in allergic conjunctivitis

Considerable evidence indicates that eosinophils are important effectors of ocular allergy. Increased worldwide prevalence of allergic eye pathologies has stimulated the identification of novel drug targets, including eosinophils and adhesion molecules. Accumulation of eosinophils in the eye is a key event in the onset and maintenance of allergic inflammation and is mediated by different adhesion molecules. Antihistamines with multiple mechanisms of action can be effective during the early and late phases of allergic conjunctivitis by blocking the interaction between β(1) integrins and vascular cell adhesion molecule (VCAM)-1. Small molecule antagonists that target key elements in the process of eosinophil recruitment have been identified and reinforce the validity of α(4)β(1) integrin as a therapeutic target. Glucocorticoids are among the most effective drugs for ocular allergy, but their use is limited by adverse effects. Novel dissociated glucocorticoids can prevent eosinophil accumulation and induce apoptosis of eosinophils, making them promising candidates for ophthalmic drugs. This article reviews recent understanding of the role of adhesion molecules in eosinophil recruitment in the inflamed conjunctiva along with effective treatments for allergic conjunctivitis.

Anti-inflammatory effects of selective glucocorticoid receptor modulators are partially dependent on up-regulation of dual specificity phosphatase 1

BACKGROUND AND PURPOSE

It is thought that the anti-inflammatory effects of glucocorticoids (GCs) are largely due to GC receptor (GR)-mediated transrepression of NF-κB and other transcription factors, whereas side effects are caused by activation of gene expression (transactivation). Selective GR modulators (SGRMs) that preferentially promote transrepression should retain anti-inflammatory properties whilst causing fewer side effects. Contradicting this model, we found that anti-inflammatory effects of the classical GC dexamethasone were partly dependent on transactivation of the dual specificity phosphatase 1 (DUSP1) gene. We wished to determine whether anti-inflammatory effects of SGRMs are also mediated by DUSP1.

EXPERIMENTAL APPROACH

Dissociated properties of two SGRMs were confirmed using GR- and NF-κB-dependent reporters, and capacity to activate GC-responsive elements of the DUSP1 gene was tested. Effects of SGRMs on the expression of DUSP1 and pro-inflammatory gene products were assessed in various cell lines and in primary murine Dusp1(+/+) and Dusp1(-/-) macrophages.

KEY RESULTS

The SGRMs were able to up-regulate DUSP1 in several cell types, and this response correlated with the ability of the compounds to suppress COX-2 expression. Several anti-inflammatory effects of SGRMs were ablated or significantly impaired in Dusp1(-/-) macrophages.

CONCLUSIONS AND IMPLICATIONS

Like dexamethasone, SGRMs appear to exert anti-inflammatory effects partly via the up-regulation of DUSP1. This finding has implications for how potentially therapeutic novel GR ligands are identified and assessed.

Maps and legends: the quest for dissociated ligands of the glucocorticoid receptor

Glucocorticoids are steroid hormones that have pleiotropic effects on development, metabolism, cognitive function and other aspects of physiology. Since the demonstration more than sixty years ago of their capacity to suppress inflammation, synthetic glucocorticoids have been extremely widely used in the treatment of inflammatory diseases. However, their clinical use is limited by numerous, unpredictable and potentially serious side effects. Glucocorticoids regulate gene expression both positively and negatively. Both of these effects are mediated by the glucocorticoid receptor, a ligand-dependent transcription factor. It has become widely accepted that anti-inflammatory effects of glucocorticoids are mostly due to inhibition of transcription, whereas the activation of transcription by the glucocorticoid receptor accounts for the majority of side effects. This dogma (which we refer to as the "transrepression hypothesis") predicts the possibility of uncoupling therapeutic, anti-inflammatory effects from side effects by identifying novel, selective ligands of the glucocorticoid receptor, which preferentially mediate inhibition rather than activation of transcription. It is argued that such "dissociated" glucocorticoid receptor ligands should retain anti-inflammatory potency but cause fewer side effects. Here we critically re-examine the history and foundations of the transrepression hypothesis. We argue that it is incompatible with the complexity of gene regulation by glucocorticoids and poorly supported by experimental evidence; that it no longer aids clear thinking about the actions of the glucocorticoid receptor; and that it will not prove a fruitful basis for continued refinement and improvement of anti-inflammatory drugs that target the glucocorticoid receptor.

Non-steroidal dissociated glucocorticoid agonists: indoles as A-ring mimetics and function-regulating pharmacophores

We report a SAR of non-steroidal glucocorticoid mimetics that utilize indoles as A-ring mimetics. Detailed SAR is discussed with a focus on improving PR and MR selectivity, GR agonism, and in vitro dissociation profile. SAR analysis led to compound (R)-33 which showed high PR and MR selectivity, potent agonist activity, and reduced transactivation activity in the MMTV and aromatase assays. The compound is equipotent to prednisolone in the LPS-TNF model of inflammation. In mouse CIA, at 30 mg/kg compound (R)-33 inhibited disease progression with an efficacy similar to the 3 mg/kg dose of prednisolone.

Beneficial pharmacological effects of selective glucocorticoid receptor agonist in external eye diseases

PURPOSE

Glucocorticoids exert their actions via the glucocorticoid receptor through at least 2 intracellular mechanisms, known as transrepression and transactivation. It has been hypothesized that transrepression is the basis of their anti-inflammatory effects, whereas transactivation has been assumed to cause their side effects. ZK209614, a recently identified, novel selective glucocorticoid receptor agonist, exerts strong transrepression and weak transactivation. The objective of this study was to determine whether its pharmacological effects can be dissociated from its side effects. For this, we employed in vitro assays and topical in vivo models.

METHODS

ZK209614 and dexamethasone were used in in vitro transrepression and transactivation assays. To evaluate anti-inflammatory and antiallergic activities in vivo, ZK209614 and betamethasone phosphate were tested in the carrageenan-induced conjunctivitis model and allergic conjunctivitis model in rats. To evaluate side effects in vivo, treatments with ZK209614 and betamethasone phosphate were tested for the ocular hypertensive effects in a feline model, each drug being administered topically.

RESULTS

ZK209614 showed strong transrepression and weak transactivation in the in vitro assays. When given as eyedrops, ZK209614 and betamethasone phosphate each had an inhibitory effect on edema weight in the rat carrageenan-induced conjunctivitis model. In the rat allergic conjunctivitis model, ZK209614 reduced the elevated vascular permeability at a concentration of 0.1%. In the feline intraocular pressure (IOP)-elevation experiment, topically administered betamethasone phosphate elevated IOP, but ZK209614 had no effect on IOP.

CONCLUSION

The present investigations suggest that ZK209614 eyedrops have both anti-inflammatory and antiallergic effects, but no unwanted IOP-elevating effect. On that basis, ZK209614 might be a promising candidate as an ophthalmic drug with a better therapeutic index than classic glucocorticoids.

Dimethyl-diphenyl-propanamide derivatives as nonsteroidal dissociated glucocorticoid receptor agonists

A series of 2,2-dimethyl-3,3-diphenyl-propanamides as novel glucocorticoid receptor modulators is reported. SAR exploration led to the identification of 4-hydroxyphenyl propanamide derivatives displaying good agonist activity in GR-mediated transrepression assays and reduced agonist activity in GR-mediated transactivation assays. Compounds 17 and 30 showed anti-inflammatory activity comparable to prednisolone in the rat carrageenan-induced paw edema model, with markedly decreased side effects with regard to increases in blood glucose and expression of hepatic tyrosine aminotransferase. A hypothetical binding mode accounting for the induction of the functional activity by a 4-hydroxyl group is proposed.

Discovery-driven research and bioinformatics in nuclear receptor and coregulator signaling

Nuclear receptors (NRs) are a superfamily of ligand-regulated transcription factors that interact with coregulators and other transcription factors to direct tissue-specific programs of gene expression. Recent years have witnessed a rapid acceleration of the output of high-content data platforms in this field, generating discovery-driven datasets that have collectively described: the organization of the NR superfamily (phylogenomics); the expression patterns of NRs, coregulators and their target genes (transcriptomics); ligand- and tissue-specific functional NR and coregulator sites in DNA (cistromics); the organization of nuclear receptors and coregulators into higher order complexes (proteomics); and their downstream effects on homeostasis and metabolism (metabolomics). Significant bioinformatics challenges lie ahead both in the integration of this information into meaningful models of NR and coregulator biology, as well as in the archiving and communication of datasets to the global nuclear receptor signaling community. While holding great promise for the field, the ascendancy of discovery-driven research in this field brings with it a collective responsibility for researchers, publishers and funding agencies alike to ensure the effective archiving and management of these data. This review will discuss factors lying behind the increasing impact of discovery-driven research, examples of high-content datasets and their bioinformatic analysis, as well as a summary of currently curated web resources in this field. This article is part of a Special Issue entitled: Translating nuclear receptors from health to disease.

Nonsteroidal dissociated glucocorticoid agonists containing azaindoles as steroid A-ring mimetics

Syntheses and structure-activity relationships (SAR) of nonsteroidal glucocorticoid receptor (GR) agonists are described. These compounds contain azaindole moieties as A-ring mimetics and display various degrees of in vitro dissociation between gene transrepression and transactivation. Collagen induced arthritis studies in mouse have demonstrated that in vitro dissociated compounds (R)-16 and (R)-37 have steroid-like anti-inflammatory properties with improved metabolic side effect profiles, such as a reduced increase in body fat and serum insulin levels, compared to steroids.