Project description:Macrocyclic retinoic acid receptor-related orphan receptor C2 (RORC2) inverse agonists have been designed with favorable properties for topical administration. Inspired by the unanticipated bound conformation of an acyclic sulfonamide-based RORC2 ligand from cocrystal structure analysis, macrocyclic linker connections between the halves of the molecule were explored. Further optimization of analogues was accomplished to maximize potency and refine physiochemical properties (MW, lipophilicity) best suited for topical application. Compound 14 demonstrated potent inhibition of interleukin-17A (IL-17A) production by human Th17 cells and in vitro permeation through healthy human skin achieving high total compound concentration in both skin epidermis and dermis layers.
Project description:Molecular docking is a key method used in virtual screening (VS) campaigns to identify small-molecule ligands for drug discovery targets. While docking provides a tangible way to understand and predict the protein-ligand complex formation, the docking algorithms are often unable to separate active ligands from inactive molecules in practical VS usage. Here, a novel docking and shape-focused pharmacophore VS protocol is demonstrated for facilitating effective hit discovery using retinoic acid receptor-related orphan receptor gamma t (RORγt) as a case study. RORγt is a prospective target for treating inflammatory diseases such as psoriasis and multiple sclerosis. First, a commercial molecular database was flexibly docked. Second, the alternative docking poses were rescored against the shape/electrostatic potential of negative image-based (NIB) models that mirror the target's binding cavity. The compositions of the NIB models were optimized via iterative trimming and benchmarking using a greedy search-driven algorithm or brute force NIB optimization. Third, a pharmacophore point-based filtering was performed to focus the hit identification on the known RORγt activity hotspots. Fourth, free energy binding affinity evaluation was performed on the remaining molecules. Finally, twenty-eight compounds were selected for in vitro testing and eight compounds were determined to be low μM range RORγt inhibitors, thereby showing that the introduced VS protocol generated an effective hit rate of ~29%.
Project description:The nuclear retinoic acid receptor-related orphan receptor γ (RORγ; NR1F3) is a key regulator of inflammatory gene programs involved in T helper 17 (TH 17) cell proliferation. As such, synthetic small-molecule repressors (inverse agonists) targeting RORγ have been extensively studied for their potential as therapeutic agents for various autoimmune diseases. Alternatively, enhancing TH 17 cell proliferation through activation (agonism) of RORγ may boost an immune response, thereby offering a potentially new approach in cancer immunotherapy. Herein we describe the development of N-arylsulfonyl indolines as RORγ agonists. Structure-activity studies reveal a critical linker region in these molecules as the major determinant for agonism. Hydrogen/deuterium exchange coupled to mass spectrometry (HDX-MS) analysis of RORγ-ligand complexes help rationalize the observed results.
Project description:The role of retinoid acid receptor-related orphan receptor alpha (RORα) on male reproductive functions during aging is unclear. Here, we analyze the morphological changes in the testis of both young and aged RORα-deficient mice, with and without melatonin supplementation. Young mutants showed vacuolation, degeneration and pyknosis of spermatogenic epithelium and Sertoli cells. Aged mutants showed atrophy of the seminiferous tubules and absence of mitotic spermatogenic cells. Absence of sperms in many tubules, loss of acrosomal cap, vacuolation and hypertrophy of Sertoli cells were detected in aged mice, with a significant reduction in the number of seminiferous tubules and a significant increase in the number of Leydig cells and telocytes. Repair in seminiferous tubules and interstitial tissues with enhancement of spermatogenesis was observed in melatonin-treated aged mice. Young mutants overexpressed VEGF that was weaker in aged animals and observed only in the spermatocytes, while melatonin increased VEGF expression in spermatocytes and spermatids. Caspase 3 increased in both young and aged mutant mice in all seminiferous tubules and interstitium; caspase 3 immunostaining in seminiferous tubules, however, showed a normal pattern of apoptosis with melatonin supplementation. The present study reports that age-dependent testicular changes in RORα mutant mice were recovered by melatonin treatment.
Project description:The hepatic circadian clock plays a pivotal role in regulating major aspects of energy homeostasis and lipid metabolism. In this study, we show that RORγ robustly regulates the rhythmic expression of several lipid metabolic genes, including the insulin-induced gene 2a, Insig2a, elongation of very long chain fatty acids-like 3, Elovl3 and sterol 12α-hydroxylase, Cyp8b1, by enhancing their expression at ZT20-4. The time-dependent increase in their expression correlates with the rhythmic expression pattern of RORγ. The enhanced recruitment of RORγ to ROREs in their promoter region, increased histone acetylation, and reporter and mutation analysis support the concept that RORγ regulates the transcription of several lipid metabolic genes directly by binding ROREs in their promoter regulatory region. Consistent with the disrupted expression of a number of lipid metabolic genes, loss of RORγ reduced the level of several lipids in liver and blood in a ZT-preferred manner. Particularly the whole-body bile acid pool size was considerably reduced in RORγ(-/-) mice in part through its regulation of several Cyp genes. Similar observations were made in liver-specific RORγ-deficient mice. Altogether, our study indicates that RORγ functions as an important link between the circadian clock and the transcriptional regulation of several metabolic genes.
Project description:BackgroundThis study followed on findings from a recent genome-wide association study of PTSD that implicated the retinoid-related orphan receptor alpha (RORA) gene (Logue et al., 2012) by examining its relationship to broader array of disorders.MethodsUsing data from the same cohort (N=540), we analyzed patterns of association between 606 single nucleotide polymorphisms (SNPs) spanning the RORA gene and comorbidity factors termed fear, distress (i.e., internalizing factors) and externalizing.ResultsResults showed that rs17303244 was associated with the fear component of internalizing (i.e., defined by symptoms of panic, agoraphobia, specific phobia, and obsessive-compulsive disorder) at a level of significance that withstood correction for gene-wide multiple testing.LimitationsThe primary limitations were the modest size of the cohort and the absence of a replication sample.ConclusionsResults add to a growing literature implicating the RORA gene in a wide range of neuropsychiatric disorders and offer new insight into possible molecular mechanisms of the effects of traumatic stress on the brain and the role of genetic factors in those processes.
Project description:Retinoids play key roles in development, differentiation, and homeostasis through regulation of specific target genes by the retinoic acid receptor/retinoid X receptor (RAR/RXR) nuclear receptor complex. Corepressors and coactivators contribute to its transcriptional control by creating the appropriate chromatin environment, but the precise composition of these nuclear receptor complexes remains to be elucidated. Using an RNA interference-based genetic screen in mouse F9 cells, we identified the transcriptional corepressor CTBP2 (C-terminal binding protein 2) as a coactivator critically required for retinoic acid (RA)-induced transcription. CTBP2 suppression by RNA interference confers resistance to RA-induced differentiation in diverse murine and human cells. Mechanistically, we find that CTBP2 associates with RAR/RXR at RA target gene promoters and is essential for their transactivation in response to RA. We show that CTBP2 is indispensable to create a chromatin environment conducive for RAR/RXR-mediated transcription by recruiting the histone acetyltransferase p300. Our data reveal an unexpected function of the corepressor CTBP2 as a coactivator for RAR/RXR in RA signaling.
Project description:Low O2 pressures present in the microenvironment of epidermis control keratinocyte differentiation and epidermal barrier function through hypoxia inducible factors (HIFs) dependent gene expression. This study focuses on investigating relations of the retinoic acid receptor-related orphan receptor alpha (RORα) to HIF-1α in keratinocytes under hypoxic conditions. The expression level of RORα is significantly elevated under hypoxia in both human and murine keratinocytes. Gene silencing of RORA attenuates hypoxia-stimulated expression of genes related to late differentiation and epidermal barrier function, and leads to an enhanced apoptotic response. While the hypoxic induction of RORα is dependent on HIF-1α, RORα is in turn critical for nuclear accumulation of HIF-1α and activation of HIF transcriptional activity. These results collectively suggest that RORα functions as an important mediator of HIF-1α activities in regulating keratinocyte differentiation/survival and epidermal barrier function during the oxygen sensing stage.
Project description:AimsRetinoic acid-related orphan receptor γ (RORγ), a master regulator of T-helper 17 (Th17) cell function and differentiation, is an attractive target for treatment of Th17-driven diseases. This first-in-human study aimed to investigate the pharmacokinetics, pharmacodynamics, safety and tolerability of the inverse RORγ agonist AZD0284.MethodsWe conducted a phase I, randomized, single-blind, placebo-controlled, two-part, first-in-human study with healthy subjects receiving single (4-238 mg) or multiple (12-100 mg) oral doses of AZD0284 or placebo after overnight fasting. Subjects in the one single dose cohort additionally received a single dose of AZD0284 after a high-calorie meal. AZD0284 plasma concentrations, as well as inhibition of ex vivo-stimulated interleukin (IL)-17A release in whole blood, were frequently measured after both single and multiple dosing.ResultsEighty-three men participated in the study. AZD0284 was absorbed rapidly into plasma after oral dosing and exhibited a terminal half-life of 13-16 hours. Both the area under the concentration-time curve (AUC) and maximum concentration (Cmax ) increased subproportionally with increasing dose (95% confidence intervals of slope parameter were 0.71-0.84 and 0.72-0.88 for AUC and Cmax , respectively). Food intake delayed the absorption of AZD0284 but did not affect the overall exposure or half-life. AZD0284 showed dose-dependent reduction of ex vivo-stimulated IL-17A release after both single and multiple doses. No significant safety concerns were identified in the study.ConclusionsAZD0284 was well tolerated, rapidly and dose-dependently absorbed, and reduced stimulated IL-17A release after single and multiple dosing. The results of this study support further clinical development of AZD0284.