Acid Receptor-related Orphan Receptor Γt Research Articles

Lithocholic acid derivatives as potent modulators of the nuclear receptor RORγt.

Retinoic acid receptor-related orphan receptor γt (RORγt) is a nuclear receptor found in various tissues that plays a crucial role in the differentiation and proliferation of T helper 17 (Th17) cells, as well as in their generation of the pro-inflammatory cytokine IL-17A. RORγt represents a promising therapeutic target for autoimmune diseases, metabolic disorders, and multiple tumors. Despite extensive research efforts focused on the development of small molecule RORγt modulators, no drug candidates have advanced to phase 3 clinical trials owing to a lack of efficacy or safety margin. This outcome highlights the unmet need to optimize small molecule drug candidates targeting RORγt to develop effective therapies for autoimmune and inflammatory diseases. In this study, we synthesized and evaluated 3-oxo-lithocholic acid amidates as a new class of RORγt modulators. Our evaluation entailed biophysical screening, cellular screening in different platforms, molecular docking, and in vitro pharmacokinetic profiling. The top compound from our study (3-oxo-lithocholic acid amidate, A2) binds to RORγt at an equilibrium dissociation constant (KD) of 16.5 ± 1.34 nM based on microscale thermophoresis (MST). Assessment of the efficacy of A2 in the cellular RORγt reporter luciferase assay revealed a half-maximal inhibitory concentration (IC50) value of 225 ± 10.4 nM. Unlike 3-oxo-lithocholic acid, A2 demonstrated the ability to reduce the IL-17A mRNA expression levels in EL4 cells with RORγt expression using quantitative reverse transcriptase PCR (RT-PCR). Validation of the desirable physicochemical properties and stability of A2 sets the stage for the preclinical evaluation of this new class of RORγt modulators in animal models of autoimmune diseases.

Increased gene expression of CCR6 and RORγt in peripheral blood cells of rheumatoid arthritis patients and their correlation with anti-cyclic citrullinated peptide and disease activity.

The significance of T helper 17 (Th17) cells in the pathogenesis of rheumatoid arthritis (RA) has recently been demonstrated in many studies. Retinoic acid receptor-related orphan receptor γt (RORγt) is a transcription factor that is specifically involved in the generation of Th17 cells. Besides, the chemokine receptor CCR6, the receptor for CCL20, is characteristically expressed by these cells. Considering the pivotal roles of Th17 cells in RA pathogenesis, in this study, we assessed the gene expression of CCR6 and RORγt in the peripheral blood leukocytes of new case RA patients. Also, we evaluated their association with anticyclic citrullinated peptide (anti-CCP) antibodies and disease activity. Forty-five new case RA patients and 45 healthy persons have been recruited in this investigation. The gene expression of CCR6 and RORγt was evaluated by quantitative real-time PCR (qRT-PCR), and anti-CCP antibodies plasma levels were measured using the enzyme-linked immunosorbent assay (ELISA) technique. Disease activity was measured according to the disease activity score-28 (DAS-28) formula. The gene expression of CCR6 and RORγt increased remarkably in new case RA patients compared to healthy controls (p < .05 and p < .01, respectively). Moreover, there was a positive correlation between RORγt gene expression and parameters, including gene expression of CCR6 (p = .001, r = .461), plasma levels of CCL20 (p = .0009, r = .477), ESR (p = .004, r = .419), DAS-28 (p = .006, r = .402), anti-CCP (p = .019, r = .346), and RF (p = .001, r = .451). Also, CCR6 gene expression was positively associated with the DAS-28 (p = .037, r = .310), plasma levels of anti-CCP (p = .037, r = .312), and ESR (p = .029, r = .327). Increased gene expression of CCR6 and RORγt in peripheral blood leukocytes of new case RA patients may contribute to the exacerbation and pathogenesis of RA.

Discovery of Biaryl Amide Derivatives as Potent, Selective, and Orally Bioavailable RORγt Agonists for Cancer Immunotherapy.

The master transcription factor receptor retinoic acid receptor-related orphan receptor γt (RORγt) regulates the differentiation of T-helper 17 (Th17) cells and the production of interleukin-17 (IL-17). Activation of RORγt+ T cells in the tumor microenvironment promotes immune infiltration to more effectively inhibit tumor growth. Therefore, RORγt agonists provide a reachable approach to cancer immunotherapy. Herein, a series of biaryl amide derivatives as novel RORγt agonists were designed, synthesized, and evaluated. Starting from the reported RORγt inverse agonist GSK805 (1), "functionality switching" and structure-based drug optimization led to the discovery of a promising RORγt agonist lead compound 14, which displayed potent and selective RORγt agonist activity and significantly improved metabolic stability. With excellent in vivo pharmacokinetic profiles, compound 14 demonstrated robust efficacy in preclinical tumor models of mouse B16F10 melanoma and LLC lung adenocarcinoma. Taken together, current studies indicate that 14 deserves further investigation as a potential lead RORγt agonist for cancer immunotherapy.

An SAR Study on a Class of 6-(Trifluoromethyl)-pyridine Derivatives as RORγt Inverse Agonists

aims: To discover novel and potent RORγt inverse agonists for the treatment of Th17 cell-related autoimmune diseases such as psoriasis, and rheumatoid arthritis. background: The nuclear receptor retinoic acid receptor-related orphan receptor γt (RORγt) is an important transcription factor in immune cells. Functionally, RORγt plays an important role in promoting the differentiation of T helper 17 cells and regulating the expression of pro-inflammatory factors such as interleukin 17. Therefore, RORγt is considered a promising target for the treatment of the autoimmune disorder. Currently, 21 RORγt inverse agonists with various scaffolds have entered clinical trials. objective: To discover novel and potent RORγt inverse agonists, a series of novel 6-(trifluoromethyl) pyridine derivatives were designed and synthesized. method: We designed and synthesized a series of potent RORγt inverse agonists W1~W16 based on VTP-43742. Molecular docking, molecular dynamics (MD) simulation, and MM/GBSA were used to study the structure-activity relationship (SAR) of the derivatives. result: The biological activity evaluation indicated that the target compounds showed potent RORγt inhibitory activities. The most active compound W14 exhibited low nanomolar inhibitory activity (IC50 = 7.5 nM) in the luciferase reporter assay, which was superior to the clinical compound VTP-43742. Analysis of the binding mode of W14 demonstrated that the interaction of -CF3 with Leu324, Leu396, and His479 has an important contribution to the binding. Furthermore, W14 broke the H-bond formed by His479 and Tyr502 via a “push-pull” mechanism. conclusion: Compound W14 could be used as a potential RORγt inverse agonist for further modification. other: No

The emerging family of RORγt+ antigen-presenting cells.

Antigen-presenting cells (APCs) are master regulators of the immune response by directly interacting with T cells to orchestrate distinct functional outcomes. Several types of professional APC exist, including conventional dendritic cells, B cells and macrophages, and numerous other cell types have non-classical roles in antigen presentation, such as thymic epithelial cells, endothelial cells and granulocytes. Accumulating evidence indicates the presence of a new family of APCs marked by the lineage-specifying transcription factor retinoic acid receptor-related orphan receptor-γt (RORγt) and demonstrates that these APCs have key roles in shaping immunity, inflammation and tolerance, particularly in the context of host-microorganism interactions. These RORγt+ APCs include subsets of group 3 innate lymphoid cells, extrathymic autoimmune regulator-expressing cells and, potentially, other emerging populations. Here, we summarize the major findings that led to the discovery of these RORγt+ APCs and their associated functions. We discuss discordance in recent reports and identify gaps in our knowledge in this burgeoning field, which has tremendous potential to advance our understanding of fundamental immune concepts.

Discovery, Synthesis, and In Vitro Characterization of 2,3 Derivatives of 4,5,6,7-Tetrahydro-Benzothiophene as Potent Modulators of Retinoic Acid Receptor-Related Orphan Receptor γt.

Retinoic acid receptor-related orphan receptor γt (RORγt) is a nuclear receptor that is expressed in a variety of tissues and is a potential drug target for the treatment of inflammatory and auto-immune diseases, metabolic diseases, and resistant cancer types. We herein report the discovery of 2,3 derivatives of 4,5,6,7-tetrahydro-benzothiophene modulators of RORγt. We also report the solubility in acidic/neutral pH, mouse/human/dog/rat microsomal stability, Caco-2, and MDR1-MDCKII permeabilities of a set of these derivatives. For this group of modulators, inverse agonism by steric clashes and push-pull mechanisms induce greater instability to protein conformation compared to agonist lock hydration. Independent of the two mechanisms, we observed a basal modulatory activity of the tested 2,3 derivatives of 4,5,6,7-tetrahydro-benzothiophene toward RORγt due to the interactions with the Cys320-Glu326 and Arg364-Phe377 hydrophilic regions. The drug discovery approach reported in the current study can be employed to discover modulators of nuclear receptors and other globular protein targets.

Optimization of carbazole carboxamide RORγt agonists: Challenges in improving the metabolic stability and maintaining the agonistic activity.

Based on two previously discovered carbazole carboxamide retinoic acid receptor-related orphan receptor-γt (RORγt) agonists 6 and 7 (t1/2=8.7min and 16.4min in mouse liver microsome, respectively), new carbazole carboxamides were designed and synthesized according to the molecular mechanism of action (MOA) and metabolic site analysis with the aim of identifying novel RORγt agonists with optimal pharmacological and metabolic profiles. By modifying the "agonist lock" touching substitutions on carbazole ring, introducing heteroatoms into different parts of the molecule and attaching a side chain to the sulfonyl benzyl moiety, several potent RORγt agonists were identified with greatly improved metabolic stability. Best overall properties were achieved in compound (R)-10f with high agonistic activities in RORγt dual FRET (EC50=15.6nM) and Gal4 reporter gene (EC50=141nM) assays and greatly improved metabolic stability (t1/2>145min) in mouse liver microsome. Besides, the binding modes of (R)-10f and (S)-10f in RORγt ligand binding domain (LBD) were also studied. Altogether, the optimization of carbazole carboxamides led to the discovery of (R)-10f as a potential small molecule therapeutics for cancer immunotherapy.

Discovery of novel triazine derivatives as potent retinoic acid receptor-related orphan receptor γt (RORγt) inverse agonists

Retinoic Acid Receptor-Related Orphan Receptor γt (RORγt) has been exploited as a promising target for the new small molecule therapeutics to treat inflammatory and autoimmune diseases via modulating the interleukin-17 (IL-17) production by T helper 17 (Th17) cells. Herein, we reported a series of triazine-based derivatives as novel RORγt inverse agonists. By screening of our in-house compound library, the hit compound 1 was identified with weak RORγt inhibitory activity. Subsequently, we engineered detailed structural modifications to explore the structure-activity relationships (SARs) of triazines derivatives, which led to discovery of a number of potent RORγt inverse agonists with IC50 values in the range of 7 nM–50 nM in RORγt dual FRET assay. Among them, compound 14g displayed potent RORγt inverse agonistic activity with an IC50 value of 22.9 nM in dual FRET assay. In a cell-based reporter gene assay, compound 14g showed an IC50 value of 0.428 μM and maximum inhibition rate of 108.9%. Compound 14g also exhibited good metabolic stability and a decent pharmacokinetic profile with a low clearance (CL = 0.229 L/h/kg) and a reasonable oral exposure (AUC0-Last = 5058 ng/mL*h). Most importantly, 14g alleviated the severity of imiquimod-induced psoriasis in mice. Taken together, triazine-based derivatives represent a new chemical class of RORγt inverse agonists as potential therapeutic agents against autoimmune diseases.

The lncRNA HOTAIR via miR-17-5p is involved in arsenite-induced hepatic fibrosis through regulation of Th17 cell differentiation.

Arsenic compounds are toxins that are widely distributed in the environment. Chronic exposure to low levels of these compounds can cause hepatic fibrosis and other damage. Th17 differentiation of CD4+ T cells and the secretion of IL-17 activates hepatic stellate cells (HSCs), which are involved in hepatic fibrosis, but their mechanisms in arsenic-induced hepatic fibrosis are unclear. We found, in arsenite-induced fibrotic livers of mice, increases of CD4+ T cell infiltration, Th17 cell nuclear receptor retinoic acid receptor-related orphan receptor γt (RORγt), and secretion of the pro-inflammatory cytokine IL-17. There were also elevated levels of the lncRNA, HOTAIR. For Jurkat cells, arsenite elevated levels of HOTAIR and protein levels of RORγt and IL-17A, decreased miR-17-5p, promoted Th17 cell differentiation, and released IL-17. The culture medium of arsenite-treated Jurkat cells activated LX-2 cells. Down-regulation of HOTAIR or up-regulation of miR-17-5p blocked arsenite-induced Th17 cell differentiation, which inhibited the LX-2 cell activation. However, down-regulation of HOTAIR and miR-17-5p reversed this inhibitory effect. For mice, silencing of HOTAIR diminished the hepatic levels of RORγt and IL-17A and alleviated arsenite-induced hepatic fibrosis. These results demonstrate that, for CD4+ T cells, arsenite promotes RORγt-mediated Th17 cell differentiation through HOTAIR down-regulation of miR-17-5p, and increases the secretion of cytokine IL-17A, which activates HSCs; the activated HSCs facilitate hepatic fibrosis. The findings reveal a new mechanism and a potential therapeutic target for arsenite-induced hepatic fibrosis.

Dispensable Role of Aire in CD11c+ Conventional Dendritic Cells for Antigen Presentation and Shaping the Transcriptome.

Aire, the defect of which is responsible for the development of autoimmunity, is predominantly expressed in medullary thymic epithelial cells, and it controls a wide variety of genes, including those of tissue-restricted Ags, for establishing thymic tolerance. Aire is also expressed from APCs in the periphery, called extrathymic Aire-expressing cells (eTACs), and their complementing role to thymic tolerance has been suggested. eTACs are composed of two distinct classes of APCs, conventional dendritic cell (cDC)-type and group 3 innate lymphoid cell (ILC3)-like-type expressing retinoic acid receptor-related orphan receptor γt (RORγt). Although the essential role of Aire in the latter in the Th17-mediated immune response against Candida albicans has been reported, the role of Aire in the cDC-type eTACs for this action has not been examined. Furthermore, the significance of Aire in the production of the transcriptome of the cDC-type eTACs remains unknown. We have approached these issues using a high-fidelity Aire-reporter mouse strain. We found that although the cDC-type eTACs dominated ILC3-like-type eTACs in number and they served as efficient APCs for the immune response against an exogenous Ag as well as for the C. albicans-specific Th17 immune response, loss of Aire in cDC-type eTACs showed no clear effect on these functions. Furthermore, loss of Aire showed no major impact on the transcriptome from cDC-type eTACs. These results suggested that Aire in cDC-type eTACs may not have a cell-intrinsic role in the immune response in contrast to the role of Aire in ILC3-like-type eTACs.

DC vaccines loaded with glioma cells killed by photodynamic therapy induce Th17 anti-tumor immunity and provide a four-gene signature for glioma prognosis

Gliomas, the most frequent type of primary tumor of the central nervous system in adults, results in significant morbidity and mortality. Despite the development of novel, complex, multidisciplinary, and targeted therapies, glioma therapy has not progressed much over the last decades. Therefore, there is an urgent need to develop novel patient-adjusted immunotherapies that actively stimulate antitumor T cells, generate long-term memory, and result in significant clinical benefits. This work aimed to investigate the efficacy and molecular mechanism of dendritic cell (DC) vaccines loaded with glioma cells undergoing immunogenic cell death (ICD) induced by photosens-based photodynamic therapy (PS-PDT) and to identify reliable prognostic gene signatures for predicting the overall survival of patients. Analysis of the transcriptional program of the ICD-based DC vaccine led to the identification of robust induction of Th17 signature when used as a vaccine. These DCs demonstrate retinoic acid receptor-related orphan receptor-γt dependent efficacy in an orthotopic mouse model. Moreover, comparative analysis of the transcriptome program of the ICD-based DC vaccine with transcriptome data from the TCGA-LGG dataset identified a four-gene signature (CFH, GALNT3, SMC4, VAV3) associated with overall survival of glioma patients. This model was validated on overall survival of CGGA-LGG, TCGA-GBM, and CGGA-GBM datasets to determine whether it has a similar prognostic value. To that end, the sensitivity and specificity of the prognostic model for predicting overall survival were evaluated by calculating the area under the curve of the time-dependent receiver operating characteristic curve. The values of area under the curve for TCGA-LGG, CGGA-LGG, TCGA-GBM, and CGGA-GBM for predicting five-year survival rates were, respectively, 0.75, 0.73, 0.9, and 0.69. These data open attractive prospects for improving glioma therapy by employing ICD and PS-PDT-based DC vaccines to induce Th17 immunity and to use this prognostic model to predict the overall survival of glioma patients.

Effect of 3,3'-diselenodipropionic Acid on Dextran Sodium Sulfate-Induced Ulcerative Colitis in Mice.

3,3'-Diselenodipropionic acid (DSePA), a synthetic organoselenium compound, has received considerable attention because of its antioxidant properties and safety. Its protective effect against dextran sodium sulfate (DSS)-induced mouse ulcerative colitis (UC) and the role of T helper 17 (Th17) cell proliferation were investigated. Fifty C57BL/6 male mice were randomly assigned to one of five groups: control (Con), DSePA, DSS, low-dose DSePA (LSe), and high-dose DSePA (HSe). Mice in the DSS, LSe, and HSe groups drank 2% DSS to induce UC, and received normal saline, 1 and 2mg/mL DSePA solution by intraperitoneal injection, respectively. The DSePA group only received 2mg/mL DSePA solution. After 5weeks, DSS challenge induced UC in the mice, which manifested as decreased body weight, shortened colon length, the loss of goblet cells, activated proliferating cells, and multiple signs of intestinal lesions by histological observation, all of which were reversed to varying degrees by DSePA administration. DSS upregulated the colonic protein expression of the macrophage marker F4/80 and proinflammatory cytokines (IL-1β, IL-6, and TNFα), whereas DSePA administration downregulated the expression of these factors. DSS upregulated the mRNA expression of retinoic acid receptor-related orphan receptor γt (RORγt, mainly expressed in Th17 cells), IL-17A, and IL-17F and the levels of IL-17A and IL-17F in the colon, whereas DSePA administration decreased them. No difference was observed between the Con group and the DSePA group without DSS induction. Thus, DSePA administration ameliorated DSS-induced UC by regulating Th17-cell proliferation and the secretion of proinflammatory cytokines.

Novel RNA polymerase I inhibitor CX-5461 suppresses imiquimod-induced experimental psoriasis.

Clinical treatment of psoriasis remains challenging because of possible long-term drug toxicities and loss of therapeutic effects over time. CX-5461 is a novel selective inhibitor of RNA polymerase I. Our previous studies have shown that CX-5461 has potent anti-inflammatory effects. Here we investigated whether CX-5461 could inhibit the development of imiquimod-induced experimental psoriasis in mice. Adult male C57BL/6 mice were used, and psoriasis-like lesions were induced by topical imiquimod treatment. In vivo, we demonstrated that topical application of CX-5461 prevented the development of imiquimod-induced psoriasis, with decreases in keratinocyte proliferation, T-cell infiltration and pathological angiogenesis. CX-5461 also reversed existing skin inflammation induced imiquimod and retarded the development of 12-O-tetradecanoylphorbol-13-acetate-induced epidermal hyperplasia and inflammation. In vitro, CX-5461 induced cell cycle arrest in keratinocytes, inhibited expressions of interleukin-17, interleukin-23 receptor and retinoic acid receptor-related orphan receptor-γt in activated T cells, and reduced angiogenic functions of endothelial cells. In conclusion, CX-5461 exhibits therapeutic effects on experimental psoriasis in mice, likely via multiple mechanisms including anti-proliferative, anti-inflammatory and anti-angiogenic activities.

Abstract P3084: T Helper Cell Polarity Determines Salt-sensitivity And Development Of Hypertension

Background: Sodium chloride drives the stable induction of pathogenic T helper (Th) 17 cells and development of hypertension. However, high-salt intake induces hypertension in salt-sensitive persons but not in salt-resistant persons. Pathogenic Th17 cell plays an important role in the development of hypertension whereas suppressive Treg cell plays an important role in the prevention of hypertension. Objective: We tested the hypothesis that . Methods and Results: Eight-week-old male SS and SR rats were fed chow (NS, 0.4% NaCl) or high-salt (HS, 4% NaCl) diet for 4 weeks. Systolic blood pressure was measured by the tail-cuff method. Cultured splenic T cells from Dahl salt-sensitive (SS) and salt-resistant (SR) rats were exposed to hypertonic salt solution with or without IL-6 or TGFβ. T helper cell (Th17 and Treg) polarity was determined via flow cytometry. The expression of Th17-related genes such as interleukin (IL)-17A, IL-23R and retinoic acid receptor-related orphan receptor (ROR) γt) as well as Treg-related genes such as IL-10, CD25 and forkhead box (Fox) P3 were measured by ELISA or qRT-PCR. Adoptive transfer of Th17 cells isolated from SS or SR donors fed HS were performed intraperitoneally into SS and SR recipients. Upon chow diet, SR has higher Treg cells than SS does. HS intake induced hypertension and increased proinflammatory Th17 cells in SS but not in SR. Hypertonic salt solution induced differentiation of cultured splenic T cells preferentially into proinflammatory Th17 cells and anti-inflammatory Treg cells in SS and SR, respectively. Polarizing cytokine IL-6 also induced differentiation of cultured splenic T cells preferentially into proinflammatory Th17 cells and anti-inflammatory Treg cells in SS and SR, respectively, which were further potentiated by hypertonic salt solution. Adoptive transfer of activated Th17 cells isolated from hypertensive SS or normotensive SR, both of which had been fed HS diet, induced hypertension in SS recipients, but not SR recipients. Conclusions: These results indicate that T helper cell polarity after HS intake determines salt-sensitivity and development of hypertension in SS and SR rats. Th17 cell polarity predicts salt-sensitivity and development of hypertension, whereas Treg cell polarity predicts salt-resistance and maintenance of normotension. SR rats protect against hypertension after HS intake through anti-inflammatory Treg cell polarity.

Antioxidant nutrients can increase high-dose Methotrexate efficacy in 4T1 breast tumor Model: An experimental study on Vitamin E Succinate and Methyl-selenic acid

BackgroundWe aimed to evaluate the anti-cancer and immune system enhancing properties of Vitamin E succinate (VES) and methylselenic acid (MSA) administration on 4T1 breast tumor model under high-dose methotrexate (HDMTX) therapy and folinic acid (FA) rescue. MethodsThirty six 4T1 mammary carcinoma bearing mice were randomly divided into six groups: control (untreated; n = 6), treatment-1 (T1 group; HDMTX; n = 6), T2 (T1 + FA; n = 6), T3 (T2 + MSA; n = 6), T4 (T2 + VES; n = 6) and T5 (T3 + VES; n = 6). On day 21 of the study, all surviving mice were sacrificed and primary tumors and peripheral tissues were examined for histological and gene expression assays. The expression of GATA Binding Protein-3 (GATA3), forkhead box-P3 (FOXP3), T-bet and Retinoic acid receptor-related orphan receptor γt (RORγt) were evaluated in tumors and spleens. Also, vascular endothelial growth factor-A (VEGF-A) and UL16-Binding Protein 1 (ULBP-1) expression were evaluated in tumors. ResultsThe control, T4 and T5 groups were able to complete the entire 21-day study period. Also, significant tumor shrinkage was occurred in T4 group (P < 0.05). Suppression of splenic FOXP3 and GATA3 were observed in the mice receiving T4 and T5 regimens. Also, induction of tumoral FOXP3 and GATA3 were achieved in the T4 and T5 groups, respectively (P < 0.05). No metastasis occurred in T4 receiving group; while, lung and liver metastasis were observed in T5 group. ConclusionIn this study, high and fixed dose of MTX was used. Further studies are needed to optimize MTX dose along with FA, VES and MSA.

Novel Therapeutic Target(s) for Psoriatic Disease.

Psoriasis and psoriatic arthritis, together known as psoriatic disease, is highly prevalent chronic relapsing inflammatory disease affecting skin, joints or both and is associated with several comorbidities such as cardiovascular, metabolic, psychiatric, renal disease etc. The etiopathogenesis of psoriasis is complex and mainly driven by aberrant immune response owing to the genetic susceptibility and various environmental factors such as trauma, infections and drugs. Recent advances in understanding molecular and cellular pathways have identified tumor necrosis factor-α (TNF-α), interleukin-17 (IL-17), IL-23, IL-22 as major contributors in psoriasis pathogenesis. Advances in the knowledge of pathophysiology, the interaction of autoinflammation and clinical phenotypes have led to the development of highly effective targeted therapeutic agents which include TNF-α, IL-17, IL-23, IL-1 α/β or IL-36 inhibitors or receptor blockers, small molecule drugs like phosphodiesterase-4 inhibitors (apremilast), Janus kinase (JAK) inhibitors, retinoic acid receptor-related orphan receptor γt (RORγt) inhibitors. These novel drugs have promised the potential of improved disease control. In recent years, the transition from biologics to biosimilars especially with TNF-α inhibitors had significant impact on decreasing health care cost and increasing therapeutic options to the patients. However, selection of right treatment for an individual patient still remains challenging. Moreover, interplay between different epigenetic mechanisms such as the DNA methylation, chromatin modifications and noncoding RNA regulation has recently been started to be deciphered. Enzymes inhibitors involved in epigenetic pathways such as DNA methyltransferases and histone deacetylases demonstrated to restore normal epigenetic patterns in clinical settings and have provided the potential as novel therapeutic targets for psoriasis. In this review, we will discuss novel biologic agents and newer therapeutic approaches in treatment of psoriatic disease.

Serum Amyloid A1: A Biomarker for Neutrophilic Airway Inflammation in Adult Asthmatic Patients.

PurposeWe evaluated the role of serum amyloid A1 (SAA1) in the pathogenesis of airway inflammation according to the phenotype of asthma.MethodsOne hundred twenty-two asthmatic patients and 60 healthy control subjects (HCs) were enrolled to measure SAA1 levels. The production of SAA1 from airway epithelial cells (AECs) and its effects on macrophages and neutrophils were investigated in vitro and in vivo.ResultsThe SAA1 levels were significantly higher in sera of asthmatic patients than in those of HCs (P = 0.014); among asthmatics, patients with neutrophilic asthma (NA) showed significantly higher SAA1 levels than those with non-NA (P < 0.001). In vitro, polyinosinic:polycytidylic acid (Poly I-C) treatment markedly enhanced the production of SAA1 from AECs, which was further augmented by neutrophils; SAA1 could induce the production of interleukin (IL)-6, IL-8, and S100 calcium-binding protein A9 from AECs. Additionally, SAA1 activated neutrophils and macrophages isolated from peripheral blood of asthmatics, releasing neutrophil extracellular traps (NETs) and secreting proinflammatory cytokines presenting M1 phenotype, respectively. In ovalbumin-induced asthma mice, Poly I-C treatment significantly increased SAA1 levels as well as IL-17A/interferon-gamma/IL-33 levels in bronchoalveolar lavage fluid (BALF), leading to airway hyperresponsiveness and inflammation. The highest levels of SAA1 and neutrophilia were noted in the BALF and sera of the NA mouse model, followed by the mixed granulocytic asthma (MA) model. Especially, SAA1 induced IL-17/retinoic acid receptor-related orphan receptor γt expression from activated CD4+ T lymphocytes in asthmatic mice.ConclusionsThe results show that SAA1 could induce neutrophilic airway inflammation by activating neutrophils along with NET formation, M1 macrophages, and Th2/Th17 predominant cells, contributing to the phenotype of NA or MA.

Discovery of 2H-chromone-4-one based sulfonamide derivatives as potent retinoic acid receptor-related orphan receptor γt inverse agonists

Retinoic acid receptor related orphan receptor γt (RORγt), identified as the essential functional regulator of IL-17 producing Th17 cells, is an attractive drug target for treating autoimmune diseases. Starting from the reported GSK2981278 (Phase II), we structurally modified and synthesized a series of 2H-chromone-4-one based sulfonamide derivatives as novel RORγt inverse agonists, which significantly improved their human metabolic stabilities while maintaining a potent RORγt inverse agonist profile. Efforts in reducing the lipophilicity and improving the LLE values led to the discovery of c9, which demonstrated potent RORγt inverse agonistic activity and consistent metabolic stability. During in vivo studies, oral administration of compound c9 exhibited a robust and dose-dependent inhibition of IL-17A cytokine expression and significantly lessened the skin inflammatory symptoms in the mouse imiquimod-induced skin inflammation model. Docking analysis of the binding mode revealed that c9 can suitably occupy the active pocket, and the introduction of the morpholine pyridine group can interact with Leu396, His479, and Cys393. Thus, compound c9 was selected as a preclinical compound for treating Th17-driven autoimmune diseases.

Discovery of N-(2-benzyl-4-oxochroman-7-yl)-2-(5-(ethylsulfonyl) pyridin-2-yl) acetamide (b12) as a potent, selective, and orally available novel retinoic acid receptor-related orphan receptor γt inverse agonist

The nuclear receptor retinoic acid receptor-related orphan receptor γ (RORγ, NR1F3, or RORc) exists in two isoforms, with one isoform (RORγ or RORc1) widely expressed in a variety of tissues, and the expression of the second isoform (RORγt or RORc2) restricted to the thymus and cells of the immune system. RORγt is a key regulator of the development and functions of T-helper 17 (Th17) cells. Clinical proof-of-concept (PoC) with small molecule inverse agonists of RORγt has been achieved with VTP-43742 (Phase II) for the treatment of psoriasis, and pre-clinical PoC for this mechanism has also been established for the treatment of autoimmune diseases. A series of aryl sulfonyl derivatives as novel RORγt inverse agonists were designed and synthesized based on VTP-43742. We conducted structural modifications that improved the activity profile. In pharmacodynamic (PD) studies, oral administration of compound b12 showed robust and dose-dependent inhibition of IL-6 and IL-17A cytokine expression. The ability of compound b12 to reduce the levels of IL-6 and IL-17A in vivo after oral dosing in mice, and a corresponding reduction in skin inflammation further supports the potential of small molecule RORγt modulation as a therapeutic target for the treatment of inflammatory diseases.

Discovery of Chromane-6-Sulfonamide Derivative as a Potent, Selective, and Orally Available Novel Retinoic Acid Receptor-Related Orphan Receptor γt Inverse Agonist.

Interleukin-17 (IL-17) is a proinflammatory cytokine that plays a dominant role in inflammation, autoimmunity, and host defense. RORγt is a key transcription factor mediating T helper 17 (Th17) cell differentiation and IL-17 production, which is able to activate CD8+ T cells and elicit antitumor efficacy. A series of sulfonamide derivatives as novel RORγt inverse agonists were designed and synthesized. Using GSK2981278 (phase II) as a starting point, we engineered structural modifications that significantly improved the activity and pharmacokinetic profile. In animal studies, oral administration of compound d3 showed a robust and dose-dependent inhibition of the IL-17A cytokine expression in a mouse imiquimod-induced skin inflammation model. Docking analysis of the binding mode revealed that the compound d3 occupied the active pocket suitably. Thus, compound d3 was selected as a clinical compound for the treatment of Th17-driven autoimmune diseases.