Retinoid Acid Receptor-related Orphan Research Articles

RORing toward immunoregulation in glomerulonephritis?

CD4+ T cells that express forkhead box protein 3 are important in maintaining tolerance and restraining effector responses. Herrnstadt etal. use a model of rapidly progressive glomerulonephritis to examine the nature and role of forkhead box protein 3-positive and retinoid acid-related orphan receptor γt-positive regulatory T cells. These cells are prominent in experimental glomerulonephritis, both locally and systemically, and are present in kidneys of people with anti-neutrophil cytoplasmic antibody-associated vasculitis. Functionally, despite their expression of retinoid acid-related orphan receptor γt, associated with T-helper cell 17 cells, they regulate cellular immunity, both systemically and within the kidney.

Screening of Biomarkers Related to Myocardial Infarction Based on the Construction of a ceRNA Regulation Network.

This study aimed to identify the biomarkers related to myocardial infarction based on building lncRNA-miRNA-mRNA ceRNA regulation network. The expression profile data were obtained from the Gene Expression Omnibus database. The differentially expressed RNAs (DElncRNAs, DEmiRNAs, and DEmRNAs) were analyzed using the limma package of R. In addition, the differential myocardial infarction-related genes were obtained and the Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway on the differential myocardial infarction-related genes were analyzed. The co-expression network of lncRNA-mRNA was constructed, and the Kyoto Encyclopedia of Genes and Genomes pathway of such a co-expression network was analyzed. Moreover, the lncRNA-miRNA-mRNA ceRNA network associated with myocardial infarction was built, and the key biomarkers of the ceRNA network were verified using the GSE141512 and GSE66752 datasets. In total, we acquired 51 DElncRNAs, 276 DEmiRNAs, and 1200 DEmRNAs as well as 291 differential myocardial infarction-related genes. Moreover, the co-expression network of lncRNA-mRNA was built, and mRNAs were found to be associated with 109 Kyoto Encyclopedia of Genes and Genomes pathways (the target gene of RP3-394A18.1 was significantly related to lipid and atherosclerosis). In addition, the ceRNA network related to myocardial infarction was constructed, and the dataset analyses of the RNAs were validated between the myocardial infarction and normal groups. It was also found that the expression levels of hsa-miR-1291 and Retinoid acid receptor-related orphan receptor α (RORA) in the myocardial infarction group were noticeably lower than those in the normal group, whereas the expression levels of ENTPD1, QSOX1, and TIMP2 in the myocardial infarction group were noticeably higher than those in the normal group. In this study, we built a ceRNA regulation network of myocardial infarction. This study could help identify the biomarkers related to myocardial infarction.

Intestinal Microflora Altered by Vancomycin Exposure in Early Life Up-regulates Type 2 Innate Lymphocyte and Aggravates Airway Inflammation in Asthmatic Mice.

Allergic asthma is a chronic inflammatory disease primarily mediated by Th2 immune mechanisms. Exposure to antibiotics during early life is associated with an increased risk of allergic asthma, although the exact mechanism is not fully understood. In this study, mice were randomly divided into a normal saline control group (NS group), an OVA-induced asthma group (OVA group), a vancomycin treatment control group (VAN.NS group), and a vancomycin treatment the OVA-induced asthma group (VAN.OVA group). The results showed that vancomycin altered dominant species in experimental mice. The phylum level histogram showed that Bacteroides abundance was increased, and Firmicutes abundance was decreased in the OVA group. Airway inflammation and airway hyperresponsiveness (AHR) were aggravated in the vancomycin-exposed group. Enzyme-linked immunosorbent assay (ELISA) showed that the serum levels of IL-5, IL-13, and IL-33 in the OVA group were higher than those in the NS group, especially in the VAN.OVA group. The expression of GATA binding protein-3(GATA3) and retinoid acid receptor-related orphan receptor alpha (RORa) increased in the OVA group, even more so in the VAN.OVA group. Group 2 innate lymphoid cells (ILC2s) in the lung detected by flow cytometry was increased in OVA mice more than those in control mice, with a more remarkable increase in the VAN.OVA. Our results demonstrated that vancomycin used in early life could alter the intestinal microecology of mice, which, in turn, aggravates airway inflammation and upregulate type 2 innate lymphocytes.

Deregulation of Cholesterol Homeostasis by a Nuclear Hormone Receptor Crosstalk in Advanced Prostate Cancer.

Simple SummaryMetastatic castration-resistant prostate cancer (mCRPC) is one of the leading causes of cancer-related death. mCRPC tumors feature high intratumoral cholesterol levels. Our current study shows that the nuclear receptor RORγ plays crucial roles in the aberrant cholesterol homeostasis of mCRPC. RORγ simultaneously stimulates cholesterol biosynthesis and suppresses cholesterol efflux programs through a RORγ and LXR crosstalk. Our study also demonstrated that RORγ antagonists alone or in combination with cholesterol-lowering drug statins are effective in inhibiting mCRPC cell and tumor growth. Our findings revealed a mechanism underlying the elevated cholesterol levels in mCRPC and suggested a potential therapeutic strategy for mCRPC patients.Metastatic castration-resistant prostate cancer (mCRPC) features high intratumoral cholesterol levels, due to aberrant regulation of cholesterol homeostasis. However, the underlying mechanisms are still poorly understood. The retinoid acid receptor-related orphan receptor gamma (RORγ), an attractive therapeutic target for cancer and autoimmune diseases, is strongly implicated in prostate cancer progression. We demonstrate in this study that in mCRPC cells and tumors, RORγ plays a crucial role in deregulation of cholesterol homeostasis. First, we found that RORγ activates the expression of key cholesterol biosynthesis proteins, including HMGCS1, HMGCR, and SQLE. Interestingly, we also found that RORγ inhibition induces cholesterol efflux gene program including ABCA1, ABCG1 and ApoA1. Our further studies revealed that liver X receptors (LXRα and LXRβ), the master regulators of cholesterol efflux pathway, mediate the function of RORγ in repression of cholesterol efflux. Finally, we demonstrated that RORγ antagonist in combination with statins has synergistic effect in killing mCRPC cells through blocking statin-induced feedback induction of cholesterol biosynthesis program and that the combination treatment also elicits stronger anti-tumor effects than either alone. Altogether, our work revealed that in mCRPC, RORγ contributes to aberrant cholesterol homeostasis by induction of cholesterol biosynthesis program and suppression of cholesterol efflux genes. Our findings support a therapeutic strategy of targeting RORγ alone or in combination with statin for effective treatment of mCRPC.

Circ_0066881 targets miR-144-5p/RORA axis to alleviate LPS-induced apoptotic and inflammatory damages in human periodontal ligament cells.

Circular RNAs (circRNAs) are involved in the regulation of various diseases, including periodontitis. The objective of this study was to analyze the biological role and regulatory mechanism of circ_0066881 in LPS-induced periodontal ligament cells (PDLCs). Circ_0066881, microRNA-144-5p (miR-144-5p) and retinoid acid-related orphan receptor A (RORA) levels were determined using reverse transcription-quantitative PCR (RT-qPCR) assay. Cell viability detection was performed by Cell Counting Kit-8 assay. Cell apoptosis was assessed through flow cytometry and caspase-3 activity assay. The protein analysis was completed via Western blot. Inflammatory cytokines were measured by ELISA. The target interaction was validated by dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay. The level of circ_0066881 was down-regulated in periodontitis tissues. Overexpression of circ_0066881 relieved LPS-induced cell viability inhibition and apoptosis or inflammation promotion in PDLCs. Circ_0066881 could bind to miR-144-5p. The protective function of circ_0066881 was achieved by sponging miR-144-5p in PDLCs. Circ_0066881 acts as a miR-144-5p sponge to mediate the RORA level. Inhibition of miR-144-5p attenuated LPS-induced cell injury via targeting RORA. All these results demonstrated that circ_0066881 partly prevented LPS-evoked cell dysfunction in PDLCs through miR-144-5p-mediated up-regulation of RORA.

AKR1C2 and AKR1C3 expression in adipose tissue: Association with body fat distribution and regulatory variants

BackgroundChanges in androgen dynamics within adipose tissue have been proposed as modulators of body fat accumulation. In this context, AKR1C2 likely plays a significant role by inactivating 5α-dihydrotestosterone. AimTo characterize AKR1C2 expression patterns across adipose depots and cell populations and to provide insight into the link with body fat distribution and genetic regulation. MethodsWe used RNA sequencing data from severely obese patients to assess patterns of AKR1C2 and AKR1C3 expression in abdominal adipose tissue depots and cell fractions. We additionally used data from 856 women to assess AKR1C2 heritability and to link its expression in adipose tissue with body fat distribution. Further, we used public resources to study AKR1C2 genetic regulation as well as reference epigenome data for regulatory element profiling and functional interpretation of genetic data. ResultsWe found that mature adipocytes and adipocyte-committed adipocyte progenitor cells (APCs) had enriched expression of AKR1C2. We found adipose tissue AKR1C2 and AKR1C3 expression to be significantly and positively associated with percentage trunk fat mass in women. We identified strong genetic regulation of AKR1C2 by rs28571848 and rs34477787 located on the binding sites of two nuclear transcription factors, namely retinoid acid-related orphan receptor alpha and the glucocorticoid receptor. ConclusionWe confirm the link between AKR1C2, adipogenic differentiation and adipose tissue distribution. We provide insight into genetic regulation of AKR1C2 by identifying regulatory variants mapping to binding sites for the glucocorticoid receptor and retinoid acid-related orphan receptor alpha which may in part mediate the effect of AKR1C2 expression on body fat distribution.

RORα Regulates Odontoblastic Differentiation and Mediates the Pro-Odontogenic Effect of Melatonin on Dental Papilla Cells.

Dental papilla cells (DPCs), precursors of odontoblasts, are considered promising seed cells for tissue engineering. Emerging evidence suggests that melatonin promotes odontoblastic differentiation of DPCs and affects tooth development, although the precise mechanisms remain unknown. Retinoid acid receptor-related orphan receptor α (RORα) is a nuclear receptor for melatonin that plays a critical role in cell differentiation and embryonic development. This study aimed to explore the role of RORα in odontoblastic differentiation and determine whether melatonin exerts its pro-odontogenic effect via RORα. Herein, we observed that RORα was expressed in DPCs and was significantly increased during odontoblastic differentiation in vitro and in vivo. The overexpression of RORα upregulated the expression of odontogenic markers, alkaline phosphatase (ALP) activity and mineralized nodules formation (p < 0.05). In contrast, odontoblastic differentiation of DPCs was suppressed by RORα knockdown. Moreover, we found that melatonin elevated the expression of odontogenic markers, which was accompanied by the upregulation of RORα (p < 0.001). Utilising small interfering RNA, we further demonstrated that RORα inhibition attenuated melatonin-induced odontogenic gene expression, ALP activity and matrix mineralisation (p < 0.01). Collectively, these results provide the first evidence that RORα can promote odontoblastic differentiation of DPCs and mediate the pro-odontogenic effect of melatonin.

Circ_0081572 inhibits the progression of periodontitis through regulating the miR-378h/RORA axis

ObjectivesRevealing the role and mechanism of circ_0081572 in periodontitis progression. DesignQuantitative real-time PCR (qRT-PCR) was applied to measure the expression of circ_0081572, microRNA (miR)-378h and retinoid acid-related orphan receptor A (RORA). Lipopolysaccharide (LPS) was used to treat periodontal ligament cells (PDLCs) to construct periodontitis cell model in vitro. Cell counting kit 8 (CCK8) assay and flow cytometry were used to measure cell viability and apoptosis. The caspase 3 activity was detected by Caspase 3 Activity Assay Kit. Western blot assay was performed to detect the expression of apoptosis-associated proteins and RORA. The inflammation response and oxidative stress were determined by detecting the levels of inflammatory cytokines and reactive oxygen species (ROS). The relationship between miR-378h and circ_0081572 or RORA was verified by dual-luciferase reporter assay, RNA immunoprecipitation (RIP) assay and biotin-labeled RNA pull-down assay. ResultsCirc_0081572 was a stability circRNA with downregulated expression in the gingival tissues of periodontitis patients. Overexpression of circ_0081572 could alleviate LPS-induced PDLCs injury. Circ_0081572 could serve as a sponge for miR-378h. Furthermore, miR-378h could reverse the inhibition of circ_0081572 on LPS-induced PDLCs injury. In addition, RORA could be targeted by miR-378h, and its silencing could reverse the suppressive effect of miR-378h inhibitor and circ_0081572 overexpression on LPS-induced PDLCs injury. ConclusionsOur results suggested that circ_0081572 might prevent periodontitis by regulating the miR-378h /RORA axis.

Decreasing lncRNA PVT1 causes Treg/Th17 imbalance via NOTCH signaling in immune thrombocytopenia

ABSTRACT Objectives: Immune thrombocytopenia (ITP) is an autoimmune disease. T helper cell 17 (Th17) cells are increased in peripheral blood of ITP patients. NOTCH signaling is involved in Th17 cell differentiation and function. Besides, lncRNA Plasmacytoma variant translocation 1 (PVT1) was decreased in experimental autoimmune encephalomyelitis, and overexpressing PVT1 inhibited Th17 cell differentiation. Here, we aimed to investigate the effect of lncRNA PVT1 on ITP and its related mechanism. Methods: The number of Th17 cells and Treg cells was carried out using flow cytometry. PVT1 levels were detected by quantitative real-time PCR. Interleukin-17 (IL-17) levels and transforming growth factor-β (TGF-β) levels were detected by enzyme-linked immunosorbent assay. Protein levels of retinoid acid-related orphan receptor γ t (RORγt), forkhead box P3 (Foxp3), and NOTCH1 were carried out by western blot. NOTCH1 ubiquitylation was detected by ubiquitination assay. Results: PVT1 was down-regulated and Th17 cells were up-regulated in ITP patients. Overexpression of PVT1 decreased the number of Th17 cells, and also decreased the levels of IL-17, RORγt, and NOTCH1. Besides, PVT1 could bind to NOTCH1 and mediated NOTCH1 degradation by increasing its ubiquitination. Additionally, excessive expression of PVT1 could increase the levels of PVT1, reduce the amount of Th17 cells, as well as the levels of IL-17, RORγt, and NOTCH1, while co-overexpressing NOTCH1 reversed the results. Conclusion: PVT1 was down-regulated in ITP patients. Overexpressing PVT1 might reduce Th17 cell differentiation by down-regulating NOTCH1, and further alleviated the development of ITP.

Detection of the 23-bp nucleotide sequence mutation in retinoid acid receptor related orphan receptor alpha (RORA) gene and its effect on sheep litter size

Retinoid acid receptor related orphan receptor alpha (RORA) transcribes steroid-related genes to regulate estrogen synthesis. As an important reproductive trait, litter size relates to estrogen synthesis. Therefore, it is important to investigate the association between RORA gene and sheep litter size. In this study, one 23-bp nucleotide sequence mutation was identified in intron 1 of RORA gene in 532 female Australian White Sheep. Moreover, the polymorphic information content (PIC) values of this locus was 0.219. The litter size of ID genotype was significantly better than II genotype and DD genotype in the second born litter size (p < 0.05). This loci was related to third born litter size and the ID is the dominant genotype (p < 0.05). The association between combined genotypes and average litter size showed that sheep with heterozygote (ID) genotypes had larger lamb than homozygous (DD and II) genotypes. To sum, this study provided theoretical references for the comprehensively research of the function of RORA gene and the breeding of Australian White Sheep. The 23-bp indel variants could be considered as molecular markers for the second and third born litter size of sheep for MAS breeding.

Lack of retinoid acid receptor-related orphan receptor alpha accelerates and melatonin supplementation prevents testicular aging.

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.

Red Wine Extract Disrupts Th17 Lymphocyte Differentiation in a Colorectal Cancer Context.

Scope: It is well established that immune response and inflammation promote tumoral progression. Immune cells communicate through direct contact or through cytokine secretion, and it is the pro-inflammatory status that will tip the balance toward tumor progression or anti-tumor immunity. It is demonstrated here that a red wine extract (RWE) can decrease inflammation through its action on the inflammasome complex. This study determines whether an RWE could impact other key actors of inflammation, including T helper 17 (Th17) immune cells in particular. Methods and results: Using an RWE containing 4.16g of polyphenols/liter of wine, it is shown that RWE decreases colorectal cancer cells in vitro and induces a reduction in colorectal tumor growth associated with a decrease in tumor-infiltrating lymphocytes in vivo. The process of T-lymphocyte differentiation in Th17 cells is altered by RWE, as revealed by the decrease in the expression of key actors controlling this process, such as signal transducer and activator of transcription 3 and retinoid acid-related orphan receptor γt. This disruption is associated with an inhibition of inflammatory interleukin 17 secretion. The data highlights the major involvement of Th17 immune cells in the biological effects of an RWE.

Isoform-Specific Lysine Methylation of RORα2 by SETD7 Is Required for Association of the TIP60 Coactivator Complex in Prostate Cancer Progression.

The retinoid acid-related orphan receptor α (RORα), a member of the orphan nuclear receptor superfamily, functions as an unknown ligand-dependent transcription factor. RORα was shown to regulate a broad array of physiological processes such as Purkinje cell development in the cerebellum, circadian rhythm, lipid and bone metabolism, inhibition of inflammation, and anti-apoptosis. The human RORα gene encodes at least four distinct isoforms (RORα1, -2, -3, -4), which differ only in their N-terminal domain (NTD). Two isoforms, RORα2 and 3, are not expressed in mice, whereas RORα1 and 4 are expressed both in mice and humans. In the present study, we identified the specific NTD of RORα2 that enhances prostate tumor progression and proliferation via lysine methylation-mediated recruitment of coactivator complex pontin/Tip60. Upregulation of the RORα2 isoform in prostate cancers putatively promotes tumor formation and progression. Furthermore, binding between coactivator complex and RORα2 is increased by lysine methylation of RORα2 because methylation permits subsequent interaction with binding partners. This methylation-dependent activation is performed by SET domain containing 7 (SETD7) methyltransferase, inducing the oncogenic potential of RORα2. Thus, post-translational lysine methylation of RORα2 modulates oncogenic function of RORα2 in prostate cancer. Exploration of the post-translational modifications of RORα2 provides new avenues for the development of tumor-suppressive therapeutic agents through modulating the human isoform-specific tumorigenic role of RORα2.

Loss of RAR-related orphan receptor alpha (RORα) selectively lowers docosahexaenoic acid in developing cerebellum

Deficiency in retinoid acid receptor-related orphan receptor alpha (RORα) of staggerer mice results in extensive granule and Purkinje cell loss in the cerebellum as well as in learned motor deficits, cognition impairments and perseverative tendencies that are commonly observed in autistic spectrum disorder (ASD). The effects of RORα on brain lipid metabolism associated with cerebellar atrophy remain unexplored. The aim of this study is to examine the effects of RORα deficiency on brain phospholipid fatty acid concentrations and compositions. Staggerer mice (Rorasg/sg) and wildtype littermates (Rora+/+) were fed n-3 polyunsaturated fatty acids (PUFA) containing diets ad libitum. At 2 months and 7 or more months old, brain total phospholipid fatty acids were quantified by gas chromatography-flame ionization detection. In the cerebellum, all fatty acid concentrations were reduced in 2 months old mice. Since total fatty acid concentrations were significantly different at 2-month-old, we examined changes in fatty acid composition. The composition of ARA was not significantly different between genotypes; though DHA composition remained significantly lowered. Despite cerebellar atrophy at >7-months-old, cerebellar fatty acid concentrations had recovered comparably to wildtype control. Therefore, RORα may be necessary for fatty acid accretions during neurodevelopment. Specifically, the effects of RORα on PUFA metabolisms are region-specific and age-dependent.

Nobiletin fortifies mitochondrial respiration in skeletal muscle to promote healthy aging against metabolic challenge

Circadian disruption aggravates age-related decline and mortality. However, it remains unclear whether circadian enhancement can retard aging in mammals. We previously reported that the small molecule Nobiletin (NOB) activates ROR (retinoid acid receptor-related orphan receptor) nuclear receptors to potentiate circadian oscillation and protect against metabolic dysfunctions. Here we show that NOB significantly improves metabolic fitness in naturally aged mice fed with a regular diet (RD). Furthermore, NOB enhances healthy aging in mice fed with a high-fat diet (HF). In HF skeletal muscle, the NOB-ROR axis broadly activates genes for mitochondrial respiratory chain complexes (MRCs) and fortifies MRC activity and architecture, including Complex II activation and supercomplex formation. These mechanisms coordinately lead to a dichotomous mitochondrial optimization, namely increased ATP production and reduced ROS levels. Together, our study illustrates a focal mechanism by a clock-targeting pharmacological agent to optimize skeletal muscle mitochondrial respiration and promote healthy aging in metabolically stressed mammals.

Inhibition of Interleukin-23–Mediated Inflammation with a Novel Small Molecule Inverse Agonist of RORγt

Blockade of interleukin (IL)-23 or IL-17 with biologics is clinically validated as a treatment of psoriasis. However, the clinical impact of targeting other nodes within the IL-23/IL-17 pathway, especially with small molecules, is less defined. We report on a novel small molecule inverse agonist of retinoid acid-related orphan receptor (ROR) γt and its efficacy in preclinical models of psoriasis and arthritis. 1-(2,4-Dichloro-3-((1,4-dimethyl-6-(trifluoromethyl)-1H-indol-2-yl)methyl)benzoyl)piperidine-4-carboxylic acid (A-9758) was optimized from material identified from a high-throughput screening campaign. A-9758 is selective for RORγt and exhibits robust potency against IL-17A release both in vitro and in vivo. In vivo, we also show that IL-23 is sufficient to drive the accumulation of RORγt+ cells, and inhibition of RORγt significantly attenuates IL-23-driven psoriasiform dermatitis. Therapeutic treatment with A-9758 (i.e., delivered during active disease) was also effective in blocking skin and joint inflammation. Finally, A-9758 exhibited efficacy in an ex vivo human whole blood assay, suggesting small molecule inverse agonists of RORγt could be efficacious in human IL-17-related diseases. SIGNIFICANCE STATEMENT: Using a novel small molecule inverse agonist, and preclinical assays, we show that RORγt is a viable target for the inhibition of RORγt/Th17-driven diseases such as psoriasis. Preclinical models of psoriasis show that inhibition of RORγt blocks both the accumulation and effector function of IL-17-producing T cells.

Bob1 enhances RORγt-mediated IL-17A expression in Th17 cells through interaction with RORγt

POU domain class 2-associating factor 1 (also called Bob1), which is mainly expressed in B cells, regulates B cell homeostasis and controls humoral immune responses. Although Bob1 is known to function reliably in T cell subsets including follicular helper T cells, Th1 cells and Th2 cells, it is unknown whether Bob1 functions in other T cell subsets. In this study, we found that Bob1 knock out (KO) mice are resistant to experimental autoimmune encephalomyelitis (EAE) induced by MOG35-55 peptide and that Bob1 KO T cells are defective in Th17 differentiation. Importantly, Bob1 interacts with retinoid acid receptor-related orphan receptor (ROR) gamma t (RORγt), a signature transcription factor for Th17 cells, through the ligand-binding domain of RORγt, thereby enhancing IL-17A transcription activity. IL-17A induction by Bob1 requires the ability for its formation of a DNA-Oct1-Bobl ternary complex. Thus, our findings demonstrate that Bob1 enhances IL-17A expression in vivo and in vitro by interacting with RORγt in Th17 cells, suggesting that Bob1 plays a pivotal role in Th17-mediated autoimmune disease.

Melatonin stabilizes rupture-prone vulnerable plaques via regulating macrophage polarization in a nuclear circadian receptor RORα-dependent manner.

Rupture of vulnerable plaques is the main trigger of acute cardio-cerebral vascular events, but mechanisms responsible for transforming a stable atherosclerotic into a vulnerable plaque remain largely unknown. Melatonin, an indoleamine hormone secreted by the pineal gland, plays pleiotropic roles in the cardiovascular system; however, the effect of melatonin on vulnerable plaque rupture and its underlying mechanisms remains unknown. Here, we generated a rupture-prone vulnerable carotid plaque model induced by endogenous renovascular hypertension combined with low shear stress in hypercholesterolemic ApoE-/- mice. Melatonin (10mg/kg/d by oral administration for 9weeks) significantly prevented vulnerable plaque rupture, with lower incidence of intraplaque hemorrhage (42.9% vs. 9.5%, P=0.014) and of spontaneous plaque rupture with intraluminal thrombus formation (38.1% vs. 9.5%, P=0.029). Mechanistic studies indicated that melatonin ameliorated intraplaque inflammation by suppressing the differentiation of intraplaque macrophages toward the proinflammatory M1 phenotype, and circadian nuclear receptor retinoid acid receptor-related orphan receptor-α (RORα) mediated melatonin-exerted vasoprotection against vulnerable plaque instability and intraplaque macrophage polarization. Further analysis in human monocyte-derived macrophages confirmed the role of melatonin in regulating macrophage polarization by regulating the AMPKα-STATs pathway in a RORα-dependent manner. In summary, our data provided the first evidence that melatonin-RORα axis acts as a novel endogenous protective signaling pathway in the vasculature, regulates intraplaque inflammation, and stabilizes rupture-prone vulnerable plaques.

Nocturnal asthma is affected by genetic interactions between RORA and NPSR1.

Neuropeptide S Receptor 1 ( NPSR1) and Retinoid Acid Receptor-Related Orphan Receptor Alpha (RORA ) interact biologically, are both known candidate genes for asthma, and are involved in controlling circadian rhythm. Thus, we assessed (1) whether interactions between RORA and NPSR1 specifically affect the nocturnal asthma phenotype and (2) how this may differ from other asthma phenotypes. Interaction effects between 24 single-nucleotide polymorphisms (SNPs) in RORA and 35 SNPs in NPSR1 on asthma and nocturnal asthma symptoms were determined in 1432 subjects (763 asthmatics [192 with nocturnal asthma symptoms]; 669 controls) from the Multicenter Asthma Genetic in Childhood/International Study of Asthma and Allergies in Childhood studies. The results were validated and extended in children from the Manchester Asthma and Allergy Study (N = 723) and the Children Allergy Milieu Stockholm and Epidemiological cohort (N = 1646). RORA* NPSR1 interactions seemed to affect both asthma and nocturnal asthma. In stratified analyses, however, interactions mainly affected nocturnal asthma and less so asthma without nocturnal symptoms or asthma severity. Results were replicated in two independent cohorts and seemed to remain constant over time throughout youth. RORA* NPSR1 interactions appear to be involved in mechanisms specific for nocturnal asthma. In contrast to previous studies focusing on the role of beta 2 receptor polymorphisms in nocturnal asthma as a feature of asthma control or severity in general, our data suggest that changes in circadian rhythm control are associated with nighttime asthma symptoms.

IL-25-regulated type 2 innate lymphoid cells activation promote allergic fungal rhinosinusitis

Objective: To investigate the regulation of IL-25 on type Ⅱ innate lymphoid cells (ILC2s) activation in the pathogenesis of allergic fungal rhinosinusitis (AFRS). Methods: Nasal mucosa tissues were collected from 16 AFRS patients and 12 patients, who underwent nasal endoscopic surgery for cerebrospinal rhinorrhea or skull base benign tumor during the period from June 2016 to June 2017 in Department of Rhinology, the First Affiliated Hospital of Zhengzhou University. Firstly, flow cytometry was used to detect ILC2s in nasal mucosa of both groups. Secondly, the expression of IL-25, IL-5 and IL-13 in nasal mucosa was detected by immunofluorescence and/or Western Blot assay. Finally, fungal extracts, IL-25 and glucocorticoids were used to stimulate nasal mucosal epithelial cells and tissues in vitro respectively to detect the regulatory effect of IL-25 on ILC2s. SPSS 16.0 software was used to analyze the data. Results: The prevalence of ILC2s in nasal tissues was higher in patients with AFRS than those of the control group ((3.85±1.52)%(Mean±SD) vs (0.32±0.10)%, U=9.00, P<0.05). There was a positive correlation between the prevalence of ILC2s and the number of eosinophils in nasal mucosa of patients with ARFS (r=0.80, P<0.05). The expression of IL-25, IL-5 and IL-13 in nasal mucosa epithelium of AFRS group was significantly higher than that of the control group (0.49±0.13 vs 0.23±0.09, 0.23±0.05 vs 0.10±0.04, 0.31±0.08 vs 0.14±0.07, t value was 5.90, 7.21, 5.69, respectively, all P<0.05). Fungal stimulation enhanced the expression of IL-25 protein in nasal epithelial cells of both groups (0.67±0.19 vs 0.25±0.12 (AFRS group), 0.62±0.17 vs 0.27±0.16 (control group), q value was 8.65, 9.26, respectively, all P<0.05). In the IL-25 stimulated nasal mucosa at a concentration of 1, 10 and 100 ng/ml, the expression level of retinoid acid-related orphan receptor α (RORα) mRNA was 2.07±1.53, 5.06±0.93, 7.38±2.30, respectively; the expression level of GATA binding protein 3 (GATA3) mRNA was 3.58±1.29, 6.14±1.55, 7.64±2.28, respectively; the expression level of IL-5 protein was 0.21±0.06, 0.32±0.06, 0.38±0.10, respectively; the expression level of IL-13 was 0.52±0.13, 0.69±0.22, 0.82±0.21, respectively, which were significantly higher than that in the unstimulated nasal mucosa (1.00±0.00, 1.00±0.00, 0.11±0.05, 0.35±0.15, F value was 63.45, 59.27, 49.35, 20.20, respectively, all P<0.05). The up-regulation could be inhibited by dexamethasone (F value was 89.20, 92.47, 99.63, 49.82, respectively, all P<0.05). Conclusions: Epithelial-derived IL-25 up-regulates the expression of IRC2s-dependent transcription factors RORα and GATA3 mRNA, which are positively correlated with elevated IL-13 and IL-5 expression levels in tissues, may be involved in AFRS inflammatory response, and are inhibited by glucocorticoids.