Nur77 induced by HIF-1α mediates vascular remodeling in hypoxic pulmonary hypertension.

Nur77 is a member of the NR4A subfamily of orphan nuclear receptors that is expressed and has a function within the immune system. This study aimed to investigate the role of Nur77 in hypoxic pulmonary hypertension. SPF male SD rats were exposed in hypobaric chamber simulating 5000 m high altitude for 0, 3, 7, 14, 21 or 28 days. Rat pulmonary artery smooth muscle cells (RPASMCs) were cultured under normoxic conditions (5% CO2-95% ambient air) or hypoxic conditions (5% O2 for 6 h, 12 h, 24 h, 48 h). Hypoxic rats developed pulmonary arterial remodeling and right ventricular hypertrophy with significantly increased pulmonary arterial pressure. The levels of Nur77, HIF-1α and PNCA were upregulated in pulmonary arterial smooth muscle from hypoxic rats. Silencing of either Nur77 or HIF-1α attenuated hypoxia-induced proliferation. Silencing of HIF-1α down-regulated Nur77 protein level, but Nur77 silence did not reduce HIF-1α. Nur77 was not con-immunoprecipitated with HIF-1α. This study demonstrated that Nur77 acted as a downstream regulator of HIF-1α under hypoxia, and plays a critical role in the hypoxia-induced pulmonary vascular remodeling, which is regulated by HIF-1α. Nur77 maybe a novel target of HPH therapy.

Cellular architecture shapes the naïve T cell response.

After antigen stimulation, naïve T cells display reproducible population-level responses, which arise from individual T cells pursuing specific differentiation trajectories. However, cell-intrinsic predeterminants controlling these single-cell decisions remain enigmatic. We found that the subcellular architectures of naïve CD8 T cells, defined by the presence (TØ) or absence (TO) of nuclear envelope invaginations, changed with maturation, activation, and differentiation. Upon T cell receptor (TCR) stimulation, naïve TØ cells displayed increased expression of the early-response gene Nr4a1, dependent upon heightened calcium entry. Subsequently, in vitro differentiation revealed that TØ cells generated effector-like cells more so compared with TO cells, which proliferated less and preferentially adopted a memory-precursor phenotype. These data suggest that cellular architecture may be a predeterminant of naïve CD8 T cell fate.

Semaglutide ameliorates cardiac remodeling in male mice by optimizing energy substrate utilization through the Creb5/NR4a1 axis.

Semaglutide, a glucagon-like peptide-1 receptor agonist, is clinically used as a glucose-lowering and weight loss medication due to its effects on energy metabolism. In heart failure, energy production is impaired due to altered mitochondrial function and increased glycolysis. However, the impact of semaglutide on cardiomyocyte metabolism under pressure overload remains unclear. Here we demonstrate that semaglutide improves cardiac function and reduces hypertrophy and fibrosis in a mouse model of pressure overload-induced heart failure. Semaglutide preserves mitochondrial structure and function under chronic stress. Metabolomics reveals that semaglutide reduces mitochondrial damage, lipid accumulation, and ATP deficiency by promoting pyruvate entry into the tricarboxylic acid cycle and increasing fatty acid oxidation. Transcriptional analysis shows that semaglutide regulates myocardial energy metabolism through the Creb5/NR4a1 axis in the PI3K/AKT pathway, reducing NR4a1 expression and its translocation to mitochondria. NR4a1 knockdown ameliorates mitochondrial dysfunction and abnormal glucose and lipid metabolism in the heart. These findings suggest that semaglutide may be a therapeutic agent for improving cardiac remodeling by modulating energy metabolism.

NR4A1 transcriptionally regulates the differentiation of stem-like CD8+ T cells in the tumor microenvironment.

CD8+ T cells are rendered exhausted in tumor and chronic infection. Among heterogeneous exhausted T cells, a subpopulation of progenitor-like (Tpex) cells have been found important for long-term tumor or pathogen control and are also the main responders in immunotherapy. Using an RFP reporter mouse for the orphan nuclear receptor NR4A1, originally characterized as critical in T cell dysfunction, we discover that the reporter is highly expressed in Tpex cells in tumor and chronic infection. Enforced expression of Nr4a1 promotes Tpex cell accumulation, whereas tumor control is improved after Nr4a1 deletion, associated with increased effector function but decreased long-term maintenance of CD8+ T cells. Integrating chromatin immunoprecipitation sequencing (ChIP-seq) and RNA sequencing (RNA-seq) analysis, NR4A1 is found to bind and promote the expression of Tpex-related genes, as well as suppress terminal differentiation-associated genes. This study therefore has identified a key role of NR4A1 in Tpex regulation and provides a promising target for immunotherapy.

Targeting KPNB1 with genkwadaphnin suppresses gastric cancer progression through the Nur77-mediated signaling pathway.

Gastric cancer (GC) remains a global challenge due to the lack of early detection and precision therapies. Genkwadaphnin (DD1), a natural diterpene isolated from the bud of Flos GenkWa (Thymelaeaceae), serves as a Karyopherin ß1 (KPNB1) inhibitor. In this study, we investigated the anti-tumor effect of DD1 in both cell culture and animal models. Our findings reveal that KPNB1, a protein involved in nuclear import, was highly expressed in GC tissues and associated with a poor prognosis in patients. We demonstrated that DD1, alongside the established KPNB1 inhibitor importazole (IPZ), inhibited GC cell proliferation and tumor growth by enhancing both genomic and non-genomic activity of Nur77. DD1 and IPZ reduced the interaction between KPNB1 and Nur77, resulting in Nur77 cytoplasmic accumulation and triggering mitochondrial apoptosis. The inhibitors also increased the expression of the Nur77 target apoptotic genes ATF3, RB1CC1 and PMAIP1, inducing apoptosis in GC cell. More importantly, loss of Nur77 effectively rescued the inhibitory effect of DD1 and IPZ on GC cells in both in vitro and in vivo experiments. In this study, we for the first time explored the relationship between KPNB1 and Nur77, and found KPNB1 inhibition could significantly increase the expression of Nur77. Moreover, we investigated the function of KPNB1 in GC for the first time, and the results suggested that KPNB1 could be a potential target for cancer therapy, and DD1 might be a prospective therapeutic candidate.

Nr4a1 regulates cell-specific transcriptional programs in inhibitory GABAergic interneurons.

The patterns of synaptic connectivity and physiological properties of diverse neuron types are shaped by distinct gene sets. Our study demonstrates that, in the mouse forebrain, the transcriptional profiles of inhibitory GABAergic interneurons are regulated by Nr4a1, an orphan nuclear receptor whose expression is transiently induced by sensory experiences and is required for normal learning. Nr4a1 exerts contrasting effects on the local axonal wiring of parvalbumin- and somatostatin-positive interneurons, which innervate different subcellular domains of their postsynaptic partners. The loss of Nr4a1 activity in these interneurons results in bidirectional, cell-type-specific transcriptional switches across multiple gene families, including those involved in surface adhesion and repulsion. Our findings reveal that combinatorial synaptic organizing codes are surprisingly flexible and highlight a mechanism by which inducible transcription factors can influence neural circuit structure and function.

The Long Non-Coding RNA MALAT1 Modulates NR4A1 Expression through a Downstream Regulatory Element in Specific Cancer Cell Types.

Long non-coding RNAs (lncRNAs) have been shown to modulate gene expression and are involved in the initiation and progression of various cancer types. Despite the wealth of studies describing transcriptome changes upon lncRNA knockdown, there is limited information describing lncRNA-mediated effects on regulatory elements (REs) modulating gene expression. In this study, we investigated how the metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) lncRNA regulates primary target genes using time-resolved MALAT1 knockdown followed by parallel RNA-seq and ATAC-seq assays. The results revealed that MALAT1 primarily regulates specific protein-coding genes and a substantial decrease in the accessibility downstream of the NR4A1 gene that was associated with a decreased NR4A1 expression. Moreover, the presence of an NR4A1-downstream RE was demonstrated by CRISPR-i assays to define a functional MALAT1/NR4A1 axis. By analyzing TCGA data, we identified a positive correlation between NR4A1 expression and NR4A1-downstream RE accessibility in breast cancer but not in pancreatic cancer. Accordingly, this regulatory mechanism was experimentally validated in breast cancer cells (MCF7) but not in pancreatic duct epithelial carcinoma (PANC1) cells. Therefore, our results demonstrated that MALAT1 is involved in a molecular mechanism that fine-tunes NR4A1 expression by modulating the accessibility of a downstream RE in a cell type-specific manner.

Nuclear receptor Nur77 regulates immunomechanics of macrophages.

Nuclear receptor Nur77 plays a pivotal role in immune regulation across various tissues, influencing pro-inflammatory signaling pathways and cellular metabolism. While cellular mechanics have been implicated in inflammation, the contribution of Nur77 to these mechanical processes remains elusive. Macrophages exhibit remarkable plasticity in their morphology and mechanics, enabling them to adapt and execute essential inflammatory functions, such as navigating through inflamed tissue and pathogen engulfment. However, the precise regulatory mechanisms governing these dynamic changes in macrophage mechanics during inflammation remain poorly understood. To establish the potential correlation of Nur77 with cellular mechanics, we compared bone marrow-derived macrophages (BMDMs) from wild-type (WT) and Nur77-deficient (Nur77-KO) mice and employed cytoskeletal imaging, single-cell acoustic force spectroscopy (AFS), migration and phagocytosis assays, and RNA-sequencing. Our findings reveal that Nur77-KO BMDMs exhibit changes to their actin networks compared to WT BMDMs, which is associated with a stiffer and more rigid phenotype. Subsequent in vitro experiments validated our observations, showcasing that Nur77 deficiency leads to enhanced migration, reduced adhesion, and increased phagocytic activity. The transcriptomics data confirmed altered mechanics-related pathways in Nur77-deficient macrophage that are accompanied by a robust pro-inflammatory phenotype. Utilizing previously obtained ChIP-data, we revealed that Nur77 directly targets differentially expressed genes associated with cellular mechanics. In conclusion, while Nur77 is recognized for its role in reducing inflammation of macrophages by inhibiting the expression of pro-inflammatory genes, our study identifies a novel regulatory mechanism where Nur77 governs macrophage inflammation through the modulation of expression of genes involved in cellular mechanics. Our findings suggest that immune regulation by Nur77 may be partially mediated through alterations in cellular mechanics, highlighting a potential avenue for therapeutic targeting.

A long-acting FGF21 attenuates metabolic dysfunction-associated steatohepatitis-related fibrosis by modulating NR4A1-mediated Ly6C phenotypic switch in macrophages.

BACKGROUND AND PURPOSE: Because of the absence of effective therapies for metabolic dysfunction-associated steatohepatitis (MASH), there is a rising interest in fibroblast growth factor 21 (FGF21) analogues due to their potential anti-fibrotic activities in MASH treatment. PsTag-FGF21, a long-acting FGF21 analogue, has demonstrated promising therapeutic effects in several MASH mouse models. However, its efficacy and mechanism against MASH-related fibrosis remain less well defined, compared with the specific mechanisms through which FGF21 improves glucose and lipid metabolism. EXPERIMENTAL APPROACH: The effectiveness of PsTag-FGF21 was evaluated in two MASH-fibrosis models. Co-culture systems involving macrophages and hepatic stellate cells (HSCs) were employed for further assessment. Hepatic macrophages were selectively depleted by administering liposome-encapsulated clodronate via tail vein injections. RNA sequencing and cytokine profiling were conducted to identify key factors involved in macrophage-HSC crosstalk. KEY RESULTS: We first demonstrated the significant attenuation of hepatic fibrosis by PsTag-FGF21 in two MASH-fibrosis models. Furthermore, we highlighted the crucial role of macrophage phenotypic switch in PsTag-FGF21-induced HSC deactivation. FGF21 was demonstrated to regulate macrophages in a PsTag-FGF21-like manner. NR4A1, a nuclear factor which is notably down-regulated in human livers with MASH, was identified as a mediator responsible for PsTag-FGF21-induced phenotypic switch. Transcriptional control over insulin-like growth factor 1, a crucial factor in macrophage-HSC crosstalk, was exerted by the intrinsically disordered region domain of NR4A1. CONCLUSION AND IMPLICATIONS: Our results have elucidated the previously unclear mechanisms through which PsTag-FGF21 treats MASH-related fibrosis and identified NR4A1 as a potential therapeutic target for fibrosis.

Progressive reduction of nuclear receptor Nr4a1 mediates age-dependent cognitive decline.

INTRODUCTION: Cognitive decline progresses with age, and Nr4a1 has been shown to participate in memory functions. However, the relationship between age-related Nr4a1 reduction and cognitive decline is undefined. METHODS: Nr4a1 expressions were evaluated by quantitative PCR and immunochemical approaches. The cognition of mice was examined by multiple behavioral tests. Patch-clamp experiments were conducted to investigate the synaptic function. RESULTS: NR4A1 in peripheral blood mononuclear cells decreased with age in humans. In the mouse brain, age-dependent Nr4a1 reduction occurred in the hippocampal CA1. Deleting Nr4a1 in CA1 pyramidal neurons (PyrNs) led to the impairment of cognition and excitatory synaptic function. Mechanistically, Nr4a1 enhanced TrkB expression via binding to its promoter. Blocking TrkB compromised the cognitive amelioration with Nr4a1-overexpression in CA1 PyrNs. DISCUSSION: Our results elucidate the mechanism of Nr4a1-dependent TrkB regulation in cognition and synaptic function, indicating that Nr4a1 is a target for the treatment of cognitive decline. HIGHLIGHTS: Nr4a1 is reduced in PBMCs and CA1 PyrNs with aging. Nr4a1 ablation in CA1 PyrNs impaired cognition and excitatory synaptic function. Nr4a1 overexpression in CA1 PyrNs ameliorated cognitive impairment of aged mice. Nr4a1 bound to TrkB promoter to enhance transcription. Blocking TrkB function compromised Nr4a1-induced cognitive improvement.

Bis-Indole Derivatives as Dual Nuclear Receptor 4A1 (NR4A1) and NR4A2 Ligands.

Bis-indole derived compounds such as 1,1-bis(3'-indolyl)-1-(3,5-disubstitutedphenyl) methane (DIM-3,5) and the corresponding 4-hydroxyl analogs (DIM8-3,5) are NR4A1 ligands that act as inverse NR4A1 agonists and are potent inhibitors of tumor growth. The high potency of several DIM-3,5 analogs (IC50 < 1 mg/kg/day), coupled with the >60% similarity of the ligand-binding domains (LBDs) of NR4A1 and NR4A2 and the pro-oncogenic activities of both receptors lead us to hypothesize that these compounds may act as dual NR4A1 and NR4A2 ligands. Using a fluorescence binding assay, it was shown that 22 synthetic DIM8-3,5 and DIM-3,5 analogs bound the LBD of NR4A1 and NR4A2 with most KD values in the low µM range. Moreover, the DIM-3,5 and DIM8-3,5 analogs also decreased NR4A1- and NR4A2-dependent transactivation in U87G glioblastoma cells transfected with GAL4-NR4A1 or GAL4-NR4A2 chimeras and a UAS-luciferase reporter gene construct. The DIM-3,5 and DIM8-3,5 analogs were cytotoxic to U87 glioblastoma and RKO colon cancer cells and the DIM-3,5 compounds were more cytotoxic than the DIM8-3,5 compounds. These studies show that both DIM-3,5 and DIM8-3,5 compounds previously identified as NR4A1 ligands bind both NR4A1 and NR4A2 and are dual NR4A1/2 ligands.

Orphan Nuclear Receptor Family 4A (NR4A) Members NR4A2 and NR4A3 Selectively Modulate Elements of the Monocyte Response to Buffered Hypercapnia.

Hypercapnia occurs when the partial pressure of carbon dioxide (CO2) in the blood exceeds 45 mmHg. Hypercapnia is associated with several lung pathologies and is transcriptionally linked to suppression of immune and inflammatory signalling through poorly understood mechanisms. Here we propose Orphan Nuclear Receptor Family 4A (NR4A) family members NR4A2 and NR4A3 as potential transcriptional regulators of the cellular response to hypercapnia in monocytes. Using a THP-1 monocyte model, we investigated the sensitivity of NR4A family members to CO2 and the impact of depleting NR4A2 and NR4A3 on the monocyte response to buffered hypercapnia (10% CO2) using RNA-sequencing. We observed that NR4A2 and NR4A3 are CO2-sensitive transcription factors and that depletion of NR4A2 and NR4A3 led to reduced CO2-sensitivity of mitochondrial and heat shock protein (Hsp)-related genes, respectively. Several CO2-sensitive genes were, however, refractory to depletion of NR4A2 and NR4A3, indicating that NR4As regulate certain elements of the cellular response to buffered hypercapnia but that other transcription factors also contribute. Bioinformatic analysis of conserved CO2-sensitive genes implicated several novel putative CO2-sensitive transcription factors, of which the ETS Proto-Oncogene 1 Transcription Factor (ETS-1) was validated to show increased nuclear expression in buffered hypercapnia. These data give significant insights into the understanding of immune responses in patients experiencing hypercapnia.

Nr4a1 enhances Wnt4 transcription to promote mesenchymal stem cell osteogenesis and alleviates inflammation-inhibited bone regeneration.

Intense inflammatory response impairs bone marrow mesenchymal stem cell (BMSC)-mediated bone regeneration, with transforming growth factor (TGF)-ß1 being the most highly expressed cytokine. However, how to find effective and safe means to improve bone formation impaired by excessive TGF-ß1 remains unclear. In this study, we found that the expression of orphan nuclear receptor Nr4a1, an endogenous repressor of TGF-ß1, was suppressed directly by TGF-ß1-induced Smad3 and indirectly by Hdac4, respectively. Importantly, Nr4a1 overexpression promoted BMSC osteogenesis and reversed TGF-ß1-mediated osteogenic inhibition and pro-fibrotic effects. Transcriptomic and histologic analyses confirmed that upregulation of Nr4a1 increased the transcription of Wnt family member 4 (Wnt4) and activated Wnt pathway. Mechanistically, Nr4a1 bound to the promoter of Wnt4 and regulated its expression, thereby enhancing the osteogenic capacity of BMSCs. Moreover, treatment with Nr4a1 gene therapy or Nr4a1 agonist Csn-B could promote ectopic bone formation, defect repair, and fracture healing. Finally, we demonstrated the correlation of NR4A1 with osteogenesis and the activation of the WNT4/ß-catenin pathway in human BMSCs and fracture samples. Taken together, these findings uncover the critical role of Nr4a1 in bone formation and alleviation of inflammation-induced bone regeneration disorders, and suggest that Nr4a1 has the potential to be a therapeutic target for accelerating bone healing.

Knockdown of NR4A1 alleviates doxorubicin-induced cardiotoxicity through inhibiting the activation of the NLRP3 inflammasome.

Doxorubicin (DOX) is a widely used antitumor drug, but its clinical applicability is hampered by the unfortunate side effect of DOX-induced cardiotoxicity (DIC). In our current study, we retrieved three high-throughput sequencing datasets related to DIC from the Gene Expression Omnibus (GEO) datasets. We conducted differential analysis using R (DESeq2) to pinpoint differentially expressed genes (DEGs, and identified 11 genes that were consistently altered in both the control and DOX-treated groups. Notably, our Random Forest analysis of these three GEO datasets highlighted the significance of nuclear receptor subfamily 4 group A member 1 (NR4A1) in the context of DIC. The DOX-induced mouse model and cell model were used for the in vivo and in vitro studies to reveal the role of NR4A1 in DIC. We found that silencing NR4A1 by adeno-associated virus serotype 9 (AAV9) contained shRNA in vivo alleviated the DOX-induced cardiac dysfunction, cardiomyocyte injury and fibrosis. Mechanistically, we found NR4A1 silencing was able to inhibit DOX-induced the cleavage of NLRP3, IL-1ß and GSDMD in vivo. Further in vitro studies have shown that inhibition of NR4A1 suppressed DOX-induced cytotoxicity and oxidative stress through the same molecular mechanism. We prove that NR4A1 plays a critical role in DOX-induced cardiotoxicity by inducing pyroptosis via activation of the NLRP3 inflammasome, and it might be a promising therapeutic target for DIC.

NR4A1 depletion inhibits colorectal cancer progression by promoting necroptosis via the RIG-I-like receptor pathway.

Necroptosis is a regulated necrotic cell death mechanism and plays a crucial role in the progression of cancers. However, the potential role and mechanism of necroptosis in colorectal cancer (CRC) has not been fully elucidated. In this study, we found that nuclear receptor subfamily 4 group A member 1 (NR4A1) was highly expressed in CRC cells treated with TNF-α, Smac mimetic, and z-VAD-FMK (TSZ). The depletion of NR4A1 significantly enhanced the sensitivity of CRC cells to TSZ-induced necroptosis, while NR4A1 overexpression suppressed these effects, as evidenced by the LDH assay, flow cytometry analysis of cell death, PI staining, and expression analysis of necrosome complexes (RIPK1, RIPK3, and MLKL). Moreover, NR4A1 deficiency made HT29 xenograft tumors sensitive to necroptotic cell death in vivo. Mechanistically, NR4A1 depletion promoted necroptosis activation in CRC through the RIG-I-like receptor pathway by interacting with DDX3. Importantly, the RIG-I pathway agonist poly(I:C) or inhibitor cFP abolished the effects of NR4A1 overexpression or suppression on necroptosis in CRC cells. Moreover, we observed that NR4A1 was highly expressed in CRC tissues and was associated with a poor prognosis. In conclusion, our results suggest that NR4A1 plays a critical role in modulating necroptosis in CRC cells and provide a new therapeutic target for CRC.

Yin Yang 1 suppresses apoptosis and oxidative stress injury in SH-SY5Y cells by facilitating NR4A1 expression.

Oxidative stress plays a significant role in the development of Parkinson's disease (PD). Previous studies implicate nuclear receptor subfamily 4 group A member 1 (NR4A1) in oxidative stress associated with PD. However, the molecular mechanism underlying the regulation of NR4A1 expression remains incompletely understood. In the present study, a PD cell model was established by using 1-methyl-4-phenylpyridinium (MPP+) in SH-SY5Y cells. Cell viability and apoptosis were assessed by using CCK-8 assay and flow cytometry, respectively. The activities of LDH and SOD, and ROS generation were used as an indicators of oxidative stress. ChIP-PCR was performed to detect the interaction between Yin Yang 1 (YY1) and the NR4A1 promoter. MPP+ treatment inhibited SH-SY5Y cell viability in a dose- and time-dependent manner. NR4A1 and YY1 expression were decreased in MPP+-treated SH-SY5Y cells. Increasing NR4A1 or YY1 alleviated MPP+-induced apoptosis and oxidative stress in SH-SY5Y cells, whereas reduction of NR4A1 aggravated MPP+-induced cell injury. Transcription factor YY1 facilitated NR4A1 expression by binding with NR4A1 promoter. In addition, in MPP+-treated SH-SY5Y cells, the inhibition of NR4A1 to apoptosis and oxidative stress was further enhanced by overexpression of YY1. The reduction of NR4A1 led to an elevation of apoptosis and oxidative stress in MPP+-induced SH-SY5Y cells, and this effect was partially reversed by the overexpression of YY1. In conclusion, YY1 suppresses MPP+-induced apoptosis and oxidative stress in SH-SY5Y cells by binding with NR4A1 promoter and boosting NR4A1 expression. Our findings suggest that NR4A1 may be a candidate target for PD treatment.HIGHLIGHTSNR4A1 and YY1 are decreased in MPP+-treated SH-SY5Y cells.NR4A1 prevents oxidative stress and apoptosis in MPP+-treated SH-SY5Y cells.YY1 binds with NR4A1 promoter and increases NR4A1 expression.YY1 enhances the inhibition of NR4A1 to SH-SY5Y cell apoptosis and oxidative stress.

Nr4a1 marks a distinctive ILC2 activation subset in the mouse inflammatory lung.

BACKGROUND: Group 2 innate lymphoid cells (ILC2s) are critical sources of type 2 cytokines and represent one of the major tissue-resident lymphoid cells in the mouse lung. However, the molecular mechanisms underlying ILC2 activation under challenges are not fully understood. RESULTS: Here, using single-cell transcriptomics, genetic reporters, and gene knockouts, we identify four ILC2 subsets, including two non-activation subsets and two activation subsets, in the mouse acute inflammatory lung. Of note, a distinct activation subset, marked by the transcription factor Nr4a1, paradoxically expresses both tissue-resident memory T cell (Trm), and effector/central memory T cell (Tem/Tcm) signature genes, as well as higher scores of proliferation, activation, and wound healing, all driven by its particular regulons. Furthermore, we demonstrate that the Nr4a1+ILC2s are restrained from activating by the programmed cell death protein-1 (PD-1), which negatively modulates their activation-related regulons. PD-1 deficiency places the non-activation ILC2s in a state that is prone to activation, resulting in Nr4a1+ILC2 differentiation through different activation trajectories. Loss of PD-1 also leads to the expansion of Nr4a1+ILC2s by the increase of their proliferation ability. CONCLUSIONS: The findings show that activated ILC2s are a heterogenous population encompassing distinct subsets that have different propensities, and therefore provide an opportunity to explore PD-1's role in modulating the activity of ILC2s for disease prevention and therapy.

Orphan nuclear receptor nr4a1 regulates winter depression-like behavior in medaka.

About 10% of the population suffers from depression in winter at high latitude. Although it has become a serious public health issue, its underlying mechanism remains unknown and new treatments and therapies are required. As an adaptive strategy, many animals also exhibit depression-like behavior in winter. Previously, it has been reported that celastrol, a traditional Chinese medicine, can rescue winter depression-like behavior in medaka, an excellent model of winter depression. Nuclear receptor subfamily 4 group A member 1 (nr4a1, also known as nur77) is a known target of celastrol, and the signaling pathway of nr4a1 was suggested to be inactive in medaka brain during winter, implying the association of nr4a1 and winter depression-like behavior. However, the direct evidence for its involvement in winter depression-like behavior remains unclear. The present study found that nr4a1 was suppressed in the medaka brain under winter conditions. Cytosporone B, nr4a1 chemical activator, reversed winter depression-like behavior under winter conditions. Additionally, nr4a1 mutant fish generated by CRISPR/Cas9 system showed decreased sociability under summer conditions. Therefore, our results demonstrate that the seasonal regulation of nr4a1 regulates winter depression-like behavior and offers potential therapeutic target.

Flavonoids Quercetin and Kaempferol Are NR4A1 Antagonists and Suppress Endometriosis in Female Mice.

Nuclear receptor 4A1 (NR4A1) plays an important role in endometriosis progression; levels of NR4A1 in endometriotic lesions are higher than in normal endometrium, and substituted bis-indole analogs (NR4A1) antagonists suppress endometriosis progression in mice with endometriosis. In addition, the flavonoids kaempferol and quercetin are natural products that directly bind NR4A1 and significantly repress the intrinsic NR4A1-dependent transcriptional activity in human endometriotic epithelial and stromal cells and Ishikawa endometrial cancer cells. NR4A1 knockdown and inhibition of NR4A1 by kaempferol and quercetin suppressed proliferation of human endometriotic epithelial cells and Ishikawa cells by inhibiting epidermal growth factor receptor/c-Myc/survivin-mediated growth-promoting and survival pathways, The mammalian target of rapamycin (mTOR) signaling and αSMA/CTGF/COL1A1/FN-mediated fibrosis signaling but increasing Thioredoxin domain Containing 5/SESN2-mediated oxidative/estrogen receptors stress signaling. In human endometriotic stromal cells, NR4A1 knockdown and inhibition of NR4A1 by kaempferol and quercetin primarily inhibited mTOR signaling by suppressing proliferation of human endometrial stromal cells. In addition, kaempferol and quercetin treatment also effectively suppressed the growth of endometriotic lesions in mice with endometriosis compared with the vehicle without any body weight changes. Therefore, kaempferol and quercetin are NR4A1 antagonists with potential as nutritional therapy for endometriosis.

NR4A1 destabilizes TNF mRNA in microglia and modulates stroke outcomes.

Microglia play a dual role in stroke depending on their pro-inflammatory and anti-inflammatory polarization. A study in PLOS Biology identifies a new mechanism, through which the transcription factor NR4A1 negatively regulates TNF expression in microglia.