Project description:Glioma is the most common type of intracranial tumor and accounts for 75% of malignant brain tumors. Glioblastoma (GBM) is the most malignant form of glioma, with strong invasive capabilities and a high relapse rate even after treatment. Here, our RNA seqencing analysis of BV2 cells treated by H2O2 and si-Nr4a2 reveal the effect of oxdiative stress and Nr4a2-knockdown on phenotype of microglia. Chip-seqencing andlysis of BV2 cells by anti-Nr4a2 antibody is to find the target genes regulated by Nr4a2. Overall, our results reveal that Nr4a2 as the major transcription factors for microglia involved in immunosuppression of glioma.
Project description:Glioma is the most common type of intracranial tumor and accounts for 75% of malignant brain tumors. Glioblastoma (GBM) is the most malignant form of glioma, with strong invasive capabilities and a high relapse rate even after treatment. Here, our RNA seqencing analysis of BV2 cells treated by H2O2 and si-Nr4a2 reveal the effect of oxdiative stress and Nr4a2-knockdown on phenotype of microglia. Chip-seqencing andlysis of BV2 cells by anti-Nr4a2 antibody is to find the target genes regulated by Nr4a2. Overall, our results reveal that Nr4a2 as the major transcription factors for microglia involved in immunosuppression of glioma.
Project description:After exposure to drugs of abuse, the reward circuit can experience persistent changes that are thought to underlie relapse behavior. These changes can be epigenetic in nature, and here we identify an epigenetic regulator of memory processes, nuclear orphan receptor subfamily4 groupA member2 (NR4A2 aka NURR1), as necessary for relapse to cocaine-seeking behavior. Nr4a2 is an epigenetically regulated immediate early gene and transcription factor that is highly expressed in the medial habenula (MHb). Despite the well-studied contributions of the MHb to nicotine-associated behaviors, the MHb is not classically included in reward circuits. Therefore, the role of MHb NR4A2 in cocaine-seeking and relapse behavior remains largely unknown. This is a key open question as NR4A2 is a powerful regulator of memory processes dependent on epigenetic mechanisms. In this study, we examined the role of MHb NR4A2 in cued reinstatement of cocaine self-administration in mice, and found that over-expressing a dominant negative form of Nr4a2 (Nurr2c) in the MHb results in a near complete block of relapse-like behavior. We used single-nucleus transcriptomics to characterize the molecular cascade following the manipulation of Nr4a2, revealing changes in transcriptional networks related to addiction, neuroplasticity, and glutamatergic signaling. Together, these results place the MHb in the reward circuit as a pivotal regulator of relapse behavior and demonstrate the importance of NR4A2 as a key mechanism driving relapse behavior in the MHb.
Project description:Sustained elevation of sympathetic activity is an important contributor to pathological cardiac hypertrophy, ventricular arrhythmias, and left ventricular contractile dysfunction in chronic heart failure. The orphan nuclear receptor NR4A2 is an immediate early response gene activated in the heart under beta-adrenergic stimulation. The goal of this study was to identify the transcriptional remodeling events induced by NR4A2 expression in cardiomyocytes, and their impact on the physiological response of those cells to sustained beta-adrenergic stimulation. Treatment of adult rat ventricular myocytes (ARVMs) with isoproterenol induced a rapid (< 4 hours) but transient (< 24 hours) increase in NR4A2 expression levels that was accompanied by increased nuclear localization of the transcription factor. Adenovirus-mediated overexpression of NR4A2 modulated the expression of genes linked to adrenoceptor signaling, calcium signaling, cell growth and proliferation, and counteracted the increase in protein synthesis rate and cell surface area mediated by chronic isoproterenol stimulation. In consistence with those findings, NR4A2 overexpression also blocked the phosphorylative activation of ERK1/2, Akt, and of their downstream effector in protein synthesis p70S6K. Prominent among the transcriptional changes induced by NR4A2 was the > 7-fold up-regulation of the dual-specificity phosphatases DUSP2 and DUSP14, two known inhibitors of ERK1/2. Pre-treatment of NR4A2-overexpressing cardiomyocytes with the DUSPs inhibitor BCI prevented the inhibition of ERK1/2 and p70S6K following isoproterenol stimulation. In conclusion, our results suggest that NR4A2 acts as a novel negative feedback regulator of the beta-adrenergic receptor-mediated growth response in cardiomyocytes, and this at least partly through DUSP-mediated inhibition of ERK1/2 signaling.
Project description:The nucleosome is a fundamental unit of chromatin in eukaryotes, and generally prevents the binding of transcription factors to genomic DNA. Pioneer transcription factors overcome the nucleosome barrier, and bind their target DNA sequences in chromatin. OCT4 is a representative pioneer transcription factor that plays a role in stem cell pluripotency. In the present study, we biochemically analyzed the nucleosome binding by OCT4. Crosslinking mass spectrometry showed that OCT4 binds the nucleosome.