Forced expression of NR4A3 induced the differentiation of human neuroblastoma-derived NB1 cells

Potential Roles of Nr4a3-Mediated Inflammation in Immunological and Neurological Diseases

As a protein of the orphan nuclear receptor Nr4a family, Nr4a3 has no identified natural ligands. However, its biological activity can be mediated by inducing conformational changes through interactions with specific certain small molecules and receptors. Nr4a3 is activated as an early stress factor under various pathological conditions and plays a regulatory role in various tissues and cells, participating in processes such as cell differentiation, apoptosis, metabolism, and homeostasis. At present, research on the role of Nr4a3 in the pathophysiology of inflammation is considerably limited, especially with respect to its role in the central nervous system (CNS). In this review, we discuss the role of Nr4a3 in multiple sclerosis, Alzheimer's disease, retinopathy, Parkinson's disease, and other CNS diseases. This review shows that Nr4a3 has considerable potential as a therapeutic target in the treatment of CNS diseases. We provide a theoretical basis for the targeted therapy of CNS diseases and neuroinflammation, among other conditions.

Identification of Hub Genes and Pathways of Middle Cerebral Artery Occlusion in Aged Rats Using the Gene Expression Omnibus Database

Stroke remained the leading cause of disability in the world, and the most important non-modifiable risk factor was age. The treatment of stroke for elder patients faced multiple difficulties due to its complicated pathogenesis and mechanism. Therefore, we aimed to identify the potential differentially expressed genes (DEGs) and singnalling pathways for aged people of stroke. To compare the DEGs in the aged rats with or without middle cerebral artery occlusion (MCAO) and to analyse the important genes and the key signaling pathways involved in the development of cerebral ischaemia in aged rats. The Gene Expression Omnibus (GEO) analysis tool was used to analyse the DEGs in the GSE166162 dataset of aged MCAO rats compared with aged sham rats. Differential expression analysis was performed in aged MCAO rats and sham rats using limma. In addition, the 74 DEGs (such as Fam111a, Lcn2, Spp1, Lgals3 and Gpnmb were up-regulated; Egr2, Nr4a3, Arc, Klf4 and Nr4a1 were down-regulated) and potential compounds corresponding to the top 20 core genes in the Protein-Protein Interaction (PPI) network was constructed using the STRING database (version 12.0). Among these 30 compounds, resveratrol, cannabidiol, honokiol, fucoxanthin, oleandrin and tyrosol were significantly enriched. These DEGs were subjected to Gene Ontology (GO) function analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis to determine the most significantly enriched pathway in aged MCAO rats. Moreover, innate immune response, the complement and coagulation cascades signaling pathway, the IL-17 and other signaling pathways were significantly correlated with the aged MCAO rats. Our study indicates that multiple genes and pathological processes involved in the aged people of stroke. The immune response might be the key pathway in the intervention of cerebral infarction in aged people.

Whole-exome sequencing in moyamoya patients of Northern-European origin identifies gene variants involved in Nitric Oxide metabolism: A pilot study

Introduction

Moyamoya disease (MMD) is a chronic cerebrovascular steno-occlusive disease of largely unknown etiology. Variants in the RNF213 gene are strongly associated with MMD in East-Asia. In MMD patients of Northern-European origin, no predominant susceptibility variants have been identified so far.

Research question

Are there specific candidate genes associated with MMD of Northern-European origin, including the known RNF213 gene? Can we establish a hypothesis for MMD phenotype and associated genetic variants identified for further research?

Material and methods

Adult patients of Northern-European origin, treated surgically for MMD at Oslo University Hospital between October 2018 to January 2019 were asked to participate. WES was performed, with subsequent bioinformatic analysis and variant filtering. The selected candidate genes were either previously reported in MMD or known to be involved in angiogenesis. The variant filtering was based on variant type, location, population frequency, and predicted impact on protein function.

Results

Analysis of WES data revealed nine variants of interest in eight genes. Five of those encode proteins involved in nitric oxide (NO) metabolism: NOS3, NR4A3, ITGAV, GRB7 and AGXT2. In the AGXT2 gene, a de novo variant was detected, not previously described in MMD. None harboured the p.R4810K missense variant in the RNF213 gene known to be associated with MMD in East-Asian patients.

Discussion and conclusion

Our findings suggest a role for NO regulation pathways in Northern-European MMD and introduce AGXT2 as a new susceptibility gene. This pilot study warrants replication in larger patient cohorts and further functional investigations.

Regulatory factors involved in Th17/Treg cell balance of immune thrombocytopenia

Immune thrombocytopenia is a common heterogeneous autoimmune disease that is characterized by decreasing peripheral blood platelet counts and increasing risk of bleeding. Studies have shown that an imbalance between T helper 17 (Th17) and Regulatory T (Treg) cells differentiated from CD4+T-cells is a key factor influencing the development and pathogenesis of immune thrombocytopenia. Th17 cells promote the development of chronic inflammatory disorders and induce autoimmune diseases, whereas Treg cells regulate immune homeostasis and prevent autoimmune diseases. Several regulators affecting the production and maintenance of these cells are also essential for proper regulation of Th17/Treg balance; these regulatory factors include cell surface proteins, miRNAs, and cytokine signaling. In this review, we focus on the function and role of balance between Th17 and Treg cells in immune thrombocytopenia, the regulatory factors, and therapeutic goals of this balance in immune thrombocytopenia.

OMICS Analyses Unraveling Related Gene and Protein-Driven Molecular Mechanisms Underlying PACAP 38-Induced Neurite Outgrowth in PC12 Cells

The study aimed to understand mechanism/s of neuronal outgrowth in the rat adrenal-derived pheochromocytoma cell line (PC12) under pituitary adenylate cyclase-activating polypeptide (PACAP) treatment. Neurite projection elongation was suggested to be mediated via Pac1 receptor-mediated dephosphorylation of CRMP2, where GSK-3β, CDK5, and Rho/ROCK dephosphorylated CRMP2 within 3 h after addition of PACAP, but the dephosphorylation of CRMP2 by PACAP remained unclear. Thus, we attempted to identify the early factors in PACAP-induced neurite projection elongation via omics-based transcriptomic (whole genome DNA microarray) and proteomic (TMT-labeled liquid chromatography-tandem mass spectrometry) analyses of gene and protein expression profiles from 5-120 min after PACAP addition. The results revealed a number of key regulators involved in neurite outgrowth, including known ones, called 'Initial Early Factors', e.g., genes Inhba, Fst, Nr4a1,2,3, FAT4, Axin2, and proteins Mis12, Cdk13, Bcl91, CDC42, including categories of 'serotonergic synapse, neuropeptide and neurogenesis, and axon guidance'. cAMP signaling and PI3K-Akt signaling pathways and a calcium signaling pathway might be involved in CRMP2 dephosphorylation. Cross-referencing previous research, we tried to map these molecular components onto potential pathways, and we may provide important new information on molecular mechanisms of neuronal differentiation induced by PACAP. Gene and protein expression data are publicly available at NCBI GSE223333 and ProteomeXchange, identifier PXD039992.

Single-cell transcriptomic analysis reveals differential cell subpopulations and distinct phenotype transition in normal and dissected ascending aorta

BACKGROUND

Acute thoracic aortic dissection (ATAD) is a fatal condition characterized by tear of intima, formation of false lumen and rupture of aorta. However, the subpopulations of normal and dissected aorta remain less studied.

METHODS

Single-cell RNA sequencing was performed including 5 patients with ATAD and 4 healthy controls. Immunohistochemistry and immunofluorescence were used to verify the findings.

RESULTS

We got 8 cell types from human ascending aorta and identified 50 subpopulations including vascular smooth muscle cells (VSMCs), endothelial cells, fibroblasts, neutrophils, monocytes and macrophages. Six transmembrane epithelial antigen of prostate 4 metalloreductase (STEAP4) was identified as a new marker of synthetic VSMCs. CytoTRACE identified subpopulations with higher differentiation potential in specified cell types including synthetic VSMCs, enolase 1⁺ fibroblasts and myeloid-derived neutrophils. Synthetic VSMCs-derived C-X-C motif chemokine ligand 12 (CXCL12) might interact with neutrophils and fibroblasts via C-X-C motif chemokine receptor 4 (CXCR4) and atypical chemokine receptor 3 (ACKR3), respectively, which might recruit neutrophils and induce transdifferentitation of fibroblasts into synthetic VSMCs.

CONCLUSION

We characterized signatures of different cell types in normal and dissected human ascending aorta and identified a new marker for isolation of synthetic VSMCs. Moreover, we proposed a potential mechanism that synthetic VSMCs might interact with neutrophils and fibroblasts via CXCL12-CXCR4/ACKR3 axis whereby deteriorating the progression of ATAD, which might provide new insights to better understand the development and progression of ATAD.

miR-106b-5p induces immune imbalance of Treg/Th17 in immune thrombocytopenic purpura through NR4A3/Foxp3 pathway

BACKGROUND

Immune imbalance of regulatory T cells (Treg)/T helper 17 cells (Th17) contributes to the development of immune thrombocytopenic purpura (ITP). The dysregulation of miRNAs is important in the development of ITP. However, the role of miR-106b-5p in Treg/Th17 imbalance remains unknown in ITP.

MATERIALS AND METHODS

Peripheral blood was collected from patients with ITP and healthy controls, and CD4 + T cells were further isolated. miR-106b-5p, nuclear receptor subfamily 4 group A member 3 (NR4A3), forkhead box protein 3 (Foxp3), IL-17A, and TGF-β expressions were detected by qRT-PCR, western blot, or ELISA. The effect of miR-106b-5p on NR4A3 was detected by dual-luciferase reporter gene assay.

RESULTS

Compared with healthy controls, miR-106b-5p was elevated in peripheral blood of patients with ITP, and NR4A3 expression was decreased. sh-NR4A3 significantly decreased Foxp3 and TGF-β expressions, indicating that NR4A3 may regulate Treg differentiation via Foxp3. Additionally, NR4A3 was identified to be a target of miR-106b-5p, and miR-106b-5p was able to negatively modulate NR4A3 expression. Moreover, we found miR-106b-5p induced immune imbalance of Treg/Th17 through NR4A3. In vivo experiments revealed that silencing miR-106b-5p promoted Treg differentiation and increased the number of platelets, suggesting the relief of ITP.

CONCLUSION

miR-106b-5p regulated immune imbalance of Treg/Th17 in ITP through the NR4A3/Foxp3 pathway.