Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “NR4A3”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

6 recordsLinked to original sources

Impact of NR4A3 on wound healing in chronic venous ulcers and its association with the PI3K/Akt signaling pathway.

BACKGROUND: To investigate the role of NR4A3 in chronic venous ulcer (VU) wound healing and to explore its potential regulatory mechanism involving the PI3K/Akt pathway. METHODS: Differential expression and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were performed using the GSE174661 dataset. DEGs were filtered by |log2FC| > 1 and adjusted P < 0.05, with KEGG significance set at P < 0.05. NR4A3 was identified as the core gene. NR4A3 knockdown and overexpression were established in HaCaT cells to evaluate proliferation, migration, and inflammatory cytokines. TNF-&#x3b1; was used to mimic the inflammatory microenvironment. Western blotting assessed phosphorylation of GSK3&#x3b2;, mTOR, PI3K, and Akt. PI3K/Akt agonist 740Y-P and inhibitor LY294002 were used in rescue experiments. RESULTS: Bioinformatic analysis revealed that NR4A3 expression was markedly downregulated in chronic venous ulcer (VU) tissues relative to normal skin and ordinary acute wound tissues. Differentially expressed genes were significantly enriched in the PI3K/Akt signaling pathway. TNF-&#x3b1; stimulation significantly upregulated NR4A3 expression and increased phosphorylation of GSK3&#x3b2; and mTOR in HaCaT cells. In cultured HaCaT keratinocytes, NR4A3 knockdown suppressed cell proliferation and invasion, enhanced cell migration, and elevated the expression and secretion of pro-inflammatory cytokines (IL-6, IL-8, CXCL5), accompanied by reduced phosphorylation of PI3K and Akt. Conversely, NR4A3 overexpression promoted cell proliferation and invasion, restrained migration, and dampened inflammatory responses, while increasing PI3K/Akt phosphorylation. Treatment with the PI3K/Akt agonist 740Y-P partially rescued the impaired proliferation, aberrant migration, and excessive inflammation caused by NR4A3 silencing, whereas PI3K/Akt inhibitor LY294002 aggravated pathway suppression. These findings suggest that NR4A3-associated changes in keratinocyte functions and inflammatory reactions are functionally linked to PI3K/Akt pathway activity, and inflammatory stimulation activates GSK3&#x3b2;/mTOR signaling accompanied by compensatory NR4A3 upregulation. CONCLUSION: These findings suggest that NR4A3 is associated with keratinocyte behavior and inflammatory responses via the PI3K/Akt pathway, potentially affecting chronic VU progression and healing. Reduced NR4A3 may impair wound repair through inflammation and abnormal cell migration, while TNF-&#x3b1; induces compensatory NR4A3 elevation.

NR4A3↗

Coexpression of NOR1 and SIX3 proteins in extraskeletal myxoid chondrosarcomas without detectable NR4A3 fusion genes.

Extraskeletal myxoid chondrosarcoma (EMC) is a rare mesenchymal tumor cytogenetically characterized by reciprocal translocations, such as t(9;22)(q22;q12) and t(9;17)(q22;q11), which result in EWSR1/NR4A3 and TAF15/NR4A3 fusion genes (alias EWS/NOR1, TAF2N/NOR1), respectively. NOR1 is an orphan nuclear receptor and acts as a transcription factor that can bind to its putative coactivator, SIX3. Although the NOR1 fusion protein has been implicated in oncogenesis of EMC, a small fraction of EMC lacks detectable rearrangements of the NR4A3 gene or 9q22. We report a case of EMC with no detectable NR4A3 gene alterations, as assessed with various molecular techniques including reverse transcription-polymerase chain reaction (RT-PCR), Southern blotting, interphase fluorescence in situ hybridization, and PCR single-strand conformation polymorphism-but with coexpression of native NOR1 and SIX3. In our survey of another 18 EMCs, we identified one more case expressing both NOR1 and SIX3 but lacking NR4A3 fusion. Fourteen tumors with detectable NR4A3 fusion genes (EWSR1-NR4A3; TAF15-NR4A3) expressed neither native NOR1 nor SIX3. SIX3 expression is normally confined specifically to the developing eye and fetal forebrain, although the expression of NR4A3 is largely ubiquitous. Our data suggest that aberrant coexpression of NOR1 and SIX3 is a potential alternative mechanism underlying the development of EMC.

Aged↗

Myoepithelioma-like tumor of the vulvar region shows a quiet genome and heterogeneous detectable mechanisms of SMARCB1 inactivation: Integrated analysis of two cases and review of the literature.

Myoepithelioma-like tumor of the vulvar region (MELTVR) is a rare SMARCB1-deficient mesenchymal neoplasm of adult women that can mimic malignant vulvar sarcomas, particularly epithelioid sarcoma. Although loss of SMARCB1/INI1 expression is a defining feature, the comprehensive genomic landscape of MELTVR remains poorly characterized. We report two cases of MELTVR and performed integrated histopathologic, immunophenotypic, and molecular analyses, including whole-exome sequencing (WES) with copy number assessment and targeted RNA-based fusion testing using the Archer FusionPlex Sarcoma panel. Histologically, both tumors consisted of relatively uniform epithelioid to short spindle cells in solid nests and cords within focal myxoid stroma, with complete loss of INI1 and positivity for smooth muscle markers and focal ER/EMA expression. Genomic profiling demonstrated a quiet molecular background in both cases, with low tumor mutation burden (0.45 and 1.03 mut/Mb) and no pathogenic SNVs/indels in major cancer-associated genes. One case showed a focal homozygous deletion of the SMARCB1 locus at 22q11.2, whereas the other case exhibited INI1 loss without detectable SMARCB1 mutation or copy number loss, suggesting heterogeneous mechanisms of inactivation. CDKN2A copy number remained neutral in both tumors. No canonical sarcoma-associated gene rearrangements, including EWSR1, FUS, PLAG1, or NR4A3, were identified. Together with a review of previously reported cases, these findings support MELTVR as an SMARCB1-inactivated neoplasm with low genomic complexity and highlight the diagnostic value of NGS-based profiling in excluding malignant mimics and preventing overtreatment.

Humans↗

Adaptive proteomic remodeling and eNOS upregulation in luminal endothelium and perivascular adipose tissue of patent saphenous vein grafts after CABG.

OBJECTIVE: Long-term patency of saphenous vein grafts (SVGs) remains a significant challenge in coronary artery bypass grafting (CABG). The biological factors underlying successful human grafts are poorly understood. We aimed to characterize the structural and molecular features associated with successful graft function. METHODS: Patent and occluded SVG and internal thoracic artery (ITA) grafts were obtained from explanted hearts of CABG patients undergoing heart transplantation for end-stage heart failure not attributable to graft failure, along with freshly harvested ITA and SVG controls. Samples underwent histomorphological analysis, immunohistochemistry (IHC), and liquid chromatography-tandem mass spectrometry (LC-MS/MS) proteomics. RESULTS: Patent ITA (ITA-P) showed minimal intimal hyperplasia with medial reinforcement, whereas patent SVGs (SVG-P) had organized, &#x3b1;-smooth muscle actin (&#x3b1;SMA)-positive myofibroblast-rich neointima. Endothelial nitric oxide synthase (eNOS) was markedly upregulated in patent grafts at two sites-the luminal endothelium and adventitial microvessels within perivascular adipose tissue (PVAT)-and lost at both sites in occluded SVG (SVG-O). Adventitial CD31-positive microvessels were significantly increased in patent grafts. Proteomically, ITA-P and SVG-P shared a largely common adaptive proteome enriched in translation, RNA processing, and extracellular matrix (ECM) organization, with shared upstream activation of NR4A3, EGFR, and STAT1, and conduit-specific signatures (IGF-1/RUNX2 in ITA-P; RETN/SRC/PTGES in SVG-P). PTGES was strongly expressed in the adventitia of SVG-P. CONCLUSIONS: Patent arterial and venous bypass grafts exhibited a shared adaptive phenotype characterized by dual-site upregulation of eNOS in both the luminal endothelium and the perivascular microvessels/PVAT. In SVG-P, PTGES was co-upregulated alongside eNOS, indicating a mechanistic link between the proteomic and IHC findings. These findings highlight the perivascular compartment as a site of adaptive, eNOS-associated changes in patent vein grafts.

Humans↗

Evolution and developmental expression of nuclear receptor genes in the ascidian Herdmania.

Nuclear receptors are a superfamily of metazoan transcription factors that have been shown to be involved in a wide range of developmental and physiological processes. A PCR-based survey of genomic DNA and developmental cDNAs from the ascidian Herdmania identifies eight members of this multigene family. Sequence comparisons and phylogenetic analyses reveal that these ascidian nuclear receptors are representative of five of the six previously defined nuclear receptor subfamilies and are apparent homologues of retinoic acid [NR1B], retinoid X [NR2B], peroxisome proliferator-activated [NR1C], estrogen related [NR3B], neuron-derived orphan (NOR) [NR4A3], nuclear orphan [NR4A], TR2 orphan [NR2C1] and COUP orphan [NR2F3] receptors. Phylogenetic analyses that include the ascidian genes produce topologically distinct trees that suggest a redefinition of some nuclear receptor subfamilies. These trees also suggest that extensive gene duplication occurred after the vertebrates split from invertebrate chordates. These ascidian nuclear receptor genes are expressed differentially during embryogenesis and metamorphosis.

Amino Acid Sequence↗

The homeotic protein Six3 is a coactivator of the nuclear receptor NOR-1 and a corepressor of the fusion protein EWS/NOR-1 in human extraskeletal myxoid chondrosarcomas.

Nuclear receptors represent a large family of transcription factors involved in development, differentiation, homeostasis, and cancer. In recent years, a growing number of cofactors has been discovered that participate in the regulation of the transcriptional activity of these proteins. We present in this study the identification of a cofactor, the homeotic protein Six3, which differentially regulates the transcriptional activity of the orphan nuclear receptor NOR-1 (NR4A3). NOR-1 is normally involved in the balance between cell proliferation and cell death, and is implicated in oncogenesis as part of the EWS/NOR-1 fusion protein found in human extraskeletal myxoid chondrosarcoma (EMC) tumors. Reverse transcription-PCR analyses indicate that EMC tumors expressing the EWS/NOR-1 mRNA also express mRNAs encoding NOR-1 and Six3. Glutathione S-transferase fusion protein assays show that Six3 binds in vitro the DNA-binding domain of NOR-1 and the EWS domain of EWS/NOR-1 and that the homeodomain of Six3 is required for these interactions. Mammalian two-hybrid experiments, using immortalized human chondrocytes as a model, indicate that Six3 also interacts with NOR-1 and EWS/NOR-1 in vivo. Cotransfection experiments show that Six3 stimulates the transcriptional activity of NOR-1, whereas it represses that of EWS/NOR-1. Considering the highly specific expression pattern of Six3, our finding that it is expressed in EMC suggests that it plays a pivotal role in the development of these tumors. We propose that Six3 maintains a transcriptional balance between the activities of NOR-1 and EWS/NOR-1, the net effect being to deregulate the expression of specific target genes and push the equilibrium toward uncontrolled cell proliferation.

Animals↗