Origin and evolutionary landscape of Nr2f transcription factors across Metazoa

Background Nuclear Receptor Subfamily 2 Group F (Nr2f) orphan nuclear hormone transcription factors (TFs) are fundamental regulators of many developmental processes in invertebrates and vertebrates. Despite the importance of these TFs throughout metazoan development, previous work has not clearly outlined their evolutionary history. Results We integrated molecular phylogeny with comparisons of intron/exon structure, domain architecture, and syntenic conservation to define critical evolutionary events that distinguish the Nr2f gene family in Metazoa. Our data indicate that a single ancestral eumetazoan Nr2f gene predated six main Bilateria subfamilies, which include single Nr2f homologs, here referred to as Nr2f1/2/5/6, that are present in invertebrate protostomes and deuterostomes, Nr2f1/2 homologs in agnathans, and Nr2f1, Nr2f2, Nr2f5, and Nr2f6 orthologs that are found in gnathostomes. Four cnidarian Nr2f1/2/5/6 and three agnathan Nr2f1/2 members are each due to independent expansions, while the vertebrate Nr2f1/Nr2f2 and Nr2f5/Nr2f6 members each form paralogous groups that arose from the established series of whole-genome duplications (WGDs). Nr2f6 members are the most divergent Nr2f subfamily in gnathostomes. Interestingly, in contrast to the other gnathostome Nr2f subfamilies, Nr2f5 has been independently lost in numerous vertebrate lineages. Furthermore, our analysis shows there are differential expansions and losses of Nr2f genes in teleosts following their additional rounds of WGDs. Conclusion Overall, our analysis of Nr2f gene evolution helps to reveal the origins and previously unrecognized relationships of this ancient TF family, which may allow for greater insights into the conservation of Nr2f functions that shape Metazoan body plans.

NR4A2 expression is not altered in placentas from cases of growth restriction or preeclampsia, but is reduced in hypoxic cytotrophoblast

Nuclear Receptor Subfamily 4 Group A Member 2 (NR4A2) transcripts are elevated in the circulation of individuals whose pregnancies are complicated by preterm fetal growth restriction (FGR). In this paper, we show that the cases with preeclampsia (PE) have increased circulating NR4A2 transcripts compared to those with normotensive FGR. We aimed to establish whether the dysfunctional placenta mirrors the increase in NR4A2 transcripts and further, to uncover the function of placental NR4A2. NR4A2 expression was detected in preterm and term placental tissue; expressed higher at term. NR4A2 mRNA expression and protein were not altered in placentas from preterm FGR or PE pregnancies. Hypoxia (1% O2 compared to 8% O2) significantly reduced cytotrophoblast NR4A2 mRNA expression, but not placental explant NR4A2 expression. Silencing cytotrophoblast NR4A2 expression under hypoxia (via short interfering (si)RNAs) did not alter angiogenic Placental Growth Factor, nor anti-angiogenic sFlt-1 mRNA expression or protein secretion, but increased expression of cellular antioxidant, oxidative stress, inflammatory, and growth genes. NR4A2 expression was also not altered in a model of tumour necrosis factor-α-induced endothelial dysfunction, or with pravastatin treatment. Further studies are required to identify the origin of the circulating transcripts in pathological pregnancies, and investigate the function of placental NR4A2.

Association of single-nucleotide NR3C1 gene polymorphisms with glucocorticosteroid responsiveness in patients with pemphigus vulgaris

The glucocorticosteroid (GC) is crucial when managing patients with pemphigus vulgaris (PV). Polymorphisms in the gene encoding the nuclear receptor subfamily 3, group C, member 1 (NR3C1) protein (the GC receptor) may explain the variations in treatment efficacy. We evaluated the effects of 10 single nucleotide polymorphisms (SNPs) in the NR3C1 gene and the correlations with the GC responsiveness in patients with PV. The accumulative GC doses were recorded, and patients were assessed for the Pemphigus Disease Activity Index (PDAI) scores until the GC doses would be tapered. Whole blood samples at the initial visit were genotyped using TaqMan SNP Genotyping. In the NR3C1 gene, SNPs were detected in 6 (rs17209237, rs11745958, rs7701443, rs41423247, rs33388, and rs6196); the genotypes rs17209237 AA, rs11745958 CC, and rs6196 AG may be associated with a need for a lower accumulative GC dose; rs17209237 AA and rs6196 AG with shorter times to commencement of tapering; and rs17209237 AA and rs11745958 CC with shorter times to attainment of 50 and 25% PDAI scores. Thus, NR3C1 gene variations may predict GC responsiveness in PV patients.

Effect of the uncoupling protein-2 (UCP-2) and nuclear receptor subfamily 3 group C member 1 (NR3C1) genes on treatment efficacy and survival in patients with multiple myeloma: a single-center study

Objective Studies on the genetic background of patients with multiple myeloma (MM) have been increasing; two important factors considered in such works are uncoupling protein-2 (UCP-2) and nuclear receptor subfamily 3 group C member 1 (NR3C1). We aim to reveal the association of MM with NR3C1 and UCP-2 gene polymorphisms. In this prospective study, 200 patients diagnosed between January 2009 and 2018 and 200 healthy individuals were included. For patients who had undergone autologous stem cell transplantation and control subjects, we statistically compared the CC, GC, and GG genotypes and the C and G alleles of the NR3C1 gene, as well as the AA, AG, and GG genotypes and the A and G alleles of the UCP-2 gene. Results While the AA genotype was significantly more common in the MM group (p = 0.001), the GG genotype was significantly more common in the control group (p = 0.016). Overall survival was found to be significantly shorter in patients with the UCP-2 GG genotype (p = 0.034). It was also found that having the GG genotype of the UCP-2 gene was a 2.48-fold risk factor for mortality. The fact that overall survival is significantly shorter in MM patients with the UCP-2 GG genotype and its definition as a risk factor for mortality have been put forward for the first time in the literature.

Effect of Three NR3C1 mutations in Pathogenesis of Pituitary ACTH Adenoma

Objective Glucocorticoids act through the glucocorticoid receptor (GR) encoded by the Nuclear Receptor Subfamily 3 Group C Member 1 (NR3C1) gene. This study aimed to examine the function of NR3C1 variants and their possible pathogenic role in Cushing’s disease (CD). Methods Next Generation Sequencing was conducted in 49 CD patients. Corticotroph tumor GR protein expression was examined by immunohistochemistry (IHC). Constructs harboring the three NR3C1-mutants and wild-type (WT) GR were transfected into the murine corticotropic adenoma cell line (AtT-20) and GR protein expression was quantified by western blot. Translocation activity was assessed by immunofluorescence and effects of the GR mutants on corticotroph tumor proliferation, pro-opiomelanocortin (POMC) transcription and ACTH secretion were tested. Results Clinical features were similar in patients harboring the NR3C1 mutations and WT GR. Recurrent adenomas showed higher GR IHC score than non-recurrent tumors. In vitro studies demonstrated that the p.R469X mutant generated a truncated GR protein, and the p.D590G and p.Y693D GR mutants resulted in lower GR expression. Dexamethasone (DEX) treatment of AtT-20 cells demonstrated decreased DEX-induced nuclear translocation, increased cell proliferation and attenuated suppression of POMC transcription of 3 GR mutants. Interestingly, the p.R469X GR mutant resulted in increased murine corticotroph tumor ACTH secretion compared to WT GR. Conclusion Our findings identify 3/49 (6.1%) consecutive human corticotroph tumors harboring GR mutations. Further findings demonstrate the role NR3C1 plays in CD pathogenesis and offer insights into a novel treatment approach in this patient subset.

Origin and evolutionary landscape of Nr2f transcription factors across Metazoa

Background: Nuclear Receptor Subfamily 2 Group F (Nr2f) orphan nuclear hormone transcription factors (TFs) are fundamental regulators of many developmental processes in invertebrates and vertebrates. Despite the importance of these TFs throughout metazoan development, previous work has not clearly outlined their evolutionary history. Results: We integrated molecular phylogeny with comparisons of intron/exon structure, domain architecture, and syntenic conservation to define critical evolutionary events that distinguish the Nr2f gene family in Metazoa. Our data indicate that a single ancestral pre-metazoan Nr2f gene, we have termed Nr2f1/2/5/6, predated six main Bilateria subfamilies, which include a single Nr2f1/2/5 homolog that is present throughout protostomes and invertebrate deuterostomes, Nr2f1/2 homologs in agnathans, and Nr2f1 , Nr2f2 , Nr2f5 , Nr2f6 orthologs that are found in gnathostomes. The three Nr2f1/2 members in agnathans are due to independent expansions not found in gnathostomes, while the vertebrate Nr2f1 , Nr2f2 , Nr2f5 members arose from whole-genome duplications (WGDs). However, Nr2f6 members are the most divergent subfamily, likely originating from an ancient duplication, and are only retained by gnathostomes. Interestingly, Nr2f5 TFs have been independently lost in both cartilaginous fish and amniotes, such as humans. Furthermore, our analysis shows there are differential expansions and losses of Nr2f genes in teleosts following their additional rounds of WGDs. Conclusion: Overall, our evolutionary genomic analysis of Nr2f proteins helps to reveal the origins and previously unrecognized relationships of this ancient transcription factor family, which may allow for greater insights into the conservation of Nr2f functions that shape Metazoan body plans.

NR2F1 database: 111 variants and 83 patients support refining the clinical synopsis of Bosch-Boonstra-Schaaf optic atrophy syndrome

Pathogenic variants of the nuclear receptor subfamily 2 group F member 1 gene (NR2F1) are responsible for Bosch-Boonstra-Schaaf optic atrophy syndrome (BBSOAS), an autosomal dominant disorder characterized by optic atrophy associated with developmental delay and intellectual disability, but with a clinical presentation which appears to be multifaceted. We created the first public locus-specific database (LSDB) dedicated to NR2F1. All variants and clinical cases reported in the literature, as well as new unpublished cases, were integrated into the database using standard nomenclature to describe both molecular and phenotypic anomalies. We subsequently pursued a comprehensive approach based on computed representation and analysis suggesting a refinement of the BBSOAS clinical description with respect to neurological features and the inclusion of musculoskeletal hypotonia and intestinal signs with feeding difficulties. This database is fully accessible for both clinician and molecular biologists and should prove useful in further refining the clinical synopsis of NR2F1 as new data is recorded.

Differential expression of nuclear receptor subfamily 3 group C member 1 in cancers of the breast.

Breast cancer affects women at relatively high frequency (1). We mined published microarray datasets (2, 3) to determine in an unbiased fashion and at the systems level genes most differentially expressed in the primary tumors of patients with breast cancer. We report here significant differential expression of the gene encoding nuclear receptor subfamily 3 group C member 1, NR3C1, when comparing primary tumors of the breast to the tissue of origin, the normal breast. NR3C1 mRNA was present at significantly lower quantities in tumors of the breast as compared to normal breast tissue. Analysis of human survival data revealed that expression of NR3C1 in primary tumors of the breast was correlated with overall survival in patients with luminal A subtype and HER2+ cancer, demonstrating a relationship between primary tumor expression of a differentially expressed gene and patient survival outcomes influenced by molecular subtype. NR3C1 may be of relevance to initiation, maintenance or progression of cancers of the female breast.