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Background and Objectives: Malan syndrome is a rare overgrowth syndrome resulting from NFIX haploinsufficiency due to heterozygous loss-of-function mutations or microdeletions of NFIX on chromosome 19 at p13.2. Phenotypic presentation can vary but is characterized by macrocephaly, long and slender body habitus, skeletal abnormalities, and intellectual disability. Methods: Here, we report on the presentation, management, and development of a patient with Malan syndrome, highlighting the clinical and behavioral aspects of this syndrome, therapeutic interventions employed, and the course of disease over a 15-year period. We review medical records, cytogenetic analysis and neuropsychologic testing results, as well as speech pathology, optometric, and medical reports. In addition, we discuss personalized therapeutic strategies that could potentially be exploited in the future for such overgrowth syndromes. Results: To our knowledge, this is the first longitudinal follow-up report of a case of Malan syndrome to highlight the clinical course, interventions employed, and resulting improvements in neurocognitive function over time. Conclusions: This case highlights the importance of early diagnosis, intervention, and preventative care in overgrowth syndromes, as well as the potential for therapeutic intervention in the future. [ABSTRACT FROM AUTHOR]

Abstract Background Osteosarcoma (OS) is a malignant bone tumor that commonly occurs in children and adolescents under the age of 20. Dysregulation of microRNAs (miRNAs) is an important factor in the occurrence and progression of OS. MicroRNA miR-744-5p is aberrantly expressed in various tumors. However, its roles and molecular targets in OS remain unclear. Methods Differentially expressed miRNAs in OS were analyzed using the Gene Expression Omnibus dataset GSE65071, and the potential hub miRNA was identified through weighted gene co-expression network analysis. Quantitative real-time PCR (qRT-PCR) was used to detect the expression of miR-744-5p in OS cell lines. In vitro experiments, including CCK-8 assays, colony formation assays, flow cytometry apoptosis assays, and tube formation assays, were performed to explore the effects of miR-744-5p on OS cell biological behaviors. The downstream target genes of miR-744-5p were predicted through bioinformatics, and the binding sites were validated by a dual-luciferase reporter assay. Results The lowly expressed miRNA, miR-744-5p, was identified as a hub miRNA involved in OS progression through bioinformatic analysis. Nuclear factor I X (NFIX) was confirmed as a direct target for miR-744-5p in OS. In vitro studies revealed that overexpression of miR-744-5p could restrain the growth of OS cells, whereas miR-744-5p inhibition showed the opposite effect. It was also observed that treatment with the conditioned medium from miR-744-5p-overexpressed OS cells led to poorer proliferation and angiogenesis in human umbilical vein endothelial cells (HUVECs). Furthermore, NFIX overexpression restored the suppression effects of miR-744-5p overexpression on OS cell growth and HUVECs angiogenesis. Conclusion Our results indicated that miR-744-5p is a potential tumor-suppressive miRNA in OS progression by targeting NFIX to restrain the growth of OS cells and angiogenesis in HUVECs.

Background: Osteosarcoma (OS) is a malignant bone tumor that commonly occurs in children and adolescents under the age of 20. Dysregulation of microRNAs (miRNAs) is an important factor in the occurrence and progression of OS. MicroRNA miR-744-5p is aberrantly expressed in various tumors. However, its roles and molecular targets in OS remain unclear. Methods: Differentially expressed miRNAs in OS were analyzed using the Gene Expression Omnibus dataset GSE65071, and the potential hub miRNA was identified through weighted gene co-expression network analysis. Quantitative real-time PCR (qRT-PCR) was used to detect the expression of miR-744-5p in OS cell lines. In vitro experiments, including CCK-8 assays, colony formation assays, flow cytometry apoptosis assays, and tube formation assays, were performed to explore the effects of miR-744-5p on OS cell biological behaviors. The downstream target genes of miR-744-5p were predicted through bioinformatics, and the binding sites were validated by a dual-luciferase reporter assay. Results: The lowly expressed miRNA, miR-744-5p, was identified as a hub miRNA involved in OS progression through bioinformatic analysis. Nuclear factor I X (NFIX) was confirmed as a direct target for miR-744-5p in OS. In vitro studies revealed that overexpression of miR-744-5p could restrain the growth of OS cells, whereas miR-744-5p inhibition showed the opposite effect. It was also observed that treatment with the conditioned medium from miR-744-5p-overexpressed OS cells led to poorer proliferation and angiogenesis in human umbilical vein endothelial cells (HUVECs). Furthermore, NFIX overexpression restored the suppression effects of miR-744-5p overexpression on OS cell growth and HUVECs angiogenesis. Conclusion: Our results indicated that miR-744-5p is a potential tumor-suppressive miRNA in OS progression by targeting NFIX to restrain the growth of OS cells and angiogenesis in HUVECs. [ABSTRACT FROM AUTHOR]

Marshall-Smith Syndrome (MSS) is a rare progressive developmental disorder that severely impairs a patient's intellectual development and physical health. The only known cause for MSS is a mutation in the nuclear factor 1 X (NFIX) gene. This mutation affects neuronal development and protein transcription. Historically, most patients with MSS do not survive beyond 3 years of age. Reports of ocular findings are limited. We report a case of a 9-year-old MSS patient with progressive craniosynostosis, elevated intracranial pressure, and catastrophic ocular complications. A comprehensive PubMed literature search from 2018 to August 2022 updating a previous review of older literature produced 72 articles relating to MSS, which are reviewed. [ABSTRACT FROM AUTHOR]

Genome-Wide Association Studies (GWASs) have identified a huge number of variants associated with different traits. However, their validation through in vitro and in vivo studies often lags well behind their identification. For variants associated with traits or diseases of biomedical interest, this gap delays the development of possible therapies. This issue also impacts beta-hemoglobinopathies, such as beta-thalassemia and sickle cell disease (SCD). The definitive cures for these diseases are currently bone marrow transplantation and gene therapy. However, limitations regarding their effective use restrict their worldwide application. Great efforts have been made to identify whether modulators of fetal hemoglobin (HbF) and, to a lesser extent, hemoglobin A2 (HbA2) are possible therapeutic targets. Herein, we performed the post-GWAS in vivo validation of two genes, cyclin D3 (CCND3) and nuclear factor I X (NFIX), previously associated with HbF and HbA2 levels. The absence of Ccnd3 expression in vivo significantly increased g (HbF) and d (HbA2) globin gene expression. Our data suggest that CCND3 is a possible therapeutic target in sickle cell disease. We also confirmed the association of Nfix with γ-globin gene expression and present data suggesting a possible role for Nfix in regulating Kruppel-like transcription factor 1 (Klf1), a master regulator of hemoglobin switching. This study contributes to filling the gap between GWAS variant identification and target validation for beta-hemoglobinopathies. [ABSTRACT FROM AUTHOR]

The NFIX gene encodes a DNA‐binding protein belonging to the nuclear factor one (NFI) family of transcription factors. Pathogenic variants of NFIX are associated with two autosomal dominant Mendelian disorders, Malan syndrome (MIM 614753) and Marshall–Smith syndrome (MIM 602535), which are clinically distinct due to different disease‐causing mechanisms. NFIX variants associated with Malan syndrome are missense variants mostly located in exon 2 encoding the N‐terminal DNA binding and dimerization domain or are protein‐truncating variants that trigger nonsense‐mediated mRNA decay (NMD) resulting in NFIX haploinsufficiency. NFIX variants associated with Marshall–Smith syndrome are protein‐truncating and are clustered between exons 6 and 10, including a recurrent Alu‐mediated deletion of exons 6 and 7, which can escape NMD. The more severe phenotype of Marshall–Smith syndrome is likely due to a dominant‐negative effect of these protein‐truncating variants that escape NMD. Here, we report a child with clinical features of Malan syndrome who has a de novo NFIX intragenic duplication. Using genome sequencing, exon‐level microarray analysis, and RNA sequencing, we show that this duplication encompasses exons 6 and 7 and leads to NFIX haploinsufficiency. To our knowledge, this is the first reported case of Malan Syndrome caused by an intragenic NFIX duplication. [ABSTRACT FROM AUTHOR]

Genome-Wide Association Studies (GWASs) have identified a huge number of variants associated with different traits. However, their validation through in vitro and in vivo studies often lags well behind their identification. For variants associated with traits or diseases of biomedical interest, this gap delays the development of possible therapies. This issue also impacts beta-hemoglobinopathies, such as beta-thalassemia and sickle cell disease (SCD). The definitive cures for these diseases are currently bone marrow transplantation and gene therapy. However, limitations regarding their effective use restrict their worldwide application. Great efforts have been made to identify whether modulators of fetal hemoglobin (HbF) and, to a lesser extent, hemoglobin A2 (HbA2) are possible therapeutic targets. Herein, we performed the post-GWAS in vivo validation of two genes, cyclin D3 (CCND3) and nuclear factor I X (NFIX), previously associated with HbF and HbA2 levels. The absence of Ccnd3 expression in vivo significantly increased g (HbF) and d (HbA2) globin gene expression. Our data suggest that CCND3 is a possible therapeutic target in sickle cell disease. We also confirmed the association of Nfix with γ-globin gene expression and present data suggesting a possible role for Nfix in regulating Kruppel-like transcription factor 1 (Klf1), a master regulator of hemoglobin switching. This study contributes to filling the gap between GWAS variant identification and target validation for beta-hemoglobinopathies.

Aims: Nfix is a transcription factor belonging to the Nuclear Factor I (NFI) family comprising four members (Nfia, b, c, x). Nfix plays important roles in the development and function of several organs. In muscle development, Nfix controls the switch from embryonic to fetal myogenesis by promoting fast twitching fibres. In the adult muscle, following injury, lack of Nfix impairs regeneration, inducing higher content of slow‐twitching fibres. Nfix is expressed also in the heart, but its function has been never investigated before. We studied Nfix role in this organ. Methods: Using Nfix‐null and wild type (WT) mice we analyzed: (1) the expression pattern of Nfix during development by qPCR and (2) the functional alterations caused by its absence, by in vivo telemetry and in vitro patch clamp analysis. Results and Conclusions: Nfix expression start in the heart from E12.5. Adult hearts of Nfix‐null mice show a hearts morphology and sarcomeric proteins expression similar to WT. However, Nfix‐null animals show tachycardia that derives form an intrinsic higher beating rate of the sinus node (SAN). Molecular and functional analysis revealed that sinoatrial cells of Nfix‐null mice express a significantly larger L‐type calcium current (Cacna1d + Cacna1c). Interestingly, downregulation of Nfix by sh‐RNA in primary cultures of neonatal rat ventricular cardiomyocytes induced a similar increase in their spontaneous beating rate and in ICaL current. In conclusion, our data provide the first demonstration of a role of Nfix that, increasing the L‐type calcium current, modulates heart rate. [ABSTRACT FROM AUTHOR]

Simple Summary: This study found that hsa_circ_0049657, a circular RNA derived from the NFIX gene, was down-regulated in NSCLC tissues and cells. In addition, we could suppress the proliferation and invasion abilities and promote apoptosis of NSCLC cells by up-regulating hsa_circ_0049657. Non-small cell lung cancer (NSCLC) is a common lung disorder. In this study, we applied bioinformatics methods to analyze and investigate the role of the NFIX gene in NSCLC. Hsa_circ_0049657 is derived from the NFIX gene, this research aimed to verify the potential role of hsa_circ_0049657 in the development of NSCLC. The results suggested that NFIX was downregulated in most cancers. In addition, the NFIX expression in lung adenocarcinoma (LUAD) was associated with the clinicopathological stage. In LUAD, NFIX expression was associated with the degree of infiltration of most immune cells. The expression levels of hsa_circ_0049657 were significantly lower in cancerous tissues than in paracancerous tissues. Moreover, the results showed that hsa_circ_0049657 expression was downregulated in NSCLC cells. After overexpression of hsa_circ_0049657, the proliferation and migration ability of NSCLC cells were significantly inhibited and the level of apoptosis was increased. We could suppress the proliferation and invasion abilities and promote apoptosis of NSCLC cells by up-regulating hsa_circ_0049657, which might be a potential biomarker for NSCLC. [ABSTRACT FROM AUTHOR]

There are few well‐validated measures that are appropriate for assessing the full range of neurobehavioral presentations in PTEN hamartoma tumor syndrome (PHTS) and other neurodevelopmental genetic syndromes (NDGS). As potential therapeutics are developed, having reliable, valid, free, and easily accessible measures to track a range of neurobehavioral domains will be crucial for future clinical trials. This study focused on the development and initial psychometric evaluation of a set of freely available informant‐report survey scales for PHTS—the Neurobehavioral Evaluation Tool (NET). Concept elicitation, quantitative ratings, and cognitive interviewing processes were conducted with stakeholders and clinician–scientist experts, used to identify the most important neurobehavioral domains for this population, and to ensure items were appropriate for the full range of individuals with PHTS. Results of this process identified a PHTS neurobehavioral impact model with 11 domains. The final NET scales assessing these domains were administered to a sample of 384 participants (median completion time = 20.6 min), including 32 people with PHTS, 141 with other NDGS, 47 with idiopathic neurodevelopmental disorder (NDD), and 164 neurotypical controls. Initial psychometric results for the total scores of each scale indicated very good model (ω = 0.83–0.99) and internal consistency reliability (α = 0.82–0.98) as well as excellent test–retest reproducibility at 1‐month follow‐up (r = 0.78–0.98) and stability at 4‐month follow‐up (r = 0.76–0.96). Conditional reliability estimates indicated very strong measurement precision in key score ranges for assessing PHTS and other people with NDGS and/or idiopathic NDD. Comparisons across domains between PHTS and the other groups revealed specific patterns of symptoms and functioning, including lower levels of challenging behavior and more developed daily living and executive functioning skills relative to other NDGS. The NET appears to be a reliable and potentially useful tool for clinical characterization and monitoring of neurobehavioral symptoms in PHTS and may also have utility in the assessment of other NDGS and idiopathic NDD. Additional validation work, including convergent and discriminant validity analyses, are needed to replicate and extend these observations. [ABSTRACT FROM AUTHOR]

The nuclear factor I/X (NFIX) gene encodes a ubiquitously expressed transcription factor whose mutations lead to two allelic disorders characterized by developmental, skeletal, and neural abnormalities, namely, Malan syndrome (MAL) and Marshall–Smith syndrome (MSS). NFIX mutations associated with MAL mainly cluster in exon 2 and are cleared by nonsense‐mediated decay (NMD) leading to NFIX haploinsufficiency, whereas NFIX mutations associated with MSS are clustered in exons 6–10 and escape NMD and result in the production of dominant‐negative mutant NFIX proteins. Thus, different NFIX mutations have distinct consequences on NFIX expression. To elucidate the in vivo effects of MSS‐associated NFIX exon 7 mutations, we used CRISPR‐Cas9 to generate mouse models with exon 7 deletions that comprised: a frameshift deletion of two nucleotides (Nfix Del2); in‐frame deletion of 24 nucleotides (Nfix Del24); and deletion of 140 nucleotides (Nfix Del140). Nfix+/Del2, Nfix+/Del24, Nfix+/Del140, NfixDel24/Del24, and NfixDel140/Del140 mice were viable, normal, and fertile, with no skeletal abnormalities, but NfixDel2/Del2 mice had significantly reduced viability (p < 0.002) and died at 2–3 weeks of age. Nfix Del2 was not cleared by NMD, and NfixDel2/Del2 mice, when compared to Nfix+/+ and Nfix+/Del2 mice, had: growth retardation; short stature with kyphosis; reduced skull length; marked porosity of the vertebrae with decreased vertebral and femoral bone mineral content; and reduced caudal vertebrae height and femur length. Plasma biochemistry analysis revealed NfixDel2/Del2 mice to have increased total alkaline phosphatase activity but decreased C‐terminal telopeptide and procollagen‐type‐1‐N‐terminal propeptide concentrations compared to Nfix+/+ and Nfix+/Del2 mice. NfixDel2/Del2 mice were also found to have enlarged cerebral cortices and ventricular areas but smaller dentate gyrus compared to Nfix+/+ mice. Thus, NfixDel2/Del2 mice provide a model for studying the in vivo effects of NFIX mutants that escape NMD and result in developmental abnormalities of the skeletal and neural tissues that are associated with MSS. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research. [ABSTRACT FROM AUTHOR]

NFIX, a member of the nuclear factor I (NFI) family of transcription factors, is known to be involved in muscle and central nervous system embryonic development. However, its expression in adults is limited. Similar to other developmental transcription factors, NFIX has been found to be altered in tumors, often promoting pro-tumorigenic functions, such as leading to proliferation, differentiation, and migration. However, some studies suggest that NFIX can also have a tumor suppressor role, indicating a complex and cancer-type dependent role of NFIX. This complexity may be linked to the multiple processes at play in regulating NFIX, which include transcriptional, post-transcriptional, and post-translational processes. Moreover, other features of NFIX, including its ability to interact with different NFI members to form homodimers or heterodimers, therefore allowing the transcription of different target genes, and its ability to sense oxidative stress, can also modulate its function. In this review, we examine different aspects of NFIX regulation, first in development and then in cancer, highlighting the important role of NFIX in oxidative stress and cell fate regulation in tumors. Moreover, we propose different mechanisms through which oxidative stress regulates NFIX transcription and function, underlining NFIX as a key factor for tumorigenesis. [ABSTRACT FROM AUTHOR]

IntroductionSotos Syndrome (SS, OMIM#117550) is a heterogeneous genetic condition, recognized by three main clinical features present in most cases: overgrowth with macrocephaly, typical facial appearance and different degrees of intellectual disability. Three different types are described caused by variants or deletions/duplications in NSD1, NFIX and APC2 genes. We aimed to describe a cohort of pediatric patients reporting the typical and unexpected findings in order to expand the phenotype of this syndrome and trying to find genotype-phenotype correlations.MethodsIn our referral center, we collected and analyzed clinical and genetic data of 31-patients cohort diagnosed with SS.ResultsAll of them presented with overgrowth, typical dysmorphic features and different degree of developmental delay. Although structural cardiac defects have been reported in SS, non-structural diseases such as pericarditis were outstanding in our cohort. Moreover, we described here novel oncological malignancies not previously linked to SS such as splenic hamartoma, retinal melanocytoma and acute lymphocytic leukemia. Finally, five patients suffered from recurrent onychocryptosis that required surgical procedures, as an unreported prevalent medical condition.DiscussionThis is the first study focusing on multiple atypical symptoms in SS at the time that revisits the spectrum of clinical and molecular basis of this heterogeneous entity trying to unravel a genotype-phenotype correlation.

The nuclear factor I/X (NFIX) gene encodes a ubiquitously expressed transcription factor whose mutations lead to two allelic disorders characterized by developmental, skeletal, and neural abnormalities, namely, Malan syndrome (MAL) and Marshall–Smith syndrome (MSS). NFIX mutations associated with MAL mainly cluster in exon 2 and are cleared by nonsense‐mediated decay (NMD) leading to NFIX haploinsufficiency, whereas NFIX mutations associated with MSS are clustered in exons 6–10 and escape NMD and result in the production of dominant‐negative mutant NFIX proteins. Thus, different NFIX mutations have distinct consequences on NFIX expression. To elucidate the in vivo effects of MSS‐associated NFIX exon 7 mutations, we used CRISPR‐Cas9 to generate mouse models with exon 7 deletions that comprised: a frameshift deletion of two nucleotides (Nfix Del2); in‐frame deletion of 24 nucleotides (Nfix Del24); and deletion of 140 nucleotides (Nfix Del140). Nfix+/Del2, Nfix+/Del24, Nfix+/Del140, NfixDel24/Del24, and NfixDel140/Del140 mice were viable, normal, and fertile, with no skeletal abnormalities, but NfixDel2/Del2 mice had significantly reduced viability (p

Abstract Background Malan syndrome (MALNS) is a recently described ultrarare syndrome lacking guidelines for diagnosis, management and monitoring of evolutive complications. Less than 90 patients are reported in the literature and limited clinical information are available to assure a proper health surveillance. Results A multidisciplinary team with high expertise in MALNS has been launched at the “Ospedale Pediatrico Bambino Gesù”, Rome, Italy. Sixteen Italian MALNS individuals with molecular confirmed clinical diagnosis of MALNS were enrolled in the program. For all patients, 1-year surveillance in a dedicated outpatient Clinic was attained. The expert panel group enrolled 16 patients and performed a deep phenotyping analysis directed to clinically profiling the disorder and performing critical revision of previously reported individuals. Some evolutive complications were also assessed. Previously unappreciated features (e.g., high risk of bone fractures in childhood, neurological/neurovegetative symptoms, noise sensitivity and Chiari malformation type 1) requiring active surveillance were identified. A second case of neoplasm was recorded. No major cardiovascular anomalies were noticed. An accurate clinical description of 9 new MALNS cases was provided. Conclusions Deep phenotyping has provided a more accurate characterization of the main clinical features of MALNS and allows broadening the spectrum of disease. A minimal dataset of clinical evaluations and follow-up timeline has been proposed for proper management of patients affected by this ultrarare disorder.

Malan syndrome is an autosomal dominant disorder caused by pathogenic variants in NFIX with less than 100 cases reported thus far. NFIX is important for stem cell proliferation, quiescence, and differentiation during development and its protein plays a role in replication, signal transduction, and transcription. As a result of pathogenic variants, symptoms of Malan syndrome include overgrowth, intellectual disability, speech delay, and dysmorphic features. Currently, the recurrence risk for this disorder is indicated at less than 1%, standard for de novo autosomal dominant disorders. Herein, we report an additional set of sisters with the same novel pathogenic variant in NFIX and clinical features consistent with Malan syndrome providing evidence of germline mosaicism. Considering the rarity of this condition in conjunction with three previous reports of germline mosaicism, it is worthwhile to investigate and re-evaluate the proper recurrence risk for this condition. This discovery would be paramount for family planning and genetic counseling practices in families with affected individuals. [ABSTRACT FROM AUTHOR]

Malan syndrome is an autosomal dominant disorder caused by pathogenic variants in NFIX with less than 100 cases reported thus far. NFIX is important for stem cell proliferation, quiescence, and differentiation during development and its protein plays a role in replication, signal transduction, and transcription. As a result of pathogenic variants, symptoms of Malan syndrome include overgrowth, intellectual disability, speech delay, and dysmorphic features. Currently, the recurrence risk for this disorder is indicated at less than 1%, standard for de novo autosomal dominant disorders. Herein, we report an additional set of sisters with the same novel pathogenic variant in NFIX and clinical features consistent with Malan syndrome providing evidence of germline mosaicism. Considering the rarity of this condition in conjunction with three previous reports of germline mosaicism, it is worthwhile to investigate and re-evaluate the proper recurrence risk for this condition. This discovery would be paramount for family planning and genetic counseling practices in families with affected individuals.

Muscular dystrophies are genetic diseases characterized by chronic inflammation and fibrosis. Macrophages are immune cells that sustain muscle regeneration upon acute injury but seem deleterious in the context of chronic muscle injury such as in muscular dystrophies. Here, we observed that the number of macrophages expressing the transcription factor Nfix increases in two distinct mouse models of muscular dystrophies. We showed that the deletion of Nfix in macrophages in dystrophic mice delays the establishment of fibrosis and muscle wasting, and increases grasp force. Macrophages lacking Nfix expressed more TNFα and less TGFβ1, thus promoting apoptosis of fibro‐adipogenic progenitors. Moreover, pharmacological treatment of dystrophic mice with a ROCK inhibitor accelerated fibrosis through the increase of Nfix expression by macrophages. Thus, we have identified Nfix as a macrophage profibrotic factor in muscular dystrophies, whose inhibition could be a therapeutic route to reduce severity of the dystrophic disease. © 2022 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland. [ABSTRACT FROM AUTHOR]

Background: Malan syndrome (MALNS) is a recently described ultrarare syndrome lacking guidelines for diagnosis, management and monitoring of evolutive complications. Less than 90 patients are reported in the literature and limited clinical information are available to assure a proper health surveillance.Results: A multidisciplinary team with high expertise in MALNS has been launched at the "Ospedale Pediatrico Bambino Gesù", Rome, Italy. Sixteen Italian MALNS individuals with molecular confirmed clinical diagnosis of MALNS were enrolled in the program. For all patients, 1-year surveillance in a dedicated outpatient Clinic was attained. The expert panel group enrolled 16 patients and performed a deep phenotyping analysis directed to clinically profiling the disorder and performing critical revision of previously reported individuals. Some evolutive complications were also assessed. Previously unappreciated features (e.g., high risk of bone fractures in childhood, neurological/neurovegetative symptoms, noise sensitivity and Chiari malformation type 1) requiring active surveillance were identified. A second case of neoplasm was recorded. No major cardiovascular anomalies were noticed. An accurate clinical description of 9 new MALNS cases was provided.Conclusions: Deep phenotyping has provided a more accurate characterization of the main clinical features of MALNS and allows broadening the spectrum of disease. A minimal dataset of clinical evaluations and follow-up timeline has been proposed for proper management of patients affected by this ultrarare disorder. [ABSTRACT FROM AUTHOR]

Stem cells in adult mammalian tissues are held in a reversible resting state, known as quiescence, for prolonged periods of time. Recent studies have greatly increased our understanding of the epigenetic and transcriptional landscapes that underlie stem cell quiescence. However, the transcription factor code that actively maintains the quiescence program remains poorly defined. Similarly, alternative splicing events affecting transcription factors in stem cell quiescence have been overlooked. Here we show that the transcription factor T-cell factor/lymphoid enhancer factor LEF1, a central player in canonical β-catenin-dependent Wnt signalling, undergoes alternative splicing and switches isoforms in quiescent neural stem cells. We found that active β-catenin and its partner LEF1 accumulated in quiescent hippocampal neural stem and progenitor cell (Q-NSPC) cultures. Accordingly, Q-NSPCs showed enhanced TCF/LEF1-driven transcription and a basal Wnt activity that conferred a functional advantage to the cultured cells in a Wnt-dependent assay. At a mechanistic level, we found a fine regulation of Lef1 gene expression. The coordinate upregulation of Lef1 transcription and retention of alternative spliced exon 6 (E6) led to the accumulation of a full-length protein isoform (LEF1-FL) that displayed increased stability in the quiescent state. Prospectively isolated GLAST + cells from the postnatal hippocampus also underwent E6 retention at the time quiescence is established in vivo. Interestingly, LEF1 motif was enriched in quiescence-associated enhancers of genes upregulated in Q-NSPCs and quiescence-related NFIX transcription factor motifs flanked the LEF1 binding sites. We further show that LEF1 interacts with NFIX and identify putative LEF1/NFIX targets. Together, our results uncover an unexpected role for LEF1 in gene regulation in quiescent NSPCs, and highlight alternative splicing as a post-transcriptional regulatory mechanism in the transition from stem cell activation to quiescence.

Abstract Background A host of researches have demonstrated the regulation of long non-coding RNAs (lncRNAs) in the progression of pancreatic cancers (PC). In this study, our main task was to analyze the function of MAF bZIP transcription factor G antisense RNA 1 (MAFG-AS1) in PC. Methods RT-qPCR measured gene expression. Functional experiments, including EdU assay, flow cytometry analysis, TUNEL assay and transwell assay, assessed the biological changes of PC cells. RNA pull down assay, luciferase reporter assay and RIP assay verified the interaction between RNAs. Results MAFG-AS1 was lowly expressed in normal pancreatic samples but up-regulated in PC tissues and cell lines. Besides, MAFG-AS1 silence suppressed cell proliferation and migration whereas promoted cell apoptosis in PC. Mechanism assays verified that miR-3196 could bind with MAFG-AS1. Moreover, miR-3196 was discovered to be lowly expressed in PC cell lines, and its overexpression inhibited PC cell growth and migration. Importantly, nuclear factor I X (NFIX), overexpressed in PC cell lines, was validated to be positively modulated by MAFG-AS1 through absorbing miR-3196. Moreover, overexpression of NFIX could countervail the restraining effects of MAFG-AS1 knockdown on the growth and migration of PC cells. Conclusion MAFG-AS1 had an oncogenic function in the progression of PC via regulating miR-3196/NFIX pathway, and decreasing MAFG-AS1 expression could attenuate PC progression.

Abstract Background Gastric cancer (GC) is a common-sighted cancer which is hard to cure over the world. Substantial researches revealed that long non-coding RNAs (lncRNAs) were fundamental regulators in the process of cancers. Nevertheless, the biological function of LINC00511 and how LINC00511 was involved in the regulatory system in GC remained unclear. Methods RIP assays and luciferase reporter assays were performed to illustrate combination between LINC00511 and miR-625-5p. Loss-of-function assays were applied for identifying LINC00511 function in GC. Results In our study, LINC00511 was discovered significantly high in expression in GC tissues and cell lines. Moreover, LINC00511 showed a strong expression in I/II and III/IV stage. Knockdown of LINC00511 could inhibit the cell proliferation while enhanced cell apoptosis rate in GC. We used nuclear–cytoplasmic fractionation to judge the subcellular localization of LINC00511. Furthermore, miR-625-5p was found to have binding sites for LINC00511 and negatively regulated by LINC00511. Overexpression of miR-625-5p repressed the course of GC. And knockdown of miR-625-5p could recover the effects of LINC00511 silence. Besides, NFIX was discovered as a downstream target of miR-625-5p and overexpression of NFIX could offset the influence of LINC00511 silence. The results of vivo studies manifested that down-regulation of LINC00511 could reduce the Ki67 expression and NFIX while lifted the expression of miR-625-5p. Conclusion Overall, the results from our study demonstrated that LINC00511 could function as a tumor promoter by targeting miR-625-5p NFIX axis, suggesting LINC00511 could be considered as a target for GC treatment.

Abstract Objective Nuclear Factor One X (NFIX) is a transcription factor expressed by neural stem cells within the developing mouse brain and spinal cord. In order to characterise the pathways by which NFIX may regulate neural stem cell biology within the developing mouse spinal cord, we performed an microarray-based transcriptomic analysis of the spinal cord of embryonic day (E)14.5 Nfix −/− mice in comparison to wild-type controls. Data description Using microarray and differential gene expression analyses, we were able to identify differentially expressed genes in the spinal cords of E14.5 Nfix −/− mice compared to wild-type controls. We performed microarray-based sequencing on spinal cords from n = 3 E14.5 Nfix −/− mice and n = 3 E14.5 Nfix +/+ mice. Differential gene expression analysis, using a false discovery rate (FDR) p-value of p ± 1.5, revealed 1351 differentially regulated genes in the spinal cord of Nfix −/− mice. Of these, 828 were upregulated, and 523 were downregulated. This resource provides a tool to interrogate the role of this transcription factor in spinal cord development.

Abstract Forming tight interaction with both Purkinje and granule cells (GCs), Bergmann glia (BG) are essential for cerebellar morphogenesis and neuronal homeostasis. However, how BG act in this process is unclear without comprehensive transcriptome landscape of BG. Here, high temporal‐resolution investigation of transcriptomes with FACS‐sorted BG revealed the dynamic expression of genes within given functions and pathways enabled BG to assist neural migration and construct neuron‐glia network. It is found that the peak time of GCs migration (P7‐10) strikingly coincides with the downregulation of extracellular matrix (ECM) related genes, and the disruption of which by Setdb1 ablation at P7‐10 in BG leads to significant migration defect of GCs emphasizing the criticality of Nfix‐Setdb1 mediated H3K9me3 repressive complex for the precise regulation of GCs migration in vivo. Thus, BG's transcriptomic landscapes offer an insight into the mechanism by which BG are in depth integrated in cerebellar neural network.

Forming tight interaction with both Purkinje and granule cells (GCs), Bergmann glia (BG) are essential for cerebellar morphogenesis and neuronal homeostasis. However, how BG act in this process is unclear without comprehensive transcriptome landscape of BG. Here, high temporal‐resolution investigation of transcriptomes with FACS‐sorted BG revealed the dynamic expression of genes within given functions and pathways enabled BG to assist neural migration and construct neuron‐glia network. It is found that the peak time of GCs migration (P7‐10) strikingly coincides with the downregulation of extracellular matrix (ECM) related genes, and the disruption of which by Setdb1 ablation at P7‐10 in BG leads to significant migration defect of GCs emphasizing the criticality of Nfix‐Setdb1 mediated H3K9me3 repressive complex for the precise regulation of GCs migration in vivo. Thus, BG's transcriptomic landscapes offer an insight into the mechanism by which BG are in depth integrated in cerebellar neural network. [ABSTRACT FROM AUTHOR]

Overgrowth-intellectual disability (OGID) syndromes are a collection of rare genetic disorders with overlapping clinical profiles. In addition to the cardinal features of general overgrowth (height and/or head circumference at least two standard deviations above the mean) and some degree of intellectual disability, the OGID syndromes are often associated with neurological anomalies including seizures. In an effort to advance research in directions that will generate meaningful treatments for people with OGID syndromes, a new collaborative partnership called the Overgrowth Syndromes Alliance (OSA) formed in 2023. By taking a phenotype-first approach, OSA aims to unite research and patient communities traditionally siloed by genetic disorder. OSA has galvanized OGID patient organizations around shared interests and developed a research roadmap to identify and address our community's greatest unmet needs. Here, we describe the literature regarding seizures among those with overgrowth syndromes and present the OSA Research Roadmap. This patient-driven guide outlines the milestones essential to reaching the outcome of effective treatments for OGID syndromes and offers resources for reaching those milestones., Competing Interests: The authors declare that there is no conflict of interest., (© The Author(s), 2024.)

Background: A host of researches have demonstrated the regulation of long non-coding RNAs (lncRNAs) in the progression of pancreatic cancers (PC). In this study, our main task was to analyze the function of MAF bZIP transcription factor G antisense RNA 1 (MAFG-AS1) in PC. Methods: RT-qPCR measured gene expression. Functional experiments, including EdU assay, flow cytometry analysis, TUNEL assay and transwell assay, assessed the biological changes of PC cells. RNA pull down assay, luciferase reporter assay and RIP assay verified the interaction between RNAs. Results: MAFG-AS1 was lowly expressed in normal pancreatic samples but up-regulated in PC tissues and cell lines. Besides, MAFG-AS1 silence suppressed cell proliferation and migration whereas promoted cell apoptosis in PC. Mechanism assays verified that miR-3196 could bind with MAFG-AS1. Moreover, miR-3196 was discovered to be lowly expressed in PC cell lines, and its overexpression inhibited PC cell growth and migration. Importantly, nuclear factor I X (NFIX), overexpressed in PC cell lines, was validated to be positively modulated by MAFG-AS1 through absorbing miR-3196. Moreover, overexpression of NFIX could countervail the restraining effects of MAFG-AS1 knockdown on the growth and migration of PC cells. Conclusion: MAFG-AS1 had an oncogenic function in the progression of PC via regulating miR-3196/NFIX pathway, and decreasing MAFG-AS1 expression could attenuate PC progression. [ABSTRACT FROM AUTHOR]

Abstract Background Malan syndrome is a recently introduced overgrowth disorder described in a limited number of individuals. Haploinsufficiency and also point mutations of NFIX gene have been proposed as its leading causative mechanism, however, due to the limited number of cases and different deletion sizes, genotype/phenotype correlations are still limited. Methods Here, we report the first Brazilian case of Malan syndrome caused by a 990 kb deletion in 19p13.2p13.12, focusing on clinical and behavioral aspects of the syndrome. Results The patient presented with macrocephaly, facial dysmorphisms, hypotonia, developmental delay, moderate thoracolumbar scoliosis, and seizures. The intellectual and behavioral assessments showed severe cognitive, language, and adaptive functions impairments. The 19p deleted region of our patient encompasses NFIX, CACNA1A, which seems to be related to a higher frequency of seizures among individuals with microdeletions in 19p13.2, and 15 other coding genes, including CC2D1A and NACC1, both known to be involved in neurobiological process and pathways. Conclusion Deletions involving NFIX gene should be considered in patients with overgrowth during childhood, macrocephaly, developmental delay, and seizures, as well as severe intellectual disability.

Abstract Objective The active place avoidance task (APA) is a behavioural task used to assess learning and memory in rodents. This task relies on the hippocampus, a region of the cerebral cortex capable of generating new neurons from neural stem cells. In this study, to gain further insight into the behavioural phenotype of mice deficient in the transcription factor Nfix, a gene expressed by adult neural stem cells, we examined learning and memory parameters from the APA task that were not published in our original investigation. We analysed time to first and second shock, maximum path and time of shock avoidance, number of entries into the shock zone and time spent in the shock zone. We also assessed performance in the APA task based on sex. Results We found mice deficient in Nfix displayed decreased latency to second shock compared to the control mice. Nfix deficient mice entered the shock zone more frequently and also spent more time in the shock zone. Our data provides further insights into the memory deficits evident in Nfix mutant mice, indicating these mice have a memory retrieval problem and may employ a different navigation strategy in the APA task.

Abstract Background Radial glial stem cells within the developing nervous system generate a variety of post-mitotic cells, including neurons and glial cells, as well as the specialised multi-ciliated cells that line the walls of the ventricular system, the ependymal cells. Ependymal cells separate the brain parenchyma from the cerebrospinal fluid and mediate osmotic regulation, the flow of cerebrospinal fluid, and the subsequent dispersion of signalling molecules via the co-ordinated beating of their cilia. Deficits to ependymal cell development and function have been implicated in the formation of hydrocephalus, but the transcriptional mechanisms underpinning ependymal development remain poorly characterised. Findings Here, we demonstrate that the transcription factor nuclear factor IX (NFIX) plays a central role in the development of the ependymal cell layer of the lateral ventricles. Expression of ependymal cell-specific markers is delayed in the absence of Nfix. Moreover, Nfix-deficient mice exhibit aberrant ependymal cell morphology at postnatal day 15, culminating in abnormal thickening and intermittent loss of this cell layer. Finally, we reveal Foxj1, a key factor promoting ependymal cell maturation, as a target for NFIX-mediated transcriptional activation. Conclusions Collectively, our data indicate that ependymal cell development is reliant, at least in part, on NFIX expression, further implicating this transcription factor as a mediator of multiple aspects of radial glial biology during corticogenesis.

Transcriptional regulation plays a central role in controlling neural stem and progenitor cell proliferation and differentiation during neurogenesis. For instance, transcription factors from the nuclear factor I (NFI) family have been shown to co-ordinate neural stem and progenitor cell differentiation within multiple regions of the embryonic nervous system, including the neocortex, hippocampus, spinal cord and cerebellum. Knockout of individual Nfi genes culminates in similar phenotypes, suggestive of common target genes for these transcription factors. However, whether or not the NFI family regulates common suites of genes remains poorly defined. Here, we use granule neuron precursors (GNPs) of the postnatal murine cerebellum as a model system to analyse regulatory targets of three members of the NFI family: NFIA, NFIB and NFIX. By integrating transcriptomic profiling (RNA-seq) of Nfia- and Nfix-deficient GNPs with epigenomic profiling (ChIP-seq against NFIA, NFIB and NFIX, and DNase I hypersensitivity assays), we reveal that these transcription factors share a large set of potential transcriptional targets, suggestive of complementary roles for these NFI family members in promoting neural development. [ABSTRACT FROM AUTHOR]

Background: Gastric cancer (GC) is a common-sighted cancer which is hard to cure over the world. Substantial researches revealed that long non-coding RNAs (lncRNAs) were fundamental regulators in the process of cancers. Nevertheless, the biological function of LINC00511 and how LINC00511 was involved in the regulatory system in GC remained unclear. Methods: RIP assays and luciferase reporter assays were performed to illustrate combination between LINC00511 and miR-625-5p. Loss-of-function assays were applied for identifying LINC00511 function in GC. Results: In our study, LINC00511 was discovered significantly high in expression in GC tissues and cell lines. Moreover, LINC00511 showed a strong expression in I/II and III/IV stage. Knockdown of LINC00511 could inhibit the cell proliferation while enhanced cell apoptosis rate in GC. We used nuclear–cytoplasmic fractionation to judge the subcellular localization of LINC00511. Furthermore, miR-625-5p was found to have binding sites for LINC00511 and negatively regulated by LINC00511. Overexpression of miR-625-5p repressed the course of GC. And knockdown of miR-625-5p could recover the effects of LINC00511 silence. Besides, NFIX was discovered as a downstream target of miR-625-5p and overexpression of NFIX could offset the influence of LINC00511 silence. The results of vivo studies manifested that down-regulation of LINC00511 could reduce the Ki67 expression and NFIX while lifted the expression of miR-625-5p. Conclusion: Overall, the results from our study demonstrated that LINC00511 could function as a tumor promoter by targeting miR-625-5p NFIX axis, suggesting LINC00511 could be considered as a target for GC treatment. [ABSTRACT FROM AUTHOR]

Muscular dystrophies (MDs) are still incurable heterogeneous diseases, characterized by muscle wasting, replacement by fibrotic tissue, and increasing weakness, which in severe cases, such as Duchenne MD, lead to premature death. MDs are due to mutations encompassing different dystrophin-glycoprotein complex (DGC) genes, which code for structural proteins that anchor the cytoskeleton to the extracellular matrix, thus conferring myofiber stability. All mutations destabilizing this complex result in different MD forms, with varying levels of severity. Independently of the genetic defect, MDs share common hallmarks, characterized by continuous cycles of muscle degeneration, due to lack of structural support during contraction, followed by regeneration cycles by satellite cells (SCs), the canonical myogenic stem cells of adult muscle. However, dystrophic SCs generate new fibres which are also prone to degeneration so that, after many cycles of degeneration/regeneration, this cell population is exhausted and muscle is replaced by connective and adipose tissue. At this stage, any therapeutic intervention is likely to fail.

The importance of gonadal mosaicism in families with apparently de novo mutations is being increasingly recognized. We report on two affected brothers initially suggestive of X‐linked or autosomal recessive inheritance. Malan syndrome due to shared NFIX variants was diagnosed in the brothers using exome sequencing. The boys shared the same paternal but not maternal haplotype around NFIX, and deep amplicon sequencing showed ~7% of the variant in paternal sperm but not in paternal blood and saliva. We performed review of previous cases of gonadal mosaicism, which suggests that the phenomenon is not uncommon. Gonadal mosaicism is often not accompanied by somatic mosaicism in tissues routinely used for testing, and if both types of mosaicism are present, the frequency of the variant in sperm is often higher than in somatic cells. In families with shared apparently de novo variants without evidence of parental somatic mosaicism, the transmitting parent may be determined through haplotyping of exome variants. Gonadal mosaicism has important consequences for recurrence risks and should be considered in genetic counseling in families with de novo variants. [ABSTRACT FROM AUTHOR]

Cerebellar granule neurons are the most numerous neuronal subtype in the central nervous system. Within the developing cerebellum, these neurons are derived from a population of progenitor cells found within the external granule layer of the cerebellar anlage, namely the cerebellar granule neuron precursors (GNPs). The timely proliferation and differentiation of these precursor cells, which, in rodents occurs predominantly in the postnatal period, is tightly controlled to ensure the normal morphogenesis of the cerebellum. Despite this, our understanding of the factors mediating how GNP differentiation is controlled remains limited. Here, we reveal that the transcription factor nuclear factor I X (NFIX) plays an important role in this process. Mice lacking Nfix exhibit reduced numbers of GNPs during early postnatal development, but elevated numbers of these cells at postnatal day 15. Moreover, Nfix−/− GNPs exhibit increased proliferation when cultured in vitro, suggestive of a role for NFIX in promoting GNP differentiation. At a mechanistic level, profiling analyses using both ChIP-seq and RNA-seq identified the actin-associated factor intersectin 1 as a downstream target of NFIX during cerebellar development. In support of this, mice lacking intersectin 1 also displayed delayed GNP differentiation. Collectively, these findings highlight a key role for NFIX and intersectin 1 in the regulation of cerebellar development. [ABSTRACT FROM AUTHOR]

The past decade has seen incredible advances in the field of stem cell biology that have greatly improved our understanding of development and provided important insights into pathological processes. Transcription factors (TFs) play a central role in mediating stem cell proliferation, quiescence, and differentiation. One TF that contributes to these processes is Nuclear Factor One X (NFIX). Recently, NFIX activity has been shown to be essential in multiple organ systems and to have important translational impacts for human health. Here, we describe recent studies showing the contribution of NFIX to muscle development and muscular dystrophies, hematopoiesis, cancer, and neural stem cell biology, highlighting the importance of this knowledge in the development of therapeutic targets. Highlights NFIX activity is tissue/cell specific and often depends on interaction partners including Fox and Sox proteins. NFIX is essential for normal muscle development and can influence muscle diseases. NFIX plays a significant role in hematopoiesis. Mutations in NFIX affect human brain development and cancer. NFIX might be a therapeutic target for different diseases, including muscle and brain disorders. [ABSTRACT FROM AUTHOR]

Aim: To study the expression profile of NFIX, its prognostic value and the mechanism of its dysregulation in lung adenocarcinoma (LUAD). Patients & materials: A retrospective study was performed by using data from the Cancer Genome Atlas and the Human Protein Atlas.Results: High NFIX RNA expression was an independent prognostic factor of favorable overall survival (HR: 0.687, 95% CI: 0.496-0.951; p = 0.024) and recurrence-free survival (HR: 0.700, 95% CI: 0.493-0.994, p = 0.046) in LUAD, but not in lung squamous cell carcinoma. NFIX DNA hypermethylation was associated with significantly decreased NFIX expression and shorter overall survival and recurrence-free survival in LUAD.Conclusion:  NFIX downregulation might independently predict poor prognosis in LUAD. DNA hypermethylation might be an important cause of the downregulation. [ABSTRACT FROM AUTHOR]

• RNA-Seq of Nfix overexpression and silencing treatment in primary chondrocytes. • Nfix regulated chondrocyte proliferation and differentiation by regulating multiple genes. • The comprehensive analysis of GO, KEGG gene expression trends and qRT-PCR. • The analysis of probable connections between Nfix and Sox9 and its downstream genes. Nuclear factor 1 X-type (Nfix) is a transcription factor related to mental and physical development. However, very few studies have reported the effects of Nfix on cartilage. This study aims to reveal the influence of Nfix on the proliferation and differentiation of chondrocytes, and to explore its potential action mechanism. We isolated primary chondrocytes from the costal cartilage of newborn C57BL/6 mice and with Nfix overexpression or silencing treatment. We used Alcian blue staining and found that Nfix overexpression significantly promoted ECM synthesis in chondrocytes while silencing inhibited ECM synthesis. Using RNA-seq technology to study the expression pattern of Nfix in primary chondrocytes. We found that Nfix overexpression significantly up-regulated genes that are related to chondrocyte proliferation and extracellular matrix (ECM) synthesis and significantly down-regulated genes related to chondrocyte differentiation and ECM degradation. Nfix silencing, however, significantly up-regulated genes associated with cartilage catabolism and significantly down-regulated genes associated with cartilage growth promotion. Furthermore, Nfix exerted a positive regulatory effect on Sox9, and we propose that Nfix may promote chondrocyte proliferation and inhibit differentiation by stimulating Sox9 and its downstream genes. Our findings suggest that Nfix may be a potential target for the regulation of chondrocyte proliferation and differentiation. [ABSTRACT FROM AUTHOR]

Nfix belongs to a family of four highly conserved proteins that act as transcriptional activators and/or repressors of cellular and viral genes. We previously showed a pivotal role for Nfix in regulating the transcriptional switch from embryonic to fetal myogenesis. Here, we show that Nfix directly represses the Myostatin promoter, thus controlling the proper timing of satellite cell differentiation and muscle regeneration. Nfix-null mice display delayed regeneration after injury, and this deficit is reversed upon in vivo Myostatin silencing. Conditional deletion of Nfix in satellite cells results in a similar delay in regeneration, confirming the functional requirement for Nfix in satellite cells. Moreover, mice lacking Nfix show reduced myofiber cross sectional area and a predominant slow twitching phenotype. These data define a role for Nfix in postnatal skeletal muscle and unveil a mechanism for Myostatin regulation, thus providing insights into the modulation of its complex signaling pathway.

Macrophages (MPs) are immune cells which are crucial for tissue repair. In skeletal muscle regeneration, pro-inflammatory cells first infiltrate to promote myogenic cell proliferation, then they switch into an anti-inflammatory phenotype to sustain myogenic cells differentiation and myofiber formation. This phenotypical switch is induced by dead cell phagocytosis. We previously demonstrated that the transcription factor Nfix, a member of the nuclear factor I (Nfi) family, plays a pivotal role during muscle development, regeneration and in the progression of muscular dystrophies. Here, we show that Nfix is mainly expressed by anti-inflammatory macrophages. Upon acute injury, mice deleted for Nfix in myeloid line displayed a significant defect in the process of muscle regeneration. Indeed, Nfix is involved in the macrophage phenotypical switch and macrophages lacking Nfix failed to adopt an anti-inflammatory phenotype and interact with myogenic cells. Moreover, we demonstrated that phagocytosis induced by the inhibition of the RhoA-ROCK1 pathway leads to Nfix expression and, consequently, to acquisition of the anti-inflammatory phenotype. Our study identified Nfix as a link between RhoA-ROCK1-dependent phagocytosis and the MP phenotypical switch, thus establishing a new role for Nfix in macrophage biology for the resolution of inflammation and tissue repair.

The transcription factor Nfix belongs to the nuclear factor one family and has an essential role in prenatal skeletal muscle development, where it is a master regulator of the transition from embryonic to foetal myogenesis. Recently, Nfix was shown to be involved in adult muscle regeneration and in muscular dystrophies. Here, we have investigated the signalling that regulates Nfix expression, and show that JunB, a member of the AP-1 family, is an activator of Nfix, which then leads to foetal myogenesis. Moreover, we demonstrate that their expression is regulated through the RhoA/ROCK axis, which maintains embryonic myogenesis. Specifically, RhoA and ROCK repress ERK kinase activity, which promotes JunB and Nfix expression. Notably, the role of ERK in the activation of Nfix is conserved postnatally in satellite cells, which represent the canonical myogenic stem cells of adult muscle. As lack of Nfix in muscular dystrophies rescues the dystrophic phenotype, the identification of this pathway provides an opportunity to pharmacologically target Nfix in muscular dystrophies. [ABSTRACT FROM AUTHOR]

Abstract: Malan syndrome is an overgrowth disorder described in a limited number of individuals. We aim to delineate the entity by studying a large group of affected individuals. We gathered data on 45 affected individuals with a molecularly confirmed diagnosis through an international collaboration and compared data to the 35 previously reported individuals. Results indicate that height is > 2 SDS in infancy and childhood but in only half of affected adults. Cardinal facial characteristics include long, triangular face, macrocephaly, prominent forehead, everted lower lip, and prominent chin. Intellectual disability is universally present, behaviorally anxiety is characteristic. Malan syndrome is caused by deletions or point mutations of NFIX clustered mostly in exon 2. There is no genotype‐phenotype correlation except for an increased risk for epilepsy with 19p13.2 microdeletions. Variants arose de novo, except in one family in which mother was mosaic. Variants causing Malan and Marshall‐Smith syndrome can be discerned by differences in the site of stop codon formation. We conclude that Malan syndrome has a well recognizable phenotype that usually can be discerned easily from Marshall–Smith syndrome but rarely there is some overlap. Differentiation from Sotos and Weaver syndrome can be made by clinical evaluation only. [ABSTRACT FROM AUTHOR]

During mouse spinal cord development, ventricular zone progenitor cells transition from producing neurons to producing glia at approximately embryonic day 11.5, a process known as the gliogenic switch. The transcription factors Nuclear Factor I (NFI) A and B initiate this developmental transition, but the contribution of a third NFI member, NFIX, remains unknown. Here, we reveal that ventricular zone progenitor cells within the spinal cord express NFIX after the onset of NFIA and NFIB expression, and after the gliogenic switch has occurred. Mice lacking NFIX exhibit normal neurogenesis within the spinal cord, and, while early astrocytic differentiation proceeds normally, aspects of terminal astrocytic differentiation are impaired. Finally, we report that, in the absence of Nfia or Nfib, there is a marked reduction in the spinal cord expression of NFIX, and that NFIB can transcriptionally activate Nfix expression in vitro . These data demonstrate that NFIX is part of the downstream transcriptional program through which NFIA and NFIB coordinate gliogenesis within the spinal cord. This hierarchical organisation of NFI protein expression and function during spinal cord gliogenesis reveals a previously unrecognised auto-regulatory mechanism within this gene family. [ABSTRACT FROM AUTHOR]

About 40% of lung cancer cases globally are diagnosed at the advanced stage. Lung cancer has a high mortality and overall survival in stage I disease is only 70%. This study was aimed at finding a candidate of transcription regulator that initiates the mechanism for metastasis by integrating computational and functional studies. The genes involved in lung cancer were retrieved using in silico software. 10 kb promoter sequences upstream were scanned for the master regulator. Transient transfection of shRNA NFIXs were conducted against A549 and NCI-H1299 cell lines. qRT-PCR and functional assays for cell proliferation, migration and invasion were carried out to validate the involvement of NFIX in metastasis. Genome-wide gene expression microarray using a HumanHT-12v4.0 Expression BeadChip Kit was performed to identify differentially expressed genes and construct a new regulatory network. The in silico analysis identified NFIX as a master regulator and is strongly associated with 17 genes involved in the migration and invasion pathways including IL6ST, TIMP1 and ITGB1. Silencing of NFIX showed reduced expression of IL6ST, TIMP1 and ITGB1 as well as the cellular proliferation, migration and invasion processes. The data was integrated with the in silico analyses to find the differentially expressed genes. Microarray analysis showed that 18 genes were expressed differentially in both cell lines after statistical analyses integration between t-test, LIMMA and ANOVA with Benjamini-Hochberg adjustment at p-value < 0.05. A transcriptional regulatory network was created using all 18 genes, the existing regulated genes including the new genes PTCH1, NFAT5 and GGCX that were found highly associated with NFIX, the master regulator of metastasis. This study suggests that NFIX is a promising target for therapeutic intervention that is expected to inhibit metastatic recurrence and improve survival rate.

About 40% of lung cancer cases globally are diagnosed at the advanced stage. Lung cancer has a high mortality and overall survival in stage I disease is only 70%. This study was aimed at finding a candidate of transcription regulator that initiates the mechanism for metastasis by integrating computational and functional studies. The genes involved in lung cancer were retrieved using in silico software. 10 kb promoter sequences upstream were scanned for the master regulator. Transient transfection of shRNA NFIXs were conducted against A549 and NCI-H1299 cell lines. qRT-PCR and functional assays for cell proliferation, migration and invasion were carried out to validate the involvement of NFIX in metastasis. Genome-wide gene expression microarray using a HumanHT-12v4.0 Expression BeadChip Kit was performed to identify differentially expressed genes and construct a new regulatory network. The in silico analysis identified NFIX as a master regulator and is strongly associated with 17 genes involved in the migration and invasion pathways including IL6ST, TIMP1 and ITGB1. Silencing of NFIX showed reduced expression of IL6ST, TIMP1 and ITGB1 as well as the cellular proliferation, migration and invasion processes. The data was integrated with the in silico analyses to find the differentially expressed genes. Microarray analysis showed that 18 genes were expressed differentially in both cell lines after statistical analyses integration between t-test, LIMMA and ANOVA with Benjamini-Hochberg adjustment at p-value < 0.05. A transcriptional regulatory network was created using all 18 genes, the existing regulated genes including the new genes PTCH1, NFAT5 and GGCX that were found highly associated with NFIX, the master regulator of metastasis. This study suggests that NFIX is a promising target for therapeutic intervention that is expected to inhibit metastatic recurrence and improve survival rate. [ABSTRACT FROM AUTHOR]

The nuclear factor I (NFI) family of transcription factors plays an important role in the development of the cerebral cortex in humans and mice. Disruption of nuclear factor IA (NFIA), nuclear factor IB (NFIB), or nuclear factor IX (NFIX) results in abnormal development of the corpus callosum, lateral ventricles, and hippocampus. However, the expression or function of these genes has not been examined in detail in the adult brain, and the cell type-specific expression of NFIA, NFIB, and NFIX is currently unknown. Here, we demonstrate that the expression of each NFI protein shows a distinct laminar pattern in the adult mouse neocortex and that their cell type-specific expression differs depending on the family member. NFIA expression was more frequently observed in astrocytes and oligodendroglia, whereas NFIB expression was predominantly localized to astrocytes and neurons. NFIX expression was most commonly observed in neurons. The NFI proteins were equally distributed within microglia, and the ependymal cells lining the ventricles of the brain expressed all three proteins. In the hippocampus, the NFI proteins were expressed during all stages of neural stem cell differentiation in the dentate gyrus, with higher expression intensity in neuroblast cells as compared to quiescent stem cells and mature granule neurons. These findings suggest that the NFI proteins may play distinct roles in cell lineage specification or maintenance, and establish the basis for further investigation of their function in the adult brain and their emerging role in disease. [ABSTRACT FROM AUTHOR]

Transcription factors from the nuclear factor one (NFI) family have been shown to play a central role in regulating neural progenitor cell differentiation within the embryonic and post-natal brain. NFIA and NFIB, for instance, promote the differentiation and functional maturation of granule neurons within the cerebellum. Mice lacking Nfix exhibit delays in the development of neuronal and glial lineages within the cerebellum, but the cell-type-specific expression of this transcription factor remains undefined. Here, we examined the expression of NFIX, together with various cell-type-specific markers, within the developing and adult cerebellum using both chromogenic immunohistochemistry and co-immunofluorescence labelling and confocal microscopy. In embryos, NFIX was expressed by progenitor cells within the rhombic lip and ventricular zone. After birth, progenitor cells within the external granule layer, as well as migrating and mature granule neurons, expressed NFIX. Within the adult cerebellum, NFIX displayed a broad expression profile, and was evident within granule cells, Bergmann glia, and interneurons, but not within Purkinje neurons. Furthermore, transcriptomic profiling of cerebellar granule neuron progenitor cells showed that multiple splice variants of Nfix are expressed within this germinal zone of the post-natal brain. Collectively, these data suggest that NFIX plays a role in regulating progenitor cell biology within the embryonic and post-natal cerebellum, as well as an ongoing role within multiple neuronal and glial populations within the adult cerebellum. [ABSTRACT FROM AUTHOR]

Introduction: Sotos Syndrome (SS, OMIM#117550) is a heterogeneous genetic condition, recognized by three main clinical features present in most cases: overgrowth with macrocephaly, typical facial appearance and different degrees of intellectual disability. Three different types are described caused by variants or deletions/duplications in NSD1, NFIX and APC2 genes. We aimed to describe a cohort of pediatric patients reporting the typical and unexpected findings in order to expand the phenotype of this syndrome and trying to find genotype-phenotype correlations., Methods: In our referral center, we collected and analyzed clinical and genetic data of 31-patients cohort diagnosed with SS., Results: All of them presented with overgrowth, typical dysmorphic features and different degree of developmental delay. Although structural cardiac defects have been reported in SS, non-structural diseases such as pericarditis were outstanding in our cohort. Moreover, we described here novel oncological malignancies not previously linked to SS such as splenic hamartoma, retinal melanocytoma and acute lymphocytic leukemia. Finally, five patients suffered from recurrent onychocryptosis that required surgical procedures, as an unreported prevalent medical condition., Discussion: This is the first study focusing on multiple atypical symptoms in SS at the time that revisits the spectrum of clinical and molecular basis of this heterogeneous entity trying to unravel a genotype-phenotype correlation., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (© 2023 Lourdes, Mario, Didac, Mercè, Loreto, Leticia, Lucia, Martínez-Monseny and Mercedes.)

During forebrain development, radial glia generate neurons through the production of intermediate progenitor cells (IPCs). The production of IPCs is a central tenet underlying the generation of the appropriate number of cortical neurons, but the transcriptional logic underpinning this process remains poorly defined. Here, we examined IPC production using mice lacking the transcription factor nuclear factor I/X (Nfix). We show that Nfix deficiency delays IPC production and prolongs the neurogenic window, resulting in an increased number of neurons in the postnatal forebrain. Loss of additional Nfi alleles (Nfib) resulted in a severe delay in IPC generation while, conversely, overexpression of NFIX led to precocious IPC generation. Mechanistically, analyses of microarray and ChIP-seq datasets, coupled with the investigation of spindle orientation during radial glial cell division, revealed that NFIX promotes the generation of IPCs via the transcriptional upregulation of inscuteable (Insc). These data thereby provide novel insights into the mechanisms controlling the timely transition of radial glia into IPCs during forebrain development. [ABSTRACT FROM AUTHOR]