T-bet Research Articles

Analysis of associations of hypertension with 16 genetic markers selected according to genome-wide studies

The multifactorial genesis of hypertension (HTN) enforced the investigation of genetically determined component of its etiopathogenesis in various populations.The aim of present work is to assess the associations between blood pressure (BP) and HTN and polymorphism of a number of genetic markers identified according to GWAS data, in a case-control study based on Siberian population cohort. Design and methods. Design of the work—case-control study in the groups aged 45–69 years old based on a caucasoid population cohort (Novosibirsk). The group of cases included HTN subjects with established diagnosis of HTN under the age of 50 (n = 346)). The control included subjects matched by sex and age to cases, and having at least 2 examinations (6 months apart) with BP levels not exceeding “normal” BP by ESH, 2018 (n = 168). A total of 514 people were included in the analysis. We used standardized epidemiological methods to assess HTN and cardiovascular diseases. Single nucleotide polymorphisms (SNPs) were tested using real-time PCR (ABI 7900HT). The analysis included 16 markers identified in GWAS studies (rs11646213, rs17367504, rs11191548, rs12946454, rs16998073, rs1530440, rs653178, rs1378942, rs1004467, rs381815, rs2681492, rs2681472, rs3184504, rs2384550, rs6495122, rs6773957).Results. For the polymorphism rs1378942 of cytoplasmic tyrosine kinase gene (CSK), in a multivariable-adjusted logistic regression, the carriers of the AC/CC vs. AA genotypes had odds ratio (OR) of HTN of 1,51 (p = 0,043) independent of age and sex; this excess risk was partly explained by the impact of body mass index (BMI). With respect to the quantitative phenotype, women carrying the AA genotype had diastolic BP (DBP) value 5 mm Hg lower than carriers of AC/CC genotypes (p = 0,026). In a multivariable-adjusted analysis, the polymorphism rs653178 of ataxin 2 gene (ATXN2) was associated with HTN independent of age and BMI (СС vs ТТ/ТС; OR = 0,61; p = 0,022); this relationship was realized due to the contribution of men (p = 0,027). With respect to the quantitative phenotype, in the multivariable analysis, the carriers of СС genotype had DBP value lower than those with ТТ/ТС (p = 0,022) independent of age and BMI, and due to the contribution of men. In a multivariableadjusted analysis, the polymorphism rs6773957 of adiponectin gene (ADIPOQ) was associated with HTN in women regardless of age and BMI (GG v. AA/AG; OR = 0,29; p = 0,001). In unadjusted analysis, we found the association between polymorphism rs2384550 of T box transcription factor gene (TBX3) and the level of systolic BP (SBP) in men (p = 0,043); when comparing homozygous groups, the level of SBP was significantly higher among carriers of the AA genotype versus GG (p = 0,013), but this association was attenuated to insignificant in in a multivariate analysis.Conclusions. In a case-control study based on Siberian population sample, we found the associations between qualitative and quantitative phenotypes of BP/HTN and polymorphism of 4 SNPs (CSK, ATXN2, ADIPOQ, TBX3 genes). Our data replicated a number of positive results obtained in genomewide studies, and we obtained the evidence of new associations not previously convincingly shown, and of the context dependency of the association between HTN and a number of molecular markers.

Loss of cytoplasmic FMR1-interacting protein 2 (CYFIP2) induces browning in 3T3-L1 adipocytes via repression of GABA-BR and activation of mTORC1.

Obesity and related metabolic disorders are epidemic diseases. Promoting thermogenesis and a functional increase in the browning of white adipocytes may counteract obesity. On the other hand, the molecular mechanism that regulates brown and beige fat-mediated thermogenesis is unclear. This article reports a molecular network led by cytoplasmic FMR1-interacting protein 2 (CYFIP2) that negatively regulates adipocyte browning in white adipocytes. Although the function of CYFIP2 in Fragile X Syndrome (FXS) and autism have been reported, its physiological roles in adipocytes remain elusive. Therefore, this study examined the physiological consequences of its deprivation in cultured 3T3-L1 white adipocytes using loss-of-function studies. Combined real-time quantitative reverse-transcription polymerase chain reaction and immunoblot analysis showed that the loss of CYFIP2 induces fat browning, as evidenced by the gene and protein expression levels of the brown fat-associated markers. A deficiency of CYFIP2 promoted mitochondrial biogenesis and significantly enhanced the expression of the core set beige fat-specific genes (Cd137, Cidea, Cited1, Tbx1, and Tmem26) and proteins (PGC-1α, PRDM16, and UCP1). In addition, a CYFIP2 deficiency promoted lipid catabolism and suppressed adipogenesis, lipogenesis, and autophagy. A mechanistic study showed that the loss of CYFIP2 induces browning in white adipocytes, independently via the activation of mTORC1 and suppression of the GABA-BR signaling pathway. The present data revealed a previously unidentified mechanism of CYFIP2 in the browning of white adipocytes and emphasized the potential of CYFIP2 as a pharmacotherapeutic target for treating obesity and other metabolic disorders.

Divergence of Tbx4 hindlimb enhancer HLEA underlies the hindlimb loss during cetacean evolution.

The cetacean hindlimb skeleton massively decreased to only vestigial limb elements as cetaceans evolved from land to aquatic lifestyles; however, the molecular mechanism underlying this major morphological transition remains unclear. In this study, four deletions and specific substitutions were detected in cetacean hindlimb enhancer A (HLEA), an enhancer that can regulate Tbx4 expression in hindlimb tissues to control hindlimb development. Transcriptional activation of HLEA was significantly weaker in bottlenose dolphin than mice, and this was found to be closely associated with cetacean-specific deletions. Furthermore, deletions in cetacean HLEA might disrupt HOX and PITX1 binding sites, which are required for enhancer activation. The ancestral state of these deletions was investigated, and all four specific deletions were found to have occurred after the species diverged from their common ancestor, suggesting that the deletion occurred recently, during a secondary aquatic adaptation. Taking these findings together, we suggest that cetacean-specific sequence changes reduced the Tbx4 gene expression pattern, and consequently drove the gradual loss of hindlimb in cetaceans.

Abstract P3-09-18: The association between genomic alterations and body mass index in patients with early breast cancer

Abstract Background: High body mass index (BMI) is an established risk factor for developing breast cancer (BC), especially estrogen receptor (ER)-positive, and also has been associated with adverse survival. Still, patients with BC are currently treated independently of their BMI given limited understandings of the association between BC biology and patient adiposity. In this study, using retrospective data retrieved from two large BC studies, we aimed to identify genomic alterations of primary BC that are associated with BMI in the most common histological BC subtype - invasive carcinoma of no special type (NST). Patients, Data and Methods: Clinicopathological and genomic alteration data were retrieved from two study cohorts: METABRIC (Pereira et al. 2016) and ICGC (Nik-Zainal et al. 2016), with BMI recorded at the time of diagnosis and represented as either a continuous variable or a categorical variable of three categories - lean, overweight and obese. Stratification according to ER and HER2 status resulted in two focused subgroups: NST ER+/HER2- (n=392) and NST ER-/HER2- (n=152). Mutations classified as oncogenic using a set of predefined criteria were used to determine gene-level mutation status. Copy number alteration (CNA) calls were distinguished into three event types: amplification, hemizygous deletion and homozygous deletion. We used multivariable Firth’s logistic regression models with the presence of a genomic alteration as the response variable, BMI as the predicting variable of interest, and data cohort (METABRIC vs ICGC), age group (≤50 vs >50) and tumor grade (I & II vs III) as covariates, to assess the associations between BMI and recurrent gene-level genomic alterations, including gene mutations and CNAs. In a similar manner, we performed multivariable linear regression analysis, adjusting for age and tumor grade, to evaluate the associations of BMI with mutational signatures (MS) and tumor mutational burden in the ICGC NST subsets where these data are available. Results: Considering BMI as a categorical variable, we observed in the NST ER+/HER2- subgroup that PIK3CA was significantly less frequently mutated in obese compared to lean patients (33% vs 46%, odds ratio (OR) = 0.57 (95% confidence interval = (0.33, 0.97)), p = .039), while PTEN and TBX3 showed an increased frequency in overweight (6% vs 1%, OR = 4.14 (1.1, 22.34), p = .034) and obese (8% vs 1%, OR = 7.41 (1.82, 70.65), p = .008) patients, respectively. Regression analyses with BMI as a continuous variable revealed an increased prevalence of mutations in CDH1 and TBX3 genes as BMI increases by 1kg/m2 (OR = 1.14 (1.05, 1.24), p = .002, and OR = 1.13 (1.04, 1.22), p = .005, respectively) in patients with NST ER+/HER2- BC. No associations between BMI and oncogenic mutations was observed in the NST ER-/HER2- subgroup. Interrogation of gene-level CNAs in both subgroups demonstrated differences according to BMI in the prevalence of CNAs affecting a number of genes, many of which are known or have been presented with evidence to be involved in regulation of or regulated by hallmark pathways of BC, such as the MAPK/ERK, JAK/STAT and Wnt/β-catenin signaling pathways. We report a strong positive association between the single-base substitution signature 1 (SBS1), an age-correlated MS, and both continuous (coefficient (coef) = 18.3 (7.7, 28.9), p < .001) and categorical BMI (obese vs lean, coef = 336.3 (187.9, 484.8), p < .001) in the ICGC NST ER+/HER2- subgroup. Conclusion: This exploratory retrospective study suggests that the genomic profiles of primary BC may differ according to BMI. Clinical implications of these differences, especially the decreased prevalence of PIK3CA mutations in obese patients in the context of alpelisib, warrant further investigation. These results however indicate that patient adiposity should be taken into account in the era of personalized medicine. Citation Format: Ha-Linh Nguyen, Tatjana Geukens, Marion Maetens, Karen Van Baelen, Maxim De Schepper, Sophia Leduc, Edoardo Isnaldi, Sam Aparicio, Ake Borg, Jane Brock, Annegien Broeks, Carlos Caldas, Andrew Green, Hazem Khout, Eyfjörð Jórunn, Stian Knappskog, Savitri Krishnamurthy, Sunil Lakhani, Anita Langerod, John WM Martens, Leigh Murphy, Serena Nik-Zainal, Colin Purdie, Emad Rakha, Andrea Richardson, Anne Salomon, Peter Simpson, Christos Sotiriou, Paul Span, Benita Kiat-Tee Tan, Alastair Thompson, Stefania Tommasi, Marc Van de Vijver, Steven Van Laere, Alain Viari, Giuseppe Floris, Elia Biganzoli, François Richard, Christine Desmedt. The association between genomic alterations and body mass index in patients with early breast cancer [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P3-09-18.

Generation of a CRISPR/Cas edited human induced pluripotent stem cell line DHMi005-A-1 carrying a patient-specific disease-causing point mutation in the TBX5 gene

A number of mutations in the human TBX5 gene have been described which cause Holt-Oram syndrome, a severe congenital disease associated with abnormalities in heart and upper limb development. We have used a prime-editing approach to introduce a patient-specific disease-causing TBX5 mutation (c.920_C > A) into an induced pluripotent stem cell (iPSC) line from a healthy donor. The resulting iPSC line provides a powerful tool to identify and analyze the biological and molecular impact of this specific TBX5 mutation in comparison to the isogenic control iPSC line during cardiac development.

DNA Methylation Levels of the TBX5 Gene Promoter Are Associated with Congenital Septal Defects in Mexican Paediatric Patients.

Simple SummaryOne of the most important health problems in the paediatric population, due to its prevalence worldwide, is the occurrence of congenital heart defects. The integration of multidisciplinary approaches to clinical diagnosis will allow us to detect this type of problem in patients in a timely way. The TBX5 gene has an important participation in cardiogenesis. Therefore, we performed a case-control study, that involved the DNA methylation assessment of the TBX5 gene promoter region in patients that were non-syndromic with congenital septal defects, to identify an epigenetic marker. Moreover, we evaluated the exposure to environmental factors during pregnancy in mothers of these patients. Additionally, we used bioinformatic tools to identify transcription factors binding to the TBX5 gene region of interest and to learn their possible functional effect. These results could help to clarify the mechanisms that regulate these pathologies and establish risk markers, which can be used in future in clinical practice.The TBX5 gene regulates morphological changes during heart development, and it has been associated with epigenetic abnormalities observed in congenital heart defects (CHD). The aim of this research was to evaluate the association between DNA methylation levels of the TBX5 gene promoter and congenital septal defects. DNA methylation levels of six CpG sites in the TBX5 gene promoter were evaluated using pyrosequencing analysis in 35 patients with congenital septal defects and 48 controls. Average methylation levels were higher in individuals with congenital septal defects than in the controls (p < 0.004). In five CpG sites, we also found higher methylation levels in patients than in the controls (p < 0.05). High methylation levels were associated with congenital septal defects (OR = 3.91; 95% CI = 1.02–14.8; p = 0.045). The analysis of Receiver Operating Characteristic (ROC) showed that the methylation levels of the TBX5 gene could be used as a risk marker for congenital septal defects (AUC = 0.68, 95% CI = 0.56–0.80; p = 0.004). Finally, an analysis of environmental factors indicated that maternal infections increased the risk (OR = 2.90; 95% CI = 1.01–8.33; p = 0.048) of congenital septal defects. Our data suggest that a high DNA methylation of the TBX5 gene could be associated with congenital septal defects.

Establishment of a patient-specific induced pluripotent stem cell line DHMi004-A from a male Holt-Oram syndrome patient with verified TBX5 mutation.

The Holt-Oram syndrome (HOS) is a rare autosomal dominant disorder, mostly based on mutations in the TBX5 gene. Patients show malformation of at least one upper limb along with congenital heart defects. The established induced pluripotent stem cell (iPSC) line was generated from a patient displaying pronounced and typical features of HOS and carrying a single-nucleotide change c.920_C>A leading to an amino acid change from proline to threonine at amino acid position 85, which appeared de novo. Adipose fibroblasts from the patient were reprogrammed using Sendai virus. Pluripotency of the iPSCs was fully demonstrated.

Human papillomavirus and herpes simplex virus infections in patients with mucocutaneous lesions can be linked to host TBX-21 gene polymorphism

Background and objective: Human papillomavirus (HPV) and herpes simplex-2 (HSV-2) are the common cause of genital lesions in women. The variation in host genetic makeup can determine the consequence of a viral infection in that host. T-bet gene polymorphism has been associated with the incidence of several types of infections. This study investigates the impact of T-bet polymorphism on the incidence of HPV and HSV in genital lesions. Methods: 215 women, including 71 HPV infected, 72 HSV-2 infected, and 72 controls were enrolled. Viral genotyping was done on genital swab samples using Realtime PCR. In all participants, the extracted DNA from blood was tested for T-bet gene variation at Ch17.rs17244587 G&gt;A site using ARMS-PCR. ELISA was done to participants sera to detect HSV-1 IgM. Results: Genotyping of HPV infection revealed that (73.0%) were at low risk. Most individuals (72.5%) were homozygous GG, while (20.9%) were heterozygous AG and (6.5%) were homozygous AA, of which 92.8% were HSV-2 infected patients. None of 18 (8.4%) HSV-1-IgM positive women were homozygous AA. Conclusion: T-bet gene allele A appears to be linked with more incidence of HSV-2 in genital lesions, but such influence was not observed for HPV genotypes and HSV-1. Keywords: HPV genotypes; HSV-2 infection; Genital lesion; T-bet polymorphism.

The T-box gene optomotor-blind organizes proximodistal leg patterning in the beetle Tribolium castaneum by repressing dorsal Dpp pathway activity

Leg axis formation in Drosophila is organized by Wingless (Wg) and Decapentaplegic (Dpp) that control a number of downstream factors to pattern the dorsoventral (DV) and proximodistal (PD) axis. The T-box genes are important downstream factors mainly involved in dorsoventral leg axis formation. The ventral side is specified by H15 and midline, whereas optomotor-blind (omb) and Dorsocross (Doc1) are factors to specify dorsal cell fates. We show here that omb also organizes PD leg axis patterning in the beetle Tribolium castaneum. In the legs, Tc-omb is expressed along the dorsal side and represses ventral factors like wg and H15. Intriguingly, removing Tc-omb function leads to the activation of the Dpp pathway along the dorsal side of the legs, thus mimicking normal dpp expression in Drosophila. Dpp activity along the dorsal side leads to altered expression of proximal-distal patterning genes such as Distal-less (Dll) and dachshund (dac). Our results indicate a cell-autonomous activation of Dll and repression of dac by dpp. These findings are compatible with the cross-regulatory “cascade model“ of proximal-distal leg imaginal disc patterning of Drosophila.

Role of T-box genes in cancer, epithelial-mesenchymal transition, and cancer stem cells.

Sharing a common DNA binding motif called T-box, transcription factor T-box gene family controls embryonic development and is also involved in cancer progression and metastasis. Cancer metastasis shows therapy resistance and involves complex processes. Among them, epithelial-mesenchymal transition (EMT) triggers cancer cell invasiveness and the acquisition of stemness of cancer cells, called cancer stem cells (CSCs). CSCs are a small fraction of tumor bulk and are capable of self-renewal and tumorsphere formation. Recent progress has highlighted the critical roles of T-box genes in cancer progression, EMT, and CSC function, and such regulatory functions of T-box genes have emerged as potential therapeutic candidates for cancer. Herein we summarize the current understanding of the regulatory mechanisms of T-box genes in cancer, EMT, and CSCs, and discuss the implications of targeting T-box genes as anticancer therapeutics.

Prednisone stimulates white adipocyte browning via β3-AR/p38 MAPK/ERK signaling pathway

AimsPrednisone is a corticosteroid-derived drug which is widely used for its role in immunosuppression and treatment of lung disorders. The current study reports, for the first time, the critical role of prednisone in the induction of white fat browning, thereby promoting thermogenic effect in cultured white adipocytes. Main methodsThe fat-browning activity of prednisone was evaluated in 3T3-L1 cells by quantitative real-time PCR, immunoblot analysis, immunofluorescence, and molecular docking techniques. Key findingsExposure to prednisone stimulated browning in 3T3-L1 white adipocytes by increasing the expressions of core fat browning marker proteins (UCP1, PGC-1α and PRDM16) as well as beige-specific genes (Cd137, Cidea, Cited1, and Tbx1) via ATF2 and CREB activation mediated by p38 MAPK and ERK signaling, respectively. Prednisone exposure also resulted in the robust activation of lipolytic and fatty acid oxidation marker proteins, thereby increasing mitochondrial biogenesis. In addition, prednisone treatment resulted in reduced expression levels of adipogenic transcription factors while elevating SIRT1, as well as attenuation of lipogenesis and lipid droplets formation. Furthermore, molecular docking and mechanistic studies demonstrated the recruitment of beige fat by prednisone via the β3-AR/p38 MAPK/ERK signaling pathway. SignificanceTaken together, these results indicate the unique role of prednisone as a fat-browning stimulant, and demonstrate its therapeutic potential in the treatment of obesity by enhancing thermogenesis.

PH Professional Network: Genetic Counseling and Pulmonary Arterial Hypertension

PH Professional Network: Genetic Counseling and Pulmonary Arterial Hypertension

Identification of deleterious single nucleotide polymorphism (SNP)s in the human TBX5 gene & prediction of their structural & functional consequences: An in silico approach

T-box transcription factor 5 gene (TBX5) encodes the transcription factor TBX5, which plays a crucial role in the development of heart and upper limbs. Damaging single nucleotide variants in this gene alter the protein structure, disturb the functions of TBX5, and ultimately cause Holt-Oram Syndrome (HOS). By analyzing the available single nucleotide polymorphism information in the dbSNP database, this study was designed to identify the most deleterious TBX5 SNPs through insilico approaches and predict their structural and functional consequences.Fifty-eight missense substitutions were found damaging by sequence homology-based tools: SIFT and PROVEAN, and structure homology-based tool PolyPhen-2. Various disease association meta-predictors further scrutinized these SNPs. Additionally, conservation profile of the amino acid residues, their surface accessibility, stability, and structural integrity of the native protein upon mutations were assessed. From these analyses, finally 5 SNPs were detected as the most damaging ones: [rs1565941579 (P85S), rs1269970792 (W121R), rs772248871 (V153D), rs769113870 (E208D), and rs1318021626 (I222N)]. Analyses of stop-lost, nonsense, UTR, and splice site SNPs were also conducted.Through integrative bioinformatics analyses, this study has identified the SNPs that are deleterious to the TBX5 protein structure and have the potential to cause HOS. Further wet-lab experiments can validate these findings.

Establishment of the TBX-code reveals aberrantly activated T-box gene TBX3 in Hodgkin lymphoma.

T-box genes encode transcription factors which control basic processes in development of several tissues including cell differentiation in the hematopoietic system. Here, we analyzed the physiological activities of all 17 human T-box genes in early hematopoiesis and in lymphopoiesis including developing and mature B-cells, T-cells, natural killer (NK)-cells and innate lymphoid cells. The resultant expression pattern comprised six genes, namely EOMES, MGA, TBX1, TBX10, TBX19 and TBX21. We termed this gene signature TBX-code which enables discrimination of normal and aberrant activities of T-box genes in lymphoid malignancies. Accordingly, expression analysis of T-box genes in Hodgkin lymphoma (HL) patients using a public profiling dataset revealed overexpression of EOMES, TBX1, TBX2, TBX3, TBX10, TBX19, TBX21 and TBXT while MGA showed aberrant downregulation. Analysis of T-cell acute lymphoid leukemia patients indicated aberrant overexpression of six T-box genes while no deregulated T-box genes were detected in anaplastic large cell lymphoma patients. As a paradigm we focused on TBX3 which was ectopically activated in about 6% of HL patients analyzed. Normally, TBX3 is expressed in tissues like lung, adrenal gland and retina but not in hematopoiesis. HL cell line KM-H2 expressed enhanced TBX3 levels and was used as an in vitro model to identify upstream regulators and downstream targets in this malignancy. Genomic studies of this cell line showed focal amplification of the TBX3 locus at 12q24 which may underlie its aberrant expression. In addition, promoter analysis and comparative expression profiling of HL cell lines followed by knockdown experiments revealed overexpressed transcription factors E2F4 and FOXC1 and chromatin modulator KDM2B as functional activators. Furthermore, we identified repressed target genes of TBX3 in HL including CDKN2A, NFKBIB and CD19, indicating its respective oncogenic function in proliferation, NFkB-signaling and B-cell differentiation. Taken together, we have revealed a lymphoid TBX-code and used it to identify an aberrant network around deregulated T-box gene TBX3 in HL which promotes hallmark aberrations of this disease. These findings provide a framework for future studies to evaluate deregulated T-box genes in lymphoid malignancies.

Analysis of related phenotype of prenatal cases with copy number variations in various region of 22q11.2

To analyze the prenatal ultrasound phenotypes of copy number variations (CNVs) in different regions of 22q11.2, their parental original, and pregnancy outcome. Prenatal phenotypes of 25 cases with CNVs of the 22q11.2 region detected by chromosomal microarray analysis (CMA) was reviewed, which including There were 13 deletions and 12 duplications. Multiplex ligation-dependent probe amplification(MLPA) was carried out to determine their parental origin. All cases were followed up for their pregnancy outcome and postnatal growth. Among the 25 cases, the ultrasound phenotypes of those involving the TBX1 gene were mostly cardiovascular system abnormalities, the ultrasound phenotypes of cases involving CRKL gene are mostly polycystic renal dysplasia. The ultrasound phenotypes of CNVs in the distal region (involving the SMARCB1 gene) are nervous system abnormalities. 12 cases (48%) of CNVs were de novo in origin. Five cases were lost during follow-up,12 had opted to terminate the pregnancy, 8 fetuses were born,7 with normal growth and development, 1 case with CNV in A-D region was abnormal.Prenatal ultrasound showed abnormalities in the cardiovascular system consistent with postnatal ultrasound, in addition with dysphagia and growth retardation. Prenatal phenotypes of the 22q11.2 region CNVs are diverse, which may be related to gene function. NT thickening may be used as an early ultrasound finding of proximal 22q11.2 CNV. More research is still required to delineate the nature of CNVs and gene function, so as to facilitate genetic counseling.

Antifibrotic factor KLF4 is repressed by the miR-10/TFAP2A/TBX5 axis in dermal fibroblasts: insights from twins discordant for systemic sclerosis

ObjectivesSystemic sclerosis (SSc) is a complex disease of unknown aetiology in which inflammation and fibrosis lead to multiple organ damage. There is currently no effective therapy that can halt the...

Tbx5a and Tbx5b paralogues act in combination to control separate vectors of migration in the fin field of zebrafish

The T-box containing family member, TBX5, has been shown to play important functional roles in the pectoral appendages of a variety of vertebrate species. While a single TBX5 gene exists in all tetrapods studied to date, the zebrafish genome retains two paralogues, designated as tbx5a and tbx5b, resulting from a whole genome duplication in the teleost lineage. Zebrafish deficient in tbx5a lack pectoral fin buds, whereas zebrafish deficient in tbx5b exhibit misshapen pectoral fins, showing that both paralogues function in fin development. The mesenchymal cells of the limb/fin bud are derived from the Lateral Plate Mesoderm (LPM). Previous fate mapping work in zebrafish has shown that wildtype (wt) fin field cells are initially located adjacent to somites (s)1–4. The wt fin field cells migrate in opposing diagonal directions placing the limb bud between s2-3 and lateral to the main body. To better characterize tbx5 paralogue functions in zebrafish, time-lapse analyses of the migrations of fin bud precursors under conditions of tbx5a knock-down, tbx5b knock-down and double-knock-down were performed. Our data suggest that zebrafish tbx5a and tbx5b have functionally separated migration direction vectors, that when combined recapitulate the migration of the wt fin field. We and others have shown that loss of Tbx5a function abolishes an fgf24 signaling cue resulting in fin field cells failing to converge in an Antero-Posterior (AP) direction and migrating only in a mediolateral (ML) direction. We show here that loss of Tbx5b function affects initial ML directed movements so that fin field cells fail to migrate laterally but continue to converge along the AP axis. Furthermore, fin field cells in the double Tbx5a/Tbx5b knock-down zebrafish do not engage in directed migrations along either the ML or AP axis. Therefore, these two paralogues may be acting to instruct separate vectors of fin field migration in order to direct proper fin bud formation.

Genetic background in pediatric pulmonary arterial hypertension. Should we change the current recommendations for genetic testing?

Abstract Background Pulmonary arterial hypertension (PAH) is a rare and severe disease, genetically predisposed in a high proportion of patients. PAH is subclassified in different subtypes depending on the underlying condition. Gene variants are more frequent among heritable or idiopathic forms. Nevertheless, pathogenic variants have been described across the entire spectrum of this disease. Evidence regarding genetics in pediatric PAH is scarce [1]. Purpose Our aim is to describe the prevalence of significant gene mutations among a pediatric PAH cohort and to define specific data in the different subtypes. Methods Samples for genetic studies were obtained from blood tests of patients included in the Spanish National Registry of Pediatric Pulmonary Hypertension (REHIPED). Guardians signed informed consent before the inclusion in the study. Qualitative variables were compared by Chi-square test. Quantitative variables were assessed by Kruskal-Wallis, considering the asymmetric distribution of variables. STATA 14.0 was used for analyses. Results Sixty four patients were included between 2011 and 2021. Median age of the entire sample was 7.1 years (2.0–12.6) and 42.2% of them were male. There were significant differences in the age at diagnosis and race between the different included groups (table). Pathogenic or likely pathogenic variants were more frequent in familial pulmonary venooclusive disease (PVOD) and familial PAH cases. A similar percentage of mutations were found in idiopathic cases and in PAH associated with congenital heart disease (Figure). Gene variants in the gene encoding the bone morphogenetic protein receptor type 2 (BMPR2) were the most frequent mutations in the PAH familial cohort and there was also the most frequent finding in congenital heart disease and sporadic PAH, in conjunction with the TBX4 gene. Homozygous or compound heterozygous EIF2AK4 (eukaryotic translation initiation factor 2 a kinase 4) mutations were found in all the patients diagnosed with PVOD. Heritable PAH and PVOD cases were diagnosed more frequently after family screening. Conclusions This study shows a comparable proportion of pathogenic-likely pathogenic gene mutations in patients diagnosed of pulmonary arterial hypertension associated with congenital heart disease and idiopathic cases, with similar distribution of specific genes. BMPR2 and TBX 4 were the most frequent gene variants in this pediatric PAH population. BMPR2 and EIF2AK4 are the most common mutations in familial PAH and PVOD subtypes, respectively. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): ACU holds a Rio Hortega Grant from the Instituto de Salud Carlos III, Spanish Ministry of Science and Innovation.JAT and NG hold grants from FEDER (Federaciόn Española de Enfermedades Raras) and from the FCHP. Table 1. Characteristics of PAH subtypesFigure 1. PAH and ACMG classification.

The influence of the &lt;i&gt;TBX6&lt;/i&gt; gene on the development of congenital spinal deformities in children

BACKGROUND: Congenital deformities of the spine are a group of serious congenital defects of the vertebrae, which can manifest themselves in the clinical picture as an isolated pathology of the axial musculoskeletal system, and are associated with congenital defects of internal organs and other systems. Recently, the TBX6 gene has been identified as the genetic cause of congenital scoliosis in about 11% of cases. This subtype of scoliosis is classified as TBX6-associated congenital scoliosis. The TBX6-associated congenital scoliosis phenotype is characterized by butterfly-shaped vertebrae and hemivertebrae in the lower thoracic and lumbar regions without pronounced malformations of the spinal cord.&#x0D; AIM: Our aim is to study and evaluate data from foreign and domestic scientific publications devoted to the study of the candidate gene for congenital scoliosis TBX6.&#x0D; MATERIALS AND METHODS: The following databases of scientific publications such as PubMed, Cochrane Library, Web of Science, SCOPUS, MEDLINE, e-Library, Cyberleninka were used to write this review. The inclusion criteria were systematic reviews, meta-analyses, multicenter studies, controlled cohort studies, uncontrolled cohort studies of patients with congenital spinal deformities. The exclusion criteria were clinical cases, observations, conference proceedings, congenital scoliosis in genetic syndromes, congenital scoliosis associated with defects of the nervous system.&#x0D; RESULTS: In order to achieve this goal, 70 scientific publications were studied relating to the data analysis of the candidate gene for congenital scoliosis TBX6. Among 49 publications that were identified, 2 were domestics, and the rest were foreign publications. These studies provided information on the molecular analysis of genes that cause congenital spinal deformities in humans and animals.&#x0D; CONCLUSIONS: An analysis of the published research work on this topic indicates the presence of a significant effect of mutations in the TBX6 gene, leading to the appearance of congenital scoliosis.&#x0D; Advances in elucidating the genetic contribution to the development of congenital spinal deformities and the molecular etiology of clinical phenotypes may uncover the opportunities for further refinement of the classification of signs of congenital scoliosis in accordance with the underlying genetic etiology.

Identification and Validation of a Seizure-Free-Related Gene Signature for Predicting Poor Prognosis in Lower-Grade Gliomas.

BackgroundLower-grade gliomas (LGGs) patients presented seizure-free have a worse survival than those presented with seizures. However, the current knowledge on its potential value in LGGs remains scarce.PurposeThis study aimed to identify a novel gene signature associated with seizures-free for predicting poor prognosis for LGGs patients.Materials and MethodsThe RNA expression and clinical information of LGGs patients were downloaded from the Cancer Genome Atlas database. Differentially expressed genes (DEGs) were screened out between LGGs patients presented seizures-free and seizures. The novel gene signature was constructed by Lasso and multivariate regression analyses for predicting prognosis in LGGs. Its prognostic value was assessed and validated by Kaplan–Meier analyses and receiver operating characteristic (ROC) curves. Multivariate regression analysis was applied to identify the independent prognostic value of the gene signature. Furthermore, bioinformatics analysis was performed to elucidate the molecular mechanisms.ResultsA total of 253 DEGs were screened out between LGG patients presented with seizures and free of seizures. A 5-gene signature (HIST1H4F, HORMAD2, LILRA3, PRSS33, and TBX20 genes) was constructed from these 253 DEGs. Kaplan–Meier analyses and ROC curves assessed and validated the good performance of the 5-gene signature in differentiating and predicting prognosis of high- and low-risk patients. Multivariate regression analysis determined the independent prognostic value of the 5-gene signature. According to bioinformatics analysis, DEGs were mainly enriched in biological processes related to positive regulation of transcription from RNA polymerase II promoter, G-protein coupled receptor signaling pathway, and pathways of cytokine–cytokine receptor interaction, chemokine signaling pathway.ConclusionOur findings suggested that the 5-gene signature might serve as a potential prognostic biomarker and provide guidance for the personalized LGGs management.