RESUMEN
How the dorsal-ventral axis of the vertebrate jaw, particularly the position of tooth initiation site, is established remains a critical and unresolved question. Tooth development starts with the formation of the dental lamina, a localized thickened strip within the maxillary and mandibular epithelium. To identify transcriptional regulatory networks (TRN) controlling the specification of dental lamina from the naïve mandibular epithelium, we utilized Laser Microdissection coupled low-input RNA-seq (LMD-RNA-seq) to profile gene expression of different domains of the mandibular epithelium along the dorsal-ventral axis. We comprehensively identified transcription factors (TFs) and signaling pathways that are differentially expressed along mandibular epithelial domains (including the dental lamina). Specifically, we found that the TFs Sox2 and Tfap2 (Tfap2a/Tfap2b) formed complimentary expression domains along the dorsal-ventral axis of the mandibular epithelium. Interestingly, both classic and novel dental lamina specific TFs-such as Pitx2, Ascl5 and Zfp536-were found to localize near the Sox2:Tfap2a/Tfap2b interface. To explore the functional significance of these domain specific TFs, we next examined loss-of-function mouse models of these domain specific TFs, including the dental lamina specific TF, Pitx2, and the ventral surface ectoderm specific TFs Tfap2a and Tfap2b. We found that disruption of domain specific TFs leads to an upregulation and expansion of the alternative domain's TRN. The importance of this cross-repression is evident by the ectopic expansion of Pitx2 and Sox2 positive dental lamina structure in Tfap2a/Tfap2b ectodermal double knockouts and the emergence of an ectopic tooth in the ventral surface ectoderm. Finally, we uncovered an unappreciated interface of mesenchymal SHH and WNT signaling pathways, at the site of tooth initiation, that were established by the epithelial domain specific TFs including Pitx2 and Tfap2a/Tfap2b. These results uncover a previously unknown molecular mechanism involving cross-repression of domain specific TFs including Pitx2 and Tfap2a/Tfap2b in patterning the dorsal-ventral axis of the mouse mandible, specifically the regulation of tooth initiation site.
Asunto(s)
Regulación del Desarrollo de la Expresión Génica , Proteína del Homeodomínio PITX2 , Proteínas de Homeodominio , Mandíbula , Factores de Transcripción SOXB1 , Factor de Transcripción AP-2 , Factores de Transcripción , Animales , Ratones , Linaje de la Célula/genética , Epitelio/metabolismo , Redes Reguladoras de Genes , Proteínas de Homeodominio/genética , Proteínas de Homeodominio/metabolismo , Mandíbula/metabolismo , Odontogénesis/genética , Transducción de Señal , Factores de Transcripción SOXB1/metabolismo , Factores de Transcripción SOXB1/genética , Diente/metabolismo , Diente/crecimiento & desarrollo , Diente/embriología , Factor de Transcripción AP-2/metabolismo , Factor de Transcripción AP-2/genética , Factores de Transcripción/genética , Factores de Transcripción/metabolismoAsunto(s)
Fibrilación Atrial , Mutación con Ganancia de Función , Proteína del Homeodomínio PITX2 , Proteínas de Homeodominio , Factores de Transcripción , Fibrilación Atrial/genética , Fibrilación Atrial/fisiopatología , Fibrilación Atrial/diagnóstico , Humanos , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Proteínas de Homeodominio/genética , Mitocondrias Cardíacas/genética , Mitocondrias Cardíacas/metabolismo , Mitocondrias Cardíacas/patología , Animales , Potencial de la Membrana Mitocondrial/genética , Predisposición Genética a la Enfermedad , Miocitos Cardíacos/metabolismo , Miocitos Cardíacos/patología , FenotipoRESUMEN
Gene regulatory networks that act upstream of skeletal muscle fate determinants are distinct in different anatomical locations. Despite recent efforts, a clear understanding of the cascade of events underlying the emergence and maintenance of the stem cell pool in specific muscle groups remains unresolved and debated. Here, we invalidated Pitx2 with multiple Cre-driver mice prenatally, postnatally, and during lineage progression. We showed that this gene becomes progressively dispensable for specification and maintenance of the muscle stem (MuSC) cell pool in extraocular muscles (EOMs) despite being, together with Myf5, a major upstream regulator during early development. Moreover, constitutive inactivation of Pax7 postnatally led to a greater loss of MuSCs in the EOMs compared to the limb. Thus, we propose a relay between Pitx2, Myf5 and Pax7 for EOM stem cell maintenance. We demonstrate also that MuSCs in the EOMs adopt a quiescent state earlier that those in limb muscles and do not spontaneously proliferate in the adult, yet EOMs have a significantly higher content of Pax7+ MuSCs per area pre- and post-natally. Finally, while limb MuSCs proliferate in the mdx mouse model for Duchenne muscular dystrophy, significantly less MuSCs were present in the EOMs of the mdx mouse model compared to controls, and they were not proliferative. Overall, our study provides a comprehensive in vivo characterisation of MuSC heterogeneity along the body axis and brings further insights into the unusual sparing of EOMs during muscular dystrophy.
Asunto(s)
Proteína del Homeodomínio PITX2 , Proteínas de Homeodominio , Factor 5 Regulador Miogénico , Músculos Oculomotores , Factor de Transcripción PAX7 , Factores de Transcripción , Animales , Humanos , Ratones , Diferenciación Celular/genética , Linaje de la Célula/genética , Proliferación Celular/genética , Regulación del Desarrollo de la Expresión Génica , Proteínas de Homeodominio/genética , Proteínas de Homeodominio/metabolismo , Ratones Endogámicos mdx , Desarrollo de Músculos/genética , Músculo Esquelético/metabolismo , Músculo Esquelético/crecimiento & desarrollo , Distrofia Muscular de Duchenne/genética , Distrofia Muscular de Duchenne/metabolismo , Distrofia Muscular de Duchenne/patología , Factor 5 Regulador Miogénico/genética , Factor 5 Regulador Miogénico/metabolismo , Músculos Oculomotores/metabolismo , Factor de Transcripción PAX7/metabolismo , Factor de Transcripción PAX7/genética , Células Madre/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismoRESUMEN
Androglobin (ADGB) is a highly conserved and recently identified member of the globin superfamily. Although previous studies revealed a link to ciliogenesis and an involvement in murine spermatogenesis, its physiological function remains mostly unknown. Apart from FOXJ1-dependent regulation, the transcriptional landscape of the ADGB gene remains unexplored. We, therefore, aimed to obtain further insights into regulatory mechanisms governing ADGB expression. To this end, changes in ADGB promoter activity were examined using luciferase reporter gene assays in the presence of a set of more than 475 different exogenous transcription factors. MYBL2 and PITX2 resulted in the most pronounced increase in ADGB promoter-dependent luciferase activity. Subsequent truncation strategies of the ADGB promoter fragment narrowed down the potential MYBL2 and PITX2 binding sites within the proximal ADGB promoter. Furthermore, MYBL2 binding sites on the ADGB promoter were further validated via a guide RNA-mediated interference strategy using reporter assays. Chromatin immunoprecipitation (ChIP)-qPCR experiments illustrated enrichment of the endogenous ADGB promoter region upon MYBL2 and PITX2 overexpression. Consistently, ectopic MYBL2 expression induced endogenous ADGB mRNA levels. Collectively, our data indicate that ADGB is strongly regulated at the transcriptional level and might have functions beyond ciliogenesis.
Asunto(s)
Regulación de la Expresión Génica , Regiones Promotoras Genéticas , Transactivadores , Factores de Transcripción , Humanos , Sitios de Unión , Expresión Génica Ectópica , Globinas/genética , Globinas/metabolismo , Proteína del Homeodomínio PITX2 , Proteínas de Homeodominio/genética , Proteínas de Homeodominio/metabolismo , Regiones Promotoras Genéticas/genética , Unión Proteica , Factores de Transcripción/metabolismo , Factores de Transcripción/genética , Transactivadores/genética , Transactivadores/metabolismo , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismoRESUMEN
Ferroptosis inhibits tumor progression in pancreatic cancer cells, while PITX2 is known to function as a pro-oncogenic factor in various tumor types, protecting them from ferroptosis and thereby promoting tumor progression. In this study, we sought to investigate the regulatory role of PITX2 in tumor cell ferroptosis within the context of pancreatic cancer. We conducted PITX2 knockdown experiments using lentiviral infection in two pancreatic cancer cell lines, namely PANC-1 and BxPC-3. We assessed protein expression through immunoblotting and mRNA expression through RT-PCR. To confirm PITX2 as a transcription factor for GPX4, we employed Chromatin Immunoprecipitation (ChIP) and Dual-luciferase assays. Furthermore, we used flow cytometry to measure reactive oxygen species (ROS), lipid peroxidation, and apoptosis and employed confocal microscopy to assess mitochondrial membrane potential. Additionally, electron microscopy was used to observe mitochondrial structural changes and evaluate PITX2's regulation of ferroptosis in pancreatic cancer cells. Our findings demonstrated that PITX2, functioning as a transcription factor for GPX4, promoted GPX4 expression, thereby exerting an inhibitory effect on ferroptosis in pancreatic cancer cells and consequently promoting tumor progression. Moreover, PITX2 enhanced the invasive and migratory capabilities of pancreatic cancer cells by activating the WNT signaling pathway. Knockdown of PITX2 increased ferroptosis and inhibited the proliferation of PANC-1 and BxPC-3 cells. Notably, the inhibitory effect on ferroptosis resulting from PITX2 overexpression in these cells could be countered using RSL3, an inhibitor of GPX4. Overall, our study established PITX2 as a transcriptional regulator of GPX4 that could promote tumor progression in pancreatic cancer by reducing ferroptosis. These findings suggest that PITX2 may serve as a potential therapeutic target for combating ferroptosis in pancreatic cancer.
Asunto(s)
Ferroptosis , Regulación Neoplásica de la Expresión Génica , Proteína del Homeodomínio PITX2 , Proteínas de Homeodominio , Neoplasias Pancreáticas , Fosfolípido Hidroperóxido Glutatión Peroxidasa , Especies Reactivas de Oxígeno , Factores de Transcripción , Animales , Humanos , Ratones , Apoptosis/genética , Línea Celular Tumoral , Movimiento Celular/genética , Proliferación Celular/genética , Ferroptosis/genética , Proteínas de Homeodominio/genética , Proteínas de Homeodominio/metabolismo , Peroxidación de Lípido , Potencial de la Membrana Mitocondrial/genética , Ratones Desnudos , Mitocondrias/metabolismo , Mitocondrias/genética , Neoplasias Pancreáticas/patología , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/metabolismo , Fosfolípido Hidroperóxido Glutatión Peroxidasa/metabolismo , Fosfolípido Hidroperóxido Glutatión Peroxidasa/genética , Especies Reactivas de Oxígeno/metabolismo , Factores de Transcripción/metabolismo , Factores de Transcripción/genética , Vía de Señalización Wnt/genéticaRESUMEN
An observational cohort study of patients diagnosed with endometrial cancer (EC) stage IA G1, or atypical endometrial hyperplasia (AEH), undergoing organ-preserving treatment, was conducted. OBJECTIVE OF THE STUDY: To determine CDO1, PITX2, and CDH13 gene methylation levels in early endometrial cancer and atypical hyperplasia specimens obtained before organ-preserving treatment in the patients with adequate response and with insufficient response to hormonal treatment. MATERIALS AND METHODS: A total of 41 endometrial specimens obtained during diagnostic uterine curettage in women with EC (n = 28) and AEH (n = 13), willing to preserve reproductive function, were studied; 18 specimens of uterine cancer IA stage G1 from peri- and early postmenopausal women (comparison group) were included in the study. The control group included 18 endometrial specimens from healthy women obtained by diagnostic curettage for missed abortion and/or intrauterine adhesions. Methylation levels were analyzed using the modified MS-HRM method. RESULTS: All 13 women with AEH had a complete response (CR) to medical treatment. In the group undergoing organ-preserving treatment for uterine cancer IA stage G1 (n = 28), 14 patients had a complete response (EC CR group) and 14 did not (EC non-CR group). It was found that all groups had statistically significant differences in CDO1 gene methylation levels compared to the control group (p < 0.001) except for the EC CR group (p = 0.21). The p-value for the difference between EC CR and EC non-CR groups was <0.001. The differences in PITX2 gene methylation levels between the control and study groups were also significantly different (p < 0.001), except for the AEH group (p = 0.21). For the difference between EC CR and EC non-CR groups, the p-value was 0.43. For CDH13 gene methylation levels, statistically significant differences were found between the control and EC non-CR groups (p < 0.001), and the control and EC comparison groups (p = 0.005). When comparing the EC CR group with EC non-CR group, the p-value for this gene was <0.001. The simultaneous assessment of CDO1 and CDH13 genes methylation allowed for an accurate distinction between EC CR and EC non-CR groups (AUC = 0.96). CONCLUSION: The assessment of CDO1 and CDH13 gene methylation in endometrial specimens from patients with endometrial cancer (IA stage G1), scheduled for medical treatment, can predict the treatment outcome.
Asunto(s)
Cadherinas , Metilación de ADN , Neoplasias Endometriales , Proteína del Homeodomínio PITX2 , Proteínas de Homeodominio , Factores de Transcripción , Humanos , Femenino , Persona de Mediana Edad , Neoplasias Endometriales/genética , Neoplasias Endometriales/patología , Neoplasias Endometriales/terapia , Cadherinas/genética , Cadherinas/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Proteínas de Homeodominio/genética , Adulto , Resultado del Tratamiento , Anciano , Biomarcadores de Tumor/genética , Estadificación de NeoplasiasRESUMEN
Recent studies have uncovered that noncoding sequence variants may relate to Axenfeld-Rieger syndrome (ARS), a rare developmental anomaly with genetic heterogeneity. However, how these genomic regions are functionally and structurally associated with ARS is still unclear. In this study, we performed genome-wide linkage analysis and whole-genome sequencing in a Chinese family with ARS and identified a heterozygous deletion of about 570 kb (termed LOH-1) in the intergenic sequence between paired-like homeodomain transcription factor 2 (PITX2) and family with sequence similarity 241 member A. Knockout of LOH-1 homologous sequences caused ARS phenotypes in mice. RNA-Seq and real-time quantitative PCR revealed a significant reduction in Pitx2 gene expression in LOH-1-/- mice, while forkhead box C1 expression remained unchanged. ChIP-Seq and bioinformatics analysis identified a potential enhancer region (LOH-E1) within LOH-1. Deletion of LOH-E1 led to a substantial downregulation of the PITX2 gene. Mechanistically, we found a sequence (hg38 chr4:111,399,594-111,399,691) that is on LOH-E1 could regulate PITX2 by binding to RAD21, a critical component of the cohesin complex. Knockdown of RAD21 resulted in reduced PITX2 expression. Collectively, our findings indicate that a potential enhancer sequence that is within LOH-1 may regulate PITX2 expression remotely through cohesin-mediated loop domains, leading to ARS when absent.
Asunto(s)
Segmento Anterior del Ojo , Anomalías del Ojo , Enfermedades Hereditarias del Ojo , Proteína del Homeodomínio PITX2 , Proteínas de Homeodominio , Factores de Transcripción , Animales , Femenino , Humanos , Masculino , Ratones , Segmento Anterior del Ojo/anomalías , Segmento Anterior del Ojo/metabolismo , ADN Intergénico/genética , Elementos de Facilitación Genéticos/genética , Anomalías del Ojo/genética , Enfermedades Hereditarias del Ojo/genética , Proteínas de Homeodominio/genética , Proteínas de Homeodominio/metabolismo , Ratones Noqueados , Linaje , Factores de Transcripción/genética , Factores de Transcripción/metabolismoRESUMEN
Axenfeld-Rieger Syndrome (ARS) type 1 is a rare autosomal dominant condition characterized by anterior chamber anomalies, umbilical defects, dental hypoplasia, and craniofacial anomalies, with Meckel's diverticulum in some individuals. Here, we describe a clinically ascertained female of childbearing age with ARS for whom clinical targeted sequencing and deletion/duplication analysis followed by clinical exome and genome sequencing resulted in no pathogenic variants or variants of unknown significance in PITX2 or FOXC1. Advanced bioinformatic analysis of the genome data identified a complex, balanced rearrangement disrupting PITX2. This case is the first reported intrachromosomal rearrangement leading to ARS, illustrating that for patients with compelling clinical phenotypes but negative genomic testing, additional bioinformatic analysis are essential to identify subtle genomic abnormalities in target genes.
Asunto(s)
Segmento Anterior del Ojo , Anomalías del Ojo , Enfermedades Hereditarias del Ojo , Proteína del Homeodomínio PITX2 , Femenino , Humanos , Segmento Anterior del Ojo/anomalías , Anomalías del Ojo/diagnóstico , Anomalías del Ojo/genética , Anomalías del Ojo/patología , Enfermedades Hereditarias del Ojo/diagnóstico , Enfermedades Hereditarias del Ojo/genética , Enfermedades Hereditarias del Ojo/patología , Factores de Transcripción Forkhead/genética , Proteínas de Homeodominio/genéticaRESUMEN
Wolf-Hirschhorn syndrome (WHS) is a developmental disorder attributed to a partial deletion on the short arm of chromosome 4. WHS patients suffer from oral manifestations including cleft lip and palate, hypodontia, and taurodontism. WHS candidate 1 (WHSC1) gene is a H3K36-specific methyltransferase that is deleted in every reported case of WHS. Mutation in this gene also results in tooth anomalies in patients. However, the correlation between genetic abnormalities and the tooth anomalies has remained controversial. In our study, we aimed to clarify the role of WHSC1 in tooth development. We profiled the Whsc1 expression pattern during mouse incisor and molar development by immunofluorescence staining and found Whsc1 expression is reduced as tooth development proceeds. Using real-time quantitative reverse transcription PCR, Western blot, chromatin immunoprecipitation, and luciferase assays, we determined that Whsc1 and Pitx2, the initial transcription factor involved in tooth development, positively and reciprocally regulate each other through their gene promoters. miRNAs are known to regulate gene expression posttranscriptionally during development. We previously reported miR-23a/b and miR-24-1/2 were highly expressed in the mature tooth germ. Interestingly, we demonstrate here that these two miRs directly target Whsc1 and repress its expression. Additionally, this miR cluster is also negatively regulated by Pitx2. We show the expression of these two miRs and Whsc1 are inversely correlated during mouse mandibular development. Taken together, our results provide new insights into the potential role of Whsc1 in regulating tooth development and a possible molecular mechanism underlying the dental defects in WHS.
Asunto(s)
Labio Leporino , Fisura del Paladar , MicroARNs , Síndrome de Wolf-Hirschhorn , Animales , Ratones , MicroARNs/genética , Factores de Transcripción , Síndrome de Wolf-Hirschhorn/genética , Síndrome de Wolf-Hirschhorn/metabolismo , Proteína del Homeodomínio PITX2RESUMEN
BACKGROUND: Experimental evidence suggests genetic variation in 4q25/PITX2 modulates pulmonary vein (PV) myocardial sleeve length. Although PV sleeves are the main target of atrial fibrillation (AF) ablation, little is known about the association between different PV sleeve characteristics with ablation outcomes. OBJECTIVES: This study sought to evaluate the association between clinical and genetic (4q25) risk factors with PV sleeve length in humans, and to evaluate the association between PV sleeve length and recurrence after AF ablation. METHODS: In a prospective, observational study of patients undergoing de novo AF ablation, PV sleeve length was measured using electroanatomic voltage mapping before ablation. The sentinel 4q25 AF susceptibility single nucleotide polymorphism, rs2200733, was genotyped. The primary analysis tested the association between clinical and genetic (4q25) risk factors with PV sleeve length using a multivariable linear regression model. Covariates included age, sex, body mass index, height, and persistent AF. The association between PV sleeve length and atrial arrhythmia recurrence (>30 seconds) was tested using a multivariable Cox proportional hazards model. RESULTS: Between 2014 and 2019, 197 participants were enrolled (median age 63 years [IQR: 55 to 70 years], 133 male [67.5%]). In multivariable modeling, men were found to have PV sleeves 2.94 mm longer than women (95% CI: 0.99-4.90 mm; P < 0.001). Sixty participants (30.5%) had one 4q25 risk allele and 6 (3.1%) had 2 alleles. There was no association between 4q25 genotype and PV sleeve length. Forty-six participants (23.4%) experienced arrhythmia recurrence within 3 to 12 months, but there was no association between recurrence and PV sleeve length. CONCLUSIONS: Common genetic variation at 4q25 was not associated with PV sleeve length and PV sleeve length was not associated with ablation outcomes. Men did have longer PV sleeves than women, but more research is needed to define the potential clinical significance of this observation.
Asunto(s)
Fibrilación Atrial , Venas Pulmonares , Femenino , Humanos , Masculino , Persona de Mediana Edad , Fibrilación Atrial/genética , Fibrilación Atrial/cirugía , Genotipo , Estudios Prospectivos , Venas Pulmonares/cirugía , Factores de Riesgo , Anciano , Proteína del Homeodomínio PITX2RESUMEN
BACKGROUND: As observed in recent genetic studies, PITX2 is one of the most popular genes with atrial fibrillation; single nucleotide polymorphism (rs2200733) at chromosome 4q25 (near PITX2) is found to be strongly associated with atrial fibrillation, but it has a difference among Chinese Han population. The basic aim of conducting this study is to find the correlation between PITX2 gene polymorphism and the risk of atrial fibrillation and to identify the possibility for early diagnosis of silent atrial fibrillation and high-risk atrial fibrillation. METHODS: The study included 98 cases of atrial fibrillation patients and 88 non-atrial fibrillation patients in Affiliated Hospital of Yangzhou University were enrolled in a case-control study. The single nucleotide polymorphism of rs2200733 at 4q25 near PITX2 was genotyped by polymerase chain reaction-restriction fragment length polymorphism analysis. RESULTS: A total of 98 patients with atrial fibrillation were genotyped, and the following frequencies were included in genotype percentages (44.9%, 50%, and 5.1%) while distribution of significant single nucleotide polymorphism rs2200733 consisted (29.55%, 53.41%, and 17.05%) which showed (χ2 = 9.159, P =.01). There was no significant difference in TC genotype frequency (P =.642), frequency of T allele (χ2 = 7.447, P =.006), and T allele was 1.806 times that of the control group (odds ratio = 1.806, 95% CI = 1.179-2.766, P =.006). According to logistic regression analysis, following results were concluded for TC genotype (odds ratio = 3.128, 95% CI = 1.053-9.287, P =.04), or TT genotype (odds ratio = 5.077, 95% CI = 1.653-15.595, P =.005) increased the risk of atrial fibrillation. CONCLUSIONS: The genotype and allele frequency distribution of rs2200733 (T/C) near PITX2 is different in the atrial fibrillation group and the control group. The T allele is a risk factor for atrial fibrillation. Compared with the CC genotype, the TT genotype increased the risk of atrial fibrillation.
Asunto(s)
Fibrilación Atrial , Proteínas de Homeodominio , Factores de Transcripción , Humanos , Fibrilación Atrial/genética , Estudios de Casos y Controles , Frecuencia de los Genes , Genotipo , Polimorfismo de Nucleótido Simple , Proteínas de Homeodominio/genética , Factores de Transcripción/genética , Proteína del Homeodomínio PITX2RESUMEN
PURPOSE: The aim of this study was to report a case of corneal plana-like phenotype with bilateral peripheral scleralization associated with a PITX2 pathogenic variant. METHODS: Clinical findings were obtained by ophthalmologic examination. Molecular diagnosis was performed by whole-exome sequencing in the patient and his parents. RESULTS: A 12-month-old male patient present with bilateral peripheral corneal scleralization, corneal plana-like phenotype, and iris hypoplasia. The genetic analysis revealed a de novo PITX2 pathogenic variant (c.323G>A, p.R108H). CONCLUSIONS: PITX2 c.323G>A (p.R108H) can be associated with a unique corneal plana-like phenotype with peripheral scleralization, and thus, PITX2 should be targeted in genetic testing of this specific phenotype.
Asunto(s)
Enfermedades de la Córnea , Proteínas de Homeodominio , Humanos , Masculino , Enfermedades de la Córnea/patología , Proteínas de Homeodominio/genética , Mutación , Linaje , Fenotipo , Factores de Transcripción/genética , Lactante , Proteína del Homeodomínio PITX2RESUMEN
PITX2 and FOXC1 are the most common pathogenic genes associated with Axenfeld-Rieger syndrome (ARS). In this study, we aimed to explore the variation spectrum of PITX2 and FOXC1 and their associated phenotype based on data from our study and previously reported literatures. Whole exome sequencing was performed on eight probands in our study. Multistep bioinformatic and co-segregation analyses were performed to detect pathogenic variants. Genotype-phenotype correlations of PITX2 and FOXC1 and the differences between them were determined. We detected three variants of FOXC1 and two variants of PITX2 in five unrelated families with ARS. Macular retinoschisis had been observed in AR1 with variant in PITX2 and it is not reported before. Additionally, a review of published literature and our study led to the identification of 593 families with variants of PITX2 or FOXC1, including 316 families with heterozygous variants in FOXC1, 251 families with heterozygous variants in PITX2, 13 families with variants in double genes, seven families with homozygous or compound heterozygous variants in FOXC1, and six families with variants in ADAMTS17, PRDM5, COL4A1 or CYP1B1. Significant differences were observed between the prevalence of missense and in-frame, truncation, and large deletion variants in PITX2 (32.00%, 42.67%, and 25.33%, respectively) and FOXC1 (34.49%, 35.13%, 30.38%, respectively) (p = 1.16E-43). Enrichment and frequency analyses revealed that missense variants were concentrated in the forkhead domain of FOXC1 (76.14%) and homeodomain of PITX2 (87.50%). The percentage of Caucasians with variants in FOXC1 was significantly higher than that of PITX2 (p = 2.00E-2). Significant differences between PITX2 and FOXC1 were observed in glaucoma (p = 3.00E-2), corectopia (p = 3.050E-6), and polycoria (p = 5.21E-08). Additionally, we observed a significant difference in best-corrected visual acuity (BCVA) between FOXC1 and PITX2 (p = 3.80E-2). Among all the family members with PITX2 or FOXC1 variants, the prevalence of systemic abnormalities was significantly higher in PITX2 than in FOXC1 (89.16% vs. 58.77%, p = 5.44E-17). In conclusion, macular retinoschisis as a novel phenotype had been observed in patient with variant in PITX2. Significant differences were detected in phenotypes and genotypes between PITX2 and FOXC1.
Asunto(s)
Anomalías del Ojo , Enfermedades Hereditarias del Ojo , Proteínas de Homeodominio , Humanos , Segmento Anterior del Ojo , Anomalías del Ojo/genética , Enfermedades Hereditarias del Ojo/genética , Factores de Transcripción Forkhead/genética , Estudios de Asociación Genética , Proteínas de Homeodominio/genética , Mutación , Linaje , Retinosquisis , Proteína del Homeodomínio PITX2RESUMEN
The bicoid-related transcription factor 2 (Pitx2) plays a crucial role in the development of many organs and tissues by affecting the mitotic cell cycle. Postnatal testis development is related to mitosis and meiosis in multiple cell types, but the role of Pitx2 gene in seasonal inhibition of testicular development remains unknown in rodents. We analyzed PITX2 protein and Pitx2 mRNA expression features using both laboratory and wild male Rattus norvegicus caraco. In postnatal testicle of laboratory colony, we found that PITX2 was expressed in Leydig cells, pachytene spermatocytes, round spermatids, and elongating spermatids rather than spermatogonia and leptotene/zygotene spermatocytes. Pitx2b expression significantly increased along with the occurrence of pachytene spermatocytes and round spermatids, while decreased along with the processes of elongated spermatids. In wild male rats with similar testes weight, a significantly suppressed Pitx2b expression occurred with an active meiotic stage in the inhibited testes in autumn and winter, compared with the normally developing testes in spring and summer. These results indicate that Pitx2b expression suppression plays a crucial role in the seasonal inhibition of testis development.
Asunto(s)
Espermatogénesis , Testículo , Animales , Masculino , Ratas , Estaciones del Año , Espermátides/metabolismo , Espermatogénesis/genética , Espermatogonias/metabolismo , Testículo/crecimiento & desarrollo , Proteína del Homeodomínio PITX2RESUMEN
The vertebrate intestine forms by asymmetric gut rotation and elongation, and errors cause lethal obstructions in human infants. Rotation begins with tissue deformation of the dorsal mesentery, which is dependent on left-sided expression of the Paired-like transcription factor Pitx2. The conserved morphogen Nodal induces asymmetric Pitx2 to govern embryonic laterality, but organ-level regulation of Pitx2 during gut asymmetry remains unknown. We found Nodal to be dispensable for Pitx2 expression during mesentery deformation. Intestinal rotation instead required a mechanosensitive latent transforming growth factor-ß (TGFß), tuning a second wave of Pitx2 that induced reciprocal tissue stiffness in the left mesentery as mechanical feedback with the right side. This signaling regulator, an accelerator (right) and brake (left), combines biochemical and biomechanical inputs to break gut morphological symmetry and direct intestinal rotation.
Asunto(s)
Gastrulación , Regulación del Desarrollo de la Expresión Génica , Proteínas de Homeodominio , Intestinos , Mecanotransducción Celular , Proteína Nodal , Factores de Transcripción , Factor de Crecimiento Transformador beta , Animales , Embrión de Pollo , Gastrulación/genética , Gastrulación/fisiología , Proteínas de Homeodominio/genética , Proteínas de Homeodominio/farmacología , Intestinos/embriología , Mecanotransducción Celular/genética , Mecanotransducción Celular/fisiología , Ratones , Proteína Nodal/genética , Factores de Transcripción/genética , Factores de Transcripción/farmacología , Factor de Crecimiento Transformador beta/metabolismo , Proteína del Homeodomínio PITX2RESUMEN
The chromatin-associated high mobility group protein N2 (HMGN2) cofactor regulates transcription factor activity through both chromatin and protein interactions. Hmgn2 expression is known to be developmentally regulated, but the post-transcriptional mechanisms that regulate Hmgn2 expression and its precise roles in tooth development remain unclear. Here, we demonstrate that HMGN2 inhibits the activity of multiple transcription factors as a general mechanism to regulate early development. Bimolecular fluorescence complementation, pull-down, and coimmunoprecipitation assays show that HMGN2 interacts with the transcription factor Lef-1 through its HMG-box domain as well as with other early development transcription factors, Dlx2, FoxJ1, and Pitx2. Furthermore, EMSAs demonstrate that HMGN2 binding to Lef-1 inhibits its DNA-binding activity. We found that Pitx2 and Hmgn2 associate with H4K5ac and H3K4me2 chromatin marks in the proximal Dlx2 promoter, demonstrating Hmgn2 association with open chromatin. In addition, we demonstrate that microRNAs (miRs) mir-23a and miR-23b directly target Hmgn2, promoting transcriptional activation at several gene promoters, including the amelogenin promoter. In vivo, we found that decreased Hmgn2 expression correlates with increased miR-23 expression in craniofacial tissues as the murine embryo develops. Finally, we show that ablation of Hmgn2 in mice results in increased amelogenin expression because of increased Pitx2, Dlx2, Lef-1, and FoxJ1 transcriptional activity. Taken together, our results demonstrate both post-transcriptional regulation of Hmgn2 by miR-23a/b and post-translational regulation of gene expression by Hmgn2-transcription factor interactions. We conclude that HMGN2 regulates tooth development through its interaction with multiple transcription factors.
Asunto(s)
Amelogénesis , Regulación de la Expresión Génica , Proteína HMGN2 , Proteínas de Homeodominio , Factor de Unión 1 al Potenciador Linfoide , Factores de Transcripción , Transcripción Genética , Amelogénesis/genética , Amelogenina/genética , Animales , Cromatina/metabolismo , Proteína HMGN2/genética , Proteína HMGN2/metabolismo , Proteínas de Homeodominio/metabolismo , Factor de Unión 1 al Potenciador Linfoide/metabolismo , Ratones , MicroARNs/genética , MicroARNs/metabolismo , Factores de Transcripción/metabolismo , Proteína del Homeodomínio PITX2RESUMEN
Atrial fibrillation (AF), the most common sustained cardiac arrhythmia and a major risk factor for stroke, often arises through ectopic electrical impulses derived from the pulmonary veins (PVs). Sequence variants in enhancers controlling expression of the transcription factor PITX2, which is expressed in the cardiomyocytes (CMs) of the PV and left atrium (LA), have been implicated in AF predisposition. Single nuclei multiomic profiling of RNA and analysis of chromatin accessibility combined with spectral clustering uncovered distinct PV- and LA-enriched CM cell states. Pitx2-mutant PV and LA CMs exhibited gene expression changes consistent with cardiac dysfunction through cell type-distinct, PITX2-directed, cis-regulatory grammars controlling target gene expression. The perturbed network targets in each CM were enriched in distinct human AF predisposition genes, suggesting combinatorial risk for AF genesis. Our data further reveal that PV and LA Pitx2-mutant CMs signal to endothelial and endocardial cells through BMP10 signaling with pathogenic potential. This work provides a multiomic framework for interrogating the basis of AF predisposition in the PVs of humans.
Asunto(s)
Fibrilación Atrial , Proteínas de Homeodominio , Factores de Transcripción , Fibrilación Atrial/genética , Fibrilación Atrial/metabolismo , Proteínas Morfogenéticas Óseas/genética , Proteínas Morfogenéticas Óseas/metabolismo , Redes Reguladoras de Genes , Atrios Cardíacos/metabolismo , Proteínas de Homeodominio/genética , Proteínas de Homeodominio/metabolismo , Humanos , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Proteína del Homeodomínio PITX2RESUMEN
PURPOSE: Axenfeld-Rieger syndrome encompasses a group of developmental disorders affecting the anterior chamber structures of the eye, with associated systemic features in some cases. This study aims to compare the difference in anterior segment phenotypes such as those involving the cornea, iris, lens, and anterior chamber angle between cases with disease-causing sequence variations in FOXC1 and PITX2 . METHODS: This cross-sectional study involved 61 individuals, from 32 families with pathogenic FOXC1 or PITX2 variants, who were registered with the Australian and New Zealand Registry of Advanced Glaucoma. RESULTS: The median age of the cohort was 39 years at the time of last assessment (range 3-85 years; females, 54%). Thirty-two patients had pathogenic variants in the FOXC1 gene, and 29 patients had pathogenic variants in the PITX2 gene. Corneal abnormalities were more common in individuals with FOXC1 variants (18/36, 50%) than those with PITX2 variants (4/25, 16%; P = 0.007). Iris abnormalities such as hypoplasia ( P = 0.008) and pseudopolycoria ( P = 0.001) were more common in individuals with PITX2 variants than those with FOXC1 variants. Glaucoma was present in 72% of participants. Corneal decompensation was positively associated with corneal abnormalities ( P < 0.001), glaucoma surgery ( P = 0.025), and cataract surgery ( P = 0.002). CONCLUSIONS: Corneal abnormalities were more common in individuals with FOXC1 than in those with PITX2 variants and were often associated with early onset glaucoma. These findings highlight that patients with FOXC1 variations require close follow-up and monitoring throughout infancy and into adulthood.
Asunto(s)
Anomalías del Ojo , Enfermedades Hereditarias del Ojo , Factores de Transcripción Forkhead , Glaucoma , Proteínas de Homeodominio , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Segmento Anterior del Ojo/anomalías , Australia , Niño , Preescolar , Estudios Transversales , Anomalías del Ojo/genética , Enfermedades Hereditarias del Ojo/genética , Femenino , Factores de Transcripción Forkhead/genética , Glaucoma/genética , Proteínas de Homeodominio/genética , Humanos , Masculino , Persona de Mediana Edad , Mutación , Linaje , Factores de Transcripción/genética , Adulto Joven , Proteína del Homeodomínio PITX2RESUMEN
PURPOSE: Stroke is a multifactorial and complex disease caused by the obstruction or rupture of cerebrovascular. To explore the influence of genetic factors on stroke susceptibility, we investigated the association between four single nucleotide polymorphisms (SNPs) in the paired-like homeodomain transcription factor 2 (PITX2) gene and stroke risk. METHODS: A total of 977 volunteers including 476 stroke patients and 501 control individuals were recruited. The association between PITX2 polymorphisms and stroke risk was evaluated using genetic models and haplotype analyses. The strength of the association between each studied polymorphisms and stroke risk was evaluated by calculating odds ratios (ORs) and 95% confidence intervals (CIs). What's more, multifactor dimensionality reduction (MDR) was used to predict the interaction between SNPs. RESULTS: Our study showed that rs6817105 in PITX2 was related to a significant increase in stroke susceptibility (OR = 1.42, 95% CI = 1.04-1.94, p = 0.028). Stratified analyses based on gender indicated that rs6817105, rs13143308, and rs6843082 polymorphisms were significantly associated with an increased risk of stroke in male (OR = 0.68, 95% CI = 0.47-0.99, p = 0.042; OR = 0.53, 95% CI = 0.30-0.96, p = 0.035; and OR = 0.55, 95% CI = 0.30-0.99, p = 0.047). Besides, SNP rs6817105 was significantly increased the risk of stroke in people at age over 65 years (OR = 1.87, 95% CI =1.12-3.11, p = 0.016). MDR showed that the interaction model of rs6817105 and rs3853445 emerged as the best predictor between the PITX2 gene and stroke susceptibility. CONCLUSIONS: This study indicated that there was a significant association between the PITX2 gene and stroke risk, and provided some data as far as possible to support the prevention of stroke.
Asunto(s)
Predisposición Genética a la Enfermedad , Variación Genética , Proteínas de Homeodominio/genética , Accidente Cerebrovascular/genética , Factores de Transcripción/genética , Anciano , China , Femenino , Proteínas de Homeodominio/metabolismo , Humanos , Masculino , Persona de Mediana Edad , Factores de Transcripción/metabolismo , Proteína del Homeodomínio PITX2RESUMEN
OBJECTIVE: We previously reported early-onset atrial fibrillation (AF) associated genetic loci among a Korean population. We explored whether the AF-associated single-nucleotide polymorphisms (SNPs) selected from the Genome-Wide Association Study (GWAS) of an external large cohort has a prediction power for AF in Korean population through a convolutional neural network (CNN). METHODS: This study included 6358 subjects (872 cases, 5486 controls) from the Korean population GWAS data. We extracted the lists of SNPs at each p value threshold of the association statistics from three different previously reported ethnical-specific GWASs. The Korean GWAS data were divided into training (64%), validation (16%) and test (20%) sets, and a stratified K-fold cross-validation was performed and repeated five times after data shuffling. RESULTS: The CNN-GWAS predictive power for AF had an area under the curve (AUC) of 0.78±0.01 based on the Japanese GWAS, AUC of 0.79±0.01 based on the European GWAS, and AUC of 0.82±0.01 based on the multiethnic GWAS, respectively. Gradient-weighted class activation mapping assigned high saliency scores for AF associated SNPs, and the PITX2 obtained the highest saliency score. The CNN-GWAS did not show AF prediction power by SNPs with non-significant p value subset (AUC 0.56±0.01) despite larger numbers of SNPs. The CNN-GWAS had no prediction power for odd-even registration numbers (AUC 0.51±0.01). CONCLUSIONS: AF can be predicted by genetic information alone with moderate accuracy. The CNN-GWAS can be a robust and useful tool for detecting polygenic diseases by capturing the cumulative effects and genetic interactions of moderately associated but statistically significant SNPs. TRIAL REGISTRATION NUMBER: NCT02138695.