Paired-like Homeodomain Transcription Factor Research Articles

TAD boundary deletion causes PITX2-related cardiac electrical and structural defects

While 3D chromatin organization in topologically associating domains (TADs) and loops mediating regulatory element-promoter interactions is crucial for tissue-specific gene regulation, the extent of their involvement in human Mendelian disease is largely unknown. Here, we identify 7 families presenting a new cardiac entity associated with a heterozygous deletion of 2 CTCF binding sites on 4q25, inducing TAD fusion and chromatin conformation remodeling. The CTCF binding sites are located in a gene desert at 1 Mb from the Paired-like homeodomain transcription factor 2 gene (PITX2). By introducing the ortholog of the human deletion in the mouse genome, we recapitulate the patient phenotype and characterize an opposite dysregulation of PITX2 expression in the sinoatrial node (ectopic activation) and ventricle (reduction), respectively. Chromatin conformation assay performed in human induced pluripotent stem cell-derived cardiomyocytes harboring the minimal deletion identified in family#1 reveals a conformation remodeling and fusion of TADs. We conclude that TAD remodeling mediated by deletion of CTCF binding sites causes a new autosomal dominant Mendelian cardiac disorder.

From cells to circulating biomarker: BMP10 is a myocyte-secreted peptide with potential to detect atrial fibrillation

Abstract Background Early onset detection and recurrence prediction of atrial fibrillation (AF) may improve therapeutic decision-making, prognosis and long-term outcome. Plasma proteome analyses and mechanistic studies identified bone morphogenetic protein 10 (BMP10) as an atrial-specific secreted biomolecule for AF associated with reduced paired-like homeodomain transcription factor 2 (PITX2) expression. Purpose Our aim is 1) to confirm BMP10 synthesis and secretion by human atrial isolated myocytes, 2) to compare BMP10 secreted levels between right atrial, left atrial and left ventricular myocytes, and 3) to assess if BMP10 secretion is indeed associated with AF in human myocytes. Methods Right atrial (RA), left atrial (LA) and left ventricular (LV) myocytes were isolated from 16 tissues samples of patients undergoing open heart surgery which were currently in sinus rhythm (SR) or AF. Freshly isolated myocytes were resuspended in minimal essential medium (MEM, M1) containing fetal bovine serum (FBS) and plated in laminin coated dishes. M1 was collected after 3 hours of culture and substituted by FBS-free medium (M2), which was collected after 48 hours of culture. Cardiomyocyte-released BMP10 levels were measured in M1 and M2 by ELISA. Results Cardiomyocytes from twelve patients (68±2.7 years, 52±2.1 % ejection fraction, 17 % women, 50 % with AF, 50 % valvular surgery and 75 % bypass) were cultured and BMP10 secreted levels analyzed. BMP10 concentrations were high in medium from atrial cardiomyocytes (2.76±1.8 ng/µl) and negligible in medium from ventricular cardiomyocytes (0.01±0.005 ng/µl). Left atrial cardiomyocytes released less BMP10 than right atrial cardiomyocytes (LA 0.02±0.007 ng/µl; RA 3.50±2.3 ng/µl). In addition, BMP10 concentrations were higher in right atrial cardiomyocytes from patients with AF (3.76±3.6 ng/µl) than in the right atrial cardiomyocytes from patients in SR (0.97±0.9 ng/µl). Conclusion Our results provide a direct proof that BMP10 is secreted by human atrial myocytes, mainly right atrial myocytes. Furthermore, atrial myocytes from patients with AF secreted significantly more BMP10 than myocytes from patients in sinus rhythm. These observations validate the atrial cardiomyocyte origin of circulating BMP10, making BMP10 a potentially attractive atrial-specific cardiac biomarker.

Neuroimaging Findings in Axenfeld-Rieger Syndrome: A Case Series.

Axenfeld-Rieger syndrome is an autosomal dominant condition associated with multisystemic features including developmental anomalies of the anterior segment of the eye. Single nucleotide and copy number variants in the paired-like homeodomain transcription factor 2 (PITX2) and forkhead box C1 (FOXC1) genes are associated with Axenfeld-Rieger syndrome as well as other CNS malformations. We determined the association between Axenfeld-Rieger syndrome and specific brain MR imaging neuroradiologic anomalies in cases with or without a genetic diagnosis. This case series included 8 individuals with pathogenic variants in FOXC1; 2, in PITX2; and 2 without a genetic diagnosis. The most common observation was vertebrobasilar artery dolichoectasia, with 46% prevalence. Other prevalent abnormalities included WM hyperintensities, cerebellar hypoplasia, and ventriculomegaly. Vertebrobasilar artery dolichoectasia and absent/hypoplastic olfactory bulbs were reported in >50% of individuals with FOXC1 variants compared with 0% of PITX2 variants. Notwithstanding the small sample size, neuroimaging abnormalities were more prevalent in individuals with FOXC1 variants compared those with PITX2 variants.

PITX2c impairment electrical remodeling increases susceptibility to atrial fibrillation

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): the National Research Foundation of Korea (NRF) grants funded by the Korea government (MSIT), the Korean Fund for Regenerative Medicine (KFRM) grant funded by the Korea government Background Functional mutations in the PITX2 (Paired-like homeodomain transcription factor 2) gene cause genetically inherited atrial fibrillation (AF). PITX2 is known to plays a pivotal role in regulating the expression of distinct ion channels, beta-adrenergic stimulation, cell-cell coupling and resulting in AF due to abnormal calcium abnormalities and electrical remodeling. However, the pathophysiological mechanisms linking impaired PITX2 with AF are still to be explored. This study was performed to generate PITX2c knockout human iPSC atrial cardiomyocytes (hiPSC-atrial CM), which are useful tools for arrhythmia modeling, and evaluate the mechanism of PITX2 deficiency leading to AF. Methods We generated a PITX2 knock-out iPSC line using a CRISPR/Cas9-based genome editing system. hiPSCs were electroporated with Cas9/sgRNA ribonucleoprotein (RNP) complexes. PITX2c knock-out hiPSC-CMs differentiated into atrial cardiomyocytes based on the manipulation of retinoic acid signaling. For the three-dimensional (3D) culture model, cells were plated in the spherical plate 5D. Electrophysiological properties and oxidative stress were assessed in PITX2c-deficient cardiomyocytes. Proarrhythmic effects of the PITX2c knock-out were quantified with AP morphology, AP duration (APD) restitution, wavelength (WL) and conduction velocity (CV) restitution using microelectrode arrays (MEA). Results We demonstrated that atrial-specific differentiated hiPSC-CMs expressed atrial-specific genes and the properties of action potentials were like those of human atrial cardiomyocytes. In addition, both 2D and 3D PITX2c knock-out atrial hiPSC-CMs showed signs of APD shortening and reduced wavelength (WL) and increased conduction velocity (CV) restitution (P<0.05). Next, a functional assessment of calcium homeostasis has shown that PITX2c causes atrial arrhythmias by impairing calcium handling genes (SERCA2a, RyR2, PLN). We then demonstrated that miR-374a-5p and miR-374b-5p could be involved in pathophysiological functions as therapeutic candidates when affinity for PITX2 was based on the upper context score percentile (> 99). Conclusions This study provides an understanding of electrical remodeling by PITX2c loss-of-function mutations and suggests the potential therapeutic candidates by miR-374a-5p and miR-374b-5p, thus helping to understand the mechanism of PITX2 deficiency leading to atrial fibrillation.

The Crucial Roles of Pitx3 in Midbrain Dopaminergic Neuron Development and Parkinson's Disease-Associated Neurodegeneration.

The degeneration of midbrain dopaminergic (mDA) neurons, particularly in the substantia nigra pars compacta (SNc), is one of the most prominent pathological hallmarks of Parkinson's disease (PD). To uncover the pathogenic mechanisms of mDA neuronal death during PD may provide therapeutic targets to prevent mDA neuronal loss and slow down the disease's progression. Paired-like homeodomain transcription factor 3 (Pitx3) is selectively expressed in the mDA neurons as early as embryonic day 11.5 and plays a critical role in mDA neuron terminal differentiation and subset specification. Moreover, Pitx3-deficient mice exhibit some canonical PD-related features, including the profound loss of SNc mDA neurons, a dramatic decrease in striatal dopamine (DA) levels, and motor abnormalities. However, the precise role of Pitx3 in progressive PD and how this gene contributes to mDA neuronal specification during early stages remains unclear. In this review, we updated the latest findings on Pitx3 by summarizing the crosstalk between Pitx3 and its associated transcription factors in mDA neuron development. We further explored the potential benefits of Pitx3 as a therapeutic target for PD in the future. To better understand the transcriptional network of Pitx3 in mDA neuron development may provide insights into Pitx3-related clinical drug-targeting research and therapeutic approaches.

Five Single-Nucleotide Polymorphisms in the PITX2 Gene as Risk Factors for Atrial Fibrillation

Highlights: A genetic variable has been identified as an atrial fibrillation risk factor. Rs2200733 is a type of SNP that increases atrial fibrillation risk, whereas rs3853445, rs6838973, and rs17570669 have the reverse effect. Abstract: Atrial fibrillation (AF) is a highly prevalent arrhythmia. The involvement of molecular mechanisms in increased AF risk remains uncertain. However, the paired-like homeodomain transcription factor 2 or pituitary homeobox 2 (PITX2) gene has been linked to AF development. A comprehensive search was carried out to identify all eligible case-control studies in order to assess the association between five single-nucleotide polymorphisms (SNPs) in the PITX2 gene and the risk of AF. This meta-analysis employed the Review Manager (RevMan) software version 5.3 (Cochrane). There were 13 clinical studies, with a total of 11,961 subjects, that met the inclusion criteria. These subjects consisted of 4,440 patients with AF and 7,521 controls. The meta-analysis of five SNP types in the PITX2 gene was done using crude odds ratios (ORs). This revealed that rs2200733 increased the risk of AF (OR=1.80; 95% CI=1.53-2.11; p=0.0005; I2=80%). On the other hand, the other three SNPs decreased the risk of AF, namely, rs385344 (OR=0.75; 95% CI=0.59-0.95; p=0.002; I2=85%), rs6838973 (OR=0.64; 95% CI=0.51-0.81; p=0.0001; I2=73%), and rs17570669 (OR=0.80; 95% CI=0.65-0.98; p=0.03; I2=70%). However, there was no significant association between rs10033464 and AF (OR=1.21; 95% CI=0.97-1.50; p=0.13; I2=83%). In conclusion, depending on the type, SNPs in the PITX2 gene correlate with AF risk factors, either by alleviating or reducing the risk.

PITX2 Knockout Induces Key Findings of Electrical Remodeling as Seen in Persistent Atrial Fibrillation.

Electrical remodeling in human persistent atrial fibrillation is believed to result from rapid electrical activation of the atria, but underlying genetic causes may contribute. Indeed, common gene variants in an enhancer region close to PITX2 (paired-like homeodomain transcription factor 2) are strongly associated with atrial fibrillation, but the mechanism behind this association remains unknown. This study evaluated the consequences of PITX2 deletion (PITX2-/-) in human induced pluripotent stem cell-derived atrial cardiomyocytes. CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats/clustered regularly interspaced short palindromic repeat-associated 9) was used to delete PITX2 in a healthy human iPSC line that served as isogenic control. Human induced pluripotent stem cell-derived atrial cardiomyocytes were differentiated with unfiltered retinoic acid and cultured in atrial engineered heart tissue. Force and action potential were measured in atrial engineered heart tissues. Single human induced pluripotent stem cell-derived atrial cardiomyocytes were isolated from atrial engineered heart tissue for ion current measurements. PITX2-/- atrial engineered heart tissue beats slightly slower than isogenic control without irregularity. Force was lower in PITX2-/- than in isogenic control (0.053±0.015 versus 0.131±0.017 mN, n=28/3 versus n=28/4, PITX2-/- versus isogenic control; P<0.0001), accompanied by lower expression of CACNA1C and lower L-type Ca2+ current density. Early repolarization was weaker (action potential duration at 20% repolarization; 45.5±13.2 versus 8.6±5.3 ms, n=18/3 versus n=12/4, PITX2-/- versus isogenic control; P<0.0001), and maximum diastolic potential was more negative (-78.3±3.1 versus -69.7±0.6 mV, n=18/3 versus n=12/4, PITX2-/- versus isogenic control; P=0.001), despite normal inward rectifier currents (both IK1 and IK,ACh) and carbachol-induced shortening of action potential duration. Complete PITX2 deficiency in human induced pluripotent stem cell-derived atrial cardiomyocytes recapitulates some findings of electrical remodeling of atrial fibrillation in the absence of fast beating, indicating that these abnormalities could be primary consequences of lower PITX2 levels.

Association of Novel C319T Variant of PITX2 Gene 3'UTR Region With Reproductive Performance in Awassi Sheep.

Several genes influence sheep's reproductive performance, among them the paired-like homeodomain transcription factor 2 (PITX2) gene. Thus, this study aimed to examine whether the variability within the PITX2 gene is associated with the reproductive performance of Awassi ewes. A total of 123 single-progeny ewes and 109 twin ewes were used to extract genomic DNA. An amplicon of 4 sequence fragments from exons 2, 4, 5 (upstream portion), and 5 (downstream portion) of the PITX2 gene was generated by polymerase chain reaction (PCR), 228, 304, 381, and 382 bp, respectively. Three genotypes of 382 bp amplicons were identified: CC, CT, and TT. Sequence analysis revealed a novel mutation in the CT genotype 319C > T. Statistical analysis revealed that single-nucleotide polymorphism (SNP) 319C > T was associated with reproductive performance. Single-nucleotide polymorphism 319C > T-carrying ewes had significantly (P ⩽ .01) lower litter sizes, twinning rates, lambing rates, and more days to lambing than those carrying CT and CC genotypes. Based on a logistic regression analysis, it was confirmed that the 319C > T SNP decreased litter size. Ewes with TT genotype produced fewer lambs than ewes with CT and CC genotypes. According to these results, the variant 319C> T SNP negatively affects the reproductive performance of Awassi sheep. Ewes carrying the 319C > T SNP have a lower litter size and are less prolific than those without the SNP.

PITX1 suppresses osteosarcoma metastasis through exosomal LINC00662-mediated M2 macrophage polarization

Paired-like homeodomain transcription factor 1 (PITX1) is frequently downregulated in cancers, including osteosarcoma (OS). However, its role in OS remains unknown. Therefore, we aimed to explore the functions and potential mechanisms of PITX1 in OS malignant progression. Elevated PITX1 suppressed OS cell proliferation and migration, based on transwell, proliferation, and colony formation assays. Pathway enrichment analysis of differentially-expressed genes between PITX1-overexpressing and control OS cells indicated that PITX1 expression was associated with the FAK/Src and PI3k/Akt signaling pathways. Mechanistically, ubiquitination assays and rescue experiments showed that PITX1 interacted with transcription factor STAT3, leading to decreased STAT3 transcriptional activity, which repressed the expression of LINC00662. Specific knockdown of LINC00662 reduced the tumor growth and invasion of OS cells induced by downregulated PITX1. Moreover, exosomal LINC00662, derived from PITX1 knockdown OS cell lines activated M2 macrophages in cell co-culture assays. M2 macrophage secreted several cytokines, among which CCL22 was found to cause OS cell EMT. Collectively, our data indicate that PITX1 suppresses OS cell proliferation and metastasis by downregulating LINC00662. Moreover, LINC00662 can be packaged into OS cell-derived exosomes to mediate M2 macrophage polarization to promote OS metastasis via CCL22.

RF01 | PMON46 Regulation of the Pituitary Cell Lineage Regulator Prop1 by the Stem Cell Determinant Musashi

Abstract The pituitary gland controls responses to changing physiological requirements during growth, pregnancy, puberty, and stress. Synthesis and secretion of appropriate pituitary hormones in response to changing organismal demands is mediated through a remarkable capacity for cellular plasticity of the distinct hormone-producing cells. The mechanisms governing pituitary cellular plasticity are not fully understood. We hypothesize that plasticity in the adult tissue is mediated through similar mechanisms to those that occur during embryonic and postnatal pituitary development. The Prophet of Pit1(Prop1), a paired-like homeodomain transcription factor, is the earliest pituitary-specific transcription factor and is highly expressed in pituitary progenitor cells where it controls lineage commitment to the distinct hormone-producing cell types. Our recent work has identified post-transcriptional regulation of pituitary gene expression in the adult tissue via the stem cell determinant, mRNA binding protein, Musashi. The full-length mouse Prop1 (mProp1) mRNA 3' untranslated region (UTR) contains 24 consensus binding elements for Musashi (MBEs) and demonstrates Musashi1-dependent translational activation in vitro. Specifically, the terminal mProp1 3' UTR MBE directs 40% of Musashi1-mediated translation activation, and mutational disruption of this terminal MBE abolishes all Musashi1-dependent translational activation. Immunoprecipitation of Musashi-mRNA complexes from adult mouse pituitaries confirmed Musashi1-mProp1 mRNA association in adult tissue. The gene sequence data for the human Prop1 (hPROP1) mRNA 3' UTR is incomplete in the Ensembl and RefSeq databases. Using published RNA sequencing datasets, we identified an expressed full-length hPROP1 mRNA 3' UTR of 6996 nucleotides with 54 predicted consensus MBEs, suggesting that the human PROP1 mRNA, like the murine Prop1 mRNA, may be subject to Musashi-dependent translational control. Our findings are consistent with the hypothesis that the Musashi protein exerts evolutionarily conserved control of Prop1 mRNA translation to facilitate plasticity of anterior pituitary function. Presentation: Saturday, June 11, 2022 1:31 p.m. - 1:36 p.m., Monday, June 13, 2022 12:30 p.m. - 2:30 p.m.

Variants rs2200733 and rs6843082 Show Different Associations in Asian and Non-Asian Populations With Ischemic Stroke.

A previous genome-wide association study (GWAS) has reported that variants rs2200733 and rs6843082 in the paired-like homeodomain transcription factor 2 (PITX2) gene may be one of the risk factors for ischemic stroke (IS) in European populations. However, more recently, studies in Asia have reported that rs2200733 and rs6843082 are only weakly or not associated with increased risk of IS. This difference may be caused by the sample size and genetic heterogeneity of rs2200733 and rs6843082 among different races. For this study, we selected eight articles with nine studies from the PubMed and Embase databases, including five articles from Asian and three articles from non-Asian, to evaluate the risk of IS caused by rs2200733 and rs6843082. Then, we investigated rs2200733 and rs6843082 single-nucleotide polymorphisms (SNPs) by analysis using allele, recessive, dominant, and additive models. We identified that rs2200733 and rs6843082 are weakly significantly associated with IS for the allele model (p = 0.8), recessive model (p = 0.8), dominant model (p = 0.49), and additive model (p = 0.76) in a pooled population. Next, we performed a subgroup analysis of the population, the result of which showed that rs2200733 and rs6843082 covey genetic risk for IS in a non-Asian population, but not in an Asian population. In conclusion, our analysis shows that the effect of PITX2 rs2200733 and rs6843082 SNPs on IS risk in Asia is inconsistent with the effect observed in European IS cohorts.

Ablation and antiarrhythmic drug effects on PITX2 +/- deficient atrial fibrillation: A computational modeling study.

IntroductionAtrial fibrillation (AF) is a heritable disease, and the paired-like homeodomain transcription factor 2 (PITX2) gene is highly associated with AF. We explored the differences in the circumferential pulmonary vein isolation (CPVI), which is the cornerstone procedure for AF catheter ablation, additional high dominant frequency (DF) site ablation, and antiarrhythmic drug (AAD) effects according to the patient genotype (wild-type and PITX2+/− deficient) using computational modeling.MethodsWe included 25 patients with AF (68% men, 59.8 ± 9.8 years of age, 32% paroxysmal AF) who underwent AF catheter ablation to develop a realistic computational AF model. The ion currents for baseline AF and the amiodarone, dronedarone, and flecainide AADs according to the patient genotype (wild type and PITX2+/− deficient) were defined by relevant publications. We tested the virtual CPVI (V-CPVI) with and without DF ablation (±DFA) and three virtual AADs (V-AADs, amiodarone, dronedarone, and flecainide) and evaluated the AF defragmentation rates (AF termination or changes to regular atrial tachycardia (AT), DF, and maximal slope of the action potential duration restitution curves (Smax), which indicates the vulnerability of wave-breaks.ResultsAt the baseline AF, mean DF (p = 0.003), and Smax (p < 0.001) were significantly lower in PITX2+/− deficient patients than wild-type patients. In the overall AF episodes, V-CPVI (±DFA) resulted in a higher AF defragmentation relative to V-AADs (65 vs. 42%, p < 0.001) without changing the DF or Smax. Although a PITX2+/− deficiency did not affect the AF defragmentation rate after the V-CPVI (±DFA), V-AADs had a higher AF defragmentation rate (p = 0.014), lower DF (p < 0.001), and lower Smax (p = 0.001) in PITX2+/− deficient AF than in wild-type patients. In the clinical setting, the PITX2+/− genetic risk score did not affect the AF ablation rhythm outcome (Log-rank p = 0.273).ConclusionConsistent with previous clinical studies, the V-CPVI had effective anti-AF effects regardless of the PITX2 genotype, whereas V-AADs exhibited more significant defragmentation or wave-dynamic change in the PITX2+/− deficient patients.

Generation of FLAG-tagged Arx knock-in mouse model.

The Aristaless-related homeobox (ARX) is a paired-like homeodomain transcription factor playing important roles in brain development. Patients with mutations in ARX have a spectrum of neurodevelopmental disorders such as epilepsy, intellectual disability, and autism spectrum disorder, with or without structural abnormalities of the brain such as lissencephaly (smooth brain), microcephaly (small brain), and/or agenesis of the corpus callosum. Mouse models have provided important clues on the pathophysiologic roles of ARX in these disorders. However, successfully isolating specific in vivo complexes of ARX, with DNA and proteins, has remained as a challenge. To facilitate in vivo detection of ARX complexes, we generated a mouse line containing one epitope of FLAG-tag (1 × FLAG) targeted at the translational start site of the endogenous Arx gene using CRSPR/Cas9 strategy. Homozygous Flag-Arx mice are viable and fertile without gross abnormality, suggesting that the FLAG-tag does not perturb the normal function of ARX. Using a FLAG antibody, we successfully detected ARX with immunofluorescent staining and pulled down ARX in embryonic brain tissues. This Flag-Arx mouse line will be a useful tool to isolate ARX complexes from mouse tissues for many applications.

PITX2 regulates steroidogenesis in granulosa cells of dairy goat by the WNT/β-catenin pathway

Paired-like homeodomain transcription factor 2 (PITX2), a major driver of multiple tissue development, is a transcription factor that regulates gene expression in organisms. However, it is unknown if PITX2 regulates goat granulosa cell (GC) steroidogenesis. Therefore, we investigated the role and mechanism of PITX2 in GC steroidogenesis. In our study, PITX2 significantly facilitated the secretion level of estrogen and progesterone through increasing CYP11A1, CYP19A1, and STAR mRNA and protein expressions in GCs. Furthermore, PITX2 participated in the WNT pathway, enhancing the production of E2 and P4 in GCs. PITX2 in GCs increased the DVL-1 and CTNNB1 expression, involved in the WNT/β-catenin signaling pathway related to steroidogenesis. Moreover, GC steroidogenesis-related gene translation was decreased by CTNNB1-siRNA but enhanced when transfected with PITX2. PITX2 regulates secretion of E2 and P4 from GCs via the WNT/β-catenin pathway and alters GC proliferation and steroidogenesis. These findings will help understand the role of PITX2 in goat ovarian follicular development and oocyte maturation.

Effect of PITX2 genetic variants on the susceptibility to stroke in the Chinese Han population.

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. 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. 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 65years (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. 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.

Upregulated Transcription Factor PITX1 Predicts Poor Prognosis in Kidney Renal Clear Cell Carcinoma-Based Bioinformatic Analysis and Experimental Verification.

Paired-like homeodomain transcription factor 1 (PITX1) is involved in numerous biological processes, including cell growth, progression, and invasion in various malignant tumors. Nevertheless, the relationship between PITX1 and kidney renal clear cell carcinoma (KIRC) remains unclear. The clinical role and functions of PITX1 were analyzed by integrating multiple open-access online datasets. Further experimental verification was performed via quantitative real-time PCR (qRT-PCR) to detect the expression of PITX1 in 10 pairs of KIRC tissues. Our results revealed that PITX1 mRNA was overexpressed in tumor tissues compared with normal tissues in the TCGA-KIRC database (p < 0.001) and numerous independent cohorts (p < 0.05). Further, high expression of PITX1 mRNA was detected in KIRC tissues compared with adjacent normal tissues in our center by qRT-PCR (N = 10, p < 0.05). Logistic regression analysis demonstrated that the PITX1 level was positively associated with KIRC patients, T and M stages, histologic grade, and pathologic stage (all p < 0.05). Survival analysis showed that upregulation of PITX1 mRNA was associated with poor overall survival (OS), disease-free survival (DFS), and disease-specific survival (DSS) (all p < 0.05). Univariate/multivariate Cox hazard regression analysis revealed that PITX1 was an independent risk factor for OS in patients with KIRC (HR = 1.998, p = 0.003). Accordingly, the time-independent receiver operating characteristic (ROC) curve confirmed that PITX1 had good predictive efficacy for OS and DSS. Meanwhile, a prediction model constructed by nomogram was used to predict the OS of KIRC patients, and the calibration plot indicated this model shows high accuracy. We also revealed some downstream target genes of PITX1-related signaling pathways. Our finding suggested that high PITX1 mRNA expression may act as an independent predictive factor of poor prognosis in patients with KIRC. The prognostic model based on the nomogram would be instrumental in evaluating the survival rate in KIRC patients.

PITX1 inhibits the growth and proliferation of melanoma cells through regulation of SOX family genes

Melanoma is one of the most aggressive types of cancer wherein resistance to treatment prevails. Therefore, it is important to discover novel molecular targets of melanoma progression as potential treatments. Here we show that paired-like homeodomain transcription factor 1 (PITX1) plays a crucial role in the inhibition of melanoma progression through regulation of SRY-box transcription factors (SOX) gene family mRNA transcription. Overexpression of PITX1 in melanoma cell lines resulted in a reduction in cell proliferation and an increase in apoptosis. Additionally, analysis of protein levels revealed an antagonistic cross-regulation between SOX9 and SOX10. Interestingly, PITX1 binds to the SOX9 promoter region as a positive regulatory transcription factor; PITX1 mRNA expression levels were positively correlated with SOX9 expression, and negatively correlated with SOX10 expression in melanoma tissues. Furthermore, transcription of the long noncoding RNA (lncRNA), survival-associated mitochondrial melanoma-specific oncogenic noncoding RNA (SAMMSON), was decreased in PITX1-overexpressing cells. Taken together, the findings in this study indicate that PITX1 may act as a negative regulatory factor in the development and progression of melanoma via direct targeting of the SOX signaling.

The significance of homeodomain transcription factor 2 in colon cancer cells

BackgroundColon cancer is a serious malignant tumor. It has been reported that paired-like homeodomain transcription factor 2 (PITX2) can promote the progression of several types of cancer via regulating the Wnt/β-catenin pathway. It has also been demonstrated that high levels of long non-coding RNA (lncRNA) gastric carcinoma high expressed transcript 1 (GHET1) can also promote the development of cervical cancer via activating the Wnt/β-catenin pathway. However, whether PITX2 can affect the development of colon cancer via regulating the expression of lncRNA GHET1 remains unclear.ResultsThe results demonstrated that PITX2 knockdown attenuated the proliferation, migration and invasion abilities of colon cancer cells. Additionally, PITX2 promoted the expression of lncRNA GHET1 via binding to its promoter. Overexpression of lncRNA GHET1 induced the expression of Wnt/β-catenin signaling-related proteins, cyclin D1, c-Myc and MMP-7. Furthermore, lncRNA GHET1 overexpression abrogated the PITX2 silencing-mediated decreased proliferation, migration and invasion abilities of colon cancer cells.ConclusionThe findings of the present study suggested that PITX2 could enhance the proliferation, migration and invasion abilities of colon cancer cells via upregulating lncRNA GHET1 and activating the Wnt/β-catenin pathway.

Paired-like homeodomain transcription factor 2 affects endometrial cell function and embryo implantation through the Wnt/β-catenin pathway.

The successful implantation of embryos is crucial for pregnancy in mammals. This complex process is inevitably dependent on the development of the endometrium. The paired-like homeodomain transcription factor 2 (PITX2) is involved in a variety of biological processes, but whether it is involved in embryo implantation has not been reported. In this study, we aimed to investigate uterine expression and regulation of PITX2 during implantation. We found that PITX2 was elevated in the human endometrium in the secretory phase. The results of the pregnant mouse models showed that PITX2 expression was spatiotemporal in mouse endometrial tissue throughout peri-implantation period, and it was significantly upregulated at the time of implantation. Interestingly, PITX2 was mainly localized to the glandular epithelium cells on D2.5-3.5 of pregnancy, while D5.5-6.5 was largely expressed in stromal cells. In vitro, PITX2 regulated endometrial cells proliferation, migration, invasion, and other functions through the Wnt/β-catenin signaling pathway. In addition, a significant decrease in the rate of embryo implantation was observed after injecting PITX2 small interfering RNA into the uterine horn. These results demonstrate the effects of PITX2 on the physiological function of endometrial cells and embryo implantation, suggesting a role in the endometrial regulatory mechanism during implantation.

Immunity-longevity tradeoff neurally controlled by GABAergic transcription factor PITX1/UNC-30.

SUMMARYA body of evidence indicates that metazoan immune and aging pathways are largely interconnected, but the mechanisms involved in their homeostatic control remain unclear. In this study, we find that the PITX (paired-like homeodomain) transcription factor UNC-30 controls the tradeoff between immunity and longevity from the nervous system in Caenorhabditis elegans. PITX/UNC-30 functional loss enhances immunity in a GATA/ELT-2- and p38 MAPK/PMK-1-dependent manner and reduced longevity by activating MXD/MDL-1 and the C2H2-type zinc finger transcription factor PQM-1. The immune inhibitory and longevity stimulatory functions of PITX/UNC-30 require the sensory neuron ASG and a signaling pathway controlled by NPR-1, which is a G protein-coupled receptor related to mammalian neuropeptide Y receptors. Our findings uncover a suppressive role of GABAergic signaling in the neural control of a biological tradeoff where energy is allocated toward immunity at the expense of longevity.