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Su D, Eliason S, Sun Z, Shao F, Amendt BA. Wolf-Hirschhorn syndrome candidate 1 (Whsc1) methyltransferase signals via a Pitx2-miR-23/24 axis to effect tooth development. J Biol Chem 2023; 299:105324. [PMID: 37806494 PMCID: PMC10656234 DOI: 10.1016/j.jbc.2023.105324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Revised: 09/01/2023] [Accepted: 09/22/2023] [Indexed: 10/10/2023] Open
Abstract
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.
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Affiliation(s)
- Dan Su
- Department of Anatomy and Cell Biology, The University of Iowa, Iowa City, Iowa, USA; Craniofacial Anomalies Research Center, Carver College of Medicine, The University of Iowa, Iowa City, Iowa, USA
| | - Steve Eliason
- Department of Anatomy and Cell Biology, The University of Iowa, Iowa City, Iowa, USA; Craniofacial Anomalies Research Center, Carver College of Medicine, The University of Iowa, Iowa City, Iowa, USA
| | - Zhao Sun
- College of Medicine, Washington University St Louis, St Louis, Missouri, USA
| | - Fan Shao
- Department of Anatomy and Cell Biology, The University of Iowa, Iowa City, Iowa, USA
| | - Brad A Amendt
- Department of Anatomy and Cell Biology, The University of Iowa, Iowa City, Iowa, USA; Craniofacial Anomalies Research Center, Carver College of Medicine, The University of Iowa, Iowa City, Iowa, USA; Iowa Institute for Oral Health Research, College of Dentistry, The University of Iowa, Iowa City, Iowa, USA.
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2
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Seidl C, Da Silva F, Zhang K, Wohlgemuth K, Omran H, Niehrs C. Mucociliary Wnt signaling promotes cilia biogenesis and beating. Nat Commun 2023; 14:1259. [PMID: 36878953 PMCID: PMC9988884 DOI: 10.1038/s41467-023-36743-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Accepted: 02/15/2023] [Indexed: 03/08/2023] Open
Abstract
It is widely thought that Wnt/Lrp6 signaling proceeds through the cytoplasm and that motile cilia are signaling-inert nanomotors. Contrasting both views, we here show in the mucociliary epidermis of X. tropicalis embryos that motile cilia transduce a ciliary Wnt signal that is distinct from canonical β-catenin signaling. Instead, it engages a Wnt-Gsk3-Ppp1r11-Pp1 signaling axis. Mucociliary Wnt signaling is essential for ciliogenesis and it engages Lrp6 co-receptors that localize to cilia via a VxP ciliary targeting sequence. Live-cell imaging using a ciliary Gsk3 biosensor reveals an immediate response of motile cilia to Wnt ligand. Wnt treatment stimulates ciliary beating in X. tropicalis embryos and primary human airway mucociliary epithelia. Moreover, Wnt treatment improves ciliary function in X. tropicalis ciliopathy models of male infertility and primary ciliary dyskinesia (ccdc108, gas2l2). We conclude that X. tropicalis motile cilia are Wnt signaling organelles that transduce a distinct Wnt-Pp1 response.
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Affiliation(s)
- Carina Seidl
- Division of Molecular Embryology, DKFZ-ZMBH Alliance, 69120, Heidelberg, Germany
| | - Fabio Da Silva
- Division of Molecular Embryology, DKFZ-ZMBH Alliance, 69120, Heidelberg, Germany
| | - Kaiqing Zhang
- Division of Molecular Embryology, DKFZ-ZMBH Alliance, 69120, Heidelberg, Germany
| | - Kai Wohlgemuth
- University Children's Hospital Muenster, Department of General Pediatrics, 48149, Muenster, Germany
| | - Heymut Omran
- University Children's Hospital Muenster, Department of General Pediatrics, 48149, Muenster, Germany
| | - Christof Niehrs
- Division of Molecular Embryology, DKFZ-ZMBH Alliance, 69120, Heidelberg, Germany. .,Institute of Molecular Biology (IMB), 55128, Mainz, Germany.
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3
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Genotype-phenotype association of PITX2 and FOXC1 in Axenfeld-Rieger syndrome. Exp Eye Res 2023; 226:109307. [PMID: 36442680 DOI: 10.1016/j.exer.2022.109307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Revised: 10/18/2022] [Accepted: 11/09/2022] [Indexed: 11/27/2022]
Abstract
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.
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Eliason S, Su D, Pinho F, Sun Z, Zhang Z, Li X, Sweat M, Venugopalan SR, He B, Bustin M, Amendt BA. HMGN2 represses gene transcription via interaction with transcription factors Lef-1 and Pitx2 during amelogenesis. J Biol Chem 2022; 298:102295. [PMID: 35872015 PMCID: PMC9418915 DOI: 10.1016/j.jbc.2022.102295] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 07/06/2022] [Accepted: 07/11/2022] [Indexed: 11/06/2022] Open
Abstract
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.
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Affiliation(s)
- Steven Eliason
- Department of Anatomy and Cell Biology, and the Craniofacial Anomalies Research Center, The University of Iowa, Iowa City, IA
| | - Dan Su
- Department of Anatomy and Cell Biology, and the Craniofacial Anomalies Research Center, The University of Iowa, Iowa City, IA
| | | | - Zhao Sun
- Washington University St. Louis, St. Louis, MO
| | | | - Xiao Li
- Texas Heart Institute, Houston, TX
| | | | | | - Bing He
- Protein Section, Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Michael Bustin
- Protein Section, Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Brad A Amendt
- Department of Anatomy and Cell Biology, and the Craniofacial Anomalies Research Center, The University of Iowa, Iowa City, IA; Department of Orthodontics, The University of Iowa, Iowa City, IA.
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5
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Sun Z, da Fontoura CSG, Moreno M, Holton NE, Sweat M, Sweat Y, Lee MK, Arbon J, Bidlack FB, Thedens DR, Nopoulos P, Cao H, Eliason S, Weinberg SM, Martin JF, Moreno-Uribe L, Amendt BA. FoxO6 regulates Hippo signaling and growth of the craniofacial complex. PLoS Genet 2018; 14:e1007675. [PMID: 30286078 PMCID: PMC6197693 DOI: 10.1371/journal.pgen.1007675] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Revised: 10/22/2018] [Accepted: 08/31/2018] [Indexed: 12/17/2022] Open
Abstract
The mechanisms that regulate post-natal growth of the craniofacial complex and that ultimately determine the size and shape of our faces are not well understood. Hippo signaling is a general mechanism to control tissue growth and organ size, and although it is known that Hippo signaling functions in neural crest specification and patterning during embryogenesis and before birth, its specific role in postnatal craniofacial growth remains elusive. We have identified the transcription factor FoxO6 as an activator of Hippo signaling regulating neonatal growth of the face. During late stages of mouse development, FoxO6 is expressed specifically in craniofacial tissues and FoxO6-/- mice undergo expansion of the face, frontal cortex, olfactory component and skull. Enlargement of the mandible and maxilla and lengthening of the incisors in FoxO6-/- mice are associated with increases in cell proliferation. In vitro and in vivo studies demonstrated that FoxO6 activates Lats1 expression, thereby increasing Yap phosphorylation and activation of Hippo signaling. FoxO6-/- mice have significantly reduced Hippo Signaling caused by a decrease in Lats1 expression and decreases in Shh and Runx2 expression, suggesting that Shh and Runx2 are also linked to Hippo signaling. In vitro, FoxO6 activates Hippo reporter constructs and regulates cell proliferation. Furthermore PITX2, a regulator of Hippo signaling is associated with Axenfeld-Rieger Syndrome causing a flattened midface and we show that PITX2 activates FoxO6 expression. Craniofacial specific expression of FoxO6 postnatally regulates Hippo signaling and cell proliferation. Together, these results identify a FoxO6-Hippo regulatory pathway that controls skull growth, odontogenesis and face morphology.
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Affiliation(s)
- Zhao Sun
- Department of Anatomy and Cell Biology, and the Craniofacial Anomalies Research Center, Carver College of Medicine, The University of Iowa, Iowa City, IA, United States of America
| | - Clarissa S. G. da Fontoura
- Iowa Institute for Oral Health Research, College of Dentistry, The University of Iowa, Iowa City, IA, United States of America
| | - Myriam Moreno
- Department of Anatomy and Cell Biology, and the Craniofacial Anomalies Research Center, Carver College of Medicine, The University of Iowa, Iowa City, IA, United States of America
| | - Nathan E. Holton
- Department of Orthodontics, College of Dentistry, The University of Iowa, Iowa City, IA, United States of America
| | - Mason Sweat
- Department of Anatomy and Cell Biology, and the Craniofacial Anomalies Research Center, Carver College of Medicine, The University of Iowa, Iowa City, IA, United States of America
| | - Yan Sweat
- Department of Anatomy and Cell Biology, and the Craniofacial Anomalies Research Center, Carver College of Medicine, The University of Iowa, Iowa City, IA, United States of America
| | - Myoung Keun Lee
- Department of Oral Biology, School of Dental Medicine, University of Pittsburgh, Pittsburgh PA, United States of America
| | - Jed Arbon
- Private practice, Cary, North Carolina United States of America
| | | | - Daniel R. Thedens
- Department of Psychiatry, Carver College of Medicine, The University of Iowa, Iowa City, IA, United States of America
| | - Peggy Nopoulos
- Department of Psychiatry, Carver College of Medicine, The University of Iowa, Iowa City, IA, United States of America
| | - Huojun Cao
- Iowa Institute for Oral Health Research, College of Dentistry, The University of Iowa, Iowa City, IA, United States of America
| | - Steven Eliason
- Department of Anatomy and Cell Biology, and the Craniofacial Anomalies Research Center, Carver College of Medicine, The University of Iowa, Iowa City, IA, United States of America
| | - Seth M. Weinberg
- Department of Oral Biology, School of Dental Medicine, University of Pittsburgh, Pittsburgh PA, United States of America
| | - James F. Martin
- Department of Physiology, Baylor College of Medicine, Houston, TX, United States of America
| | - Lina Moreno-Uribe
- Iowa Institute for Oral Health Research, College of Dentistry, The University of Iowa, Iowa City, IA, United States of America
- Department of Orthodontics, College of Dentistry, The University of Iowa, Iowa City, IA, United States of America
| | - Brad A. Amendt
- Department of Anatomy and Cell Biology, and the Craniofacial Anomalies Research Center, Carver College of Medicine, The University of Iowa, Iowa City, IA, United States of America
- Iowa Institute for Oral Health Research, College of Dentistry, The University of Iowa, Iowa City, IA, United States of America
- Department of Orthodontics, College of Dentistry, The University of Iowa, Iowa City, IA, United States of America
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6
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Abstract
There are multiple intrinsic mechanisms for diastolic dysfunction ranging from molecular to structural derangements in ventricular myocardium. The molecular mechanisms regulating the progression from normal diastolic function to severe dysfunction still remain poorly understood. Recent studies suggest a potentially important role of core cardio-enriched transcription factors (TFs) in the control of cardiac diastolic function in health and disease through their ability to regulate the expression of target genes involved in the process of adaptive and maladaptive cardiac remodeling. The current relevant findings on the role of a variety of such TFs (TBX5, GATA-4/6, SRF, MYOCD, NRF2, and PITX2) in cardiac diastolic dysfunction and failure are updated, emphasizing their potential as promising targets for novel treatment strategies. In turn, the new animal models described here will be key tools in determining the underlying molecular mechanisms of disease. Since diastolic dysfunction is regulated by various TFs, which are also involved in cross talk with each other, there is a need for more in-depth research from a biomedical perspective in order to establish efficient therapeutic strategies.
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7
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Liang B, He X, Shang D, Tian Y, Liu Z. The link between FOXJ1 expression level in bladder carcinoma and tumor recurrence. Oncol Lett 2018; 15:1483-1486. [PMID: 29434839 PMCID: PMC5774442 DOI: 10.3892/ol.2017.7504] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Accepted: 12/16/2016] [Indexed: 11/24/2022] Open
Abstract
We studied the expression level of FOXJ1 in bladder epithelial carcinoma and its relation to clinical features and tumor recurrence. From January 2014 to June 2015, 66 patients with bladder epithelial carcinoma were enrolled in this study and their tumor and para-carcinoma tissue samples were collected. FOXJ1 positive expression rate was evaluated using immunohistochemical staining, and FOXJ1 mRNA expression level was measured by RT-PCR. RT-PCR and immunohistochemistry results showed that FOXJ1 expression level in tumor samples was significantly lower than that in para-carcinoma tissue samples. The median survival time in patients with positive expression of FOXJ1 was significantly longer than that of patients with negative expression of FOXJ1. We also showed that FOXJ1 expression level was negatively correlated with neoplasm staging and tumor recurrence rate. We concluded that FOXJ1 was expressed in low quantities in bladder epithelial carcinoma, which was closely correlated with the biological characteristics of the tumor. FOXJ1 expression presents a promising application prospect for further exploration of the specific biological mechanism of FOXJ1 in regulating the occurrence and development of bladder epithelial carcinoma. FOXJ1 may be used as a new marker for early diagnosis and prediction of recurrence.
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Affiliation(s)
- Bing Liang
- Department of Oncology, The Second Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450052, P.R. China
| | - Xinwei He
- Department of Infection, The Second Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450052, P.R. China
| | - Donghao Shang
- Department of Urology, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, P.R. China
| | - Ye Tian
- Department of Urology, Beijing Friendship Hospital, Capital Medical University, Beijing 100050, P.R. China
| | - Zongwen Liu
- Department of Radiotherapy, The Second Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450052, P.R. China
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8
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Ramanathan A, Srijaya TC, Sukumaran P, Zain RB, Abu Kasim NH. Homeobox genes and tooth development: Understanding the biological pathways and applications in regenerative dental science. Arch Oral Biol 2017; 85:23-39. [PMID: 29031235 DOI: 10.1016/j.archoralbio.2017.09.033] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 09/27/2017] [Accepted: 09/30/2017] [Indexed: 12/31/2022]
Abstract
OBJECTIVES Homeobox genes are a group of conserved class of transcription factors that function as key regulators during the embryonic developmental processes. They act as master regulator for developmental genes, which involves coordinated actions of various auto and cross-regulatory mechanisms. In this review, we summarize the expression pattern of homeobox genes in relation to the tooth development and various signaling pathways or molecules contributing to the specific actions of these genes in the regulation of odontogenesis. MATERIALS AND METHODS An electronic search was undertaken using combination of keywords e.g. Homeobox genes, tooth development, dental diseases, stem cells, induced pluripotent stem cells, gene control region was used as search terms in PubMed and Web of Science and relevant full text articles and abstract were retrieved that were written in English. A manual hand search in text books were also carried out. Articles related to homeobox genes in dentistry and tissue engineering and regenerative medicine of odontogenesis were selected. RESULTS The possible perspective of stem cells technology in odontogenesis and subsequent analysis of gene correction pertaining to dental disorders through the possibility of induced pluripotent stem cells technology is also inferred. CONCLUSIONS We demonstrate the promising role of tissue engineering and regenerative medicine on odontogenesis, which can generate a new ray of hope in the field of dental science.
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Affiliation(s)
- Anand Ramanathan
- Oral Cancer Research and Coordinating Center, Faculty of Dentistry, University of Malaya, Kuala Lumpur, Malaysia; Department of Oral & Maxillofacial Clinical Science, Faculty of Dentistry, University of Malaya, Kuala Lumpur, Malaysia.
| | | | - Prema Sukumaran
- Department of Restorative Dentistry, Faculty of Dentistry, University of Malaya, Kuala Lumpur, Malaysia.
| | - Rosnah Binti Zain
- Oral Cancer Research and Coordinating Center, Faculty of Dentistry, University of Malaya, Kuala Lumpur, Malaysia; Department of Oral & Maxillofacial Clinical Science, Faculty of Dentistry, University of Malaya, Kuala Lumpur, Malaysia; Faculty of Dentistry, MAHSA University, Jenjarom, Selangor, Malaysia.
| | - Noor Hayaty Abu Kasim
- Department of Restorative Dentistry, Faculty of Dentistry, University of Malaya, Kuala Lumpur, Malaysia.
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9
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Bifsha P, Balsalobre A, Drouin J. Specificity of Pitx3-Dependent Gene Regulatory Networks in Subsets of Midbrain Dopamine Neurons. Mol Neurobiol 2016; 54:4921-4935. [PMID: 27514757 DOI: 10.1007/s12035-016-0040-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2016] [Accepted: 08/05/2016] [Indexed: 01/16/2023]
Abstract
Dysfunction of midbrain dopaminergic (mDA) neurons is involved in Parkinson's disease (PD) and neuropsychiatric disorders. Pitx3 is expressed in mDA neuron subsets of the substantia nigra compacta (SNc) and of the ventral tegmental area (VTA) that are degeneration-sensitive in PD. The genetic network(s) and mode(s) of action of Pitx3 in these mDA neurons remain poorly characterized. We hypothesized that, given their distinct neuronal identities, Pitx3-expressing neurons of SNc and VTA should differ in their Pitx3-controlled gene expression networks and this may involve subset-specific co-regulators. Expression profiling of purified mDA neuronal subsets indicates that Pitx3 regulates different sets of genes in SNc and VTA, such as activating the expression of primary cilium gene products specifically in VTA neurons. Interaction network analysis pointed to the participation of differentially expressed Lhx/Lmo family members in the modulation of Pitx3 action in SNc and VTA mDA neurons. Conversely, global binding patterns of Pitx3 on genomic DNA of human dopaminergic cells revealed that Pitx3 is often co-recruited to regions that foster the formation of GATA-bHLH-BRN complexes, which usually involve Lmo co-regulatory proteins. We focused on Lmo3 for its preferential expression in SNc neurons and demonstrated that it functions as a transcriptional co-activator of Pitx3 by enhancing its activity on genomic regulatory elements. In summary, we defined the SN and VTA-specific programs of Pitx3-dependent gene expression and identified Lmo3 as a SN-specific co-regulator of Pitx3-dependent transcription.
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Affiliation(s)
- Panojot Bifsha
- Laboratoire de génétique moléculaire, Institut de recherches cliniques de Montréal (IRCM), 110, avenue des Pins Ouest, Montréal, Québec, H2W 1R7, Canada.,Division of Experimental Medicine, McGill University, Montréal, Quebec, H3A 1A3, Canada
| | - Aurelio Balsalobre
- Laboratoire de génétique moléculaire, Institut de recherches cliniques de Montréal (IRCM), 110, avenue des Pins Ouest, Montréal, Québec, H2W 1R7, Canada
| | - Jacques Drouin
- Laboratoire de génétique moléculaire, Institut de recherches cliniques de Montréal (IRCM), 110, avenue des Pins Ouest, Montréal, Québec, H2W 1R7, Canada. .,Division of Experimental Medicine, McGill University, Montréal, Quebec, H3A 1A3, Canada.
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10
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Sharp T, Wang J, Li X, Cao H, Gao S, Moreno M, Amendt BA. A pituitary homeobox 2 (Pitx2):microRNA-200a-3p:β-catenin pathway converts mesenchymal cells to amelogenin-expressing dental epithelial cells. J Biol Chem 2014; 289:27327-27341. [PMID: 25122764 PMCID: PMC4175363 DOI: 10.1074/jbc.m114.575654] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2014] [Revised: 08/12/2014] [Indexed: 12/21/2022] Open
Abstract
Pitx2, Wnt/β-catenin signaling, and microRNAs (miRs) play a critical role in the regulation of dental stem cells during embryonic development. In this report, we have identified a Pitx2:β-catenin regulatory pathway involved in epithelial cell differentiation and conversion of mesenchymal cells to amelogenin expressing epithelial cells via miR-200a. Pitx2 and β-catenin are expressed in the labial incisor cervical loop or epithelial stem cell niche, with decreased expression in the differentiating ameloblast cells of the mouse lower incisor. Bioinformatics analyses reveal that miR-200a-3p expression is activated in the pre-ameloblast cells to enhance epithelial cell differentiation. We demonstrate that Pitx2 activates miR-200a-3p expression and miR-200a-3p reciprocally represses Pitx2 and β-catenin expression. Pitx2 and β-catenin interact to synergistically activate gene expression during odontogenesis and miR-200a-3p attenuates their expression and directs differentiation. To understand how this mechanism controls cell differentiation and cell fate, oral epithelial and odontoblast mesenchymal cells were reprogrammed by a two-step induction method using Pitx2 and miR-200a-3p. Conversion to amelogenin expressing dental epithelial cells involved an up-regulation of the stem cell marker Sox2 and proliferation genes and decreased expression of mesenchymal markers. E-cadherin expression was increased as well as ameloblast specific factors. The combination of Pitx2, a regulator of dental stem cells and miR-200a converts mesenchymal cells to a fully differentiated dental epithelial cell type. This pathway and reprogramming can be used to reprogram mesenchymal or oral epithelial cells to dental epithelial (ameloblast) cells, which can be used in tissue repair and regeneration studies.
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Affiliation(s)
- Thad Sharp
- Department of Anatomy and Cell Biology, Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242
| | - Jianbo Wang
- Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, Texas 77030, and
| | - Xiao Li
- Department of Anatomy and Cell Biology, Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242
| | - Huojun Cao
- Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, Texas 77030, and
| | - Shan Gao
- Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, Texas 77030, and
| | - Myriam Moreno
- Department of Anatomy and Cell Biology, Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242
| | - Brad A Amendt
- Department of Anatomy and Cell Biology, Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242,; Craniofacial Anomalies Research Center, Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242.
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11
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Torrado M, Franco D, Hernández-Torres F, Crespo-Leiro MG, Iglesias-Gil C, Castro-Beiras A, Mikhailov AT. Pitx2c is reactivated in the failing myocardium and stimulates myf5 expression in cultured cardiomyocytes. PLoS One 2014; 9:e90561. [PMID: 24595098 PMCID: PMC3942452 DOI: 10.1371/journal.pone.0090561] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2013] [Accepted: 02/01/2014] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Pitx2 (paired-like homeodomain 2 transcription factor) is crucial for heart development, but its role in heart failure (HF) remains uncertain. The present study lays the groundwork implicating Pitx2 signalling in different modalities of HF. METHODOLOGY/PRINCIPAL FINDINGS A variety of molecular, cell-based, biochemical, and immunochemical assays were used to evaluate: (1) Pitx2c expression in the porcine model of diastolic HF (DHF) and in patients with systolic HF (SHF) due to dilated and ischemic cardiomyopathy, and (2) molecular consequences of Pitx2c expression manipulation in cardiomyocytes in vitro. In pigs, the expression of Pitx2c, physiologically downregulated in the postnatal heart, is significantly re-activated in left ventricular (LV) failing myocardium which, in turn, is associated with increased expression of a restrictive set of Pitx2 target genes. Among these, Myf5 was identified as the top upregulated gene. In vitro, forced expression of Pitx2c in cardiomyocytes, but not in skeletal myoblasts, activates Myf5 in dose-dependent manner. In addition, we demonstrate that the level of Pitx2c is upregulated in the LV-myocardium of SHF patients. CONCLUSIONS/SIGNIFICANCE The results provide previously unrecognized evidence that Pitx2c is similarly reactivated in postnatal/adult heart at distinct HF phenotypes and suggest that Pitx2c is involved, directly or indirectly, in the regulation of Myf5 expression in cardiomyocytes.
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Affiliation(s)
- Mario Torrado
- Institute of Health Sciences, University of La Coruña, La Coruña, Spain
| | - Diego Franco
- Department of Experimental Biology, University of Jaen, Jaen, Spain
| | | | | | | | - Alfonso Castro-Beiras
- Institute of Health Sciences, University of La Coruña, La Coruña, Spain
- University Hospital Center of La Coruña, La Coruña, Spain
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12
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Li X, Venugopalan SR, Cao H, Pinho FO, Paine ML, Snead ML, Semina EV, Amendt BA. A model for the molecular underpinnings of tooth defects in Axenfeld-Rieger syndrome. Hum Mol Genet 2014; 23:194-208. [PMID: 23975681 PMCID: PMC3857954 DOI: 10.1093/hmg/ddt411] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Accepted: 08/19/2013] [Indexed: 12/18/2022] Open
Abstract
Patients with Axenfeld-Rieger Syndrome (ARS) present various dental abnormalities, including hypodontia, and enamel hypoplasia. ARS is genetically associated with mutations in the PITX2 gene, which encodes one of the earliest transcription factors to initiate tooth development. Thus, Pitx2 has long been considered as an upstream regulator of the transcriptional hierarchy in early tooth development. However, because Pitx2 is also a major regulator of later stages of tooth development, especially during amelogenesis, it is unclear how mutant forms cause ARS dental anomalies. In this report, we outline the transcriptional mechanism that is defective in ARS. We demonstrate that during normal tooth development Pitx2 activates Amelogenin (Amel) expression, whose product is required for enamel formation, and that this regulation is perturbed by missense PITX2 mutations found in ARS patients. We further show that Pitx2-mediated Amel activation is controlled by chromatin-associated factor Hmgn2, and that Hmgn2 prevents Pitx2 from efficiently binding to and activating the Amel promoter. Consistent with a physiological significance to this interaction, we show that K14-Hmgn2 transgenic mice display a severe loss of Amel expression on the labial side of the lower incisors, as well as enamel hypoplasia-consistent with the human ARS phenotype. Collectively, these findings define transcriptional mechanisms involved in normal tooth development and shed light on the molecular underpinnings of the enamel defect observed in ARS patients who carry PITX2 mutations. Moreover, our findings validate the etiology of the enamel defect in a novel mouse model of ARS.
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Affiliation(s)
- Xiao Li
- Department of Anatomy and Cell Biology and Craniofacial Anomalies Research Center, The University of Iowa, Iowa City, IA 52244, USA
| | - Shankar R. Venugopalan
- Department of Anatomy and Cell Biology and Craniofacial Anomalies Research Center, The University of Iowa, Iowa City, IA 52244, USA
| | - Huojun Cao
- Department of Anatomy and Cell Biology and Craniofacial Anomalies Research Center, The University of Iowa, Iowa City, IA 52244, USA
| | - Flavia O. Pinho
- Department of Anatomy and Cell Biology and Craniofacial Anomalies Research Center, The University of Iowa, Iowa City, IA 52244, USA
| | - Michael L. Paine
- Center for Craniofacial Molecular Biology, Ostrow School of Dentistry, University of Southern California, Los Angeles, CA, USA and
| | - Malcolm L. Snead
- Center for Craniofacial Molecular Biology, Ostrow School of Dentistry, University of Southern California, Los Angeles, CA, USA and
| | - Elena V. Semina
- Division of Developmental Biology, Department of Pediatrics, The Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Brad A. Amendt
- Department of Anatomy and Cell Biology and Craniofacial Anomalies Research Center, The University of Iowa, Iowa City, IA 52244, USA
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13
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Tan FE, Vladar EK, Ma L, Fuentealba LC, Hoh R, Espinoza FH, Axelrod JD, Alvarez-Buylla A, Stearns T, Kintner C, Krasnow MA. Myb promotes centriole amplification and later steps of the multiciliogenesis program. Development 2013; 140:4277-86. [PMID: 24048590 PMCID: PMC3787764 DOI: 10.1242/dev.094102] [Citation(s) in RCA: 93] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The transcriptional control of primary cilium formation and ciliary motility are beginning to be understood, but little is known about the transcriptional programs that control cilium number and other structural and functional specializations. One of the most intriguing ciliary specializations occurs in multiciliated cells (MCCs), which amplify their centrioles to nucleate hundreds of cilia per cell, instead of the usual monocilium. Here we report that the transcription factor MYB, which promotes S phase and drives cycling of a variety of progenitor cells, is expressed in postmitotic epithelial cells of the mouse airways and ependyma destined to become MCCs. MYB is expressed early in multiciliogenesis, as progenitors exit the cell cycle and amplify their centrioles, then switches off as MCCs mature. Conditional inactivation of Myb in the developing airways blocks or delays centriole amplification and expression of FOXJ1, a transcription factor that controls centriole docking and ciliary motility, and airways fail to become fully ciliated. We provide evidence that MYB acts in a conserved pathway downstream of Notch signaling and multicilin, a protein related to the S-phase regulator geminin, and upstream of FOXJ1. MYB can activate endogenous Foxj1 expression and stimulate a cotransfected Foxj1 reporter in heterologous cells, and it can drive the complete multiciliogenesis program in Xenopus embryonic epidermis. We conclude that MYB has an early, crucial and conserved role in multiciliogenesis, and propose that it promotes a novel S-like phase in which centriole amplification occurs uncoupled from DNA synthesis, and then drives later steps of multiciliogenesis through induction of Foxj1.
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Affiliation(s)
- Fraser E Tan
- Department of Biochemistry and Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA 94305, USA
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14
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Cao H, Jheon A, Li X, Sun Z, Wang J, Florez S, Zhang Z, McManus MT, Klein OD, Amendt BA. The Pitx2:miR-200c/141:noggin pathway regulates Bmp signaling and ameloblast differentiation. Development 2013; 140:3348-59. [PMID: 23863486 PMCID: PMC3737717 DOI: 10.1242/dev.089193] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/10/2013] [Indexed: 02/06/2023]
Abstract
The mouse incisor is a remarkable tooth that grows throughout the animal's lifetime. This continuous renewal is fueled by adult epithelial stem cells that give rise to ameloblasts, which generate enamel, and little is known about the function of microRNAs in this process. Here, we describe the role of a novel Pitx2:miR-200c/141:noggin regulatory pathway in dental epithelial cell differentiation. miR-200c repressed noggin, an antagonist of Bmp signaling. Pitx2 expression caused an upregulation of miR-200c and chromatin immunoprecipitation assays revealed endogenous Pitx2 binding to the miR-200c/141 promoter. A positive-feedback loop was discovered between miR-200c and Bmp signaling. miR-200c/141 induced expression of E-cadherin and the dental epithelial cell differentiation marker amelogenin. In addition, miR-203 expression was activated by endogenous Pitx2 and targeted the Bmp antagonist Bmper to further regulate Bmp signaling. miR-200c/141 knockout mice showed defects in enamel formation, with decreased E-cadherin and amelogenin expression and increased noggin expression. Our in vivo and in vitro studies reveal a multistep transcriptional program involving the Pitx2:miR-200c/141:noggin regulatory pathway that is important in epithelial cell differentiation and tooth development.
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Affiliation(s)
- Huojun Cao
- Department of Anatomy and Cell Biology, The University of Iowa, Iowa City, IA 52242, USA
| | - Andrew Jheon
- Department of Orofacial Sciences and Program in Craniofacial and Mesenchymal Biology, UCSF, San Francisco, CA 94143-0442, USA
| | - Xiao Li
- Department of Anatomy and Cell Biology, The University of Iowa, Iowa City, IA 52242, USA
| | - Zhao Sun
- Department of Anatomy and Cell Biology, The University of Iowa, Iowa City, IA 52242, USA
| | - Jianbo Wang
- Department of Anatomy and Cell Biology, The University of Iowa, Iowa City, IA 52242, USA
| | - Sergio Florez
- Department of Anatomy and Cell Biology, The University of Iowa, Iowa City, IA 52242, USA
| | - Zichao Zhang
- Department of Anatomy and Cell Biology, The University of Iowa, Iowa City, IA 52242, USA
| | - Michael T. McManus
- Department of Microbiology and Immunology and Diabetes Center, UCSF, San Francisco, CA 94143-0442, USA
| | - Ophir D. Klein
- Department of Orofacial Sciences and Program in Craniofacial and Mesenchymal Biology, UCSF, San Francisco, CA 94143-0442, USA
- Department of Pediatrics and Institute for Human Genetics, UCSF, San Francisco, CA 94143-0442, USA
| | - Brad A. Amendt
- Department of Anatomy and Cell Biology, The University of Iowa, Iowa City, IA 52242, USA
- Craniofacial Anomalies Research Center, University of Iowa, Iowa City, IA 52242, USA
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15
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Didon L, Zwick RK, Chao IW, Walters MS, Wang R, Hackett NR, Crystal RG. RFX3 modulation of FOXJ1 regulation of cilia genes in the human airway epithelium. Respir Res 2013; 14:70. [PMID: 23822649 PMCID: PMC3710277 DOI: 10.1186/1465-9921-14-70] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2013] [Accepted: 06/10/2013] [Indexed: 11/30/2022] Open
Abstract
Background Ciliated cells play a central role in cleansing the airways of inhaled contaminants. They are derived from basal cells that include the airway stem/progenitor cells. In animal models, the transcription factor FOXJ1 has been shown to induce differentiation to the ciliated cell lineage, and the RFX transcription factor-family has been shown to be necessary for, but not sufficient to induce, correct cilia development. Methods To test the hypothesis that FOXJ1 and RFX3 cooperatively induce expression of ciliated genes in the differentiation process of basal progenitor cells toward a ciliated cell linage in the human airway epithelium, primary human airway basal cells were assessed under conditions of in vitro differentiation induced by plasmid-mediated gene transfer of FOXJ1 and/or RFX3. TaqMan PCR was used to quantify mRNA levels of basal, secretory, and cilia-associated genes. Results Basal cells, when cultured in air-liquid interface, differentiated into a ciliated epithelium, expressing FOXJ1 and RFX3. Transfection of FOXJ1 into resting basal cells activated promoters and induced expression of ciliated cell genes as well as both FOXJ1 and RFX3, but not basal cell genes. Transfection of RFX3 induced expression of RFX3 but not FOXJ1, nor the expression of cilia-related genes. The combination of FOXJ1 + RFX3 enhanced ciliated gene promoter activity and mRNA expression beyond that due to FOXJ1 alone. Corroborating immunoprecipitation studies demonstrated an interaction between FOXJ1 and RFX3. Conclusion FOXJ1 is an important regulator of cilia gene expression during ciliated cell differentiation, with RFX3 as a transcriptional co-activator to FOXJ1, helping to induce the expression of cilia genes in the process of ciliated cell differentiation of basal/progenitor cells.
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Affiliation(s)
- Lukas Didon
- Department of Genetic Medicine, Weill Cornell Medical College, New York, NY 10065, USA
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16
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Wang J, Sun Z, Zhang Z, Saadi I, Wang J, Li X, Gao S, Engle JJ, Kuburas A, Fu X, Yu W, Klein WH, Russo AF, Amendt BA. Protein inhibitors of activated STAT (Pias1 and Piasy) differentially regulate pituitary homeobox 2 (PITX2) transcriptional activity. J Biol Chem 2013; 288:12580-95. [PMID: 23515314 PMCID: PMC3642306 DOI: 10.1074/jbc.m112.374561] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2012] [Revised: 03/12/2013] [Indexed: 12/31/2022] Open
Abstract
Protein inhibitors of activated STAT (Pias) proteins can act independent of sumoylation to modulate the activity of transcription factors and Pias proteins interacting with transcription factors can either activate or repress their activity. Pias proteins are expressed in many tissues and cells during development and we asked if Pias proteins regulated the pituitary homeobox 2 (PITX2) homeodomain protein, which modulates developmental gene expression. Piasy and Pias1 proteins are expressed during craniofacial/tooth development and directly interact and differentially regulate PITX2 transcriptional activity. Piasy and Pias1 are co-expressed in craniofacial tissues with PITX2. Yeast two-hybrid, co-immunoprecipitation and pulldown experiments demonstrate Piasy and Pias1 interactions with the PITX2 protein. Piasy interacts with the PITX2 C-terminal tail to attenuate its transcriptional activity. In contrast, Pias1 interacts with the PITX2 C-terminal tail to increase PITX2 transcriptional activity. The E3 ligase activity associated with the RING domain in Piasy is not required for the attenuation of PITX2 activity, however, the RING domain of Pias1 is required for enhanced PITX2 transcriptional activity. Bimolecular fluorescence complementation assays reveal PITX2 interactions with Piasy and Pias1 in the nucleus. Piasy represses the synergistic activation of PITX2 with interacting co-factors and Piasy represses Pias1 activation of PITX2 transcriptional activity. In contrast, Pias1 did not affect the synergistic interaction of PITX2 with transcriptional co-factors. Last, we demonstrate that Pias proteins form a complex with PITX2 and Lef-1, and PITX2 and β-catenin. Lef-1, β-catenin, and Pias interactions with PITX2 provide new molecular mechanisms for the regulation of PITX2 transcriptional activity and the activity of Pias proteins.
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Affiliation(s)
- Jianbo Wang
- From the Center for Environmental and Genetic Medicine, Institute of Biosciences and Technology, Texas A&M University Health Science Center, Houston, Texas 77030
| | - Zhao Sun
- From the Center for Environmental and Genetic Medicine, Institute of Biosciences and Technology, Texas A&M University Health Science Center, Houston, Texas 77030
| | - Zichao Zhang
- From the Center for Environmental and Genetic Medicine, Institute of Biosciences and Technology, Texas A&M University Health Science Center, Houston, Texas 77030
| | - Irfan Saadi
- the Departments of Molecular Physiology and Biophysics
| | - Jun Wang
- the Center for Stem Cell Engineering, Texas Heart Institute, Houston, Texas 77030, and
| | - Xiao Li
- Anatomy and Cell Biology, and
| | - Shan Gao
- From the Center for Environmental and Genetic Medicine, Institute of Biosciences and Technology, Texas A&M University Health Science Center, Houston, Texas 77030
| | | | - Adisa Kuburas
- the Departments of Molecular Physiology and Biophysics
| | - Xueyao Fu
- the Department of Biochemistry and Molecular Biology, The University of Texas M.D. Anderson Cancer Center, Houston, Texas 77030
| | | | - William H. Klein
- the Department of Biochemistry and Molecular Biology, The University of Texas M.D. Anderson Cancer Center, Houston, Texas 77030
| | | | - Brad A. Amendt
- Anatomy and Cell Biology, and
- Craniofacial Anomalies Research Center, University of Iowa, Iowa City, Iowa 52242
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17
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Basu M, Roy SS. Wnt/β-catenin pathway is regulated by PITX2 homeodomain protein and thus contributes to the proliferation of human ovarian adenocarcinoma cell, SKOV-3. J Biol Chem 2013; 288:4355-67. [PMID: 23250740 PMCID: PMC3567686 DOI: 10.1074/jbc.m112.409102] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2012] [Revised: 11/26/2012] [Indexed: 01/22/2023] Open
Abstract
Pituitary homeobox-2 (PITX2) plays a substantial role in the development of pituitary, heart, and brain. Although the role of PITX2 isoforms in embryonic development has been extensively studied, its possible involvement in regulating the Wnt signaling pathway has not been reported. Because the Wnt pathway is strongly involved in ovarian development and cancer, we focused on the possible association between PITX2 and Wnt pathway in ovarian carcinoma cells. Remarkably, we found that PITX2 interacts and regulates WNT2/5A/9A/6/2B genes of the canonical, noncanonical, or other pathways in the human ovarian cancer cell SKOV-3. Chromatin immunoprecipitation and promoter-reporter assays further indicated the significant association of PITX2 with WNT2 and WNT5A promoters. Detailed study further reveals that the PITX2 isoform specifically activates the canonical Wnt signaling pathway either directly or through Wnt ligands. Thus, the activated Wnt pathway subsequently enhances cell proliferation. Moreover, we found the activation of Wnt pathway reduces the expression of different FZD receptors that limit further Wnt activation, demonstrating the existence of an auto-regulatory feedback loop. In contrast, PITX2 could not activate the noncanonical pathway as the Wnt5A-specific ROR2 receptor does not express in SKOV-3 cells. Collectively, our findings demonstrated that, despite being a target of the canonical Wnt signaling pathway, PITX2 itself induces the same, thus leading to the activation of the cell cycle regulating genes as well as the proliferation of SKOV-3 cells. Collectively, we highlighted that the PITX2 and Wnt pathway exerts a positive feedback regulation, whereas frizzled receptors generate a negative feedback in this pathway. Our findings will help to understand the molecular mechanism of proliferation in ovarian cancer cells.
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Affiliation(s)
- Moitri Basu
- From the Cell Biology and Physiology Division, Council of Scientific and Industrial Research-Indian Institute of Chemical Biology, 4 Raja Subodh Chandra Mullick Road, Kolkata 700032, India
| | - Sib Sankar Roy
- From the Cell Biology and Physiology Division, Council of Scientific and Industrial Research-Indian Institute of Chemical Biology, 4 Raja Subodh Chandra Mullick Road, Kolkata 700032, India
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18
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Jerber J, Thomas J, Durand B. [Transcriptional control of ciliogenesis in animal development]. Biol Aujourdhui 2012; 206:205-18. [PMID: 23171843 DOI: 10.1051/jbio/2012023] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2012] [Indexed: 12/20/2022]
Abstract
Cilia and flagella are eukaryotic organelles with a conserved structure and function from unicellular organisms to human. In animals, different types of cilia can be found and cilia assembly during development is a highly dynamic process. Ciliary defects in human lead to a wide spectrum of diseases called ciliopathies. Understanding the molecular mechanisms that govern dynamic cilia assembly during development and in different tissues in metazoans is an important biological challenge. The FOXJ1 (Forkhead Box J1) and RFX (Regulatory Factor X) family of transcription factors have been shown to be important factors in ciliogenesis control. FOXJ1 proteins are required for motile ciliogenesis in vertebrates. By contrast, RFX proteins are essential to assemble both primary and motile cilia through the regulation of specific sets of genes such as those encoding intraflagellar transport components. Recently, new actors with more specific roles in cilia biogenesis and physiology have also been discovered. All these factors are subject to complex regulation, allowing for the dynamic and specific regulation of ciliogenesis in metazoans.
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Affiliation(s)
- Julie Jerber
- Centre de Genetique et de Physiologie Moleculare et Cellulaire, Universite Lyon, Villeurbanne, Lyon, France
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19
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Strungaru MH, Footz T, Liu Y, Berry FB, Belleau P, Semina EV, Raymond V, Walter MA. PITX2 is involved in stress response in cultured human trabecular meshwork cells through regulation of SLC13A3. Invest Ophthalmol Vis Sci 2011; 52:7625-33. [PMID: 21873665 PMCID: PMC3183983 DOI: 10.1167/iovs.10-6967] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2010] [Revised: 05/17/2011] [Accepted: 06/04/2011] [Indexed: 10/17/2022] Open
Abstract
PURPOSE Mutations of the PITX2 gene cause Axenfeld-Rieger syndrome (ARS) and glaucoma. In this study, the authors investigated genes directly regulated by the PITX2 transcription factor to gain insight into the mechanisms underlying these disorders. METHODS RNA from nonpigmented ciliary epithelium cells transfected with hormone-inducible PITX2 and activated by mifepristone was subjected to microarray analyses. Data were analyzed using dCHIP algorithms to detect significant differences in expression. Genes with significantly altered expression in multiple microarray experiments in the presence of activated PITX2 were subjected to in silico and biochemical analyses to validate them as direct regulatory targets. One target gene was further characterized by studying the effect of its knockdown in a cell model of oxidative stress, and its expression in zebrafish embryos was analyzed by in situ hybridization. RESULTS Solute carrier family 13 sodium-dependent dicarboxylate transporter member 3 (SLC13A3) was identified as 1 of 47 potential PITX2 target genes in ocular cells. PITX2 directly regulates SLC13A3 expression, as demonstrated by luciferase reporter and chromatin immunoprecipitation assays. Reduction of PITX2 or SLC13A3 levels by small interfering RNA (siRNA)-mediated knockdown augmented the death of transformed human trabecular meshwork cells exposed to hydrogen peroxide. Zebrafish slc13a3 is expressed in anterior ocular regions in a pattern similar to that of pitx2. CONCLUSIONS The results indicate that SLC13A3 is a direct downstream target of PITX2 transcriptional regulation and that levels of PITX2 and SLC13A3 modulate responses to oxidative stress in ocular cells.
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Affiliation(s)
| | - Tim Footz
- From the Departments of Medical Genetics and
| | - Yi Liu
- Department of Pediatrics and Children's Research Institute, Medical College of Wisconsin and Children's Hospital of Wisconsin, Milwaukee, Wisconsin
| | - Fred B. Berry
- From the Departments of Medical Genetics and
- Surgery, University of Alberta, Edmonton, Alberta, Canada
| | - Pascal Belleau
- Department of Molecular Medicine, Université Laval, Québec City, Quebec, Canada; and
| | - Elena V. Semina
- Department of Pediatrics and Children's Research Institute, Medical College of Wisconsin and Children's Hospital of Wisconsin, Milwaukee, Wisconsin
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Vincent Raymond
- Department of Molecular Medicine, Université Laval, Québec City, Quebec, Canada; and
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20
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Venugopalan SR, Li X, Amen MA, Florez S, Gutierrez D, Cao H, Wang J, Amendt BA. Hierarchical interactions of homeodomain and forkhead transcription factors in regulating odontogenic gene expression. J Biol Chem 2011; 286:21372-83. [PMID: 21504905 PMCID: PMC3122197 DOI: 10.1074/jbc.m111.252031] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2011] [Indexed: 11/06/2022] Open
Abstract
FoxJ1 is a forkhead transcription factor expressed in multiple tissues during development and a major regulator of cilia development. FoxJ1(-/-) mice present with defects in odontogenesis, and we correlate these defects to hierarchical interactions between homeodomain factors Pitx2 and Dlx2 with FoxJ1 in regulating their expression through direct physical interactions. Chromatin immunoprecipitation assays reveal endogenous Pitx2 and Dlx2 binding to the Dlx2 promoter and Dlx2 binding to the FoxJ1 promoter as well as Dlx2 and FoxJ1 binding to the amelogenin promoter. PITX2 activation of the Dlx2 promoter is attenuated by a direct Dlx2 physical interaction with PITX2. Dlx2 autoregulates its promoter, and Dlx2 transcriptionally activates the downstream gene FoxJ1. Dlx2 and FoxJ1 physically interact and synergistically regulate both Dlx2 and FoxJ1 promoters. Dlx2 and FoxJ1 also activate the amelogenin promoter, and amelogenin is required for enamel formation and late stage tooth development. FoxJ1(-/-) mice maxillary and mandibular incisors are reduced in length and width and have reduced amelogenin expression. FoxJ1(-/-) mice show a reduced and defective ameloblast layer, revealing a biological effect of these transcription factor hierarchies during tooth morphogenesis. These transcriptional mechanisms may contribute to other developmental processes such as neuronal, pituitary, and heart development.
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Affiliation(s)
- Shankar R. Venugopalan
- From the Texas A&M University Health Science Center, Institute of Biosciences and Technology, Houston, Texas 77030
| | - Xiao Li
- From the Texas A&M University Health Science Center, Institute of Biosciences and Technology, Houston, Texas 77030
| | - Melanie A. Amen
- From the Texas A&M University Health Science Center, Institute of Biosciences and Technology, Houston, Texas 77030
| | - Sergio Florez
- From the Texas A&M University Health Science Center, Institute of Biosciences and Technology, Houston, Texas 77030
| | - Diana Gutierrez
- From the Texas A&M University Health Science Center, Institute of Biosciences and Technology, Houston, Texas 77030
| | - Huojun Cao
- From the Texas A&M University Health Science Center, Institute of Biosciences and Technology, Houston, Texas 77030
| | - Jianbo Wang
- From the Texas A&M University Health Science Center, Institute of Biosciences and Technology, Houston, Texas 77030
| | - Brad A. Amendt
- From the Texas A&M University Health Science Center, Institute of Biosciences and Technology, Houston, Texas 77030
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Cao H, Florez S, Amen M, Huynh T, Skobe Z, Baldini A, Amendt BA. Tbx1 regulates progenitor cell proliferation in the dental epithelium by modulating Pitx2 activation of p21. Dev Biol 2010; 347:289-300. [PMID: 20816801 PMCID: PMC3334818 DOI: 10.1016/j.ydbio.2010.08.031] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2010] [Revised: 08/23/2010] [Accepted: 08/25/2010] [Indexed: 11/19/2022]
Abstract
Tbx1(-/-) mice present with phenotypic effects observed in DiGeorge syndrome patients however, the molecular mechanisms of Tbx1 regulating craniofacial and tooth development are unclear. Analyses of the Tbx1 null mice reveal incisor microdontia, small cervical loops and BrdU labeling reveals a defect in epithelial cell proliferation. Furthermore, Tbx1 null mice molars are lacking normal cusp morphology. Interestingly, p21 (associated with cell cycle arrest) is up regulated in the dental epithelium of Tbx1(-/-) embryos. These data suggest that Tbx1 inhibits p21 expression to allow for cell proliferation in the dental epithelial cervical loop, however Tbx1 does not directly regulate p21 expression. A new molecular mechanism has been identified where Tbx1 inhibits Pitx2 transcriptional activity and decreases the expression of Pitx2 target genes, p21, Lef-1 and Pitx2c. p21 protein is increased in PITX2C transgenic mouse embryo fibroblasts (MEF) and chromatin immunoprecipitation assays demonstrate endogenous Pitx2 binding to the p21 promoter. Tbx1 attenuates PITX2 activation of endogenous p21 expression and Tbx1 null MEFs reveal increased Pitx2a and activation of Pitx2c isoform expression. Tbx1 physically interacts with the PITX2 C-terminus and represses PITX2 transcriptional activation of the p21, LEF-1, and Pitx2c promoters. Tbx1(-/+)/Pitx2(-/+) double heterozygous mice present with an extra premolar-like tooth revealing a genetic interaction between these factors. The ability of Tbx1 to repress PITX2 activation of p21 may promote cell proliferation. In addition, PITX2 regulation of p21 reveals a new role for PITX2 in repressing cell proliferation. These data demonstrate new functional mechanisms for Tbx1 in tooth morphogenesis and provide a molecular basis for craniofacial defects in DiGeorge syndrome patients.
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Affiliation(s)
- Huojun Cao
- Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, TX
| | - Sergio Florez
- Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, TX
| | - Melanie Amen
- Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, TX
| | - Tuong Huynh
- Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, TX
| | - Ziedonis Skobe
- Department of Biomineralization, The Forsyth Institute, Boston, MA
| | - Antonio Baldini
- Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, TX
- Institute of Genetics and Biophysics CNR, Naples, Italy
| | - Brad A. Amendt
- Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, TX
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22
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Transcriptional control of genes involved in ciliogenesis: a first step in making cilia. Biol Cell 2010; 102:499-513. [PMID: 20690903 DOI: 10.1042/bc20100035] [Citation(s) in RCA: 115] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Cilia and flagella have essential functions in a wide range of organisms. Cilia assembly is dynamic during development and different types of cilia are found in multicellular organisms. How this dynamic and specific assembly is regulated remains an important question in cilia biology. In metazoans, the regulation of the overall expression level of key components necessary for cilia assembly or function is an important way to achieve ciliogenesis control. The FOXJ1 (forkhead box J1) and RFX (regulatory factor X) family of transcription factors have been shown to be important players in controlling ciliary gene expression. They fulfill a complementary and synergistic function by regulating specific and common target genes. FOXJ1 is essential to allow for the assembly of motile cilia in vertebrates through the regulation of genes specific to motile cilia or necessary for basal body apical transport, whereas RFX proteins are necessary to assemble both primary and motile cilia in metazoans, in particular, by regulating genes involved in intraflagellar transport. Recently, different transcription factors playing specific roles in cilia biogenesis and physiology have also been discovered. All these factors are subject to complex regulation to allow for the dynamic and specific regulation of ciliogenesis in metazoans.
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23
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Abouhamed M, Grobe K, San IVLC, Thelen S, Honnert U, Balda MS, Matter K, Bähler M. Myosin IXa regulates epithelial differentiation and its deficiency results in hydrocephalus. Mol Biol Cell 2010; 20:5074-85. [PMID: 19828736 DOI: 10.1091/mbc.e09-04-0291] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The ependymal multiciliated epithelium in the brain restricts the cerebrospinal fluid to the cerebral ventricles and regulates its flow. We report here that mice deficient for myosin IXa (Myo9a), an actin-dependent motor molecule with a Rho GTPase-activating (GAP) domain, develop severe hydrocephalus with stenosis and closure of the ventral caudal 3rd ventricle and the aqueduct. Myo9a is expressed in maturing ependymal epithelial cells, and its absence leads to impaired maturation of ependymal cells. The Myo9a deficiency further resulted in a distorted ependyma due to irregular epithelial cell morphology and altered organization of intercellular junctions. Ependymal cells occasionally delaminated, forming multilayered structures that bridged the CSF-filled ventricular space. Hydrocephalus formation could be significantly attenuated by the inhibition of the Rho-effector Rho-kinase (ROCK). Administration of ROCK-inhibitor restored maturation of ependymal cells, but not the morphological distortions of the ependyma. Similarly, down-regulation of Myo9a by siRNA in Caco-2 adenocarcinoma cells increased Rho-signaling and induced alterations in differentiation, cell morphology, junction assembly, junctional signaling, and gene expression. Our results demonstrate that Myo9a is a critical regulator of Rho-dependent and -independent signaling mechanisms that guide epithelial differentiation. Moreover, Rho-kinases may represent a new target for therapeutic intervention in some forms of hydrocephalus.
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Affiliation(s)
- Marouan Abouhamed
- Institute of General Zoology and Genetics, Westfalian Wilhelms University, 48149 Münster, Germany
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24
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Simard A, Di Giorgio L, Amen M, Westwood A, Amendt BA, Ryan AK. The Pitx2c N-terminal domain is a critical interaction domain required for asymmetric morphogenesis. Dev Dyn 2009; 238:2459-70. [PMID: 19681163 PMCID: PMC3014603 DOI: 10.1002/dvdy.22062] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The paired-like homeodomain transcription factor Pitx2c has an essential role in patterning the left-right axis. However, neither its transcriptional targets nor the molecular mechanisms through which it exerts its patterning function are known. Here we provide evidence that the N-terminal domain of Pitx2c is important for this activity. Overexpression of the Pitx2c N-terminus in ovo randomizes the direction of heart looping, the first morphological asymmetry conserved in vertebrate embryos. In addition, the Pitx2c N-terminal domain blocks the ability of Pitx2c to synergize with Nkx2.5 to transactivate the procollagen lysyl hydroxylase (Plod-1) promoter in transient transfection assays. A five amino acid region containing leucine-41 is required for both of these effects. Our data suggest that the Pitx2c N-terminal domain competes with endogenous Pitx2c for binding to a protein interaction partner that is required for the activation of genes that direct asymmetric morphogenesis along the left-right axis.
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Affiliation(s)
- Annie Simard
- The Research Institute of the McGill University Health Center, Montreal, Quebec
| | | | - Melanie Amen
- Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, TX
| | - Ashley Westwood
- Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, TX
| | - Brad A. Amendt
- Institute of Biosciences and Technology, Texas A&M Health Science Center, Houston, TX
| | - Aimee K. Ryan
- The Research Institute of the McGill University Health Center, Montreal, Quebec
- Department of Human Genetics, McGill University, Montreal, Quebec
- Department of Pediatrics, McGill University, Montreal, Quebec
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25
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Georges AB, Benayoun BA, Caburet S, Veitia RA. Generic binding sites, generic DNA‐binding domains: where does specific promoter recognition come from? FASEB J 2009; 24:346-56. [DOI: 10.1096/fj.09-142117] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Adrien B. Georges
- Unité Mixte de Recherche 7592‐Centre National de la Recherche ScientifiqueInstitut Jacques MonodParisFrance
| | - Berenice A. Benayoun
- Unité Mixte de Recherche 7592‐Centre National de la Recherche ScientifiqueInstitut Jacques MonodParisFrance
| | - Sandrine Caburet
- Unité Mixte de Recherche 7592‐Centre National de la Recherche ScientifiqueInstitut Jacques MonodParisFrance
| | - Reiner A. Veitia
- Unité Mixte de Recherche 7592‐Centre National de la Recherche ScientifiqueInstitut Jacques MonodParisFrance
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26
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Huang Y, Huang K, Boskovic G, Dementieva Y, Denvir J, Primerano DA, Zhu GZ. Proteomic and genomic analysis of PITX2 interacting and regulating networks. FEBS Lett 2009; 583:638-42. [PMID: 19174163 PMCID: PMC2667122 DOI: 10.1016/j.febslet.2009.01.028] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2008] [Revised: 12/20/2008] [Accepted: 01/15/2009] [Indexed: 10/21/2022]
Abstract
Pituitary homeobox 2 (PITX2) is a homeodomain transcription factor that has a substantial role in cell proliferation and differentiation in various tissues. In this report, we have conducted a systematic study, using proteomic and genomic approaches, to characterize PITX2-interacting proteins and PITX2-regulating genes. We identified four novel PITX2-associated protein partners Y box binding factor-1, heterogeneous ribonucleoprotein K, nucleolin and heterogeneous nuclear ribonucleoprotein U in mass spectrometry analysis. We also found that overexpression of PITX2 upregulated 868 genes (2-25-fold) and downregulated 191 genes (2-15-fold) in DNA microarray analysis. These data provide an insightful perspective for further studying PITX2 function and mechanism of action.
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Affiliation(s)
- Yue Huang
- Biomedical Science Graduate Program, Marshall University, Huntington, WV 25755, USA
| | - Kan Huang
- Biomedical Science Graduate Program, Marshall University, Huntington, WV 25755, USA
| | - Goran Boskovic
- Department of Biochemistry and Microbiology, Marshall University, Huntington, WV 25755, USA
| | - Yulia Dementieva
- Department of Mathematics, Marshall University, Huntington, WV 25755, USA
| | - James Denvir
- Department of Statistics, West Virginia University, Morgantown, WV 26506, USA
| | - Donald A. Primerano
- Biomedical Science Graduate Program, Marshall University, Huntington, WV 25755, USA
- Department of Biochemistry and Microbiology, Marshall University, Huntington, WV 25755, USA
| | - Guo-Zhang Zhu
- Biomedical Science Graduate Program, Marshall University, Huntington, WV 25755, USA
- Department of Biological Sciences, Marshall University, Huntington, WV 25755, USA
- Cell Differentiation and Development Center, Marshall University, Huntington, WV 25755, USA
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