1
|
Jaiswal SK, Raj S, DePamphilis ML. Developmental Acquisition of p53 Functions. Genes (Basel) 2021; 12:genes12111675. [PMID: 34828285 PMCID: PMC8622856 DOI: 10.3390/genes12111675] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 10/14/2021] [Accepted: 10/21/2021] [Indexed: 12/12/2022] Open
Abstract
Remarkably, the p53 transcription factor, referred to as “the guardian of the genome”, is not essential for mammalian development. Moreover, efforts to identify p53-dependent developmental events have produced contradictory conclusions. Given the importance of pluripotent stem cells as models of mammalian development, and their applications in regenerative medicine and disease, resolving these conflicts is essential. Here we attempt to reconcile disparate data into justifiable conclusions predicated on reports that p53-dependent transcription is first detected in late mouse blastocysts, that p53 activity first becomes potentially lethal during gastrulation, and that apoptosis does not depend on p53. Furthermore, p53 does not regulate expression of genes required for pluripotency in embryonic stem cells (ESCs); it contributes to ESC genomic stability and differentiation. Depending on conditions, p53 accelerates initiation of apoptosis in ESCs in response to DNA damage, but cell cycle arrest as well as the rate and extent of apoptosis in ESCs are p53-independent. In embryonic fibroblasts, p53 induces cell cycle arrest to allow repair of DNA damage, and cell senescence to prevent proliferation of cells with extensive damage.
Collapse
Affiliation(s)
- Sushil K. Jaiswal
- National Institute of Child Health and Human Development, Bethesda, MD 20892, USA;
- National Human Genome Research Institute, Bethesda, MD 20892, USA
| | - Sonam Raj
- National Cancer Institute, Bethesda, MD 20892, USA;
| | - Melvin L. DePamphilis
- National Institute of Child Health and Human Development, Bethesda, MD 20892, USA;
- Correspondence:
| |
Collapse
|
2
|
Luo X, Yin J, Miao S, Feng W, Ning T, Xu S, Huang S, Zhang S, Liao Y, Hao C, Wu B, Ma D. mTORC1 promotes mineralization via p53 pathway. FASEB J 2021; 35:e21325. [PMID: 33508145 DOI: 10.1096/fj.202002016r] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 12/04/2020] [Accepted: 12/14/2020] [Indexed: 12/30/2022]
Abstract
The objectives of our study were to investigate the roles of mTORC1 in odontoblast proliferation and mineralization and to determine the mechanism by which mTORC1 regulates odontoblast mineralization. In vitro, MDPC23 cells were treated with rapamycin (10 nmol/L) and transfected with a lentivirus for short hairpin (shRNA)-mediated silencing of the tuberous sclerosis complex (shTSC1) to inhibit and activate mTORC1, respectively. CCK8 assays, flow cytometry, Alizarin red S staining, ALP staining, qRT-PCR, and western blot analysis were performed. TSC1-conditional knockout (DMP1-Cre+ ; TSC1f/f , hereafter CKO) mice and littermate control (DMP1-Cre- ; TSC1f/f , hereafter WT) mice were generated. H&E staining, immunofluorescence, and micro-CT analysis were performed. Transcriptome sequencing analysis was used to screen the mechanism of this process. mTORC1 inactivation decreased the cell proliferation. The qRT-PCR and western blot results showed that mineralization-related genes and proteins were downregulated in mTORC1-inactivated cells. Moreover, mTORC1 overactivation promoted cell proliferation and mineralization-related gene and protein expression. In vivo, the micro-CT results showed that DV/TV and dentin thickness were higher in CKO mice than in controls and H&E staining showed the same results. Mineralization-related proteins expression was upregulated. Transcriptome sequencing analysis revealed that p53 pathway-associated genes were differentially expressed in TSC1-deficient cells. By inhibiting p53 alone or both mTORC1 and p53 with rapamycin and a p53 inhibitor, we elucidated that p53 acts downstream of mTORC1 and that mTORC1 thereby promotes odontoblast mineralization. Taken together, our findings demonstrate that the role of mTORC1 in odontoblast proliferation and mineralization, and confirm that mTORC1 upregulates odontoblast mineralization via the p53 pathway.
Collapse
Affiliation(s)
- Xinghong Luo
- Department of Stomatology, Nanfang Hospital, Southern Medical University, Guangzhou, China.,College of Stomatology, Southern Medical University, Guangzhou, China
| | - Jingyao Yin
- Department of Stomatology, Nanfang Hospital, Southern Medical University, Guangzhou, China.,College of Stomatology, Southern Medical University, Guangzhou, China
| | - Shenghong Miao
- Department of Stomatology, Nanfang Hospital, Southern Medical University, Guangzhou, China.,College of Stomatology, Southern Medical University, Guangzhou, China
| | - Weiqing Feng
- Department of Stomatology, Nanfang Hospital, Southern Medical University, Guangzhou, China.,College of Stomatology, Southern Medical University, Guangzhou, China
| | - Tingting Ning
- College of Stomatology, Southern Medical University, Guangzhou, China.,Department of Endodontics, Stomatology Hospital, Southern Medical University, Guangzhou, China
| | - Shuaimei Xu
- College of Stomatology, Southern Medical University, Guangzhou, China.,Department of Endodontics, Stomatology Hospital, Southern Medical University, Guangzhou, China
| | - Shijiang Huang
- Department of Cell Biology, School of Basic Medical Science, Southern Medical University, Guangzhou, China
| | - Sheng Zhang
- Department of Cell Biology, School of Basic Medical Science, Southern Medical University, Guangzhou, China
| | - Yunjun Liao
- Department of Plastic and Cosmetic Surgery, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Chunbo Hao
- Department of Stomatology, Hainan General Hospital, Hainan Affiliated Hospital of Hainan Medical University, Haikou, China
| | - Buling Wu
- Department of Stomatology, Nanfang Hospital, Southern Medical University, Guangzhou, China.,College of Stomatology, Southern Medical University, Guangzhou, China
| | - Dandan Ma
- Department of Endodontics, Stomatology Hospital, Southern Medical University, Guangzhou, China.,Department of Advanced Oral Sciences & Therapeutics, University of Maryland School of Dentistry, Baltimore, MD, USA
| |
Collapse
|
3
|
Hilliard SA, Li Y, Dixon A, El-Dahr SS. Mdm4 controls ureteric bud branching via regulation of p53 activity. Mech Dev 2020; 163:103616. [PMID: 32464196 DOI: 10.1016/j.mod.2020.103616] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 05/19/2020] [Accepted: 05/21/2020] [Indexed: 02/07/2023]
Abstract
The antagonism between Mdm2 and its close homolog Mdm4 (also known as MdmX) and p53 is vital for embryogenesis and organogenesis. Previously, we demonstrated that targeted disruption of Mdm2 in the Hoxb7+ ureteric bud (Ub) lineage, which gives rise to the renal collecting system, causes renal hypodysplasia culminating in perinatal lethality. In this study, we examine the unique role of Mdm4 in establishing the collecting duct system of the murine kidney. Hoxb7Cre driven loss of Mdm4 in the Ub lineage (UbMdm4-/-) disrupts branching morphogenesis and triggers UB cell apoptosis. UbMdm4-/- kidneys exhibit abnormally dilated Ub tips while the medulla is hypoplastic. These structural alterations result in secondary depletion of nephron progenitors and nascent nephrons. As a result, newborn UbMdm4-/- mice have hypo-dysplastic kidneys. Transcriptional profiling revealed downregulation of the Ret-tyrosine kinase pathway components, Gdnf, Wnt11, Sox8, Etv4 and Cxcr4 in the UbMdm4-/- mice relative to controls. Moreover, the expression levels of the canonical Wnt signaling members Axin2 and Wnt9b are downregulated. Mdm4 deletion upregulated p53 activity and p53-target gene expression including Cdkn1a (p21), Gdf15, Ccng1, PERP, and Fas. Germline loss of p53 in UbMdm4-/- mice largely rescues kidney development and terminal differentiation of the collecting duct. We conclude that Mdm4 plays a unique and vital role in Ub branching morphogenesis and collecting system development.
Collapse
Affiliation(s)
- Sylvia A Hilliard
- Tulane University School of Medicine, Department of Pediatrics, Section of Pediatric Nephrology, New Orleans, LA 70112, United States of America
| | - Yuwen Li
- Tulane University School of Medicine, Department of Pediatrics, Section of Pediatric Nephrology, New Orleans, LA 70112, United States of America
| | - Angelina Dixon
- Tulane University School of Medicine, Department of Pediatrics, Section of Pediatric Nephrology, New Orleans, LA 70112, United States of America
| | - Samir S El-Dahr
- Tulane University School of Medicine, Department of Pediatrics, Section of Pediatric Nephrology, New Orleans, LA 70112, United States of America.
| |
Collapse
|
4
|
Zheng H, Yang G, Fu J, Chen Z, Yuan G. Mdm2 Promotes Odontoblast-like Differentiation by Ubiquitinating Dlx3 and p53. J Dent Res 2020; 99:320-328. [PMID: 31847675 DOI: 10.1177/0022034519893672] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Dentin is an important structural component of the tooth. Odontoblast differentiation is an essential biological process that guarantees normal dentin formation, which is precisely regulated by various proteins. Murine double minute 2 (Mdm2) is an E3 ubiquitin ligase, and it plays a pivotal role in the differentiation of different cell types, such as osteoblasts and myoblasts. However, whether Mdm2 plays a role in odontoblast differentiation remains unknown. Here, we investigated the spatiotemporal expression of Mdm2 by immunostaining and found that Mdm2 was highly expressed in the odontoblasts and slightly in the dental papilla cells of mouse incisors and molars. Gene knockdown and overexpression experiments verified that Mdm2 promoted the odontoblast-like differentiation of mouse dental papilla cells (mDPCs). Intranuclear colocalization and physical interaction between Mdm2 and distal-less 3 (Dlx3), a transcription factor important for odontoblast differentiation, was found during the odontoblast-like differentiation of mDPCs by double immunofluorescence and immunoprecipitation. Mdm2 was proved to monoubiquitinate Dlx3, which enhanced the expression of Dlx3 target gene Dspp. In addition, p53, the canonical substrate of Mdm2, was validated to be also ubiquitinated but degraded by Mdm2 during the odontoblast-like differentiation of mDPCs. Gene knockdown experiments confirmed that p53 inhibited the odontoblast-like differentiation of mDPCs. p53 and Mdm2 double knockdown partially rescued the reduced odontoblast-like differentiation by knockdown of Mdm2 alone. Taken together, our study revealed that Mdm2 promoted the odontoblast-like differentiation of mDPCs by ubiquitinating both Dlx3 and p53. On one hand, the monoubiquitination of Dlx3 by Mdm2 led to upregulation of Dspp, which is a marker of the odontoblast differentiation. On the other hand, ubiquitination of p53 by Mdm2 resulted in its degradation, which eliminated the inhibitory effect of p53 on the odontoblast-like differentiation of mDPCs.
Collapse
Affiliation(s)
- H Zheng
- The State Key Laboratory Breeding Base of Basic Science of Stomatology and Key Laboratory for Oral Biomedicine of Ministry of Education, School and Hospital of Stomatology, Wuhan University, Wuhan, China
- Department of Pediatric Dentistry, School and Hospital of Stomatology, Wuhan University, Wuhan, China
| | - G Yang
- The State Key Laboratory Breeding Base of Basic Science of Stomatology and Key Laboratory for Oral Biomedicine of Ministry of Education, School and Hospital of Stomatology, Wuhan University, Wuhan, China
| | - J Fu
- The State Key Laboratory Breeding Base of Basic Science of Stomatology and Key Laboratory for Oral Biomedicine of Ministry of Education, School and Hospital of Stomatology, Wuhan University, Wuhan, China
- Department of Pediatric Dentistry, School and Hospital of Stomatology, Wuhan University, Wuhan, China
| | - Z Chen
- The State Key Laboratory Breeding Base of Basic Science of Stomatology and Key Laboratory for Oral Biomedicine of Ministry of Education, School and Hospital of Stomatology, Wuhan University, Wuhan, China
| | - G Yuan
- The State Key Laboratory Breeding Base of Basic Science of Stomatology and Key Laboratory for Oral Biomedicine of Ministry of Education, School and Hospital of Stomatology, Wuhan University, Wuhan, China
- Department of Pediatric Dentistry, School and Hospital of Stomatology, Wuhan University, Wuhan, China
| |
Collapse
|
5
|
Roles and regulation of histone methylation in animal development. Nat Rev Mol Cell Biol 2019; 20:625-641. [PMID: 31267065 DOI: 10.1038/s41580-019-0151-1] [Citation(s) in RCA: 283] [Impact Index Per Article: 56.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/24/2019] [Indexed: 12/26/2022]
Abstract
Histone methylation can occur at various sites in histone proteins, primarily on lysine and arginine residues, and it can be governed by multiple positive and negative regulators, even at a single site, to either activate or repress transcription. It is now apparent that histone methylation is critical for almost all stages of development, and its proper regulation is essential for ensuring the coordinated expression of gene networks that govern pluripotency, body patterning and differentiation along appropriate lineages and organogenesis. Notably, developmental histone methylation is highly dynamic. Early embryonic systems display unique histone methylation patterns, prominently including the presence of bivalent (both gene-activating and gene-repressive) marks at lineage-specific genes that resolve to monovalent marks during differentiation, which ensures that appropriate genes are expressed in each tissue type. Studies of the effects of methylation on embryonic stem cell pluripotency and differentiation have helped to elucidate the developmental roles of histone methylation. It has been revealed that methylation and demethylation of both activating and repressive marks are essential for establishing embryonic and extra-embryonic lineages, for ensuring gene dosage compensation via genomic imprinting and for establishing body patterning via HOX gene regulation. Not surprisingly, aberrant methylation during embryogenesis can lead to defects in body patterning and in the development of specific organs. Human genetic disorders arising from mutations in histone methylation regulators have revealed their important roles in the developing skeletal and nervous systems, and they highlight the overlapping and unique roles of different patterns of methylation in ensuring proper development.
Collapse
|
6
|
Bowen ME, Attardi LD. The role of p53 in developmental syndromes. J Mol Cell Biol 2019; 11:200-211. [PMID: 30624728 PMCID: PMC6478128 DOI: 10.1093/jmcb/mjy087] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 11/22/2018] [Accepted: 01/06/2019] [Indexed: 12/17/2022] Open
Abstract
While it is well appreciated that loss of the p53 tumor suppressor protein promotes cancer, growing evidence indicates that increased p53 activity underlies the developmental defects in a wide range of genetic syndromes. The inherited or de novo mutations that cause these syndromes affect diverse cellular processes, such as ribosome biogenesis, DNA repair, and centriole duplication, and analysis of human patient samples and mouse models demonstrates that disrupting these cellular processes can activate the p53 pathway. Importantly, many of the developmental defects in mouse models of these syndromes can be rescued by loss of p53, indicating that inappropriate p53 activation directly contributes to their pathogenesis. A role for p53 in driving developmental defects is further supported by the observation that mouse strains with broad p53 hyperactivation, due to mutations affecting p53 pathway components, display a host of tissue-specific developmental defects, including hematopoietic, neuronal, craniofacial, cardiovascular, and pigmentation defects. Furthermore, germline activating mutations in TP53 were recently identified in two human patients exhibiting bone marrow failure and other developmental defects. Studies in mice suggest that p53 drives developmental defects by inducing apoptosis, restraining proliferation, or modulating other developmental programs in a cell type-dependent manner. Here, we review the growing body of evidence from mouse models that implicates p53 as a driver of tissue-specific developmental defects in diverse genetic syndromes.
Collapse
Affiliation(s)
- Margot E Bowen
- Division of Radiation and Cancer Biology in the Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, USA
| | - Laura D Attardi
- Division of Radiation and Cancer Biology in the Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, USA
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
| |
Collapse
|
7
|
Abstract
Most human cancers harbor mutations in the gene encoding p53. As a result, research on p53 in the past few decades has focused primarily on its role as a tumor suppressor. One consequence of this focus is that the functions of p53 in development have largely been ignored. However, recent advances, such as the genomic profiling of embryonic stem cells, have uncovered the significance and mechanisms of p53 functions in mammalian cell differentiation and development. As we review here, these recent findings reveal roles that complement the well-established roles for p53 in tumor suppression.
Collapse
Affiliation(s)
- Abhinav K Jain
- Department of Epigenetics and Molecular Carcinogenesis, Center for Stem Cell and Development Biology, Center for Cancer Epigenetics, The University of Texas MD Anderson UT Health Graduate School of Biomedical Sciences, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Michelle Craig Barton
- Department of Epigenetics and Molecular Carcinogenesis, Center for Stem Cell and Development Biology, Center for Cancer Epigenetics, The University of Texas MD Anderson UT Health Graduate School of Biomedical Sciences, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| |
Collapse
|
8
|
Van Nostrand JL, Bowen ME, Vogel H, Barna M, Attardi LD. The p53 family members have distinct roles during mammalian embryonic development. Cell Death Differ 2017; 24:575-579. [PMID: 28211873 DOI: 10.1038/cdd.2016.128] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 10/04/2016] [Accepted: 10/04/2016] [Indexed: 01/01/2023] Open
Abstract
The p53 tumor suppressor is a member of a multi-protein family, including the p63 and p73 transcription factors. These proteins can bind to the same consensus sites in DNA and activate the same target genes, suggesting that there could be functional redundancy between them. Indeed, double mutant mice heterozygous for any two family member-encoding genes display enhanced cancer phenotypes relative to single heterozygous mutants. However, whether the family members play redundant roles during embryonic development has remained largely unexplored. Although p53-/-; p73-/- mice are born and manifest phenotypes characteristic of each of the single mutants, the consequences of combined deficiency of p63 and either p53 or p73 have not been elucidated. To examine the functional overlap of p53 family members during development, we bred and analyzed compound mutant embryo phenotypes. We discovered that double knockout embryos and five allele knockout embryos only displayed obvious defects accounted for by loss of single p53 family members. Surprisingly, at mid-gestation (E11), we identified a single viable triple knockout embryo that appeared grossly normal. Together, these results suggest that the p53 family is not absolutely required for early embryogenesis and that p53 family members are largely non-redundant during early development.
Collapse
Affiliation(s)
- Jeanine L Van Nostrand
- Division of Radiation and Cancer Biology, Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Margot E Bowen
- Division of Radiation and Cancer Biology, Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Hannes Vogel
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Maria Barna
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA 94305, USA.,Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Laura D Attardi
- Division of Radiation and Cancer Biology, Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA.,Department of Genetics, Stanford University School of Medicine, Stanford, CA 94305, USA
| |
Collapse
|
9
|
Hovorakova M, Smrckova L, Lesot H, Lochovska K, Peterka M, Peterkova R. Sequential Shh expression in the development of the mouse upper functional incisor. JOURNAL OF EXPERIMENTAL ZOOLOGY PART B-MOLECULAR AND DEVELOPMENTAL EVOLUTION 2013; 320:455-64. [PMID: 23913503 DOI: 10.1002/jez.b.22522] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Revised: 05/21/2013] [Accepted: 06/03/2013] [Indexed: 11/06/2022]
Abstract
The mouse incisor is a frequently used model in studies of the molecular control of organ development. The appropriate interpretation of data on normogenesis is essential for understanding the data obtained in mutant mice. For this reason, we performed a very detailed investigation of the development of the upper incisor in wild-type mice from embryonic day (ED) 11.5 till 14.5. A combination of histology, whole mount in situ hybridization, computer-aided three-dimensional reconstructions, and fluorescent microscopy, has been used. Several sonic hedgehog (Shh) expression domains have been detected in the upper incisor region during early prenatal development. At ED11.5-13.5, there was a single Shh positive domain present in the anterior part of left or right upper jaw arches, corresponding to the epithelial thickening. More posteriorly, a new Shh expression domain appeared in the incisor bud in the developmentally more advanced ED13.5 embryos. At ED14.5, only this posterior Shh expression in the incisor germ remained detectable. This study brings new insights into the early development of the upper incisor in mice and completes the data on normal mouse incisor development. The temporal-spatial pattern of Shh expression reflects the development of two tooth generations, being detectable in two successive, antero-posteriorly located areas in the prospective incisor region in the upper jaw. The first, anterior and superficial Shh expression domain reflects the rudimentary tooth development suppressed during evolution. Only the subsequent, posterior and deeper Shh expression region, appearing at ED13.5, correlates with the prospective upper functional incisor in wild-type mice.
Collapse
Affiliation(s)
- Maria Hovorakova
- Institute of Experimental Medicine, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | | | | | | | | | | |
Collapse
|
10
|
Matsuura T, Kawata VKS, Nagoshi H, Tomooka Y, Sasaki K, Ikawa S. Regulation of proliferation and differentiation of mouse tooth germ epithelial cells by distinct isoforms of p51/p63. Arch Oral Biol 2012; 57:1108-15. [PMID: 22440406 DOI: 10.1016/j.archoralbio.2012.02.023] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2011] [Revised: 02/21/2012] [Accepted: 02/26/2012] [Indexed: 12/15/2022]
Abstract
OBJECTIVES p51/p63 gene, one of the p53 families, is specifically expressed in tooth germ epithelial cells and is essential for tooth development. This study aims to elucidate roles of p51/p63 in ameloblastic cell differentiation. MATERIALS AND METHODS We determined expression pattern of each of p51/p63 isoforms by reverse transcriptase-polymerase chain reaction (RT-PCR) and western blotting using emtg (epithelium of molar tooth germ)-1, -2, -3, -4, and -5 cell lines established from a mandibular molar tooth germ of p53-deficient mice and SF2 cells which differentiates into ameloblasts upon exposure to NT4. Furthermore, we investigated the function of p51/p63 in these cells by Tet system, which enables inducible expression and knock down of the target genes of interest by exposing cells to doxycycline. RESULTS The expression of ΔNp51B/ΔNp63α, an isoform without transactivation domain, was detected at high level in immature cells, while the expression of TAp51/TAp63 isoforms, isoforms of with the transactivation domain, was detected at high level in mature cells. Moreover, induction of TAp51A/TAp63γ expression led to down-regulation of ΔNp51B/ΔNp63α expression and cell proliferation. Interestingly, this also led to up-regulation of ameloblastin expression, a differentiation marker of amelogenesis. CONCLUSIONS The results suggested that p51/p63 might regulate the cell proliferation and differentiation of tooth germ epithelial cells.
Collapse
Affiliation(s)
- Takashi Matsuura
- Division of Advanced Prosthetic Dentistry, Tohoku University Graduate School of Dentistry, 4-1 Seiryomachi Aoba-ku, Sendai 980-8575, Japan
| | | | | | | | | | | |
Collapse
|
11
|
Charles C, Hovorakova M, Ahn Y, Lyons DB, Marangoni P, Churava S, Biehs B, Jheon A, Lesot H, Balooch G, Krumlauf R, Viriot L, Peterkova R, Klein OD. Regulation of tooth number by fine-tuning levels of receptor-tyrosine kinase signaling. Development 2011; 138:4063-73. [PMID: 21862563 DOI: 10.1242/dev.069195] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Much of our knowledge about mammalian evolution comes from examination of dental fossils, because the highly calcified enamel that covers teeth causes them to be among the best-preserved organs. As mammals entered new ecological niches, many changes in tooth number occurred, presumably as adaptations to new diets. For example, in contrast to humans, who have two incisors in each dental quadrant, rodents only have one incisor per quadrant. The rodent incisor, because of its unusual morphogenesis and remarkable stem cell-based continuous growth, presents a quandary for evolutionary biologists, as its origin in the fossil record is difficult to trace, and the genetic regulation of incisor number remains a largely open question. Here, we studied a series of mice carrying mutations in sprouty genes, the protein products of which are antagonists of receptor-tyrosine kinase signaling. In sprouty loss-of-function mutants, splitting of gene expression domains and reduced apoptosis was associated with subdivision of the incisor primordium and a multiplication of its stem cell-containing regions. Interestingly, changes in sprouty gene dosage led to a graded change in incisor number, with progressive decreases in sprouty dosage leading to increasing numbers of teeth. Moreover, the independent development of two incisors in mutants with large decreases in sprouty dosage mimicked the likely condition of rodent ancestors. Together, our findings indicate that altering genetic dosage of an antagonist can recapitulate ancestral dental characters, and that tooth number can be progressively regulated by changing levels of activity of a single signal transduction pathway.
Collapse
Affiliation(s)
- Cyril Charles
- Department of Orofacial Sciences and Program in Craniofacial and Mesenchymal Biology, University of California San Francisco, San Francisco, CA 94143, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
12
|
Orthodontic treatment of bilateral geminated maxillary permanent incisors. Am J Orthod Dentofacial Orthop 2011; 139:698-703. [DOI: 10.1016/j.ajodo.2009.03.045] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2009] [Revised: 03/01/2009] [Accepted: 03/01/2009] [Indexed: 11/17/2022]
|
13
|
Hosako H, Francisco LE, Martin GS, Mirkes PE. The roles of p53 and p21 in normal development and hyperthermia-induced malformations. ACTA ACUST UNITED AC 2009; 86:40-7. [PMID: 19140129 DOI: 10.1002/bdrb.20180] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
BACKGROUND Hyperthermia (HS) is a well-studied teratogen that induces serious malformations, including neural tube defects. Our previous studies have shown that HS induces apoptosis by activating the mitochondrial apoptotic pathway. Prior to activation of the mitochondrial apoptotic pathway, HS also activates p53 and its target genes. In the present study, we determine whether p53 and/or p21 play a role as teratogen suppressors or inducers of HS-induced malformations. METHODS Pregnant mice carrying all three p53 or p21 genotype embryos were exposed to HS on day 8.5. Subsequently, fetuses were collected on day 15.5, and genotyped. In addition to genotype, we also determined the number of resorptions and dead fetuses as well as the number and types of external malformations. RESULTS In the absence of HS exposure, fetuses exhibiting exencephaly and spina bifida were observed in approximately 11% of p53 -/- fetuses, whereas no malformations were observed among p21 -/- fetuses. Exposure to HS resulted in an increase in exencephaly and polydactyly in fetuses of all three p53 genotypes. However, the incidence of these malformations was statistically significantly higher in p53 -/- compared to p53 +/- and p53 +/+ fetuses. Exencephaly was the only malformation observed in p21 fetuses exposed to HS, with an approximately 2-fold increase among p21 +/- and a 3-fold increase among p21 -/- compared to p21 +/+ fetuses. CONCLUSIONS Our study confirms that p53 plays a role in normal development and has shown, for the first time that p53 and p21 function to suppress HS-induced malformations.
Collapse
Affiliation(s)
- Hiromi Hosako
- Department of Veterinary Physiology and Pharmacology, Texas A&M University, College Station, TX 77843,
| | | | | | | |
Collapse
|
14
|
Jirkovská M, Náprstková I, Janácek J, Kucera T, Macásek J, Karen P, Kubínová L. Three-dimensional reconstructions from non-deparaffinized tissue sections. ACTA ACUST UNITED AC 2005; 210:163-73. [PMID: 16189720 DOI: 10.1007/s00429-005-0006-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/07/2005] [Indexed: 10/25/2022]
Abstract
Three-dimensional (3-D) reconstruction from microscopic images represents a useful tool for the study of biological structures in embryology and developmental biology. However, it is usually necessary to cope with many difficulties connected with the preparation of specimens. In order to minimize mutual displacement of structures in successive sections, the applicability of non-deparaffinized tissue sections for 3-D reconstruction was tested. Chicken embryos were fixed and stained in toto with eosin and then embedded in paraffin. About 30-mum-thick non-deparaffinized serial sections were used for obtaining initial data for 3-D reconstruction of larger stacks of embryonic bodies using either fluorescence or confocal microscope. The same sections served for both collecting optical serial sections of mesonephros as source images for its 3-D reconstruction, and immunohistochemical detection of fibronectin, laminin and vimentin. It was found that sections with retained paraffin preserve the mutual spatial relationships of tissue components as well as provide an excellent differentiation of structure. It makes the process of 3-D reconstruction easier. The localization of the products of immunohistochemical reactions demonstrated the co-localization of fibronectin and laminin in basal laminas and the presence of vimentin in glomeruli and mesenchymal tissue. The use of non-deparaffinized sections represents a less time consuming and more effective alternative to thin histological sections for the purpose of 3-D reconstruction, and enables further application of material.
Collapse
Affiliation(s)
- Marie Jirkovská
- Institute of Histology and Embryology, 1st Faculty of Medicine, Charles University, Prague, Czech Republic.
| | | | | | | | | | | | | |
Collapse
|
15
|
Tendler Y, Weisinger G, Coleman R, Diamond E, Lischinsky S, Kerner H, Rotter V, Zinder O. Tissue-specific p53 expression in the nervous system. BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 1999; 72:40-6. [PMID: 10521597 DOI: 10.1016/s0169-328x(99)00202-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
P53 is a transcription factor that has been found to be expressed in association with cell proliferation and apoptosis. Previously, bacterial chloramphenicol acetyl transferase (CAT) enzymatic expression was predominantly found in the testes of p53 promoter driven-CAT transgenic mice. In the current study, we extended this study to survey p53 expression across both the central and peripheral nervous systems of the same strain of transgenic mice as well as their parental strain. High levels of p53 promoter driven-CAT activity was observed in the cerebellum, hippocampus, hypothalamus, pons, thalamus and upper cerebral spine. Furthermore, we consistently found unexpectedly high levels of p53 promoter-driven CAT expression in the eyes. These observations were reinforced by p53 protein analysis using a p53 pan ELISA assay. Immunohistochemical studies confirmed and further defined p53 expression in several regions of the nervous system. Significantly, p53 promoter-driven CAT expression was visualized in the Ammon horn of the hippocampus, in the Purkinje cells of the cerebellum and in the cornea as well as in the retina of the eye. Furthermore, strong p53 protein expression was found in the cornea of the parental mouse strain. p53 ELISA demonstrated a profile of p53 protein concentration, which correlate well with the high p53 promoter-driven CAT activities observed in the cerebellum, hindbrain, hypothalamus, thalamus, hippocampus, whole eyes as well as with the low CAT activities observed in the cortex and spinal cord. In both of these assays considerable p53 promoter activity and p53 protein levels were found in post-mitotic non-dividing cells.
Collapse
Affiliation(s)
- Y Tendler
- Department of Clinical Biochemistry, Rambam Medical Center, P.O. Box 9602, Haifa, Israel.
| | | | | | | | | | | | | | | |
Collapse
|