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Yuan L, Yang R, Deng H. Auricular fistula: a review of its clinical manifestations, genetics, and treatments. J Mol Med (Berl) 2023; 101:1041-1058. [PMID: 37458758 DOI: 10.1007/s00109-023-02343-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 06/21/2023] [Accepted: 06/22/2023] [Indexed: 09/07/2023]
Abstract
Auricular fistula is a common congenital auricular malformation, characterized as a small opening in the skin and a subcutaneous cyst. It can be classified in different ways according to positions of pits and directions of fistula tracts. The term preauricular fistula and variant type of preauricular fistula (postauricular fistula) are used. Auricular fistula prevalence varies in countries and populations, and its actual prevalence is presently unknown. The most accepted and widely cited theory of auricular fistula etiopathogenesis is an incorrect or incomplete fusion of six auricular hillocks that are mesenchymal proliferations. Auricular fistula can occur either sporadically or genetically. The pattern in inherited cases is thought to be incomplete autosomal dominant, with variable expressions, reduced penetrance, and inapparent gender differences. Auricular fistula has several forms and is reported as being a component of many syndromes. In the field of genetics, currently, there is no related review to comprehensively summarize the genetic basis of auricular fistula and related disorders. This article provides a comprehensive review of auricular fistula, especially congenital preauricular fistula, which accounts for the majority of auricular fistula, by summarizing the clinical manifestations, histological and embryological development, genetics, examinations, and treatments, as well as syndromes with auricular fistula.
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Affiliation(s)
- Lamei Yuan
- Health Management Center, the Third Xiangya Hospital, Central South University, Changsha, 410013, China
- Center for Experimental Medicine, the Third Xiangya Hospital, Central South University, Changsha, 410013, China
- Disease Genome Research Center, Central South University, Changsha, 410013, China
- Department of Neurology, the Third Xiangya Hospital, Central South University, Changsha, 410013, China
| | - Ruikang Yang
- Health Management Center, the Third Xiangya Hospital, Central South University, Changsha, 410013, China
- Center for Experimental Medicine, the Third Xiangya Hospital, Central South University, Changsha, 410013, China
- Disease Genome Research Center, Central South University, Changsha, 410013, China
| | - Hao Deng
- Health Management Center, the Third Xiangya Hospital, Central South University, Changsha, 410013, China.
- Center for Experimental Medicine, the Third Xiangya Hospital, Central South University, Changsha, 410013, China.
- Disease Genome Research Center, Central South University, Changsha, 410013, China.
- Department of Neurology, the Third Xiangya Hospital, Central South University, Changsha, 410013, China.
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Adadey SM, Wonkam-Tingang E, Alves de Souza Rios L, Aboagye ET, Esoh K, Manyisa N, De Kock C, Awandare GA, Mowla S, Wonkam A. Cell-based analysis of CLIC5A and SLC12A2 variants associated with hearing impairment in two African families. Front Genet 2022; 13:924904. [PMID: 36035115 PMCID: PMC9403182 DOI: 10.3389/fgene.2022.924904] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Accepted: 07/18/2022] [Indexed: 01/18/2023] Open
Abstract
We have previously reported CLIC5A and SLC12A2 variants in two families from Cameroon and Ghana, segregating non-syndromic hearing impairment (NSHI). In this study, biological assays were performed to further functionally investigate the pathogenicity of CLIC5 [c.224T>C; p.(L75P)] and SCL12A2 [c.2935G>A: p.(E979K)] variants. Ectopic expression of the proteins in a cell model shows that compared to wild-type, both the CLIC5A and SLC12A2 variants were overexpressed. The mutant CLIC5A protein appears as aggregated perinuclear bodies while the wild-type protein was evenly distributed in the cytoplasm. Furthermore, cells transfected with the wild-type CLIC5A formed thin membrane filopodia-like protrusions which were absent in the CLIC5A mutant expressing and control cells. On the other hand, the wild-type SLC12A2 expressing cells had an axon-like morphology which was not observed in the mutant expressing and control cells. A network analysis revealed that CLIC5A can interact with at least eight proteins at the base of the stereocilia. This study has generated novel biological data associated with the pathogenicity of targeted variants in CLIC5A and SLC12A2, found in two African families, and therefore expands our understanding of their pathobiology in hearing impairment.
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Affiliation(s)
- Samuel Mawuli Adadey
- Department of Pathology, Division of Human Genetics, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
- Department of Biochemistry, Cell, and Molecular Biology, West African Centre for Cell Biology of Infectious Pathogens (WACCBIP), University of Ghana, Accra, Ghana
| | - Edmond Wonkam-Tingang
- Department of Pathology, Division of Human Genetics, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Leonardo Alves de Souza Rios
- Department of Pathology, Division of Haematology, Faculty of Health Sciences, University of Cape Town, Observatory, Cape Town, South Africa
| | - Elvis Twumasi Aboagye
- Department of Pathology, Division of Human Genetics, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
- Department of Biochemistry, Cell, and Molecular Biology, West African Centre for Cell Biology of Infectious Pathogens (WACCBIP), University of Ghana, Accra, Ghana
| | - Kevin Esoh
- Department of Pathology, Division of Human Genetics, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Noluthando Manyisa
- Department of Pathology, Division of Human Genetics, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Carmen De Kock
- Department of Pathology, Division of Human Genetics, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
| | - Gordon A. Awandare
- Department of Biochemistry, Cell, and Molecular Biology, West African Centre for Cell Biology of Infectious Pathogens (WACCBIP), University of Ghana, Accra, Ghana
| | - Shaheen Mowla
- Department of Pathology, Division of Haematology, Faculty of Health Sciences, University of Cape Town, Observatory, Cape Town, South Africa
| | - Ambroise Wonkam
- Department of Pathology, Division of Human Genetics, Faculty of Health Sciences, University of Cape Town, Cape Town, South Africa
- McKusick-Nathans Institute and Department of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States
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Feng H, Xu H, Chen B, Sun S, Zhai R, Zeng B, Tang W, Lu W. Genetic and Phenotypic Variability in Chinese Patients With Branchio-Oto-Renal or Branchio-Oto Syndrome. Front Genet 2021; 12:765433. [PMID: 34868248 PMCID: PMC8634836 DOI: 10.3389/fgene.2021.765433] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Accepted: 09/30/2021] [Indexed: 12/29/2022] Open
Abstract
Background: Branchio-oto-renal syndrome (BOR) and branchio-oto syndrome (BOS) are rare autosomal dominant disorders defined by varying combinations of branchial, otic, and renal anomalies. Here, we characterized the clinical features and genetic etiology of BOR/BOS in several Chinese families and then explored the genotypes and phenotypes of BOR/BOS-related genes, as well as the outcomes of auditory rehabilitation in different modalities. Materials and Methods: Probands and all affected family members underwent detailed clinical examinations. Their DNA was subjected to whole-exome sequencing to explore the underlying molecular etiology of BOR/BOS; candidate variants were validated using Sanger sequencing and interpreted in accordance with the American College of Medical Genetics guidelines. In addition, a literature review concerning EYA1 and SIX1 alterations was performed to explore the genotypes and phenotypes of BOR/BOS-related genes. Results: Genetic testing identified the novel deletion (c.1425delC, p(Asp476Thrfs*4); NM_000,503.6), a nonsense variant (c.889C > T, p(Arg297*)), and two splicing variants in the EYA1 gene (c.1050+1G > T and c.1140+1G > A); it also identified one novel missense variant in the SIX1 gene (c.316G > A, p(Val106Met); NM_005,982.4). All cases exhibited a degree of phenotypic variability between or within families. Middle ear surgeries for improving bone-conduction component hearing loss had unsuccessful outcomes; cochlear implantation (CI) contributed to hearing gains. Conclusion: This is the first report of BOR/BOS caused by the SIX1 variant in China. Our findings increase the numbers of known EYA1 and SIX1 variants. They also emphasize the usefulness of genetic testing in the diagnosis and prevention of BOR/BOS while demonstrating that CI for auditory rehabilitation is a feasible option in some BOR/BOS patients.
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Affiliation(s)
- Haifeng Feng
- Department of Otorhinolaryngology-Head and Neck Surgery, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Hongen Xu
- Center for Applied Precision Medicine, The Second Affiliated Hospital of Zhengzhou University, Zhengzhou, China.,Precision Medicine Center, Academy of Medical Science, Zhengzhou University, Zhengzhou, China
| | - Bei Chen
- Department of Otorhinolaryngology-Head and Neck Surgery, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Shuping Sun
- Department of Otorhinolaryngology-Head and Neck Surgery, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Rongqun Zhai
- Department of Otorhinolaryngology-Head and Neck Surgery, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Beiping Zeng
- Precision Medicine Center, Academy of Medical Science, Zhengzhou University, Zhengzhou, China
| | - Wenxue Tang
- Center for Applied Precision Medicine, The Second Affiliated Hospital of Zhengzhou University, Zhengzhou, China.,Precision Medicine Center, Academy of Medical Science, Zhengzhou University, Zhengzhou, China.,Henan Institute of Medical and Pharmaceutical Sciences, Zhengzhou University, Zhengzhou, China
| | - Wei Lu
- Department of Otorhinolaryngology-Head and Neck Surgery, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
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Coppenrath K, Tavares ALP, Shaidani NI, Wlizla M, Moody SA, Horb M. Generation of a new six1-null line in Xenopus tropicalis for study of development and congenital disease. Genesis 2021; 59:e23453. [PMID: 34664392 DOI: 10.1002/dvg.23453] [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: 08/05/2021] [Revised: 09/02/2021] [Accepted: 09/04/2021] [Indexed: 12/15/2022]
Abstract
The vertebrate Six (Sine oculis homeobox) family of homeodomain transcription factors plays critical roles in the development of several organs. Six1 plays a central role in cranial placode development, including the precursor tissues of the inner ear, as well as other cranial sensory organs and the kidney. In humans, mutations in SIX1 underlie some cases of Branchio-oto-renal (BOR) syndrome, which is characterized by moderate-to-severe hearing loss. We utilized CRISPR/Cas9 technology to establish a six1 mutant line in Xenopus tropicalis that is available to the research community. We demonstrate that at larval stages, the six1-null animals show severe disruptions in gene expression of putative Six1 target genes in the otic vesicle, cranial ganglia, branchial arch, and neural tube. At tadpole stages, six1-null animals display dysmorphic Meckel's, ceratohyal, and otic capsule cartilage morphology. This mutant line will be of value for the study of the development of several organs as well as congenital syndromes that involve these tissues.
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Affiliation(s)
- Kelsey Coppenrath
- Eugene Bell Center for Regenerative Biology and Tissue Engineering and National Xenopus Resource, Marine Biological Laboratory, Woods Hole, Massachusetts, USA
| | - Andre L P Tavares
- Department of Anatomy and Cell Biology, George Washington University School of Medicine and Health Sciences, Washington, District of Columbia, USA
| | - Nikko-Ideen Shaidani
- Eugene Bell Center for Regenerative Biology and Tissue Engineering and National Xenopus Resource, Marine Biological Laboratory, Woods Hole, Massachusetts, USA
| | - Marcin Wlizla
- Eugene Bell Center for Regenerative Biology and Tissue Engineering and National Xenopus Resource, Marine Biological Laboratory, Woods Hole, Massachusetts, USA.,Embryology Department, Charles River Laboratories, Wilmington, Massachusetts, USA
| | - Sally A Moody
- Department of Anatomy and Cell Biology, George Washington University School of Medicine and Health Sciences, Washington, District of Columbia, USA
| | - Marko Horb
- Eugene Bell Center for Regenerative Biology and Tissue Engineering and National Xenopus Resource, Marine Biological Laboratory, Woods Hole, Massachusetts, USA
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Wu J, Huang B, He HB, Lu WZ, Wang WG, Liu H. Two naturally derived small molecules disrupt the sineoculis homeobox homolog 1-eyes absent homolog 1 (SIX1-EYA1) interaction to inhibit colorectal cancer cell growth. Chin Med J (Engl) 2021; 134:2340-2352. [PMID: 34561318 PMCID: PMC8509980 DOI: 10.1097/cm9.0000000000001736] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND Emerging evidence indicates that the sineoculis homeobox homolog 1-eyes absent homolog 1 (SIX1-EYA1) transcriptional complex significantly contributes to the pathogenesis of multiple cancers by mediating the expression of genes involved in different biological processes, such as cell-cycle progression and metastasis. However, the roles of the SIX1-EYA1 transcriptional complex and its targets in colorectal cancer (CRC) are still being investigated. This study aimed to investigate the roles of SIX1-EYA1 in the pathogenesis of CRC, to screen inhibitors disrupting the SIX1-EYA1 interaction and to evaluate the efficiency of small molecules in the inhibition of CRC cell growth. METHODS Real-time quantitative polymerase chain reaction and western blotting were performed to examine gene and protein levels in CRC cells and clinical tissues (collected from CRC patients who underwent surgery in the Department of Integrated Traditional and Western Medicine, West China Hospital of Sichuan University, between 2016 and 2018, n = 24). In vivo immunoprecipitation and in vitro pulldown assays were carried out to determine SIX1-EYA1 interaction. Cell proliferation, cell survival, and cell invasion were determined using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, clonogenic assay, and Boyden chamber assay, respectively. The Amplified Luminescent Proximity Homogeneous Assay Screen (AlphaScreen) method was used to obtain small molecules that specifically disrupted SIX1-EYA1 interaction. CRC cells harboring different levels of SIX1/EYA1 were injected into nude mice to establish tumor xenografts, and small molecules were also injected into mice to evaluate their efficiency to inhibit tumor growth. RESULTS Both SIX1 and EYA1 were overexpressed in CRC cancerous tissues (for SIX1, 7.47 ± 3.54 vs.1.88 ± 0.35, t = 4.92, P = 0.008; for EYA1, 7.61 ± 2.03 vs. 2.22 ± 0.45, t = 6.73, P = 0.005). The SIX1/EYA1 complex could mediate the expression of two important genes including cyclin A1 (CCNA1) and transforming growth factor beta 1 (TGFB1) by binding to the myocyte enhancer factor 3 consensus. Knockdown of both SIX1 and EYA1 could decrease cell proliferation, cell invasion, tumor growth, and in vivo tumor growth (all P < 0.01). Two small molecules, NSC0191 and NSC0933, were obtained using AlphaScreen and they could significantly inhibit the SIX1-EYA1 interaction with a half-maximal inhibitory concentration (IC50) of 12.60 ± 1.15 μmol/L and 83.43 ± 7.24 μmol/L, respectively. Administration of these two compounds could significantly repress the expression of CCNA1 and TGFB1 and inhibit the growth of CRC cells in vitro and in vivo. CONCLUSIONS Overexpression of the SIX1/EYA1 complex transactivated the expression of CCNA1 and TGFB1, causing the pathogenesis of CRC. Pharmacological inhibition of the SIX1-EYA1 interaction with NSC0191 and NSC0933 significantly inhibited CRC cell growth by affecting cell-cycle progression and metastasis.
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Affiliation(s)
- Jing Wu
- Department of Integrated Traditional and Western Medicine, West China Hospital of Sichuan University, Chengdu, Sichuan 610041, China
| | - Bin Huang
- Department of Vascular Surgery, West China Hospital of Sichuan University, Chengdu, Sichuan 610041, China
| | - Hong-Bo He
- Department of Integrated Traditional and Western Medicine, West China Hospital of Sichuan University, Chengdu, Sichuan 610041, China
| | - Wen-Zhu Lu
- Department of Integrated Traditional and Western Medicine, West China Hospital of Sichuan University, Chengdu, Sichuan 610041, China
| | - Wei-Guo Wang
- Department of Integrated Traditional and Western Medicine, West China Hospital of Sichuan University, Chengdu, Sichuan 610041, China
| | - Hong Liu
- Department of Integrated Traditional and Western Medicine, West China Hospital of Sichuan University, Chengdu, Sichuan 610041, China
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Xu J, Yang X, Deng Q, Yang C, Wang D, Jiang G, Yao X, He X, Ding J, Qiang J, Tu J, Zhang R, Lei QY, Shao ZM, Bian X, Hu R, Zhang L, Liu S. TEM8 marks neovasculogenic tumor-initiating cells in triple-negative breast cancer. Nat Commun 2021; 12:4413. [PMID: 34285210 PMCID: PMC8292527 DOI: 10.1038/s41467-021-24703-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Accepted: 07/01/2021] [Indexed: 12/12/2022] Open
Abstract
Enhanced neovasculogenesis, especially vasculogenic mimicry (VM), contributes to the development of triple-negative breast cancer (TNBC). Breast tumor-initiating cells (BTICs) are involved in forming VM; however, the specific VM-forming BTIC population and the regulatory mechanisms remain undefined. We find that tumor endothelial marker 8 (TEM8) is abundantly expressed in TNBC and serves as a marker for VM-forming BTICs. Mechanistically, TEM8 increases active RhoC level and induces ROCK1-mediated phosphorylation of SMAD5, in a cascade essential for promoting stemness and VM capacity of breast cancer cells. ASB10, an estrogen receptor ERα trans-activated E3 ligase, ubiquitylates TEM8 for degradation, and its deficiency in TNBC resulted in a high homeostatic level of TEM8. In this work, we identify TEM8 as a functional marker for VM-forming BTICs in TNBC, providing a target for the development of effective therapies against TNBC targeting both BTIC self-renewal and neovasculogenesis simultaneously. Vasculogenic mimicry (VM) contributes to the development of triple-negative breast cancer. In this study, the authors show that TEM8 is expressed in VM-forming breast cancer stem cells and it promotes stemness and VM differentiation capacity through a RhoC/ROCK1/SMAD5 axis
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Affiliation(s)
- Jiahui Xu
- Fudan University Shanghai Cancer Center & Institutes of Biomedical Sciences; Cancer Institutes; Key Laboratory of Breast Cancer in Shanghai; The Shanghai Key Laboratory of Medical Epigenetics; The International Co-laboratory of Medical Epigenetics and Metabolism, Ministry of Science and Technology; Shanghai Medical College, Fudan University, Shanghai, China
| | - Xiaoli Yang
- Fudan University Shanghai Cancer Center & Institutes of Biomedical Sciences; Cancer Institutes; Key Laboratory of Breast Cancer in Shanghai; The Shanghai Key Laboratory of Medical Epigenetics; The International Co-laboratory of Medical Epigenetics and Metabolism, Ministry of Science and Technology; Shanghai Medical College, Fudan University, Shanghai, China
| | - Qiaodan Deng
- Fudan University Shanghai Cancer Center & Institutes of Biomedical Sciences; Cancer Institutes; Key Laboratory of Breast Cancer in Shanghai; The Shanghai Key Laboratory of Medical Epigenetics; The International Co-laboratory of Medical Epigenetics and Metabolism, Ministry of Science and Technology; Shanghai Medical College, Fudan University, Shanghai, China
| | - Cong Yang
- School of Medicine, Guizhou University, Guiyang, Guizhou, China
| | - Dong Wang
- WPI Nano Life Science Institute, Kanazawa University, Kakuma-machi, Kanazawa, Japan
| | - Guojuan Jiang
- Fudan University Shanghai Cancer Center & Institutes of Biomedical Sciences; Cancer Institutes; Key Laboratory of Breast Cancer in Shanghai; The Shanghai Key Laboratory of Medical Epigenetics; The International Co-laboratory of Medical Epigenetics and Metabolism, Ministry of Science and Technology; Shanghai Medical College, Fudan University, Shanghai, China
| | - Xiaohong Yao
- Institute of Pathology and Southwest Cancer Center, Southwest Hospital, Third Military Medical University (Army Medical University); Key Laboratory of Tumor Immunopathology, Ministry of Education of China, Chongqing, China
| | - Xueyan He
- Fudan University Shanghai Cancer Center & Institutes of Biomedical Sciences; Cancer Institutes; Key Laboratory of Breast Cancer in Shanghai; The Shanghai Key Laboratory of Medical Epigenetics; The International Co-laboratory of Medical Epigenetics and Metabolism, Ministry of Science and Technology; Shanghai Medical College, Fudan University, Shanghai, China
| | - Jiajun Ding
- Fudan University Shanghai Cancer Center & Institutes of Biomedical Sciences; Cancer Institutes; Key Laboratory of Breast Cancer in Shanghai; The Shanghai Key Laboratory of Medical Epigenetics; The International Co-laboratory of Medical Epigenetics and Metabolism, Ministry of Science and Technology; Shanghai Medical College, Fudan University, Shanghai, China
| | - Jiankun Qiang
- Fudan University Shanghai Cancer Center & Institutes of Biomedical Sciences; Cancer Institutes; Key Laboratory of Breast Cancer in Shanghai; The Shanghai Key Laboratory of Medical Epigenetics; The International Co-laboratory of Medical Epigenetics and Metabolism, Ministry of Science and Technology; Shanghai Medical College, Fudan University, Shanghai, China
| | - Juchuanli Tu
- Fudan University Shanghai Cancer Center & Institutes of Biomedical Sciences; Cancer Institutes; Key Laboratory of Breast Cancer in Shanghai; The Shanghai Key Laboratory of Medical Epigenetics; The International Co-laboratory of Medical Epigenetics and Metabolism, Ministry of Science and Technology; Shanghai Medical College, Fudan University, Shanghai, China
| | - Rui Zhang
- Fudan University Shanghai Cancer Center & Institutes of Biomedical Sciences; Cancer Institutes; Key Laboratory of Breast Cancer in Shanghai; The Shanghai Key Laboratory of Medical Epigenetics; The International Co-laboratory of Medical Epigenetics and Metabolism, Ministry of Science and Technology; Shanghai Medical College, Fudan University, Shanghai, China
| | - Qun-Ying Lei
- Fudan University Shanghai Cancer Center & Institutes of Biomedical Sciences; Cancer Institutes; Key Laboratory of Breast Cancer in Shanghai; The Shanghai Key Laboratory of Medical Epigenetics; The International Co-laboratory of Medical Epigenetics and Metabolism, Ministry of Science and Technology; Shanghai Medical College, Fudan University, Shanghai, China
| | - Zhi-Min Shao
- Fudan University Shanghai Cancer Center & Institutes of Biomedical Sciences; Cancer Institutes; Key Laboratory of Breast Cancer in Shanghai; The Shanghai Key Laboratory of Medical Epigenetics; The International Co-laboratory of Medical Epigenetics and Metabolism, Ministry of Science and Technology; Shanghai Medical College, Fudan University, Shanghai, China
| | - Xiuwu Bian
- Institute of Pathology and Southwest Cancer Center, Southwest Hospital, Third Military Medical University (Army Medical University); Key Laboratory of Tumor Immunopathology, Ministry of Education of China, Chongqing, China.
| | - Ronggui Hu
- State Key Laboratory of Molecular Biology; CAS Center for Excellence in Molecular Cell Science; Shanghai Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, Shanghai, China.
| | - Lixing Zhang
- Fudan University Shanghai Cancer Center & Institutes of Biomedical Sciences; Cancer Institutes; Key Laboratory of Breast Cancer in Shanghai; The Shanghai Key Laboratory of Medical Epigenetics; The International Co-laboratory of Medical Epigenetics and Metabolism, Ministry of Science and Technology; Shanghai Medical College, Fudan University, Shanghai, China.
| | - Suling Liu
- Fudan University Shanghai Cancer Center & Institutes of Biomedical Sciences; Cancer Institutes; Key Laboratory of Breast Cancer in Shanghai; The Shanghai Key Laboratory of Medical Epigenetics; The International Co-laboratory of Medical Epigenetics and Metabolism, Ministry of Science and Technology; Shanghai Medical College, Fudan University, Shanghai, China.
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Mutations in SIX1 Associated with Branchio-oto-Renal Syndrome (BOR) Differentially Affect Otic Expression of Putative Target Genes. J Dev Biol 2021; 9:jdb9030025. [PMID: 34208995 PMCID: PMC8293042 DOI: 10.3390/jdb9030025] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 06/16/2021] [Accepted: 06/26/2021] [Indexed: 12/12/2022] Open
Abstract
Several single-nucleotide mutations in SIX1 underlie branchio-otic/branchio-oto-renal (BOR) syndrome, but the clinical literature has not been able to correlate different variants with specific phenotypes. We previously assessed whether variants in either the cofactor binding domain (V17E, R110W) or the DNA binding domain (W122R, Y129C) might differentially affect early embryonic gene expression, and found that each variant had a different combination of effects on neural crest and placode gene expression. Since the otic vesicle gives rise to the inner ear, which is consistently affected in BOR, herein we focused on whether the variants differentially affected the otic expression of genes previously found to be likely Six1 targets. We found that V17E, which does not bind Eya cofactors, was as effective as wild-type Six1 in reducing most otic target genes, whereas R110W, W122R and Y129C, which bind Eya, were significantly less effective. Notably, V17E reduced the otic expression of prdm1, whereas R110W, W122R and Y129C expanded it. Since each mutant has defective transcriptional activity but differs in their ability to interact with Eya cofactors, we propose that altered cofactor interactions at the mutated sites differentially interfere with their ability to drive otic gene expression, and these differences may contribute to patient phenotype variability.
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Shah AM, Krohn P, Baxi AB, Tavares ALP, Sullivan CH, Chillakuru YR, Majumdar HD, Neilson KM, Moody SA. Six1 proteins with human branchio-oto-renal mutations differentially affect cranial gene expression and otic development. Dis Model Mech 2020; 13:dmm043489. [PMID: 31980437 PMCID: PMC7063838 DOI: 10.1242/dmm.043489] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Accepted: 01/14/2020] [Indexed: 12/15/2022] Open
Abstract
Single-nucleotide mutations in human SIX1 result in amino acid substitutions in either the protein-protein interaction domain or the homeodomain, and cause ∼4% of branchio-otic (BOS) and branchio-oto-renal (BOR) cases. The phenotypic variation between patients with the same mutation, even within affected members of the same family, make it difficult to functionally distinguish between the different SIX1 mutations. We made four of the BOS/BOR substitutions in the Xenopus Six1 protein (V17E, R110W, W122R, Y129C), which is 100% identical to human in both the protein-protein interaction domain and the homeodomain, and expressed them in embryos to determine whether they cause differential changes in early craniofacial gene expression, otic gene expression or otic morphology. We confirmed that, similar to the human mutants, all four mutant Xenopus Six1 proteins access the nucleus but are transcriptionally deficient. Analysis of craniofacial gene expression showed that each mutant causes specific, often different and highly variable disruptions in the size of the domains of neural border zone, neural crest and pre-placodal ectoderm genes. Each mutant also had differential effects on genes that pattern the otic vesicle. Assessment of the tadpole inner ear demonstrated that while the auditory and vestibular structures formed, the volume of the otic cartilaginous capsule, otoliths, lumen and a subset of the hair cell-containing sensory patches were reduced. This detailed description of the effects of BOS/BOR-associated SIX1 mutations in the embryo indicates that each causes subtle changes in gene expression in the embryonic ectoderm and otocyst, leading to inner ear morphological anomalies.
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Affiliation(s)
- Ankita M Shah
- Department of Anatomy and Cell Biology, George Washington University School of Medicine and Health Sciences, Washington, DC 20037, USA
| | - Patrick Krohn
- Department of Anatomy and Cell Biology, George Washington University School of Medicine and Health Sciences, Washington, DC 20037, USA
- Institute of Zoology, University of Hohenheim, Stuttgart 70599, Germany
| | - Aparna B Baxi
- Department of Anatomy and Cell Biology, George Washington University School of Medicine and Health Sciences, Washington, DC 20037, USA
| | - Andre L P Tavares
- Department of Anatomy and Cell Biology, George Washington University School of Medicine and Health Sciences, Washington, DC 20037, USA
| | - Charles H Sullivan
- Department of Anatomy and Cell Biology, George Washington University School of Medicine and Health Sciences, Washington, DC 20037, USA
- Department of Biology, Grinnell College, Grinnell, IA 50112, USA
| | - Yeshwant R Chillakuru
- Department of Anatomy and Cell Biology, George Washington University School of Medicine and Health Sciences, Washington, DC 20037, USA
| | - Himani D Majumdar
- Department of Anatomy and Cell Biology, George Washington University School of Medicine and Health Sciences, Washington, DC 20037, USA
| | - Karen M Neilson
- Department of Anatomy and Cell Biology, George Washington University School of Medicine and Health Sciences, Washington, DC 20037, USA
| | - Sally A Moody
- Department of Anatomy and Cell Biology, George Washington University School of Medicine and Health Sciences, Washington, DC 20037, USA
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Sullivan CH, Majumdar HD, Neilson KM, Moody SA. Six1 and Irx1 have reciprocal interactions during cranial placode and otic vesicle formation. Dev Biol 2019; 446:68-79. [PMID: 30529252 PMCID: PMC6349505 DOI: 10.1016/j.ydbio.2018.12.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2018] [Revised: 12/02/2018] [Accepted: 12/03/2018] [Indexed: 01/04/2023]
Abstract
The specialized sensory organs of the vertebrate head are derived from thickened patches of cells in the ectoderm called cranial sensory placodes. The developmental program that generates these placodes and the genes that are expressed during the process have been studied extensively in a number of animals, yet very little is known about how these genes regulate one another. We previously found via a microarray screen that Six1, a known transcriptional regulator of cranial placode fate, up-regulates Irx1 in ectodermal explants. In this study, we investigated the transcriptional relationship between Six1 and Irx1 and found that they reciprocally regulate each other throughout cranial placode and otic vesicle formation. Although Irx1 expression precedes that of Six1 in the neural border zone, its continued and appropriately patterned expression in the pre-placodal region (PPR) and otic vesicle requires Six1. At early PPR stages, Six1 expands the Irx1 domain, but this activity subsides over time and changes to a predominantly repressive effect. Likewise, Irx1 initially expands Six1 expression in the PPR, but later represses it. We also found that Irx1 and Sox11, a known direct target of Six1, reciprocally affect each other. This work demonstrates that the interactions between Six1 and Irx1 are continuous during PPR and placode development and their transcriptional effects on one another change over developmental time.
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Affiliation(s)
- Charles H Sullivan
- Department of Biology, Grinnell College, Grinnell, IA, 50112, USA; bDepartment of Anatomy and Cell Biology, George Washington University School of Medicine and Health Sciences, 2300 I (eye) Street, N.W., Washington DC 20037, USA
| | - Himani D Majumdar
- bDepartment of Anatomy and Cell Biology, George Washington University School of Medicine and Health Sciences, 2300 I (eye) Street, N.W., Washington DC 20037, USA
| | - Karen M Neilson
- bDepartment of Anatomy and Cell Biology, George Washington University School of Medicine and Health Sciences, 2300 I (eye) Street, N.W., Washington DC 20037, USA
| | - Sally A Moody
- bDepartment of Anatomy and Cell Biology, George Washington University School of Medicine and Health Sciences, 2300 I (eye) Street, N.W., Washington DC 20037, USA.
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10
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Delpire E, Gagnon KB. Na + -K + -2Cl - Cotransporter (NKCC) Physiological Function in Nonpolarized Cells and Transporting Epithelia. Compr Physiol 2018; 8:871-901. [PMID: 29687903 DOI: 10.1002/cphy.c170018] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Two genes encode the Na+ -K+ -2Cl- cotransporters, NKCC1 and NKCC2, that mediate the tightly coupled movement of 1Na+ , 1K+ , and 2Cl- across the plasma membrane of cells. Na+ -K+ -2Cl- cotransport is driven by the chemical gradient of the three ionic species across the membrane, two of them maintained by the action of the Na+ /K+ pump. In many cells, NKCC1 accumulates Cl- above its electrochemical potential equilibrium, thereby facilitating Cl- channel-mediated membrane depolarization. In smooth muscle cells, this depolarization facilitates the opening of voltage-sensitive Ca2+ channels, leading to Ca2+ influx, and cell contraction. In immature neurons, the depolarization due to a GABA-mediated Cl- conductance produces an excitatory rather than inhibitory response. In many cell types that have lost water, NKCC is activated to help the cells recover their volume. This is specially the case if the cells have also lost Cl- . In combination with the Na+ /K+ pump, the NKCC's move ions across various specialized epithelia. NKCC1 is involved in Cl- -driven fluid secretion in many exocrine glands, such as sweat, lacrimal, salivary, stomach, pancreas, and intestine. NKCC1 is also involved in K+ -driven fluid secretion in inner ear, and possibly in Na+ -driven fluid secretion in choroid plexus. In the thick ascending limb of Henle, NKCC2 activity in combination with the Na+ /K+ pump participates in reabsorbing 30% of the glomerular-filtered Na+ . Overall, many critical physiological functions are maintained by the activity of the two Na+ -K+ -2Cl- cotransporters. In this overview article, we focus on the functional roles of the cotransporters in nonpolarized cells and in epithelia. © 2018 American Physiological Society. Compr Physiol 8:871-901, 2018.
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Affiliation(s)
- Eric Delpire
- Department of Anesthesiology, Vanderbilt University Medical School, Nashville, Tennessee, USA
| | - Kenneth B Gagnon
- Division of Nephrology and Hypertension, Department of Medicine, University of Louisville School of Medicine, Louisville, Keystone, USA
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11
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Zhang T, Xu J, Maire P, Xu PX. Six1 is essential for differentiation and patterning of the mammalian auditory sensory epithelium. PLoS Genet 2017; 13:e1006967. [PMID: 28892484 PMCID: PMC5593176 DOI: 10.1371/journal.pgen.1006967] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Accepted: 08/08/2017] [Indexed: 11/19/2022] Open
Abstract
The organ of Corti in the cochlea is a two-cell layered epithelium: one cell layer of mechanosensory hair cells that align into one row of inner and three rows of outer hair cells interdigitated with one cell layer of underlying supporting cells along the entire length of the cochlear spiral. These two types of epithelial cells are derived from common precursors in the four- to five-cell layered primordium and acquire functionally important shapes during terminal differentiation through the thinning process and convergent extension. Here, we have examined the role of Six1 in the establishment of the auditory sensory epithelium. Our data show that prior to terminal differentiation of the precursor cells, deletion of Six1 leads to formation of only a few hair cells and defective patterning of the sensory epithelium. Previous studies have suggested that downregulation of Sox2 expression in differentiating hair cells must occur after Atoh1 mRNA activation in order to allow Atoh1 protein accumulation due to antagonistic effects between Atoh1 and Sox2. Our analysis indicates that downregulation of Sox2 in the differentiating hair cells depends on Six1 activity. Furthermore, we found that Six1 is required for the maintenance of Fgf8 expression and dynamic distribution of N-cadherin and E-cadherin in the organ of Corti during differentiation. Together, our analyses uncover essential roles of Six1 in hair cell differentiation and formation of the organ of Corti in the mammalian cochlea.
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Affiliation(s)
- Ting Zhang
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Jinshu Xu
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Pascal Maire
- INSERM U1016, Institut Cochin, Paris, France; CNRS UMR 8104, Paris, France; Université Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Pin-Xian Xu
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
- Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
- * E-mail:
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12
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Riddiford N, Schlosser G. Dissecting the pre-placodal transcriptome to reveal presumptive direct targets of Six1 and Eya1 in cranial placodes. eLife 2016; 5. [PMID: 27576864 PMCID: PMC5035141 DOI: 10.7554/elife.17666] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Accepted: 08/29/2016] [Indexed: 11/13/2022] Open
Abstract
The pre-placodal ectoderm, marked by the expression of the transcription factor Six1 and its co-activator Eya1, develops into placodes and ultimately into many cranial sensory organs and ganglia. Using RNA-Seq in Xenopus laevis we screened for presumptive direct placodal target genes of Six1 and Eya1 by overexpressing hormone-inducible constructs of Six1 and Eya1 in pre-placodal explants, and blocking protein synthesis before hormone-inducing nuclear translocation of Six1 or Eya1. Comparing the transcriptome of explants with non-induced controls, we identified hundreds of novel Six1/Eya1 target genes with potentially important roles for placode development. Loss-of-function studies confirmed that target genes encoding known transcriptional regulators of progenitor fates (e.g. Sox2, Hes8) and neuronal/sensory differentiation (e.g. Ngn1, Atoh1, Pou4f1, Gfi1) require Six1 and Eya1 for their placodal expression. Our findings provide insights into the gene regulatory network regulating placodal neurogenesis downstream of Six1 and Eya1 suggesting new avenues of research into placode development and disease.
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Affiliation(s)
- Nick Riddiford
- School of Natural Sciences, National University of Ireland, Galway, Ireland.,Regenerative Medicine Institute (REMEDI), National University of Ireland, Galway, Ireland
| | - Gerhard Schlosser
- School of Natural Sciences, National University of Ireland, Galway, Ireland.,Regenerative Medicine Institute (REMEDI), National University of Ireland, Galway, Ireland
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Sato S, Yajima H, Furuta Y, Ikeda K, Kawakami K. Activation of Six1 Expression in Vertebrate Sensory Neurons. PLoS One 2015; 10:e0136666. [PMID: 26313368 PMCID: PMC4551851 DOI: 10.1371/journal.pone.0136666] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Accepted: 08/05/2015] [Indexed: 12/31/2022] Open
Abstract
SIX1 homeodomain protein is one of the essential key regulators of sensory organ development. Six1-deficient mice lack the olfactory epithelium, vomeronasal organs, cochlea, vestibule and vestibuloacoustic ganglion, and also show poor neural differentiation in the distal part of the cranial ganglia. Simultaneous loss of both Six1 and Six4 leads to additional abnormalities such as small trigeminal ganglion and abnormal dorsal root ganglia (DRG). The aim of this study was to understand the molecular mechanism that controls Six1 expression in sensory organs, particularly in the trigeminal ganglion and DRG. To this end, we focused on the sensory ganglia-specific Six1 enhancer (Six1-8) conserved between chick and mouse. In vivo reporter assays using both animals identified an important core region comprising binding consensus sequences for several transcription factors including nuclear hormone receptors, TCF/LEF, SMAD, POU homeodomain and basic-helix-loop-helix proteins. The results provided information on upstream factors and signals potentially relevant to Six1 regulation in sensory neurons. We also report the establishment of a new transgenic mouse line (mSix1-8-NLSCre) that expresses Cre recombinase under the control of mouse Six1-8. Cre-mediated recombination was detected specifically in ISL1/2-positive sensory neurons of Six1-positive cranial sensory ganglia and DRG. The unique features of the mSix1-8-NLSCre line are the absence of Cre-mediated recombination in SOX10-positive glial cells and central nervous system and ability to induce recombination in a subset of neurons derived from the olfactory placode/epithelium. This mouse model can be potentially used to advance research on sensory development.
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Affiliation(s)
- Shigeru Sato
- Division of Biology, Center for Molecular Medicine, Jichi Medical University, Shimotsuke, Tochigi, Japan
- * E-mail:
| | - Hiroshi Yajima
- Division of Biology, Center for Molecular Medicine, Jichi Medical University, Shimotsuke, Tochigi, Japan
| | - Yasuhide Furuta
- Animal Resource Development Unit and Genetic Engineering Team, Division of Bio-function Dynamics Imaging, RIKEN Center for Life Science Technologies (CLST), Kobe, Hyogo, Japan
| | - Keiko Ikeda
- Division of Biology, Hyogo College of Medicine, Nishinomiya, Hyogo, Japan
| | - Kiyoshi Kawakami
- Division of Biology, Center for Molecular Medicine, Jichi Medical University, Shimotsuke, Tochigi, Japan
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Yajima H, Suzuki M, Ochi H, Ikeda K, Sato S, Yamamura KI, Ogino H, Ueno N, Kawakami K. Six1 is a key regulator of the developmental and evolutionary architecture of sensory neurons in craniates. BMC Biol 2014; 12:40. [PMID: 24885223 PMCID: PMC4084797 DOI: 10.1186/1741-7007-12-40] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2014] [Accepted: 05/22/2014] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Various senses and sensory nerve architectures of animals have evolved during adaptation to exploit diverse environments. In craniates, the trunk sensory system has evolved from simple mechanosensory neurons inside the spinal cord (intramedullary), called Rohon-Beard (RB) cells, to multimodal sensory neurons of dorsal root ganglia (DRG) outside the spinal cord (extramedullary). The fish and amphibian trunk sensory systems switch from RB cells to DRG during development, while amniotes rely exclusively on the DRG system. The mechanisms underlying the ontogenic switching and its link to phylogenetic transition remain unknown. RESULTS In Xenopus, Six1 overexpression promoted precocious apoptosis of RB cells and emergence of extramedullary sensory neurons, whereas Six1 knockdown delayed the reduction in RB cell number. Genetic ablation of Six1 and Six4 in mice led to the appearance of intramedullary sensory neuron-like cells as a result of medial migration of neural crest cells into the spinal cord and production of immature DRG neurons and fused DRG. Restoration of SIX1 expression in the neural crest-linage partially rescued the phenotype, indicating the cell autonomous requirements of SIX1 for normal extramedullary sensory neurogenesis. Mouse Six1 enhancer that mediates the expression in DRG neurons activated transcription in Xenopus RB cells earlier than endogenous six1 expression, suggesting earlier onset of mouse SIX1 expression than Xenopus during sensory development. CONCLUSIONS The results indicated the critical role of Six1 in transition of RB cells to DRG neurons during Xenopus development and establishment of exclusive DRG system of mice. The study provided evidence that early appearance of SIX1 expression, which correlated with mouse Six1 enhancer, is essential for the formation of DRG-dominant system in mice, suggesting that heterochronic changes in Six1 enhancer sequence play an important role in alteration of trunk sensory architecture and contribute to the evolution of the trunk sensory system.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Kiyoshi Kawakami
- Division of Biology, Center for Molecular Medicine, Jichi Medical University, 3311-1 Yakushiji, Shimotsuke, Tochigi 329-0498, Japan.
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15
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Wu W, Ren Z, Li P, Yu D, Chen J, Huang R, Liu H. Six1: A critical transcription factor in tumorigenesis. Int J Cancer 2014; 136:1245-53. [DOI: 10.1002/ijc.28755] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2013] [Revised: 01/15/2014] [Accepted: 01/20/2014] [Indexed: 12/16/2022]
Affiliation(s)
- Wangjun Wu
- Department of Animal Genetics; Breeding and Reproduction; College of Animal Science and Technology; Nanjing Agricultural University; Nanjing China
- Huaian Academy of Nanjing Agricultural University; Huaian Jiangsu China
| | - Zhuqing Ren
- Key Laboratory of Swine Genetics and Breeding; Ministry of Agriculture; Key Lab of Agriculture Animal Genetics; Breeding and Reproduction; Ministry of Education; College of Animal Science; Huazhong Agricultural University; Wuhan Hubei China
| | - Pinghua Li
- Department of Animal Genetics; Breeding and Reproduction; College of Animal Science and Technology; Nanjing Agricultural University; Nanjing China
| | - Debing Yu
- Department of Animal Genetics; Breeding and Reproduction; College of Animal Science and Technology; Nanjing Agricultural University; Nanjing China
| | - Jie Chen
- Department of Animal Genetics; Breeding and Reproduction; College of Animal Science and Technology; Nanjing Agricultural University; Nanjing China
| | - Ruihua Huang
- Department of Animal Genetics; Breeding and Reproduction; College of Animal Science and Technology; Nanjing Agricultural University; Nanjing China
| | - Honglin Liu
- Department of Animal Genetics; Breeding and Reproduction; College of Animal Science and Technology; Nanjing Agricultural University; Nanjing China
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16
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Hetzler KL, Collins BC, Shanely RA, Sue H, Kostek MC. The homoeobox gene SIX1 alters myosin heavy chain isoform expression in mouse skeletal muscle. Acta Physiol (Oxf) 2014; 210:415-28. [PMID: 24102895 DOI: 10.1111/apha.12168] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2013] [Revised: 08/21/2013] [Accepted: 09/10/2013] [Indexed: 01/06/2023]
Abstract
AIM Six1 is necessary for the genesis of several tissues, but in adults, it is expressed primarily in skeletal muscle where its function is unclear. Overexpression of Six1 with a cofactor in skeletal muscle causes slow-to-fast fibre-type transition. We sought to characterize the effects of a physiologically relevant Six1 knockdown. METHODS The tibialis anterior (TA) muscles of C57BL/6 mice were electroporated with Six1 knockdown vector (siRNA) or empty vector. Muscles were collected at 2 or 14 days after transfection for Six1 and myosin heavy chain (MHC) expression analysis. C2C12 mouse myoblasts were grown in standard conditions. Cells were cotransfected with MHC promoter vectors and Six1 expression vectors. Cells were harvested after 4 days of differentiation. RESULTS In vivo, the Six1 siRNA caused a decreased expression of Six1,1.8-fold (±0.1, P < 0.05). With decreased Six1, MHC IIB expression decreased 2.7-fold (±0.7, P = 0.04). Proportion of muscle fibres expressing MHC IIB decreased (45.3 ± 4.8% vs. 65.1 ± 7.3% in control group, P = 0.04), and total area expressing MHC IIB decreased with decreased Six1 (59.6 ± 4.3% vs. 75.2 ± 5.4% in control group, P < 0.05). Decreased Six1 increased MHC IIA expression 1.9-fold (±0.3, P = 0.04). In vitro, Six1 overexpression increased promoter activation of MHC IIB 2.9-fold (±0.3, P < 0.01). Six1 knockdown repressed MHC IIB promoter 2.9-fold (±0.1, P < 0.05) and MHC IIX 3.7-fold (±0.08, P < 0.01). CONCLUSION Six1 knockdown caused a fast-to-slow shift in MHC isoform, and this was confirmed by promoter activity of MHC genes. Six1 may ultimately control the contractile and metabolic properties that define muscle fibre phenotype.
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Affiliation(s)
- K. L. Hetzler
- Department of Exercise Science; University of South Carolina; Columbia SC USA
| | - B. C. Collins
- Department of Exercise Science; University of South Carolina; Columbia SC USA
| | - R. A. Shanely
- Appalachian State University-North Carolina Research Campus Human Performance Laboratory; Appalachian State University; Kannapolis NC USA
| | - H. Sue
- Department of Exercise Science; University of South Carolina; Columbia SC USA
| | - M. C. Kostek
- Department of Exercise Science; University of South Carolina; Columbia SC USA
- Department of Physical Therapy; Duquesne University; Pittsburgh PA USA
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17
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Xu PX. The EYA-SO/SIX complex in development and disease. Pediatr Nephrol 2013; 28:843-54. [PMID: 22806561 PMCID: PMC6592036 DOI: 10.1007/s00467-012-2246-1] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2012] [Revised: 06/10/2012] [Accepted: 06/12/2012] [Indexed: 10/28/2022]
Abstract
Eyes absent (EYA) and Sine oculis (SO/SIX) proteins function as transcriptional activation complexes and play essential roles in organogenesis during embryonic development in regulating cell proliferation and survival and coordination of particular differentiation programs. Mutations of the Eya and So/Six genes cause profound developmental defects in organisms as diverse as flies, frogs, fish, mice, and humans. EYA proteins also possess an intrinsic phosphatase activity, which is essential for normal development. Here, we review crucial roles of EYA and SO/SIX in development and disease in mice and humans.
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Affiliation(s)
- Pin-Xian Xu
- Department of Genetics and Genomic Sciences and Developmental and Regenerative Biology, Mount Sinai School of Medicine, New York, NY 10029, USA.
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18
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Tadjuidje E, Hegde RS. The Eyes Absent proteins in development and disease. Cell Mol Life Sci 2012; 70:1897-913. [PMID: 22971774 DOI: 10.1007/s00018-012-1144-9] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2012] [Revised: 07/24/2012] [Accepted: 08/20/2012] [Indexed: 10/27/2022]
Abstract
The Eyes Absent (EYA) proteins, first described in the context of fly eye development, are now implicated in processes as disparate as organ development, innate immunity, DNA damage repair, photoperiodism, angiogenesis, and cancer metastasis. These functions are associated with an unusual combination of biochemical activities: tyrosine phosphatase and threonine phosphatase activities in separate domains, and transactivation potential when associated with a DNA-binding partner. EYA mutations are linked to multiorgan developmental disorders, as well as to adult diseases ranging from dilated cardiomyopathy to late-onset sensorineural hearing loss. With the growing understanding of EYA biochemical and cellular activity, biological function, and association with disease, comes the possibility that the EYA proteins are amenable to the design of targeted therapeutics. The availability of structural information, direct links to disease states, available animal models, and the fact that they utilize unconventional reaction mechanisms that could allow specificity, suggest that EYAs are well-positioned for drug discovery efforts. This review provides a summary of EYA structure, activity, and function, as they relate to development and disease, with particular emphasis on recent findings.
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Affiliation(s)
- Emmanuel Tadjuidje
- Division of Developmental Biology, Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, OH 45229, USA
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19
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Sági B, Maraghechi P, Urbán VS, Hegyi B, Szigeti A, Fajka-Boja R, Kudlik G, Német K, Monostori É, Gócza E, Uher F. Positional Identity of Murine Mesenchymal Stem Cells Resident in Different Organs Is Determined in the Postsegmentation Mesoderm. Stem Cells Dev 2012; 21:814-28. [DOI: 10.1089/scd.2011.0551] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Affiliation(s)
- Bernadett Sági
- National Blood Service, Stem Cell Biology Unit, Budapest, Hungary
| | | | - Veronika S. Urbán
- National Blood Service, Stem Cell Biology Unit, Budapest, Hungary
- Department of Morphology and Physiology, Faculty of Health Sciences, Semmelweis University, Budapest, Hungary
| | - Beáta Hegyi
- National Blood Service, Stem Cell Biology Unit, Budapest, Hungary
| | - Anna Szigeti
- National Blood Service, Laboratory of Experimental Gene Therapy, Budapest, Hungary
| | - Roberta Fajka-Boja
- Lymphocyte Signal Transduction Laboratory, Biological Research Center of Hungarian Academy of Sciences, Institute of Genetics, Szeged, Hungary
| | - Gyöngyi Kudlik
- National Blood Service, Stem Cell Biology Unit, Budapest, Hungary
| | - Katalin Német
- National Blood Service, Laboratory of Experimental Gene Therapy, Budapest, Hungary
| | - Éva Monostori
- Lymphocyte Signal Transduction Laboratory, Biological Research Center of Hungarian Academy of Sciences, Institute of Genetics, Szeged, Hungary
| | - Elen Gócza
- Agricultural Biotechnology Center, Gödöllő, Hungary
| | - Ferenc Uher
- National Blood Service, Stem Cell Biology Unit, Budapest, Hungary
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Farabaugh SM, Micalizzi DS, Jedlicka P, Zhao R, Ford HL. Eya2 is required to mediate the pro-metastatic functions of Six1 via the induction of TGF-β signaling, epithelial-mesenchymal transition, and cancer stem cell properties. Oncogene 2011; 31:552-62. [PMID: 21706047 PMCID: PMC3183358 DOI: 10.1038/onc.2011.259] [Citation(s) in RCA: 99] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Six1 is a critical regulator of embryonic development that requires interaction with the Eya family of proteins (Eya1-4) to activate the transcription of genes involved in neurogenesis, myogenesis, and nephrogenesis. While expression of Six1 and Eya family members is predominantly observed in development, their overexpression is observed in numerous cancers. Importantly, both Six1 and Eya have independently been shown to mediate breast cancer metastasis, but whether they functionally interact during tumor progression has not been explored. Herein we demonstrate that knockdown of Eya2 in MCF7 mammary carcinoma cells reverses the ability of Six1 to induce TGF-β signaling, as well as to induce characteristics associated with epithelial-mesenchymal transition (EMT) and cancer stem cells (CSCs), suggesting that Six1 is dependent on Eya2 to mediate numerous pro-metastatic characteristics. The importance of the Six1/Eya interaction in human breast cancer is underscored by the finding that high levels of Six1 correlate with shortened time to relapse and metastasis as well as decreased survival only when co-expressed with high levels of Eya2. Overall, these data implicate Eya2 as a necessary cofactor for many of the metastasis promoting functions of Six1, suggesting that targeting the Six1/Eya interaction may inhibit breast cancer progression. Since Six1 and Eya2 are not highly expressed in most adult tissues, the Six1-Eya interaction may be a valuable future therapeutic target whose inhibition would be expected to impair breast cancer progression while conferring limited side effects.
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Affiliation(s)
- S M Farabaugh
- Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
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Molecular cloning, promoter analysis, SNP detection of Clusterin gene and their associations with mastitis in Chinese Holstein cows. Mol Biol Rep 2011; 39:2439-45. [PMID: 21667239 DOI: 10.1007/s11033-011-0994-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2011] [Accepted: 05/31/2011] [Indexed: 01/05/2023]
Abstract
To examine the effect of Clusterin (CLU) on mastitis, genetic association analysis was applied on mastitis and milk production traits of 1,137 Chinese Holstein cows. We detected two novel single nucleotide polymorphisms (SNPs), G+15781A in the seventh exon and C-994T before 5'-upstream region (UTR) of CLU gene, found five TATA box, one CpG island and more transcription factor binding sites in promoter region, respectively, Milk fat rate in genotype AA was significantly higher than in GG on fat rate (P < 0.01), milk fat and milk yield in combined haplotype H1H4 (AGCT) were significantly higher than in H3H4 (GGCT) (P < 0.05), H1H4 was decided advantage in nine milk production traits. Quadruplet cows in G+15781A were decided advantage in each milk production traits that 305-day milk yield, fat rate, protein rate and somatic cell scores (SCS) increased following with birth order. A allele and T allele had positive effect on SCS. In conclusion, this study showed that the haplotype AA may be a genetic marker on mastitis and other performance for Chinese Holstein cows.
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22
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Six family genes control the proliferation and differentiation of muscle satellite cells. Exp Cell Res 2010; 316:2932-44. [DOI: 10.1016/j.yexcr.2010.08.001] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2010] [Revised: 07/19/2010] [Accepted: 08/03/2010] [Indexed: 12/23/2022]
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Liu Y, Chu A, Chakroun I, Islam U, Blais A. Cooperation between myogenic regulatory factors and SIX family transcription factors is important for myoblast differentiation. Nucleic Acids Res 2010; 38:6857-71. [PMID: 20601407 PMCID: PMC2978361 DOI: 10.1093/nar/gkq585] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Precise regulation of gene expression is crucial to myogenesis and is thought to require the cooperation of various transcription factors. On the basis of a bioinformatic analysis of gene regulatory sequences, we hypothesized that myogenic regulatory factors (MRFs), key regulators of skeletal myogenesis, cooperate with members of the SIX family of transcription factors, known to play important roles during embryonic skeletal myogenesis. To this day little is known regarding the exact molecular mechanism by which SIX factors regulate muscle development. We have conducted a functional genomic study of the role played by SIX1 and SIX4 during the differentiation of skeletal myoblasts, a model of adult muscle regeneration. We report that SIX factors cooperate with the members of the MRF family to activate gene expression during myogenic differentiation, and that their function is essential to this process. Our findings also support a model where SIX factors function not only ‘upstream’ of the MRFs during embryogenesis, but also ‘in parallel’ to them during myoblast differentiation. We have identified new essential nodes that depend on SIX factor function, in the myogenesis regulatory network, and have uncovered a novel way by which MRF function is modulated during differentiation.
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Affiliation(s)
- Yubing Liu
- Ottawa Institute of Systems Biology and Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Faculty of Medicine, 451 Smyth Road, Ottawa, ON K1H 8M5, Canada
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Inactivation of Six2 in mouse identifies a novel genetic mechanism controlling development and growth of the cranial base. Dev Biol 2010; 344:720-30. [PMID: 20515681 DOI: 10.1016/j.ydbio.2010.05.509] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2009] [Revised: 05/03/2010] [Accepted: 05/24/2010] [Indexed: 12/17/2022]
Abstract
The cranial base is essential for integrated craniofacial development and growth. It develops as a cartilaginous template that is replaced by bone through the process of endochondral ossification. Here, we describe a novel and specific role for the homeoprotein Six2 in the growth and elongation of the cranial base. Six2-null newborn mice display premature fusion of the bones in the cranial base. Chondrocyte differentiation is abnormal in the Six2-null cranial base, with reduced proliferation and increased terminal differentiation. Gain-of-function experiments indicate that Six2 promotes cartilage development and growth in other body areas and appears therefore to control general regulators of chondrocyte differentiation. Our data indicate that the main factors restricting Six2 function to the cranial base are tissue-specific transcription of the gene and compensatory effects of other Six family members. The comparable expression during human embryogenesis and the high protein conservation from mouse to human implicate SIX2 loss-of-function as a potential congenital cause of anterior cranial base defects in humans.
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Jeong Y, Oh S. Identification of an evolutionarily conserved, functional noncoding element regulated by Six1 homeoprotein. Genes Genet Syst 2010; 85:233-40. [DOI: 10.1266/ggs.85.233] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Affiliation(s)
- Yongsu Jeong
- Department of Genetic Engineering, College of Life Sciences and Graduate School of Biotechnology, Kyung Hee University
| | - Sangtaek Oh
- PharmacoGenomics Research Center, Inje University
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Bosman EA, Quint E, Fuchs H, Hrabé de Angelis M, Steel KP. Catweasel mice: a novel role for Six1 in sensory patch development and a model for branchio-oto-renal syndrome. Dev Biol 2009; 328:285-96. [PMID: 19389353 PMCID: PMC2682643 DOI: 10.1016/j.ydbio.2009.01.030] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2008] [Revised: 01/20/2009] [Accepted: 01/22/2009] [Indexed: 11/18/2022]
Abstract
Large-scale mouse mutagenesis initiatives have provided new mouse mutants that are useful models of human deafness and vestibular dysfunction. Catweasel is a novel N-ethyl-N-nitrosourea (ENU)-induced mutation. Heterozygous catweasel mutant mice exhibit mild headtossing associated with a posterior crista defect. We mapped the catweasel mutation to a critical region of 13 Mb on chromosome 12 containing the Six1, -4 and -6 genes. We identified a basepair substitution in exon 1 of the Six1 gene that changes a conserved glutamic acid (E) at position 121 to a glycine (G) in the Six1 homeodomain. Cwe/Cwe animals lack Preyer and righting reflexes, display severe headshaking and have severely truncated cochlea and semicircular canals. Cwe/Cwe animals had very few hair cells in the utricle, but their ampullae and cochlea were devoid of any hair cells. Bmp4, Jag1 and Sox2 expression were largely absent at early stages of sensory development and NeuroD expression was reduced in the developing vestibulo-acoustic ganglion. Lastly we show that Six1 genetically interacts with Jag1. We propose that the catweasel phenotype is due to a hypomorphic mutation in Six1 and that catweasel mice are a suitable model for branchio-oto-renal syndrome. In addition Six1 has a pivotal role in early sensory patch development and may act in the same genetic pathway as Jag1.
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Affiliation(s)
- Erika A. Bosman
- The Wellcome Trust Sanger Institute, The Wellcome Trust Genome Campus, Hinxton CB10 1SA, UK
| | | | - Helmut Fuchs
- Helmholtz Zentrum München, GmbH, Ingolstädter Landstraβe 1, D-85764 Neuherberg, Germany
| | | | - Karen P. Steel
- The Wellcome Trust Sanger Institute, The Wellcome Trust Genome Campus, Hinxton CB10 1SA, UK
- Corresponding author. Fax: +44 1223 494840.
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27
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Kumar JP. The sine oculis homeobox (SIX) family of transcription factors as regulators of development and disease. Cell Mol Life Sci 2009; 66:565-83. [PMID: 18989625 PMCID: PMC2716997 DOI: 10.1007/s00018-008-8335-4] [Citation(s) in RCA: 190] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The sine oculis homeobox (SIX) protein family is a group of evolutionarily conserved transcription factors that are found in diverse organisms that range from flatworms to humans. These factors are expressed within, and play pivotal developmental roles in, cell populations that give rise to the head, retina, ear, nose, brain, kidney, muscle and gonads. Mutations within the fly and mammalian versions of these genes have adverse consequences on the development of these organs/tissues. Several SIX proteins have been shown to directly influence the cell cycle and are present at elevated levels during tumorigenesis and within several cancers. This review aims to highlight aspects of (1) the evolutionary history of the SIX family; (2) the structural differences and similarities amongst the different SIX proteins; (3) the role that these genes play in retinal development; and (4) the influence that these proteins have on cell proliferation and growth.
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Affiliation(s)
- J P Kumar
- Department of Biology, Indiana University, Bloomington, 47405, USA.
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28
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Kutejova E, Engist B, Self M, Oliver G, Kirilenko P, Bobola N. Six2 functions redundantly immediately downstream of Hoxa2. Development 2008; 135:1463-70. [PMID: 18321982 DOI: 10.1242/dev.017624] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Hox transcription factors control morphogenesis along the head-tail axis of bilaterians. Because their direct functional targets are still poorly understood in vertebrates, it remains unclear how the positional information encoded by Hox genes is translated into morphogenetic changes. Here, we conclusively demonstrate that Six2 is a direct downstream target of Hoxa2 in vivo and show that the ectopic expression of Six2, observed in the absence of Hoxa2, contributes to the Hoxa2 mouse mutant phenotype. We propose that Six2 acts to mediate Hoxa2 control over the insulin-like growth factor pathway during branchial arch development.
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Affiliation(s)
- Eva Kutejova
- Department of Developmental Biology, Max-Planck Institute of Immunobiology, Freiburg, Germany
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29
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Hu S, Mamedova A, Hegde RS. DNA-Binding and Regulation Mechanisms of the SIX Family of Retinal Determination Proteins. Biochemistry 2008; 47:3586-94. [DOI: 10.1021/bi702186s] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Affiliation(s)
- Shengyong Hu
- Division of Developmental Biology, Cincinnati Children’s Hospital Medical Center, and Department of Pediatrics, University of Cincinnati School of Medicine, 3333 Burnet Avenue, Cincinnati, Ohio 45229
| | - Aygun Mamedova
- Division of Developmental Biology, Cincinnati Children’s Hospital Medical Center, and Department of Pediatrics, University of Cincinnati School of Medicine, 3333 Burnet Avenue, Cincinnati, Ohio 45229
| | - Rashmi S. Hegde
- Division of Developmental Biology, Cincinnati Children’s Hospital Medical Center, and Department of Pediatrics, University of Cincinnati School of Medicine, 3333 Burnet Avenue, Cincinnati, Ohio 45229
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30
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van Dijk ADJ, ter Braak CJF, Immink RG, Angenent GC, van Ham RCHJ. Predicting and understanding transcription factor interactions based on sequence level determinants of combinatorial control. ACTA ACUST UNITED AC 2007; 24:26-33. [PMID: 18024974 DOI: 10.1093/bioinformatics/btm539] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
MOTIVATION Transcription factor interactions are the cornerstone of combinatorial control, which is a crucial aspect of the gene regulatory system. Understanding and predicting transcription factor interactions based on their sequence alone is difficult since they are often part of families of factors sharing high sequence identity. Given the scarcity of experimental data on interactions compared to available sequence data, however, it would be most useful to have accurate methods for the prediction of such interactions. RESULTS We present a method consisting of a Random Forest-based feature-selection procedure that selects relevant motifs out of a set found using a correlated motif search algorithm. Prediction accuracy for several transcription factor families (bZIP, MADS, homeobox and forkhead) reaches 60-90%. In addition, we identified those parts of the sequence that are important for the interaction specificity, and show that these are in agreement with available data. We also used the predictors to perform genome-wide scans for interaction partners and recovered both known and putative new interaction partners.
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Affiliation(s)
- A D J van Dijk
- Applied Bioinformatics, PRI, Wageningen UR, Droevendaalsesteeg 1, Wageningen, The Netherlands
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31
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Jemc J, Rebay I. The eyes absent family of phosphotyrosine phosphatases: properties and roles in developmental regulation of transcription. Annu Rev Biochem 2007; 76:513-38. [PMID: 17341163 DOI: 10.1146/annurev.biochem.76.052705.164916] [Citation(s) in RCA: 116] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Integration of multiple signaling pathways at the level of their transcriptional effectors provides an important strategy for fine-tuning gene expression and ensuring a proper program of development. Posttranslational modifications, such as phosphorylation, play important roles in modulating transcription factor activity. The discovery that the transcription factor Eyes absent (Eya) possesses protein phosphatase activity provides an interesting new paradigm. Eya may regulate the phosphorylation state of either itself or its transcriptional cofactors, thereby directly affecting transcriptional output. The identification of a growing number of transcription factors with enzymic activity suggests that such dual-function proteins exert greater control of signaling events than previously imagined. Given the conservation of both its phosphatase and transcription factor activity across mammalian species, Eya provides an excellent model for studying how a single protein integrates these two functions under the influence of multiple signaling pathways to promote development.
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Affiliation(s)
- Jennifer Jemc
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, USA
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32
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Zhu X, Gleiberman AS, Rosenfeld MG. Molecular physiology of pituitary development: signaling and transcriptional networks. Physiol Rev 2007; 87:933-63. [PMID: 17615393 DOI: 10.1152/physrev.00006.2006] [Citation(s) in RCA: 237] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The pituitary gland is a central endocrine organ regulating basic physiological functions, including growth, the stress response, reproduction, metabolic homeostasis, and lactation. Distinct hormone-producing cell types in the anterior pituitary arise from a common ectodermal primordium during development by extrinsic and intrinsic mechanisms, providing a powerful model system for elucidating general principles in mammalian organogenesis. The central purpose of this review is to inspect the integrated signaling and transcriptional events that affect precursor proliferation, cell lineage commitment, terminal differentiation, and physiological regulation by hypothalamic tropic factors.
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Affiliation(s)
- Xiaoyan Zhu
- Howard Hughes Medical Institute, Department and School of Medicine, University of California, San Diego, La Jolla, California 92093, USA.
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33
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Abstract
Branchio-oto-renal syndrome, a phenotype consisting of hearing loss, auricular malformations, branchial arch remnants, and renal anomalies is now recognized as one of the more common forms of autosomal dominant syndromic hearing impairment. Three loci known to be associated with the BOR phenotype have been identified and two genes that act in a regulatory network have been cloned, EYA1 and SIX1. EYA1 and SIX1 are homologous to genes involved in Drosophila eye development, eyes absent gene (eya), and sine oculis (so), respectively. EYA1, a transcriptional co-activator has a conserved, 271-amino acid, C-terminal known as the Eya Domain (ED). SIX1 has two highly conserved domains; a homeodomain (HD) and a specific Six-domain (SD) whose products function as transcription factors with specific DNA-binding activity that are crucial for protein-protein interaction. To determine the molecular basis for the organ defects that occur in BOR syndrome, many studies have focused on the effects of mutations to EYA and effects of mutations of the EYA-SIX regulatory system. However, over 60% of BOR syndrome patients do not have known mutations in EYA1 and relatively little is known about mutations to SIX1. Further evaluation of SIX1 and its related target genes may provide a better understanding of the pathophysiology of BOR syndrome and offer greater clues to the disease mechanisms.
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Affiliation(s)
- Amit Kochhar
- Molecular Otolaryngology Research Laboratories, University of Iowa, Iowa City, Iowa 52242, USA
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34
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Kobayashi H, Kawakami K, Asashima M, Nishinakamura R. Six1 and Six4 are essential for Gdnf expression in the metanephric mesenchyme and ureteric bud formation, while Six1 deficiency alone causes mesonephric-tubule defects. Mech Dev 2007; 124:290-303. [PMID: 17300925 DOI: 10.1016/j.mod.2007.01.002] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2006] [Revised: 12/24/2006] [Accepted: 01/05/2007] [Indexed: 12/22/2022]
Abstract
Interaction between the ureteric-bud epithelium and the metanephric mesenchyme is important for kidney development. Six1 and Six4 are the mammalian homologs of Drosophila sine oculis, and they are coexpressed in the nephrogenic mesenchyme. Six1-deficient mice show varying kidney defects, while Six4-deficient mice have no apparent abnormalities. Here, we report Six1/Six4-deficient mice that we generated in order to elucidate the functions of Six4 in Six1-deficient kidney development. The Six1/Six4-deficient mice exhibited more severe kidney phenotypes than the Six1-deficient mice; kidney and ureter agenesis was observed in all the neonates examined. The Six1/Six4-deficient metanephric mesenchyme cells were directed toward kidney lineage but failed to express Pax2, Pax8, or Gdnf, whereas the expression of these genes was partially reduced or unchanged in the case of Six1 deficiency. Thus, Six4 cooperates with Six1 in the metanephric mesenchyme to regulate the level of Gdnf expression; this could explain the absence of the ureteric bud in the Six1/Six4-deficient mice. In contrast, Six1 deficiency alone caused defects in mesonephric-tubule formation, and these defects were not exacerbated in the Six1/Six4-deficient mesonephros. These results highlight the fact that Six1 and Six4 have collaborative functions in the metanephros but not in the mesonephros.
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Affiliation(s)
- Hiroki Kobayashi
- Division of Integrative Cell Biology, Institute of Molecular Embryology and Genetics, Kumamoto University, 2-2-1 Honjo, Kumamoto 860-0811, Japan
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