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Huang C, Chen W, Wang X. Studies on the fat mass and obesity-associated (FTO) gene and its impact on obesity-associated diseases. Genes Dis 2023; 10:2351-2365. [PMID: 37554175 PMCID: PMC10404889 DOI: 10.1016/j.gendis.2022.04.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2021] [Revised: 03/29/2022] [Accepted: 04/01/2022] [Indexed: 10/18/2022] Open
Abstract
Obesity has become a major health crisis in the past ∼50 years. The fat mass and obesity-associated (FTO) gene, identified by genome-wide association studies (GWAS), was first reported to be positively associated with obesity in humans. Mice with more copies of the FTO gene were observed to be obese, while loss of the gene in mice was found to protect from obesity. Later, FTO was found to encode an m6A RNA demethylase and has a profound effect on many biological and metabolic processes. In this review, we first summarize recent studies that demonstrate the critical roles and regulatory mechanisms of FTO in obesity and metabolic disease. Second, we discuss the ongoing debates concerning the association between FTO polymorphisms and obesity. Third, since several small molecule drugs and micronutrients have been found to regulate metabolic homeostasis through controlling the expression or activity of FTO, we highlight the broad potential of targeting FTO for obesity treatment. Improving our understanding of FTO and the underlying mechanisms may provide new approaches for treating obesity and metabolic diseases.
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Affiliation(s)
- Chaoqun Huang
- College of Animal Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China
- Key Laboratory of Molecular Animal Nutrition, Zhejiang University, Ministry of Education, Hangzhou, Zhejiang 310058, China
- Key Laboratory of Animal Nutrition and Feed Science (Eastern of China), Ministry of Agriculture and Rural Affairs, Hangzhou, Zhejiang 310058, China
- Key Laboratory of Animal Feed and Nutrition of Zhejiang Province, Hangzhou, Zhejiang 310058, China
| | - Wei Chen
- College of Animal Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China
- Key Laboratory of Molecular Animal Nutrition, Zhejiang University, Ministry of Education, Hangzhou, Zhejiang 310058, China
- Key Laboratory of Animal Nutrition and Feed Science (Eastern of China), Ministry of Agriculture and Rural Affairs, Hangzhou, Zhejiang 310058, China
- Key Laboratory of Animal Feed and Nutrition of Zhejiang Province, Hangzhou, Zhejiang 310058, China
| | - Xinxia Wang
- College of Animal Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China
- Key Laboratory of Molecular Animal Nutrition, Zhejiang University, Ministry of Education, Hangzhou, Zhejiang 310058, China
- Key Laboratory of Animal Nutrition and Feed Science (Eastern of China), Ministry of Agriculture and Rural Affairs, Hangzhou, Zhejiang 310058, China
- Key Laboratory of Animal Feed and Nutrition of Zhejiang Province, Hangzhou, Zhejiang 310058, China
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2
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Wu Y, Zhou J, Yang Y. Peripheral and central control of obesity by primary cilia. J Genet Genomics 2023; 50:295-304. [PMID: 36632916 DOI: 10.1016/j.jgg.2022.12.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 12/29/2022] [Accepted: 12/30/2022] [Indexed: 01/10/2023]
Abstract
Primary cilia are hair-like structures that protrude from the cell surface. They are capable of sensing external cues and conveying a vast array of signals into cells to regulate a variety of physiological activities. Mutations in cilium-associated genes are linked to a group of diseases with overlapping clinical manifestations, collectively known as ciliopathies. A significant proportion of human ciliopathy cases are accompanied by metabolic disorders such as obesity and type 2 diabetes. Nevertheless, the mechanisms through which dysfunction of primary cilia contributes to obesity are complex. In this article, we present an overview of primary cilia and highlight obesity-related ciliopathies. We also discuss the potential role of primary cilia in peripheral organs, with a focus on adipose tissues. In addition, we emphasize the significance of primary cilia in the central regulation of obesity, especially the involvement of ciliary signaling in the hypothalamic control of feeding behavior. This article therefore proposes a framework of both peripheral and central regulation of obesity by primary cilia, which may benefit further exploration of the ciliary role in metabolic regulation.
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Affiliation(s)
- Yue Wu
- Center for Cell Structure and Function, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, College of Life Sciences, Shandong Normal University, Jinan, Shandong, 250014, China
| | - Jun Zhou
- Center for Cell Structure and Function, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, College of Life Sciences, Shandong Normal University, Jinan, Shandong, 250014, China; State Key Laboratory of Medicinal Chemical Biology, Haihe Laboratory of Cell Ecosystem, College of Life Sciences, Nankai University, Tianjin, 300071, China.
| | - Yunfan Yang
- Department of Cell Biology, School of Basic Medical Sciences, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, 250012, China.
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3
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Engle SE, Bansal R, Antonellis PJ, Berbari NF. Cilia signaling and obesity. Semin Cell Dev Biol 2020; 110:43-50. [PMID: 32466971 DOI: 10.1016/j.semcdb.2020.05.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 05/08/2020] [Accepted: 05/10/2020] [Indexed: 12/11/2022]
Abstract
An emerging number of rare genetic disorders termed ciliopathies are associated with pediatric obesity. It is becoming clear that the mechanisms associated with cilia dysfunction and obesity in these syndromes are complex. In addition to ciliopathic syndromic forms of obesity, several cilia-associated signaling gene mutations also lead to morbid obesity. While cilia have critical and diverse functions in energy homeostasis including their roles in centrally mediated food intake as well as in peripheral tissues, many questions remain. Here, we briefly discuss the syndromic ciliopathies and monoallelic cilia signaling gene mutations associated with obesity. We also describe potential ways cilia may be involved in common obesity. We discuss how neuronal cilia impact food intake potentially through leptin signaling and changes in ciliary G protein-coupled receptor (GPCR) signaling. We highlight several recent studies that have implicated the potential for cilia in peripheral tissues such as adipose and the pancreas to contribute to metabolic dysfunction. Then we discuss the potential for cilia to impact energy homeostasis through their roles in both development and adult tissue homeostasis. The studies discussed in this review highlight how a comprehensive understanding of the requirement of cilia for the regulation of diverse biological functions will contribute to our understanding of common forms of obesity.
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Affiliation(s)
- Staci E Engle
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, IN, USA
| | - Ruchi Bansal
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, IN, USA
| | - Patrick J Antonellis
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, IN, USA
| | - Nicolas F Berbari
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, IN, USA; Stark Neurosciences Research Institute, Indiana University, Indianapolis, IN, USA; Center for Diabetes and Metabolic Diseases, Indiana University School of Medicine, Indianapolis, IN, USA.
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4
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Gill R, Stratigopoulos G, Lee JH, Leibel RL. Functional genomic characterization of the FTO locus in African Americans. Physiol Genomics 2019; 51:517-528. [PMID: 31530225 DOI: 10.1152/physiolgenomics.00057.2019] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND SNPs in the first intron of the fat mass and obesity-associated (FTO) gene represent the strongest genome-wide associations with adiposity [body mass index (BMI)]; the molecular basis for these associations is under intense investigation. In European populations, the focus of most genome-wide association studies conducted to date, the single nucleotide polymorphisms (SNPs) have indistinguishable associations due to the high level of linkage disequilibrium (LD). However, in African American (AA) individuals, reduced LD and increased haplotype diversity permit finer distinctions among obesity-associated SNPs. Such distinctions are important to mechanistic inferences and for selection of disease SNPs relevant to specific populations. METHODS To identify specific FTO SNP(s) directly related to adiposity, we performed: 1) haplotype analyses of individual-level data in 3,335 AAs from the Atherosclerosis Risk in Communities Cohort (ARIC) study; as well as 2) statistical fine-mapping using summary statistics from a study of FTO in over 20 000 AAs and over 1000 functional genomic annotations. RESULTS Our haplotype analyses suggest that in AAs at least two distinct signals underlie the intron 1 FTO-adiposity signal. Fine mapping showed that two SNPs have the highest posterior probability of association (PPA) with BMI: rs9927317 (PPA = 0.94) and rs62033405 (PPA = 0.99). These variants overlap possible enhancer sites and the 5'-regions of transcribed genes in the substantia nigra, chondrocytes, and white adipocytes. CONCLUSIONS We found two SNPs in FTO with the highest probability of direct association with BMI in AAs, as well as tissue-specific mechanisms by which these variants may contribute to the pathogenesis of obesity.
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Affiliation(s)
- Richard Gill
- Division of Molecular Genetics, Department of Pediatrics, College of Physicians and Surgeons, Columbia University Medical Center, New York, New York.,Department of Epidemiology, Mailman School of Public Health, Columbia University Medical Center, New York, New York.,Genomics Analysis Unit, Amgen Research, Cambridge, Massachusetts
| | - George Stratigopoulos
- Division of Molecular Genetics, Department of Pediatrics, College of Physicians and Surgeons, Columbia University Medical Center, New York, New York
| | - Joseph H Lee
- Department of Epidemiology, Mailman School of Public Health, Columbia University Medical Center, New York, New York.,The Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University, New York, New York.,Gertrude H. Sergievsky Center, Columbia University, New York, New York
| | - Rudolph L Leibel
- Division of Molecular Genetics, Department of Pediatrics, College of Physicians and Surgeons, Columbia University Medical Center, New York, New York
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5
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Chen B, Li Z, Chen J, Ji J, Shen J, Xu Y, Zhao Y, Liu D, Shen Y, Zhang W, Shen J, Wang Y, Shi Y. Association of fat mass and obesity-associated and retinitis pigmentosa guanosine triphosphatase (GTPase) regulator-interacting protein-1 like polymorphisms with body mass index in Chinese women. Endocr J 2018; 65:783-791. [PMID: 29657248 DOI: 10.1507/endocrj.ej17-0554] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Body mass index (BMI) is the most commonly used quantitative measure of adiposity. It is a kind of complex genetic diseases which are caused by multiple susceptibility genes. The first intron of fat mass and obesity-associated (FTO) has been widely discovered to be associated with BMI. Retinitis pigmentosa GTPase regulator-interacting protein-1 like (RPGRIP1L) is located in the upstream region of FTO and has been proved to be linked with obesity through functional tests. We carried out a genetic association analysis to figure out the role of the FTO gene and the RPGRIP1L gene in BMI. A quantitative traits study with 6,102 Chinese female samples, adjusted for age, was performed during our project. Among the twelve SNPs, rs1421085, rs1558902, rs17817449, rs8050136, rs9939609, rs7202296, rs56137030, rs9930506 and rs12149832 in the FTO gene were significantly associated with BMI after Bonferroni correction. Meanwhile, rs9934800 in the RPGRIP1L gene showed significance with BMI before Bonferroni correction, but this association was eliminated after Bonferroni correction. Our results suggested that genetic variants in the FTO gene were strongly associated with BMI in Chinese women, which may serve as targets of pharmaceutical research and development concerning BMI. Meanwhile, we didn't found the significant association between RPGRIP1L and BMI in Chinese women.
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Affiliation(s)
- Boyu Chen
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), the Collaborative Innovation Center for Brain Science, Shanghai Jiao Tong University, Shanghai 200030, China
| | - Zhiqiang Li
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), the Collaborative Innovation Center for Brain Science, Shanghai Jiao Tong University, Shanghai 200030, China
- The Affiliated Hospital of Qingdao University & The Biomedical Sciences Institute of Qingdao University (Qingdao Branch of SJTU Bio-X Institutes), Qingdao University, Qingdao 266003, China
- Institute of Social Cognitive and Behavioral Sciences, Shanghai Jiao Tong University, Shanghai 200240, China
- Institute of Neuropsychiatric Science and Systems Biological Medicine, Shanghai Jiao Tong University, Shanghai 200042, China
| | - Jianhua Chen
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), the Collaborative Innovation Center for Brain Science, Shanghai Jiao Tong University, Shanghai 200030, China
- Institute of Social Cognitive and Behavioral Sciences, Shanghai Jiao Tong University, Shanghai 200240, China
- Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200030, China
| | - Jue Ji
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), the Collaborative Innovation Center for Brain Science, Shanghai Jiao Tong University, Shanghai 200030, China
| | - Jingyi Shen
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), the Collaborative Innovation Center for Brain Science, Shanghai Jiao Tong University, Shanghai 200030, China
| | - Yufeng Xu
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), the Collaborative Innovation Center for Brain Science, Shanghai Jiao Tong University, Shanghai 200030, China
| | - Yingying Zhao
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), the Collaborative Innovation Center for Brain Science, Shanghai Jiao Tong University, Shanghai 200030, China
| | - Danping Liu
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), the Collaborative Innovation Center for Brain Science, Shanghai Jiao Tong University, Shanghai 200030, China
| | - Yinhuan Shen
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), the Collaborative Innovation Center for Brain Science, Shanghai Jiao Tong University, Shanghai 200030, China
| | - Weijie Zhang
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), the Collaborative Innovation Center for Brain Science, Shanghai Jiao Tong University, Shanghai 200030, China
| | - Jiawei Shen
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), the Collaborative Innovation Center for Brain Science, Shanghai Jiao Tong University, Shanghai 200030, China
| | - Yonggang Wang
- Department of Neurology, School of Medicine, Renji Hospital, Shanghai Jiao Tong University, Shanghai 200127, China
| | - Yongyong Shi
- Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), the Collaborative Innovation Center for Brain Science, Shanghai Jiao Tong University, Shanghai 200030, China
- The Affiliated Hospital of Qingdao University & The Biomedical Sciences Institute of Qingdao University (Qingdao Branch of SJTU Bio-X Institutes), Qingdao University, Qingdao 266003, China
- Institute of Social Cognitive and Behavioral Sciences, Shanghai Jiao Tong University, Shanghai 200240, China
- Institute of Neuropsychiatric Science and Systems Biological Medicine, Shanghai Jiao Tong University, Shanghai 200042, China
- Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200030, China
- Changning Mental Health Center, Shanghai 200042, China
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6
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Wiegering A, Dildrop R, Kalfhues L, Spychala A, Kuschel S, Lier JM, Zobel T, Dahmen S, Leu T, Struchtrup A, Legendre F, Vesque C, Schneider-Maunoury S, Saunier S, Rüther U, Gerhardt C. Cell type-specific regulation of ciliary transition zone assembly in vertebrates. EMBO J 2018; 37:embj.201797791. [PMID: 29650680 PMCID: PMC5978567 DOI: 10.15252/embj.201797791] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Revised: 03/12/2018] [Accepted: 03/15/2018] [Indexed: 01/07/2023] Open
Abstract
Ciliopathies are life-threatening human diseases caused by defective cilia. They can often be traced back to mutations of genes encoding transition zone (TZ) proteins demonstrating that the understanding of TZ organisation is of paramount importance. The TZ consists of multimeric protein modules that are subject to a stringent assembly hierarchy. Previous reports place Rpgrip1l at the top of the TZ assembly hierarchy in Caenorhabditis elegans By performing quantitative immunofluorescence studies in RPGRIP1L-/- mouse embryos and human embryonic cells, we recognise a different situation in vertebrates in which Rpgrip1l deficiency affects TZ assembly in a cell type-specific manner. In cell types in which the loss of Rpgrip1l alone does not affect all modules, additional truncation or removal of vertebrate-specific Rpgrip1 results in an impairment of all modules. Consequently, Rpgrip1l and Rpgrip1 synergistically ensure the TZ composition in several vertebrate cell types, revealing a higher complexity of TZ assembly in vertebrates than in invertebrates.
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Affiliation(s)
- Antonia Wiegering
- Institute for Animal Developmental and Molecular Biology, Heinrich Heine University, Düsseldorf, Germany
| | - Renate Dildrop
- Institute for Animal Developmental and Molecular Biology, Heinrich Heine University, Düsseldorf, Germany
| | - Lisa Kalfhues
- Institute for Animal Developmental and Molecular Biology, Heinrich Heine University, Düsseldorf, Germany
| | - André Spychala
- Institute for Animal Developmental and Molecular Biology, Heinrich Heine University, Düsseldorf, Germany
| | - Stefanie Kuschel
- Institute for Animal Developmental and Molecular Biology, Heinrich Heine University, Düsseldorf, Germany
| | - Johanna Maria Lier
- Institute for Animal Developmental and Molecular Biology, Heinrich Heine University, Düsseldorf, Germany
| | - Thomas Zobel
- Center for Advanced Imaging (CAi), Heinrich Heine University, Düsseldorf, Germany
| | - Stefanie Dahmen
- Institute for Animal Developmental and Molecular Biology, Heinrich Heine University, Düsseldorf, Germany
| | - Tristan Leu
- Institute for Animal Developmental and Molecular Biology, Heinrich Heine University, Düsseldorf, Germany
| | - Andreas Struchtrup
- Institute for Animal Developmental and Molecular Biology, Heinrich Heine University, Düsseldorf, Germany
| | - Flora Legendre
- INSERM, U983, Hôpital Necker-Enfants Malades, Paris, France.,Sorbonne Paris Cité, Faculté de Médecine, Université Paris-Descartes, Paris, France
| | - Christine Vesque
- Paris-Seine (IBPS) - Developmental Biology Laboratory, Institut de Biologie, CNRS, UMR7622, INSERM U1156, Paris, France.,Sorbonne Universités, UPMC Univ Paris 06, Paris, France
| | - Sylvie Schneider-Maunoury
- Paris-Seine (IBPS) - Developmental Biology Laboratory, Institut de Biologie, CNRS, UMR7622, INSERM U1156, Paris, France.,Sorbonne Universités, UPMC Univ Paris 06, Paris, France
| | - Sophie Saunier
- INSERM, U983, Hôpital Necker-Enfants Malades, Paris, France.,Sorbonne Paris Cité, Faculté de Médecine, Université Paris-Descartes, Paris, France
| | - Ulrich Rüther
- Institute for Animal Developmental and Molecular Biology, Heinrich Heine University, Düsseldorf, Germany
| | - Christoph Gerhardt
- Institute for Animal Developmental and Molecular Biology, Heinrich Heine University, Düsseldorf, Germany
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7
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Abstract
The ciliopathies Bardet-Biedl syndrome and Alström syndrome cause obesity. How ciliary dysfunction leads to obesity has remained mysterious, partly because of a lack of understanding of the physiological roles of primary cilia in the organs and pathways involved in the regulation of metabolism and energy homeostasis. Historically, the study of rare monogenetic disorders that present with obesity has informed our molecular understanding of the mechanisms involved in nonsyndromic forms of obesity. Here, we present a framework, based on genetic studies in mice and humans, of the molecular and cellular pathways underlying long-term regulation of energy homeostasis. We focus on recent progress linking these pathways to the function of the primary cilia with a particular emphasis on the roles of neuronal primary cilia in the regulation of satiety.
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Affiliation(s)
- Christian Vaisse
- Diabetes Center and Department of Medicine, University of California San Francisco, San Francisco, California 94143
| | - Jeremy F Reiter
- Department of Biochemistry and Biophysics, Cardiovascular Research Institute, University of California, San Francisco, San Francisco, California 94158
| | - Nicolas F Berbari
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana 46202
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8
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Abstract
Nephronophthisis-related ciliopathies (NPHP-RC) are a group of inherited diseases that affect genes encoding proteins that localize to primary cilia or centrosomes. With few exceptions, ciliopathies are inherited in an autosomal recessive manner, and affected individuals manifest early during childhood or adolescence. NPHP-RC are genetically very heterogeneous, and, currently, mutations in more than 90 genes have been described as single-gene causes. The phenotypes of NPHP-RC are very diverse, and include cystic-fibrotic kidney disease, brain developmental defects, retinal degeneration, skeletal deformities, facial dimorphism, and, in some cases, laterality defects, and congenital heart disease. Mutations in the same gene can give rise to diverse phenotypes depending on the mutated allele. At the same time, there is broad phenotypic overlap between different monogenic genes. The identification of monogenic causes of ciliopathies has furthered the understanding of molecular mechanism and cellular pathways involved in the pathogenesis.
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9
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Masyukova SV, Landis DE, Henke SJ, Williams CL, Pieczynski JN, Roszczynialski KN, Covington JE, Malarkey EB, Yoder BK. A Screen for Modifiers of Cilia Phenotypes Reveals Novel MKS Alleles and Uncovers a Specific Genetic Interaction between osm-3 and nphp-4. PLoS Genet 2016; 12:e1005841. [PMID: 26863025 PMCID: PMC4749664 DOI: 10.1371/journal.pgen.1005841] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Accepted: 01/12/2016] [Indexed: 12/04/2022] Open
Abstract
Nephronophthisis (NPHP) is a ciliopathy in which genetic modifiers may underlie the variable penetrance of clinical features. To identify modifiers, a screen was conducted on C. elegans nphp-4(tm925) mutants. Mutations in ten loci exacerbating nphp-4(tm925) ciliary defects were obtained. Four loci have been identified, three of which are established ciliopathy genes mks-1, mks-2, and mks-5. The fourth allele (yhw66) is a missense mutation (S316F) in OSM-3, a kinesin required for cilia distal segment assembly. While osm-3(yhw66) mutants alone have no overt cilia phenotype, nphp-4(tm925);osm-3(yhw66) double mutants lack distal segments and are dye-filling (Dyf) and osmotic avoidance (Osm) defective, similar to osm-3(mn357) null mutants. In osm-3(yhw66) mutants anterograde intraflagellar transport (IFT) velocity is reduced. Furthermore, expression of OSM-3(S316F)::GFP reduced IFT velocities in nphp-4(tm925) mutants, but not in wild type animals. In silico analysis indicates the S316F mutation may affect a phosphorylation site. Putative phospho-null OSM-3(S316F) and phospho-mimetic OSM-3(S316D) proteins accumulate at the cilia base and tip respectively. FRAP analysis indicates that the cilia entry rate of OSM-3(S316F) is slower than OSM-3 and that in the presence of OSM-3(S316F), OSM-3 and OSM-3(S316D) rates decrease. In the presence OSM-3::GFP or OSM-3(S316D)::GFP, OSM-3(S316F)::tdTomato redistributes along the cilium and accumulates in the cilia tip. OSM-3(S316F) and OSM-3(S316D) are functional as they restore cilia distal segment formation in osm-3(mn357) null mutants; however, only OSM-3(S316F) rescues the osm-3(mn357) null Dyf phenotype. Despite rescue of cilia length in osm-3(mn357) null mutants, neither OSM-3(S316F) nor OSM-3(S316D) restores ciliary defects in nphp-4(tm925);osm-3(yhw66) double mutants. Thus, these OSM-3 mutations cause NPHP-4 dependent and independent phenotypes. These data indicate that in addition to regulating cilia protein entry or exit, NPHP-4 influences localization and function of a distal ciliary kinesin. Moreover, data suggest human OSM-3 homolog (Kif17) could act as a modifying locus affecting disease penetrance or expressivity in NPHP patients. Nephronophthisis (NPHP) is a genetically heterogeneous ciliopathy that has minimal genotype-phenotype correlation. The cause of this variation is not known, but could result from additional mutations in the patients’ backgrounds capable of modifying the phenotype. To identify candidate NPHP modifying loci, we conducted an enhancer mutagenesis screen using C. elegans nphp-4(tm925) mutants. Mutations in ten loci were obtained that severely exacerbated the cilia defects in the nphp-4(tm925) mutants, but importantly, had minimal defects in the absence of the nphp-4 mutation. Here we identified four of these loci, each encoding a cilia protein. Three mutations are in known ciliopathy genes, mks-1, mks-2 and mks-5. The fourth allele is a missense (S316F) mutation in OSM-3, a kinesin required for distal cilia assembly and is the sole kinesin responsible for intraflagellar transport along the cilia distal segment in C. elegans. The osm-3(yhw66) mutation affects a putative phosphorylation site that is important for OSM-3 localization, movement, and function, largely in an nphp-4 dependent manner. These data establish a genetic interaction between osm-3 and nphp-4 that regulates kinesin activity and localization and raises the possibility that mutations in Kif17, the mammalian homolog of osm-3, may influence the phenotypes in human NPHP patients.
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Affiliation(s)
- Svetlana V. Masyukova
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham Medical School, Birmingham, Alabama, United States of America
| | - Dawn E. Landis
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham Medical School, Birmingham, Alabama, United States of America
| | - Scott J. Henke
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham Medical School, Birmingham, Alabama, United States of America
| | - Corey L. Williams
- Department of Pharmacology and Therapeutics, College of Medicine, University of Florida, Gainesville, Florida, United States of America
| | - Jay N. Pieczynski
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham Medical School, Birmingham, Alabama, United States of America
| | - Kelly N. Roszczynialski
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham Medical School, Birmingham, Alabama, United States of America
| | - Jannese E. Covington
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham Medical School, Birmingham, Alabama, United States of America
| | - Erik B. Malarkey
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham Medical School, Birmingham, Alabama, United States of America
| | - Bradley K. Yoder
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham Medical School, Birmingham, Alabama, United States of America
- * E-mail:
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10
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Jensen VL, Li C, Bowie RV, Clarke L, Mohan S, Blacque OE, Leroux MR. Formation of the transition zone by Mks5/Rpgrip1L establishes a ciliary zone of exclusion (CIZE) that compartmentalises ciliary signalling proteins and controls PIP2 ciliary abundance. EMBO J 2015; 34:2537-56. [PMID: 26392567 PMCID: PMC4609185 DOI: 10.15252/embj.201488044] [Citation(s) in RCA: 97] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Revised: 08/22/2015] [Accepted: 08/26/2015] [Indexed: 01/09/2023] Open
Abstract
Cilia are thought to harbour a membrane diffusion barrier within their transition zone (TZ) that compartmentalises signalling proteins. How this "ciliary gate" assembles and functions remains largely unknown. Contrary to current models, we present evidence that Caenorhabditis elegans MKS-5 (orthologue of mammalian Mks5/Rpgrip1L/Nphp8 and Rpgrip1) may not be a simple structural scaffold for anchoring > 10 different proteins at the TZ, but instead, functions as an assembly factor. This activity is needed to form TZ ultrastructure, which comprises Y-shaped axoneme-to-membrane connectors. Coiled-coil and C2 domains within MKS-5 enable TZ localisation and functional interactions with two TZ modules, consisting of Meckel syndrome (MKS) and nephronophthisis (NPHP) proteins. Discrete roles for these modules at basal body-associated transition fibres and TZ explain their redundant functions in making essential membrane connections and thus sealing the ciliary compartment. Furthermore, MKS-5 establishes a ciliary zone of exclusion (CIZE) at the TZ that confines signalling proteins, including GPCRs and NPHP-2/inversin, to distal ciliary subdomains. The TZ/CIZE, potentially acting as a lipid gate, limits the abundance of the phosphoinositide PIP2 within cilia and is required for cell signalling. Together, our findings suggest a new model for Mks5/Rpgrip1L in TZ assembly and function that is essential for establishing the ciliary signalling compartment.
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Affiliation(s)
- Victor L Jensen
- Department of Molecular Biology and Biochemistry and Centre for Cell Biology, Development and Disease, Simon Fraser University, Burnaby, BC, Canada
| | - Chunmei Li
- Department of Molecular Biology and Biochemistry and Centre for Cell Biology, Development and Disease, Simon Fraser University, Burnaby, BC, Canada
| | - Rachel V Bowie
- School of Biomolecular and Biomedical Science, University College Dublin, Belfield, Dublin 4, Ireland
| | - Lara Clarke
- School of Biomolecular and Biomedical Science, University College Dublin, Belfield, Dublin 4, Ireland
| | - Swetha Mohan
- Department of Molecular Biology and Biochemistry and Centre for Cell Biology, Development and Disease, Simon Fraser University, Burnaby, BC, Canada
| | - Oliver E Blacque
- School of Biomolecular and Biomedical Science, University College Dublin, Belfield, Dublin 4, Ireland
| | - Michel R Leroux
- Department of Molecular Biology and Biochemistry and Centre for Cell Biology, Development and Disease, Simon Fraser University, Burnaby, BC, Canada
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11
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Sanders AAWM, Kennedy J, Blacque OE. Image analysis of Caenorhabditis elegans ciliary transition zone structure, ultrastructure, molecular composition, and function. Methods Cell Biol 2015; 127:323-47. [PMID: 25837399 DOI: 10.1016/bs.mcb.2015.01.010] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The transition zone (TZ) at the ciliary base has emerged as an important regulator of the composition and functions of cilia, which are microtubule-based structures extending from the surfaces of most eukaryotic cells, serving motility, chemo-/mechano-/photosensation and developmental signaling roles. Possessing distinct ultrastructural features such as microtubule-membrane spanning Y-links, the ∼0.2-1.0-μm long TZ is thought to act as a gated cytosolic (size dependent) and membrane diffusion barrier that drives ciliary compartmentalization by preventing unregulated protein exchange between the cilium and the rest of the cell. Multiple proteins associated with ciliary diseases (ciliopathies) such as Meckel-Gruber syndrome (MKS) and nephronophthisis are specifically found in the TZ, and work from a number of model systems, including Chlamydomonas reinharditii, Caenorhabditis elegans and the mouse indicates TZ-gating and associated ciliogenic functions for a number of these proteins. Here we present a suite of assays for probing the structure, function, and molecular composition of the C. elegans TZ, with emphasis on TZ ultrastructure, diffusion barrier kinetics, MKS module assembly hierarchy, and TZ-dependent behaviors.
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Affiliation(s)
- Anna A W M Sanders
- School of Biomolecular and Biomedical Science, University College Dublin, Belfield, Dublin, Ireland
| | - Julie Kennedy
- School of Biomolecular and Biomedical Science, University College Dublin, Belfield, Dublin, Ireland
| | - Oliver E Blacque
- School of Biomolecular and Biomedical Science, University College Dublin, Belfield, Dublin, Ireland
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12
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Caenorhabditis elegans Models to Study the Molecular Biology of Ataxias. Mov Disord 2015. [DOI: 10.1016/b978-0-12-405195-9.00068-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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13
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Stratigopoulos G, Martin Carli JF, O'Day DR, Wang L, Leduc CA, Lanzano P, Chung WK, Rosenbaum M, Egli D, Doherty DA, Leibel RL. Hypomorphism for RPGRIP1L, a ciliary gene vicinal to the FTO locus, causes increased adiposity in mice. Cell Metab 2014; 19:767-79. [PMID: 24807221 PMCID: PMC4131684 DOI: 10.1016/j.cmet.2014.04.009] [Citation(s) in RCA: 129] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Revised: 11/11/2013] [Accepted: 04/18/2014] [Indexed: 12/31/2022]
Abstract
Common polymorphisms in the first intron of FTO are associated with increased body weight in adults. Previous studies have suggested that a CUX1-regulatory element within the implicated FTO region controls expression of FTO and the nearby ciliary gene, RPGRIP1L. Given the role of ciliary genes in energy homeostasis, we hypothesized that mice hypomorphic for Rpgrip1l would display increased adiposity. We find that Rpgrip1l⁺/⁻ mice are hyperphagic and fatter, and display diminished suppression of food intake in response to leptin administration. In the hypothalamus of Rpgrip1l⁺/⁻ mice, and in human fibroblasts with hypomorphic mutations in RPGRIP1L, the number of AcIII-positive cilia is diminished, accompanied by impaired convening of the leptin receptor to the vicinity of the cilium, and diminished pStat3 in response to leptin. These findings suggest that RPGRIP1L may be partly or exclusively responsible for the obesity susceptibility signal at the FTO locus.
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Affiliation(s)
- George Stratigopoulos
- Naomi Berrie Diabetes Center and Division of Molecular Genetics, Department of Pediatrics, College of Physicians and Surgeons of Columbia University, New York, NY 10032, USA.
| | - Jayne F Martin Carli
- Naomi Berrie Diabetes Center and Division of Molecular Genetics, Department of Pediatrics, College of Physicians and Surgeons of Columbia University, New York, NY 10032, USA
| | - Diana R O'Day
- Divisions of Developmental Medicine and Genetic Medicine, Department of Pediatrics, Seattle Children's Research Institute and University of Washington 1959 NE Pacific St, Seattle, WA 98195, USA
| | - Liheng Wang
- Naomi Berrie Diabetes Center and Division of Molecular Genetics, Department of Pediatrics, College of Physicians and Surgeons of Columbia University, New York, NY 10032, USA
| | - Charles A Leduc
- Naomi Berrie Diabetes Center and Division of Molecular Genetics, Department of Pediatrics, College of Physicians and Surgeons of Columbia University, New York, NY 10032, USA
| | - Patricia Lanzano
- Naomi Berrie Diabetes Center and Division of Molecular Genetics, Department of Pediatrics, College of Physicians and Surgeons of Columbia University, New York, NY 10032, USA
| | - Wendy K Chung
- Naomi Berrie Diabetes Center and Division of Molecular Genetics, Department of Pediatrics, College of Physicians and Surgeons of Columbia University, New York, NY 10032, USA
| | - Michael Rosenbaum
- Naomi Berrie Diabetes Center and Division of Molecular Genetics, Department of Pediatrics, College of Physicians and Surgeons of Columbia University, New York, NY 10032, USA
| | - Dieter Egli
- Naomi Berrie Diabetes Center and Division of Molecular Genetics, Department of Pediatrics, College of Physicians and Surgeons of Columbia University, New York, NY 10032, USA
| | - Daniel A Doherty
- Divisions of Developmental Medicine and Genetic Medicine, Department of Pediatrics, Seattle Children's Research Institute and University of Washington 1959 NE Pacific St, Seattle, WA 98195, USA
| | - Rudolph L Leibel
- Naomi Berrie Diabetes Center and Division of Molecular Genetics, Department of Pediatrics, College of Physicians and Surgeons of Columbia University, New York, NY 10032, USA.
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14
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Koefoed K, Veland IR, Pedersen LB, Larsen LA, Christensen ST. Cilia and coordination of signaling networks during heart development. Organogenesis 2013; 10:108-25. [PMID: 24345806 DOI: 10.4161/org.27483] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Primary cilia are unique sensory organelles that coordinate a wide variety of different signaling pathways to control cellular processes during development and in tissue homeostasis. Defects in function or assembly of these antenna-like structures are therefore associated with a broad range of developmental disorders and diseases called ciliopathies. Recent studies have indicated a major role of different populations of cilia, including nodal and cardiac primary cilia, in coordinating heart development, and defects in these cilia are associated with congenital heart disease. Here, we present an overview of the role of nodal and cardiac primary cilia in heart development.
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Affiliation(s)
- Karen Koefoed
- Department of Biology; University of Copenhagen; Copenhagen, Denmark; Wilhelm Johannsen Centre for Functional Genome Research; Department of Cellular and Molecular Medicine; University of Copenhagen; Copenhagen, Denmark
| | - Iben Rønn Veland
- Department of Biology; University of Copenhagen; Copenhagen, Denmark
| | | | - Lars Allan Larsen
- Wilhelm Johannsen Centre for Functional Genome Research; Department of Cellular and Molecular Medicine; University of Copenhagen; Copenhagen, Denmark
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15
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Photoreceptor sensory cilia and ciliopathies: focus on CEP290, RPGR and their interacting proteins. Cilia 2012; 1:22. [PMID: 23351659 PMCID: PMC3563624 DOI: 10.1186/2046-2530-1-22] [Citation(s) in RCA: 110] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2012] [Accepted: 09/19/2012] [Indexed: 02/08/2023] Open
Abstract
Ciliopathies encompass a broad array of clinical findings associated with genetic defects in biogenesis and/or function of the primary cilium, a ubiquitous organelle involved in the transduction of diverse biological signals. Degeneration or dysfunction of retinal photoreceptors is frequently observed in diverse ciliopathies. The sensory cilium in a photoreceptor elaborates into unique outer segment discs that provide extensive surface area for maximal photon capture and efficient visual transduction. The daily renewal of approximately 10% of outer segments requires a precise control of ciliary transport. Here, we review the ciliopathies with associated retinal degeneration, describe the distinctive structure of the photoreceptor cilium, and discuss mouse models that allow investigations into molecular mechanisms of cilia biogenesis and defects. We have specifically focused on two ciliary proteins - CEP290 and RPGR - that underlie photoreceptor degeneration and syndromic ciliopathies. Mouse models of CEP290 and RPGR disease, and of their multiple interacting partners, have helped unravel new functional insights into cell type-specific phenotypic defects in distinct ciliary proteins. Elucidation of multifaceted ciliary functions and associated protein complexes will require concerted efforts to assimilate diverse datasets from in vivo and in vitro studies. We therefore discuss a possible framework for investigating genetic networks associated with photoreceptor cilia biogenesis and pathology.
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16
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Avasthi P, Marshall WF. Stages of ciliogenesis and regulation of ciliary length. Differentiation 2011; 83:S30-42. [PMID: 22178116 DOI: 10.1016/j.diff.2011.11.015] [Citation(s) in RCA: 170] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2011] [Revised: 11/30/2011] [Accepted: 11/30/2011] [Indexed: 12/25/2022]
Abstract
Cilia and flagella are highly conserved eukaryotic microtubule-based organelles that protrude from the surface of most mammalian cells. These structures require large protein complexes and motors for distal addition of tubulin and extension of the ciliary membrane. In order for ciliogenesis to occur, coordination of many processes must take place. An intricate concert of cell cycle regulation, vesicular trafficking, and ciliary extension must all play out with accurate timing to produce a cilium. Here, we review the stages of ciliogenesis as well as regulation of the length of the assembled cilium. Regulation of ciliogenesis during cell cycle progression centers on centrioles, from which cilia extend upon maturation into basal bodies. Centriole maturation involves a shift from roles in cell division to cilium nucleation via migration to the cell surface and docking at the plasma membrane. Docking is dependent on a variety of proteinaceous structures, termed distal appendages, acquired by the mother centriole. Ciliary elongation by the process of intraflagellar transport (IFT) ensues. Direct modification of ciliary structures, as well as modulation of signal transduction pathways, play a role in maintenance of the cilium. All of these stages are tightly regulated to produce a cilium of the right size at the right time. Finally, we discuss the implications of abnormal ciliogenesis and ciliary length control in human disease as well as some open questions.
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Affiliation(s)
- Prachee Avasthi
- Department of Biochemistry & Biophysics, University of California GH-N372F Genentech Hall, Box 2200, UCSF, 600 16th St. San Francisco, CA 94158, USA
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