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Tomlinson JW. Bardet-Biedl syndrome: A focus on genetics, mechanisms and metabolic dysfunction. Diabetes Obes Metab 2024; 26 Suppl 2:13-24. [PMID: 38302651 DOI: 10.1111/dom.15480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 01/18/2024] [Accepted: 01/18/2024] [Indexed: 02/03/2024]
Abstract
Bardet-Biedl syndrome (BBS) is a rare, monogenic, multisystem disorder characterized by retinal dystrophy, renal abnormalities, polydactyly, learning disabilities, as well as metabolic dysfunction, including obesity and an increased risk of type 2 diabetes. It is a primary ciliopathy, and causative mutations in more than 25 different genes have been described. Multiple cellular mechanisms contribute to the development of the metabolic phenotype associated with BBS, including hyperphagia as a consequence of altered hypothalamic appetite signalling as well as alterations in adipocyte biology promoting adipocyte proliferation and adipogenesis. Within this review, we describe in detail the metabolic phenotype associated with BBS and discuss the mechanisms that drive its evolution. In addition, we review current approaches to the metabolic management of patients with BBS, including the use of weight loss medications and bariatric surgery. Finally, we evaluate the potential of targeting hypothalamic appetite signalling to limit hyperphagia and induce clinically significant weight loss.
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Affiliation(s)
- Jeremy W Tomlinson
- Oxford Centre for Diabetes, Endocrinology and Metabolism, NIHR Oxford Biomedical Research Centre, University of Oxford, Churchill Hospital, Oxford, UK
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2
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Gupta M, Pazour GJ. Intraflagellar transport: A critical player in photoreceptor development and the pathogenesis of retinal degenerative diseases. Cytoskeleton (Hoboken) 2023:10.1002/cm.21823. [PMID: 38140908 PMCID: PMC11193844 DOI: 10.1002/cm.21823] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2023] [Revised: 12/01/2023] [Accepted: 12/08/2023] [Indexed: 12/24/2023]
Abstract
In vertebrate vision, photons are detected by highly specialized sensory cilia called outer segments. Photoreceptor outer segments form by remodeling the membrane of a primary cilium into a stack of flattened disks. Intraflagellar transport (IFT) is critical to the formation of most types of eukaryotic cilia including the outer segments. This review covers the state of knowledge of the role of IFT in the formation and maintenance of outer segments and the human diseases that result from mutations in genes encoding the IFT complex and associated motors.
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Affiliation(s)
- Mohona Gupta
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Suite 213 Biotech II, 373 Plantation Street, Worcester MA USA 01605
- Morningside Graduate School of Biological Sciences, University of Massachusetts Chan Medical School, 55 Lake Avenue North, Worcester MA USA 01655
| | - Gregory J. Pazour
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Suite 213 Biotech II, 373 Plantation Street, Worcester MA USA 01605
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Peng Y, Zhou L, Chen J, Huang X, Pang J, Liu J, Tang W, Yang S, Liang C, Xie W. Clinical features and genetic analysis of a case series of skeletal ciliopathies in a prenatal setting. BMC Med Genomics 2023; 16:318. [PMID: 38062428 PMCID: PMC10704717 DOI: 10.1186/s12920-023-01753-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Accepted: 11/24/2023] [Indexed: 12/18/2023] Open
Abstract
BACKGROUND Short-rib polydactyly syndrome (SRPS) refers to a group of lethal skeletal dysplasias that can be difficult to differentiate between subtypes or from other non-lethal skeletal dysplasias such as Ellis-van Creveld syndrome and Jeune syndrome in a prenatal setting. We report the ultrasound and genetic findings of four unrelated fetuses with skeletal dysplasias. METHODS Systemic prenatal ultrasound examination was performed in the second or third trimester. Genetic tests including GTG-banding, single nucleotide polymorphism (SNP) array and exome sequencing were performed with amniocytes or aborted fetal tissues. RESULTS The major and common ultrasound anomalies for the four unrelated fetuses included short long bones of the limbs and narrow thorax. No chromosomal abnormalities and pathogenic copy number variations were detected. Exome sequencing revealed three novel variants in the DYNC2H1 gene, namely NM_001080463.2:c.6809G > A p.(Arg2270Gln), NM_001080463.2:3133C > T p.(Gln1045Ter), and NM_001080463.2:c.337C > T p.(Arg113Trp); one novel variant in the IFT172 gene, NM_015662.3:4540-5 T > A; and one novel variant in the WDR19 gene, NM_025132.4:c.2596G > C p.(Gly866Arg). The genotypes of DYNC2H1, IFT172 and WDR19 and the phenotypes of the fetuses give hints for the diagnosis of short-rib thoracic dysplasia (SRTD) with or without polydactyly 3, 10, and 5, respectively. CONCLUSION Our findings expand the mutation spectrum of DYNC2H1, IFT172 and WDR19 associated with skeletal ciliopathies, and provide useful information for prenatal diagnosis and genetic counseling on rare skeletal disorders.
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Affiliation(s)
- Ying Peng
- Prenatal Diagnosis Center, National Health Commission Key Laboratory of Birth Defects for Research and Prevention, Hunan Provincial Maternal and Child Health Care Hospital, Changsha, 410008, Hunan, China, No. 53 Xiangchun Road.
| | - Lin Zhou
- Prenatal Diagnosis Center, National Health Commission Key Laboratory of Birth Defects for Research and Prevention, Hunan Provincial Maternal and Child Health Care Hospital, Changsha, 410008, Hunan, China, No. 53 Xiangchun Road
| | - Jing Chen
- Prenatal Diagnosis Center, National Health Commission Key Laboratory of Birth Defects for Research and Prevention, Hunan Provincial Maternal and Child Health Care Hospital, Changsha, 410008, Hunan, China, No. 53 Xiangchun Road
| | - Xiaoliang Huang
- Prenatal Diagnosis Center, National Health Commission Key Laboratory of Birth Defects for Research and Prevention, Hunan Provincial Maternal and Child Health Care Hospital, Changsha, 410008, Hunan, China, No. 53 Xiangchun Road
| | - Jialun Pang
- Prenatal Diagnosis Center, National Health Commission Key Laboratory of Birth Defects for Research and Prevention, Hunan Provincial Maternal and Child Health Care Hospital, Changsha, 410008, Hunan, China, No. 53 Xiangchun Road
| | - Jing Liu
- Prenatal Diagnosis Center, National Health Commission Key Laboratory of Birth Defects for Research and Prevention, Hunan Provincial Maternal and Child Health Care Hospital, Changsha, 410008, Hunan, China, No. 53 Xiangchun Road
| | - Wanglan Tang
- Prenatal Diagnosis Center, National Health Commission Key Laboratory of Birth Defects for Research and Prevention, Hunan Provincial Maternal and Child Health Care Hospital, Changsha, 410008, Hunan, China, No. 53 Xiangchun Road
| | - Shuting Yang
- Prenatal Diagnosis Center, National Health Commission Key Laboratory of Birth Defects for Research and Prevention, Hunan Provincial Maternal and Child Health Care Hospital, Changsha, 410008, Hunan, China, No. 53 Xiangchun Road
| | - Changbiao Liang
- Prenatal Diagnosis Center, National Health Commission Key Laboratory of Birth Defects for Research and Prevention, Hunan Provincial Maternal and Child Health Care Hospital, Changsha, 410008, Hunan, China, No. 53 Xiangchun Road
| | - Wanqin Xie
- Prenatal Diagnosis Center, National Health Commission Key Laboratory of Birth Defects for Research and Prevention, Hunan Provincial Maternal and Child Health Care Hospital, Changsha, 410008, Hunan, China, No. 53 Xiangchun Road.
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Abstract
Obesity is a common complex trait that elevates the risk for various diseases, including type 2 diabetes and cardiovascular disease. A combination of environmental and genetic factors influences the pathogenesis of obesity. Advances in genomic technologies have driven the identification of multiple genetic loci associated with this disease, ranging from studying severe onset cases to investigating common multifactorial polygenic forms. Additionally, findings from epigenetic analyses of modifications to the genome that do not involve changes to the underlying DNA sequence have emerged as key signatures in the development of obesity. Such modifications can mediate the effects of environmental factors, including diet and lifestyle, on gene expression and clinical presentation. This review outlines what is known about the genetic and epigenetic contributors to obesity susceptibility, along with the albeit limited therapeutic options currently available. Furthermore, we delineate the potential mechanisms of actions through which epigenetic changes can mediate environmental influences and the related opportunities they present for future interventions in the management of obesity.
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Affiliation(s)
- Khanh Trang
- Center for Spatial and Functional Genomics, Children’s Hospital of Philadelphia, Philadelphia, PA 19104 USA
- Division of Human Genetics, Children’s Hospital of Philadelphia, Philadelphia, PA 19104 USA
| | - Struan F.A. Grant
- Center for Spatial and Functional Genomics, Children’s Hospital of Philadelphia, Philadelphia, PA 19104 USA
- Division of Human Genetics, Children’s Hospital of Philadelphia, Philadelphia, PA 19104 USA
- Division of Diabetes and Endocrinology, Children’s Hospital of Philadelphia, Philadelphia, PA 19104 USA
- Department of Pediatrics, The University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104 USA
- Department of Genetics, University of Pennsylvania, Philadelphia, PA 19104 USA
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Tasaki K, Zhou Z, Ishida Y, Katoh Y, Nakayama K. Compound heterozygous IFT81 variations in a skeletal ciliopathy patient cause Bardet-Biedl syndrome-like ciliary defects. Hum Mol Genet 2023; 32:2887-2900. [PMID: 37427975 DOI: 10.1093/hmg/ddad112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 07/04/2023] [Accepted: 07/04/2023] [Indexed: 07/11/2023] Open
Abstract
Owing to their crucial roles in development and homeostasis, defects in cilia cause ciliopathies with diverse clinical manifestations. The intraflagellar transport (IFT) machinery, containing the IFT-A and IFT-B complexes, mediates not only the intraciliary bidirectional trafficking but also import and export of ciliary proteins together with the kinesin-2 and dynein-2 motor complexes. The BBSome, containing eight subunits encoded by causative genes of Bardet-Biedl syndrome (BBS), connects the IFT machinery to ciliary membrane proteins to mediate their export from cilia. Although mutations in subunits of the IFT-A and dynein-2 complexes cause skeletal ciliopathies, mutations in some IFT-B subunits are also known to cause skeletal ciliopathies. We here show that compound heterozygous variations of an IFT-B subunit, IFT81, found in a patient with skeletal ciliopathy cause defects in its interactions with other IFT-B subunits, and in ciliogenesis and ciliary protein trafficking when one of the two variants was expressed in IFT81-knockout (KO) cells. Notably, we found that IFT81-KO cells expressing IFT81(Δ490-519), which lacks the binding site for the IFT25-IFT27 dimer, causes ciliary defects reminiscent of those found in BBS cells and those in IFT74-KO cells expressing a BBS variant of IFT74, which forms a heterodimer with IFT81. In addition, IFT81-KO cells expressing IFT81(Δ490-519) in combination with the other variant, IFT81 (L645*), which mimics the cellular conditions of the above skeletal ciliopathy patient, demonstrated essentially the same phenotype as those expressing only IFT81(Δ490-519). Thus, our data indicate that BBS-like defects can be caused by skeletal ciliopathy variants of IFT81.
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Affiliation(s)
- Koshi Tasaki
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto 606-8501, Japan
| | - Zhuang Zhou
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto 606-8501, Japan
| | - Yamato Ishida
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto 606-8501, Japan
| | - Yohei Katoh
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto 606-8501, Japan
| | - Kazuhisa Nakayama
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto 606-8501, Japan
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Neřoldová M, Ciara E, Slatinská J, Fraňková S, Lišková P, Kotalová R, Globinovská J, Šafaříková M, Pfeiferová L, Zůnová H, Mrázová L, Stránecký V, Vrbacká A, Fabián O, Sticová E, Skanderová D, Šperl J, Kalousová M, Zima T, Macek M, Pawlowska J, Knisely AS, Kmoch S, Jirsa M. Exome sequencing reveals IFT172 variants in patients with non-syndromic cholestatic liver disease. PLoS One 2023; 18:e0288907. [PMID: 37471416 PMCID: PMC10358992 DOI: 10.1371/journal.pone.0288907] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Accepted: 07/05/2023] [Indexed: 07/22/2023] Open
Abstract
BACKGROUND AND AIM Gene defects contribute to the aetiology of intrahepatic cholestasis. We aimed to explore the outcome of whole-exome sequencing (WES) in a cohort of 51 patients with this diagnosis. PATIENTS AND METHODS Both paediatric (n = 33) and adult (n = 18) patients with cholestatic liver disease of unknown aetiology were eligible. WES was used for reassessment of 34 patients (23 children) without diagnostic genotypes in ABCB11, ATP8B1, ABCB4 or JAG1 demonstrable by previous Sanger sequencing, and for primary assessment of additional 17 patients (10 children). Nasopharyngeal swab mRNA was analysed to address variant pathogenicity in two families. RESULTS WES revealed biallelic variation in 3 ciliopathy genes (PKHD1, TMEM67 and IFT172) in 4 clinically unrelated index subjects (3 children and 1 adult), heterozygosity for a known variant in PPOX in one adult index subject, and homozygosity for an unreported splice-site variation in F11R in one child. Whereas phenotypes of the index patients with mutated PKHD1, TMEM67, and PPOX corresponded with those elsewhere reported, how F11R variation underlies liver disease remains unclear. Two unrelated patients harboured different novel biallelic variants in IFT172, a gene implicated in short-rib thoracic dysplasia 10 and Bardet-Biedl syndrome 20. One patient, a homozygote for IFT172 rs780205001 c.167A>C p.(Lys56Thr) born to first cousins, had liver disease, interpreted on biopsy aged 4y as glycogen storage disease, followed by adult-onset nephronophthisis at 25y. The other, a compound heterozygote for novel frameshift variant IFT172 NM_015662.3 c.2070del p.(Met690Ilefs*11) and 2 syntenic missense variants IFT172 rs776310391 c.157T>A p.(Phe53Ile) and rs746462745 c.164C>G p.(Thr55Ser), had a severe 8mo cholestatic episode in early infancy, with persisting hyperbilirubinemia and fibrosis on imaging studies at 17y. No patient had skeletal malformations. CONCLUSION Our findings suggest association of IFT172 variants with non-syndromic cholestatic liver disease.
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Affiliation(s)
- Magdaléna Neřoldová
- Institute for Clinical and Experimental Medicine, Prague, Czech Republic
- Institute of Medical Biochemistry and Laboratory Diagnostics, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic
| | - Elżbieta Ciara
- Department of Medical Genetics, The Children's Memorial Health Institute, Warsaw, Poland
| | - Janka Slatinská
- Institute for Clinical and Experimental Medicine, Prague, Czech Republic
| | - Soňa Fraňková
- Institute for Clinical and Experimental Medicine, Prague, Czech Republic
| | - Petra Lišková
- Department of Ophthalmology, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic
- Department of Pediatrics and Inherited Metabolic Diseases, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic
| | - Radana Kotalová
- Department of Pediatrics, Second Faculty of Medicine, Charles University and Faculty Hospital Motol, Prague, Czech Republic
| | | | - Markéta Šafaříková
- Institute of Medical Biochemistry and Laboratory Diagnostics, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic
| | - Lucie Pfeiferová
- Institute of Medical Biochemistry and Laboratory Diagnostics, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic
- Department of Informatics and Chemistry, University of Chemistry and Technology in Prague, Prague, Czech Republic
| | - Hana Zůnová
- Department of Biology and Medical Genetics, Second Faculty of Medicine, Charles University and Motol University Hospital, Prague, Czech Republic
| | - Lenka Mrázová
- Department of Pediatrics and Inherited Metabolic Diseases, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic
| | - Viktor Stránecký
- Department of Pediatrics and Inherited Metabolic Diseases, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic
| | - Alena Vrbacká
- Department of Pediatrics and Inherited Metabolic Diseases, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic
| | - Ondřej Fabián
- Institute for Clinical and Experimental Medicine, Prague, Czech Republic
- Department of Pathology and Molecular Medicine, 3rd Faculty of Medicine, Charles University and Thomayer Hospital, Prague, Czech Republic
| | - Eva Sticová
- Institute for Clinical and Experimental Medicine, Prague, Czech Republic
| | - Daniela Skanderová
- Department of Pathology, Faculty of Medicine and Dentistry, Palacky University Olomouc and Faculty Hospital, Olomouc, Czech Republic
| | - Jan Šperl
- Institute for Clinical and Experimental Medicine, Prague, Czech Republic
| | - Marta Kalousová
- Institute of Medical Biochemistry and Laboratory Diagnostics, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic
| | - Tomáš Zima
- Institute of Medical Biochemistry and Laboratory Diagnostics, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic
| | - Milan Macek
- Department of Biology and Medical Genetics, Second Faculty of Medicine, Charles University and Motol University Hospital, Prague, Czech Republic
| | - Joanna Pawlowska
- Department of Gastroenterology, Hepatology, Nutritional Disorders and Pediatrics, The Children's Memorial Health Institute, Warsaw, Poland
| | - A S Knisely
- Diagnostik- und Forschungsinstitut für Pathologie, Medizinische Universität Graz, Graz, Austria
| | - Stanislav Kmoch
- Department of Pediatrics and Inherited Metabolic Diseases, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic
| | - Milan Jirsa
- Institute for Clinical and Experimental Medicine, Prague, Czech Republic
- Institute of Medical Biochemistry and Laboratory Diagnostics, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic
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Williams J, Hurling C, Munir S, Harley P, Machado CB, Cujba AM, Alvarez-Fallas M, Danovi D, Lieberam I, Sancho R, Beales P, Watt FM. Modelling renal defects in Bardet-Biedl syndrome patients using human iPS cells. Front Cell Dev Biol 2023; 11:1163825. [PMID: 37333983 PMCID: PMC10272764 DOI: 10.3389/fcell.2023.1163825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2023] [Accepted: 05/19/2023] [Indexed: 06/20/2023] Open
Abstract
Bardet-Biedl syndrome (BBS) is a ciliopathy with pleiotropic effects on multiple tissues, including the kidney. Here we have compared renal differentiation of iPS cells from healthy and BBS donors. High content image analysis of WT1-expressing kidney progenitors showed that cell proliferation, differentiation and cell shape were similar in healthy, BBS1, BBS2, and BBS10 mutant lines. We then examined three patient lines with BBS10 mutations in a 3D kidney organoid system. The line with the most deleterious mutation, with low BBS10 expression, expressed kidney marker genes but failed to generate 3D organoids. The other two patient lines expressed near normal levels of BBS10 mRNA and generated multiple kidney lineages within organoids when examined at day 20 of organoid differentiation. However, on prolonged culture (day 27) the proximal tubule compartment degenerated. Introducing wild type BBS10 into the most severely affected patient line restored organoid formation, whereas CRISPR-mediated generation of a truncating BBS10 mutation in a healthy line resulted in failure to generate organoids. Our findings provide a basis for further mechanistic studies of the role of BBS10 in the kidney.
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Affiliation(s)
- James Williams
- Centre for Gene Therapy and Regenerative Medicine, King’s College London, Guy’s Hospital, London, United Kingdom
| | - Chloe Hurling
- Centre for Gene Therapy and Regenerative Medicine, King’s College London, Guy’s Hospital, London, United Kingdom
| | - Sabrina Munir
- Centre for Gene Therapy and Regenerative Medicine, King’s College London, Guy’s Hospital, London, United Kingdom
| | - Peter Harley
- Centre for Gene Therapy and Regenerative Medicine, King’s College London, Guy’s Hospital, London, United Kingdom
| | - Carolina Barcellos Machado
- Centre for Gene Therapy and Regenerative Medicine, King’s College London, Guy’s Hospital, London, United Kingdom
| | - Ana-Maria Cujba
- Centre for Gene Therapy and Regenerative Medicine, King’s College London, Guy’s Hospital, London, United Kingdom
| | - Mario Alvarez-Fallas
- Centre for Gene Therapy and Regenerative Medicine, King’s College London, Guy’s Hospital, London, United Kingdom
| | - Davide Danovi
- Centre for Gene Therapy and Regenerative Medicine, King’s College London, Guy’s Hospital, London, United Kingdom
- Bit.bio, Babraham Research Campus, Cambridge, United Kingdom
| | - Ivo Lieberam
- Centre for Gene Therapy and Regenerative Medicine, King’s College London, Guy’s Hospital, London, United Kingdom
- Centre for Developmental Neurobiology and MRC Centre for Neurodevelopmental Disorders, King’s College London, London, United Kingdom
| | - Rocio Sancho
- Centre for Gene Therapy and Regenerative Medicine, King’s College London, Guy’s Hospital, London, United Kingdom
| | - Philip Beales
- Institute of Child Health, Genetic and Genomic Medicine, University College London, London, United Kingdom
| | - Fiona M. Watt
- Centre for Gene Therapy and Regenerative Medicine, King’s College London, Guy’s Hospital, London, United Kingdom
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Zheng NX, Miao YT, Zhang X, Huang MZ, Jahangir M, Luo S, Lang B. Primary cilia-associated protein IFT172 in ciliopathies. Front Cell Dev Biol 2023; 11:1074880. [PMID: 36733456 PMCID: PMC9887189 DOI: 10.3389/fcell.2023.1074880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Accepted: 01/09/2023] [Indexed: 01/18/2023] Open
Abstract
Cilium is a highly conserved antenna-like structure protruding from the surface of the cell membrane, which is widely distributed on most mammalian cells. Two types of cilia have been described so far which include motile cilia and immotile cilia and the latter are also known as primary cilia. Dysfunctional primary cilia are commonly associated with a variety of congenital diseases called ciliopathies with multifaceted presentations such as retinopathy, congenital kidney disease, intellectual disability, cancer, polycystic kidney, obesity, Bardet Biedl syndrome (BBS), etc. Intraflagellar transport (IFT) is a bi-directional transportation process that helps maintain a balanced flow of proteins or signaling molecules essential for the communication between cilia and cytoplasm. Disrupted IFT contributes to the abnormal structure or function of cilia and frequently promotes the occurrence of ciliopathies. Intraflagellar transport 172 (IFT172) is a newly identified member of IFT proteins closely involved in some rare ciliopathies such as Mainzer-Saldino syndrome (MZSDS) and BBS, though the underpinning causal mechanisms remain largely elusive. In this review, we summarize the key findings on the genetic and protein characteristic of IFT172, as well as its function in intraflagellar transport, to provide comprehensive insights to understand IFT172-related ciliopathies.
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Affiliation(s)
- Nan-Xi Zheng
- Department of Psychiatry, National Clinical Research Centre for Mental Health, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Ya-Ting Miao
- Department of Psychiatry, National Clinical Research Centre for Mental Health, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Xi Zhang
- Department of Psychiatry, National Clinical Research Centre for Mental Health, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Mu-Zhi Huang
- Department of Psychiatry, National Clinical Research Centre for Mental Health, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Muhammad Jahangir
- Department of Psychiatry, National Clinical Research Centre for Mental Health, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Shilin Luo
- Department of Pharmacy, The Second Xiangya Hospital, Central South University, Changsha, China,Hunan Provincial Engineering Research Centre of Translational Medicine and Innovative Drug, Changsha, China,*Correspondence: Shilin Luo, ; Bing Lang,
| | - Bing Lang
- Department of Psychiatry, National Clinical Research Centre for Mental Health, The Second Xiangya Hospital, Central South University, Changsha, China,*Correspondence: Shilin Luo, ; Bing Lang,
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Zhou Z, Katoh Y, Nakayama K. CEP19-RABL2-IFT-B axis controls BBSome-mediated ciliary GPCR export. Mol Biol Cell 2022; 33:ar126. [PMID: 36074075 PMCID: PMC9634966 DOI: 10.1091/mbc.e22-05-0161] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
The intraflagellar transport (IFT) machinery mediates the import and export of ciliary proteins across the ciliary gate, as well as bidirectional protein trafficking within cilia. In addition to ciliary anterograde protein trafficking, the IFT-B complex participates in the export of membrane proteins together with the BBSome, which consists of eight subunits encoded by the causative genes of Bardet-Biedl syndrome (BBS). The IFT25-IFT27/BBS19 dimer in the IFT-B complex constitutes its interface with the BBSome. We show here that IFT25-IFT27 and the RABL2 GTPase bind the IFT74/BBS22-IFT81 dimer of the IFT-B complex in a mutually exclusive manner. Cells expressing GTP-locked RABL2 [RABL2(Q80L)], but not wild-type RABL2, phenocopied IFT27-knockout cells, that is, they demonstrated BBS-associated ciliary defects, including accumulation of LZTFL1/BBS17 and the BBSome within cilia and the suppression of export of the ciliary GPCRs GPR161 and Smoothened. RABL2(Q80L) enters cilia in a manner dependent on the basal body protein CEP19, but its entry into cilia is not necessary for causing BBS-associated ciliary defects. These observations suggest that GTP-bound RABL2 is likely to be required for recruitment of the IFT-B complex to the ciliary base, where it is replaced with IFT25-IFT27.
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Affiliation(s)
| | - Yohei Katoh
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan,*Address correspondence to: Kazuhisa Nakayama (); Yohei Katoh ()
| | - Kazuhisa Nakayama
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan,*Address correspondence to: Kazuhisa Nakayama (); Yohei Katoh ()
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10
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Cai M, Lin M, Lin N, Xu L, Huang H. Novel homozygous nonsense mutation associated with Bardet-Biedl syndrome in fetuses with congenital renal malformation. Medicine (Baltimore) 2022; 101:e30003. [PMID: 35960079 PMCID: PMC9371496 DOI: 10.1097/md.0000000000030003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND The Bardet-Biedl syndrome (BBS) is a rare autosomal recessive disorder, characterized by clinical and genetic heterogeneity. BBS is more commonly reported in adults and children than in fetuses. Here, a retrospective study on 210 fetuses with congenital renal malformation was conducted. METHODS The fetuses were diagnosed using invasive prenatal tests, including chromosome karyotype analysis, whole exome sequencing (WES), and single-nucleotide polymorphism array. We found the intrauterine phenotype of a fetus presenting enlarged kidneys, enhanced echo, and oligohydramnios; therefore, the fetus was characterized to have BBS. RESULTS Chromosome karyotype analysis presented normal results. Analysis using an Affymetrix CytoScan 750K array revealed 2 homozygous regions. However, WES revealed a homozygous mutation of c.1177C>T (p.Arg393*) on exon 12 of BBS1 and a heterozygous variation of c.2704G>A (p.Asp902Asn) on exon 22 of CC2D2A. The American College of Medical Genetics and Genomics guidelines identified c.1177C>T and c.2704G>A as a pathogenic mutation and of uncertain significance, respectively. Sanger sequencing identified heterozygous mutation, that is, c.1177C>T and heterozygous variation, that is, c.2704G>A in the parents of the fetus. CONCLUSIONS WES identified a novel homozygous nonsense mutation c.1177C>T in BBS1 of a Chinese fetus with congenital renal malformation. This finding provides insight into the BBS1 mutations in Asian populations in general and shows the necessity of genetic counseling.
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Affiliation(s)
- Meiying Cai
- Medical Genetic Diagnosis and Therapy Center, Fujian Maternity and Child Health Hospital College of Clinical Medicine for Obstetrics and Gynecology and Pediatrics, Fujian Medical University, Fujian Key Laboratory for Prenatal Diagnosis and Birth Defect, Fuzhou, China
| | - Min Lin
- Medical Genetic Diagnosis and Therapy Center, Fujian Maternity and Child Health Hospital College of Clinical Medicine for Obstetrics and Gynecology and Pediatrics, Fujian Medical University, Fujian Key Laboratory for Prenatal Diagnosis and Birth Defect, Fuzhou, China
| | - Na Lin
- Medical Genetic Diagnosis and Therapy Center, Fujian Maternity and Child Health Hospital College of Clinical Medicine for Obstetrics and Gynecology and Pediatrics, Fujian Medical University, Fujian Key Laboratory for Prenatal Diagnosis and Birth Defect, Fuzhou, China
| | - Liangpu Xu
- Medical Genetic Diagnosis and Therapy Center, Fujian Maternity and Child Health Hospital College of Clinical Medicine for Obstetrics and Gynecology and Pediatrics, Fujian Medical University, Fujian Key Laboratory for Prenatal Diagnosis and Birth Defect, Fuzhou, China
| | - Hailong Huang
- Medical Genetic Diagnosis and Therapy Center, Fujian Maternity and Child Health Hospital College of Clinical Medicine for Obstetrics and Gynecology and Pediatrics, Fujian Medical University, Fujian Key Laboratory for Prenatal Diagnosis and Birth Defect, Fuzhou, China
- *Correspondence: Hailong Huang, Fujian Maternity and Child Health Hospital, No. 18 Daoshan Road, Gulou District, Fuzhou 350001, China (e-mail: )
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11
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Ishida Y, Tasaki K, Katoh Y, Nakayama K. Molecular basis underlying the ciliary defects caused by IFT52 variations found in skeletal ciliopathies. Mol Biol Cell 2022; 33:ar83. [PMID: 35704471 PMCID: PMC9582644 DOI: 10.1091/mbc.e22-05-0188] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Bidirectional protein trafficking within cilia is mediated by the intraflagellar transport (IFT) machinery, which contains the IFT-A and IFT-B complexes powered by the kinesin-2 and dynein-2 motors. Mutations in genes encoding subunits of the IFT-A and dynein-2 complexes cause skeletal ciliopathies. Some subunits of the IFT-B complex, including IFT52, IFT80, and IFT172, are also mutated in skeletal ciliopathies. We here show that IFT52 variants found in individuals with short-rib polydactyly syndrome (SRPS) are compromised in terms of formation of the IFT-B holocomplex from two subcomplexes and its interaction with heterotrimeric kinesin-II. IFT52-knockout (KO) cells expressing IFT52 variants that mimic the cellular conditions of individuals with SRPS demonstrated mild ciliogenesis defects and a decrease in ciliary IFT-B level. Furthermore, in IFT52-KO cells expressing an SRPS variant of IFT52, ciliary tip localization of ICK/CILK1 and KIF17, both of which are likely to be transported to the tip via binding to the IFT-B complex, was significantly impaired. Altogether these results indicate that impaired anterograde trafficking caused by a decrease in the ciliary level of IFT-B or in its binding to kinesin-II underlies the ciliary defects found in skeletal ciliopathies caused by IFT52 variations.
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Affiliation(s)
- Yamato Ishida
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | - Koshi Tasaki
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | - Yohei Katoh
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
| | - Kazuhisa Nakayama
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
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12
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Walczak-Sztulpa J, Wawrocka A, Doornbos C, van Beek R, Sowińska-Seidler A, Jamsheer A, Bukowska-Olech E, Latos-Bieleńska A, Grenda R, Bongers EMHF, Schmidts M, Obersztyn E, Krawczyński MR, Oud MM. Identical IFT140 Variants Cause Variable Skeletal Ciliopathy Phenotypes—Challenges for the Accurate Diagnosis. Front Genet 2022; 13:931822. [PMID: 35873489 PMCID: PMC9300986 DOI: 10.3389/fgene.2022.931822] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 06/15/2022] [Indexed: 11/13/2022] Open
Abstract
Ciliopathies are rare congenital disorders, caused by defects in the cilium, that cover a broad clinical spectrum. A subgroup of ciliopathies showing significant phenotypic overlap are known as skeletal ciliopathies and include Jeune asphyxiating thoracic dysplasia (JATD), Mainzer-Saldino syndrome (MZSDS), cranioectodermal dysplasia (CED), and short-rib polydactyly (SRP). Ciliopathies are heterogeneous disorders with >187 associated genes, of which some genes are described to cause more than one ciliopathy phenotype. Both the clinical and molecular overlap make accurate diagnosing of these disorders challenging. We describe two unrelated Polish patients presenting with a skeletal ciliopathy who share the same compound heterozygous variants in IFT140 (NM_014,714.4) r.2765_2768del; p.(Tyr923Leufs*28) and exon 27–30 duplication; p.(Tyr1152_Thr1394dup). Apart from overlapping clinical symptoms the patients also show phenotypic differences; patient 1 showed more resemblance to a Mainzer-Saldino syndrome (MZSDS) phenotype, while patient 2 was more similar to the phenotype of cranioectodermal dysplasia (CED). In addition, functional testing in patient-derived fibroblasts revealed a distinct cilium phenotyps for each patient, and strikingly, the cilium phenotype of CED-like patient 2 resembled that of known CED patients. Besides two variants in IFT140, in depth exome analysis of ciliopathy associated genes revealed a likely-pathogenic heterozygous variant in INTU for patient 2 that possibly affects the same IFT-A complex to which IFT140 belongs and thereby could add to the phenotype of patient 2. Taken together, by combining genetic data, functional test results, and clinical findings we were able to accurately diagnose patient 1 with “IFT140-related ciliopathy with MZSDS-like features” and patient 2 with “IFT140-related ciliopathy with CED-like features”. This study emphasizes that identical variants in one ciliopathy associated gene can lead to a variable ciliopathy phenotype and that an in depth and integrated analysis of clinical, molecular and functional data is necessary to accurately diagnose ciliopathy patients.
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Affiliation(s)
| | - Anna Wawrocka
- Department of Medical Genetics, Poznan University of Medical Sciences, Poznan, Poland
| | - Cenna Doornbos
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, Netherlands
| | - Ronald van Beek
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, Netherlands
| | - Anna Sowińska-Seidler
- Department of Medical Genetics, Poznan University of Medical Sciences, Poznan, Poland
| | - Aleksander Jamsheer
- Department of Medical Genetics, Poznan University of Medical Sciences, Poznan, Poland
- Centers for Medical Genetics, Poznan, Poland
| | | | - Anna Latos-Bieleńska
- Department of Medical Genetics, Poznan University of Medical Sciences, Poznan, Poland
| | - Ryszard Grenda
- Department of Nephrology, Kidney Transplantation and Hypertension, The Children’s Memorial Health Institute, Warsaw, Poland
| | | | - Miriam Schmidts
- Center for Pediatrics and Adolescent Medicine, University Hospital Freiburg, Freiburg University Faculty of Medicine, Freiburg, Germany
- CIBSS—Centre for Integrative Biological Signalling Studies, Freiburg University, Freiburg, Germany
| | - Ewa Obersztyn
- Department of Medical Genetics, Institute of Mother and Child, Warsaw, Poland
| | - Maciej R. Krawczyński
- Department of Medical Genetics, Poznan University of Medical Sciences, Poznan, Poland
- Centers for Medical Genetics, Poznan, Poland
| | - Machteld M. Oud
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, Netherlands
- *Correspondence: Machteld M. Oud,
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13
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Wallmeier J, Dallmayer M, Omran H. The role of cilia for hydrocephalus formation. AMERICAN JOURNAL OF MEDICAL GENETICS. PART C, SEMINARS IN MEDICAL GENETICS 2022; 190:47-56. [PMID: 35470956 DOI: 10.1002/ajmg.c.31972] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 04/06/2022] [Accepted: 04/07/2022] [Indexed: 06/14/2023]
Abstract
Hydrocephalus is a common finding in newborns. In most cases, it is caused by intraventricular hemorrhage associated with prematurity, whereas in some patients the cause of hydrocephalus can be traced back to genetic changes, associated with disease syndromes such as RASopathies, lysosomal storage diseases, dystroglycanopathies, craniosynostosis but also ciliopathies. Ciliopathies are a group of diseases that can affect multiple organ systems due to dysfunction or the absence of cilia. Cilia are small organelles, extending from the cell surface. Nonmotile monocilia are ubiquitously present during cell development fulfilling chemosensory functions, whereas specialized epithelia such as the ependyma, lining the inner surface of the brain ventricles, exhibit multiciliated cells propelling fluids along the cell surface. This review highlights ciliopathies and their pathophysiology in congenital hydrocephalus. While nonmotile ciliopathies are often associated with severe prenatal hydrocephalus combined with other severe congenital brain malformations, motile ciliopathies, especially those associated with defects in multiciliogenesis can cause hydrocephalus and chronic lung disease.
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Affiliation(s)
- Julia Wallmeier
- Department of General Pediatrics, University Clinic Muenster, Münster, Germany
| | - Marlene Dallmayer
- Department of General Pediatrics, University Clinic Muenster, Münster, Germany
| | - Heymut Omran
- Department of General Pediatrics, University Clinic Muenster, Münster, Germany
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14
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Chandra B, Tung ML, Hsu Y, Scheetz T, Sheffield VC. Retinal ciliopathies through the lens of Bardet-Biedl Syndrome: Past, present and future. Prog Retin Eye Res 2021; 89:101035. [PMID: 34929400 DOI: 10.1016/j.preteyeres.2021.101035] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 12/10/2021] [Accepted: 12/13/2021] [Indexed: 12/15/2022]
Abstract
The primary cilium is a highly specialized and evolutionary conserved organelle in eukaryotes that plays a significant role in cell signaling and trafficking. Over the past few decades tremendous progress has been made in understanding the physiology of cilia and the underlying pathomechanisms of various ciliopathies. Syndromic ciliopathies consist of a group of disorders caused by ciliary dysfunction or abnormal ciliogenesis. These disorders have multiorgan involvement in addition to retinal degeneration underscoring the ubiquitous distribution of primary cilia in different cell types. Genotype-phenotype correlation is often challenging due to the allelic heterogeneity and pleiotropy of these disorders. In this review, we discuss the clinical and genetic features of syndromic ciliopathies with a focus on Bardet-Biedl syndrome (BBS) as a representative disorder. We discuss the structure and function of primary cilia and their role in retinal photoreceptors. We describe the progress made thus far in understanding the functional and genetic characterization including expression quantitative trait locus (eQTL) analysis of BBS genes. In the future directions section, we discuss the emerging technologies, such as gene therapy, as well as anticipated challenges and their implications in therapeutic development for ciliopathies.
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Affiliation(s)
- Bharatendu Chandra
- Stead Family Department of Pediatrics, Division of Medical Genetics and Genomics, University of Iowa Carver College of Medicine, Iowa City, IA, USA; Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Moon Ley Tung
- Stead Family Department of Pediatrics, Division of Medical Genetics and Genomics, University of Iowa Carver College of Medicine, Iowa City, IA, USA; Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Ying Hsu
- Department of Ophthalmology and Visual Sciences, Carver College of Medicine, Iowa City, IA, USA
| | - Todd Scheetz
- Department of Ophthalmology and Visual Sciences, Carver College of Medicine, Iowa City, IA, USA
| | - Val C Sheffield
- Stead Family Department of Pediatrics, Division of Medical Genetics and Genomics, University of Iowa Carver College of Medicine, Iowa City, IA, USA; Department of Ophthalmology and Visual Sciences, Carver College of Medicine, Iowa City, IA, USA.
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15
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Zhou Z, Qiu H, Castro-Araya RF, Takei R, Nakayama K, Katoh Y. Impaired cooperation between IFT74/BBS22-IFT81 and IFT25-IFT27/BBS19 causes Bardet-Biedl syndrome. Hum Mol Genet 2021; 31:1681-1693. [PMID: 34888642 DOI: 10.1093/hmg/ddab354] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 11/19/2021] [Accepted: 12/06/2021] [Indexed: 02/03/2023] Open
Abstract
The IFT-B complex mediates ciliary anterograde protein trafficking and membrane protein export together with the BBSome. Bardet-Biedl syndrome (BBS) is caused by mutations in not only all BBSome subunits, but also in some IFT-B subunits, including IFT74/BBS22 and IFT27/BBS19, which form heterodimers with IFT81 and IFT25, respectively. We found that the IFT25-IFT27 dimer bind the C-terminal region of the IFT74-IFT81 dimer, and that the IFT25-IFT27-binding region encompasses the region deleted in the BBS variants of IFT74. In addition, we found that the missense BBS variants of IFT27 are impaired in IFT74-IFT81 binding, and are unable to rescue the BBS-like phenotypes of IFT27-knockout cells. Furthermore, the BBS variants of IFT74 rescued the ciliogenesis defect of IFT74-knockout cells, but the rescued cells demonstrated BBS-like abnormal phenotypes. Taken together, we conclude that the impaired interaction between IFT74-IFT81 and IFT25-IFT27 causes the BBS-associated ciliary defects.
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Affiliation(s)
- Zhuang Zhou
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto 606-8501, Japan
| | - Hantian Qiu
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto 606-8501, Japan
| | - Roiner-Francisco Castro-Araya
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto 606-8501, Japan
| | - Ryota Takei
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto 606-8501, Japan
| | - Kazuhisa Nakayama
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto 606-8501, Japan
| | - Yohei Katoh
- Department of Physiological Chemistry, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto 606-8501, Japan
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16
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Ttc30a affects tubulin modifications in a model for ciliary chondrodysplasia with polycystic kidney disease. Proc Natl Acad Sci U S A 2021; 118:2106770118. [PMID: 34548398 PMCID: PMC8488674 DOI: 10.1073/pnas.2106770118] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/04/2021] [Indexed: 12/14/2022] Open
Abstract
Cilia are tubulin-based cellular appendages, and their dysfunction has been linked to a variety of genetic diseases. Ciliary chondrodysplasia is one such condition that can co-occur with cystic kidney disease and other organ manifestations. We modeled skeletal ciliopathies by mutating two established disease genes in Xenopus tropicalis frogs. Bioinformatic analysis identified ttc30a as a ciliopathy network component, and targeting it replicated skeletal malformations and renal cysts as seen in patients and the amphibian models. A loss of Ttc30a affected cilia by altering posttranslational tubulin modifications. Our findings identify TTC30A/B as a component of ciliary segmentation essential for cartilage differentiation and renal tubulogenesis. These findings may lead to novel therapeutic targets in treating ciliary skeletopathies and cystic kidney disease. Skeletal ciliopathies (e.g., Jeune syndrome, short rib polydactyly syndrome, and Sensenbrenner syndrome) are frequently associated with nephronophthisis-like cystic kidney disease and other organ manifestations. Despite recent progress in genetic mapping of causative loci, a common molecular mechanism of cartilage defects and cystic kidneys has remained elusive. Targeting two ciliary chondrodysplasia loci (ift80 and ift172) by CRISPR/Cas9 mutagenesis, we established models for skeletal ciliopathies in Xenopus tropicalis. Froglets exhibited severe limb deformities, polydactyly, and cystic kidneys, closely matching the phenotype of affected patients. A data mining–based in silico screen found ttc30a to be related to known skeletal ciliopathy genes. CRISPR/Cas9 targeting replicated limb malformations and renal cysts identical to the models of established disease genes. Loss of Ttc30a impaired embryonic renal excretion and ciliogenesis because of altered posttranslational tubulin acetylation, glycylation, and defective axoneme compartmentalization. Ttc30a/b transcripts are enriched in chondrocytes and osteocytes of single-cell RNA-sequenced embryonic mouse limbs. We identify TTC30A/B as an essential node in the network of ciliary chondrodysplasia and nephronophthisis-like disease proteins and suggest that tubulin modifications and cilia segmentation contribute to skeletal and renal ciliopathy manifestations of ciliopathies in a cell type–specific manner. These findings have implications for potential therapeutic strategies.
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17
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Husson H, Bukanov NO, Moreno S, Smith MM, Richards B, Zhu C, Picariello T, Park H, Wang B, Natoli TA, Smith LA, Zanotti S, Russo RJ, Madden SL, Klinger KW, Modur V, Ibraghimov-Beskrovnaya O. Correction of cilia structure and function alleviates multi-organ pathology in Bardet-Biedl syndrome mice. Hum Mol Genet 2021; 29:2508-2522. [PMID: 32620959 PMCID: PMC7471507 DOI: 10.1093/hmg/ddaa138] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 06/22/2020] [Accepted: 07/01/2020] [Indexed: 12/21/2022] Open
Abstract
Bardet–Biedl syndrome (BBS) is a pleiotropic autosomal recessive ciliopathy affecting multiple organs. The development of potential disease-modifying therapy for BBS will require concurrent targeting of multi-systemic manifestations. Here, we show for the first time that monosialodihexosylganglioside accumulates in Bbs2−/− cilia, indicating impairment of glycosphingolipid (GSL) metabolism in BBS. Consequently, we tested whether BBS pathology in Bbs2−/− mice can be reversed by targeting the underlying ciliary defect via reduction of GSL metabolism. Inhibition of GSL synthesis with the glucosylceramide synthase inhibitor Genz-667161 decreases the obesity, liver disease, retinal degeneration and olfaction defect in Bbs2−/− mice. These effects are secondary to preservation of ciliary structure and signaling, and stimulation of cellular differentiation. In conclusion, reduction of GSL metabolism resolves the multi-organ pathology of Bbs2−/− mice by directly preserving ciliary structure and function towards a normal phenotype. Since this approach does not rely on the correction of the underlying genetic mutation, it might translate successfully as a treatment for other ciliopathies.
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Affiliation(s)
- Hervé Husson
- Rare and Neurologic Diseases Research, Sanofi, Framingham, MA 01701, USA
| | - Nikolay O Bukanov
- Rare and Neurologic Diseases Research, Sanofi, Framingham, MA 01701, USA
| | - Sarah Moreno
- Rare and Neurologic Diseases Research, Sanofi, Framingham, MA 01701, USA
| | - Mandy M Smith
- Rare and Neurologic Diseases Research, Sanofi, Framingham, MA 01701, USA
| | | | - Cheng Zhu
- Translational Sciences, Sanofi, Framingham, MA 01701, USA
| | - Tyler Picariello
- Rare and Neurologic Diseases Research, Sanofi, Framingham, MA 01701, USA
| | - Hyejung Park
- Pre-Development Sciences, Sanofi, Waltham, MA 02451, USA
| | - Bing Wang
- Pre-Development Sciences, Sanofi, Waltham, MA 02451, USA
| | - Thomas A Natoli
- Rare and Neurologic Diseases Research, Sanofi, Framingham, MA 01701, USA
| | - Laurie A Smith
- Rare and Neurologic Diseases Research, Sanofi, Framingham, MA 01701, USA
| | - Stefano Zanotti
- Rare and Neurologic Diseases Research, Sanofi, Framingham, MA 01701, USA
| | - Ryan J Russo
- Rare and Neurologic Diseases Research, Sanofi, Framingham, MA 01701, USA
| | | | | | - Vijay Modur
- Rare Diseases Development, Sanofi, Cambridge, MA 02142, USA
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18
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Zhang S, Liu Y, Huang Q, Yuan S, Liu H, Shi L, Yap YT, Li W, Zhen J, Zhang L, Hess RA, Zhang Z. Murine germ cell-specific disruption of Ift172 causes defects in spermiogenesis and male fertility. Reproduction 2021; 159:409-421. [PMID: 31958312 DOI: 10.1530/rep-17-0789] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2017] [Accepted: 01/20/2020] [Indexed: 01/21/2023]
Abstract
Intraflagellar transport (IFT) is a conserved mechanism essential for the assembly and maintenance of most eukaryotic cilia and flagella. IFT172 is a component of the IFT complex. Global disruption of mouse Ift172 gene caused typical phenotypes of ciliopathy. Mouse Ift172 gene appears to translate two major proteins; the full-length protein is highly expressed in the tissues enriched in cilia and the smaller 130 kDa one is only abundant in the testis. In male germ cells, IFT172 is highly expressed in the manchette of elongating spermatids. A germ cell-specific Ift172 mutant mice were generated, and the mutant mice did not show gross abnormalities. There was no difference in testis/body weight between the control and mutant mice, but more than half of the adult homozygous mutant males were infertile and associated with abnormally developed germ cells in the spermiogenesis phase. The cauda epididymides in mutant mice contained less developed sperm that showed significantly reduced motility, and these sperm had multiple defects in ultrastructure and bent tails. In the mutant mice, testicular expression levels of some IFT components, including IFT20, IFT27, IFT74, IFT81 and IFT140, and a central apparatus protein SPAG16L were not changed. However, expression levels of ODF2, a component of the outer dense fiber, and AKAP4, a component of fibrous sheath, and two IFT components IFT25 and IFT57 were dramatically reduced. Our findings demonstrate that IFT172 is essential for normal male fertility and spermiogenesis in mice, probably by modulating specific IFT proteins and transporting/assembling unique accessory structural proteins into spermatozoa.
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Affiliation(s)
- Shiyang Zhang
- School of Public Health, Wuhan University of Science and Technology, Wuhan, Hubei, China.,Department of Physiology, Wayne State University, Detroit, Michigan, USA
| | - Yunhao Liu
- School of Public Health, Wuhan University of Science and Technology, Wuhan, Hubei, China.,Hubei Province Key Laboratory of Occupational Hazard Identification and Control, Wuhan University of Science and Technology, Wuhan, Hubei, China
| | - Qian Huang
- School of Public Health, Wuhan University of Science and Technology, Wuhan, Hubei, China.,Department of Physiology, Wayne State University, Detroit, Michigan, USA
| | - Shuo Yuan
- School of Public Health, Wuhan University of Science and Technology, Wuhan, Hubei, China.,Department of Physiology, Wayne State University, Detroit, Michigan, USA
| | - Hong Liu
- School of Public Health, Wuhan University of Science and Technology, Wuhan, Hubei, China.,Department of Physiology, Wayne State University, Detroit, Michigan, USA
| | - Lin Shi
- School of Public Health, Wuhan University of Science and Technology, Wuhan, Hubei, China.,Department of Physiology, Wayne State University, Detroit, Michigan, USA
| | - Yi Tian Yap
- Department of Physiology, Wayne State University, Detroit, Michigan, USA
| | - Wei Li
- Department of Physiology, Wayne State University, Detroit, Michigan, USA
| | - Jingkai Zhen
- School of Public Health, Wuhan University of Science and Technology, Wuhan, Hubei, China
| | - Ling Zhang
- School of Public Health, Wuhan University of Science and Technology, Wuhan, Hubei, China.,Hubei Province Key Laboratory of Occupational Hazard Identification and Control, Wuhan University of Science and Technology, Wuhan, Hubei, China
| | - Rex A Hess
- Department of Comparative Biosciences, College of Veterinary Medicine, University of Illinois, Urbana, Illinois, USA
| | - Zhibing Zhang
- Department of Physiology, Wayne State University, Detroit, Michigan, USA.,Department of Obstetrics and Gynecology, Wayne State University, Detroit, Michigan, USA
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19
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Mardy AH, Hodoglugil U, Yip T, Slavotinek AM. Third case of Bardet-Biedl syndrome caused by a biallelic variant predicted to affect splicing of IFT74. Clin Genet 2021; 100:93-99. [PMID: 33748949 DOI: 10.1111/cge.13962] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 03/17/2021] [Accepted: 03/18/2021] [Indexed: 12/19/2022]
Abstract
Bardet-Biedl syndrome (BBS) is a rare ciliopathy characterized by rod-cone dystrophy, postaxial polydactyly, truncal obesity and renal anomalies with autosomal recessive inheritance. We describe a 6-year-old male with early onset retinal dystrophy, postaxial polydactyly, truncal obesity and motor delays. Exome sequencing revealed a homozygous variant predicted to affect splicing of the IFT74 gene, c.1685-1G > T. This is the third patient with BBS due to variants predicting loss of function in IFT74. All three patients have had retinal dystrophy, polydactyly, obesity, developmental differences, and a notable lack of renal anomalies. We recommend that IFT74 is added to gene panels for the diagnosis of BBS.
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Affiliation(s)
- Anne H Mardy
- Division of Maternal Fetal Medicine, Department of Obstetrics, Gynecology, and Reproductive Sciences, University of California, San Francisco, California, USA
| | - Ugur Hodoglugil
- Genomic Medicine Lab, University of California, San Francisco, California, USA
| | - Tiffany Yip
- Institute for Human Genetics, University of California, San Francisco, California, USA
| | - Anne M Slavotinek
- Institute for Human Genetics, University of California, San Francisco, California, USA.,Division of Medical Genetics, Department of Pediatrics, University of California, San Francisco, California, USA
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20
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BBS Proteins Affect Ciliogenesis and Are Essential for Hedgehog Signaling, but Not for Formation of iPSC-Derived RPE-65 Expressing RPE-Like Cells. Int J Mol Sci 2021; 22:ijms22031345. [PMID: 33572860 PMCID: PMC7866284 DOI: 10.3390/ijms22031345] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 01/23/2021] [Accepted: 01/24/2021] [Indexed: 12/31/2022] Open
Abstract
Bardet-Biedl syndrome (BBS) is a ciliopathy characterized by retinal dystrophy, renal cysts, obesity and polydactyly. BBS genes have been implicated in ciliogenesis, hedgehog signaling and retinal pigment epithelium maturation. BBS1 and BBS5 are members of the BBSome, implicated in cilia transport of proteins, and BBS10 is a member of the chaperonin-complex, mediating BBSome assembly. In this study, involvement of BBS1, BBS5 and BBS10 in ciliogenesis and hedgehog signaling were investigated in BBS-defective patient fibroblasts as well as in RPE-hTERT cells following siRNA-mediated knockdown of the BBS genes. Furthermore, the ability of BBS1-defective induced pluripotent stem-cells (iPSCs) to differentiate into RPE cells was assessed. We report that cells lacking functional BBS5 or BBS10 have a reduced number of primary cilia, whereas cells lacking functional BBS1 display shorter primary cilia compared to wild-type cells. Hedgehog signaling was substantially impaired and Smoothened, a component of hedgehog signaling, was trapped inside the cilia of the BBS-defective cells, even in the absence of Smoothened agonist. Preliminary results demonstrated the ability of BBS1-defective iPSC to differentiate into RPE-65 expressing RPE-like cells. The BBS1-/--defective RPE-like cells were less pigmented, compared to RPE-like cells differentiated from control iPSCs, indicating an impact of BBS1 on RPE maturation.
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21
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Romano F, Dautaj A, Esposito RA, Bertelli M, Staurenghi G, Salvetti AP. Multimodal imaging of retinitis pigmentosa associated with Mainzer-Saldino syndrome. Ophthalmic Genet 2021; 42:218-221. [PMID: 33393400 DOI: 10.1080/13816810.2020.1867755] [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] [Indexed: 02/08/2023]
Abstract
Background: Syndromic ciliopathies have been variably linked to different retinal dystrophies. However, to date, few reports have characterized by means of multimodal imaging the retinal degeneration occurring in Mainzer-Saldino syndrome (MSS).Methods: Two siblings with history of kidney disease and other systemic abnormalities presented at our eye clinic in October 2017 complaining of night blindness and visual loss. They underwent a complete ophthalmologic examination including visual acuity (VA) assessment, optical coherence tomography (OCT) and blue-light autofluorescence (BAF). A screen for inherited retinal dystrophies was performed in this occasion.Results: At baseline, the youngest sister had slightly worse VA (20/30 vs. 20/20-25 Snellen equivalents). On fundoscopy, both siblings had severe thinning of the peripheral retina, attenuation of retinal vessels and widespread accumulation of pigmented deposits. Significant outer retinal atrophy with apparent foveal sparing was appreciable on OCT.During the 3 years of follow-up, vision remained overall stable in both patients whereas minimal progression of outer retinal atrophy was observed by means of OCT. Genetic analysis revealed compound heterozygosity in the IFT172 gene. Based on these findings, a diagnosis of retinitis pigmentosa (RP) associated with MSS was formulated.Conclusions: Our report describes the cases of two siblings affected by retinitis pigmentosa associated with MSS. Although both carrying the same mutations and a severe RP phenotype, the youngest sister had slightly more advanced retinal degeneration highlighting the remarkable variability related to the IFT172 retinopathy.
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Affiliation(s)
- Francesco Romano
- Eye Clinic, Department of Biomedical and Clinical Science, Luigi Sacco Hospital, University of Milan, Milan, Italy
| | | | - Raffaele Antonio Esposito
- Eye Clinic, Department of Biomedical and Clinical Science, Luigi Sacco Hospital, University of Milan, Milan, Italy
| | | | - Giovanni Staurenghi
- Eye Clinic, Department of Biomedical and Clinical Science, Luigi Sacco Hospital, University of Milan, Milan, Italy
| | - Anna Paola Salvetti
- Eye Clinic, Department of Biomedical and Clinical Science, Luigi Sacco Hospital, University of Milan, Milan, Italy
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22
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Regan JA, Shah SH. Obesity Genomics and Metabolomics: a Nexus of Cardiometabolic Risk. Curr Cardiol Rep 2020; 22:174. [PMID: 33040225 DOI: 10.1007/s11886-020-01422-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/14/2020] [Indexed: 12/24/2022]
Abstract
PURPOSE OF REVIEW Obesity is a significant international public health epidemic with major downstream consequences on morbidity and mortality. While lifestyle factors contribute, there is an evolving understanding of genomic and metabolomic pathways involved with obesity and its relationship with cardiometabolic risk. This review will provide an overview of some of these important findings from both a biologic and clinical perspective. RECENT FINDINGS Recent studies have identified polygenic risk scores and metabolomic biomarkers of obesity and related outcomes, which have also highlighted biological pathways, such as the branched-chain amino acid (BCAA) pathway that is dysregulated in this disease. These biomarkers may help in personalizing obesity interventions and for mitigation of future cardiometabolic risk. A multifaceted approach is necessary to impact the growing epidemic of obesity and related diseases. This will likely include incorporating precision medicine approaches with genomic and metabolomic biomarkers to personalize interventions and improve risk prediction.
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Affiliation(s)
- Jessica A Regan
- Department of Medicine, Duke University, Durham, NC, USA.,Duke Molecular Physiology Institute, Duke University, 300 N. Duke Street, DUMC, Box 104775, Durham, NC, 27701, USA
| | - Svati H Shah
- Department of Medicine, Duke University, Durham, NC, USA. .,Duke Molecular Physiology Institute, Duke University, 300 N. Duke Street, DUMC, Box 104775, Durham, NC, 27701, USA.
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23
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Bardet-Biedl syndrome and related disorders in Japan. J Hum Genet 2020; 65:847-853. [PMID: 32451492 DOI: 10.1038/s10038-020-0778-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 04/19/2020] [Accepted: 05/06/2020] [Indexed: 02/03/2023]
Abstract
Bardet-Biedl syndrome (BBS) is a rare autosomal recessive disorder characterized by obesity, mental impairment, rod-cone dystrophy, polydactyly, male hypogonadism, and renal abnormalities. This disorder is caused by mutations in BBS1-21. Alström syndrome (AS), caused solely by mutations in ALMS1, is another genetic obesity syndrome clinically similar to BBS. We previously conducted the first nationwide survey of BBS in Japan and found four patients with genetically definite BBS. In this study, exome analyses were performed on new patients whose symptoms fulfilled the diagnostic criteria for BBS. We identified one reported heterozygous mutation in BBS1 (p.R429*) in one patient, two novel mutations (p.L493R and p.H719Y) in BBS20 in a second patient, and one novel mutation (p.Q920*) and one reported mutation (p.R2928*) in ALMS1 in a third patient, who was subsequently diagnosed with AS. The first patient with BBS was previously considered to have digenic heterozygous mutations in BBS1 and BBS4. RT-PCR and long-range genomic PCR analyses identified a new heterozygous mutation in BBS1, the deletion of exons 10 and 11. Thus, this patient was compound heterozygous for mutations in BBS1. Many studies have described digenic heterozygous mutations in BBS. However, undetected mutations might have existed in either one of the mutated genes.
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24
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Tao T, Wang L, Chong W, Yang L, Li G. Characteristics of genotype and phenotype in Chinese patients with Bardet-Biedl syndrome. Int Ophthalmol 2020; 40:2325-2343. [PMID: 32448990 DOI: 10.1007/s10792-020-01415-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Accepted: 05/02/2020] [Indexed: 12/31/2022]
Abstract
PURPOSE To investigate complex and different phenotypes in seven Chinese patients diagnosed with Bardet-Biedl syndrome (BBS) and carrying pathogenic mutations. METHODS Seven unrelated BBS patients were enrolled. Their medical and ophthalmic histories were reviewed, and comprehensive clinical examinations, such as fundus photography, optical coherence tomography, and medical imaging, were performed. A specific hereditary eye disease enrichment panel based on exome-capture technology was used to collect and amplify the protein-coding regions of 441 targeted hereditary eye disease genes, followed by high-throughput sequencing using the Illumina HiSeq platform. RESULTS All patients exhibited the primary clinical phenotype of BBS. Seven BBS mutations were found in five patients (BBS7 in two patients, BBS10 in two patients, BBS12 in one patient), for a detection rate of 71% (5/7). The ratio of novel to known BBS mutations was 5:2. CONCLUSIONS This study showed the phenotypic and genotypic spectrum of BBS patients from China, and the findings underscore the importance of obtaining comprehensive clinical observations and molecular analyses for ciliopathies.
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Affiliation(s)
- Tianchang Tao
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Lab, Beijing, People's Republic of China
| | - Lei Wang
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Lab, Beijing, People's Republic of China
| | - Weihua Chong
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Lab, Beijing, People's Republic of China
| | - Liping Yang
- Department of Ophthalmology, Peking University Third Hospital, Key Laboratory of Restoration of Damaged Ocular Nerve Beijing, Beijing, People's Republic of China
| | - Genlin Li
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University; Beijing Ophthalmology & Visual Sciences Key Lab, Beijing, People's Republic of China.
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25
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Second case of Bardet-Biedl syndrome caused by biallelic variants in IFT74. Eur J Hum Genet 2020; 28:943-946. [PMID: 32144365 DOI: 10.1038/s41431-020-0594-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Revised: 01/26/2020] [Accepted: 02/18/2020] [Indexed: 02/02/2023] Open
Abstract
Bardet-Biedl syndrome (BBS) is a rare autosomal recessive disorder of the cilia, often resulting in a phenotype of obesity, rod-cone dystrophy, a variable degree of intellectual disability, polydactyly, renal problems, and/or hypogonadism in males or genital abnormalities in females. We here report the case of an 11-year-old girl who presented with postaxial polydactyly, retinal dystrophy, and childhood obesity, suggesting Bardet-Biedl syndrome. She had no renal problems, developmental delay, or intellectual disability. Genetic testing revealed compound heterozygous variants in the IFT74 gene (c.371_372del p.Gln124Argfs*9 and c.16850-1G>T p.?). We here report the second patient with Bardet-Biedl syndrome due to biallelic IFT74 variants. Both patients have obesity, polydactyly, retinal dystrophy, and no renal abnormalities. The present case however, has normal intellect, whereas the other patient has intellectual disability. We hereby confirm IFT74 as a BBS gene and encourage diagnostic genetic testing laboratories to add IFT74 to their BBS gene panels.
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26
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Yang H, Huang K. Dissecting the Vesicular Trafficking Function of IFT Subunits. Front Cell Dev Biol 2020; 7:352. [PMID: 32010685 PMCID: PMC6974671 DOI: 10.3389/fcell.2019.00352] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2019] [Accepted: 12/05/2019] [Indexed: 12/22/2022] Open
Abstract
Intraflagellar transport (IFT) was initially identified as a transport machine with multiple protein subunits, and it is essential for the assembly, disassembly, and maintenance of cilium/flagellum, which serves as the nexus of extracellular-to-intracellular signal integration. To date, in addition to its well-established and indispensable roles in ciliated cells, most IFT subunits have presented more general functions of vesicular trafficking in the non-ciliated cells. Thus, this review aims to summarize the recent progress on the vesicular trafficking functions of the IFT subunits and to highlight the issues that may arise in future research.
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Affiliation(s)
- Huihui Yang
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China.,Institute of Hydrobiology, University of Chinese Academy of Sciences, Beijing, China
| | - Kaiyao Huang
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, China
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27
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Singh SK, Gui M, Koh F, Yip MC, Brown A. Structure and activation mechanism of the BBSome membrane protein trafficking complex. eLife 2020; 9:53322. [PMID: 31939736 PMCID: PMC7018513 DOI: 10.7554/elife.53322] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Accepted: 01/06/2020] [Indexed: 12/19/2022] Open
Abstract
Bardet-Biedl syndrome (BBS) is a currently incurable ciliopathy caused by the failure to correctly establish or maintain cilia-dependent signaling pathways. Eight proteins associated with BBS assemble into the BBSome, a key regulator of the ciliary membrane proteome. We report the electron cryomicroscopy (cryo-EM) structures of the native bovine BBSome in inactive and active states at 3.1 and 3.5 Å resolution, respectively. In the active state, the BBSome is bound to an Arf-family GTPase (ARL6/BBS3) that recruits the BBSome to ciliary membranes. ARL6 recognizes a composite binding site formed by BBS1 and BBS7 that is occluded in the inactive state. Activation requires an unexpected swiveling of the β-propeller domain of BBS1, the subunit most frequently implicated in substrate recognition, which widens a central cavity of the BBSome. Structural mapping of disease-causing mutations suggests that pathogenesis results from folding defects and the disruption of autoinhibition and activation.
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Affiliation(s)
- Sandeep K Singh
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, United States
| | - Miao Gui
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, United States
| | - Fujiet Koh
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, United States
| | - Matthew Cj Yip
- Department of Cell Biology, Blavatnik Institute, Harvard Medical School, Boston, United States
| | - Alan Brown
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, United States
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28
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Zhang L, Zhen J, Huang Q, Liu H, Li W, Zhang S, Min J, Li Y, Shi L, Woods J, Chen X, Shi Y, Liu Y, Hess RA, Song S, Zhang Z. Mouse spermatogenesis-associated protein 1 (SPATA1), an IFT20 binding partner, is an acrosomal protein. Dev Dyn 2020; 249:543-555. [PMID: 31816150 DOI: 10.1002/dvdy.141] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Revised: 11/16/2019] [Accepted: 11/18/2019] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND Intraflagellar transport is a motor-driven trafficking system that is required for the formation of cilia. Intraflagellar transport protein 20 (IFT20) is a master regulator for the control of spermatogenesis and male fertility in mice. However, the mechanism of how IFT20 regulates spermatogenesis is unknown. RESULTS Spermatogenesis associated 1 (SPATA1) was identified to be a major potential binding partner of IFT20 by a yeast two-hybrid screening. The interaction between SPATA1 and IFT20 was examined by direct yeast two-hybrid, co-localization, and co-immunoprecipitation assays. SPATA1 is highly abundant in the mouse testis, and is also expressed in the heart and kidney. During the first wave of spermatogenesis, SPATA1 is detectable at postnatal day 24 and its expression is increased at day 30 and 35. Immunofluorescence staining of mouse testis sections and epididymal sperm demonstrated that SPATA1 is localized mainly in the acrosome of developing spermatids but not in epididymal sperm. IFT20 is also present in the acrosome area of round spermatids. In conditional Ift20 knockout mice, testicular expression level and acrosomal localization of SPATA1 are not changed. CONCLUSIONS SPATA1 is an IFT20 binding protein and may provide a docking site for IFT20 complex binding to the acrosome area.
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Affiliation(s)
- Ling Zhang
- Department of Occupational and Environmental Health, Hubei Province Key Laboratory of Occupational Hazard Identification and Control, School of Public Health, Wuhan University of Science and Technology, Wuhan, China
| | - Jingkai Zhen
- Department of Occupational and Environmental Health, Hubei Province Key Laboratory of Occupational Hazard Identification and Control, School of Public Health, Wuhan University of Science and Technology, Wuhan, China
| | - Qian Huang
- Department of Occupational and Environmental Health, Hubei Province Key Laboratory of Occupational Hazard Identification and Control, School of Public Health, Wuhan University of Science and Technology, Wuhan, China.,Department of Physiology, Wayne State University, Detroit, Michigan
| | - Hong Liu
- Department of Occupational and Environmental Health, Hubei Province Key Laboratory of Occupational Hazard Identification and Control, School of Public Health, Wuhan University of Science and Technology, Wuhan, China.,Department of Physiology, Wayne State University, Detroit, Michigan
| | - Wei Li
- Department of Physiology, Wayne State University, Detroit, Michigan
| | - Shiyang Zhang
- Department of Occupational and Environmental Health, Hubei Province Key Laboratory of Occupational Hazard Identification and Control, School of Public Health, Wuhan University of Science and Technology, Wuhan, China.,Department of Physiology, Wayne State University, Detroit, Michigan
| | - Jie Min
- Department of Occupational and Environmental Health, Hubei Province Key Laboratory of Occupational Hazard Identification and Control, School of Public Health, Wuhan University of Science and Technology, Wuhan, China
| | - Yuhong Li
- Department of Occupational and Environmental Health, Hubei Province Key Laboratory of Occupational Hazard Identification and Control, School of Public Health, Wuhan University of Science and Technology, Wuhan, China.,Department of Physiology, Wayne State University, Detroit, Michigan
| | - Lin Shi
- Department of Occupational and Environmental Health, Hubei Province Key Laboratory of Occupational Hazard Identification and Control, School of Public Health, Wuhan University of Science and Technology, Wuhan, China.,Department of Physiology, Wayne State University, Detroit, Michigan
| | - James Woods
- Department of Physiology, Wayne State University, Detroit, Michigan
| | - Xuequn Chen
- Department of Physiology, Wayne State University, Detroit, Michigan
| | - Yuqin Shi
- Department of Occupational and Environmental Health, Hubei Province Key Laboratory of Occupational Hazard Identification and Control, School of Public Health, Wuhan University of Science and Technology, Wuhan, China
| | - Yunhao Liu
- Department of Occupational and Environmental Health, Hubei Province Key Laboratory of Occupational Hazard Identification and Control, School of Public Health, Wuhan University of Science and Technology, Wuhan, China
| | - Rex A Hess
- Department of Comparative Biosciences, College of Veterinary Medicine, University of Illinois, Urbana, Illinois
| | - Shizhen Song
- Department of Occupational and Environmental Health, Hubei Province Key Laboratory of Occupational Hazard Identification and Control, School of Public Health, Wuhan University of Science and Technology, Wuhan, China
| | - Zhibing Zhang
- Department of Physiology, Wayne State University, Detroit, Michigan.,Department of Obstetrics and Gynecology, Wayne State University, Detroit, Michigan
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29
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A novel missense variant in the BBS7 gene underlying Bardet-Biedl syndrome in a consanguineous Pakistani family. Clin Dysmorphol 2020; 29:17-23. [DOI: 10.1097/mcd.0000000000000294] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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30
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Pazour GJ, Quarmby L, Smith AO, Desai PB, Schmidts M. Cilia in cystic kidney and other diseases. Cell Signal 2019; 69:109519. [PMID: 31881326 DOI: 10.1016/j.cellsig.2019.109519] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Revised: 12/21/2019] [Accepted: 12/21/2019] [Indexed: 12/23/2022]
Abstract
Epithelial cells lining the ducts and tubules of the kidney nephron and collecting duct have a single non-motile cilium projecting from their surface into the lumen of the tubule. These organelles were long considered vestigial remnants left as a result of evolution from a ciliated ancestor, but we now recognize them as critical sensory antennae. In the kidney, the polycystins and fibrocystin, products of the major human polycystic kidney disease genes, localize to this organelle. The polycystins and fibrocystin, through an unknown mechanism, monitor the diameter of the kidney tubules and regulate the proliferation and differentiation of the cells lining the tubule. When the polycystins, fibrocystin or cilia themselves are defective, the cell perceives this as a pro-proliferative signal, which leads to tubule dilation and cystic disease. In addition to critical roles in preventing cyst formation in the kidney, cilia are also important in cystic and fibrotic diseases of the liver and pancreas, and ciliary defects lead to a variety of developmental abnormalities that cause structural birth defects in most organs.
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Affiliation(s)
- Gregory J Pazour
- Program in Molecular Medicine, University of Massachusetts Medical School, Biotech II, Suite 213, 373 Plantation Street, Worcester, MA 01605, United States of America.
| | - Lynne Quarmby
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada.
| | - Abigail O Smith
- Program in Molecular Medicine, University of Massachusetts Medical School, Biotech II, Suite 213, 373 Plantation Street, Worcester, MA 01605, United States of America
| | - Paurav B Desai
- Program in Molecular Medicine, University of Massachusetts Medical School, Biotech II, Suite 213, 373 Plantation Street, Worcester, MA 01605, United States of America
| | - Miriam Schmidts
- Center for Pediatrics and Adolescent Medicine, University Hospital Freiburg, Freiburg University Faculty of Medicine, Mathildenstrasse 1, 79112 Freiburg, Germany.
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31
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Jaffal L, Joumaa WH, Assi A, Helou C, Cherfan G, Zibara K, Audo I, Zeitz C, El Shamieh S. Next Generation Sequencing Identifies Five Novel Mutations in Lebanese Patients with Bardet-Biedl and Usher Syndromes. Genes (Basel) 2019; 10:genes10121047. [PMID: 31888296 PMCID: PMC6947157 DOI: 10.3390/genes10121047] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 12/10/2019] [Accepted: 12/10/2019] [Indexed: 01/15/2023] Open
Abstract
AIM To identify disease-causing mutations in four Lebanese families: three families with Bardet-Biedl and one family with Usher syndrome (BBS and USH respectively), using next generation sequencing (NGS). METHODS We applied targeted NGS in two families and whole exome sequencing (WES) in two other families. Pathogenicity of candidate mutations was evaluated according to frequency, conservation, in silico prediction tools, segregation with disease, and compatibility with inheritance pattern. The presence of pathogenic variants was confirmed via Sanger sequencing followed by segregation analysis. RESULTS Most likely disease-causing mutations were identified in all included patients. In BBS patients, we found (M1): c.2258A > T, p. (Glu753Val) in BBS9, (M2): c.68T > C; p. (Leu23Pro) in ARL6, (M3): c.265_266delTT; p. (Leu89Valfs*11) and (M4): c.880T > G; p. (Tyr294Asp) in BBS12. A previously known variant (M5): c.551A > G; p. (Asp184Ser) was also detected in BBS5. In the USH patient, we found (M6): c.188A > C, p. (Tyr63Ser) in CLRN1. M2, M3, M4, and M6 were novel. All of the candidate mutations were shown to be likely disease-causing through our bioinformatic analysis. They also segregated with the corresponding phenotype in available family members. CONCLUSION This study expanded the mutational spectrum and showed the genetic diversity of BBS and USH. It also spotlighted the efficiency of NGS techniques in revealing mutations underlying clinically and genetically heterogeneous disorders.
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Affiliation(s)
- Lama Jaffal
- Department of Biological and Environmental Sciences, Faculty of Science, Beirut Arab University, Debbieh 1107 2809, Lebanon;
| | - Wissam H Joumaa
- Rammal Hassan Rammal Research Laboratory, Physiotoxicity (PhyTox), Faculty of Sciences, Lebanese University, Nabatieh 1700, Lebanon;
| | - Alexandre Assi
- Retinal Service, Beirut Eye & ENT Specialist Hospital, Beirut 1106, Lebanon; (A.A.); (C.H.); (G.C.)
| | - Charles Helou
- Retinal Service, Beirut Eye & ENT Specialist Hospital, Beirut 1106, Lebanon; (A.A.); (C.H.); (G.C.)
| | - George Cherfan
- Retinal Service, Beirut Eye & ENT Specialist Hospital, Beirut 1106, Lebanon; (A.A.); (C.H.); (G.C.)
| | - Kazem Zibara
- ER045, PRASE, DSST, Lebanese University, Beirut 1700, Lebanon;
- Biology Department, Faculty of Sciences-I, Lebanese University, Beirut 1700, Lebanon
| | - Isabelle Audo
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 75012 Paris, France; (I.A.); (C.Z.)
- CHNO des Quinze-Vingts, INSERM-DGOS CIC1423, 75012 Paris, France
- University College London Institute of Ophthalmology, London EC1V 9EL, UK
| | - Christina Zeitz
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 75012 Paris, France; (I.A.); (C.Z.)
| | - Said El Shamieh
- Rammal Hassan Rammal Research Laboratory, Physiotoxicity (PhyTox), Faculty of Sciences, Lebanese University, Nabatieh 1700, Lebanon;
- Department of Medical Laboratory Technology, Faculty of Health Sciences, Beirut Arab University, Beirut 1107 2809, Lebanon
- Correspondence:
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32
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Pruski M, Hu L, Yang C, Wang Y, Zhang JB, Zhang L, Huang Y, Rajnicek AM, St Clair D, McCaig CD, Lang B, Ding YQ. Roles for IFT172 and Primary Cilia in Cell Migration, Cell Division, and Neocortex Development. Front Cell Dev Biol 2019; 7:287. [PMID: 31850339 PMCID: PMC6890611 DOI: 10.3389/fcell.2019.00287] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Accepted: 11/04/2019] [Indexed: 12/25/2022] Open
Abstract
The cilium of a cell translates varied extracellular cues into intracellular signals that control embryonic development and organ function. The dynamic maintenance of ciliary structure and function requires balanced bidirectional cargo transport involving intraflagellar transport (IFT) complexes. IFT172 is a member of the IFT complex B, and IFT172 mutation is associated with pathologies including short rib thoracic dysplasia, retinitis pigmentosa and Bardet-Biedl syndrome, but how it underpins these conditions is not clear. We used the WIM cell line, derived from embryonic fibroblasts of Wimple mice (carrying homozygous Leu1564Pro mutation in Ift172), to probe roles of Ift172 and primary cilia in cell behavior. WIM cells had ablated cilia and deficiencies in directed migration (electrotaxis), cell proliferation and intracellular signaling. Additionally, WIM cells displayed altered cell cycle progression, with increased numbers of chromatids, highlighting dysfunctional centrosome status. Exposure to a physiological electric field promoted a higher percentage of primary cilia in wild-type cells. Interestingly, in situ hybridization revealed an extensive and dynamic expression profile of Ift172 in both developing and adult mouse cortex. In vivo manipulation of Ift172 expression in germinal regions of embryonic mouse brains perturbed neural progenitor proliferation and radial migration of post-mitotic neurons, revealing a regulatory role of Ift172 in cerebral morphogenesis. Our data suggest that Ift172 regulates a range of fundamental biological processes, highlighting the pivotal roles of the primary cilium in cell physiology and brain development.
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Affiliation(s)
- Michal Pruski
- Department of Psychiatry, The Second Xiangya Hospital, Central South University, Changsha, China.,National Clinical Research Center for Mental Disorders, Changsha, China.,State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, China.,Key Laboratory of Arrhythmias, Ministry of Education, East Hospital, Department of Anatomy and Neurobiology, Collaborative Innovation Centre for Brain Science, Tongji University School of Medicine, Shanghai, China.,School of Medicine, Medical Sciences and Nutrition, Institute of Medical Sciences, University of Aberdeen, Aberdeen, United Kingdom
| | - Ling Hu
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, China.,School of Medicine, Medical Sciences and Nutrition, Institute of Medical Sciences, University of Aberdeen, Aberdeen, United Kingdom
| | - Cuiping Yang
- Key Laboratory of Arrhythmias, Ministry of Education, East Hospital, Department of Anatomy and Neurobiology, Collaborative Innovation Centre for Brain Science, Tongji University School of Medicine, Shanghai, China
| | - Yubing Wang
- Key Laboratory of Arrhythmias, Ministry of Education, East Hospital, Department of Anatomy and Neurobiology, Collaborative Innovation Centre for Brain Science, Tongji University School of Medicine, Shanghai, China
| | - Jin-Bao Zhang
- Department of Histology and Embryology, Institute of Neuroscience, Wenzhou Medical University, Wenzhou, China
| | - Lei Zhang
- Key Laboratory of Arrhythmias, Ministry of Education, East Hospital, Department of Anatomy and Neurobiology, Collaborative Innovation Centre for Brain Science, Tongji University School of Medicine, Shanghai, China.,School of Medicine, Medical Sciences and Nutrition, Institute of Medical Sciences, University of Aberdeen, Aberdeen, United Kingdom
| | - Ying Huang
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, China.,Key Laboratory of Arrhythmias, Ministry of Education, East Hospital, Department of Anatomy and Neurobiology, Collaborative Innovation Centre for Brain Science, Tongji University School of Medicine, Shanghai, China.,School of Medicine, Medical Sciences and Nutrition, Institute of Medical Sciences, University of Aberdeen, Aberdeen, United Kingdom
| | - Ann M Rajnicek
- School of Medicine, Medical Sciences and Nutrition, Institute of Medical Sciences, University of Aberdeen, Aberdeen, United Kingdom
| | - David St Clair
- School of Medicine, Medical Sciences and Nutrition, Institute of Medical Sciences, University of Aberdeen, Aberdeen, United Kingdom
| | - Colin D McCaig
- School of Medicine, Medical Sciences and Nutrition, Institute of Medical Sciences, University of Aberdeen, Aberdeen, United Kingdom
| | - Bing Lang
- Department of Psychiatry, The Second Xiangya Hospital, Central South University, Changsha, China.,National Clinical Research Center for Mental Disorders, Changsha, China.,School of Medicine, Medical Sciences and Nutrition, Institute of Medical Sciences, University of Aberdeen, Aberdeen, United Kingdom
| | - Yu-Qiang Ding
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, China.,Key Laboratory of Arrhythmias, Ministry of Education, East Hospital, Department of Anatomy and Neurobiology, Collaborative Innovation Centre for Brain Science, Tongji University School of Medicine, Shanghai, China
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33
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Yamada M, Uehara T, Suzuki H, Takenouchi T, Fukushima H, Morisada N, Tominaga K, Onoda M, Kosaki K. IFT172 as the 19th gene causative of oral-facial-digital syndrome. Am J Med Genet A 2019; 179:2510-2513. [PMID: 31587445 DOI: 10.1002/ajmg.a.61373] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Revised: 08/27/2019] [Accepted: 09/11/2019] [Indexed: 02/05/2023]
Affiliation(s)
- Mamiko Yamada
- Center for Medical Genetics, Keio University School of Medicine, Tokyo, Japan
| | - Tomoko Uehara
- Center for Medical Genetics, Keio University School of Medicine, Tokyo, Japan
| | - Hisato Suzuki
- Center for Medical Genetics, Keio University School of Medicine, Tokyo, Japan
| | - Toshiki Takenouchi
- Department of Pediatrics, Keio University School of Medicine, Tokyo, Japan
| | - Hiroyuki Fukushima
- Department of Pediatrics, Tokyo Dental College Ichikawa General Hospital, Chiba, Japan
| | - Naoya Morisada
- Department of Clinical Genetics, Hyogo Prefectural Kobe Children's Hospital, Kobe, Hyogo, Japan
| | - Kenta Tominaga
- Department of Cardiology, Hyogo Prefectural Kobe Children's Hospital, Kobe, Hyogo, Japan
| | - Motohiro Onoda
- Department of Plastic Surgery, Hyogo Prefectural Kobe Children's Hospital, Kobe, Hyogo, Japan
| | - Kenjiro Kosaki
- Center for Medical Genetics, Keio University School of Medicine, Tokyo, Japan
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34
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Niederlova V, Modrak M, Tsyklauri O, Huranova M, Stepanek O. Meta-analysis of genotype-phenotype associations in Bardet-Biedl syndrome uncovers differences among causative genes. Hum Mutat 2019; 40:2068-2087. [PMID: 31283077 DOI: 10.1002/humu.23862] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Revised: 06/17/2019] [Accepted: 07/03/2019] [Indexed: 12/16/2022]
Abstract
Bardet-Biedl syndrome (BBS) is a recessive genetic disease causing multiple organ anomalies. Most patients carry mutations in genes encoding for the subunits of the BBSome, an octameric ciliary transport complex, or accessory proteins involved in the BBSome assembly or function. BBS proteins have been extensively studied using in vitro, cellular, and animal models. However, the molecular functions of particular BBS proteins and the etiology of the BBS symptoms are still largely elusive. In this study, we applied a meta-analysis approach to study the genotype-phenotype association in humans using our database of all reported BBS patients. The analysis revealed that the identity of the causative gene and the character of the mutation partially predict the clinical outcome of the disease. Besides their potential use for clinical prognosis, our analysis revealed functional differences of particular BBS genes in humans. Core BBSome subunits BBS2, BBS7, and BBS9 manifest as more critical for the function and development of kidneys than peripheral subunits BBS1, BBS4, and BBS8/TTC8, suggesting that incomplete BBSome retains residual function at least in the kidney.
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Affiliation(s)
- Veronika Niederlova
- Laboratory of Adaptive Immunity, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Martin Modrak
- Institute of Microbiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Oksana Tsyklauri
- Laboratory of Adaptive Immunity, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Martina Huranova
- Laboratory of Adaptive Immunity, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
| | - Ondrej Stepanek
- Laboratory of Adaptive Immunity, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czech Republic
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35
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Abstract
Rods and cones are retinal photoreceptor neurons required for our visual sensation. Because of their highly polarized structures and well-characterized processes of G protein-coupled receptor-mediated phototransduction signaling, these photoreceptors have been excellent models for studying the compartmentalization and sorting of proteins. Rods and cones have a modified ciliary compartment called the outer segment (OS) as well as non-OS compartments. The distinct membrane protein compositions between OS and non-OS compartments suggest that the OS is separated from the rest of the cellular compartments by multiple barriers or gates that are selectively permissive to specific cargoes. This review discusses the mechanisms of protein sorting and compartmentalization in photoreceptor neurons. Proper sorting and compartmentalization of membrane proteins are required for signal transduction and transmission. This review also discusses the roles of compartmentalized signaling, which is compromised in various retinal ciliopathies.
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Affiliation(s)
- Yoshikazu Imanishi
- Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, Ohio 44106, USA;
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36
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Pruski M, Lang B. Primary Cilia-An Underexplored Topic in Major Mental Illness. Front Psychiatry 2019; 10:104. [PMID: 30886591 PMCID: PMC6409319 DOI: 10.3389/fpsyt.2019.00104] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Accepted: 02/12/2019] [Indexed: 12/20/2022] Open
Abstract
Though much progress has been made in recent years towards understanding the function and physiology of primary cilia, they remain a somewhat elusive organelle. Some studies have explored the role of primary cilia in the developing nervous system, and their dysfunction has been linked with several neurosensory deficits. Yet, very little has been written on their potential role in psychiatric disorders. This article provides an overview of some of the functions of primary cilia in signalling pathways, and demonstrates that they are a worthy candidate in psychiatric research. The links between primary cilia and major mental illness have been demonstrated to exist at several levels, spanning genetics, signalling pathways, and pharmacology as well as cell division and migration. The primary focus of this review is on the sensory role of the primary cilium and the neurodevelopmental hypothesis of psychiatric disease. As such, the primary cilium is demonstrated to be a key link between the cellular environment and cell behaviour, and hence of key importance in the considerations of the nature and nurture debate in psychiatric research.
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Affiliation(s)
- Michal Pruski
- Department of Psychiatry, The Second Xiangya Hospital, Central South University, Changsha, China
- Critical Care Laboratory, Critical Care Directorate, Manchester Royal Infirmary, Manchester University NHS Foundation Trust, Manchester, United Kingdom
- School of Healthcare Science, Faculty of Science and Engineering, Manchester Metropolitan University, Manchester, United Kingdom
| | - Bing Lang
- Department of Psychiatry, The Second Xiangya Hospital, Central South University, Changsha, China
- School of Medicine, Medical Sciences and Nutrition, Institute of Medical Sciences, University of Aberdeen, Aberdeen, United Kingdom
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37
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Tam V, Turcotte M, Meyre D. Established and emerging strategies to crack the genetic code of obesity. Obes Rev 2019; 20:212-240. [PMID: 30353704 DOI: 10.1111/obr.12770] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Revised: 08/27/2018] [Accepted: 08/28/2018] [Indexed: 12/11/2022]
Abstract
Tremendous progress has been made in the genetic elucidation of obesity over the past two decades, driven largely by technological, methodological and organizational innovations. Current strategies for identifying obesity-predisposing loci/genes, including cytogenetics, linkage analysis, homozygosity mapping, admixture mapping, candidate gene studies, genome-wide association studies, custom genotyping arrays, whole-exome sequencing and targeted exome sequencing, have achieved differing levels of success, and the identified loci in aggregate explain only a modest fraction of the estimated heritability of obesity. This review outlines the successes and limitations of these approaches and proposes novel strategies, including the use of exceptionally large sample sizes, the study of diverse ethnic groups and deep phenotypes and the application of innovative methods and study designs, to identify the remaining obesity-predisposing genes. The use of both established and emerging strategies has the potential to crack the genetic code of obesity in the not-too-distant future. The resulting knowledge is likely to yield improvements in obesity prediction, prevention and care.
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Affiliation(s)
- V Tam
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, ON, Canada
| | - M Turcotte
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, ON, Canada
| | - D Meyre
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, ON, Canada.,Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada
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38
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Schaefer E, Delvallée C, Mary L, Stoetzel C, Geoffroy V, Marks-Delesalle C, Holder-Espinasse M, Ghoumid J, Dollfus H, Muller J. Identification and Characterization of Known Biallelic Mutations in the IFT27 ( BBS19) Gene in a Novel Family With Bardet-Biedl Syndrome. Front Genet 2019; 10:21. [PMID: 30761183 PMCID: PMC6363664 DOI: 10.3389/fgene.2019.00021] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Accepted: 01/15/2019] [Indexed: 12/30/2022] Open
Abstract
Bardet-Biedl syndrome (BBS; MIM 209900) is a rare ciliopathy characterized by retinitis pigmentosa, postaxial polydactyly, obesity, hypogonadism, cognitive impairment and kidney dysfunction. Mutations in 22 BBS genes have been identified to cause the disease. We report a family with typical BBS features (retinitis pigmentosa, postaxial polydactyly, obesity, cognitive impairment, and atrioventricular septal defect) mutated in IFT27/BBS19. IFT27 is part of the Intraflagellar transport (IFT), a bidirectional mechanism allowing the protein motility within the cilia. Using whole exome sequencing, two compound heterozygous mutations were found in the proband (NM_006860.4:c.[104A > G];[349+1G > T], p.[Tyr35Cys];[?]) consistent with the expected autosomal recessive inheritance mode. These two mutations have already been reported but independently in other families and lacking either familial segregation or functional validation. This is the third report of IFT27 mutations in BBS patients confirming IFT27 as a BBS gene (BBS19). Mutations in IFT genes (IFT27, IFT172 and IFT74) confirm the IFT-pathway as a pathomechanism for BBS.
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Affiliation(s)
- Elise Schaefer
- Laboratoire de Génétique Médicale, Institut de Génétique Médicale d'Alsace, INSERM U1112, Fédération de Médecine Translationnelle de Strasbourg, Université de Strasbourg, Strasbourg, France.,Service de Génétique Médicale, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Clarisse Delvallée
- Laboratoire de Génétique Médicale, Institut de Génétique Médicale d'Alsace, INSERM U1112, Fédération de Médecine Translationnelle de Strasbourg, Université de Strasbourg, Strasbourg, France
| | - Laura Mary
- Laboratoire de Diagnostic Génétique, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Corinne Stoetzel
- Laboratoire de Génétique Médicale, Institut de Génétique Médicale d'Alsace, INSERM U1112, Fédération de Médecine Translationnelle de Strasbourg, Université de Strasbourg, Strasbourg, France
| | - Véronique Geoffroy
- Laboratoire de Génétique Médicale, Institut de Génétique Médicale d'Alsace, INSERM U1112, Fédération de Médecine Translationnelle de Strasbourg, Université de Strasbourg, Strasbourg, France
| | - Caroline Marks-Delesalle
- Service d'Exploration de la Vision et Neuro-Ophtalmologie, Hôpital Roger Salengro, CHRU Lille, Lille, France
| | | | - Jamal Ghoumid
- Service de Génétique Clinique, Hôpital Jeanne de Flandre, CHRU Lille, Lille, France
| | - Hélène Dollfus
- Laboratoire de Génétique Médicale, Institut de Génétique Médicale d'Alsace, INSERM U1112, Fédération de Médecine Translationnelle de Strasbourg, Université de Strasbourg, Strasbourg, France.,Service de Génétique Médicale, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Jean Muller
- Laboratoire de Génétique Médicale, Institut de Génétique Médicale d'Alsace, INSERM U1112, Fédération de Médecine Translationnelle de Strasbourg, Université de Strasbourg, Strasbourg, France.,Laboratoire de Diagnostic Génétique, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
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39
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Chandrasekar SP, Namboothiri S, Sen P, Sarangapani S. Screening for mutation hotspots in Bardet-Biedl syndrome patients from India. Indian J Med Res 2018; 147:177-182. [PMID: 29806606 PMCID: PMC5991121 DOI: 10.4103/ijmr.ijmr_1822_15] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Background & objectives: Bardet–Biedl syndrome (BBS) is a genetically heterogeneous autosomal recessive disorder characterized by multiple organ defects involving retina, kidney, liver and brain. Disease-causing mutations in BBS genes narrowed down by homozygosity mapping in small consanguineous and non-consanguineous pedigrees were reported in 80 per cent of the study population. This study was aimed to screen these genes (BBS3, BBS10) and specific exons of BBS genes (BBS1, BBS5, MKKS, BBS9, BBS11 and BBS12) for recurrent mutations in a selected sample of BBS patients. Methods: The recurrent mutations in BBS genes were screened in the BBS affected individuals by PCR based direct sequencing. The pathogenicity of the observed mutations were confirmed by co-segregation analysis, screening of healthy unrelated controls and in silico analysis. Results: In the 64 BBS patients (44 males, 20 females) were studied, mutations were predominant in BBS10 and ARL6 genes; the c.272T>C; p.(I91T) mutation in ARL6 gene was a recurrent mutation. One novel non-sense mutation c.425T>G; p(L142*) was obtained in BBS5 gene (family BSI-31). Interpretation & conclusions: BBS10 gene mutations clustered in exon 2 of the gene suggesting the exon as a probable hotspot for mutations in Indian population. A cost- and time-effective strategy for the molecular diagnosis of BBS was designed based on these results.
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Affiliation(s)
- Sathya Priya Chandrasekar
- SN ONGC Department of Genetics & Molecular Biology, Vision Research Foundation, Chennai; School of Chemical & Biotechnology, SASTRA University, Thanjavur, India
| | - Sheela Namboothiri
- Department of Paediatric Genetics, Amrita Institute of Medical Sciences & Research Centre, Kochi, India
| | - Parveen Sen
- Department of Vitreo Retina Clinic, Medical Research Foundation, Chennai, India
| | - Sripriya Sarangapani
- SN ONGC Department of Genetics & Molecular Biology, Vision Research Foundation, Chennai, India
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40
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The complexity of the cilium: spatiotemporal diversity of an ancient organelle. Curr Opin Cell Biol 2018; 55:139-149. [PMID: 30138887 DOI: 10.1016/j.ceb.2018.08.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 07/31/2018] [Accepted: 08/02/2018] [Indexed: 02/06/2023]
Abstract
Cilia are microtubule-based appendages present on almost all vertebrate cell types where they mediate a myriad of cellular processes critical for development and homeostasis. In humans, impaired ciliary function is associated with an ever-expanding repertoire of phenotypically-overlapping yet highly variable genetic disorders, the ciliopathies. Extensive work to elucidate the structure, function, and composition of the cilium is offering hints that the `static' representation of the cilium is a gross oversimplification of a highly dynamic organelle whose functions are choreographed dynamically across cell types, developmental, and homeostatic contexts. Understanding this diversity will require discerning ciliary versus non-ciliary roles for classically-defined `ciliary' proteins; defining ciliary protein-protein interaction networks within and beyond the cilium; and resolving the spatiotemporal diversity of ciliary structure and function. Here, focusing on one evolutionarily conserved ciliary module, the intraflagellar transport system, we explore these ideas and propose potential future studies that will improve our knowledge gaps of the oversimplified cilium and, by extension, inform the reasons that underscore the striking range of clinical pathologies associated with ciliary dysfunction.
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41
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Gupta PR, Pendse N, Greenwald SH, Leon M, Liu Q, Pierce EA, Bujakowska KM. Ift172 conditional knock-out mice exhibit rapid retinal degeneration and protein trafficking defects. Hum Mol Genet 2018; 27:2012-2024. [PMID: 29659833 PMCID: PMC5961092 DOI: 10.1093/hmg/ddy109] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Revised: 03/19/2018] [Accepted: 03/26/2018] [Indexed: 01/01/2023] Open
Abstract
Intraflagellar transport (IFT) is a bidirectional transport process that occurs along primary cilia and specialized sensory cilia, such as photoreceptor outersegments. Genes coding for various IFT components are associated with ciliopathies. Mutations in IFT172 lead to diseases ranging from isolated retinal degeneration to severe syndromic ciliopathies. In this study, we created a mouse model of IFT172-associated retinal degeneration to investigate the ocular disease mechanism. We found that depletion of IFT172 in rod photoreceptors leads to a rapid degeneration of the retina, with severely reduced electroretinography (ERG) responses by 1 month and complete outer-nuclear layer (ONL) degeneration by 2 months. We investigated molecular mechanisms of degeneration and show that IFT172 protein reduction leads to mislocalization of specific photoreceptor outersegment (OS) proteins (RHO, RP1, IFT139), aberrant light-driven translocation of alpha transducin and altered localization of glioma-associated oncogene family member 1 (GLI1). This mouse model exhibits key features of the retinal phenotype observed in patients with IFT172-associated blindness and can be used for in vivo testing of ciliopathy therapies.
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Affiliation(s)
- Priya R Gupta
- Department of Ophthalmology, Ocular Genomics Institute, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA 02114, USA
- Weill Cornell Medical College, New York, NY 10021, USA
| | - Nachiket Pendse
- Department of Ophthalmology, Ocular Genomics Institute, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA 02114, USA
| | - Scott H Greenwald
- Department of Ophthalmology, Ocular Genomics Institute, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA 02114, USA
| | - Mihoko Leon
- Department of Ophthalmology, Ocular Genomics Institute, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA 02114, USA
| | - Qin Liu
- Department of Ophthalmology, Ocular Genomics Institute, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA 02114, USA
| | - Eric A Pierce
- Department of Ophthalmology, Ocular Genomics Institute, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA 02114, USA
| | - Kinga M Bujakowska
- Department of Ophthalmology, Ocular Genomics Institute, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA 02114, USA
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42
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Geoffroy V, Stoetzel C, Scheidecker S, Schaefer E, Perrault I, Bär S, Kröll A, Delbarre M, Antin M, Leuvrey AS, Henry C, Blanché H, Decker E, Kloth K, Klaus G, Mache C, Martin-Coignard D, McGinn S, Boland A, Deleuze JF, Friant S, Saunier S, Rozet JM, Bergmann C, Dollfus H, Muller J. Whole-genome sequencing in patients with ciliopathies uncovers a novel recurrent tandem duplication in IFT140. Hum Mutat 2018; 39:983-992. [PMID: 29688594 DOI: 10.1002/humu.23539] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Revised: 04/10/2018] [Accepted: 04/16/2018] [Indexed: 12/30/2022]
Abstract
Ciliopathies represent a wide spectrum of rare diseases with overlapping phenotypes and a high genetic heterogeneity. Among those, IFT140 is implicated in a variety of phenotypes ranging from isolated retinis pigmentosa to more syndromic cases. Using whole-genome sequencing in patients with uncharacterized ciliopathies, we identified a novel recurrent tandem duplication of exon 27-30 (6.7 kb) in IFT140, c.3454-488_4182+2588dup p.(Tyr1152_Thr1394dup), missed by whole-exome sequencing. Pathogenicity of the mutation was assessed on the patients' skin fibroblasts. Several hundreds of patients with a ciliopathy phenotype were screened and biallelic mutations were identified in 11 families representing 12 pathogenic variants of which seven are novel. Among those unrelated families especially with a Mainzer-Saldino syndrome, eight carried the same tandem duplication (two at the homozygous state and six at the heterozygous state). In conclusion, we demonstrated the implication of structural variations in IFT140-related diseases expanding its mutation spectrum. We also provide evidences for a unique genomic event mediated by an Alu-Alu recombination occurring on a shared haplotype. We confirm that whole-genome sequencing can be instrumental in the ability to detect structural variants for genomic disorders.
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Affiliation(s)
- Véronique Geoffroy
- Laboratoire de Génétique médicale, UMR_S INSERM U1112, IGMA, Faculté de Médecine FMTS, Université de Strasbourg, Strasbourg, France
| | - Corinne Stoetzel
- Laboratoire de Génétique médicale, UMR_S INSERM U1112, IGMA, Faculté de Médecine FMTS, Université de Strasbourg, Strasbourg, France
| | - Sophie Scheidecker
- Laboratoire de Génétique médicale, UMR_S INSERM U1112, IGMA, Faculté de Médecine FMTS, Université de Strasbourg, Strasbourg, France.,Laboratoires de Diagnostic Génétique, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Elise Schaefer
- Laboratoire de Génétique médicale, UMR_S INSERM U1112, IGMA, Faculté de Médecine FMTS, Université de Strasbourg, Strasbourg, France.,Service de Génétique Médicale, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Isabelle Perrault
- Laboratory of Genetics in Ophthalmology (LGO), INSERM UMR1163, Institute of Genetic Diseases, Imagine, Paris Descartes University, Paris, France
| | - Séverine Bär
- Department of Molecular and Cellular Genetics, UMR7156, Centre National de Recherche Scientifique (CNRS), Université de Strasbourg, Strasbourg, France
| | - Ariane Kröll
- Laboratoire de Génétique médicale, UMR_S INSERM U1112, IGMA, Faculté de Médecine FMTS, Université de Strasbourg, Strasbourg, France
| | - Marion Delbarre
- Laboratoires de Diagnostic Génétique, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Manuela Antin
- Laboratoires de Diagnostic Génétique, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Anne-Sophie Leuvrey
- Laboratoires de Diagnostic Génétique, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | | | - Hélène Blanché
- Centre d'études du polymorphisme humain-Fondation Jean Dausset, Paris, France
| | - Eva Decker
- Center for Human Genetics, Bioscientia, Ingelheim, Germany
| | - Katja Kloth
- Institut für Humangenetik, Universitätsklinikum Hamburg-Eppendorf, Hamburg, Germany
| | - Günter Klaus
- University Marburg, KfH-Nierenzentrum für Kinder und Jugendliche, Marburg, Germany
| | - Christoph Mache
- Department of Pediatrics, Medical University of Graz, Graz, Austria
| | | | - Steven McGinn
- CNRGH, Institut de Biologie François Jacob, DRF, CEA, Evry, France
| | - Anne Boland
- CNRGH, Institut de Biologie François Jacob, DRF, CEA, Evry, France
| | - Jean-François Deleuze
- Centre d'études du polymorphisme humain-Fondation Jean Dausset, Paris, France.,CNRGH, Institut de Biologie François Jacob, DRF, CEA, Evry, France
| | - Sylvie Friant
- Department of Molecular and Cellular Genetics, UMR7156, Centre National de Recherche Scientifique (CNRS), Université de Strasbourg, Strasbourg, France
| | | | - Jean-Michel Rozet
- Laboratory of Genetics in Ophthalmology (LGO), INSERM UMR1163, Institute of Genetic Diseases, Imagine, Paris Descartes University, Paris, France
| | - Carsten Bergmann
- Center for Human Genetics, Bioscientia, Ingelheim, Germany.,Department of Medicine, University Hospital Freiburg, Freiburg, Germany
| | - Hélène Dollfus
- Laboratoire de Génétique médicale, UMR_S INSERM U1112, IGMA, Faculté de Médecine FMTS, Université de Strasbourg, Strasbourg, France.,Centre de Référence pour les affections rares en génétique ophtalmologique, CARGO, Filière SENSGENE, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Jean Muller
- Laboratoire de Génétique médicale, UMR_S INSERM U1112, IGMA, Faculté de Médecine FMTS, Université de Strasbourg, Strasbourg, France.,Laboratoires de Diagnostic Génétique, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
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43
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Quélin C, Loget P, Boutaud L, Elkhartoufi N, Milon J, Odent S, Fradin M, Demurger F, Pasquier L, Thomas S, Attié-Bitach T. Loss of function IFT27 variants associated with an unclassified lethal fetal ciliopathy with renal agenesis. Am J Med Genet A 2018; 176:1610-1613. [PMID: 29704304 DOI: 10.1002/ajmg.a.38685] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 02/18/2018] [Accepted: 02/27/2018] [Indexed: 11/06/2022]
Abstract
Ciliopathies comprise a group of clinically heterogeneous and overlapping disorders with a wide spectrum of phenotypes ranging from prenatal lethality to adult-onset disorders. Pathogenic variants in more than 100 ciliary protein-encoding genes have been described, most notably those involved in intraflagellar transport (IFT) which comprises two protein complexes, responsible for retrograde (IFT-A) and anterograde transport (IFT-B). Here we describe a fetus with an unclassified severe ciliopathy phenotype including short ribs, polydactyly, bilateral renal agenesis, and imperforate anus, with compound heterozygosity for c.118_125del, p.(Thr40Glyfs*11) and a c.352 +1G > T in IFT27, which encodes a small GTPase component of the IFT-B complex. We conclude that bilateral renal agenesis is a rare feature of this severe ciliopathy and this report highlights the phenotypic overlap of Pallister-Hall syndrome and ciliopathies. The phenotype in patients with IFT27 gene variants is wide ranging from Bardet-Biedl syndrome to a lethal phenotype.
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Affiliation(s)
- Chloé Quélin
- Service de Génétique Clinique, Centre de Référence Maladies Rares CLAD-Ouest, CHU Hôpital Sud, Rennes, France
| | - Philippe Loget
- Service d'Anatomopathologie, CHU Pontchaillou, Rennes, France
| | - Lucile Boutaud
- Unité d'Embryofoetopathologie, Service d'Histologie-Embryologie-Cytogénétique, Hôpital Necker-Enfants Malades, Assistance Publique - Hôpitaux de Paris (AP-HP), Paris, France.,Inserm U1163, Université Paris Descartes - Sorbonne Paris Cité, Institut Imagine, Paris, France
| | - Nadia Elkhartoufi
- Unité d'Embryofoetopathologie, Service d'Histologie-Embryologie-Cytogénétique, Hôpital Necker-Enfants Malades, Assistance Publique - Hôpitaux de Paris (AP-HP), Paris, France
| | - Joelle Milon
- Pôle d'imagerie médicale, CHU Hôpital Sud, Rennes, France
| | - Sylvie Odent
- Service de Génétique Clinique, Centre de Référence Maladies Rares CLAD-Ouest, CHU Hôpital Sud, Rennes, France
| | - Mélanie Fradin
- Service de Génétique Clinique, Centre de Référence Maladies Rares CLAD-Ouest, CHU Hôpital Sud, Rennes, France
| | - Florence Demurger
- Service de Génétique Clinique, Centre de Référence Maladies Rares CLAD-Ouest, CHU Hôpital Sud, Rennes, France
| | - Laurent Pasquier
- Service de Génétique Clinique, Centre de Référence Maladies Rares CLAD-Ouest, CHU Hôpital Sud, Rennes, France
| | - Sophie Thomas
- Inserm U1163, Université Paris Descartes - Sorbonne Paris Cité, Institut Imagine, Paris, France
| | - Tania Attié-Bitach
- Unité d'Embryofoetopathologie, Service d'Histologie-Embryologie-Cytogénétique, Hôpital Necker-Enfants Malades, Assistance Publique - Hôpitaux de Paris (AP-HP), Paris, France.,Inserm U1163, Université Paris Descartes - Sorbonne Paris Cité, Institut Imagine, Paris, France
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44
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Assaying sensory ciliopathies using calcium biosensor expression in zebrafish ciliated olfactory neurons. Cilia 2018; 7:2. [PMID: 29568513 PMCID: PMC5856005 DOI: 10.1186/s13630-018-0056-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Accepted: 02/22/2018] [Indexed: 12/12/2022] Open
Abstract
Background Primary cilia mediate signal transduction by acting as an organizing scaffold for receptors, signalling proteins and ion channels. Ciliated olfactory sensory neurons (OSNs) organize olfactory receptors and ion channels on cilia and generate a calcium influx as a primary signal in odourant detection. In the zebrafish olfactory placode, ciliated OSNs and microvillus OSNs constitute the major OSN cell types with distinct odourant sensitivity. Methods Using transgenic expression of the calcium biosensor GCaMP5 in OSNs, we analysed sensory cilia-dependent odour responses in live zebrafish, at individual cell resolution. oval/ift88 mutant and ift172 knockdown zebrafish were compared with wild-type siblings to establish ciliated OSN sensitivity to different classes of odourants. Results oval/ift88 mutant and ift172 knockdown zebrafish showed fewer and severely shortened OSN cilia without a reduction in OSN number. The fraction of responding OSNs and response amplitudes to bile acids and food odour, both sensed by ciliated OSNs, were significantly reduced in ift88 mutants and ift172-deficient embryos, while the amino acids responses were not significantly changed. Conclusions Our approach presents a quantitative model for studying sensory cilia signalling using zebrafish OSNs. Our results also implicate ift172-deficiency as a novel cause of hyposmia, a reduced sense of smell, highlighting the value of directly assaying sensory cilia signalling in vivo and supporting the idea that hyposmia can be used as a diagnostic indicator of ciliopathies. Electronic supplementary material The online version of this article (10.1186/s13630-018-0056-1) contains supplementary material, which is available to authorized users.
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Forsythe E, Kenny J, Bacchelli C, Beales PL. Managing Bardet-Biedl Syndrome-Now and in the Future. Front Pediatr 2018; 6:23. [PMID: 29487844 PMCID: PMC5816783 DOI: 10.3389/fped.2018.00023] [Citation(s) in RCA: 112] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Accepted: 01/25/2018] [Indexed: 11/13/2022] Open
Abstract
Bardet-Biedl syndrome is a rare autosomal recessive multisystem disorder caused by defects in genes encoding for proteins that localize to the primary cilium/basal body complex. Twenty-one disease-causing genes have been identified to date. It is one of the most well-studied conditions in the family of diseases caused by defective cilia collectively known as ciliopathies. In this review, we provide an update on diagnostic developments, clinical features, and progress in the management of Bardet-Biedl syndrome. Advances in diagnostic technologies including exome and whole genome sequencing are expanding the spectrum of patients who are diagnosed with Bardet-Biedl syndrome and increasing the number of cases with diagnostic uncertainty. As a result of the diagnostic developments, a small number of patients with only one or two clinical features of Bardet-Biedl syndrome are being diagnosed. Our understanding of the syndrome-associated renal disease has evolved and is reviewed here. Novel interventions are developing at a rapid pace and are explored in this review including genetic therapeutics such as gene therapy, exon skipping therapy, nonsense suppression therapy, and gene editing. Other non-genetic therapies such as gene repurposing, targeted therapies, and non-pharmacological interventions are also discussed.
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Affiliation(s)
- Elizabeth Forsythe
- Genetics and Genomic Medicine Programme, UCL Great Ormond Street Institute of Child Health, University College London, London, United Kingdom
| | - Joanna Kenny
- Genetics and Genomic Medicine Programme, UCL Great Ormond Street Institute of Child Health, University College London, London, United Kingdom
| | - Chiara Bacchelli
- Genetics and Genomic Medicine Programme, UCL Great Ormond Street Institute of Child Health, University College London, London, United Kingdom
| | - Philip L Beales
- Genetics and Genomic Medicine Programme, UCL Great Ormond Street Institute of Child Health, University College London, London, United Kingdom
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46
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Stryjecki C, Alyass A, Meyre D. Ethnic and population differences in the genetic predisposition to human obesity. Obes Rev 2018; 19:62-80. [PMID: 29024387 DOI: 10.1111/obr.12604] [Citation(s) in RCA: 87] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Revised: 06/17/2017] [Accepted: 08/02/2017] [Indexed: 12/22/2022]
Abstract
Obesity rates have escalated to the point of a global pandemic with varying prevalence across ethnic groups. These differences are partially explained by lifestyle factors in addition to genetic predisposition to obesity. This review provides a comprehensive examination of the ethnic differences in the genetic architecture of obesity. Using examples from evolution, heritability, admixture, monogenic and polygenic studies of obesity, we provide explanations for ethnic differences in the prevalence of obesity. The debate over definitions of race and ethnicity, the advantages and limitations of multi-ethnic studies and future directions of research are also discussed. Multi-ethnic studies have great potential to provide a better understanding of ethnic differences in the prevalence of obesity that may result in more targeted and personalized obesity treatments.
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Affiliation(s)
- C Stryjecki
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, ON, Canada
| | - A Alyass
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, ON, Canada
| | - D Meyre
- Department of Health Research Methods, Evidence, and Impact, McMaster University, Hamilton, ON, Canada.,Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada
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47
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Gehrig J, Pandey G, Westhoff JH. Zebrafish as a Model for Drug Screening in Genetic Kidney Diseases. Front Pediatr 2018; 6:183. [PMID: 30003073 PMCID: PMC6031734 DOI: 10.3389/fped.2018.00183] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Accepted: 06/04/2018] [Indexed: 12/17/2022] Open
Abstract
Genetic disorders account for a wide range of renal diseases emerging during childhood and adolescence. Due to the utilization of modern biochemical and biomedical techniques, the number of identified disease-associated genes is increasing rapidly. Modeling of congenital human disease in animals is key to our understanding of the biological mechanism underlying pathological processes and thus developing novel potential treatment options. The zebrafish (Danio rerio) has been established as a versatile small vertebrate organism that is widely used for studying human inherited diseases. Genetic accessibility in combination with elegant experimental methods in zebrafish permit modeling of human genetic diseases and dissecting the perturbation of underlying cellular networks and physiological processes. Beyond its utility for genetic analysis and pathophysiological and mechanistic studies, zebrafish embryos, and larvae are amenable for phenotypic screening approaches employing high-content and high-throughput experiments using automated microscopy. This includes large-scale chemical screening experiments using genetic models for searching for disease-modulating compounds. Phenotype-based approaches of drug discovery have been successfully performed in diverse zebrafish-based screening applications with various phenotypic readouts. As a result, these can lead to the identification of candidate substances that are further examined in preclinical and clinical trials. In this review, we discuss zebrafish models for inherited kidney disease as well as requirements and considerations for the technical realization of drug screening experiments in zebrafish.
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Affiliation(s)
- Jochen Gehrig
- Acquifer is a Division of Ditabis, Digital Biomedical Imaging Systems AG, Pforzheim, Germany
| | - Gunjan Pandey
- Acquifer is a Division of Ditabis, Digital Biomedical Imaging Systems AG, Pforzheim, Germany.,Department of Pediatrics I, University Children's Hospital Heidelberg, Heidelberg, Germany
| | - Jens H Westhoff
- Department of Pediatrics I, University Children's Hospital Heidelberg, Heidelberg, Germany
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Chacón-Camacho OF, García-Montaño LA, Zenteno JC. The clinical implications of molecular monitoring and analyses of inherited retinal diseases. Expert Rev Mol Diagn 2017; 17:1009-1021. [DOI: 10.1080/14737159.2017.1384314] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Oscar F. Chacón-Camacho
- Genetics Department-research Unit, Institute of Ophthalmology ‘Conde de Valenciana’, Mexico City, Mexico
| | - Leopoldo A. García-Montaño
- Genetics Department-research Unit, Institute of Ophthalmology ‘Conde de Valenciana’, Mexico City, Mexico
| | - Juan C Zenteno
- Genetics Department-research Unit, Institute of Ophthalmology ‘Conde de Valenciana’, Mexico City, Mexico
- Biochemistry Department, Faculty of Medicine, UNAM, Mexico City, Mexico
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49
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Kenny J, Forsythe E, Beales P, Bacchelli C. Toward personalized medicine in Bardet–Biedl syndrome. Per Med 2017; 14:447-456. [DOI: 10.2217/pme-2017-0019] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Personalized medicine is becoming routine in the treatment of common diseases such as cancer, but has lagged behind in the field of rare diseases. It is currently in the early stages for the treatment of Bardet–Biedl syndrome. Advances in the understanding of ciliary biology and diagnostic techniques have opened up the prospect of treating BBS in a patient-specific manner. Owing to their structure and function, cilia provide an attractive therapeutic target and genetic therapies are being explored in ciliopathy treatment. Promising avenues include gene therapy, gene editing techniques and splice-correcting and read-through therapies. Targeted drug design has been successful in the treatment of genetic disease and research is underway in the discovery of known and novel drugs to treat Bardet–Biedl syndrome.
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Affiliation(s)
- Joanna Kenny
- NIHR Great Ormond Street Hospital Biomedical Research Centre, UCL Great Ormond Street Institute of Child Health, 30 Guildford St, London WC1N 1EH, UK
| | - Elizabeth Forsythe
- NIHR Great Ormond Street Hospital Biomedical Research Centre, UCL Great Ormond Street Institute of Child Health, 30 Guildford St, London WC1N 1EH, UK
| | - Philip Beales
- NIHR Great Ormond Street Hospital Biomedical Research Centre, UCL Great Ormond Street Institute of Child Health, 30 Guildford St, London WC1N 1EH, UK
| | - Chiara Bacchelli
- NIHR Great Ormond Street Hospital Biomedical Research Centre, UCL Great Ormond Street Institute of Child Health, 30 Guildford St, London WC1N 1EH, UK
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50
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Prieto-Echagüe V, Lodh S, Colman L, Bobba N, Santos L, Katsanis N, Escande C, Zaghloul NA, Badano JL. BBS4 regulates the expression and secretion of FSTL1, a protein that participates in ciliogenesis and the differentiation of 3T3-L1. Sci Rep 2017; 7:9765. [PMID: 28852127 PMCID: PMC5575278 DOI: 10.1038/s41598-017-10330-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Accepted: 08/08/2017] [Indexed: 01/01/2023] Open
Abstract
Bardet-Biedl syndrome is a model ciliopathy. Although the characterization of BBS proteins has evidenced their involvement in cilia, extraciliary functions for some of these proteins are also being recognized. Importantly, understanding both cilia and cilia-independent functions of the BBS proteins is key to fully dissect the cellular basis of the syndrome. Here we characterize a functional interaction between BBS4 and the secreted protein FSTL1, a protein linked to adipogenesis and inflammation among other functions. We show that BBS4 and cilia regulate FSTL1 mRNA levels, but BBS4 also modulates FSTL1 secretion. Moreover, we show that FSTL1 is a novel regulator of ciliogenesis thus underscoring a regulatory loop between FSTL1 and cilia. Finally, our data indicate that BBS4, cilia and FSTL1 are coordinated during the differentiation of 3T3-L1 cells and that FSTL1 plays a role in this process, at least in part, by modulating ciliogenesis. Therefore, our findings are relevant to fully understand the development of BBS-associated phenotypes such as obesity.
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Affiliation(s)
- Victoria Prieto-Echagüe
- Human Molecular Genetics Laboratory, Institut Pasteur de Montevideo, Mataojo 2020, Montevideo, CP11400, Uruguay.,INDICyO Institutional Program, Institut Pasteur de Montevideo, Mataojo 2020, Montevideo, CP11400, Uruguay
| | - Sukanya Lodh
- Division of Endocrinology, Diabetes, and Nutrition, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Laura Colman
- INDICyO Institutional Program, Institut Pasteur de Montevideo, Mataojo 2020, Montevideo, CP11400, Uruguay.,Metabolic Diseases and Aging Laboratory, Institut Pasteur de Montevideo, Mataojo 2020, Montevideo, CP11400, Uruguay
| | - Natalia Bobba
- INDICyO Institutional Program, Institut Pasteur de Montevideo, Mataojo 2020, Montevideo, CP11400, Uruguay.,Metabolic Diseases and Aging Laboratory, Institut Pasteur de Montevideo, Mataojo 2020, Montevideo, CP11400, Uruguay
| | - Leonardo Santos
- INDICyO Institutional Program, Institut Pasteur de Montevideo, Mataojo 2020, Montevideo, CP11400, Uruguay.,Metabolic Diseases and Aging Laboratory, Institut Pasteur de Montevideo, Mataojo 2020, Montevideo, CP11400, Uruguay
| | - Nicholas Katsanis
- Department of Cell Biology and Center for Human Disease Modeling, Duke University Medical Center, Durham, NC, 27710, USA
| | - Carlos Escande
- INDICyO Institutional Program, Institut Pasteur de Montevideo, Mataojo 2020, Montevideo, CP11400, Uruguay.,Metabolic Diseases and Aging Laboratory, Institut Pasteur de Montevideo, Mataojo 2020, Montevideo, CP11400, Uruguay
| | - Norann A Zaghloul
- Division of Endocrinology, Diabetes, and Nutrition, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Jose L Badano
- Human Molecular Genetics Laboratory, Institut Pasteur de Montevideo, Mataojo 2020, Montevideo, CP11400, Uruguay. .,INDICyO Institutional Program, Institut Pasteur de Montevideo, Mataojo 2020, Montevideo, CP11400, Uruguay.
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