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Han S, Hu Y, Jia D, Lv Y, Liu M, Wang D, Chao J, Xia X, Wang Q, Liu P, Cai Y, Ren X. IFT27 regulates the long-term maintenance of photoreceptor outer segments in zebrafish. Gene 2024; 905:148237. [PMID: 38310983 DOI: 10.1016/j.gene.2024.148237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 01/22/2024] [Accepted: 01/30/2024] [Indexed: 02/06/2024]
Abstract
Approximately a quarter of Retinitis Pigmentosa (RP) is caused by mutations in transport-related genes in cilia. IFT27 (Intraflagellar Transport 27), a core component of the ciliary intraflagellar transport (IFT) system, has been implicated as a significant pathogenic gene in RP. The pathogenic mechanisms and subsequent pathology related to IFT27 mutations in RP are largely obscure. Here, we utilized TALEN technology to create an ift27 knockout (ift27-/-) zebrafish model. Electroretinography (ERG) detection showed impaired vision in this model. Histopathological examinations disclosed that ift27 mutations cause progressive degeneration of photoreceptors in zebrafish, and this degeneration was late-onset. Immunofluorescence labeling of outer segments showed that rods degenerated before cones, aligning with the conventional characterization of RP. In cultured human retinal pigment epithelial cells, we found that IFT27 was involved in maintaining ciliary morphology. Furthermore, decreased IFT27 expression resulted in the inhibition of the Hedgehog (Hh) signaling pathway, including decreased expression of key factors in the Hh pathway and abnormal localization of the ciliary mediator Gli2. In summary, we generated an ift27-/- zebrafish line with retinal degeneration which mimicked the symptoms of RP patients, highlighting IFT27's integral role in the long-term maintenance of cilia via the Hh signaling pathway. This work may furnish new insights into the treatment or delay of RP caused by IFT27 mutations.
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Affiliation(s)
- Shanshan Han
- Hubei Key Laboratory of Tumor Microenvironment and Immunotherapy, China Three Gorges University, Yichang 443002, Hubei, China; College of Basic Medical Sciences, China Three Gorges University, Yichang 443002, Hubei, China.
| | - Yue Hu
- Hubei Key Laboratory of Tumor Microenvironment and Immunotherapy, China Three Gorges University, Yichang 443002, Hubei, China; College of Basic Medical Sciences, China Three Gorges University, Yichang 443002, Hubei, China
| | - Danna Jia
- Shanxi Bethune Hospital, Shanxi Academy of Medical Sciences, Tongji Shanxi Hospital, Third Hospital of Shanxi Medical University, Taiyuan, 030032, China
| | - Yuexia Lv
- Prenatal Diagnosis Center, The Third Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450052, China
| | - Mugen Liu
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Decheng Wang
- Hubei Key Laboratory of Tumor Microenvironment and Immunotherapy, China Three Gorges University, Yichang 443002, Hubei, China; College of Basic Medical Sciences, China Three Gorges University, Yichang 443002, Hubei, China
| | - Jin Chao
- Hubei Key Laboratory of Tumor Microenvironment and Immunotherapy, China Three Gorges University, Yichang 443002, Hubei, China; College of Basic Medical Sciences, China Three Gorges University, Yichang 443002, Hubei, China
| | - Xuan Xia
- Hubei Key Laboratory of Tumor Microenvironment and Immunotherapy, China Three Gorges University, Yichang 443002, Hubei, China; College of Basic Medical Sciences, China Three Gorges University, Yichang 443002, Hubei, China
| | - Qiong Wang
- Hubei Key Laboratory of Tumor Microenvironment and Immunotherapy, China Three Gorges University, Yichang 443002, Hubei, China; College of Basic Medical Sciences, China Three Gorges University, Yichang 443002, Hubei, China
| | - Pei Liu
- Hubei Key Laboratory of Tumor Microenvironment and Immunotherapy, China Three Gorges University, Yichang 443002, Hubei, China; College of Basic Medical Sciences, China Three Gorges University, Yichang 443002, Hubei, China
| | - Yu Cai
- Hubei Key Laboratory of Tumor Microenvironment and Immunotherapy, China Three Gorges University, Yichang 443002, Hubei, China; College of Basic Medical Sciences, China Three Gorges University, Yichang 443002, Hubei, China
| | - Xiang Ren
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, China.
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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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Rouabhi Y, Guo DF, Zhao Y, Rahmouni K. Metabolic consequences of skeletal muscle- and liver-specific BBSome deficiency. Am J Physiol Endocrinol Metab 2023; 325:E711-E722. [PMID: 37909854 PMCID: PMC10864019 DOI: 10.1152/ajpendo.00174.2023] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 10/04/2023] [Accepted: 10/19/2023] [Indexed: 11/03/2023]
Abstract
The BBSome is a protein complex composed of eight Bardet-Biedl syndrome (BBS) proteins including BBS1. Humans and mice lacking a functional BBSome display obesity and type 2 diabetes, highlighting the importance of this protein complex for metabolic regulation. However, the contribution of the BBSome in insulin-sensitive tissues such as skeletal muscle and liver to metabolic regulation is ill-defined. Here, we show that disruption of the BBSome through Bbs1 gene deletion in the skeletal muscle had no effect on body weight or glucose handling, but improved insulin sensitivity of female mice without changing insulin receptor signaling. Interestingly, when fed an obesogenic diet, male mice lacking the Bbs1 gene in skeletal muscle exhibited heightened insulin sensitivity despite the comparable weight gain and glucose tolerance relative to controls. On the other hand, normal chow-fed mice missing the Bbs1 gene in hepatocytes displayed increased body weight, as well as impaired glucose handling and insulin sensitivity. This was associated with attenuated insulin signaling in liver and hepatocytes, but not skeletal muscle and white adipose tissue. Moreover, hepatocytes lacking the Bbs1 gene displayed significant reduction in plasma membrane insulin receptor levels due to the mitochondrial dysfunction evoked by loss of the BBSome. Together, these findings demonstrate that myocyte BBSome is minimally involved in metabolic regulation, whereas the hepatic BBSome plays a critical role in the control of energy homeostasis and insulin sensitivity through its requirement for insulin receptor trafficking.NEW & NOTEWORTHY The ongoing epidemic of obesity and associated illnesses highlights the need to understand the biological processes that regulate energy balance. Here, we identified an important role for a protein complex called BBSome in the control of hepatic function. We show that the liver BBSome is necessary to maintain body weight and blood glucose levels due to its requirements to generate energy and detect insulin, a hormone that is essential for metabolic regulation.
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Affiliation(s)
- Younes Rouabhi
- Department of Neuroscience and Pharmacology, University of Iowa Carver College of Medicine, Iowa City, Iowa, United States
| | - Deng-Fu Guo
- Department of Neuroscience and Pharmacology, University of Iowa Carver College of Medicine, Iowa City, Iowa, United States
- Veterans Affairs Health Care System, Iowa City, Iowa, United States
| | - Yuying Zhao
- Department of Neuroscience and Pharmacology, University of Iowa Carver College of Medicine, Iowa City, Iowa, United States
| | - Kamal Rahmouni
- Department of Neuroscience and Pharmacology, University of Iowa Carver College of Medicine, Iowa City, Iowa, United States
- Veterans Affairs Health Care System, Iowa City, Iowa, United States
- Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, Iowa, United States
- Fraternal Order of Eagles Diabetes Research Center, University of Iowa Carver College of Medicine, Iowa City, Iowa, United States
- Obesity Research and Education Initiative, University of Iowa Carver College of Medicine, Iowa City, Iowa, United States
- Iowa Neuroscience Institute, University of Iowa Carver College of Medicine, Iowa City, Iowa, United States
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4
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Fassad MR, Rumman N, Junger K, Patel MP, Thompson J, Goggin P, Ueffing M, Beyer T, Boldt K, Lucas JS, Mitchison HM. Defective airway intraflagellar transport underlies a combined motile and primary ciliopathy syndrome caused by IFT74 mutations. Hum Mol Genet 2023; 32:3090-3104. [PMID: 37555648 PMCID: PMC10586200 DOI: 10.1093/hmg/ddad132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 08/01/2023] [Indexed: 08/10/2023] Open
Abstract
Ciliopathies are inherited disorders caused by defective cilia. Mutations affecting motile cilia usually cause the chronic muco-obstructive sinopulmonary disease primary ciliary dyskinesia (PCD) and are associated with laterality defects, while a broad spectrum of early developmental as well as degenerative syndromes arise from mutations affecting signalling of primary (non-motile) cilia. Cilia assembly and functioning requires intraflagellar transport (IFT) of cargos assisted by IFT-B and IFT-A adaptor complexes. Within IFT-B, the N-termini of partner proteins IFT74 and IFT81 govern tubulin transport to build the ciliary microtubular cytoskeleton. We detected a homozygous 3-kb intragenic IFT74 deletion removing the exon 2 initiation codon and 40 N-terminal amino acids in two affected siblings. Both had clinical features of PCD with bronchiectasis, but no laterality defects. They also had retinal dysplasia and abnormal bone growth, with a narrowed thorax and short ribs, shortened long bones and digits, and abnormal skull shape. This resembles short-rib thoracic dysplasia, a skeletal ciliopathy previously linked to IFT defects in primary cilia, not motile cilia. Ciliated nasal epithelial cells collected from affected individuals had reduced numbers of shortened motile cilia with disarranged microtubules, some misorientation of the basal feet, and disrupted cilia structural and IFT protein distributions. No full-length IFT74 was expressed, only truncated forms that were consistent with N-terminal deletion and inframe translation from downstream initiation codons. In affinity purification mass spectrometry, exon 2-deleted IFT74 initiated from the nearest inframe downstream methionine 41 still interacts as part of the IFT-B complex, but only with reduced interaction levels and not with all its usual IFT-B partners. We propose that this is a hypomorphic mutation with some residual protein function retained, which gives rise to a primary skeletal ciliopathy combined with defective motile cilia and PCD.
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Affiliation(s)
- Mahmoud R Fassad
- Genetics and Genomic Medicine Research and Teaching Department, University College London, UCL Great Ormond Street Institute of Child Health, 30 Guilford Street, London WC1N 1EH, United Kingdom
- Department of Human Genetics, Medical Research Institute, Alexandria University, 22 El-Guish Road, El-Shatby, Alexandria 21526, Egypt
| | - Nisreen Rumman
- Department of Pediatrics, Faculty of Medicine, Makassed Hospital and Al-Quds University, East Jerusalem 91220, Palestine
- Section of Pulmonary, Critical Care and Sleep Medicine, Department of Internal Medicine, Yale University School of Medicine, 300 Cedar St #441, New Haven, CT 06520, United States
| | - Katrin Junger
- Institute for Ophthalmic Research, Eberhard Karl University of Tübingen, Elfreide-Alhorn-Strasse 5-7, Tübingen 72076, Germany
| | - Mitali P Patel
- Genetics and Genomic Medicine Research and Teaching Department, University College London, UCL Great Ormond Street Institute of Child Health, 30 Guilford Street, London WC1N 1EH, United Kingdom
- MRC Prion Unit at UCL, Institute of Prion Diseases, University College London, 33 Cleveland Street, London W1W 7FF, United Kingdom
| | - James Thompson
- Primary Ciliary Dyskinesia Centre, NIHR Biomedical Research Centre, University Hospital Southampton NHS Foundation Trust, Southampton SO16 6YD, United Kingdom
- School of Clinical and Experimental Sciences, University of Southampton Faculty of Medicine, University Road, Southampton SO17 1BJ, United Kingdom
- Biomedical Imaging Unit, University of Southampton Faculty of Medicine, University Road, Southampton SO17 1BJ, United Kingdom
| | - Patricia Goggin
- Primary Ciliary Dyskinesia Centre, NIHR Biomedical Research Centre, University Hospital Southampton NHS Foundation Trust, Southampton SO16 6YD, United Kingdom
- Biomedical Imaging Unit, University of Southampton Faculty of Medicine, University Road, Southampton SO17 1BJ, United Kingdom
| | - Marius Ueffing
- Institute for Ophthalmic Research, Eberhard Karl University of Tübingen, Elfreide-Alhorn-Strasse 5-7, Tübingen 72076, Germany
| | - Tina Beyer
- Institute for Ophthalmic Research, Eberhard Karl University of Tübingen, Elfreide-Alhorn-Strasse 5-7, Tübingen 72076, Germany
| | - Karsten Boldt
- Institute for Ophthalmic Research, Eberhard Karl University of Tübingen, Elfreide-Alhorn-Strasse 5-7, Tübingen 72076, Germany
| | - Jane S Lucas
- Primary Ciliary Dyskinesia Centre, NIHR Biomedical Research Centre, University Hospital Southampton NHS Foundation Trust, Southampton SO16 6YD, United Kingdom
- School of Clinical and Experimental Sciences, University of Southampton Faculty of Medicine, University Road, Southampton SO17 1BJ, United Kingdom
| | - Hannah M Mitchison
- Genetics and Genomic Medicine Research and Teaching Department, University College London, UCL Great Ormond Street Institute of Child Health, 30 Guilford Street, London WC1N 1EH, United Kingdom
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5
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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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6
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Zhang RK, Sun WY, Liu YX, Zhang EY, Fan ZC. RABL2 promotes the outward transition zone passage of signaling proteins in cilia via ARL3. Proc Natl Acad Sci U S A 2023; 120:e2302603120. [PMID: 37579161 PMCID: PMC10450674 DOI: 10.1073/pnas.2302603120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Accepted: 07/10/2023] [Indexed: 08/16/2023] Open
Abstract
Certain transmembrane and membrane-tethered signaling proteins export from cilia as BBSome cargoes via the outward BBSome transition zone (TZ) diffusion pathway, indispensable for maintaining their ciliary dynamics to enable cells to sense and transduce extracellular stimuli inside the cell. Murine Rab-like 2 (Rabl2) GTPase resembles Chlamydomonas Arf-like 3 (ARL3) GTPase in promoting outward TZ passage of the signaling protein cargo-laden BBSome. During this process, ARL3 binds to and recruits the retrograde IFT train-dissociated BBSome as its effector to diffuse through the TZ for ciliary retrieval, while how RABL2 and ARL3 cross talk in this event remains uncertain. Here, we report that Chlamydomonas RABL2 in a GTP-bound form (RABL2GTP) cycles through cilia via IFT as an IFT-B1 cargo, dissociates from retrograde IFT trains at a ciliary region right above the TZ, and converts to RABL2GDP for activating ARL3GDP as an ARL3 guanine nucleotide exchange factor. This confers ARL3GTP to detach from the ciliary membrane and become available for binding and recruiting the phospholipase D (PLD)-laden BBSome, autonomous of retrograde IFT association, to diffuse through the TZ for ciliary retrieval. Afterward, RABL2GDP exits cilia by being bound to the ARL3GTP/BBSome entity as a BBSome cargo. Our data identify ciliary signaling proteins exported from cilia via the RABL2-ARL3 cascade-mediated outward BBSome TZ diffusion pathway. According to this model, hedgehog signaling defect-induced Bardet-Biedl syndrome caused by RABL2 mutations in humans could be well explained in a mutation-specific manner, providing us with a mechanistic understanding behind the outward BBSome TZ passage required for proper ciliary signaling.
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Affiliation(s)
- Rui-Kai Zhang
- State Key Laboratory of Food Nutrition and Safety, Institute of Health Biotechnology, Tianjin University of Science and Technology, Tianjin300457, China
| | - Wei-Yue Sun
- State Key Laboratory of Food Nutrition and Safety, Institute of Health Biotechnology, Tianjin University of Science and Technology, Tianjin300457, China
| | - Yan-Xia Liu
- State Key Laboratory of Food Nutrition and Safety, Institute of Health Biotechnology, Tianjin University of Science and Technology, Tianjin300457, China
| | | | - Zhen-Chuan Fan
- State Key Laboratory of Food Nutrition and Safety, Institute of Health Biotechnology, Tianjin University of Science and Technology, Tianjin300457, China
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7
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Bakey Z, Cabrera OA, Hoefele J, Antony D, Wu K, Stuck MW, Micha D, Eguether T, Smith AO, van der Wel NN, Wagner M, Strittmatter L, Beales PL, Jonassen JA, Thiffault I, Cadieux-Dion M, Boyes L, Sharif S, Tüysüz B, Dunstheimer D, Niessen HWM, Devine W, Lo CW, Mitchison HM, Schmidts M, Pazour GJ. IFT74 variants cause skeletal ciliopathy and motile cilia defects in mice and humans. PLoS Genet 2023; 19:e1010796. [PMID: 37315079 DOI: 10.1371/journal.pgen.1010796] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Accepted: 05/23/2023] [Indexed: 06/16/2023] Open
Abstract
Motile and non-motile cilia play critical roles in mammalian development and health. These organelles are composed of a 1000 or more unique proteins, but their assembly depends entirely on proteins synthesized in the cell body and transported into the cilium by intraflagellar transport (IFT). In mammals, malfunction of non-motile cilia due to IFT dysfunction results in complex developmental phenotypes that affect most organs. In contrast, disruption of motile cilia function causes subfertility, disruption of the left-right body axis, and recurrent airway infections with progressive lung damage. In this work, we characterize allele specific phenotypes resulting from IFT74 dysfunction in human and mice. We identified two families carrying a deletion encompassing IFT74 exon 2, the first coding exon, resulting in a protein lacking the first 40 amino acids and two individuals carrying biallelic splice site mutations. Homozygous exon 2 deletion cases presented a ciliary chondrodysplasia with narrow thorax and progressive growth retardation along with a mucociliary clearance disorder phenotype with severely shorted cilia. Splice site variants resulted in a lethal skeletal chondrodysplasia phenotype. In mice, removal of the first 40 amino acids likewise results in a motile cilia phenotype but with little effect on primary cilia structure. Mice carrying this allele are born alive but are growth restricted and developed hydrocephaly in the first month of life. In contrast, a strong, likely null, allele of Ift74 in mouse completely blocks ciliary assembly and causes severe heart defects and midgestational lethality. In vitro studies suggest that the first 40 amino acids of IFT74 are dispensable for binding of other IFT subunits but are important for tubulin binding. Higher demands on tubulin transport in motile cilia compared to primary cilia resulting from increased mechanical stress and repair needs could account for the motile cilia phenotype observed in human and mice.
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Affiliation(s)
- Zeineb Bakey
- Center for Pediatrics and Adolescent Medicine, University Hospital Freiburg, Freiburg University Faculty of Medicine, Freiburg, Germany
- Human Genetics Department, Radboud University Medical Center Nijmegen and Radboud Institute for Molecular Life Sciences (RIMLS), Nijmegen, The Netherlands
| | - Oscar A Cabrera
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Biotech II, Worcester, Massachusetts, United States of America
| | - Julia Hoefele
- Institute for Human Genetics, Technical University Munich (TUM), School of Medicine, Munich, Germany
| | - Dinu Antony
- Center for Pediatrics and Adolescent Medicine, University Hospital Freiburg, Freiburg University Faculty of Medicine, Freiburg, Germany
- Human Genetics Department, Radboud University Medical Center Nijmegen and Radboud Institute for Molecular Life Sciences (RIMLS), Nijmegen, The Netherlands
| | - Kaman Wu
- Human Genetics Department, Radboud University Medical Center Nijmegen and Radboud Institute for Molecular Life Sciences (RIMLS), Nijmegen, The Netherlands
| | - Michael W Stuck
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Biotech II, Worcester, Massachusetts, United States of America
| | - Dimitra Micha
- Department of Human Genetics, Amsterdam Movement Sciences, Amsterdam UMC, Amsterdam, The Netherlands
| | - Thibaut Eguether
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Biotech II, Worcester, Massachusetts, United States of America
| | - Abigail O Smith
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Biotech II, Worcester, Massachusetts, United States of America
| | - Nicole N van der Wel
- Electron microscopy Center Amsterdam, Department of Medical Biology, VUMC, Amsterdam, The Netherlands
| | - Matias Wagner
- Institute for Human Genetics, Technical University Munich (TUM), School of Medicine, Munich, Germany
| | - Lara Strittmatter
- Electron Microscopy Core, University of Massachusetts Chan Medical School, Worcester, Massachusetts, United States of America
| | - Philip L Beales
- Genetics and Genomic Medicine Programme, University College London, UCL Great Ormond Street Institute of Child Health, London, United Kingdom
| | - Julie A Jonassen
- Department of Microbiology and Physiological Systems, University of Massachusetts Chan Medical School, Worcester, Massachusetts, United States of America
| | - Isabelle Thiffault
- Genomic Medicine Center, Children's Mercy Hospital, Kansas City, Missouri, United States of America
| | - Maxime Cadieux-Dion
- Genomic Medicine Center, Children's Mercy Hospital, Kansas City, Missouri, United States of America
| | - Laura Boyes
- West Midlands Genomic Medicine Hub, Birmingham Women's Hospital, Birmingham, United Kingdom
| | - Saba Sharif
- West Midlands Genomic Medicine Hub, Birmingham Women's Hospital, Birmingham, United Kingdom
| | - Beyhan Tüysüz
- Department of Pediatrics, Division of Pediatric Genetics, Cerrahpasa Medical Faculty, University-Cerrahpasa, Istanbul, Turkey
| | - Desiree Dunstheimer
- Center for Pediatrics and Adolescent Medicine, University Hospital Augsburg, Augsburg, Germany
| | - Hans W M Niessen
- Department of Pathology, Amsterdam University Medical Center (AUMC), Amsterdam, The Netherlands
| | - William Devine
- Department of Developmental Biology, University of Pittsburgh, 8111 Rangos Research Center, Pittsburgh, Pennsylvania, United States of America
| | - Cecilia W Lo
- Department of Developmental Biology, University of Pittsburgh, 8111 Rangos Research Center, Pittsburgh, Pennsylvania, United States of America
| | - Hannah M Mitchison
- Genetics and Genomic Medicine Programme, University College London, UCL Great Ormond Street Institute of Child Health, London, United Kingdom
| | - Miriam Schmidts
- Center for Pediatrics and Adolescent Medicine, University Hospital Freiburg, Freiburg University Faculty of Medicine, Freiburg, Germany
- Human Genetics Department, Radboud University Medical Center Nijmegen and Radboud Institute for Molecular Life Sciences (RIMLS), Nijmegen, The Netherlands
- CIBSS-Center for Integrative Biological Signaling Studies, University of Freiburg, Freiburg, Germany
| | - Gregory J Pazour
- Program in Molecular Medicine, University of Massachusetts Chan Medical School, Biotech II, Worcester, Massachusetts, United States of America
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8
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Liu YX, Zhang RK, Fan ZC. RABL4/IFT27 in a nucleotide-independent manner promotes phospholipase D ciliary retrieval via facilitating BBSome reassembly at the ciliary tip. J Cell Physiol 2023; 238:549-565. [PMID: 36852649 DOI: 10.1002/jcp.30945] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 12/24/2022] [Accepted: 01/02/2023] [Indexed: 03/01/2023]
Abstract
Certain ciliary transmembrane and membrane-associated signaling proteins export from cilia as intraflagellar transport (IFT) cargoes in a BBSome-dependent manner. Upon reaching the ciliary tip via anterograde IFT, the BBSome disassembles before being reassembled to form an intact entity for cargo phospholipase D (PLD) coupling. During this BBSome remodeling process, Chlamydomonas Rab-like 4 GTPase IFT27, by binding its partner IFT25 to form the heterodimeric IFT25/27, is indispensable for BBSome reassembly. Here, we show that IFT27 binds IFT25 in an IFT27 nucleotide-independent manner. IFT25/27 and the IFT subcomplexes IFT-A and -B are irrelevant for maintaining the stability of one another. GTP-loading onto IFT27 enhances the IFT25/27 affinity for binding to the IFT-B subcomplex core IFT-B1 entity in cytoplasm, while GDP-bound IFT27 does not prevent IFT25/27 from entering and cycling through cilia by integrating into IFT-B1. Upon at the ciliary tip, IFT25/27 cycles on and off IFT-B1 and this process is irrelevant with the nucleotide state of IFT27. During BBSome remodeling at the ciliary tip, IFT25/27 promotes BBSome reassembly independent of IFT27 nucleotide state, making postremodeled BBSomes available for PLD to interact with. Thus, IFT25/27 facilitates BBSome-dependent PLD export from cilia via controlling availability of intact BBSomes at the ciliary tip, while IFT27 nucleotide state does not participate in this regulatory event.
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Affiliation(s)
- Yan-Xia Liu
- State Key Laboratory of Food Nutrition and Safety, Institute of Health Biotechnology, Tianjin University of Science and Technology, Tianjin, China
| | - Rui-Kai Zhang
- State Key Laboratory of Food Nutrition and Safety, Institute of Health Biotechnology, Tianjin University of Science and Technology, Tianjin, China
| | - Zhen-Chuan Fan
- State Key Laboratory of Food Nutrition and Safety, Institute of Health Biotechnology, Tianjin University of Science and Technology, Tianjin, China
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9
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Bakey Z, Cabrera OA, Hoefele J, Antony D, Wu K, Stuck MW, Micha D, Eguether T, Smith AO, van der Wel NN, Wagner M, Strittmatter L, Beales PL, Jonassen JA, Thiffault I, Cadieux-Dion M, Boyes L, Sharif S, Tüysüz B, Dunstheimer D, Niessen HW, Devine W, Lo CW, Mitchison HM, Schmidts M, Pazour GJ. IFT74 variants cause skeletal ciliopathy and motile cilia defects in mice and humans. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.02.23.23286106. [PMID: 36865301 PMCID: PMC9980244 DOI: 10.1101/2023.02.23.23286106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/27/2023]
Abstract
Motile and non-motile cilia are critical to mammalian development and health. Assembly of these organelles depends on proteins synthesized in the cell body and transported into the cilium by intraflagellar transport (IFT). A series of human and mouse IFT74 variants were studied to understand the function of this IFT subunit. Humans missing exon 2, which codes for the first 40 residues, presented an unusual combination of ciliary chondrodysplasia and mucociliary clearance disorders while individuals carrying biallelic splice site variants developed a lethal skeletal chondrodysplasia. In mice, variants thought to remove all Ift74 function, completely block ciliary assembly and result in midgestational lethality. A mouse allele that removes the first 40 amino acids, analogous to the human exon 2 deletion, results in a motile cilia phenotype with mild skeletal abnormalities. In vitro studies suggest that the first 40 amino acids of IFT74 are dispensable for binding of other IFT subunits but are important for tubulin binding. Higher demands on tubulin transport in motile cilia compared to primary cilia could account for the motile cilia phenotype observed in human and mice.
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10
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Stump M, Guo DF, Rahmouni K. T cell-specific deficiency in BBSome component BBS1 interferes with selective immune responses. Am J Physiol Regul Integr Comp Physiol 2023; 324:R161-R170. [PMID: 36534590 PMCID: PMC9844976 DOI: 10.1152/ajpregu.00243.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 12/09/2022] [Accepted: 12/09/2022] [Indexed: 12/24/2022]
Abstract
Bsardet Biedl syndrome (BBS) is a genetic condition associated with various clinical features including cutaneous disorders and certain autoimmune and inflammatory diseases pointing to a potential role of BBS proteins in the regulation of immune function. BBS1 protein, which is a key component of the BBSome, a protein complex involved in the regulation of cilia function and other cellular processes, has been implicated in the immune synapse assembly by promoting the centrosome polarization to the antigen-presenting cells. Here, we assessed the effect of disrupting the BBSome, through Bbs1 gene deletion, in T cells. Interestingly, mice lacking the Bbs1 gene specifically in T cells (T-BBS1-/-) displayed normal body weight, adiposity, and glucose handling, but have smaller spleens. However, T-BBS1-/- mice had no change in the proportion and absolute number of B cells and T cells in the spleen and lymph nodes. There was also no alteration in the CD4/CD8 lineage commitment or survival in the thymus of T-BBS1-/- mice. On the other hand, T-BBS1-/- mice treated with Imiquimod dermally exhibited a significantly higher percentage of CD3-positive splenocytes that was due to CD4 but not CD8 T cell predominance. Notably, we found that T-BBS1-/- mice had significantly decreased wound closure, an effect that was more pronounced in males indicating that the BBSome plays an important role in T cell-mediated skin repair. Together, these findings implicate the BBSome in the regulation of selective functions of T cells.
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Affiliation(s)
- Madeliene Stump
- Department of Neuroscience and Pharmacology, University of Iowa Carver College of Medicine, Iowa City, Iowa
- Physician Scientist Training Program, University of Iowa Carver College of Medicine, Iowa City, Iowa
- Department of Dermatology, University of Iowa Carver College of Medicine, Iowa City, Iowa
| | - Deng Fu Guo
- Department of Neuroscience and Pharmacology, University of Iowa Carver College of Medicine, Iowa City, Iowa
- Veterans Affairs Health Care System, Iowa City, Iowa
| | - Kamal Rahmouni
- Department of Neuroscience and Pharmacology, University of Iowa Carver College of Medicine, Iowa City, Iowa
- Veterans Affairs Health Care System, Iowa City, Iowa
- Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, Iowa
- Fraternal Order of Eagles Diabetes Research Center, University of Iowa Carver College of Medicine, Iowa City, Iowa
- Obesity Research and Education Initiative, University of Iowa Carver College of Medicine, Iowa City, Iowa
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11
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Petriman NA, Loureiro‐López M, Taschner M, Zacharia NK, Georgieva MM, Boegholm N, Wang J, Mourão A, Russell RB, Andersen JS, Lorentzen E. Biochemically validated structural model of the 15-subunit intraflagellar transport complex IFT-B. EMBO J 2022; 41:e112440. [PMID: 36354106 PMCID: PMC9753473 DOI: 10.15252/embj.2022112440] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 10/17/2022] [Accepted: 10/20/2022] [Indexed: 11/11/2022] Open
Abstract
Cilia are ubiquitous eukaryotic organelles impotant for cellular motility, signaling, and sensory reception. Cilium formation requires intraflagellar transport of structural and signaling components and involves 22 different proteins organized into intraflagellar transport (IFT) complexes IFT-A and IFT-B that are transported by molecular motors. The IFT-B complex constitutes the backbone of polymeric IFT trains carrying cargo between the cilium and the cell body. Currently, high-resolution structures are only available for smaller IFT-B subcomplexes leaving > 50% structurally uncharacterized. Here, we used Alphafold to structurally model the 15-subunit IFT-B complex. The model was validated using cross-linking/mass-spectrometry data on reconstituted IFT-B complexes, X-ray scattering in solution, diffraction from crystals as well as site-directed mutagenesis and protein-binding assays. The IFT-B structure reveals an elongated and highly flexible complex consistent with cryo-electron tomographic reconstructions of IFT trains. The IFT-B complex organizes into IFT-B1 and IFT-B2 parts with binding sites for ciliary cargo and the inactive IFT dynein motor, respectively. Interestingly, our results are consistent with two different binding sites for IFT81/74 on IFT88/70/52/46 suggesting the possibility of different structural architectures for the IFT-B1 complex. Our data present a structural framework to understand IFT-B complex assembly, function, and ciliopathy variants.
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Affiliation(s)
- Narcis A Petriman
- Department of Molecular Biology and GeneticsAarhus UniversityAarhus CDenmark
| | - Marta Loureiro‐López
- Department for Biochemistry and Molecular BiologyUniversity of Southern DenmarkOdense MDenmark
| | - Michael Taschner
- Department of Fundamental MicrobiologyUniversity of LausanneLausanneSwitzerland
| | - Nevin K Zacharia
- Department of Molecular Biology and GeneticsAarhus UniversityAarhus CDenmark
| | | | - Niels Boegholm
- Department of Molecular Biology and GeneticsAarhus UniversityAarhus CDenmark
| | - Jiaolong Wang
- Department of Molecular Biology and GeneticsAarhus UniversityAarhus CDenmark
| | - André Mourão
- Institute of Structural BiologyHelmholtz Zentrum MünchenNeuherbergGermany
| | | | - Jens S Andersen
- Department for Biochemistry and Molecular BiologyUniversity of Southern DenmarkOdense MDenmark
| | - Esben Lorentzen
- Department of Molecular Biology and GeneticsAarhus UniversityAarhus CDenmark
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12
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Yan X, Shen Y. Rab-like small GTPases in the regulation of ciliary Bardet-Biedl syndrome (BBS) complex transport. FEBS J 2022; 289:7359-7367. [PMID: 34655445 DOI: 10.1111/febs.16232] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 08/13/2021] [Accepted: 10/15/2021] [Indexed: 01/13/2023]
Abstract
Primary cilia, microtubule-based hair-like structures protruding from most cells, contain membranes enriched in signaling molecules and function as sensory and regulatory organelles critical for development and tissue homeostasis. Intraflagellar transport (IFT), cilia-specific bidirectional transport, is required for the assembly, maintenance, and function of cilia. BBSome, the coat complex, acts as the adaptor between the IFT complex and membrane proteins and is therefore essential for establishing the specific compartmentalization of signaling molecules in the cilia. Recent findings have revealed that three ciliary Rab-like small GTPases, IFT27, IFT22, and Rabl2, play critical regulatory roles in ciliary BBSome transport. In this review, we provide an overview of these three Rab-like small GTPases and their relationship with BBSome.
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Affiliation(s)
- Xiumin Yan
- Ministry of Education-Shanghai Key Laboratory of Children's Environmental Health, Institute of Early Life Health, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, China
| | - Yidong Shen
- State Key Laboratory of Cell Biology, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, Chinese Academy of Sciences, Shanghai, China
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13
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Chang KJ, Wu HY, Yarmishyn AA, Li CY, Hsiao YJ, Chi YC, Lo TC, Dai HJ, Yang YC, Liu DH, Hwang DK, Chen SJ, Hsu CC, Kao CL. Genetics behind Cerebral Disease with Ocular Comorbidity: Finding Parallels between the Brain and Eye Molecular Pathology. Int J Mol Sci 2022; 23:9707. [PMID: 36077104 PMCID: PMC9456058 DOI: 10.3390/ijms23179707] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 08/18/2022] [Accepted: 08/22/2022] [Indexed: 11/30/2022] Open
Abstract
Cerebral visual impairments (CVIs) is an umbrella term that categorizes miscellaneous visual defects with parallel genetic brain disorders. While the manifestations of CVIs are diverse and ambiguous, molecular diagnostics stand out as a powerful approach for understanding pathomechanisms in CVIs. Nevertheless, the characterization of CVI disease cohorts has been fragmented and lacks integration. By revisiting the genome-wide and phenome-wide association studies (GWAS and PheWAS), we clustered a handful of renowned CVIs into five ontology groups, namely ciliopathies (Joubert syndrome, Bardet-Biedl syndrome, Alstrom syndrome), demyelination diseases (multiple sclerosis, Alexander disease, Pelizaeus-Merzbacher disease), transcriptional deregulation diseases (Mowat-Wilson disease, Pitt-Hopkins disease, Rett syndrome, Cockayne syndrome, X-linked alpha-thalassaemia mental retardation), compromised peroxisome disorders (Zellweger spectrum disorder, Refsum disease), and channelopathies (neuromyelitis optica spectrum disorder), and reviewed several mutation hotspots currently found to be associated with the CVIs. Moreover, we discussed the common manifestations in the brain and the eye, and collated animal study findings to discuss plausible gene editing strategies for future CVI correction.
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Affiliation(s)
- Kao-Jung Chang
- School of Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan
- Institute of Clinical Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
| | - Hsin-Yu Wu
- School of Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan
| | | | - Cheng-Yi Li
- School of Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan
| | - Yu-Jer Hsiao
- School of Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan
| | - Yi-Chun Chi
- Department of Ophthalmology, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
| | - Tzu-Chen Lo
- School of Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei 11217, Taiwan
| | - He-Jhen Dai
- School of Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Department of Medical Research, Taipei Veterans General Hospital, Taipei 11217, Taiwan
| | - Yi-Chiang Yang
- Department of Physical Medicine and Rehabilitation, Taipei Veterans General Hospital, Taipei 11217, Taiwan
| | - Ding-Hao Liu
- Institute of Clinical Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Department of Physical Medicine and Rehabilitation, Taipei Veterans General Hospital, Taipei 11217, Taiwan
| | - De-Kuang Hwang
- School of Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Institute of Clinical Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Department of Ophthalmology, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
| | - Shih-Jen Chen
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei 11217, Taiwan
| | - Chih-Chien Hsu
- School of Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Institute of Clinical Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Department of Ophthalmology, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
| | - Chung-Lan Kao
- Institute of Clinical Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Department of Physical Medicine and Rehabilitation, Taipei Veterans General Hospital, Taipei 11217, Taiwan
- Department of Physical Medicine and Rehabilitation, School of Medicine, National Yang Ming Chiao Tung University, Taipei 112304, Taiwan
- Center for Intelligent Drug Systems and Smart Bio-Devices (IDS2B), National Yang Ming Chiao Tung University, Hsinchu 300093, Taiwan
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14
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Rosina E, Pezzani L, Pezzoli L, Marchetti D, Bellini M, Pilotta A, Calabrese O, Nicastro E, Cirillo F, Cereda A, Scatigno A, Milani D, Iascone M. Atypical, Composite, or Blended Phenotypes: How Different Molecular Mechanisms Could Associate in Double-Diagnosed Patients. Genes (Basel) 2022; 13:genes13071275. [PMID: 35886058 PMCID: PMC9319862 DOI: 10.3390/genes13071275] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 07/13/2022] [Accepted: 07/13/2022] [Indexed: 12/10/2022] Open
Abstract
In the last few years, trio-Whole Exome Sequencing (WES) analysis has revolutionized the diagnostic process for patients with rare genetic syndromes, demonstrating its potential even in non-specific clinical pictures and in atypical presentations of known diseases. Multiple disorders in a single patient have been estimated to occur in approximately 2–7.5% of diagnosed cases, with higher frequency in consanguineous families. Here, we report the clinical and molecular characterisation of eight illustrative patients for whom trio-WES allowed for identifing more than one genetic condition. Double homozygosity represented the causal mechanism in only half of them, whereas the other half showed peculiar multilocus combinations. The paper takes into consideration difficulties and learned lessons from our experience and therefore supports the powerful role of wide analyses for ascertaining multiple genetic diseases in complex patients, especially when a clinical suspicion could account for the majority of clinical signs. It finally makes clear how a patient’s “deep phenotyping” might not be sufficient to suggest the presence of multiple genetic diagnoses but remains essential to validate an unexpected multilocus result from genetic tests.
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Affiliation(s)
- Erica Rosina
- Laboratory of Medical Genetics, ASST Papa Giovanni XXIII, 24127 Bergamo, Italy; (E.R.); (L.P.); (D.M.); (M.B.); (M.I.)
| | - Lidia Pezzani
- Paediatric Unit, ASST Papa Giovanni XXIII, 24127 Bergamo, Italy; (L.P.); (E.N.); (A.C.); (A.S.)
- Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, 20122 Milano, Italy
| | - Laura Pezzoli
- Laboratory of Medical Genetics, ASST Papa Giovanni XXIII, 24127 Bergamo, Italy; (E.R.); (L.P.); (D.M.); (M.B.); (M.I.)
| | - Daniela Marchetti
- Laboratory of Medical Genetics, ASST Papa Giovanni XXIII, 24127 Bergamo, Italy; (E.R.); (L.P.); (D.M.); (M.B.); (M.I.)
| | - Matteo Bellini
- Laboratory of Medical Genetics, ASST Papa Giovanni XXIII, 24127 Bergamo, Italy; (E.R.); (L.P.); (D.M.); (M.B.); (M.I.)
| | - Alba Pilotta
- Auxo-Endocrinology, Diabetology and Medical Genetic Unit, Department of Paediatrics, ASST Spedali Civili, 25123 Brescia, Italy;
| | - Olga Calabrese
- Medical Genetics Unit, Azienda Ospedaliera Universitaria di Modena, 41125 Modena, Italy;
| | - Emanuele Nicastro
- Paediatric Unit, ASST Papa Giovanni XXIII, 24127 Bergamo, Italy; (L.P.); (E.N.); (A.C.); (A.S.)
| | - Francesco Cirillo
- Pediatric Hepatology and Paediatric Liver Transplantation, Istituto Mediterraneo per i Trapianti e Terapie ad Alta Specializzazione, 90127 Palermo, Italy;
| | - Anna Cereda
- Paediatric Unit, ASST Papa Giovanni XXIII, 24127 Bergamo, Italy; (L.P.); (E.N.); (A.C.); (A.S.)
| | - Agnese Scatigno
- Paediatric Unit, ASST Papa Giovanni XXIII, 24127 Bergamo, Italy; (L.P.); (E.N.); (A.C.); (A.S.)
| | - Donatella Milani
- Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, 20122 Milano, Italy
- Correspondence: ; Tel.: +39-02-55032560
| | - Maria Iascone
- Laboratory of Medical Genetics, ASST Papa Giovanni XXIII, 24127 Bergamo, Italy; (E.R.); (L.P.); (D.M.); (M.B.); (M.I.)
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15
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Wang L, Sun L, Wan QH, Fang SG. Comparative Genomics Provides Insights into Adaptive Evolution in Tactile-Foraging Birds. Genes (Basel) 2022; 13:genes13040678. [PMID: 35456484 PMCID: PMC9028243 DOI: 10.3390/genes13040678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 04/07/2022] [Accepted: 04/11/2022] [Indexed: 11/28/2022] Open
Abstract
Tactile-foraging birds have evolved an enlarged principal sensory nucleus (PrV) but smaller brain regions related to the visual system, which reflects the difference in sensory dependence. The “trade-off” may exist between different senses in tactile foragers, as well as between corresponding sensory-processing areas in the brain. We explored the mechanism underlying the adaptive evolution of sensory systems in three tactile foragers (kiwi, mallard, and crested ibis). The results showed that olfaction-related genes in kiwi and mallard and hearing-related genes in crested ibis were expanded, indicating they may also have sensitive olfaction or hearing, respectively. However, some genes required for visual development were positively selected or had convergent amino acid substitutions in all three tactile branches, and it seems to show the possibility of visual degradation. In addition, we may provide a new visual-degradation candidate gene PDLIM1 who suffered dense convergent amino acid substitutions within the ZM domain. At last, two genes responsible for regulating the proliferation and differentiation of neuronal progenitor cells may play roles in determining the relative sizes of sensory areas in brain. This exploration offers insight into the relationship between specialized tactile-forging behavior and the evolution of sensory abilities and brain structures.
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16
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Abstract
The BBSome is an octameric protein complex involved in Bardet-Biedl syndrome (BBS), a human pleiotropic, autosomal recessive condition. Patients with BBS display various clinical features including obesity, hypertension, and renal abnormalities. Association studies have also linked the BBS genes to hypertension and other cardiovascular risks in the general population. The BBSome was originally associated with the function of cilia, a highly specialized organelle that extend from the cell membrane of most vertebrate cells. However, subsequent studies have implicated the BBSome in the control of a myriad of other cellular processes not related to cilia including cell membrane localization of receptors and gene expression. The development of animal models of BBS such as mouse lines lacking various components of the BBSome and associated proteins has facilitated studying their role in the control of cardiovascular function and deciphering the pathophysiological mechanisms responsible for the cardiovascular aberrations associated with BBS. These studies revealed the importance of the neuronal, renal, vascular, and cardiac BBSome in the regulation of blood pressure, renal function, vascular reactivity, and cardiac development. The BBSome has also emerged as a critical regulator of key systems involved in cardiovascular control including the renin-angiotensin system. Better understanding of the influence of the BBSome on the molecular and physiological processes relevant to cardiovascular health and disease has the potential of identifying novel mechanisms underlying hypertension and other cardiovascular risks.
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Affiliation(s)
- Yuying Zhao
- Department of Neuroscience and Pharmacology, University of Iowa Carver College of Medicine, Iowa City, IA, USA,Human Toxicology Graduate Program, University of Iowa Graduate College, Iowa City, IA, USA
| | - Kamal Rahmouni
- Department of Neuroscience and Pharmacology, University of Iowa Carver College of Medicine, Iowa City, IA, USA,Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, IA, USA,Fraternal Order of Eagles Diabetes Research Center, University of Iowa Carver College of Medicine, Iowa City, IA, USA,Obesity Research and Educational Initiative, University of Iowa Carver College of Medicine, Iowa City, IA, USA,Iowa City VA Health Care System, Iowa City, IA, USA,Corresponding author: Kamal Rahmouni, Ph.D., Department of Neuroscience and Pharmacology, University of Iowa Carver College of Medicine, Iowa City, IA, 52242, USA, , Tel: 319 353 5256, Fax: 319 353 5350
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17
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Aleissa M, Aloraini T, Alsubaie LF, Hassoun M, Abdulrahman G, Swaid A, Eyaid WA, Mutairi FA, Ababneh F, Alfadhel M, Alfares A. Common disease-associated gene variants in a Saudi Arabian population. Ann Saudi Med 2022; 42:29-35. [PMID: 35112591 PMCID: PMC8812157 DOI: 10.5144/0256-4947.2022.29] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND Screening programs for the most prevalent conditions occurring in a country is an evidence-based prevention strategy. The burden of autosomal recessive disease variations in Saudi Arabia is high because of the highly consanguineous population. The optimal solution for estimating the carrier frequency of the most prevalent diseases is carrier screening. OBJECTIVES Identify the most influential recessive alleles associated with disease in the Saudi population. DESIGN We used clinical whole-exome sequencing data from an in-house familial database to evaluate the most prevalent genetic variations associated with disease in a Saudi population. SETTINGS King Abdullah International Medical Research Center (KAIMRC) and King Abdulaziz Medical City. METHODS Whole exome sequencing data obtained from clinical studies of family members, a cohort of 1314 affected and unaffected individuals, were filtered using the in-house pipeline to extract the most prevalent variant in the dataset. MAIN OUTCOME MEASURES Most prevalent genetic variations associated with disease in the Saudi population. SAMPLE SIZE 1314 affected and unaffected individuals. RESULTS We identified 37 autosomal recessive variants and two heterozygous X-linked variants in 35 genes associated with the most prevalent disorders, which included hematologic (32%), endocrine (21%), metabolic (11%) and immunological (10%) diseases. CONCLUSION This study provides an update of the most frequently occurring alleles, which support future carrier screening programs. LIMITATIONS Single center that might represent the different regions but may be biased. In addition, most of the families included in the database are part of the proband's genetic identification for specific phenotypes. CONFLICT OF INTEREST None.
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Affiliation(s)
- Mariam Aleissa
- From the Division of Translational Pathology, Department of Laboratory Medicine, King Abdulaziz Medical City.,From the Department of Molecular Genetics, Public Health Laboratory, Public Health Authority, Riyadh.,From the College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
| | - Taghrid Aloraini
- From the Division of Translational Pathology, Department of Laboratory Medicine, King Abdulaziz Medical City.,From the King Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences
| | - Lamia Fahad Alsubaie
- From the Department of Genetics, King Abdullah Specialized Children Hospital, King Abdulaziz Medical City, MNGHA.,From the King Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences
| | - Madawi Hassoun
- From the Division of Translational Pathology, Department of Laboratory Medicine, King Abdulaziz Medical City.,From the King Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences
| | - Ghada Abdulrahman
- From the Division of Translational Pathology, Department of Laboratory Medicine, King Abdulaziz Medical City.,From the King Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences
| | - Abdulrahman Swaid
- From the Department of Genetics, King Abdullah Specialized Children Hospital, King Abdulaziz Medical City, MNGHA.,From the King Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences
| | - Wafa Al Eyaid
- From the Department of Genetics, King Abdullah Specialized Children Hospital, King Abdulaziz Medical City, MNGHA.,From the King Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences
| | - Fuad Al Mutairi
- From the Department of Genetics, King Abdullah Specialized Children Hospital, King Abdulaziz Medical City, MNGHA.,From the King Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences
| | - Faroug Ababneh
- From the Department of Genetics, King Abdullah Specialized Children Hospital, King Abdulaziz Medical City, MNGHA.,From the King Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences
| | - Majid Alfadhel
- From the Department of Genetics, King Abdullah Specialized Children Hospital, King Abdulaziz Medical City, MNGHA.,From the King Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences
| | - Ahmed Alfares
- From the Division of Translational Pathology, Department of Laboratory Medicine, King Abdulaziz Medical City.,From the King Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences.,From the Department of Pediatrics, College of Medicine, Qassim University, Qassim
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18
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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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19
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Dallali H, Kheriji N, Kammoun W, Mrad M, Soltani M, Trabelsi H, Hamdi W, Bahlous A, Ben Ahmed M, Mahjoub F, Jamoussi H, Abdelhak S, Kefi R. Multiallelic Rare Variants in BBS Genes Support an Oligogenic Ciliopathy in a Non-obese Juvenile-Onset Syndromic Diabetic Patient: A Case Report. Front Genet 2021; 12:664963. [PMID: 34691137 PMCID: PMC8526562 DOI: 10.3389/fgene.2021.664963] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2021] [Accepted: 08/31/2021] [Indexed: 01/28/2023] Open
Abstract
Juvenile-onset diabetes may occur in the context of a rare syndromic presentation, suggesting a monogenic etiology rather than a common multifactorial diabetes. In the present study, we report the case of a young diabetic Tunisian patient presenting learning problems, speech deficits, short stature, brachydactyly, and a normal weight. Whole exome sequencing analysis revealed five heterozygous genetic variants in BBS1, BBS4, BBS8, MKS1, and CEP290. These genes are involved in the regulation of cilium biogenesis and function. We analyzed variant combinations pathogenicity using the recently developed ORVAL tool, and we hypothesized that cumulative synergetic effects of these variants could explain the syndromic phenotype observed in our patient. Therefore, our investigation suggested a genetic diagnosis of Bardet-Biedl syndrome with an oligogenic inheritance pattern rather than a monogenic diabetes. Although there is no curative therapy for this ciliopathy at the moment, a genetic diagnosis may offer other supportive care options, including the prevention of other possible clinical manifestations of this syndrome, mainly renal abnormalities, obesity, liver fibrosis, and hypertension, as well as the genetic counseling for family members.
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Affiliation(s)
- Hamza Dallali
- Laboratory of Biomedical Genomics and Oncogenetics, Institut Pasteur in Tunis, Tunis, Tunisia
| | - Nadia Kheriji
- Laboratory of Biomedical Genomics and Oncogenetics, Institut Pasteur in Tunis, Tunis, Tunisia
| | - Wafa Kammoun
- Laboratory of Biomedical Genomics and Oncogenetics, Institut Pasteur in Tunis, Tunis, Tunisia
| | - Mehdi Mrad
- Central Laboratory of Medical Biology, Institut Pasteur in Tunis, Tunis, Tunisia
| | - Manel Soltani
- Central Laboratory of Medical Biology, Institut Pasteur in Tunis, Tunis, Tunisia
| | - Hajer Trabelsi
- Central Laboratory of Medical Biology, Institut Pasteur in Tunis, Tunis, Tunisia
| | - Walid Hamdi
- Laboratory of Transmission, Control and Immunobiology of Infections, Institut Pasteur in Tunis, Tunis, Tunisia
| | - Afef Bahlous
- Central Laboratory of Medical Biology, Institut Pasteur in Tunis, Tunis, Tunisia
| | - Melika Ben Ahmed
- Laboratory of Transmission, Control and Immunobiology of Infections, Institut Pasteur in Tunis, Tunis, Tunisia
| | - Faten Mahjoub
- Research Unit on Obesity, National Institute of Nutrition and Food Technology, Tunis, Tunisia
| | - Henda Jamoussi
- Laboratory of Biomedical Genomics and Oncogenetics, Institut Pasteur in Tunis, Tunis, Tunisia
- Research Unit on Obesity, National Institute of Nutrition and Food Technology, Tunis, Tunisia
| | - Sonia Abdelhak
- Laboratory of Biomedical Genomics and Oncogenetics, Institut Pasteur in Tunis, Tunis, Tunisia
- University of Tunis El Manar, Tunis, Tunisia
| | - Rym Kefi
- Laboratory of Biomedical Genomics and Oncogenetics, Institut Pasteur in Tunis, Tunis, Tunisia
- University of Tunis El Manar, Tunis, Tunisia
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20
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Yang C, Georgiou M, Atkinson R, Collin J, Al-Aama J, Nagaraja-Grellscheid S, Johnson C, Ali R, Armstrong L, Mozaffari-Jovin S, Lako M. Pre-mRNA Processing Factors and Retinitis Pigmentosa: RNA Splicing and Beyond. Front Cell Dev Biol 2021; 9:700276. [PMID: 34395430 PMCID: PMC8355544 DOI: 10.3389/fcell.2021.700276] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2021] [Accepted: 07/09/2021] [Indexed: 12/20/2022] Open
Abstract
Retinitis pigmentosa (RP) is the most common inherited retinal disease characterized by progressive degeneration of photoreceptors and/or retinal pigment epithelium that eventually results in blindness. Mutations in pre-mRNA processing factors (PRPF3, 4, 6, 8, 31, SNRNP200, and RP9) have been linked to 15–20% of autosomal dominant RP (adRP) cases. Current evidence indicates that PRPF mutations cause retinal specific global spliceosome dysregulation, leading to mis-splicing of numerous genes that are involved in a variety of retina-specific functions and/or general biological processes, including phototransduction, retinol metabolism, photoreceptor disk morphogenesis, retinal cell polarity, ciliogenesis, cytoskeleton and tight junction organization, waste disposal, inflammation, and apoptosis. Importantly, additional PRPF functions beyond RNA splicing have been documented recently, suggesting a more complex mechanism underlying PRPF-RPs driven disease pathogenesis. The current review focuses on the key RP-PRPF genes, depicting the current understanding of their roles in RNA splicing, impact of their mutations on retinal cell’s transcriptome and phenome, discussed in the context of model species including yeast, zebrafish, and mice. Importantly, information on PRPF functions beyond RNA splicing are discussed, aiming at a holistic investigation of PRPF-RP pathogenesis. Finally, work performed in human patient-specific lab models and developing gene and cell-based replacement therapies for the treatment of PRPF-RPs are thoroughly discussed to allow the reader to get a deeper understanding of the disease mechanisms, which we believe will facilitate the establishment of novel and better therapeutic strategies for PRPF-RP patients.
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Affiliation(s)
- Chunbo Yang
- Biosciences Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Maria Georgiou
- Biosciences Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Robert Atkinson
- Biosciences Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Joseph Collin
- Biosciences Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Jumana Al-Aama
- Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia
| | | | - Colin Johnson
- Leeds Institute of Molecular Medicine, University of Leeds, Leeds, United Kingdom
| | - Robin Ali
- King's College London, London, United Kingdom
| | - Lyle Armstrong
- Biosciences Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Sina Mozaffari-Jovin
- Medical Genetics Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.,Department of Medical Genetics, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.,Department of Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Majlinda Lako
- Biosciences Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
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21
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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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22
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Ectopic expression of BBS1 rescues male infertility, but not retinal degeneration, in a BBS1 mouse model. Gene Ther 2021; 29:227-235. [PMID: 33664503 PMCID: PMC9422088 DOI: 10.1038/s41434-021-00241-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 01/12/2021] [Accepted: 02/05/2021] [Indexed: 11/30/2022]
Abstract
Bardet-Biedl syndrome (BBS) is a rare ciliopathy for which there are no current effective treatments. BBS is a genetically heterogeneous disease, though the M390R mutation in BBS1 is involved in approximately 25% of all genetic diagnoses of BBS. The principle features of BBS include retinal degeneration, obesity, male infertility, polydactyly, intellectual disability, and renal abnormalities. Patients with mutations in BBS genes often present with night blindness within the first decade of life, which progresses to complete blindness. This is due to progressive loss of photoreceptor cells. Male infertility is caused by a lack of spermatozoa flagella, rendering them immobile. In this study, we have crossed the wild-type human BBS1 gene, driven by the CAG promoter, onto the Bbs1M390R/M390R mouse model to determine if ectopic expression of BBS1 rescues male infertility and retinal degeneration. qRT-PCR indicates that the BBS1 transgene is expressed in multiple tissues throughout the mouse, with the highest expression seen in the testes, and much lower expression in the eye and hypothalamus. Immunohistochemistry of the transgene in the eye showed little if any expression in the photoreceptor outer nuclear layer. When male Bbs1M30R/M390R;BBS1TG+ mice are housed with WT females, they are able to sire offspring, indicating that the male infertility phenotype of BBS is rescued by the transgene. Using electroretinography (ERGs) to measure retinal function and optical coherence tomography to measure retinal thickness, we show that the transgene does not confer protection against retinal degeneration in Bbs1M300R/M390R;BBS1TG+ mice. The results of this study indicate the male infertility aspect of BBS is an attractive target for gene therapy.
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23
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Koscinski I, Mark M, Messaddeq N, Braun JJ, Celebi C, Muller J, Zinetti-Bertschy A, Goetz N, Dollfus H, Rossignol S. Reproduction Function in Male Patients With Bardet Biedl Syndrome. J Clin Endocrinol Metab 2020; 105:dgaa551. [PMID: 32835378 PMCID: PMC7538103 DOI: 10.1210/clinem/dgaa551] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2020] [Accepted: 08/12/2020] [Indexed: 12/23/2022]
Abstract
PURPOSE Bardet-Biedl syndrome (BBS) is a ciliopathy with a wide spectrum of symptoms due to primary cilia dysfunction, including genitourinary developmental anomalies as well as impaired reproduction, particularly in males. Primary cilia are known to be required at the following steps of reproduction function: (i) genitourinary organogenesis, (ii) in fetal firing of hypothalamo-pituitary axe, (iii) sperm flagellum structure, and (iv) first zygotic mitosis conducted by proximal sperm centriole. BBS phenotype is not fully understood. METHODS This study explored all steps of reproduction in 11 French male patients with identified BBS mutations. RESULTS BBS patients frequently presented with genitourinary malformations, such as cryptorchidism (5/11), short scrotum (5/8), and micropenis (5/8), but unexpectedly, with normal testis size (7/8). Ultrasonography highlighted epididymal cysts or agenesis of one seminal vesicle in some cases. Sexual hormones levels were normal in all patients except one. Sperm numeration was normal in 8 out of the 10 obtained samples. Five to 45% of sperm presented a progressive motility. Electron microscopy analysis of spermatozoa did not reveal any homogeneous abnormality. Moreover, a psychological approach pointed to a decreased self-confidence linked to blindness and obesity explaining why so few BBS patients express a child wish. CONCLUSIONS Primary cilia dysfunction in BBS impacts the embryology of the male genital tract, especially epididymis, penis, and scrotum through an insufficient fetal androgen production. However, in adults, sperm structure does not seem to be impacted. These results should be confirmed in a greater BBS patient cohort, focusing on fertility.
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Affiliation(s)
- Isabelle Koscinski
- Laboratoire de Biologie de la Reproduction/CECOS Lorraine, Hôpitaux universitaires de Nancy, Nancy, France
- Université de Lorraine, Inserm, NGERE, Nancy, France
| | - Manuel Mark
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch-Graffenstaden, France
- Laboratoire de Biologie de la Reproduction, Hôpitaux universitaires de Strasbourg (HUS), Strasbourg, France
| | - Nadia Messaddeq
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Illkirch-Graffenstaden, France
| | - Jean Jacques Braun
- Service ORL et CCF, Hôpitaux universitaires de Strasbourg (HUS), Strasbourg, France
| | - Catherine Celebi
- Laboratoire de Biologie de la Reproduction, Hôpitaux universitaires de Strasbourg (HUS), Strasbourg, France
| | - Jean Muller
- Laboratoire de Génétique Médicale, INSERM, UMRS_1112, Institut de Génétique Médicale d’Alsace (IGMA), Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Faculté de médecine de Strasbourg, Strasbourg, France
- Laboratoires de Diagnostic Génétique, Hôpitaux Universitaires de Strasbourg, Institut de Génétique Médicale d’Alsace (IGMA), Strasbourg, France
| | - Anna Zinetti-Bertschy
- Pôle de Psychiatrie, Santé Mentale et Addictologie, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
- Neuropsychologie cognitive et physiopathologie de la schizophrénie, Unité de recherche INSERM U1114, Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Strasbourg, France
| | - Nathalie Goetz
- Filière SENSGENE, Centre de Référence pour les affections rares en génétique ophtalmologique (CARGO), Institut de Génétique Médicale d’Alsace (IGMA), Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Hélène Dollfus
- Laboratoire de Génétique Médicale, INSERM, UMRS_1112, Institut de Génétique Médicale d’Alsace (IGMA), Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Faculté de médecine de Strasbourg, Strasbourg, France
- Laboratoires de Diagnostic Génétique, Hôpitaux Universitaires de Strasbourg, Institut de Génétique Médicale d’Alsace (IGMA), Strasbourg, France
- Filière SENSGENE, Centre de Référence pour les affections rares en génétique ophtalmologique (CARGO), Institut de Génétique Médicale d’Alsace (IGMA), Hôpitaux Universitaires de Strasbourg, Strasbourg, France
- Service de Génétique Médicale, Hôpitaux Universitaires de Strasbourg, Institut de Génétique Médicale d’Alsace (IGMA), Strasbourg, France
| | - Sylvie Rossignol
- Laboratoire de Génétique Médicale, INSERM, UMRS_1112, Institut de Génétique Médicale d’Alsace (IGMA), Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Faculté de médecine de Strasbourg, Strasbourg, France
- Laboratoires de Diagnostic Génétique, Hôpitaux Universitaires de Strasbourg, Institut de Génétique Médicale d’Alsace (IGMA), Strasbourg, France
- Service de Génétique Médicale, Hôpitaux Universitaires de Strasbourg, Institut de Génétique Médicale d’Alsace (IGMA), Strasbourg, France
- Service de Pédiatrie, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
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24
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Review: Intraflagellar transport proteins in the retina. Mol Vis 2020; 26:652-660. [PMID: 33088169 PMCID: PMC7553723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2020] [Accepted: 10/02/2020] [Indexed: 10/28/2022] Open
Abstract
Intraflagellar transport (IFT) is an essential process in all organisms that serves to move proteins along flagella or cilia in either direction. IFT is performed by IFT particles, which are multiprotein complexes organized into two subcomplexes, A and B. The IFT proteins form interactions with each other, with cargo proteins, and with membranes during the transport process. Several IFT proteins are expressed in many parts of the retina, such as the outer plexiform and outer nuclear layers, and function in the transport of photoreceptor proteins between the inner and outer segments. Mutants of IFT protein genes have been characterized in model organisms such as Chlamydomonas, C. elegans, zebrafish, and the mouse. These mutants have defective ciliogenesis or abnormalities in retinal photoreceptors. Mutations in IFT genes are associated with syndromic and non-syndromic forms of retinal disease in humans, frequently with early onset of disease.
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25
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Gumus E, Tuncez E, Oz O, Saka Guvenc M. Clinical and exome sequencing findings in seven children with Bardet-Biedl syndrome from Turkey. Ann Hum Genet 2020; 85:27-36. [PMID: 32686083 DOI: 10.1111/ahg.12401] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Revised: 07/02/2020] [Accepted: 07/02/2020] [Indexed: 12/14/2022]
Abstract
BACKGROUND Bardet-Biedl syndrome (BBS) is a very-rare autosomal recessive genetic disorder with severe multisystem manifestations. Genetic testing plays an important role in the early diagnosis of the disease. In this study, while trying to elucidate the genetic etiology of seven individuals with clinical BBS diagnosis from six different families, we also aimed to examine the distribution of BBS variations in this region of Turkey. METHODS AND MATERIALS Exome sequencing analysis is performed for clinically diagnosed patients with BBS in the present study followed by parental segregation. The unreported and previously described clinical features are presented. RESULTS Homozygous variants, four of which are unreported, in BBS-related genes (BBS5 [c.682-2A > G], MKKS [c.775del], BBS7 [c.849+1G > T], BBS9 [c.965G > A], BBS10 [c.145C > T], LZTFL1[c.384G > A]) are detected for all the seven individuals included in the study. The most common clinical finding is polydactyly followed by renal anomalies. The clinical features not previously described are correlated to the unreported variant. CONCLUSIONS In this study, exome sequencing findings are discussed and four previously unreported disease-associated variants are described including the fifth BBS-implicated LZTFL1 change and possible genotype-phenotype correlation is described.
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Affiliation(s)
- Evren Gumus
- Department of Medical Genetics, Faculty of Medicine, University of Harran, Sanliurfa, Turkey.,Department of Medical Genetics, Faculty of Medicine, University of Mugla Sitki Kocman, Mugla, Turkey
| | - Ebru Tuncez
- Clinic of Medical Genetics, Sanliurfa Training and Research Hospital, Sanliurfa, Turkey
| | - Ozlem Oz
- Department of Medical Genetics, Faculty of Medicine, University of Harran, Sanliurfa, Turkey
| | - Merve Saka Guvenc
- Genetic Diagnosis Center, Tepecik Training and Research Hospital, University of Health Sciences, Izmir, Turkey
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26
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Jespersgaard C, Hey AB, Ilginis T, Hjortshøj TD, Fang M, Bertelsen M, Bech N, Jensen H, Larsen LJ, Tümer Z, Rosenberg T, Brøndum-Nielsen K, Møller LB, Grønskov K. A Missense Mutation in RAB28 in a Family with Cone-Rod Dystrophy and Postaxial Polydactyly Prevents Localization of RAB28 to the Primary Cilium. Invest Ophthalmol Vis Sci 2020; 61:29. [PMID: 32084271 PMCID: PMC7326575 DOI: 10.1167/iovs.61.2.29] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Purpose Cone-rod dystrophy (CRD) is a rare hereditary eye disorder that causes progressive degeneration of cone and rod photoreceptors. More than 30 genes, including RAB28, have been associated with CRD; however, only a few RAB28 variants have been reported to be associated with CRD. In this study, we describe two brothers with CRD and a homozygous missense variant, c.55G>A (p.Gly19Arg), in RAB28. Methods The missense variant was identified as part of a study investigating underlying genetic defects in a large patient cohort (n = 667) using targeted next-generation sequencing of 125 genes associated with retinal dystrophy. Cellular localization of RAB28 and ciliogenesis in patient fibroblasts were investigated by immunofluorescence microscopy. The effect of the missense variant on RAB28 expression level was investigated by quantitative real-time PCR. Results Two brothers of a consanguineous couple presented with CRD, postaxial polydactyly (PAP), and myopia. Both brothers had a homozygous missense RAB28 variant located in the G1 box of the guanosine triphosphate/guanosine diphosphate binding domain of RAB28. This missense variant caused a considerable reduction of RAB28 localized to the cilia, whereas ciliogenesis seemed unaffected. Conclusions The missense variant in RAB28 is classified as likely pathogenic with functional effect on protein localization. The combination of retinal dystrophy and PAP are well known from ciliopathies; however, more data are needed to finally conclude that the RAB28 variant described here is the cause of PAP in these brothers.
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27
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Patnaik SR, Farag A, Brücker L, Volz AK, Schneider S, Kretschmer V, May-Simera HL. Tissue-dependent differences in Bardet-Biedl syndrome gene expression. Biol Cell 2020; 112:39-52. [PMID: 31845361 DOI: 10.1111/boc.201900077] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 11/20/2019] [Accepted: 11/28/2019] [Indexed: 12/24/2022]
Abstract
BACKGROUND INFORMATION Primary cilia are highly conserved multifunctional cell organelles that extend from the cell membrane. A range of genetic disorders, collectively termed ciliopathies, is attributed to primary cilia dysfunction. The archetypical ciliopathy is the Bardet-Biedl syndrome (BBS), patients of which display virtually all symptoms associated with dysfunctional cilia. The primary cilium acts as a sensory organelle transmitting intra- and extracellular signals thereby transducing various signalling pathways facilitated by the BBS proteins. Growing evidence suggests that cilia proteins also have alternative functions in ciliary independent mechanisms, which might be contributing to disease etiology. RESULTS In an attempt to gain more insight into possible differences in organ specific roles, we examined whether relative gene expression for individual Bbs genes was constant across different tissues in mouse, in order to distinguish possible differences in organ specific roles. All tested tissues show differentially expressed Bbs transcripts with some tissues showing a more similar stoichiometric composition of transcripts than others do. However, loss of Bbs6 or Bbs8 affects expression of other Bbs transcripts in a tissue-dependent way. CONCLUSIONS AND SIGNIFICANCE Our data support the hypothesis that in some organs, BBS proteins not only function in a complex but might also have alternative functions in a ciliary independent context. This significantly alters our understanding of disease pathogenesis and development of possible treatment strategies.
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Affiliation(s)
- Sarita Rani Patnaik
- Cilia Cell Biology, Institute of Molecular Physiology, Johannes-Gutenberg University, Mainz, 55128, Germany
| | - Aalaa Farag
- Cilia Cell Biology, Institute of Molecular Physiology, Johannes-Gutenberg University, Mainz, 55128, Germany
| | - Lena Brücker
- Cilia Cell Biology, Institute of Molecular Physiology, Johannes-Gutenberg University, Mainz, 55128, Germany
| | - Ann-Kathrin Volz
- Cilia Cell Biology, Institute of Molecular Physiology, Johannes-Gutenberg University, Mainz, 55128, Germany
| | - Sandra Schneider
- Cilia Cell Biology, Institute of Molecular Physiology, Johannes-Gutenberg University, Mainz, 55128, Germany
| | - Viola Kretschmer
- Cilia Cell Biology, Institute of Molecular Physiology, Johannes-Gutenberg University, Mainz, 55128, Germany
| | - Helen Louise May-Simera
- Cilia Cell Biology, Institute of Molecular Physiology, Johannes-Gutenberg University, Mainz, 55128, Germany
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28
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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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