1
|
Satomura Y, Bessho K, Nawa N, Kondo H, Ito S, Togawa T, Yano M, Yamano Y, Inoue T, Fukui M, Onuma S, Fukuoka T, Yasuda K, Kimura T, Tachibana M, Kitaoka T, Nabatame S, Ozono K. Novel gene mutations in three Japanese patients with ARC syndrome associated mild phenotypes: a case series. J Med Case Rep 2022; 16:60. [PMID: 35151346 PMCID: PMC8841066 DOI: 10.1186/s13256-022-03279-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Accepted: 01/18/2022] [Indexed: 11/17/2022] Open
Abstract
Background Arthrogryposis, renal dysfunction, and cholestasis syndrome (ARCS) is a rare autosomal recessive disorder caused by mutations in VPS33B (ARCS1) and VIPAS39 (ARCS2). As per literature, most patients with ARCS died of persistent infections and bleeding by the age of 1 year. We report the first Japanese cases with ARCS1 and ARCS2 who presented with mild phenotypes and were diagnosed via genetic testing. Case presentation Case 1: A 6-year-old boy born to nonconsanguineous Japanese parents presented with jaundice and normal serum gamma-glutamyl transferase (GGT) levels, proteinuria, bilateral nerve deafness, motor delay, failure to thrive, and persistent pruritus. After cochlear implantation for deafness at the age of 2 years, despite a normal platelet count and prothrombin time-international normalized ratio, the patient presented with persistent bleeding that required hematoma removal. Although he did not show any obvious signs of arthrogryposis, he was suspected to have ARCS based on other symptoms. Compound heterozygous mutations in VPS33B were identified using targeted next-generation sequencing (NGS), which resulted in no protein expression. Case 2: A 7-month-old boy, the younger brother of case 1, presented with bilateral deafness, renal tubular dysfunction, failure to thrive, and mild cholestasis. He had the same mutations that were identified in his brother’s VPS33B. Case 3: A 24-year-old man born to nonconsanguineous Japanese parents was suspected to have progressive familial intrahepatic cholestasis 1 (PFIC1) in his childhood on the basis of low GGT cholestasis, renal tubular dysfunction, sensory deafness, mental retardation, and persistent itching. A liver biopsy performed at the age of 16 years showed findings that were consistent with PFIC1. He developed anemia owing to intraperitoneal hemorrhage from a peripheral intrahepatic artery the day after the biopsy, and transcatheter arterial embolization was required. ARCS2 was diagnosed using targeted NGS, which identified novel compound heterozygous mutations in VIPAS39. Conclusions The first Japanese cases of ARCS1 and ARCS2 diagnosed using genetic tests were reported in this study. These cases are milder than those previously reported. For patients with ARCS, invasive procedures should be performed with meticulous care to prevent bleeding.
Collapse
|
2
|
Ning Y, Zeng Z, Deng Y, Feng W, Huang L, Liu H, Lin J, Zhang C, Fan Y, Liu L. VPS33B interacts with NESG1 to suppress cell growth and cisplatin chemoresistance in ovarian cancer. Cancer Sci 2021; 112:1785-1797. [PMID: 33788346 PMCID: PMC8088924 DOI: 10.1111/cas.14864] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 02/12/2021] [Accepted: 02/17/2021] [Indexed: 12/12/2022] Open
Abstract
The pathogenesis and cisplatin chemoresistance of ovarian cancer (OC) are still unclear. Vacuolar protein sorting‐associated 33B (VPS33B) has not been reported in OC to date. In this study, immunohistochemistry was used to detect VPS33B protein expression between OC and ovarian tissues. MTT, EdU, colony formation, cell cycle, in vivo tumorigenesis, western blot, ChIP, EMSA, co‐immunoprecipitation (CoIP), qRT‐PCR, and microconfocal microscopy were used to explore the function and molecular mechanisms of VPS33B in OC cells. The results of the present study demonstrated that VPS33B protein expression was obviously reduced in OC compared with that in ovarian tissues. Overexpressed VPS33B suppressed cell cycle transition, cell growth, and chemoresistance to cisplatin in vitro and in vivo. Analysis of the mechanism indicated that overexpressed VPS33B regulated the epidermal growth factor receptor (EGFR)/PI3K/AKT/c‐Myc/p53/miR‐133a‐3p feedback loop and reduced the expression of the cell cycle factor CDK4. Nasopharyngeal epithelium‐specific protein 1 (NESG1) as a tumor suppressor not only interacted with VPS33B, but was also induced by VPS33B by the attenuation of PI3K/AKT/c‐Jun‐mediated transcription inhibition. Overexpressed NESG1 further suppressed cell growth by mediating VPS33B‐modulated signals in VPS33B‐overexpressing OC cells. Finally, NESG1 induced VPS33B expression by reducing the inhibition of PI3K/AKT/c‐Jun‐mediated transcription. Our study is the first to demonstrate that VPS33B serves as a tumor suppressor, and VPS33B can interact with NESG1 to suppress cell growth and promote cisplatin sensitivity by regulating the EGFR/PI3K/AKT/c‐Myc/p53/miR‐133a‐3p feedback loop in OC cells.
Collapse
Affiliation(s)
- Yingxia Ning
- Department of Gynecology, the Integrated Hospital of Traditional Chinese Medicine, Southern Medical University, Guangzhou, China.,Department of Gynaecology and Obstetrics, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Zhaoyang Zeng
- Department of Gynecology, the Integrated Hospital of Traditional Chinese Medicine, Southern Medical University, Guangzhou, China
| | - Yuao Deng
- Department of Gynecology and Obstetrics, Shenzhen People's Hospital, Shenzhen, China
| | - Weifeng Feng
- The First Affiliated Hospital of Jinan University, Guangzhou, China
| | - Lun Huang
- Department of Gynaecology and Obstetrics, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Huiling Liu
- Department of Gynaecology and Obstetrics, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Jiazhi Lin
- Department of Gynaecology and Obstetrics, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China
| | - Chen Zhang
- Department of Clinical Pharmacy, Guangzhou First People's Hospital, Guangzhou, China
| | - Yue Fan
- Cancer Research Institute, Southern Medical University, Guangzhou, China
| | - Longyang Liu
- Cancer Center, Integrated Hospital of Traditional Chinese Medicine, Southern Medical University, Guangzhou, China
| |
Collapse
|
3
|
Ciesielska A, Matyjek M, Kwiatkowska K. TLR4 and CD14 trafficking and its influence on LPS-induced pro-inflammatory signaling. Cell Mol Life Sci 2020; 78:1233-1261. [PMID: 33057840 PMCID: PMC7904555 DOI: 10.1007/s00018-020-03656-y] [Citation(s) in RCA: 519] [Impact Index Per Article: 129.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 08/25/2020] [Accepted: 09/22/2020] [Indexed: 02/07/2023]
Abstract
Toll-like receptor (TLR) 4 belongs to the TLR family of receptors inducing pro-inflammatory responses to invading pathogens. TLR4 is activated by lipopolysaccharide (LPS, endotoxin) of Gram-negative bacteria and sequentially triggers two signaling cascades: the first one involving TIRAP and MyD88 adaptor proteins is induced in the plasma membrane, whereas the second engaging adaptor proteins TRAM and TRIF begins in early endosomes after endocytosis of the receptor. The LPS-induced internalization of TLR4 and hence also the activation of the TRIF-dependent pathway is governed by a GPI-anchored protein, CD14. The endocytosis of TLR4 terminates the MyD88-dependent signaling, while the following endosome maturation and lysosomal degradation of TLR4 determine the duration and magnitude of the TRIF-dependent one. Alternatively, TLR4 may return to the plasma membrane, which process is still poorly understood. Therefore, the course of the LPS-induced pro-inflammatory responses depends strictly on the rates of TLR4 endocytosis and trafficking through the endo-lysosomal compartment. Notably, prolonged activation of TLR4 is linked with several hereditary human diseases, neurodegeneration and also with autoimmune diseases and cancer. Recent studies have provided ample data on the role of diverse proteins regulating the functions of early, late, and recycling endosomes in the TLR4-induced inflammation caused by LPS or phagocytosis of E. coli. In this review, we focus on the mechanisms of the internalization and intracellular trafficking of TLR4 and CD14, and also of LPS, in immune cells and discuss how dysregulation of the endo-lysosomal compartment contributes to the development of diverse human diseases.
Collapse
Affiliation(s)
- Anna Ciesielska
- Laboratory of Molecular Membrane Biology, Nencki Institute of Experimental Biology of Polish Academy of Sciences, 3 Pasteur St., 02-093, Warsaw, Poland.
| | - Marta Matyjek
- Laboratory of Molecular Membrane Biology, Nencki Institute of Experimental Biology of Polish Academy of Sciences, 3 Pasteur St., 02-093, Warsaw, Poland
| | - Katarzyna Kwiatkowska
- Laboratory of Molecular Membrane Biology, Nencki Institute of Experimental Biology of Polish Academy of Sciences, 3 Pasteur St., 02-093, Warsaw, Poland
| |
Collapse
|
4
|
A Novel Mutation of VPS33 B Gene Associated with Incomplete Arthrogryposis-Renal Dysfunction-Cholestasis Phenotype. Case Rep Genet 2020; 2020:8872294. [PMID: 33029437 PMCID: PMC7532373 DOI: 10.1155/2020/8872294] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 08/28/2020] [Accepted: 09/12/2020] [Indexed: 02/05/2023] Open
Abstract
Arthrogryposis-renal dysfunction-cholestasis (ARC) syndrome is an autosomal recessive disorder caused by mutations of the VPS33B encoding the vacuolar protein sorting 33B (VPS33B), which is involved in the intracellular protein sorting and vesicular trafficking. We report a rare case of ARC syndrome without arthrogryposis caused by a novel mutation of VPS33B. A female patient of Greek origin presented on the 14th day of life with renal tubular acidosis, Fanconi syndrome, nephrogenic diabetes insipidus, and cholestasis with normal gamma-glutamyl transpeptidase, without arthrogryposis and dysmorphic features. She was born to apparently healthy, nonconsanguineous parents. Additional features included dry and scaling skin, generalized hypotonia, hypoplastic corpus callosum, neurodevelopmental delay, failure to thrive, short stature, recurrent febrile episodes with and without infections, and gastrointestinal bleeding. DNA testing revealed that the patient was homozygous for the novel c.1098_1099delTG (p.Glu367Alafs∗17) mutation of exon 14 of VPS33B gene (NM_018668) on chromosome 15q26.1, leading to a nonsense frameshift variant of VPS33B with premature termination of translation. Her parents were heterozygous for the same VPS33B mutation. The prognosis was predictably poor in the context of the intractable polyuria necessitating long-term parenteral fluid administration via indwelling central catheter leading to catheter-related sepsis, to which she eventually succumbed at the age of 7 months. This is the first published VPS33B mutation in an ARC patient of Greek origin. The current case adds to the spectrum of ARC-associated VPS33B mutations and provides evidence supporting the existence of incomplete ARC phenotype. Increased awareness and early genetic testing for ARC are suggested in cases with isolated cholestasis and/or renal tubular dysfunction, even in the absence of arthrogryposis.
Collapse
|
5
|
Zhang J, Tracy C, Pasare C, Zeng J, Krämer H. Hypersensitivity of Vps33B mutant flies to non-pathogenic infections is dictated by aberrant activation of p38b MAP kinase. Traffic 2020; 21:578-589. [PMID: 32677257 DOI: 10.1111/tra.12756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2020] [Revised: 07/10/2020] [Accepted: 07/12/2020] [Indexed: 11/29/2022]
Abstract
Loss of the arthrogryposis-renal dysfunction-cholestasis (ARC) syndrome-linked Vps33B protein results in exaggerated inflammatory responses upon activation of receptors of the innate immune system in both vertebrates and flies. However, little is known about the signaling elements downstream of these receptors that are critical for the hypersensitivity of Vps33B mutants. Here, we show that p38b MAP kinase contributes to the enhanced inflammatory responses in flies lacking Vps33B. Loss of p38b mitogen-activated protein kinase (MAPK) reduces enhanced inflammatory responses and prolongs the survival of infected Vps33B deficient flies. The function of p38 MAPK is not limited to its proinflammatory effects downstream of the PGRP-LC receptor as p38 also modulates endosomal trafficking of PGRP-LC and phagocytosis of bacteria. Expression of constitutively active p38b MAPK, but not dominant negative p38b MAPK enhances accumulation of endocytosed PGRP-LC receptors or phagocytosed bacteria within cells. Moreover, p38 MAPK is required for induction of macropinocytosis, an alternate pathway for the downregulation of immune receptors. Together, our data indicate that p38 MAPK activates multiple pathways that can contribute to the dysregulation of innate immune signaling in ARC syndrome.
Collapse
Affiliation(s)
- Jian Zhang
- Department of Neuroscience, UT Southwestern Medical Center, Dallas, Texas, USA.,Department of Neurology, The First Affiliated Hospital, Sun Yat-sen University, Guangdong Provincial Key Laboratory for Diagnosis and Treatment of Major Neurological Diseases, National Key Clinical Department and Key Discipline of Neurology, Guangzhou, China
| | - Charles Tracy
- Department of Neuroscience, UT Southwestern Medical Center, Dallas, Texas, USA
| | - Chandrashekhar Pasare
- Division of Immunobiology and Center for Inflammation and Tolerance, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA.,Department of Pediatrics, University of Cincinnati, College of Medicine, Cincinnati, Ohio, USA
| | - Jinsheng Zeng
- Department of Neurology, The First Affiliated Hospital, Sun Yat-sen University, Guangdong Provincial Key Laboratory for Diagnosis and Treatment of Major Neurological Diseases, National Key Clinical Department and Key Discipline of Neurology, Guangzhou, China
| | - Helmut Krämer
- Department of Neuroscience, UT Southwestern Medical Center, Dallas, Texas, USA.,Department of Cell Biology, UT Southwestern Medical Center, Dallas, Texas, USA
| |
Collapse
|
6
|
Chen Y, Liu Z, Wang H, Tang Z, Liu Y, Liang Z, Deng X, Zhao M, Fu Q, Li L, Cai H, Xie W, Fang W. VPS33B negatively modulated by nicotine functions as a tumor suppressor in colorectal cancer. Int J Cancer 2019; 146:496-509. [PMID: 31125123 DOI: 10.1002/ijc.32429] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Revised: 04/12/2019] [Accepted: 05/13/2019] [Indexed: 12/19/2022]
Abstract
The biological role of vacuolar protein sorting 33B (VPS33B) has not been examined in colorectal cancer (CRC). We report that VPS33B was downregulated in dextran sulfate sodium/azoxymethane (DSS/AOM) -induced CRC mice models and nicotine-treated CRC cells via the PI3K/AKT/c-Jun pathway. Reduced VPS33B is an unfavorable factor promoting poor prognosis in human CRC patients. VPS33B overexpression suppressed CRC proliferation, intrahepatic metastasis and chemoresistance of cisplatin (DDP) in vivo and in vitro through modulating the epidermal growth factor receptor (EGFR)/RAS/ERK/c-Myc/p53/miR-133a-3p feedback loop and the downstream cell cycle or EMT-related factors. Furthermore, NESG1 as a newly identified tumor suppressor interacted with VPS33B via colocalization in the cytoplasm, and it was stimulated by VPS33B through the downregulation of RAS/ERK/c-Jun-mediated transcription. NESG1 also activated VPS33B expression via the RAS/ERK/c-Jun pathway. Suppression of NESG1 increased cell growth, migration and invasion via the reversion of the VPS33B-modulating signal in VPS33B-overexpressed cells. Taken together, VPS33B as a tumor suppressor is easily dysregulated by chemical carcinogens and it interacts with NESG1 to modulate the EGFR/RAS/ERK/c-Myc/p53/miR-133a-3p feedback loop and thus suppress the malignant phenotype of CRC.
Collapse
Affiliation(s)
- Yiyu Chen
- Cancer Center, Integrated Hospital of Traditional Chinese Medicine, Southern Medical University, Guangzhou, Guangdong, China.,School of Forensic Medicine, Southern Medical University, Guangzhou, Guangdong, China
| | - Zhen Liu
- Key Laboratory of Protein Modification and Degradation, School of Basic Medical Sciences, Affiliated Cancer Hospital & Institute of Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Huijun Wang
- School of Forensic Medicine, Southern Medical University, Guangzhou, Guangdong, China
| | - Zibo Tang
- Cancer Center, Integrated Hospital of Traditional Chinese Medicine, Southern Medical University, Guangzhou, Guangdong, China
| | - Yiyi Liu
- Cancer Center, Integrated Hospital of Traditional Chinese Medicine, Southern Medical University, Guangzhou, Guangdong, China
| | - Zixi Liang
- Cancer Center, Integrated Hospital of Traditional Chinese Medicine, Southern Medical University, Guangzhou, Guangdong, China
| | - Xiaojie Deng
- Cancer Center, Integrated Hospital of Traditional Chinese Medicine, Southern Medical University, Guangzhou, Guangdong, China
| | - Mengyang Zhao
- Cancer Center, Integrated Hospital of Traditional Chinese Medicine, Southern Medical University, Guangzhou, Guangdong, China
| | - Qiaofen Fu
- Cancer Center, Integrated Hospital of Traditional Chinese Medicine, Southern Medical University, Guangzhou, Guangdong, China
| | - Libo Li
- Cancer Center, Integrated Hospital of Traditional Chinese Medicine, Southern Medical University, Guangzhou, Guangdong, China
| | - Hongbing Cai
- Cancer Center, Integrated Hospital of Traditional Chinese Medicine, Southern Medical University, Guangzhou, Guangdong, China
| | - Weibing Xie
- School of Forensic Medicine, Southern Medical University, Guangzhou, Guangdong, China
| | - Weiyi Fang
- Cancer Center, Integrated Hospital of Traditional Chinese Medicine, Southern Medical University, Guangzhou, Guangdong, China
| |
Collapse
|
7
|
van der Beek J, Jonker C, van der Welle R, Liv N, Klumperman J. CORVET, CHEVI and HOPS – multisubunit tethers of the endo-lysosomal system in health and disease. J Cell Sci 2019; 132:132/10/jcs189134. [DOI: 10.1242/jcs.189134] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
ABSTRACT
Multisubunit tethering complexes (MTCs) are multitasking hubs that form a link between membrane fusion, organelle motility and signaling. CORVET, CHEVI and HOPS are MTCs of the endo-lysosomal system. They regulate the major membrane flows required for endocytosis, lysosome biogenesis, autophagy and phagocytosis. In addition, individual subunits control complex-independent transport of specific cargoes and exert functions beyond tethering, such as attachment to microtubules and SNARE activation. Mutations in CHEVI subunits lead to arthrogryposis, renal dysfunction and cholestasis (ARC) syndrome, while defects in CORVET and, particularly, HOPS are associated with neurodegeneration, pigmentation disorders, liver malfunction and various forms of cancer. Diseases and phenotypes, however, vary per affected subunit and a concise overview of MTC protein function and associated human pathologies is currently lacking. Here, we provide an integrated overview on the cellular functions and pathological defects associated with CORVET, CHEVI or HOPS proteins, both with regard to their complexes and as individual subunits. The combination of these data provides novel insights into how mutations in endo-lysosomal proteins lead to human pathologies.
Collapse
Affiliation(s)
- Jan van der Beek
- Section Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, Institute for Biomembranes, Utrecht University, Utrecht 3584 CX, The Netherlands
| | - Caspar Jonker
- Section Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, Institute for Biomembranes, Utrecht University, Utrecht 3584 CX, The Netherlands
| | - Reini van der Welle
- Section Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, Institute for Biomembranes, Utrecht University, Utrecht 3584 CX, The Netherlands
| | - Nalan Liv
- Section Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, Institute for Biomembranes, Utrecht University, Utrecht 3584 CX, The Netherlands
| | - Judith Klumperman
- Section Cell Biology, Center for Molecular Medicine, University Medical Center Utrecht, Institute for Biomembranes, Utrecht University, Utrecht 3584 CX, The Netherlands
| |
Collapse
|
8
|
Alter S, Hotz A, Jahn A, Di Donato N, Schröck E, Smitka M, von der Hagen M, Schallner J, Menschikowski M, Gillitzer C, Laass MW, Fischer J, Tzschach A. Novel VPS33B mutation in a patient with autosomal recessive keratoderma-ichthyosis-deafness syndrome. Am J Med Genet A 2018; 176:2862-2866. [DOI: 10.1002/ajmg.a.40634] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Revised: 07/20/2018] [Accepted: 08/21/2018] [Indexed: 12/13/2022]
Affiliation(s)
- Svenja Alter
- Faculty of Medicine; Institute of Human Genetics, Medical Center - University of Freiburg; Freiburg Germany
| | - Alrun Hotz
- Faculty of Medicine; Institute of Human Genetics, Medical Center - University of Freiburg; Freiburg Germany
| | - Arne Jahn
- Institute of Clinical Genetics, Technische Universität Dresden; Dresden Germany
| | - Nataliya Di Donato
- Institute of Clinical Genetics, Technische Universität Dresden; Dresden Germany
| | - Evelin Schröck
- Institute of Clinical Genetics, Technische Universität Dresden; Dresden Germany
| | - Martin Smitka
- Children´s hospital, Medical Faculty Carl Gustav Carus; Technische Universität Dresden; Dresden Germany
| | - Maja von der Hagen
- Children´s hospital, Medical Faculty Carl Gustav Carus; Technische Universität Dresden; Dresden Germany
| | - Jens Schallner
- Children´s hospital, Medical Faculty Carl Gustav Carus; Technische Universität Dresden; Dresden Germany
| | - Mario Menschikowski
- Institute of Clinical Chemistry and Laboratory Medicine; Medical Faculty Carl Gustav Carus, Technische Universität Dresden; Dresden Germany
| | - Claus Gillitzer
- Children´s hospital, Medical Faculty Carl Gustav Carus; Technische Universität Dresden; Dresden Germany
| | - Martin W. Laass
- Children´s hospital, Medical Faculty Carl Gustav Carus; Technische Universität Dresden; Dresden Germany
| | - Judith Fischer
- Faculty of Medicine; Institute of Human Genetics, Medical Center - University of Freiburg; Freiburg Germany
| | - Andreas Tzschach
- Institute of Clinical Genetics, Technische Universität Dresden; Dresden Germany
| |
Collapse
|
9
|
Sharma A, Poddar U, Agnihotry S, Phadke SR, Yachha SK, Aggarwal R. Spectrum of genomic variations in Indian patients with progressive familial intrahepatic cholestasis. BMC Gastroenterol 2018; 18:107. [PMID: 29973134 PMCID: PMC6032793 DOI: 10.1186/s12876-018-0835-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Accepted: 06/26/2018] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND Progressive familial intrahepatic cholestasis (PFIC) is caused by variations in ATP8B1, ABCB11 or ABCB4 genes. Data on genetic variations in Indian patients with PFIC are lacking. METHODS Coding and splice regions of the three genes were sequenced in unrelated Indian children with PFIC phenotype. The variations identified were looked for in parents, 30 healthy persons and several variation databases, and their effect was assessed in-silico. RESULTS Among 25 children (aged 1-144 months), nine (36%) had unique major genomic variations (ATP8B1: 4, ABCB11: 3 and ABCB4: 2). Seven had homozygous variations, which were assessed as 'pathogenic' or 'likely pathogenic'. These included: (i) four amino acid substitutions (ATP8B1: c.1660G > A/p.Asp554Asn and c.2941G > A/p.Glu981Lys; ABCB11: c.548 T > C/p.Met183Thr; ABCB4: c.431G > A/p.Arg144Gln); (ii) one 3-nucleotide deletion causing an amino acid deletion (ATP8B1: c.1587_1589delCTT/p.Phe529del); (iii) one single-nucleotide deletion leading to frame-shift and premature termination (ABCB11: c.1360delG/p.Val454Ter); and (iv) a complex inversion of 4 nucleotides with a single-nucleotide insertion leading to frame-shift and premature termination (ATP8B1: c.[589_592inv;592_593insA]/p.Gly197LeufsTer10). Two variations were found in heterozygous form: (i) a splice-site variation likely to cause abnormal splicing (ABCB11: c.784 + 1G > C), and (ii) a nucleotide substitution that created a premature stop codon (ABCB4: c.475C > T/p.Arg159Ter); these were considered as variations of uncertain significance. Three of the nine variations were novel. CONCLUSIONS Nine major genomic variations, including three novel ones, were identified in nearly one-third of Indian children with PFIC. No variation was identified in nearly two-thirds of patients, who may have been related to variations in promoter or intronic regions of the three PFIC genes, or in other bile-salt transport genes.
Collapse
Affiliation(s)
- Anjali Sharma
- Department of Gastroenterology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, 226014 India
| | - Ujjal Poddar
- Department of Pediatric Gastroenterology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, 226014 India
| | - Shikha Agnihotry
- Department of Gastroenterology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, 226014 India
| | - Shubha R. Phadke
- Department of Medical Genetics, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, 226014 India
| | - Surender K. Yachha
- Department of Pediatric Gastroenterology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, 226014 India
| | - Rakesh Aggarwal
- Department of Gastroenterology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, 226014 India
| |
Collapse
|
10
|
Akbar MA, Mandraju R, Tracy C, Hu W, Pasare C, Krämer H. ARC Syndrome-Linked Vps33B Protein Is Required for Inflammatory Endosomal Maturation and Signal Termination. Immunity 2016; 45:267-79. [PMID: 27496733 DOI: 10.1016/j.immuni.2016.07.010] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Revised: 03/03/2016] [Accepted: 05/17/2016] [Indexed: 12/13/2022]
Abstract
Toll-like receptors (TLRs) and other pattern-recognition receptors (PRRs) sense microbial ligands and initiate signaling to induce inflammatory responses. Although the quality of inflammatory responses is influenced by internalization of TLRs, the role of endosomal maturation in clearing receptors and terminating inflammatory responses is not well understood. Here, we report that Drosophila and mammalian Vps33B proteins play critical roles in the maturation of phagosomes and endosomes following microbial recognition. Vps33B was necessary for clearance of endosomes containing internalized PRRs, failure of which resulted in enhanced signaling and expression of inflammatory mediators. Lack of Vps33B had no effect on trafficking of endosomes containing non-microbial cargo. These findings indicate that Vps33B function is critical for determining the fate of signaling endosomes formed following PRR activation. Exaggerated inflammatory responses dictated by persistence of receptors in aberrant endosomal compartments could therefore contribute to symptoms of ARC syndrome, a disease linked to loss of Vps33B.
Collapse
Affiliation(s)
- Mohammed Ali Akbar
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Rajakumar Mandraju
- Department of Immunology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Charles Tracy
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Wei Hu
- Department of Immunology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Chandrashekhar Pasare
- Department of Immunology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
| | - Helmut Krämer
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
| |
Collapse
|