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Thareja SK, Anfinson M, Cavanaugh M, Kim MS, Lamberton P, Radandt J, Brown R, Liang HL, Stamm K, Afzal MZ, Strande J, Frommelt MA, Lough JW, Fitts RH, Mitchell ME, Tomita-Mitchell A. Altered contractility, Ca 2+ transients, and cell morphology seen in a patient-specific iPSC-CM model of Ebstein's anomaly with left ventricular noncompaction. Am J Physiol Heart Circ Physiol 2023; 325:H149-H162. [PMID: 37204873 PMCID: PMC10312315 DOI: 10.1152/ajpheart.00658.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 05/15/2023] [Accepted: 05/15/2023] [Indexed: 05/21/2023]
Abstract
Patients with two congenital heart diseases (CHDs), Ebstein's anomaly (EA) and left ventricular noncompaction (LVNC), suffer higher morbidity than either CHD alone. The genetic etiology and pathogenesis of combined EA/LVNC remain largely unknown. We investigated a familial EA/LVNC case associated with a variant (p.R237C) in the gene encoding Kelch-like protein 26 (KLHL26) by differentiating induced pluripotent stem cells (iPSCs) generated from affected and unaffected family members into cardiomyocytes (iPSC-CMs) and assessing iPSC-CM morphology, function, gene expression, and protein abundance. Compared with unaffected iPSC-CMs, CMs containing the KLHL26 (p.R237C) variant exhibited aberrant morphology including distended endo(sarco)plasmic reticulum (ER/SR) and dysmorphic mitochondria and aberrant function that included decreased contractions per minute, altered calcium transients, and increased proliferation. Pathway enrichment analyses based on RNASeq data indicated that the "structural constituent of muscle" pathway was suppressed, whereas the "ER lumen" pathway was activated. Taken together, these findings suggest that iPSC-CMs containing this KLHL26 (p.R237C) variant develop dysregulated ER/SR, calcium signaling, contractility, and proliferation.NEW & NOTEWORTHY We demonstrate here that iPSCs derived from patients with Ebstein's anomaly and left ventricular noncompaction, when differentiated into cardiomyocytes, display significant structural and functional changes that offer insight into disease pathogenesis, including altered ER/SR and mitochondrial morphology, contractility, and calcium signaling.
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Affiliation(s)
- Suma K Thareja
- Division of Congenital Heart Surgery, Department of Surgery, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
- Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Melissa Anfinson
- Division of Congenital Heart Surgery, Department of Surgery, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
- Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Matthew Cavanaugh
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin, United States
| | - Min-Su Kim
- Division of Congenital Heart Surgery, Department of Surgery, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
- Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Peter Lamberton
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin, United States
| | - Jackson Radandt
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin, United States
| | - Ryan Brown
- Department of Microbiology and Immunology, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Huan-Ling Liang
- Division of Congenital Heart Surgery, Department of Surgery, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Karl Stamm
- Division of Congenital Heart Surgery, Department of Surgery, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Muhammad Zeeshan Afzal
- Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Jennifer Strande
- Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Michele A Frommelt
- Division of Pediatric Cardiology, Department of Pediatrics, Children's Wisconsin, Milwaukee, Wisconsin, United States
- Herma Heart Institute, Children's Wisconsin, Milwaukee, Wisconsin, United States
| | - John W Lough
- Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
| | - Robert H Fitts
- Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin, United States
| | - Michael E Mitchell
- Division of Congenital Heart Surgery, Department of Surgery, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
- Herma Heart Institute, Children's Wisconsin, Milwaukee, Wisconsin, United States
| | - Aoy Tomita-Mitchell
- Division of Congenital Heart Surgery, Department of Surgery, Medical College of Wisconsin, Milwaukee, Wisconsin, United States
- Herma Heart Institute, Children's Wisconsin, Milwaukee, Wisconsin, United States
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Hirabayashi T, Kawaguchi M, Harada S, Mouri M, Takamiya R, Miki Y, Sato H, Taketomi Y, Yokoyama K, Kobayashi T, Tokuoka SM, Kita Y, Yoda E, Hara S, Mikami K, Nishito Y, Kikuchi N, Nakata R, Kaneko M, Kiyonari H, Kasahara K, Aiba T, Ikeda K, Soga T, Kurano M, Yatomi Y, Murakami M. Hepatic phosphatidylcholine catabolism driven by PNPLA7 and PNPLA8 supplies endogenous choline to replenish the methionine cycle with methyl groups. Cell Rep 2023; 42:111940. [PMID: 36719796 DOI: 10.1016/j.celrep.2022.111940] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 11/10/2022] [Accepted: 12/19/2022] [Indexed: 01/31/2023] Open
Abstract
Choline supplies methyl groups for regeneration of methionine and the methyl donor S-adenosylmethionine in the liver. Here, we report that the catabolism of membrane phosphatidylcholine (PC) into water-soluble glycerophosphocholine (GPC) by the phospholipase/lysophospholipase PNPLA8-PNPLA7 axis enables endogenous choline stored in hepatic PC to be utilized in methyl metabolism. PNPLA7-deficient mice show marked decreases in hepatic GPC, choline, and several metabolites related to the methionine cycle, accompanied by various signs of methionine insufficiency, including growth retardation, hypoglycemia, hypolipidemia, increased energy consumption, reduced adiposity, increased fibroblast growth factor 21 (FGF21), and an altered histone/DNA methylation landscape. Moreover, PNPLA8-deficient mice recapitulate most of these phenotypes. In contrast to wild-type mice fed a methionine/choline-deficient diet, both knockout strains display decreased hepatic triglyceride, likely via reductions of lipogenesis and GPC-derived glycerol flux. Collectively, our findings highlight the biological importance of phospholipid catabolism driven by PNPLA8/PNPLA7 in methyl group flux and triglyceride synthesis in the liver.
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Affiliation(s)
- Tetsuya Hirabayashi
- Laboratory of Biomembrane, Department of Basic Medical Sciences, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan; Lipid Metabolism Project, Department of Advanced Science for Biomolecules, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan.
| | - Mai Kawaguchi
- Laboratory of Biomembrane, Department of Basic Medical Sciences, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan; Laboratory of Microenvironmental Metabolic Health Sciences, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan
| | - Sayaka Harada
- Laboratory of Microenvironmental Metabolic Health Sciences, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan
| | - Misa Mouri
- Lipid Metabolism Project, Department of Advanced Science for Biomolecules, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan; Department of Biology, Faculty of Science, Ochanomizu University, Tokyo 112-8610, Japan
| | - Rina Takamiya
- Laboratory of Microenvironmental Metabolic Health Sciences, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan
| | - Yoshimi Miki
- Lipid Metabolism Project, Department of Advanced Science for Biomolecules, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan; Laboratory of Microenvironmental Metabolic Health Sciences, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan
| | - Hiroyasu Sato
- Lipid Metabolism Project, Department of Advanced Science for Biomolecules, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan; Laboratory of Microenvironmental Metabolic Health Sciences, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan
| | - Yoshitaka Taketomi
- Lipid Metabolism Project, Department of Advanced Science for Biomolecules, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan; Laboratory of Microenvironmental Metabolic Health Sciences, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan
| | - Kohei Yokoyama
- Laboratory of Biomembrane, Department of Basic Medical Sciences, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan; Lipid Metabolism Project, Department of Advanced Science for Biomolecules, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan
| | - Tetsuyuki Kobayashi
- Department of Biology, Faculty of Science, Ochanomizu University, Tokyo 112-8610, Japan
| | - Suzumi M Tokuoka
- Department of Lipidomics, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
| | - Yoshihiro Kita
- Department of Lipidomics, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan; Life Sciences Core Facility, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
| | - Emiko Yoda
- Division of Health Chemistry, Department of Healthcare and Regulatory Sciences, School of Pharmacy, Showa University, Tokyo 142-8555, Japan
| | - Shuntaro Hara
- Division of Health Chemistry, Department of Healthcare and Regulatory Sciences, School of Pharmacy, Showa University, Tokyo 142-8555, Japan
| | - Kyohei Mikami
- Center for Basic Technology Research, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan
| | - Yasumasa Nishito
- Center for Basic Technology Research, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan
| | - Norihito Kikuchi
- Laboratory of Biomembrane, Department of Basic Medical Sciences, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan
| | - Rieko Nakata
- Department of Food Science and Nutrition, Nara Women's University, Nara, 630-8506, Japan
| | - Mari Kaneko
- Laboratory for Animal Resources and Genetic Engineering, RIKEN Center for Biosystems Dynamics Research, Kobe, Hyogo 650-0047, Japan
| | - Hiroshi Kiyonari
- Laboratory for Animal Resources and Genetic Engineering, RIKEN Center for Biosystems Dynamics Research, Kobe, Hyogo 650-0047, Japan
| | - Kohji Kasahara
- Laboratory of Biomembrane, Department of Basic Medical Sciences, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan
| | - Toshiki Aiba
- Laboratory of Microenvironmental Metabolic Health Sciences, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan; Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba 263-8555, Japan
| | - Kazutaka Ikeda
- Kazusa DNA Research Institute, Kisarazu, Chiba 292-0818, Japan
| | - Tomoyoshi Soga
- Institute for Advanced Biosciences, Keio University, Tsuruoka, Yamagata 997-0052, Japan
| | - Makoto Kurano
- Department of Clinical Laboratory Medicine, The University of Tokyo, Tokyo 113-8655, Japan
| | - Yutaka Yatomi
- Department of Clinical Laboratory Medicine, The University of Tokyo, Tokyo 113-8655, Japan
| | - Makoto Murakami
- Lipid Metabolism Project, Department of Advanced Science for Biomolecules, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan; Laboratory of Microenvironmental Metabolic Health Sciences, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan; AMED-CREST, Japan Agency for Medical Research and Development, Tokyo 100-0004, Japan.
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Yang L, Wang ZA, Geng R, Niu S, Zuo H, Weng S, He J, Xu X. A kelch motif-containing protein KLHDC2 regulates immune responses against Vibrio parahaemolyticus and white spot syndrome virus in Penaeus vannamei. FISH & SHELLFISH IMMUNOLOGY 2022; 127:187-194. [PMID: 35716970 DOI: 10.1016/j.fsi.2022.06.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2022] [Revised: 06/04/2022] [Accepted: 06/08/2022] [Indexed: 06/15/2023]
Abstract
The kelch motif-containing proteins are widely present in organisms and known to be involved in various biological processes, but their roles in immunity remain unclear. In this study, a kelch motif-containing protein KLHDC2 was identified from Pacific white shrimp Penaeus vannamei and its immune function was investigated. The klhdc2 gene was widely expressed in shrimp tissues and its protein product was mainly present in the nucleus. Expression of klhdc2 was regulated by shrimp NF-κB family members Dorsal and Relish, and changed after immune stimulation. KLHDC2 could enhance the immune defense against Vibrio parahaemolyticus in shrimp but inhibit that against white spot syndrome virus (WSSV). Further analyses showed that KLHDC2 did not affect the phagocytosis of hemocytes but regulated the expression of a series of immune effector genes. KLHDC2 has a complex regulatory relationship with Dorsal and Relish, which may partly contribute to its positive role in antibacterial response by regulating humoral immunity. Moreover, the regulatory effect of KLHDC2 on WSSV ie1 gene contributed to its negative effect on antiviral response. Therefore, the current study enrichs the knowledge on the Kelch family and helps to learn more about the regulatory mechanism of shrimp immunity.
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Affiliation(s)
- Linwei Yang
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, PR China; Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, PR China; Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, Guangzhou, PR China
| | - Zi-Ang Wang
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, PR China; Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, PR China; Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, Guangzhou, PR China
| | - Ran Geng
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, PR China; Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, PR China; Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, Guangzhou, PR China
| | - Shengwen Niu
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, PR China; Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, PR China; Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, Guangzhou, PR China
| | - Hongliang Zuo
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, PR China; Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, PR China; Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, Guangzhou, PR China
| | - Shaoping Weng
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, PR China; Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, PR China; Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, Guangzhou, PR China
| | - Jianguo He
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, PR China; Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, PR China; Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, Guangzhou, PR China
| | - Xiaopeng Xu
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, PR China; Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, PR China; Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, Guangzhou, PR China.
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4
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Hatem G, Hjort L, Asplund O, Minja DTR, Msemo OA, Møller SL, Lavstsen T, Groth-Grunnet L, Lusingu JPA, Hansson O, Christensen DL, Vaag AA, Artner I, Theander T, Groop L, Schmiegelow C, Bygbjerg IC, Prasad RB. Mapping the Cord Blood Transcriptome of Pregnancies Affected by Early Maternal Anemia to Identify Signatures of Fetal Programming. J Clin Endocrinol Metab 2022; 107:1303-1316. [PMID: 35021220 PMCID: PMC9016468 DOI: 10.1210/clinem/dgac010] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Indexed: 11/19/2022]
Abstract
CONTEXT Anemia during early pregnancy (EP) is common in developing countries and is associated with adverse health consequences for both mothers and children. Offspring of women with EP anemia often have low birth weight, which increases risk for cardiometabolic diseases, including type 2 diabetes (T2D), later in life. OBJECTIVE We aimed to elucidate mechanisms underlying developmental programming of adult cardiometabolic disease, including epigenetic and transcriptional alterations potentially detectable in umbilical cord blood (UCB) at time of birth. METHODS We leveraged global transcriptome- and accompanying epigenome-wide changes in 48 UCB from newborns of EP anemic Tanzanian mothers and 50 controls to identify differentially expressed genes (DEGs) in UCB exposed to maternal EP anemia. DEGs were assessed for association with neonatal anthropometry and cord insulin levels. These genes were further studied in expression data from human fetal pancreas and adult islets to understand their role in beta-cell development and/or function. RESULTS The expression of 137 genes was altered in UCB of newborns exposed to maternal EP anemia. These putative signatures of fetal programming, which included the birth weight locus LCORL, were potentially mediated by epigenetic changes in 27 genes and associated with neonatal anthropometry. Among the DEGs were P2RX7, PIK3C2B, and NUMBL, which potentially influence beta-cell development. Insulin levels were lower in EP anemia-exposed UCB, supporting the notion of developmental programming of pancreatic beta-cell dysfunction and subsequently increased risk of T2D in offspring of mothers with EP anemia. CONCLUSIONS Our data provide proof-of-concept on distinct transcriptional and epigenetic changes detectable in UCB from newborns exposed to maternal EP anemia.
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Affiliation(s)
- Gad Hatem
- Genomics, Diabetes and Endocrinology, Department of Clinical Sciences, Clinical Research Centre, Lund University Diabetes Centre, 205 02, Malmö, Sweden
| | - Line Hjort
- Department of Obstetrics, Center for Pregnant Women with Diabetes, Rigshospitalet, 2100 Copenhagen, Denmark
- Department of Endocrinology (Diabetes and Bone-Metabolic Research Unit), 2100 Copenhagen, Denmark
| | - Olof Asplund
- Genomics, Diabetes and Endocrinology, Department of Clinical Sciences, Clinical Research Centre, Lund University Diabetes Centre, 205 02, Malmö, Sweden
| | - Daniel T R Minja
- National Institute for Medical Research, Tanga Center, 0255 Tanga, Tanzania
| | - Omari Abdul Msemo
- National Institute for Medical Research, Tanga Center, 0255 Tanga, Tanzania
| | - Sofie Lykke Møller
- Section of Global Health, Department of Public Health, University of Copenhagen, 1353 Copenhagen, Denmark
| | - Thomas Lavstsen
- Center for Medical Parasitology, Department of Immunology and Microbiology, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Louise Groth-Grunnet
- Department of Endocrinology (Diabetes and Bone-Metabolic Research Unit), 2100 Copenhagen, Denmark
- Section of Global Health, Department of Public Health, University of Copenhagen, 1353 Copenhagen, Denmark
| | - John P A Lusingu
- National Institute for Medical Research, Tanga Center, 0255 Tanga, Tanzania
- Center for Medical Parasitology, Department of Immunology and Microbiology, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Ola Hansson
- Genomics, Diabetes and Endocrinology, Department of Clinical Sciences, Clinical Research Centre, Lund University Diabetes Centre, 205 02, Malmö, Sweden
| | - Dirk Lund Christensen
- Section of Global Health, Department of Public Health, University of Copenhagen, 1353 Copenhagen, Denmark
| | - Allan A Vaag
- Steno Diabetes Center Copenhagen, 2730 Gentofte, Denmark
| | - Isabella Artner
- Genomics, Diabetes and Endocrinology, Department of Clinical Sciences, Clinical Research Centre, Lund University Diabetes Centre, 205 02, Malmö, Sweden
| | - Thor Theander
- Center for Medical Parasitology, Department of Immunology and Microbiology, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Leif Groop
- Genomics, Diabetes and Endocrinology, Department of Clinical Sciences, Clinical Research Centre, Lund University Diabetes Centre, 205 02, Malmö, Sweden
- Finnish Institute of Molecular Medicine (FIMM), 00290 Helsinki, Finland
| | - Christentze Schmiegelow
- Center for Medical Parasitology, Department of Immunology and Microbiology, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Ib Christian Bygbjerg
- Section of Global Health, Department of Public Health, University of Copenhagen, 1353 Copenhagen, Denmark
| | - Rashmi B Prasad
- Genomics, Diabetes and Endocrinology, Department of Clinical Sciences, Clinical Research Centre, Lund University Diabetes Centre, 205 02, Malmö, Sweden
- Finnish Institute of Molecular Medicine (FIMM), 00290 Helsinki, Finland
- Correspondence: Rashmi B Prasad, PhD, Genomics, Diabetes and Endocrinology, Department of Clinical Sciences, Clinical Research Centre, Lund University Diabetes Centre, Jan Waldenströms gata 35, 205 02 Malmö, Sweden.
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Thareja SK, Frommelt MA, Lincoln J, Lough JW, Mitchell ME, Tomita-Mitchell A. A Systematic Review of Ebstein’s Anomaly with Left Ventricular Noncompaction. J Cardiovasc Dev Dis 2022; 9:jcdd9040115. [PMID: 35448091 PMCID: PMC9031964 DOI: 10.3390/jcdd9040115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2022] [Revised: 03/31/2022] [Accepted: 04/07/2022] [Indexed: 11/16/2022] Open
Abstract
Traditional definitions of Ebstein’s anomaly (EA) and left ventricular noncompaction (LVNC), two rare congenital heart defects (CHDs), confine disease to either the right or left heart, respectively. Around 15–29% of patients with EA, which has a prevalence of 1 in 20,000 live births, commonly manifest with LVNC. While individual EA or LVNC literature is extensive, relatively little discussion is devoted to the joint appearance of EA and LVNC (EA/LVNC), which poses a higher risk of poor clinical outcomes. We queried PubMed, Medline, and Web of Science for all peer-reviewed publications from inception to February 2022 that discuss EA/LVNC and found 58 unique articles written in English. Here, we summarize and extrapolate commonalities in clinical and genetic understanding of EA/LVNC to date. We additionally postulate involvement of shared developmental pathways that may lead to this combined disease. Anatomical variation in EA/LVNC encompasses characteristics of both CHDs, including tricuspid valve displacement, right heart dilatation, and left ventricular trabeculation, and dictates clinical presentation in both age and severity. Disease treatment is non-specific, ranging from symptomatic management to invasive surgery. Apart from a few variant associations, mainly in sarcomeric genes MYH7 and TPM1, the genetic etiology and pathogenesis of EA/LVNC remain largely unknown.
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Affiliation(s)
- Suma K. Thareja
- Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, WI 53226, USA; (S.K.T.); (J.W.L.)
- Department of Surgery, Division of Congenital Heart Surgery, Medical College of Wisconsin, Milwaukee, WI 53226, USA;
| | - Michele A. Frommelt
- Department of Pediatrics, Division of Pediatric Cardiology, Children’s Wisconsin, Milwaukee, WI 53226, USA; (M.A.F.); (J.L.)
- Herma Heart Institute, Children’s Wisconsin, Milwaukee, WI 53226, USA
| | - Joy Lincoln
- Department of Pediatrics, Division of Pediatric Cardiology, Children’s Wisconsin, Milwaukee, WI 53226, USA; (M.A.F.); (J.L.)
- Herma Heart Institute, Children’s Wisconsin, Milwaukee, WI 53226, USA
| | - John W. Lough
- Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, WI 53226, USA; (S.K.T.); (J.W.L.)
| | - Michael E. Mitchell
- Department of Surgery, Division of Congenital Heart Surgery, Medical College of Wisconsin, Milwaukee, WI 53226, USA;
- Department of Pediatrics, Division of Pediatric Cardiology, Children’s Wisconsin, Milwaukee, WI 53226, USA; (M.A.F.); (J.L.)
- Herma Heart Institute, Children’s Wisconsin, Milwaukee, WI 53226, USA
| | - Aoy Tomita-Mitchell
- Department of Surgery, Division of Congenital Heart Surgery, Medical College of Wisconsin, Milwaukee, WI 53226, USA;
- Department of Pediatrics, Division of Pediatric Cardiology, Children’s Wisconsin, Milwaukee, WI 53226, USA; (M.A.F.); (J.L.)
- Herma Heart Institute, Children’s Wisconsin, Milwaukee, WI 53226, USA
- Correspondence:
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Jung J, Kim E, Rhee M. Kapd Is Essential for Specification of the Dopaminergic Neurogenesis in Zebrafish Embryos. Mol Cells 2021; 44:233-244. [PMID: 33820883 PMCID: PMC8112167 DOI: 10.14348/molcells.2021.0005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 02/17/2021] [Accepted: 02/22/2021] [Indexed: 01/23/2023] Open
Abstract
To define novel networks of Parkinson's disease (PD) pathogenesis, the substantia nigra pars compacta of A53T mice, where a death-promoting protein, FAS-associated factor 1 was ectopically expressed for 2 weeks in the 2-, 4-, 6-, and 8-month-old mice, and was subjected to transcriptomic analysis. Compendia of expression profiles and a hierarchical clustering heat map of differentially expressed genes associated with PD were bioinformatically generated. Transcripts level of a particular gene was fluctuated by 20, 60, and 0.75 fold in the 4-, 6-, and 8-month-old mice compared to the 2 months old. Because the gene contained Kelch domain, it was named as Kapd (Kelch-containing protein associated with PD). Biological functions of Kapd were systematically investigated in the zebrafish embryos. First, transcripts of a zebrafish homologue of Kapd, kapd were found in the floor plate of the neural tube at 10 h post fertilization (hpf), and restricted to the tegmentum, hypothalamus, and cerebellum at 24 hpf. Second, knockdown of kapd caused developmental defects of DA progenitors in the midbrain neural keel and midbrain? hindbrain boundary at 10 hpf. Third, overexpression of kapd increased transcripts level of the dopaminergic immature neuron marker, shha in the prethalamus at 16.5 hpf. Finally, developmental consequences of kapd knockdown reduced transcripts level of the markers for the immature and mature DA neurons, nkx2.2, olig2, otx2b, and th in the ventral diencephalon of the midbrain at 18 hpf. It is thus most probable that Kapd play a key role in the specification of the DA neuronal precursors in zebrafish embryos.
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Affiliation(s)
- Jangham Jung
- Department of Life Science, BK21 Plus Program, Graduate School, Chungnam National University, Daejeon 34134, Korea
| | - Eunhee Kim
- Department of Biological Sciences, College of Bioscience and Biotechnology, Chungnam National University, Daejeon 34134, Korea
| | - Myungchull Rhee
- Department of Life Science, BK21 Plus Program, Graduate School, Chungnam National University, Daejeon 34134, Korea
- Department of Biological Sciences, College of Bioscience and Biotechnology, Chungnam National University, Daejeon 34134, Korea
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7
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Blondelle J, Biju A, Lange S. The Role of Cullin-RING Ligases in Striated Muscle Development, Function, and Disease. Int J Mol Sci 2020; 21:E7936. [PMID: 33114658 PMCID: PMC7672578 DOI: 10.3390/ijms21217936] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 10/11/2020] [Accepted: 10/13/2020] [Indexed: 02/07/2023] Open
Abstract
The well-orchestrated turnover of proteins in cross-striated muscles is one of the fundamental processes required for muscle cell function and survival. Dysfunction of the intricate protein degradation machinery is often associated with development of cardiac and skeletal muscle myopathies. Most muscle proteins are degraded by the ubiquitin-proteasome system (UPS). The UPS involves a number of enzymes, including E3-ligases, which tightly control which protein substrates are marked for degradation by the proteasome. Recent data reveal that E3-ligases of the cullin family play more diverse and crucial roles in cross striated muscles than previously anticipated. This review highlights some of the findings on the multifaceted functions of cullin-RING E3-ligases, their substrate adapters, muscle protein substrates, and regulatory proteins, such as the Cop9 signalosome, for the development of cross striated muscles, and their roles in the etiology of myopathies.
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Affiliation(s)
- Jordan Blondelle
- Department of Medicine, University of California, La Jolla, CA 92093, USA
| | - Andrea Biju
- Department of Medicine, University of California, La Jolla, CA 92093, USA
| | - Stephan Lange
- Department of Medicine, University of California, La Jolla, CA 92093, USA
- Department of Molecular and Clinical Medicine, University of Gothenburg, 41345 Gothenburg, Sweden
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8
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Samudrala SSK, North LM, Stamm KD, Earing MG, Frommelt MA, Willes R, Tripathi S, Dsouza NR, Zimmermann MT, Mahnke DK, Liang HL, Lund M, Lin C, Geddes GC, Mitchell ME, Tomita‐Mitchell A. Novel KLHL26 variant associated with a familial case of Ebstein's anomaly and left ventricular noncompaction. Mol Genet Genomic Med 2020; 8:e1152. [PMID: 31985165 PMCID: PMC7196453 DOI: 10.1002/mgg3.1152] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Accepted: 01/11/2020] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND Ebstein's anomaly (EA) is a rare congenital heart disease of the tricuspid valve and right ventricle. Patients with EA often manifest with left ventricular noncompaction (LVNC), a cardiomyopathy. Despite implication of cardiac sarcomere genes in some cases, very little is understood regarding the genetic etiology of EA/LVNC. Our study describes a multigenerational family with at least 10 of 17 members affected by EA/LVNC. METHODS We performed echocardiography on all family members and conducted exome sequencing of six individuals. After identifying candidate variants using two different bioinformatic strategies, we confirmed segregation with phenotype using Sanger sequencing. We investigated structural implications of candidate variants using protein prediction models. RESULTS Exome sequencing analysis of four affected and two unaffected members identified a novel, rare, and damaging coding variant in the Kelch-like family member 26 (KLHL26) gene located on chromosome 19 at position 237 of the protein (GRCh37). This variant region was confirmed by Sanger sequencing in the remaining family members. KLHL26 (c.709C > T p.R237C) segregates only with EA/LVNC-affected individuals (FBAT p < .05). Investigating structural implications of the candidate variant using protein prediction models suggested that the KLHL26 variant disrupts electrostatic interactions when binding to part of the ubiquitin proteasome, specifically Cullin3 (CUL3), a component of E3 ubiquitin ligase. CONCLUSION In this familial case of EA/LVNC, we have identified a candidate gene variant, KLHL26 (p.R237C), which may have an important role in ubiquitin-mediated protein degradation during cardiac development.
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Affiliation(s)
- Sai Suma K. Samudrala
- Department of Cell Biology, Neurobiology and AnatomyMedical College of WisconsinMilwaukeeWIUSA
| | - Lauren M. North
- Department of Otolaryngology and Communication SciencesMedical College of WisconsinMilwaukeeWIUSA
| | - Karl D. Stamm
- Department of SurgeryDivision of Cardiothoracic SurgeryMedical College of WisconsinMilwaukeeWIUSA
| | - Michael G. Earing
- Department of PediatricsChildren’s Hospital of WisconsinMilwaukeeWIUSA
- Herma Heart InstituteChildren’s Hospital of WisconsinMilwaukeeWIUSA
| | - Michele A. Frommelt
- Department of PediatricsChildren’s Hospital of WisconsinMilwaukeeWIUSA
- Herma Heart InstituteChildren’s Hospital of WisconsinMilwaukeeWIUSA
| | - Richard Willes
- Department of PediatricsChildren’s Hospital of WisconsinMilwaukeeWIUSA
| | - Swarnendu Tripathi
- Bioinformatics Research and Developmental LabGenomic Sciences and Precision Medicine CenterMedical College of WisconsinMilwaukeeWIUSA
| | - Nikita R. Dsouza
- Bioinformatics Research and Developmental LabGenomic Sciences and Precision Medicine CenterMedical College of WisconsinMilwaukeeWIUSA
| | - Michael T. Zimmermann
- Bioinformatics Research and Developmental LabGenomic Sciences and Precision Medicine CenterMedical College of WisconsinMilwaukeeWIUSA
- Clinical and Translational Science InstituteMedical College of WisconsinMilwaukeeWIUSA
| | - Donna K. Mahnke
- Department of SurgeryDivision of Cardiothoracic SurgeryMedical College of WisconsinMilwaukeeWIUSA
| | - Huan Ling Liang
- Department of SurgeryDivision of Cardiothoracic SurgeryMedical College of WisconsinMilwaukeeWIUSA
| | - Michael Lund
- Department of Obstetrics and GynecologyMedical College of WisconsinMilwaukeeWIUSA
| | - Chien‐Wei Lin
- Division of BiostatisticsMedical College of WisconsinMilwaukeeWIUSA
| | | | - Michael E. Mitchell
- Department of SurgeryDivision of Cardiothoracic SurgeryMedical College of WisconsinMilwaukeeWIUSA
- Herma Heart InstituteChildren’s Hospital of WisconsinMilwaukeeWIUSA
| | - Aoy Tomita‐Mitchell
- Department of SurgeryDivision of Cardiothoracic SurgeryMedical College of WisconsinMilwaukeeWIUSA
- Herma Heart InstituteChildren’s Hospital of WisconsinMilwaukeeWIUSA
- Department of Biomedical EngineeringMedical College of WisconsinMilwaukeeWIUSA
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9
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Okumura F, Fujiki Y, Oki N, Osaki K, Nishikimi A, Fukui Y, Nakatsukasa K, Kamura T. Cul5-type Ubiquitin Ligase KLHDC1 Contributes to the Elimination of Truncated SELENOS Produced by Failed UGA/Sec Decoding. iScience 2020; 23:100970. [PMID: 32200094 PMCID: PMC7090344 DOI: 10.1016/j.isci.2020.100970] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 02/10/2020] [Accepted: 03/04/2020] [Indexed: 02/06/2023] Open
Abstract
The UGA codon signals protein translation termination, but it can also be translated into selenocysteine (Sec, U) to produce selenocysteine-containing proteins (selenoproteins) by dedicated machinery. As Sec incorporation can fail, Sec-containing longer and Sec-lacking shorter proteins co-exist. Cul2-type ubiquitin ligases were recently shown to destabilize such truncated proteins; however, which ubiquitin ligase targets truncated proteins for degradation remained unclear. We report that the Cul5-type ubiquitin ligase KLHDC1 targets truncated SELENOS, a selenoprotein, for proteasomal degradation. SELENOS is involved in endoplasmic reticulum (ER)-associated degradation, which is linked to reactive oxygen species (ROS) production, and the knockdown of KLHDC1 in U2OS cells decreased ER stress-induced cell death. Knockdown of SELENOS increased the cell population with lower ROS levels. Our findings reveal that, in addition to Cul2-type ubiquitin ligases, KLHDC1 is involved in the elimination of truncated oxidoreductase-inactive SELENOS, which would be crucial for maintaining ROS levels and preventing cancer development. KLHDC1 is a Cul5-type ubiquitin ligase KLHDC1 targets immature SELENOS for proteasomal degradation KLHDC1 knockdown in U2OS cells decreases ER stress-induced cell death
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Affiliation(s)
- Fumihiko Okumura
- Department of Food and Health Sciences, International College of Arts and Sciences, Fukuoka Women's University, Fukuoka 813-8582, Japan.
| | - Yuha Fujiki
- Department of Food and Health Sciences, International College of Arts and Sciences, Fukuoka Women's University, Fukuoka 813-8582, Japan
| | - Nodoka Oki
- Department of Food and Health Sciences, International College of Arts and Sciences, Fukuoka Women's University, Fukuoka 813-8582, Japan
| | - Kana Osaki
- Department of Food and Health Sciences, International College of Arts and Sciences, Fukuoka Women's University, Fukuoka 813-8582, Japan
| | - Akihiko Nishikimi
- Laboratory of Biosafety Research, National Center for Geriatrics and Gerontology, Aichi 474-8511, Japan
| | - Yoshinori Fukui
- Division of Immunogenetics, Department of Immunobiology and Neuroscience and Research Center for Advanced Immunology, Medical Institute of Bioregulation, Kyushu University, Fukuoka 812-8582, Japan
| | - Kunio Nakatsukasa
- Graduate School of Natural Sciences, Nagoya City University, Aichi 467-8501, Japan
| | - Takumi Kamura
- Division of Biological Science, Graduate School of Science, Nagoya University, Aichi 464-8602, Japan.
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10
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Hanlon K, Thompson A, Pantano L, Hutchinson JN, Al-Obeidi A, Wang S, Bliss-Moreau M, Helble J, Alexe G, Stegmaier K, Bauer DE, Croker BA. Single-cell cloning of human T-cell lines reveals clonal variation in cell death responses to chemotherapeutics. Cancer Genet 2019; 237:69-77. [PMID: 31447068 DOI: 10.1016/j.cancergen.2019.06.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 04/18/2019] [Accepted: 06/09/2019] [Indexed: 12/12/2022]
Abstract
Genetic modification of human leukemic cell lines using CRISPR-Cas9 has become a staple of gene-function studies. Single-cell cloning of modified cells is frequently used to facilitate studies of gene function. Inherent in this approach is an assumption that the genetic drift, amplified in some cell lines by mutations in DNA replication and repair machinery, as well as non-genetic factors will not introduce significant levels of experimental cellular heterogeneity in clones derived from parental populations. In this study, we characterize the variation in cell death of fifty clonal cell lines generated from human Jurkat and MOLT-4 T-cells edited by CRISPR-Cas9. We demonstrate a wide distribution of sensitivity to chemotherapeutics between non-edited clonal human leukemia T-cell lines, and also following CRISPR-Cas9 editing at the NLRP1 locus, or following transfection with non-targeting sgRNA controls. The cell death sensitivity profile of clonal cell lines was consistent across experiments and failed to revert to the non-clonal parental phenotype. Whole genome sequencing of two clonal cell lines edited by CRISPR-Cas9 revealed unique and shared genetic variants, which had minimal read support in the non-clonal parental population and were not suspected CRISPR-Cas9 off-target effects. These variants included genes related to cell death and drug metabolism. The variation in cell death phenotype of clonal populations of human T-cell lines may be a consequence of T-cell line genetic instability, and to a lesser extent clonal heterogeneity in the parental population or CRISPR-Cas9 off-target effects not predicted by current models. This work highlights the importance of genetic variation between clonal T-cell lines in the design, conduct, and analysis of experiments to investigate gene function after single-cell cloning.
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Affiliation(s)
- Kathleen Hanlon
- Division of Hematology/Oncology, Boston Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, United States
| | - Alex Thompson
- Division of Hematology/Oncology, Boston Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, United States
| | - Lorena Pantano
- Department of Biostatistics, Harvard Chan School of Public Health, Boston, MA, United States
| | - John N Hutchinson
- Department of Biostatistics, Harvard Chan School of Public Health, Boston, MA, United States
| | - Arshed Al-Obeidi
- Division of Hematology/Oncology, Boston Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, United States
| | - Shu Wang
- Division of Hematology/Oncology, Boston Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, United States
| | - Meghan Bliss-Moreau
- Division of Hematology/Oncology, Boston Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, United States
| | - Jennifer Helble
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA, United States
| | - Gabriela Alexe
- Department of Pediatric Oncology, Dana-Farber Cancer Institute and Boston Children's Hospital, Boston, MA, United States
| | - Kimberly Stegmaier
- Department of Pediatric Oncology, Dana-Farber Cancer Institute and Boston Children's Hospital, Boston, MA, United States
| | - Daniel E Bauer
- Division of Hematology/Oncology, Boston Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, United States; Department of Pediatrics, Harvard Medical School, Boston, MA, United States
| | - Ben A Croker
- Division of Hematology/Oncology, Boston Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, United States; Department of Pediatrics, Harvard Medical School, Boston, MA, United States.
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11
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The role of prostate tumor overexpressed 1 in cancer progression. Oncotarget 2017; 8:12451-12471. [PMID: 28029646 PMCID: PMC5355357 DOI: 10.18632/oncotarget.14104] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Accepted: 11/14/2016] [Indexed: 12/15/2022] Open
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12
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Gupta VA, Beggs AH. Kelch proteins: emerging roles in skeletal muscle development and diseases. Skelet Muscle 2014; 4:11. [PMID: 24959344 PMCID: PMC4067060 DOI: 10.1186/2044-5040-4-11] [Citation(s) in RCA: 103] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2014] [Accepted: 05/06/2014] [Indexed: 12/11/2022] Open
Abstract
Our understanding of genes that cause skeletal muscle disease has increased tremendously over the past three decades. Advances in approaches to genetics and genomics have aided in the identification of new pathogenic mechanisms in rare genetic disorders and have opened up new avenues for therapeutic interventions by identification of new molecular pathways in muscle disease. Recent studies have identified mutations of several Kelch proteins in skeletal muscle disorders. The Kelch superfamily is one of the largest evolutionary conserved gene families. The 66 known family members all possess a Kelch-repeat containing domain and are implicated in diverse biological functions. In skeletal muscle development, several Kelch family members regulate the processes of proliferation and/or differentiation resulting in normal functioning of mature muscles. Importantly, many Kelch proteins function as substrate-specific adaptors for Cullin E3 ubiquitin ligase (Cul3), a core component of the ubiquitin-proteasome system to regulate the protein turnover. This review discusses the emerging roles of Kelch proteins in skeletal muscle function and disease.
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Affiliation(s)
- Vandana A Gupta
- Division of Genetics and Genomics, The Manton Center for Orphan Disease Research, Boston Children's Hospital, Harvard Medical School, 300 Longwood Ave., Boston, MA 02115, USA
| | - Alan H Beggs
- Division of Genetics and Genomics, The Manton Center for Orphan Disease Research, Boston Children's Hospital, Harvard Medical School, 300 Longwood Ave., Boston, MA 02115, USA
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13
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Chan CP, Kok KH, Tang HMV, Wong CM, Jin DY. Internal ribosome entry site-mediated translational regulation of ATF4 splice variant in mammalian unfolded protein response. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2013; 1833:2165-75. [PMID: 23665047 DOI: 10.1016/j.bbamcr.2013.05.002] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2013] [Revised: 04/30/2013] [Accepted: 05/02/2013] [Indexed: 02/04/2023]
Abstract
Activating transcription factor 4 (ATF4) is a master regulator of genes involved in unfolded protein response (UPR) and its translation is regulated through reinitiation at upstream open reading frames. Here, we demonstrate internal ribosome entry site (IRES)-mediated translation of an alternatively spliced variant of human ATF4. This variant that contains four upstream open reading frames in the 5' leader region was expressed in leukocytes and other tissues. mRNA and protein expression of this variant was activated in the UPR. Its translation was neither inhibited by steric hindrance nor affected by eIF4G1 inactivation, indicating a cap-independent and IRES-dependent mechanism not mediated by ribosome scanning-reinitiation. The IRES activity mapped to a highly structured region that partially overlaps with the third and fourth open reading frames was unlikely attributed to cryptic promoter or splicing, but was activated by PERK-induced eIF2α phosphorylation. Taken together, our findings reveal a new mechanism for translational regulation of ATF4 in mammalian UPR.
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Affiliation(s)
- Ching-Ping Chan
- Department of Biochemistry, The University of Hong Kong, Pokfulam, Hong Kong
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14
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Liu J, Li F, Rozovsky S. The intrinsically disordered membrane protein selenoprotein S is a reductase in vitro. Biochemistry 2013; 52:3051-61. [PMID: 23566202 DOI: 10.1021/bi4001358] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Selenoprotein S (SelS or VIMP) is an intrinsically disordered membrane enzyme that provides protection against reactive oxidative species. SelS is a member of the endoplasmic reticulum-associated protein degradation pathway, but its precise enzymatic function is unknown. Because it contains the rare amino acid selenocysteine, it belongs to the family of selenoproteins, which are typically oxidoreductases. Its exact enzymatic function is key to understanding how the cell regulates the response to oxidative stress and thus influences human health and aging. To identify its enzymatic function, we have isolated the selenocysteine-containing enzyme by relying on the aggregation of forms that do not have this reactive residue. That allows us to establish that SelS is primarily a thioredoxin-dependent reductase. It is capable of reducing hydrogen peroxide but is not an efficient or broad-spectrum peroxidase. Only the selenocysteine-containing enzyme is active. In addition, the reduction potential of SelS was determined to be -234 mV using electrospray ionization mass spectrometry. This value is consistent with SelS being a partner of thioredoxin. On the basis of this information, SelS can directly combat reactive oxygen species but is also likely to participate in a signaling pathway, via a yet unidentified substrate.
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Affiliation(s)
- Jun Liu
- Department of Chemistry and Biochemistry, University of Delaware, Newark, DE 19716, USA
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15
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Chan CP, Mak TY, Chin KT, Ng IOL, Jin DY. N-linked glycosylation is required for optimal proteolytic activation of membrane-bound transcription factor CREB-H. J Cell Sci 2010; 123:1438-48. [PMID: 20356926 DOI: 10.1242/jcs.067819] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
CREB-H is a liver-enriched bZIP transcription factor of the CREB3 subfamily. CREB-H is activated by intramembrane proteolysis that removes a C-terminal transmembrane domain. Aberrant expression of CREB-H is implicated in liver cancer. In this study we characterized N-linked glycosylation of CREB-H in the luminal domain at the C-terminus. We found that CREB-H is modified at three N-linked glycosylation sites in this region. Disruption of all three sites by site-directed mutagenesis completely abrogated N-linked glycosylation of CREB-H. The unglycosylated mutant of CREB-H was not unstable, unfolded or aggregated. Upon stimulation with an activator of intramembrane proteolysis such as brefeldin A and KDEL-tailed site 1 protease, unglycosylated or deglycosylated CREB-H was largely uncleaved, retained in an inactive form in the endoplasmic reticulum, and less capable of activating transcription driven by unfolded protein response element or C-reactive protein promoter. Taken together, our findings suggest that N-linked glycosylation is required for full activation of CREB-H through intramembrane proteolysis. Our work also reveals a novel mechanism for the regulation of CREB-H-dependent transcription.
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Affiliation(s)
- Chi-Ping Chan
- Department of Biochemistry, The University of Hong Kong, Faculty of Medicine Building, 21 Sassoon Road, Pokfulam, Hong Kong
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