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Jalil S, Keskinen T, Juutila J, Sartori Maldonado R, Euro L, Suomalainen A, Lapatto R, Kuuluvainen E, Hietakangas V, Otonkoski T, Hyvönen ME, Wartiovaara K. Genetic and functional correction of argininosuccinate lyase deficiency using CRISPR adenine base editors. Am J Hum Genet 2024; 111:714-728. [PMID: 38579669 PMCID: PMC11023919 DOI: 10.1016/j.ajhg.2024.03.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Revised: 03/06/2024] [Accepted: 03/06/2024] [Indexed: 04/07/2024] Open
Abstract
Argininosuccinate lyase deficiency (ASLD) is a recessive metabolic disorder caused by variants in ASL. In an essential step in urea synthesis, ASL breaks down argininosuccinate (ASA), a pathognomonic ASLD biomarker. The severe disease forms lead to hyperammonemia, neurological injury, and even early death. The current treatments are unsatisfactory, involving a strict low-protein diet, arginine supplementation, nitrogen scavenging, and in some cases, liver transplantation. An unmet need exists for improved, efficient therapies. Here, we show the potential of a lipid nanoparticle-mediated CRISPR approach using adenine base editors (ABEs) for ASLD treatment. To model ASLD, we first generated human-induced pluripotent stem cells (hiPSCs) from biopsies of individuals homozygous for the Finnish founder variant (c.1153C>T [p.Arg385Cys]) and edited this variant using the ABE. We then differentiated the hiPSCs into hepatocyte-like cells that showed a 1,000-fold decrease in ASA levels compared to those of isogenic non-edited cells. Lastly, we tested three different FDA-approved lipid nanoparticle formulations to deliver the ABE-encoding RNA and the sgRNA targeting the ASL variant. This approach efficiently edited the ASL variant in fibroblasts with no apparent cell toxicity and minimal off-target effects. Further, the treatment resulted in a significant decrease in ASA, to levels of healthy donors, indicating restoration of the urea cycle. Our work describes a highly efficient approach to editing the disease-causing ASL variant and restoring the function of the urea cycle. This method relies on RNA delivered by lipid nanoparticles, which is compatible with clinical applications, improves its safety profile, and allows for scalable production.
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Affiliation(s)
- Sami Jalil
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Timo Keskinen
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Juhana Juutila
- Faculty of Biological and Environmental Sciences University of Helsinki, Helsinki, Finland; Institute of Biotechnology, Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
| | - Rocio Sartori Maldonado
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Liliya Euro
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Anu Suomalainen
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Risto Lapatto
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland; New Children's Hospital, Pediatric Research Center, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Emilia Kuuluvainen
- Faculty of Biological and Environmental Sciences University of Helsinki, Helsinki, Finland; Institute of Biotechnology, Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
| | - Ville Hietakangas
- Faculty of Biological and Environmental Sciences University of Helsinki, Helsinki, Finland; Institute of Biotechnology, Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
| | - Timo Otonkoski
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland; New Children's Hospital, Pediatric Research Center, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Mervi E Hyvönen
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland; New Children's Hospital, Pediatric Research Center, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
| | - Kirmo Wartiovaara
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland; Clinical Genetics, Helsinki University Hospital, Helsinki, Finland.
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Rönkkö J, Rodriguez Y, Rasila T, Torregrosa-Muñumer R, Pennonen J, Kvist J, Kuuluvainen E, Bosch LVD, Hietakangas V, Bultynck G, Tyynismaa H, Ylikallio E. Human IP 3 receptor triple knockout stem cells remain pluripotent despite altered mitochondrial metabolism. Cell Calcium 2023; 114:102782. [PMID: 37481871 DOI: 10.1016/j.ceca.2023.102782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Revised: 06/14/2023] [Accepted: 07/13/2023] [Indexed: 07/25/2023]
Abstract
Inositol 1,4,5-trisphosphate receptors (IP3Rs) are ER Ca2+-release channels that control a broad set of cellular processes. Animal models lacking IP3Rs in different combinations display severe developmental phenotypes. Given the importance of IP3Rs in human diseases, we investigated their role in human induced pluripotent stem cells (hiPSC) by developing single IP3R and triple IP3R knockouts (TKO). Genome edited TKO-hiPSC lacking all three IP3R isoforms, IP3R1, IP3R2, IP3R3, failed to generate Ca2+ signals in response to agonists activating GPCRs, but retained stemness and pluripotency. Steady state metabolite profiling and flux analysis of TKO-hiPSC indicated distinct alterations in tricarboxylic acid cycle metabolites consistent with a deficiency in their pyruvate utilization via pyruvate dehydrogenase, shifting towards pyruvate carboxylase pathway. These results demonstrate that IP3Rs are not essential for hiPSC identity and pluripotency but regulate mitochondrial metabolism. This set of knockout hiPSC is a valuable resource for investigating IP3Rs in human cell types of interest.
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Affiliation(s)
- Julius Rönkkö
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, 00290, Finland
| | - Yago Rodriguez
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, 00290, Finland
| | - Tiina Rasila
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, 00290, Finland
| | - Rubén Torregrosa-Muñumer
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, 00290, Finland
| | - Jana Pennonen
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, 00290, Finland
| | - Jouni Kvist
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, 00290, Finland
| | - Emilia Kuuluvainen
- Molecular and Integrative Bioscience Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, 00790, Finland; Institute of Biotechnology, HiLIFE, University of Helsinki, Helsinki, 00790, Finland
| | - Ludo Van Den Bosch
- Department of Neurosciences, Experimental Neurology and Leuven Brain Institute, KU Leuven - University of Leuven, 3000, Leuven, Belgium; VIB Center for Brain & Disease Research, Laboratory of Neurobiology, 3000, Leuven, Belgium
| | - Ville Hietakangas
- Molecular and Integrative Bioscience Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, 00790, Finland; Institute of Biotechnology, HiLIFE, University of Helsinki, Helsinki, 00790, Finland
| | - Geert Bultynck
- KU Leuven, Laboratory of Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine & Leuven Kanker Instituut, Leuven, 3000, Belgium
| | - Henna Tyynismaa
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, 00290, Finland
| | - Emil Ylikallio
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, 00290, Finland; Clinical Neurosciences, Neurology, University of Helsinki and Helsinki University Hospital, Helsinki, 00290, Finland.
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3
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Barsby T, Vähäkangas E, Ustinov J, Montaser H, Ibrahim H, Lithovius V, Kuuluvainen E, Chandra V, Saarimäki-Vire J, Katajisto P, Hietakangas V, Otonkoski T. Aberrant metabolite trafficking and fuel sensitivity in human pluripotent stem cell-derived islets. Cell Rep 2023; 42:112970. [PMID: 37556323 DOI: 10.1016/j.celrep.2023.112970] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 06/09/2023] [Accepted: 07/26/2023] [Indexed: 08/11/2023] Open
Abstract
Pancreatic islets regulate blood glucose homeostasis through the controlled release of insulin; however, current metabolic models of glucose-sensitive insulin secretion are incomplete. A comprehensive understanding of islet metabolism is integral to studies of endocrine cell development as well as diabetic islet dysfunction. Human pluripotent stem cell-derived islets (SC-islets) are a developmentally relevant model of human islet function that have great potential in providing a cure for type 1 diabetes. Using multiple 13C-labeled metabolic fuels, we demonstrate that SC-islets show numerous divergent patterns of metabolite trafficking in proposed insulin release pathways compared with primary human islets but are still reliant on mitochondrial aerobic metabolism to derive function. Furthermore, reductive tricarboxylic acid cycle activity and glycolytic metabolite cycling occur in SC-islets, suggesting that non-canonical coupling factors are also present. In aggregate, we show that many facets of SC-islet metabolism overlap with those of primary islets, albeit with a retained immature signature.
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Affiliation(s)
- Tom Barsby
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland.
| | - Eliisa Vähäkangas
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Jarkko Ustinov
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Hossam Montaser
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Hazem Ibrahim
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Väinö Lithovius
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Emilia Kuuluvainen
- Institute of Biotechnology, Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
| | - Vikash Chandra
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Jonna Saarimäki-Vire
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Pekka Katajisto
- Institute of Biotechnology, Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
| | - Ville Hietakangas
- Institute of Biotechnology, Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
| | - Timo Otonkoski
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland; Children's Hospital, Helsinki University Hospital and University of Helsinki, Helsinki, Finland.
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4
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Balboa D, Barsby T, Lithovius V, Saarimäki-Vire J, Omar-Hmeadi M, Dyachok O, Montaser H, Lund PE, Yang M, Ibrahim H, Näätänen A, Chandra V, Vihinen H, Jokitalo E, Kvist J, Ustinov J, Nieminen AI, Kuuluvainen E, Hietakangas V, Katajisto P, Lau J, Carlsson PO, Barg S, Tengholm A, Otonkoski T. Functional, metabolic and transcriptional maturation of human pancreatic islets derived from stem cells. Nat Biotechnol 2022; 40:1042-1055. [PMID: 35241836 PMCID: PMC9287162 DOI: 10.1038/s41587-022-01219-z] [Citation(s) in RCA: 102] [Impact Index Per Article: 51.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Accepted: 01/11/2022] [Indexed: 12/19/2022]
Abstract
Transplantation of pancreatic islet cells derived from human pluripotent stem cells is a promising treatment for diabetes. Despite progress in the generation of stem-cell-derived islets (SC-islets), no detailed characterization of their functional properties has been conducted. Here, we generated functionally mature SC-islets using an optimized protocol and benchmarked them comprehensively against primary adult islets. Biphasic glucose-stimulated insulin secretion developed during in vitro maturation, associated with cytoarchitectural reorganization and the increasing presence of alpha cells. Electrophysiology, signaling and exocytosis of SC-islets were similar to those of adult islets. Glucose-responsive insulin secretion was achieved despite differences in glycolytic and mitochondrial glucose metabolism. Single-cell transcriptomics of SC-islets in vitro and throughout 6 months of engraftment in mice revealed a continuous maturation trajectory culminating in a transcriptional landscape closely resembling that of primary islets. Our thorough evaluation of SC-islet maturation highlights their advanced degree of functionality and supports their use in further efforts to understand and combat diabetes. Pancreatic islets derived from stem cells are benchmarked against primary cells.
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Affiliation(s)
- Diego Balboa
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland.,Bioinformatics and Genomics Program, Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology (BIST), Barcelona, Spain.,Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Barcelona, Spain
| | - Tom Barsby
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Väinö Lithovius
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Jonna Saarimäki-Vire
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | | | - Oleg Dyachok
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | - Hossam Montaser
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Per-Eric Lund
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | - Mingyu Yang
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | - Hazem Ibrahim
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Anna Näätänen
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Vikash Chandra
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Helena Vihinen
- Electron Microscopy Unit, Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Eija Jokitalo
- Electron Microscopy Unit, Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Jouni Kvist
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Jarkko Ustinov
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Anni I Nieminen
- Metabolomics Unit, Institute for Molecular Medicine Finland, Helsinki, Finland
| | - Emilia Kuuluvainen
- Institute of Biotechnology, Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
| | - Ville Hietakangas
- Institute of Biotechnology, Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland.,Molecular and Integrative Bioscience Research Program, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Pekka Katajisto
- Institute of Biotechnology, Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland.,Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | - Joey Lau
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | - Per-Ola Carlsson
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | - Sebastian Barg
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | - Anders Tengholm
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | - Timo Otonkoski
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland. .,Children's Hospital, Helsinki University Hospital and University of Helsinki, Helsinki, Finland.
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5
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Döhla J, Kuuluvainen E, Gebert N, Amaral A, Englund JI, Gopalakrishnan S, Konovalova S, Nieminen AI, Salminen ES, Torregrosa Muñumer R, Ahlqvist K, Yang Y, Bui H, Otonkoski T, Käkelä R, Hietakangas V, Tyynismaa H, Ori A, Katajisto P. Metabolic determination of cell fate through selective inheritance of mitochondria. Nat Cell Biol 2022; 24:148-154. [PMID: 35165416 PMCID: PMC7612378 DOI: 10.1038/s41556-021-00837-0] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 12/20/2021] [Indexed: 12/13/2022]
Abstract
Metabolic characteristics of adult stem cells are distinct from their differentiated progeny, and cellular metabolism is emerging as a potential driver of cell fate conversions1-4. How these metabolic features are established remains unclear. Here we identified inherited metabolism imposed by functionally distinct mitochondrial age-classes as a fate determinant in asymmetric division of epithelial stem-like cells. While chronologically old mitochondria support oxidative respiration, the electron transport chain of new organelles is proteomically immature and they respire less. After cell division, selectively segregated mitochondrial age-classes elicit a metabolic bias in progeny cells, with oxidative energy metabolism promoting differentiation in cells that inherit old mitochondria. Cells that inherit newly synthesized mitochondria with low levels of Rieske iron-sulfur polypeptide 1 have a higher pentose phosphate pathway activity, which promotes de novo purine biosynthesis and redox balance, and is required to maintain stemness during early fate determination after division. Our results demonstrate that fate decisions are susceptible to intrinsic metabolic bias imposed by selectively inherited mitochondria.
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Affiliation(s)
- Julia Döhla
- Institute of Biotechnology, HiLIFE, University of Helsinki, Helsinki, Finland
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | - Emilia Kuuluvainen
- Institute of Biotechnology, HiLIFE, University of Helsinki, Helsinki, Finland
| | - Nadja Gebert
- Leibniz Institute on Aging-Fritz Lipmann Institute (FLI), Jena, Germany
| | - Ana Amaral
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | - Johanna I Englund
- Institute of Biotechnology, HiLIFE, University of Helsinki, Helsinki, Finland
| | | | - Svetlana Konovalova
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Anni I Nieminen
- Institute of Biotechnology, HiLIFE, University of Helsinki, Helsinki, Finland
- Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Ella S Salminen
- Institute of Biotechnology, HiLIFE, University of Helsinki, Helsinki, Finland
| | - Rubén Torregrosa Muñumer
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Kati Ahlqvist
- Institute of Biotechnology, HiLIFE, University of Helsinki, Helsinki, Finland
| | - Yang Yang
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Hien Bui
- Institute of Biotechnology, HiLIFE, University of Helsinki, Helsinki, Finland
| | - Timo Otonkoski
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Reijo Käkelä
- Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Ville Hietakangas
- Institute of Biotechnology, HiLIFE, University of Helsinki, Helsinki, Finland
- Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
| | - Henna Tyynismaa
- Stem Cells and Metabolism Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
- Neuroscience Center, HiLIFE, University of Helsinki, Helsinki, Finland
| | - Alessandro Ori
- Leibniz Institute on Aging-Fritz Lipmann Institute (FLI), Jena, Germany
| | - Pekka Katajisto
- Institute of Biotechnology, HiLIFE, University of Helsinki, Helsinki, Finland.
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden.
- Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland.
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6
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Kuuluvainen E, Hakala H, Havula E, Sahal Estimé M, Rämet M, Hietakangas V, Mäkelä TP. Cyclin-dependent kinase 8 module expression profiling reveals requirement of mediator subunits 12 and 13 for transcription of Serpent-dependent innate immunity genes in Drosophila. J Biol Chem 2014; 289:16252-61. [PMID: 24778181 DOI: 10.1074/jbc.m113.541904] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The Cdk8 (cyclin-dependent kinase 8) module of Mediator integrates regulatory cues from transcription factors to RNA polymerase II. It consists of four subunits where Med12 and Med13 link Cdk8 and cyclin C (CycC) to core Mediator. Here we have investigated the contributions of the Cdk8 module subunits to transcriptional regulation using RNA interference in Drosophila cells. Genome-wide expression profiling demonstrated separation of Cdk8-CycC and Med12-Med13 profiles. However, transcriptional regulation by Cdk8-CycC was dependent on Med12-Med13. This observation also revealed that Cdk8-CycC and Med12-Med13 often have opposite transcriptional effects. Interestingly, Med12 and Med13 profiles overlapped significantly with that of the GATA factor Serpent. Accordingly, mutational analyses indicated that GATA sites are required for Med12-Med13 regulation of Serpent-dependent genes. Med12 and Med13 were also found to be required for Serpent-activated innate immunity genes in defense to bacterial infection. The results reveal a novel role for the Cdk8 module in Serpent-dependent transcription and innate immunity.
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Affiliation(s)
- Emilia Kuuluvainen
- From the Institute of Biotechnology, University of Helsinki, P. O. Box 56, 00014 Helsinki
| | - Heini Hakala
- From the Institute of Biotechnology, University of Helsinki, P. O. Box 56, 00014 Helsinki
| | - Essi Havula
- From the Institute of Biotechnology, University of Helsinki, P. O. Box 56, 00014 Helsinki, the Department of Biosciences, University of Helsinki, P. O. Box 65, 00014 Helsinki
| | - Michelle Sahal Estimé
- From the Institute of Biotechnology, University of Helsinki, P. O. Box 56, 00014 Helsinki
| | - Mika Rämet
- the Institute of Biomedical Technology, and BioMediTech, University of Tampere, 33014 Tampere, the Department of Pediatrics, Tampere University Hospital, 22521 Tampere, the Department of Pediatrics, Institute of Clinical Medicine, and Medical Research Center Oulu, University of Oulu, 90014 Oulu, and the Department of Children and Adolescents, Oulu University Hospital, 90029 Oulu, Finland
| | - Ville Hietakangas
- From the Institute of Biotechnology, University of Helsinki, P. O. Box 56, 00014 Helsinki, the Department of Biosciences, University of Helsinki, P. O. Box 65, 00014 Helsinki
| | - Tomi P Mäkelä
- From the Institute of Biotechnology, University of Helsinki, P. O. Box 56, 00014 Helsinki,
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7
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Abstract
The Cdk8 kinase and associated proteins form a nonessential transcriptional repressor module of the Mediator in the budding yeast Saccharomyces cerevisiae. Genetic analyses of this module have demonstrated functions ranging from environmental responses in budding yeast to organogenesis and development in worms, flies, and zebrafish. Here we have investigated the function of mammalian Cdk8 using mice harboring a gene trap insertion at the Cdk8 locus inactivating this kinase. No phenotypes were noted in heterozygote Cdk8+/- mice, but intercrossing these did not produce homozygous Cdk8-/- offspring. Developmental analysis demonstrated a requirement for Cdk8 prior to implantation at embryonic days 2.5 to 3.0. Cdk8-/- preimplantation embryos had fragmented blastomeres and did not proceed to compaction. As Cdk8 deficiency in cultured metazoan cells did not affect cell viability, the results suggest that transcriptional repression of genes critical for early-cell-fate determination underlies the requirement of Cdk8 in embryogenesis.
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Affiliation(s)
- Thomas Westerling
- Genome-Scale Biology Program and Institute of Biomedicine, Biomedicum Helsinki, University of Helsinki, P.O. Box 63, 00014 Helsinki, Finland
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