1
|
Martin P, Szkop KJ, Robert F, Bhattacharyya S, Beauchamp RL, Brenner J, Redmond NE, Huang S, Erdin S, Larsson O, Ramesh V. TSC2 loss in neural progenitor cells suppresses translation of ASD/NDD-associated transcripts in an mTORC1- and MNK1/2-reversible fashion. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.04.597393. [PMID: 38895292 PMCID: PMC11185676 DOI: 10.1101/2024.06.04.597393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/21/2024]
Abstract
Tuberous sclerosis complex (TSC) is an inherited neurodevelopmental disorder (NDD) with frequent manifestations of epilepsy and autism spectrum disorder (ASD). TSC is caused by inactivating mutations in TSC1 or TSC2 tumor suppressor genes, with encoded proteins hamartin (TSC1) and tuberin (TSC2) forming a functional complex inhibiting mechanistic target of rapamycin complex 1 (mTORC1) signaling. This has led to treatment with allosteric mTORC1 inhibitor rapamycin analogs ("rapalogs") for TSC tumors; however, rapalogs are ineffective for treating neurodevelopmental manifestations. mTORC1 signaling controls protein synthesis by regulating formation of the eIF4F complex, with further modulation by MNK1/2 kinases via phosphorylation of the eIF4F subunit eIF4E. While both these pathways modulate translation, comparing their impact on transcriptome-wide mRNA translation, as well as effects of inhibiting these pathways in TSC has not been explored. Here, employing CRISPR-modified, isogenic TSC2 patient-derived neural progenitor cells (NPCs), we have examined transcriptome-wide changes in mRNA translation upon TSC2 loss. Our results reveal dysregulated translation in TSC2 -Null NPCs, which significantly overlaps with the translatome from TSC1 -Null NPCs. Interestingly, numerous non-monogenic ASD-, NDD-and epilepsy-associated genes identified in patients harboring putative loss-of-function mutations, were translationally suppressed in TSC2 -Null NPCs. Importantly, translation of these ASD- and NDD-associated genes was reversed upon inhibition of either mTORC1 or MNK1/2 signaling using RMC-6272 or eFT-508, respectively. This study establishes the importance of mTORC1-eIF4F- and MNK-eIF4E-sensitive mRNA translation in TSC, ASD and other neurodevelopmental disorders laying the groundwork for evaluating drugs in clinical development that target these pathways as a treatment strategy for these disorders.
Collapse
|
2
|
Mi J, Ren L, Andersson O. Leveraging zebrafish to investigate pancreatic development, regeneration, and diabetes. Trends Mol Med 2024:S1471-4914(24)00124-2. [PMID: 38825440 DOI: 10.1016/j.molmed.2024.05.002] [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: 01/31/2024] [Revised: 04/30/2024] [Accepted: 05/01/2024] [Indexed: 06/04/2024]
Abstract
The zebrafish has become an outstanding model for studying organ development and tissue regeneration, which is prominently leveraged for studies of pancreatic development, insulin-producing β-cells, and diabetes. Although studied for more than two decades, many aspects remain elusive and it has only recently been possible to investigate these due to technical advances in transcriptomics, chemical-genetics, genome editing, drug screening, and in vivo imaging. Here, we review recent findings on zebrafish pancreas development, β-cell regeneration, and how zebrafish can be used to provide novel insights into gene functions, disease mechanisms, and therapeutic targets in diabetes, inspiring further use of zebrafish for the development of novel therapies for diabetes.
Collapse
Affiliation(s)
- Jiarui Mi
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden; Department of Gastroenterology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, China.
| | - Lipeng Ren
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden; Department of Medical Cell Biology, Uppsala University, Biomedical Centre, Uppsala, Sweden
| | - Olov Andersson
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden; Department of Medical Cell Biology, Uppsala University, Biomedical Centre, Uppsala, Sweden.
| |
Collapse
|
3
|
Ren L, Charbord J, Chu L, Kemas AM, Bertuzzi M, Mi J, Xing C, Lauschke VM, Andersson O. Adjudin improves beta cell maturation, hepatic glucose uptake and glucose homeostasis. Diabetologia 2024; 67:137-155. [PMID: 37843554 PMCID: PMC10709271 DOI: 10.1007/s00125-023-06020-4] [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: 03/07/2023] [Accepted: 08/10/2023] [Indexed: 10/17/2023]
Abstract
AIMS/HYPOTHESIS Recovering functional beta cell mass is a promising approach for future diabetes therapies. The aim of the present study is to investigate the effects of adjudin, a small molecule identified in a beta cell screen using zebrafish, on pancreatic beta cells and diabetes conditions in mice and human spheroids. METHODS In zebrafish, insulin expression was examined by bioluminescence and quantitative real-time PCR (qPCR), glucose levels were examined by direct measurements and distribution using a fluorescent glucose analogue, and calcium activity in beta cells was analysed by in vivo live imaging. Pancreatic islets of wild-type postnatal day 0 (P0) and 3-month-old (adult) mice, as well as adult db/db mice (i.e. BKS(D)-Leprdb/JOrlRj), were cultured in vitro and analysed by qPCR, glucose stimulated insulin secretion and whole mount staining. RNA-seq was performed for islets of P0 and db/db mice. For in vivo assessment, db/db mice were treated with adjudin and subjected to analysis of metabolic variables and islet cells. Glucose consumption was examined in primary human hepatocyte spheroids. RESULTS Adjudin treatment increased insulin expression and calcium response to glucose in beta cells and decreased glucose levels after beta cell ablation in zebrafish. Adjudin led to improved beta cell function, decreased beta cell proliferation and glucose responsive insulin secretion by decreasing basal insulin secretion in in vitro cultured newborn mouse islets. RNA-seq of P0 islets indicated that adjudin treatment resulted in increased glucose metabolism and mitochondrial function, as well as downstream signalling pathways involved in insulin secretion. In islets from db/db mice cultured in vitro, adjudin treatment strengthened beta cell identity and insulin secretion. RNA-seq of db/db islets indicated adjudin-upregulated genes associated with insulin secretion, membrane ion channel activity and exocytosis. Moreover, adjudin promoted glucose uptake in the liver of zebrafish in an insulin-independent manner, and similarly promoted glucose consumption in primary human hepatocyte spheroids with insulin resistance. In vivo studies using db/db mice revealed reduced nonfasting blood glucose, improved glucose tolerance and strengthened beta cell identity after adjudin treatment. CONCLUSIONS/INTERPRETATION Adjudin promoted functional maturation of immature islets, improved function of dysfunctional islets, stimulated glucose uptake in liver and improved glucose homeostasis in db/db mice. Thus, the multifunctional drug adjudin, previously studied in various contexts and conditions, also shows promise in the management of diabetic states. DATA AVAILABILITY Raw and processed RNA-seq data for this study have been deposited in the Gene Expression Omnibus under accession number GSE235398 ( https://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE235398 ).
Collapse
Affiliation(s)
- Lipeng Ren
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | - Jérémie Charbord
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | - Lianhe Chu
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | - Aurino M Kemas
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Maria Bertuzzi
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Jiarui Mi
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | - Chen Xing
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Volker M Lauschke
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
- Dr Margarete Fischer-Bosch Institute of Clinical Pharmacology, Stuttgart, Germany
- Tübingen University, Tübingen, Germany
| | - Olov Andersson
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden.
| |
Collapse
|
4
|
Chen YC, Taylor AJ, Fulcher JM, Swensen AC, Dai XQ, Komba M, Wrightson KL, Fok K, Patterson AE, Klein Geltink RI, MacDonald PE, Qian WJ, Verchere CB. Deletion of Carboxypeptidase E in β-Cells Disrupts Proinsulin Processing but Does Not Lead to Spontaneous Development of Diabetes in Mice. Diabetes 2023; 72:1277-1288. [PMID: 37364047 PMCID: PMC10450824 DOI: 10.2337/db22-0945] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Accepted: 06/22/2023] [Indexed: 06/28/2023]
Abstract
Carboxypeptidase E (CPE) facilitates the conversion of prohormones into mature hormones and is highly expressed in multiple neuroendocrine tissues. Carriers of CPE mutations have elevated plasma proinsulin and develop severe obesity and hyperglycemia. We aimed to determine whether loss of Cpe in pancreatic β-cells disrupts proinsulin processing and accelerates development of diabetes and obesity in mice. Pancreatic β-cell-specific Cpe knockout mice (βCpeKO; Cpefl/fl x Ins1Cre/+) lack mature insulin granules and have elevated proinsulin in plasma; however, glucose-and KCl-stimulated insulin secretion in βCpeKO islets remained intact. High-fat diet-fed βCpeKO mice showed weight gain and glucose tolerance comparable with those of Wt littermates. Notably, β-cell area was increased in chow-fed βCpeKO mice and β-cell replication was elevated in βCpeKO islets. Transcriptomic analysis of βCpeKO β-cells revealed elevated glycolysis and Hif1α-target gene expression. On high glucose challenge, β-cells from βCpeKO mice showed reduced mitochondrial membrane potential, increased reactive oxygen species, reduced MafA, and elevated Aldh1a3 transcript levels. Following multiple low-dose streptozotocin injections, βCpeKO mice had accelerated development of hyperglycemia with reduced β-cell insulin and Glut2 expression. These findings suggest that Cpe and proper proinsulin processing are critical in maintaining β-cell function during the development of hyperglycemia. ARTICLE HIGHLIGHTS Carboxypeptidase E (Cpe) is an enzyme that removes the carboxy-terminal arginine and lysine residues from peptide precursors. Mutations in CPE lead to obesity and type 2 diabetes in humans, and whole-body Cpe knockout or mutant mice are obese and hyperglycemic and fail to convert proinsulin to insulin. We show that β-cell-specific Cpe deletion in mice (βCpeKO) does not lead to the development of obesity or hyperglycemia, even after prolonged high-fat diet treatment. However, β-cell proliferation rate and β-cell area are increased, and the development of hyperglycemia induced by multiple low-dose streptozotocin injections is accelerated in βCpeKO mice.
Collapse
Affiliation(s)
- Yi-Chun Chen
- Department of Surgery, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
- BC Children’s Hospital Research Institute, Vancouver, British Columbia, Canada
| | - Austin J. Taylor
- BC Children’s Hospital Research Institute, Vancouver, British Columbia, Canada
- Department of Pathology and Laboratory Medicine, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - James M. Fulcher
- Integrative Omics, Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA
| | - Adam C. Swensen
- Integrative Omics, Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA
| | - Xiao-Qing Dai
- Department of Pharmacology, University of Alberta, Edmonton, Alberta, Canada
| | - Mitsuhiro Komba
- Department of Surgery, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
- BC Children’s Hospital Research Institute, Vancouver, British Columbia, Canada
| | | | - Kenny Fok
- BC Children’s Hospital Research Institute, Vancouver, British Columbia, Canada
| | - Annette E. Patterson
- BC Children’s Hospital Research Institute, Vancouver, British Columbia, Canada
- Department of Pathology and Laboratory Medicine, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | - Ramon I. Klein Geltink
- BC Children’s Hospital Research Institute, Vancouver, British Columbia, Canada
- Department of Pathology and Laboratory Medicine, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| | | | - Wei-Jun Qian
- Integrative Omics, Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA
| | - C. Bruce Verchere
- Department of Surgery, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
- BC Children’s Hospital Research Institute, Vancouver, British Columbia, Canada
- Department of Pathology and Laboratory Medicine, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
- Centre for Molecular Medicine and Therapeutics, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| |
Collapse
|
5
|
Mi J, Liu KC, Andersson O. Decoding pancreatic endocrine cell differentiation and β cell regeneration in zebrafish. SCIENCE ADVANCES 2023; 9:eadf5142. [PMID: 37595046 PMCID: PMC10438462 DOI: 10.1126/sciadv.adf5142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Accepted: 07/20/2023] [Indexed: 08/20/2023]
Abstract
In contrast to mice, zebrafish have an exceptional yet elusive ability to replenish lost β cells in adulthood. Understanding this framework would provide mechanistic insights for β cell regeneration, which may be extrapolated to humans. Here, we characterize a krt4-expressing ductal cell type, which is distinct from the putative Notch-responsive cells, showing neogenic competence and giving rise to the majority of endocrine cells during postembryonic development. Furthermore, we demonstrate a marked ductal remodeling process featuring a Notch-responsive to krt4+ luminal duct transformation during late development, indicating several origins of krt4+ ductal cells displaying similar transcriptional patterns. Single-cell transcriptomics upon a series of time points during β cell regeneration unveil a previously unrecognized dlb+ transitional endocrine precursor cell, distinct regulons, and a differentiation trajectory involving cellular shuffling through differentiation and dedifferentiation dynamics. These results establish a model of zebrafish pancreatic endocrinogenesis and highlight key values of zebrafish for translational studies of β cell regeneration.
Collapse
Affiliation(s)
| | - Ka-Cheuk Liu
- Department of Cell and Molecular Biology, Karolinska Institutet, 17177 Stockholm, Sweden
| | | |
Collapse
|
6
|
Subramanian E, Elewa A, Brito G, Kumar A, Segerstolpe Å, Karampelias C, Björklund Å, Sandberg R, Echeverri K, Lui WO, Andersson O, Simon A. A small noncoding RNA links ribosome recovery and translation control to dedifferentiation during salamander limb regeneration. Dev Cell 2023; 58:450-460.e6. [PMID: 36893754 DOI: 10.1016/j.devcel.2023.02.007] [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: 09/15/2021] [Revised: 08/11/2022] [Accepted: 02/09/2023] [Indexed: 03/11/2023]
Abstract
Building a blastema from the stump is a key step of salamander limb regeneration. Stump-derived cells temporarily suspend their identity as they contribute to the blastema by a process generally referred to as dedifferentiation. Here, we provide evidence for a mechanism that involves an active inhibition of protein synthesis during blastema formation and growth. Relieving this inhibition results in a higher number of cycling cells and enhances the pace of limb regeneration. By small RNA profiling and fate mapping of skeletal muscle progeny as a cellular model for dedifferentiation, we find that the downregulation of miR-10b-5p is critical for rebooting the translation machinery. miR-10b-5p targets ribosomal mRNAs, and its artificial upregulation causes decreased blastema cell proliferation, reduction in transcripts that encode ribosomal subunits, diminished nascent protein synthesis, and retardation of limb regeneration. Taken together, our data identify a link between miRNA regulation, ribosome biogenesis, and protein synthesis during newt limb regeneration.
Collapse
Affiliation(s)
| | - Ahmed Elewa
- Department of Genetics, Microbiology and Statistics, Faculty of Biology, University of Barcelona, Barcelona, Spain
| | - Gonçalo Brito
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | - Anoop Kumar
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | - Åsa Segerstolpe
- Klarman Cell Observatory, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Christos Karampelias
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | - Åsa Björklund
- Department of Cell and Molecular Biology, National Infrastructure of Sweden, Science for Life Laboratory, Uppsala University, Uppsala, Sweden
| | - Rickard Sandberg
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | - Karen Echeverri
- Marine Biological Laboratory, Eugene Bell Center for Regenerative Biology and Tissue Engineering, University of Chicago, Woods Hole, MA, USA
| | - Weng-Onn Lui
- Department of Oncology-Pathology, Karolinska University Hospital, Stockholm, Sweden
| | - Olov Andersson
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden
| | - András Simon
- Department of Cell and Molecular Biology, Karolinska Institutet, Stockholm, Sweden.
| |
Collapse
|
7
|
Goode RA, Hum JM, Kalwat MA. Therapeutic Strategies Targeting Pancreatic Islet β-Cell Proliferation, Regeneration, and Replacement. Endocrinology 2022; 164:6836713. [PMID: 36412119 PMCID: PMC9923807 DOI: 10.1210/endocr/bqac193] [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: 09/09/2022] [Revised: 11/16/2022] [Accepted: 11/18/2022] [Indexed: 11/23/2022]
Abstract
Diabetes results from insufficient insulin production by pancreatic islet β-cells or a loss of β-cells themselves. Restoration of regulated insulin production is a predominant goal of translational diabetes research. Here, we provide a brief overview of recent advances in the fields of β-cell proliferation, regeneration, and replacement. The discovery of therapeutic targets and associated small molecules has been enabled by improved understanding of β-cell development and cell cycle regulation, as well as advanced high-throughput screening methodologies. Important findings in β-cell transdifferentiation, neogenesis, and stem cell differentiation have nucleated multiple promising therapeutic strategies. In particular, clinical trials are underway using in vitro-generated β-like cells from human pluripotent stem cells. Significant challenges remain for each of these strategies, but continued support for efforts in these research areas will be critical for the generation of distinct diabetes therapies.
Collapse
Affiliation(s)
- Roy A Goode
- Division of Biomedical Sciences, College of Osteopathic Medicine, Marian University, Indianapolis, IN, USA
| | - Julia M Hum
- Division of Biomedical Sciences, College of Osteopathic Medicine, Marian University, Indianapolis, IN, USA
| | - Michael A Kalwat
- Correspondence: Michael A. Kalwat, PhD, Lilly Diabetes Center of Excellence, Indiana Biosciences Research Institute, 1210 Waterway Blvd, Suite 2000, Indianapolis, IN 46202, USA. or
| |
Collapse
|