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Rutter GA, Gresch A, Delgadillo Silva L, Benninger RKP. Exploring pancreatic beta-cell subgroups and their connectivity. Nat Metab 2024:10.1038/s42255-024-01097-6. [PMID: 39117960 DOI: 10.1038/s42255-024-01097-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2024] [Accepted: 07/05/2024] [Indexed: 08/10/2024]
Abstract
Functional pancreatic islet beta cells are essential to ensure glucose homeostasis across species from zebrafish to humans. These cells show significant heterogeneity, and emerging studies have revealed that connectivity across a hierarchical network is required for normal insulin release. Here, we discuss current thinking and areas of debate around intra-islet connectivity, cellular hierarchies and potential "controlling" beta-cell populations. We focus on methodologies, including comparisons of different cell preparations as well as in vitro and in vivo approaches to imaging and controlling the activity of human and rodent islet preparations. We also discuss the analytical approaches that can be applied to live-cell data to identify and study critical subgroups of cells with a disproportionate role in control Ca2+ dynamics and thus insulin secretion (such as "first responders", "leaders" and "hubs", as defined by Ca2+ responses to glucose stimulation). Possible mechanisms by which this hierarchy is achieved, its physiological relevance and how its loss may contribute to islet failure in diabetes mellitus are also considered. A glossary of terms and links to computational resources are provided.
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Affiliation(s)
- Guy A Rutter
- CHUM Research Center and Faculty of Medicine, University of Montréal, Montréal, QC, Canada.
- Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, London, UK.
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore.
| | - Anne Gresch
- Department of Bioengineering, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Luis Delgadillo Silva
- CHUM Research Center and Faculty of Medicine, University of Montréal, Montréal, QC, Canada
| | - Richard K P Benninger
- Department of Bioengineering, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
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MacCalman A, De Franco E, Franklin A, Flaxman CS, Richardson SJ, Murrall K, Burrage J, Walker EM, Morgan NG, Hattersley AT, Dempster EL, Hannon E, Jeffries AR, Owens NDL, Mill J. Developmentally dynamic changes in DNA methylation in the human pancreas. BMC Genomics 2024; 25:553. [PMID: 38831310 PMCID: PMC11145889 DOI: 10.1186/s12864-024-10450-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2024] [Accepted: 05/24/2024] [Indexed: 06/05/2024] Open
Abstract
Development of the human pancreas requires the precise temporal control of gene expression via epigenetic mechanisms and the binding of key transcription factors. We quantified genome-wide patterns of DNA methylation in human fetal pancreatic samples from donors aged 6 to 21 post-conception weeks. We found dramatic changes in DNA methylation across pancreas development, with > 21% of sites characterized as developmental differentially methylated positions (dDMPs) including many annotated to genes associated with monogenic diabetes. An analysis of DNA methylation in postnatal pancreas tissue showed that the dramatic temporal changes in DNA methylation occurring in the developing pancreas are largely limited to the prenatal period. Significant differences in DNA methylation were observed between males and females at a number of autosomal sites, with a small proportion of sites showing sex-specific DNA methylation trajectories across pancreas development. Pancreas dDMPs were not distributed equally across the genome and were depleted in regulatory domains characterized by open chromatin and the binding of known pancreatic development transcription factors. Finally, we compared our pancreas dDMPs to previous findings from the human brain, identifying evidence for tissue-specific developmental changes in DNA methylation. This study represents the first systematic exploration of DNA methylation patterns during human fetal pancreas development and confirms the prenatal period as a time of major epigenomic plasticity.
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Affiliation(s)
- Ailsa MacCalman
- Department of Clinical and Biomedical Sciences, Faculty of Health and Life Sciences, University of Exeter, RILD Building, Royal Devon & Exeter Hospital, Barrack Rd, Exeter, EX2 5DW, UK
| | - Elisa De Franco
- Department of Clinical and Biomedical Sciences, Faculty of Health and Life Sciences, University of Exeter, RILD Building, Royal Devon & Exeter Hospital, Barrack Rd, Exeter, EX2 5DW, UK
| | - Alice Franklin
- Department of Clinical and Biomedical Sciences, Faculty of Health and Life Sciences, University of Exeter, RILD Building, Royal Devon & Exeter Hospital, Barrack Rd, Exeter, EX2 5DW, UK
| | - Christine S Flaxman
- Department of Clinical and Biomedical Sciences, Faculty of Health and Life Sciences, University of Exeter, RILD Building, Royal Devon & Exeter Hospital, Barrack Rd, Exeter, EX2 5DW, UK
| | - Sarah J Richardson
- Department of Clinical and Biomedical Sciences, Faculty of Health and Life Sciences, University of Exeter, RILD Building, Royal Devon & Exeter Hospital, Barrack Rd, Exeter, EX2 5DW, UK
| | - Kathryn Murrall
- Department of Clinical and Biomedical Sciences, Faculty of Health and Life Sciences, University of Exeter, RILD Building, Royal Devon & Exeter Hospital, Barrack Rd, Exeter, EX2 5DW, UK
| | - Joe Burrage
- Department of Clinical and Biomedical Sciences, Faculty of Health and Life Sciences, University of Exeter, RILD Building, Royal Devon & Exeter Hospital, Barrack Rd, Exeter, EX2 5DW, UK
| | - Emma M Walker
- Department of Clinical and Biomedical Sciences, Faculty of Health and Life Sciences, University of Exeter, RILD Building, Royal Devon & Exeter Hospital, Barrack Rd, Exeter, EX2 5DW, UK
| | - Noel G Morgan
- Department of Clinical and Biomedical Sciences, Faculty of Health and Life Sciences, University of Exeter, RILD Building, Royal Devon & Exeter Hospital, Barrack Rd, Exeter, EX2 5DW, UK
| | - Andrew T Hattersley
- Department of Clinical and Biomedical Sciences, Faculty of Health and Life Sciences, University of Exeter, RILD Building, Royal Devon & Exeter Hospital, Barrack Rd, Exeter, EX2 5DW, UK
| | - Emma L Dempster
- Department of Clinical and Biomedical Sciences, Faculty of Health and Life Sciences, University of Exeter, RILD Building, Royal Devon & Exeter Hospital, Barrack Rd, Exeter, EX2 5DW, UK
| | - Eilis Hannon
- Department of Clinical and Biomedical Sciences, Faculty of Health and Life Sciences, University of Exeter, RILD Building, Royal Devon & Exeter Hospital, Barrack Rd, Exeter, EX2 5DW, UK
| | - Aaron R Jeffries
- Department of Biosciences, Faculty of Health and Life Sciences, University of Exeter, Exeter, UK
| | - Nick D L Owens
- Department of Clinical and Biomedical Sciences, Faculty of Health and Life Sciences, University of Exeter, RILD Building, Royal Devon & Exeter Hospital, Barrack Rd, Exeter, EX2 5DW, UK
| | - Jonathan Mill
- Department of Clinical and Biomedical Sciences, Faculty of Health and Life Sciences, University of Exeter, RILD Building, Royal Devon & Exeter Hospital, Barrack Rd, Exeter, EX2 5DW, UK.
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Yu V, Yong F, Marta A, Khadayate S, Osakwe A, Bhattacharya S, Varghese SS, Chabosseau P, Tabibi SM, Chen K, Georgiadou E, Parveen N, Suleiman M, Stamoulis Z, Marselli L, De Luca C, Tesi M, Ostinelli G, Delgadillo-Silva L, Wu X, Hatanaka Y, Montoya A, Elliott J, Patel B, Demchenko N, Whilding C, Hajkova P, Shliaha P, Kramer H, Ali Y, Marchetti P, Sladek R, Dhawan S, Withers DJ, Rutter GA, Millership SJ. Differential CpG methylation at Nnat in the early establishment of beta cell heterogeneity. Diabetologia 2024; 67:1079-1094. [PMID: 38512414 PMCID: PMC11058053 DOI: 10.1007/s00125-024-06123-6] [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: 11/15/2023] [Accepted: 01/09/2024] [Indexed: 03/23/2024]
Abstract
AIMS/HYPOTHESIS Beta cells within the pancreatic islet represent a heterogenous population wherein individual sub-groups of cells make distinct contributions to the overall control of insulin secretion. These include a subpopulation of highly connected 'hub' cells, important for the propagation of intercellular Ca2+ waves. Functional subpopulations have also been demonstrated in human beta cells, with an altered subtype distribution apparent in type 2 diabetes. At present, the molecular mechanisms through which beta cell hierarchy is established are poorly understood. Changes at the level of the epigenome provide one such possibility, which we explore here by focusing on the imprinted gene Nnat (encoding neuronatin [NNAT]), which is required for normal insulin synthesis and secretion. METHODS Single-cell RNA-seq datasets were examined using Seurat 4.0 and ClusterProfiler running under R. Transgenic mice expressing enhanced GFP under the control of the Nnat enhancer/promoter regions were generated for FACS of beta cells and downstream analysis of CpG methylation by bisulphite sequencing and RNA-seq, respectively. Animals deleted for the de novo methyltransferase DNA methyltransferase 3 alpha (DNMT3A) from the pancreatic progenitor stage were used to explore control of promoter methylation. Proteomics was performed using affinity purification mass spectrometry and Ca2+ dynamics explored by rapid confocal imaging of Cal-520 AM and Cal-590 AM. Insulin secretion was measured using homogeneous time-resolved fluorescence imaging. RESULTS Nnat mRNA was differentially expressed in a discrete beta cell population in a developmental stage- and DNA methylation (DNMT3A)-dependent manner. Thus, pseudo-time analysis of embryonic datasets demonstrated the early establishment of Nnat-positive and -negative subpopulations during embryogenesis. NNAT expression is also restricted to a subset of beta cells across the human islet that is maintained throughout adult life. NNAT+ beta cells also displayed a discrete transcriptome at adult stages, representing a subpopulation specialised for insulin production, and were diminished in db/db mice. 'Hub' cells were less abundant in the NNAT+ population, consistent with epigenetic control of this functional specialisation. CONCLUSIONS/INTERPRETATION These findings demonstrate that differential DNA methylation at Nnat represents a novel means through which beta cell heterogeneity is established during development. We therefore hypothesise that changes in methylation at this locus may contribute to a loss of beta cell hierarchy and connectivity, potentially contributing to defective insulin secretion in some forms of diabetes. DATA AVAILABILITY The mass spectrometry proteomics data have been deposited to the ProteomeXchange Consortium via the PRIDE partner repository with the dataset identifier PXD048465.
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Affiliation(s)
- Vanessa Yu
- Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, London, UK
| | - Fiona Yong
- Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, London, UK
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Republic of Singapore
| | - Angellica Marta
- Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, London, UK
| | | | - Adrien Osakwe
- Quantitative Life Sciences Program, McGill University, Montréal, QC, Canada
| | - Supriyo Bhattacharya
- Department of Computational and Quantitative Medicine, Beckman Research Institute, City of Hope, Duarte, CA, USA
| | - Sneha S Varghese
- Department of Translational Research and Cellular Therapeutics, Arthur Riggs Diabetes and Metabolism Research Institute, City of Hope, Duarte, CA, USA
| | - Pauline Chabosseau
- Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, London, UK
| | - Sayed M Tabibi
- Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, London, UK
| | - Keran Chen
- Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, London, UK
- Biomedical Research Centre, School of Biological Sciences, University of East Anglia, Norwich, UK
| | - Eleni Georgiadou
- Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, London, UK
| | - Nazia Parveen
- Department of Translational Research and Cellular Therapeutics, Arthur Riggs Diabetes and Metabolism Research Institute, City of Hope, Duarte, CA, USA
| | - Mara Suleiman
- Department of Clinical and Experimental Medicine, and AOUP Cisanello University Hospital, University of Pisa, Pisa, Italy
| | - Zoe Stamoulis
- Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, London, UK
- Medical Sciences Division, University of Oxford, Oxford, UK
| | - Lorella Marselli
- Department of Clinical and Experimental Medicine, and AOUP Cisanello University Hospital, University of Pisa, Pisa, Italy
| | - Carmela De Luca
- Department of Clinical and Experimental Medicine, and AOUP Cisanello University Hospital, University of Pisa, Pisa, Italy
| | - Marta Tesi
- Department of Clinical and Experimental Medicine, and AOUP Cisanello University Hospital, University of Pisa, Pisa, Italy
| | - Giada Ostinelli
- CHUM Research Center and Faculty of Medicine, University of Montréal, Montréal, QC, Canada
| | - Luis Delgadillo-Silva
- CHUM Research Center and Faculty of Medicine, University of Montréal, Montréal, QC, Canada
| | - Xiwei Wu
- Department of Computational and Quantitative Medicine, Beckman Research Institute, City of Hope, Duarte, CA, USA
| | - Yuki Hatanaka
- MRC Laboratory of Medical Sciences, London, UK
- Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, UK
| | | | | | | | - Nikita Demchenko
- MRC Laboratory of Medical Sciences, London, UK
- Imaging Resource Facility, Research Operations, St George's, University of London, London, UK
| | | | - Petra Hajkova
- MRC Laboratory of Medical Sciences, London, UK
- Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, UK
| | | | | | - Yusuf Ali
- Nutrition, Metabolism and Health Programme & Centre for Microbiome Medicine, Lee Kong Chian School of Medicine, Nanyang Technological University Singapore, Singapore, Republic of Singapore
- Singapore Eye Research Institute (SERI), Singapore General Hospital, Singapore, Republic of Singapore
- Clinical Research Unit, Khoo Teck Puat Hospital, National Healthcare Group, Singapore, Republic of Singapore
| | - Piero Marchetti
- Department of Clinical and Experimental Medicine, and AOUP Cisanello University Hospital, University of Pisa, Pisa, Italy
| | - Robert Sladek
- Quantitative Life Sciences Program, McGill University, Montréal, QC, Canada
- Departments of Medicine and Human Genetics, McGill University, Montréal, QC, Canada
| | - Sangeeta Dhawan
- Department of Translational Research and Cellular Therapeutics, Arthur Riggs Diabetes and Metabolism Research Institute, City of Hope, Duarte, CA, USA
| | - Dominic J Withers
- MRC Laboratory of Medical Sciences, London, UK
- Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, UK
| | - Guy A Rutter
- Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, London, UK.
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Republic of Singapore.
- CHUM Research Center and Faculty of Medicine, University of Montréal, Montréal, QC, Canada.
| | - Steven J Millership
- Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, London, UK.
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Nakhe AY, Dadi PK, Kim J, Dickerson MT, Behera S, Dobson JR, Shrestha S, Cartailler JP, Sampson L, Magnuson MA, Jacobson DA. The MODY-associated KCNK16 L114P mutation increases islet glucagon secretion and limits insulin secretion resulting in transient neonatal diabetes and glucose dyshomeostasis in adults. eLife 2024; 12:RP89967. [PMID: 38700926 PMCID: PMC11068355 DOI: 10.7554/elife.89967] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/05/2024] Open
Abstract
The gain-of-function mutation in the TALK-1 K+ channel (p.L114P) is associated with maturity-onset diabetes of the young (MODY). TALK-1 is a key regulator of β-cell electrical activity and glucose-stimulated insulin secretion. The KCNK16 gene encoding TALK-1 is the most abundant and β-cell-restricted K+ channel transcript. To investigate the impact of KCNK16 L114P on glucose homeostasis and confirm its association with MODY, a mouse model containing the Kcnk16 L114P mutation was generated. Heterozygous and homozygous Kcnk16 L114P mice exhibit increased neonatal lethality in the C57BL/6J and the CD-1 (ICR) genetic background, respectively. Lethality is likely a result of severe hyperglycemia observed in the homozygous Kcnk16 L114P neonates due to lack of glucose-stimulated insulin secretion and can be reduced with insulin treatment. Kcnk16 L114P increased whole-cell β-cell K+ currents resulting in blunted glucose-stimulated Ca2+ entry and loss of glucose-induced Ca2+ oscillations. Thus, adult Kcnk16 L114P mice have reduced glucose-stimulated insulin secretion and plasma insulin levels, which significantly impairs glucose homeostasis. Taken together, this study shows that the MODY-associated Kcnk16 L114P mutation disrupts glucose homeostasis in adult mice resembling a MODY phenotype and causes neonatal lethality by inhibiting islet insulin secretion during development. These data suggest that TALK-1 is an islet-restricted target for the treatment for diabetes.
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Affiliation(s)
- Arya Y Nakhe
- Department of Molecular Physiology and Biophysics, Vanderbilt UniversityNashvilleUnited States
| | - Prasanna K Dadi
- Department of Molecular Physiology and Biophysics, Vanderbilt UniversityNashvilleUnited States
| | - Jinsun Kim
- Department of Molecular Physiology and Biophysics, Vanderbilt UniversityNashvilleUnited States
- Department of Chemistry, Vanderbilt UniversityNashvilleUnited States
| | - Matthew T Dickerson
- Department of Molecular Physiology and Biophysics, Vanderbilt UniversityNashvilleUnited States
| | - Soma Behera
- Department of Molecular Physiology and Biophysics, Vanderbilt UniversityNashvilleUnited States
| | - Jordyn R Dobson
- Department of Molecular Physiology and Biophysics, Vanderbilt UniversityNashvilleUnited States
| | - Shristi Shrestha
- Center for Stem Cell Biology, Vanderbilt UniversityNashvilleUnited States
| | | | - Leesa Sampson
- Center for Stem Cell Biology, Vanderbilt UniversityNashvilleUnited States
| | - Mark A Magnuson
- Department of Molecular Physiology and Biophysics, Vanderbilt UniversityNashvilleUnited States
- Center for Stem Cell Biology, Vanderbilt UniversityNashvilleUnited States
- Department of Cell and Developmental Biology, Vanderbilt UniversityNashvilleUnited States
| | - David A Jacobson
- Department of Molecular Physiology and Biophysics, Vanderbilt UniversityNashvilleUnited States
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Nakhe AY, Dadi PK, Kim J, Dickerson MT, Behera S, Dobson JR, Shrestha S, Cartailler JP, Sampson L, Magnuson MA, Jacobson DA. The MODY-associated KCNK16 L114P mutation increases islet glucagon secretion and limits insulin secretion resulting in transient neonatal diabetes and glucose dyshomeostasis in adults. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.06.20.545631. [PMID: 37546831 PMCID: PMC10401960 DOI: 10.1101/2023.06.20.545631] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/08/2023]
Abstract
The gain-of-function mutation in the TALK-1 K + channel (p.L114P) is associated with maturity-onset diabetes of the young (MODY). TALK-1 is a key regulator of β-cell electrical activity and glucose-stimulated insulin secretion (GSIS). The KCNK16 gene encoding TALK-1, is the most abundant and β-cell-restricted K + channel transcript. To investigate the impact of KCNK16 L114P on glucose homeostasis and confirm its association with MODY, a mouse model containing the Kcnk16 L114P mutation was generated. Heterozygous and homozygous Kcnk16 L114P mice exhibit increased neonatal lethality in the C57BL/6J and the mixed C57BL/6J:CD-1(ICR) genetic background, respectively. Lethality is likely a result of severe hyperglycemia observed in the homozygous Kcnk16 L114P neonates due to lack of glucose-stimulated insulin secretion and can be reduced with insulin treatment. Kcnk16 L114P increased whole-cell β-cell K + currents resulting in blunted glucose-stimulated Ca 2+ entry and loss of glucose-induced Ca 2+ oscillations. Thus, adult Kcnk16 L114P mice have reduced glucose-stimulated insulin secretion and plasma insulin levels, which significantly impaired glucose homeostasis. Taken together, this study shows that the MODY-associated Kcnk16 L114P mutation disrupts glucose homeostasis in adult mice resembling a MODY phenotype and causes neonatal lethality by inhibiting islet hormone secretion during development. These data strongly suggest that TALK-1 is an islet-restricted target for the treatment of diabetes.
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Yu V, Yong F, Marta A, Khadayate S, Osakwe A, Bhattacharya S, Varghese SS, Chabosseau P, Tabibi SM, Chen K, Georgiadou E, Parveen N, Suleiman M, Stamoulis Z, Marselli L, De Luca C, Tesi M, Ostinelli G, Delgadillo-Silva L, Wu X, Hatanaka Y, Montoya A, Elliott J, Patel B, Demchenko N, Whilding C, Hajkova P, Shliaha P, Kramer H, Ali Y, Marchetti P, Sladek R, Dhawan S, Withers DJ, Rutter GA, Millership SJ. Differential CpG methylation at Nnat in the early establishment of beta cell heterogeneity. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.04.527050. [PMID: 38076935 PMCID: PMC10705251 DOI: 10.1101/2023.02.04.527050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/21/2023]
Abstract
Aims/hypothesis Beta cells within the pancreatic islet represent a heterogenous population wherein individual sub-groups of cells make distinct contributions to the overall control of insulin secretion. These include a subpopulation of highly-connected 'hub' cells, important for the propagation of intercellular Ca2+ waves. Functional subpopulations have also been demonstrated in human beta cells, with an altered subtype distribution apparent in type 2 diabetes. At present, the molecular mechanisms through which beta cell hierarchy is established are poorly understood. Changes at the level of the epigenome provide one such possibility which we explore here by focussing on the imprinted gene neuronatin (Nnat), which is required for normal insulin synthesis and secretion. Methods Single cell RNA-seq datasets were examined using Seurat 4.0 and ClusterProfiler running under R. Transgenic mice expressing eGFP under the control of the Nnat enhancer/promoter regions were generated for fluorescence-activated cell (FAC) sorting of beta cells and downstream analysis of CpG methylation by bisulphite and RNA sequencing, respectively. Animals deleted for the de novo methyltransferase, DNMT3A from the pancreatic progenitor stage were used to explore control of promoter methylation. Proteomics was performed using affinity purification mass spectrometry and Ca2+ dynamics explored by rapid confocal imaging of Cal-520 and Cal-590. Insulin secretion was measured using Homogeneous Time Resolved Fluorescence Imaging. Results Nnat mRNA was differentially expressed in a discrete beta cell population in a developmental stage- and DNA methylation (DNMT3A)-dependent manner. Thus, pseudo-time analysis of embryonic data sets demonstrated the early establishment of Nnat-positive and negative subpopulations during embryogenesis. NNAT expression is also restricted to a subset of beta cells across the human islet that is maintained throughout adult life. NNAT+ beta cells also displayed a discrete transcriptome at adult stages, representing a sub-population specialised for insulin production, reminiscent of recently-described "βHI" cells and were diminished in db/db mice. 'Hub' cells were less abundant in the NNAT+ population, consistent with epigenetic control of this functional specialization. Conclusions/interpretation These findings demonstrate that differential DNA methylation at Nnat represents a novel means through which beta cell heterogeneity is established during development. We therefore hypothesise that changes in methylation at this locus may thus contribute to a loss of beta cell hierarchy and connectivity, potentially contributing to defective insulin secretion in some forms of diabetes.
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Affiliation(s)
- Vanessa Yu
- Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, Du Cane Road, London, W12 0NN, UK
| | - Fiona Yong
- Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, Du Cane Road, London, W12 0NN, UK
- Lee Kong Chian School of Medicine, Nanyang Technological University, 637553, Singapore
| | - Angellica Marta
- Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, Du Cane Road, London, W12 0NN, UK
| | - Sanjay Khadayate
- MRC Laboratory of Medical Sciences, Du Cane Road, London, W12 0NN, UK
| | - Adrien Osakwe
- Departments of Medicine, Human Genetics and Quantitative Life Sciences, McGill University and Genome Quebec Innovation Centre, Montreal, QC, Canada
| | - Supriyo Bhattacharya
- Department of Computational and Quantitative Medicine, Beckman Research Institute, City of Hope, 1500 E Duarte Road, Duarte, CA 91010, USA
| | - Sneha S. Varghese
- Department of Translational Research and Cellular Therapeutics, Arthur Riggs Diabetes and Metabolism Research Institute, City of Hope, 1500 E Duarte Road, Duarte, CA 91010, USA
| | - Pauline Chabosseau
- Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, Du Cane Road, London, W12 0NN, UK
| | - Sayed M. Tabibi
- Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, Du Cane Road, London, W12 0NN, UK
| | - Keran Chen
- Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, Du Cane Road, London, W12 0NN, UK
| | - Eleni Georgiadou
- Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, Du Cane Road, London, W12 0NN, UK
| | - Nazia Parveen
- Department of Translational Research and Cellular Therapeutics, Arthur Riggs Diabetes and Metabolism Research Institute, City of Hope, 1500 E Duarte Road, Duarte, CA 91010, USA
| | - Mara Suleiman
- Department of Clinical and Experimental Medicine, and AOUP Cisanello University Hospital, University of Pisa, Pisa 56126, Italy
| | - Zoe Stamoulis
- Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, Du Cane Road, London, W12 0NN, UK
| | - Lorella Marselli
- Department of Clinical and Experimental Medicine, and AOUP Cisanello University Hospital, University of Pisa, Pisa 56126, Italy
| | - Carmela De Luca
- Department of Clinical and Experimental Medicine, and AOUP Cisanello University Hospital, University of Pisa, Pisa 56126, Italy
| | - Marta Tesi
- Department of Clinical and Experimental Medicine, and AOUP Cisanello University Hospital, University of Pisa, Pisa 56126, Italy
| | - Giada Ostinelli
- CHUM Research Center and Faculty of Medicine, University of Montréal, 900 Rue St Denis, Montréal, H2X OA9, QC, Canada
| | - Luis Delgadillo-Silva
- CHUM Research Center and Faculty of Medicine, University of Montréal, 900 Rue St Denis, Montréal, H2X OA9, QC, Canada
| | - Xiwei Wu
- Department of Computational and Quantitative Medicine, Beckman Research Institute, City of Hope, 1500 E Duarte Road, Duarte, CA 91010, USA
| | - Yuki Hatanaka
- MRC Laboratory of Medical Sciences, Du Cane Road, London, W12 0NN, UK
| | - Alex Montoya
- MRC Laboratory of Medical Sciences, Du Cane Road, London, W12 0NN, UK
| | - James Elliott
- MRC Laboratory of Medical Sciences, Du Cane Road, London, W12 0NN, UK
| | - Bhavik Patel
- MRC Laboratory of Medical Sciences, Du Cane Road, London, W12 0NN, UK
| | - Nikita Demchenko
- MRC Laboratory of Medical Sciences, Du Cane Road, London, W12 0NN, UK
| | - Chad Whilding
- MRC Laboratory of Medical Sciences, Du Cane Road, London, W12 0NN, UK
| | - Petra Hajkova
- MRC Laboratory of Medical Sciences, Du Cane Road, London, W12 0NN, UK
| | - Pavel Shliaha
- MRC Laboratory of Medical Sciences, Du Cane Road, London, W12 0NN, UK
| | - Holger Kramer
- MRC Laboratory of Medical Sciences, Du Cane Road, London, W12 0NN, UK
| | - Yusuf Ali
- Nutrition, Metabolism and Health Programme & Centre for Microbiome Medicine, Lee Kong Chian School of Medicine, Nanyang Technological University Singapore, Singapore, 308232
- Singapore Eye Research Institute (SERI), Singapore General Hospital, Singapore, 168751
- Clinical Research Unit, Khoo Teck Puat Hospital, National Healthcare Group, Singapore, 768828
| | - Piero Marchetti
- Department of Clinical and Experimental Medicine, and AOUP Cisanello University Hospital, University of Pisa, Pisa 56126, Italy
| | - Robert Sladek
- Departments of Medicine, Human Genetics and Quantitative Life Sciences, McGill University and Genome Quebec Innovation Centre, Montreal, QC, Canada
| | - Sangeeta Dhawan
- Department of Translational Research and Cellular Therapeutics, Arthur Riggs Diabetes and Metabolism Research Institute, City of Hope, 1500 E Duarte Road, Duarte, CA 91010, USA
| | - Dominic J. Withers
- MRC Laboratory of Medical Sciences, Du Cane Road, London, W12 0NN, UK
- Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, Du Cane Road, London, W12 0NN, UK
| | - Guy A. Rutter
- Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, Du Cane Road, London, W12 0NN, UK
- Lee Kong Chian School of Medicine, Nanyang Technological University, 637553, Singapore
- CHUM Research Center and Faculty of Medicine, University of Montréal, 900 Rue St Denis, Montréal, H2X OA9, QC, Canada
| | - Steven J. Millership
- Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, Du Cane Road, London, W12 0NN, UK
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Sadria M, Layton A, Bader GD. Adversarial training improves model interpretability in single-cell RNA-seq analysis. BIOINFORMATICS ADVANCES 2023; 3:vbad166. [PMID: 38099262 PMCID: PMC10719216 DOI: 10.1093/bioadv/vbad166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 09/28/2023] [Accepted: 11/22/2023] [Indexed: 12/17/2023]
Abstract
Motivation Predictive computational models must be accurate, robust, and interpretable to be considered reliable in important areas such as biology and medicine. A sufficiently robust model should not have its output affected significantly by a slight change in the input. Also, these models should be able to explain how a decision is made to support user trust in the results. Efforts have been made to improve the robustness and interpretability of predictive computational models independently; however, the interaction of robustness and interpretability is poorly understood. Results As an example task, we explore the computational prediction of cell type based on single-cell RNA-seq data and show that it can be made more robust by adversarially training a deep learning model. Surprisingly, we find this also leads to improved model interpretability, as measured by identifying genes important for classification using a range of standard interpretability methods. Our results suggest that adversarial training may be generally useful to improve deep learning robustness and interpretability and that it should be evaluated on a range of tasks. Availability and implementation Our Python implementation of all analysis in this publication can be found at: https://github.com/MehrshadSD/robustness-interpretability. The analysis was conducted using numPy 0.2.5, pandas 2.0.3, scanpy 1.9.3, tensorflow 2.10.0, matplotlib 3.7.1, seaborn 0.12.2, sklearn 1.1.1, shap 0.42.0, lime 0.2.0.1, matplotlib_venn 0.11.9.
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Affiliation(s)
- Mehrshad Sadria
- Department of Applied Mathematics, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - Anita Layton
- Department of Applied Mathematics, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
- Cheriton School of Computer Science, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
- Department of Biology, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
- School of Pharmacy, University of Waterloo, Waterloo, Ontario N2G 1C5, Canada
| | - Gary D Bader
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5S 1A8, Canada
- The Donnelly Centre, University of Toronto, Toronto, Ontario M5S 3E1, Canada
- Department of Computer Science, University of Toronto, Toronto, Ontario M5S 2E4, Canada
- The Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, Ontario M5G 1X5, Canada
- Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario M5G 2M9, Canada
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8
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Bohuslavova R, Fabriciova V, Smolik O, Lebrón-Mora L, Abaffy P, Benesova S, Zucha D, Valihrach L, Berkova Z, Saudek F, Pavlinkova G. NEUROD1 reinforces endocrine cell fate acquisition in pancreatic development. Nat Commun 2023; 14:5554. [PMID: 37689751 PMCID: PMC10492842 DOI: 10.1038/s41467-023-41306-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2023] [Accepted: 08/30/2023] [Indexed: 09/11/2023] Open
Abstract
NEUROD1 is a transcription factor that helps maintain a mature phenotype of pancreatic β cells. Disruption of Neurod1 during pancreatic development causes severe neonatal diabetes; however, the exact role of NEUROD1 in the differentiation programs of endocrine cells is unknown. Here, we report a crucial role of the NEUROD1 regulatory network in endocrine lineage commitment and differentiation. Mechanistically, transcriptome and chromatin landscape analyses demonstrate that Neurod1 inactivation triggers a downregulation of endocrine differentiation transcription factors and upregulation of non-endocrine genes within the Neurod1-deficient endocrine cell population, disturbing endocrine identity acquisition. Neurod1 deficiency altered the H3K27me3 histone modification pattern in promoter regions of differentially expressed genes, which resulted in gene regulatory network changes in the differentiation pathway of endocrine cells, compromising endocrine cell potential, differentiation, and functional properties.
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Affiliation(s)
- Romana Bohuslavova
- Laboratory of Molecular Pathogenetics, Institute of Biotechnology CAS, 25250, Vestec, Czechia
| | - Valeria Fabriciova
- Laboratory of Molecular Pathogenetics, Institute of Biotechnology CAS, 25250, Vestec, Czechia
| | - Ondrej Smolik
- Laboratory of Molecular Pathogenetics, Institute of Biotechnology CAS, 25250, Vestec, Czechia
| | - Laura Lebrón-Mora
- Laboratory of Molecular Pathogenetics, Institute of Biotechnology CAS, 25250, Vestec, Czechia
| | - Pavel Abaffy
- Laboratory of Gene Expression, Institute of Biotechnology CAS, 25250, Vestec, Czechia
| | - Sarka Benesova
- Laboratory of Gene Expression, Institute of Biotechnology CAS, 25250, Vestec, Czechia
| | - Daniel Zucha
- Laboratory of Gene Expression, Institute of Biotechnology CAS, 25250, Vestec, Czechia
| | - Lukas Valihrach
- Laboratory of Gene Expression, Institute of Biotechnology CAS, 25250, Vestec, Czechia
| | - Zuzana Berkova
- Diabetes Centre, Experimental Medicine Centre, Institute for Clinical and Experimental Medicine, 14021, Prague, Czechia
| | - Frantisek Saudek
- Diabetes Centre, Experimental Medicine Centre, Institute for Clinical and Experimental Medicine, 14021, Prague, Czechia
| | - Gabriela Pavlinkova
- Laboratory of Molecular Pathogenetics, Institute of Biotechnology CAS, 25250, Vestec, Czechia.
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9
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Pandit M, Akhtar MN, Sundaram S, Sahoo S, Manjunath LE, Eswarappa SM. Termination codon readthrough of NNAT mRNA regulates calcium-mediated neuronal differentiation. J Biol Chem 2023; 299:105184. [PMID: 37611826 PMCID: PMC10506107 DOI: 10.1016/j.jbc.2023.105184] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2023] [Revised: 08/15/2023] [Accepted: 08/16/2023] [Indexed: 08/25/2023] Open
Abstract
Termination codon readthrough (TCR) is a process in which ribosomes continue to translate an mRNA beyond a stop codon generating a C-terminally extended protein isoform. Here, we demonstrate TCR in mammalian NNAT mRNA, which encodes NNAT, a proteolipid important for neuronal differentiation. This is a programmed event driven by cis-acting RNA sequences present immediately upstream and downstream of the canonical stop codon and is negatively regulated by NONO, an RNA-binding protein known to promote neuronal differentiation. Unlike the canonical isoform NNAT, we determined that the TCR product (NNATx) does not show detectable interaction with the sarco/endoplasmic reticulum Ca2+-ATPase isoform 2 Ca2+ pump, cannot increase cytoplasmic Ca2+ levels, and therefore does not enhance neuronal differentiation in Neuro-2a cells. Additionally, an antisense oligonucleotide that targets a region downstream of the canonical stop codon reduced TCR of NNAT and enhanced the differentiation of Neuro-2a cells to cholinergic neurons. Furthermore, NNATx-deficient Neuro-2a cells, generated using CRISPR-Cas9, showed increased cytoplasmic Ca2+ levels and enhanced neuronal differentiation. Overall, these results demonstrate regulation of neuronal differentiation by TCR of NNAT. Importantly, this process can be modulated using a synthetic antisense oligonucleotide.
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Affiliation(s)
- Madhuparna Pandit
- Department of Biochemistry, Indian Institute of Science, Bengaluru, Karnataka, India
| | - Md Noor Akhtar
- Department of Biochemistry, Indian Institute of Science, Bengaluru, Karnataka, India
| | - Susinder Sundaram
- Department of Biochemistry, Indian Institute of Science, Bengaluru, Karnataka, India
| | - Sarthak Sahoo
- Undergraduate Program, Indian Institute of Science, Bengaluru, India
| | - Lekha E Manjunath
- Department of Biochemistry, Indian Institute of Science, Bengaluru, Karnataka, India
| | - Sandeep M Eswarappa
- Department of Biochemistry, Indian Institute of Science, Bengaluru, Karnataka, India.
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10
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Rudolph A, Stengel A, Suhs M, Schaper S, Wölk E, Rose M, Hofmann T. Circulating Neuronatin Levels Are Positively Associated with BMI and Body Fat Mass but Not with Psychological Parameters. Nutrients 2023; 15:3657. [PMID: 37630847 PMCID: PMC10459747 DOI: 10.3390/nu15163657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Revised: 08/17/2023] [Accepted: 08/18/2023] [Indexed: 08/27/2023] Open
Abstract
Human genetic studies have associated Neuronatin gene variants with anorexia nervosa (AN) and obesity. Studies on the expression of the Neuronatin gene product, a proteolipid, are lacking. We investigated the relationship between circulating Neuronatin, body mass index (BMI), body composition (BC), physical activity (PA), and psychometric outcomes in patients with AN, normal weight, and obesity. Plasma Neuronatin was measured by ELISA in (1) 79 subjects of five BMI categories (AN/BMI < 17.5 kg/m2; normal weight/BMI 18.5-25 kg/m2; obesity/BMI 30-40 kg/m2; obesity/BMI 40-50 kg/m2; obesity/BMI > 50 kg/m2) with assessment of BC (bioimpedance analysis; BIA); (2) 49 women with AN (BMI 14.5 ± 1.8 kg/m2) with measurements of BC (BIA) and PA (accelerometry); (3) 79 women with obesity (BMI 48.8 ± 7.8 kg/m2) with measurements of anxiety (GAD-7), stress (PSQ-20), depression (PHQ-9) and eating behavior (EDI-2). Overall, a positive correlation was found between Neuronatin and BMI (p = 0.006) as well as total fat mass (FM; p = 0.036). In AN, Neuronatin did not correlate with BMI, FM, or PA (p > 0.05); no correlations were found between Neuronatin and psychometric outcomes in obesity (p > 0.05). The findings suggest an FM-dependent peripheral Neuronatin expression. The decreased Neuronatin expression in AN provides evidence that Neuronatin is implicated in the pathogenesis of eating disorders.
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Affiliation(s)
- Amelie Rudolph
- Center for Internal Medicine and Dermatology, Department of Psychosomatic Medicine, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 12203 Berlin, Germany; (A.S.)
| | - Andreas Stengel
- Center for Internal Medicine and Dermatology, Department of Psychosomatic Medicine, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 12203 Berlin, Germany; (A.S.)
- Department of Psychosomatic Medicine and Psychotherapy, University Hospital Tübingen, 72076 Tübingen, Germany
| | - Maria Suhs
- Center for Internal Medicine and Dermatology, Department of Psychosomatic Medicine, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 12203 Berlin, Germany; (A.S.)
| | - Selina Schaper
- Center for Internal Medicine and Dermatology, Department of Psychosomatic Medicine, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 12203 Berlin, Germany; (A.S.)
| | - Ellen Wölk
- Center for Internal Medicine and Dermatology, Department of Psychosomatic Medicine, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 12203 Berlin, Germany; (A.S.)
| | - Matthias Rose
- Center for Internal Medicine and Dermatology, Department of Psychosomatic Medicine, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 12203 Berlin, Germany; (A.S.)
- Quantitative Health Sciences, Outcomes Measurement Science, University of Massachusetts Medical School, Worcester, MA 01655, USA
| | - Tobias Hofmann
- Center for Internal Medicine and Dermatology, Department of Psychosomatic Medicine, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 12203 Berlin, Germany; (A.S.)
- Department of Psychosomatic Medicine, DRK Kliniken Berlin Wiegmann Klinik, 14050 Berlin, Germany
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11
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Ke F, Wu X, Zheng J, Li C. Tilianin alleviates lipid deposition and fibrosis in mice with nonalcoholic steatohepatitis by activating the PPARα/Nnat axis. Drug Dev Res 2023; 84:922-936. [PMID: 37052239 DOI: 10.1002/ddr.22062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2022] [Revised: 03/28/2023] [Accepted: 04/03/2023] [Indexed: 04/14/2023]
Abstract
The understanding and treatment of nonalcoholic steatohepatitis (NASH) are still very limited. This study reports the therapeutic effect of tilianin on mice with NASH and further explores its possible molecular mechanisms. A mice model of NASH was established using low-dose streptozotocin combined with a high-fat diet and tilianin treatment. Liver function was assessed by determining serum aspartate aminotransferase and alanine aminotransferase in serum. Interleukin (IL)-1β, IL-6, transforming growth factor β1 (TGF-β1), and tumor necrosis factor α (TNF-α) levels in serum were determined. Hepatocyte apoptosis was assessed using terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labeling staining. Oil Red O staining and boron dipyrrin staining were used to determine lipid deposition in liver tissues. Masson staining was used to evaluate liver fibrosis, and immunohistochemistry and western blot analysis were used to determine the expression of target proteins. Tilianin treatment significantly ameliorated liver function, inhibited hepatocyte apoptosis, and reduced lipid deposition and liver fibrosis in mice with NASH. The expression of neuronatin (Nnat) and peroxisome proliferator-activated receptor (PPAR) α was upregulated, whereas that of sterol regulatory element-binding protein 1 (SREBP-1), TGF-β1, nuclear factor (NF)-κB p65, and phosphorylated p65 was downregulated in the liver tissues of mice with NASH after tilianin treatment. The above effects of tilianin were significantly reversed after Nnat knock-down, but its effect on PPARα expression was unaffected. Thus, the natural drug tilianin shows potential in treatig NASH. Its mechanism of action may be related to the targeted activation of PPARα/Nnat, thereby inhibiting the activation of the NF-κB signaling pathway.
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Affiliation(s)
- Fan Ke
- Department of Endocrinology, Jiujiang No. 1 People's Hospital, Jiujiang, People's Republic of China
| | - Xu Wu
- Department of Endocrinology, Jiujiang No. 1 People's Hospital, Jiujiang, People's Republic of China
| | - Jing Zheng
- Department of Endocrinology, Jiujiang No. 1 People's Hospital, Jiujiang, People's Republic of China
| | - Cuihong Li
- Department of Gastroenterology, Jiujiang No. 1 People's Hospital, Jiujiang, People's Republic of China
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12
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Vanderkruk B, Maeshima N, Pasula DJ, An M, McDonald CL, Suresh P, Luciani DS, Lynn FC, Hoffman BG. Methylation of histone H3 lysine 4 is required for maintenance of beta cell function in adult mice. Diabetologia 2023; 66:1097-1115. [PMID: 36912927 PMCID: PMC10163146 DOI: 10.1007/s00125-023-05896-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2022] [Accepted: 02/08/2023] [Indexed: 03/14/2023]
Abstract
AIMS/HYPOTHESIS Beta cells control glucose homeostasis via regulated production and secretion of insulin. This function arises from a highly specialised gene expression programme that is established during development and then sustained, with limited flexibility, in terminally differentiated cells. Dysregulation of this programme is seen in type 2 diabetes but mechanisms that preserve gene expression or underlie its dysregulation in mature cells are not well resolved. This study investigated whether methylation of histone H3 lysine 4 (H3K4), a marker of gene promoters with unresolved functional importance, is necessary for the maintenance of mature beta cell function. METHODS Beta cell function, gene expression and chromatin modifications were analysed in conditional Dpy30 knockout mice, in which H3K4 methyltransferase activity is impaired, and in a mouse model of diabetes. RESULTS H3K4 methylation maintains expression of genes that are important for insulin biosynthesis and glucose responsiveness. Deficient methylation of H3K4 leads to a less active and more repressed epigenome profile that locally correlates with gene expression deficits but does not globally reduce gene expression. Instead, developmentally regulated genes and genes in weakly active or suppressed states particularly rely on H3K4 methylation. We further show that H3K4 trimethylation (H3K4me3) is reorganised in islets from the Leprdb/db mouse model of diabetes in favour of weakly active and disallowed genes at the expense of terminal beta cell markers with broad H3K4me3 peaks. CONCLUSIONS/INTERPRETATION Sustained methylation of H3K4 is critical for the maintenance of beta cell function. Redistribution of H3K4me3 is linked to gene expression changes that are implicated in diabetes pathology.
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Affiliation(s)
- Ben Vanderkruk
- Diabetes Research Group, British Columbia Children's Hospital Research Institute, Vancouver, BC, Canada
- Department of Surgery, University of British Columbia, Vancouver, BC, Canada
| | - Nina Maeshima
- Department of Surgery, University of British Columbia, Vancouver, BC, Canada
| | - Daniel J Pasula
- Diabetes Research Group, British Columbia Children's Hospital Research Institute, Vancouver, BC, Canada
- Department of Surgery, University of British Columbia, Vancouver, BC, Canada
| | - Meilin An
- Diabetes Research Group, British Columbia Children's Hospital Research Institute, Vancouver, BC, Canada
| | - Cassandra L McDonald
- Diabetes Research Group, British Columbia Children's Hospital Research Institute, Vancouver, BC, Canada
| | - Priya Suresh
- Diabetes Research Group, British Columbia Children's Hospital Research Institute, Vancouver, BC, Canada
| | - Dan S Luciani
- Diabetes Research Group, British Columbia Children's Hospital Research Institute, Vancouver, BC, Canada
- Department of Surgery, University of British Columbia, Vancouver, BC, Canada
| | - Francis C Lynn
- Diabetes Research Group, British Columbia Children's Hospital Research Institute, Vancouver, BC, Canada
- Department of Surgery, University of British Columbia, Vancouver, BC, Canada
| | - Brad G Hoffman
- Diabetes Research Group, British Columbia Children's Hospital Research Institute, Vancouver, BC, Canada.
- Department of Surgery, University of British Columbia, Vancouver, BC, Canada.
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13
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Choi KM, Ko CY, An SM, Cho SH, Rowland DJ, Kim JH, Fasoli A, Chaudhari AJ, Bers DM, Yoon JC. Regulation of beige adipocyte thermogenesis by the cold-repressed ER protein NNAT. Mol Metab 2023; 69:101679. [PMID: 36708951 PMCID: PMC9932177 DOI: 10.1016/j.molmet.2023.101679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 01/17/2023] [Accepted: 01/18/2023] [Indexed: 01/26/2023] Open
Abstract
OBJECTIVE Cold stimuli trigger the conversion of white adipose tissue into beige adipose tissue, which is capable of non-shivering thermogenesis. However, what process drives this activation of thermogenesis in beige fat is not well understood. Here, we examine the ER protein NNAT as a regulator of thermogenesis in adipose tissue. METHODS We investigated the regulation of adipose tissue NNAT expression in response to changes in ambient temperature. We also evaluated the functional role of NNAT in thermogenic regulation using Nnat null mice and primary adipocytes that lack or overexpress NNAT. RESULTS Cold exposure or treatment with a β3-adrenergic agonist reduces the expression of adipose tissue NNAT in mice. Genetic disruption of Nnat in mice enhances inguinal adipose tissue thermogenesis. Nnat null mice exhibit improved cold tolerance both in the presence and absence of UCP1. Gain-of-function studies indicate that ectopic expression of Nnat abolishes adrenergic receptor-mediated respiration in beige adipocytes. NNAT physically interacts with the ER Ca2+-ATPase (SERCA) in adipocytes and inhibits its activity, impairing Ca2+ transport and heat dissipation. We further demonstrate that NHLRC1, an E3 ubiquitin protein ligase implicated in proteasomal degradation of NNAT, is induced by cold exposure or β3-adrenergic stimulation, thus providing regulatory control at the protein level. This serves to link cold stimuli to NNAT degradation in adipose tissue, which in turn leads to enhanced SERCA activity. CONCLUSIONS Our study implicates NNAT in the regulation of adipocyte thermogenesis.
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Affiliation(s)
- Kyung-Mi Choi
- Division of Endocrinology, Department of Internal Medicine, University of California Davis School of Medicine, Davis, CA 95616, USA; Institute of Molecular Biology and Genetics, School of Biological Sciences, Seoul National University, Seoul 08826, South Korea
| | - Christopher Y Ko
- Department of Pharmacology, University of California Davis School of Medicine, Davis, CA 95616, USA
| | - Sung-Min An
- Division of Endocrinology, Department of Internal Medicine, University of California Davis School of Medicine, Davis, CA 95616, USA
| | - Seung-Hee Cho
- Division of Endocrinology, Department of Internal Medicine, University of California Davis School of Medicine, Davis, CA 95616, USA
| | - Douglas J Rowland
- Center for Molecular and Genomic Imaging, Department of Biomedical Engineering, University of California Davis, Davis, CA 95616, USA
| | - Jung Hak Kim
- Division of Endocrinology, Department of Internal Medicine, University of California Davis School of Medicine, Davis, CA 95616, USA
| | - Anna Fasoli
- Department of Pharmacology, University of California Davis School of Medicine, Davis, CA 95616, USA
| | - Abhijit J Chaudhari
- Department of Radiology, University of California Davis School of Medicine, Sacramento, CA 95825, USA
| | - Donald M Bers
- Department of Pharmacology, University of California Davis School of Medicine, Davis, CA 95616, USA
| | - John C Yoon
- Division of Endocrinology, Department of Internal Medicine, University of California Davis School of Medicine, Davis, CA 95616, USA.
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14
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Azmi MB, Naeem U, Saleem A, Jawed A, Usman H, Qureshi SA, Azim MK. In silico identification of the rare-coding pathogenic mutations and structural modeling of human NNAT gene associated with anorexia nervosa. Eat Weight Disord 2022; 27:2725-2744. [PMID: 35655118 DOI: 10.1007/s40519-022-01422-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Accepted: 05/10/2022] [Indexed: 10/18/2022] Open
Abstract
PURPOSE Increased susceptibility towards anorexia nervosa (AN) was reported with reduced levels of neuronatin (NNAT) gene. We sought to investigate the most pathogenic rare-coding missense mutations, non-synonymous single-nucleotide polymorphisms (nsSNPs) of NNAT and their potential damaging impact on protein function through transcript level sequence and structure based in silico approaches. METHODS Gene sequence, single nucleotide polymorphisms (SNPs) of NNAT was retrieved from public databases and the putative post-translational modification (PTM) sites were analyzed. Distinctive in silico algorithms were recruited for transcript level SNPs analyses and to characterized high-risk rare-coding nsSNPs along with their impact on protein stability function. Ab initio 3D-modeling of wild-type, alternate model prediction for most deleterious nsSNP, validation and recognition of druggable binding pockets were also performed. AN 3D therapeutic compounds that followed rule of drug-likeness were docked with most pathogenic variant of NNAT to estimate the drugs' binding free energies. RESULTS Conclusively, 10 transcript (201-205)-based nsSNPs from 3 rare-coding missense variants, i.e., rs539681368, rs542858994, rs560845323 out of 840 exonic SNPs were identified. Transcript-based functional impact analyses predicted rs539681368 (C30Y) from NNAT-204 as the high-risk rare-coding pathogenic nsSNP, deviating protein functions. The 3D-modeling analysis of AN drugs' binding energies indicated lowest binding free energy (ΔG) and significant inhibition constant (Ki) with mutant models C30Y. CONCLUSIONS Mutant model (C30Y) exhibiting significant drug binding affinity and the commonest interaction observed at the acetylation site K59. Thus, based on these findings, we concluded that the identified nsSNP may serve as potential targets for various studies, diagnosis and therapeutic interventions. LEVEL OF EVIDENCE No level of evidence-open access bioinformatics research.
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Affiliation(s)
- Muhammad Bilal Azmi
- Department of Biochemistry, Dow Medical College, Dow University of Health Sciences, Karachi, Pakistan.
| | - Unaiza Naeem
- Dow Medical College, Dow University of Health Sciences, Karachi, Pakistan
| | - Arisha Saleem
- Dow Medical College, Dow University of Health Sciences, Karachi, Pakistan
| | - Areesha Jawed
- Dow Medical College, Dow University of Health Sciences, Karachi, Pakistan
| | - Haroon Usman
- Department of Biochemistry, University of Karachi, Karachi, Pakistan
| | | | - M Kamran Azim
- Department of Biosciences, Mohammad Ali Jinnah University, Karachi, Pakistan
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15
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Yang CH, Fagnocchi L, Apostle S, Wegert V, Casaní-Galdón S, Landgraf K, Panzeri I, Dror E, Heyne S, Wörpel T, Chandler DP, Lu D, Yang T, Gibbons E, Guerreiro R, Bras J, Thomasen M, Grunnet LG, Vaag AA, Gillberg L, Grundberg E, Conesa A, Körner A, Pospisilik JA. Independent phenotypic plasticity axes define distinct obesity sub-types. Nat Metab 2022; 4:1150-1165. [PMID: 36097183 PMCID: PMC9499872 DOI: 10.1038/s42255-022-00629-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Accepted: 07/29/2022] [Indexed: 01/04/2023]
Abstract
Studies in genetically 'identical' individuals indicate that as much as 50% of complex trait variation cannot be traced to genetics or to the environment. The mechanisms that generate this 'unexplained' phenotypic variation (UPV) remain largely unknown. Here, we identify neuronatin (NNAT) as a conserved factor that buffers against UPV. We find that Nnat deficiency in isogenic mice triggers the emergence of a bi-stable polyphenism, where littermates emerge into adulthood either 'normal' or 'overgrown'. Mechanistically, this is mediated by an insulin-dependent overgrowth that arises from histone deacetylase (HDAC)-dependent β-cell hyperproliferation. A multi-dimensional analysis of monozygotic twin discordance reveals the existence of two patterns of human UPV, one of which (Type B) phenocopies the NNAT-buffered polyphenism identified in mice. Specifically, Type-B monozygotic co-twins exhibit coordinated increases in fat and lean mass across the body; decreased NNAT expression; increased HDAC-responsive gene signatures; and clinical outcomes linked to insulinemia. Critically, the Type-B UPV signature stratifies both childhood and adult cohorts into four metabolic states, including two phenotypically and molecularly distinct types of obesity.
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Affiliation(s)
- Chih-Hsiang Yang
- Van Andel Institute, Grand Rapids, MI, USA
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany
| | | | | | - Vanessa Wegert
- Van Andel Institute, Grand Rapids, MI, USA
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany
| | | | - Kathrin Landgraf
- Medical Faculty, University of Leipzig, University Hospital for Children & Adolescents, Center for Pediatric Research Leipzig, Leipzig, Germany
| | - Ilaria Panzeri
- Van Andel Institute, Grand Rapids, MI, USA
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany
| | - Erez Dror
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany
| | - Steffen Heyne
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany
- Roche Diagnostics Deutschland, Mannheim, Germany
| | - Till Wörpel
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany
| | | | - Di Lu
- Van Andel Institute, Grand Rapids, MI, USA
| | - Tao Yang
- Van Andel Institute, Grand Rapids, MI, USA
| | - Elizabeth Gibbons
- Department of Neurodegenerative Science, Van Andel Institute, Grand Rapids, MI, USA
| | - Rita Guerreiro
- Department of Neurodegenerative Science, Van Andel Institute, Grand Rapids, MI, USA
| | - Jose Bras
- Department of Neurodegenerative Science, Van Andel Institute, Grand Rapids, MI, USA
| | - Martin Thomasen
- Department of Endocrinology, Rigshospitalet, Copenhagen, Denmark
| | - Louise G Grunnet
- Department of Endocrinology, Rigshospitalet, Copenhagen, Denmark
- Steno Diabetes Center Copenhagen, Herlev, Denmark
| | - Allan A Vaag
- Department of Endocrinology, Rigshospitalet, Copenhagen, Denmark
- Steno Diabetes Center Copenhagen, Herlev, Denmark
- Lund University Diabetes Centre, Lund University, Malmö, Sweden
| | - Linn Gillberg
- Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Elin Grundberg
- Genomic Medicine Center, Children's Mercy Research Institute, Children's Mercy Kansas City, MO, USA
| | - Ana Conesa
- Institute for Integrative Systems Biology, Spanish National Research Council (CSIC), Paterna, Valencia, Spain
- Microbiology and Cell Science Department, University of Florida, Gainesville, FL, USA
| | - Antje Körner
- Medical Faculty, University of Leipzig, University Hospital for Children & Adolescents, Center for Pediatric Research Leipzig, Leipzig, Germany
- Helmholtz Institute for Metabolic, Obesity and Vascular Research (HI-MAG) of the Helmholtz Zentrum München at the University of Leipzig and University Hospital Leipzig, Leipzig, Germany
| | - J Andrew Pospisilik
- Van Andel Institute, Grand Rapids, MI, USA.
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany.
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16
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Macias-Velasco JF, St Pierre CL, Wayhart JP, Yin L, Spears L, Miranda MA, Carson C, Funai K, Cheverud JM, Semenkovich CF, Lawson HA. Parent-of-origin effects propagate through networks to shape metabolic traits. eLife 2022; 11:e72989. [PMID: 35356864 PMCID: PMC9075957 DOI: 10.7554/elife.72989] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Accepted: 03/25/2022] [Indexed: 11/16/2022] Open
Abstract
Parent-of-origin effects are unexpectedly common in complex traits, including metabolic and neurological traits. Parent-of-origin effects can be modified by the environment, but the architecture of these gene-by-environmental effects on phenotypes remains to be unraveled. Previously, quantitative trait loci (QTL) showing context-specific parent-of-origin effects on metabolic traits were mapped in the F16 generation of an advanced intercross between LG/J and SM/J inbred mice. However, these QTL were not enriched for known imprinted genes, suggesting another mechanism is needed to explain these parent-of-origin effects phenomena. We propose that non-imprinted genes can generate complex parent-of-origin effects on metabolic traits through interactions with imprinted genes. Here, we employ data from mouse populations at different levels of intercrossing (F0, F1, F2, F16) of the LG/J and SM/J inbred mouse lines to test this hypothesis. Using multiple populations and incorporating genetic, genomic, and physiological data, we leverage orthogonal evidence to identify networks of genes through which parent-of-origin effects propagate. We identify a network comprised of three imprinted and six non-imprinted genes that show parent-of-origin effects. This epistatic network forms a nutritional responsive pathway and the genes comprising it jointly serve cellular functions associated with growth. We focus on two genes, Nnat and F2r, whose interaction associates with serum glucose levels across generations in high-fat-fed females. Single-cell RNAseq reveals that Nnat expression increases and F2r expression decreases in pre-adipocytes along an adipogenic trajectory, a result that is consistent with our observations in bulk white adipose tissue.
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Affiliation(s)
- Juan F Macias-Velasco
- Department of Genetics, Washington University School of MedicineSaint LouisUnited States
| | - Celine L St Pierre
- Department of Genetics, Washington University School of MedicineSaint LouisUnited States
| | - Jessica P Wayhart
- Department of Genetics, Washington University School of MedicineSaint LouisUnited States
| | - Li Yin
- Department of Medicine, Washington University School of MedicineSaint LouisUnited States
| | - Larry Spears
- Department of Medicine, Washington University School of MedicineSaint LouisUnited States
| | - Mario A Miranda
- Department of Genetics, Washington University School of MedicineSaint LouisUnited States
| | - Caryn Carson
- Department of Genetics, Washington University School of MedicineSaint LouisUnited States
| | - Katsuhiko Funai
- Diabetes and Metabolism Research Center, University of UtahSalt Lake CityUnited States
| | | | - Clay F Semenkovich
- Department of Medicine, Washington University School of MedicineSaint LouisUnited States
| | - Heather A Lawson
- Department of Genetics, Washington University School of MedicineSaint LouisUnited States
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17
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Zhang T, Wang T, Niu Q, Xu L, Chen Y, Gao X, Gao H, Zhang L, Liu GE, Li J, Xu L. Transcriptional atlas analysis from multiple tissues reveals the expression specificity patterns in beef cattle. BMC Biol 2022; 20:79. [PMID: 35351103 PMCID: PMC8966188 DOI: 10.1186/s12915-022-01269-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2021] [Accepted: 03/03/2022] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND A comprehensive analysis of gene expression profiling across tissues can provide necessary information for an in-depth understanding of their biological functions. We performed a large-scale gene expression analysis and generated a high-resolution atlas of the transcriptome in beef cattle. RESULTS Our transcriptome atlas was generated from 135 bovine tissues in adult beef cattle, covering 51 tissue types of major organ systems (e.g., muscular system, digestive system, immune system, reproductive system). Approximately 94.76% of sequencing reads were successfully mapped to the reference genome assembly ARS-UCD1.2. We detected a total of 60,488 transcripts, and 32% of them were not reported before. We identified 2654 housekeeping genes (HKGs) and 477 tissue-specific genes (TSGs) across tissues. Using weighted gene co-expression network analysis, we obtained 24 modules with 237 hub genes (HUBGs). Functional enrichment analysis showed that HKGs mainly maintain the basic biological activities of cells, while TSGs were involved in tissue differentiation and specific physiological processes. HKGs in bovine tissues were more conserved in terms of expression pattern as compared to TSGs and HUBGs among multiple species. Finally, we obtained a subset of tissue-specific differentially expressed genes (DEGs) between beef and dairy cattle and several functional pathways, which may be involved in production and health traits. CONCLUSIONS We generated a large-scale gene expression atlas across the major tissues in beef cattle, providing valuable information for enhancing genome assembly and annotation. HKGs, TSGs, and HUBGs further contribute to better understanding the biology and evolution of multiple tissues in cattle. DEGs between beef and dairy cattle also fill in the knowledge gaps about differential transcriptome regulation of bovine tissues underlying economically important traits.
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Affiliation(s)
- Tianliu Zhang
- Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, 100193 People’s Republic of China
| | - Tianzhen Wang
- Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, 100193 People’s Republic of China
| | - Qunhao Niu
- Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, 100193 People’s Republic of China
| | - Lei Xu
- Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, 100193 People’s Republic of China
| | - Yan Chen
- Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, 100193 People’s Republic of China
| | - Xue Gao
- Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, 100193 People’s Republic of China
| | - Huijiang Gao
- Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, 100193 People’s Republic of China
| | - Lupei Zhang
- Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, 100193 People’s Republic of China
| | - George E. Liu
- Animal Genomics and Improvement Laboratory, United States Department of Agriculture, Agricultural Research Service, Beltsville, Maryland 20705 USA
| | - Junya Li
- Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, 100193 People’s Republic of China
| | - Lingyang Xu
- Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, 100193 People’s Republic of China
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18
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McIlwraith EK, Lieu CV, Belsham DD. Bisphenol A induces miR-708-5p through an ER stress-mediated mechanism altering neuronatin and neuropeptide Y expression in hypothalamic neuronal models. Mol Cell Endocrinol 2022; 539:111480. [PMID: 34624438 DOI: 10.1016/j.mce.2021.111480] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 09/26/2021] [Accepted: 10/01/2021] [Indexed: 01/15/2023]
Abstract
Bisphenol A (BPA) is an endocrine disrupting chemical that promotes obesity. It acts on the hypothalamus by increasing expression of the orexigenic neuropeptides, Npy and Agrp. Exactly how BPA dysregulates energy homeostasis is not completely clear. Since microRNAs (miRNA) have emerged as crucial weight regulators, the question of whether BPA could alter hypothalamic miRNA profiles was examined. Treatment of the mHypoA-59 cell line with 100 μM BPA altered a specific subset of miRNAs, and the most upregulated was miR-708-5p. BPA was found to increase the levels of miR-708-5p, and its parent gene Odz4, through the ER stress-related protein Chop. Overexpression of an miR-708-5p mimic resulted in a reduction of neuronatin, a proteolipid whose loss of expression is associated with obesity, and an increase in orexigenic Npy expression, thus potentially increasing feeding through converging regulatory pathways. Therefore, hypothalamic exposure to BPA can increase miR-708-5p that controls neuropeptides directly linked to obesity.
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Affiliation(s)
- Emma K McIlwraith
- Departments of Physiology, University of Toronto, Ontario, M5S 1A8, Canada
| | - Calvin V Lieu
- Departments of Physiology, University of Toronto, Ontario, M5S 1A8, Canada
| | - Denise D Belsham
- Departments of Physiology, University of Toronto, Ontario, M5S 1A8, Canada; Departments of Medicine, University of Toronto, Ontario, M5S 1A8, Canada; Departments of Obstetrics and Gynaecology, University of Toronto, Ontario, M5S 1A8, Canada.
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19
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Ninkina N, Millership SJ, Peters OM, Connor-Robson N, Chaprov K, Kopylov AT, Montoya A, Kramer H, Withers DJ, Buchman VL. β-synuclein potentiates synaptic vesicle dopamine uptake and rescues dopaminergic neurons from MPTP-induced death in the absence of other synucleins. J Biol Chem 2021; 297:101375. [PMID: 34736896 PMCID: PMC8633583 DOI: 10.1016/j.jbc.2021.101375] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 10/20/2021] [Accepted: 10/28/2021] [Indexed: 12/11/2022] Open
Abstract
Synucleins, a family of three proteins highly expressed in neurons, are predominantly known for the direct involvement of α-synuclein in the etiology and pathogenesis of Parkinson's and certain other neurodegenerative diseases, but their precise physiological functions are still not fully understood. Previous studies have demonstrated the importance of α-synuclein as a modulator of various mechanisms implicated in chemical neurotransmission, but information concerning the involvement of other synuclein family members, β-synuclein and γ-synuclein, in molecular processes within presynaptic terminals is limited. Here, we demonstrated that the vesicular monoamine transporter 2-dependent dopamine uptake by synaptic vesicles isolated from the striatum of mice lacking β-synuclein is significantly reduced. Reciprocally, reintroduction, either in vivo or in vitro, of β-synuclein but not α-synuclein or γ-synuclein improves uptake by triple α/β/γ-synuclein-deficient striatal vesicles. We also showed that the resistance of dopaminergic neurons of the substantia nigra pars compacta to subchronic administration of the Parkinson's disease-inducing prodrug 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine depends on the presence of β-synuclein but only when one or both other synucleins are absent. Furthermore, proteomic analysis of synuclein-deficient synaptic vesicles versus those containing only β-synuclein revealed differences in their protein compositions. We suggest that the observed potentiation of dopamine uptake by β-synuclein might be caused by different protein architecture of the synaptic vesicles. It is also feasible that such structural changes improve synaptic vesicle sequestration of 1-methyl-4-phenylpyridinium, a toxic metabolite of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine, which would explain why dopaminergic neurons expressing β-synuclein and lacking α-synuclein and/or γ-synuclein are resistant to this neurotoxin.
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Affiliation(s)
- Natalia Ninkina
- School of Biosciences, Cardiff University, Cardiff, United Kingdom; Institute of Physiologically Active Compounds, Russian Academy of Sciences, Chernogolovka, Russian Federation
| | - Steven J Millership
- School of Biosciences, Cardiff University, Cardiff, United Kingdom; Metabolic Signalling, MRC London Institute of Medical Sciences, London, United Kingdom; Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Owen M Peters
- School of Biosciences, Cardiff University, Cardiff, United Kingdom
| | | | - Kirill Chaprov
- School of Biosciences, Cardiff University, Cardiff, United Kingdom; Institute of Physiologically Active Compounds, Russian Academy of Sciences, Chernogolovka, Russian Federation
| | - Arthur T Kopylov
- Department of Proteomic Research and Mass Spectrometry, Institute of Biomedical Chemistry, Moscow, Russian Federation
| | - Alex Montoya
- Metabolic Signalling, MRC London Institute of Medical Sciences, London, United Kingdom
| | - Holger Kramer
- Metabolic Signalling, MRC London Institute of Medical Sciences, London, United Kingdom
| | - Dominic J Withers
- Metabolic Signalling, MRC London Institute of Medical Sciences, London, United Kingdom; Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, United Kingdom
| | - Vladimir L Buchman
- School of Biosciences, Cardiff University, Cardiff, United Kingdom; Institute of Physiologically Active Compounds, Russian Academy of Sciences, Chernogolovka, Russian Federation.
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20
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Xing P, Hong L, Yan G, Tan B, Qiao J, Wang S, Li Z, JieYang, Zheng E, Cai G, Wu Z, Gu T. Neuronatin gene expression levels affect foetal growth and development by regulating glucose transport in porcine placenta. Gene 2021; 809:146051. [PMID: 34756962 DOI: 10.1016/j.gene.2021.146051] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 10/18/2021] [Accepted: 10/26/2021] [Indexed: 11/04/2022]
Abstract
Imprinted genes play important regulatory roles in the growth and development of placentas and foetuses during pregnancy. In a previous study, we found that the imprinted gene Neuronatin (NNAT) is involved in foetal development; NNAT expression was significantly lower in the placentas of piglets that died neonatally compared to the placentas of surviving piglets. However, the function and mechanism of NNAT in regulating porcine placental development is still unknown. In this study, we collected the placentas of high- and low-weight foetuses at gestational day (GD 65, 90), (n = 4-5 litters/GD) to investigate the role of NNAT in regulating foetal growth and development. We found that the mRNA and protein levels of NNAT were significantly higher in the placentas of high-weight than low-weight foetuses. We then overexpressed NNAT in porcine placental trophoblast cell lines (pTr2) and demonstrated that NNAT activated the PI3K-AKT pathway, and further promoted the expression of glucose transporter 1 (GLUT1) and increased cellular calcium ion levels, which improved glucose transport in placental trophoblast cells in vitro. To conclude, our study suggests that NNAT expression impacts porcine foetal development by regulating placental glucose transport.
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Affiliation(s)
- Pingping Xing
- National Engineering Research Center for Breeding Swine Industry, Guangzhou, China & College of Animal Science, South China Agricultural University, Guangzhou, China
| | - Linjun Hong
- National Engineering Research Center for Breeding Swine Industry, Guangzhou, China & College of Animal Science, South China Agricultural University, Guangzhou, China
| | - Guanhao Yan
- National Engineering Research Center for Breeding Swine Industry, Guangzhou, China & College of Animal Science, South China Agricultural University, Guangzhou, China
| | - Baohua Tan
- National Engineering Research Center for Breeding Swine Industry, Guangzhou, China & College of Animal Science, South China Agricultural University, Guangzhou, China
| | - Jiaxin Qiao
- National Engineering Research Center for Breeding Swine Industry, Guangzhou, China & College of Animal Science, South China Agricultural University, Guangzhou, China
| | - Shanshan Wang
- National Engineering Research Center for Breeding Swine Industry, Guangzhou, China & College of Animal Science, South China Agricultural University, Guangzhou, China
| | - Zicong Li
- National Engineering Research Center for Breeding Swine Industry, Guangzhou, China & College of Animal Science, South China Agricultural University, Guangzhou, China; State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangzhou, China; Guangdong Provincial Laboratory of Lingnan Modern Agricultural Science and Technology, Guangzhou, China; Guangdong Provincial Key Laboratory of Agro-animal Genomics and Molecular Breeding, Guangzhou, China; Guangdong Wens Breeding Swine Technology Co., Ltd, Yunfu, China
| | - JieYang
- National Engineering Research Center for Breeding Swine Industry, Guangzhou, China & College of Animal Science, South China Agricultural University, Guangzhou, China
| | - Enqin Zheng
- National Engineering Research Center for Breeding Swine Industry, Guangzhou, China & College of Animal Science, South China Agricultural University, Guangzhou, China
| | - Gengyuan Cai
- National Engineering Research Center for Breeding Swine Industry, Guangzhou, China & College of Animal Science, South China Agricultural University, Guangzhou, China
| | - Zhenfang Wu
- National Engineering Research Center for Breeding Swine Industry, Guangzhou, China & College of Animal Science, South China Agricultural University, Guangzhou, China; State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangzhou, China; Guangdong Provincial Laboratory of Lingnan Modern Agricultural Science and Technology, Guangzhou, China; Guangdong Provincial Key Laboratory of Agro-animal Genomics and Molecular Breeding, Guangzhou, China; Guangdong Wens Breeding Swine Technology Co., Ltd, Yunfu, China
| | - Ting Gu
- National Engineering Research Center for Breeding Swine Industry, Guangzhou, China & College of Animal Science, South China Agricultural University, Guangzhou, China.
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21
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Braun JL, Teng ACT, Geromella MS, Ryan CR, Fenech RK, MacPherson REK, Gramolini AO, Fajardo VA. Neuronatin promotes SERCA uncoupling and its expression is altered in skeletal muscles of high-fat diet-fed mice. FEBS Lett 2021; 595:2756-2767. [PMID: 34693525 DOI: 10.1002/1873-3468.14213] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2021] [Revised: 10/07/2021] [Accepted: 10/15/2021] [Indexed: 11/09/2022]
Abstract
Neuronatin (NNAT) is a transmembrane protein in the endoplasmic reticulum involved in metabolic regulation. It shares sequence homology with sarcolipin (SLN), which negatively regulates the sarco(endo)plasmic reticulum Ca2+ -ATPase (SERCA) that maintains energy homeostasis in muscles. Here, we examined whether NNAT could uncouple the Ca2+ transport activity of SERCA from ATP hydrolysis, similarly to SLN. NNAT significantly reduced Ca2+ uptake without altering SERCA activity, ultimately lowering the apparent coupling ratio of SERCA. This effect of NNAT was reversed by the adenylyl cyclase activator forskolin. Furthermore, soleus muscles from high fat diet (HFD)-fed mice showed a significant downregulation in NNAT content compared with chow-fed mice, whereas an upregulation in NNAT content was observed in fast-twitch muscles from HFD- versus chow- fed mice. Therefore, NNAT is a SERCA uncoupler in cells and may function in adaptive thermogenesis.
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Affiliation(s)
- Jessica L Braun
- Department of Kinesiology, Brock University, St. Catharines, Canada.,Centre for Bone and Muscle Health, Brock University, St. Catharines, Canada.,Centre for Neuroscience, Brock University, St. Catharines, Canada
| | - Allen C T Teng
- Department of Physiology, University of Toronto, Canada.,Translational Biology and Engineering Program, Ted Rogers Centre for Heart Research, Toronto, Canada
| | - Mia S Geromella
- Department of Kinesiology, Brock University, St. Catharines, Canada.,Centre for Bone and Muscle Health, Brock University, St. Catharines, Canada.,Centre for Neuroscience, Brock University, St. Catharines, Canada
| | - Chantal R Ryan
- Centre for Neuroscience, Brock University, St. Catharines, Canada.,Department of Health Sciences, Brock University, St. Catharines, Canada
| | - Rachel K Fenech
- Centre for Neuroscience, Brock University, St. Catharines, Canada.,Department of Health Sciences, Brock University, St. Catharines, Canada
| | - Rebecca E K MacPherson
- Centre for Neuroscience, Brock University, St. Catharines, Canada.,Department of Health Sciences, Brock University, St. Catharines, Canada
| | - Anthony O Gramolini
- Department of Physiology, University of Toronto, Canada.,Translational Biology and Engineering Program, Ted Rogers Centre for Heart Research, Toronto, Canada
| | - Val A Fajardo
- Department of Kinesiology, Brock University, St. Catharines, Canada.,Centre for Bone and Muscle Health, Brock University, St. Catharines, Canada.,Centre for Neuroscience, Brock University, St. Catharines, Canada
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22
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Cimino I, Rimmington D, Tung YCL, Lawler K, Larraufie P, Kay RG, Virtue S, Lam BYH, Fagnocchi L, Ma MKL, Saudek V, Zvetkova I, Vidal-Puig A, Yeo GSH, Farooqi IS, Pospisilik JA, Gribble FM, Reimann F, O'Rahilly S, Coll AP. Murine neuronatin deficiency is associated with a hypervariable food intake and bimodal obesity. Sci Rep 2021; 11:17571. [PMID: 34475432 PMCID: PMC8413370 DOI: 10.1038/s41598-021-96278-8] [Citation(s) in RCA: 4] [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: 05/15/2021] [Accepted: 08/04/2021] [Indexed: 12/15/2022] Open
Abstract
Neuronatin (Nnat) has previously been reported to be part of a network of imprinted genes downstream of the chromatin regulator Trim28. Disruption of Trim28 or of members of this network, including neuronatin, results in an unusual phenotype of a bimodal body weight. To better characterise this variability, we examined the key contributors to energy balance in Nnat+/-p mice that carry a paternal null allele and do not express Nnat. Consistent with our previous studies, Nnat deficient mice on chow diet displayed a bimodal body weight phenotype with more than 30% of Nnat+/-p mice developing obesity. In response to both a 45% high fat diet and exposure to thermoneutrality (30 °C) Nnat deficient mice maintained the hypervariable body weight phenotype. Within a calorimetry system, food intake in Nnat+/-p mice was hypervariable, with some mice consuming more than twice the intake seen in wild type littermates. A hyperphagic response was also seen in Nnat+/-p mice in a second, non-home cage environment. An expected correlation between body weight and energy expenditure was seen, but corrections for the effects of positive energy balance and body weight greatly diminished the effect of neuronatin deficiency on energy expenditure. Male and female Nnat+/-p mice displayed subtle distinctions in the degree of variance body weight phenotype and food intake and further sexual dimorphism was reflected in different patterns of hypothalamic gene expression in Nnat+/-p mice. Loss of the imprinted gene Nnat is associated with a highly variable food intake, with the impact of this phenotype varying between genetically identical individuals.
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Affiliation(s)
- Irene Cimino
- MRC Metabolic Diseases Unit, University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, CB2 0SL, UK
| | - Debra Rimmington
- MRC Metabolic Diseases Unit, University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, CB2 0SL, UK
| | - Y C Loraine Tung
- MRC Metabolic Diseases Unit, University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, CB2 0SL, UK
| | - Katherine Lawler
- University of Cambridge Metabolic Research Laboratories and NIHR Cambridge Biomedical Research Centre, Wellcome Trust‑MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, CB2 0SL, UK
| | - Pierre Larraufie
- MRC Metabolic Diseases Unit, University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, CB2 0SL, UK
- Université Paris-Saclay, AgroParisTech, INRAE, UMR PNCA, 75005, Paris, France
| | - Richard G Kay
- MRC Metabolic Diseases Unit, University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, CB2 0SL, UK
| | - Samuel Virtue
- MRC Metabolic Diseases Unit, University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, CB2 0SL, UK
| | - Brian Y H Lam
- MRC Metabolic Diseases Unit, University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, CB2 0SL, UK
| | - Luca Fagnocchi
- Department of Epigenetics, Van Andel Institute, Grand Rapids, MI, 49503, USA
| | - Marcella K L Ma
- MRC Metabolic Diseases Unit, University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, CB2 0SL, UK
| | - Vladimir Saudek
- MRC Metabolic Diseases Unit, University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, CB2 0SL, UK
| | - Ilona Zvetkova
- MRC Metabolic Diseases Unit, University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, CB2 0SL, UK
| | - Antonio Vidal-Puig
- MRC Metabolic Diseases Unit, University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, CB2 0SL, UK
| | - Giles S H Yeo
- MRC Metabolic Diseases Unit, University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, CB2 0SL, UK
| | - I Sadaf Farooqi
- University of Cambridge Metabolic Research Laboratories and NIHR Cambridge Biomedical Research Centre, Wellcome Trust‑MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, CB2 0SL, UK
| | - J Andrew Pospisilik
- Department of Epigenetics, Van Andel Institute, Grand Rapids, MI, 49503, USA
| | - Fiona M Gribble
- MRC Metabolic Diseases Unit, University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, CB2 0SL, UK
| | - Frank Reimann
- MRC Metabolic Diseases Unit, University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, CB2 0SL, UK
| | - Stephen O'Rahilly
- MRC Metabolic Diseases Unit, University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, CB2 0SL, UK
| | - Anthony P Coll
- MRC Metabolic Diseases Unit, University of Cambridge Metabolic Research Laboratories, Wellcome Trust-MRC Institute of Metabolic Science, Addenbrooke's Hospital, Cambridge, CB2 0SL, UK.
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23
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Mousavy Gharavy SN, Owen BM, Millership SJ, Chabosseau P, Pizza G, Martinez-Sanchez A, Tasoez E, Georgiadou E, Hu M, Fine NHF, Jacobson DA, Dickerson MT, Idevall-Hagren O, Montoya A, Kramer H, Mehta Z, Withers DJ, Ninov N, Gadue PJ, Cardenas-Diaz FL, Cruciani-Guglielmacci C, Magnan C, Ibberson M, Leclerc I, Voz M, Rutter GA. Sexually dimorphic roles for the type 2 diabetes-associated C2cd4b gene in murine glucose homeostasis. Diabetologia 2021; 64:850-864. [PMID: 33492421 PMCID: PMC7829492 DOI: 10.1007/s00125-020-05350-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 10/28/2020] [Indexed: 12/16/2022]
Abstract
AIMS/HYPOTHESIS Variants close to the VPS13C/C2CD4A/C2CD4B locus are associated with altered risk of type 2 diabetes in genome-wide association studies. While previous functional work has suggested roles for VPS13C and C2CD4A in disease development, none has explored the role of C2CD4B. METHODS CRISPR/Cas9-induced global C2cd4b-knockout mice and zebrafish larvae with c2cd4a deletion were used to study the role of this gene in glucose homeostasis. C2 calcium dependent domain containing protein (C2CD)4A and C2CD4B constructs tagged with FLAG or green fluorescent protein were generated to investigate subcellular dynamics using confocal or near-field microscopy and to identify interacting partners by mass spectrometry. RESULTS Systemic inactivation of C2cd4b in mice led to marked, but highly sexually dimorphic changes in body weight and glucose homeostasis. Female C2cd4b mice displayed unchanged body weight compared with control littermates, but abnormal glucose tolerance (AUC, p = 0.01) and defective in vivo, but not in vitro, insulin secretion (p = 0.02). This was associated with a marked decrease in follicle-stimulating hormone levels as compared with wild-type (WT) littermates (p = 0.003). In sharp contrast, male C2cd4b null mice displayed essentially normal glucose tolerance but an increase in body weight (p < 0.001) and fasting blood glucose (p = 0.003) after maintenance on a high-fat and -sucrose diet vs WT littermates. No metabolic disturbances were observed after global inactivation of C2cd4a in mice, or in pancreatic beta cell function at larval stages in C2cd4a null zebrafish. Fasting blood glucose levels were also unaltered in adult C2cd4a-null fish. C2CD4B and C2CD4A were partially localised to the plasma membrane, with the latter under the control of intracellular Ca2+. Binding partners for both included secretory-granule-localised PTPRN2/phogrin. CONCLUSIONS/INTERPRETATION Our studies suggest that C2cd4b may act centrally in the pituitary to influence sex-dependent circuits that control pancreatic beta cell function and glucose tolerance in rodents. However, the absence of sexual dimorphism in the impact of diabetes risk variants argues for additional roles for C2CD4A or VPS13C in the control of glucose homeostasis in humans. DATA AVAILABILITY The datasets generated and/or analysed during the current study are available in the Biorxiv repository ( www.biorxiv.org/content/10.1101/2020.05.18.099200v1 ). RNA-Seq (GSE152576) and proteomics (PXD021597) data have been deposited to GEO ( www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE152576 ) and ProteomeXchange ( www.ebi.ac.uk/pride/archive/projects/PXD021597 ) repositories, respectively.
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Affiliation(s)
- S Neda Mousavy Gharavy
- Section of Cell Biology and Functional Genomics, Department of Metabolism, Digestion and Reproduction, Imperial College London, Hammersmith Hospital, London, UK
| | - Bryn M Owen
- Section of Investigative Medicine, Department of Metabolism, Digestion and Reproduction, Imperial College London, Hammersmith Hospital, London, UK
| | - Steven J Millership
- Section of Cell Biology and Functional Genomics, Department of Metabolism, Digestion and Reproduction, Imperial College London, Hammersmith Hospital, London, UK
- MRC London Institute of Medical Sciences, Imperial College London, Hammersmith Campus, London, UK
- Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, UK
| | - Pauline Chabosseau
- Section of Cell Biology and Functional Genomics, Department of Metabolism, Digestion and Reproduction, Imperial College London, Hammersmith Hospital, London, UK
| | - Grazia Pizza
- Section of Cell Biology and Functional Genomics, Department of Metabolism, Digestion and Reproduction, Imperial College London, Hammersmith Hospital, London, UK
| | - Aida Martinez-Sanchez
- Section of Cell Biology and Functional Genomics, Department of Metabolism, Digestion and Reproduction, Imperial College London, Hammersmith Hospital, London, UK
| | - Emirhan Tasoez
- DFG-Center for Regenerative Therapies, Technische Universität Dresden, Dresden, Germany
| | - Eleni Georgiadou
- Section of Cell Biology and Functional Genomics, Department of Metabolism, Digestion and Reproduction, Imperial College London, Hammersmith Hospital, London, UK
| | - Ming Hu
- Section of Cell Biology and Functional Genomics, Department of Metabolism, Digestion and Reproduction, Imperial College London, Hammersmith Hospital, London, UK
| | - Nicholas H F Fine
- Section of Cell Biology and Functional Genomics, Department of Metabolism, Digestion and Reproduction, Imperial College London, Hammersmith Hospital, London, UK
| | - David A Jacobson
- Department of Molecular Physiology and Biophysics Vanderbilt University, Nashville, TN, USA
| | - Matthew T Dickerson
- Department of Molecular Physiology and Biophysics Vanderbilt University, Nashville, TN, USA
| | | | - Alex Montoya
- MRC London Institute of Medical Sciences, Imperial College London, Hammersmith Campus, London, UK
| | - Holger Kramer
- MRC London Institute of Medical Sciences, Imperial College London, Hammersmith Campus, London, UK
| | - Zenobia Mehta
- Section of Cell Biology and Functional Genomics, Department of Metabolism, Digestion and Reproduction, Imperial College London, Hammersmith Hospital, London, UK
| | - Dominic J Withers
- MRC London Institute of Medical Sciences, Imperial College London, Hammersmith Campus, London, UK
- Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, London, UK
| | - Nikolay Ninov
- DFG-Center for Regenerative Therapies, Technische Universität Dresden, Dresden, Germany
| | - Paul J Gadue
- Children's Hospital of Philadelphia, CTRB, Philadelphia, PA, USA
| | | | | | - Christophe Magnan
- Regulation of Glycemia by Central Nervous System, BFA, UMR 8251, CNRS Université de Paris, Paris, France
| | - Mark Ibberson
- Vital-IT Group, SIB Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Isabelle Leclerc
- Section of Cell Biology and Functional Genomics, Department of Metabolism, Digestion and Reproduction, Imperial College London, Hammersmith Hospital, London, UK
| | - Marianne Voz
- Laboratory of Zebrafish Development and Disease Models, University of Liège (ULg), Liège, Belgium
| | - Guy A Rutter
- Section of Cell Biology and Functional Genomics, Department of Metabolism, Digestion and Reproduction, Imperial College London, Hammersmith Hospital, London, UK.
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore.
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Inglis A, Ubungen R, Farooq S, Mata P, Thiam J, Saleh S, Shibin S, Al-Mohanna FA, Collison KS. Strain-based and sex-biased differences in adrenal and pancreatic gene expression between KK/HlJ and C57BL/6 J mice. BMC Genomics 2021; 22:180. [PMID: 33711921 PMCID: PMC7953684 DOI: 10.1186/s12864-021-07495-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Accepted: 02/26/2021] [Indexed: 11/15/2022] Open
Abstract
Background The ever-increasing prevalence of diabetes and associated comorbidities serves to highlight the necessity of biologically relevant small-animal models to investigate its etiology, pathology and treatment. Although the C57BL/6 J model is amongst the most widely used mouse model due to its susceptibility to diet-induced obesity (DIO), there are a number of limitations namely [1] that unambiguous fasting hyperglycemia can only be achieved via dietary manipulation and/or chemical ablation of the pancreatic beta cells. [2] Heterogeneity in the obesogenic effects of hypercaloric feeding has been noted, together with sex-dependent differences, with males being more responsive. The KK mouse strain has been used to study aspects of the metabolic syndrome and prediabetes. We recently conducted a study which characterized the differences in male and female glucocentric parameters between the KK/HlJ and C57BL/6 J strains as well as diabetes-related behavioral differences (Inglis et al. 2019). In the present study, we further characterize these models by examining strain- and sex-dependent differences in pancreatic and adrenal gene expression using Affymetrix microarray together with endocrine-associated serum analysis. Results In addition to strain-associated differences in insulin tolerance, we found significant elevations in KK/HlJ mouse serum leptin, insulin and aldosterone. Additionally, glucagon and corticosterone were elevated in female mice of both strains. Using 2-factor ANOVA and a significance level set at 0.05, we identified 10,269 pancreatic and 10,338 adrenal genes with an intensity cut-off of ≥2.0 for all 4 experimental groups. In the pancreas, gene expression upregulated in the KK/HlJ strain related to increased insulin secretory granule biofunction and pancreatic hyperplasia, whereas ontology of upregulated adrenal differentially expressed genes (DEGs) related to cell signaling and neurotransmission. We established a network of functionally related DEGs commonly upregulated in both endocrine tissues of KK/HlJ mice which included the genes coding for endocrine secretory vesicle biogenesis and regulation: PCSK2, PCSK1N, SCG5, PTPRN, CHGB and APLP1. We also identified genes with sex-biased expression common to both strains and tissues including the paternally expressed imprint gene neuronatin. Conclusion Our novel results have further characterized the commonalities and diversities of pancreatic and adrenal gene expression between the KK/HlJ and C57BL/6 J strains as well as differences in serum markers of endocrine physiology. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-021-07495-4.
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Affiliation(s)
- Angela Inglis
- Department of Cell Biology, King Faisal Specialist Hospital & Research Centre, PO BOX 3354, Riyadh, 11211, Saudi Arabia
| | - Rosario Ubungen
- Department of Cell Biology, King Faisal Specialist Hospital & Research Centre, PO BOX 3354, Riyadh, 11211, Saudi Arabia
| | - Sarah Farooq
- Department of Cell Biology, King Faisal Specialist Hospital & Research Centre, PO BOX 3354, Riyadh, 11211, Saudi Arabia
| | - Princess Mata
- Department of Cell Biology, King Faisal Specialist Hospital & Research Centre, PO BOX 3354, Riyadh, 11211, Saudi Arabia
| | - Jennifer Thiam
- Department of Cell Biology, King Faisal Specialist Hospital & Research Centre, PO BOX 3354, Riyadh, 11211, Saudi Arabia
| | - Soad Saleh
- Department of Cell Biology, King Faisal Specialist Hospital & Research Centre, PO BOX 3354, Riyadh, 11211, Saudi Arabia
| | - Sherin Shibin
- Department of Cell Biology, King Faisal Specialist Hospital & Research Centre, PO BOX 3354, Riyadh, 11211, Saudi Arabia
| | - Futwan A Al-Mohanna
- Department of Cell Biology, King Faisal Specialist Hospital & Research Centre, PO BOX 3354, Riyadh, 11211, Saudi Arabia
| | - Kate S Collison
- Department of Cell Biology, King Faisal Specialist Hospital & Research Centre, PO BOX 3354, Riyadh, 11211, Saudi Arabia.
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Lipovsky A, Slivka PF, Su Z, Wang Y, Paulsboe S, Wetter J, Namovic MT, Gauvin D, Perron D, Gauld SB, McGaraughty S, Goedken ER. ACT1 Is Required for Murine IL-23-Induced Psoriasiform Inflammation Potentially Independent of E3 Ligase Activity. J Invest Dermatol 2021; 141:1772-1779.e6. [PMID: 33548244 DOI: 10.1016/j.jid.2020.10.029] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 10/14/2020] [Accepted: 10/15/2020] [Indexed: 01/22/2023]
Abstract
Psoriasis is a debilitating skin disease characterized by epidermal thickening, abnormal keratinocyte differentiation, and proinflammatory immune cell infiltrate into the affected skin. IL-17A plays a critical role in the etiology of psoriasis. ACT1, an intracellular adaptor protein and a putative ubiquitin E3 ligase, is essential for signal transduction downstream of the IL-17A receptor. Thus, IL-17A signaling in general, and ACT1 specifically, represent attractive targets for the treatment of psoriasis. We generated Act1 knockout and Act1 L286G knockin (ligase domain) mice to investigate the potential therapeutic effects of targeting ACT1 and its U-box domain, respectively. Act1 knockout, but not Act1 L286G knockin, mice were resistant to increases in CXCL1 plasma levels induced by subcutaneous injection of recombinant IL-17A. Moreover, in a mouse model of psoriasiform dermatitis induced by intradermal IL-23 injection, Act1 knockout, but not Act1 L286G knockin, was protective against increases in ear thickness, keratinocyte hyperproliferation, expression of genes for antimicrobial peptides and chemokines, and infiltration of monocytes and macrophages. Our studies highlight the critical contribution of ACT1 to proinflammatory skin changes mediated by the IL-23/IL-17 signaling axis and illustrate the need for further insight into ACT1 E3 ligase activity.
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Affiliation(s)
- Alex Lipovsky
- Dermatology, AbbVie Bioresearch Center, Worcester, Massachusetts, USA
| | - Peter F Slivka
- Dermatology, AbbVie Bioresearch Center, Worcester, Massachusetts, USA.
| | - Zhi Su
- Dermatology, AbbVie Inc, North Chicago, Illinois, USA
| | - Yibing Wang
- Dermatology, AbbVie Inc, North Chicago, Illinois, USA
| | | | - Joseph Wetter
- Dermatology, AbbVie Inc, North Chicago, Illinois, USA
| | | | - Donna Gauvin
- Dermatology, AbbVie Inc, North Chicago, Illinois, USA
| | - Denise Perron
- Dermatology, AbbVie Bioresearch Center, Worcester, Massachusetts, USA
| | | | | | - Eric R Goedken
- Dermatology, AbbVie Bioresearch Center, Worcester, Massachusetts, USA
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Chabosseau P, Rutter GA, Millership SJ. Importance of Both Imprinted Genes and Functional Heterogeneity in Pancreatic Beta Cells: Is There a Link? Int J Mol Sci 2021; 22:1000. [PMID: 33498234 PMCID: PMC7863946 DOI: 10.3390/ijms22031000] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 01/12/2021] [Accepted: 01/14/2021] [Indexed: 02/02/2023] Open
Abstract
Diabetes mellitus now affects more than 400 million individuals worldwide, with significant impacts on the lives of those affected and associated socio-economic costs. Although defects in insulin secretion underlie all forms of the disease, the molecular mechanisms which drive them are still poorly understood. Subsets of specialised beta cells have, in recent years, been suggested to play critical roles in "pacing" overall islet activity. The molecular nature of these cells, the means through which their identity is established and the changes which may contribute to their functional demise and "loss of influence" in both type 1 and type 2 diabetes are largely unknown. Genomic imprinting involves the selective silencing of one of the two parental alleles through DNA methylation and modified imprinted gene expression is involved in a number of diseases. Loss of expression, or loss of imprinting, can be shown in mouse models to lead to defects in beta cell function and abnormal insulin secretion. In the present review we survey the evidence that altered expression of imprinted genes contribute to loss of beta cell function, the importance of beta cell heterogeneity in normal and disease states, and hypothesise whether there is a direct link between the two.
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Affiliation(s)
| | | | - Steven J. Millership
- Section of Cell Biology and Functional Genomics, Division of Diabetes, Endocrinology and Metabolism, Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, Du Cane Road, London W12 0NN, UK; (P.C.); (G.A.R.)
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27
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Villanueva-Hayes C, Millership SJ. Imprinted Genes Impact Upon Beta Cell Function in the Current (and Potentially Next) Generation. Front Endocrinol (Lausanne) 2021; 12:660532. [PMID: 33986727 PMCID: PMC8112240 DOI: 10.3389/fendo.2021.660532] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 04/01/2021] [Indexed: 11/23/2022] Open
Abstract
Beta cell failure lies at the centre of the aetiology and pathogenesis of type 2 diabetes and the epigenetic control of the expression of critical beta cell genes appears to play a major role in this decline. One such group of epigenetically-controlled genes, termed 'imprinted' genes, are characterised by transgenerational monoallelic expression due to differential allelic DNA methylation and play key functional roles within beta cells. Here, we review the evidence for this functional importance of imprinted genes in beta cells as well as their nutritional regulation by the diet and their altered methylation and/or expression in rodent models of diabetes and in type 2 diabetic islets. We also discuss imprinted genes in the context of the next generation, where dietary overnutrition in the parents can lead to their deregulation in the offspring, alongside beta cell dysfunction and defective glucose handling. Both the modulation of imprinted gene expression and the likelihood of developing type 2 diabetes in adulthood are susceptible to the impact of nutritional status in early life. Imprinted loci, therefore, represent an excellent opportunity with which to assess epigenomic changes in beta cells due to the diet in both the current and next generation.
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28
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Braun JL, Geromella MS, Hamstra SI, Fajardo VA. Neuronatin regulates whole-body metabolism: is thermogenesis involved? FASEB Bioadv 2020; 2:579-586. [PMID: 33089074 PMCID: PMC7566048 DOI: 10.1096/fba.2020-00052] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 07/20/2020] [Accepted: 07/22/2020] [Indexed: 12/16/2022] Open
Abstract
Neuronatin (NNAT) was originally discovered in 1995 and labeled as a brain developmental gene due to its abundant expression in developing brains. Over the past 25 years, researchers have uncovered NNAT in other tissues; notably, the hypothalamus, pancreatic β‐cells, and adipocytes. Recent evidence in these tissues indicates that NNAT plays a significant role in metabolism whereby it regulates food intake, insulin secretion, and adipocyte differentiation. Furthermore, genetic deletion of Nnat in mice lowers whole‐body energy expenditure and increases susceptibility to diet‐induced obesity and glucose intolerance; however, the underlying cellular mechanisms remain unknown. Based on its sequence homology with phospholamban, NNAT has a purported role in regulating the sarco(endo)plasmic reticulum Ca2+ ATPase (SERCA) pump. However, NNAT also shares sequence homology with sarcolipin, which has the unique property of uncoupling the SERCA pump, increasing whole‐body energy expenditure and thus promoting adaptive thermogenesis in states of caloric excess or cold exposure. Thus, in this article, we discuss the accumulating evidence suggestive of NNAT’s role in whole‐body metabolic regulation, while highlighting its potential to mediate adaptive thermogenesis via SERCA uncoupling.
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Affiliation(s)
- Jessica L Braun
- Department of Kinesiology Brock University St. Catharines ON USA.,Centre for Bone and Muscle Health Brock University St. Catharines ON USA.,Centre for Neuroscience Brock University St. Catharines ON USA
| | - Mia S Geromella
- Department of Kinesiology Brock University St. Catharines ON USA.,Centre for Bone and Muscle Health Brock University St. Catharines ON USA
| | - Sophie I Hamstra
- Department of Kinesiology Brock University St. Catharines ON USA.,Centre for Bone and Muscle Health Brock University St. Catharines ON USA
| | - Val A Fajardo
- Department of Kinesiology Brock University St. Catharines ON USA.,Centre for Bone and Muscle Health Brock University St. Catharines ON USA.,Centre for Neuroscience Brock University St. Catharines ON USA
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Sui Q, Liang J, Hu Z, Chen Z, Bi G, Huang Y, Li M, Zhan C, Lin Z, Wang Q. Genetic and microenvironmental differences in non-smoking lung adenocarcinoma patients compared with smoking patients. Transl Lung Cancer Res 2020; 9:1407-1421. [PMID: 32953513 PMCID: PMC7481643 DOI: 10.21037/tlcr-20-276] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Background Non-smoking-related lung adenocarcinoma (LUAD) has its own characteristics. Genetic and microenvironmental differences in smoking and non-smoking LUAD patients were analyzed to elucidate the oncogenesis of non-smoking-related LUAD, which will improve our understanding of the underlying molecular mechanism and be of clinical use in the future. Methods The Cancer Genome Atlas (TCGA), Gene Expression Omnibus (GEO) databases were used for clinical and genomic information. Various bioinformatics tools were used to analyze differences in somatic mutations, RNA and microRNA (miRNA) expression, immune infiltration, and stemness indices. GO, KEGG, and GSVA analyses were performed with R. A merged protein-protein interaction (PPI) network was constructed and analyzed. A miRNA-differentially expressed gene network was constructed with miRNet. qRT-PCR was used for validation of 4 most significantly differently expressed genes and 2 miRNAs in tumor samples obtained from 20 pairs of non-smoking and smoking patients. Results Five hundred and one patients with LUAD were obtained, including 210 in the non-smoking group and 292 in the smoking group. A total of 174 significantly altered somatic mutations were detected, including mutations in tumor protein p53 and epidermal growth factor receptor, which were downregulated in non-smoking-related LUAD. At the RNA level, 231 significantly differentially expressed genes were obtained; 124 were upregulated and 107 downregulated in the non-smoking group. GSVA analysis revealed 42 significant pathways. Other functional and enrichment analyses of somatic mutations and RNA expression levels revealed that these genes were significantly enriched in receptor activity regulation and receptor binding. Differences in microenvironments including immune infiltration (e.g., CD8+ T cells and resting mast cells) and stemness indices were also found between groups. A 79-pair interaction was found between differentially expressed genes and miRNAs, of which miR-335-5p and miR-34a-5p were located in the center. Twenty-one genes, including vitronectin, neurotensin, and neuronatin, were differentially expressed in both non-smoking LUAD patients and DMSO-treated A549 cells. And the different expression of neurotensin, neuronatin, trefoil factor family2, regenerating family member 4, miR-377-5p, miR-34a were verified with the same tendency in our own samples. Conclusions Non-smoking LUAD patients, compared to smokers, have different characteristics in terms of somatic mutation, gene, and miRNA expression and the microenvironment, indicating a diverse mechanism of oncogenesis.
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Affiliation(s)
- Qihai Sui
- Department of Thoracic Surgery, Zhongshan Hospital, Fudan University, Shanghai, China.,Eight-Year Program Clinical Medicine, Grade of 2016, Shanghai Medical College, Fudan University, Shanghai, China
| | - Jiaqi Liang
- Department of Thoracic Surgery, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Zhengyang Hu
- Department of Thoracic Surgery, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Zhencong Chen
- Department of Thoracic Surgery, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Guoshu Bi
- Department of Thoracic Surgery, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Yiwei Huang
- Department of Thoracic Surgery, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Ming Li
- Department of Thoracic Surgery, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Cheng Zhan
- Department of Thoracic Surgery, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Zongwu Lin
- Department of Thoracic Surgery, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Qun Wang
- Department of Thoracic Surgery, Zhongshan Hospital, Fudan University, Shanghai, China
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30
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Xu H, Zhao L, Feng X, Ma Y, Chen W, Zou L, Yang Q, Sun J, Yu H, Jiao B. Landscape of genomic imprinting and its functions in the mouse mammary gland. J Mol Cell Biol 2020; 12:857-869. [PMID: 32369566 PMCID: PMC7883822 DOI: 10.1093/jmcb/mjaa020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2020] [Revised: 04/12/2020] [Accepted: 04/20/2020] [Indexed: 11/17/2022] Open
Abstract
Genomic imprinting is an epigenetic modification of DNA, whereby gene expression is restricted to either maternally or paternally inherited alleles. Imprinted genes (IGs) in the placenta and embryo are essential for growth regulation and nutrient supply. However, despite being an important nutrition delivery organ, studies on mammary gland genomic imprinting remain limited. In this study, we found that both the number of IGs and their expression levels decreased during development of the mouse mammary gland. IG expression was lineage-specific and related to mammary gland development and lactation. Meta-analysis of single-cell RNA sequencing data revealed that mammary gland IGs were co-expressed in a network that regulated cell stemness and differentiation, which was confirmed by our functional studies. Accordingly, our data indicated that IGs were essential for the self-renewal of mammary gland stem cells and IG decline was correlated with mammary gland maturity. Taken together, our findings revealed the importance of IGs in a poorly studied nutrition-related organ, i.e. the mammary gland, thus providing a reference for further studies on genomic imprinting.
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Affiliation(s)
- Haibo Xu
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China
- Kunming College of Life Science, University of Chinese Academy of Sciences, Kunming 650223, China
| | - Lina Zhao
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China
- Kunming College of Life Science, University of Chinese Academy of Sciences, Kunming 650223, China
| | - Xu Feng
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China
| | - Yujie Ma
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China
| | - Wei Chen
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China
| | - Li Zou
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China
| | - Qin Yang
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China
| | - Jihong Sun
- Department of Radiology, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou 310016, China
| | - Hong Yu
- Department of General Surgery, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou 310016, China
| | - Baowei Jiao
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China
- KIZ-CUHK Joint Laboratory of Bioresources and Molecular Research in Common Diseases, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China
- Center for Excellence in Animal Evolution and Genetics, Chinese Academy of Sciences, Kunming 650223, China
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31
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Ebrahimi AG, Hollister-Lock J, Sullivan BA, Tsuchida R, Bonner-Weir S, Weir GC. Beta cell identity changes with mild hyperglycemia: Implications for function, growth, and vulnerability. Mol Metab 2020; 35:100959. [PMID: 32244186 PMCID: PMC7082551 DOI: 10.1016/j.molmet.2020.02.002] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 02/03/2020] [Accepted: 02/04/2020] [Indexed: 02/08/2023] Open
Abstract
OBJECTIVE As diabetes develops, marked reductions of insulin secretion are associated with very modest elevations of glucose. We wondered if these glucose changes disrupt beta cell differentiation enough to account for the altered function. METHODS Rats were subjected to 90% partial pancreatectomies and those with only mild glucose elevations 4 weeks or 10 weeks after surgery had major alterations of gene expression in their islets as determined by RNAseq. RESULTS Changes associated with glucose toxicity demonstrated that many of the critical genes responsible for insulin secretion were downregulated while the expression of normally suppressed genes increased. Also, there were marked changes in genes associated with replication, aging, senescence, stress, inflammation, and increased expression of genes controlling both class I and II MHC antigens. CONCLUSIONS These findings suggest that mild glucose elevations in the early stages of diabetes lead to phenotypic changes that adversely affect beta cell function, growth, and vulnerability.
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Affiliation(s)
- Aref G Ebrahimi
- Section on Islet Cell and Regenerative Biology, Joslin Diabetes Center, One Joslin Place, Harvard Medical School, Boston, MA 02215, USA
| | - Jennifer Hollister-Lock
- Section on Islet Cell and Regenerative Biology, Joslin Diabetes Center, One Joslin Place, Harvard Medical School, Boston, MA 02215, USA
| | - Brooke A Sullivan
- Section on Islet Cell and Regenerative Biology, Joslin Diabetes Center, One Joslin Place, Harvard Medical School, Boston, MA 02215, USA
| | - Ryohei Tsuchida
- Section on Islet Cell and Regenerative Biology, Joslin Diabetes Center, One Joslin Place, Harvard Medical School, Boston, MA 02215, USA
| | - Susan Bonner-Weir
- Section on Islet Cell and Regenerative Biology, Joslin Diabetes Center, One Joslin Place, Harvard Medical School, Boston, MA 02215, USA
| | - Gordon C Weir
- Section on Islet Cell and Regenerative Biology, Joslin Diabetes Center, One Joslin Place, Harvard Medical School, Boston, MA 02215, USA.
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Yang W, Chi Y, Meng Y, Chen Z, Xiang R, Yan H, Yang J. FAM3A plays crucial roles in controlling PDX1 and insulin expressions in pancreatic beta cells. FASEB J 2020; 34:3915-3931. [PMID: 31944392 DOI: 10.1096/fj.201902368rr] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 12/22/2019] [Accepted: 12/24/2019] [Indexed: 11/11/2022]
Abstract
So far, the mechanism that links mitochondrial dysfunction to PDX1 inhibition in the pathogenesis of pancreatic β cell dysfunction under diabetic condition remains largely unclear. This study determined the role of mitochondrial protein FAM3A in regulating PDX1 expression in pancreatic β cells using gain- and loss-of function methods in vitro and in vivo. Within pancreas, FAM3A is highly expressed in β, α, δ, and pp cells of islets. Islet FAM3A expression was correlated with insulin expression under physiological and diabetic conditions. Mice with specific knockout of FAM3A in islet β cells exhibited markedly blunted insulin secretion and glucose intolerance. FAM3A-deficient islets showed significant decrease in PDX1 expression, and insulin expression and secretion. FAM3A overexpression upregulated PDX1 and insulin expressions, and augmented insulin secretion in cultured islets and β cells. Mechanistically, FAM3A enhanced ATP production to elevate cellular Ca2+ level and promote insulin secretion. Furthermore, FAM3A-induced ATP release activated CaM to function as a co-activator of FOXA2, stimulating PDX1 gene transcription. In conclusion, FAM3A plays crucial roles in controlling PDX1 and insulin expressions in pancreatic β cells. Inhibition of FAM3A will trigger mitochondrial dysfunction to repress PDX1 and insulin expressions.
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Affiliation(s)
- Weili Yang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Key Laboratory of Molecular Cardiovascular Science of the Ministry of Education, Center for Non-coding RNA Medicine, Peking University Health Science Center, Beijing, China.,Beijing Key Laboratory of Diabetes Research and Care, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Yujing Chi
- Department of Central Laboratory & Institute of Clinical Molecular Biology, Peking University People's Hospital, Beijing, China
| | - Yuhong Meng
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Key Laboratory of Molecular Cardiovascular Science of the Ministry of Education, Center for Non-coding RNA Medicine, Peking University Health Science Center, Beijing, China
| | - Zhenzhen Chen
- State Key Laboratory of Cardiovascular Disease, Hypertension Center, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Rui Xiang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Key Laboratory of Molecular Cardiovascular Science of the Ministry of Education, Center for Non-coding RNA Medicine, Peking University Health Science Center, Beijing, China
| | - Han Yan
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Key Laboratory of Molecular Cardiovascular Science of the Ministry of Education, Center for Non-coding RNA Medicine, Peking University Health Science Center, Beijing, China
| | - Jichun Yang
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Key Laboratory of Molecular Cardiovascular Science of the Ministry of Education, Center for Non-coding RNA Medicine, Peking University Health Science Center, Beijing, China
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33
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Kanno N, Fujiwara K, Yoshida S, Kato T, Kato Y. Dynamic Changes in the Localization of Neuronatin-Positive Cells during Neurogenesis in the Embryonic Rat Brain. Cells Tissues Organs 2019; 207:127-137. [DOI: 10.1159/000504359] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2019] [Accepted: 10/24/2019] [Indexed: 11/19/2022] Open
Abstract
Neuronatin (NNAT) was first identified as a gene selectively and abundantly expressed in the cytoplasm of the newborn mouse brain, and involved in neonatal neurogenesis. However, the particular roles of NNAT in the developing prenatal brain have not been identified, especially in mid to late stages. In this study, we performed immunohistochemical analyses of NNAT and SOX2 proteins, a nuclear transcription factor and neural stem/progenitor marker, in the rat brain on embryonic days 13.5, E16.5, and E20.5. NNAT signals were broadly observed across the developing brain on E13.5 and gradually more localized in later stages, eventually concentrated in the alar and basal parts of the terminal hypothalamus, the alar plate of prosomere 2 of the thalamus, and the choroid plexus in the lateral and fourth ventricles on E20.5. In particular, the mammillary body in the basal part of the terminal hypothalamus, a region with a high number of SOX2-positive cells, evidenced intense NNAT signals on E20.5. The intracellular localization of NNAT showed diverse profiles, suggesting that NNAT was involved in various cellular functions, such as cell differentiation and functional maintenance, during prenatal neurogenesis in the rat brain. Thus, the present observations suggested diverse and active roles of the NNAT protein in neurogenesis. Determining the function of this molecule may assist in the elucidation of the mechanisms involved in brain development.
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Millership SJ, Van de Pette M, Withers DJ. Genomic imprinting and its effects on postnatal growth and adult metabolism. Cell Mol Life Sci 2019; 76:4009-4021. [PMID: 31270580 PMCID: PMC6785587 DOI: 10.1007/s00018-019-03197-z] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Revised: 06/10/2019] [Accepted: 06/17/2019] [Indexed: 12/25/2022]
Abstract
Imprinted genes display parent-of-origin-specific expression with this epigenetic system of regulation found exclusively in therian mammals. Historically, defined imprinted gene functions were almost solely focused on pregnancy and the influence on the growth parameters of the developing embryo and placenta. More recently, a number of postnatal functions have been identified which converge on resource allocation, both for animals in the nest and in adults. While many of the prenatal functions of imprinted genes that have so far been described adhere to the "parental conflict" hypothesis, no clear picture has yet emerged on the functional role of imprints on postnatal metabolism. As these roles are uncovered, interest in the potential for these genes to influence postnatal metabolism and associated adult-onset disease outcomes when dysregulated has gathered pace. Here, we review the published data on imprinted genes and their influence on postnatal metabolism, starting in the nest, and then progressing through to adulthood. When observing the functional effects of these genes on adult metabolism, we must always be careful to acknowledge the influence both of direct expression in the relevant metabolic tissue, but also indirect metabolic programming effects caused by their modulation of both in utero and postnatal growth trajectories.
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Affiliation(s)
- Steven J Millership
- MRC London Institute of Medical Sciences, Du Cane Road, London, W12 0NN, UK.
- Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, Du Cane Road, London, W12 0NN, UK.
| | - Mathew Van de Pette
- MRC London Institute of Medical Sciences, Du Cane Road, London, W12 0NN, UK
- Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, Du Cane Road, London, W12 0NN, UK
| | - Dominic J Withers
- MRC London Institute of Medical Sciences, Du Cane Road, London, W12 0NN, UK.
- Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, Du Cane Road, London, W12 0NN, UK.
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35
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36
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Wang X, Sterr M, Ansarullah, Burtscher I, Böttcher A, Beckenbauer J, Siehler J, Meitinger T, Häring HU, Staiger H, Cernilogar FM, Schotta G, Irmler M, Beckers J, Wright CVE, Bakhti M, Lickert H. Point mutations in the PDX1 transactivation domain impair human β-cell development and function. Mol Metab 2019; 24:80-97. [PMID: 30930126 PMCID: PMC6531841 DOI: 10.1016/j.molmet.2019.03.006] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Revised: 03/04/2019] [Accepted: 03/13/2019] [Indexed: 01/03/2023] Open
Abstract
OBJECTIVE Hundreds of missense mutations in the coding region of PDX1 exist; however, if these mutations predispose to diabetes mellitus is unknown. METHODS In this study, we screened a large cohort of subjects with increased risk for diabetes and identified two subjects with impaired glucose tolerance carrying common, heterozygous, missense mutations in the PDX1 coding region leading to single amino acid exchanges (P33T, C18R) in its transactivation domain. We generated iPSCs from patients with heterozygous PDX1P33T/+, PDX1C18R/+ mutations and engineered isogenic cell lines carrying homozygous PDX1P33T/P33T, PDX1C18R/C18R mutations and a heterozygous PDX1 loss-of-function mutation (PDX1+/-). RESULTS Using an in vitro β-cell differentiation protocol, we demonstrated that both, heterozygous PDX1P33T/+, PDX1C18R/+ and homozygous PDX1P33T/P33T, PDX1C18R/C18R mutations impair β-cell differentiation and function. Furthermore, PDX1+/- and PDX1P33T/P33T mutations reduced differentiation efficiency of pancreatic progenitors (PPs), due to downregulation of PDX1-bound genes, including transcription factors MNX1 and PDX1 as well as insulin resistance gene CES1. Additionally, both PDX1P33T/+ and PDX1P33T/P33T mutations in PPs reduced the expression of PDX1-bound genes including the long-noncoding RNA, MEG3 and the imprinted gene NNAT, both involved in insulin synthesis and secretion. CONCLUSIONS Our results reveal mechanistic details of how common coding mutations in PDX1 impair human pancreatic endocrine lineage formation and β-cell function and contribute to the predisposition for diabetes.
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Affiliation(s)
- Xianming Wang
- Institute of Diabetes and Regeneration Research, Helmholtz Zentrum München, 85764 Neuherberg, Germany; Institute of Stem Cell Research, Helmholtz Zentrum München, 85764 Neuherberg, Germany; Technische Universität München, Ismaningerstraße 22, 81675 München, Germany
| | - Michael Sterr
- Institute of Diabetes and Regeneration Research, Helmholtz Zentrum München, 85764 Neuherberg, Germany; Institute of Stem Cell Research, Helmholtz Zentrum München, 85764 Neuherberg, Germany; Technische Universität München, Ismaningerstraße 22, 81675 München, Germany
| | - Ansarullah
- Institute of Diabetes and Regeneration Research, Helmholtz Zentrum München, 85764 Neuherberg, Germany; Institute of Stem Cell Research, Helmholtz Zentrum München, 85764 Neuherberg, Germany
| | - Ingo Burtscher
- Institute of Diabetes and Regeneration Research, Helmholtz Zentrum München, 85764 Neuherberg, Germany; Institute of Stem Cell Research, Helmholtz Zentrum München, 85764 Neuherberg, Germany
| | - Anika Böttcher
- Institute of Diabetes and Regeneration Research, Helmholtz Zentrum München, 85764 Neuherberg, Germany; Institute of Stem Cell Research, Helmholtz Zentrum München, 85764 Neuherberg, Germany
| | - Julia Beckenbauer
- Institute of Diabetes and Regeneration Research, Helmholtz Zentrum München, 85764 Neuherberg, Germany; Institute of Stem Cell Research, Helmholtz Zentrum München, 85764 Neuherberg, Germany
| | - Johanna Siehler
- Institute of Diabetes and Regeneration Research, Helmholtz Zentrum München, 85764 Neuherberg, Germany; Institute of Stem Cell Research, Helmholtz Zentrum München, 85764 Neuherberg, Germany; Technische Universität München, Ismaningerstraße 22, 81675 München, Germany
| | - Thomas Meitinger
- Institute of Human Genetics, Helmholtz Zentrum München, Neuherberg, Germany
| | - Hans-Ulrich Häring
- Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Zentrum München at the University of Tübingen, 72076 Tübingen, Germany; Department of Internal Medicine, Division of Endocrinology, Diabetology, Vascular Medicine, Nephrology and Clinical Chemistry, University of Tübingen, 72076 Tübingen, Germany; German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany
| | - Harald Staiger
- Institute for Diabetes Research and Metabolic Diseases of the Helmholtz Zentrum München at the University of Tübingen, 72076 Tübingen, Germany; Institute of Pharmaceutical Sciences, Department of Pharmacy and Biochemistry, Eberhard Karls University Tübingen, 72076 Tübingen, Germany; German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany
| | - Filippo M Cernilogar
- Biomedical Center and Center for Integrated Protein Science Munich, Ludwig-Maximilians-University, 82152 Planegg-Martinsried, Germany
| | - Gunnar Schotta
- Biomedical Center and Center for Integrated Protein Science Munich, Ludwig-Maximilians-University, 82152 Planegg-Martinsried, Germany
| | - Martin Irmler
- Institute of Experimental Genetics, Helmholtz Zentrum München, 85764 Neuherberg, Germany
| | - Johannes Beckers
- German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany; Institute of Experimental Genetics, Helmholtz Zentrum München, 85764 Neuherberg, Germany; Chair of Experimental Genetics, School of Life Sciences Weihenstephan, Technische Universität München, 85354 Freising, Germany
| | - Christopher V E Wright
- Vanderbilt University Program in Developmental Biology, Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37232, USA; Vanderbilt Center for Stem Cell Biology, Vanderbilt University, Nashville, TN 37232, USA
| | - Mostafa Bakhti
- Institute of Diabetes and Regeneration Research, Helmholtz Zentrum München, 85764 Neuherberg, Germany; Institute of Stem Cell Research, Helmholtz Zentrum München, 85764 Neuherberg, Germany; German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany
| | - Heiko Lickert
- Institute of Diabetes and Regeneration Research, Helmholtz Zentrum München, 85764 Neuherberg, Germany; Institute of Stem Cell Research, Helmholtz Zentrum München, 85764 Neuherberg, Germany; Technische Universität München, Ismaningerstraße 22, 81675 München, Germany; German Center for Diabetes Research (DZD), 85764 Neuherberg, Germany.
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Kanno N, Yoshida S, Kato T, Kato Y. Characteristic Localization of Neuronatin in Rat Testis, Hair Follicle, Tongue, and Pancreas. J Histochem Cytochem 2019; 67:495-509. [PMID: 30869556 DOI: 10.1369/0022155419836433] [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] [Indexed: 11/22/2022] Open
Abstract
Neuronatin (Nnat) is expressed in the pituitary, pancreas, and other tissues; however, the function of NNAT is still unclear. Recent studies have demonstrated that NNAT is localized in the sex-determining region Y-box 2-positive stem/progenitor cells in the developing rat pituitary primordium and is downregulated during differentiation into mature hormone-producing cells. Moreover, NNAT is widely localized in subcellular organelles, excluding the Golgi. Here, we further evaluated NNAT-positive cells and intracellular localization in embryonic and postnatal rat tissues such as the pancreas, tongue, whisker hair follicle, and testis. Immunohistochemistry revealed that NNAT was localized in undifferentiated cells (i.e., epithelial basal cells and basement cells in the papillae of the tongue and round and elongated spermatids of the testis) as well as in differentiated cells (insulin-positive cells and exocrine cells of the pancreas, taste receptor cells of the fungiform papilla, the inner root sheath of whisker hair follicles, and spermatozoa). In addition, NNAT exhibited novel intracellular localization in acrosomes in the spermatozoa. Because the endoplasmic reticulum (ER) is excluded from spermatozoa and sarco/ER Ca2+-ATPase isoform 2 (SERCA2) is absent from the inner root sheath, these findings suggested that NNAT localization in the ER and its interaction with SERCA2 are cell- or tissue-specific properties.
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Affiliation(s)
- Naoko Kanno
- Division of Life Science, Meiji University, Kanagawa, Japan
| | - Saishu Yoshida
- Institute of Endocrinology, Meiji University, Kanagawa, Japan
| | - Takako Kato
- Institute of Endocrinology, Meiji University, Kanagawa, Japan
| | - Yukio Kato
- Division of Life Science, Meiji University, Kanagawa, Japan.,Graduate School of Agriculture, Meiji University, Kanagawa, Japan.,Institute of Endocrinology, Meiji University, Kanagawa, Japan
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Yang CH, Andrew Pospisilik J. Polyphenism - A Window Into Gene-Environment Interactions and Phenotypic Plasticity. Front Genet 2019; 10:132. [PMID: 30863426 PMCID: PMC6399471 DOI: 10.3389/fgene.2019.00132] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Accepted: 02/08/2019] [Indexed: 02/01/2023] Open
Abstract
Phenotypic plasticity describes the capacity of a single genotype to exhibit a variety of phenotypes as well as the mechanisms that translate environmental variation into reproducible phenotypic modifications. Polyphenism describes the unique sub-type of phenotypic plasticity where the outputs are not continuous, but rather discrete and multi-stable, resulting in several distinct phenotypes on the same genetic background. Epigenetic regulation underpins the stable phenotypic divergences that exemplify polyphenism and their evolutionary origin. Here, we briefly summarize the apparent ubiquity and diversity of polyphenisms across the animal kingdom. We briefly review the best characterized models across taxa and highlight the consistent themes both in their epidemiology and what little we know about molecular mechanisms. Finally, we highlight work that supports the possibility that humans may have a subtle polyphenism at the level of metabolism.
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Affiliation(s)
- Chih-Hsiang Yang
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany.,Van Andel Research Institute, Grand Rapids, MI, United States
| | - John Andrew Pospisilik
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany.,Van Andel Research Institute, Grand Rapids, MI, United States
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39
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Asahara SI. Neuronatin and glucose-induced stress in pancreatic β-cells. J Diabetes Investig 2019; 10:574-576. [PMID: 30565863 PMCID: PMC6497585 DOI: 10.1111/jdi.12993] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 12/16/2018] [Accepted: 12/17/2018] [Indexed: 01/12/2023] Open
Abstract
Recently, reports have described the association between neuronatin (Nnat) and endoplasmic reticulum stress, and the promotion of insulin processing by Nnat, the expression of which is greatly induced by glucose stimulation. The roles of Nnat are worthy of note under both physiological and pathological conditions. In this Commentary, I discuss the association between Nnat and glucose‐induced stress on the basis of recent knowledge.![]()
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Affiliation(s)
- Shun-Ichiro Asahara
- Division of Diabetes and Endocrinology, Department of Internal Medicine, Kobe University Graduate School of Medicine, Kobe, Japan
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40
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Millership SJ, Tunster SJ, Van de Pette M, Choudhury AI, Irvine EE, Christian M, Fisher AG, John RM, Scott J, Withers DJ. Neuronatin deletion causes postnatal growth restriction and adult obesity in 129S2/Sv mice. Mol Metab 2018; 18:97-106. [PMID: 30279096 PMCID: PMC6308027 DOI: 10.1016/j.molmet.2018.09.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Accepted: 09/10/2018] [Indexed: 01/31/2023] Open
Abstract
OBJECTIVE Imprinted genes are crucial for the growth and development of fetal and juvenile mammals. Altered imprinted gene dosage causes a variety of human disorders, with growth and development during these crucial early stages strongly linked with future metabolic health in adulthood. Neuronatin (Nnat) is a paternally expressed imprinted gene found in neuroendocrine systems and white adipose tissue and is regulated by the diet and leptin. Neuronatin expression is downregulated in obese children and has been associated with stochastic obesity in C57BL/6 mice. However, our recent studies of Nnat null mice on this genetic background failed to display any body weight or feeding phenotypes but revealed a defect in glucose-stimulated insulin secretion due to the ability of neuronatin to potentiate signal peptidase cleavage of preproinsulin. Nnat deficiency in beta cells therefore caused a lack of appropriate storage and secretion of mature insulin. METHODS To further explore the potential role of Nnat in the regulation of body weight and adiposity, we studied classical imprinting-related phenotypes such as placental, fetal, and postnatal growth trajectory patterns that may impact upon subsequent adult metabolic phenotypes. RESULTS Here we find that, in contrast to the lack of any body weight or feeding phenotypes on the C57BL/6J background, deletion of Nnat in mice on 129S2/Sv background causes a postnatal growth restriction with reduced adipose tissue accumulation, followed by catch up growth after weaning. This was in the absence of any effect on fetal growth or placental development. In adult 129S2/Sv mice, Nnat deletion was associated with hyperphagia, reduced energy expenditure, and partial leptin resistance. Lack of neuronatin also potentiated obesity caused by either aging or high fat diet feeding. CONCLUSIONS The imprinted gene Nnat plays a key role in postnatal growth, adult energy homeostasis, and the pathogenesis of obesity via catch up growth effects, but this role is dependent upon genetic background.
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Affiliation(s)
- Steven J Millership
- MRC London Institute of Medical Sciences, Du Cane Road, London, W12 0NN, UK; Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, Du Cane Road, London, W12 0NN, UK
| | - Simon J Tunster
- School of Biosciences, Cardiff University, Museum Avenue, Cardiff, CF10 3AX, UK
| | | | | | - Elaine E Irvine
- MRC London Institute of Medical Sciences, Du Cane Road, London, W12 0NN, UK
| | - Mark Christian
- Institute of Reproductive and Developmental Biology, Department of Surgery and Cancer, Imperial College London, Du Cane Road, London, W12 0NN, UK
| | - Amanda G Fisher
- MRC London Institute of Medical Sciences, Du Cane Road, London, W12 0NN, UK
| | - Rosalind M John
- School of Biosciences, Cardiff University, Museum Avenue, Cardiff, CF10 3AX, UK
| | - James Scott
- National Heart and Lung Institute, Department of Medicine, Imperial College London, Du Cane Road, London, W12 0NN, UK
| | - Dominic J Withers
- MRC London Institute of Medical Sciences, Du Cane Road, London, W12 0NN, UK; Institute of Clinical Sciences, Faculty of Medicine, Imperial College London, Du Cane Road, London, W12 0NN, UK.
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