1
|
Osipovich AB, Zhou FY, Chong JJ, Trinh LT, Cottam MA, Shrestha S, Cartailler JP, Magnuson MA. Deletion of Ascl1 in pancreatic β-cells improves insulin secretion, promotes parasympathetic innervation, and attenuates dedifferentiation during metabolic stress. Mol Metab 2023; 78:101811. [PMID: 37769990 PMCID: PMC10570713 DOI: 10.1016/j.molmet.2023.101811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 09/20/2023] [Accepted: 09/22/2023] [Indexed: 10/03/2023] Open
Abstract
OBJECTIVE ASCL1, a pioneer transcription factor, is essential for neural cell differentiation and function. Previous studies have shown that Ascl1 expression is increased in pancreatic β-cells lacking functional KATP channels or after feeding of a high fat diet (HFD) suggesting that it may contribute to the metabolic stress response of β-cells. METHODS We generated β-cell-specific Ascl1 knockout mice (Ascl1βKO) and assessed their glucose homeostasis, islet morphology and gene expression after feeding either a normal diet or HFD for 12 weeks, or in combination with a genetic disruption of Abcc8, an essential KATP channel component. RESULTS Ascl1 expression is increased in response to both a HFD and membrane depolarization and requires CREB-dependent Ca2+ signaling. No differences in glucose homeostasis or islet morphology were observed in Ascl1βKO mice fed a normal diet or in the absence of KATP channels. However, male Ascl1βKO mice fed a HFD exhibited decreased blood glucose levels, improved glucose tolerance, and increased β-cell proliferation. Bulk RNA-seq analysis of islets from Ascl1βKO mice from three studied conditions showed alterations in genes associated with the secretory function. HFD-fed Ascl1βKO mice showed the most extensive changes with increased expression of genes necessary for glucose sensing, insulin secretion and β-cell proliferation, and a decrease in genes associated with β-cell dysfunction, inflammation and dedifferentiation. HFD-fed Ascl1βKO mice also displayed increased expression of parasympathetic neural markers and cholinergic receptors that was accompanied by increased insulin secretion in response to acetylcholine and an increase in islet innervation. CONCLUSIONS Ascl1 expression is induced by stimuli that cause Ca2+-signaling to the nucleus and contributes in a multifactorial manner to the loss of β-cell function by promoting the expression of genes associated with cellular dedifferentiation, attenuating β-cells proliferation, suppressing acetylcholine sensitivity, and repressing parasympathetic innervation of islets. Thus, the removal of Ascl1 from β-cells improves their function in response to metabolic stress.
Collapse
Affiliation(s)
- Anna B Osipovich
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232, USA; Center for Stem Cell Biology, Vanderbilt University, Nashville, TN 37232, USA
| | - Frank Y Zhou
- College of Arts and Sciences, Vanderbilt University, Nashville, TN 37232, USA
| | - Judy J Chong
- College of Arts and Sciences, Vanderbilt University, Nashville, TN 37232, USA
| | - Linh T Trinh
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37232, USA
| | - Mathew A Cottam
- Center for Stem Cell Biology, Vanderbilt University, Nashville, TN 37232, USA
| | - Shristi Shrestha
- Center for Stem Cell Biology, Vanderbilt University, Nashville, TN 37232, USA
| | | | - Mark A Magnuson
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232, USA; Center for Stem Cell Biology, Vanderbilt University, Nashville, TN 37232, USA; Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37232, USA.
| |
Collapse
|
2
|
Cha J, Tong X, Walker EM, Dahan T, Cochrane VA, Ashe S, Russell R, Osipovich AB, Mawla AM, Guo M, Liu JH, Loyd ZA, Huising MO, Magnuson MA, Hebrok M, Dor Y, Stein R. Species-specific roles for the MAFA and MAFB transcription factors in regulating islet β cell identity. JCI Insight 2023; 8:e166386. [PMID: 37606041 PMCID: PMC10543725 DOI: 10.1172/jci.insight.166386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Accepted: 07/06/2023] [Indexed: 08/23/2023] Open
Abstract
Type 2 diabetes (T2D) is associated with compromised identity of insulin-producing pancreatic islet β cells, characterized by inappropriate production of other islet cell-enriched hormones. Here, we examined how hormone misexpression was influenced by the MAFA and MAFB transcription factors, closely related proteins that maintain islet cell function. Mice specifically lacking MafA in β cells demonstrated broad, population-wide changes in hormone gene expression with an overall gene signature closely resembling islet gastrin+ (Gast+) cells generated under conditions of chronic hyperglycemia and obesity. A human β cell line deficient in MAFB, but not one lacking MAFA, also produced a GAST+ gene expression pattern. In addition, GAST was detected in human T2D β cells with low levels of MAFB. Moreover, evidence is provided that human MAFB can directly repress GAST gene transcription. These results support a potentially novel, species-specific role for MafA and MAFB in maintaining adult mouse and human β cell identity, respectively. Here, we discuss the possibility that induction of Gast/GAST and other non-β cell hormones, by reduction in the levels of these transcription factors, represents a dysfunctional β cell signature.
Collapse
Affiliation(s)
- Jeeyeon Cha
- Division of Diabetes, Endocrinology, and Metabolism, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Xin Tong
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, USA
| | - Emily M. Walker
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, USA
| | - Tehila Dahan
- Department of Developmental Biology and Cancer Research, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Veronica A. Cochrane
- Diabetes Center, Department of Medicine, University of California, San Francisco, San Francisco, California, USA
| | - Sudipta Ashe
- Diabetes Center, Department of Medicine, University of California, San Francisco, San Francisco, California, USA
| | - Ronan Russell
- Diabetes Center, Department of Medicine, University of California, San Francisco, San Francisco, California, USA
| | - Anna B. Osipovich
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, USA
| | - Alex M. Mawla
- Department of Neurobiology, Physiology & Behavior, College of Biological Sciences, University of California, Davis, Davis, California, USA
| | - Min Guo
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, USA
| | - Jin-hua Liu
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, USA
| | - Zachary A. Loyd
- Division of Diabetes, Endocrinology, and Metabolism, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Mark O. Huising
- Department of Neurobiology, Physiology & Behavior, College of Biological Sciences, University of California, Davis, Davis, California, USA
| | - Mark A. Magnuson
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, USA
| | - Matthias Hebrok
- Diabetes Center, Department of Medicine, University of California, San Francisco, San Francisco, California, USA
| | - Yuval Dor
- Department of Developmental Biology and Cancer Research, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Roland Stein
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, USA
| |
Collapse
|
3
|
Trinh LT, Osipovich AB, Liu B, Shrestha S, Cartailler JP, Wright CVE, Magnuson MA. Single-Cell RNA Sequencing of Sox17-Expressing Lineages Reveals Distinct Gene Regulatory Networks and Dynamic Developmental Trajectories. Stem Cells 2023; 41:643-657. [PMID: 37085274 PMCID: PMC10465087 DOI: 10.1093/stmcls/sxad030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Accepted: 04/04/2023] [Indexed: 04/23/2023]
Abstract
During early embryogenesis, the transcription factor SOX17 contributes to hepato-pancreato-biliary system formation and vascular-hematopoietic emergence. To better understand Sox17 function in the developing endoderm and endothelium, we developed a dual-color temporal lineage-tracing strategy in mice combined with single-cell RNA sequencing to analyze 6934 cells from Sox17-expressing lineages at embryonic days 9.0-9.5. Our analyses showed 19 distinct cellular clusters combined from all 3 germ layers. Differential gene expression, trajectory and RNA-velocity analyses of endothelial cells revealed a heterogenous population of uncommitted and specialized endothelial subtypes, including 2 hemogenic populations that arise from different origins. Similarly, analyses of posterior foregut endoderm revealed subsets of hepatic, pancreatic, and biliary progenitors with overlapping developmental potency. Calculated gene-regulatory networks predict gene regulons that are dominated by cell type-specific transcription factors unique to each lineage. Vastly different Sox17 regulons found in endoderm versus endothelial cells support the differential interactions of SOX17 with other regulatory factors thereby enabling lineage-specific regulatory actions.
Collapse
Affiliation(s)
- Linh T Trinh
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN, USA
- Center for Stem Cell Biology, Vanderbilt University, Nashville, TN, USA
- Program in Developmental Biology, Vanderbilt University, Nashville, TN, USA
| | - Anna B Osipovich
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA
- Center for Stem Cell Biology, Vanderbilt University, Nashville, TN, USA
| | - Bryan Liu
- College of Arts and Sciences, Vanderbilt University, Nashville, TN, USA
| | - Shristi Shrestha
- Center for Stem Cell Biology, Vanderbilt University, Nashville, TN, USA
| | | | - Christopher V E Wright
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN, USA
- Center for Stem Cell Biology, Vanderbilt University, Nashville, TN, USA
- Program in Developmental Biology, Vanderbilt University, Nashville, TN, USA
| | - Mark A Magnuson
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN, USA
- Center for Stem Cell Biology, Vanderbilt University, Nashville, TN, USA
- Program in Developmental Biology, Vanderbilt University, Nashville, TN, USA
| |
Collapse
|
4
|
Osipovich AB, Dudek KD, Trinh LT, Kim LH, Shrestha S, Cartailler JP, Magnuson MA. ZFP92, a KRAB domain zinc finger protein enriched in pancreatic islets, binds to B1/Alu SINE transposable elements and regulates retroelements and genes. PLoS Genet 2023; 19:e1010729. [PMID: 37155670 PMCID: PMC10166502 DOI: 10.1371/journal.pgen.1010729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Accepted: 04/02/2023] [Indexed: 05/10/2023] Open
Abstract
Repressive KRAB domain-containing zinc-finger proteins (KRAB-ZFPs) are abundant in mammalian genomes and contribute both to the silencing of transposable elements (TEs) and to the regulation of developmental stage- and cell type-specific gene expression. Here we describe studies of zinc finger protein 92 (Zfp92), an X-linked KRAB-ZFP that is highly expressed in pancreatic islets of adult mice, by analyzing global Zfp92 knockout (KO) mice. Physiological, transcriptomic and genome-wide chromatin binding studies indicate that the principal function of ZFP92 in mice is to bind to and suppress the activity of B1/Alu type of SINE elements and modulate the activity of surrounding genomic entities. Deletion of Zfp92 leads to changes in expression of select LINE and LTR retroelements and genes located in the vicinity of ZFP92-bound chromatin. The absence of Zfp92 leads to altered expression of specific genes in islets, adipose and muscle that result in modest sex-specific alterations in blood glucose homeostasis, body mass and fat accumulation. In islets, Zfp92 influences blood glucose concentration in postnatal mice via transcriptional effects on Mafb, whereas in adipose and muscle, it regulates Acacb, a rate-limiting enzyme in fatty acid metabolism. In the absence of Zfp92, a novel TE-Capn11 fusion transcript is overexpressed in islets and several other tissues due to de-repression of an IAPez TE adjacent to ZFP92-bound SINE elements in intron 3 of the Capn11 gene. Together, these studies show that ZFP92 functions both to repress specific TEs and to regulate the transcription of specific genes in discrete tissues.
Collapse
Affiliation(s)
- Anna B. Osipovich
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States of America
- Center for Stem Cell Biology, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Karrie D. Dudek
- Center for Stem Cell Biology, Vanderbilt University, Nashville, Tennessee, United States of America
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Linh T. Trinh
- Center for Stem Cell Biology, Vanderbilt University, Nashville, Tennessee, United States of America
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Lily H. Kim
- College of Arts and Sciences, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Shristi Shrestha
- Center for Stem Cell Biology, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Jean-Philippe Cartailler
- Center for Stem Cell Biology, Vanderbilt University, Nashville, Tennessee, United States of America
| | - Mark A. Magnuson
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States of America
- Center for Stem Cell Biology, Vanderbilt University, Nashville, Tennessee, United States of America
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, Tennessee, United States of America
| |
Collapse
|
5
|
Ho KH, Jayathilake A, Yagan M, Nour A, Osipovich AB, Magnuson MA, Gu G, Kaverina I. CAMSAP2 localizes to the Golgi in islet β-cells and facilitates Golgi-ER trafficking. iScience 2023; 26:105938. [PMID: 36718359 PMCID: PMC9883185 DOI: 10.1016/j.isci.2023.105938] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 12/07/2022] [Accepted: 01/04/2023] [Indexed: 01/09/2023] Open
Abstract
Glucose stimulation induces the remodeling of microtubules, which potentiates insulin secretion in pancreatic β-cells. CAMSAP2 binds to microtubule minus ends to stabilize microtubules in several cultured clonal cells. Here, we report that the knockdown of CAMSAP2 in primary β-cells reduces total insulin content and attenuates GSIS without affecting the releasability of insulin vesicles. Surprisingly, CAMSAP2 knockdown does not change microtubule stability. Unlike in cultured insulinoma cells, CAMSAP2 in primary β-cells predominantly localizes to the Golgi apparatus instead of microtubule minus ends. This novel localization is specific to primary β- but not α-cells and is independent of microtubule binding. Consistent with its specific localization at the Golgi, CAMSAP2 promotes efficient Golgi-ER trafficking in primary β-cells. Moreover, primary β-cells and insulinoma cells likely express different CAMSAP2 isoforms. We propose that a novel CAMSAP2 isoform in primary β-cells has a non-canonical function, which promotes Golgi-ER trafficking to support efficient production of insulin and secretion.
Collapse
Affiliation(s)
- Kung-Hsien Ho
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN, USA
| | - Anissa Jayathilake
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN, USA
| | - Mahircan Yagan
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN, USA
| | - Aisha Nour
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN, USA
| | - Anna B. Osipovich
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA
| | - Mark A. Magnuson
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA
| | - Guoqiang Gu
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN, USA
| | - Irina Kaverina
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN, USA
| |
Collapse
|
6
|
Lee HY, Jang HR, Li H, Samuel VT, Dudek KD, Osipovich AB, Magnuson MA, Sklar J, Shulman GI. Deletion of Jazf1 gene causes early growth retardation and insulin resistance in mice. Proc Natl Acad Sci U S A 2022; 119:e2213628119. [PMID: 36442127 PMCID: PMC9894197 DOI: 10.1073/pnas.2213628119] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Single-nucleotide polymorphisms in the human juxtaposed with another zinc finger protein 1 (JAZF1) gene have repeatedly been associated with both type 2 diabetes (T2D) and height in multiple genome-wide association studies (GWAS); however, the mechanism by which JAZF1 causes these traits is not yet known. To investigate the possible functional role of JAZF1 in growth and glucose metabolism in vivo, we generated Jazf1 knockout (KO) mice and examined body composition and insulin sensitivity both in young and adult mice by using 1H-nuclear magnetic resonance and hyperinsulinemic-euglycemic clamp techniques. Plasma concentrations of insulin-like growth factor 1 (IGF-1) were reduced in both young and adult Jazf1 KO mice, and young Jazf1 KO mice were shorter in stature than age-matched wild-type mice. Young Jazf1 KO mice manifested reduced fat mass, whereas adult Jazf1 KO mice manifested increased fat mass and reductions in lean body mass associated with increased plasma growth hormone (GH) concentrations. Adult Jazf1 KO manifested muscle insulin resistance that was further exacerbated by high-fat diet feeding. Gene set enrichment analysis in Jazf1 KO liver identified the hepatocyte hepatic nuclear factor 4 alpha (HNF4α), which was decreased in Jazf1 KO liver and in JAZF1 knockdown cells. Moreover, GH-induced IGF-1 expression was inhibited by JAZF1 knockdown in human hepatocytes. Taken together these results demonstrate that reduction of JAZF1 leads to early growth retardation and late onset insulin resistance in vivo which may be mediated through alterations in the GH-IGF-1 axis and HNF4α.
Collapse
Affiliation(s)
- Hui-Young Lee
- aLaboratory of Mitochondria and Metabolic Diseases, School of Medicine, Gachon University, Incheon21999, Korea
- bDepartment of Molecular Medicine, School of Medicine, Gachon University, Incheon21999, Korea
- cKorea Mouse Metabolic Phenotyping Center, Lee Gil Ya Cancer and Diabetes Institute, Gachon University, Incheon21999, Korea
| | - Hye Rim Jang
- aLaboratory of Mitochondria and Metabolic Diseases, School of Medicine, Gachon University, Incheon21999, Korea
- bDepartment of Molecular Medicine, School of Medicine, Gachon University, Incheon21999, Korea
| | - Hui Li
- dDepartment of Pathology, University of Virginia, Charlottesville, VA22908
| | - Varman T. Samuel
- eDepartment of Internal Medicine, Yale School of Medicine, New Haven, CT06510
- fWest Haven Veterans Affairs Medical Center, West Haven, CT06516
| | - Karrie D. Dudek
- gDepartment of Cell and Developmental Biology, Vanderbilt University, NashvilleTN37232
| | - Anna B. Osipovich
- hDepartment of Molecular Physiology and Biophysics, Vanderbilt UniversityNashville, TN37232
| | - Mark A. Magnuson
- hDepartment of Molecular Physiology and Biophysics, Vanderbilt UniversityNashville, TN37232
- 1To whom correspondence may be addressed. , , or
| | - Jeffrey Sklar
- iDepartment of Pathology, Yale School of Medicine, New HavenCT06510
- 1To whom correspondence may be addressed. , , or
| | - Gerald I. Shulman
- eDepartment of Internal Medicine, Yale School of Medicine, New Haven, CT06510
- jDepartment of Cellular & Molecular Physiology, Yale School of Medicine, New Haven, CT06510
- 1To whom correspondence may be addressed. , , or
| |
Collapse
|
7
|
Trinh LT, Osipovich AB, Sampson L, Wong J, Wright CV, Magnuson MA. Differential regulation of alternate promoter regions in Sox17 during endodermal and vascular endothelial development. iScience 2022; 25:104905. [PMID: 36046192 PMCID: PMC9421400 DOI: 10.1016/j.isci.2022.104905] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 04/06/2022] [Accepted: 08/05/2022] [Indexed: 11/20/2022] Open
Abstract
Sox17 gene expression is essential for both endothelial and endodermal cell differentiation. To better understand the genetic basis for the expression of multiple Sox17 mRNA forms, we identified and performed CRISPR/Cas9 mutagenesis of two evolutionarily conserved promoter regions (CRs). The deletion of the upstream and endothelial cell-specific CR1 caused only a modest increase in lympho-vasculogenesis likely via reduced Notch signaling downstream of SOX17. In contrast, the deletion of the downstream CR2 region, which functions in both endothelial and endodermal cells, impairs both vascular and endodermal development causing death by embryonic day 12.5. Analyses of 3D chromatin looping, transcription factor binding, histone modification, and chromatin accessibility data at the Sox17 locus and surrounding region further support differential regulation of the two promoters during the development. Two Sox17 conserved regions (CR1/CR2) are differentially active during embryogenesis CR1 deletion increases lympho-vasculogenesis by reducing Sox17 and Notch signaling CR2 deletion lethally impairs hepatopancreatobiliary and vascular development Transcription factors bind at CR1 and a distal element interacts with CR2
Collapse
Affiliation(s)
- Linh T. Trinh
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37232, USA
- Center for Stem Cell Biology, Vanderbilt University, Nashville, TN 37232, USA
- Program in Developmental Biology, Vanderbilt University, Nashville, TN 37232, USA
| | - Anna B. Osipovich
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232, USA
- Center for Stem Cell Biology, Vanderbilt University, Nashville, TN 37232, USA
| | - Leesa Sampson
- Center for Stem Cell Biology, Vanderbilt University, Nashville, TN 37232, USA
| | - Jonathan Wong
- College of Arts and Science, Vanderbilt University, Nashville, TN 37232, USA
| | - Chris V.E. Wright
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37232, USA
- Center for Stem Cell Biology, Vanderbilt University, Nashville, TN 37232, USA
- Program in Developmental Biology, Vanderbilt University, Nashville, TN 37232, USA
| | - Mark A. Magnuson
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37232, USA
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232, USA
- Center for Stem Cell Biology, Vanderbilt University, Nashville, TN 37232, USA
- Program in Developmental Biology, Vanderbilt University, Nashville, TN 37232, USA
- Corresponding author
| |
Collapse
|
8
|
Trogden KP, Lee J, Bracey KM, Ho KH, McKinney H, Zhu X, Arpag G, Folland TG, Osipovich AB, Magnuson MA, Zanic M, Gu G, Holmes WR, Kaverina I. Microtubules regulate pancreatic β-cell heterogeneity via spatiotemporal control of insulin secretion hot spots. eLife 2021; 10:59912. [PMID: 34783306 PMCID: PMC8635970 DOI: 10.7554/elife.59912] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Accepted: 11/08/2021] [Indexed: 12/25/2022] Open
Abstract
Heterogeneity of glucose-stimulated insulin secretion (GSIS) in pancreatic islets is physiologically important but poorly understood. Here, we utilize mouse islets to determine how microtubules (MTs) affect secretion toward the vascular extracellular matrix at single cell and subcellular levels. Our data indicate that MT stability in the β-cell population is heterogenous, and that GSIS is suppressed in cells with highly stable MTs. Consistently, MT hyper-stabilization prevents, and MT depolymerization promotes the capacity of single β-cell for GSIS. Analysis of spatiotemporal patterns of secretion events shows that MT depolymerization activates otherwise dormant β-cells via initiation of secretion clusters (hot spots). MT depolymerization also enhances secretion from individual cells, introducing both additional clusters and scattered events. Interestingly, without MTs, the timing of clustered secretion is dysregulated, extending the first phase of GSIS and causing oversecretion. In contrast, glucose-induced Ca2+ influx was not affected by MT depolymerization yet required for secretion under these conditions, indicating that MT-dependent regulation of secretion hot spots acts in parallel with Ca2+ signaling. Our findings uncover a novel MT function in tuning insulin secretion hot spots, which leads to accurately measured and timed response to glucose stimuli and promotes functional β-cell heterogeneity.
Collapse
Affiliation(s)
- Kathryn P Trogden
- Department of Cell and Developmental Biology and Program in Developmental Biology, Vanderbilt University, Nashville, United States
| | - Justin Lee
- Department of Cell and Developmental Biology and Program in Developmental Biology, Vanderbilt University, Nashville, United States
| | - Kai M Bracey
- Department of Cell and Developmental Biology and Program in Developmental Biology, Vanderbilt University, Nashville, United States
| | - Kung-Hsien Ho
- Department of Cell and Developmental Biology and Program in Developmental Biology, Vanderbilt University, Nashville, United States
| | - Hudson McKinney
- Department of Cell and Developmental Biology and Program in Developmental Biology, Vanderbilt University, Nashville, United States
| | - Xiaodong Zhu
- Department of Cell and Developmental Biology and Program in Developmental Biology, Vanderbilt University, Nashville, United States.,Department of Medicine, Vanderbilt University, Nashville, United States
| | - Goker Arpag
- Department of Cell and Developmental Biology and Program in Developmental Biology, Vanderbilt University, Nashville, United States
| | - Thomas G Folland
- Department of Mechanical Engineering, Vanderbilt University, Nashville, United States
| | - Anna B Osipovich
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, United States.,Center for Stem Cell Biology, Vanderbilt University, Nashville, United States
| | - Mark A Magnuson
- Department of Cell and Developmental Biology and Program in Developmental Biology, Vanderbilt University, Nashville, United States.,Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, United States.,Center for Stem Cell Biology, Vanderbilt University, Nashville, United States
| | - Marija Zanic
- Department of Cell and Developmental Biology and Program in Developmental Biology, Vanderbilt University, Nashville, United States.,Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, United States.,Department of Biochemistry, Vanderbilt University, Nashville, United States
| | - Guoqiang Gu
- Department of Cell and Developmental Biology and Program in Developmental Biology, Vanderbilt University, Nashville, United States
| | - William R Holmes
- Department of Physics and Astronomy, Vanderbilt University, Nashville, United States.,Department of Mathematics, Vanderbilt University, Nashville, United States.,Quantitative Systems Biology Center, Vanderbilt University, Nashville, United States
| | - Irina Kaverina
- Department of Cell and Developmental Biology and Program in Developmental Biology, Vanderbilt University, Nashville, United States
| |
Collapse
|
9
|
Dudek KD, Osipovich AB, Cartailler JP, Gu G, Magnuson MA. Insm1, Neurod1, and Pax6 promote murine pancreatic endocrine cell development through overlapping yet distinct RNA transcription and splicing programs. G3 (Bethesda) 2021; 11:6358139. [PMID: 34534285 PMCID: PMC8527475 DOI: 10.1093/g3journal/jkab303] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 08/19/2021] [Indexed: 11/13/2022]
Abstract
Insm1, Neurod1, and Pax6 are essential for the formation and function of pancreatic endocrine cells. Here, we report comparative immunohistochemical, transcriptomic, functional enrichment, and RNA splicing analyses of these genes using gene knock-out mice. Quantitative immunohistochemical analysis confirmed that elimination of each of these three factors variably impairs the proliferation, survival, and differentiation of endocrine cells. Transcriptomic analysis revealed that each factor contributes uniquely to the transcriptome although their effects were overlapping. Functional enrichment analysis revealed that genes downregulated by the elimination of Insm1, Neurod1, and Pax6 are commonly involved in mRNA metabolism, chromatin organization, secretion, and cell cycle regulation, and upregulated genes are associated with protein degradation, autophagy, and apoptotic process. Elimination of Insm1, Neurod1, and Pax6 impaired expression of many RNA-binding proteins thereby altering RNA splicing events, including for Syt14 and Snap25, two genes required for insulin secretion. All three factors are necessary for normal splicing of Syt14, and both Insm1 and Pax6 are necessary for the processing of Snap25. Collectively, these data provide new insights into how Insm1, Neurod1, and Pax6 contribute to the formation of functional pancreatic endocrine cells.
Collapse
Affiliation(s)
- Karrie D Dudek
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37232, USA.,Center for Stem Cell Biology, Vanderbilt University, Nashville, TN 37232, USA
| | - Anna B Osipovich
- Center for Stem Cell Biology, Vanderbilt University, Nashville, TN 37232, USA.,Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232, USA
| | | | - Guoquing Gu
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37232, USA.,Center for Stem Cell Biology, Vanderbilt University, Nashville, TN 37232, USA
| | - Mark A Magnuson
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37232, USA.,Center for Stem Cell Biology, Vanderbilt University, Nashville, TN 37232, USA.,Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232, USA
| |
Collapse
|
10
|
Osipovich AB, Dudek KD, Greenfest-Allen E, Cartailler JP, Manduchi E, Potter Case L, Choi E, Chapman AG, Clayton HW, Gu G, Stoeckert CJ, Magnuson MA. A developmental lineage-based gene co-expression network for mouse pancreatic β-cells reveals a role for Zfp800 in pancreas development. Development 2021; 148:dev.196964. [PMID: 33653874 DOI: 10.1242/dev.196964] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Accepted: 02/17/2021] [Indexed: 12/15/2022]
Abstract
To gain a deeper understanding of pancreatic β-cell development, we used iterative weighted gene correlation network analysis to calculate a gene co-expression network (GCN) from 11 temporally and genetically defined murine cell populations. The GCN, which contained 91 distinct modules, was then used to gain three new biological insights. First, we found that the clustered protocadherin genes are differentially expressed during pancreas development. Pcdhγ genes are preferentially expressed in pancreatic endoderm, Pcdhβ genes in nascent islets, and Pcdhα genes in mature β-cells. Second, after extracting sub-networks of transcriptional regulators for each developmental stage, we identified 81 zinc finger protein (ZFP) genes that are preferentially expressed during endocrine specification and β-cell maturation. Third, we used the GCN to select three ZFPs for further analysis by CRISPR mutagenesis of mice. Zfp800 null mice exhibited early postnatal lethality, and at E18.5 their pancreata exhibited a reduced number of pancreatic endocrine cells, alterations in exocrine cell morphology, and marked changes in expression of genes involved in protein translation, hormone secretion and developmental pathways in the pancreas. Together, our results suggest that developmentally oriented GCNs have utility for gaining new insights into gene regulation during organogenesis.
Collapse
Affiliation(s)
- Anna B Osipovich
- Center for Stem Cell Biology, Vanderbilt University, Nashville, TN 37232, USA.,Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232, USA
| | - Karrie D Dudek
- Center for Stem Cell Biology, Vanderbilt University, Nashville, TN 37232, USA.,Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37240, USA
| | - Emily Greenfest-Allen
- Department of Genetics, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA.,Institute for Biomedical Informatics, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
| | | | - Elisabetta Manduchi
- Department of Genetics, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA.,Institute for Biomedical Informatics, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
| | - Leah Potter Case
- Center for Stem Cell Biology, Vanderbilt University, Nashville, TN 37232, USA.,Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232, USA
| | - Eunyoung Choi
- Center for Stem Cell Biology, Vanderbilt University, Nashville, TN 37232, USA.,Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232, USA
| | - Austin G Chapman
- Center for Stem Cell Biology, Vanderbilt University, Nashville, TN 37232, USA
| | - Hannah W Clayton
- Center for Stem Cell Biology, Vanderbilt University, Nashville, TN 37232, USA.,Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37240, USA
| | - Guoqiang Gu
- Center for Stem Cell Biology, Vanderbilt University, Nashville, TN 37232, USA.,Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37240, USA
| | - Christian J Stoeckert
- Department of Genetics, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA.,Institute for Biomedical Informatics, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
| | - Mark A Magnuson
- Center for Stem Cell Biology, Vanderbilt University, Nashville, TN 37232, USA .,Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232, USA.,Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN 37240, USA
| |
Collapse
|
11
|
Ho KH, Yang X, Osipovich AB, Cabrera O, Hayashi ML, Magnuson MA, Gu G, Kaverina I. Glucose Regulates Microtubule Disassembly and the Dose of Insulin Secretion via Tau Phosphorylation. Diabetes 2020; 69:1936-1947. [PMID: 32540877 PMCID: PMC7458041 DOI: 10.2337/db19-1186] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Accepted: 06/07/2020] [Indexed: 12/16/2022]
Abstract
The microtubule cytoskeleton of pancreatic islet β-cells regulates glucose-stimulated insulin secretion (GSIS). We have reported that the microtubule-mediated movement of insulin vesicles away from the plasma membrane limits insulin secretion. High glucose-induced remodeling of microtubule network facilitates robust GSIS. This remodeling involves disassembly of old microtubules and nucleation of new microtubules. Here, we examine the mechanisms whereby glucose stimulation decreases microtubule lifetimes in β-cells. Using real-time imaging of photoconverted microtubules, we demonstrate that high levels of glucose induce rapid microtubule disassembly preferentially in the periphery of individual β-cells, and this process is mediated by the phosphorylation of microtubule-associated protein tau. Specifically, high glucose induces tau hyper-phosphorylation via glucose-responsive kinases GSK3, PKA, PKC, and CDK5. This causes dissociation of tau from and subsequent destabilization of microtubules. Consequently, tau knockdown in mouse islet β-cells facilitates microtubule turnover, causing increased basal insulin secretion, depleting insulin vesicles from the cytoplasm, and impairing GSIS. More importantly, tau knockdown uncouples microtubule destabilization from glucose stimulation. These findings suggest that tau suppresses peripheral microtubules turning over to restrict insulin oversecretion in basal conditions and preserve the insulin pool that can be released following stimulation; high glucose promotes tau phosphorylation to enhance microtubule disassembly to acutely enhance GSIS.
Collapse
Affiliation(s)
- Kung-Hsien Ho
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN
- Program of Developmental Biology and Vanderbilt Center for Stem Cell Biology, Vanderbilt University, Nashville, TN
| | - Xiaodun Yang
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN
- Program of Developmental Biology and Vanderbilt Center for Stem Cell Biology, Vanderbilt University, Nashville, TN
| | - Anna B Osipovich
- Program of Developmental Biology and Vanderbilt Center for Stem Cell Biology, Vanderbilt University, Nashville, TN
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN
| | | | | | - Mark A Magnuson
- Program of Developmental Biology and Vanderbilt Center for Stem Cell Biology, Vanderbilt University, Nashville, TN
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN
| | - Guoqiang Gu
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN
- Program of Developmental Biology and Vanderbilt Center for Stem Cell Biology, Vanderbilt University, Nashville, TN
| | - Irina Kaverina
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN
- Program of Developmental Biology and Vanderbilt Center for Stem Cell Biology, Vanderbilt University, Nashville, TN
| |
Collapse
|
12
|
Osipovich AB, Stancill JS, Cartailler JP, Dudek KD, Magnuson MA. Excitotoxicity and Overnutrition Additively Impair Metabolic Function and Identity of Pancreatic β-Cells. Diabetes 2020; 69:1476-1491. [PMID: 32332159 PMCID: PMC7809715 DOI: 10.2337/db19-1145] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 04/20/2020] [Indexed: 12/14/2022]
Abstract
A sustained increase in intracellular Ca2+ concentration (referred to hereafter as excitotoxicity), brought on by chronic metabolic stress, may contribute to pancreatic β-cell failure. To determine the additive effects of excitotoxicity and overnutrition on β-cell function and gene expression, we analyzed the impact of a high-fat diet (HFD) on Abcc8 knockout mice. Excitotoxicity caused β-cells to be more susceptible to HFD-induced impairment of glucose homeostasis, and these effects were mitigated by verapamil, a Ca2+ channel blocker. Excitotoxicity, overnutrition, and the combination of both stresses caused similar but distinct alterations in the β-cell transcriptome, including additive increases in genes associated with mitochondrial energy metabolism, fatty acid β-oxidation, and mitochondrial biogenesis and their key regulator Ppargc1a Overnutrition worsened excitotoxicity-induced mitochondrial dysfunction, increasing metabolic inflexibility and mitochondrial damage. In addition, excitotoxicity and overnutrition, individually and together, impaired both β-cell function and identity by reducing expression of genes important for insulin secretion, cell polarity, cell junction, cilia, cytoskeleton, vesicular trafficking, and regulation of β-cell epigenetic and transcriptional program. Sex had an impact on all β-cell responses, with male animals exhibiting greater metabolic stress-induced impairments than females. Together, these findings indicate that a sustained increase in intracellular Ca2+, by altering mitochondrial function and impairing β-cell identity, augments overnutrition-induced β-cell failure.
Collapse
Affiliation(s)
- Anna B Osipovich
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN
- Vanderbilt Center for Stem Cell Biology, Vanderbilt University, Nashville, TN
| | - Jennifer S Stancill
- Vanderbilt Center for Stem Cell Biology, Vanderbilt University, Nashville, TN
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN
| | | | - Karrie D Dudek
- Vanderbilt Center for Stem Cell Biology, Vanderbilt University, Nashville, TN
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN
| | - Mark A Magnuson
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN
- Vanderbilt Center for Stem Cell Biology, Vanderbilt University, Nashville, TN
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN
| |
Collapse
|
13
|
Spaeth JM, Liu JH, Peters D, Guo M, Osipovich AB, Mohammadi F, Roy N, Bhushan A, Magnuson MA, Hebrok M, Wright CVE, Stein R. The Pdx1-Bound Swi/Snf Chromatin Remodeling Complex Regulates Pancreatic Progenitor Cell Proliferation and Mature Islet β-Cell Function. Diabetes 2019; 68:1806-1818. [PMID: 31201281 PMCID: PMC6702633 DOI: 10.2337/db19-0349] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Accepted: 06/06/2019] [Indexed: 12/13/2022]
Abstract
Transcription factors positively and/or negatively impact gene expression by recruiting coregulatory factors, which interact through protein-protein binding. Here we demonstrate that mouse pancreas size and islet β-cell function are controlled by the ATP-dependent Swi/Snf chromatin remodeling coregulatory complex that physically associates with Pdx1, a diabetes-linked transcription factor essential to pancreatic morphogenesis and adult islet cell function and maintenance. Early embryonic deletion of just the Swi/Snf Brg1 ATPase subunit reduced multipotent pancreatic progenitor cell proliferation and resulted in pancreas hypoplasia. In contrast, removal of both Swi/Snf ATPase subunits, Brg1 and Brm, was necessary to compromise adult islet β-cell activity, which included whole-animal glucose intolerance, hyperglycemia, and impaired insulin secretion. Notably, lineage-tracing analysis revealed Swi/Snf-deficient β-cells lost the ability to produce the mRNAs for Ins and other key metabolic genes without effecting the expression of many essential islet-enriched transcription factors. Swi/Snf was necessary for Pdx1 to bind to the Ins gene enhancer, demonstrating the importance of this association in mediating chromatin accessibility. These results illustrate how fundamental the Pdx1:Swi/Snf coregulator complex is in the pancreas, and we discuss how disrupting their association could influence type 1 and type 2 diabetes susceptibility.
Collapse
Affiliation(s)
- Jason M Spaeth
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN
| | - Jin-Hua Liu
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN
| | - Daniel Peters
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN
| | - Min Guo
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN
| | - Anna B Osipovich
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN
| | - Fardin Mohammadi
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN
| | - Nilotpal Roy
- Diabetes Center, Department of Medicine, University of California, San Francisco, San Francisco, CA
| | - Anil Bhushan
- Diabetes Center, Department of Medicine, University of California, San Francisco, San Francisco, CA
| | - Mark A Magnuson
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN
| | - Matthias Hebrok
- Diabetes Center, Department of Medicine, University of California, San Francisco, San Francisco, CA
| | | | - Roland Stein
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN
| |
Collapse
|
14
|
Stancill JS, Osipovich AB, Cartailler JP, Magnuson MA. Transgene-associated human growth hormone expression in pancreatic β-cells impairs identification of sex-based gene expression differences. Am J Physiol Endocrinol Metab 2019; 316:E196-E209. [PMID: 30532991 PMCID: PMC6397359 DOI: 10.1152/ajpendo.00229.2018] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Fluorescent protein reporter genes are widely used to identify and sort murine pancreatic β-cells. In this study, we compared use of the MIP-GFP transgene, which exhibits aberrant expression of human growth hormone (hGH), with a newly derived Ins2Apple allele that lacks hGH expression on the expression of sex-specific genes. β-Cells from MIP-GFP transgenic mice exhibit changes in the expression of 7,733 genes, or greater than half of their transcriptome, compared with β-cells from Ins2Apple/+ mice. To determine how these differences might affect a typical differential gene expression study, we analyzed the effect of sex on gene expression using both reporter lines. Six hundred fifty-seven differentially expressed genes were identified between male and female β-cells containing the Ins2Apple allele. Female β-cells exhibit higher expression of Xist, Tmed9, Arpc3, Eml2, and several islet-enriched transcription factors, including Nkx2-2 and Hnf4a, whereas male β-cells exhibited a generally higher expression of genes involved in cell cycle regulation. In marked contrast, the same male vs. female comparison of β-cells containing the MIP-GFP transgene revealed only 115 differentially expressed genes, and comparison of the 2 lists of differentially expressed genes revealed only 17 that were common to both analyses. These results indicate that 1) male and female β-cells differ in their expression of key transcription factors and cell cycle regulators and 2) the MIP-GFP transgene may attenuate sex-specific differences that distinguish male and female β-cells, thereby impairing the identification of sex-specific variations.
Collapse
Affiliation(s)
- Jennifer S Stancill
- Department of Cell and Developmental Biology, Vanderbilt University , Nashville, Tennessee
- Center for Stem Cell Biology, Vanderbilt University , Nashville, Tennessee
| | - Anna B Osipovich
- Department of Molecular Physiology and Biophysics, Vanderbilt University , Nashville, Tennessee
- Center for Stem Cell Biology, Vanderbilt University , Nashville, Tennessee
| | | | - Mark A Magnuson
- Department of Cell and Developmental Biology, Vanderbilt University , Nashville, Tennessee
- Department of Molecular Physiology and Biophysics, Vanderbilt University , Nashville, Tennessee
- Center for Stem Cell Biology, Vanderbilt University , Nashville, Tennessee
| |
Collapse
|
15
|
Cigliola V, Ghila L, Thorel F, van Gurp L, Baronnier D, Oropeza D, Gupta S, Miyatsuka T, Kaneto H, Magnuson MA, Osipovich AB, Sander M, Wright CEV, Thomas MK, Furuyama K, Chera S, Herrera PL. Pancreatic islet-autonomous insulin and smoothened-mediated signalling modulate identity changes of glucagon + α-cells. Nat Cell Biol 2018; 20:1267-1277. [PMID: 30361701 PMCID: PMC6215453 DOI: 10.1038/s41556-018-0216-y] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Accepted: 09/17/2018] [Indexed: 02/06/2023]
Abstract
The mechanisms restricting regeneration and maintaining cell identity following injury are poorly characterized in higher vertebrates. Upon β-cell loss, 1–2% of the glucagon-producing α-cells spontaneously engage in insulin production in mice. Here we explore the mechanisms inhibiting α-cell plasticity. We show that the adaptive α-cell identity changes are constrained by intra-islet Insulin- and Smoothened-mediated signaling, among others. The combination of β-cell loss, or insulin signaling inhibition, with Smoothened inactivation in α- or δ-cells, stimulates insulin production in more α-cells. These findings suggest that removing constitutive “brake signals” is crucial for neutralizing the refractoriness to adaptive cell-fate changes. It appears that cell identity maintenance is an active process mediated by repressive signals, released by neighbor cells, curbing an intrinsic trend of differentiated cells to change.
Collapse
Affiliation(s)
- Valentina Cigliola
- Department of Genetic Medicine and Development, iGE3 and Centre facultaire du diabète, Faculty of Medicine, University of Geneva, Geneva, Switzerland.,Department of Cell Biology, Duke University Medical Center, Durham, NC, USA
| | - Luiza Ghila
- Department of Genetic Medicine and Development, iGE3 and Centre facultaire du diabète, Faculty of Medicine, University of Geneva, Geneva, Switzerland.,Department of Clinical Science and KG Jebsen Center for Diabetes Research, University of Bergen, Bergen, Norway
| | - Fabrizio Thorel
- Department of Genetic Medicine and Development, iGE3 and Centre facultaire du diabète, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Léon van Gurp
- Department of Genetic Medicine and Development, iGE3 and Centre facultaire du diabète, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Delphine Baronnier
- Department of Genetic Medicine and Development, iGE3 and Centre facultaire du diabète, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Daniel Oropeza
- Department of Genetic Medicine and Development, iGE3 and Centre facultaire du diabète, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Simone Gupta
- Lilly Research Laboratories, Lilly Corporate Center, Indianapolis, IN, USA
| | - Takeshi Miyatsuka
- Department of Metabolism and Endocrinology, Graduate School of Medicine , Juntendo University , Tokyo, Japan
| | - Hideaki Kaneto
- Department of Metabolic Medicine, Graduate School of Medicine, Osaka University, Osaka, Japan
| | - Mark A Magnuson
- Departments of Molecular Physiology and Biophysics, Center for Stem Cell Biology, Vanderbilt University, Nashville, TN, USA
| | - Anna B Osipovich
- Departments of Molecular Physiology and Biophysics, Center for Stem Cell Biology, Vanderbilt University, Nashville, TN, USA
| | - Maike Sander
- Department of Pediatrics and Cellular and Molecular Medicine, University of California, San Diego, CA, USA
| | - Christopher E V Wright
- Department of Cell and Developmental Biology, Program in Developmental Biology and Center for Stem Cell Biology, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Melissa K Thomas
- Lilly Research Laboratories, Lilly Corporate Center, Indianapolis, IN, USA
| | - Kenichiro Furuyama
- Department of Genetic Medicine and Development, iGE3 and Centre facultaire du diabète, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Simona Chera
- Department of Genetic Medicine and Development, iGE3 and Centre facultaire du diabète, Faculty of Medicine, University of Geneva, Geneva, Switzerland.,Department of Clinical Science and KG Jebsen Center for Diabetes Research, University of Bergen, Bergen, Norway
| | - Pedro L Herrera
- Department of Genetic Medicine and Development, iGE3 and Centre facultaire du diabète, Faculty of Medicine, University of Geneva, Geneva, Switzerland.
| |
Collapse
|
16
|
|
17
|
Stancill JS, Cartailler JP, Clayton HW, O'Connor JT, Dickerson MT, Dadi PK, Osipovich AB, Jacobson DA, Magnuson MA. Chronic β-Cell Depolarization Impairs β-Cell Identity by Disrupting a Network of Ca 2+-Regulated Genes. Diabetes 2017; 66:2175-2187. [PMID: 28550109 PMCID: PMC5521870 DOI: 10.2337/db16-1355] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Accepted: 05/17/2017] [Indexed: 12/18/2022]
Abstract
We used mice lacking Abcc8, a key component of the β-cell KATP-channel, to analyze the effects of a sustained elevation in the intracellular Ca2+ concentration ([Ca2+]i) on β-cell identity and gene expression. Lineage tracing analysis revealed the conversion of β-cells lacking Abcc8 into pancreatic polypeptide cells but not to α- or δ-cells. RNA-sequencing analysis of FACS-purified Abcc8-/- β-cells confirmed an increase in Ppy gene expression and revealed altered expression of more than 4,200 genes, many of which are involved in Ca2+ signaling, the maintenance of β-cell identity, and cell adhesion. The expression of S100a6 and S100a4, two highly upregulated genes, is closely correlated with membrane depolarization, suggesting their use as markers for an increase in [Ca2+]i Moreover, a bioinformatics analysis predicts that many of the dysregulated genes are regulated by common transcription factors, one of which, Ascl1, was confirmed to be directly controlled by Ca2+ influx in β-cells. Interestingly, among the upregulated genes is Aldh1a3, a putative marker of β-cell dedifferentiation, and other genes associated with β-cell failure. Taken together, our results suggest that chronically elevated β-cell [Ca2+]i in Abcc8-/- islets contributes to the alteration of β-cell identity, islet cell numbers and morphology, and gene expression by disrupting a network of Ca2+-regulated genes.
Collapse
Affiliation(s)
- Jennifer S Stancill
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN
- Center for Stem Cell Biology, Vanderbilt University, Nashville, TN
| | | | - Hannah W Clayton
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN
- Center for Stem Cell Biology, Vanderbilt University, Nashville, TN
| | - James T O'Connor
- Center for Stem Cell Biology, Vanderbilt University, Nashville, TN
| | - Matthew T Dickerson
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN
| | - Prasanna K Dadi
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN
| | - Anna B Osipovich
- Center for Stem Cell Biology, Vanderbilt University, Nashville, TN
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN
| | - David A Jacobson
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN
| | - Mark A Magnuson
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, TN
- Center for Stem Cell Biology, Vanderbilt University, Nashville, TN
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN
| |
Collapse
|
18
|
Osipovich AB, Gangula R, Vianna PG, Magnuson MA. Setd5 is essential for mammalian development and the co-transcriptional regulation of histone acetylation. Development 2016; 143:4595-4607. [PMID: 27864380 PMCID: PMC5201031 DOI: 10.1242/dev.141465] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Accepted: 11/06/2016] [Indexed: 02/02/2023]
Abstract
SET domain-containing proteins play a vital role in regulating gene expression during development through modifications in chromatin structure. Here we show that SET domain-containing 5 (Setd5) is divergently transcribed with Gt(ROSA26)Sor, is necessary for mammalian development, and interacts with the PAF1 co-transcriptional complex and other proteins. Setd5-deficient mouse embryos exhibit severe defects in neural tube formation, somitogenesis and cardiac development, have aberrant vasculogenesis in embryos, yolk sacs and placentas, and die between embryonic day 10.5 and 11.5. Setd5-deficient embryonic stem cells have impaired cellular proliferation, increased apoptosis, defective cell cycle progression, a diminished ability to differentiate into cardiomyocytes and greatly perturbed gene expression. SETD5 co-immunoprecipitates with multiple components of the PAF1 and histone deacetylase-containing NCoR complexes and is not solely required for major histone lysine methylation marks. In the absence of Setd5, histone acetylation is increased at transcription start sites and near downstream regions. These findings suggest that SETD5 functions in a manner similar to yeast Set3p and Drosophila UpSET, and that it is essential for regulating histone acetylation during gene transcription.
Collapse
Affiliation(s)
- Anna B Osipovich
- Center for Stem Cell Biology, Vanderbilt University, Nashville, TN 37232, USA
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232, USA
| | - Rama Gangula
- Center for Stem Cell Biology, Vanderbilt University, Nashville, TN 37232, USA
| | - Pedro G Vianna
- Center for Stem Cell Biology, Vanderbilt University, Nashville, TN 37232, USA
| | - Mark A Magnuson
- Center for Stem Cell Biology, Vanderbilt University, Nashville, TN 37232, USA
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232, USA
| |
Collapse
|
19
|
Lorenzen SM, Duggan A, Osipovich AB, Magnuson MA, García-Añoveros J. Insm1 promotes neurogenic proliferation in delaminated otic progenitors. Mech Dev 2015; 138 Pt 3:233-45. [PMID: 26545349 DOI: 10.1016/j.mod.2015.11.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Revised: 10/02/2015] [Accepted: 11/02/2015] [Indexed: 01/12/2023]
Abstract
INSM1 is a zinc-finger protein expressed throughout the developing nervous system in late neuronal progenitors and nascent neurons. In the embryonic cortex and olfactory epithelium, Insm1 may promote the transition of progenitors from apical, proliferative, and uncommitted to basal, terminally-dividing and neuron producing. In the otocyst, delaminating and delaminated progenitors express Insm1, whereas apically-dividing progenitors do not. This expression pattern is analogous to that in embryonic olfactory epithelium and cortex (basal/subventricular progenitors). Lineage analysis confirms that auditory and vestibular neurons originate from Insm1-expressing cells. In the absence of Insm1, otic ganglia are smaller, with 40% fewer neurons. Accounting for the decrease in neurons, delaminated progenitors undergo fewer mitoses, but there is no change in apoptosis. We conclude that in the embryonic inner ear, Insm1 promotes proliferation of delaminated neuronal progenitors and hence the production of neurons, a similar function to that in other embryonic neural epithelia. Unexpectedly, we also found that differentiating, but not mature, outer hair cells express Insm1, whereas inner hair cells do not. Insm1 is the earliest known gene expressed in outer versus inner hair cells, demonstrating that nascent outer hair cells initiate a unique differentiation program in the embryo, much earlier than previously believed.
Collapse
Affiliation(s)
- Sarah M Lorenzen
- Department of Anesthesiology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Anne Duggan
- Department of Anesthesiology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Anna B Osipovich
- Center for Stem Cell Biology, Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Mark A Magnuson
- Center for Stem Cell Biology, Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Jaime García-Añoveros
- Department of Anesthesiology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA; Departments of Neurology and Physiology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA; Hugh Knowles Center for Clinical and Basic Science in Hearing and Its Disorders, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA.
| |
Collapse
|
20
|
Golson ML, Dunn JC, Maulis MF, Dadi PK, Osipovich AB, Magnuson MA, Jacobson DA, Gannon M. Activation of FoxM1 Revitalizes the Replicative Potential of Aged β-Cells in Male Mice and Enhances Insulin Secretion. Diabetes 2015; 64:3829-38. [PMID: 26251404 PMCID: PMC4613976 DOI: 10.2337/db15-0465] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2015] [Accepted: 07/26/2015] [Indexed: 12/11/2022]
Abstract
Type 2 diabetes incidence increases with age, while β-cell replication declines. The transcription factor FoxM1 is required for β-cell replication in various situations, and its expression declines with age. We hypothesized that increased FoxM1 activity in aged β-cells would rejuvenate proliferation. Induction of an activated form of FoxM1 was sufficient to increase β-cell mass and proliferation in 12-month-old male mice after just 2 weeks. Unexpectedly, at 2 months of age, induction of activated FoxM1 in male mice improved glucose homeostasis with unchanged β-cell mass. Cells expressing activated FoxM1 demonstrated enhanced glucose-stimulated Ca2+ influx, which resulted in improved glucose tolerance through enhanced β-cell function. Conversely, our laboratory has previously demonstrated that mice lacking FoxM1 in the pancreas display glucose intolerance or diabetes with only a 60% reduction in β-cell mass, suggesting that the loss of FoxM1 is detrimental to β-cell function. Ex vivo insulin secretion was therefore examined in size-matched islets from young mice lacking FoxM1 in β-cells. Foxm1-deficient islets indeed displayed reduced insulin secretion. Our studies reveal that activated FoxM1 increases β-cell replication while simultaneously enhancing insulin secretion and improving glucose homeostasis, making FoxM1 an attractive therapeutic target for diabetes.
Collapse
Affiliation(s)
- Maria L Golson
- VA Tennessee Valley Healthcare System, Nashville, TN Division of Diabetes, Endocrinology, and Metabolism, Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN
| | - Jennifer C Dunn
- VA Tennessee Valley Healthcare System, Nashville, TN Division of Diabetes, Endocrinology, and Metabolism, Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN
| | - Matthew F Maulis
- VA Tennessee Valley Healthcare System, Nashville, TN Division of Diabetes, Endocrinology, and Metabolism, Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN
| | - Prasanna K Dadi
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN
| | - Anna B Osipovich
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN Vanderbilt Center for Stem Cell Biology, Vanderbilt University Medical Center, Nashville, TN
| | - Mark A Magnuson
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN Vanderbilt Center for Stem Cell Biology, Vanderbilt University Medical Center, Nashville, TN
| | - David A Jacobson
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN
| | - Maureen Gannon
- VA Tennessee Valley Healthcare System, Nashville, TN Division of Diabetes, Endocrinology, and Metabolism, Department of Medicine, Vanderbilt University School of Medicine, Nashville, TN Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN
| |
Collapse
|
21
|
Brouwers B, de Faudeur G, Osipovich AB, Goyvaerts L, Lemaire K, Boesmans L, Cauwelier EJG, Granvik M, Pruniau VPEG, Van Lommel L, Van Schoors J, Stancill JS, Smolders I, Goffin V, Binart N, in't Veld P, Declercq J, Magnuson MA, Creemers JWM, Schuit F, Schraenen A. Impaired islet function in commonly used transgenic mouse lines due to human growth hormone minigene expression. Cell Metab 2014; 20:979-90. [PMID: 25470546 PMCID: PMC5674787 DOI: 10.1016/j.cmet.2014.11.004] [Citation(s) in RCA: 133] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Revised: 09/29/2014] [Accepted: 11/04/2014] [Indexed: 11/15/2022]
Abstract
The human growth hormone (hGH) minigene is frequently used in the derivation of transgenic mouse lines to enhance transgene expression. Although this minigene is present in the transgenes as a secondcistron, and thus not thought to be expressed, we found that three commonly used lines, Pdx1-Cre(Late), RIP-Cre, and MIP-GFP, each expressed significant amounts of hGH in pancreatic islets. Locally secreted hGH binds to prolactin receptors on β cells, activates STAT5 signaling, and induces pregnancy-like changes in gene expression, thereby augmenting pancreatic β cell mass and insulin content. In addition, islets of Pdx1-Cre(Late) mice have lower GLUT2 expression and reduced glucose-induced insulin release and are protected against the β cell toxin streptozotocin. These findings may be important when interpreting results obtained when these and other hGH minigene-containing transgenic mice are used.
Collapse
Affiliation(s)
- Bas Brouwers
- Laboratory for Biochemical Neuroendocrinology, Department of Human Genetics, KU Leuven, Leuven 3000, Belgium
| | - Geoffroy de Faudeur
- Gene Expression Unit, Department of Cellular and Molecular Medicine, KU Leuven, Leuven 3000, Belgium
| | - Anna B Osipovich
- Center for Stem Cell Biology and Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Lotte Goyvaerts
- Gene Expression Unit, Department of Cellular and Molecular Medicine, KU Leuven, Leuven 3000, Belgium
| | - Katleen Lemaire
- Gene Expression Unit, Department of Cellular and Molecular Medicine, KU Leuven, Leuven 3000, Belgium
| | - Leen Boesmans
- Gene Expression Unit, Department of Cellular and Molecular Medicine, KU Leuven, Leuven 3000, Belgium
| | - Elisa J G Cauwelier
- Laboratory for Biochemical Neuroendocrinology, Department of Human Genetics, KU Leuven, Leuven 3000, Belgium
| | - Mikaela Granvik
- Gene Expression Unit, Department of Cellular and Molecular Medicine, KU Leuven, Leuven 3000, Belgium
| | - Vincent P E G Pruniau
- Laboratory for Biochemical Neuroendocrinology, Department of Human Genetics, KU Leuven, Leuven 3000, Belgium
| | - Leentje Van Lommel
- Gene Expression Unit, Department of Cellular and Molecular Medicine, KU Leuven, Leuven 3000, Belgium
| | - Jolien Van Schoors
- Center for Neurosciences, Department of Pharmaceutical Chemistry and Drug Analysis, Vrije Universiteit Brussel, Brussels 1090, Belgium
| | - Jennifer S Stancill
- Center for Stem Cell Biology and Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Ilse Smolders
- Center for Neurosciences, Department of Pharmaceutical Chemistry and Drug Analysis, Vrije Universiteit Brussel, Brussels 1090, Belgium
| | - Vincent Goffin
- INSERM U845, Research Center Growth and Signaling, PRL/GH Pathophysiology Laboratory, Faculty of Medicine, University Paris Descartes, Sorbonne Paris Cité, Paris 75993, France
| | - Nadine Binart
- INSERM U693, Faculté de Médecine Paris-Sud, University Paris-Sud, Le Kremlin-Bicêtre 94276, France
| | - Peter in't Veld
- Diabetes Research Center, Vrije Universiteit Brussel, Brussels 1090, Belgium
| | - Jeroen Declercq
- Laboratory for Biochemical Neuroendocrinology, Department of Human Genetics, KU Leuven, Leuven 3000, Belgium
| | - Mark A Magnuson
- Center for Stem Cell Biology and Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - John W M Creemers
- Laboratory for Biochemical Neuroendocrinology, Department of Human Genetics, KU Leuven, Leuven 3000, Belgium.
| | - Frans Schuit
- Gene Expression Unit, Department of Cellular and Molecular Medicine, KU Leuven, Leuven 3000, Belgium.
| | - Anica Schraenen
- Gene Expression Unit, Department of Cellular and Molecular Medicine, KU Leuven, Leuven 3000, Belgium
| |
Collapse
|
22
|
Osipovich AB, Long Q, Manduchi E, Gangula R, Hipkens SB, Schneider J, Okubo T, Stoeckert CJ, Takada S, Magnuson MA. Insm1 promotes endocrine cell differentiation by modulating the expression of a network of genes that includes Neurog3 and Ripply3. Development 2014; 141:2939-49. [PMID: 25053427 PMCID: PMC4197673 DOI: 10.1242/dev.104810] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Insulinoma associated 1 (Insm1) plays an important role in regulating the development of cells in the central and peripheral nervous systems, olfactory epithelium and endocrine pancreas. To better define the role of Insm1 in pancreatic endocrine cell development we generated mice with an Insm1GFPCre reporter allele and used them to study Insm1-expressing and null populations. Endocrine progenitor cells lacking Insm1 were less differentiated and exhibited broad defects in hormone production, cell proliferation and cell migration. Embryos lacking Insm1 contained greater amounts of a non-coding Neurog3 mRNA splice variant and had fewer Neurog3/Insm1 co-expressing progenitor cells, suggesting that Insm1 positively regulates Neurog3. Moreover, endocrine progenitor cells that express either high or low levels of Pdx1, and thus may be biased towards the formation of specific cell lineages, exhibited cell type-specific differences in the genes regulated by Insm1. Analysis of the function of Ripply3, an Insm1-regulated gene enriched in the Pdx1-high cell population, revealed that it negatively regulates the proliferation of early endocrine cells. Taken together, these findings indicate that in developing pancreatic endocrine cells Insm1 promotes the transition from a ductal progenitor to a committed endocrine cell by repressing a progenitor cell program and activating genes essential for RNA splicing, cell migration, controlled cellular proliferation, vasculogenesis, extracellular matrix and hormone secretion.
Collapse
Affiliation(s)
- Anna B Osipovich
- Center for Stem Cell Biology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Qiaoming Long
- Department of Animal Science, Cornell University, Ithaca, NY 14850, USA
| | - Elisabetta Manduchi
- Penn Center for Bioinformatics, Department of Genetics, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
| | - Rama Gangula
- Center for Stem Cell Biology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Susan B Hipkens
- Center for Stem Cell Biology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Judsen Schneider
- Center for Stem Cell Biology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Tadashi Okubo
- Department of Laboratory Animal Science, Kitasato University School of Medicine, Sagamihara, 252-0374, Japan
| | - Christian J Stoeckert
- Penn Center for Bioinformatics, Department of Genetics, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
| | - Shinji Takada
- Okazaki Institute for Integrative Bioscience, National Institutes of Natural Sciences, Okazaki, Aichi, 444-8787, Japan
| | - Mark A Magnuson
- Center for Stem Cell Biology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| |
Collapse
|
23
|
Abstract
Cre/LoxP has broad utility for studying the function, development, and oncogenic transformation of pancreatic cells in mice. Here we provide an overview of the Cre driver lines that are available for such studies. We discuss how variegated expression, transgene silencing, and recombination in undesired cell types have conspired to limit the performance of these lines, sometimes leading to serious experimental concerns. We also discuss preferred strategies for achieving high-fidelity driver lines and remind investigators of the continuing need for caution when interpreting results obtained from any Cre/LoxP-based experiment performed in mice.
Collapse
Affiliation(s)
- Mark A Magnuson
- Center for Stem Cell Biology and Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, TN 37232, USA.
| | | |
Collapse
|
24
|
Chen SX, Osipovich AB, Ustione A, Potter LA, Hipkens S, Gangula R, Yuan W, Piston DW, Magnuson MA. Quantification of factors influencing fluorescent protein expression using RMCE to generate an allelic series in the ROSA26 locus in mice. Dis Model Mech 2011; 4:537-47. [PMID: 21324933 PMCID: PMC3124063 DOI: 10.1242/dmm.006569] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2010] [Accepted: 12/22/2010] [Indexed: 11/20/2022] Open
Abstract
Fluorescent proteins (FPs) have great utility in identifying specific cell populations and in studying cellular dynamics in the mouse. To quantify the factors that determine both the expression and relative brightness of FPs in mouse embryonic stem cells (mESCs) and in mice, we generated eight different FP-expressing ROSA26 alleles using recombinase-mediated cassette exchange (RMCE). These alleles enabled us to analyze the effects on FP expression of a translational enhancer and different 3'-intronic and/or polyadenylation sequences, as well as the relative brightness of five different FPs, without the confounding position and copy number effects that are typically associated with randomly inserted transgenes. We found that the expression of a given FP can vary threefold or more depending on the genetic features present in the allele. The optimal FP expression cassette contained both a translational enhancer sequence in the 5'-untranslated region (UTR) and an intron-containing rabbit β-globin sequence within the 3'-UTR. The relative expressed brightness of individual FPs varied up to tenfold. Of the five different monomeric FPs tested, Citrine (YFP) was the brightest, followed by Apple, eGFP, Cerulean (CFP) and Cherry. Generation of a line of Cherry-expressing mice showed that there was a 30-fold variation of Cherry expression among different tissues and that there was a punctate expression pattern within cells of all tissues examined. This study should help investigators make better-informed design choices when expressing FPs in mESCs and mice.
Collapse
Affiliation(s)
| | | | - Alessandro Ustione
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, TN 37232-0494, USA
| | - Leah A. Potter
- Center for Stem Cell Biology and
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, TN 37232-0494, USA
| | | | | | | | - David W. Piston
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, TN 37232-0494, USA
| | - Mark A. Magnuson
- Center for Stem Cell Biology and
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, TN 37232-0494, USA
| |
Collapse
|
25
|
Cao S, Carlesso G, Osipovich AB, Llanes J, Lin Q, Hoek KL, Khan WN, Ruley HE. Subunit 1 of the prefoldin chaperone complex is required for lymphocyte development and function. J Immunol 2008; 181:476-84. [PMID: 18566413 DOI: 10.4049/jimmunol.181.1.476] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Prefoldin is a hexameric chaperone that facilitates posttranslational folding of actins and other cytoskeletal proteins by the Tcp1-containing ring complex chaperonin, TriC. The present study characterized mice with a null mutation in Pfdn1, which encodes the first subunit of the Prefoldin complex. Pfdn1-deficient mice displayed phenotypes characteristic of defects in cytoskeletal function, including manifestations of ciliary dyskinesia, neuronal loss, and defects in B and T cell development and function. B and T cell maturation was markedly impaired at relatively early stages, namely at the transitions from pre-pro-B to pre-B cells in the bone marrow and from CD4-CD8- double-negative to CD4+CD8+ double-positive T cells in the thymus. In addition, mature B and T lymphocytes displayed cell activation defects upon Ag receptor cross-linking accompanied by impaired Ag receptor capping in B cells. These phenotypes illustrate the importance of cytoskeletal function in immune cell development and activation.
Collapse
Affiliation(s)
- Shang Cao
- Department of Microbiology and Immunology, Vanderbilt University, School of Medicine, Nashville, TN 37232, USA
| | | | | | | | | | | | | | | |
Collapse
|
26
|
Abstract
The present study describes a genome-wide method for biallelic mutagenesis in mammalian cells. Novel poly(A) gene trap vectors, which contain features for direct cloning vector–cell fusion transcripts and for post-entrapment genome engineering, were used to generate a library of 979 mutant ES cells. The entrapment mutations generally disrupted gene expression and were readily transmitted through the germline, establishing the library as a resource for constructing mutant mice. Cells homozygous for most entrapment loci could be isolated by selecting for enhanced expression of an inserted neomycin-resistance gene that resulted from losses of heterozygosity (LOH). The frequencies of LOH measured at 37 sites in the genome ranged from 1.3 × 10−5 to 1.2 × 10−4 per cell and increased with increasing distance from the centromere, implicating mitotic recombination in the process. The ease and efficiency of obtaining homozygous mutations will (i) facilitate genetic studies of gene function in cultured cells, (ii) permit genome-wide studies of recombination events that result in LOH and mediate a type of chromosomal instability important in carcinogenesis, and (iii) provide new strategies for phenotype-driven mutagenesis screens in mammalian cells.
Collapse
Affiliation(s)
| | | | | | | | | | - H. Earl Ruley
- To whom correspondence should be addressed. Tel: +615 343 1379; Fax: +615 343 7392;
| |
Collapse
|
27
|
Osipovich AB, Singh A, Ruley HE. Post-entrapment genome engineering: first exon size does not affect the expression of fusion transcripts generated by gene entrapment. Genome Res 2005; 15:428-35. [PMID: 15741512 PMCID: PMC551569 DOI: 10.1101/gr.3258105] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Gene trap mutagenesis in mouse embryonic stem cells has been widely used for genome-wide studies of mammalian gene function. However, while large numbers of genes can be disrupted, individual mutations may suffer from limitations due to the structure and/or placement of targeting vector. To extend the utility of gene trap mutagenesis, replaceable 3' [or poly(A)] gene trap vectors were developed that permit sequences inserted in individual entrapment clones to be engineered by Cre-mediated recombination. 3' traps incorporating different drug resistance genes could be readily exchanged, simply by selecting for the drug-resistance gene of the replacement vector. By substituting different 3' traps, we show that otherwise identical fusion genes containing a large first exon (804 nt) are not expressed at appreciably lower levels than genes expressing small first exons (384 and 151 nt). Thus, size appears to have less effect on the expression and processing of first exons than has been reported for internal exons. Finally, a retroviral poly(A) trap (consisting of a RNA polymerase II promoter, a neomycin-resistance gene, and 5'-splice site) typically produced mutagenized clones in which vector sequences spliced to the 3'-terminal exons of cellular transcription units, suggesting strong selection for fusion transcripts that evade nonsense-mediated decay. The efficient exchange of poly(A) traps should greatly extend the utility of mutant libraries generated by gene entrapment and provides new strategies to study the rules that govern the expression of exons inserted throughout the genome.
Collapse
Affiliation(s)
- Anna B Osipovich
- Department of Microbiology and Immunology, Vanderbilt University, School of Medicine, Nashville, Tennessee 37232-2363, USA
| | | | | |
Collapse
|
28
|
Kharytonchyk SA, Kireyeva AI, Osipovich AB, Fomin IK. Evidence for preferential copackaging of Moloney murine leukemia virus genomic RNAs transcribed in the same chromosomal site. Retrovirology 2005; 2:3. [PMID: 15656910 PMCID: PMC546228 DOI: 10.1186/1742-4690-2-3] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2004] [Accepted: 01/18/2005] [Indexed: 11/11/2022] Open
Abstract
Background Retroviruses have a diploid genome and recombine at high frequency. Recombinant proviruses can be generated when two genetically different RNA genomes are packaged into the same retroviral particle. It was shown in several studies that recombinant proviruses could be generated in each round of HIV-1 replication, whereas the recombination rates of SNV and Mo-MuLV are 5 to 10-fold lower. The reason for these differences is not clear. One possibility is that these retroviruses may differ in their ability to copackage genomic RNAs produced at different chromosomal loci. Results To investigate whether there is a difference in the efficiency of heterodimer formation when two proviruses have the same or different chromosomal locations, we introduced two different Mo-MuLV-based retroviral vectors into the packaging cell line using either the cotransfection or sequential transfection procedure. The comparative study has shown that the frequency of recombination increased about four-fold when the cotransfection procedure was used. This difference was not associated with possible recombination of retroviral vectors during or after cotransfection and the ratios of retroviral virion RNAs were the same for two variants of transfection. Conclusions The results of this study indicate that a mechanism exists to enable the preferential copackaging of Mo-MuLV genomic RNA molecules that are transcribed on the same DNA template. The properties of Mo-MuLV genomic RNAs transport, processing or dimerization might be responsible for this preference. The data presented in this report can be useful when designing methods to study different aspects of replication and recombination of a diploid retroviral genome.
Collapse
Affiliation(s)
- Sergey A Kharytonchyk
- Laboratory of Cellular and Molecular Immunology, Institute of Hematology and Blood Transfusion, 223059 Minsk, Republic of Belarus
| | - Alla I Kireyeva
- Laboratory of Cellular and Molecular Immunology, Institute of Hematology and Blood Transfusion, 223059 Minsk, Republic of Belarus
| | - Anna B Osipovich
- Laboratory of Cellular and Molecular Immunology, Institute of Hematology and Blood Transfusion, 223059 Minsk, Republic of Belarus
- Present address: Department of Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, TN37232, USA
| | - Igor K Fomin
- Laboratory of Cellular and Molecular Immunology, Institute of Hematology and Blood Transfusion, 223059 Minsk, Republic of Belarus
| |
Collapse
|
29
|
Osipovich AB, White-Grindley EK, Hicks GG, Roshon MJ, Shaffer C, Moore JH, Ruley HE. Activation of cryptic 3' splice sites within introns of cellular genes following gene entrapment. Nucleic Acids Res 2004; 32:2912-24. [PMID: 15155860 PMCID: PMC419606 DOI: 10.1093/nar/gkh604] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Gene trap vectors developed for genome-wide mutagenesis can be used to study factors governing the expression of exons inserted throughout the genome. For example, entrapment vectors consisting of a partial 3'-terminal exon [i.e. a neomycin resistance gene (Neo), a poly(A) site, but no 3' splice site] were typically expressed following insertion into introns, from cellular transcripts that spliced to cryptic 3' splice sites present either within the targeting vector or in the adjacent intron. A vector (U3NeoSV1) containing the wild-type Neo sequence preferentially disrupted genes that spliced in-frame to a cryptic 3' splice site in the Neo coding sequence and expressed functional neomycin phosphotransferase fusion proteins. Removal of the cryptic Neo 3' splice site did not reduce the proportion of clones with inserts in introns; rather, the fusion transcripts utilized cryptic 3' splice sites present in the adjacent intron or generated by virus integration. However, gene entrapment with U3NeoSV2 was considerably more random than with U3NeoSV1, consistent with the widespread occurrence of potential 3' splice site sequences in the introns of cellular genes. These results clarify the mechanisms of gene entrapment by U3 gene trap vectors and illustrate features of exon definition required for 3' processing and polyadenylation of cellular transcripts.
Collapse
Affiliation(s)
- Anna B Osipovich
- Department of Microbiology and Immunology, Vanderbilt University School of Medicine, 1161 21st Avenue South, Nashville, TN 37232-2363, USA
| | | | | | | | | | | | | |
Collapse
|