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Cited by 366Pancreatic function and diabetesDiabetes and associated disordersEpigenetics and DNA Methylation

Polycomb protein Ezh2 regulates pancreatic β-cell Ink4a/Arf expression and regeneration in diabetes mellitus

Open access
Chen, Hainan, Gu, Xueying, Su, I-hsin, Bottino, Rita, Contreras, Juan L., Tarakhovsky, Alexander, Kim, Seung K.·2009·Genes & Development
DOI 10.1101/gad.1742509PMC PMC2675862
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Abstract

Proliferation of pancreatic islet β cells is an important mechanism for self-renewal and for adaptive islet expansion. Increased expression of the Ink4a/Arf locus, which encodes the cyclin-dependent kinase inhibitor p16 INK4a and tumor suppressor p19 Arf, limits β-cell regeneration in aging mice, but the basis of β-cell Ink4a/Arf regulation is poorly understood. Here we show that Enhancer of zeste homolog 2 (Ezh2), a histone methyltransferase and component of a Polycomb group (PcG) protein complex, represses Ink4a/Arf in islet β cells. Ezh2 levels decline in aging islet β cells, and this attrition coincides with reduced histone H3 trimethylation at Ink4a/Arf, and increased levels of p16 INK4a and p19 Arf. Conditional deletion of β-cell Ezh2 in juvenile mice also reduced H3 trimethylation at the Ink4a/Arf locus, leading to precocious increases of p16 INK4a and p19 Arf. These mutant mice had reduced β-cell proliferation and mass, hypoinsulinemia, and mild diabetes, phenotypes rescued by germline deletion of Ink4a/Arf. β-Cell destruction with streptozotocin in controls led to increased Ezh2 expression that accompanied adaptive β-cell proliferation and re-establishment of β-cell mass; in contrast, mutant mice treated similarly failed to regenerate β cells, resulting in lethal diabetes. Our discovery of Ezh2-dependent β-cell proliferation revealed unique epigenetic mechanisms underlying normal β-cell expansion and β-cell regenerative failure in diabetes pathogenesis.

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Crossref · 10.1101/gad.1742509

Cites

Statistics

Nothing to recompute.

Claims the paper makes

0 of 3 cited sources checked · 0 supported · 0 flagged

  • Findingown data

    Conditional deletion of Ezh2 in juvenile mouse beta cells reduces H3 trimethylation at the Ink4a/Arf locus.

    “Conditional deletion of b-cell Ezh2 in juvenile mice also reduced H3 trimethylation at the Ink4a/Arf locus”
    • Also stated in: § Conditional Ezh2 inactivation in islet b cells induces premature Ink4a/Arf expression · plain
      “ChIP studies of islets from 1-mo-old bEzh2KO mice revealed severe, premature reduction of Ezh2 and H3K27me3 levels (Fig. 4F,G)”
    Quote in the paperSubstantial claim
  • Findingown data

    bEzh2KO mice have reduced beta-cell proliferation.

    “These mutant mice had reduced b-cell proliferation and mass”
    • Also stated in: § b-Cell hypoplasia and mild diabetes mellitus in bEzh2KO mice · plain
      “incorporation of bromodeoxyuridine (BrdU) in bEzh2KO mice at 1 mo showed that b-cell proliferation was reduced”
    Quote in the paperSubstantial claim
  • Findingown data

    Germline deletion of Ink4a/Arf rescues the phenotypes of bEzh2KO mice.

    “phenotypes rescued by germline deletion of Ink4a/Arf”
    • Also stated in: § Cdkn2a inactivation restores normoglycemia and b-cell expansion in bEzh2KO mice · plain
      “Cdkn2a deficiency was sufficient to restore normoglycemia and insulin levels to mice lacking b-cell Ezh2.”
    Quote in the paperSubstantial claim
  • Findingown data

    bEzh2KO mice have hypoinsulinemia.

    “hypoinsulinemia”
    • Also stated in: § b-Cell hypoplasia and mild diabetes mellitus in bEzh2KO mice · plain
      “bEzh2KO mice had a 50% reduction in plasma insulin levels compared with littermates”
    Quote in the paperSubstantial claim
  • Findingown data

    The age-related decline of Ezh2 in islets coincides with increased p16 and p19 levels.

    “and increased levels of p16 INK4a and p19 Arf”
    • Also stated in: § Results · plain
      “Reduced b-cell proliferation in mice corresponds with increased islet expression of Ink4a and Arf”
    Quote in the paperSubstantial claim
  • May combine two claims. 22
  • The quote only partly states this claim. 1
  • Classified as probably not a substantial claim. 7

  • May combine two claims. The quote only partly states this claim.

    Findingown data

    Ezh2 mRNA and protein levels decline in aging mouse islet beta cells.

    “Ezh2 levels decline in aging islet b cells”
    • Also stated in: § Results · plain
      “levels of Ezh2 mRNA declined during this period, marked by a rapid reduction in neonatal and juvenile mice, followed by a slower decline in aging adults”
    • Also stated in: § Results · plain
      “Ezh2 protein level in b cells from 384-d-old mice (Fig. 1H-J) was reduced compared with b cells from 23-d-old mice (Fig. 1E-G)”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Streptozotocin-treated control mice show adaptive beta-cell proliferation and re-establishment of beta-cell mass.

    “that accompanied adaptive b-cell proliferation and re-establishment of b-cell mass”
    • Also stated in: § Cdkn2a inactivation restores normoglycemia and b-cell expansion in bEzh2KO mice · plain
      “b-cell mass from 2 to 8 wk after STZ challenge was significantly increased in control mice compared with bEzh2KO mice”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Streptozotocin-treated bEzh2KO mice fail to regenerate beta cells and develop lethal diabetes.

    “in contrast, mutant mice treated similarly failed to regenerate b cells, resulting in lethal diabetes”
    • Also stated in: § Cdkn2a inactivation restores normoglycemia and b-cell expansion in bEzh2KO mice · plain
      “bEzh2KO developed severe diabetes that persisted throughout the 9 wk course of our studies, with average blood glucose levels exceeding 500 mg/dL during ad libitum feeding”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    In mouse pancreatic beta cells, Ezh2 expression declines with age while Ink4a/Arf expression increases.

    “Declining Ezh2 expression accompanies increased Ink4a/Arf expression in mouse pancreatic b cells during aging.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    bEzh2KO mice have elevated blood glucose and prolonged hyperglycemia after acute glucose challenge.

    “acute glucose challenge by intraperitoneal injection following overnight fasting revealed significantly elevated blood glucose levels and prolonged hyperglycemia in bEzh2KO mice compared with littermate controls”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Bmi-1 and Suz12 mRNA levels and non-beta-cell Ezh2 protein are unchanged in bEzh2KO mice.

    “islet mRNA levels of Bmi-1 and Suz12, and Ezh2 protein levels in pancreatic non-b cells (e.g., acinar cells) were indistinguishable in bEzh2KO and littermate control mice”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    bEzh2KO mice have beta-cell hypoplasia and mild diabetes mellitus.

    “b-cell hypoplasia and mild diabetes mellitus in bEzh2KO mice.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Islet Ink4a/Arf expression increases in aging bEzh2KO mice, but the increase is blunted compared with controls.

    “Islet Ink4a/Arf expression increased in aging bEzh2KO mice (Fig. 4D,E), although the level of this increase was blunted compared with controls”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    bEzh2KO mice fail to regenerate beta cells and recover from STZ-induced diabetes.

    “Failure of b-cell regeneration and recovery from STZ-induced diabetes in bEzh2KO mice.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: The pathogenesis of diabetes involves beta-cell responses to systemic stress, and beta-cell toxins such as STZ can cause diabetes and then trigger regenerative beta-cell expansion that restores beta-cell mass in mice.

  • May combine two claims.

    Findingown data

    The late phase of beta-cell expansion in bEzh2KO mice does not restore normal beta-cell mass or glucose control.

    “This late phase of b-cell expansion did not re-establish normal b-cell mass or glucose control in bEzh2KO mice”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Findingown data

    Ezh2 expression is increased in maternal islets during pregnancy.

    “we recently observed increased Ezh2 expression in maternal islets during pregnancy (H.Chen and S.K. Kim, unpubl.)”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    bEzh2KO mice have persistent postprandial hyperglycemia and diabetes in older age.

    “we observed persistent postprandial hyperglycemia and diabetes in older bEzh2KO mice”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    EZH2 protein decreases and INK4A increases in human pancreatic beta cells with advancing age.

    “Immunohistology revealed EZH2 protein reduction and INK4A increase in human pancreatic b cells with advancing age”
    Quote in the paperSubstantial claim
    • Rests on an assumption: The human islet samples used for age-dependent EZH2 analysis are representative of normal human aging.

  • May combine two claims.

    Findingown data

    Body mass and insulin sensitivity are not detectably altered in bEzh2KO mice.

    “In contrast, body mass and insulin sensitivity were not detectably altered in bEzh2KO mice”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    bEzh2KO mice show increased beta-cell mass and pancreatic insulin content with aging.

    “we observed that b-cell mass and pancreatic insulin content increased in bEzh2KO mice as they aged”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Pancreatic insulin content, beta-cell mass, and beta-cell proliferation in bEzh2KO; Cdkn2a-/- mice are indistinguishable from controls.

    “pancreatic insulin content and b-cell mass, and b-cell proliferation in bEzh2KO; Cdkn2a À/À mice and littermate controls were indistinguishable”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationown data

    Ezh2 is required for beta-cell proliferation and for establishing appropriate beta-cell mass in juvenile mice.

    “Thus, Ezh2 is essential for b-cell proliferation and establishing appropriate b-cell mass in juvenile mice.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given

    Each antibody was tested in three to five separate ChIP experiments using independent islet preparations.

    “Three to five independent ChIP experiments were performed for each antibody using separate islet preparations.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given

    For each donor pancreas, EZH2 and INK4A immunostaining was performed on at least three sections.

    “Immunostaining of EZH2 and INK4A was repeated on at least three sections for every donor pancreas.”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim. May combine two claims.

    Study design and conductnone given

    For morphometric measurement of beta-cell mass or BrdU, four or six mice per genotype per age were analyzed, and at least five sections separated by more than 300 mm were immunostained and assessed per mouse.

    “For measuring pancreatic b-cell mass or BrdU by morphometry, four or six mice of each genotype at every age were analyzed.At least five sections separated by more than 300 b-Cell proliferation regulated by Ezh2 mm were immunostained and assessed for each mouse.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given

    At least 200 islets were examined for each genotype overall.

    “In total, at least 200 islets per genotype were investigated.”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim. May combine two claims.

    Study design and conductown data

    The STZ experiments used age-matched (5-7 wk) mice of the indicated genotypes with gender-matched controls.

    “Mice of the indicated genotypes, including gender-matched controls, aged 5-7 wk, were treated with a single intraperitoneal injection of freshly dissolved STZ (Sigma; 150 mg/kg or 100 mg/ kg body weight as indicated) in 0.1 mol/L sodium citrate (pH 4.5).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationown data

    Ezh2 is required to regulate histone methylation and repression of Ink4a/Arf in pancreatic islets, permitting physiological beta-cell expansion in neonatal mice and adaptive regeneration after chemical ablation in adults.

    “Here we show that Ezh2 is required to regulate histone methylation and repression of the Ink4a/Arf locus in pancreatic islets, thereby permitting physiological islet b-cell expansion in neonatal mice, and adaptive b-cell regeneration after conditional chemical ablation of b-cell in adults”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Study design and conductown data

    bEzh2KO islets lack Ezh2 mRNA and beta cells lack Ezh2 protein.

    “bEzh2KO islets were deficient for Ezh2 mRNA, and b cells lacked Ezh2 as judged by realtime RT-PCR and immunostaining”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationown data

    Ezh2 is required to maintain H3K27 methylation and repression of the Ink4a/Arf locus in pancreatic beta cells.

    “Thus, Ezh2 is required to maintain H3K27 methylation and repression of the Ink4a/Arf locus in pancreatic b cells.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Study design and conductnone given

    Deaths were recorded, but deaths occurring within two days of STZ injection were excluded as acute STZ-induced.

    “Mouse deaths were recorded, with exclusion of acute STZ-induced death (defined as death within 2 d after STZ injection).”
    Quote in the paperNot a substantial claim
26 of 26

  • The paper relies on this without support.

    The streptozotocin-induced beta-cell destruction model in mice is representative of the regenerative failure relevant to human diabetes mellitus.

    “We treated mice with STZ to examine islet Ezh2 expression and function in adult b-cell regeneration and diabetes pathogenesis.”

  • The paper relies on this without support.

    The human islet samples used for age-dependent EZH2 analysis are representative of normal human aging.

    “RT-PCR analysis of isolated human islets revealed age-dependent reduction of EZH2 mRNA compared with SUZ12, with the greatest reductions occurring in juveniles, followed by a slower decline in adults”

  • The paper relies on this without support.

    The pathogenesis of diabetes involves beta-cell responses to systemic stress, and beta-cell toxins such as STZ can cause diabetes and then trigger regenerative beta-cell expansion that restores beta-cell mass in mice.

    “Diabetes pathogenesis is a complex process that reflects b-cell adaptations to systemic stress.Destruction of b cells by toxins like STZ can lead to diabetes and subsequent regenerative b-cell expansion with restoration of b-cell mass in mice”
3 of 3

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

  • Conditional Ezh2 inactivation in β-cells results in premature p16INK4a expression.

    “Conditional Ezh2 inactivation in β-cells accelerated loss of H3K27me3 repression at Cdkn2a, resulting in premature p16INK4a expression, impaired β-cell proliferation, reduced β-cell mass and inadequate β-cell regenerative recovery after β-cell ablation13.”

    From PDGF signalling controls age-dependent proliferation in pancreatic β-cells (2011) · cites this paper as [13]

  • Ezh2 expression in mouse and human β-cells declines rapidly in juveniles, then slowly in adults, similar to the tempo of age-dependent decline in β-cell proliferation.

    “Ezh2 expression in mouse and human β-cells declines rapidly in juveniles, then slowly in adults13, similar to the tempo of age-dependent decline in β-cell proliferation9,10.”

    From PDGF signalling controls age-dependent proliferation in pancreatic β-cells (2011) · cites this paper as [13]

  • Ezh2 represses Cdkn2a and promotes β-cell proliferation in juvenile mouse islets.

    “We showed that the polycomb group protein Ezh2 represses Cdkn2a and promotes β-cell proliferation in juvenile mouse islets13.”

    From PDGF signalling controls age-dependent proliferation in pancreatic β-cells (2011) · cites this paper as [13]

  • Conditional Ezh2 inactivation in β-cells accelerates loss of H3K27me3 repression at Cdkn2a.

    “Conditional Ezh2 inactivation in β-cells accelerated loss of H3K27me3 repression at Cdkn2a, resulting in premature p16INK4a expression, impaired β-cell proliferation, reduced β-cell mass and inadequate β-cell regenerative recovery after β-cell ablation13.”

    From PDGF signalling controls age-dependent proliferation in pancreatic β-cells (2011) · cites this paper as [13]

  • Conditional Ezh2 inactivation in β-cells causes inadequate β-cell regenerative recovery after β-cell ablation.

    “Conditional Ezh2 inactivation in β-cells accelerated loss of H3K27me3 repression at Cdkn2a, resulting in premature p16INK4a expression, impaired β-cell proliferation, reduced β-cell mass and inadequate β-cell regenerative recovery after β-cell ablation13.”

    From PDGF signalling controls age-dependent proliferation in pancreatic β-cells (2011) · cites this paper as [13]

The citation lists haven’t been fetched yet

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Authors
Chen, H., Gu, X., Su, I.-H., Bottino, R., Contreras, J. L., Tarakhovsky, A., & Kim, S. K.
Affiliations
  • Stanford Medicine (US)
  • Rockefeller University (US)
  • University of Pittsburgh (US)
  • University of Alabama (US)
  • Howard Hughes Medical Institute (US)
ORCID
Venue
Genes & Development
Publisher
Cold Spring Harbor Laboratory
Published
2009-04-15
Volume
23
Issue
8
Pages
975-985
ISSN
  • 0890-9369 (ISSN-L)
  • 1549-5477
DOI
10.1101/gad.1742509
PMC
PMC2675862
OpenAlex
W2158300687
Semantic Scholar
53cdec103a4f55efb3d9aeffb3989745dc81c057
Cited by
366
References
43
Citations by year
2026: 9 · 2025: 6 · 2024: 14 · 2023: 15 · 2022: 15 · 2021: 24 · 2020: 20 · 2019: 23 · 2018: 24 · 2017: 25 · 2016: 26 · 2015: 26 · 2014: 21 · 2013: 24 · 2012: 30
Type
posted content
Language
en
Open access
Locations
  • Genes & Development (publishedVersion)
  • PubMed Central (publishedVersion)
  • PubMed (publishedVersion)
Funders
  • Howard Hughes Medical Institute
  • Larry L. Hillblom Foundation
  • National Institutes of Health
Topics
  • Health Sciences › Medicine › Surgery › Pancreatic function and diabetes
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Genetics › Diabetes and associated disorders
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Epigenetics and DNA Methylation
Keywords
EZH2, Polycomb group proteins, INK4a/ARF locus, p16INK4a, p19ARF, pancreatic beta cells, beta cell regeneration, beta-cell proliferation, histone H3 trimethylation, epigenetic regulation, diabetes mellitus, conditional gene deletion, beta-cell mass
MeSH terms
Enhancer of Zeste Homolog 2 Protein, Aging, Animals, Antibiotics, Antineoplastic, Cells, Cultured, Diabetes Mellitus, Female, Gene Expression Regulation, Histones, Humans, Male, Mice, Inbred C57BL, Histone-Lysine N-Methyltransferase, Streptozocin, Gene Deletion, Cyclin-Dependent Kinase Inhibitor p16, Cell Proliferation, Insulin-Secreting Cells, Mice, Polycomb Repressive Complex 2

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