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Specific control of pancreatic endocrine β- and δ-cell mass by class IIa histone deacetylases HDAC4, HDAC5, and HDAC9.

Lenoir O, Flosseau K, Ma FX, Blondeau B, Mai A, Bassel-Duby R, Ravassard P, Olson EN, Haumaitre C, Scharfmann R - Diabetes (2011)

Bottom Line: Conversely, HDAC4 and HDAC5 overexpression showed a decreased pool of insulin-producing β-cells and somatostatin-producing δ-cells.We conclude that HDAC4, -5, and -9 are key regulators to control the pancreatic β/δ-cell lineage.These results highlight the epigenetic mechanisms underlying the regulation of endocrine cell development and suggest new strategies for β-cell differentiation-based therapies.

View Article: PubMed Central - PubMed

Affiliation: Institut National de la Santé et de la Recherche Médicale, U845, Research Center Growth and Signalling, Paris Descartes University, Sorbonne Paris Cité, Necker Hospital, Paris, France.

ABSTRACT

Objective: Class IIa histone deacetylases (HDACs) belong to a large family of enzymes involved in protein deacetylation and play a role in regulating gene expression and cell differentiation. Previously, we showed that HDAC inhibitors modify the timing and determination of pancreatic cell fate. The aim of this study was to determine the role of class IIa HDACs in pancreas development.

Research design and methods: We took a genetic approach and analyzed the pancreatic phenotype of mice lacking HDAC4, -5, and -9. We also developed a novel method of lentiviral infection of pancreatic explants and performed gain-of-function experiments.

Results: We show that class IIa HDAC4, -5, and -9 have an unexpected restricted expression in the endocrine β- and δ-cells of the pancreas. Analyses of the pancreas of class IIa HDAC mutant mice revealed an increased pool of insulin-producing β-cells in Hdac5(-/-) and Hdac9(-/-) mice and an increased pool of somatostatin-producing δ-cells in Hdac4(-/-) and Hdac5(-/-) mice. Conversely, HDAC4 and HDAC5 overexpression showed a decreased pool of insulin-producing β-cells and somatostatin-producing δ-cells. Finally, treatment of pancreatic explants with the selective class IIa HDAC inhibitor MC1568 enhances expression of Pax4, a key factor required for proper β-and δ-cell differentiation and amplifies endocrine β- and δ-cells.

Conclusions: We conclude that HDAC4, -5, and -9 are key regulators to control the pancreatic β/δ-cell lineage. These results highlight the epigenetic mechanisms underlying the regulation of endocrine cell development and suggest new strategies for β-cell differentiation-based therapies.

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HDAC5 loss-of-function enhances β- and δ-cell mass. A: Immunohistological analyses of wild-type and Hdac5−/− pancreas at E18.5 and P7. On the left panel, β-cells were detected with insulin (INS) staining (brown) at E18.5. On the middle panel, β-cells were detected with insulin staining (brown) at P7. On the right panel, δ-cells were detected with somatostatin (SST) staining (brown) at P7. B: Morphometric analysis of β- and δ-cell surfaces by quantification of areas occupied by insulin- and somatostatin-positive cells. β-Cell surface is shown at E18.5 on the left panel and at P7 on the middle panel. δ-Cell surface is shown at P7 on the right panel. β-Cell and δ-cell surfaces were normalized to wild-type (WT) values (100%). Data are shown as means ± SEM from at least three pancreata per genotype. At E18.5, we analyzed three WT and five Hdac5−/− pancreata. At P7, we analyzed four pancreata of each genotype. *P < 0.05; **P < 0.005; ***P < 0.001. Scale bar, 100 μm. (A high-quality digital representation of this figure is available in the online issue.)
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Figure 5: HDAC5 loss-of-function enhances β- and δ-cell mass. A: Immunohistological analyses of wild-type and Hdac5−/− pancreas at E18.5 and P7. On the left panel, β-cells were detected with insulin (INS) staining (brown) at E18.5. On the middle panel, β-cells were detected with insulin staining (brown) at P7. On the right panel, δ-cells were detected with somatostatin (SST) staining (brown) at P7. B: Morphometric analysis of β- and δ-cell surfaces by quantification of areas occupied by insulin- and somatostatin-positive cells. β-Cell surface is shown at E18.5 on the left panel and at P7 on the middle panel. δ-Cell surface is shown at P7 on the right panel. β-Cell and δ-cell surfaces were normalized to wild-type (WT) values (100%). Data are shown as means ± SEM from at least three pancreata per genotype. At E18.5, we analyzed three WT and five Hdac5−/− pancreata. At P7, we analyzed four pancreata of each genotype. *P < 0.05; **P < 0.005; ***P < 0.001. Scale bar, 100 μm. (A high-quality digital representation of this figure is available in the online issue.)

Mentions: HDAC5 is expressed in skeletal muscle, heart, and brain (11,29), and mice lacking Hdac5 are hypersensitive to cardiac stress (10). Because we found HDAC5 expression in β- and δ-cells, we examined the pancreas of Hdac5−/− mice during embryogenesis (E18.5) and after birth (P7) to determine if HDAC5 plays a role in the differentiation of these endocrine cell types. Body weight and pancreatic weight did not differ between Hdac5−/− and wild-type mice (data not shown). Quantification of insulin staining indicated that, at E18.5 and P7, β-cell mass was 2.91 ± 0.148 and 1.56 ± 0.092 higher in Hdac5−/− mice than in wild-type mice (Fig. 5A and B). At E18.5, β-cell proliferation measured by Ki67 immunostaining did not differ between Hdac5−/− and wild-type pancreata (Supplementary Fig. 5C). Quantification of somatostatin staining at P7 revealed a 1.32 ± 0.85-fold increase in δ-cell mass in the pancreas of Hdac5−/− mice (Fig. 5A and B). No change in α-cell mass was observed (Supplementary Fig. 5A and B). Thus, mice lacking HDAC5 in the pancreas have enhanced β- and δ-cell mass.


Specific control of pancreatic endocrine β- and δ-cell mass by class IIa histone deacetylases HDAC4, HDAC5, and HDAC9.

Lenoir O, Flosseau K, Ma FX, Blondeau B, Mai A, Bassel-Duby R, Ravassard P, Olson EN, Haumaitre C, Scharfmann R - Diabetes (2011)

HDAC5 loss-of-function enhances β- and δ-cell mass. A: Immunohistological analyses of wild-type and Hdac5−/− pancreas at E18.5 and P7. On the left panel, β-cells were detected with insulin (INS) staining (brown) at E18.5. On the middle panel, β-cells were detected with insulin staining (brown) at P7. On the right panel, δ-cells were detected with somatostatin (SST) staining (brown) at P7. B: Morphometric analysis of β- and δ-cell surfaces by quantification of areas occupied by insulin- and somatostatin-positive cells. β-Cell surface is shown at E18.5 on the left panel and at P7 on the middle panel. δ-Cell surface is shown at P7 on the right panel. β-Cell and δ-cell surfaces were normalized to wild-type (WT) values (100%). Data are shown as means ± SEM from at least three pancreata per genotype. At E18.5, we analyzed three WT and five Hdac5−/− pancreata. At P7, we analyzed four pancreata of each genotype. *P < 0.05; **P < 0.005; ***P < 0.001. Scale bar, 100 μm. (A high-quality digital representation of this figure is available in the online issue.)
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Figure 5: HDAC5 loss-of-function enhances β- and δ-cell mass. A: Immunohistological analyses of wild-type and Hdac5−/− pancreas at E18.5 and P7. On the left panel, β-cells were detected with insulin (INS) staining (brown) at E18.5. On the middle panel, β-cells were detected with insulin staining (brown) at P7. On the right panel, δ-cells were detected with somatostatin (SST) staining (brown) at P7. B: Morphometric analysis of β- and δ-cell surfaces by quantification of areas occupied by insulin- and somatostatin-positive cells. β-Cell surface is shown at E18.5 on the left panel and at P7 on the middle panel. δ-Cell surface is shown at P7 on the right panel. β-Cell and δ-cell surfaces were normalized to wild-type (WT) values (100%). Data are shown as means ± SEM from at least three pancreata per genotype. At E18.5, we analyzed three WT and five Hdac5−/− pancreata. At P7, we analyzed four pancreata of each genotype. *P < 0.05; **P < 0.005; ***P < 0.001. Scale bar, 100 μm. (A high-quality digital representation of this figure is available in the online issue.)
Mentions: HDAC5 is expressed in skeletal muscle, heart, and brain (11,29), and mice lacking Hdac5 are hypersensitive to cardiac stress (10). Because we found HDAC5 expression in β- and δ-cells, we examined the pancreas of Hdac5−/− mice during embryogenesis (E18.5) and after birth (P7) to determine if HDAC5 plays a role in the differentiation of these endocrine cell types. Body weight and pancreatic weight did not differ between Hdac5−/− and wild-type mice (data not shown). Quantification of insulin staining indicated that, at E18.5 and P7, β-cell mass was 2.91 ± 0.148 and 1.56 ± 0.092 higher in Hdac5−/− mice than in wild-type mice (Fig. 5A and B). At E18.5, β-cell proliferation measured by Ki67 immunostaining did not differ between Hdac5−/− and wild-type pancreata (Supplementary Fig. 5C). Quantification of somatostatin staining at P7 revealed a 1.32 ± 0.85-fold increase in δ-cell mass in the pancreas of Hdac5−/− mice (Fig. 5A and B). No change in α-cell mass was observed (Supplementary Fig. 5A and B). Thus, mice lacking HDAC5 in the pancreas have enhanced β- and δ-cell mass.

Bottom Line: Conversely, HDAC4 and HDAC5 overexpression showed a decreased pool of insulin-producing β-cells and somatostatin-producing δ-cells.We conclude that HDAC4, -5, and -9 are key regulators to control the pancreatic β/δ-cell lineage.These results highlight the epigenetic mechanisms underlying the regulation of endocrine cell development and suggest new strategies for β-cell differentiation-based therapies.

View Article: PubMed Central - PubMed

Affiliation: Institut National de la Santé et de la Recherche Médicale, U845, Research Center Growth and Signalling, Paris Descartes University, Sorbonne Paris Cité, Necker Hospital, Paris, France.

ABSTRACT

Objective: Class IIa histone deacetylases (HDACs) belong to a large family of enzymes involved in protein deacetylation and play a role in regulating gene expression and cell differentiation. Previously, we showed that HDAC inhibitors modify the timing and determination of pancreatic cell fate. The aim of this study was to determine the role of class IIa HDACs in pancreas development.

Research design and methods: We took a genetic approach and analyzed the pancreatic phenotype of mice lacking HDAC4, -5, and -9. We also developed a novel method of lentiviral infection of pancreatic explants and performed gain-of-function experiments.

Results: We show that class IIa HDAC4, -5, and -9 have an unexpected restricted expression in the endocrine β- and δ-cells of the pancreas. Analyses of the pancreas of class IIa HDAC mutant mice revealed an increased pool of insulin-producing β-cells in Hdac5(-/-) and Hdac9(-/-) mice and an increased pool of somatostatin-producing δ-cells in Hdac4(-/-) and Hdac5(-/-) mice. Conversely, HDAC4 and HDAC5 overexpression showed a decreased pool of insulin-producing β-cells and somatostatin-producing δ-cells. Finally, treatment of pancreatic explants with the selective class IIa HDAC inhibitor MC1568 enhances expression of Pax4, a key factor required for proper β-and δ-cell differentiation and amplifies endocrine β- and δ-cells.

Conclusions: We conclude that HDAC4, -5, and -9 are key regulators to control the pancreatic β/δ-cell lineage. These results highlight the epigenetic mechanisms underlying the regulation of endocrine cell development and suggest new strategies for β-cell differentiation-based therapies.

Show MeSH
Related in: MedlinePlus