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Insm1 cooperates with Neurod1 and Foxa2 to maintain mature pancreatic β-cell function.

Jia S, Ivanov A, Blasevic D, Müller T, Purfürst B, Sun W, Chen W, Poy MN, Rajewsky N, Birchmeier C - EMBO J. (2015)

Bottom Line: We defined Insm1, Neurod1 and Foxa2 binding sites associated with genes deregulated in Insm1 mutant β-cells.Human genomic sequences corresponding to the murine sites occupied by Insm1/Neurod1/Foxa2 were enriched in single nucleotide polymorphisms associated with glycolytic traits.Thus, our data explain part of the mechanisms by which β-cells maintain maturity: Combinatorial Insm1/Neurod1/Foxa2 binding identifies regulatory sequences that maintain the mature gene expression program in β-cells, and disruption of this network results in functional failure.

View Article: PubMed Central - PubMed

Affiliation: Developmental Biology, Max-Delbrück-Center for Molecular Medicine, Berlin, Germany cbirch@mdc-berlin.de jshiqi@mdc-berlin.de.

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Mutation of Insm1 disrupts mature gene expression in adult isletsGO term analysis of differentially expressed genes identified by microarray analysis in isolated islets from control and coInsm1 mutant mice. Shown are GO terms, the P-value for their enrichment and the number of differentially expressed genes associated with a particular GO term.Verification of differential expression of genes previously implicated in the control of insulin secretion; RNA from isolated islets of control and coInsm1 mutant mice was compared by qRT–PCR (n = 5).Comparison of the deregulated genes identified in coInsm1 mutant versus control islets and sorted β-cells from P1 and adult mice. 1,232 genes were differentially expressed in coInsm1 mutant islets, and among these, 358 were previously identified as differentially expressed in immature versus mature β-cells.Analysis of Ucn3, Glut2 and Glp1r protein by Western blotting; a representative of three experiments is shown.Insulin secretion from isolated islets of control and coInsm1 mutant mice in response to glucose (3.3 and 16.7 mM), and in response to 16.7 mM glucose and additional secretagogues, that is, 100 mM pyruvate (Pyr), 20 nM exendin-4 (Ex-4), 100 nM gastric inhibitory polypeptide (GIP), 200 μM of the ATP-sensitive K+ channel inhibitor tolbutamide (Tol) and in response to membrane depolarization (30 mM KCl) (n = 3–4).Insulin secretion from isolated islets of P1 and adult mice in response to glucose, secretagogues and membrane depolarization (n = 3–4).Secretory vesicle appearance and density in control and coInsm1 mutant β-cells (n = 3).Arginine-induced insulin secretion was intact in coInsm1 mutant mice (n = 6–15).Data information: Data are presented as means ± SD; statistical significance was assessed by ANOVA and 2-tailed unpaired Student's t-test. *P < 0.05; **P < 0.01; ***P < 0.001. Scale bar: 1 μm. Source data are available online for this figure.
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fig04: Mutation of Insm1 disrupts mature gene expression in adult isletsGO term analysis of differentially expressed genes identified by microarray analysis in isolated islets from control and coInsm1 mutant mice. Shown are GO terms, the P-value for their enrichment and the number of differentially expressed genes associated with a particular GO term.Verification of differential expression of genes previously implicated in the control of insulin secretion; RNA from isolated islets of control and coInsm1 mutant mice was compared by qRT–PCR (n = 5).Comparison of the deregulated genes identified in coInsm1 mutant versus control islets and sorted β-cells from P1 and adult mice. 1,232 genes were differentially expressed in coInsm1 mutant islets, and among these, 358 were previously identified as differentially expressed in immature versus mature β-cells.Analysis of Ucn3, Glut2 and Glp1r protein by Western blotting; a representative of three experiments is shown.Insulin secretion from isolated islets of control and coInsm1 mutant mice in response to glucose (3.3 and 16.7 mM), and in response to 16.7 mM glucose and additional secretagogues, that is, 100 mM pyruvate (Pyr), 20 nM exendin-4 (Ex-4), 100 nM gastric inhibitory polypeptide (GIP), 200 μM of the ATP-sensitive K+ channel inhibitor tolbutamide (Tol) and in response to membrane depolarization (30 mM KCl) (n = 3–4).Insulin secretion from isolated islets of P1 and adult mice in response to glucose, secretagogues and membrane depolarization (n = 3–4).Secretory vesicle appearance and density in control and coInsm1 mutant β-cells (n = 3).Arginine-induced insulin secretion was intact in coInsm1 mutant mice (n = 6–15).Data information: Data are presented as means ± SD; statistical significance was assessed by ANOVA and 2-tailed unpaired Student's t-test. *P < 0.05; **P < 0.01; ***P < 0.001. Scale bar: 1 μm. Source data are available online for this figure.

Mentions: We next tested systematically for changes in gene expression in coInsm1 mutant islets by microarray analysis (GSE54044), which revealed deregulated genes in mutant islets (P-value < 0.05; 1,232 genes with FC > 1.2 and < 0.8; 352 with FC > 1.4 and < 0.6). Similar numbers of genes were up- and down-regulated. To define affected cellular processes, we performed Gene Ontology (GO) term analysis of differentially expressed genes. Consistent with glucose intolerance, deregulated genes were associated with biological processes critical for β-cell function, such as regulation of insulin secretion, response to hormone and glucose stimulus, and glucose metabolism (Fig 4A; Supplementary Table S1). Comparison with Insm1-dependent genes identified previously in the developing pancreas (Gierl et al, 2006) revealed little overlap (61 overlapping genes, Pearson's coefficient 0.21, Supplementary Table S2). Thus, Insm1 controls distinct sets of genes in developing and mature β-cells.


Insm1 cooperates with Neurod1 and Foxa2 to maintain mature pancreatic β-cell function.

Jia S, Ivanov A, Blasevic D, Müller T, Purfürst B, Sun W, Chen W, Poy MN, Rajewsky N, Birchmeier C - EMBO J. (2015)

Mutation of Insm1 disrupts mature gene expression in adult isletsGO term analysis of differentially expressed genes identified by microarray analysis in isolated islets from control and coInsm1 mutant mice. Shown are GO terms, the P-value for their enrichment and the number of differentially expressed genes associated with a particular GO term.Verification of differential expression of genes previously implicated in the control of insulin secretion; RNA from isolated islets of control and coInsm1 mutant mice was compared by qRT–PCR (n = 5).Comparison of the deregulated genes identified in coInsm1 mutant versus control islets and sorted β-cells from P1 and adult mice. 1,232 genes were differentially expressed in coInsm1 mutant islets, and among these, 358 were previously identified as differentially expressed in immature versus mature β-cells.Analysis of Ucn3, Glut2 and Glp1r protein by Western blotting; a representative of three experiments is shown.Insulin secretion from isolated islets of control and coInsm1 mutant mice in response to glucose (3.3 and 16.7 mM), and in response to 16.7 mM glucose and additional secretagogues, that is, 100 mM pyruvate (Pyr), 20 nM exendin-4 (Ex-4), 100 nM gastric inhibitory polypeptide (GIP), 200 μM of the ATP-sensitive K+ channel inhibitor tolbutamide (Tol) and in response to membrane depolarization (30 mM KCl) (n = 3–4).Insulin secretion from isolated islets of P1 and adult mice in response to glucose, secretagogues and membrane depolarization (n = 3–4).Secretory vesicle appearance and density in control and coInsm1 mutant β-cells (n = 3).Arginine-induced insulin secretion was intact in coInsm1 mutant mice (n = 6–15).Data information: Data are presented as means ± SD; statistical significance was assessed by ANOVA and 2-tailed unpaired Student's t-test. *P < 0.05; **P < 0.01; ***P < 0.001. Scale bar: 1 μm. Source data are available online for this figure.
© Copyright Policy - open-access
Related In: Results  -  Collection

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fig04: Mutation of Insm1 disrupts mature gene expression in adult isletsGO term analysis of differentially expressed genes identified by microarray analysis in isolated islets from control and coInsm1 mutant mice. Shown are GO terms, the P-value for their enrichment and the number of differentially expressed genes associated with a particular GO term.Verification of differential expression of genes previously implicated in the control of insulin secretion; RNA from isolated islets of control and coInsm1 mutant mice was compared by qRT–PCR (n = 5).Comparison of the deregulated genes identified in coInsm1 mutant versus control islets and sorted β-cells from P1 and adult mice. 1,232 genes were differentially expressed in coInsm1 mutant islets, and among these, 358 were previously identified as differentially expressed in immature versus mature β-cells.Analysis of Ucn3, Glut2 and Glp1r protein by Western blotting; a representative of three experiments is shown.Insulin secretion from isolated islets of control and coInsm1 mutant mice in response to glucose (3.3 and 16.7 mM), and in response to 16.7 mM glucose and additional secretagogues, that is, 100 mM pyruvate (Pyr), 20 nM exendin-4 (Ex-4), 100 nM gastric inhibitory polypeptide (GIP), 200 μM of the ATP-sensitive K+ channel inhibitor tolbutamide (Tol) and in response to membrane depolarization (30 mM KCl) (n = 3–4).Insulin secretion from isolated islets of P1 and adult mice in response to glucose, secretagogues and membrane depolarization (n = 3–4).Secretory vesicle appearance and density in control and coInsm1 mutant β-cells (n = 3).Arginine-induced insulin secretion was intact in coInsm1 mutant mice (n = 6–15).Data information: Data are presented as means ± SD; statistical significance was assessed by ANOVA and 2-tailed unpaired Student's t-test. *P < 0.05; **P < 0.01; ***P < 0.001. Scale bar: 1 μm. Source data are available online for this figure.
Mentions: We next tested systematically for changes in gene expression in coInsm1 mutant islets by microarray analysis (GSE54044), which revealed deregulated genes in mutant islets (P-value < 0.05; 1,232 genes with FC > 1.2 and < 0.8; 352 with FC > 1.4 and < 0.6). Similar numbers of genes were up- and down-regulated. To define affected cellular processes, we performed Gene Ontology (GO) term analysis of differentially expressed genes. Consistent with glucose intolerance, deregulated genes were associated with biological processes critical for β-cell function, such as regulation of insulin secretion, response to hormone and glucose stimulus, and glucose metabolism (Fig 4A; Supplementary Table S1). Comparison with Insm1-dependent genes identified previously in the developing pancreas (Gierl et al, 2006) revealed little overlap (61 overlapping genes, Pearson's coefficient 0.21, Supplementary Table S2). Thus, Insm1 controls distinct sets of genes in developing and mature β-cells.

Bottom Line: We defined Insm1, Neurod1 and Foxa2 binding sites associated with genes deregulated in Insm1 mutant β-cells.Human genomic sequences corresponding to the murine sites occupied by Insm1/Neurod1/Foxa2 were enriched in single nucleotide polymorphisms associated with glycolytic traits.Thus, our data explain part of the mechanisms by which β-cells maintain maturity: Combinatorial Insm1/Neurod1/Foxa2 binding identifies regulatory sequences that maintain the mature gene expression program in β-cells, and disruption of this network results in functional failure.

View Article: PubMed Central - PubMed

Affiliation: Developmental Biology, Max-Delbrück-Center for Molecular Medicine, Berlin, Germany cbirch@mdc-berlin.de jshiqi@mdc-berlin.de.

Show MeSH
Related in: MedlinePlus