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Abstract
The different forms of diabetes mellitus differ in their pathogenesis but, ultimately, they are all characterized by progressive islet β-cell loss. Restoring the β-cell mass is therefore a major goal for future therapeutic approaches. The number of β-cells found at birth is determined by proliferation and differentiation of pancreatic progenitor cells, and it has been considered to remain mostly unchanged throughout adult life. Recent studies in mice have revealed an unexpected plasticity in islet endocrine cells in response to stress; under certain conditions, islet non-β-cells have the potential to reprogram into insulin producers, thus contributing to restore the β-cell mass. Here, we discuss the latest findings on pancreas and islet cell plasticity upon physiological, pathological and experimental conditions of stress. Understanding the mechanisms involved in cell reprogramming in these models will allow the development of new strategies for the treatment of diabetes, by exploiting the intrinsic regeneration capacity of the pancreas.
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Affiliation(s)
- V Cigliola
- Department of Genetic Medicine and Development, Faculty of Medicine, Institute of Genetics and Genomics in Geneva (iGE3), and Centre facultaire du diabète, University of Geneva, Geneva, Switzerland
| | - F Thorel
- Department of Genetic Medicine and Development, Faculty of Medicine, Institute of Genetics and Genomics in Geneva (iGE3), and Centre facultaire du diabète, University of Geneva, Geneva, Switzerland
| | - S Chera
- Department of Clinical Science, Faculty of Medicine and Dentistry, University of Bergen, Bergen, Norway
| | - P L Herrera
- Department of Genetic Medicine and Development, Faculty of Medicine, Institute of Genetics and Genomics in Geneva (iGE3), and Centre facultaire du diabète, University of Geneva, Geneva, Switzerland.
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2
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Abstract
To unravel the cellular and molecular mechanisms involved in beta-cell renewal and expansion throughout life, several different experimental models were devised in the past. A number of experimental approaches and transgenic models have been engineered to trigger specifically pancreatic injury and thus explore regeneration. Globally, three main strategies are followed to induce pancreas damage: surgical, chemical and genetic. Some of the most relevant studies regarding these three approaches are briefly summarized in this short overview. Although significant progress has been achieved in recent years, there is much room for improving our understanding of many fundamental processes regulating beta-cell mass maintenance.
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Affiliation(s)
- P L Herrera
- Department of Genetic Medicine and Development, University of Geneva Medical School, Switzerland.
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3
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Riggs AC, Bernal-Mizrachi E, Ohsugi M, Wasson J, Fatrai S, Welling C, Murray J, Schmidt RE, Herrera PL, Permutt MA. Mice conditionally lacking the Wolfram gene in pancreatic islet beta cells exhibit diabetes as a result of enhanced endoplasmic reticulum stress and apoptosis. Diabetologia 2005; 48:2313-21. [PMID: 16215705 DOI: 10.1007/s00125-005-1947-4] [Citation(s) in RCA: 151] [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] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/23/2005] [Accepted: 06/01/2005] [Indexed: 01/02/2023]
Abstract
AIMS/HYPOTHESIS Wolfram syndrome is an autosomal recessive disorder characterised by childhood diabetes mellitus, optic atrophy and severe neurodegeneration, resulting in premature death. The aim of this study was to investigate the mechanisms responsible for the phenotype of carbohydrate intolerance and loss of pancreatic beta cells in this disorder. MATERIALS AND METHODS To study the role of the Wolfram gene (Wfs1) in beta cells, we developed a mouse model with conditional deletion of Wfs1 in beta cells by crossing floxed Wfs1 exon 8 animals with mice expressing Cre recombinase under the control of a rat insulin promoter (RIP2-Cre). Complementary experiments using RNA interference of Wfs1 expression were performed in mouse insulinoma (MIN6) cell lines (WfsKD). RESULTS Male knockout mice (betaWfs(-/-)) began developing variable and progressive glucose intolerance and concomitant insulin deficiency, compared with littermate controls, by 12 weeks of age. Analysis of islets from betaWfs(-/-) mice revealed a reduction in beta cell mass, enhanced apoptosis, elevation of a marker of endoplasmic reticulum stress (immunoglobulin heavy chain-binding protein [BiP]), and dilated endoplasmic reticulum with decreased secretory granules by electron microscopy. WfsKD cell lines had significantly increased apoptosis and elevated expression of the genes encoding BiP and C/EBP-homologous protein (CHOP), two markers of endoplasmic reticulum stress. CONCLUSIONS/INTERPRETATION These results indicate that (1) lack of expression of Wfs1 in beta cells was sufficient to result in the diabetes mellitus phenotype; (2) beta cell death occurred by an accelerated process of apoptosis; and (3) lack of Wfs1 was associated with dilated endoplasmic reticulum and increased markers of endoplasmic reticulum stress, which appears to be a significant contributor to the reduction in beta cell survival.
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Affiliation(s)
- A C Riggs
- Division of Endocrinology, Metabolism and Lipid Research, Washington University School of Medicine, St Louis, MO 63110-1010, USA
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Hagenfeldt-Johansson KA, Herrera PL, Wang H, Gjinovci A, Ishihara H, Wollheim CB. Beta-cell-targeted expression of a dominant-negative hepatocyte nuclear factor-1 alpha induces a maturity-onset diabetes of the young (MODY)3-like phenotype in transgenic mice. Endocrinology 2001; 142:5311-20. [PMID: 11713231 DOI: 10.1210/endo.142.12.8592] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Mutations in the transcription factor hepatocyte nuclear factor-1 alpha (HNF-1 alpha) cause maturity-onset diabetes of the young 3, a severe form of diabetes characterized by pancreatic beta-cell dysfunction. We have used targeted expression of a dominant-negative mutant of HNF-1 alpha to specifically suppress HNF-1 alpha function in beta-cells of transgenic mice. We show that males expressing the mutant protein became overtly diabetic within 6 wk of age, whereas females displayed glucose intolerance. Transgenic males exhibited impaired glucose-stimulated insulin secretion, detected both in vivo and in the perfused pancreas. Pancreatic insulin content was markedly decreased in diabetic animals, whereas the glucagon content was increased. Postnatal islet development was altered, with an increased alpha-cell to beta-cell ratio. beta-Cell ultrastructure showed signs of severe beta-cell damage, including mitochondrial swelling. This animal model of maturity-onset diabetes of the young 3 should be useful for the further elucidation of the mechanism by which HNF-1 alpha deficiency causes beta-cell dysfunction in this disease.
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Affiliation(s)
- K A Hagenfeldt-Johansson
- Division of Clinical Biochemistry, Department of Internal Medicine, University Medical Center, 1211 Geneva 4, Switzerland
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Fuhrmann-Benzakein E, García-Gabay I, Pepper MS, Vassalli JD, Herrera PL. Inducible and irreversible control of gene expression using a single transgene. Nucleic Acids Res 2000; 28:E99. [PMID: 11095695 PMCID: PMC115183 DOI: 10.1093/nar/28.23.e99] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Experimental or therapeutic designs involving the conditional expression of genes often require the use of two different transgenes; this can represent a major undertaking. One of these systems takes advantage of inducible recombinases. Here we show a novel use of such enzymes, in that an inducible recombinase-encoding sequence can function to both block the transcription of a gene placed downstream and, subsequently, irreversibly activate transcription of this very same gene. This double function, which circumvents the need for two transgenes, can be achieved by flanking the inducible recombinase gene by two of its target sequences. In our design we used as the inducible recombinase gene the Cre-ER(T) gene flanked by two loxP sites. This cassette was placed between a mouse phosphoglycerate kinase promoter and the enhanced green fluorescent protein (EGFP) coding sequence. Massive EGFP gene expression in BHK cells bearing this transgene was observed upon administration of 4-hydroxytamoxifen (4-OHT), the inducer of the recombinant activity of Cre-ER(T). In the absence of 4-OHT EGFP production was prevented. Because of its simplicity (only a single transgene needs to be used) this strategy is of obvious interest in certain protocols of gene or cell therapy and in a variety of experimental designs in which conditional expression of genes is required.
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Affiliation(s)
- E Fuhrmann-Benzakein
- Department of Morphology and Department of Pathology, University of Geneva Medical School, 1 Rue Michel-Servet, CH-1211 Geneva 4, Switzerland
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Charollais A, Gjinovci A, Huarte J, Bauquis J, Nadal A, Martín F, Andreu E, Sánchez-Andrés JV, Calabrese A, Bosco D, Soria B, Wollheim CB, Herrera PL, Meda P. Junctional communication of pancreatic beta cells contributes to the control of insulin secretion and glucose tolerance. J Clin Invest 2000; 106:235-43. [PMID: 10903339 PMCID: PMC314309 DOI: 10.1172/jci9398] [Citation(s) in RCA: 109] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2000] [Accepted: 06/07/2000] [Indexed: 12/20/2022] Open
Abstract
Proper insulin secretion requires the coordinated functioning of the numerous beta cells that form pancreatic islets. This coordination depends on a network of communication mechanisms whereby beta cells interact with extracellular signals and adjacent cells via connexin channels. To assess whether connexin-dependent communication plays a role in vivo, we have developed transgenic mice in which connexin 32 (Cx32), one of the vertebrate connexins found in the pancreas, is expressed in beta cells. We show that the altered beta-cell coupling that results from this expression causes reduced insulin secretion in response to physiologically relevant concentrations of glucose and abnormal tolerance to the sugar. These alterations were observed in spite of normal numbers of islets, increased insulin content, and preserved secretory response to glucose by individual beta cells. Moreover, glucose-stimulated islets showed improved electrical synchronization of these cells and increased cytosolic levels of Ca(2+). The results show that connexins contribute to the control of beta cells in vivo and that their excess is detrimental for insulin secretion.
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Affiliation(s)
- A Charollais
- Department of Morphology, and. Department of Medicine, University of Geneva, Medical School, Geneva, Switzerland
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7
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Abstract
To analyze cell lineage in the pancreatic islets, we have irreversibly tagged all the progeny of cells through the activity of Cre recombinase. Adult glucagon alpha and insulin beta cells are shown to derive from cells that have never transcribed insulin or glucagon, respectively. Also, the beta-cell progenitors, but not alpha-cell progenitors, transcribe the pancreatic polypeptide (PP) gene. Finally, the homeodomain gene PDX1, which is expressed by adult beta-cells, is also expressed by alpha-cell progenitors. Thus the islet alpha- and beta-cell lineages appear to arise independently during ontogeny, probably from a common precursor.
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Affiliation(s)
- P L Herrera
- Department of Morphology, University of Geneva Medical School, rue Michel-Servet, Switzerland.
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8
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Affiliation(s)
- M Gannon
- Department of Cell Biology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
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Herrera PL, Harlan DM, Vassalli P. A mouse CD8 T cell-mediated acute autoimmune diabetes independent of the perforin and Fas cytotoxic pathways: possible role of membrane TNF. Proc Natl Acad Sci U S A 2000; 97:279-84. [PMID: 10618409 PMCID: PMC26654 DOI: 10.1073/pnas.97.1.279] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Double transgenic mice [rat insulin promoter (RIP)-tumor necrosis factor (TNF) and RIP-CD80] whose pancreatic beta cells release TNF and bear CD80 all develop an acute early (6 wk) and lethal diabetes mediated by CD8 T cells. The first ultrastructural changes observed in beta cells, so far unreported, are focal lesions of endoplasmic reticulum swelling at the points of contact with islet-infiltrating lymphoblasts, followed by cytoplasmic, but not nuclear, apoptosis. Such double transgenic mice were made defective in either the perforin, Fas, or TNF pathways. Remarkably, diabetes was found to be totally independent of perforin and Fas. Mice lacking TNF receptor (TNFR) II had no or late diabetes, but only a minority had severe insulitis. Mice lacking the TNF-lymphotoxin (LTalpha) locus (whose sole source of TNF are the beta cells) all had insulitis comparable to that of nondefective mice, but no diabetes or a retarded and milder form, with lesions suggesting different mechanisms of injury. Because both TNFR II and TNF-LTalpha mutations have complex effects on the immune system, these data do not formally incriminate membrane TNF as the major T cell mediator of this acute autoimmune diabetes; nevertheless, in the absence of involvement of the perforin or Fas cytotoxic pathways, membrane TNF appears to be the likeliest candidate.
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Affiliation(s)
- P L Herrera
- Department of Morphology, University of Geneva Medical School, 1 rue Michel-Servet, 1211 Geneva 4, Switzerland.
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10
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Abstract
Ontogenic relationships between the different endocrine cell types of the islets of Langerhans were explored by generating transgenic mice, in which cells transcribing the glucagon, insulin, or pancreatic polypeptide genes were destroyed through the promoter-targeted expression of the diphtheria toxin A chain. In an alternate approach, to assess whether insulin cells are derived from precursors producing glucagon or PP, transgenic mice were generated bearing an insulin promoter-driven, and loxP-containing ('floxed') reporter transgene that can be irreversibly 'tagged' by recombination. They were crossed with mice expressing another transgene ('tagger') encoding Cre (cyclization recombination) recombinase in either glucagon or PP cells. The results obtained using both approaches indicate that neither glucagon nor insulin gene-expressing cells are the precursors to the other islet cells; also, they suggest that PP gene-expressing cells are necessary for the differentiation of islet insulin and somatostatin cells, through a cell lineage or a paracrine relationship.
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Affiliation(s)
- P L Herrera
- Department of Morphology, Faculty of Medicine, Geneva, Switzerland
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11
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Sanvito F, Nichols A, Herrera PL, Huarte J, Wohlwend A, Vassalli JD, Orci L. TGF-beta 1 overexpression in murine pancreas induces chronic pancreatitis and, together with TNF-alpha, triggers insulin-dependent diabetes. Biochem Biophys Res Commun 1995; 217:1279-86. [PMID: 8554587 DOI: 10.1006/bbrc.1995.2906] [Citation(s) in RCA: 101] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
We have generated transgenic mice overexpressing TGF-beta 1 in pancreatic beta cells. This resulted in massive fibrosis of the pancreas; in adult mice, most of the acini were replaced by fibrotic and adipose tissues. A conspicuous disorganization of the islets of Langerhans was also observed; however, the number of beta cells was not decreased and the mice were normoglycemic. Backcrossing to transgenic mice overexpressing TNF-alpha in their islet beta cells (which also remain normoglycemic, (1)) yielded double transgenics, most of which became diabetic by the age of 4 months; histological analysis revealed a dramatic decrease in insulin-containing beta cells.
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Affiliation(s)
- F Sanvito
- Département de Morphologie, Centre Médical Universitaire, Genève 4, Switzerland
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12
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Herrera PL, Huarte J, Zufferey R, Nichols A, Mermillod B, Philippe J, Muniesa P, Sanvito F, Orci L, Vassalli JD. Ablation of islet endocrine cells by targeted expression of hormone-promoter-driven toxigenes. Proc Natl Acad Sci U S A 1994; 91:12999-3003. [PMID: 7809163 PMCID: PMC45568 DOI: 10.1073/pnas.91.26.12999] [Citation(s) in RCA: 113] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Ontogenic relationships between the different types of endocrine cells in the islets of Langerhans were explored by generating transgenic mouse embryos in which cells transcribing the glucagon, insulin, or pancreatic polypeptide genes were destroyed through the promoter-targeted expression of the diphtheria toxin A chain. Embryos lacking glucagon- or insulin-containing cells did not exhibit alterations in the development of the nontargeted islet cell types, whereas embryos lacking pancreatic polypeptide gene-expressing cells also lacked pancreatic insulin- and somatostatin-containing cells. These results show that neither glucagon nor insulin gene-expressing cells are essential for the differentiation of the other islet endocrine-cell types. These results also suggest that pancreatic polypeptide gene-expressing cells are indispensable for the differentiation of islet beta and delta cells because the former produce a necessary paracrine or endocrine factor and/or operate through a cell-lineage relationship.
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Affiliation(s)
- P L Herrera
- Département de Morphologie, University of Geneva Medical School, Switzerland
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Herrera PL, Harlan DM, Fossati L, Izui S, Huarte J, Orci L, Vassalli JD, Vassalli P. A CD8+ T-lymphocyte-mediated and CD4+ T-lymphocyte-independent autoimmune diabetes of early onset in transgenic mice. Diabetologia 1994; 37:1277-9. [PMID: 7534735 DOI: 10.1007/bf00399802] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
While transgenic mice expressing tumour necrosis factor-alpha under the control of the beta-cell-specific insulin promoter display a marked lymphocytic infiltration of the islets, they never develop insulin-dependent diabetes mellitus (IDDM). In striking contrast, "double" transgenic mice whose beta cells express both tumour necrosis factor-alpha as well as the co-stimulatory B7-1 molecule all develop IDDM at an early age. Furthermore, administration of anti-CD8 but not anti-CD4 immunoglobulins prevents diabetes onset. These results indicate that while tumour necrosis factor-alpha induced lymphocytic infiltration is not sufficient to effect beta-cell destruction, locally co-stimulated islet-infiltrating CD8+ T lymphocytes could play a critical role in the development of IDDM.
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Affiliation(s)
- P L Herrera
- Department of Morphology, University of Geneva Medical School, Switzerland
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Sanvito F, Herrera PL, Huarte J, Nichols A, Montesano R, Orci L, Vassalli JD. TGF-beta 1 influences the relative development of the exocrine and endocrine pancreas in vitro. Development 1994; 120:3451-62. [PMID: 7821214 DOI: 10.1242/dev.120.12.3451] [Citation(s) in RCA: 139] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Pancreatic rudiments from E12.5 mouse embryos undergo extensive development and differentiation when cultured in three-dimensional gels of extracellular matrix proteins for up to 12 days. Whereas collagen gels promote the formation of numerous exocrine acini and relatively small clusters of endocrine cells, in basement membrane (EHS) matrices the development of endocrine cells is dramatically favoured over that of acinar tissue. Buds embedded in a collagen gel contiguous to an EHS gel also fail to develop acini, suggesting the involvement of diffusible factor(s). Addition of cytokines to cultures of pancreatic buds in collagen gels modifies the relative proportions of the epithelial components of the gland. In the presence of EGF the proportion of the tissue occupied by ducts overrides that of acinar structures, whereas the endocrine portion of the tissue is not significantly modified. TGF-beta 1 partially mimicks the effect of EHS matrix in inhibiting the development of acinar tissue without decreasing the amount of ducts and mesenchyme; TGF-beta 1 also promotes the development of endocrine cells, in particular of insulin-containing beta cells and of cells expressing genes of the PP-fold family. These results show that cytokines can modulate the development of the pancreas and suggest a role for TGF-beta 1 in regulating the balance between the acinar and endocrine portions of the gland in vivo. More generally, they are compatible with the notion that, during organogenesis, cytokines act as paracrine factors responsible for the development and maintenance of appropriate proportions of different tissue constituents.
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Affiliation(s)
- F Sanvito
- Department of Morphology, University of Geneva Medical School, Switzerland
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Herrera PL, Huarte J, Sanvito F, Meda P, Orci L, Vassalli JD. Embryogenesis of the murine endocrine pancreas; early expression of pancreatic polypeptide gene. Development 1991; 113:1257-65. [PMID: 1811941 DOI: 10.1242/dev.113.4.1257] [Citation(s) in RCA: 184] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
By immunofluorescence on cytospin preparations and on semithin sections of mouse pancreatic buds, we have found glucagon and pancreatic polypeptide (PP)-containing cells at embryonal day 10.5 (E 10.5) in dorsal buds and at E 11.5 in ventral buds. Insulin-containing cells appear in dorsal buds at E 11.5, and one to two days later in ventral buds. Somatostatin-containing cells are detectable from E 13.5 in both dorsal and ventral buds. A quantitative analysis shows that up to E 15.5, PP-containing cells are relatively abundant in both buds. By PCR amplification of oligo(dT)-primed cDNAs prepared from total pancreatic RNA, we also detect PP mRNA from E 10.5 onwards, thus confirming the early expression of the PP gene in the developing mouse pancreas. Analysis of endocrine cells in situ suggests three major patterns of cell distribution in embryonic pancreas. First, individual hormone-containing cells are located within the epithelium of pancreatic ducts. In both dorsal and ventral buds, the majority of these endocrine cells contain PP, but many also contain glucagon, insulin or somatostatin. Secondly, clusters of endocrine cells are found in the pancreatic interstitium. Many of these cells contain both glucagon and PP which, by immunogold labelling of consecutive thin sections, can be shown to co-exist within individual secretory granules. Finally, starting on E 18.5, typical islets are formed with centrally located B cells and with the adult 'one cell-one hormone' phenotype. These results suggest an intriguing ontogenic relationship between A- and PP-cells, and also indicate that PP-containing cells may occupy a hitherto unexpected place in the lineage of endocrine islet cells.
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Affiliation(s)
- P L Herrera
- Institute of Histology and Embryology, University of Geneva Medical School, Switzerland
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