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Sushil K Mahata - One of the best experts on this subject based on the ideXlab platform.
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Chapter Five - Granins and Catecholamines: Functional Interaction in Chromaffin Cells and Adipose Tissue
Advances in pharmacology (San Diego Calif.), 2013Co-Authors: Ricardo Borges, Sushil K Mahata, Natalia Domínguez, Corey B. Smith, Gautam Bandyopadhyay, Daniel T. O'connor, Alessandro BartolomucciAbstract:Catecholamines (CAs) and Granin peptides are costored in dense-core vesicles within the chromaffin cells of the adrenal medulla and in other endocrine organs and neurons. Granins play a major functional and structural role in chromaffin cells but are ubiquitous proteins, which are present also in secretory cells of the nervous, endocrine, and immune systems, where they regulate a number of cellular functions. Furthermore, recent studies also demonstrate that Granin-derived peptides can functionally interact with CA to modulate key physiological functions such as lipolysis and blood pressure. In this chapter, we will provide a brief update on the interaction between CA and Granins at the cellular and organ levels. We will first discuss recent data on the regulation of exocytosis of CA and peptides from the chromaffin cells by the sympathetic nervous system with a specific reference to the prominent role played by splanchnic nerve-derived pituitary adenylate cyclase-activating peptide (PACAP). Secondly, we will discuss the role of Granins in the storage and regulation of exocytosis in large dense-core vesicles. Finally, we will provide an up-to-date review of the roles played by two Granin-derived peptides, the chromoGranin A-derived peptide catestatin and the VGF-derived peptide TLQP-21, on lipolysis and obesity. In conclusion, the knowledge gathered from recent findings on the role played by proteins/peptides in the sympathetic/target cell synapses, discussed in this chapter, would contribute to and provide novel mechanistic support for an increased appreciation of the physiological role of CA in human pathophysiology.
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the extended Granin family structure function and biomedical implications
Endocrine Reviews, 2011Co-Authors: Alessandro Bartolomucci, Roberta Possenti, Sushil K Mahata, Reiner Fischercolbrie, Peng Y Loh, Stephen R J SaltonAbstract:The chromoGranins (chromoGranin A and chromoGranin B), secretoGranins (secretoGranin II and secretoGranin III), and additional related proteins (7B2, NESP55, proSAAS, and VGF) that together comprise the Granin family subserve essential roles in the regulated secretory pathway that is responsible for controlled delivery of peptides, hormones, neurotransmitters, and growth factors. Here we review the structure and function of Granins and Granin-derived peptides and expansive new genetic evidence, including recent single-nucleotide polymorphism mapping, genomic sequence comparisons, and analysis of transgenic and knockout mice, which together support an important and evolutionarily conserved role for these proteins in large dense-core vesicle biogenesis and regulated secretion. Recent data further indicate that their processed peptides function prominently in metabolic and glucose homeostasis, emotional behavior, pain pathways, and blood pressure modulation, suggesting future utility of Granins and Granin-derived peptides as novel disease biomarkers.
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sorting of the neuroendocrine secretory protein secretoGranin ii into the regulated secretory pathway role of n and c terminal α helical domains
Journal of Biological Chemistry, 2008Co-Authors: Maite Courel, Sushil K Mahata, Michael S Vasquez, Vivian Hook, Laurent TaupenotAbstract:SecretoGranin II (SgII) belongs to the Granin family of prohormones widely distributed in dense-core secretory granules (DCGs) of endocrine, neuroendocrine, and neuronal cells, including sympathoadrenal chromaffin cells. The mechanisms by which secretory proteins, and Granins in particular, are sorted into the regulated secretory pathway are unsettled. We designed a strategy based on novel chimeric forms of human SgII fused to fluorescent (green fluorescent protein) or chemiluminescent (embryonic alkaline phosphatase) reporters to identify trafficking determinants mediating DCG targeting of SgII in sympathoadrenal cells. Three-dimensional deconvolution fluorescence microscopy and secretagogue-stimulated release studies demonstrate that SgII chimeras are correctly targeted to DCGs and released by exocytosis in PC12 and primary chromaffin cells. Results from a Golgi-retained mutant form of SgII suggest that sorting of SgII into DCGs depends on a saturable sorting machinery at the trans-Golgi/trans-Golgi network. Truncation analyses reveal the presence of DCG-targeting signals within both the N- and C-terminal regions of SgII, with the putative α-helix-containing SgII-(25-41) and SgII-(334-348) acting as sufficient, independent sorting domains. This study defines sequence features of SgII mediating vesicular targeting in sympathoadrenal cells and suggests a mechanism by which discrete domains of the molecule function in sorting, perhaps by virtue of a particular arrangement in tertiary structure and/or interaction with a specific component of the DCG membrane.
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an ancestral variant of secretoGranin ii confers regulation by phox2 transcription factors and association with hypertension
Human Molecular Genetics, 2007Co-Authors: Gen Wen, Mats Stridsberg, Sushil K Mahata, Jennifer Wessel, Weidong Zhou, Georg B Ehret, Fangwen Rao, Peter M Gent, Madhusudan DasAbstract:Granins regulate secretory vesicle formation in neuroendocrine cells and Granin-derived peptides are co-released with neurotransmitters as modulatory signals at sympathetic sites. We report evidenc ...
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Identification of a novel sorting determinant for the regulated pathway in the secretory protein chromoGranin A.
Journal of cell science, 2002Co-Authors: Laurent Taupenot, Sushil K Mahata, Kimberly L Harper, Nitish R Mahapatra, Robert J Parmer, Daniel T. O'connorAbstract:ChromoGranin A (CgA) is the index member of the chromoGranin/secretoGranin (or 'Granin') family of regulated secretory proteins that are ubiquitously distributed in amine- and peptide-containing secretory granules of endocrine, neuroendocrine and neuronal cells. Because of their abundance and such widespread occurrence, Granins have often been used as prototype proteins to elucidate mechanisms of protein targeting into dense-core secretory granules. In this study, we used a series of full-length, point mutant or truncated CgA-green fluorescent protein (GFP) chimeras to explore routing of CgA in neuroendocrine PC12 cells. Using sucrose gradient fractionation and 3D deconvolution microscopy to determine the subcellular localization of the GFP chimeras, as well as secretagogue-stimulated release, the present study establishes that a CgA-GFP fusion protein expressed in neuroendocrine PC12 cells is trafficked to the dense core secretory granule and thereby sorted to the regulated pathway for exocytosis. We show that information necessary for such trafficking is contained within the N-terminal but not the C-terminal region of CgA. We find that CgA's conserved N-terminal hydrophobic Cys(17)-Cys(38) loop structure may not be sufficient for sorting of CgA into dense-core secretory granules, nor is its stabilization by a disulfide bond necessary for such sorting. Moreover, our data reveal for the first time that the CgA(77-115) domain of the mature protein may be necessary (though perhaps not sufficient) for trafficking CgA into the regulated pathway of secretion.
Laurent Taupenot - One of the best experts on this subject based on the ideXlab platform.
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sorting of the neuroendocrine secretory protein secretoGranin ii into the regulated secretory pathway role of n and c terminal α helical domains
Journal of Biological Chemistry, 2008Co-Authors: Maite Courel, Sushil K Mahata, Michael S Vasquez, Vivian Hook, Laurent TaupenotAbstract:SecretoGranin II (SgII) belongs to the Granin family of prohormones widely distributed in dense-core secretory granules (DCGs) of endocrine, neuroendocrine, and neuronal cells, including sympathoadrenal chromaffin cells. The mechanisms by which secretory proteins, and Granins in particular, are sorted into the regulated secretory pathway are unsettled. We designed a strategy based on novel chimeric forms of human SgII fused to fluorescent (green fluorescent protein) or chemiluminescent (embryonic alkaline phosphatase) reporters to identify trafficking determinants mediating DCG targeting of SgII in sympathoadrenal cells. Three-dimensional deconvolution fluorescence microscopy and secretagogue-stimulated release studies demonstrate that SgII chimeras are correctly targeted to DCGs and released by exocytosis in PC12 and primary chromaffin cells. Results from a Golgi-retained mutant form of SgII suggest that sorting of SgII into DCGs depends on a saturable sorting machinery at the trans-Golgi/trans-Golgi network. Truncation analyses reveal the presence of DCG-targeting signals within both the N- and C-terminal regions of SgII, with the putative α-helix-containing SgII-(25-41) and SgII-(334-348) acting as sufficient, independent sorting domains. This study defines sequence features of SgII mediating vesicular targeting in sympathoadrenal cells and suggests a mechanism by which discrete domains of the molecule function in sorting, perhaps by virtue of a particular arrangement in tertiary structure and/or interaction with a specific component of the DCG membrane.
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Identification of a novel sorting determinant for the regulated pathway in the secretory protein chromoGranin A.
Journal of cell science, 2002Co-Authors: Laurent Taupenot, Sushil K Mahata, Kimberly L Harper, Nitish R Mahapatra, Robert J Parmer, Daniel T. O'connorAbstract:ChromoGranin A (CgA) is the index member of the chromoGranin/secretoGranin (or 'Granin') family of regulated secretory proteins that are ubiquitously distributed in amine- and peptide-containing secretory granules of endocrine, neuroendocrine and neuronal cells. Because of their abundance and such widespread occurrence, Granins have often been used as prototype proteins to elucidate mechanisms of protein targeting into dense-core secretory granules. In this study, we used a series of full-length, point mutant or truncated CgA-green fluorescent protein (GFP) chimeras to explore routing of CgA in neuroendocrine PC12 cells. Using sucrose gradient fractionation and 3D deconvolution microscopy to determine the subcellular localization of the GFP chimeras, as well as secretagogue-stimulated release, the present study establishes that a CgA-GFP fusion protein expressed in neuroendocrine PC12 cells is trafficked to the dense core secretory granule and thereby sorted to the regulated pathway for exocytosis. We show that information necessary for such trafficking is contained within the N-terminal but not the C-terminal region of CgA. We find that CgA's conserved N-terminal hydrophobic Cys(17)-Cys(38) loop structure may not be sufficient for sorting of CgA into dense-core secretory granules, nor is its stabilization by a disulfide bond necessary for such sorting. Moreover, our data reveal for the first time that the CgA(77-115) domain of the mature protein may be necessary (though perhaps not sufficient) for trafficking CgA into the regulated pathway of secretion.
Tommaso Angelone - One of the best experts on this subject based on the ideXlab platform.
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ChromoGranins: from discovery to current times
Pflugers Archiv : European journal of physiology, 2017Co-Authors: Karen B Helle, Maria Carmela Cerra, Marie-hélène Metz-boutigue, Tommaso AngeloneAbstract:The discovery in 1953 of the chromaffin granules as co-storage of catecholamines and ATP was soon followed by identification of a range of uniquely acidic proteins making up the isotonic vesicular storage complex within elements of the diffuse sympathoadrenal system. In the mid-1960s, the enzymatically inactive, major core protein, chromoGranin A was shown to be exocytotically discharged from the stimulated adrenal gland in parallel with the co-stored catecholamines and ATP. A prohormone concept was introduced when one of the main storage proteins collectively named Granins was identified as the insulin release inhibitory polypeptide pancreastatin. A wide range of Granin-derived biologically active peptides have subsequently been identified. Both chromoGranin A and chromoGranin B give rise to antimicrobial peptides of relevance for combat of pathogens. While two of the chromoGranin A-derived peptides, vasostatin-I and pancreastatin, are involved in modulation of calcium and glucose homeostasis, respectively, vasostatin-I and catestatin are important modulators of endothelial permeability, angiogenesis, myocardial contractility, and innate immunity. A physiological role is now evident for the full-length chromoGranin A and vasostatin-I as circulating stabilizers of endothelial integrity and in protection against myocardial injury. The high circulating levels of chromoGranin A and its fragments in patients suffering from various inflammatory diseases have emerged as challenges for future research and clinical applications.
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Granin-derived peptides.
Progress in neurobiology, 2017Co-Authors: Markus Theurl, Rudolf Kirchmair, Teresa Pasqua, Bruno Tota, Tommaso Angelone, Maria Carmela Cerra, Yvonne Nowosielski, Raphaela Mätzler, Josef TrogerAbstract:The Granin family comprises altogether 7 different proteins originating from the diffuse neuroendocrine system and elements of the central and peripheral nervous systems. The family is dominated by three uniquely acidic members, namely chromoGranin A (CgA), chromoGranin B (CgB) and secretoGranin II (SgII). Since the late 1980s it has become evident that these proteins are proteolytically processed, intragranularly and/or extracellularly into a range of biologically active peptides; a number of them with regulatory properties of physiological and/or pathophysiological significance. The aim of this comprehensive overview is to provide an up-to-date insight into the distribution and properties of the well established Granin-derived peptides and their putative roles in homeostatic regulations. Hence, focus is directed to peptides derived from the three main Granins, e.g. to the chromoGranin A derived vasostatins, betaGranins, pancreastatin and catestatins, the chromoGranin B-derived secretolytin and the secretoGranin II-derived secretoneurin (SN). In addition, the distribution and properties of the chromoGranin A-derived peptides prochromacin, chromofungin, WE14, parastatin, GE-25 and serpinins, the CgB-peptide PE-11 and the SgII-peptides EM66 and manserin will also be commented on. Finally, the opposing effects of the CgA-derived vasostatin-I and catestatin and the SgII-derived peptide SN on the integrity of the vasculature, myocardial contractility, angiogenesis in wound healing, inflammatory conditions and tumors will be discussed.
Hanshermann Gerdes - One of the best experts on this subject based on the ideXlab platform.
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Signal-mediated sorting of chromoGranins to secretory granules.
Advances in experimental medicine and biology, 2000Co-Authors: Hanshermann Gerdes, Michael M. GlombikAbstract:The proteins chromoGranin A (CGA) and B (CGB) are constitutents of neuropeptideand hormone-containing secretory granules. As members of the Granin protein family (Huttner et al., 1991) they represent widespread marker proteins for these organelles. CGA was the first discovered member of this family (Helle, 1966, Blaschko et al 1967, Smith and Winkler 1967), followed by secretoGranin II (SgII) (Rosa and Zanini 1981, Zanini and Rosa 1981, Lee and Huttner 1983), a more distantly related protein, and CGB (Lee and Huttner 1983, Falkensammer et al 1985). In addition, other members of this family have been described (Huttner et al 199 1). Because of their abundance, widespread distribution in neuroendocrine tissues, and specific localization in secretory granules (Wiedenmann and Huttner 1989, Winkler and Fischer-Colbrie 1992, Rosa and Gerdes 1994) the Granins have been used as prime candidates to study sorting to these organelles.
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essential role of the disulfide bonded loop of chromoGranin b for sorting to secretory granules is revealed by expression of a deletion mutant in the absence of endogenous Granin synthesis
Journal of Cell Biology, 1998Co-Authors: Andreas Kromer, Wieland B Huttner, Michael M. Glombik, Hanshermann GerdesAbstract:Sorting of regulated secretory proteins in the TGN to immature secretory granules (ISG) is thought to involve at least two steps: their selective aggregation and their interaction with membrane components destined to ISG. Here, we have investigated the sorting of chromoGranin B (CgB), a member of the Granin family present in the secretory granules of many endocrine cells and neurons. Specifically, we have studied the role of a candidate structural motif implicated in the sorting of CgB, the highly conserved NH2-terminal disulfide- bonded loop. Sorting to ISG of full-length human CgB and a deletion mutant of human CgB (Deltacys-hCgB) lacking the 22-amino acid residues comprising the disulfide-bonded loop was compared in the rat neuroendocrine cell line PC12. Upon transfection, i.e., with ongoing synthesis of endogenous Granins, the sorting of the deletion mutant was only slightly impaired compared to full-length CgB. To investigate whether this sorting was due to coaggregation of the deletion mutant with endogenous Granins, we expressed human CgB using recombinant vaccinia viruses, under conditions in which the synthesis of endogenous Granins in the infected PC12 cells was shut off. In these conditions, Deltacys-hCgB, in contrast to full-length hCgB, was no longer sorted to ISG, but exited from the TGN in constitutive secretory vesicles. Coexpression of full-length hCgB together with Deltacys-hCgB by double infection, using the respective recombinant vaccinia viruses, rescued the sorting of the deletion mutant to ISG. In conclusion, our data show that (a) the disulfide-bonded loop is essential for sorting of CgB to ISG and (b) the lack of this structural motif can be compensated by coexpression of loop-bearing CgB. Furthermore, comparison of the two expression systems, transfection and vaccinia virus-mediated expression, reveals that analyses under conditions in which host cell secretory protein synthesis is blocked greatly facilitate the identification of sequence motifs required for sorting of regulated secretory proteins to secretory granules.
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the organisation of the mouse secretoGranin ii gene
FEBS Letters, 1992Co-Authors: Angelika Schimmell, Wieland B Huttner, Otto Braunling, Ulrich Ruther, Hanshermann GerdesAbstract:We have characterized the gene which encodes mouse secretoGranin II (previously also referred to as chromoGranin C), a tyrosine-sulfated secretory protein belonging to the Granin (chromoGranin/secretoGranin) family which is found in secretory granules of most endocrine cells and neurons. The secretoGranin II gene was found to contain 2 exons. In contrast to chromoGranin A and chromoGranin B, the two previously characterized Granin genes, the entire secretoGranin II protein is encoded by a single exon, exon 2, with exon 1 containing only a 5′-untranslated sequence. Consistent with previous data on the expression of secretoGranin II, the putative promoter region was found to contain a cAMP-responsive element and a potential AP-1 binding site.
Wieland B Huttner - One of the best experts on this subject based on the ideXlab platform.
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essential role of the disulfide bonded loop of chromoGranin b for sorting to secretory granules is revealed by expression of a deletion mutant in the absence of endogenous Granin synthesis
Journal of Cell Biology, 1998Co-Authors: Andreas Kromer, Wieland B Huttner, Michael M. Glombik, Hanshermann GerdesAbstract:Sorting of regulated secretory proteins in the TGN to immature secretory granules (ISG) is thought to involve at least two steps: their selective aggregation and their interaction with membrane components destined to ISG. Here, we have investigated the sorting of chromoGranin B (CgB), a member of the Granin family present in the secretory granules of many endocrine cells and neurons. Specifically, we have studied the role of a candidate structural motif implicated in the sorting of CgB, the highly conserved NH2-terminal disulfide- bonded loop. Sorting to ISG of full-length human CgB and a deletion mutant of human CgB (Deltacys-hCgB) lacking the 22-amino acid residues comprising the disulfide-bonded loop was compared in the rat neuroendocrine cell line PC12. Upon transfection, i.e., with ongoing synthesis of endogenous Granins, the sorting of the deletion mutant was only slightly impaired compared to full-length CgB. To investigate whether this sorting was due to coaggregation of the deletion mutant with endogenous Granins, we expressed human CgB using recombinant vaccinia viruses, under conditions in which the synthesis of endogenous Granins in the infected PC12 cells was shut off. In these conditions, Deltacys-hCgB, in contrast to full-length hCgB, was no longer sorted to ISG, but exited from the TGN in constitutive secretory vesicles. Coexpression of full-length hCgB together with Deltacys-hCgB by double infection, using the respective recombinant vaccinia viruses, rescued the sorting of the deletion mutant to ISG. In conclusion, our data show that (a) the disulfide-bonded loop is essential for sorting of CgB to ISG and (b) the lack of this structural motif can be compensated by coexpression of loop-bearing CgB. Furthermore, comparison of the two expression systems, transfection and vaccinia virus-mediated expression, reveals that analyses under conditions in which host cell secretory protein synthesis is blocked greatly facilitate the identification of sequence motifs required for sorting of regulated secretory proteins to secretory granules.
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the organisation of the mouse secretoGranin ii gene
FEBS Letters, 1992Co-Authors: Angelika Schimmell, Wieland B Huttner, Otto Braunling, Ulrich Ruther, Hanshermann GerdesAbstract:We have characterized the gene which encodes mouse secretoGranin II (previously also referred to as chromoGranin C), a tyrosine-sulfated secretory protein belonging to the Granin (chromoGranin/secretoGranin) family which is found in secretory granules of most endocrine cells and neurons. The secretoGranin II gene was found to contain 2 exons. In contrast to chromoGranin A and chromoGranin B, the two previously characterized Granin genes, the entire secretoGranin II protein is encoded by a single exon, exon 2, with exon 1 containing only a 5′-untranslated sequence. Consistent with previous data on the expression of secretoGranin II, the putative promoter region was found to contain a cAMP-responsive element and a potential AP-1 binding site.
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Monensin and brefeldin A differentially affect the phosphorylation and sulfation of secretory proteins.
Journal of Biological Chemistry, 1992Co-Authors: P. Di Rosa, R Rosboch, Simone Mantovani, Wieland B HuttnerAbstract:Abstract ChromoGranin B and secretoGranin II, two members of the Granin family, are known to be post-translationally modified by the addition of O-linked carbohydrates to serine and/or threonine, phosphate to serine and threonine, and sulfate to carbohydrate and tyrosine residues. In the present study, chromoGranin B and secretoGranin II were used as model proteins to investigate in which subcompartment of the Golgi complex secretory proteins become phosphorylated. Monensin, a drug known to block the transport from the medial to the trans cisternae of the Golgi stack, inhibited the phosphorylation of the Granins, indicating that this modification occurred distal to the medial Golgi. Monensin also blocked the addition of galactose to O-linked carbohydrates and the sulfation of the Granins, confirming previous data that these modifications take place in the trans Golgi. To distinguish, within the trans Golgi, between the trans cisternae of the Golgi stack and the trans Golgi network, we made use of the previous observation that brefeldin A results in the redistribution to the endoplasmic reticulum of membrane-bound enzymes of the trans cisternae of the Golgi stack, but not of the trans Golgi network. Brefeldin A treatment abolished Granin sulfation but resulted in the accumulation of phosphorylated and galactosylated Granins. Differential effects of brefeldin A on membranes of the Golgi stack versus the trans Golgi network were also observed by immunofluorescence analysis of marker proteins specific for either compartment. Our results suggest that the phosphorylation of secretory proteins, like their galactosylation, largely occurs in the trans cisternae of the Golgi stack, whereas the sulfation of secretory proteins on both carbohydrate and tyrosine residues takes place selectively in the trans Golgi network.
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Widespread occurrence of chromoGranins/secretoGranins in the matrix of secretory granules of endocrinologically silent pituitary adenomas.
The journal of histochemistry and cytochemistry : official journal of the Histochemistry Society, 1992Co-Authors: Patrizia Rosa, Monique Bassetti, U. Weiss, Wieland B HuttnerAbstract:To investigate the constituents of the matrix of endocrine secretory granules, we analyzed endocrinoilogically silent ("non-functioning") human pituitary adenomas for the occurrence of the chromoGranins/secretoGranins (Granins), a protein family normally stored together with many different hormones. When five non-functioning pituitary adenomas were analyzed by immunoblotting using polyclonal and monoclonal antibodies specific for individual members of the Granin family, chromoGranin A was detected in four cases and chromoGranin B and secretoGranin II were detected in all cases. The cellular distribution of the Granins and of various hormones known to be expressed in the anterior pituitary was studied by immunocytochemistry in fixed, frozen tissue sections from five additional adenomas. Of the eight hormones investigated, only thyroid-stimulating hormone, luteinizing hormone, and follicle-stimulating hormone were detected, occurring in only two of the five adenomas. In contrast, Granins were found in all f...
