The Comparative Anatomy of Islets

Heller, R. Scott

doi:10.1007/978-94-007-6686-0_2

Cited by 4 publications

(4 citation statements)

References 74 publications

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“…Immunolocalization of glucagon, insulin, somatostatin and PP in the pancreas identified most main cell types within the islets. The arrangement of mouse pancreatic islets described here is consistent with numerous other studies of rodent islets, with a well-defined core-mantle structure of central b-cells surrounded by non-b-cells fewer in number in the periphery (Heller, 2010;Steiner et al 2010). Unlike this characteristic distribution of rodent islet cells, platypus pancreas had an arrangement where b-cells were mainly located in the periphery, an arrangement previously observed in horse (Helmstaedter et al 1976;Furuoka et al 1989).…”

Section: Discussionsupporting

confidence: 88%

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Immunohistochemical analysis of pancreatic islets of platypus (Ornithorhynchus anatinus) and echidna (Tachyglossus aculeatus ssp.)

Myers

Forbes

et al. 2015

Journal of Anatomy

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Monotremes have undergone remarkable changes to their digestive and metabolic control system; however, the monotreme pancreas remains poorly characterized. Previous work in echidna demonstrated the presence of pancreatic islets, but no information is available for platypus and the fine structure has not been described for either monotreme. Based on our recent finding that monotremes lack the ghrelin gene, which is expressed in mouse and human pancreatic islets, we investigated the structure of monotreme islets in more detail. Generally, as in birds, the islets of monotremes were smaller but greater in number compared with mouse. b-cells were the most abundant endocrine cell population in platypus islets and were located peripherally, while a-cells were observed both in the interior and periphery of the islets. d-cells and pancreatic polypeptide (PP)-cells were mainly found in the islet periphery. Distinct PP-rich (PP-lobe) and PP-poor areas (non-PP-lobe) are present in therian mammals, and we identified these areas in echidna but not platypus pancreas. Interestingly, in some of the echidna islets, a-and b-cells tended to form two poles within the islets, which to our knowledge is the first time this has been observed in any species. Overall, monotreme pancreata share the feature of consisting of distinct PP-poor and PP-rich islets with other mammals. A higher number of islets and a-or b-cell only islets are shared between monotremes and birds. The islets of monotremes were larger than those of birds but smaller compared with therian mammals. This may indicate a trend of having fewer larger islets comprising several endocrine cell types during mammalian evolution.

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Section: Discussionsupporting

confidence: 88%

“…This may reflect evolutionary adaptations to different diets or other environmental conditions (Cabrera et al 2006). Consistent with their phylogenetic position, the histology of monotreme endocrine pancreas showed greater resemblance to that of birds and marsupials than to eutherian mammals (reviewed by Steiner et al 2010;Heller, 2010).…”

Section: Discussionmentioning

confidence: 88%

Immunohistochemical analysis of pancreatic islets of platypus (Ornithorhynchus anatinus) and echidna (Tachyglossus aculeatus ssp.)

Myers

Forbes

et al. 2015

Journal of Anatomy

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“…Pancreatic islets are complex microorgans composed of five different types of endocrine cells that show a close topological association in a 3D cellular structure (15). A number of ESC studies have tried to generate functional β-cells by mimicking pancreatic development (13), but many of these studies generated pancreatic cells under 2D adherent culture conditions during the final maturation stage of their differentiation protocols.…”

Section: Discussionmentioning

confidence: 99%

Pancreatic Islet-Like Three-Dimensional Aggregates Derived from Human Embryonic Stem Cells Ameliorate Hyperglycemia in Streptozotocin-Induced Diabetic Mice

et al. 2015

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We previously reported the in vitro differentiation of human embryonic stem cells (hESCs) into pancreatic endoderm. Here we demonstrate that islet-like three-dimensional (3D) aggregates can be derived from the pancreatic endoderm by optimizing our previous protocol. Sequential treatment with Wnt3a, activin A, and noggin induced a transient upregulation of T and MixL1, followed by increased expression of endodermal genes, including FOXA2, SOX17, and CXCR4. Subsequent treatment with retinoic acid highly upregulated PDX1 expression. We also show that inhibition of sonic hedgehog signaling by bFGF/activin bB and cotreatment with VEGF and FGF7 produced many 3D cellular clusters that express both SOX17 and PDX1. We found for the first time that proteoglycans and vimentin + mesenchymal cells were mainly localized in hESC-derived PDX1 + clusters. Importantly, treatment with chlorate, an inhibitor of proteoglycan sulfation, together with inhibition of Notch signaling significantly increased the expression of Neurog3 and NeuroD1, promoting a transition from PDX1 + progenitor cells toward mature pancreatic endocrine cells. Purified dithizone + 3D aggregates generated by our refined protocol produced pancreatic hormones and released insulin in response to both glucose and pharmacological drugs in vitro. Furthermore, the islet-like 3D aggregates decreased blood glucose levels and continued to exhibit pancreatic features after transplantation into diabetic mice. Generation of islet-like 3D cell aggregates from human pluripotent stem cells may overcome the shortage of cadaveric donor islets for future cases of clinical islet transplantation.

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“…Alpha cells were responsible for the secretion of glucagon hormone that works to raise the concentration of glucose and fatty acids in the bloodstream (Geser, 1976). On the other hand, it has been reported that the islet organ in the hagfish consisted only of insulin and somatostatin cells with absence of glucagon cells (Heller, 2015).…”

Section: Discussionmentioning

confidence: 99%

Unique localization of disseminated pancreas in the oesophagus of catfish (clarias gariepinus) with reference to sexual dimorphism

Karkit

Salem

Bareedy

et al. 2021

Anat Histol Embryol

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Background:The fish pancreas has been reported to be composed of two portions: compact and disseminated. However, little has been elucidated in catfish. The present study describes a unique localization of the disseminated pancreas in African catfish. Methods:The sections were obtained and used for either routine histological examination following staining with haematoxylin and eosin (H & E), periodic acid-Schiff's, or were subjected to immunohistochemical staining for detection of both insulinproducing β cells and glucagon-producing alpha cells.Results: Our investigation showed that the pancreas of catfish consisted of both compact and disseminated portions. The compact pancreas was embedded in the mesenteric adipose tissue between the spleen, stomach and liver. However, the disseminated one showed unique localization in the tunica adventitia of the middle portion of the oesophagus. The pancreas consisted of two portions, exocrine and endocrine. Furthermore, in both types of pancreas, the female showed a significantly higher ratio for the endocrine islet area/pancreatic tissue area than that of the male and also a significantly higher ratio for both insulin-and glucagon-positive area/islet area in the female pancreas (compact and disseminated) than that of the male. In conclusion:The present study provides evidence on a unique localization of the disseminated pancreas in the oesophagus of catfish. Furthermore, we revealed sexrelated difference in the endocrine portion in both pancreatic tissues with more development in the female. The study suggests that sex hormones could be contributed to such sexual dimorphism. However, further investigation is required to compare the degree of development during the spawning and resting seasons. K E Y W O R D Sglucagon-secreting alpha cells, insulin-secreting beta cells, islets of Langerhans, oesophagus, pancreas | 595 KARKIT eT Al.

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The Comparative Anatomy of Islets

Cited by 4 publications

References 74 publications

Immunohistochemical analysis of pancreatic islets of platypus (Ornithorhynchus anatinus) and echidna (Tachyglossus aculeatus ssp.)

Immunohistochemical analysis of pancreatic islets of platypus (Ornithorhynchus anatinus) and echidna (Tachyglossus aculeatus ssp.)

Pancreatic Islet-Like Three-Dimensional Aggregates Derived from Human Embryonic Stem Cells Ameliorate Hyperglycemia in Streptozotocin-Induced Diabetic Mice

Unique localization of disseminated pancreas in the oesophagus of catfish (clarias gariepinus) with reference to sexual dimorphism

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