scholarly journals Embryogenesis of the murine endocrine pancreas; early expression of pancreatic polypeptide gene

Development ◽  
1991 ◽  
Vol 113 (4) ◽  
pp. 1257-1265 ◽  
Author(s):  
P.L. Herrera ◽  
J. Huarte ◽  
F. Sanvito ◽  
P. Meda ◽  
L. Orci ◽  
...  
Keyword(s):  
Pancreatic Polypeptide ◽  
Endocrine Cells ◽  
Islet Cells ◽  
Secretory Granules ◽  
Pcr Amplification ◽  
Immunogold Labelling ◽  
Pancreatic Ducts ◽  
Thin Sections ◽  
Embryonic Pancreas ◽  
Early Expression

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.

scholarly journals Immunocytochemical localization of cathepsins B, H, and their endogenous inhibitor, cystatin beta, in islet endocrine cells of rat pancreas.

1988 ◽  
Vol 36 (7) ◽  
pp. 783-791 ◽  
Author(s):  
M Watanabe ◽  
T Watanabe ◽  
Y Ishii ◽  
H Matsuba ◽  
S Kimura ◽  
...  
Keyword(s):  
Endocrine Cells ◽  
Islet Cells ◽  
Secretory Granules ◽  
Double Immunostaining ◽  
Thin Sections ◽  
Cathepsin H ◽  
Immunocytochemical Techniques ◽  
The Difference ◽  
Immunocytochemical Reaction ◽  
Strong Immunoreactivity

To determine the characteristics of lysosomes in rat islet endocrine cells, we examined the precise localization of cathepsins B, H, and L and their specific inhibitors, cystatins alpha and beta, using immunocytochemical techniques. By use of serial semi-thin sections, we detected immunoreactivity for cathepsin B in insulin-, glucagon-, somatostatin-, and pancreatic polypeptide-positive (PP) cells. Strong immunoreactivity for cathepsin H was seen in A-cells and weak immunoreactivity in PP cells, but none in others. Immunodeposits for cystatin beta were demonstrated in B-cells. Brief dipping of thin sections in 1% sodium methoxide before the following immunocytochemical reaction enhanced specific deposits of immunogold particles on the target organelles. Use of a double-immunostaining technique showed co-localization of insulin with cystatin beta in many secretory granules. This suggests that cystatin beta may regulate converting enzymes participating in the maturation process of insulin. By use of an immunogold technique, heterogeneous localization of cathepsins B and H in lysosomes was also found among islet cells at the light microscopic level. This may be due to the difference in peptides degraded in lysosomes among the cells.

scholarly journals SARS-CoV-2 Cell Entry Factors ACE2 and TMPRSS2 are Expressed in the Pancreas but are Not Enriched in Islet Endocrine Cells

2020 ◽  
Author(s):  
Katie C. Coate ◽  
Jeeyeon Cha ◽  
Shristi Shrestha ◽  
Wenliang Wang ◽  
Luciana Mateus Gonçalves ◽  
...  
Keyword(s):  
Pancreatic Islet ◽  
Endocrine Cells ◽  
Islet Cells ◽  
Cell Entry ◽  
Pancreatic Ducts ◽  
Human Pancreas ◽  
Β Cells ◽  
Ductal Cells ◽  
Putative Receptor ◽  
New Onset

Summary/AbstractReports of new-onset diabetes and diabetic ketoacidosis in individuals with COVID-19 have led to the hypothesis that SARS-CoV-2, the virus that causes COVID-19, is directly cytotoxic to pancreatic islet β cells. This would require binding and entry of SARS-CoV-2 into host β cells via cell surface co-expression of ACE2 and TMPRSS2, the putative receptor and effector protease, respectively. To define ACE2 and TMPRSS2 expression in the human pancreas, we examined six transcriptional datasets from primary human islet cells and assessed protein expression by immunofluorescence in pancreata from donors with and without diabetes. ACE2 and TMPRSS2 transcripts were low or undetectable in pancreatic islet endocrine cells as determined by bulk or single cell RNA sequencing, and neither protein was detected in α or β cells from these donors. Instead, ACE2 protein was expressed in the islet and exocrine tissue microvasculature and also found in a subset of pancreatic ducts, whereas TMPRSS2 protein was restricted to ductal cells. The absence of significant ACE2 and TMPRSS2 co-expression in islet endocrine cells reduces the likelihood that SARS-CoV-2 directly infects pancreatic islet β cells through these cell entry proteins.

scholarly journals Anti-lymphocyte antibody Leu-7 (HNK-1) recognizes a constituent of neuroendocrine granule matrix.

1986 ◽  
Vol 34 (9) ◽  
pp. 1213-1216 ◽  
Author(s):  
A S Tischler ◽  
H Mobtaker ◽  
K Mann ◽  
G Nunnemacher ◽  
W J Jason ◽  
...  
Keyword(s):  
Anterior Pituitary ◽  
Endocrine Cells ◽  
Islet Cells ◽  
Secretory Granules ◽  
Pancreatic Islet Cells ◽  
Cell Surfaces ◽  
Intracellular Protein ◽  
Myelin Associated Glycoprotein ◽  
Granule Matrix ◽  
Leu 7

Anti-lymphocyte monoclonal antibody HNK-1 (Leu-7) reacts with the cell surfaces of natural killer (NK) lymphocytes and with myelin-associated glycoprotein (MAG). This antibody reacts intensely with normal and neoplastic adrenal medullary cells. A small proportion of normal pancreatic islet cells, anterior pituitary, and gastroenteropancreatic endocrine cells also show Leu-7 immunoreactivity. In adrenal medulla, ultrastructural immunocytochemical studies and immunoblot analyses reveal that Leu-7 reacts with an intracellular protein of MW 75 KD which is localized within the matrices of the chromaffin granules. The MW of this protein differs from those of MAG and chromogranin A. The findings suggest that Leu-7 immunoreactivity might be a new marker for specific subsets of secretory granules.

scholarly journals Immunohistochemistry of Pancreatic Islet Cell Tumors in the Ferret (Mustela putorius furo)

1997 ◽  
Vol 34 (5) ◽  
pp. 387-393 ◽  
Author(s):  
G. A. Andrews ◽  
N. C. Myers ◽  
C. Chard-Bergstrom
Keyword(s):  
Pancreatic Islets ◽  
Pancreatic Islet ◽  
Pancreatic Polypeptide ◽  
Islet Cell ◽  
Islet Cells ◽  
Neuron Specific Enolase ◽  
Islet Cell Tumors ◽  
Pancreatic Islet Cell ◽  
Formalin Fixed Paraffin Embedded ◽  
Pancreatic Islet Cell Tumors

Twenty-two pancreatic islet cell tumors and normal pancreatic islets from ferrets were evaluated by immunohistochemistry for expression of the peptide hormones insulin, somatostatin, glucagon, and pancreatic polypeptide (PP) and the neuroendocrine markers chromogranin A (CgA) and neuron-specific enolase (NSE). In normal pancreatic islets, the majority of cells stained strongly with CgA and NSE. A cells, B cells, D cells, and PP cells stained strongly with glucagon, insulin, somatostatin, and PP, respectively. All 22 tumors stained with CgA and NSE. The proportion of cells within tumors staining for CgA was variable, but more than half of the cells stained positively in 18 of the tumors. The intensity of staining for CgA was strong (reactivity equivalent to or greater than normal islet cells in adjacent tissue) in 11 moderate in six, and weak in five of the tumors. All tumors stained for NSE, with ≥50% of the cells staining in 21 of the tumors, and the intensity of staining was strong in 18 of the tumors. Twenty of 22 tumors stained positively for insulin, with ≥50% of the cells staining in 19 of them. The intensity of staining for insulin was strong in 12, moderate in seven, and weak in one of the tumors. Approximately ≤1% of the cells in 15 of 22 tumors stained for somatostatin, five tumors stained for pancreatic polypeptide, and three tumors stained for glucagon. These data indicate that the majority of islet cell tumors of ferrets express immunohistochemically detectable insulin. CgA and NSE are both useful general markers for such tumors, including those that are insulin negative. Commercially available antisera to CgA, NSE, insulin, glucagon, somatostatin, and PP work well in formalin-fixed, paraffin-embedded tissue for immunophenotyping islet cell tumors in the ferret.

Impaired migration and delayed differentiation of pancreatic islet cells in mice lacking EGF-receptors

Development ◽  
2000 ◽  
Vol 127 (12) ◽  
pp. 2617-2627 ◽  
Author(s):  
P.J. Miettinen ◽  
M. Huotari ◽  
T. Koivisto ◽  
J. Ustinov ◽  
J. Palgi ◽  
...  
Keyword(s):  
Beta Cells ◽  
Islet Cells ◽  
Branching Morphogenesis ◽  
Late Gestation ◽  
Pancreatic Ducts ◽  
Egf Receptors ◽  
Plasminogen Activator Inhibitor 1 ◽  
Pancreatic Acini ◽  
Delayed Differentiation ◽  
Pai 1

Pancreatic acini and islets are believed to differentiate from common ductal precursors through a process requiring various growth factors. Epidermal growth factor receptor (EGF-R) is expressed throughout the developing pancreas. We have analyzed here the pancreatic phenotype of EGF-R deficient (−/−) mice, which generally die from epithelial immaturity within the first postnatal week. The pancreata appeared macroscopically normal. The most striking feature of the EGF-R (−/−) islets was that instead of forming circular clusters, the islet cells were mainly located in streak-like structures directly associated with pancreatic ducts. Based on BrdU-labelling, proliferation of the neonatal EGF-R (−/−) beta-cells was significantly reduced (2.6+/−0.4 versus 5.8+/−0.9%, P<0.01) and the difference persisted even at 7–11 days of age. Analysis of embryonic pancreata revealed impaired branching morphogenesis and delayed islet cell differentiation in the EGF-R (−/−) mice. Islet development was analyzed further in organ cultures of E12.5 pancreata. The proportion of insulin-positive cells was significantly lower in the EGF-R (−/−) explants (27+/−6 versus 48+/−8%, P<0.01), indicating delayed differentiation of the beta cells. Branching of the epithelium into ducts was also impaired. Matrix metalloproteinase (MMP-2 and MMP-9) activity was reduced 20% in EGF-R (−/−) late-gestation pancreata, as measured by gelatinase assays. Furthermore, the levels of secreted plasminogen activator inhibitor-1 (PAI-1) were markedly higher, while no apparent differences were seen in the levels of active uPA and tPa between EGF-R (−/−) and wild-type pancreata. Our findings suggest that the perturbation of EGF-R-mediated signalling can lead to a generalized proliferation defect of the pancreatic epithelia associated with a delay in beta cell development and disturbed migration of the developing islet cells as they differentiate from their precursors. Upregulated PAI-1 production and decreased gelatinolytic activity correlated to this migration defect. An intact EGF-R pathway appears to be a prerequisite for normal pancreatic development.

The distribution of endocrine cell progenitors in the gut of chick embryos

Development ◽  
1984 ◽  
Vol 82 (1) ◽  
pp. 131-145
Author(s):  
B. B. Rawdon ◽  
Beverley Kramer ◽  
Ann Andrew
Keyword(s):  
Gastrointestinal Tract ◽  
Progenitor Cells ◽  
Digestive Tract ◽  
Pancreatic Polypeptide ◽  
Endocrine Cell ◽  
Endocrine Cells ◽  
Chick Embryos ◽  
Intact Embryo ◽  
Pancreatic Endocrine Cells ◽  
Gut Endocrine Cells

The aim of this experiment was to find out whether or not, at early stages of development, progenitors of the various types of gut endocrine cells are localized to one or more specific regions of the gastrointestinal tract. Transverse strips of blastoderm two to four somites in length were excised between the levels of somites 5 and 27 in chick embryos at 5- to 24-somite stages and were cultured as chorioallantoic grafts. The distribution of endocrine cells in the grafts revealed confined localization of progenitor cells only in the case of insulinimmunoreactive cells. Theprogenitors of cells with somatostatin-, pancreatic polypeptide-, glucagon-, secretin-, gastrin/CCK-, motilin-, neurotensin- and serotonin-like immunoreactivity were distributed along the length of the presumptive gut at the time of explantation; indeed, in many cases they were more widespread than are their differentiated progeny in normal gut of the same age. This finding indicates that conditions in grafts must differ from those that operate in the intact embryo. Also it may explain the occurrence of ectopic gut or pancreatic endocrine cells in tumours of the digestive tract.

scholarly journals Distribution of glucagon-like peptide I in canine and feline pancreas and gastrointestinal tract.

1986 ◽  
Vol 34 (9) ◽  
pp. 1117-1121 ◽  
Author(s):  
C R Vaillant ◽  
P K Lund
Keyword(s):  
Gastrointestinal Tract ◽  
Endocrine Cells ◽  
Northern Blot Analysis ◽  
Islet Cells ◽  
Cleavage Product ◽  
Antigenic Determinants ◽  
Normal Pancreas ◽  
Fetal Rat ◽  
Islet Tissue ◽  
Glucagon Like Peptide

Recently, a putative hormone, glucagon-like peptide I (GLP I), has been identified in the predicted sequences of the precursors to pancreatic glucagon in human, rat, hamster, and ox. The distribution of GLP I immunoreactivity in canine and feline pancreas and gastrointestinal tract was examined immunohistochemically and was compared with that of two other antigenic determinants of pancreatic pro-glucagon, i.e., glucagon and the NH2 terminus of glicentin. All three determinants occurred in the same population of islet cells in normal pancreas and in pancreas consisting predominantly of islet tissue from dogs with canine pancreatic acinar atrophy. Northern blot analysis of mRNA from the latter tissue, using a rat pre-pro-glucagon complementary DNA probe, revealed a single mRNA species similar in size to the pre-pro-glucagon mRNA detected in fetal rat pancreas. The three antigenic determinants of pancreatic pro-glucagon were co-localized also in intestinal L-cells and in canine gastric A-cells. Canine and feline pancreatic pro-glucagons therefore resemble those identified in other mammals and may also occur in gastrointestinal endocrine cells. Although there is evidence that the GLP I sequence is not liberated from pancreatic pro-glucagon, our results raise the possibility that this putative hormone may be a cleavage product of pro-glucagon in the gastrointestinal tract.

scholarly journals REST is a major negative regulator of endocrine differentiation during pancreas organogenesis

2021 ◽  
Author(s):  
Meritxell Rovira ◽  
Goutham Atla ◽  
Miguel Angel Maestro ◽  
Vane Grau ◽  
Javier García-Hurtado ◽  
...  
Keyword(s):  
Endocrine Cells ◽  
Negative Regulator ◽  
Β Cell ◽  
Knock Out ◽  
Endocrine Differentiation ◽  
Conditional Allele ◽  
Embryonic Pancreas ◽  
Pancreatic Endocrine Cells ◽  
Knock Out Mice

SUMMARYUnderstanding genomic regulatory mechanisms of pancreas differentiation is relevant to the pathophysiology of diabetes mellitus, and to the development of replacement therapies. Numerous transcription factors promote β cell differentiation, although less is known about negative regulators. Earlier epigenomic studies suggested that the transcriptional repressor REST could be a suppressor of endocrine gene programs in the embryonic pancreas. However, pancreaticRestknock-out mice failed to show increased numbers of endocrine cells, suggesting that REST is not a major regulator of endocrine differentiation. Using a different conditional allele that enables profound REST inactivation, we now observe a marked increase in the formation of pancreatic endocrine cells. REST inhibition also promoted endocrinogenesis in zebrafish and mouse early postnatal ducts, and induced β-cell specific genes in human adult duct-derived organoids. Finally, we define REST genomic programs that suppress pancreatic endocrine differentiation. These results establish a crucial role of REST as a negative regulator of pancreatic endocrine differentiation.

scholarly journals Immunocytochemical localization of histamine in secretory granules of rat peritoneal mast cells with conventional or rapid microwave fixation and an ultrastructural post-embedding immunogold technique.

1992 ◽  
Vol 40 (9) ◽  
pp. 1247-1256 ◽  
Author(s):  
G R Login ◽  
S J Galli ◽  
A M Dvorak
Keyword(s):  
Electron Microscopy ◽  
Mast Cells ◽  
Guinea Pig ◽  
Secretory Granules ◽  
Fixation Method ◽  
Structural Localization ◽  
Thin Sections ◽  
Aldehyde Fixation ◽  
Peritoneal Mast Cells ◽  
Rat Peritoneal Mast Cells

We used a post-embedding immunogold labeling approach to define the fine-structural localization of histamine in rat peritoneal mast cells that were fixed using either standard aldehyde fixation or a fast microwave-aldehyde fixation method. Specimens were processed routinely for electron microscopy. Thin sections were exposed first to guinea pig antihistamine antiserum and then to gold-conjugated goat IgG directed against guinea pig IgG. By transmission electron microscopy, gold particles were localized to the matrix of cytoplasmic granules. Control sections treated with non-immune sera did not show labeling of mast cells. Adsorption of antihistamine antiserum with purified histamine or histamine bound to agarose showed a significant reduction (p less than 0.005) in granule staining. We also confirmed that our isolation procedures yielded functionally competent mast cells which released histamine when stimulated with sheep anti-rat IgE antiserum or with compound 48/80. These studies define the conditions of fixation for electron microscopy that are appropriate for the localization of histamine in the granule matrix of rat peritoneal mast cells.

Persistent expression of HNF6 in islet endocrine cells causes disrupted islet architecture and loss of beta cell function

Development ◽  
2000 ◽  
Vol 127 (13) ◽  
pp. 2883-2895 ◽  
Author(s):  
M. Gannon ◽  
M.K. Ray ◽  
K. Van Zee ◽  
F. Rausa ◽  
R.H. Costa ◽  
...  
Keyword(s):  
Beta Cell ◽  
Beta Cells ◽  
Endocrine Cells ◽  
Spatial Organization ◽  
Glucose Transporter ◽  
Cell Function ◽  
Regulatory Element ◽  
Cell Physiology ◽  
Pancreatic Ducts ◽  
And Function

We used transgenesis to explore the requirement for downregulation of hepatocyte nuclear factor 6 (HNF6) expression in the assembly, differentiation, and function of pancreatic islets. In vivo, HNF6 expression becomes downregulated in pancreatic endocrine cells at 18. 5 days post coitum (d.p.c.), when definitive islets first begin to organize. We used an islet-specific regulatory element (pdx1(PB)) from pancreatic/duodenal homeobox (pdx1) gene to maintain HNF6 expression in endocrine cells beyond 18.5 d.p.c. Transgenic animals were diabetic. HNF6-overexpressing islets were hyperplastic and remained very close to the pancreatic ducts. Strikingly, alpha, delta, and PP cells were increased in number and abnormally intermingled with islet beta cells. Although several mature beta cell markers were expressed in beta cells of transgenic islets, the glucose transporter GLUT2 was absent or severely reduced. As glucose uptake/metabolism is essential for insulin secretion, decreased GLUT2 may contribute to the etiology of diabetes in pdx1(PB)-HNF6 transgenics. Concordantly, blood insulin was not raised by glucose challenge, suggesting profound beta cell dysfunction. Thus, we have shown that HNF6 downregulation during islet ontogeny is critical to normal pancreas formation and function: continued expression impairs the clustering of endocrine cells and their separation from the ductal epithelium, disrupts the spatial organization of endocrine cell types within the islet, and severely compromises beta cell physiology, leading to overt diabetes.

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