scholarly journals FINE STRUCTURE OF DIFFERENTIATING MOUSE PANCREATIC EXOCRINE CELLS IN TRANSFILTER CULTURE

1964 ◽  
Vol 20 (3) ◽  
pp. 399-413 ◽  
Author(s):  
Frances Kallman ◽  
Clifford Grobstein
Keyword(s):  
Endoplasmic Reticulum ◽  
Epithelial Surface ◽  
Embryonic Mouse ◽  
Exocrine Cells ◽  
Differentiated Cells ◽  
Pancreatic Epithelium ◽  
Pancreatic Exocrine ◽  
Transfilter Culture ◽  
Specific Synthesis ◽  
Made In

Fine structural observations have been made in the 11-day embryonic mouse of exocrine cells in pancreatic epithelium developing in tissue culture transfilter from salivary gland mesenchyme of the 13-day embryonic mouse. After 2 days in culture, the exocrine cells show increased cytoplasmic density, abundant ribosomes in aggregate or "rosette" form, and expanded profiles of rough-surfaced endoplasmic reticulum. After 3 and 4 days in culture, the cells exhibit continued expansion of the profiles of endoplasmic reticulum, increased amounts of Golgi membranes, and large areas of light density (prozymogen granules). After 5 days in culture, dense zymogen granules are present in the most highly differentiated cells. In addition, at the filter-epithelial surface, at 2 days, small fibers can be discerned which, after 4 days in culture, show obvious periodicity and are thought to be collagen. The significance of these changes, in relation to the mesenchymal effect, to the onset of specific synthesis and to the stabilization of differentiation is discussed.

scholarly journals PANCREATIC MICROSOMES

1956 ◽  
Vol 2 (6) ◽  
pp. 671-690 ◽  
Author(s):  
G. E. Palade ◽  
P. Siekevitz
Keyword(s):  
Endoplasmic Reticulum ◽  
Islet Cells ◽  
Reductase Activity ◽  
Liver Microsomes ◽  
Basal Region ◽  
Cytoplasmic Matrix ◽  
Exocrine Cells ◽  
Dense Granules ◽  
Microsome Fraction ◽  
Pancreatic Exocrine

The pancreatic exocrine cell of the guinea pig has a voluminous endoplasmic reticulum distinguished by extensive association with small, dense particles, and by its orderly disposition in the basal region of the cell. In addition to the small, (∼15 mµ), dense particles attached to the limiting membrane of the endoplasmic reticulum, numerous particles of similar appearance are found freely scattered in the cytoplasmic matrix. The various cell structures of pancreatic exocrine cells can be satisfactorily identified in pancreatic homogenates. The microsome fraction consists primarily of spherical vesicles (80 to 300 mµ), limited by a thin membrane (7 mµ) which bears small (∼15 mµ) dense particles attached on its outer surface. The content of the microsomal vesicles is usually of high density. Pancreatic microsomes derive by extensive fragmentation mainly from the rough surfaced parts of the endoplasmic reticula of exocrine cells. A few damaged mitochondria and certain dense granules (∼150 mµ) originating probably from islet cells, contaminate the microsome fraction. Pancreatic microsomes contain RNA, protein, and a relatively small amount of phospholipide and hemochromogen. They do not have DPNH-cytochrome c reductase activity. In six experiments the RNA/protein N ratios were found grouped around two different means, namely 0.6 and 1.3. Pancreatic microsomes are more labile than liver microsomes but react in a similar way to RN-ase-(loss of the particulate component and RNA), and deoxycholate treatment (loss of the membranous component and of phospholipide, hemochromogen, and most of the protein). Postmicrosomal fractions consisting primarly of small (∼15 mµ), dense particles of ribonucleoprotein (RNA/protein N ratio = 1 to 2) were obtained by further centrifugation of the microsomal supernatant. The small nucleoprotein particles of these fractions are frequently found associated in chains or clusters.

83-OR: Pancreatic Exocrine to Endocrine Cell Cross Talk Mediates Endoplasmic Reticulum Stress and Beta-Cell Dysfunction in MODY8

Diabetes ◽  
2020 ◽  
Vol 69 (Supplement 1) ◽  
pp. 83-OR
Author(s):  
SEVIM KAHRAMAN ◽  
DANIELLE DIEGISSER ◽  
BENTE B. JOHANSSON ◽  
ANDERS MOLVEN ◽  
ROHIT KULKARNI
Keyword(s):  
Endoplasmic Reticulum ◽  
Endoplasmic Reticulum Stress ◽  
Beta Cell ◽  
Cross Talk ◽  
Endocrine Cell ◽  
Beta Cell Dysfunction ◽  
Cell Dysfunction ◽  
Pancreatic Exocrine

scholarly journals Characterization of Endoplasmic Reticulum (ER) in Human Pluripotent Stem Cells Revealed Increased Susceptibility to Cell Death upon ER Stress

Cells ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 1078
Author(s):  
Tae Won Ha ◽  
Ji Hun Jeong ◽  
HyeonSeok Shin ◽  
Hyun Kyu Kim ◽  
Jeong Suk Im ◽  
...  
Keyword(s):  
Stem Cells ◽  
Endoplasmic Reticulum ◽  
Er Stress ◽  
Pluripotent Stem Cells ◽  
Meta Analysis ◽  
Embryonic Stem ◽  
Structural Features ◽  
Human Pluripotent Stem Cells ◽  
Differentiated Cells ◽  
Induced Apoptosis

Human pluripotent stem cells (hPSCs), such as embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs), have a well-orchestrated program for differentiation and self-renewal. However, the structural features of unique proteostatic-maintaining mechanisms in hPSCs and their features, distinct from those of differentiated cells, in response to cellular stress remain unclear. We evaluated and compared the morphological features and stress response of hPSCs and fibroblasts. Compared to fibroblasts, electron microscopy showed simpler/fewer structures with fewer networks in the endoplasmic reticulum (ER) of hPSCs, as well as lower expression of ER-related genes according to meta-analysis. As hPSCs contain low levels of binding immunoglobulin protein (BiP), an ER chaperone, thapsigargin treatment sharply increased the gene expression of the unfolded protein response. Thus, hPSCs with decreased chaperone function reacted sensitively to ER stress and entered apoptosis faster than fibroblasts. Such ER stress-induced apoptotic processes were abolished by tauroursodeoxycholic acid, an ER-stress reliever. Hence, our results revealed that as PSCs have an underdeveloped structure and express fewer BiP chaperone proteins than somatic cells, they are more susceptible to ER stress-induced apoptosis in response to stress.

scholarly journals An essential dimer-forming subregion of the endoplasmic reticulum stress sensor Ire1

2005 ◽  
Vol 391 (1) ◽  
pp. 135-142 ◽  
Author(s):  
Daisuke Oikawa ◽  
Yukio Kimata ◽  
Masato Takeuchi ◽  
Kenji Kohno
Keyword(s):  
Endoplasmic Reticulum ◽  
Recombinant Protein ◽  
Endoplasmic Reticulum Stress ◽  
Transmembrane Protein ◽  
Type I ◽  
Unfolded Protein ◽  
The Unfolded Protein Response ◽  
Protein Response ◽  
Recombinant Fragments ◽  
Made In

The luminal domain of the type I transmembrane protein Ire1 senses endoplasmic reticulum stress by an undefined mechanism to up-regulate the signalling pathway for the unfolded protein response. Previously, we proposed that the luminal domain of yeast Ire1 is divided into five subregions, termed subregions I–V sequentially from the N-terminus. Ire1 lost activity when internal deletions of subregion II or IV were made. In the present paper, we show that partial proteolysis of a recombinant protein consisting of the Ire1 luminal domain suggests that subregions II–IV are tightly folded. We also show that a recombinant protein of subregions II–IV formed homodimers, and that this homodimer formation was impaired by an internal deletion of subregion IV. Furthermore, recombinant fragments of subregion IV exhibited a self-binding ability. Therefore, although its sequence is little conserved evolutionarily, subregion IV plays an essential role to promote Ire1 dimer formation.

scholarly journals Gene delivery to pancreatic exocrine cells in vivo and in vitro

2012 ◽  
Vol 12 (1) ◽  
Author(s):  
Isabelle Houbracken ◽  
Luc Baeyens ◽  
Philippe Ravassard ◽  
Harry Heimberg ◽  
Luc Bouwens
Keyword(s):  
Gene Delivery ◽  
Exocrine Cells ◽  
Pancreatic Exocrine
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