Preexisting pancreatic acinar cells contribute to acinar cell, but not islet β cell, regeneration

Abstract Context Chronic pancreatitis (CP) is characterized by inflammation, fibrosis, and a loss of pancreatic acinar cells, which can result in exocrine and eventually endocrine deficiency. Pancreatitis has been reported to induce formation of new endocrine cells (neogenesis) in mice. Our recent data have implicated chromogranin A–positive hormone-negative (CPHN) cells as potential evidence of neogenesis in humans. Objective We sought to establish if CPHN cells were more abundant in CP in humans. Design, Setting, and Participants We investigated the frequency and distribution of CPHN cells and the expression of the chemokine C-X-C motif ligand 10 (CXCL10) and its receptor chemokine C-X-C motif receptor 3 in pancreas of nondiabetic subjects with CP. Results CPHN cell frequency in islets was increased sevenfold in CP [2.1% ± 0.67% vs 0.35% ± 0.09% CPHN cells in islets, CP vs nonpancreatitis (NP), P < 0.01], as were the CPHN cells found as scattered cells in the exocrine areas (17.4 ± 2.9 vs 4.2 ± 0.6, CP vs NP, P < 0.001). Polyhormonal endocrine cells were also increased in CP (2.7 ± 1.2 vs 0.1 ± 0.04, CP vs NP, % of polyhormonal cells of total endocrine cells, P < 0.01), as was expression of CXCL10 in α and β cells. Conclusion There is increased islet endogenous expression of the inflammation marker CXCL10 in islets in the setting of nondiabetic CP and an increase in polyhormonal (insulin-glucagon expressing) cells. The increase in CPHN cells in CP, often in a lobular distribution, may indicate foci of attempted endocrine cell regeneration.

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Crambene induces pancreatic acinar cell apoptosis via the activation of mitochondrial pathway

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.00520.2005 ◽

2006 ◽

Vol 291 (1) ◽

pp. G95-G101 ◽

Cited By ~ 4

Author(s):

Yang Cao ◽

Sharmila Adhikari ◽

Abel Damien Ang ◽

Marie Véronique Clément ◽

Matthew Wallig ◽

...

Keyword(s):

Acinar Cell ◽

Cell Apoptosis ◽

Caspase 3 ◽

Fas Ligand ◽

Annexin V ◽

Acinar Cells ◽

Mitochondrial Pathway ◽

Pancreatic Acinar Cell ◽

Pancreatic Acinar Cells ◽

Pancreatic Acini

We investigated the apoptotic pathway activated by crambene (1-cyano-2-hydroxy-3-butene), a plant nitrile, on pancreatic acinar cells. As evidenced by annexin V-FITC staining, crambene treatment for 3 h induced the apoptosis but not necrosis of pancreatic acini. Caspase-3, -8, and -9 activities in acini treated with crambene were significantly higher than in untreated acini. Treatment with caspase-3, -8, and -9 inhibitors inhibited annexin V staining, as well as caspase-3 activity, pointing to an important role of these caspases in crambene-induced acinar cell apoptosis. The mitochondrial membrane potential was collapsed, and cytochrome c was released from the mitochondria in crambene-treated acini. Neither TNF-α nor Fas ligand levels were changed in pancreatic acinar cells after crambene treatment. These results provide evidence for the induction of pancreatic acinar cell apoptosis in vitro by crambene and suggest the involvement of mitochondrial pathway in pancreatic acinar cell apoptosis.

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Multiple isoforms of the ryanodine receptor are expressed in rat pancreatic acinar cells

Biochemical Journal ◽

10.1042/bj3510265 ◽

2000 ◽

Vol 351 (1) ◽

pp. 265-271 ◽

Cited By ~ 22

Author(s):

Timothy J. FITZSIMMONS ◽

Ilya GUKOVSKY ◽

James A. McROBERTS ◽

Edward RODRIGUEZ ◽

F. Anthony LAI ◽

...

Keyword(s):

Western Blot ◽

Ryanodine Receptor ◽

Acinar Cell ◽

Acinar Cells ◽

Protein Band ◽

Pancreatic Acinar Cell ◽

Pancreatic Acinar Cells ◽

Rt Pcr ◽

Pancreatic Acini ◽

Cell Functions

Regulation of cytosolic Ca2+ is important for a variety of cell functions. The ryanodine receptor (RyR) is a Ca2+ channel that conducts Ca2+ from internal pools to the cytoplasm. To demonstrate the presence of the RyR in the pancreatic acinar cell, we performed reverse transcriptase (RT)-PCR, Western blot, immunocytochemistry and microscopic Ca2+-release measurements on these cells. RT-PCR showed the presence of mRNA for RyR isoforms 1, 2 and 3 in both rat pancreas and dispersed pancreatic acini. Furthermore, mRNA expression for RyR isoforms 1 and 2 was demonstrated by RT-PCR in individual pancreatic acinar cells selected under the microscope. Western-blot analysis of acinar cell immunoprecipitates, using antibodies against RyR1 and RyR2, showed a high-molecular-mass (> 250kDa) protein band that was much less intense when immunoprecipitated in the presence of RyR peptide. Functionally, permeablized acinar cells stimulated with the RyR activator, palmitoyl-CoA, released Ca2+ from both basolateral and apical regions. These data show that pancreatic acinar cells express multiple isoforms of the RyR and that there are functional receptors throughout the cell.

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SEC23B is required for pancreatic acinar cell function in adult mice

Molecular Biology of the Cell ◽

10.1091/mbc.e17-01-0001 ◽

2017 ◽

Vol 28 (15) ◽

pp. 2146-2154 ◽

Cited By ~ 7

Author(s):

Rami Khoriaty ◽

Nancy Vogel ◽

Mark J. Hoenerhoff ◽

M. Dolors Sans ◽

Guojing Zhu ◽

...

Keyword(s):

Acinar Cell ◽

Cell Function ◽

Acinar Cells ◽

Cell Loss ◽

Normal Function ◽

Pancreatic Acinar Cell ◽

Pancreatic Acinar Cells ◽

Total Protein Content ◽

Pancreatic Cell ◽

Adult Mice

Mice with germline absence of SEC23B die perinatally, exhibiting massive pancreatic degeneration. We generated mice with tamoxifen-inducible, pancreatic acinar cell–specific Sec23b deletion. Inactivation of Sec23b exclusively in the pancreatic acinar cells of adult mice results in decreased overall pancreatic weights from pancreatic cell loss (decreased pancreatic DNA, RNA, and total protein content), as well as degeneration of exocrine cells, decreased zymogen granules, and alterations in the endoplasmic reticulum (ER), ranging from vesicular ER to markedly expanded cisternae with accumulation of moderate-density content or intracisternal granules. Acinar Sec23b deletion results in induction of ER stress and increased apoptosis in the pancreas, potentially explaining the loss of pancreatic cells and decreased pancreatic weight. These findings demonstrate that SEC23B is required for normal function of pancreatic acinar cells in adult mice.

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Enhanced Secretion of Amylase from Exocrine Pancreas of Connexin32-deficient Mice

The Journal of Cell Biology ◽

10.1083/jcb.141.5.1267 ◽

1998 ◽

Vol 141 (5) ◽

pp. 1267-1275 ◽

Cited By ~ 52

Author(s):

Marc Chanson ◽

Marjorie Fanjul ◽

Domenico Bosco ◽

Eric Nelles ◽

Susanne Suter ◽

...

Keyword(s):

Acinar Cell ◽

Intercellular Communication ◽

Plaque Assay ◽

Acinar Cells ◽

Pancreatic Acinar Cells ◽

Amylase Secretion ◽

Wild Type ◽

Patch Clamp Recording ◽

Junctional Communication

To determine whether junctional communication between pancreatic acinar cells contributes to their secretory function in vivo, we have compared wild-type mice, which express the gap junctional proteins connexin32 (Cx32) and connexin26, to mice deficient for the Cx32 gene. Pancreatic acinar cells from Cx32 (−/−) mice failed to express Cx32 as evidenced by reverse transcription–PCR and immunolabeling and showed a marked reduction (4.8- and 25-fold, respectively) in the number and size of gap junctions. Dye transfer studies showed that the extent of intercellular communication was inhibited in Cx32 (−/−) acini. However, electrical coupling was detected by dual patch clamp recording in Cx32 (−/−) acinar cell pairs. Although wild-type and Cx32 (−/−) acini were similarly stimulated to release amylase by carbamylcholine, Cx32 (−/−) acini showed a twofold increase of their basal secretion. This effect was caused by an increase in the proportion of secreting acini, as detected with a reverse hemolytic plaque assay. Blood measurements further revealed that Cx32 (−/−) mice had elevated basal levels of circulating amylase. The results, which demonstrate an inverse relationship between the extent of acinar cell coupling and basal amylase secretion in vivo, support the view that the physiological recruitment of secretory acinar cells is regulated by gap junction mediated intercellular communication.

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Monoclonal antibodies as probes for plasma membrane domains in the exocrine pancreas.

Journal of Histochemistry & Cytochemistry ◽

10.1177/36.8.3292643 ◽

1988 ◽

Vol 36 (8) ◽

pp. 1043-1051 ◽

Cited By ~ 9

Author(s):

R C De Lisle ◽

C D Logsdon ◽

S R Hootman ◽

J A Williams

Keyword(s):

Monoclonal Antibodies ◽

Acinar Cell ◽

Apical Membrane ◽

Acinar Cells ◽

Pancreatic Acinar Cell ◽

Pancreatic Acinar Cells ◽

Apical Surface ◽

Membrane Domains ◽

Monolayer Cultures ◽

Apical Membranes

Monoclonal antibodies (mAb) were generated as probes for the plasma membrane domains of pancreatic acinar cells. Primary monolayer cultures of mouse pancreatic acinar cells, which have an expanded apical surface relative to normal pancreas, were used to immunize rats. With conventional immunization and fusion protocols, 3% of the hybridomas were positive against the acinar lumen by indirect immunofluorescence of mouse pancreas cryosections. Culturing of spleen cells from an immunized rat on the apical surface of acinar cell monolayer cultures before fusion with the myeloma (an in vitro boost) doubled the percentage of hybridomas producing apical membrane-specific mAb. Monoclonal antibodies were characterized by immunofluorescence, ultrastructural immunoperoxidase cytochemistry, immunoprecipitation, and immunoblotting. One antibody, acinar-1 (IgG2a), labeled the apical membranes of pancreatic acinar cells, hepatocytes, salivary and lacrimal gland acinar cells, and the brush border of small intestine enterocytes. This mAb precipitated and blotted a protein of 94 KD. Acinar-2 (IgM) also labeled pancreatic acinar cell apical membranes but did not label other tissues and did not precipitate or blot. Acinar-3 labeled pancreatic acinar cell lateral membranes. Duct-1 (IgM) labeled pancreatic duct apical membrane and ducts in liver and salivary glands but did not precipitate or blot. These domain-specific mAb demonstrate that common antigenic determinants occur in the apical surfaces of several exocrine epithelia and may be important in secretion.

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Upregulation of dynamin II expression during the acquisition of a mature pancreatic acinar cell phenotype.

Journal of Histochemistry & Cytochemistry ◽

10.1177/44.12.8985129 ◽

1996 ◽

Vol 44 (12) ◽

pp. 1373-1378 ◽

Cited By ~ 4

Author(s):

T A Cook ◽

K J Mesa ◽

B A Gebelein ◽

R A Urrutia

Keyword(s):

Acinar Cell ◽

Growth Factor Receptor ◽

Acinar Cells ◽

Pancreatic Acinar Cell ◽

Pancreatic Acinar Cells ◽

Cell Phenotype ◽

Receptor Mediated Endocytosis ◽

Ar42j Cells

Members of the dynamin superfamily are GTPases which have been shown to support receptor-mediated endocytosis in vivo and bind to growth factor receptor-associated proteins in vitro. In acinar cells of the pancreas, receptor-mediated endocytosis is very important for the recycling of membranes after secretory granule release. Therefore, characterization of the molecular machinery responsible for this process is critical for a better understanding of this phenomenon. In this study we sought to determine the expression pattern of the endocytic GTPase dynamin II during pancreatic acinar cell differentiation in developing rat embryos and in dexamethasone-treated AR42J cells using Western blot, Northern blot, and immunocytochemical analyses. During pancreatic development, dynamin immunoreactivity is almost undetectable until day E17 but undergoes significant upregulation in acinar cells starting at E18. In addition, the levels of dynamin mRNA and protein in AR42J cells increase approximately threefold during dexamethasone-induced acinar differentiation. The increase in dynamin levels that occurs in both embryonic pancreatic cells and dexamethasone-treated AR42J cells correlates with the establishment of a more differentiated acinar phenotype. Therefore, these results suggest a potential role for dynamin in supporting receptor-mediated endocytosis in mature pancreatic acinar cells.

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Identification and localization of cholecystokinin-binding sites on rat pancreatic plasma membranes and acinar cells: a biochemical and autoradiographic study.

The Journal of Cell Biology ◽

10.1083/jcb.96.5.1288 ◽

1983 ◽

Vol 96 (5) ◽

pp. 1288-1297 ◽

Cited By ~ 91

Author(s):

S A Rosenzweig ◽

L J Miller ◽

J D Jamieson

Keyword(s):

Acinar Cell ◽

Binding Sites ◽

Plasma Membranes ◽

Acinar Cells ◽

Pancreatic Acinar Cells ◽

Cross Linking ◽

Dependent Manner ◽

Electron Microscopic ◽

Electron Microscopic Autoradiography ◽

Pancreatic Acini

Using the combined approaches of affinity labeling and light and electron microscopic autoradiography, we investigated the identification and localization of cholecystokinin (CCK)-binding sites on rat pancreatic acinar cells. To define the molecular properties of the CCK-binding site, we incubated rat pancreatic plasma membranes with 125-I-CCK-33 for 15 min at 23 degrees C followed by washing and cross-linking with disuccinimidyl suberate. Specific labeling of a major Mr 85,000 component was revealed as assessed by SDS PAGE under reducing conditions and autoradiography of the dried gels. Components of Mr greater than 200,000, Mr 130,000-140,000, and, Mr 55,000 were labeled under maximal cross-linking conditions. The labeling of all components was specifically inhibited by CCK-8 in a dose-dependent manner (Kd approximately 9 nM). The Mr 85,000 component had identical electrophoretic mobilities under reducing and nonreducing conditions indicating that it likely does not contain intramolecular disulfide bonds. The larger labeled species may be cross-linked oligomers of this binding protein or complexes between it and neighboring polypeptides. For studies on the distribution of CCK-binding sites, pancreatic acini were incubated with 125I-CCK-33 (0.1 nM) in the absence or presence of CCK-8 (1 microM) for 2 or 15 min at 37 degrees C, washed, and fixed in 2% glutaraldehyde. Quantitative autoradiographic analysis indicated that approximately 60% of the total grains were located within +/- 1 HD (1 HD = 100 nm) of the lateral and basal plasmalemma with little or no labeling of the apical plasmalemma. From these data, it was estimated that each acinar cell possesses at least 5,000-10,000 CCK-binding sites on its basolateral plasmalemma. The remaining grains showed no preferential concentration over the cytoplasm or nucleus. Together, these data indicate that CCK interacts with a Mr 85,000 protein located on the basolateral plasmalemma of the pancreatic acinar cell.

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Spatiotemporal analysis of exocytosis in mouse parotid acinar cells

AJP Cell Physiology ◽

10.1152/ajpcell.00159.2005 ◽

2005 ◽

Vol 289 (5) ◽

pp. C1209-C1219 ◽

Cited By ~ 27

Author(s):

Ying Chen ◽

Jennifer D. Warner ◽

David I. Yule ◽

David R. Giovannucci

Keyword(s):

Acinar Cell ◽

Digestive Enzyme ◽

Acinar Cells ◽

Optical Measurements ◽

Pancreatic Acinar Cells ◽

Second Phase ◽

Zymogen Granule ◽

Exocrine Cells ◽

Parotid Acinar Cells ◽

Camp Elevation

Exocrine cells of the digestive system are specialized to secrete protein and fluid in response to neuronal and/or hormonal input. Although morphologically similar, parotid and pancreatic acinar cells exhibit important functional divergence in Ca2+ signaling properties. To address whether there are fundamental differences in exocytotic release of digestive enzyme from exocrine cells of salivary gland versus pancreas, we applied electrophysiological and optical methods to investigate spatial and temporal characteristics of zymogen-containing secretory granule fusion at the single-acinar cell level by direct or agonist-induced Ca2+ and cAMP elevation. Temporally resolved membrane capacitance measurements revealed that two apparent phases of exocytosis were induced by Ca2+ elevation: a rapidly activated initial phase that could not be resolved as individual fusion events and a second phase that was activated after a delay, increased in a staircaselike fashion, was augmented by cAMP elevation, and likely reflected both sequential compound and multivesicular fusion of zymogen-containing granules. Optical measurements of exocytosis with time-differential imaging analysis revealed that zymogen granule fusion was induced after a minimum delay of ∼200 ms, occurred initially at apical and basolateral borders of acinar cells, and under strong stimulation proceeded from apical pole to deeper regions of the cell interior. Zymogen granule fusions appeared to coordinate subsequent fusions and produced persistent structures that generally lasted several minutes. In addition, parotid gland slices were used to assess secretory dynamics in a more physiological context. Parotid acinar cells were shown to exhibit both similar and divergent properties compared with the better-studied pancreatic acinar cell regarding spatial organization and kinetics of exocytotic fusion of zymogen granules.

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