scholarly journals c-Jun/AP-1 is required for CCK-induced pancreatic acinar cell dedifferentiation and DNA synthesis in vitro

2012 ◽  
Vol 302 (12) ◽  
pp. G1381-G1396 ◽  
Author(s):  
Lili Guo ◽  
Maria Dolors Sans ◽  
Yanan Hou ◽  
Stephen A. Ernst ◽  
John A. Williams
Keyword(s):  
Dna Synthesis ◽  
Cyclin D1 ◽  
Signaling Pathways ◽  
Acinar Cell ◽  
Acinar Cells ◽  
Pancreatic Acinar Cell ◽  
Dominant Negative ◽  
Cell Dedifferentiation ◽  
Cell Markers

Endogenous CCK plays an important role in pancreatic regeneration after pancreatitis. We used primary culture of mouse pancreatic acinar cells to evaluate the effect of CCK on acinar cell morphology and gene expression and to determine signaling pathways required for proliferation of acinar cells in vitro. Over 4 days in culture, cells grew out from acini and formed patches of monolayer, which displayed a reduced expression of acinar cell markers including digestive enzymes and Mist1 and an increased expression of ductal and embryonic markers, including cytokeratin 7, β-catenin, E-cadherin, pdx-1, and nestin. There was no appearance of stellate cell markers. CCK enhanced cellular spreading, DNA synthesis, and cyclin D1 expression. When signaling pathways were evaluated, CCK stimulation increased c-Jun expression, JNK and ERK activity, and AP-1 activation. Chemical inhibitors of JNK and ERK pathways, dominant-negative JNK and c-Jun, and c-Jun shRNA significantly inhibited CCK-induced DNA synthesis, CCK-induced AP-1 activation, and cyclin D1 expression. Furthermore, dominant-negative c-Jun reduced the increased expression of β-catenin and the decreased expression of amylase during culture. These results show that MAPK/c-Jun/AP-1 pathway plays an important role in pancreatic acinar cell dedifferentiation and proliferation in culture. Monolayer culture can serve as a model to study acinar cell proliferation similar to regeneration after pancreatitis in vivo.

scholarly journals MECOM permits pancreatic acinar cell dedifferentiation avoiding cell death under stress conditions

2020 ◽  
Author(s):  
Elyne Backx ◽  
Elke Wauters ◽  
Jonathan Baldan ◽  
Mathias Van Bulck ◽  
Ellis Michiels ◽  
...  
Keyword(s):  
Cell Death ◽  
Acinar Cell ◽  
Acinar Cells ◽  
Pancreatic Acinar Cell ◽  
Stress Conditions ◽  
Loss Of Function ◽  
Cell Dedifferentiation ◽  
Duct Cells

ABSTRACTMaintenance of the pancreatic acinar cell phenotype suppresses tumor formation. Hence, repetitive acute or chronic pancreatitis, stress conditions in which the acinar cells dedifferentiate, predispose for cancer formation in the pancreas. Dedifferentiated acinar cells acquire a large panel of duct cell specific markers. However, it remains unclear to what extent dedifferentiated acini differ from native duct cells and which genes are uniquely regulating acinar cell dedifferentiation. Moreover, most studies have been performed in mouse since the availability of human cells is scarce.Here, we applied a non-genetic lineage tracing method in our culture model of human pancreatic exocrine cells that allowed cell-type specific gene expression profiling by RNA sequencing. Subsequent to this discovery analysis, one transcription factor that was unique for dedifferentiated acinar cells was functionally characterized using in vitro and in vivo genetic loss-of-function experimental models.RNA sequencing analysis showed that human dedifferentiated acinar cells expressed genes in ‘Pathways of cancer’ with prominence of the transcription factor MECOM (EVI-1) that was absent from duct cells. During mouse embryonic development, pre-acinar cells transiently expressed MECOM and MECOM was re-expressed in experimental in vivo models of acute and chronic pancreatitis in vivo, conditions in which acinar cells dedifferentiate. MECOM expression correlated with and was directly regulated by SOX9. MECOM loss-of-function in mouse acinar cells in vitro and in vivo impaired cell adhesion resulting in more prominent acinar cell death and suppressed acinar cell dedifferentiation by limiting ERK signaling.In conclusion, we transcriptionally profiled the two major human pancreatic exocrine cell types, acinar and duct cells, during experimental stress conditions. We provide insights that in dedifferentiated acinar cells, cancer pathways are upregulated in which MECOM is a critical regulator that suppresses acinar cell death by permitting cellular dedifferentiation.

scholarly journals Induction of pancreatic acinar cell proliferation by thyroid hormone

2005 ◽  
Vol 185 (3) ◽  
pp. 393-399 ◽  
Author(s):  
G M Ledda-Columbano ◽  
A Perra ◽  
M Pibiri ◽  
F Molotzu ◽  
A Columbano
Keyword(s):  
Cell Proliferation ◽  
Thyroid Hormone ◽  
Dna Synthesis ◽  
Acinar Cell ◽  
Acinar Cells ◽  
Pancreatic Acinar Cell ◽  
Labeling Index ◽  
Metabolic Effects ◽  
Brdu Incorporation ◽  
Pancreatic Cell

Thyroid hormone is known to elicit diverse cellular and metabolic effects in various organs, including mitogenesis in the rat liver. In the present study, experiments were carried out to determine whether thyroid hormone is able to stimulate cell proliferation in another quiescent organ such as the pancreas. 3,5,3′-l-tri-iodothyronine (T3) added to the diet at a concentration of 4 mg/kg caused a striking increase in nuclear bromodeoxyuridine (BrdU) incorporation of rat acinar cells 7 days after treatment (the labeling index was 46.7% in T3-treated rats vs 7.1% in controls). BrdU incorporation was limited to the acinar cells, with duct cells and islet cells being essentially negative. The increase in DNA synthesis was accompanied by the presence of several mitotic figures. Histological examination of the pancreas did not exhibit any sign of T3-induced toxicity. Determination of the apoptotic index, measurement of the serum levels of α-amylase and lipase, and glycemia determination did not show any increase over control values, suggesting that the enhanced proliferation of acinar cells was a direct effect induced by T3 and not a regenerative response consequent to acinar or β-cell injury. Additional experiments showed that DNA synthesis was induced as early as 2 days after T3 treatment (the labeling index was 9.4 vs 1.9% in controls) and was associated with increased protein levels of cyclin D1, cyclin A and proliferating cell nuclear antigen, with no substantial differences in the expression of the cyclin-dependent kinase inhibitor p27. The mitogenic effect of T3 on the pancreas was not limited to the rat, since extensive acinar cell proliferation was also observed in the pancreas of mice treated with T3 for 1 week (the labeling index was 28% in T3-treated mice vs 1.8% in controls). Treatment with three other ligands of nuclear receptors, ciprofibrate, all-trans retinoic acid and 1,4-bis[2-(3,5-dichloropyridyloxy)]benzene, induced little or no pancreatic cell proliferation. These results demonstrated that T3 is a powerful inducer of cell proliferation in the pancreas and suggested that pancreatic acinar cell proliferation by selected agents may have potential for therapeutic use.

Adenovirus-mediated gene transfer of RasN17 inhibits specific CCK actions on pancreatic acinar cells

1999 ◽  
Vol 276 (2) ◽  
pp. G499-G506 ◽  
Author(s):  
Barbara Nicke ◽  
Min-Jen Tseng ◽  
Marycarol Fenrich ◽  
Craig D. Logsdon
Keyword(s):  
Dna Synthesis ◽  
Intracellular Signaling ◽  
Acinar Cells ◽  
Dominant Negative ◽  
Pancreatic Acinar Cells ◽  
Dominant Negative Mutant ◽  
Ras Gene ◽  
Amylase Release ◽  
Jun Kinase

CCK stimulates pleiotrophic responses in pancreatic acinar cells; however, the intracellular signaling pathways involved are not well understood. To evaluate the role of the ras gene product in CCK actions, a strategy involving in vitro adenoviral-mediated gene delivery of a dominant-negative mutant Ras (RasN17) was utilized. Isolated acini were infected with various titers of either a control adenovirus or an adenoviral construct expressing RasN17 for 24 h before being treated with CCK. Titer-dependent expression of RasN17 in the acini was confirmed by Western blotting. Infection with control adenovirus [106–109plaque-forming units/mg acinar protein (multiplicity of infection of ∼1–1,000)] had no effect on CCK stimulation of acinar cell amylase release, extracellular-regulated kinase (ERK) or c-Jun kinase (JNK) kinases, or DNA synthesis. In contrast, infection with adenovirus bearing ras N17 increased basal amylase release, inhibited CCK-mediated JNK activation, had no effect on CCK activation of ERK, and inhibited DNA synthesis. These data demonstrate important roles for Ras in specific actions of CCK on pancreatic acinar function.

Effects of pancreatic acinar cell surface antibodies and complement on isolated rat acinar cells in vitro

1988 ◽  
Vol 55 (1) ◽  
Author(s):  
H. -U. Schulz ◽  
G. Letko ◽  
H. -J. Hass ◽  
H. Spormann ◽  
P. Kemnitz ◽  
...  
Keyword(s):  
Cell Surface ◽  
Acinar Cell ◽  
Acinar Cells ◽  
Pancreatic Acinar Cell ◽  
Surface Antibodies ◽  
Isolated Rat

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

1996 ◽  
Vol 44 (12) ◽  
pp. 1373-1378 ◽  
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.

Smad4 mediates activation of mitogen-activated protein kinases by TGF-β in pancreatic acinar cells

2001 ◽  
Vol 281 (1) ◽  
pp. C311-C319 ◽  
Author(s):  
Diane M. Simeone ◽  
Lizhi Zhang ◽  
Kathleen Graziano ◽  
Barbara Nicke ◽  
Trinh Pham ◽  
...  
Keyword(s):  
Map Kinase ◽  
Signaling Pathways ◽  
Acinar Cell ◽  
Acinar Cells ◽  
Dominant Negative ◽  
Pancreatic Acinar Cells ◽  
Kinase Signaling ◽  
Erk Activation ◽  
Smad Proteins ◽  
Mitogen Activated Protein

Transforming growth factor-β (TGF-β) inhibits pancreatic acinar cell growth. In many cell types, TGF-β mediates its growth inhibitory effects by activation of Smad proteins. Recently, it has been reported that Smad proteins may interact with the mitogen-activated protein (MAP) kinase signaling pathways. In this study, we report on the interactions between the TGF-β and MAP kinase signaling pathways in isolated rat pancreatic acinar cells. TGF-β activated the MAP kinases extracellular signal-related kinases (ERKs) and p38 in pancreatic acinar cells, but had no effect on c- junNH2-terminal kinase activity. Activation of MAP kinase by TGF-β was maximal 4 h after treatment. The ability of TGF-β to activate ERKs was concentration dependent and dependent on protein synthesis. TGF-β's stimulation of ERK activation was blocked by PD-98059, an inhibitor of MAP kinase kinase 1, and by adenoviral transfer of dominant negative RasN17. Furthermore, adenoviral-mediated expression of dominant negative Smad4 blocked the ability of TGF-β to activate acinar cell MAP kinase, demonstrating that this activation is downstream of Smads. The biological relevance of ERK activation by TGF-β was indicated by demonstrating that inhibition of ERK signaling by PD-98059 blocked the ability of TGF-β to activate the transcription factor activator protein-1. These studies provide new insight into the signaling mechanisms by which TGF-β mediates biological actions in pancreatic acinar cells.

scholarly journals MECOM permits pancreatic acinar cell dedifferentiation avoiding cell death under stress conditions

2021 ◽  
Author(s):  
Elyne Backx ◽  
Elke Wauters ◽  
Jonathan Baldan ◽  
Mathias Van Bulck ◽  
Ellis Michiels ◽  
...  
Keyword(s):  
Cell Death ◽  
Transcription Factor ◽  
Chronic Pancreatitis ◽  
Acinar Cell ◽  
Acinar Cells ◽  
Pancreatic Acinar Cell ◽  
Stress Conditions ◽  
Cell Dedifferentiation ◽  
Duct Cells ◽  
Pancreatic Exocrine

AbstractMaintenance of the pancreatic acinar cell phenotype suppresses tumor formation. Hence, repetitive acute or chronic pancreatitis, stress conditions in which the acinar cells dedifferentiate, predispose for cancer formation in the pancreas. Dedifferentiated acinar cells acquire a large panel of duct cell-specific markers. However, it remains unclear to what extent dedifferentiated acini differ from native duct cells and which genes are uniquely regulating acinar cell dedifferentiation. Moreover, most studies have been performed on mice since the availability of human cells is scarce. Here, we applied a non-genetic lineage tracing method of human pancreatic exocrine acinar and duct cells that allowed cell-type-specific gene expression profiling by RNA sequencing. Subsequent to this discovery analysis, one transcription factor that was unique for dedifferentiated acinar cells was functionally characterized. RNA sequencing analysis showed that human dedifferentiated acinar cells expressed genes in “Pathways of cancer” with a prominence of MECOM (EVI-1), a transcription factor that was not expressed by duct cells. During mouse embryonic development, pre-acinar cells also transiently expressed MECOM and in the adult mouse pancreas, MECOM was re-expressed when mice were subjected to acute and chronic pancreatitis, conditions in which acinar cells dedifferentiate. In human cells and in mice, MECOM expression correlated with and was directly regulated by SOX9. Mouse acinar cells that, by genetic manipulation, lose the ability to upregulate MECOM showed impaired cell adhesion, more prominent acinar cell death, and suppressed acinar cell dedifferentiation by limited ERK signaling. In conclusion, we transcriptionally profiled the two major human pancreatic exocrine cell types, acinar and duct cells, during experimental stress conditions. We provide insights that in dedifferentiated acinar cells, cancer pathways are upregulated in which MECOM is a critical regulator that suppresses acinar cell death by permitting cellular dedifferentiation.

Stimulation of pancreatic acinar cell growth by CCK, epidermal growth factor, and insulin in vitro

1986 ◽  
Vol 251 (4) ◽  
pp. G487-G494 ◽  
Author(s):  
C. D. Logsdon
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Dna Synthesis ◽  
Acinar Cell ◽  
Acinar Cells ◽  
Pancreatic Acinar Cell ◽  
Pancreatic Acinar Cells ◽  
Intracellular Camp ◽  
Ionophore A23187 ◽  
Epidermal Growth

Effects of regulatory molecules on growth of mouse pancreatic acinar cells in culture were examined. The cholecystokinin (CCK) analogue caerulein and cholecystokinin octapeptide (CCK-8) each led to threefold increases in incorporation of [3H]thymidine into DNA. Gastrin, which interacts weakly with the CCK receptor, stimulated DNA synthesis, but only at much higher concentrations. In contrast, other secretagogues that utilize Ca2+ as an intracellular messenger, including carbachol, bombesin, substance P, and the ionophore A23187, did not induce trophic responses. Factors that affect intracellular cAMP concentration, such as secretin, somatostatin, VIP, DBcAMP, and forskolin, did not increase DNA synthesis in cultured pancreatic cells. Insulin and epidermal growth factor induced two- and threefold increases in [3H] thymidine incorporation into DNA, respectively. The effects of insulin were mediated via insulin-like growth factor I receptors. Steroid hormones had little effect on pancreatic acinar cell DNA synthesis. The stimulatory effects of CCK, insulin, and EGF were additive. The combination of caerulein, EGF, and insulin in a hormonally defined medium led to a tenfold increase in the incorporation of [3H]thymidine into DNA. These data indicate that CCK, EGF, and insulin directly increase DNA synthesis in pancreatic acinar cells.

scholarly journals CaMK II Inhibition Attenuates ROS Dependent Necroptosis in Acinar Cells and Protects against Acute Pancreatitis in Mice

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Qingtian Zhu ◽  
Lu Hao ◽  
Qinhao Shen ◽  
Jiajia Pan ◽  
Weili Liu ◽  
...  
Keyword(s):  
Acute Pancreatitis ◽  
Protective Effect ◽  
Acinar Cell ◽  
Acinar Cells ◽  
Serum Levels ◽  
Pancreatic Acinar Cell ◽  
Pancreatic Duct Ligation ◽  
Duct Ligation ◽  
Prevention And Treatment

As a calcium-regulated protein, CaMK II is closely related to cell death, and it participates in the development of pathological processes such as reperfusion injury, myocardial infarction, and oligodendrocyte death. The function of CaMK II activation in acute pancreatitis (AP) remains unclear. In our study, we confirmed that the expression of p-CaMK II was increased significantly and consistently in injured pancreatic tissues after caerulein-induced AP. Then, we found that KN93, an inhibitor of CaMK II, could mitigate the histopathological manifestations in pancreatic tissues, reduce serum levels of enzymology, and decrease oxidative stress products. Accordingly, we elucidated the effect of KN93 in vitro and found that KN93 had a protective effect on the pancreatic acinar cell necroptosis pathway by inhibiting the production of ROS and decreasing the expression of RIP3 and p-MLKL. In addition, we identified the protective effect of KN93 on AP through another mouse model induced by pancreatic duct ligation (PDL). Together, these data demonstrated that CaMK II participates in the development of AP and that inhibiting CaMK II activation could protect against AP by reducing acinar cell necroptosis, which may provide a new idea target for the prevention and treatment of AP in the clinic.

TNF-α Suppresses Autophagic Flux in Acinar Cells in IgG4-Related Sialadenitis

2019 ◽  
Vol 98 (12) ◽  
pp. 1386-1396 ◽  
Author(s):  
X. Hong ◽  
S.N. Min ◽  
Y.Y. Zhang ◽  
Y.T. Lin ◽  
F. Wang ◽  
...  
Keyword(s):  
Acinar Cell ◽  
Cell Injury ◽  
Ex Vivo ◽  
Secretory Granules ◽  
Acinar Cells ◽  
Autophagic Flux ◽  
C6 Cells ◽  
Tnf Α ◽  
Α Level

IgG4-related sialadenitis (IgG4-RS) is a newly recognized immune-mediated systemic fibroinflammatory disease that affects salivary glands and leads to hyposalivation. Tumor necrosis factor–α (TNF-α) is a critical proinflammatory cytokine involved in several salivary gland disorders, but its role and mechanism regarding acinar cell injury in IgG4-RS are unknown. Here, we found that TNF-α level was significantly increased in serum and submandibular gland (SMG) of patients and that serum TNF-α level was negatively correlated with saliva flow rate. Ultrastructural observations of IgG4-RS SMGs revealed accumulation of large autophagic vacuoles, as well as dense fibrous bundles, decreased secretory granules, widened intercellular spaces, swollen mitochondria, and expanded endoplasmic reticulum. Expression levels of LC3 and p62 were both increased in patients’ SMGs. TNF-α treatment led to elevated levels of LC3II and p62 in both SMG-C6 cells and cultured human SMG tissues but did not further increase their levels when combined with bafilomycin A1 treatment. Moreover, transfection of Ad-mCherry-GFP-LC3B in SMG-C6 cells confirmed the suppression of autophagic flux after TNF-α treatment. Immunofluorescence imaging revealed that costaining of LC3 and the lysosomal marker LAMP2 was significantly decreased in patients, TNF-α–treated SMG-C6 cells, and cultured human SMGs, indicating a reduction in autophagosome-lysosome fusion. Furthermore, the ratio of pro/mature cathepsin D was elevated in vivo, ex vivo, and in vitro. TNF-α also appeared to induce abnormal acidification of lysosomes in acinar cells, as assessed by lysosomal pH and LysoTracker DND-26 fluorescence intensity. In addition, TNF-α treatment induced transcription factor EB (TFEB) redistribution in SMG-C6 cells, which was consistent with the changes observed in IgG4-RS patients. TNF-α increased the phosphorylation of extracellular signal–regulated kinase (ERK) 1/2, and inhibition of ERK1/2 by U0126 reversed TNF-α–induced TFEB redistribution, lysosomal dysfunction, and autophagic flux suppression. These findings suggest that TNF-α is a key cytokine related to acinar cell injury in IgG4-RS through ERK1/2-mediated autophagic flux suppression.

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