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

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.

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

10.1101/2020.08.21.260539 ◽

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.

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Anti-inflammatory and Anti-necrotic Effect of Lectins from Canavalia ensiformis and Canavalia brasiliensis in Experimental Acute Pancreatitis

10.21203/rs.3.rs-172690/v1 ◽

2021 ◽

Author(s):

Samara Rodrigues Bonfim Damasceno Oliveira ◽

Álvaro Xavier Franco ◽

Marielle Pires Quaresma ◽

Cecília Mendes Morais de Carvalho ◽

Fabrícia da Cunha Jácome Marques ◽

...

Keyword(s):

Acute Pancreatitis ◽

Cell Death ◽

Acinar Cell ◽

Acinar Cells ◽

Pancreatic Acinar Cell ◽

Cell Necrosis ◽

Experimental Acute Pancreatitis ◽

Canavalia Ensiformis ◽

Acinar Cell Necrosis ◽

Canavalia Brasiliensis

Abstract Lectins isolated from Canavalia ensiformis (ConA) and Canavalia brasiliensis (ConBr) are promising molecules to modulate cell death. Acute pancreatitis, characterized by acinar cell necrosis and inflammation, presents significant morbidity and mortality. This study has investigated the effects of ConA and ConBr on experimental acute pancreatitis and pancreatic acinar cell death induced by bile acid. Pancreatitis was induced by retrograde pancreatic ductal injection of 3% sodium taurocholate (Na-TC) in male Swiss mice. ConA or ConBr (0.1, 1 or 10 mg/kg) were intravenously applied to mice 1 h and 12 h after induction. After 24 hours, the severity of pancreatitis was evaluated by serum amylase and lipase, histopathological changes and myeloperoxidase assay. Pancreatic acinar cells were incubated with ConA (200 µg/ml) or ConBr (200 µg/ml) and taurolithocholic acid 3-sulfate (TLCS; 500 µM). Necrosis and changes in mitochondrial membrane potential (ΔѰm) were detected by fluorescence confocal microscopy. Treatment (post-insult) with ConA and ConBr decreased pancreatic damage caused by retrograde injection of Na-TC in mice, reducing pancreatic neutrophil infiltration, edema and necrosis. In addition, ConA and ConBr decreased pancreatic acinar cell necrosis and depolarization of ΔѰm caused by TLCS. The inhibition of necrosis was prevented by the lectin domain blockade; molecular docking analysis showed strong interaction of ConA and ConBr crystal structures with mannose residues. In conclusion, ConA and ConBr markedly inhibited in vitro and in vivo damage, effects partly dependent on the interaction with mannose residues on acinar cells. These data support the potential application of these proteins for treatment of acute pancreatitis.

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

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.00129.2010 ◽

2012 ◽

Vol 302 (12) ◽

pp. G1381-G1396 ◽

Cited By ~ 13

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.

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Apoptosis versus necrosis in acute pancreatitis

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.00304.2003 ◽

2004 ◽

Vol 286 (2) ◽

pp. G189-G196 ◽

Cited By ~ 118

Author(s):

Madhav Bhatia

Keyword(s):

Acute Pancreatitis ◽

Cell Death ◽

Acinar Cell ◽

Cell Apoptosis ◽

Cell Injury ◽

Experimental Studies ◽

Acinar Cells ◽

Inflammatory Cells ◽

Pancreatic Acinar Cell ◽

Mild Acute Pancreatitis

Acute pancreatitis is a disease of variable severity in which some patients experience mild, self-limited attacks, whereas others manifest a severe, highly morbid, and frequently lethal attack. The events that regulate the severity of acute pancreatitis are, for the most part, unknown. It is generally believed that the earliest events in acute pancreatitis occur within acinar cells and result in acinar cell injury. Other processes, such as recruitment of inflammatory cells and generation of inflammatory mediators, are believed to occur subsequent to acinar cell injury, and these “downstream” events are believed to influence the severity of the disease. Several recently reported studies, however, have suggested that the acinar cell response to injury may, itself, be an important determinant of disease severity. In these studies, mild acute pancreatitis was found to be associated with extensive apoptotic acinar cell death, whereas severe acute pancreatitis was found to involve extensive acinar cell necrosis but very little acinar cell apoptosis. These observations led to the hypothesis that apoptosis could be a favorable response to acinar cells and that interventions that favor induction of apoptotic, as opposed to necrotic, acinar cell death might reduce the severity of an attack of acute pancreatitis. Indeed, in an experimental setting, the induction of pancreatic acinar cell apoptosis protects mice against acute pancreatitis. Little is known about the mechanism of apoptosis in the pancreatic acinar cell, although some early attempts have been made in that direction. Also, clinical relevance of these experimental studies remains to be investigated.

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Autophagy in acinar cells protects from increasing the number of zymogen granules and inducing continuous acinar cell death and chronic pancreatitis

Pancreatology ◽

10.1016/j.pan.2016.06.190 ◽

2016 ◽

Vol 16 (4) ◽

pp. S51

Author(s):

Kiyoshi Iwahashi ◽

Hayato Hikita ◽

Minoru Shigekawa ◽

Kenji Ikezawa ◽

Ryotaro Sakamori ◽

...

Keyword(s):

Cell Death ◽

Chronic Pancreatitis ◽

Acinar Cell ◽

Acinar Cells ◽

Zymogen Granules

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Induction of pancreatic acinar cell proliferation by thyroid hormone

Journal of Endocrinology ◽

10.1677/joe.1.06110 ◽

2005 ◽

Vol 185 (3) ◽

pp. 393-399 ◽

Cited By ~ 30

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.

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Short-term effects of feeding raw soya flour on pancreatic cell turnover in the rat

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.1984.247.6.g667 ◽

1984 ◽

Vol 247 (6) ◽

pp. G667-G673

Author(s):

P. S. Oates ◽

R. G. Morgan

Keyword(s):

Dna Synthesis ◽

Cell Damage ◽

Acinar Cells ◽

Pancreatic Acinar Cell ◽

Soya Flour ◽

Cell Turnover ◽

Tissue Necrosis ◽

Short Term ◽

Pancreatic Cell ◽

Duct Cells

Pancreatic acinar cell turnover was studied after a 48-h fast and in rats fed raw soya flour (RSF) for up to 28 days. Feeding RSF for 2 days resulted in a significant increase in pancreatic weight and RNA content while protein was increased by the 4th day compared with rats fasted for 48 h. RSF also resulted in a significant increase in RNA by the 4th day and weight and protein by the 7th day compared with rats fed heated soya flour (HSF). This pancreatic hypertrophy was maintained for the rest of the study period. Two days after starting RSF, pancreatic DNA synthesis, measured bythe rate of incorporation of [3H]thymidine into pancreatic DNA, had increased sixfold compared with that in animals fedHSF but returned to control values again by the 4th day on the diet. Autoradiography showed that this increase in DNA synthesis occurred in both acinar and duct cells, with turnover in acinar cells preceding that in duct cells. A second moregradual rise in DNA synthesis was seen from the 7th to 28th day. This peak in DNA synthesis was associated with an increased total pancreatic DNA content and occurred predominately in duct cells with a smaller contribution from acinar cells. Histological studies of the pancreas during the 1st wk showed cell damage and tissue necrosis, possibly due to exposure to high levels of cholecystokinin released by RSF. The first peak in DNA synthesis may be a regenerative response to this damage. The second more delayed peak appears to be hyperplasia in response to a trophic stimulus, again possibly mediated by cholecystokinin.

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Mechanism and regulation of folate uptake by pancreatic acinar cells: effect of chronic alcohol consumption

AJP Gastrointestinal and Liver Physiology ◽

10.1152/ajpgi.00068.2010 ◽

2010 ◽

Vol 298 (6) ◽

pp. G985-G993 ◽

Cited By ~ 17

Author(s):

Hamid M. Said ◽

Lisa Mee ◽

V. Thillai Sekar ◽

Balasubramaniem Ashokkumar ◽

Stephen J. Pandol

Keyword(s):

Acinar Cells ◽

Pancreatic Acinar Cell ◽

Pancreatic Acinar Cells ◽

Exocrine Function ◽

Acid Uptake ◽

Human Pancreas ◽

Chronic Alcohol ◽

Transport Inhibitors ◽

Pancreatic Exocrine ◽

One Carbon Metabolism

Folate plays an essential role in one-carbon metabolism, and a relationship exists between methyl group metabolism and pancreatic exocrine function. Little, however, is known about the mechanism(s) and regulation of folate uptake by pancreatic acinar cells and the effect of chronic alcohol use on the process. We addressed these issues using the rat-derived pancreatic acinar cell line AR42J and freshly isolated primary rat pancreatic acinar cells as models. We found [3H]folic acid uptake to be 1) temperature and pH dependent with a higher uptake at acidic than at neutral/alkaline pH; 2) saturable as a function of substrate concentration at both buffer pH 7.4 and 6.0; 3) inhibited by folate structural analogs and by anion transport inhibitors at both buffer pH 7.4 and 6.0; 4) trans-stimulated by unlabeled folate; 5) adaptively regulated by the prevailing extracellular folate level, and 6) inhibited by modulators of the cAMP/PKA-mediated pathway. Both the reduced folate carrier (RFC) and the proton-coupled folate transporter (PCFT) were found to be expressed in AR42J and in primary pancreatic acinar cells, as well as in native human pancreas with expression of RFC being higher than PCFT. Chronic alcohol feeding of rats (4 wk; 36% of calories from ethanol) led to a significant decrease in folate uptake by freshly isolated primary pancreatic acinar cells compared with cells from pair-fed controls; this effect was associated with a parallel decrease in the level of expression of RFC and PCFT. These studies reveal that folate uptake by pancreatic acinar cells is via a regulated carrier-mediated process which may involve RFC and PCFT. In addition, chronic alcohol feeding leads to a marked inhibition in folate uptake by pancreatic acinar cells, an effect that is associated with reduction in level of expression of RFC and PCFT.

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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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