PSD-95 protects the pancreas against pathological damage through p38 MAPK signaling pathway in acute pancreatitis

Acute pancreatitis is one of the leading causes of gastrointestinal disorder-related hospitalizations, yet its pathogenesis remains to be fully elucidated. Postsynaptic density protein-95 (PSD-95) is closely associated with tissue inflammation and injury. We aimed to investigate the expression of PSD-95 in pancreatic acinar cells, and its function in regulating the inflammatory response and pancreatic pathological damage in acute pancreatitis. A mouse model of edematous acute pancreatitis was induced with caerulein and lipopolysaccharide in C57BL/6 mice. Tat-N-dimer was injected to inhibit the PSD-95 activity separately, or simultaneously with SB203580, inhibitor of p38 MAPK phosphorylation. Rat pancreatic acinar cells AR42J were cultured with 1 μM caerulein to build a cell model of acute pancreatitis. PSD-95-knockdown and negative control cell lines were constructed by lentiviral transfection of AR42J cells. Paraffin-embedded pancreatic tissue samples were processed for routine HE staining to evaluate the pathological changes of human and mouse pancreatic tissues. Serum amylase and inflammatory cytokine levels were detected with specific ELISA kits. Immunofluorescence, immunohistochemical, Western-blot, and qRT-PCR were used to detect the expression levels of PSD-95, p38, and phosphorylated p38. Our findings showed that PSD-95 is expressed in the pancreatic tissues of humans, C57BL/6 mice, and AR42J cells, primarily in the cytoplasm. PSD-95 expression increased at 2 h, reaching the peak at 6 h in mice and 12 h in AR42J cells. IL-6, IL-8, and TNF-α increased within 2 h of disease induction. The pancreatic histopathologic score was greater in the PSD-95 inhibition group compared with the control ( P < 0.05), while it was lesser when phosphorylation of p38 MAPK was inhibited compared with the PSD-95 inhibition group ( P < 0.05). Moreover, phosphorylation of p38 MAPK increased statistically after PSD-95 knocked-down. In conclusion, PSD-95 effectively influences the pathological damage of the pancreas in acute pancreatitis by affecting the phosphorylation of p38 MAPK.

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Saikosaponin D Attenuates Pancreatic Injury Through Suppressing the Apoptosis of Acinar Cell via Modulation of the MAPK Signaling Pathway

Frontiers in Pharmacology ◽

10.3389/fphar.2021.735079 ◽

2021 ◽

Vol 12 ◽

Author(s):

Caixia Li ◽

Lihua Cui ◽

Lanqiu Zhang ◽

Lei Yang ◽

Yuzhen Zhuo ◽

...

Keyword(s):

P38 Mapk ◽

Mapk Pathway ◽

Acinar Cells ◽

Pancreatic Injury ◽

Mapk Signaling ◽

Pancreatic Stellate Cells ◽

Pancreatic Acinar Cells ◽

Drug Induced ◽

Chinese Medicinal Herb ◽

Ar42j Cells

Chronic pancreatitis (CP) is a progressive fibro-inflammatory syndrome. The damage of acinar cells is the main cause of inflammation and the activation of pancreatic stellate cells (PSCs), which can thereby possibly further aggravate the apoptosis of more acinar cells. Saikosaponind (SSd), a major active ingredient derived from Chinese medicinal herb bupleurum falcatum, which exerted multiple pharmacological effects. However, it is not clear whether SSd protects pancreatic injury of CP via regulating the apoptosis of pancreatic acinar cells. This study systematically investigated the effect of SSd on pancreatic injury of CP in vivo and in vitro. The results revealed that SSd attenuate pancreatic damage, decrease the apoptosis and suppress the phosphorylation level of MAPK family proteins (JNK1/2, ERK1/2, and p38 MAPK) significantly in the pancreas of CP rats. In addition, SSd markedly reduced the apoptosis and inflammation of pancreatic acinar AR42J cells induced by cerulein, a drug induced CP, or Conditioned Medium from PSCs (PSCs-CM) or the combination of PSCs-CM and cerulein. Moreover, SSd significantly inhibited the activated phosphorylation of JNK1/2, ERK1/2, and p38 MAPK induced by cerulein or the combination of PSCs-CM and cerulein in AR42J cells. Furthermore, SSd treatment markedly decreased the protein levels of p-JNK and p-p38 MAPK caused by PSCs-CM alone. In conclusion, SSd ameliorated pancreatic injury, suppressed AR42J inflammation and apoptosis induced by cerulein, interrupted the effect of PSCs-CM on AR42J cells inflammation and apoptosis, possibly through MAPK pathway.

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α-Lipoic Acid Inhibits IL-6 Expression by Upregulating PPAR-γ-Mediated Expression of Antioxidants in Cerulein/Resistin-Stimulated Pancreatic Acinar Cells

Current Developments in Nutrition ◽

10.1093/cdn/nzab061_017 ◽

2021 ◽

Vol 5 (Supplement_2) ◽

pp. 1133-1133

Author(s):

Yujin Lee ◽

Joo Weon Lim ◽

Hyeyoung Kim

Keyword(s):

Acute Pancreatitis ◽

Mrna Expression ◽

Lipoic Acid ◽

Acinar Cells ◽

Pancreatic Acinar Cells ◽

Pcr Analysis ◽

Heme Oxygenase 1 ◽

Ros Production ◽

Ar42j Cells ◽

Ppar Γ

Abstract Objectives Oxidative stress is regarded as a major pathogenic factor in acute pancreatitis. Obesity is thought to be a negative prognostic factor in acute pancreatitis. Levels of serum resistin, an adipocytokine secreted by fat tissues, increase with obesity. Recent study showed that resistin aggravates the expression of inflammatory cytokines such as interleukine-6 (IL-6) and production of reactive oxygen species (ROS) in pancreatic acinar cells stimulated with cerulein, a cholecystokinin analogue, as an in vitro acute pancreatitis model. Peroxisome proliferator-activated receptor (PPAR)-γ increases expression of antioxidant enzymes such as catalase and heme oxygenase-1 (HO-1). α-Lipoic acid is a powerful antioxidant and anti-inflammatory nutrient. The present study was purposed to investigate whether α-lipoic acid inhibits IL-6 expression in resistin/cerulein-stimulated pancreatic acinar cells and to determine whether it reduces ROS in AR42J cells by upregulating PPAR-γ-mediated expression of HO-1 and catalase in pancreatic acinar cells. Methods Rat pancreatic acinar cell line, AR42J cells, were stimulated with resistin (2 ng/ml) and cerulean (10−8 M), in the presence or absence of α-lipoic acid. mRNA expression of IL-6 was determined by real-time PCR analysis. ROS levels were measured using DCF-DA fluorescence. Expression of PPAR-γ, HO-1, and catalase were determined by Western blotting. Results α-Lipoic acid significantly decreased IL-6 mRNA expression and ROS production in resistin/cerulein-stimulated AR42J cells. α-Lipoic acid also increased expression of PPAR-γ, HO-1 and catalase. Inhibitory effect of α-lipoic acid on resistin/cerulein–induced IL-6 expression was suppressed by addition of a specific PPAR-γ inhibitor GW9662. GW9662 reversed the effect of α-lipoic acid on expression of HO-1 and catalase in AR42J cells. Conclusions α-Lipoic acid suppresses cerulein/resistin-induced IL-6 expression and ROS production through PPAR-γ-mediated expression of HO-1 and catalase in pancreatic acinar cells. Funding Sources This study was supported by a Brain Korea 21 FOUR Project, Yonsei University, Seoul, Republic of Korea.

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Docosahexaenoic Acid Induces Expression of NAD(P)H: Quinone Oxidoreductase and Heme Oxygenase-1 through Activation of Nrf2 in Cerulein-Stimulated Pancreatic Acinar Cells

Antioxidants ◽

10.3390/antiox9111084 ◽

2020 ◽

Vol 9 (11) ◽

pp. 1084

Author(s):

Yu Jin Ahn ◽

Joo Weon Lim ◽

Hyeyoung Kim

Keyword(s):

Oxidative Stress ◽

Acute Pancreatitis ◽

Docosahexaenoic Acid ◽

Heme Oxygenase ◽

Acinar Cells ◽

Pancreatic Acinar Cells ◽

Heme Oxygenase 1 ◽

Omega 3 ◽

Quinone Oxidoreductase ◽

Ar42j Cells

Oxidative stress is a major risk factor for acute pancreatitis. Reactive oxygen species (ROS) mediate expression of inflammatory cytokines such as interleukin-6 (IL-6) which reflects the severity of acute pancreatitis. The nuclear factor erythroid-2-related factor 2 (Nrf2) pathway is activated to induce the expression of antioxidant enzymes such as NAD(P)H: quinone oxidoreductase 1 (NQO1) and heme oxygenase-1 (HO-1) as a cytoprotective response to oxidative stress. In addition, binding of Kelch-like ECH-associated protein 1 (Keap1) to Nrf2 promotes degradation of Nrf2. Docosahexaenoic acid (DHA)—an omega-3 fatty acid—exerts anti-inflammatory and antioxidant effects. Oxidized omega-3 fatty acids react with Keap1 to induce Nrf2-regulated gene expression. In this study, we investigated whether DHA reduces ROS levels and inhibits IL-6 expression via Nrf2 signaling in pancreatic acinar (AR42J) cells stimulated with cerulein, as an in vitro model of acute pancreatitis. The cells were pretreated with or without DHA for 1 h and treated with cerulein (10−8 M) for 1 (ROS levels, protein levels of NQO1, HO-1, pNrf2, Nrf2, and Keap1), 6 (IL-6 mRNA expression), and 24 h (IL-6 protein level in the medium). Our results showed that DHA upregulates the expression of NQO1 and HO-1 in cerulein-stimulated AR42J cells by promoting phosphorylation and nuclear translocation of Nrf2. DHA increased interaction between Keap1 and Nrf2 in AR42J cells, which may increase Nrf2 activity by inhibiting Keap1-mediated sequestration of Nrf2. In addition, DHA-induced expression of NQO1 and HO-1 is related to reduction of ROS and IL-6 levels in cerulein-stimulated AR42J cells. In conclusion, DHA inhibits ROS-mediated IL-6 expression by upregulating Nrf2-mediated expression of NQO1 and HO-1 in cerulein-stimulated pancreatic acinar cells. DHA may exert positive modulatory effects on acute pancreatitis by inhibiting oxidative stress and inflammatory cytokine production by activating Nrf2 signaling in pancreatic acinar cells.

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Astaxanthin Inhibits Interleukin-6 Expression in Cerulein/Resistin-Stimulated Pancreatic Acinar Cells

Mediators of Inflammation ◽

10.1155/2021/5587297 ◽

2021 ◽

Vol 2021 ◽

pp. 1-14

Author(s):

Min Seung Kwak ◽

Joo Weon Lim ◽

Hyeyoung Kim

Keyword(s):

Acute Pancreatitis ◽

Nadph Oxidase ◽

Interleukin 6 ◽

Acinar Cells ◽

Pancreatic Acinar Cells ◽

Dependent Manner ◽

Ros Production ◽

Ar42j Cells ◽

Proinflammatory Mediators ◽

Nadph Oxidase 1

Acute pancreatitis is a common clinical condition with increasing the proinflammatory mediators, including interleukin-6 (IL-6). Obesity is a negative prognostic factor in acute pancreatitis. Obese patients with acute pancreatitis have a higher systemic inflammatory response rate. Levels of serum resistin, an adipocytokine secreted by fat tissues, increase with obesity. Cerulein, a cholecystokinin analog, induces calcium (Ca2+) overload, oxidative stress, and IL-6 expression in pancreatic acinar cells, which are hallmarks of acute pancreatitis. A recent study showed that resistin aggravates the expression of inflammatory cytokines in cerulein-stimulated pancreatic acinar cells. We aimed to investigate whether resistin amplifies cerulein-induced IL-6 expression and whether astaxanthin (ASX), an antioxidant carotenoid with anti-inflammatory properties, inhibits ceruelin/resistin-induced IL-6 expression in pancreatic acinar AR42J cells. We found that resistin enhanced intracellular Ca2+ levels, NADPH oxidase activity, intracellular reactive oxygen species (ROS) production, NF-κB activity, and IL-6 expression in cerulein-stimulated AR42J cells, which were inhibited by ASX in a dose-dependent manner. The calcium chelator BAPTA-AM inhibited cerulein/resistin-induced NADPH oxidase activation and ROS production. Antioxidant N-acetyl cysteine (NAC) and ML171, a specific NADPH oxidase 1 inhibitor, suppressed cerulein/resistin-induced ROS production, NF-κB activation, and IL-6 expression. In conclusion, ASX inhibits IL-6 expression, by reducing Ca2+ overload, NADPH oxidase-mediated ROS production, and NF-κB activity in cerulein/resistin-stimulated pancreatic acinar cells. Consumption of ASX-rich foods could be beneficial for preventing or delaying the incidence of obesity-associated acute pancreatitis.

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Absence of the neutrophil serine protease cathepsin G decreases neutrophil granulocyte infiltration but does not change the severity of acute pancreatitis

Scientific Reports ◽

10.1038/s41598-019-53293-0 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 1

Author(s):

Ali A. Aghdassi ◽

Daniel S. John ◽

Matthias Sendler ◽

Christian Storck ◽

Cindy van den Brandt ◽

...

Keyword(s):

Acute Pancreatitis ◽

Serine Protease ◽

Acinar Cells ◽

Neutrophil Infiltration ◽

Cathepsin G ◽

Pancreatic Acinar Cells ◽

Neutrophil Granulocyte ◽

Zymogen Activation ◽

Trypsinogen Activation ◽

Extracellular Matrix Components

AbstractAcute pancreatitis is characterized by an early intracellular protease activation and invasion of leukocytes into the pancreas. Cathepsins constitute a large group of lysosomal enzymes, that have been shown to modulate trypsinogen activation and neutrophil infiltration. Cathepsin G (CTSG) is a neutrophil serine protease of the chymotrypsin C family known to degrade extracellular matrix components and to have regulatory functions in inflammatory disorders. The aim of this study was to investigate the role of CTSG in pancreatitis. Isolated acinar cells were exposed to recombinant CTSG and supramaximal cholezystokinin stimulation. In CTSG−/− mice and corresponding controls acute experimental pancreatitis was induced by serial caerulein injections. Severity was assessed by histology, serum enzyme levels and zymogen activation. Neutrophil infiltration was quantified by chloro-acetate ersterase staining and myeloperoxidase measurement. CTSG was expessed in inflammatory cells but not in pancreatic acinar cells. CTSG had no effect on intra-acinar-cell trypsinogen activation. In CTSG−/− mice a transient decrease of neutrophil infiltration into the pancreas and lungs was found during acute pancreatitis while the disease severity remained largely unchanged. CTSG is involved in pancreatic neutrophil infiltration during pancreatitis, albeit to a lesser degree than the related neutrophil (PMN) elastase. Its absence therefore leaves pancreatitis severity essentially unaffected.

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Nitric oxide protects the ultrastructure of pancreatic acinar cells in the course of caerulein-induced acute pancreatitis

International Journal of Experimental Pathology ◽

10.1046/j.1365-2613.1999.00126.x ◽

2001 ◽

Vol 80 (6) ◽

pp. 317-324 ◽

Cited By ~ 16

Author(s):

Anna Andrzejewska ◽

Grazyna Jurkowska

Keyword(s):

Nitric Oxide ◽

Acute Pancreatitis ◽

Acinar Cells ◽

Pancreatic Acinar Cells

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TRANSCRIPTION FACTOR PROFILING OF PANCREATIC ACINAR CELLS FOLLOWING TNF-α INDUCTION OF ACUTE PANCREATITIS.

Shock ◽

10.1097/00024382-200306001-00057 ◽

2003 ◽

Vol 19 (Supplement) ◽

pp. 20

Author(s):

L. Vona-Davis ◽

K. Magabo ◽

B. Jackson ◽

T. Evans ◽

D. Riggs ◽

...

Keyword(s):

Acute Pancreatitis ◽

Transcription Factor ◽

Acinar Cells ◽

Pancreatic Acinar Cells ◽

Tnf Α

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Acinar Akt1 in pancreatic acinar cells supports proliferation and limits acinar-to-ductal metaplasia formation upon induction of acute pancreatitis

Pancreatology ◽

10.1016/j.pan.2019.05.268 ◽

2019 ◽

Vol 19 ◽

pp. S101

Author(s):

Rong Chen ◽

Ermanno Malagola ◽

Maren Dietrich ◽

Richard Zuellig ◽

Marta Bombardo ◽

...

Keyword(s):

Acute Pancreatitis ◽

Acinar Cells ◽

Pancreatic Acinar Cells ◽

Acinar To Ductal Metaplasia

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MiR-155 aggravates impaired autophagy of pancreatic acinar cells through targeting Rictor

Acta Biochimica et Biophysica Sinica ◽

10.1093/abbs/gmz152 ◽

2020 ◽

Vol 52 (2) ◽

pp. 192-199 ◽

Cited By ~ 1

Author(s):

Xueming Zhang ◽

Jiangtao Chu ◽

Haijun Sun ◽

Dali Zhao ◽

Biao Ma ◽

...

Keyword(s):

Acinar Cells ◽

Immunofluorescence Assay ◽

Pancreatic Acinar Cell ◽

Pancreatic Acinar Cells ◽

Luciferase Reporter ◽

Cellular Model ◽

Protein Levels ◽

Ar42j Cells ◽

Direct Target ◽

Dual Luciferase Reporter Assay

Abstract The aim of this study was to investigate the role and mechanism of miR-155 in regulating autophagy in a caerulein-induced acute pancreatitis (AP) cellular model. GFP-LC3 immunofluorescence assay was performed to detect autophagy vesicle formation in pancreatic acinar cell line AR42J. AR42J cells were transfected with miR-155 mimic, inhibitor, and corresponding controls to explore the effect of miR-155 on autophagy. The protein levels of LC3-I, LC3-II, Beclin-1, and p62 were analyzed by western blot analysis. Dual-luciferase reporter assay was performed to verify the interaction between miR-155 and Rictor (RPTOR independent companion of MTOR complex 2). The results showed that caerulein treatment induced impaired autophagy as evidenced by an increase in the accumulation of p62 together with LC3-II in AR42J cells, accompanied by miR-155 upregulation. Furthermore, miR-155 overexpression aggravated, whereas miR-155 silencing reduced the caerulein-induced impairment of autophagy. Mechanistically, Rictor was confirmed to be a direct target of miR-155, which could rescue the miR-155 overexpression-mediated aggravation of impaired autophagy. Collectively, these findings indicate that miR-155 aggravates impaired autophagy in caerulein-treated pancreatic acinar cells by targeting Rictor.

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