scholarly journals 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 ◽  
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.

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

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.

scholarly journals Effect of Docosahexaenoic Acid on Ca2+ Signaling Pathways in Cerulein-Treated Pancreatic Acinar Cells, Determined by RNA-Sequencing Analysis

Nutrients ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1445
Author(s):  
Kim ◽  
Park ◽  
Lim ◽  
Kim
Keyword(s):  
Acute Pancreatitis ◽  
Docosahexaenoic Acid ◽  
Signaling Pathways ◽  
Rna Sequencing ◽  
Acinar Cells ◽  
Transcriptional Activator ◽  
Pancreatic Acinar Cells ◽  
Sequencing Analysis ◽  
Omega 3 ◽  
Activator Complex

Intracellular Ca2+ homeostasis is commonly disrupted in acute pancreatitis. Sustained Ca2+ release from internal stores in pancreatic acinar cells (PACs), mediated by inositol triphosphate receptor (IP3R) and the ryanodine receptor (RyR), plays a key role in the initiation and propagation of acute pancreatitis. Pancreatitis induced by cerulein, an analogue of cholecystokinin, causes premature activation of digestive enzymes and enhanced accumulation of cytokines and Ca2+ in the pancreas and, as such, it is a good model of acute pancreatitis. High concentrations of the omega-3 fatty acid docosahexaenoic acid (DHA) inhibit inflammatory signaling pathways and cytokine expression in PACs treated with cerulein. In the present study, we determined the effect of DHA on key regulators of Ca2+ signaling in cerulein-treated pancreatic acinar AR42 J cells. The results of RNA-Sequencing (RNA-Seq) analysis showed that cerulein up-regulates the expression of IP3R1 and RyR2 genes, and that pretreatment with DHA blocks these effects. The results of real-time PCR confirmed that DHA inhibits cerulein-induced IP3R1 and RyR2 gene expression, and demonstrated that DHA pre-treatment decreases the expression of the Relb gene, which encodes a component of the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) transcriptional activator complex, and the c-fos gene, which encodes a component of activator protein-1 (AP-1) transcriptional activator complex. Taken together, DHA inhibits mRNA expression of IP3R1, RyR2, Relb, and c-fos, which is related to Ca2+ network in cerulein-stimulated PACs.

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

2021 ◽  
pp. 153537022110032
Author(s):  
Yinan Guo ◽  
Weikai Hu ◽  
Xueyan Wang ◽  
Chunyun Li ◽  
Tianyu Cui ◽  
...  
Keyword(s):  
Acute Pancreatitis ◽  
P38 Mapk ◽  
Cell Model ◽  
Control Cell ◽  
Acinar Cells ◽  
Mapk Signaling ◽  
Pancreatic Tissue ◽  
Pancreatic Acinar Cells ◽  
Ar42j Cells ◽  
Inhibition Group

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.

scholarly journals The role of intracellular Ca2+ signaling in the exocrine pancreatic damage during acute pancreatitis

2020 ◽  
Author(s):  
Júlia Fanczal
Keyword(s):  
Oxidative Stress ◽  
Acute Pancreatitis ◽  
Bile Acid ◽  
Bile Acids ◽  
Digestive Enzyme ◽  
Acinar Cells ◽  
Mitochondrial Damage ◽  
Enzyme Activation ◽  
Pancreatic Acinar Cells ◽  
Biliary Pancreatitis

Acute biliary pancreatitis poses a significant clinical challenge as currently no specific pharmaceutical treatment exists. Disturbed intracellular Ca2+ signalling caused by bile acids is a hallmark of the disease, which induces increased reactive oxygen species (ROS) production, mitochondrial damage, intra-acinar digestive enzyme activation and cell death. Because of this mechanism of action, prevention of toxic cellular Ca2+ overload is a promising therapeutic target. Transient receptor potential melastatin 2 (TRPM2) is a non-selective cation channel that has recently emerged as an important contributor to oxidative-stress-induced cellular Ca2+ overload across different diseases. However, the expression and possible functions of TRPM2 in the exocrine pancreas remain unknown. Here we found that TRPM2 is expressed in the plasma membrane of mouse pancreatic acinar, which can be activated by increased oxidative stress induced by H2O2 treatment. TRPM2 activity was found to contribute to bile acid-induced extracellular Ca2+ influx in acinar cells. The generation of intracellular ROS in response to bile acids was remarkably higher in pancreatic acinar cells. This activity promoted acinar cell necrosis in vitro independently from mitochondrial damage or mitochondrial fragmentation. In addition, bile-acid-induced experimental pancreatitis was less severe in TRPM2 knockout mice, whereas the lack of TRPM2 had no protective effect in cerulein-induced acute pancreatitis. Our results suggest that the inhibition of TRPM2 may be a potential treatment option for biliary pancreatitis.

scholarly journals Expression of stress proteins heme oxygenase-1 and -2 in acute pancreatitis and pancreatic islet βTC3 and acinar AR42J cells

FEBS Letters ◽  
1997 ◽  
Vol 405 (2) ◽  
pp. 219-223 ◽  
Author(s):  
Hideyo Sato ◽  
Richard C.M. Siow ◽  
Simon Bartlett ◽  
Shigeru Taketani ◽  
Tetsuro Ishii ◽  
...  
Keyword(s):  
Acute Pancreatitis ◽  
Pancreatic Islet ◽  
Heme Oxygenase ◽  
Stress Proteins ◽  
Heme Oxygenase 1 ◽  
Ar42j Cells

scholarly journals Protective effects of baicalin on caerulein-induced AR42J pancreatic acinar cells by attenuating oxidative stress through miR-136-5p downregulation

2021 ◽  
Vol 104 (2) ◽  
pp. 003685042110261
Author(s):  
Zhu-fen Zhao ◽  
Ye Zhang ◽  
Yang Sun ◽  
Chun-hai Zhang ◽  
Ming-wei Liu
Keyword(s):  
Oxidative Stress ◽  
Acute Pancreatitis ◽  
Relative Survival ◽  
Acinar Cells ◽  
Pancreatic Acinar Cells ◽  
Amylase Level ◽  
Sod1 Gene ◽  
Expression Levels ◽  
Thiazolyl Blue Tetrazolium Bromide ◽  
Gene And Protein Expression

Baicalin, the main active component of Scutellaria baicalensis, has antioxidant and anti-apoptotic effects and is used to treat acute pancreatitis; however, its specific mechanism is unclear. This study aims to determine the protective effect and underlying mechanism of baicalin on AR42J pancreatic acinar cell injury. AR42J acinar cells (caerulein, 10 nmol/L) were induced in vitro to establish a cell model for acute pancreatitis. Cell relative survival was measured by thiazolyl blue tetrazolium bromide, and cell apoptosis and death were examined by flow cytometry. The expression levels of superoxide dismutase1 (SOD1), Bax, survivin, Bcl-2, caspase-3, and caspase-7 proteins were analyzed by Western blot, and those of SOD1 mRNA and miR-136-5p were determined by RT-PCR. The activities of GSH, SOD1, ROS, and MDA were also investigated. Compared with those of the caerulein group, the relative survival rate and activity of AR42J pancreatic acinar cells with different baicalin concentrations were significantly increased ( p < 0.05), and the supernatant amylase level was markedly decreased ( p < 0.05). In addition, the ROS and MDA activities and mir-136-5p expression were significantly decreased, and the GSH activities and SOD1 gene and protein expression levels were markedly increased ( p < 0.05). These results suggest that baicalin reduced the caerulein-induced death of AR42J acinar cells and alleviated the caerulein-induced injury in pancreatic acinar cells by inhibiting oxidative stress. The mechanism may be related to the decreased expression of Mir-136-5p and the increased expression of SOD1 gene and protein.

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