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

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.

Antioxidants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1084
Author(s):  
Yu Jin Ahn ◽  
Joo Weon Lim ◽  
Hyeyoung Kim

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.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Ali A. Aghdassi ◽  
Daniel S. John ◽  
Matthias Sendler ◽  
Christian Storck ◽  
Cindy van den Brandt ◽  
...  

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.


2021 ◽  
Author(s):  
Jiabin Zhao ◽  
Binjiahui Zhao ◽  
Limin Hou

Abstract Background: The study aimed to examine the molecular mechanism and clinical significance of A-kinase interacting protein 1 (AKIP1) in prostate cancer. Methods: The effect of AKIP1 on cell proliferation, migration, invasion, apoptosis and stemness was determined by overexpressing and knocking down AKIP1 in LNCaP and 22Rv1 cells via lentivirus infection. Furthermore, differentially expressed genes (DEGs) by AKIP1 modification were determined using RNA sequencing. Besides, the correlation of AKIP1 with clinicopathological features and prognosis in 130 prostate cancer patients was assessed. Results: AKIP1 expression was increased in VCaP, LNCaP, DU145 cells while similar in 22Rv1 cells compared with RWPE-1 cells. Furthermore, AKIP1 overexpression promoted 22Rv1 and LNCaP cell proliferation, invasion, but inhibited apoptosis; meanwhile, AKIP1 overexpression increased CD133+ cell rate and enhanced spheres formation efficiency in 22Rv1 and LNCaP cells. Reversely, AKIP1 knockdown exhibited the opposite effect in 22Rv1 and LNCaP cells. Further RNA sequencing analysis exhibited that AKIP1-modified DEGs were enriched in the oncogenic signaling pathways related to prostate cancer, such as PI3K-Akt, MEK/ERK, mTOR signaling pathways. The following western blot indicated that AKIP1 overexpression activated while its knockdown blocked PI3K-Akt, MEK/ERK, mTOR signaling pathways in prostate cancer cells. Clinically, AKIP1 was upregulated in the prostate tumor tissues compared with paired adjacent tissues, and its tumor high expression correlated with increased pathological T, pathological N stage and poor prognosis in prostate cancer patients. Conclusion: AKIP1 promotes cell proliferation, invasion, stemness, activates PI3K-Akt, MEK/ERK, mTOR signaling pathways and correlates with worse tumor features and prognosis in prostate cancer.


Shock ◽  
2003 ◽  
Vol 19 (Supplement) ◽  
pp. 20
Author(s):  
L. Vona-Davis ◽  
K. Magabo ◽  
B. Jackson ◽  
T. Evans ◽  
D. Riggs ◽  
...  

Pancreatology ◽  
2019 ◽  
Vol 19 ◽  
pp. S101
Author(s):  
Rong Chen ◽  
Ermanno Malagola ◽  
Maren Dietrich ◽  
Richard Zuellig ◽  
Marta Bombardo ◽  
...  

2015 ◽  
Vol 149 (2) ◽  
pp. 481-492.e7 ◽  
Author(s):  
Li Wen ◽  
Svetlana Voronina ◽  
Muhammad A. Javed ◽  
Muhammad Awais ◽  
Peter Szatmary ◽  
...  

2003 ◽  
Vol 285 (4) ◽  
pp. G726-G734 ◽  
Author(s):  
Claus Schäfer ◽  
Hanna Steffen ◽  
Karen J. Krzykowski ◽  
Burkhard Göke ◽  
Guy E. Groblewski

Ca2+-regulated heat-stable protein of 24 kDa (CRHSP-24) is a serine phosphoprotein originally identified as a physiological substrate for the Ca2+-calmodulin regulated protein phosphatase calcineurin (PP2B). CRHSP-24 is a paralog of the brain-specific mRNA-binding protein PIPPin and was recently shown to interact with the STYX/dead phosphatase protein in developing spermatids (Wishart MJ and Dixon JE. Proc Natl Acad Sci USA 99: 2112–2117, 2002). Investigation of the effects of phorbol ester (12- o-tetradecanoylphorbol-13-acetate; TPA) and cAMP analogs in 32P-labeled pancreatic acini revealed that these agents acutely dephosphorylated CRHSP-24 by a Ca2+-independent mechanism. Indeed, cAMP- and TPA-mediated dephosphorylation of CRHSP-24 was fully inhibited by the PP1/PP2A inhibitor calyculin A, indicating that the protein is regulated by an additional phosphatase other than PP2B. Supporting this, CRHSP-24 dephosphorylation in response to the Ca2+-mobilizing hormone cholecystokinin was differentially inhibited by calyculin A and the PP2B-selective inhibitor cyclosporin A. Stimulation of acini with secretin, a secretagogue that signals through the cAMP pathway in acini, induced CRHSP-24 dephosphorylation in a concentration-dependent manner. Isoelectric focusing and immunoblotting indicated that elevated cellular Ca2+ dephosphorylated CRHSP-24 on at least three serine sites, whereas cAMP and TPA partially dephosphorylated the protein on at least two sites. The cAMP-mediated dephosphorylation of CRHSP-24 was inhibited by low concentrations of okadaic acid (10 nM) and fostriecin (1 μM), suggesting that CRHSP-24 is regulated by PP2A or PP4. Collectively, these data indicate that CRHSP-24 is regulated by diverse and physiologically relevant signaling pathways in acinar cells, including Ca2+, cAMP, and diacylglycerol.


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