4-Phenylbutyric Acid Attenuates Endoplasmic Reticulum Stress-Mediated Intestinal Epithelial Cell Apoptosis in Rats with Severe Acute Pancreatitis.

OBJECTIVES: The present study aimed to determine whether intestinal epithelial cell (IECs) apoptosis could be induced by endoplasmic reticulum stress (ERS) in severe acute pancreatitis (SAP), and the role of chemical chaperone 4-phenylbutyric acid (4-PBA) in SAP-associated intestinal barrier injury. METHODS: Twenty-four male Sprague Dawley rats were randomly divided into three groups: the sham operation group, the SAP group, and the SAP model plus 4-PBA treatment group (4-PBA group). A rat model of SAP was induced by retrograde injection of 5% sodium taurocholate (STC) into the biliopancreatic duct; in the 4-PBA group, 4-PBA was injected intraperitoneally at a dose of 50 mg/kg body weight for 3 days before modeling. RESULTS: The results indicated that 4-PBA attenuated the following: (1) pancreas and intestinal pathological injuries, (2) serum TNF-α, IL-1ß, and IL-6, (3) serum DAO level, serum endotoxin level, (4) the apoptosis of IECs, (5) ER stress markers (caspase-12, CHOP, GRP78, PERK, IRE1α, ATF6) and caspase-3 expression in intestinal. However, the serum AMY, LIPA levels, and the expression of caspase-9, caspase-8 were just slightly decreased. CONCLUSIONS: ERS may be considered a predominant pathway, which is involved in the apoptosis of IECs during SAP. Furthermore, 4-PBA protects IECs against apoptosis in STC-induced SAP by attenuating the severity of ERS.

Inhibition of endoplasmic reticulum stress by 4-phenylbutyric acid prevents vital organ injury in rat acute pancreatitis.

This study was conducted to investigate the effect of 4-phenylbutyric acid (4-PBA) on vital organ injury following sodium taurocholate-induced acute pancreatitis (AP) in rats and the pertinent mechanism. The serum biochemical indicators and key inflammatory cytokines, histopathological damage and apoptosis of vital organs in rat AP, were evaluated in the presence or absence of 4-PBA. Moreover, mRNA and protein levels of endoplasmic reticulum stress (ERS) markers were assessed. 4-PBA significantly attenuated the structural and functional damage of vital organs, including serum pancreatic enzymes, hepatic enzymes, creatinine, and urea. The morphological changes and infiltration of neutrophils and macrophages were reduced as well. These effects were accompanied by decreased serum levels of proinflammatory TNF-α and IL-1ß. Furthermore, 4-PBA diminished the expression of ERS markers (glucose-regulated protein 78, CCAAT/enhancer-binding protein homologous protein, protein kinase R-like ER kinase, activated transcription factor 6, and type-1 inositol requiring enzyme) in vital organs of AP rats. 4-PBA also reduced AP-induced apoptosis in lung, liver, and kidney tissues as shown by TUNEL assay. The present study demonstrated that 4-PBA protected pancreas, lung, liver, and kidney from injury in rat AP by regulating ERS and mitigating inflammatory response to restrain cell death and further suggested that 4-PBA may have potential therapeutic implications in the disease. NEW & NOTEWORTHY In this study, we suggest that endoplasmic reticulum stress (ERS) is an important player in the development of acute pancreatitis-induced multiorgan injury, providing additional evidence for the proinflammatory role of ERS. Because 4-phenylbutyric acid has been suggested to inhibit ERS in many pathological conditions, it is possible that this effect can be involved in alleviating inflammatory response and cell death to ameliorate vital organ damage following acute pancreatitis induced by sodium taurocholate in rats.

Serum thyroid hormones levels are significantly decreased in pregnant rats with acute pancreatitis.

Acute pancreatitis in pregnancy (APIP), which was thought to be a rare but severe disease, with a high perinatal mortality among maternal-fetuses. Our research aimed to study and assess thyroid injury in a rat model of APIP and its possible mechanisms. The APIP model was established by retrograde injection with sodium taurocholate. Sham-operated (SO) and APIP groups were performed at 3 time-points. Histological changes in the maternal thyroid and pancreas were assessed. The activities of serum amylase, lipase and levels of FT3, FT4, MDA, TNF-α and IL-1ß were detected in maternal rats, and the expression of MIF, ICAM-1 and CD68 in the maternal thyroids were determined. In this study, maternal thyroid injury as well as pancreas injury occurred in a time-dependent manner. The activities of serum amylase, lipase and levels of MDA, TNF-α and IL-1ß were markedly increased in acute pancreatitis rats, the levels of serum FT3 and FT4 were obviously decreased in APIP groups, and the expressions of MIF, ICAM-1 and CD68 were significantly increased in the thyroid of the APIP group. Ultrastructural thyroid injuries were observed in the APIP group. Our research suggests that thyroid injury is involved in the rat experimental model of APIP. The degree of thyroid dysfunction is associated with APIP, which may affect the prognosis of acute pancreatitis.

Fetal liver injury ameliorated by migration inhibitory factor inhibition in a rat model of acute pancreatitis in pregnancy.

AIM: This study was designed to investigate and assess fetal liver injury in a rat model of acute pancreatitis in pregnancy (APIP) as well as its possible mechanisms and potential therapeutic targets. METHODS: The APIP model was induced by sodium taurocholate in Sprague-Dawley rats during the third trimester. ISO-1, a macrophage migration inhibitory factor (MIF) antagonist, was given before the induction of APIP. In addition, sham-operated rats at later gestation were set as controls. Histological changes in the fetal liver and maternal pancreas were assessed. Amylase and lipase activity as well as the levels of tumor necrosis factor (TNF)-α and interleukin (IL)-1ß were examined. The expression of MIF in fetal liver was determined by immunochemistry and the expression of NF-κB, IκBα, high mobility group box-1 protein (HMGB1), TNF-α, and IL-1ß in fetal liver was determined by Western blot analysis. Ultrastructures of hepatic cells in fetal rats were observed under transmission electron microscopy. RESULTS: ISO-1 ameliorated the following: (i) pathological injuries in maternal pancreas and fetal liver; (ii) levels of TNF-α and IL-1ß in maternal serum; and (iii) levels of MIF, myeloperoxidase, NF-κB, HMGB1, TNF-α, and IL-1ß in fetal liver. CONCLUSION: Pathological damage and an inflammatory response in fetal liver were induced by APIP, and MIF inhibition ameliorated fetal liver injury by inhibiting the inflammatory cascade.

Hydrogen-rich saline attenuates acute renal injury in sodium taurocholate-induced severe acute pancreatitis by inhibiting ROS and NF-κB pathway.

Hydrogen (H2), a new antioxidant, was reported to reduce (•)OH and ONOO(-) selectively and inhibit certain proinflammatory mediators to product, without disturbing metabolic redox reactions or ROS involved in cell signaling. We herein aim to explore its protective effects on acute renal injury in sodium taurocholate-induced acute pancreatitis and its possible mechanisms. Rats were injected with hydrogen-rich saline (HRS group) or normal saline (SO and SAP group) through tail intravenously (6 mL/kg) and compensated subcutaneously (20 mL/kg) after successful modeling. Results showed that hydrogen-rich saline attenuated the following: (1) serum Cr and BUN, (2) pancreatic and renal pathological injuries, (3) renal MDA, (4) renal MPO, (5) serum IL-1ß, IL-6, and renal TNF-α, HMGB1, and (6) tyrosine nitration, IκB degradation, and NF-κB activation in renal tissues. In addition, it increased the level of IL-10 and SOD activity in renal tissues. These results proved that hydrogen-rich saline attenuates acute renal injury in sodium taurocholate-induced acute pancreatitis, presumably because of its detoxification activity against excessive ROS, and inhibits the activation of NF-κB by affecting IκB nitration and degradation. Our findings highlight the potential value of hydrogen-rich saline as a new therapeutic method on acute renal injury in severe acute pancreatitis clinically.

XsFAD2 gene encodes the enzyme responsible for the high linoleic acid content in oil accumulated in Xanthoceras sorbifolia seeds.

BACKGROUND: Xanthoceras sorbifolia Bunge is a valuable oilseed tree that has linoleic acid-rich seed oil. Microsomal oleate desaturase (FAD2; EC 1.3.1.35) is responsible for the conversion of oleic acid to linoleic acid during fatty acid synthesis. In this study, XsFAD2 was cloned from developing embryos of X. sorbifolia. RESULTS: XsFAD2 contained three histidine boxes, a C-terminal endoplasmic reticulum retrieval motif, and five putative transmembrane domains representing the characteristics of membrane-bound fatty acid desaturase. XsFAD2 expression in yeast cells resulted in linoleic acid (18:2) and palmitolinoleic acid (16:2) production, confirming the biological activity of the enzyme encoded by XsFAD2. These fatty acids are not normally present in wild-type yeast. Phylogenetic analysis indicated that XsFAD2 is located in a subgroup of FAD2 enzymes specifically or highly expressed in developing seeds. The expression level of XsFAD2 in seeds was much higher than those in leaves and petals. Furthermore, XsFAD2 expression pattern correlated well with linoleic acid accumulated in seeds. CONCLUSION: Results suggested that XsFAD2 is responsible for the high linoleic acid content in X. sorbifolia seed oil. This study provides insight on the regulation mechanism of fatty acid synthesis in X. sorbifolia seeds and a valuable gene for improving the oil quality in oilseed trees.

MicroRNA-328-3p facilitates the progression of gastric cancer via KEAP1/NRF2 axis.

Gastric cancer is a common lethal malignancy and causes great cancer-related mortality worldwide. MicroRNA (miR)-328-3p is implicated in the progression of various human cancers; however, its role and mechanism in the progression of gastric cancer remain unclear.Human gastric cancer cells were incubated with miR-328-3p mimic, inhibitor or the matched negative control. Cell viability, colony formation, migrative and invasive capacity, cell apoptosis and oxidative stress were measured. To clarify the involvement of nuclear factor-E2-related factor 2 (NRF2) and kelch-like ECH-associated protein 1 (KEAP1), small interfering RNA was used. miR-328-3p was upregulated in human gastric cancer cells and tissues, and its level positively correlated with the progression of gastric cancer. miR-328-3p promoted cell viability, colony formation, migration and invasion, thereby facilitating the progression of gastric cancer. miR-328-3p mimic reduced, while miR-328-3p inhibitor increased apoptosis and oxidative stress of human gastric cancer cells. Mechanistically, miR-328-3p upregulated NRF2 via targeting KEAP1to attenuate excessive free radical production and cell apoptosis. miR-328-3p functions as an oncogenic gene and inhibiting miR-328-3p may help to develop novel therapeutic strategies of human gastric cancer.

High-Fat Diet Aggravates Acute Pancreatitis via TLR4-Mediated Necroptosis and Inflammation in Rats.

High-fat diet (HFD) often increases oxidative stress and enhances inflammatory status in the body. Toll-like receptor 4 (TLR4) is widely expressed in the pancreatic tissues and plays an important role in pancreatitis. This study is aimed at investigating the effect of HFD on acute pancreatitis (AP) and the role of TLR4-mediated necroptosis and inflammation in this disease. Weight-matched rats were allocated for an 8-week feeding on the standard chow diet (SCD) or HFD, and then, the AP model was induced by infusion of 5% sodium taurocholate into the biliopancreatic duct. Rats were sacrificed at an indicated time point after modeling. Additionally, inhibition of TLR4 signaling by TAK-242 in HFD rats with AP was conducted in vivo. The results showed that the levels of serum free fatty acid (FFA) in HFD rats were higher than those in SCD rats. Moreover, HFD rats were more vulnerable to AP injury than SCD rats, as indicated by more serious pathological damage and much higher pancreatic malondialdehyde (MDA) and lipid peroxidation (LPO) levels as well as lower pancreatic superoxide dismutase (SOD) activities and reduced glutathione (GSH) contents and more intense infiltration of MPO-positive neutrophils and CD68-positive macrophages. In addition, HFD markedly increased the expressions of TLR4 and necroptosis marker (RIP3) and aggravated the activation of NF-κB p65 and the expression of TNF-α in the pancreas of AP rats at indicated time points. However, TLR4 inhibition significantly attenuated the structural and functional damage of the pancreas induced by AP in HFD rats, as indicated by improvement of the above indexes. Taken together, these findings suggest that HFD exacerbated the extent and severity of AP via oxidative stress, inflammatory response, and necroptosis. Inhibition of TLR4 signaling by TAK-242 alleviated oxidative stress and decreased inflammatory reaction and necroptosis, exerting a protective effect during AP in HFD rats.

Corrigendum to "4-Phenylbutyric Acid Attenuates Pancreatic Beta-Cell Injury in Rats with Experimental Severe Acute Pancreatitis".

[This corrects the article DOI: 10.1155/2016/4592346.].

A preliminary study on fetal lung injury in a rat model of acute pancreatitis in pregnancy.

Acute pancreatitis in pregnancy (APIP), which was thought to be rare, is becoming more frequent. In addition, high perinatal mortality among fetuses has been reported. Our research aimed to investigate and assess fetal lung injury in a rat model of APIP and its possible mechanisms. The APIP model was induced by sodium taurocholate in Sprague-Dawley rats during the third trimester. Sham-operated (SO) rats in late gestation were used as controls, and dynamic observation and detection in the SO and acute pancreatitis (AP) groups were performed at 3 time-points. Histological changes in the fetal lungs, as well as the maternal pancreas and placenta were assessed. The levels of serum amylase, lipase, TNF-α and IL-1ß were detected in maternal rats, and the expression of surfactant proteins A, B, C and D as well as their mRNA were determined. In this study, fetal lung injury as well as maternal pancreas and placenta injuries occurred in a time-dependent manner. The levels of serum amylase, lipase and TNF-α were markedly increased in maternal rats, and the levels of surfactant proteins A, B, C and D in fetal lungs were significantly decreased in the fetal lungs of the AP group. Ultrastructure injuries and the dysregulated synthesis and secretion of pulmonary surfactant proteins were observed in the AP group. Our research suggests that fetal lung injury is involved in the rat model of APIP and that the dysregulated synthesis and secretion of pulmonary surfactant proteins play a critical role in fetal lung injury during APIP.

Mitogen-Activated Protein Kinases Are Activated in Placental Injury in Rat Model of Acute Pancreatitis in Pregnancy.

OBJECTIVES: To establish a rat model of acute pancreatitis in pregnancy (APIP) and evaluate its general presentations, assess placental injury, and discuss possible mechanisms. METHODS: The APIP rat model was induced by sodium taurocholate in Sprague-Dawley rats of later gestation. Normal and sham-operated (SO) rats in later gestation were set as controls, 3 time points were set in SO and APIP groups to determine optimal modeling time. Histological changes of pancreas and placenta were assessed. Placental injury was determined by immunohistochemistry stain of caspase-3. Serum levels of amylase, lipase, and Ca; proinflammatory cytokines as tumor necrosis factor-α, interleukin-1ß (IL-1ß), IL-6, and anti-inflammatory cytokine IL-10 by enzyme-linked immunosorbent assay; mitogen-activated protein kinases and their phosphorylated forms by Western blotting. RESULTS: Pancreatic necrotizing and placental injury occurred in time-dependent patterns. Serum levels of amylase and lipase significantly increased but Ca decreased; tumor necrosis factor-α, IL-1ß, IL-6, and IL-10 were all increased in the APIP group; c-Jun N-terminal kinase, p38, and ERK1/2 were activated but with different distributing patterns in the placenta. CONCLUSIONS: Placental injury is involved in the rat model of APIP, and a modeling time of 6 hours is optimal and conducive to further studies; c-Jun N-terminal kinase and p38 may play important roles in placental injury during APIP.

4-Phenylbutyric Acid Attenuates Pancreatic Beta-Cell Injury in Rats with Experimental Severe Acute Pancreatitis.

Endoplasmic reticulum (ER) stress is a particular process with an imbalance of homeostasis, which plays an important role in pancreatitis, but little is known about how ER stress is implicated in severe acute pancreatitis (SAP) induced pancreatic beta-cell injury. To investigate the effect of 4-phenylbutyric acid (4-PBA) on the beta-cell injury following SAP and the underlying mechanism, twenty-four Sprague-Dawley rats were randomly divided into sham-operation (SO) group, SAP model group, and 4-PBA treatment group. SAP model was induced by infusion of 5% sodium taurocholate into the biliopancreatic duct. 4-PBA or normal saline was injected intraperitoneally for 3 days in respective group before successful modeling. Results showed that 4-PBA attenuated the following: (1) pancreas and islet pathological injuries, (2) serum TNF-α and IL-1ß, (3) serum insulin and glucose, (4) beta-cell ultrastructural changes, (5) ER stress markers (BiP, ORP150, and CHOP), Caspase-3, and insulin expression in islet. These results suggested that 4-PBA mitigates pancreatic beta-cell injury and endocrine disorder in SAP, presumably because of its role in inhibiting excessive endoplasmic reticulum stress. This may serve as a new therapeutic target for reducing pancreatic beta-cell injury and endocrine disorder in SAP upon 4-PBA treatment.

Hydrogen-Rich Saline Attenuates Acute Hepatic Injury in Acute Necrotizing Pancreatitis by Inhibiting Inflammation and Apoptosis, Involving JNK and p38 Mitogen-Activated Protein Kinase-dependent Reactive Oxygen Species.

OBJECTIVES: The objective of this study was to study the role of hydrogen-rich saline (HRS) on acute hepatic injury (AHI) in acute necrotizing pancreatitis (ANP). METHODS: Rats were used for this study and an ANP model was induced by injecting 5% sodium taurocholate into the biliary-pancreatic duct. Experiments were performed in 3 groups: sham, ANP, and ANP + HRS (HRS). Animals were killed at 3, 12, and 24 hours after operation, and then blood and tissue samples were harvested. Various physiological, histological, and cellular and molecular parameters were analyzed. RESULTS: Analyses of serum, lipase, alanine transaminase, and aspartate aminotransferase indicated that ANP-induced AHI model was established successfully and HRS attenuated hepatic dysfunction. Hepatic superoxide dismutase and malondialdehyde levels showed HRS against oxidative stress. Cellular and molecular analyses including p-p38, p-JNK, p-ERK, and caspase-3, caspase-9, NF-κB, and TNF-α in hepatic tissues revealed that HRS attenuated ANP-induced AHI by inhibiting apoptosis and phosphorylation of JNK and p38, as well as NF-κB activation. CONCLUSIONS: Hydrogen-rich saline plays a protective role in ANP-induced AHI through inhibiting inflammation and apoptosis, involving JNK and p38 MAPK-dependent reactive oxygen species.

Relationship between expression of NADPH oxidase 2 and invasion and prognosis of human gastric cancer.

AIM: To assess the expression and prognostic value of nicotinamide adenine dinucleotide phosphate oxidase 2 (NOX2) in gastric cancer, and its correlation with vascular endothelial growth factor (VEGF) and epidermal growth factor receptor (EGFR). METHODS: Tumor and adjacent tissues were obtained from 123 patients who underwent radical surgery for gastric cancer at Renmin Hospital of Wuhan University from 2008-2009. The expression of NOX2, VEGF, EGFR and CD68 in tumor tissues was detected by immunohistochemistry. The expression of NOX2 in gastric cancer and adjacent tissues was detected by Western blot analysis. Spearman(')s correlation was performed to elucidate the relationship of NOX2 with VEGF and EGFR. The Kaplan-Meier method was used to calculate survival time, and the log-rank test was used to evaluate differences in survival. Cox's proportional hazards regression model was applied in a stepwise manner to analyze the independent prognostic factors. RESULTS: NOX2 exhibited positive expression in 47.2% (58/123) of the gastric cancer tissues. Western blot analysis revealed that NOX2 was up-regulated in tumor tissues compared to the adjacent tissue [39.0% (48/123)]. Immunohistochemistry staining revealed that CD68, which is a specific marker of macrophages, and NOX expression presented a similar localization and staining intensity. The expression of NOX2 was positively correlated with that of VEGF and EGFR. Comparison of the 5-year survival rates of the NOX2 positive and NOX2 negative groups showed that the NOX2 positive group presented a poor prognosis. CONCLUSION: NOX2 positively correlates with the levels of VEGF and EGFR. NOX2 may be used as a new biomarker and a potential therapeutic target for gastric cancer.

Rosiglitazone attenuates the severity of hyperlipidemic severe acute pancreatitis in rats.

Peroxisome proliferator-activated receptor-γ (PPAR-γ) ligand regulates adipocyte differentiation and insulin sensitivity, and exerts antihyperlipidemic and anti-inflammatory effects. However, the mechanisms by which PPAR-γ ligands affect hyperlipidemia with severe acute pancreatitis (SAP) have not been fully elucidated. The present study investigated the effects of rosiglitazone, a PPAR-γ ligand, on hyperlipidemia with SAP in a rat model. The hyperlipidemia was induced with a high-fat diet and SAP was induced by the administration of sodium taurocholate (TCA). The hyperlipidemia was shown to aggravate the severity of the sodium taurocholate-induced SAP. However, rosiglitazone demonstrated significant antihyperlipidemic and anti-inflammatory effects in the rats with high-lipid diet-induced hyperlipidemia and SAP.

Changes of inflammation and apoptosis in adrenal gland after experimental injury in rats with acute necrotizing pancreatitis.

We hypothesize that adrenal insufficiency in acute necrotizing pancreatitis (ANP) is attributable to hemorrhagic inflammation, necrosis, and apoptosis of the adrenal cortex. Arguments to support this view are presented in the study that investigated morphological and functional changes of adrenal and the distinct roles of inflammatory mediator secretory phospholipase A(2) (sPLA(2)) and apoptosis-related genes Bax and Bcl-2 played in acute adrenal injury in ANP. After ANP model was induced, pancreatic histology, serum amylase, sPLA(2), and corticosterone were analyzed. The adrenal morphology, apoptotic cells by TUNEL assay, and ultrastructures were observed. sPLA(2)-IIA and Bcl-2 and Bax expressions were detected by immunohistochemistry. Histopathologic grading of adrenal was higher in ANP group than in controls. Serum corticosterone was stimulated to maximal level at 3 h, then dropped to the bottom at 24 h (P<0.05). Apoptotic index, sPLA2-IIA, and Bax expression were increased steeply after pancreatitis, and the Bax/Bcl-2 ratio was elevated gradually (P<0.05). Sustained decrease in serum corticosterone level following adrenal injury during ANP appears to be, in part, due to the crucial roles of inflammation and apoptosis in adrenal cortex. These findings could suggest that sPLA2, Bax, and Bcl-2 may be involved in the course of adrenal injury after ANP.

Effects of ORP150 on appearance and function of pancreatic beta cells following acute necrotizing pancreatitis.

Pancreatic beta cells produce and release insulin, which decreases the blood glucose level. Endoplasmic reticulum stress caused pancreatic beta cell dysfunction and death in acute necrotizing pancreatitis (ANP). The 150kD oxygen-regulated protein (ORP150) took part in the process of endoplasmic reticulum stress. This study investigated the effect of ORP150 on appearance and function of pancreatic beta cells in ANP. Acute necrotizing pancreatitis relied on retrograde infusion of 5% sodium taurocholate into the bile-pancreatic duct. The severity of ANP was estimated by serum amylase, secretory phospholipase A(2,) and pancreatic histopathology. The changes in appearance and function of pancreatic beta cells were detected by light and electron microscopy and the levels of serum glucose, insulin, and C-peptide. ORP150 expression was studied using western blot and immunohistochemisty assay. The expression of ORP150 mainly appeared on pancreatic beta cells and decreased gradually during the pathogenesis of ANP. The results of light and electron microscopy indicated pancreatic beta cell dysfunction and death, concomitant with elevation of serum glucose, insulin, and C-peptide in ANP. These results imply a probable role of ORP150 in the changes in appearance and function of pancreatic beta cells following acute necrotizing pancreatitis, through the pathway of endoplasmic reticulum stress.

[Effects of Dendrolimus punctatus feeding and methyl jasmonate (MeJA)--or terpenes fumigation on abscisic acid and jasmonic acid contents in Pinus massoniana seedling needles].

Abscisic acid (ABA) and Jasmonic acid (JA) play an important role in inducing the stress-resistance of plants. In this study, parts of the needles on a ring of Pinus massoniana seedling shoots were subjected to 4 hours Dendrolimus punctatus feeding or 4 hours fumigation with 10 micromol x L(-1) of methyl jasmonate (MeJA) or terpenes, and the ABA and JA contents in treated needles, untreated neighboring sister needles, and untreated needles above and below the ring were determined by GC/MS. An obvious increase of ABA and JA contents was observed in all of the needles, whether they were treated or not, illustrating that ABA and JA were the vital signaling molecules in the wound signal transduction pathway, and participated in the formation of systematic resistance of P. massoniana seedlings.