C/EBPα alleviates hepatic ischemia-reperfusion injury by inhibiting endoplasmic reticulum stress via HDAC1-mediated deacetylation of ATF4.

Hepatic ischemia-reperfusion (IR) injury is a complex systemic process causing a series clinical problem. C/EBPα is a key transcription factor for hepatocyte function, but its role and mechanism in regulating hepatic IR injury are largely unknown. Occluding portal vein and hepatic artery was used to establish a mouse model of hepatic IR injury. C/EBPα expression was decreased in IR-injured liver compared with the sham, accompanied by increased contents of serum alanine transaminase (ALT), aspartate transaminase (AST), high mobility group box-1, and proportion of hepatic cells. Oxygen and glucose deprivation/recovery (OGD/R) was used to establish a cellular hepatic IR model in WRL-68 hepatocytes in vitro, and C/EBPα was overexpressed in the hepatocytes to evaluate its effect on hepatic IR injury. OGD/R promoted oxidative stress, cell apoptosis and endoplasmic reticulum (ER) stress in hepatocytes, which was reversed by C/EBPα overexpression. Then, we found that C/EBPα promoted histone deacetylase 1 (HDAC1) transcription through binding to HDAC1 promoter. Moreover, HDAC1 deacetylated the activating transcription factor 4 (ATF4), a key positive regulator of ER stress. Trichostatin-A (an HDAC inhibitor) or ATF4 overexpression reversed the improvement of C/EBPα on OGD/R-induced ER stress and hepatocyte dysfunction. 4-Phenylbutyric acid (an endoplasmic reticulum stress inhibitor) also reversed the hepatic IR injury induced by ATF4 overexpression. Finally, lentivirus-mediated C/EBPα overexpression vector was applied to administrate hepatic IR mice, and the results showed that C/EBPα overexpression ameliorated IR-induced hepatic injury, manifesting with reduced ALT/AST, oxidative stress and ER stress. Altogether, our findings suggested that C/EBPα ameliorated hepatic IR injury by inhibiting ER stress via HDAC1-mediated deacetylation of ATF4 promoter.

SNHG1, interacting with SND1, contributes to sorafenib resistance of liver cancer cells by increasing m6A-mediated SLC7A11 expression and promoting aerobic glycolysis.

Aerobic glycolysis plays an important role in multidrug resistance of cancer cells. Here, we screened different expressed lncRNAs associated with sorafenib resistance of liver cancer cells, by intersecting the bioinformatics analyses of TCGA and GEO (the GSE62813 dataset) databases. Our results revealed that the 18 upregulated lncRNAs in the intersection are associated with and enriched in metabolism of small molecule organic acids, suggesting their potential in glycolysis. The lncRNA small nucleolar RNA host gene 1 (Snhg1) was chosen as a potential regulator of aerobic glycolysis in liver cancer cells, for its significant promotion on lactate production. Gain- and loss-of-function experiments mediated by Crispr-Cas9 technique in HepG2 cells indicated that Snhg1 promoted cell proliferation, invasion, sorafenib resistance, and aerobic glycolysis. In the mechanism exploration, we found that Snhg1 can interact with SND1 protein, a famous RNA binding protein and recently identified "Reader" of N6-methyladenosine (m6A). SND1 was demonstrated to be positively regulated by Snhg1 and had similar promoting effects on proliferation, invasion, sorafenib resistance, and aerobic glycolysis of HepG2 cells. SND1 bound with and promoted the expression of SLC7A11, an aerobic glycolysis regulator. Furthermore, either silencing SLC7A11 or blocking aerobic glycolysis with 2-deoxy-d-glucose (2-DG) was able to reverse the promotion of Snhg1 overexpression on malignancy, sorafenib resistance, and aerobic glycolysis of HepG2 cells. Finally, in a liver cancer xenograft mouse model, we found that formed tumors with Snhg1-knocked-down HepG2 cells were more sensitive to sorafenib administration. Altogether, SNHG1 contributes to sorafenib resistance of liver cancer cells by promoting SND1-m6A-SLC7A11-mediated aerobic glycolysis.

Circ_SNX27 regulates hepatocellular carcinoma development via miR-637/FGFR1 axis.

BACKGROUND: Circular RNAs (circRNAs) serve as critical regulatory factors in cancer development. Nonetheless, the potential regulatory mechanism of circRNA sorting nexin 27 (circ_SNX27) in hepatocellular carcinoma (HCC) is still unknown. METHODS: The circ_SNX27, microRNA-637 (miR-637), and fibroblast growth factor receptor 1 (FGFR1) levels were quantified by quantitative real-time polymerase chain reaction and western blot analysis. Next, function experiments were conducted using in vitro assays and in vivo senograft study. The relationship between miR-637 with circ_SNX27 or FGFR1 was uncovered by dual-luciferase reporter and RNA pull-down assays. RESULTS: The circ_SNX27 and FGFR1 levels were up-regulated, but miR-637 content was reduced in HCC. Circ_SNX27 down-regulation inhibited HCC cell proliferation, motility, and invasion and promoted apoptosis in vitro, as well as weakened tumor growth in vivo. Circ_SNX27 served as a sponge of miR-637 to promote FGFR1 expression. MiR-637 reduction abolished the restrained effect of circ_SNX27 absence on HCC cell development. Moreover, miR-637 curbed HCC cell malignant phenotype by regulating FGFR1. CONCLUSION: Circ_SNX27 contributed to HCC development via miR-637/FGFR1 axis, offering a new idea for the treatment of HCC.

DDX3 acts as a tumor suppressor in colorectal cancer as loss of DDX3 in advanced cancer promotes tumor progression by activating the MAPK pathway.

Objective: The treatment and prognosis of patients with advanced colorectal cancer (CRC) remain a difficult problem. Herein, we investigated the role of DEAD (Asp-Glu-Ala-Asp) box helicase 3 (DDX3) in CRC and proposed potential therapeutic targets for advanced CRC. Methods: The expression of DDX3 in CRC and its effect on prognosis were explored by databases and CRC tissue microarrays. Stable DDX3 knockdown and overexpression cell lines were established with lentiviral vectors. The effects of DDX3 on CRC were investigated by functional experiments in vitro and in vivo. The molecular mechanism of DDX3 in CRC was explored by western blotting. Molecular-specific inhibitors were further used to explore potential therapeutic targets for advanced CRC. Results: The expression of DDX3 was decreased in advanced CRC, and patients with low DDX3 expression had a poor prognosis. In vitro and in vivo experiments showed that low DDX3 expression promoted the proliferation, migration and invasion of CRC. DDX3 loss regulated E-cadherin and ß-catenin signaling through the mitogen-activated protein kinase (MAPK) pathway as shown by western blotting. In addition, the MEK inhibitor, PD98059, significantly reduced the increased cell proliferation, migration and invasion caused by knockdown of DDX3. Conclusions: DDX3 acts as a tumor suppressor gene in CRC. DDX3 loss in advanced cancer promotes cancer progression by regulating E-cadherin and ß-catenin signaling through the MAPK pathway, and targeting the MAPK pathway may be a therapeutic approach for advanced CRC.

LOXL3-promoted hepatocellular carcinoma progression via promotion of Snail1/USP4-mediated epithelial-mesenchymal transition.

Lysyl-oxidase-like 3 (LOXL3) was reported to be essential in epithelial-mesenchymal transition (EMT) of cancers. However, the role of LOXL3 in hepatocellular carcinoma (HCC) remained unclear. In this study, we explored clinical significance, biological functions, and regulatory mechanisms of LOXL3 in HCC. Our study found that LOXL3 expression was markedly associated with the tumor size and clinical stage of HCC, and it was highly expressed in tumor tissues of metastatic HCC patients. High expression of LOXL3 predicted a poor prognosis of HCC. TGF-ß1 treatment elevated LOXL3 protein expression and cell invasion, and reduced cell apoptosis in HCC cell lines (SMMC-7721 and Huh-7), while downregulation of LOXL3 reversed the promotive effects of TGF-ß1 treatment on LOXL3 protein expression and cell invasion, and the inhibitory effect on cell apoptosis. Mechanistically, LOXL3 interacted with snail family transcriptional repressor 1 (Snail1) through STRING database and RIP assay, and Snail1 bound to ubiquitin-specific peptidase 4 (USP4) promoter by JASPAR database, luciferase reporter gene and Co-IP assays. Overexpression of USP4 reversed the inhibitory effect of LOXL3 silence on EMT in HCC cells through deubiquitinating and stabilizing the expression of Snail1. Moreover, LOXL3-promoted HCC EMT through Wnt/ß-catenin/Snail1 signaling pathway. In vivo study revealed that silence of LOXL3-inhibited HCC tumor growth. In conclusion, LOXL3 silence inhibited HCC invasion and EMT through Snail1/USP4-mediated circulation loop and Wnt/ß-catenin signaling pathway.

Erratum: PD-L1 expression in colon cancer and its relationship with clinical prognosis.

[This corrects the article on p. 1764 in vol. 12, PMID: 31933995.].

Tumor Suppressor Gene XEDAR Promotes Differentiation and Suppresses Proliferation and Migration of Gastric Cancer Cells Through Upregulating the RELA/LXRα Axis and Deactivating the Wnt/ß-Catenin Pathway.

X-linked ectodermal dysplasia receptor (XEDAR) is a new member of the tumor necrosis factor receptor (TNFR) family that induces cell death. The purpose of this study is to determine the tumor-suppressive potential of XEDAR in the development and differentiation of gastric cancer (GC). XEDAR levels were analyzed in human GC tissues and adjacent normal tissues by immunohistochemistry (IHC), quantitative real-time reverse transcription PCR (RT-qPCR), and Western blot analysis. We found that XEDAR expression was significantly downregulated in GC tissues and further decreased in low differentiated GC tissues. Overexpression of XEDAR in MKN45 and MGC803 cells suppressed the ability of cell proliferation and migration, whereas silencing XEDAR showed the opposite effect. Additionally, XEDAR silencing resulted in the upregulation of the differentiation molecular markers ß-catenin, CD44 and Cyclin D1 at the protein levels, whereas XEDAR overexpression showed the opposite effect. Notably, XEDAR positively regulated the expression of liver X receptor alpha (LXRα) through upregulating the RELA gene that was characterized as a transcription factor of LXRα in this study. Inhibition of LXRα by GSK2033 or activation of the Wnt/ß-catenin pathway by Wnt agonist 1 impaired the effect of XEDAR overexpression on differentiation of MKN45 cells. Moreover, inhibition of RELA mediated by siRNA could promote cell proliferation/migration and rescue the effect of XEDAR overexpression on cell behaviors and expression of genes. Subsequently, overexpression of XEDAR suppressed the growth of GC cells in vivo. Taken together, our findings showed that XEDAR could promote differentiation and suppress proliferation and invasion of GC cells.

M2­TAM subsets altered by lactic acid promote T­cell apoptosis through the PD­L1/PD­1 pathway.

The aim of the study was to investigate the effects of lactic acid on the phenotypic polarization and immune function of macrophages. The human monocyte/macrophage cell line, THP­1, was selected and treated with lactic acid. Immunofluorescence staining, laser confocal microscopy, reverse­transcription polymerase chain reaction (RT­PCR), western blot, siRNA, and ELISA analyses were used to observe changes in the levels of cluster of differentiation (CD)68, CD163, hypoxia inducible factor (HIF)­1α, and programmed death ligand­1 (PD­L1) as well as those of cytokines, tumor necrosis factor (TNF)­α, interferon (IFN)­Î³, interleukin (IL)­12, and IL­10. THP­1 macrophages and T cells were co­cultured in vitro to observe the changes in proliferation and apoptosis of T cells. The results showed that, lactic acid (15 mmol/l) significantly upregulated the expression of the macrophage M2 marker CD163 (P<0.05), cytokines, IFN­Î³ and IL­10, secreted by M2­tumor­associated macrophages (TAM, P<0.05), and HIF­1α and PD­L1 (P<0.05), and downregulated the expression of cytokines, TNF­α and IL­12, secreted by M1­TAM (P<0.05). Redistribution of M2­TAM subsets and PD­L1 expression was reversed after further transfection of THP­1 cells with HIF­1α siRNA (P<0.05). After co­culturing, T­cell proliferation was inhibited and apoptosis was promoted. In summary, modulation of lactic acid level can redistribute M2­TAM subsets and upregulate PD­L1 to assist tumor immune escape. The HIF­1α signaling pathway may participate in this process, revealing that macrophages, as 'checkpoints' in organisms, are links that connect the immune status and tumor evolution, and can be used as a target in tumor treatment.

RP11­619L19.2 promotes colon cancer development by regulating the miR­1271­5p/CD164 axis.

Colon cancer (CC) is one of the leading causes of cancer­related mortality in China and western countries. Several studies have demonstrated that long non­coding RNAs (lncRNAs) play critical roles in cancer development. However, the function of lncRNA RP11­619L19.2 in colon cancer remains unclear. The aim of the present study was to investigate the expression pattern, function and underlying mechanism of action of RP11­619L19.2 in CC development and metastasis. RP11­619L19.2 was found to be highly expressed in CC tissues and cell lines, and it was associated with advanced TNM stage and lymph node metastasis. Furthermore, knockdown of RP11­619L19.2 inhibited CC cell proliferation, migration, invasion and epithelial­to­mesenchymal transition (EMT). It was also observed that RP11­619L19.2 was reciprocally repressed by miR­1271­5p. Of note, miR­1271­5p negatively regulated CD164 expression by directly targeting the 3'­untranslated region of CD164. Overexpression of CD164 reversed the antimetastatic activity of RP11­619L19.2 knockdown in CC cells. Mechanistically, it was demonstrated that lncRNA RP11­619L19.2 played an oncogenic role and promoted CC development and metastasis by regulating the miR­1271­5p/CD164 axis and EMT. In conclusion, the findings of the present study indicated that RP11­619L19.2 regulates CD164 expression and EMT by sponging miR­1271­5p, which may provide novel targets for lncRNA­directed diagnosis and therapy for patients with CC.

The long non-coding RNA HCG18 promotes the growth and invasion of colorectal cancer cells through sponging miR-1271 and upregulating MTDH/Wnt/ß-catenin.

Long non-coding RNAs (lncRNAs) have recently emerged as key regulators of the occurrence and progression of various human cancers, including colorectal cancer. However, the regulatory mechanism of lncRNAs in the tumorigenesis of colorectal cancer remains poorly understood. In this study, we aimed to elucidate the potential role of lncRNA HCG18 in colorectal cancer. Herein, we found that HCG18 expression was significantly upregulated in colorectal cancer tissues and cell lines. Knockdown of HCG18 significantly inhibited the growth and invasion of colorectal cancer cells, while its overexpression had the opposite effect. Moreover, HCG18 was identified as a sponge of miR-1271. Our results showed that knockdown of HCG18 markedly upregulated miR-1271 expression in colorectal cancer cells. Notably, HCG18 expression was inversely correlated with miR-1271 expression in colorectal cancer specimens. Further investigation revealed that HCG18 contributed to the enhancement of MTDH/Wnt/ß-catenin signalling in colorectal cancer cells. The antitumour effect of HCG18 inhibition was significantly reversed by miR-1271 inhibition or MTDH overexpression. Overall, the results of our study demonstrate that HCG18 exerts a potential oncogenic function in colorectal cancer by enhancing MTDH/Wnt/ß-catenin signalling via sponging of miR-1271, highlighting the importance of HCG18/miR-1271/ MTDH/Wnt/ß-catenin signalling in the progression of colorectal cancer.

PD-L1 expression in colon cancer and its relationship with clinical prognosis.

OBJECTIVES: PD-L1 is closely associated with tumorigenesis and development. However, expression of PD-L1 protein in colon cancer and its significance in clinical prognosis are yet to be fully clarified. This study examined the relationship between PD-L1 expression with the clinicopathological features and prognosis of colon cancer. METHODS: This study collected cases of primary colon cancer that had not undergone preoperative chemotherapy and had complete clinical data. Eighty specimens each were obtained from cancer tissues, paracancer tissues, and normal tissues. Immunohistochemical assays were performed to detect PD-L1 expression. The relationship between PD-L1 expression and clinicopathologic features was compared. This was combined with follow-up data, to analyze the relationship between positive or negative PD-L1 expression and prognosis. RESULTS: Among 80 tumor specimens, 22 cases (27.5%) showed high PD-L1 expression, 24 cases (30.0%) showed moderate expression, and 34 cases (42.5%) showed weak or no PD-L1 staining. High expression of PD-L1 in paracancer and normal tissues were 9 (11.3%) and 5 (6.3%) cases, respectively. PD-L1 expression was also positively correlated with TNM stage (P=0.009), lymph node metastasis (P=0.000), distant metastasis (P=0.014). There were no significant differences in different age, gender, histologic grade, and tumor size groups (P>0.05). Regression analysis revealed that poorer tumor differentiation, later TNM stages, presence of lymph node metastasis, and positive PD-L1 expression were factors that influenced prognosis. Multivariate analysis indicated that late TNM stage and positive PD-L1 expression were independent risk factors that influenced prognosis. CONCLUSION: PD-L1 expression is significantly elevated in colon cancer tissues, and is closely associated with lymph node metastasis, prognosis, and survival.

Ginkgolic acid suppresses the invasion of HepG2 cells via downregulation of HGF/c­Met signaling.

Liver cancer is one of the most devastating types of cancer worldwide. Despite years of improvements in treatment, the prognosis of patients with this type of malignancy remains poor due to frequent recurrence and metastasis after surgical resection. Ginkgolic acid (GA) is a botanical drug extracted from the seed coat of Ginkgo biloba L. that possesses a wide range of bioactive properties. However, to the best of our knowledge, whether GA can inhibit the invasion of liver cancer cells and the underlying mechanisms remains unknown. The aim of the present study was to investigate the effects of GA on the migration and invasion abilities of liver cancer cells and the underlying molecular mechanism. The results revealed that GA suppressed the migration and invasion abilities of HepG2 cells. In addition, GA treatment inhibited the expression of invasion­related molecules (MMP­2 and MMP­9) and prevented the epithelial­mesenchymal transition (EMT) of HepG2 cells. Further experiments revealed that GA­reduced hepatocyte growth factor (HGF) production and suppressed c­Met phosphorylation may be the underlying mechanisms. Exogenous recombinant HGF supplementation improved the cell invasion ability impaired by GA. Moreover, the in vivo experiment revealed that GA inhibited the tumor growth of liver cancer and prevented EMT. Collectively, these data indicated that GA effectively suppressed the invasion and EMT of HepG2 cells via downregulation of HGF/c­Met signaling, thus GA may serve as a novel chemotherapeutic agent for the treatment of HCC.

MMP7 Induces T-DM1 Resistance and Leads to the Poor Prognosis of Gastric Adenocarcinoma via a DKK1-Dependent Manner.

BACKGROUND: Gastric adenocarcinoma is one of the most common and lethal cancer types and is known as the second leading cause of cancer-related death of Asian adults, early diagnosis based on either pathology or molecular biology could be one of the most efficient ways to improve the outcomes of gastric adenocarcinoma patients. METHODS: Quantitative Real-Time PCR and Western-blot were used in detection of mRNA and protein expression. Lentivirus infection was used to overexpression or knock down target gene. Alarma blue assay was used to monitor cells proliferation. Flow cytometry analysis was performed to test protein expression and apoptosis level. Immunohistochemistry was used to identify protein expression in tissue. Statistical differences between two groups are evaluated by two-tailed t-tests. The comparison among multiple groups is performed by one-way Analysis of Variance (ANOVA) followed by Dunnett's posttest. The statistical significance of the Kaplan-Meier survival plot is determined by log-rank analysis. RESULTS: MMP7 as one of the most up-regulated genes in T-DM1 resistant NCI-N87 gastric adenocarcinoma cells compared to matched naïve cell lines. T-DM1 resistant NCI-N87 cell lines by exposed to T-DM1 in vitro. Exogenous overexpression of MMP7 promotes T-DM1 resistance and tumor growth in NCI-N87 cell lines while MMP7 knockdown enhanced sensitivity to T-DM1 in T-DM1 resistant NCI-N87 cell lines established previously. MMP7 was enriched in high WHO grade GC samples and implies poor outcomes for these patients. DKK1 as one of the most correlated genes to MMP7 in gastric adenocarcinoma and knock-down of DKK1 or inhibition of Wnt/ß-catenin pathway led to a decreased expression of MMP7 and resistance to T-DM1. CONCLUSION: DKK1 and Wnt/ß-catenin-dependent activation of MMP7 induces T-DM1 resistance and leads to the poor prognosis of gastric adenocarcinoma, which might be a novel potential therapeutical target for T-DM1 resistant gastric adenocarcinoma.

Knockdown of TMPRSS3 inhibits gastric cancer cell proliferation, invasion and EMT via regulation of the ERK1/2 and PI3K/Akt pathways.

The transmembrane protease, serine 3 (TMPRSS3), a member of the type II transmembrane serine protease family, plays an important role in mediating tissue development, homeostasis and various biological processes. Recently, TMPRSS3 has been reported to be involved in cancer progression. However, the role of TMPRSS3 in gastric cancer (GC) remains largely unknown. In this study, we found that TMPRSS3 was highly expressed in GC tissues and cell lines. Knockdown of TMPRSS3 inhibited GC cell proliferation, invasion and epithelial-mesenchymal transition (EMT) in vitro as well as suppressed GC cell growth and dissemination in vivo. These inhibitory effects were mediated by regulation of the ERK1/2 signaling pathway. Moreover, TMPRSS3-mediated ERK1/2 activation was dependent on the PI3K/Akt pathway. In conclusion, TMPRSS3 contributed to GC progression via activation of the PI3K/Akt/ERK signaling pathway and might act as a therapeutic target for GC treatment.

Low-dose heparin in the prevention of post endoscopic retrograde cholangiopancreatography pancreatitis: a systematic review and meta-analysis.

One of the most frequent and serious complications of endoscopic retrograde cholangiopancreatography (ERCP) is acute pancreatitis. The aim of this study was to evaluate the preventive effect of low-dose heparin (unfractionated or low-molecular-weight heparin) on post-ERCP pancreatitis (PEP) and its side-effects by a systematic review and meta-analysis of clinical trials. Searching PubMed and EMBASE, up to August 2011, two independent reviewers systematically identified prospective clinical trials detecting the effect of prophylactic low-dose heparin on the incidence of PEP, severe PEP, and post-ERCP hemorrhage complications. Four clinical trials fulfilled our selection criteria, with three prospective randomized and one nonrandomized. A meta-analysis of these clinical trials was then performed. A total of 1438 patients were included. Meta-analysis of these trials indicated that there was no significant association between the use of heparin and the reduction of PEP [relative risk (RR) 0.67, 95% confidence interval (CI): 0.44-1.03, P=0.07] and severe PEP (RR 0.62, 95% CI: 0.15-2.60, P=0.51). However, low-dose heparin did not increase the incidence of post-ERCP hemorrhage complications (RR 0.84, 95% CI: 0.34-2.03, P=0.69). This meta-analysis did not demonstrate a statistically significant benefit of prophylactic heparin use for the prevention of post-ERCP pancreatitis. More multicenter trials involving a larger number of patients are needed to show a possible prevention effect of PEP from heparin and its related compounds.

Role of heparin on serum VEGF levels and local VEGF contents in reducing the severity of experimental severe acute pancreatitis in rats.

OBJECTIVE: The aims of this study were to examine the effects of prophylactic heparin treatment during taurocholate-induced pancreatitis in rats and its impact on serum VEGF levels and local VEGF contents within the pancreas. METHODS: Severe acute pancreatitis (SAP) was induced by injecting 4% sodium taurocholate into the pancreatic duct. Heparin at a dose of 150 IU/kg s.c. was administered 30 min before the operation. The rats were sacrificed 1 h, 3 h, 6 h and 12 h (n = 5 per time point) after the onset of pancreatitis. The severity of pancreatitis, serum VEGF levels and local VEGF contents were evaluated with and without heparin pretreatment. RESULTS: The serum VEGF levels increased at an early phase of pancreatitis, and the highest level was found at 12 h after inducing pancreatitis. The gray value of the local VEGF showed a remarkable increase from the onset of the pancreatitis. However, the gray value of VEGF did not show an increase over time but maintained a high level during the entire process. Prophylactic heparin treatment significantly improved the morphologic changes, myeloperoxidase (MPO), TNF-α and malondialdehyde (MDA) activities. Meanwhile, it decreased the serum VEGF levels and the contents of VEGF within the pancreatic tissue. CONCLUSIONS: The present study suggests that prophylactic heparin ameliorates the severity of taurocholate-induced pancreatitis via its anti-inflammatory properties. These protective effects may be partly due to decreasing serum VEGF levels and VEGF contents within the pancreas.

[Role of vascular endothelial growth factor in rats with severe acute pancreatitis].

OBJECTIVE: To investigate the role of vascular endothelial growth factor (VEGF) in the pathogenesis of severe acute pancreatitis (SAP) in rats. METHODS: Sixty-four male SD rats were randomly divided into control group and SAP group, and in the latter group, SAP was induced by retrograde injection of 5% sodium taurocholate in the pancreaticobiliary duct. The rats were sacrificed at 1, 3, 6 and 12 h after the operation, and the severity of pancreatitis was assessed according to histological scoring. The serum levels of VEGF were examined with enzyme-linked immunosorbent assay, and the expression of VEGF in the pancreatic tissues was measured by SP immunohistochemistry. Another 30 SD rats were randomized into the control group, SAP group and SAP+recombinant rat VEGF injection group, and the vascular permeability of the pancreatic microcirculation was determined by Evans Blue leakage test. RESULTS: At each of the time points for measurement, both the serum VEGF level and scores of pancreatic tissue injury were significantly higher in SAP group than in the control group (P<0.05). Compared with the control group, the expressions of VEGF in the pancreatic tissues of SAP group were significantly up-regulated following the operation (P<0.05). The vascular permeability of the pancreatic microcirculation significantly increased after the onset of SAP, and injection of recombinant rat VEGF significantly increased the leakage rate of Evans Blue. CONCLUSION: VEGF may play an important role in the pathogenesis of pancreatitis and in causing edema and hemorrhage in SAP, and the level of serum VEGF may reflect the severity of pancreatic injury.

[Protective effects of captopril against lung injury in rats with severe acute pancreatitis].

OBJECTIVE: To investigate the protective effects of captopril against lung injury in a rat model of severe acute pancreatitis (SAP). METHODS: Seventy-two male SD rats were randomized into sham-operated group (SO group), SAP group and captopril intervention group (CAP group). Serum amylase and myeloperoxidase (MPO) activity in the lung tissue were examined at 1, 6 and 12 h after the operation. TNF-α and AngII in the lung tissue were detected by ELISA, and the histopathological changes of the pancreas and lung were observed microscopically. RESULTS: The MPO activity , which was similar between SAP group and CAP group at 1 h, were significantly lowered in CAP group at 6 and 12 h (P<0.05). Serum amylase level and the levels of TNF-α and AngII in the lung tissue homogenate were all reduced significantly in CAP group as compared to those in SAP group (P<0.01). The pathological injury of the lung was obviously lessened in CAP group in comparison with that in SAP group. CONCLUSION: Captopril can ameliorate SAP-induced lung injury in rats.

Proteasome inhibitor ameliorates severe acute pancreatitis and associated lung injury of rats.

AIM: To observe the effect of proteasome inhibitor MG-132 on severe acute pancreatitis (SAP) and associated lung injury of rats. METHODS: Male adult SD rats were randomly divided into SAP group, sham-operation group, and MG-132 treatment group. A model of SAP was established by injection of 5% sodium taurocholate into the biliary-pancreatic duct of rats. The MG-132 group was pretreated with 10 mg/kg MG-132 intraperitoneally (ip) 30 min before the induction of pancreatitis. The changes in serum amylase, myeloperoxidase (MPO) activity of pancreatic and pulmonary tissue were measured. The TNF-alpha level in pancreatic cytosolic fractions was assayed with an enzyme-linked immunosorbent assay (ELISA) kit. Meanwhile, the pathological changes in both pancreatic and pulmonary tissues were also observed. RESULTS: MG-132 significantly decreased serum amylase, pancreatic weight/body ratio, pancreatic TNF-alpha level, pancreatic and pulmonary MPO activity (P < 0.05). Histopathological examinations revealed that pancreatic and pulmonary samples from rats pretreated with MG-132 demonstrated milder edema, cellular damage, and inflammatory activity (P < 0.05). CONCLUSION: The proteasome inhibitor MG-132 shows a protective effect on severe acute pancreatitis and associated lung injury of rats.

[Protective effect of proteasome inhibitor MG-132 in rats with severe acute pancreatitis and lung injury].

OBJECTIVE: To observe the protective effect of the proteasome inhibitor MG-132 in rats with severe acute pancreatitis (SAP) and the associated lung injury. METHODS: In rat models of the SAP established with injection of 5% sodium taurocholate into the biliary-pancreatic duct, the changes of the serum amylase and myeloperoxidase (MPO) activity in the pancreatic and lung tissues were evaluated. The pathological changes of the pancreatic and lung tissues were also observed. RESULTS: MG-132 significantly decreased serum amylase, pancreatic weight/body weight ratio, and pancreatic and pulmonary myeloperoxidase activity (P<0.05). Histopathological examinations revealed milder edema, cellular damage, and inflammation in the pancreatic and lung tissues of rats pretreated with the peptide (P<0.05). CONCLUSION: MG-132 ameliorates SAP and the associated lung injury in rats.