• BMB Reports
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• v.43 no.9
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• pp.604-608
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• 2010

Tumor necrosis factor-$\alpha$ (TNF-$\alpha$) mediates proinflammatory responses in primary human umbilical vein endothelial cells (HUVECs), and it upregulates the expression of secretory group IIA phospholipase $A_2$ ($sPLA_2$-IIA). $sPLA_2$-IIA plays a pivotal role in inflammation, and antithrombin (AT) possesses properties that are beneficial to endothelial cells. Therefore, we investigated the effects of AT on the expression of $sPLA_2$-IIA in TNF-$\alpha$-stimulated HUVECs. TNF-$\alpha$ potently upregulated the expression of $sPLA_2$-IIA, and prior treatment of cells with AT inhibited the expression of $sPLA_2$-IIA in HUVECs. Also, antibodies or siRNA for syndecan-4 blocked the protective effect of AT. Furthermore, PI3-kinase and the AKT pathway are significantly involved in the AT-mediated inhibition of the expression of $sPLA_2$-IIA. These results show that AT effectively suppresses the upregulated $sPLA_2$-IIA expression, which might contribute to the cytoprotective effects of AT in the treatment of severe inflammatory diseases.

• Korean Journal of Pharmacognosy
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• v.33 no.1 s.128
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• pp.49-52
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• 2002

Amentoflavone, naturally occurring biflavonoid, isolated from the leaves of Ginko biloba, selectively inhibited human seceretory phospholipase $A_2$. This compound potently and irreversibly inhibited human group IIA in a dose dependent manner with an $IC_50$ about $3\;{\mu}M$. Amentoflavone inhibited phospholipase $A_2$ by a noncompetitive manner with the apparent Ki value of $1{\times}10^{-5}M$. In addition, the inhibitory activity of amentoflavone is rather specific against group IIA phospholipase $A_2$ than group IB phospholipase $A_2$. Furthermore, this compound strong inhibit histamine release from $A_{23187}$ treated rat peritoneal mast cells. These results indicate naturally occurring biflavonoid represents a novel anti-inflammatory agent.

• Journal of Yeungnam Medical Science
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• v.21 no.2
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• pp.177-190
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• 2004

Background: Secretory phospholipase $A_2$ ($sPLA_2$) are a group of extracellular enzymes that release fatty acids at the sn-2 position of phospholipids. Group IIA $sPLA_2$ ($sPLA_2$-IIA) has been detected in the inflammatory fluids, and its plasma level increases in the inflammatory disease. This study examined the effect of $sPLA_2$-IIA on mouse macropahges in order to investigate the potential mechanism of $sPLA_2$-induced inflammation. Materials and Methods: Wild type $PLA_2$ and mutant H48Q $PLA_2$ were purified from HEK293 cells transfected with the corresponding plasmids, and the $PLA_2$ activities were measured using 1-palmitoyl-2-[1-$^{14}C$]linoleoyl-3-phosphatidylethanolamine as substrates. The TNF-${\alpha}$ and IL-6 released in the supernatants were determined by ELISA. In addition, the TNF-${\alpha}$ and IL-6 mRNA were analyzed by RT-PCR. Results: $sPLA_2$-IIA stimulated the production of TNF-${\alpha}$ and IL-6 in a dose- and time-dependent manner. In addition, the effect of $sPLA_2$-IIA on cytokine production from the macrophage was found to be associated with the accumulation of their specific mRNA. The mRNA levels of TNF-${\alpha}$ and IL-6 peaked at 2 and 6 hours in a time-dependent manner, respectively. Conclusion: In conclusion, the production of proinflammatory cytokine might be mediated by the binding of $sPLA_2$-IIA to the receptors.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.21
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• pp.9417-9421
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• 2014

Background: Esophageal cancer is one of the most frequently occurring malignancies and the seventh leading cause of cancer-related deaths in the world. The esophageal squamous cell carcinoma (ESCC) is the most common histological type of esophageal cancer worldwide. Materials and Methods: Our goal in this study was to detect phospholipase A2 Group IIA (PLA2G2A) and cyclooxygenase-2 (COX-2) immuno-expression in ESCC in a high-risk population in China. Results: Positive expression of PLA2G2A protein was observed in 57.2% (166/290) of the cases, while COX-2 was found in 257 of 290 samples (88.6%), both PLA2G2A and COX-2 being expressed in 153 cases (52.8%), with a significant agreement (Kappa=0.091, p=0.031).Overexpression of PLA2G2A was significantly correlated with the depth of invasion (p=0.001). Co-expression of PLA2G2A and COX-2 not only significantly correlated with the depth of invasion (p=0.004) but also with TNM stage (p=0.04). Conclusions: Our results showed that in patients with ESCC, PLA2G2A overexpression and PLA2G2A co-expression with COX-2 is significantly correlated with advanced stage. The biological role and pathophysiologic regulation of PLA2G2A and COX-2 overexpression in ESCC deserve further investigation.

• Food Science and Preservation
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• v.19 no.2
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• pp.287-293
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• 2012

Lycopene, found in tomatoes and tomato products, has antioxidant, anticancer, and anti-inflammatory effects. High-mobility-group box 1 (HMGB1) mediates the pro-inflammatory responses in several inflammatory diseases. In this study, the potential roles of lycopene in the HMGB1-mediated pro-inflammatory gene expressions in the primary human-umbilical-vein endothelial cells (HUVECs) were investigated. The data showed that HMGB1 upregulated the expressions of monocyte chemotactic protein 1 (MCP-1), interleukin-6 (IL-6), secretory phospholipase A2 (sPLA2)-IIA, and prostaglandin E2 (PGE2). Lycopene pre-incubation for 6 h decreased the HMGB1-mediated induction of MCP-1, IL-6, sPLA2-IIA, and PGE2. Further study revealed that the inhibitory effects of lycopene on the HMGB-1 induced expression of pro-inflammatory genes were mediated by the inhibition of two important inflammatory cytokines: tumor necrosis factor (TNF)-${\alpha}$ and nuclear factor (NF)-${\kappa}B$. These results suggest that HMGB1 upregulated the expression of pro-inflammatory genes and lycopene inhibited HMGB-1-induced pro-inflammatory genes by inhibiting TNF-${\alpha}$ and NF-${\kappa}B$. This finding will serve as an important evidence in the development of a new medicine for the treatment of inflammatory diseases.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.4
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• pp.1797-1802
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• 2014

Background: The prostaglandin-endoperoxide synthase 2 (PTGS2) and phospholipase A2 group IIA (PLA2G2A) genes encode enzymes that are involved in arachidonic acid and prostaglandin biosynthesis. Dysregulation of both genes is associated with inflammation and carcinogenesis, including esophageal squamous cell carcinoma (ESCC). We therefore hypothesized that there is an association between single nucleotide polymorphisms (SNPs) in these genes and susceptibility to ESCC. Methods: We performed a gene-wide tag SNP-based association study to examine the association of SNPs in PTGS2 and PLA2G2A with ESCC in 269 patients and 269 healthy controls from Taihangshan Mountain, Henan and Hebei Provinces, the rural area of China which has the highest incidence of esophageal cancer in the world. Thirteen tag SNPs in PLA2G2A and 4 functional SNPs in PTGS2 were selected and genotyped using a high-throughput Mass Array genotyping platform. Results: We found a modest increased risk of ESCC in subjects with the PTGS2 rs12042763 AA genotype (OR=1.23; 95% CI, 1.00-3.04) compared with genotype GG. For PLA2G2A, a decreased risk of ESCC was observed in subjects with the rs11677 CT (OR=0.51, 95%CI, 0.29-0.85) or TT genotype (OR=0.51, 95%CI, 0.17-0.96) or the T carriers (CT+TT) (OR=0.52, 95%CI, 0.31-0.85) when compared with the CC genotype. Also for PLA2G2A, rs2236771 C allele carriers were more frequent in the control group (P=0.02). Subjects with the GC (OR=0.55, 95%CI, 0.33-0.93) or CC genotype (OR=0.38, 95% CI, 0.16-0.94) or the C carriers (GC+CC) (OR=0.52, 95%CI, 0.32-0.85) showed a negative association with ESCC susceptibility. Conclusions: Our results suggest that PTGS2 and PLA2G2A gene polymorphisms may modify the risk of ESCC development.