Cox-2 gene variants in migraine

Purpose

Migraine is a multifactorial and complex disorder, and any clear diagnostic marker to assess the status of the migraineurs has not been established, yet. Nonsteroidal anti-inflammatory drugs reduce production of prostanoids including PGE2 by inhibiting COX-1 and/or COX-2, and thereby suppress inflammatory pain in patients suffering from rheumatoid arthritis, osteoarthritis, and migraine. Thus, COX-2 regulation is important in the pathogenesis and treatment of migraine. We prospectively investigated COX-2-765G → C and COX-2-1195A → G gene polymorphisms which may account for an increased risk of migraine.

Methods

The present analyses are based on 144 case subjects with migraine disease and 123 non-case subjects. Genotyping of COX-2 gene polymorphisms (COX-2-765G → C, COX-2-1195A → G) was detected by PCR-RFLP.

Results

We, for the first time, demonstrated positive association of COX-2 gene variants with an increased risk for development of migraine. Carriers of COX-2-765 C + genotype in controls were higher than in the patients (57.7% and 36.1% respectively; P < 0.0001) and the frequencies of G + genotype in patients were higher than in the controls (97.9% and 88.6% respectively; P: 0.002). In addition, frequencies of COX-2-765 GG and GC genotypes in patients were higher than in the controls (P < 0.0001, P < 0.0001 respectively). It seems that COX-2-765 G + genotype had increased and COX-2-765 C + genotype had decreased risk for migraine. In COX-2-1195 polymorphism only AG genotype was statistically significantly different in patients than in the controls (P < 0.05).

Conclusions

Our findings have suggested that COX-2-765 G + genotype could facilitate the development of migraine disease.     

Delayed production of arachidonic acid contributes to the delay of proteinase-activated receptor-1 (PAR1)-triggered prostaglandin E2 release in rat gastric epithelial RGM1 cells

Proteinase-activated receptor-1 (PAR1), upon activation, exerts prostanoid-dependent gastroprotection, and increases prostaglandin E(2) (PGE(2)) release through cyclooxygenase-2 (COX-2) upregulation in rat gastric mucosal epithelial RGM1 cells. However, there is a big time lag between the PAR1-triggered PGE(2) release and COX-2 upregulation in RGM1 cells; that is, the former event takes 18 h to occur, while the latter rapidly develops and reaches a plateau in 6 h. The present study thus aimed at clarifying mechanisms for the delay of PGE(2) release after PAR1 activation in RGM1 cells. Although a PAR1-activating peptide, TFLLR-NH(2), alone caused PGE(2) release at 18 h, but not 6 h, TFLLR-NH(2) in combination with arachidonic acid dramatically enhanced PGE(2) release even for 1-6 h. TFLLR-NH(2) plus linoleic acid caused a similar rapid response. CP-24879, a Δ(5)/Δ(6)-desaturase inhibitor, abolished the PGE(2) release induced by TFLLR-NH(2) plus linoleic acid, but not by TFLLR-NH(2) alone. The TFLLR-NH(2)-induced PGE(2) release was not affected by inhibitors of cytosolic phospholipase A(2) (cPLA(2)), Ca(2+)-independent PLA(2) (cPLA(2)) or secretory PLA(2) (sPLA(2)), but was abolished by their mixture or a pan-PLA(2) inhibitor. Among PLA(2) isozymes, mRNA of group IIA sPLA(2) (sPLA(2)-IIA) was upregulated following PAR1 stimulation for 6-18 h, whereas protein levels of PGE synthases were unchanged. These data suggest that the delay of PGE(2) release after COX-2 upregulation triggered by PAR1 is due to the poor supply of free arachidonic acid at the early stage in RGM1 cells, and that plural isozymes of PLA(2) including sPLA(2)-IIA may complementarily contribute to the liberation of free arachidonic acid.     

Knockout mice lacking cPGES/p23, a constitutively expressed PGE2 synthetic enzyme, are peri-natally lethal

Cytosolic prostaglandin (PG) E synthase (cPGES) is constitutively expressed in various cells and regulates cyclooxygenase (COX)-1-dependent immediate PGE(2) generation. Its primary structure is identical to co-chaperone p23, a heat shock protein 90 (Hsp90)-binding protein. We have revealed that Hsp90 regulated both cPGES/p23 and its client protein kinase CK2. In this study, in order to examine the role of cPGES/p23 in vivo, we generated mice deficient in cPGES/p23 by a targeted disruption of exons 2 and 3, containing Tyr9, which is essential for catalytic activity. Heterozygotes are viable, fertile, and appear normal, despite a decrease in cPGES/p23 protein level. A generation of offsprings derived from intercrosses of cPGES/p23 homozygous mice revealed that 109, 247, and 10 pups were wild type, heterozygous, and homozygous, respectively; however, all homozygotes died at birth. The absence of viable null mutants, with heterozygotes and wild-type offspring obtained at a ratio of approximately 2:1, indicated that homozygosity for the cPGES/p23 null mutant leads to peri-natal lethality. Embryos homozygous for cPGES/p23-null had lower body weights than wild-type embryos, and abnormal morphology of skin and lungs. Moreover, the PGE(2) content in the lungs of cPGES/p23-null embryos was lower than that of the wild type. These results indicate that cPGES-derived PGES is involved in the normal development of mouse embryonic lung.     

Blockade of Fas Signaling in Breast Cancer Cells Suppresses Tumor Growth and Metastasis via Disruption of Fas Signaling-initiated Cancer-related Inflammation

Mechanisms for cancer-related inflammation remain to be fully elucidated. Non-apoptotic functions of Fas signaling have been proposed to play an important role in promoting tumor progression. It has yet to be determined if targeting Fas signaling can control tumor progression through suppression of cancer-related inflammation. In the current study we found that breast cancer cells with constitutive Fas expression were resistant to apoptosis induction by agonistic anti-Fas antibody (Jo2) ligation or Fas ligand cross-linking. Higher expression of Fas in human breast cancer tissue has been significantly correlated with poorer prognosis in breast cancer patients. To determine whether blockade of Fas signaling in breast cancer could suppress tumor progression, we prepared an orthotopic xenograft mouse model with mammary cancer cells 4T1 and found that blockade of Fas signaling in 4T1 cancer cells markedly reduced tumor growth, inhibited tumor metastasis in vivo, and prolonged survival of tumor-bearing mice. Mechanistically, blockade of Fas signaling in cancer cells significantly decreased systemic or local recruitment of myeloid derived suppressor cells (MDSCs) in vivo. Furthermore, blockade of Fas signaling markedly reduced IL-6, prostaglandin E2 production from breast cancer cells by impairing p-p38, and activity of the NFκB pathway. In addition, administration of a COX-2 inhibitor and anti-IL-6 antibody significantly reduced MDSC accumulation in vivo. Therefore, blockade of Fas signaling can suppress breast cancer progression by inhibiting proinflammatory cytokine production and MDSC accumulation, indicating that Fas signaling-initiated cancer-related inflammation in breast cancer cells may be a potential target for treatment of breast cancer.     

In vivo and in vitro anti-inflammatory activity of Cryptostegia grandiflora Roxb. ex R. Br. leaves

Background

Despite Cryptostegia grandiflora Roxb. ex R. Br. (Apocynaceae) leaves are widely used in folk Caribbean Colombian medicine for their anti-inflammatory effects, there are no studies that support this traditional use. Therefore, this work aimed to evaluate the effect of the total extract and primary fractions obtained from Cryptostegia grandiflora leaves, using in vivo and in vitro models of inflammation, and further get new insights on the mechanisms involved in this activity.

Results

Ethanolic extract of Cryptostegia grandiflora leaves, and its corresponding ether and dichloromethane fractions, significantly reduced inflammation and myeloperoxidase activity (MPO) in ear tissue of mice treated with 12-O-tetradecanoyl-phorbol-13-acetate (TPA). Histological analysis revealed a reduction of edema and leukocyte infiltration. Complementarily, we demonstrated that extract and fractions reduced nitric oxide (NO•) and prostaglandin E2 (PGE2) production in LPS-stimulated RAW 264.7 macrophages, as well as scavenging activity on DPPH and ABTS radicals.

Conclusions

Our results demonstrated for the first time the anti-inflammatory activity of Cryptostegia grandiflora leaves, supporting its traditional use. This activity was related to inhibition of MPO activity, and PGE2 and NO• production. These mechanisms and its antioxidant activity could contribute, at least in part, to the anti-inflammatory effect showed by this plant.     

Tick salivary secretion as a source of antihemostatics

Ticks are mostly obligatory blood feeding ectoparasites that have an impact on human and animal health. In addition to direct damage due to feeding, some tick species serve as the vectors for the causative agents of several diseases, such as the spirochetes of the genus Borrelia causing Lyme disease, the virus of tick-borne encephalitis, various Rickettsial pathogens or even protozoan parasites like Babesia spp. Hard ticks are unique among bloodfeeders because of their prolonged feeding period that may last up to two weeks. During such a long period of blood uptake, the host develops a wide range of mechanisms to prevent blood loss. The arthropod ectoparasite, in turn, secretes saliva in the sites of bite that assists blood feeding. Indeed, tick saliva represents a rich source of proteins with potent pharmacologic action that target different mechanisms of coagulation, platelet aggregation and vasoconstriction. Tick adaptation to their vertebrate hosts led to the inclusion of a powerful protein armamentarium in their salivary secretion that has been investigated by high-throughput methods. The resulting knowledge can be exploited for the isolation of novel antihemostatic agents. Here we review the tick salivary antihemostatics and their characterized functions at the molecular and cellular levels.     

噬菌体展示技术筛选大鼠佐剂性关节炎中PGE2受体的拮抗剂

目的：通过筛选PGE2受体拮抗剂,来探讨其在类风湿性关节炎（rheumatoid arthritis, RA）中的作用,为RA的治疗开辟新的途径。方法：应用噬菌体展示技术,以PGE2为靶点,对噬菌体环七肽库进行"吸附-洗脱-扩增"筛选过程,5轮筛选后,随机挑取噬菌体克隆进行亲和力鉴定,并选取亲和力高的克隆进行测序并对序列进行分析。合成环七肽后,建立佐剂性关节炎（AA）动物模型,通过分析足爪肿胀度,以及采用ELISA方法检测关节浸液中细胞因子的含量,对小肽的抗炎作用进行探讨。结果：噬菌体经过富集后,随机挑选的23个克隆中有21个阳性克隆,而在测序的8个克隆中4个具有相同的序列,其余也具有保守氨基酸。合成的环七肽能降低AA关节的肿胀度并减少关节浸液中前炎症细胞因子的含量。结论:噬菌体筛选PGE2受体拮抗剂的方法可行,并且得到的环七肽具有一定的抗炎作用。     

牙周炎病人牙龈组织PGE2龈下韦荣菌的相关分析

目的 探讨牙周炎病人牙龈组织PGE2的含量及与细菌的关系。方法 采用放射免疫方法测定PGE2含量,以厌氧培养及活菌计数（CFU）的方法检测了链球菌及韦荣菌的含量。结果 牙周炎病人牙龈组织PGE2的含量显著于健康对照组,并与韦菌的量呈显著正相关。结论 PGE2与牙周炎骨质破坏关系密切,韦荣菌在牙周炎发病中具有重大作用.     

牙周夹板联合正畸治疗对牙周炎所致前牙扇形移位患者咀嚼功能和龈沟液PGE2、sICAM-1、PAK5的影响

目的:探讨牙周夹板联合正畸治疗对牙周炎所致前牙扇形移位患者咀嚼功能和龈沟液中前列素E2(PGE2)、可溶性细胞间黏附分子-1(s ICAM-1)、p2l活化激酶5(PAK5)的影响。方法:采用随机数字表法,将我院2018年2月~2020年2月间接收的93例牙周炎所致前牙扇形移位患者分为对照组(46例,牙周基础治疗、牙周夹板治疗)和研究组(47例,牙周基础治疗、牙周夹板治疗联合正畸治疗),观察两组疗效,对比两组治疗前后的牙周情况,咀嚼功能、美观度,龈沟液PGE2、s ICAM-1、PAK5水平。结果:研究组的临床总有效率高于对照组(P<0.05)。研究组治疗后牙周菌斑指数(PLI)、探诊深度(PD)、牙龈指数(GI)、附着丧失(AL)、龈沟出血指数(SBI)低于对照组(P<0.05)。研究组治疗后探诊出血率、前牙咬合低于对照组,咀嚼功能评分高于对照组(P<0.05)。研究组治疗后牙周袋深度、前牙覆盖度、牙槽骨高度低于对照组(P<0.05)。研究组治疗后龈沟液PGE2、s ICAM-1、PAK5水平低于对照组(P<0.05)。结论:牙周夹板联合正畸治疗可有效恢复牙周炎所致前牙扇形移位患者牙周功能和咀嚼功能,且美观效果好,还可减轻对龈沟液PGE2、s ICAM-1、PAK5水平的影响。