吐温80对体外HeLa细胞的杀伤抑制

研究吐温80对体外培养HeLa细胞的杀伤抑制。通过MTT法检测并观察了不同浓度吐温80、大肠杆菌内毒素(LPS)及前列腺素E1(PGEI)对体外培养HeLa细胞作用后细胞抑制率;将作用后细胞裂解液经SDS-PAGE及Western-blotting法测定其热休克蛋白70(Heat Shock Protein70,HSP70)表达。结果:0.02％吐温80具有明显杀伤HeLa细胞的作用,且作用后的HeLa细胞几乎无HSP70蛋白表达(正常HeLa细胞有一定量HSP70蛋白表达),但却有一种分子量为70kDa的蛋白高表达,表明吐温80显著抑制HSP70表达,以至HeLa细胞死亡,同时促使某一种蛋白大量堆积。大肠杆菌内毒素、前列腺素E1对HeLa细胞无明显抑制杀伤作用,且与吐温80无明显协同效应,同时亦对HeLa细胞HSP70表达无显著影响。推测:吐温80对HeLa细胞HSP70表达的显著抑制作用可能是其杀伤HeLa细胞的 作用机制之一,为理想的温热治疗肿瘤的协同合并作用药物,但其使细胞内大量某70kDa蛋白堆积现象有待进一步探讨。     

用流式细胞光度术研究PGE2对小鼠骨髓CFU—GM细胞周期的影响

在一定PGE_2浓度(4.8×10~(-9)mol/L)作用下,小鼠骨髓细胞CFU-GM经4.5d和7d培养后,其增殖状态下的细胞G_n/G_r期细胞数均比对照组增加,S期细胞数减少,G_2 M期细胞数也有下降,但不明显。在不同PGE_2浓度(2.8×10~(-9)～2.8×10~(-6)mol/L)作用下,经4d培养,随着PGE_2浓度增加,G_n/G_1期细胞数递增,而S期细胞数却随PGE_2浓度增加而减少,G_2 M细胞数也减少,但与PGE_2剂量关系不明显。以上实验结果提示,PGE_2主要抑制G_1期细胞向S期细胞的转化,阻断S期细胞生长。 此外,通过流式细胞光度术(FCM)对小鼠骨髓细胞CFU-GM集落细胞的前向角和90°散射光测定,与对照组比较,前者无变化,后者变化较明显。此结果表明,PGE_2对细胞内部颗粒的折光度有影响。     

Trisubstituted ureas as potent and selective mPGES-1 inhibitors

A novel series of trisubstituted ureas has been identified as potent and selective mPGES-1 inhibitors. These compounds are selective over other prostanoid enzymes such as PGF synthase and TX synthase. This series of inhibitors was developed by lead optimization of a hit from an internal HTS campaign. Lead compound 42 is potent in A549 cell assay (IC₅₀ of 0.34 μM) and in human whole blood assay (IC₅₀ of 2.1 μM). An efficient and versatile one-pot strategy for the formation of ureas, involving a reductive amination, was developed to generate these inhibitors.     

Nimesulide analogues: From anti-inflammatory to antitumor agents

Nimesulide is a nonsteroidal anti-inflammatory drug possessing analgesic and antipyretic properties. This drug is considered a selective cyclooxygenase-2 (COX-2) inhibitor and, more recently, has been associated to antitumor activity. Thus, numerous works have been developed to modify the nimesulide skeleton aiming to develop new and more potent and selective COX-2 inhibitors as well as potential anticancer agents. This review intends to provide an overview on analogues of nimesulide, including the general synthetic approaches used for their preparation and structural diversification and their main anti-inflammatory and/or antitumor properties.     

Arylpropionic acid-derived NSAIDs: New insights on derivatization,anticancer activity and potential mechanism of action

NSAIDs displayed chemopreventive and anticancer effects against several types of cancers. Moreover, combination of NSAIDs with anticancer agents resulted in enhanced anticancer activity. These findings have attracted much attention of researchers working in this field. The 2-arylpropionic acid-derived NSAIDs represent one of the most widely used anti-inflammatory agents. Additionally, they displayed antiproliferative activities against different types of cancer cells. Large volume of research was performed to identify molecular targets responsible for this activity. However, the exact mechanism underlying the anticancer activity of profens is still unclear. In this review article, the anticancer potential, structure activity relationship and synthesis of selected profen derivatives were summarized. This review is focused also on non-COX targets which can mediate the anticancer activity of this derivatives. The data in this review highlighted profens as promising lead compounds in future research to develop potent and safe anticancer agents.     

Impact of advanced glycation end products (AGEs) signaling in coronary artery disease

Coronary artery disease remains the leading cause of mortality in adult diabetic population with however, a high predominance also in non-diabetic subjects. In search of common molecular mechanisms and metabolic by-products with potential pathogenic role, increased advanced glycation end products (AGEs) present a critical biomarker for CAD development in both cases. Interaction of AGEs with their transmembrane cell receptor, RAGE in endothelial and smooth muscle cells as well as in platelets, activates intracellular signaling that leads to endothelial injury, modulation of vascular smooth muscle cell function and altered platelet activity. Furthermore, tissue accumulation of AGEs affects current treatment approaches being involved in stent restenosis. The present review provides an update of AGE-induced molecular mechanisms involved in CAD pathophysiology while it discusses emerging therapeutic interventions targeting AGE reduction and AGE-RAGE signaling with beneficial clinical outcome.     

An amperometric pyruvate biosensor based on pyruvate oxidase nanoparticles immobilized onto pencil graphite electrode

This present study was aimed to fabricate a sensitive and improved amperometric biosensor by the nanoparticles of pyruvate oxidase, which were prepared and immobilized covalently onto pencil graphite electrode. The biosensor showed ideal working within 5 s under defined conditions of pH 6.0 and incubation temperature of 30 °C at an applied voltage of -0.1 V. Under standard assay conditions, a linear response was obtained between pyruvate concentration ranging from 0.001 to 6000 μM and current (μA). A lower detection limit (0.58 μM) and an excellent correlation coefficient (R² = 0.999) with standard spectrophotometric assay was obtained for the present biosensor. Within and between batches of coefficients of variation were calculated and found to be 3.61 % and 3.33 %, respectively. The biosensor was put to continual use for over 210 days. The biosensor was employed for the measurement of pyruvate level in sera of normal healthy individuals and persons suffering from heart disease.     

PGE2 MEDIATES OENOCYTOID CELL LYSIS VIA A SODIUM‐POTASSIUM‐CHLORIDE COTRANSPORTER

Prostaglandin E₂ (PGE₂) mediates immune responses of the beet armyworm, Spodoptera exigua, including oenocytoid cell lysis (a class of lepidopteran hemocytes: OCL) via its specific membrane receptor to release inactive prophenoloxidase (PPO) into hemolymph. PPO is activated into phenoloxidase in the plasma to play crucial roles in the immune responses of S. exigua. The mechanism of OCL has not been elucidated, however we posed the hypothesis that a rapid accumulation of sodium ions within the oenocytoids allows a massive influx of water by the ion gradient, which leads to the cell lysis. It remains unclear which sodium channel is responsible for the OCL in response to PGE₂. This study identified a specific sodium channel called sodium‐potassium‐chloride cotransporter 1 (Se‐NKCC1) expressed in hemocytes of S. exigua and analyzed its function in the OCL in response to PGE₂. Se‐NKCC1 encodes a basic membrane protein (pI value = 8.445) of 1,066 amino acid residues, which contains 12 putative transmembrane domains. Se‐NKCC1 was expressed in all developmental stages and tissues. qPCR showed that bacterial challenge significantly induced its expression. A specific inhibitor of NKCC, bumetanide, prevented the OCL in a dose‐dependent manner. When RNA interference (RNAi) using double‐stranded RNA specific to Se‐NKCC1 suppressed its expression, the OCL and PPO activation were significantly inhibited in response to PGE₂. The RNAi treatment also reduced nodule formation to bacterial challenge. These results suggest that Se‐NKCC1 is associated with OCL by facilitating inward transport of ions in response to PGE₂.