Deleterious brain cell membrane effects after NMDA receptor antagonist administration to newborn piglets

Previous studies have shown that administration of the N-methyl- -aspartate (NMDA) receptor antagonist 3-(2-carboxypiperazin-4-yl)-1-phosphonic acid (CPP) reduces NMDA-mediated neurotoxicity in animal models of hypoxia/ischemia but also may induce brain tissue vacuolization and alter glucose metabolism. The present study tests the hypothesis that CPP administration alters brain cell membrane structure and function in the cerebral cortex of normoxic newborn piglets through the generation of oxygen free radicals and induction of lipid peroxidation. Twenty six anesthetized, ventilated newborn piglets—13 treated with 2 mg/kg i.v. CPP and 13 untreated controls—were studied. ATP and phosphocreatine (PCr) levels were measured as an index of cellular energy metabolism and tissue glucose levels determined. Na⁺,K⁺-ATPase activity was measured as an index of brain cell membrane function and the lipid peroxidation products conjugated dienes (CD) and fluorescent compounds (FC) measured. Free radical generation was detected on cortical biopsies homogenized with α-phenyl-N-tert-butyl-nitrone (PBN) through electron spin resonance spectroscopy. Signal height of spectrum was divided by dry tissue weight and expressed as mm/g tissue. In the two groups brain tissue ATP and PCr levels were not different. Tissue glucose levels were higher in the CPP group (24±5 mg/dl) than in controls (14±3 mg/dl), p<0.05, whereas Na⁺,K⁺-ATPase activity was lower in the CPP group than in controls (34±4 vs. 43±6 μmol Pi/mg protein/h), p<0.05. Lipid peroxidation products were higher in the CPP group (CD: 57±19 nmol/g brain, FC: 1.5±0.3 μg/g brain) than in controls (CD: 0±0 nmol/g brain, FC: 0.9±0.2 μg/g brain), p<0.05. Free radical intensity was higher in the CPP group (493±397 mm/g tissue) than in controls (51±83 mm/g tissue), p<0.05. In vitro administration of CPP to brain cell membranes did not change Na⁺,K⁺-ATPase activity or the generation of lipid peroxidation products. The data demonstrate that administration of CPP induces lipid peroxidation, results in free radical generation, decreases brain cell membrane Na⁺,K⁺-ATPase activity and alters glucose metabolism in the cerebral cortex of newborn piglets. Since CPP is a potent antagonist of the NMDA receptor, we speculate that CPP generates free radicals through a pathway independent of the NMDA receptor by altering cellular metabolism and possibly glucose utilization during normoxia in newborn piglets.     

间氯苯哌嗪诱导的小鼠明暗箱焦虑模型 一种新的经济简便抗焦虑药筛选模型

目的　建立经济简便的抗焦虑药模型。方法　用间氯苯哌嗪 (mCPP)诱导产生焦虑 ,观察ddy小鼠和ICR小鼠在明暗箱的行为表现。结果　mCPP在sc 1～ 4mg·kg-1的剂量下即可显著降低ddy小鼠在明箱的活动次数 ,而对暗箱的活动次数影响不显著 ;mCPP在sc 2～ 10mg·kg-1的剂量下对ICR小鼠在明箱的的活动次数影响不明显 ;用地西泮对该模型进行验证 ,发现只用较小的样本量即可得出显著结果。结论　ddy小鼠可取代Wistar大鼠进行mCPP诱导焦虑的明暗箱模型 ,且简便易得 ,经济有效。     

Using drug-excipient interactions for siRNA delivery

SiRNA is the trigger of RNA interference, a mechanism discovered in the late 1990s. To release the therapeutic potential of this versatile but large and fragile molecule, excipients are used which either interact by electrostatic interaction, passively encapsulate siRNA or are covalently attached to enable specific and safe delivery of the drug substance. Controlling the delicate balance between protective complexation and release of siRNA at the right point and time is done by understanding excipients-siRNA interactions. These can be lipids, polymers such as PEI, PLGA, Chitosans, Cyclodextrins, as well as aptamers and peptides. This review describes the mechanisms of interaction of the most commonly used siRNA delivery vehicles, and looks at the results of their clinical and preclinical studies.     

Direct inhibition of NF-κB activation by peptide targeting the NOA ubiquitin binding domain of NEMO

Aberrant and constitutive NF-κB activation are frequently reported in numerous tumor types, making its inhibition an attractive target for the treatment of certain cancers. NEMO (NF-κB essential modulator) is the crucial component of the canonical NF-κB pathway that mediates IκB kinase (IKK) complex activation. IKK activation resides in the ability of the C-terminal domain of NEMO to properly dimerize and interact with linear and K63-linked polyubiquitin chains. Here, we have identified a new NEMO peptide inhibitor, termed UBI (ubiquitin binding inhibitor) that derives from the NOA/NUB/UBAN ubiquitin binding site located in the CC2-LZ domain of NEMO. UBI specifically inhibits the NF-κB pathway at the IKK level in different cell types stimulated by a variety of NF-κB signals. Circular dichroïsm and fluorescence studies showed that UBI exhibits an increased α-helix character and direct, good-affinity binding to the NOA-LZ region of NEMO. We also showed that UBI targets NEMO in cells but its mode of inhibition is completely different from the previously reported LZ peptide (herein denoted NOA-LZ). UBI does not promote dissociation of NEMO subunits in cells but impairs the interaction between the NOA UBD of NEMO and polyubiquitin chains. Importantly, we showed that UBI efficiently competes with the in vitro binding of K63-linked chains, but not with linear chains. The identification of this new NEMO inhibitor emphasizes the important contribution of K63-linked chains for IKK activation in NF-κB signaling and would provide a new tool for studying the complex role of NF-κB in inflammation and cancer.     

慢性盆腔疼痛病症的中医药治疗

慢性盆腔疼痛病症为妇科的常见和难治性疾病,其核心病机为瘀血内阻,湿热、肾虚、寒凝、气滞是导致瘀血内阻的常见病因,其中又以湿热瘀结最为常见。临床治疗可根据异病同治的原则,采用内外合治的综合疗法,可取得良好的临床疗效。     

Role of MEK‐ERK pathway in morphine‐induced conditioned place preference in ventral tegmental area of rats

A major goal of research on drug addiction is to develop the effective treatments to deal with the long‐term behavioral disorders especially reinstatement induced by the addictive drugs such as opiates, cocaine, and cannabinoid. The molecular mechanisms underlying these substance‐related disorders remain unclear so far. Here we used the model of morphine‐induced conditioned place preference (CPP) in rats to mimic the progress of drug‐taking, withdrawal and relapse in human. The tissue of ventral tegmental area (VTA), one of the most important brain structures associated with abused drug‐related disorders, was taken and two‐dimensional electrophoresis (2‐DE) was performed to analyze and compare the changes of protein expression patterns during the different stages of morphine‐induced CPP. First, we found that there were 80 proteins identified to be changed in the process of morphine‐induced CPP. Furthermore, as the mitogen‐activated protein kinase kinase 1 (MAPKK1) was increased significantly in the stages of establishment and reinstatement, we confirmed the change of activated extracellular signal‐regulated kinase (ERK) by Western blotting in VTA tissue and cultured cell. The results demonstrated that the activated MEK‐ERK pathway by chronic morphine treatment in VTA was involved in morphine‐induced reinstatement. Moreover, inhibition of MEK‐ERK pathway by infusion the MEK inhibitor U0126 in VTA blocked the establishment of morphine‐induced CPP. The present study found significant changes in a group of protein expressions in VTA during morphine‐induced CPP and further confirmed the role of MEK‐ERK cell signaling pathway of VTA in morphine addiction. © 2010 Wiley‐Liss, Inc.     

Novel immunotherapeutic approaches to skin cancer treatments using protein transduction technology

Protein-transduction domains (PTDs) are short stretches of cationic amino acids that enable peptides, proteins, oligonucleotides, and other reagents to efficiently enter multiple cell types. Therefore, PTDs offer unique therapeutic opportunities for the treatment of many diseases. Previous studies examined the in vivo distribution of PTD-containing fusion proteins following administration via different routes, including portal vein, intravenous, intraperitoneal, and oral administration. Skin may be an appropriate target organ for this new molecular-carrier system; however, there are no studies on the in vivo kinetics and biological effects of PTD-containing proteins following intradermal application. Among the PTDs, poly-arginine peptides, especially nona-arginine (R9), is transported most efficiently with minimal cytotoxicity. Here, we review protein transduction technology from a different angle, as a novel tool in immunotherapeutic approaches to the skin cancers that depend on the biological characteristics of poly-arginine. This could be used in place of gene therapy for skin cancer patients.     

针刺对海洛因依赖康复期小鼠欣快记忆激发的影响

目的:研究针刺对海洛因欣快记忆激发的抑制作用,为针刺防复吸提供依据。方法:经行为学筛选后的90只雄性昆明种小鼠,随机分为空白组、针空组、模型组、腧穴组、非穴组、纳曲酮组。按剂量逐日递增原则进行海洛因心理依赖造模,针刺“内关”、“三阴交”、“四神聪”穴,每日1次,10次为1疗程。运用计算机条件位置偏爱系统测试进行欣快记忆激发的行为学评价。结果:治疗后模型组条件位置偏爱时间较空白组和针空组延长,显著性差异,P<0.01;腧穴组、纳曲酮组条件位置偏爱时间较模型组缩短,有显著性差异,P<0.01;非穴组和模型组比较,无统计学差异,P>0.05。结论:针刺能缩短小鼠海洛因心理依赖形成后在条件位置偏爱装置中偏爱箱中的停留时间,对环境激发海洛因欣快记忆具有一定抑制作用。