Discovery of a small-molecule inhibitor and cellular probe of Keap1–Nrf2 protein–protein interaction

A high-throughput screen (HTS) of the MLPCN library using a homogenous fluorescence polarization assay identified a small molecule as a first-in-class direct inhibitor of Keap1–Nrf2 protein–protein interaction. The HTS hit has three chiral centers; a combination of flash and chiral chromatographic separation demonstrated that Keap1-binding activity resides predominantly in one stereoisomer (SRS)-5 designated as ML334 (LH601A), which is at least 100× more potent than the other stereoisomers. The stereochemistry of the four cis isomers was assigned using X-ray crystallography and confirmed using stereospecific synthesis. (SRS)-5 is functionally active in both an ARE gene reporter assay and an Nrf2 nuclear translocation assay. The stereospecific nature of binding between (SRS)-5 and Keap1 as well as the preliminary but tractable structure–activity relationships support its use as a lead for our ongoing optimization     

Therapeutic and pharmacokinetic characterizations of an anti-amyloidogenic bis-styrylbenzene derivative for Alzheimer’s disease treatment

Alzheimer’s disease drug discovery regarding exploration into the molecules and processes has focused on the intrinsic causes of the brain disorder correlated with the accumulation of amyloid-β. An anti-amyloidogenic bis-styrylbenzene derivative, KMS80013, showed excellent oral bioavailability (F = 46.2%), facilitated brain penetration (26%, iv) in mouse and target specific in vivo efficacy in acute AD mouse model attenuating the cognitive deficiency in Y-maze test. Acute toxicity (LD₅₀ >2000 mg/kg) and hERG channel inhibition (14% at 10 μM) results indicated safety of KMS80013.     

235例危重艾滋病患者临床急救体会

目的 探讨危重艾滋病患者的临床特点及急诊救治流程和管理,以提高危重艾滋病患者的识别及抢救成功率,实现安全救治.方法 收集急诊抢救的235例危重艾滋病患者的临床资料,对其临床特点进行回顾性分析,并于2012年实施了系统的急救管理,其有效性与未实施系统管理进行对比.结果 艾滋病病情复杂多样,常因为呼吸衰竭、休克、意识改变、出血等被送入急诊科;收入急诊科的艾滋病患者大多为晚期患者,CD4+T淋巴细胞数多低于50个/μl,常出现多个部位的症状.实施系统的管理方法,提高了危重患者抢救成功率,职业暴露减少,污染物品处理和细菌学监测全部合格,减少了医院感染和职业感染发生的风险.结论 晚期艾滋病症状复杂多样,临床应加强识别;建立健全危重艾滋病急救规范,是提高医疗质量,实现安全有效救治的重要因素.     

人参皂甙Rb1对心力衰竭大鼠蛋白激酶R样内质网激酶途径的影响

目的探讨人参皂甙Rbl（Gs—Rbl）改善阿霉素所致心力衰竭（HF）效应是否与调整蛋白激酶R样内质网激酶（PERK）通路有关。方法阿霉素（Adr）诱导的HF大鼠随机分为HF组（n=15）和Gs．Rbl组（70rng／kg／d,n=17）,另随机选取同龄大鼠作为对照组（n=10）。干预结束并进行心脏超声检查后,TUNNEL检测心肌细胞凋亡率（AR）,Western blot和Rt-PCR检测葡萄糖调节蛋白78（GRP78）、PERK、p-PERK、真核细胞起始因子2-（elF2a）、p-elF2a、C／EBP同源蛋白（CHOP）和cleavedcaspase-12。结果1．Adr干预成功构建HF模型,Gs—Rbl显著提高左室射血分数（LVEF）和降低心肌细胞AR（P〈O．01）;2．HF组GRP78mRNA和蛋白均显著高于对照组,Gs—Rbl显著低于HF组和对照组二组的表达（P〈0．01）;3．Gs—Rbl显著降低HF大鼠PERK和p-PERK表达（P〈0．01）;4．HF导致elF2amRNA和蛋白、p-elF2a显著升高,Gs—Rbl显著下调三者的表达（P〈O．01）;5．HF组CHOPmRNA和蛋白显著高于对照组,Gs—Rbl组显著抑制其表达（P〈0．01）;6．Gs—Rbl显著抑制阿霉素所致的caspase-121TIRNA和cleaved caspase-12蛋白表达（P〈0．01）。结论Gs—Rbl通过调节PERK内质网通路介导其改善HF效应。     

Highly sensitive near-simultaneous assay of multiple "lean meat agent" residues in swine urine using a disposable electrochemiluminescent immunosensors array

Nowadays, β(2)-agonists are abused illegally as "lean meat agents" for food-producing animals, and cause increasing food-safety accidents in some countries. Due to their hazard to the human health, "lean meat agents" are banned in most countries and required to be routinely monitored. We herein report a disposable electrochemiluminescent immunosensors array for near-simultaneous assay of multiple β(2)-agonist residues in swine urine, by using ractopamine and salbutamol as the models. In this investigation, a screen-printed carbon electrodes array was assembled and acted as the substrate of the immunosensors array. Then the immunosensors array was constructed by site-selectively immobilizing the antigens of ractopamine and salbutamol on the working electrodes of array. After the competitive immuno-binding, with the aid of a homemade single-pore-four-throw switch, the electrochemiluminescent signals of the two β(2)-agonists were sequentially detected using a non-array detector. The limits of detection for ractopamine and salbutamol were 8.5 and 17pg/mL, respectively, which were much lower than those of the most previous reports. Compared with other routine methods based on chromatography and ELISA, this method is more suitable for screening of multiple β(2)-agonists in quantities of samples, owing to its merits of low cost, user-friendliness and high throughput, and shows great promise in food safety and agonist surveillance.     

The HECTD3 E3 ubiquitin ligase facilitates cancer cell survival by promoting K63-linked polyubiquitination of caspase-8

Apoptosis resistance is a hurdle for cancer treatment. HECTD3, a new E3 ubiquitin ligase, interacts with caspase-8 death effector domains and ubiquitinates caspase-8 with K63-linked polyubiquitin chains that do not target caspase-8 for degradation but decrease the caspase-8 activation. HECTD3 depletion can sensitize cancer cells to extrinsic apoptotic stimuli. In addition, HECTD3 inhibits TNF-related apoptosis-inducing ligand (TRAIL)-induced caspase-8 cleavage in an E3 ligase activity-dependent manner. Mutation of the caspase-8 ubiquitination site at K215 abolishes the HECTD3 protection from TRAIL-induced cleavage. Finally, HECTD3 is frequently overexpressed in breast carcinomas. These findings suggest that caspase-8 ubiquitination by HECTD3 confers cancer cell survival.     

RhoGAPs Attenuate Cell Proliferation by Direct Interaction with p53 Tetramerization Domain

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Photoluminescent Gold Nanoclusters as Sensing Probes for Uropathogenic Escherichia coli

Glycan-bound nanoprobes have been demonstrated as suitable sensing probes for bacteria containing glycan binding sites. In this study, we demonstrated a facile approach for generating glycan-bound gold nanoclusters (AuNCs). The generated AuNCs were used as sensing probes for corresponding target bacteria. Mannose-capped AuNCs (AuNCs@Mann) were generated and used as the model sensors for target bacteria. A one-step synthesis approach was employed to generate AuNCs@Mann. In this approach, an aqueous solution of tetrachloroauric acid and mannoside that functionized with a thiol group (Mann-SH) was stirred at room temperature for 48 h. The mannoside functions as reducing and capping agent. The size of the generated AuNCs@Mann is 1.95±0.27 nm, whereas the AuNCs with red photoluminescence have a maximum emission wavelength of ∼630 nm (λ_excitation = 375 nm). The synthesis of the AuNCs@Mann was accelerated by microwave heating, which enabled the synthesis of the AuNCs@Mann to complete within 1 h. The generated AuNCs@Mann are capable of selectively binding to the urinary tract infection isolate Escherichia coli J96 containing the mannose binding protein FimH expressed on the type 1 pili. On the basis of the naked eye observation, the limit of detection of the sensing approach is as low as ∼2×10⁶ cells/mL.     

Trans-Ethnical Shift of the Risk Genotype in the CETP I405V with Longevity: A Chinese Case-Control Study and Meta-Analysis

Background

The I405V polymorphism of the cholesteryl ester transfer protein gene (CETP) has been suggested to be a protective factor conferring longevity in Ashkenazi Jews, although findings in other races are not supportive. This paper describes a case-control study and a meta-analysis conducted to derive a more precise estimation of the association between CETP 405V and longevity.

Methods

We enrolled 1,021 ethnic Han Chinese participants (506 in the longevity group and 515 controls), then performed a meta-analysis that integrated the current study and previously published ones. Pooled odds ratios (OR) were calculated for allele contrasts, dominant and recessive inheritance models to assess the association between CETP 405V and longevity according to the ethnic stratification.

Results

Our case-control data indicated that CETP 405V is a longevity risk allele in all genetic models (P _additive=0.008; P _dominant=0.008, OR_dominant=0.673; P _recessive=0.017, OR_recessive=0.654) after adjustment for the apolipoprotein E (APOE) ε4 allele, body mass index and high-density lipoprotein cholesterol. A synergy was detected between 405V and APOE ε4 (P=0.001, OR=0.530). Eight studies were eligible for meta-analysis, which confirmed 405V is the risky allele against longevity in all genetic models: allele contrasts (OR=0.81, 95%CI=0.74-0.88), dominant model (OR=0.72, 95%CI=0.64-0.82) and recessive model (OR=0.80, 95%CI=0.67-0.96). After ethnic stratification, 405V remained a risk allele in East Asians but no significant association was found in Europeans or white Americans.

Conclusion

Our case-control study suggests CETP 405V as a risk allele against longevity in Chinese. The meta-analysis suggests the involvement of CETP 405V is protective in Ashkenazi Jews but is a risk allele against longevity in the East Asian (Chinese) population.