不同强度运动抑制糖尿病大鼠肾脏PI3K/AKT/mTOR信号通路改善自噬的比较

背景:2型糖尿病损害肾功能。研究表明运动干预可以保护肾脏;鸢尾素可以通过抑制磷脂酰肌醇3-激酶/蛋白激酶B/雷帕霉素靶蛋白信号通路恢复自噬,保护糖尿病肾病患者的肾功能。目的:探讨运动能否通过抑制肾脏磷脂酰肌醇3-激酶/蛋白激酶B/雷帕霉素靶蛋白信号通路过度激活来恢复自噬,改善肾损伤,以及分析不同方式运动产生影响的差异。方法:将6周龄的SD大鼠随机分为空白对照组(正常大鼠)和糖尿病组,其中糖尿病组大鼠经过高脂高糖喂养加腹腔注射低剂量1%链脲佐菌素(30 mg/kg)建立2型糖尿病模型。造模成功后再将糖尿病组大鼠随机分成糖尿病模型组、中强度持续运动组和高强度间歇运动组。两个运动组大鼠分别进行8周不同强度运动干预。取材后采用葡萄糖氧化酶法检测大鼠空腹血糖,使用试剂盒检测糖化血红蛋白水平,Elisa法检测血清胰岛素浓度,计算胰岛素抵抗指数,RT-PCR检测肾组织磷脂酰肌醇3-激酶、蛋白激酶B、雷帕霉素靶蛋白、Beclin-1、podocin、nephrin的基因表达量,Western Blot检测肾组织雷帕霉素靶蛋白及自噬标记蛋白LC3-1、LC3-2、Beclin-1的蛋白表达量。结果与结论:①2型糖尿病大鼠空腹血糖和糖化血红蛋白水平极显著性升高,胰岛素抵抗水平显著上升,胰岛素水平显著下降;两种运动均能使2型糖尿病大鼠空腹血糖和糖化血红蛋白水平极显著下降,胰岛素抵抗水平显著下降,胰岛素水平显著上升;与中强度持续运动组相比,高强度间歇运动组胰岛素水平显著上升。②2型糖尿病大鼠podocin、nephrin基因表达量显著降低;两种不同形式运动均能显著提高其表达;与高强度间歇运动组相比,中等强度持续性运动组足细胞相关蛋白基因表达有进一步上升趋势,但无显著性差异。③2型糖尿病大鼠肾组织磷脂酰肌醇3-激酶、蛋白激酶B、mTORC1的mRNA及蛋白的表达量显著增加,自噬标志蛋白Beclin-1、LC3-2表达量以及LC3-2/LC3-1显著降低;两种不同形式运动均能使肾组织磷脂酰肌醇3-激酶、蛋白激酶B、mTORC1的mRNA及雷帕霉素靶蛋白蛋白的表达量显著降低,自噬标志蛋白Beclin-1、LC3-2以及LC3-2/LC3-1显著升高;与中等强度持续性运动组相比,高强度间歇运动的磷脂酰肌醇3-激酶、蛋白激酶B、mTORC1的mRNA及雷帕霉素靶蛋白的蛋白表达量有进一步下降的趋势,Beclin-1、LC3-2以及LC3-2/LC3-1有进一步升高的趋势,但仅Beclin-1有显著性差异。④结果说明2型糖尿病肾脏足细胞损伤,自噬受到抑制,与磷脂酰肌醇3-激酶/蛋白激酶B/mTORC1信号通路被异常激活密切相关。高强度间歇运动和中等强度持续性运动可以保护糖尿病肾脏,减少足细胞损伤,促进自噬恢复,这可能与运动抑制磷脂酰肌醇3-激酶/蛋白激酶B/雷帕霉素靶蛋白信号通路过度激活有关。与中等强度持续性运动相比,高强度间歇运动恢复自噬的效果呈更优趋势,但足细胞蛋白表达稍有下降。

k-center问题的算法研究综述

k-center问题是设施选址的基础问题,同样是NP难问题,在分配、紧急服务等领域也有着实际的应用。随着问题规模的扩大,原有的算法已不再适用,需要进一步优化或者改进。为了找到求解该问题的高效算法,对现有算法进行研究。对各类求解k-center问题的算法进行梳理,将求解算法划分为精确算法、启发式算法、元启发式算法、近似算法等,从算法原理、改进思路、性能和精度等方面进行对比综述。精确算法在求解小规模k-center问题时可在多项式时间内得到最优解,但是算法效率低,不适用于大规模问题;启发式算法可以在多项式时间内给出相对最优解,但是没有理论保证,无法衡量与最优解的关系;元启发式算法可根据对目前存在的智能优化算法进行改进,给出相对最优解,但是解的质量无法保证;利用近似算法得到的解具有近似比保证,有较大的理论研究价值,但是实用价值较弱。目前求解k-center问题的元启发式算法已取得一定的研究成果,但是在求解时间、求解规模、算法效率等方面仍待突破,这将是未来k-center问题的研究重点。

Serum proteins differentially expressed in gestational diabetes mellitus assessed using isobaric tag for relative and absolute quantitation proteomics

BACKGROUND As a well-known fact to the public,gestational diabetes mellitus(GDM)could bring serious risks for both pregnant women and infants.During this important investigation into the linkage between GDM patients and their altered expression in the serum,proteomics techniques were deployed to detect the differentially expressed proteins(DEPs)of in the serum of GDM patients to further explore its pathogenesis,and find out possible biomarkers to forecast GDM occurrence.METHODS Subjects were divided into GDM and normal control groups according to the IADPSG diagnostic criteria.Serum samples were randomly selected from four cases in each group at 24-28 wk of gestation,and the blood samples were identified by applying iTRAQ technology combined with liquid chromatography-tandem mass spectrometry.Key proteins and signaling pathways associated with GDM were identified by bioinformatics analysis,and the expression of key proteins in serum from 12 wk to 16 wk of gestation was further verified using enzyme-linked immunosorbent assay (ELISA).RESULTS Forty-seven proteins were significantly differentially expressed by analyzing the serum samples between the GDMgravidas as well as the healthy ones. Among them, 31 proteins were found to be upregulated notably and the rest16 proteins were downregulated remarkably. Bioinformatic data report revealed abnormal expression of proteinsassociated with lipid metabolism, coagulation cascade activation, complement system and inflammatory responsein the GDM group. ELISA results showed that the contents of RBP4, as well as ANGPTL8, increased in the serumof GDM gravidas compared with the healthy ones, and this change was found to initiate from 12 wk to 16 wk ofgestation.CONCLUSION GDM symptoms may involve abnormalities in lipid metabolism, coagulation cascade activation, complementsystem and inflammatory response. RBP4 and ANGPTL8 are expected to be early predictors of GDM.

Incorporating empirical knowledge into data-driven variable selection for quantitative analysis of coal ash content by laser-induced breakdown spectroscopy

Laser-induced breakdown spectroscopy(LIBS)has become a widely used atomic spectroscopic technique for rapid coal analysis.However,the vast amount of spectral information in LIBS contains signal uncertainty,which can affect its quantification performance.In this work,we propose a hybrid variable selection method to improve the performance of LIBS quantification.Important variables are first identified using Pearson's correlation coefficient,mutual information,least absolute shrinkage and selection operator(LASSO)and random forest,and then filtered and combined with empirical variables related to fingerprint elements of coal ash content.Subsequently,these variables are fed into a partial least squares regression(PLSR).Additionally,in some models,certain variables unrelated to ash content are removed manually to study the impact of variable deselection on model performance.The proposed hybrid strategy was tested on three LIBS datasets for quantitative analysis of coal ash content and compared with the corresponding data-driven baseline method.It is significantly better than the variable selection only method based on empirical knowledge and in most cases outperforms the baseline method.The results showed that on all three datasets the hybrid strategy for variable selection combining empirical knowledge and data-driven algorithms achieved the lowest root mean square error of prediction(RMSEP)values of 1.605,3.478 and 1.647,respectively,which were significantly lower than those obtained from multiple linear regression using only 12 empirical variables,which are 1.959,3.718 and 2.181,respectively.The LASSO-PLSR model with empirical support and 20 selected variables exhibited a significantly improved performance after variable deselection,with RMSEP values dropping from 1.635,3.962 and 1.647 to 1.483,3.086 and 1.567,respectively.Such results demonstrate that using empirical knowledge as a support for datadriven variable selection can be a viable approach to improve the accuracy and reliability of LIBS quantification.

Identification of protein targets for the antidepressant effects of Kai-Xin-San in Chinese medicine using isobaric tags for relative and absolute quantitation

Kai-Xin-San consists of Ginseng Radix, Polygalae Radix, Acori Tatarinowii Rhizoma, and Poria at a ratio of 3:3:2:2. Kai-Xin-San has been widely used for the treatment of emotional disorders in China. However, no studies have identified the key proteins implicated in response to Kai-Xin-San treatment. In this study, rat models of chronic mild stress were established using different stress methods over 28 days. After 14 days of stress stimulation, rats received daily intragastric administrations of 600 mg/kg Kai-Xin-San. The sucrose preference test was used to determine depression-like behavior in rats, while isobaric tags were used for relative and absolute quantitation-based proteomics to identify altered proteins following Kai-Xin-San treatment. Kai-Xin-San treatment for 2 weeks noticeably improved depression-like behaviors in rats with chronic mild stress. We identified 33 differentially expressed proteins: 7 were upregulated and 26 were downregulated. Functional analysis showed that these differentially expressed proteins participate in synaptic plasticity, neurodevelopment, and neurogenesis. Our results indicate that Kai-Xin-San has an important role in regulating the key node proteins in the synaptic signaling network, and are helpful to better understand the mechanism of the antidepressive effects of Kai-Xin-San and to provide objective theoretical support for its clinical application. The study was approved by the Ethics Committee for Animal Research from the Chinese PLA General Hospital(approval No. X5-2016-07) on March 5, 2016.

Research on batch multielement rapid quantitative analysis based on the standard curve-assisted calibration-free laserinduced breakdown spectroscopy method

This study proposes a batch rapid quantitative analysis method for multiple elements by combining the advantages of standard curve(SC)and calibration-free laser-induced breakdown spectroscopy(CF-LIBS)technology to achieve synchronous,rapid,and accurate measurement of elements in a large number of samples,namely,SC-assisted CF-LIBS.Al alloy standard samples,divided into calibration and test samples,were applied to validate the proposed method.SC was built based on the characteristic line of Pb and Cr in the calibration sample,and the contents of Pb and Cr in the test sample were calculated with relative errors of 6%and 4%,respectively.SC built using Cr with multiple characteristic lines yielded better calculation results.The relative contents of ten elements in the test sample were calculated using CF-LIBS.Subsequently,the SC-assisted CF-LIBS was executed,with the majority of the calculation relative errors falling within the range of 2%-5%.Finally,the Al and Na contents of the Al alloy were predicted.The results demonstrate that it effectively enables the rapid and accurate quantitative analysis of multiple elements after a single-element SC analysis of the tested samples.Furthermore,this quantitative analysis method was successfully applied to soil and Astragalus samples,realizing an accurate calculation of the contents of multiple elements.Thus,it is important to advance the LIBS quantitative analysis and its related applications.

Novel damage constitutive models and new quantitative identification method for stress thresholds of rocks under uniaxial compression

Four key stress thresholds exist in the compression process of rocks,i.e.,crack closure stress(σ_(cc)),crack initiation stress(σ_(ci)),crack damage stress(σ_(cd))and compressive strength(σ_(c)).The quantitative identifications of the first three stress thresholds are of great significance for characterizing the microcrack growth and damage evolution of rocks under compression.In this paper,a new method based on damage constitutive model is proposed to quantitatively measure the stress thresholds of rocks.Firstly,two different damage constitutive models were constructed based on acoustic emission(AE)counts and Weibull distribution function considering the compaction stages of the rock and the bearing capacity of the damage element.Then,the accumulative AE counts method(ACLM),AE count rate method(CRM)and constitutive model method(CMM)were introduced to determine the stress thresholds of rocks.Finally,the stress thresholds of 9 different rocks were identified by ACLM,CRM,and CMM.The results show that the theoretical stress−strain curves obtained from the two damage constitutive models are in good agreement with that of the experimental data,and the differences between the two damage constitutive models mainly come from the evolutionary differences of the damage variables.The results of the stress thresholds identified by the CMM are in good agreement with those identified by the AE methods,i.e.,ACLM and CRM.Therefore,the proposed CMM can be used to determine the stress thresholds of rocks.

Artificial Immune Detection for Network Intrusion Data Based on Quantitative Matching Method

Artificial immune detection can be used to detect network intrusions in an adaptive approach and proper matching methods can improve the accuracy of immune detection methods.This paper proposes an artificial immune detection model for network intrusion data based on a quantitative matching method.The proposed model defines the detection process by using network data and decimal values to express features and artificial immune mechanisms are simulated to define immune elements.Then,to improve the accuracy of similarity calculation,a quantitative matching method is proposed.The model uses mathematical methods to train and evolve immune elements,increasing the diversity of immune recognition and allowing for the successful detection of unknown intrusions.The proposed model’s objective is to accurately identify known intrusions and expand the identification of unknown intrusions through signature detection and immune detection,overcoming the disadvantages of traditional methods.The experiment results show that the proposed model can detect intrusions effectively.It has a detection rate of more than 99.6%on average and a false alarm rate of 0.0264%.It outperforms existing immune intrusion detection methods in terms of comprehensive detection performance.

Quantitative hepatitis B core antibody and quantitative hepatitis B surface antigen:Novel viral biomarkers for chronic hepatitis B management

The management of hepatitis B virus(HBV)infection now involves regular and appropriate monitoring of viral activity,disease progression,and treatment response.Traditional HBV infection biomarkers are limited in their ability to predict clinical outcomes or therapeutic effectiveness.Quantitation of HBV core antibodies(qAnti-HBc)is a novel non-invasive biomarker that may help with a variety of diagnostic issues.It was shown to correlate strongly with infection stages,hepatic inflammation and fibrosis,chronic infection exacerbations,and the presence of occult infection.Furthermore,qAnti-HBc levels were shown to be predictive of spontaneous or treatment-induced HBeAg and HBsAg seroclearance,relapse after medication termination,re-infection following liver transplantation,and viral reactivation in the presence of immunosuppression.qAnti-HBc,on the other hand,cannot be relied on as a single diagnostic test to address all problems,and its diagnostic and prognostic potential may be greatly increased when paired with qHBsAg.Commercial qAnti-HBc diagnostic kits are currently not widely available.Because many methodologies are only semi-quantitative,comparing data from various studies and defining universal cut-off values remains difficult.This review focuses on the clinical utility of qAnti-HBc and qHBsAg in chronic hepatitis B management.

Validation of Two Real-Time PCR Approaches for the Relative Quantitation of Pork and Horse DNA in Food Samples

Two real-time PCR methods for the relative quantitation of DNA from meat species in food samples are described: these methods are applicable for horse in processed beef meat products, and pork in raw/processed beef meat products. Test samples were prepared using raw meat admixtures or processed horse/pork in beef food products made to an industry-standard recipe. The methods were subjected to single laboratory method validation, evaluating the performance characteristics of specificity, PCR efficiency and r-squared (r2), Limit of Detection (LOD), Limit of Quantitation (LOQ), and precision and trueness. A limited UK-based inter-laboratory trial of the two methods was completed involving four participating laboratories. Full statistical analysis of the data qualified the applicability of the methods for accurate and sensitive trace-level analysis. The methods were deemed fit for purpose for reproducibly distinguishing between adventitious contamination at 0.1% (w/w), the level for further enforcement action at 1% (w/w), and a level representative of deliberate economically motivated adulteration (10% (w/w)). The data provided evidence that the precision of the two methods was applicable for qualitative and quantitative detection at topically important levels of adulteration. This work has added significant value to the current state of the art in quantitative determination of topical meat species adulteration, allowing analysts to distinguish between adventitious contamination and deliberate adulteration. The resulting methods described in this paper can easily be deployed and used by analytical laboratories for controls and due-diligence testing based on standard laboratory equipment.

Compound 3k治疗骨关节炎:调控氧化应激通路改善软骨细胞糖酵解的作用机制

背景:骨关节炎现已被认为是一种代谢性疾病,既往研究表明糖酵解在骨关节炎的发生发展中起重要作用。Compound 3k作为一种新型糖酵解小分子抑制剂,具有抗炎及抗肿瘤等功效,因此可靶向糖酵解,有望为骨关节炎治疗提供新的思路。目的:基于缺氧诱导因子1α/活性氧的氧化应激通路探究Compound 3k在糖酵解过度活跃所导致的骨关节炎中的作用机制。方法:取对数生长期的ATDC5成软骨细胞,用10 ng/mL白细胞介素1β作用24 h诱导骨关节炎体外细胞模型,以CCK-8法检测不同浓度(0.25,0.5,1,2.5,5,10,15μmol/L)Compound 3k的细胞毒性,选出合适浓度进行后续实验。将软骨细胞随机分为对照组、模型组、治疗组,模型组以10 ng/mL的白细胞介素1β诱导,治疗组以Compound 3k预刺激2 h后与白细胞介素1β共培养,用CCK-8法检测各组细胞增殖情况;用ELISA试剂盒检测各组细胞炎症水平;用试剂盒检测各组细胞活性氧、细胞外乳酸脱氢酶及葡萄糖含量;qRT-PCR及Western blot检测相关炎症因子白细胞介素6、肿瘤坏死因子α及糖酵解相关基因葡萄糖转运蛋白1、甘油醛3-磷酸脱氢酶、单羧酸转运蛋白1和缺氧诱导因子1α的表达水平。结果与结论:①与对照组相比,模型组细胞增殖活性下降、糖酵解水平活跃,表现为细胞外乳酸脱氢酶含量增加(P<0.001),葡萄糖含量减少(P<0.001),相关炎症因子白细胞介素6(P<0.0001)及肿瘤坏死因子α(P<0.001),糖酵解相关基因葡萄糖转运蛋白1(P<0.001)、甘油醛3-磷酸脱氢酶(P<0.001)、单羧酸转运蛋白1(P<0.001)及缺氧诱导因子1α(P<0.001)的表达水平均上调,并伴随氧化应激,活性氧过量产生。②与模型组相比,Compound 3k的治疗有效提高细胞增殖活性,抑制过度活跃的糖酵解水平的同时,抑制了骨关节炎软骨细胞炎症(P<0.001)及糖酵解相关基因的表达(P<0.001),且抑制氧化应激,缺氧诱导因子1α的表达水平下调(P<0.0001),活性氧水平下降。③上述结果证实,Compound 3k抑制了白细胞介素1β诱导的软骨细胞炎症,其机制可能与糖酵解及缺氧诱导因子1α/活性氧介导的氧化应激有关。

Preparation and Application of Silica-based Perfusion Packing of Size Exclusion Chromatography for Quantitation of Polyacrylamide in Enhanced Oil Recovery Systems

The synthesis and characterization of a novel macroporous silica derived size exclusion chromatography （SEC） packing for quantitative analysis of high molecular weight （MW） polyacrylamide （PAM） are presented. Using this packing, a fast, sensitive and reproducible approach for quantitation of super high-MW PAM in demanding enhanced oil recovery （EOR） waters was developed and the effect of synthesis parameters on the properties of resultant materials was investigated. These parameters include salt addition, reaction temperature and duration, activation condition of functional groups on the silica surface, as well as the reaction cycles required for optimal silica modification. Moreover, SEC analysis conditions, such as mobile phase composition, flow rate, detection and sample preparation, were also explored and an optimal analysis protocol was developed. Under this optimized SEC analysis conditions, the synthesized macroporous materials proved satisfactory for quantification of PAM with average MW up to 22 million Daltons. An SEC analysis required less than few minutes with a detection limit of 1 ng, a linear response range of 0.1 to 75 mg/L with squared R value of 0.99 and reproducibility better than 9.2% RSD （relative standard deviation）. The analysis of PAM in highly saline oilfield production water containing interfering high MW polymeric surfactants indicated the recovery ranges from 92.5% to 110.1% for 1.0 mg/L PAM and 94.2% to 103.8% for 50 mg/L PAM solution. This study presented for the ftrst time that the reliable quantization of high MW PAM in highly demanding EOR waters can be achieved by SEC.

二甲双胍抑制PI3K/AKT/mTOR信号通路保护骨关节炎模型大鼠关节软骨

背景:研究表明,二甲双胍具有抗炎、抗肿瘤、抗衰老与血管保护作用,可抑制骨关节炎的进展,但其具体的作用机制仍不明确。目的:探讨二甲双胍对骨关节炎模型大鼠软骨保护的作用机制。方法:取40只雄性SD大鼠,采用随机数字表法分4组(n=10):空白组不进行任何手术,假手术组暴露关节腔,模型组、二甲双胍组采用改良Hulth法建立骨关节炎模型;造模后1 d,二甲双胍组大鼠灌胃给予二甲双胍200 mg/(kg·d),模型组、空白组、假手术组灌胃给予生理盐水,连续给药4周。给药结束后,苏木精-伊红、甲苯胺蓝和番红O-固绿染色观察大鼠膝关节软骨病理形态,免疫组化染色与Western blotting检测大鼠软骨组织中SOX9、Ⅱ型胶原、ADAMTS5、Beclin1、P62、p-PI3K、PI3K、p-AKT、AKT、p-mTOR、mTOR的蛋白表达。结果与结论:①苏木精-伊红、甲苯胺蓝和番红O-固绿染色结果显示,空白组、假手术组大鼠膝关节软骨表面光滑,组织形态正常;模型组大鼠膝关节软骨表面不规则,软骨组织出现缺损,软骨细胞数量减少,软骨基质中蛋白多糖含量减少;相较于模型组,二甲双胍组大鼠膝关节软骨结构损伤有明显改善,软骨表面趋于平整,软骨细胞数量与软骨基质中蛋白多糖含量增加;②免疫组化染色与Western blotting检测结果显示,与空白组、假手术组比较,模型组大鼠软骨组织中SOX9、Ⅱ型胶原、Beclin1蛋白表达降低(P<0.05),ADAMTS5、P62及p-PI3K、p-AKT、p-mTOR蛋白表达升高(P<0.05);与模型组比较,二甲双胍组大鼠软骨组织中SOX9、Ⅱ型胶原、Beclin1蛋白表达升高(P<0.05),ADAMTS5、P62及p-PI3K、p-AKT、p-mTOR蛋白表达降低(P<0.05);③结果表明,二甲双胍可通过抑制PI3K/AKT/mTOR信号通路的活化提高骨关节炎模型大鼠软骨细胞自噬活性、减少软骨基质降解,进而发挥关节软骨保护作用。

The potential mechanism and clinical application value of remote ischemic conditioning in stroke

Some studies have confirmed the neuroprotective effect of remote ischemic conditioning against stroke. Although numerous animal researches have shown that the neuroprotective effect of remote ischemic conditioning may be related to neuroinflammation, cellular immunity, apoptosis, and autophagy, the exact underlying molecular mechanisms are unclear. This review summarizes the current status of different types of remote ischemic conditioning methods in animal and clinical studies and analyzes their commonalities and differences in neuroprotective mechanisms and signaling pathways. Remote ischemic conditioning has emerged as a potential therapeutic approach for improving stroke-induced brain injury owing to its simplicity, non-invasiveness, safety, and patient tolerability. Different forms of remote ischemic conditioning exhibit distinct intervention patterns, timing, and application range. Mechanistically, remote ischemic conditioning can exert neuroprotective effects by activating the Notch1/phosphatidylinositol 3-kinase/Akt signaling pathway, improving cerebral perfusion, suppressing neuroinflammation, inhibiting cell apoptosis, activating autophagy, and promoting neural regeneration. While remote ischemic conditioning has shown potential in improving stroke outcomes, its full clinical translation has not yet been achieved.

Critical Considerations in the Immunochemical Detection and Quantitation of Antigenic Biomarkers

The formation of covalent adducts as a result of the interaction of metabolically activated chemicals with host macromolecules is a common critical event in mutagenic, carcinogenic, and immunologic phenomena. Because of their antigenicity and their immunogenicity, covalent adducts may be detected using sensitive immunochemical techniques. The immunochemical approaches to biomonitoring and molecular dosimetry of DNA damage are particularly attractive because they allow sensitive quantitation of specific DNA adducts present in small samples and do not rely on the use of radiolabeled adducts. Two examples of biomarker immunoassay development are presented: an avidin/biotin-amplified ELISA for the major DNA adduct of the human bladder carcinogen 4-aminobiphenyl (ABP), and a particle concentration fluorescent immunoassay (PCFIA) for the major protein adduct associated with toxicity by the prototype hepatotoxin acetaminophen. The examples illustrate critical steps in the development of biomarker immunoassays which include selection of the relevant adduct, preparation of an appropriate immunogen, immunization, characterization of antisera, and development of application-specific sample processing techniques for biomarker quantitation. Immunochemical procedures may be combined with other analytical techniques to form hybrid systems which take advantage of both the antigenicity and the physical or chemical properties of a biomarker to achieve greater specificity and/or sensitivity. The future usefulness of these new tools of molecular epidemiology will depend on a compound-by-compound validation of methods and critical evaluation of the biologic importance of the particular antigenic biomarker as an indicator of exposure and as an indicator of risk.

Human-induced pluripotent stem cell-derived neural stem cell exosomes improve blood-brain barrier function after intracerebral hemorrhage by activating astrocytes via PI3K/AKT/MCP-1 axis

Cerebral edema caused by blood-brain barrier injury after intracerebral hemorrhage is an important factor leading to poor prognosis.Human-induced pluripotent stem cell-derived neural stem cell exosomes(hiPSC-NSC-Exos)have shown potential for brain injury repair in central nervous system diseases.In this study,we explored the impact of hiPSC-NSC-Exos on blood-brain barrier preservation and the underlying mechanism.Our results indicated that intranasal delivery of hiPSC-NSC-Exos mitigated neurological deficits,enhanced blood-brain barrier integrity,and reduced leukocyte infiltration in a mouse model of intracerebral hemorrhage.Additionally,hiPSC-NSC-Exos decreased immune cell infiltration,activated astrocytes,and decreased the secretion of inflammatory cytokines like monocyte chemoattractant protein-1,macrophage inflammatory protein-1α,and tumor necrosis factor-αpost-intracerebral hemorrhage,thereby improving the inflammatory microenvironment.RNA sequencing indicated that hiPSC-NSC-Exo activated the PI3K/AKT signaling pathway in astrocytes and decreased monocyte chemoattractant protein-1 secretion,thereby improving blood-brain barrier integrity.Treatment with the PI3K/AKT inhibitor LY294002 or the monocyte chemoattractant protein-1 neutralizing agent C1142 abolished these effects.In summary,our findings suggest that hiPSC-NSC-Exos maintains blood-brain barrier integrity,in part by downregulating monocyte chemoattractant protein-1 secretion through activation of the PI3K/AKT signaling pathway in astrocytes.

Prevalence and Study of the Clonality of Extended-Spectrum Beta-Lactamase-Producing Klebsiella pneumoniae Strains in Neonatology at the University Hospitals of Abidjan by the Pulsed Field Gel Electrophoresis and the Quantitative Antibiogram

Background: ESBL-producing strains of Klebsiella pneumoniae, one of the main causes of nosocomial and hospital-acquired infections, are commonly associated with therapeutic impasses. Surveillance of these multidrug-resistant pathogens is a crucial tool for controlling and preventing infections. This surveillance involves the use of appropriate molecular and phenotypic typing techniques. The choice of techniques is based on criteria such as discriminatory power, intra- and inter-laboratory reproducibility, epidemiological concordance, ease of use and cost. The aim of our study was to identify clusters of Extended-Spectrum Beta-Lactamase-producing Klebsiella pneumoniae (ESBL-K. pneumoniae) strains circulating in neonatology using quantitative antibiogram (QA) and Pulsed Field Gel Electrophoresis (PFGE). Materials and Methods: This cross-sectional study included 55 K. pneumoniae strains isolated from a total of 513 samples. These various samples are taken from newborns, healthcare personnel, and the environment. K. pneumoniae identification followed standard bacteriological procedures and was confirmed using the Vitek® 2 (bioMérieux). The detection of the ESBL phenotype was performed using the synergy test. QA and PFGE were used to identify clonal relationships between the various strains isolated. Concordance between these two methods was assessed by calculating Cohen’s KAPPA coefficient and Simpson’s diversity index. Results: Among the 55 K. pneumoniae strains included in this study, 58.2% (32/55) were found to be Extended-Spectrum Beta-Lactamase (ESBL) producers. Most of these strains were isolated from neonatal samples (blood samples and rectal swabs). The quantitative antibiogram method applied to 28 out of the 32 ESBL-producing strains revealed that the isolates were grouped into 5 clusters. Pulsed Field Gel Electrophoresis performed on a total of 16 ESBL-producing strains showed the existence of four profiles. A perfect concordance was observed between the two methods. Conclusion: The results of this study highlighted the existence of clonal strains of various origins within neonatology units.

Human neural stem cell-derived extracellular vesicles protect against ischemic stroke by activating the PI3K/AKT/mTOR pathway

Human neural stem cell-derived extracellular vesicles exhibit analogous functions to their parental cells,and can thus be used as substitutes for stem cells in stem cell therapy,thereby mitigating the risks of stem cell therapy and advancing the frontiers of stem cell-derived treatments.This lays a foundation for the development of potentially potent new treatment modalities for ischemic stroke.However,the precise mechanisms underlying the efficacy and safety of human neural stem cell-derived extracellular vesicles remain unclear,presenting challenges for clinical translation.To promote the translation of therapy based on human neural stem cell-derived extracellular vesicles from the bench to the bedside,we conducted a comprehensive preclinical study to evaluate the efficacy and safety of human neural stem cell-derived extracellular vesicles in the treatment of ischemic stroke.We found that administration of human neural stem cell-derived extracellular vesicles to an ischemic stroke rat model reduced the volume of cerebral infarction and promoted functional recovery by alleviating neuronal apoptosis.The human neural stem cell-derived extracellular vesicles reduced neuronal apoptosis by enhancing phosphorylation of phosphoinositide 3-kinase,mammalian target of rapamycin,and protein kinase B,and these effects were reversed by treatment with a phosphoinositide 3-kinase inhibitor.These findings suggest that human neural stem cell-derived extracellular vesicles play a neuroprotective role in ischemic stroke through activation of phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin signaling pathway.Finally,we showed that human neural stem cell-derived extracellular vesicles have a good in vivo safety profile.Therefore,human neural stem cell-derived extracellular vesicles are a promising potential agent for the treatment of ischemic stroke.

血浆蛋白与骨质疏松症的关系及潜在治疗靶点:基于国际UK Biobank数据库信息

背景:骨质疏松症是全球范围内增加疾病负担和致残率的重要因素。血浆蛋白参与体内复杂的生物过程,在揭示疾病机制和发现潜在治疗靶点方面起着关键作用。尽管已有研究显示血浆蛋白与骨质疏松症之间存在关联,但这些关联的因果性质尚未得到充分阐明。因此,利用大规模的血浆蛋白数据探究与骨质疏松症相关的因果蛋白并识别潜在的药物靶点,对于骨质疏松症的防治至关重要。目的:运用两样本孟德尔随机化分析,以国际UK Biobank数据库为来源信息,评估血浆蛋白与骨质疏松症之间的因果关联。方法:从UK Biobank数据库获取1001种血浆蛋白相关的全基因组显著性水平(P<5×10-8)的蛋白质数量性状位点作为工具变量,并排除连锁不平衡。骨质疏松症的汇总数据来自FinnGen数据库,共涉及438872名欧洲血统个体。研究采用逆方差加权、MR-Egger回归、加权中位数等方法进行分析,并进行多项敏感性分析以确保结果的稳健性。进一步构建蛋白-蛋白互作网络,结合基因本体富集分析和京都基因与基因组百科全书通路分析,探索血浆蛋白的功能相关性及潜在作用机制。结果与结论:①孟德尔随机化逆方差加权法结果显示有50种血浆蛋白与骨质疏松症存在因果关系(P<0.05),包括染色体19开放阅读框12(chromosome 19 open reading frame 12,C19orf12;OR=0.610,95%CI:0.483-0.769,P=2.967×10-5)、表皮生长因子(OR=0.877,95%CI:0.770-0.999,P=0.049)等20种血浆蛋白可能与骨质疏松症的风险降低相关,有CCL18(OR=1.091,95%CI:1.037-1.147,P=0.001)、CD209(OR=1.036,95%CI:1.003-1.070,P=0.034)等30种血浆蛋白可能增加骨质疏松症的风险,经Bonferroni校正后,只有C19orf12与骨质疏松症存在显著的因果关联。②多项敏感性分析显示研究不存在多效性和异质性,说明结果具有稳健性。③通过构建蛋白-蛋白互作网络明确了表皮生长因子、CCL5、CXCL13、CXCL5、血管内皮生长因子C、CCL18、CCL17、TEK受体酪氨酸激酶、含免疫球蛋白样和表皮生长因子样结构域的酪氨酸激酶1(TIE1)和CCL23为核心蛋白。④基因本体富集分析和京都基因与基因组百科全书通路分析表明这些血浆蛋白在免疫系统中具有重要作用,通过参与信号传导、细胞迁移和趋化等过程影响骨质疏松症。⑤文章结果揭示了1001种血浆蛋白与骨质疏松症的潜在因果关联,这种基于大规模数据驱动的分析方法有助于在中国人群中识别新的生物标志物和药物靶点;其次,文章结果表明,免疫系统信号传导、细胞迁移和趋化等过程在骨质疏松症发病机制中发挥重要作用,这为特定遗传背景和环境因素下的骨质疏松症研究提供了新的方向;最后,研究中识别的核心蛋白(如表皮生长因子、CCL5及CXCL13等)有望成为新的生物标志物或药物靶点,为骨质疏松症的精准防治提供新的依据。

Identification of Quantitative Trait Loci for Anthesis-Silking Interval and Yield Components Under Drought Stress in Maize

A genetic linkage map with 89 SSR marker loci was constructed based on a maize (Zea mays L.) population consisting of 184 F-2 individuals from the cross, Huangzao 4 X Ye 107. The 184 F-3 families were evaluated in the field under well-watered and drought-stressed regimes in Shanxi Province of China. The objectives of the study were to identify genetic segments responsible for the expression of anthesis-silking interval (ASI), ear setting and grain yield, and to examine if the quantitative trait loci (QTLs) for ASI or yield components can be used in marker-assisted selection (MAS) to improve grain yield under drought conditions. Results showed that under well-watered and drought-stressed regimes, three and two QTLs involved in the expression of ASI were detected on chromosomes 1, 2 and 3, and 2 and 5, respectively. Under well-watered regime, two QTLs for ear setting were detected on chromosomes 3 and 6, explaining about 19.9% of the phenotypic variance, and displayed additive and partial dominant effects, respectively. Under drought-stressed condition, four QTLs for ear setting were detected on chromosomes 3, 7 and 10, which were responsible for interpreting 60.4% of the phenotypic variance, and showed dominant or partial dominant effects. Under well-watered condition, four QTLs controlling grain yield were identified on chromosomes 3, 6 and 7, while five QTLs were identified under drought stress on chromosomes 1, 2, 4 and 8. The gene action was of additive or partial dominant effects, and each QTL could explain 7.3% to 22.0% of the phenotypic variance, respectively. Under drought conditions, ASI and ear setting percentage were highly correlated with grain yield, which can be used as secondary traits for grain yield selection. Based on linked markers detected and gene action analyzed, an MAS strategy for yield improvement under drought condition could be established, which consists of QTLs contributing to decreased ASI and to increased ear setting and grain yield, respectively.