Engineering The Neck Hinge Reshapes The Processive Movement of Kinesin-3

Objective In kinesin-3,the neck coil correlates with the following segments to form an extended neck that contains a characteristic hinge diverse from a proline in KIF13B to a long flexible linker in KIF1A.The function of this neck hinge for controlling processive movement,however,remains unclear.Methods We made a series of modifications to the neck hinges of KIF13B and KIF1A and tested their movement using a single-molecule motility assay.Results In KIF13B,the insertion of flexible residues before or after the proline differentially impacts the processivity or velocity,while the removal of this proline increases the both.In KIF1A,the deletion of entire flexible neck hinge merely enhances the processivity.The engineering of these hinge-truncated necks of kinesin-3 into kinesin-1 similarly boosts the processive movement of kinesin-1.Conclusion The neck hinge in kinesin-3 controls its processive movement and proper modifications tune the motor motility,which provides a novel strategy to reshape the processive movement of kinesin motors.

Knockdown of CD146 reduces the migration and proliferation of human endothelial cells

Our previous study has demonstrated that CD 146 molecule is a biomarker on vascular endothelium, which is involved in angiogenesis and tumor growth. However the mechanism behind is not clear. Here we have for the first time developed a novel CD146 blockade system using CD146 siRNA to study its function on endothelial cells. Our data showed that CD146 siRNA specifically blocked the expression of CD146 on both mRNA and protein levels, leading to the significant suppression of HUVEC proliferation, adhesion and migration. These results demonstrate that CD146 plays a key role in vascular endothelial cell activity and angiogenesis, and CD146 siRNA can be used as a new inhibitor for anti-angiogenesis therapy.

Identification of biomarkers for hepatocellular carcinoma by semiquantitative immunocytochemistry

AIM: To investigate the expression of key biomarkers in hepatoma cell lines, tumor cells from patients’ blood samples, and tumor tissues.

The anti-obesity effects of EGCG in relation to oxidative stress and air-pollution in China

Modern China,similar to most developing nations,has seen a rise in the prevalence of both obesity and diesel exhaust based air pollution.The cause of obesity is multi-factorial encompassing diet,lifestyle and social factors.Also there has been a reduction in the consumption of fruit,vegetables,and traditional medicinal foods such as polyphenol containing green tea.Replacing these,are high fat and carbohydrate based processed foods which are quickly displacing these wholefoods in the diet.This review paper proposes evidence that a potential cause of obesity is also linked to environmental stress stimuli such as air pollutants,particularly diesel exhaust fumes(DEF)of>2.5μm particulate matter,and discusses a role for a green tea catechin(EGCG)for use as a dietary defence against diet and environmentally induced obesity.China is now at a critical point of a public health pandemic with rising air-borne pollution(via car exhaust fumes DEF),industry pollution such as heavy metals,and the benzene hydrocarbon based‘2PM’particulate matter,now accepted as a major environmental issue for public health.Relevant data published in MEDLINE since 1995 has been gathered to formulate the following review.

Similarity measurement method of high-dimensional data based on normalized net lattice subspace

The performance of conventional similarity measurement methods is affected seriously by the curse of dimensionality of high-dimensional data.The reason is that data difference between sparse and noisy dimensionalities occupies a large proportion of the similarity,leading to the dissimilarities between any results.A similarity measurement method of high-dimensional data based on normalized net lattice subspace is proposed.The data range of each dimension is divided into several intervals,and the components in different dimensions are mapped onto the corresponding interval.Only the component in the same or adjacent interval is used to calculate the similarity.To validate this method,three data types are used,and seven common similarity measurement methods are compared.The experimental result indicates that the relative difference of the method is increasing with the dimensionality and is approximately two or three orders of magnitude higher than the conventional method.In addition,the similarity range of this method in different dimensions is [0,1],which is fit for similarity analysis after dimensionality reduction.

Troglitazone inhibits cell proliferation by attenuation of epidermal growth factor receptor signaling independent of peroxisome proliferator-activated receptor γ

Peroxisome proliferator-activated receptors （PPAR） belong to the nuclear hormone receptor superfamily of ligand-dependent transcription factors. Recent results have shown that agonists of PPARy, such as troglitazone （TGZ）, can inhibit cell proliferation and promote cell differentiation independent of PPARy. In the present study, we provide evidence that TGZ may bind directly to EGFR and trigger its signaling and internalization independent of PPARγ. Detailed studies revealed that prolonged incubation with TGZ effectively attenuated EGFR signaling by targeting the receptor to the endo-lysosomal degradation machinery. Although the extracellular signal-regulated kinasesignaling pathway was transiently activated by TGZ in EGFR overexpressing cancer cells, inhibition of EGF-induced Akt phosphorylation most likely accounted for the growth arrest of tumor cells caused by TGZ at pharmacologically achievable concentrations. Therefore, we have provided a new line of evidence indicating that TGZ inhibits cell pro- liferation by promoting EGFR degradation and attenuating Akt phosphorylation.

Characterization of a full-length infectious clone of bovine foamy virus 3026

The biological features of most foamy viruses(FVs) are poorly understood, including bovine foamy virus(BFV). BFV strain 3026(BFV3026) was isolated from the peripheral blood mononuclear cells of an infected cow in Zhangjiakou, China. A full-length genomic clone of BFV3026 was obtained from BFV3026-infected cells, and it exhibited more than 99% amino acid(AA) homology to another BFV strain isolated in the USA. Upon transfection into fetal canine thymus cells, the full-length BFV3026 clone produced viral structural and auxiliary proteins, typical cytopathic effects, and virus particles. These results demonstrate that the full-length BFV3026 clone is fully infectious and can be used in further BFV3026 research.

Real-time and label-free detection of biomolecular interactions by oblique-incidence reflectivity difference method

We successfully conduct the label-free and real-time detection of the interactions between epoxy groups and rabbit IgG and 5＇ CTT CAG GTC ATG AGC CTG AT 3＇ oligonucleotide, and between the hybridization of 5＇ CTT CAG GTC ATG AGC CTG AT 3＇ and its complementary 3＇ GAA GTC CAC TAC TCG GAC TA 5＇ oligonucleotide, by the oblique-incidence reflectivity difference （OI-RD） method. The dynamic curves of OI-RD signals, corresponding to the kinetic processes of biomolecular combination or hybridization, are acquired. In our case, the combination of epoxy groups with rabbit IgG and 5＇ CTT CAC CTC ATG AGC CTG AT 3＇ oligonucleotide need almost one and a half hours and about two hundred seconds, respectively; and the hybridization of the two oligonucleotides needs about five hundred seconds. The experimental results show that the OI-RD is a promising method for the real-time and label-free detection of biomolecular interactions.

Visualization of Mitochondrial Membrane Dynamics in Primary Cultured Neurons by Cryo-electron Tomography

Dear Editor,Mitochondria acts as a cellular organelle that produces ATP and buffers Ca2+,and plays an important role in neuronal growth,survival and function[1].Loss of mitochondria will make the ATP supply insufficient,resulting in synaptic transmission dysfunction[2].Further,presynaptic mitochondrial dysfunctions are often associated with severe neurological diseases[3].Abnormal mitochondrial function can also lead to neurodegenerative diseases because of the degeneration of synapse transmission,such as Alzheimer’s disease[4]and Parkinson’s disease[5].In neurons,mitochondria have a wide range of size,shape and number,which can be constantly changed through fission and fusion events to form a highly dynamic and organized network[6]and also a way of mitochondrial quality control.

A nearest neighbor search algorithm of high-dimensional data based on sequential NPsim matrix

Problems existin similarity measurement and index tree construction which affect the performance of nearest neighbor search of high-dimensional data. The equidistance problem is solved using NPsim function to calculate similarity. And a sequential NPsim matrix is built to improve indexing performance. To sum up the above innovations,a nearest neighbor search algorithm of high-dimensional data based on sequential NPsim matrix is proposed in comparison with the nearest neighbor search algorithms based on KD-tree or SR-tree on Munsell spectral data set. Experimental results show that the proposed algorithm similarity is better than that of other algorithms and searching speed is more than thousands times of others. In addition,the slow construction speed of sequential NPsim matrix can be increased by using parallel computing.

Wnt/β-catenin Signaling Cascades in Cardiovascular Diseases

Cardiovascular diseases are a group of disorders of the heart and blood vessels,primarily including coronary heart disease,stroke,and other diseases.It is the world’s leading cause of death,and its incidence is increasing yearly.Hypertension is a major risk factor for cardiovascular disease.Wnt signaling comprises a series of highly conservative cascading events controlling fundamental biological processes.Wnt signaling pathways include the canonical Wnt pathway(or Wnt/β-catenin pathway),the non canonical planar cell-polarity pathway,and the non-canonical calcium-dependent pathways.Abnormal Wnt signaling promotes cell proliferation and differentiation,cardiac malformations,various malignancies,so drugs targeting Wnt signaling play a great therapeutic potential.Wnt/β-catenin pathway is involved in the occurrence and development of cardiovascular diseases such as atherosclerosis and stroke by regulating cell proliferation,migration,apoptosis,blood-brain barrier permeability,inflammation,oxidative stress,and immune response.Based on the latest research progress,this review summarizes the role of Wnt/β-catenin signaling in cardiovascular diseases,in order to provide new ideas for the prevention and treatment of cardiovascular diseases.

RUVBL2, a novel AS160-binding protein, regulates insulinstimulated GLUT4 translocation

In fat and muscle cells, insulin-stimulated glucose uptake is mainly mediated by glucose transporter 4 （GLUT4）, which translocates from intracellular compartments to the cell surface in response to insulin stimulation. AS160 is one of the substrates of Akt and plays important roles in insulin-regulated GLUT4 translocation. In this study, RuvB- like protein 2 （RUVBL2） is identified as a new AS160-binding protein using mammalian tandem affinity purification （TAP） combined with mass spectrometry. In 3T3-L1 adipocytes, RUVBL2 is highly expressed and is mainly distrib- uted in the cytosol. Depletion of RUVBL2 in adipocytes inhibits insulin-stimulated GLUT4 translocation and glucose uptake through reducing insulin-stimulated ASI60 phosphorylation. However, introduction of human RUVBL2 can reverse this inhibitory effect. These data suggest that RUVBL2 plays an important role in insulin-stimulated GLUT4 translocation through its interaction with AS160.

A new prospect in cancer therapy: targeting cancer stem cells to eradicate cancer

According to the cancer stem cell theory, cancers can be initiated by cancer stem cells. This makes cancer stem cells prime targets for therapeutic intervention. Eradicating cancer stem cells by efficient targeting agents may have the potential to cure cancer. In this review, we summarize recent breakthroughs that have improved our understanding of cancer stem cells, and we discuss the therapeutic strategy of targeting cancer stem cells, a promising future direction for cancer stem cell research.

Cross-kingdom regulation by plant-derived miRNAs in mammalian systems

MicroRNAs(miRNAs)are small noncoding RNA molecules ubiquitously distributed across diverse organisms,serving as pivotal regulators of genetic expression.Notably,plant-derived miRNAs have been demonstrated to have unique bioactivity and certain stability in mammalian systems,thereby facilitating their capacity for cross-kingdom modulation of gene expression.While there is substantial evidence supporting the regulation of mammalian cells by plant-derived miRNAs,several questions remain unanswered.Specifically,a comprehensive investigation of the mechanisms underlying the stability and transport of plant miRNAs and their cross-kingdom regulation of gene expression in mammals remains to be done.In this review,we summarized the origin,processing,and functional mechanisms of plant miRNAs in mammalian tissues and circulation,emphasizing their greater resistance to mammalian digestion and circulation systems compared to animal miRNAs.Additionally,we introduce four well-known plant miRNAs that have been extensively studied for their functions and mechanisms in mammalian systems.By delving into these aspects,we aim to offer a fundamental understanding of this intriguing field and shed light on the complex interactions between plant miRNAs and mammalian biology.

Targeting androgen receptor and trail： a novel treatment paradigm for breast cancer

OBJECTIVE TNF-related apoptosis-inducing ligand(TRAIL)is a promising cancer therapeutic agent due to its minimal toxicity to normal tissues and remarkable apoptotic activity in tumors.However,most breast cancer cells are resistant to TRAIL-induced apoptosis.Our objectives are to investigate the underlying molecular mechanisms and to develop strategies to overcome such resistance.METHODS To identify modulators of TRAIL-induced apoptosis,we carried out a genome wide si RNA screen.To validate the screening result,we either silenced or overexpressed the identified genes in various breast cancer cells and changes in growth and TRAIL-induced cell apoptosis were determined in vitro and in an orthotopic xenograft mouse model.Finally,we investigated whether small molecules targeting the identified genes improve the effectiveness of TRAIL-therapy.RESULTS We unexpectedly identified androgen receptor(AR)to be responsible for TRAIL resistance.While AR is classically viewed as the key factor in prostate cancer progression,we found that AR expression levels were markedly elevated in human invasive breast cancer specimens including triple-negative breast cancers(TNBC)that are highly aggressive with poor prognosis.Importantly,breast cancer cell lines express different levels of AR that correlated with their TRAIL resistance.AR overexpression in MDA-MB-231 and MDA-MB-436 cells suppressed the TRAIL sensitivity whereas knockdown of AR rendered MCF-7 and MDA-MB-453 cells sensitive to TRAIL-induced apoptosis.AR overexpression also induced TRAIL resistance in breast tumors in vivo.Further,we observed an upregulation of the TRAIL receptor,death receptor 5(DR5)in breast cancer cells,following the removal or inhibition of AR by its antagonists Casodex and MDV3100.Treatment with AR antagonists also enhanced TRAIL-induced breast cancer cell apoptosis.CONCLUSION AR signaling suppresses TRAIL-induced breast cancer cell apoptosis,in part,by suppressing DR5 expression,and a combination of AR antagonists together with TRAIL may be a novel and effective therapy for TNBC.

人源核小体组装蛋白1类似蛋白5(NAP1L5)促进293T细胞增殖（英文）

Dear Editor,The nucleosome assembly protein 1(NAP-1),being a histone chaperone[1],primarily participates in the processes of nucleosome assembly and disassembly,histone transport,and histone eviction.

GSH-responsive curcumin/doxorubicin encapsulated Bactrian camel serum albumin nanocomposites with synergistic effect against lung cancer cells

The aim of this study was to prepare camel serum albumin(CSA) nanoparticles using a self-assembly strategy to co-immobilize curcumin(CCM) and doxorubicin(Dox) which was in favor of combined chemotherapy and biomedical applications of bactrian(Camelus bactrianus) CSA. The constructed CSA nanoparticles(CSA-NPs)with the size around 200 nm displayed a high degree of polydispersity and further encapsulation of CCM and Dox caused no apparent morphological changes to the nanocomposite(CCM/Dox CSA-NPs). The synergistic cytotoxic effect of CCM and Dox on cancer cell A549 was observed with the calculated combination index less than 1.0. Moreover, the release kinetic profile of encapsulated drugs showed a concentration dependence of glutathione(GSH) originating from the GSH used in nanoparticle formation to break the intramolecular disulfide bonds. In vitro cytotoxicity evaluations also revealed that CCM/Dox CSA-NPs showed higher cytotoxicity than that of single drug loaded CSA-NPs, which was also validated by high content screen assay. Taken together, the CCM/Dox CSA-NPs with redox-responsive attributes provided an integrated protein-based combinational drugdelivery matrix to exert synergistic effects.

机械力诱导MHC-Ⅰ构象变化增强TCR抗原识别及T细胞活化

CD8+T细胞主要通过T细胞表面受体(T cell recep tor,TCR)识别并与Ⅰ型主要组织性复合物提呈的抗原(pMHC-Ⅰ)相互作用[1]。TCR对刺激型抗原的识别在CD8+T细胞毒性和适应性免疫中发挥着关键作用。许多证据表明机械力可以延长TCR与刺激性pMHC作用的键合时间(bond lifetime)形成抗原特异性逆锁键(catch bond)[2],并且这种逆锁键对抗原识别非常重要。然而,机械力调控TCR抗原识别的具体结构机制仍不清楚。通过分子动力学模拟、单分子生物膜力学探针、磁镊、T细胞活化实验和动物模型对此问题展开了系统的研究[4]。发现作用在TCR-pMHC-Ⅰ复合体上的拉力可以作用在TCR-pMHC-Ⅰ复合体上的拉力可以打破MHC-I分子内部α1-α2和β2结构域间的相互作用,导致α1-α2结构域旋转并发生构象变化。力诱导的MHC-I构象变化可以进一步别构地调节TCR与刺激性抗原肽及α1-α2结构域的构象及相互作用,诱导产生新的氢键,增强TCR-pMHC-Ⅰ之间的键合时间,但并不能增强TCR与抑制性pMHC-Ⅰ之间的作用。当用点突变阻断这些新形成的氢键,或者α1-α2和β2结构域被二硫键锁住时,最佳力诱导的TCR-pMHC-Ⅰ作用的键合时间明显缩短并且T细胞的活化受到抑制。另外,在人TCR和HLA-A2相互作用中发现了类似机制,并且与肿瘤相关的HLA-A2点突变[3]可以通过限制HLA-A2α1--α2和β2结构域之间的构象打开减弱TCR对肿瘤抗原的识别及T细胞的功能。研究结果表明,机械力诱导的MHC-I构象变化对TCR抗原识别和T细胞活化非常重要,进一步地阐明了机械力调控TCR抗原识别机制,为临床肿瘤的免疫治疗和药物设计提供了新思路和新靶点。

CAS Scientists Visualize the "Annual Rings" in Human Genome

Aging,the major risk factor for a wide range of chronic diseases,is determined by both genetic and epigenetic factors.Accurate technology to track the chromatin dynamics in live cells is required for understanding the deeper mechanisms of aging process.So far,several technologies,including fluorescent in situ hybridization(FISH),TALE and CRISPR/d Cas9system,have been utilized to image specific loci in human genome.However,they are limited to