3',4',5',5,7-Pentamethoxyflavone Sensitizes Cisplatin-Resistant A549 Cells to Cisplatin by Inhibition of Nrf2 Pathway

Xiangyu Hou,Xupeng Bai,Xiaoli Gou,Hang Zeng,Chen Xia,Wei Zhuang,Xinmeng Chen,Zhongxiang Zhao,Min Huang,Jing Jin 한국분자세포생물학회 2015 Molecules and cells Vol.38 No.5

Nuclear factor erythroid 2-related factor 2 (Nrf2) is an important redox-sensitive transcription factor that regulates the expression of several cytoprotective genes. More recently, genetic analyses of human tumors have indicated that Nrf2 may cause resistance to chemotherapy. In this study, we found that the expression levels of Nrf2 and its target genes GCLC, HO-1, NQO1 were significantly higher in cisplatinresistant A549 (A549/CDDP) cells than those in A549 cells, and this resistance was partially reversed by Nrf2 siRNA. 3',4',5',5,7-Pentamethoxyflavone (PMF), a natural flavonoid extracted from Rutaceae plants, sensitized A549/CDDP to CDDP and substantially induced apoptosis compared with that of CDDP alone treated group, and this reversal effect decreased when Nrf2 was downregulated by siRNA. Mechanistically, PMF reduced Nrf2 expression leading to a reduction of Nrf2 downstream genes, and in contrast, this effect was decreased by blocking Nrf2 with siRNA. Taken together, these results demonstrated that PMF could be used as an effective adjuvant sensitizer to increase the efficacy of chemotherapeutic drugs by downregulating Nrf2 signaling pathway.

3',4',5',5,7-Pentamethoxyflavone Sensitizes Cisplatin-Resistant A549 Cells to Cisplatin by Inhibition of Nrf2 Pathway

Hou, Xiangyu,Bai, Xupeng,Gou, Xiaoli,Zeng, Hang,Xia, Chen,Zhuang, Wei,Chen, Xinmeng,Zhao, Zhongxiang,Huang, Min,Jin, Jing Korean Society for Molecular and Cellular Biology 2015 Molecules and cells Vol.38 No.5

Nuclear factor erythroid 2-related factor 2 (Nrf2) is an important redox-sensitive transcription factor that regulates the expression of several cytoprotective genes. More recently, genetic analyses of human tumors have indicated that Nrf2 may cause resistance to chemotherapy. In this study, we found that the expression levels of Nrf2 and its target genes GCLC, HO-1, NQO1 were significantly higher in cisplatin-resistant A549 (A549/CDDP) cells than those in A549 cells, and this resistance was partially reversed by Nrf2 siRNA. 3,4,5,5,7-Pentamethoxyflavone (PMF), a natural flavon extracted from Rutaceae plants, sensitized A549/CDDP to CDDP and substantially induced apoptosis compared with that of CDDP alone treated group, and this reversal effect decreased when Nrf2 was downregulated by siRNA. Mechanistically, PMF reduced Nrf2 expression leading to a reduction of Nrf2 downstream genes, and in contrast, this effect was decreased by blocking Nrf2 with siRNA. Taken together, these results demonstrated that PMF could be used as an effective adjuvant sensitizer to increase the efficacy of chemotherapeutic drugs by downregulating Nrf2 signaling pathway.

Fabrication of a Thermoregulating Cotton Fabric with Enhanced Flame Retardancy via Layer-by-layer Assembly

Yunbo Chen,Xiangyu Zhu,Luying Chen,Bijia Wang,ZhiPing Mao,Xueling Feng,Xiaofeng Sui,Hong Xu 한국섬유공학회 2022 Fibers and polymers Vol.23 No.9

The lack of thermoregulating functionality and high flammability for cotton fabrics greatly restricts theirapplication in high-performance fields. Herein, we report a versatile layer-by-layer (LBL) assembly strategy for introducing amultilayered film consisting of phase change microcapsules and ammonium polyphosphate to cotton fabric, endowing cottonwith thermoregulation and flame retardant properties. The coated fabrics were characterized based on scanning electronmicroscopy (SEM), water-vapor transmission rate (WVT), thermogravimetry (TG), differential scanning calorimetry (DSC),limiting oxygen index (LOI) and infrared thermal imaging. A fabric deposited with 20 bilayers (MCPM/APP-20) shows anappropriate WVT (50.57 g/m2·h) and improved flame retardancy with an LOI of 24.5 % and residual carbon of 34.53 %. Italso shows a melting enthalpy of 30.09 J/g, which results in a temperature difference of 6.4 °C compared with pristine cotton. The functional properties endowed by the LBL assembly are found to be reasonably durable, with the melting enthalpy andresidual carbon of MPCM/APP-20 reduced to 17.69 J/g and 19.64 %, respectively, after 30 laundering cycles. This studyprovides a convenient way to develop multifunctional cotton fabrics that can be good candidates for high-performancetextiles.

An Improved Mathematical Calculation Method for Beam String Structure Based on Static Equilibrium Principle

Xiangyu Yan,Hong Hu,Zhi-Hua Chen,Yan Yang 한국강구조학회 2020 International Journal of Steel Structures Vol.20 No.4

The beam string structure (BSS) has been widely applied to public buildings (e.g. sports venues and exhibition centers) for its strong adaptability to architectural form and reasonable load bearing mechanism. However, most mathematical calculation methods for BSS are too complicated to be generally mastered by structural engineers, which limits the promotion and actual application. In this paper, two analytical calculation methods for the BSS are proposed based on displacement control objectives and work-energy principle. The computational formulas are then derived to calculate the member internal force and structural deformation. On this basis, the tension and static load tests and the fi nite element analytical method have been carried out to assess the calculation methods. The results of the tests and simulation are in good agreement with the analytical solution obtained by the computational formulas. Moreover, the formulas can be more appropriate with a greater beam span, proper rise–span and sag–span ratios (between 1/15 and 1/12) as well as more brace struts.

The Step-by-Step Model Technology Considering Nonlinear Effect Used for Construction Simulation Analysis

Zhihua Chen,Zhongwei Zhao,Han Zhu,Xiaodun Wang,Xiangyu Yan 한국강구조학회 2015 International Journal of Steel Structures Vol.15 No.2

Long-span spatial structures have advantages over other structural systems in terms of novelty and aesthetics in architectural form. However, the complexity of stress distribution causes these kinds of structures to change significantly between the construction and utilization stages. One-time loading method was used in the traditional design method to calculate and evaluate structural stress and structural deflection, either of which could cause problems in component size and residual stress during construction process. Therefore, construction simulation analysis of these structures must be performed. Element birth and death technology and step-by-step model technology (SSMT) are the main approaches in the finite element method used in construction analysis. This paper proposes a theory basis for the SSMT that was used in the constructional analysis of the Yujiapu Railway Station Building. Results obtained by the proposed method were compared with those by element birth and death technology. In addition, the preset construction deformation value was calculated to validate the correctness and efficiency of the proposed method.

Classification of Metro Station Areas Using Multi-Source Big Data: Case Studies in Beijing

Shuo Chen,Xiangyu Li Council on Tall Building and Urban Habitat Korea 2023 International journal of high-rise buildings Vol.12 No.1

Large-capacity public transportation systems, represented by urban metro lines, are the key to alleviating the significant increase in urbanization and motorization in China. But to improve the agglomeration effect of metro stations in a more accurate and targeted way requires scientific evaluation and classification of the surrounding areas of metro stations. As spatial and functional design are the core factors for urban renewal design, this study took Beijing as an example, using multi-source data to evaluate the morphology and functional composition surrounding areas of metro stations, and the Boston Consulting Group (BCG) matrix was used to classify and characterize each type of surrounding areas from morphological-functional dimensions. It shows a negative correlation of the mix-use index with the floor area ratio, and only about 20% of the areas achieve the ideal situation of high construction intensity with high mix-use diversity. Hoping to provide a reference for city managers and designers in dealing with the surrounding metro stations with different construction intensities in a more precise way.

Exploration on Damage Mechanism and Equivalent Damage Model of High Arch Dams under Earthquakes

Jianyun Chen,Xiangyu Cao,Qiang Xu,Jing Li 대한토목학회 2020 KSCE JOURNAL OF CIVIL ENGINEERING Vol.24 No.4

Damage identification technology of high arch dams has been well developed under strong earthquakes. However, the failure mechanism of high arch dams at different locations remains unclear. For this purpose, a series of deterministic dynamic analyses for a 3D 289-m-high arch dam based on concrete damaged plasticity constitutive model are performed. The failure mechanism at different locations of high arch dams under earthquakes is studied systematically. According to the sensitivity of different indicators to different damaged positions, an effective sensor placement scheme is proposed to assess the seismic reliability in practical engineering. Furthermore, a new effective equivalent damage model based on prior information is proposed, which can improve the efficiency of damage identification, as well as solving the problem that the real damage is concealed by homogenizing the damage in a pre-set region. The results provide suggestions and theoretical basis for sensor placement in actual monitoring of high arch dams; and the equivalent damage model provides a new solution to balance the efficiency and accuracy of damage identification.

Synthesis of acid-activated reversible conversion supramolecular nanoplatform: application in drug delivery and anti-tumor activity

Yang Cuiting,Xiangyu Chen,Jinkui Teng,Shuai Chen,Jianmei Yang,Xiaoqing Liu,Junnan He,Jin Zhang,Yan Zhao 한국고분자학회 2024 Macromolecular Research Vol.32 No.1

Supramolecular nanoplatforms with stimuli-responsive behavior feature sensitive performance and effective drug delivery, which are desirable as intelligent drug delivery systems. Generally, tumor cells are characterized by excessive acid production, resulting in a lower pH in the tumor microenvironment (pH < 6.5) than in normal tissues (pH ≈7.4) and providing the possibility for the drug delivery system to exploit this decrease in pH as a trigger for drug release. Here, an acid-sensitive supramolecular nanoplatform (CM-β-CD/FC12 +Br− NPs) with assembly/disassembly properties was designed and constructed, which was exploited to capture, deliver, and release anti-tumor compound CSL. 2D NOESY was utilized to examine the host–guest interaction and the potential mechanism for CM-β-CD/FC12 +Br− NPs loading CSL. CM-β-CD/FC12 +Br− NPs present good blood compatibility. Cytotoxicity assay revealed that CSL-loaded NPs display minimal toxicity against normal cells BEAS-2B and good anticancer ability against five human cancer cell lines, especially for Human hepatoma cell line SMMC-7721. In addition, cell apoptosis and cycle assay further verified that CSL-loaded NPs-induced apoptosis in SMMC- 7721 cells up to ~ 93%, as well as blocking the cells in G0/G1 phase and inhibiting the proliferation of SMMC-7721 cells in a dose-dependent manner. We expect that CM-β-CD/FC12 +Br− NPs will be potential acid-answered drug delivery candidates.

Formation Mechanism and Adhesion Evaluation of Debris in Ti–6Al–4V Alloy Turning

Changping Li,Xiangyu Liu,Moran Xu,Jielin Chen,Shujian Li,Pengnan Li,Tae Jo Ko 한국정밀공학회 2023 International Journal of Precision Engineering and Vol.10 No.5

In this paper, the formation mechanism of adhered debris on the surface of turned titanium alloy was studied. The adhesion rate of debris was calculated and evaluated using image extraction technology. The effects of cutting parameters and cooling conditions on the debris adhesion rate were also studied. Moreover, the chip temperature and trajectory in the turning process are analyzed using a finite element simulation and a thermal camera. The results show that there are three primary sources of adhered debris: the adhesion of the built-up edge, the micro-chips formed during the cutting process, and the micro-chips generated by the friction between the chip and the machined surface. In addition, the cutting speed is also one of the most significant factors affecting the adhesion of debris. The debris adhesion rate drops significantly as the cutting speed decreases. It was also found that the coolant can effectively reduce the debris adhesion rate, and this effect is more evident at low feed rates.

Phenylboronic acid-functionalized gelatin–oleic acid nanoparticles for high loading and efficient transdermal delivery of Celastrol towards the treatment of psoriasis

Jiangtao Su,Na Lin,Xiangyu You,Heshuang Dai,Meng Rao,Lu Ye,Fan Ye,Le Cai,Yuxin Chen,Gao Zhou,Xiaoxia Guo 한국고분자학회 2023 Macromolecular Research Vol.31 No.11

Systemic toxicity, poor aqueous solubility, and poorly cell permeable ability hindered the clinical application of Celastrol. In this study, we aimed to design and synthesize an amphiphilic conjugate to encapsulate Celastrol into micelles to improve its water solubility, cellular membrane penetration, improving the clinic translation potential of Celastrol for the treatment of psoriasis. For this purpose, we first synthesized gelatin and oleic acid conjugate (GOC-1), and then covalently bonded 4-(3-boronophenylamino)-4-oxobutanoic acid (BPOA) with GOC-1 to form a stable GOC-2 conjugate which can self-assemble into micelles in aqueous solution. Celastrol (Cel) was physically encapsulated into the core of GOCs micelles. The dynamic stability, particle size, drug release, zeta potential, drug-loading efficiency, and surface morphology of Cel/loaded GOCs nano-micelles were determined. In addition, cell viability, cellular uptake of Cel/loaded GOC-2, and skin permeation and in vivo anti-psoriasis effect of Cel-loaded GOC-2 were investigated. Our results have shown that Cel/loaded GOC-1 and Cel/loaded GOC-2 have spherical shapes with diameters of around 200–300 nm. Compared to GOC-1, GOC-2 micelles showed higher drug-loading efficiency and excellent permeation ability in vitro. Moreover, Cel/GOC-2 micelles reduced erythema and white scales on the dorsal skin of psoriatic mice. In conclusion, BPOA attached GOC nanoparticles as a Celastrol carrier not only increase its water solubility but also improve drug-loading efficiency and cell permeation ability, exhibiting superior anti-psoriatic effect than the commercially available tacrolimus. Our work is expected to provide a facile approach to prepare nanocarrier for Celastrol to improve the clinic translation potential of Celastrol.