Epigenetic inactivation of ACAT1 promotes epithelial-mesenchymal transition of clear cell renal cell carcinoma

Han Peipei,Wu Shu,Li Limei,Li Danping,Zhao Jun,Zhang Haishan,Wang Yifang,Zhong Xuemin,Zhang Zhe,Li Ping,Matskova Liudmila,Zhou Xiaoying 한국유전학회 2022 Genes & Genomics Vol.44 No.4

Background: Acetyl-CoA acyltransferase 1 (ACAT1) is a key enzyme catalyzing the production of mitochondrial ketone bodies. We have shown that ACAT1 is down-regulated in kidney renal clear cell carcinoma (KIRC) previously. Objective: To investigate the reasons for downregulation of ACAT1 in KIRC and explore the underlying mechanisms involved in metastatic inhibition regulated by ACAT1. Methods: The Gene Expression Omnibus (GEO) database was queried for meta-analysis of ACAT1 mRNA expression in KIRC. The UALCAN website was used to compare the methylation levels of the ACAT1 promoter region in KIRC and normal tissues. RT-qPCR was used to quantitate ACAT1 transcription levels. The GCBI and Tarbase V.8 databases were used to predict miRNAs that may target the mRNA of ACAT1. The correlation between mRNA expression of ACAT1, MMP7 (matrix metallopeptidase 7), CDH1 (E-cadherin), EpCAM (epithelial cell adhesion molecule), and VIM (vimentin) was analyzed. Extracellular MMP7 protein was quantitated using an ELISA assay. Results: The methylation level of the ACAT1 promoter region in KIRC was significantly higher than that in the normal kidney tissues. The ACAT1 mRNA expression in the KIRC cell lines was restored after treatment with 5-aza-dC (p < 0.05). MiR-21-5p is a conserved microRNA targeting ACAT1. It is expressed at a significantly higher level in KIRC than in normal tissues (p < 0.001). MiR-21-5p miRNA expression negatively correlates with ACAT1 mRNA expression. The expression of miR-21-5p is higher at the T3-T4 stages and in the histologic grades G3-G4. Patients with high miR-21-5p expression tended to have lower overall survival, suggesting that miR-21-5p could serve as a potentially valuable diagnostic biomarker for KIRC (AUC = 0.957; p < 0.001). A mimetic of miR-21-5p inhibited the expression of ACAT1 mRNA and protein. In addition, ACAT1 mRNA expression positively correlates with CDH1 and EpCAM but is negatively correlated with VIM. Overexpression of ACAT1 suppresses the secretion of MMP7 in KIRC cells. Conclusion: Expression of ACAT1 in KIRC is controlled at two levels, firstly by the hypermethylation of the ACAT1 promoter region and secondly by overexpression of miR-21-5p. Downregulation of ACAT1 expression correlates with epithelial-mesenchymal transition (EMT).

An optimal method for improving volumetric error compensation in machine tools based on squareness error identification

Xuemin Zhong,Hongqi Liu,Xinyong Mao,Bin Li 한국정밀공학회 2019 International Journal of Precision Engineering and Vol.20 No.10

This paper proposes a new method to identify the squareness errors of machine tools and gives an optimal method to improve the volumetric compensation accuracy based on the identified squareness errors. The volumetric error model based on screw theory is proposed and the effects of the squareness errors on the volumetric errors have been analyzed to clarify the possibility of improving volumetric error compensation by proper and accurate squareness errors. Then the identification method of the squareness errors is deduced in theory considering a 3-axis horizontal machine tool. With the identified squareness errors, an optimal method to improve volumetric error compensation in machine tools has been proposed. Experiments have verified that the 3 identified squareness errors are in accordance with the measured squareness errors within the accuracy range. Moreover, compared with the traditional measurement of squareness errors not considering the PDGEs, the proposed method is more effective and shows error compensation improvement in the volumetric error compensation process.

Effect of serrated trailing-edge blades on aerodynamic noise of an axial fan

Xuemin Ye,Nan Zheng,Ruixing Zhang,Chunxi Li 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.6

A bionic geometric modification inspired by the trailing-edge serrations of owl wings provides a new approach for controlling the aerodynamic noise of rotary fluid machinery. The effect of different serrated trailing-edges (STEs) on aerodynamic performance and noise of a single-stage variable-pitch axial fan was numerically investigated using steady Reynolds averaged Navier-Stokes and large eddy simulation model, respectively. Results show that STEs could improve fan efficiency at the design and low flow rates, and significantly reduce the noise in the middle- and low-frequency as well as suppress the pressure pulsation of airflow. STEs split large-scale vortices into small ones by intensifying the turbulent flow mixing. STEs with appropriate serration parameters improve the spanwise distribution of the vortex, reduce the span dimension of wake vortices, and induce wake vortices distribution to be more uniform. The innovation of this paper is that a novel blade with partial serrations is presented for the realization of the apparent noise reduction and more preferred aerodynamic performance of the axial fan by improving serration parameters and rearranging the region of the serration.

Effect of Adding Surfactant for Transforming Lignocellulose into Fermentable Sugars during Biocatalysing

Yuqing Zhang,Xuemin Xu,Yuyuan Zhang,Jianfa Li 한국생물공학회 2011 Biotechnology and Bioprocess Engineering Vol.16 No.5

Fuel ethanol is one of the most important alternative fuels used as a substitute for fossil fuel. Lignocellulose is the most abundant biomass resource for the production of fuel ethanol. However, the hydrolysis of lignocellulose requires high enzyme loading. In order to strengthen the process of enzyme hydrolysis of lignocellulose,surfactant-polyethylene glycol (PEG) was applied to the catalysis of lignocellulose into fermentable sugars. The effect of PEG on both the enzymatic hydrolysis and adsorption of cellulose were investigated. The addition of surfactant obviously facilitated enzymatic hydrolysis. In particular, upon addition of PEG4000, the enzyme catalytic efficiency increased by 51.06%. Meanwhile,the adsorption quantity of cellulase decreased by 11.25%. In addition, the mechanism of the effect of PEG on enzymatic hydrolysis and cellulase adsorption is discussed.

Type synthesis of the fully-decoupled two-rotational and one-translational parallel mechanism

Yanbin Zhang,Xuemin Wei,Shuang Zhang,Zhenzhen Chang,Yaoguang Li 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.12

Type synthesis of parallel mechanism is regarded as the theoretical basis and source for the original innovation design of mechanical devices and robots. A new method for type synthesis of the fully-decoupled two-rotational and one-translational (2R1T) parallel mechanisms with three degrees of freedom is proposed in this paper. Based on the actuation wrench screw theory, the mathematical model mapping the input and output velocity vector space of the fully-decoupled 2R1T parallel mechanism is established. The actuation wrench screws and the actuated twist screws of the corresponding branches are derived according to the mathematic model. The forms of the unactuated screws are determined in terms of the reciprocal product theory. Structural synthesis of the branch chains is realized. Then type synthesis of parallel mechanisms is completed as well and lots of novel mechanisms are obtained. Finally, a 2RUPU-PU parallel mechanism synthesized is taken as an example to analyze its mobility and kinematics. Results show that the mechanism has two-rotational and onetranslational degrees of freedom and its Jacobian matrix is a diagonal matrix, i.e., it has the fully-decoupled kinematic characteristics. Therefore, the method proposed is correct and effective to synthesize the fully-decoupled 2R1T parallel mechanisms.

Geometry effect in the drug delivery for therapy with nanomedicines based on the conditions of the sport

Zhu, Lemei,Zou, Xuemin,Li, Xi,Zhang, Yuan,Liu, Juan,Xiang, Yuhan Techno-Press 2022 Advances in nano research Vol.13 No.3

This study investigates the geometrical impact on the nanomedicine drug delivery via nanodevices. A nanomotor made of the nanotube carrying the drug as the motor blade is considered in the blood flow. Physical activities change the blood flow, and sports training enhances the blood flow and plays a significant role in the stability of drug delivery devices. This paper studies the impact of geometrical parameters on the nanomotors carrying the nanomedicine. The effect of physical exercise on the dynamic response regarding the stability of drug delivery devices is discussed in detail.

Sciatic nerve leachate of cattle causes neuronal differentiation of PC12 cells via ERK1/2 signaling pathway

Ziqiang Zhang,Yumei Liu,Xuemin Zhu,Lan Wei,Jiamin Zhu,Ke Shi,Guotao Wang,Li Pan 대한수의학회 2018 Journal of Veterinary Science Vol.19 No.4

Previous studies have shown that the sciatic nerve has neurotrophic activity, and nerve regeneration, differentiation, and axon outgrowth can be modulated by different sciatic nerve preparations. However, numerous animals may have to be sacrificed to obtain enough sciatic nerves to make a sciatic nerve preparation. Some studies have demonstrated that the role of sciatic nerve preparations in neural differentiation depends on the neurotrophins that Schwann cells secrete, and these factors are highly conserved among different species. To reduce the use of experimental animals, in this study, we made a leachate by using the sciatic nerve of cattle and explored its effect on neuronal differentiation of rat PC12 cells (a useful model for studying neuronal differentiation). Results showed the neurite outgrowth of PC12 cells treated with the cattle sciatic nerve leachate for 3, 6, and 9 days was significantly improved, and the expressions of β3-tubulin and microtubule-associated protein 2 (two neuron-specific proteins) were increased. Moreover, the ERK1/2 signaling pathway was activated after PC12 cells were incubated with cattle sciatic nerve leachate for 9 days. Thus, a sciatic nerve leachate obtained from cattle can effectively induce neuronal differentiation of rat PC12 cells via ERK1/2 signaling pathway.

Bioprocess Production of Sea Cucumber Rice Wine and Characterization of Functional Components and Antioxidant Activities

Shuai He,Lin Wang,Hao Dong,Pei Liu,Peiyu Shi,Xuemin Li,Xingchen Ren,Ning Lv,Yanan Liu,Changhu Xue,Hong Lin,Xiangzhao Mao 한국식품과학회 2014 Food Science and Biotechnology Vol.23 No.3

A new production bioprocess for sea cucumberrice wine (SCRW) was established. The traditional productiontechnology of Chinese rice wine was combined with additionof sea cucumber hydrosylates. The optimal enzymaticconditions of sea cucumber and the fermentation process ofSCRW were determined. The weight of sea cucumberenzymatic hydrolysates was 2.5% of millet while cookingthe millet. SCRW contained abundant free amino acids (30total at 1,681.216 mg/L), oligosaccharides (4 total at10,999.380 mg/L), total phenols (658.850 mg/L), andmineral elements (9 total at 1,911.353 mg/kg), and anantioxidant activity, all of which were higher than forcontrol rice wine (CRW). Galactosamine and glucuronicacid, both sea cucumber polysaccharides, were present inSCRW, but not in CRW.

MRTF-A-NF-κB/p65 axis-mediated PDL1 transcription and expression contributes to immune evasion of non-small-cell lung cancer via TGF-β

Du Fu,Qi Xin,Zhang Aotong,Sui Fanfan,Wang Xuemin,Proud Christopher G.,Lin Cunzhi,Fan Xinglong,Li Jing 생화학분자생물학회 2021 Experimental and molecular medicine Vol.53 No.-

PD-L1 is abnormally regulated in many cancers and is critical for immune escape. Fully understanding the regulation of PD-L1 expression is vital for improving the clinical efficacy of relevant anticancer agents. TGF-β plays an important role in the low reactivity of PD-1/PD-L1 antibody immunotherapy. However, it is not very clear whether and how TGF-β affects PD-L1 expression. In the present study, we show that TGF-β upregulates the expression of the transcriptional coactivator MRTF-A in non-small-cell lung cancer cells, which subsequently interacts with NF-κB/p65 rather than SRF to facilitate the binding of NF-κB/p65 to the PDL1 promoter, thereby activating the transcription and expression of PD-L1. This leads to the immune escape of NSCLC cells. This process is dependent on the activation of the TGF-β signaling pathway. In vivo, inhibition of MRTF-A effectively suppresses the growth of lung tumor s y ngrafts with enrichment of NK and T cells in tumor tissue. Our study defines a new signaling pathway that regulates the transcription and expression of PD-L1 upon TGF-β treatment, which may have a significant impact on research into the application of immunotherapy in treating lung cancer.

Spatio-Temporal Consistency Enhancement for Disparity Sequence

Haixu Liu,Chenyu Liu,Yufang Tang,Haohui Sun,Xueming Li 보안공학연구지원센터 2014 International Journal of Signal Processing, Image Vol.7 No.5

Disparity estimation for still images has attracted much interest and acquired many promising results. However, simply applying these methods to produce a disparity sequence may suffer from the undesirable flickering artifacts. These errors not only distinctly decrease the visible quality of the synthesized video, but also significantly reduce the coding efficiency of the disparity sequence. In this paper, a novel temporal consistency enhancement algorithm based on Guided Filter and Temporal Gradient (GFTG) is proposed. The flickering artifacts and noises are effectively removed and the edges of objects are well preserved. Both quantitative and qualitative evaluations show that the spatio-temporal consistency has been highly improved by utilizing our approach.