Cloning and characterization of a selenium-independent glutathione peroxidase (HC29) from adult Haemonchus contortus

Wei Sun,Xiaokai Song,Ruofeng Yan,Lixin Xu,Xiangrui Li 대한수의학회 2012 Journal of Veterinary Science Vol.13 No.1

The complete coding sequence of Haemonchus (H.) contortus HC29 cDNA was generated by rapid amplification of cDNA ends in combination with PCR using primers targeting the 5´- and 3´-ends of the partial mRNA sequence. The cloned HC29 cDNA was shown to be 1,113 bp in size with an open reading frame of 507 bp, encoding a protein of 168 amino acid with a calculated molecular mass of 18.9 kDa. Amino acid sequence analysis revealed that the cloned HC29 cDNA contained the conserved catalytic triad and dimer interface of selenium-independent glutathione peroxidase (GPX). Alignment of the predicted amino acid sequences demonstrated that the protein shared 44.7∼80.4% similarity with GPX homologues in the thioredoxin-like family. Phylogenetic analysis revealed close evolutionary proximity of the GPX sequence to the counterpart sequences. These results suggest that HC29 cDNA is a GPX, a member of the thioredoxin-like family. Alignment of the nucleic acid and amino acid sequences of HC29 with those of the reported selenium-independent GPX of H. contortus showed that HC29 contained different types of spliced leader sequences as well as dimer interface sites, although the active sites of both were identical. Enzymatic analysis of recombinant prokaryotic HC29 protein showed activity for the hydrolysis of H2O2. These findings indicate that HC29 is a selenium-independent GPX of H. contortus.

MicroRNA-138 Suppresses Adipogenic Differentiation in Human Adipose Tissue-Derived Mesenchymal Stem Cells by Targeting Lipoprotein Lipase

Yuting Wang,Lixin Lin,Yong Huang,Junjun Sun,Xueming Wang,Peng Wang 연세대학교의과대학 2019 Yonsei medical journal Vol.60 No.12

Purpose: Adipogenic differentiation of adipose tissue-derived mesenchymal stem cells (AMSCs) is critical to many disease-relateddisorders, such as obesity and diabetes. Studies have demonstrated that miRNA-138 (miR-138) is closely involved in adipogenesis. However, the mechanisms affected by miR-138 remain unclear. This work aimed to investigate interactions between miR-138and lipoprotein lipase (LPL), a key lipogenic enzyme, in AMSCs. Materials and Methods: Human AMSCs (hAMSCs) isolated from human abdomen tissue were subjected to adipogenic differentiationmedium. Quantitative real-time polymerase chain reaction and Western blot assay were applied to measure the expressionsof miR-138, LPL, and the two adipogenic transcription factors cytidine-cytidine-adenosine-adenosine-thymidine enhancerbinding protein alpha (C/EBPα) and peroxisome proliferator-activated receptor gamma (PPARγ). The relationship between miR-138 and LPL was predicted utilizing the miRTarBase database and validated by dual luciferase reporter assay. Results: Showing increases in C/EBPα and PPARγ expression levels, hAMSCs were induced into adipogenic differentiation. Duringadipogenesis of hAMSCs, miR-138 expression was significantly downregulated. Overexpression of miR-138 by transfection inhibitedhAMSCs adipogenic differentiation in vitro. Mechanically, LPL was a target of miR-138. LPL expression was upregulated duringadipogenesis of hAMSCs, and this upregulation was reversed by miR-138 overexpression. Functionally, silencing of LPL by transfectionexerted similar inhibition of the expressions of C/EBPα and PPARγ. Meanwhile, LPL ectopic expression was able to partlyabolish the suppressive effect of miR-138 overexpression on adipogenic differentiation of hAMSCs. Conclusion: Upregulation of miR-138 inhibits adipogenic differentiation of hAMSCs by directly downregulating LPL.

Development of Toxoplasma gondii Chinese I genotype Wh6 Strain in Cat Intestinal Epithelial Cells

Gui-Hua Zhao,Lixin Zhang,Lisha Dai,Haozhi Xu,Chao Xu,Ting Xiao,Jin Li,Hui Sun,Beibei Zhou,Kun Yin 대한기생충학ㆍ열대의학회 2022 The Korean Journal of Parasitology Vol.60 No.4

Felids are the unique definitive host of Toxoplasma gondii. The intestine of felid is the only site for initiating Toxoplasma gondii sexual reproduction. T. gondii excretes millions of infectious oocysts from the intestine, which are the primary source of infection. There are many difficulties in developing vaccines and drugs to control oocyst excretion due to the lack of an appropriate experimental model. Here, we established an in vitro feline intestinal epithelial cell (IEC) infection system and an efficient animal model of T. gondii Chinese 1 genotype, Wh6 strain (TgCtwh6). The Kunming mice brain tissues containing TgCtwh6 cysts were harvested 42-day post-infection. The bradyzoites were co-cultured with cat IECs in vitro at a ratio of 1:10. Five 3-month-old domestic cats were orally inoculated with 600 cysts each. The oocysts were detected by daily observation of cat feces by microscopy and polymerase chain reaction. We found that the parasite adhered and invaded cat IECs in vitro, transformed into tachyzoites, and then divided to form rose-like structures. These parasites eventually destroyed host cells, escaped, and finished the asexual reproduction process. Schizonts associated with sexual reproduction have not been observed during development in vitro cultured cells. However, schizonts were detected in all infected cat intestinal epithelial cells, and oocysts were presented in all cat feces. Our study provides a feasible cell model and an efficient infection system for the following studies of T. gondii sexual reproduction, and also lays a foundation to develop drugs and vaccines for blocking excretion and transmission of oocysts.

Evaluation of Cracking and Serviceability Performance of Lightweight Aggregate Concrete Deep Beams

Hui Wei,Tao Wu,Lixin Sun,Xi Liu 대한토목학회 2020 KSCE Journal of Civil Engineering Vol.24 No.11

This paper investigated the diagonal crack propagation and serviceability performance of fifteen deep beams fabricated using lightweight aggregate concrete (LWAC). Experimental variables included the shear span-depth ratio, beam section depth, and bearing plate width. The test results were reported in terms of crack propagation, diagonal crack width, diagonal cracking load, and size effect on the serviceability of deep beams; they were also employed to establish a relationship between residual shear bearing capacity and maximum diagonal crack width for such components. In addition, the crack width limits in current code provisions were utilized to further evaluate the serviceability of LWAC deep beams. The test results revealed that the diagonal crack propagation is almost independent of the variation of beam depth, while the diagonal crack width exhibited an obvious increasing trend as shear span-depth ratio or bearing plate width increased. At service load level, the crack width limit of 0.4 mm stipulated in ACI 224-R-01 can be satisfied by LWAC deep beams with horizontal and vertical shear reinforcement ratios more than 0.3%.

Fatty Acids in Leaves of Magnoliaceae

Liqun Huang,Hanzhou Sun,Lixin He,Zhihui Li,Mohua Yang 한국원예학회 2006 한국원예학회 기타간행물 Vol.- No.-

Spatio-temporal Variability in Sea Surface Temperatures for the Yellow Sea based on MODIS Dataset

Chunli Liu,Qiwei Sun,Qianguo Xing,Zhenlin Liang,Yue Deng,Lixin Zhu 한국해양과학기술원 2017 Ocean science journal Vol.52 No.1

The spatio-temporal variabilities in sea surface temperature (SST) were analyzed using a time series of MODIS datasets for four separate regions in the Yellow Sea (YS) that were located along a north-south axis. The space variant temporal anomaly was further decomposed using an empirical orthogonal function (EOF) for estimating spatially distributed SST. The monthly SSTs showed similar temporal patterns in each region, which ranged from 2.4°C to 28.4°C in the study years 2011 to 2013, with seasonal cycles being stronger at the higher latitudes and weaker at the lower latitudes. Spatially, although there were no significant differences among the four regions (p < 0.05) in any year, the geographical distribution of SST was characterized by an obvious gradient whereby SST decreased along the north-south axis. The monthly thermal difference among regions was largest in winter since the SST in the southeast was mainly affected by the Yellow Sea Warm Currents. The EOF1 mode accounted for 56% of the total spatial variance and exhibited a warming signal during the study period. The EOF2 mode accounted for 8% of the total variance and indicated the warm current features in the YS. The EOF3 mode accounted for 6% of the total variance and indicated the topographical features. The methodology used in this study demonstrated the spatiotemporal variabilities in the YS.

Submicron silicon encapsulated with graphene and carbon as a scalable anode for lithium-ion batteries

Lee, Byeongyong,Liu, Tianyuan,Kim, Sun Kyung,Chang, Hankwon,Eom, Kwangsup,Xie, Lixin,Chen, Shuo,Jang, Hee Dong,Lee, Seung Woo Elsevier 2017 Carbon Vol.119 No.-

<P>Silicon (Si) is an emerging anode material for rechargeable lithium-ion battery owing to its high theoretical capacity. However, Si-based anodes suffer from poor cycling stability because of its large volume change during lithiation/delithiation processes. Although nanostructured Si electrodes have significantly improved the cycling stability, the scale-up of these electrodes is another critical huddle for commercialization. To address these issues, we introduce a simple and scalable electrode fabrication process using low-cost submicron Si particles (<similar to 1 mu m) that was recycled from industrial Si waste. During the electrode fabrication, the submicron Si particles are encapsulated with 3D carbon matrix including a carbon coating on the Si particles and interconnected reduced graphene layers, which can effectively mitigate volume variation of the Si as well as support electrical conductivity. The submicron Si particle based electrodes exhibit a reversible capacity of 1192 mAh g(-1) at 100th cycle, retaining up to 84% of initial capacity. The introduced approach based on Si waste provides a new opportunity in fabricating sustainable and scalable Si-based anodes for high-capacity lithium-ion batteries. (C) 2017 Elsevier Ltd. All rights reserved.</P>

Characterization of HC58cDNA, a putative cysteine protease from the parasite Haemonchus contortus

Charles I. Muleke,Yan Ruofeng,Xu Lixin,Sun Yanming,Li Xiangrui 대한수의학회 2006 Journal of Veterinary Science Vol.7 No.3

Because of the complexity of the cathepsin B-like (CBL) family, an information on the biological and biochemical characteristics of individual CBL genes is lacking. In this study, we investigated the degradative effects of the recombinant HC58 protein isolated from Haemonchus contortus parasites on protein substrates over a broad pH range in vitro. This protein, which hydrolyzed the synthetic peptide substrates Z-FR-AMC and Z-RR-AMC, had characteristics of the cysteine protease class of proteins. In the acidic pH range, the isolated protein actively degraded hemoglobin (Hb), the heavy chain of goat immunoglobulin G, and azocasein. By contrast, it degraded fibrinogen in the alkaline pH range. These activities were strongly inhibited in the presence of the cysteine protease inhibitor E-64. While the protein digested Hb, it did not induce the agglutination of erythrocytes from its natural host. These results suggest that the HC58 protein may play a role in the nutrition of this parasite.

Taurocholic acid promotes hepatic stellate cell activation via S1PR2/p38 MAPK/YAP signaling under cholestatic conditions

Jing Yang,Xujiao Tang,Zhu Liang,Mingzhu Chen,Lixin Sun 대한간학회 2023 Clinical and Molecular Hepatology(대한간학회지) Vol.29 No.2

Background/Aims: Disrupted bile acid regulation and accumulation in the liver can contribute to progressive liver damage and fibrosis. However, the effects of bile acids on the activation of hepatic stellate cells (HSCs) remain unclear. This study investigated the effects of bile acids on HSC activation during liver fibrosis, and examined the underlying mechanisms. Methods: The immortalized HSCs, LX-2 and JS-1cells were used for the in vitro study. in vitro, the adeno-associated viruses adeno-associated virus-sh-S1PR2 and JTE-013 were used to pharmacologically inhibit the activity of S1PR2 in a murine model of fibrosis induced by a 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) diet. Histological and biochemical analyses were performed to study the involvement of S1PR2 in the regulation of fibrogenic factors as well as the activation properties of HSCs. Results: S1PR2 was the predominant S1PR expressed in HSCs and was upregulated during taurocholic acid (TCA) stimulation and in cholestatic liver fibrosis mice. TCA-induced HSC proliferation, migration and contraction and extracellular matrix protein secretion were inhibited by JTE-013 and a specific shRNA targeting S1PR2 in LX-2 and JS-1 cells. Meanwhile, treatment with JTE-013 or S1PR2 deficiency significantly attenuated liver histopathological injury, collagen accumulation, and the expression of fibrogenesis-associated genes in mice fed a DDC diet. Furthermore, TCAmediated activation of HSCs through S1PR2 was closely related to the yes-associated protein (YAP) signaling pathway via p38 mitogen-activated protein kinase (p38 MAPK). Conclusions: TCA-induced activation of the S1PR2/p38 MAPK/YAP signaling pathways plays a vital role in regulating HSC activation, which might be therapeutically relevant for targeting cholestatic liver fibrosis.

Erratum: Characterization of HC58cDNA, a putative cysteine protease from the parasite Haemonchus contortus

Li Xiangrui,Charles I. Muleke,Yan Ruofeng,Xu Lixin,Sun Yanming 대한수의학회 2006 Journal of Veterinary Science Vol.7 No.4

Vol. 7, No. 3, pp. 249-255, 2006 The correspondence is changed by authors' request.