Global Inactivation of the Pla2g6 Gene in Mice Does Not Cause Dyslipidemia under Chow or High-fat Diet Conditions

Li Zhang,Shumei Zhong,Ying Li,Guang Ji,Meenakshi Sundaram,Zemin Yao 대한암예방학회 2013 Journal of cancer prevention Vol.18 No.3

Background: Genome-wide association studies suggest that plasma triacylglyceride (TAG) in humans was associated with variation in the PLA2G6 locus, a gene that encodes calcium-independent phospholipase A2 (iPLA2Ղ). The objective of the present study is to understand the impact of genetic inactivation of iPLA2Ղ on hepatic TAG metabolism in C57BL/6 mice.Methods: Male iPLA2Ղ+/− mice were backcrossed with female iPLA2Ղ−/− mice for up to 10 generations prior to experiments. Lipid and lipoprotein metabolism from plasma, hepatocytes, thigh subcutaneous adipose and thigh skeletal muscle tissues of the mice were determined under various experimental conditions.Results: The iPLA2Ղ−/− mice, either male or female as compared with iPLA2Ղ+/+ littermates, showed no change in fasted or postprandial plasma TAG or total cholesterol at young (12-15 weeks) or old (40-44 weeks) ages under chow diet or high-fat diet (HFD) conditions. However, fractionation of plasma lipoproteins showed that under HFD conditions, there was a significant increase (by 40%) in apoB-100 association with VLDL1 fractions in iPLA2Ղ−/− mice as compared with iPLA2Ղ+/+ littermates. There was no significant difference in triglyceride or cholesterol contents in the liver, muscle, or adipose tissue between iPLA2Ղ−/− and iPLA2Ղ+/+ littermates. Metabolic labeling experiments with cultured primary hepatocytes isolated from iPLA2Ղ−/− mice also showed 2-fold increase in the secretion of [35S]methionine-labeled apoB-100 in VLDL1 fractions as compared with that from iPLA2Ղ+/+hepatocytes. Likewise, secretion of [3H]palmitate-labeled TAG from the iPLA2Ղ−/− hepatocytes was increased by 2-fold.Conclusions: Although iPLA2Ղ may play a role in TAG-rich VLDL1 production from cultured hepatocytes, there is no evidence that inactivation of iPLA2Ղ would lead to dyslipidemia in mice in vivo.

Design and control method of a hydraulic power unit for a wheel-legged robot

Zemin Cui,Xuewen Rong,Yibin Li 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.4

For a hydraulic wheel-legged robot (WLR), it is essential to have a powerful and lightweight power supply. In this paper, a compact hydraulic power unit (HPU) is developed, and a control method to reduce the energy consumption of the robot is proposed. To achieve a high jump of the robot, an accumulator serves as an auxiliary oil source. To reduce the pressure loss caused by the throttle of the servo valve, we control the pressure of the system through load sensing. Simulation results showed that the power of the HPU using the accumulator could be amplified 3.3 times. The experimental results obtained through physical testing showed that the power consumption of the system using the load sensing mechanism was reduced by more than 50 %.

PspAG97A: A Halophilic α-Glucoside Hydrolase with Wide Substrate Specificity from Glycoside Hydrolase Family 97^s

( Wei Li ),( Han Fan ),( Chao He ),( Xuecheng Zhang ),( Xiaotang Wang ),( Jing Yuan ),( Zemin Fang ),( Wei Fang ),( Yazhong Xiao ) 한국미생물 · 생명공학회 2016 Journal of microbiology and biotechnology Vol.26 No.11

A novel α-glucoside hydrolase (named PspAG97A) from glycoside hydrolase family 97 (GH97) was cloned from the deep-sea bacterium Pseudoalteromonas sp. K8, which was screened from the sediment of Kongsfjorden. Sequence analysis showed that PspAG97A belonged to GH97, and shared 41% sequence identity with the characterized α-glucosidase BtGH97a. PspAG97A possessed three key catalytically related glutamate residues. Mutation of the glutamate residues indicated that PspAG97A belonged to the inverting subfamily of GH97. PspAG97A showed significant reversibility against changes in salt concentration. It exhibited halophilic ability and improved thermostability in NaCl solution, with maximal activity at 1.0 M NaCl/KCl, and retained more than 80% activity at NaCl concentrations ranging from 0.8 to 2.0 M for over 50 h. Furthermore, PspAG97A hydrolyzed not only α-1,4-glucosidic linkage, but also α-1,6- and α-1,2-glucosidic linkages. Interestingly, PspAG97A possessed high catalytic efficiency for long-chain substrates with α-1,6-linkage. These characteristics are clearly different from other known α-glucoside hydrolases in GH97, implying that PspAG97A is a unique α-glucoside hydrolase of GH97.

TGF-β1 suppresses CCL3/4 expression through the ERK signaling pathway and inhibits intervertebral disc degeneration and inflammation-related pain in a rat model

Jian Zhang,Zemin Li,Fan Chen,Hui Liu,Hua Wang,Xiang Li,Xianguo Liu,Jianru Wang,Zhaomin Zheng 생화학분자생물학회 2017 Experimental and molecular medicine Vol.49 No.-

The objective of this study was to investigate the regulatory effects of TGF-β1 on CCL3/4 expression and inflammation-related pain during intervertebral disc degeneration (IVDD). TGF-β1 and CCL3/4 expression patterns in different degenerative human nucleus pulposus (NP) tissues were measured by qPCR and immunohistochemistry (IHC), and the effects of TGF-β1 on CCL3/4 expression were measured by qPCR, ELISA and immunofluorescence. The roles of NF-κB and MAPK in TGF-β1-mediated CCL3/4 promoter activity were studied using siRNAs, western blotting and qPCR. After establishing an IVDD rat model in vivo, we administered intradiscal injections of TGF-β1. The effects of TGF-β1 on IVDD were determined by MRI and histological analyses, and the effects of TGF-β1 on dorsal root ganglion (DRG) inflammation and pain development were determined by IHC staining and pain-behavior testing, respectively. TGF-β1 and CCL3/4 expression was elevated in degenerative NP tissue. CCL4 expression was significantly inhibited by TGF-β1 treatment. Pharmacological inhibition or siRNA knockdown of the ERK1/2 signaling attenuated TGF-β1-mediated suppression of CCL4 expression. In vivo, TGF-β1 injection inhibited the development of degenerative features in the IVDD model. Moreover, TGF-β1 prevented the inflammatory response and pain development. The results of this study show that TGF-β1 downregulates CCL4 expression through ERK1/2 signaling activation in NP cells. Furthermore, TGF-β1 can prevent degenerative processes, inhibit inflammatory responses in the DRG and prevent pain development in the IVDD rat model. The results of this study indicate that TGF-β1 may represent a therapeutic target for the control of inflammation-related pain associated with IVDD.

Grem1 accelerates nucleus pulposus cell apoptosis and intervertebral disc degeneration by inhibiting TGF-β-mediated Smad2/3 phosphorylation

Chen Shunlun,Lei Linchuan,Li Zemin,Chen Fan,Huang Yuming,Jiang Guowei,Guo Xingyu,Zhao Zhuoyang,Liu Hui,Wang Hua,Liu Caijun,Zheng Zhaomin,Wang Jianru 생화학분자생물학회 2022 Experimental and molecular medicine Vol.54 No.-

Intervertebral disc degeneration (IVDD) is a main cause of low back pain, and inflammatory factors play key roles in its pathogenesis. Gremlin-1 (Grem1) was reported to induce an inflammatory response in other fields. This study aimed to investigate the mechanisms of Grem1 in the degenerative process of intervertebral discs. Dysregulated genes were determined by analyzing microarray profiles. The expression of Grem1 in 17 human disc samples (male:female = 9:8) and rat models (n = 5 each group) was measured by western blotting (WB), real-time quantitative PCR (RT-qPCR), and immunohistochemistry (IHC). The regulatory effects of Grem1 on apoptosis were examined using siRNAs, flow cytometry, immunofluorescence (IF), and WB. The therapeutic effect was evaluated by locally injecting specific Grem1 siRNA into IVDD rats. The expression of Grem1 was significantly increased in human degenerative intervertebral discs; furthermore, the expression of Grem1 positively correlated with the level of intervertebral disc degeneration. Grem1 was significantly overexpressed in tumor necrosis factor (TNF)-α-induced degenerative NP cells. Apoptosis in degenerative NP cells transfected with siRNA targeting Grem1 was significantly lower than that in the control group. Specific Grem1 siRNA markedly repressed the development of IVDD in surgery-induced IVDD rats. These results indicated that the expression of Grem1 was positively correlated with the severity of intervertebral disc degeneration, and Grem1 siRNA could inhibit Grem1-induced apoptosis and extracellular matrix alterations by mediating the TGF-β/Smad signaling pathway. This study may provide a therapeutic strategy for alleviating inflammation-induced apoptosis associated with intervertebral disc degeneration.

Analysis of thermoelastic damping in bilayered rectangular microplate resonators with three-dimensional heat conduction

Linlin Wang,Xiaopeng Li,Wujiu Pan,Zemin Yang,Jinchi Xu 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.4

Thermoelastic damping (TED) is considered to be the main internal energy dissipation mechanism in microresonators, the study of which has become increasingly significant in the design of microresonators with high quality factor. In this paper, the bilayered cantilever, fixed-fixed and fully clamped rectangular microplate resonators are taken as the research object, and then three theoretical models of thermoelastic damping with three-dimensional heat conduction are built. The analysis on convergence items of the present threedimensional models with different combinations of materials are carried out, and the influence of material plating on TED in Si microplate resonators is also analyzed. The analysis on the effects of the geometry size and boundary conditions on thermoelastic damping of microresonators at the first-order natural frequency are both carried out. Moreover, in order to verify the validation and accuracy of the present three-dimensional (3-D) models, the previous one-dimensional (1-D) models and the FEM models built in this paper are used to compare with the present models. Finally, the validation and accuracy of the present three-dimensional models are confirmed.

Integrated transcriptomic analysis on small yellow follicles reveals that sosondowah ankyrin repeat domain family member A inhibits chicken follicle selection

Zhong, Conghao,Liu, Zemin,Qiao, Xibo,Kang, Li,Sun, Yi,Jiang, Yunliang Asian Australasian Association of Animal Productio 2021 Animal Bioscience Vol.34 No.8

Objective: Follicle selection is an important process in chicken egg laying. Among several small yellow (SY) follicles, the one exhibiting the highest expression of follicle stimulation hormone receptor (FSHR) will be selected to become a hierarchal follicle. The role of lncRNA, miRNA and other non-coding RNA in chicken follicle selection is unclear. Methods: In this study, the whole transcriptome sequencing of SY follicles with different expression levels of FSHR in Jining Bairi hens was performed, and the expression of 30 randomly selected mRNAs, lncRNAs and miRNAs was validated by quantitative real-time polymerase chain reaction. Preliminary studies and bioinformatics analysis were performed on the selected mRNA, lncRNA, miRNA and their target genes. The effect of identified gene was examined in the granulosa cells of chicken follicles. Results: Integrated transcriptomic analysis on chicken SY follicles differing in FSHR expression revealed 467 differentially expressed mRNA genes, 134 differentially expressed lncRNA genes and 34 differentially expressed miRNA genes, and sosondowah ankyrin repeat domain family member A (SOWAHA) was the common target gene of three miRNAs and one lncRNA. SOWAHA was mainly expressed in small white (SW) and SY follicles and was affected by follicle stimulation hormone (FSH) treatment in the granulosa cells. Knockdown of SOWAHA inhibited the expression of Wnt family member 4 (Wnt4) and steroidogenic acute regulatory protein (StAR) in the granulosa cells of prehierarchal follicles, while stimulated Wnt4 in hierarchal follicles. Overexpression of SOWAHA increased the expression of Wnt4 in the granulosa cells of prehierarchal follicles, decreased that of StAR and cytochrome P450 family 11 subfamily A member 1 in the granulosa cells of hierarchal follicles and inhibited the proliferation of granulosa cells. Conclusion: Integrated analysis of chicken SY follicle transcriptomes identified SOWAHA as a network gene that is affected by FSH in granulosa cells of ovarian follicles. SOWAHA affected the expression of genes involved in chicken follicle selection and inhibited the proliferation of granulosa cells, suggesting an inhibitory role in chicken follicle selection.

Comparison of biological characteristics between purified polysaccharides and water extract from Laminaria japonica

Jiamei Cui,Eunyoung Kim,Zemin Li,Guiguo Zhang,Yunkyoung Lee 한국식품영양과학회 2019 한국식품영양과학회 학술대회발표집 Vol.2019 No.10

Rational design of porous NiCo2S4 nanotubes for hybrid supercapacitor

Wang Haiyang,Liang Miaomiao,He Zemin,Guo Zhun,Zhao Yang,Li Kexuan,Song Wenqi,Zhang Yongming,Zhang Xin,Zhao Yuzhen,Miao Zongcheng 한국물리학회 2022 Current Applied Physics Vol.35 No.-

The nanotube-consisted flower-like NiCo2S4 is successfully fabricated by a novel two-step hydrothermal technique. X-ray diffraction (XRD) identifies the spinel structure, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) imply the flower-like morphology of the synthesized NiCo2S4. The electrochemical behaviors are studied by cyclic voltammetry and galvanostatic charge-discharge measurements. The NiCo2S4 nanotubes demonstrate enhanced pseudocapacitive performance of 429.5 C g− 1 at current density of 0.5 A g− 1 . The NiCo2S4//AC device delivers high energy density of 37.69 Wh kg− 1 , maximum power density of 4000.6 W kg− 1 and satisfied cycle property of 96% capacitance retention after over 7000 cycles. The results show that the NiCo2S4 nanotubes are promising electrode material for high performance supercapacitor applications.

Circular RNA circ-4099 is induced by TNF-α and regulates ECM synthesis by blocking miR-616-5p inhibition of Sox9 in intervertebral disc degeneration

Hua Wang,Peiheng He,Hehai Pan,Jun long,Jianru Wang,Zemin Li,Hui Liu,Weiying Jiang,Zhaomin Zheng 생화학분자생물학회 2018 Experimental and molecular medicine Vol.50 No.-

Circular RNAs (circRNAs) play important roles in the initiation and development of different diseases. Here, we detected their role in intervertebral disc (IVD) degeneration. An Arraystar human circular RNA microarray assay was used to detect circRNAs in normal and degenerated human IVD nucleus pulposus (NP) tissues. The role of circ-4099 in IVDD and its mechanism were evaluated by qRT-PCR and gain-of-function/loss-of-function studies. Interaction networks for competing endogenous RNAs (ceRNAs), miRNAs, and miRNA target gene were detected by bioinformatics analysis, RNA immunoprecipitation and luciferase assay. Expression of seventy-two circRNAs were increased by more than twofold in degenerated NP tissues. qRT-PCR showed that the expression of circ-4099 in NP tissues was consistent with that of the array screening. Over-expression of circ-4099 increased the expression of Collagen II and Aggrecan and decreased the secretion of the pro-inflammatory factors IL-1β, TNF-α, and PGE2. TNF-α treatment increased circ-4099 expression in NP cells. NF-κB/MAPK inhibitors or shRNAs abolished the inductive effects of TNF-α on circ-4099 expression. We further demonstrated that circ-4099 was able to function as a “sponge” by competitively binding miR-616-5p, which reversed the suppression of Sox9 by miR-616-5p. We used DNA pull-down and spectrometry experiments to show that TNF-α can promote circ-4099 transcription through upregulation of GRP78. We provide the first evidence that shows circRNAs are differentially expressed in degenerated and normal NP tissues. Circ-4099 may play a role in a protective mechanism and be part of a compensatory response that maintains the synthesis and secretion of the extracellular matrix in NP cells and might be a protective factor in IVD degeneration as well as restore NP cell function.