Rho-GTPase Effector ROCK Phosphorylates Cofilin in Actin-Meditated Cytokinesis During Mouse Oocyte Meiosis

Duan, Xing,Jun-Liu,Dai, Xiao-Xin,Liu, Hong-Lin,Cui, Xiang-Shun,Kim, Nam-Hyung,Wang, Zhen-Bo,Qiang-Wang,Sun, Shao-Chen Society for the Study of Reproduction [etc.] 2014 BIOLOGY OF REPRODUCTION Vol.90 No.2

During oocyte meiosis, a spindle forms in the central cytoplasm and migrates to the cortex. Subsequently, the oocyte extrudes a small body and forms a highly polarized egg; this process is regulated primarily by actin. ROCK is a Rho-GTPase effector that is involved in various cellular functions, such as stress fiber formation, cell migration, tumor cell invasion, and cell motility. In this study, we investigated possible roles for ROCK in mouse oocyte meiosis. ROCK was localized around spindles after germinal vesicle breakdown and was colocalized with cytoplasmic actin and mitochondria. Disrupting ROCK activity by RNAi or an inhibitor resulted in cell cycle progression and polar body extrusion failure. Time-lapse microscopy showed that this may have been due to spindle migration and cytokinesis defects, as chromosomes segregated but failed to extrude a polar body and then realigned. Actin expression at oocyte membranes and in cytoplasm was significantly decreased after these treatments. Actin caps were also disrupted, which was confirmed by a failure to form cortical granule-free domains. The mitochondrial distribution was also disrupted, which indicated that mitochondria were involved in the ROCK-mediated actin assembly. In addition, the phosphorylation levels of Cofilin, a downstream molecule of ROCK, decreased after disrupting ROCK activity. Thus, our results indicated that a ROCK-Cofilinactin pathway regulated meiotic spindle migration and cytokinesis during mouse oocyte maturation.

RhoA-mediated MLC2 regulates actin dynamics for cytokinesis in meiosis

Duan, Xing,Liu, Jun,Zhu, Cheng-Cheng,Wang, Qiao-Chu,Cui, Xiang-Shun,Kim, Nam-Hyung,Xiong, Bo,Sun, Shao-Chen Informa UK (TaylorFrancis) 2016 Cell Cycle Vol.15 No.3

<P>During oocyte meiosis, the bipolar spindle forms in the central cytoplasm and then migrates to the cortex. Subsequently, the oocyte extrudes the polar body through two successive asymmetric divisions, which are regulated primarily by actin filaments. Myosin light chain2 (MLC2) phosphorylation plays pivotal roles in smooth muscle contraction, stress fiber formation, cell motility and cytokinesis. However, whether MLC2 phosphorylation participates in the oocyte polarization and asymmetric division has not been clarified. The present study investigated the expression and functions of MLC2 during mouse oocyte meiosis. Our result showed that p-MLC2 was localized in the oocyte cortex, with a thickened cap above the chromosomes. Meanwhile, p-MLC2 was also localized in the poles of spindle. Disruption of MLC2 activity by MLC2 knock down (K-D) caused the failure of polar body extrusion. Immunofluorescent staining showed that a large proportion of oocytes arrested in telophase stage and failed to undergo cytokinesis after culturing for 12hours. In the meantime, actin filament staining at oocyte membrane and cytoplasm were reduced in MLC2K(D) oocytes. Finally, we found that the phosphorylation of MLC2 protein levels was decreased after disruption of RhoA activity. Above all, our data indicated that the RhoA-mediated MLC2 regulates the actin organization for cytokinesis during mouse oocyte maturation.</P>

Long Noncoding RNA HEIH Promotes Colorectal Cancer Tumorigenesis via Counteracting miR-939Mediated Transcriptional Repression of Bcl-xL

Chunhui Cui,Duanyang Zhai,Lianxu Cai,Qiaobin Duan,Lang Xie,Jinlong Yu 대한암학회 2018 Cancer Research and Treatment Vol.50 No.3

Purpose Studies have found that long noncoding RNA HEIH (lncRNA-HEIH) is upregulated and facilitates hepatocellular carcinoma tumor growth. However, its clinical significances, roles, and action mechanism in colorectal cancer (CRC) remains unidentified. Materials and Methods lncRNA-HEIH expression in CRC tissues and cell lines was measured by quantitative realtime polymerase chain reaction. Cell Counting Kit-8, ethynyl deoxyuridine incorporation assay, terminal deoxynucleotidyl transferase dUTP nick end labeling staining, and nude mice xenografts assays were performed to investigate the roles of lncRNA-HEIH. RNA pull-down, RNA immunoprecipitation, chromatin immunoprecipitation, and luciferase reporter assays were performed to investigate the action mechanisms of lncRNA-HEIH. Results In this study, we found that lncRNA-HEIH is significantly increased in CRC tissues and cell lines. lncRNA-HEIH expression is positively associated with tumor size, invasion depth, and poor prognosis of CRC patients. Enhanced expression of lncRNA-HEIH promotes CRC cell proliferation and decreases apoptosis in vitro, and promotes CRC tumor growth in vivo. Whereas knockdown of lncRNA-HEIH inhibits CRC cell proliferation and induces apoptosis in vitro, and suppresses CRC tumor growth in vivo. Mechanistically, lncRNA-HEIH physically binds to miR-939. The interaction between lncRNA-HEIH and miR-939 damages the binding between miR-939 and nuclear factor B (NF-B), increases the binding of NF-B to Bcl-xL promoter, and promotes the transcription and expression of Bcl-xL. Moreover, Bcl-xL expression is positively associated with lncRNA-HEIH in CRC tissues. Blocking the interaction between lncRNA-HEIH and miR-939 abolishes the effects of lncRNA-HEIH on CRC tumorigenesis. Conclusion This study demonstrated that lncRNA-HEIH promotes CRC tumorigenesis through counteracting miR-939mediated transcriptional repression of Bcl-xL, and suggested that lncRNAHEIH may serve as a prognostic biomarker and therapeutic target for CRC.

Effect of calcination atmospheres on the catalytic performance of nano-CeO2 in direct synthesis of DMC from methanol and CO2

Zixiang Cui,Jie Fan,Huijuan Duan,Junfeng Zhang,Yongqiang Xue,Yisheng Tan 한국화학공학회 2017 Korean Journal of Chemical Engineering Vol.34 No.1

Nano-CeO2 was prepared through the calcination of Ce(OH)3 precursor in different atmospheres (H2, Ar, air, O2), which was prepared by a hydrothermal method, and then used as catalysts in the direct synthesis of dimethyl carbonate (DMC) from methanol and CO2. The results indicated that the catalyst calcined in O2 (CeO2-O2) showed an optimum catalytic performance, and the yield of DMC reached to 1.304mmol/mmolcat. In addition, reaction temperature and weight of catalyst were optimized. Based on characterizations of the catalysts, the ratio of Ce(IV)/Ce(III) and Lewis acid-base property of nano-CeO2 catalyst could be adjusted through different calcination atmosphere treatment. It was determined that the higher activity of CeO2-O2 catalyst is mainly attributed to its higher ratio of Ce(IV)/Ce(III) as well as abundant and moderate intensity Lewis acid base sites.

Potent in Vitro Anticancer Activity of Metacycloprodigiosin and Undecylprodigiosin from a Sponge-Derived Actinomycete Saccharopolyspora sp. nov.

Liu, Rui,Cui, Cheng-Bin,Duan, Lin,Gu, Qian-Qun,Zhu, Wei-Ming The Pharmaceutical Society of Korea 2005 Archives of Pharmacal Research Vol.28 No.12

Bioassay-guided fractionation of $CHCl_{3}$ extract from the fermentation broth of a sponge Mycale plumose-derived actinomycete Saccharopolyspora sp. nov., led to the isolation of two known prodigiosin analogs - metacycloprodigiosin (1) and undecylprodigiosin (2). These compounds exhibited significant cytotoxic activities against five cancer cell lines: P388, HL60, A-549, BEL­7402, and SPCA4. This is the first report on the significant cytotoxicity of metacycloprodigiosin (1) against human cancer cell lines.

Potent in Vitro Anticancer Activity of Metacycloprodigiosin and Undecylprodigiosin from a Sponge-Derived Actinomycete Saccharopolyspora sp. nov.

Rui Liu,Cheng-Bin Cui,Lin Duan,Qian-Qun Gu,Wei-Ming Zhu 대한약학회 2005 Archives of Pharmacal Research Vol.28 No.12

Bioassay-guided fractionation of CHCl3 extract from the fermentation broth of a sponge Mycale plumose-derived actinomycete Saccharopolyspora sp. nov., led to the isolation of two known prodigiosin analogs - metacycloprodigiosin (1) and undecylprodigiosin (2). These compounds exhibited significant cytotoxic activities against five cancer cell lines: P388, HL60, A-549, BEL- 7402, and SPCA4. This is the first report on the significant cytotoxicity of metacycloprodigiosin (1) against human cancer cell lines.

The influences of lateral leakage on hysteresis effects in flexible organic light-emitting diodes array

Xiong Zhiyong,Wen Zhuoqi,Cui Zhongjie,Mei Shiliang,He Haiyang,Duan Zhongtao,Zhang Wanlu,Xie Fengxian,Guo Ruiqian 한국물리학회 2023 Current Applied Physics Vol.45 No.-

Hysteresis effects in self-luminous devices like organic light-emitting diodes (OLEDs) and perovskite light-emitting diodes (PeLEDs) have been discovered recently, besides emerging in thin film transistors (TFTs). However, the influences of lateral leakage caused by next-door devices on hysteresis effects in flexible OLEDs array have rarely been demonstrated. To mitigate the impact of lateral leakage and figure out the detailed relationship with hysteresis effects, a series of experiments for OLEDs array involving p-doping in holes transport layer (HTL) were employed. It is found that the lateral leakage and hysteresis effects have a trade-off exhibition, which means stronger lateral leakage has induced weaker hysteresis effects. In order to get rid of the role of lateral leakage, the experiments with mono blue devices were also performed to substantiate the intrinsic hysteresis effects existence. The research opens the possibility of considering more internal relationships between different performances on self-luminous arrays for their actual application.

Synthesis of Star-Shaped Poly(N-isopropylacrylamide) via Atom Transfer Radical Polymerization and Its Photocatalytic Oxidation of Rhodamine B

Zhengguo Gao,Qian Duan,Jinaying Liang,Xiangdong Tao,Yuan Cui,Toshifumi Satoh,Toyoji Kakuchi 한국고분자학회 2012 Macromolecular Research Vol.20 No.5

Zinc(II) tetra-(2-chloropropionylamido) phthalocyanine (TAPcCl) was synthesized as the initiator for atom transfer radical polymerization (ATRP). Using CuBr/tris(2-dimethylaminoethyl)amine as the catalyst system,ATRP of N-isopropylacrylamide (NIPAM) was performed to create a new star-shaped poly(N-isopropylacrylamide)(PNIPAM) with a zinc phthalocyanine core and PNIPAM arms (TAPc-PAM). The structures of the initiator and the polymers were characterized by means of Fourier transform infrared spectroscopy and proton nuclear magnetic resonance. The polydispersity index obtained by gel permeation chromatography indicated that the molecular weight distribution was narrow. The lower critical solution temperatures (LCST) for the TAPc-PAM aqueous solutions measured using the turbidimetry method were increased due to incorporation of the phthalocyanine core and decreased as molecular weight increased. TAPc-PAM possessed photocatalytic activity, a finding that was verified by Rhodamine B degradation in the presence of hydrogen peroxide under visible light. Moreover, the catalytic efficiency was higher at its LCST, which encouraged reuse of the photocatalyst.

Chk2 Regulates Cell Cycle Progression during Mouse Oocyte Maturation and Early Embryo Development

Dai, Xiao-Xin,Duan, Xing,Liu, Hong-Lin,Cui, Xiang-Shun,Kim, Nam-Hyung,Sun, Shao-Chen Korean Society for Molecular and Cellular Biology 2014 Molecules and cells Vol.37 No.2

As a tumor suppressor homologue during mitosis, Chk2 is involved in replication checkpoints, DNA repair, and cell cycle arrest, although its functions during mouse oocyte meiosis and early embryo development remain uncertain. We investigated the functions of Chk2 during mouse oocyte maturation and early embryo development. Chk2 exhibited a dynamic localization pattern; Chk2 expression was restricted to germinal vesicles at the germinal vesicle (GV) stage, was associated with centromeres at pro-metaphase I (Pro-MI), and localized to spindle poles at metaphase I (MI). Disrupting Chk2 activity resulted in cell cycle progression defects. First, inhibitor-treated oocytes were arrested at the GV stage and failed to undergo germinal vesicle breakdown (GVBD); this could be rescued after Chk2 inhibition release. Second, Chk2 inhibition after oocyte GVBD caused MI arrest. Third, the first cleavage of early embryo development was disrupted by Chk2 inhibition. Additionally, in inhibitor-treated oocytes, checkpoint protein Bub3 expression was consistently localized at centromeres at the MI stage, which indicated that the spindle assembly checkpoint (SAC) was activated. Moreover, disrupting Chk2 activity in oocytes caused severe chromosome misalignments and spindle disruption. In inhibitor-treated oocytes, centrosome protein ${\gamma}$-tubulin and Polo-like kinase 1 (Plk1) were dissociated from spindle poles. These results indicated that Chk2 regulated cell cycle progression and spindle assembly during mouse oocyte maturation and early embryo development.

Lack of Influence of an XRCC3 Gene Polymorphism on Oral Cancer Susceptibility: Meta-analysis

Zhang, En-Jiao,Cui, Zhi-Gang,Xu, Zhong-Fei,Duan, Wei-Yi,Huang, Shao-Hui,Tan, Xue-Xin,Yin, Zhi-Hua,Sun, Chang-Fu,Lu, Li Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.23

Background: To systematically summarize the association between the X-ray repair cross complementing 3 (XRCC3) gene polymorphism and oral cancer susceptibility by meta-analysis. Materials and Methods: Databases including PubMed, EMbase, CNKI, VIP and WanFang Data were searched to identify case-control studies concerning the association between an XRCC3 gene polymorphism and the risk of oral cancer from the inception to June 2014. Two reviewers independently screened the literature according to the criteria, extracted the data and assessed the quality. Then meta-analysis was performed using Stata 11.0 software. Results: Seven published case-control studies including 775 patients with oral cancer and 1922 controls were selected. Associations between the rs861539 polymorphism and overall oral cancer risk were not statistically significant in all kinds of comparison models (CT vs CC: OR=0.94, 95%CI=0.74-1.18; TT vs CC: OR=0.94, 95%CI=0.64-1.38; dominant model: OR=0.95, 95%CI=0.76-1.18; recessive model: OR=0.94, 95%CI=0.69-1.29; allele T vs C: OR=0.97, 95%CI=0.84-1.11). In the stratified analysis by ethnicity, no significant associations were found among Asians and Caucasians. On stratification by tumor type, no significant associations were found for cancer and oral premalignant lesions. Conclusions: The XRCC3 gene polymorphism was not found to be associated with the risk of oral cancer. Considering the limited quality of the included case-control studies, more high quality studies with large sample size are needed to verify the above conclusion.