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.

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.

Preparation and Antitumor Activity of a Tamibarotene-Furoxan Derivative

Wang, Xue-Jian,Duan, Yu,Li, Zong-Tao,Feng, Jin-Hong,Pan, Xiang-Po,Zhang, Xiu-Rong,Shi, Li-Hong,Zhang, Tao Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.15

Multi-target drug design, in which drugs are designed as single molecules to simultaneously modulate multiple physiological targets, is an important strategy in the field of drug discovery. QT-011, a tamibarotene-furoxan derivative, was here prepared and proposed to exert synergistic effects on antileukemia by releasing nitric oxide and tamibarotene. Compared with tamibarotene itself, QT-011 displayed stronger antiproliferative effects on U937 and HL-60 cells and was more effective evaluated in a nude mice U937 xenograft model in vivo. In addition, QT-011 could release nitric oxide which might contribute to the antiproliferative activity. Autodocking assays showed that QT-011 fits well with the hydrophobic pocket of retinoic acid receptors. Taken together, these results suggest that QT-011 might be a highly effective derivative of tamibarotene and a potential candidate compound as antileukemia agent.

Characterization of free and glycosidically bound volatile compounds, fatty acids, and amino acids in Vitis davidii Foex grape species native to China

Yi-Bin Lan,Xiao-Feng Xiang,Wei-Xi Yang,Bao-Qing Zhu,Hong-Tie Pu,Chang-Qing Duan 한국식품과학회 2020 Food Science and Biotechnology Vol.29 No.12

Berries of six Vitis davidii Foex (spine grape)cultivars (‘Baiputao’, ‘Gaoshan 1’, ‘Gaoshan 2’, ‘Seputao’,‘Miputao’, and ‘Tianputao’) were harvested from a commercialvineyard in Hunan Province in China. Free andbound volatile compounds and fatty acids were analyzedby GC–MS, and amino acids were analyzed by HPLC. ‘Tianputao’ and ‘Miputao’ were characterized by relativelyhigher concentrations of aromatic amino acids and lowerconcentrations of branched-chain amino acids. The majorfree volatile compounds of spine grapes were hexanal, (E)-2-hexenal, 1-hexanol, (E)-2-hexenol, (E)-b-damascenone,and benzeneacetaldehyde. The major glycosidically boundvolatile compounds identified were 1-hexanol, menthol,nerol, 1-butanol, 3-methyl-3-butenol, benzenemethanol, bphenylethanol,eugenol, and guaiacol. (E)-b-damascenone,benzeneacetaldehyde, guaiacol, and eugenol had odoractivity values (OAVs)[1 in all cultivar grapes. Partialleast squares discriminant analysis (PLS-DA) revealed‘Tianputao’ to be distinct from the other cultivars due to itsrelatively higher concentrations of major terpenoids,norisoprenoids, higher alcohols, and aromatic amino acids.

Role of Nucleation-Promoting Factors in Mouse Early Embryo Development

Wang, Qiao-Chu,Liu, Jun,Wang, Fei,Duan, Xing,Dai, Xiao-Xin,Wang, Teng,Liu, Hong-Lin,Cui, Xiang-Shun,Sun, Shao-Chen,Kim, Nam-Hyung Cambridge University Press 2013 Microscopy and microanalysis Vol.19 No.3

<B>Abstract</B><P>During mitosis nucleation-promoting factors (NPFs) bind to the Arp2/3 complex and activate actin assembly. JMY and WAVE2 are two critical members of the NPFs. Previous studies have demonstrated that NPFs promote multiple processes such as cell migration and cytokinesis. However, the role of NPFs in development of mammalian embryos is still unknown. Results of the present study show that the NPFs JMY and WAVE2 are critical for cytokinesis during development of mouse embryos. Both JMY and WAVE2 are expressed in mouse embryos. After injection of JMY or WAVE2 siRNA, all embryos failed to develop to the morula or blastocyst stages. Moreover, using fluorescence intensity analysis, we found that the expression of actin decreased, and multiple nuclei were observed within a single cell indicating that NPFs-induced actin reduction caused the failure of cell division. In addition, injection of JMY and WAVE2 siRNA also caused ARP2 degradation, indicating that involvement of NPFs in development of mouse embryos is mainly through regulation of ARP2/3-induced actin assembly. Taken together, these data suggested that WAVE2 and JMY are involved in development of mouse embryos, and their regulation may be through a NPFs-Arp2/3-actin pathway.</P>

Dynamic Hand Gesture Trajectory Recognition Based on Block Feature and Skin-Color Clustering

Zhang Qiu-yu,Lv Lu,Lu Jun-chi,Zhang Mo-yi,Duan Hong-xiang 보안공학연구지원센터 2016 International Journal of Multimedia and Ubiquitous Vol.11 No.12

In recent years, dynamic hand gesture recognition has been a research hotspot of human-computer interaction. Since most existing algorithms contain problems with high computational complexity, poor real-time performance and low recognition rate, which cannot satisfy the need of many practical applications. Moreover, key frames obtained by inter-frame difference degree algorithm contain less information, which leads to less identified species and lower recognition rate. To solve these problems, we present a dynamic hand gesture trajectory recognition method based on the theory of block feature to extract key frames and the skin-color clustering’s hand gesture segmentation. Firstly, this method extracts block feature of degree of difference between frames in hand gesture sequence to select key frames accurately. Secondly, the method based on skin-color clustering is applied to obtain the area of hand gesture after segmenting hand gestures from images. Finally, hidden Markov model (HMM), in which the angle data of hand gesture trajectories are input, is used for modeling and identifying dynamic hand gestures. Experimental results show that the method of key-frame extraction is used to obtain information of dynamic hand gestures accurately, which would improve the recognition rate of dynamic hand gesture recognition and, at the same time, can guarantee the real-time of hand gesture recognition system. The average recognition rate is up to 86.67%, and the average time efficiency is 0.39s.

A Dynamic Gesture Trajectory Recognition Based on Key Frame Extraction and HMM

Zhang Qiu-yu,Lv Lu,Zhang Mo-yi,Duan Hong-xiang,Lu Jun-chi 보안공학연구지원센터 2015 International Journal of Signal Processing, Image Vol.8 No.6

Aiming at changing high computational complexity, underdeveloped real time, low recognition rate of dynamic gesture recognition algorithms, this paper present a real-time dynamic gesture trajectory recognition method based on key frame extraction and HMM. Key frames are selected without keeping track of all the details of one dynamic gesture, which is based on difference degree between frames. The trajectory data stream, sorted by the time-warping algorithm, is used to construct the Hidden Markov Method model of dynamic gesture. Finally, optimal transition probabilities are employed to implement dynamic gesture recognition. The result of this experiment implies that this method has high robustness and real time. The average recognition rate of dynamic gesture (0~9) is up to 87.67%, and average time efficiency is 0.46s.

Hand Gesture Segmentation Method Based on YCbCr Color Space and K-Means Clustering

Zhang Qiu-yu,Lu Jun-chi,Zhang Mo-yi,Duan Hong-xiang,Lv Lu 보안공학연구지원센터 2015 International Journal of Signal Processing, Image Vol.8 No.5

Aiming at the problems that current skin-color detection segmentation technologies have unsatisfied segmentation results under conditions of complex illumination or backgrounds, we present a new method based on YCbCr color space and K-means clustering algorithm for segmentation hand gesture. Firstly, image in RGB color space is converted to YCbCr color space; and then YCbCr color space of image is divided into luminance Y and chrominance Cb and Cr. Lastly, the binary image is achieved by clustering values of chrominance using k-means clustering algorithm, and hand gesture segmentation is completed by conducting morphological process of binary image obtained. The experimental results illustrate that the proposed method can segment hand gestures from complex backgrounds and obtain segmentation results. The phenomena of similar skin color interference and skin color overlapping are solved with this method effectively. In addition, it is robust to illumination condition.

Dynamic Hand Gesture Segmentation Method Based on Improved Kalman Filter and Weighted Skin-Color Model

Zhang Qiu-yu,Lu Jun-chi,Wei Hui-yi,Zhang Mo-yi,Duan Hong-xiang 보안공학연구지원센터 2016 International Journal of Signal Processing, Image Vol.9 No.6

In order to improve the problems of segmentation accuracy and real-time existing in dynamic hand gesture under complex backgrounds, this paper presents a kind of dynamic hand gesture segmentation method based on improved Kalman filter and weighted skin-color model. Firstly, improved Kalman filter is utilized to process hand gesture image of hand gesture video sequences and get rough hand gesture results. Secondly, weighted skin-color model is applied to process rough results of hand gesture segmentation and segment hand gesture. Finally, morphological method is utilized to deal with gesture segmentation result, getting rid of the holes in the hand gesture’s binary image to realize the segmentation of dynamic hand gesture. Experiments show that the proposed method can segment hand gesture from dynamic hand gesture video sequences with complex backgrounds effectively. And the accuracy of hand gesture segmentation is high.

A Multi-center Survey of HPV Knowledge and Attitudes Toward HPV Vaccination among Women, Government Officials, and Medical Personnel in China

Zhao, Fang-Hui,Tiggelaar, Sarah M.,Hu, Shang-Ying,Zhao, Na,Hong, Ying,Niyazi, Mayinuer,Gao, Xiao-Hong,Ju, Li-Rong,Zhang, Li-Qin,Feng, Xiang-Xian,Duan, Xian-Zhi,Song, Xiu-Ling,Wang, Jing,Yang, Yun,Li, Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.5

Objectives: To assess knowledge of HPV and attitudes towards HPV vaccination among the general female population, government officials, and healthcare providers in China to assist the development of an effective national HPV vaccination program. Methods: A cross-sectional epidemiologic survey was conducted across 21 urban and rural sites in China using a short questionnaire. 763 government officials, 760 healthcare providers, and 11,681 women aged 15-59 years were included in the final analysis. Data were analyzed using standard descriptive statistics and logistic regression. Results: Knowledge of HPV among the general female population was low; only 24% had heard of HPV. Less than 20% of healthcare providers recognized sexually na$\ddot{i}$ve women as the most appropriate population for HPV vaccination. There was high acceptance of the HPV vaccine for all categories of respondents. Only 6% of women were willing to pay more than US $300 for the vaccine. Conclusions: Aggressive education is necessary to increase knowledge of HPV and its vaccine. Further proof of vaccine safety and efficacy and government subsidies combined with increased awareness could facilitate development and implementation of HPV vaccination in China.