Induction of Apoptosis by Chelerythrine Chloride through Mitochondrial Pathway and Bcl-2 Family Proteins in Human Hepatoma SMMC-7721 Cell

Zheng-fu Zhang,Ying Guo,Jian-bin Zhang,Xiong-hui Wei 대한약학회 2011 Archives of Pharmacal Research Vol.34 No.5

The objective of this study was to evaluate the antitumor activity of chelerythrine chloride (CHE) and investigate its potential apoptotic induction mechanism in SMMC-7721 cells. Our results suggested that the proliferation of SMMC-7721 cells was inhibited by CHE in a time and dose dependent manner, with a significant accumulation in S phase, and the cells exhibited typical apoptotic features. Moreover, CHE remarkably induced apoptosis by disruption of the mitochondrial membrane potential, release of Cyt-c, activation of caspase-3, and cleavage of poly-ADP-ribose polymerase in a dose dependent manner. Furthermore, the expression of Bcl-xl was downregulated while Bax and Bid expression was upregulated, and no variation was found for Bcl-2. These results indicated that CHE may play an important role in suppression of tumor growth by inducing apoptosis in human hepatoma cells via the activation of a mitochondrial pathway and regulating the expression of Bcl-2 family proteins.

Metabolic Pathways of Hydrogen Production in Fermentative Acidogenic Microflora

( Li Guo Zhang ),( Jian Zheng Li ),( Qiao Ying Ban ),( Jun Guo He ),( Ajay Kumar Jha ) 한국미생물 · 생명공학회 2012 Journal of microbiology and biotechnology Vol.22 No.5

Biohydrogen production from organic wastewater by anaerobically activated sludge fermentation has already been extensively investigated, and it is known that hydrogen can be produced by glucose fermentation through three metabolic pathways, including the oxidative decarboxylation of pyruvic acid to acetyl-CoA, oxidation of NADH to NAD+, and acetogenesis by hydrogen-producing acetogens. However, the exact or dominant pathways of hydrogen production in the anaerobically activated sludge fermentation process have not yet been identified. Thus, a continuous stirred-tank reactor (CSTR) was introduced and a specifically acclimated acidogenic fermentative microflora obtained under certain operation conditions. The hydrogen production activity and potential hydrogen-producing pathways in the acidogenic fermentative microflora were then investigated using batch cultures in Erlenmeyer flasks with a working volume of 500 ml. Based on an initial glucose concentration of 10 g/l, pH 6.0, and a biomass of 1.01 g/l of a mixed liquid volatile suspended solid (MLVSS), 247.7 ml of hydrogen was obtained after a 68 h cultivation period at 35±1oC. Further tests indicated that 69% of the hydrogen was produced from the oxidative decarboxylation of pyruvic acid, whereas the remaining 31% was from the oxidation of NADH to NAD+. There were no hydrogen-producing acetogens or they were unable to work effectively in the anaerobically activated sludge with a hydraulic retention time (HRT) of less than 8 h.

Prevalence and Molecular Characterization of Echinococcus granulosus sensu stricto in Northern Xinjiang, China

Baoping Guo,Zhuangzhi Zhang,Xueting Zheng,Yongzhong Guo,Li Zhao,Ren Cai,Bingjie Wang,Mei Yang,Xi Shou,Wenbao Zhang,Bin Jia 대한기생충학ㆍ열대의학회 2019 The Korean Journal of Parasitology Vol.57 No.2

Echinococcus granulosus is an important zoonotic parasite globally causing cystic echinococcosis (CE) in hu- mans and animals. In this study, prevalence of CE and variation of cox1 gene sequence were analyzed with isolates E. granulosus collected from different areas in northern Xinjiang, China. The survey showed that 3.5% of sheep and 4.1% of cattle were infected with CE. Fragment of cox1 was amplified from all the positive sheep and cattle samples by PCR. In addition, 26 positive samples across the 4 areas were included. The isolates were all E. granulosus sensu stricto (s.s.) containing 15 haplotypes (Hap1-15), and clustered into 2 genotypes, G1 (90.1%, 91/101) and G3 (9.9%, 10/101). Hap1 was the most common haplotype (48.5%, 49/101). Hap9 were found in humans samples, indicating that sheep and cattle reservoir human CE. It is indicate that E. granulosus may impact on control of CE in livestock and humans in the region.

PKCβII inhibits the ubiquitination of β-arrestin2 in an autophosphorylation-dependent manner

Zheng, M.,Zhang, X.,Guo, S.,Zhang, X.,Choi, H.J.,Lee, M.Y.,Kim, K.M. North-Holland Pub ; Elsevier Science Ltd 2015 FEBS letters Vol.589 No.24

GPCR kinase 2 (GRK2)/β-arrestins and protein kinase A (PKA)/protein kinase C (PKC) mediate homologous and heterologous regulations of GPCRs, respectively. Conventional protein kinase C enzymes (PKCs), as exemplified by PKCβII, selectively inhibit internalization of dopamine D<SUB>2</SUB> receptor and β<SUB>2</SUB> adrenoceptor in a β-arrestin- but not GRK2-dependent manner. PKCβII interacts with β-arrestin2 upon autophosphorylation at T250, and inhibits the receptor internalization by decreasing the ubiquitination of β-arrestin2. PKCβII interferes with the interaction between β-arrestin2 and MDM2 in the cytosol, resulting in the redistribution of MDM2 to the nucleus. Subsequently, deubiquitination of β-arrestin2 and inhibition of agonist-induced receptor internalization follow. Thus, our study suggests that the extent of β-arrestin ubiquitination and the autophosphorylation status of PKCs determine PKCβII-mediated inhibition of homologous regulatory processes of GPCRs.

Identification of a Cancer Stem-like Population in the Lewis Lung Cancer Cell Line

Zhang, An-Mei,Fan, Ye,Yao, Quan,Ma, Hu,Lin, Sheng,Zhu, Cong-Hui,Wang, Xin-Xin,Liu, Jia,Zhu, Bo,Sun, Jian-Guo,Chen, Zheng-Tang Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.3

Objective: Although various human cancer stem cells (CSCs) have been defined, their applications are restricted to immunocompromised models. Developing a novel CSC model which could be used in immunocompetent or transgenic mice is essential for further understanding of the biomolecular characteristics of tumor stem cells. Therefore, in this study, we analyzed murine lung cancer cells for the presence of CSCs. Methods: Side population (SP) cells were isolated by fluorescence activated cell sorting, followed by serum-free medium (SFM) culture, using Lewis lung carcinoma cell (LLC) line. The self-renewal, differentiated progeny, chemosensitivity, and tumorigenic properties in SP and non-SP cells were investigated through in vitro culture and in vivo serial transplantation. Differential expression profiles of stem cell markers were examined by RT-PCR. Results: The SP cell fraction comprised 1.1% of the total LLC population. SP cells were available to grow in SFM, and had significantly enhanced capacity for cell proliferation and colony formation. They were also more resistant to cisplatin in comparison to non-SP cells, and displayed increased tumorigenic ability. Moreover, SP cells showed higher mRNA expression of Oct-4, ABCG2, and CD44. Conclusion: We identified SP cells from a murine lung carcinoma, which possess well-known characteristics of CSCs. Our study established a useful model that should allow investigation of the biological features and pharmacosensitivity of lung CSCs, both in vitro and in syngeneic immunocompetent or transgenic/knockout mice.

Focus Improvement of High-Squint SAR Based on Azimuth Dependence of Quadratic Range Cell Migration Correction

Zhang, Shuang-Xi,Xing, Meng-Dao,Xia, Xiang-Gen,Zhang, Lei,Guo, Rui,Bao, Zheng IEEE 2013 IEEE geoscience and remote sensing letters Vol.10 No.1

<P>In this letter, we discuss the problem that linear range cell walk correction in the azimuth time domain may cause space variation along the azimuth not only to the quadratic phase but also to the quadratic range cell migration (QRCM) under the conditions of high resolution and large scene along the azimuth. Moreover, an algorithm is proposed to deal with this problem. The proposed algorithm adopts the azimuth space variation filtering in the range frequency domain. In addition, the range-dependence component of QRCM is corrected by linear chirp scaling, and the unified QRCM can be corrected in the 2-D frequency domain. The proposed algorithm, without interpolation, can be easily implemented by integrating with motion compensation for image processing. Simulation and airborne strip-map real data show the accuracy and efficiency of the proposed algorithm.</P>

A Research of High Frequency Isolated Photovoltaic Inverter

( Zheng Guo Piao ),( Teng Zhang ) 조선대학교 공학기술연구원 2014 공학기술논문지 Vol.7 No.2

In recent years, high frequency inverter technology has become a research focus for renewable energy power generation system. High frequency isolated inverter has electrical isolation, light weight, small volume etc. In this paper, we research on the control technology of high frequency isolation inverter, and introduce the soft switching technology of the high frequency isolation photovoltaic grid connected inverter. Using the LCL resonant circuit, reduce the switching loss of the switching devices. Finally, its feasibility is validated by simulation.

ZNF217 is Overexpressed and Enhances Cell Migration and Invasion in Colorectal Carcinoma

Zhang, Zi-Chao,Zheng, Li-Qiang,Pan, Li-Jie,Guo, Jin-Xing,Yang, Guo-Shan Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.6

Background: To investigate the expression and clinical significance of zinc finger protein 217 (ZNF217) in human colorectal carcinoma (CRC). Materials and Methods: The expression of ZNF217 in 60 CRC tissues and matched tumor adjacent tissues, collected between January 2013 and June 2014, was assessed immunohistochemically. The relationship between the expression of ZNF217 and clinicopathlogical features was analyzed by Pearson chi-square test. In addition, siRNA was used to down-regulate the expression of ZNF217 in CRC cells. The effects of ZNF217 for cell migration and invasion were measured by wound healing assay and transwell assay, respectively. Results: The expression level of ZNF217 was significantly higher in CRC tissues than in tumor adjacent tissues (p<0.05), positively correlating with tumor size, lymphatic metastasis and advanced TNM stage (p<0.05). Down-regulation of ZNF217 in CRC cells could significantly suppress cell migration and invasion. Conclusions: ZNF217 is overexpressed in colorectal carcinoma tissues and is associated with tumor malignant clinicopathological features. ZNF217 may promote CRC progression by inducing cell migration and invasion.

Effects of miR-155 Antisense Oligonucleotide on Breast Carcinoma Cell Line MDA-MB-157 and Implanted Tumors

Zheng, Shu-Rong,Guo, Gui-Long,Zhai, Qi,Zou, Zhang-Yong,Zhang, Wei Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.4

Diverse studies have shown that miR-155 is overexpressed in different tumor types. However, the precise molecular mechanism of the ectopic expression of miR-155 in breast cancer is still poorly understood. To further explore the role of miR-155 in breast tumorigenesis, we here assessed the influence of miR-155 antisense oligonucleotide (miR-155 ASO) on MDA-MB-157 cell viability and apoptosis in vitro. Furthermore, the effects of inhibitory effects of miR-155 on the growth of xenograft tumors in vivo were determined with performance of immunohistochemistry to detect expression of caspase-3, a pivotal apoptosis regulatory factor, in xenografts. Transfection efficiency detected by laser confocal microscope was higher than 80%. The level of miR-155 expression was significantly decreased (P<0.05) in the cells transfected with miR-155 ASO, compared with that in cells transfected with a negative control. After being transfected with miR-155 ASO, the viability of MDA-MB-157 cells was reduced greatly (P<0.05) and the number of apoptotic cells was increased significantly. Additionally, miR-155 ASO inhibited the growth of transplanted tumor in vivo and significantly increased the expression of caspase-3. Taken together, our study revealed that miR-155 ASO can induce cell apoptosis and inhibit cell proliferation in vitro. Moreover, miR-155 ASO could significantly repress tumor growth in vivo, presumably by inducing apoptosis via caspase-3 up-regulation. These findings provide experimental evidence for using miR-155 as a therapeutic target of breast carcinoma.

Multi-Variable and Bi-Objective Optimization of Electric Upsetting Process for Grain Refinement and Its Uniform Distribution

Guo-zheng Quan,Le Zhang,Chao An,Zhen-yu Zou 한국정밀공학회 2018 International Journal of Precision Engineering and Vol.19 No.6

It is significant to adjust the microstructures of preforms in pursuit of high-quality exhaust valves. This work is a novel attempt to identify the optimum process parameters in electric upsetting of 3Cr20Ni10W2 high-alloy to achieve grain refinement and uniform distribution by multi-objective genetic algorithm (MOGA) optimization. A finite element (FE) model on basis of electric-thermalmechanical and macro-micro sequential multi-physics analysis methods was developed in software MSC. Mar. And different schedules of four independent process variables (heating current (I), clamping length (L), upsetting pressure (Pset) and velocity of the anvil cylinder (v)) were performed aiming to achieve two objective indicators (average grain size (dav) and inhomogeneous degree of grain distribution (σd)). Then, two objective response surfaces were constructed as the functions between the two indicators and the four independent process variables. As per the criterion that simultaneously minimize dav and σd, the processing parameters (Pset, L, v, I) were optimized by MOGA, and corresponding numerical simulation were performed. The results show that both dav and σd are improved significantly at the optimal process condition as verified by the trial-manufacture experiments, which validated the optimal design and corresponding simulation based on grain refinement and uniform distribution by MOGA was credible and effective.