1.Inhibitory effects and mechanisms of snake venom tripeptide pENW on platelet adhesion.
Li BAI ; Wei-rong FANG ; Yi KONG ; Yun-man LI
Acta Pharmaceutica Sinica 2015;50(9):1107-1115
This study was designed to investigate inhibitory effects and possible mechanisms of snake venom tripeptide (pENW) on platelet adhesion in order to promote the development of a novel anti-platelet therapy. To study the inhibitory effects of pENW on platelet adhesion, washed platelets pre-incubated with pENW (116.5-466.2 μmol x L(-1)) were used to test the ability of platelet adhesion to fibrinogen. Effect of pENW on fibrin clot retraction was also tested. Effect of pENW on platelets viability was tested by MTT assay. Effect of pENW on reactive-oxygen species (ROS) levels of platelet was studied by flow cytometry assay. Calcium mobilization in Fura-2/AM-loaded platelets was monitored with a spectrofluorimeter. Cyclic guanosine monophosphate (cGMP) and cyclic adenosine monophosphate (cAMP), thromboxane A2 (determined as its metabolite thromboxane B2) were measured using enzyme immunoassay kits. Akt, ERK and p38 phosphorylation were tested by Western blot. The results showed that pENW inhibited platelet adhesion and fibrin clot retraction in a concentration-dependent manner without cytotoxicity. Intracellular cGMP and cAMP in both resting and thrombin-activated platelets were increased by pENW. In addition, pENW attenuated intracellular Ca2+ mobilization and TXA2 production in platelets stimulated by thrombin. As shown by Western blot assay, Akt, ERK and p38 phosphorylation in thrombin-induced platelet were attenuated by pENW. However, inhibitory effects of pENW had nothing to do with ROS. Thus, pENW exhibited a significant inhibition on platelet adhesion to fibrinogen, which means pENW could block the first step of thrombosis as while as retard the more stable clot formation. The mechanisms of pENW on inhibition platelet adhesion might be related to instant regulations, such as protein kinases.
Blood Platelets
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drug effects
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Blotting, Western
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Calcium
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metabolism
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Cyclic AMP
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metabolism
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Cyclic GMP
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metabolism
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Flow Cytometry
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Phosphorylation
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Platelet Aggregation
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drug effects
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Reactive Oxygen Species
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metabolism
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Snake Venoms
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chemistry
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Thromboxane A2
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metabolism
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Thromboxane B2
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metabolism
2.Expression of angiopoietin-like proteins for animal breeding: a review.
Weiwei FU ; Yun MA ; Ningbo CHEN ; He LI ; Yueyu BAI
Chinese Journal of Biotechnology 2015;31(11):1567-1578
Angiopoietin-like proteins are a family of proteins that are closely related to lipid, glucose and energy metabolism, as well as angiogenesis. To date, eight Angptls have been discovered, namely Angptl1 to Angptl8 that play key roles in metabolic regulation and marker assisted selection. In this review, we summarized current progress on the structure, signaling pathways, upstream regulatory genes and metabolic network of Angptl1-8. Finally, in combination with our work, the status and problems of animal breeding as well as the future prospects for Angptls were discussed.
Angiopoietins
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genetics
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metabolism
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Animals
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Breeding
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Energy Metabolism
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Gene Regulatory Networks
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Glucose
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metabolism
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Lipid Metabolism
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Metabolic Networks and Pathways
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Signal Transduction
3.Genetics in different subtypes of ischemic stroke
Wen BAI ; Yun LI ; Zhizhong ZHANG ; Gelin XU
International Journal of Cerebrovascular Diseases 2013;21(5):369-373
Stroke is a class of complex diseases,and it is the result of the combined action of environmental and genetic factors.With the development of molecular biology techniques,a large number of candidate genes associated with stroke and susceptibility loci have been identified.This article reviews the recent progress in research on the genetics of different subtypes of ischemic stroke.
4.Promoting effect of p75NTR receptor overexpression on oxidative stress injury in human retinal pigment epithelium cells
Yun, QI ; Yujing, BAI ; Xiaoxin, LI ; Xuan, SHI
Chinese Journal of Experimental Ophthalmology 2016;34(1):17-23
Background Choroidal neovascularization (CNV) is the primary pathogenic cause of many fundus diseases.Oxidative stress injury of retinal pigment epithelial (RPE) cells plays important role in angiogenesis of choroid new blood vessels.Oxidative stress injury can active p75NTR receptor, a member of tumor necrosis factors family,resulting in the proliferation of vascular endothelial cells.However, the mechanisms of vascular endothelial cell proliferation remain unclear.Objective This study was conducted to investigate the effect of p75NTR overexpression on CNV and the relative mechanism.Methods The ARPE-19 cell line was used in this study.RPE cells were transfected with p75NTR receptor overexpressed plasmid, and untransfected cells served as the control group.The transfected results were verified by reverse transcription-PCR and Western blot assay.Viability of the cells over time was determined in the p75NTR receptor plasmid transfected group by using BrdU assay.The percentage of apoptotic cells was detected by flow cytometry using Annexin V-FITC/PI fluorescence staining.The percentage of reactive oxygen species (ROS) expression in the cells was detected by using H2 DCFDA fluorescence and flow cytometry.Mitochondrial membrane potential and cytochrome C expression were examined under the confocal microscope.The protein expressions of cleaved caspase-3, Fas and VEGF were determined by Western blot assay.Results The relative expression level of p75 NTR receptor mRNA was (6.11 ±0.77) times higher than that of the control group, and relative expression level of p75NTR receptor protein in the cells in the p75NTR receptor plasmid transfected group was (7.42±0.48) times higher than that in the control group (t=11.49 and 23.17 ,both at P<0.01).The absorbency values of the p75NTR receptor plasmid transfected group were (93.12±0.56) % , (86.30±0.66) % , (72.53-±0.86) % and (60.77 ±2.81) % in 12,24,36 and 48 hours after plasmid transfection, which were significantly lower than 100% in the control group, and the apoptotic percentages were evidently higher than that in the control group (all at P<0.05).The relative fluorescence intensity of ROS fluorescence in the p75NTR receptor plasmid transfected group was 2.4 times higher than that in the control group,showing significant difference (t=16.45, P<0.01).The positive expressing rate of mitomarker (mitochondrial membrane potentials) was 100% in the control group and (37.30± 2.06)% in the p75NTR receptor plasmid transfected group, with significant difference between them (t =57.71,P<0.01).The fluorescence intensity of cytochrome C expression was elevated in the p75NTR receptor plasmid transfected group compared with the control group.Compared with the control group,the expressing levels of cleaved caspase-3 ,Fas and VEGF165 proteins in the cells were significantly raised in the p75NTR receptor plasmid transfected group (all at P<0.01).Conclusions Overexpression of p75NTR receptors in RPE cells leads to mitochondrial damage and cellular apoptosis and the secretion of VEGF protein, which sequentially promote CNV.P75NTR receptor may be another important regulation pathway in RPE oxygen damage.
5.The hemoprotective effects of a rotary magnetic field in mice exposed to?irradiation
Bai-Miao JI ; Guo-Li SONG ; Xiao-Yun ZHANG ;
Chinese Journal of Physical Medicine and Rehabilitation 2003;0(07):-
Objective To study the hemoprotective effects of a rotary magnetic field(RMF)with radiation- injured mice.Methods C57 BL6/J mice were randomly divided into a control group and a magnetic treatment group.The mice received total body irradiation with 7.0 Gy and 6.5 Gy ~(137)Cs?rays.The treatment group was trea- ted with a RMF for one hour at a time,twice a day.The intensity of the RMF was 0.6T.The survival rate was ob- served for 30 days.On day 7,10,14,21,28 after irradiation,the subjects' peripheral blood cells were counted.On day 12 and 16,the number of bone marrow mononuelear cells(BMNCs)was measured and their ability to form granu- locyte-macruphage colony-forming unit(CFU-GM)was assessed.The pathological sectioning of the femur was per- formed and the expression level of bone morphogenetic proteins(BMPs)in the bone marrow were evaluated.Re- sults The RMF treatment increased the survival rate and duration among the irradiated mice and the number of blood cells in their peripheral blood.Also,RMF treatment could increase the number of BMNCs and improve their ability to form CFU-GM on days 12-16.Furthermore,RMF could improve angiogenesis and the expression level of BMPs. Conclusion The RMF treatment had an obvious protective effect against the effects of irradiation,and it accelerated the recovery of hematopoiesis and the hematopoietic microenviroment in mouse bone marrow.
6.The Role of Predictive Microbiology in Food Safety Risk Assessment
Jie-Yun HU ; Jie OU ; Bai-Lin LI ;
Microbiology 2008;0(09):-
With the development of the food industry in China,it has been found that food safety is becoming the biggest issue in the food manufacture and logistics. Accurate and timely to establish a risk assessment method in produce market is the challenge for food safety system. Predictive microbiology is a core early warning technology in the food safety risk assessment. According to the microorganism predicting model,the pathogen and spoilage microorganism's growth in food can be fast judgment in advance. And it plays an important part in controlling the growth of pathogen and the spoilage microorganism in food. This paper summarized the predictive microbiology model's establishment and the present research situation,and discussed the present situation and application of predictive microbiology in food safety risk assessment. The future trend of predictive microbiology in food safety risk assessment was prospected as well.
7.Construction and eukaryotic expression of human CD137-Fc chimeric molecule
Gang HUANG ; Wanling LI ; Man JIANG ; Yun BAI ;
Journal of Third Military Medical University 2003;0(24):-
Objective To construct eukaryotic expression plasmid of hCD137 Fc gene and express hCD137 Fc fusion protein with high biological activity. Methods PCR technique was employed to clone the human CD137 cDNA from a normal human activated T cells cDNA library, and then clone its extramembrane encoding region. The extramembrane sequence together with human IgG1 Fc cDNA were inserted into the eukaryotic expression plasmid pcDNA3. CD137 Fc gene was expressed transiently in 293T cells, and then CD137 Fc protein was purified by recombinated protein A affinity chromatography column. At last, the MW, purity and antigenicity of CD137 Fc were identified by sandwich ELISA, SDS PAGE and Western blotting, respectively. Results The ORF of CD137 Fc gene was coincident with what we expected. ELISA and SDS PAGE confirmed protein expression in 293T cells. Western blotting proved the antigenicity of the purified CD137 Fc protein. Conclusion We obtained a purified recombinated CD137 Fc protein with biological activity and the expected MW. This lays the foundation for further studies of CD137 such as its role in immune homeostasis and other biological functions.
8.Cloning of human LIGHT gene and expression of the cloned molecule on 293T cells
Man JIANG ; Gang HUANG ; Wanling LI ; Yun BAI ;
Journal of Third Military Medical University 2003;0(08):-
Objective To clone the full length cDNA of human LIGHT and to construct the recombinant eukaryotic expression plasmid pCI neo LIGHT for the stable expression on 293T cells. Methods Human LIGHT cDNA was cloned from a normal human activated T cell cDNA library phAD.CAD by PCR. After sequencing, LIGHT cDNA was inserted into plasmid pCI neo for the construction of the eukaryotic expression. The recombinant was transfected into 293T cells by electroporation. The expression of LIGHT on the surface of 293T cells was detected by flow cytometry after screening with G418. Results Sequencing confirmed that ORF of LIGHT gene was intact and right. Restrictive enzyme digestion proved that LIGHT gene was inserted into the recombinant plasmid of LIGHT pCI neo correctly. FACS analysis revealed that about 78.69% 293T cells expressed LIGHT protein on the cell surfaces at 3 months after screening with G418. Conclusion LIGHT gene has been cloned successfully, and a 293T cell line expressing LIGHT protein on its membrane surface has been obtained.
9.Inhibitory effect of recombinant LIGHT-Fc gene on the proliferation of human esophageal squamous carcinoma cell line Eca109
Gang XIONG ; Wei WU ; Jun LI ; Kang YANG ; Yun BAI
Chinese Journal of Digestive Surgery 2008;7(4):307-309
Objective To investigate the inhibitory effect of recombinant LIGHT-Fe gene on the proliferation of human esophageal carcinoma cell line Eea109. Methods LIGHT-Fc expression vector was transfected into human esophageal squamous carcinoma cell line Eca109 by using DOTAP liposomal transfection reagents. The effects of LIGHT-Fc gene on the proliferation of esophageal carcinoma cell line Eca109 in vitro were detected by cell growth curve and MTr assay. Forty-five nude mice were equally divided into Eea109/Wt group, Eca109/neo group and Eca109/LIGHT group. Carcinogenesis and pathological expression of the esophageal carcinoma tissues were observed. Results The expressions of LIGHT receptors were detected in Eca109 cells. The proliferation of Eca109 cells was inhibited after trasfecting LIGHT-Fc gene into Eca109 cells. The numbers of tumors generated in Eea109/Wt group, Eca109/neo group and Eca109/LIGHT group were 12, 11 and 5, with statistical significance between Eca109/LIGHT group and the other two groups (X2 =6.652, 4.821, P <0.05). The result of histopatholagical examination indicated that the tissue necrosis appeared significantly in tumors derived from Eea109/LIGHT cells. Conclusions The growth of esophageal squamous carcinoma cell line Eca109 can be suppressed by LIGHT-Fc gene whether in vitro or in vivo.
10.Major assessment study and practice based on protecting teaching quality
Xiaojie ZHANG ; Li BAI ; Changhai YUN ; Qingdong LUO ; Dan XIN
Chinese Journal of Medical Education Research 2015;(3):248-251
The major assessment is the key link of the applied undergraduate education quality guarantee system. According to the spirit of the Ministry of Education, The Qiqihar Medical University developed the internal major assessment study and founded 8 first grade indexes and 26 second level indexes including educational idea, teaching staff, major construction. The university also established the major evaluation system, monitor and improve the university's teaching quality. This system makes sense to the establishment and improvement of undergraduate teaching quality guarantee system and has attained great achievement in the building of teaching staff, major construction, teaching environ-ment and teaching idea. Also the school has rectified the problems, making the work more perfect and the teaching better and better.