1.Anti-HIV therapy in central nervous system:challenges and strategies
Yulin ZHANG ; Dexi CHEN ; Ronghua JIN
Chinese Journal of Clinical Infectious Diseases 2015;(4):376-380
Combined antiretroviral therapy ( cART) is widely used for infections of human immune deficiency virus ( HIV) .However , some antiviral drugs can not reach the effective concentrations in central nervous system due to the hinder of blood-brain barrier ( BBB) , resulting in the formation of viral reservoir in central nervous system .BBB is formed by human brain microvascular endothelial cells ( HBMVECs ) , which are connected by tight junction and a thick basement membrane , and astrocytic end-feet.This paper reviews possible mechanisms of BBB hindrance and anti-HIV drug efflux by transport proteins , as well as effective methods to deliver antiretroviral drugs into brain , including the application of nano technology .
2.CLONING OF HUMAN ANGIOPOIETIN-1 GENE AND CONSTRUCTION OF ITS EUKARYOTIC AND PROKARYOTIC EXPRESSION VECTORS
Jun WANG ; Kaichun WU ; Dexi ZHANG
Medical Journal of Chinese People's Liberation Army 1983;0(02):-
Angiopoietin is a novel angiogenesis related molecule. To investigate its roles in tumor angiogenesis and metastasis,angiopoietin 1 gene was obtained from human placental tissue by reverse transcription polymerase chain reaction (RT PCR). The sense, antisense eukaryotic expression vector pcDNA3.1/hangiopoietin1(+), antisense eakaryotic expression vector pcDNA3.1/hangiopoietin1(-), and prokaryotic expression vector pRSETC hangiopoietin1 were successfully constructed by directional cloning the target gene into pcDNA3.1 V5 His C and pRSET C vectors, respectively. This lays good foundation for further study on the roles of angiopoietin 1 in angiogenesis in tumors of the digestive tract.
3.RP-HPLC method for the quantitation of β-Sitosterol in Elaeagnus Gonyanthes Benth
Dexi JIANG ; Wenzhi CHEN ; Dan ZHANG
Journal of Pharmaceutical Analysis 2010;22(3):160-162,167
Objective To establish an RP-HPLC method for the determination of β-Sitosterol in Elaeagnus Gonyanthes Benth. Methods The separation was performed on a luna C8 (2) (150 mm×4.6 mm, 5μm) column with the mobile phase of methanol-water (88∶12, v/v) at a flow rate of 1.0 mL/min, the detection wavelength was set at 210 nm, and the temperature of the column was maintained at 35 ℃. Results The calibration curve of β-Sitosterol was linear over the concentration range of 0.075-0.375 mg/mL (r=0.9999) and the average recovery of β-Sitosterol was 96.30% with RSD of 3.60%(n=3). Conclusion The method is simple, rapid, and accurate, and can be used for the quality control of Elaeagnus Gonyanthes Benth.
4.Role of P53 outside the nucleus
Qingsheng HOU ; Yulin ZHANG ; Dexi CHEN ; Hongliang GUO
Journal of International Oncology 2012;39(9):665-668
P53 protein plays a crucial role in inhibition tumor development.It will accumulate in cells in the condition of DNA damage,oncogenes activation or stress.As a nuclear transcription factor,P53 can transactivate the genes which correlate with apoptosis,cell cycle control and other procedures. Current research reveals P53 outside the nucleus can induce apoptosis and inhibit autophagy which contributes to its function of tumor suppression.The study of the extranuclear function of P53 is beneficial to further understanding the mechanism of P53 in the genesis and development of tumor.
5.Determination and pharmacokinetic study of catechin in rat plasma by HPLC
Li XIE ; Xinnan LI ; Dexi JIANG ; Dan ZHANG
Journal of Pharmaceutical Analysis 2011;01(4):297-301
A high performance liquid chromatographic method was developed and validated for the quantitative determination of catechin in rat plasma and its pharmacokinetic study after intragastric administration of Catechu and Xiongdanjiangre Wan into SD rats. Plasma samples were prepared by protein precipitation using methanol- 5% aqueous zinc sulfate (70:30, v/v) as precipitant. Chromatographic separation was achieved on Hypersil C18 column (250 mm × 4.6 mm, 10 μm) with acetonitrile water triethylamine (6:94:0.3, v/v/v, pH 4.0±0.1, adjusted with phosphoric acid) as mobile phase, followed by a UV detection at 207 nm. Good linearity was obtained over the range of 0.143-7.15 mg/L of catechin, with correlation coefficient of 0.9992.The method was simple, sensitive, accurate and reproducible and has been successfully applied to the pharmacokinetic study of catechin in rat plasma.
6.Determination of metabolite of nicergoline in human plasma by high-performance liquid chromatography and its application in pharmacokinetic studies
Rong ZHENG ; Yihong WU ; Dexi JIANG ; Dan ZHANG
Journal of Pharmaceutical Analysis 2012;02(1):62-66
A fast,simple and sensitive high performance liquid chromatographic (HPLC) method has been developed for determination of 10α-methoxy-6-methyl ergoline-8β-methanol (MDL,a main metabolite of nicergoline) in human plasma.One-step liquid-liquid extraction (LLE) with diethyl ether was employed as the sample preparation method.Tizanidine hydrochloride was selected as the internal standard (IS).Analysis was carried out on a Diamonsil ODS column (150 mm × 4.6 mm,5 μm) using acetonitrile-ammonium acetate (0.1 mol/L) (15/85,v/v) as mobile phase at detection wavelength of 224 nm.The calibration curves were linear over the range of 2.288-73.2 ng/mL with a lower limit of quantitation (LLOQ) of 2.288 ng/mL.The intra- and inter-day precision values were below 13% and the recoveries were from 74.47% to 83.20% at three qtality control levels.The method herein described was successfully applied in a randomized crossover bioequivalence study of two different nicergoline preparations after administration of 30 mg in 20 healthy volunteers.
7.Comparison of HIV-1 DNA in different parts of early antiretroviral treatment patients
Yanmei JIAO ; Rui WANG ; Tong ZHANG ; Dexi CHEN ; Hao WU
Chinese Journal of Laboratory Medicine 2012;35(5):453-456
ObjectiveTo study HIV-1 DNA levels in different parts of HIV patients during the early stage of antiretroviral therapy.MethodsThe peripheral blood,gut associated lymphoid tissues and lymph nodes samples were collected before and 12 weeks after treatment in regular follow-up HIV-1/AIDS patients in Beijing Youan Hospital ( n =11 ).The average age was 39 years old ( 25 to 55 ).Mononuclear Cells were isolated by density gradient centrifugation and then used DNA extraction kit to extract DNA.Realtime quantitative polymerase chain reaction was used to examine HIV-1 DNA copy-number.Non-parametric test was used to analyse the differences of HIV-1 DNA copy numbers among groups.Results Before treatment,HIV-1 DNA copy-number in both gut associated lymphoid tissues ( 10 714 ± 2043 ) copies/106 cells and lymph nodes (9145 ± 1202) copies/106 cells were higher than that in the peripheral blood (66 ± 8) copies/106 cells ( U =0.00,P <0.05 ),There was no significant difference between lymph nodes and gut associated lymphoid tissues (U =46.00,P >0.05).After 12 weeks of treatment,HIV-1 DNA copy-number in both gut associated lymphoid tissues (1701 ± 790) copies/106 cells and lymph node (11 591 ± 1781 ) copies/106 cells were higher than the peripheral blood ( 18 ± 3 ) copies/106 cells ( Z =- 2.934,P < 0.05 ).There was a significant reduction of DNA copy-number in gut associated lymphoid tissues and peripheral blood after treatment (Z =- 2.934,P < 0.05 ).Conclusion Gut associated lymphoid tissues and lymph nodes may be important latent reservoirs for HIV-1 DNA.
8.The role of ASPP2 in starvation-induced autophagy and apoptosis of HCT116 cell line
Qingsheng HOU ; Wei DING ; Dexi CHEN ; Yulin ZHANG ; Hongliang GUO
Chinese Journal of General Surgery 2013;(2):129-133
Objective To investigate the role of ASPP2 (apoptosis stimulating protein 2 of p53,ASPP2) in starvation-induced autophagy and apoptosis of colorectal cancer HCT116 p53-/-(p53 gene deletion) cell line.Methods The study included three experiment groups:green fluorescent protein adenovirus (rAd-GFP) infection group,autophagy inhibitor LY294002 treatment group and ASPP2 adenovirus (rAd-ASPP2) infection group.Celluar autophagy and apoptosis were induced by coculturing with serum-free medium for 0 h,24 h,48 h.Apoptosis level was detected by Calcein/PI uptaking test.Autophagy level was observed under the fluorescence microscope via transfection with cerise fluorescent protein autophagy plasmid CFP-Lc3.Results In control group,starvation for 24 hours significantly promoted autophagy of HCT116 cells (0 h:1.04 ±0.24; 24 h:12.17 ±0.86,P <0.05),while apoptosis was not increased (0 h:2.01% ±0.06%; 24 h:3.23% ±0.34%,P >0.05).With 48 h starvation,autophagy(0 h:1.04 ±0.24; 48 h:21.09 ±3.32) and apoptosis(0 h:2.01% ±0.06% ; 48 h:30.20% ±3.18%)of HCT116 increased (P < 0.05).With the use of LY294002 apoptosis induced by 24 h starvation significantly increased (rAd-GFP group:3.23% ± 0.34% ; LY294002 group:15.68% ± 1.24%,P <0.01),but aopotosis under 48 h starvation decreased (rAd-GFP group:30.20% ± 3.18%; LY294002group:25.44% ± 3.01%,P < 0.05).With ASPP2 transfection,autophagy under 24 h starvation significantly declined (rAd-GFP group:12.17 ± 0.86,ASPP2 group:1.45 ± 0.45,P < 0.01),and apoptosis increased(rAd-GFP group:3.23% ± 0.34% ; ASPP2 group:10.45% ± 0.81%,P < 0.05).Both autophagy (rAd-GFP group:21.09 ± 3.32; ASPP2 group:29.93 ± 3.48) and apoptosis (rAd-GFP group:30.20% ±3.18% ; ASPP2 group:36.72% ±2.74%) were higher than that in controls under 48 h starvation (P < 0.05).Conclusions ASPP2 probably promotes apoptosis of colorectal cancer cells by two-way regulated autophagy.
9.Activated peroxisome proliferator-activated receptor αinhibiting the lipopolysaccharide-induced macrophage-mediated inflammatory responses by promoting the autophagy
Rongrong YANG ; Li ZHANG ; Xiangying ZHANG ; Hongbo SHI ; Dexi CHEN ; Zhongping DUAN ; Feng REN ; Qi WANG
Chinese Journal of Microbiology and Immunology 2015;(6):431-435
Objective To investigate the effects of peroxisome proliferator-activated receptor α( PPARα) on macrophage-mediated inflammatory responses with the interference of lipopolysaccharide and the possible mechanism.Methods The bone marrow stem cells were isolated from the femora of mice.The granulocyte-macrophage colony stimulating factor ( GM-CSF) was used to stimulate the in vitro differentiation from bone marrow stem cells into primary macrophages.An in vitro model with cultured cells expressing in-flammatory cytokines was established by treating the primary macrophages with lipopolysaccharide ( LPS) .A specific chemical agonist, Wy-14643, was used to activate PPARα. Autophagy inhibitors including 3-methyladenine (3-MA) and small interfering RNA against Atg7 ( Atg7 siRNA) were used to inhibit the autophagy.Western blot assay was performed to detect the expression of autophagy-related proteins ( Atg5, Atg7, Beclin-1 and LC3).The transcriptional levels of TNF-α, IL-1β, IL-6, Atg5, Atg7 and Beclin-1 were analyzed by qRT-PCR.Results Compared with the macrophages treated with LPS alone, those pretreated with various concentrations of Wy-14643 (10 μmol/L, 25 μmol/L and 50 μmol/L) showed inhibited ex-pression of proinflammatory cytokines ( TNF-α,IL-1βand IL-6) and enhanced expression of autophagy-relat-ed proteins (Atg5, Atg7 and Beclin-1) at mRNA level in a dose-dependent manner.The expression of auto-phagy-related proteins (Atg5, Atg7, Beclin-1 and LC3) by macrophages was promoted with the pretreatment of Wy-14643 as indicated by Western blot assay.The transcriptional levels of TNF-α, IL-1βand IL-6 were increased in Wy-14643 pretreated-macrophages after stimulation with 3-MA or Atg7 siRNA .Conclusion PPARαsuppressed the macrophage-mediated inflammatory responses by promoting autophagy, suggesting that the PPARα-autophagy pathway might be one of the signaling pathways regulating LPS induced-inflamma-tory responses.
10.Caspase-1 aggravates the D-galactosamine/lipopolysaccharide induced acute liver failure in mice through activating glycogen synthase kinase-3β
Rongrong YANG ; Feng REN ; Li ZHANG ; Xiangying ZHANG ; Hongbo SHI ; Dexi CHEN ; Zhongping DUAN ; Qi WANG
Chinese Journal of Microbiology and Immunology 2016;36(2):132-137
Objective To analyze the role of cysteinyl aspartate specific proteinase-1 (caspase-1) in a mouse model of D-galactosamine (D-GalN) and lipopolysaccharide (LPS) induced acute liver failure (ALF) and to study the possible mechanism. Methods C57BL/ 6 mice were randomly divided into four groups including control group, Z-WEHD-FMK (caspase-1 inhibitor) treatment group, ALF model group and Z-WEHD-FMK-treated ALF group. The mouse model of ALF was established by intraperitoneally injec-ting the mice with D-GalN (450 mg/ kg) and LPS (10 μg/ kg). The damages in liver tissues were evaluated based on the histopathological examination and the levels of alanine transaminase (ALT) and aspartate trans-aminase (AST) in serum samples. Western blot assay was performed to analyze the expression of caspase-1 and the phosphorylation of glycogen synthase kinase 3β (GSK-3β). The qRT-PCR was used to measure the expression of inflammatory cytokines at transcriptional level. Results The expression of caspase-1 at both mRNA and protein levels were gradually increased during the development of ALF. Compared with the mice with ALF, those in the Z-WEHD-FMK-treated ALF group showed less severe liver damages on histopatholog-ical examination and decreased levels of ALT and AST in serum samples [ALT: (479. 2±39. 5) U/ L vs (998. 5±60. 4 ) U/ L, P<0. 05; AST: ( 478. 5±28. 6) U/ L vs ( 1 180. 7±91. 4) U/ L, P<0. 05]. The expression of TNF-α, IL-1β, IL-18 and IL-33 at transcriptional level were significantly suppressed in mice with ALF upon the Z-WEHD-FMK intervention. Results of the Western blot assay indicated that Z-WEHD-FMK suppressed the activities of GSK-3β by enhancing its phosphorylation. Conclusion This study demon-strated that caspase-1 could promote the activation of GSK-3β resulting in the development of inflammation responses and liver damages during the development of ALF in mice.