2.Experimental Study on Activation of Caspase-3 and Apoptosis of K562 Cell Induced by Iron-Deprivation
you-cai, TANG ; guo-cun, JIA ; feng-yi, LI ; qing-kui, LIAO ; bin, CHEN ; wen-zhong, NIU
Journal of Applied Clinical Pediatrics 2006;0(15):-
Objective To observe the relationship between apoptosis of K562 cell induced by iron-deprivation and activation of Caspase-3.Methods K562 cells were treated with desferrioxamine(DFO) in different dosages were collected at different time points.K562 cells were labelled with Annexin V/PI,and then the rate of apoptosis was measured by flow cytometry;The activation of Caspase-3 were detected by colorimetric method with pAN labelled substrate;The active protein of Caspase-3 were analyzed by Western blot.Results When K562 cells were treated with different concentrations of DFO,the apoptosis rate and the activity of Caspase-3 increases gradually.When K562 cells were incubated with DFO(50 ?mol/L and 100 ?mol/L) 24 h later,the enzymatic activity of Caspase-3 increases dramatically more than that of control group,and the difference was significantly(P0.05).All those effect above can be counteracted by equal mole concentration of FeCl_3.Conclusion Iron-deprivation maybe induce the apoptosis of K562 cell by chelating intracellular iron and activing Caspase-3.
3.Expression of iNOS and levels of NO in THP-1 and J774A. 1 cells during Leptospira interrogans infec-tion
Peili LI ; Ying LIU ; Qing MA ; Xiaoyu WEI ; Lyu YOU ; Guangpeng TANG ; Dingming WANG ; Bijun ZHOU ; Shijun LI
Chinese Journal of Microbiology and Immunology 2015;(8):577-581
Objective To investigate the expression of inducible nitric oxide synthase ( iNOS) and the levels of nitric oxide (NO) in THP-1 and J774A. 1 cells during Leptospira interrogans (L. interrogans) infection for a better understanding of the mechanism of macrophages involved defense against L. interrogans strains in different hosts. Methods The human mononuclear macrophages (THP-1) and the murine mono-nuclear macrophages (J774A. 1) were infected with L. interrogans strain 56601. The expression of iNOS at mRNA and protein levels were determined by using real-time RT-PCR and flow cytometry analysis. The lev-els of NO were detected with Griess test. Results The expression of iNOS at mRNA level in J774A. 1 and THP-1 cells infected with L. interrogans strains for 2, 4, 12 and 24 hours were respectively 1. 37, 2. 82, 25. 76, 27. 47 times and 1. 59, 3. 98, 3. 89, 8. 81 times than that of cells without infection (P<0. 05). The expression rates of iNOS protein in J774A. 1 cells were increased from 34. 16% to 85. 85%, 93. 82%, 91. 77% and 93. 65% along with the increased time of infection time (P<0. 05). The expression rates of iNOS protein in THP-1 cells were up-regulated from 22. 08% to 72. 64%, 81. 33%, 80. 03% and 65. 72%after 2, 4, 12 and 24 hours of infection (P<0. 05), respectively. Results of the Griess test indicated that the levels of NO in J774A. 1 and THP-1 cells were respectively increased from 0. 1588 μmol/L to 0. 2208μmol/L, 0. 2668μmol/L, 0. 3808μmol/L, 0. 3828μmol/L and from 0. 0988μmol/L to 0. 2848μmol/L,0. 3228 μmol/L, 0. 2608μmol/L and 0. 3308μmol/L after infection with L. interrogans strains for 2, 4, 12 and 24 hours (P<0. 05). Conclusion The expression of iNOS and the levels of NO in J774A. 1 and THP-1 cells were significantly increased during L. interrogans infection. This study might help to explain the bactericidal mechanism of macrophages derived from different hosts against L. interrogans infection.
4.Effects of Leptospira interrogans infection on the activation of NLRP3 in THP-1 and J774A. 1 cells
Ming WANG ; Hong CHEN ; Ying LIU ; Qing MA ; Xiaoyu WEI ; Lyu YOU ; Guangpeng TANG ; Dingming WANG ; Shijun LI ; Bijun ZHOU
Chinese Journal of Microbiology and Immunology 2016;36(12):894-899
Objective To analyze the effects of Leptospira interrogans ( L. interrogans) infection on the activation of NLRP3 in THP-1 and J774A. 1 cells and to further understand the mechanism of inflam-mation caused by L. interrogans in different hosts. Methods Human mononuclear macrophage cell line (THP-1) and murine mononuclear macrophage cell line (J774A. 1) were infected with L. interrogans strain 56601. The expression of NLRP3 at mRNA and protein levels were measured by using real-time RT-PCR and flow cytometry analysis, respectively. The NLRP3-mediated secretion of IL-1β, IL-18 and IL-33 was detec-ted by ELISA combined with the NLRP3 inhibitory test. Results Compared with the normal cells, the ex-pression of NLRP3 at mRNA level in L. interrogans-infected THP-1 cells was respectively increased by 4. 05, 0. 34, 0. 33, 0. 06 and 1. 66 times at the time points of 1 h, 2 h, 4 h, 12 h and 24 h after infection ( P<0. 05), while that in L. interrogans-infected J774A. 1 cells was respectively increased by 12. 98, 16. 19, 10. 68, 5. 8 and 0. 57 times (P<0. 05). The expression rates of NLRP3 protein in THP-1 and J774A. 1 cells respectively increased from 9. 26% to 94. 01%, 89. 24%, 31. 80%, 19. 74%, 11. 28% and from 18. 71%to 58. 78%, 43. 64%, 36. 42%, 76. 46%, 85. 21% at the time points of 1 h, 2 h, 4 h, 12 h and 24 h af-ter L. interrogans infection (P<0. 05). The level of IL-1β in L. interrogans-infected THP-1 cells was 73. 07 pg/ml, 939. 24 pg/ml, 939. 24 pg/ml, 843. 22 pg/ml and 851. 06 pg/ml at the time points of 1 h, 2 h, 4 h, 12 h and 24 h, respectively (P<0. 05), while the level of IL-1β in L. interrogans-infected J774A. 1 cells began to rise at the time point of 12 h from 191. 17 pg/ml to 254. 4 pg/mL at the time point of 24 h (P<0. 05). The level of IL-18 in L. interrogans-infected THP-1 cells was 913. 89 pg/ml, 808. 19 pg/ml, 483. 54 pg/ml, 204. 19 pg/ml and 189. 09 pg/ml at the time points of 1 h, 2 h, 4 h, 12 h and 24 h, re-spectively (P<0. 05), while the level of IL-18 in L. interrogans-infected J774A. 1 cells increased at the time point of 24 h, which was 113. 37 pg/ml (P<0. 05). A slight increase in the level of IL-33 was detected in L. interrogans-infected J774A. 1 cells at the time points of 12 h and 24 h to 201. 14 pg/ml and 155. 68 pg/ml, respectively (P<0. 05), but no significant change was detected in L. interrogans-infected THP-1 cells (P>0. 05). Results of the inhibitory test showed that the up-regulation of IL-1β , IL-18 and IL-33 in THP-1 and J774A. 1 cells were effectively inhibited by the specific inhibitor of NLRP3. Conclusion NL-RP3 inflammasome was activated and involved in the production of specific inflammatory cytokines IL-1βand IL-18 in both THP-1 and J774A. 1 cells after L. interrogans infection, but the inflammatory cytokines induced by L. interrogans infection varied in different cells. L. interrogans induced earlier and higher level of IL-1βand IL-18 production in human macrophages than in murine macrophages.
5.Deferoxamine induces apoptosis of K562 cells.
Guo-Cun JIA ; You-Cai TANG ; Feng-Yi LI ; Qing-Kui LIAO
Chinese Journal of Contemporary Pediatrics 2011;13(8):674-676
OBJECTIVETo study the molecular mechanism of apoptosis of leukemic cells (K562 cells) induced by iron chelating agent deferoxamine (DFO).
METHODSThe exponentially growing K562 cells were used (1×10(6)/mL) in this study. The K562 cells were treated with different concentrations of DFO (10, 50 and 100 mmol/L), DFO+FeCl3 (10 μmol/L each) or normal saline (blank control). The cellular labile iron pool was measured with a fluorimetric assay using the metalsensitive probe calcein-AM. The viable count and cell viability were determined by typanblue assay. Cell apoptosis was determined by morphological study and flow cytometry assay. Caspase-3 activity in K562 cells was detected by colorimetry.
RESULTSAfter DFO treatment, the cellular labile iron pool and the viability of K562 cells were reduced and the cell apoptosis increased in a time- and dose-dependent manner compared with the blank control group. The apoptosis rate of K562 cells in the DFO+FeCl3 treatment group was not significantly different from that in the blank control group. The caspase-3 activity in K562 cells increased significantly 24 hrs after 50 and 100 μmmol DFO treatment when compared with the blank control group (P<0.01). There was a negative correlation between cellular labile iron pool and caspase-3 activity of K562 cells (r=-0.894, P<0.05).
CONCLUSIONSDFO induces apoptosis of leukemic cells possibly through decreasing cellular labile iron pool and increasing caspase-3 activity of the cells.
Apoptosis ; drug effects ; Caspase 3 ; metabolism ; Deferoxamine ; pharmacology ; Flow Cytometry ; Humans ; Iron Chelating Agents ; pharmacology ; K562 Cells
6.Induction of apoptosis by proteasome inhibitor MG-132 in human erythroleukemia cell line K562.
Xi-Ge WANG ; Qing-Fei HAO ; You-Cai TANG
Chinese Journal of Contemporary Pediatrics 2009;11(4):255-258
OBJECTIVETo investigate whether proteasome inhibitor MG-132 induces apoptosis of human erythroleukemia cell line K562 and possible mechanisms.
METHODSK562 cells were incubated with RPMI 1640 and exposed to 0, 1, 5, 10, 15 micromol/L of MG-132 for 24 hrs, respectively. The apoptosis of cells were detected by fluorescence microscope, DNA fragments and flow cytometry. The NF-kappaB mRNA expression was quantified by reverse transcription-polymerase chain reaction (RT-PCR). Expression of NF-kappaB and caspase-3 was semiquantitatively analyzed with SABC techniques. Caspase-3 activities were measured with a colorimetric method.
RESULTSThe growth of K562 cells was inhibited and the apoptosis of the cells increased after MG-132 treatment in a dose-dependent manner. After 24 hrs of 15 micromol/L MG-132 treatment, the percentage of apoptotic cells (26.5+/-0.6%) increased significantly when compared with the untreated controls (1.2+/-0.1%) (P<0.01). MG-132 treatment decreased the mRNA and protein expression of NF-kappaB, and increased the protein expression of caspase-3.
CONCLUSIONSMG-132 can induce apoptosis of human erythroleukemia cell line K562 through the down-regulation of NF-kappaB expression and up-regulation of caspase-3 expression.
Antineoplastic Agents ; pharmacology ; Apoptosis ; drug effects ; Caspase 3 ; metabolism ; Cysteine Proteinase Inhibitors ; pharmacology ; Dose-Response Relationship, Drug ; Humans ; K562 Cells ; Leupeptins ; pharmacology ; NF-kappa B ; Proteasome Inhibitors ; Reverse Transcriptase Polymerase Chain Reaction
7.Diesel pollution biodegradation: synergetic effect of Mycobacterium and filamentous fungi.
You-Qing LI ; Hong-Fang LIU ; Zhen-Le TIAN ; Li-Hua ZHU ; Ying-Hui WU ; He-Qing TANG
Biomedical and Environmental Sciences 2008;21(3):181-187
OBJECTIVETo biodegrade the diesel pollution in aqueous solution inoculated with Mycobacterium and filamentous fungi.
METHODSBacteria sampled from petroleum hydrocarbons contaminated sites in Karamay Oilfield were isolated and identified as Mycobacterium hyalinum (MH) and cladosporium. Spectrophotometry and gas chromatography (GC) were used to analyze of the residual concentrations of diesel oil and its biodegradation products.
RESULTSFrom the GC data, the values of apparent biodegradation ratio of the bacterial strain MH to diesel oil were close to those obtained in the control experiments. Moreover, the number of MH did not increase with degradation time. However, by using n-octadecane instead of diesel oil, the real biotic degradation ratio increased to 20.9% over 5 days of degradation. Cladosporium strongly biodegraded diesel oil with a real degradation ratio of up to 34% after 5 days treatment. When the two strains were used simultaneously, a significant synergistic effect between them resulted in almost complete degradation of diesel oil, achieving a total diesel removal of 99% over 5 days of treatment, in which one part of about 80% and another part of about 19% were attributed to biotic and abiotic processes, respectively.
CONCLUSIONThe observed synergistic effect was closely related to the aromatics-degrading ability of Cladosporium, which favored the growth of MH and promoted the bioavailability of diesel oil.
Biodegradation, Environmental ; Cladosporium ; metabolism ; Environmental Pollutants ; metabolism ; Gasoline ; Mycobacterium ; metabolism
8.Relationship between oxidized lipoprotein, angiogenesis and human coronary atherosclerotic plaque stabilization.
Li-xin WEI ; Qing-he TANG ; Lu SUN ; Huai-yin SHI ; Ai-tao GUO ; Lian-bi YOU
Chinese Journal of Pathology 2006;35(3):138-141
OBJECTIVESTo analyze the relationship between oxidized low density lipoprotein (oxLDL), angiogenesis and stabilization of atherosclerotic plaques in human coronary arteries; and to investigate the role of oxLDL in creating vulnerable sites in atherosclerotic plaques.
METHODSSamples of coronary arteries were obtained at autopsies of 42 patients with acute coronary syndrome. Eighty randomly selected blocks were studied by immunohistochemistry using antibodies against oxLDL and endothelial cells (factor VIII). Computer-aided planimeter was used for quantitative analysis.
RESULTSIn unstable plaques, percentage of immunoreactive areas for oxLDL was significantly higher than that in stable plaques. Most of the oxLDL were located in shoulder region of these plaques, as compared to the fibrous cap and basal regions. The details of distribution of oxLDL were as follows: shoulder region (20.43 +/- 3.12 for unstable plaques and 17.65 +/- 4.22 for stable plaques), fibrous cap (4.77 +/- 2.03 for unstable plaque and 2.80 +/- 0.22 for stable plaques) and basal region (5.65 +/- 1.65 for unstable plaques and 3.22 +/- 1.02 for unstable plaques). OxLDL was also a main component in the lipid core. In the shoulder region, there was a significant positive correlation between neovascularization and oxLDL (r = 0.8247, P = 0.000).
CONCLUSIONSThe amount of oxLDL is significantly higher in unstable atherosclerotic plaques, especially over the shoulder region. OxLDL in coronary atherosclerotic plaques is thus an important factor in determining stabilization of the plaques. OxLDL may induce influx of inflammatory cells which subsequently leads to decreased plaque stabilization.
Angina, Unstable ; metabolism ; pathology ; Coronary Artery Disease ; metabolism ; pathology ; Humans ; Immunohistochemistry ; Lipoproteins, LDL ; metabolism ; Myocardial Infarction ; metabolism ; pathology ; Neovascularization, Pathologic ; metabolism ; pathology
9.Progress in diagnosis and management of syncope in children
rui Wen XU ; Ying LIAO ; fang Hong JIN ; you Qing ZHANG ; shu Chao TANG ; bao Jun DU
Journal of Peking University(Health Sciences) 2017;49(5):756-759
Syncope is a common emergency of children and adolescents,which has serious influence on the quality of life.Neurally-mediated syncope,including postural tachycardia syndrome,vasovagal syncope,orthostatic hypotension and orthostatic hypertension,is the main cause of syncope in children and adolescents.The main manifestations of neurally-mediated syncope are diverse,such as dizziness,headache,chest tightness,chest pain,pale complexion,fatigue,pre-syncope and syncope.Although the clinical manifestations are similar,each subtype of syncope has its hemodynamic feature and optimal treatment option.The diagnosis rate of syncope in children has been greatly improved on account of the development of the diagnostic procedures and methods.In recent years,with the promotion of head-up tilt test and drug-provocated head-up tilt test,the hemodynamic classification of neurally-mediated syncope gets continually refined.In recent years,with the effort of clinicians,an appropriate diagnostic protocol for children with syncope has been established.The initial evaluation consists of history taking,physical examination,standing test and standard electrocardiography.After the initial evaluation,some patients could be diagnosed definitely,such as postural tachycardia syndrome,orthostatic hypotension,and situational syncope.Those with a specific entity causing syncope need selective clinical and laboratory investigations.Patients for whom the cause of syncope remained undetermined should undergo head-up tilt test.The precise pathogenesis of neurally-mediated syncope is not entirely clear.In recent years,studies have shown that neurally-mediated syncope may be related to several factors,including hypovolemia,high catecholamine status,abnormal local vascular tension,decreased skeletal muscle pump activity and abnormal neurohumoral factors.Currently based on the possible pathogenesis,the individualized treatment of neurally-mediated syncope has also been studied in-depth.Generally,the management of neurallymediated syncope includes non-pharmacological and pharmacological interventions.Patient education is the fundamental part above all.In addition to exercise training,the first-line treatments mainly include oral rehydration salts,beta adrenoreceptor blockers,and alpha adrenoreceptor agonists.By analyzing the patient's physiological indexes and biomarkers before treatment,the efficacy of medication could be well predicted.The individualized treatment will become the main direction in the future researches.
10.Changes Hydrogen Sulfide in Plasma of Children with Congenital Heart Disease
yu-wen, SU ; ya-guang, DING ; chun-yu, ZHANG ; qing-you, ZHANG ; jian-guang, QI ; chao-shu, TANG ; jun-bao, DU
Journal of Applied Clinical Pediatrics 2004;0(07):-
Objective To investigate the changes of hydrogen sulfide (H_2S) level in plasma in order to explore the role of H_2S in the development of pulmonary hypertension (PH) secondary to congenital heart disease (CHD).Methods There were 9 CHD patients and 9 normal children in this study. The plasma concentration of H_2S and pulmonary artery pressure (PAP) of each child were measured. Meanwhile, the relationship between H_2S level and PAP was analyzed.Results The plasma level of H_2S in the group of CHD significantly decreased compared with control group (32.13?2.25) ?mol/L vs [(43.69?2.05)?mol/L, P