1.Antagonistic action of epigallocatechin-3-gallate on apoptosis in rat PC12 cells induced by 1-methyl-4-phenylpyridinium ion
Chen XU ; Jing GUO ; Bing-Fu LI ; Jun-Hua LV ;
Chinese Pharmacological Bulletin 1987;0(01):-
Aim To investigate the antagonistic action of EGCG on apoptosis of rat PC12 cell induced by MPP+.Methods PC12 cells were cultured and the apoptosis induced by MPP+(900 ?mol?L-1)was observed.The cells were randomly divided into 6 groups:blank group without any treatment,MPP+ control group,vitamin E group and EGCG groups(10,50,100 ?mol?L-1).After treatment of drugs,cell viability,leakage of LDH,morphological changes of mitochondria and apoptosis were detected by MTT,Hoechst 33342 staining,transmission electron microscope and flow cytometry,respectively.Results After treatment of cultured PC12 cells with MPP+,cell viability was decreased,leakage of LDH and apoptotic rate were increased,and mitochondria swelling,vacuole and cristae breakage were observed.Vitamin E and EGCG en-hanced cell viability,reduced the leakage of LDH and apoptotic rate,and decreased the damage degree of mitochondria.Conclusions EGCG possesses the ability of inhibiting rat PC12 cell apoptosis induced by MPP+,and its protective action may relate to its function of keeping mitochondria integrality.
2.Effects of epigallocatechin-3-gallate on 1-methyl-4-phenylpyridinium ion-induced apoptosis in rat PC12 cells
Jing GUO ; Chen XU ; Bing-Fu LI ; Jun-Hua LV
Chinese Journal of Pathophysiology 1986;0(04):-
AIM: To investigate the effects of epigallocatechin-3-gallate(EGCG) on 1-methyl-4-phenylpyridinium ion(MPP+)-induced apoptosis in rat pheochromocytoma(PC12) cells and to explore the relationships between its roles of anti-oxidation,intracellular calcium homeostasis and anti-apoptosis.METHODS: Rat PC12 cells were pretreated with vehicle control or EGCG(10,50,and 100 ?mol/L) for 30 min,then cultured with MPP+(900 ?mol/L) for 24 h.The cell viability and apoptosis were monitored by MTT assay and flow cytometry using Annexin V and PI.The activity of intracellular reactive oxygen species(ROS),contents of superoxide dismutase(SOD) and malondialdehyde(MDA),cytoplasmic Ca2+ density and apoptotic morphology of mitochondria were examined by fluorescent plate-based assays,confocal microscope,and transmission electron microscope,respectively.RESULTS: MPP+ impaired the PC12 cells in a concentration-dependent pattern and induced apoptosis of the cells(31% versus control).Compared with the control,the cells pretreated with EGCG showed markedly higher rate of viability and lower apoptosis.Meanwhile,EGCG pretreatment significantly increased the SOD activity and decreased the levels of MDA and ROS.Interestingly,EGCG also decreased the concentration of cytoplasmic Ca2+ and improved the morphology of mitochondria.CONCLUSION: EGCG exhibits inhibitory effects on MPP+-induced apoptosis in rat PC12 cells,which is possibly associated with increasing the cell ability of anti-oxidation and decreasing the concentration of cytoplasmic Ca2+.
3.Action potential duration restitution properties and ventricular fibrillation maintenance mechanism
Jing-Jun LV ; Jie WEI ; Dong-Dong ZHAO ; Bo CUI ; Guo-Sheng LIN ;
Chinese Journal of Emergency Medicine 2006;0(12):-
Objective Toinvestigate the role of dynamic dispersion of electrical recovery in ventricular fibrillation maintenance mechanism.Method Thirty-seren male Yorkshire pigs weighing (23?2.5) kg at 3 months age were randomly divided into Sham-operated group and myocardial infarction group in which the first branch of left anterior descending coronary artery of animals was hgated.After 4 weeks,according to VF occurrence by programmed electrical simulation,the myocardial infarction hearts were divided into two groups, twelve hearts in VF (+) group or six hearts in VF (-) group;and the normal hearts were divided into two groups,five hearts in VF (+) group or ten hearts in VF (-) group.Action potential duration (APD) of subendocardial,subepicardial and mid-layer myocardium of left ventricular anterior wall were recorded simultaneously.The relationship between APD and diastolic interval was quantified as an electrical restitution curve.A Student's-test was used to specify differences between groups.Results At the fourth week after coronary artery ligation,eighteen myocardial infarction hearts and fifteen normal hearts were investigated.When investigating transmural dispersion of reporlarization (TDR) of left ventricle,there was no difference between VF (+) group and VF (-) group [ (20.43?7.01) ms vs (22.32?7.53) ms,P=0.45],although there was statistically significant between normal hearts and myocardial infarction hearts [ (15.66?4.45) ms vs (25.72?6.70) ms,P =0.001].The percentage of APD restitution slope exceed 1 and APD restitution slope maximum were high in the VF (+) group with myocardial infarction hearts and in the VF (+) group with normal hearts, lower in the the VF (-) with normal hearts and lowest in the the VF (-) group with myocardial infarction hearts.Conclusion Dynamic APD restitution properties may play an important role in the ventricular fibrillation maintenance mechanism.The APD restitution slope and not static TDR have prognostic value regarding ventricular fibrillation events.The hearts with the steepest of APD restitution curves has the greatest liability of ventricular fibrillation to happen.
4.Construction of M1GS for Targeted Cleavage of HCMV UL54 mRNA Segments
Jing-Zhu LV ; Hong-Jian LI ; Hao-Jun CHEN ; Yue-Qin LI ; Tian-Hong ZHOU ;
Microbiology 1992;0(02):-
Human cytomegalovirus (HCMV) is a DNA virus and serious opportunistic pathogen for both newborn and immunocompromised individuals.To research technique for gene silence and antiviral agents, ribozyme M1GS-T6 was constructed from external guide sequences(EGSs)that consist of a sequence complementary to HCMV UL54 gene RNA and M1 RNA, the catalytic RNA subunit of RNase P from Escherichia coli. The results showed that M1GS can efficiently cleave the mRNA sequence encoding UL54 protein in vitro.
5.Genotypes of Plasmid-mediated AmpC Beta-lactamases in Klebsiella pneumoniae
Jing-Hong PENG ; Zi-Yong SUN ; You-Li ZHOU ; Jun LV ;
Chinese Journal of Nosocomiology 2006;0(09):-
OBJECTIVE To investigate the genotypes of plasmid-mediated AmpC beta-lactamases carried in Klebsiella pneumoniae,to provide reasonable use of antibacterial agents and to reduce the spread of these drug resistant genes.METHODS Two hundred and eighteen strains of K.pneumoniae were performed in Tongji Hospital in Wuhan.Plasmid-mediated AmpC beta-lactamases-producing strains were screened by improved three-dimensional method and identified by multiplex PCR.DNA sequencing method was used to confirm these drug resistant strains.The MIC of 15 kinds of antibacterial agents against the clinical isolates was detected by double agar dilution method.RESULTS Thirteen strains of K.pneumoniae were detected by improved three-dimensional method.The detection rates were 5.96%.There were seven of thirteen positive strains of K.pneumoniae through improved three-dimensional method harboring DHA-1 type plasmid-mediated AmpC beta-lactamase by multiplex PCR and confirmed by DNA sequencing.Plasmid-mediated AmpC beta-lactamase producers revealed a highly drug resistance to cephalosporins,monobactams,beta-lactam/beta-lactamase inhibitor combinations,aminoglycosides and fluoroquinolones.Only imipenem was susceptible to all of these detected strains.CONCLUSIONS DHA-1 plasmid-mediated AmpC beta-lactamase is detected in K.pneumoniae strains from Tongji Hospital.The detection rate is 3.2%.The pAmpC-producing strains reveal multi-drug resistance.Only imipenem is susceptible to them.
6.β-adrenergic Receptor Activity in the Hippocampal Dentate Gyrus Participates in Spatial Learning and Memory Impairment in Sleep-deprived Rats
Experimental Neurobiology 2021;30(2):144-154
Sleep deprivation (SD) leads to cognitive impairment, especially hippocampus-dependent learning and memory (L&M). The hippocampal dentate gyrus (DG) is the key structure involved in spatial L&M while long-term potentiation (LTP) is an important cellular mechanism responsible for L&M. Physiological and behavioral evidences support the hypothesis that norepinephrine (NE) and β-adrenoceptors (β-AR) may play an important role in regulating L&M, including LTP. However, it is enigmatic how β-AR influences the LTP disruption or memory impairment under SD circumstances. In the present study, the rats were subjected to SD for 18 h per day for 21 consecutive days and cognitive capacity was assessed by the Morris water maze (MWM) test. We examined the extracellular concentration of NE in the DG using in vivo brain microdialysis and HPLC analysis. The amplitudes of field excitatory postsynaptic potential (fEPSP) were subsequently measured in the DG during MWM test in freely moving conscious rats. The extracellular concentrations of NE and fEPSP amplitudes in the DG were significantly increased during MWM test, while these responses were suppressed in SD rats. When fEPSP amplitudes in the DG were measured after local injection of isoproterenol (an agonist of β-AR), SD rats significantly alleviated the fEPSP impairment and rescued deficits of spatial L&M. In addition, the reduced expression of N-methyl-Daspartate (NMDA) and α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) receptors in SD rats significantly increased by activation of β-AR by isoproterenol in the DG. In conclusion, we propose that β-adrenergic signaling can improve memory impairment in sleep-deficient rats by regulating synaptic efficiency and glutamatergic receptor expression.
7.β-adrenergic Receptor Activity in the Hippocampal Dentate Gyrus Participates in Spatial Learning and Memory Impairment in Sleep-deprived Rats
Experimental Neurobiology 2021;30(2):144-154
Sleep deprivation (SD) leads to cognitive impairment, especially hippocampus-dependent learning and memory (L&M). The hippocampal dentate gyrus (DG) is the key structure involved in spatial L&M while long-term potentiation (LTP) is an important cellular mechanism responsible for L&M. Physiological and behavioral evidences support the hypothesis that norepinephrine (NE) and β-adrenoceptors (β-AR) may play an important role in regulating L&M, including LTP. However, it is enigmatic how β-AR influences the LTP disruption or memory impairment under SD circumstances. In the present study, the rats were subjected to SD for 18 h per day for 21 consecutive days and cognitive capacity was assessed by the Morris water maze (MWM) test. We examined the extracellular concentration of NE in the DG using in vivo brain microdialysis and HPLC analysis. The amplitudes of field excitatory postsynaptic potential (fEPSP) were subsequently measured in the DG during MWM test in freely moving conscious rats. The extracellular concentrations of NE and fEPSP amplitudes in the DG were significantly increased during MWM test, while these responses were suppressed in SD rats. When fEPSP amplitudes in the DG were measured after local injection of isoproterenol (an agonist of β-AR), SD rats significantly alleviated the fEPSP impairment and rescued deficits of spatial L&M. In addition, the reduced expression of N-methyl-Daspartate (NMDA) and α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) receptors in SD rats significantly increased by activation of β-AR by isoproterenol in the DG. In conclusion, we propose that β-adrenergic signaling can improve memory impairment in sleep-deficient rats by regulating synaptic efficiency and glutamatergic receptor expression.
8.The role of platelet activation and related immune response in sepsis
Chinese Journal of Infection Control 2019;18(3):271-276
Platelet activation plays an important role in the occurrence and development of sepsis. During sepsis stage, platelet activation can cause endothelial cell damage, promote the formation of neutrophil extracellular traps (NETs) and microthrombosis, aggravate coagulation dysfunction and inflammatory response disorder, and ultimately lead to multiple organ dysfunction syndrome (MODS) in septic patients. During the infection, platelets also participate in the process of congenital immune response and acquired immune response, through the interaction with immune mediators, platelets can actively defend the invasion and spread of pathogens, but also may aggravate the disease and even cause septic shock due to overactive immune response. This paper mainly introduces the role of platelet activation in the occurrence and development of sepsis, and highlights the role of platelet-mediated immune response in anti-infection of human body.
9.Effects of total glucosides of paeony on enhancing insulin sensitivity and antagonizing nonalcoholic fatty liver in rats.
Lin-Ying ZHENG ; Jing-Qiang PAN ; Jun-Hua LV
China Journal of Chinese Materia Medica 2008;33(20):2385-2390
OBJECTIVETo study the pathological changes of blood glucose, serum lipid, insulin resistance, liver function, liver cell denaturalization of total glucosides of paeony on nonalcoholic fatty liver rats caused by insulin resistance and discuss the acting mechanism.
METHODAdult SD rats were maintained on high-fat-sugar-salt diet for 56 days. In the 57th day, their fasting blood glucose (FBG) and 2-hours blood glucose after oral glucose tolerance test (OGTT-2 hBG) were mensurated, according to which and the weight the rats were divided randomly into nonalcoholic fatty liver model group, metformin group (0.2 g x kg(-1)) and total glucosides of paeony group (high dosage 0.15 g x kg(-1), low dosage 0.05 g x kg(-1)). All the rats were still administered the same diet and given different drugs by intragastric administration for 28 days. In the 29th day, all of them were killed and the blood was sampled to measure the levels of blood glucose [FBG, OGTT-2 hBG, fasting insulin (Fins)] and serum lipid [free fatty acids (FFA), triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C)], then the HOMA insulin resistance index (HOMA-IRI, fasting glucosexinsulin) and insulin sensitivity index (ISI) were counted. The activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT), cholinesterase (ChE), superoxide dismutase (SOD) and the contents of malondialdehyde (MDA) were measured also. Livers were weighed and collected to be observed the pathological changes.
RESULTCompared with normal group, in nonalcoholic fatty liver model group the levels of Fins and IRI were increased obviously (P < 0.01), ISI were decreased (P < 0.01), FFA, TG, TC, LDL-C were increased (P < 0.01), HDL-C were decreased (P < 0.05); the content of MDA were increased (P < 0.05), the activities of SOD were decreased (P < 0.01); AST, ALT and ChE were increased (P < 0.05, or P < 0.01), the pathological changes of liver fat were severe (P < 0.01). In glucosides of paeony group and metformin group, hyperinsulinaemia and insulin resistence were resisted (P < 0.05, or P < 0.01); the levels of FFA, TG, TC, LDL-C were decreased and HDL-C were increased (P < 0.05, or P < 0.01); the activities of AST, ALT, ChE were decreased (P < 0.05, or P < 0.01) and SOD were increased (P < 0.01). The contents of MDA were decreased (P < 0.05). The levels of FBG and 2 hBG in metformin group were decreased but in total glucosides of paeony group were not decreased obviously.
CONCLUSIONTotal glucosides of paeony may protect liver function and modulate serum lipid for the fatty liver rats caused by insulin resistance, and its action mechanism may be concerned with enhancing insulin sensitivity and antioxidative ability, decreasing serum lipid.
Alanine Transaminase ; metabolism ; Animals ; Aspartate Aminotransferases ; metabolism ; Blood Glucose ; drug effects ; Cholesterol, LDL ; blood ; Cholinesterases ; metabolism ; Drugs, Chinese Herbal ; pharmacology ; therapeutic use ; Enzyme Activation ; drug effects ; Fatty Liver ; drug therapy ; prevention & control ; Female ; Glucose Tolerance Test ; Glucosides ; chemistry ; pharmacology ; therapeutic use ; Insulin Resistance ; Lipids ; blood ; Liver ; drug effects ; metabolism ; pathology ; Male ; Malondialdehyde ; metabolism ; Paeonia ; chemistry ; Rats ; Rats, Sprague-Dawley ; Superoxide Dismutase ; metabolism
10.Resection of the fourth ventricle tumors through lateral wall type of the cerebellomedullary fissure approach under endoscope
Jun SHEN ; Jing LUO ; Hongwei CHENG ; Chunguo FENG ; Xiaojian WANG ; Baochun CHENG ; Jin XIAO ; Liang ZHAO ; Qingxin LI ; Bo LV
Chinese Journal of Microsurgery 2012;35(5):384-386
Objective To investigate the therapeutic effect of the fourth ventricle tumors through lateral wall type of the transcerebellomedullary fissure approach under endoscope.Methods Clinical data of 14 cases with the fourth ventricle lesions were analyzed retrospectively.All the patients were treated by lateral wall type of the transcerebellomedullary fissure approach surgery.The endoscope was used if the lesions develop to the aqueduct and hard to be exposed.Both neurophysiological monitoring and intraoperative ultrasound were used regularly.Results Tumors were totally removed in 12 cases,subtotally in 1,and partially in 1.All the patients were diagnosed in postoperative histopathology,including 4 medulloblastoma,three epidermoid cyst,two ependymoma,two hemangioblastoma,one meningioma,one cavernous hemangioma and 1 astrocytoma.Hypopnea occurred immediate after operation in 1 patient.Ventilatory support was performed by Ventilator,and the respiration was restored 1 day later.Normal cerebrospinal fluid circulation was return in all cases.Neither aggravation of preoperative symptoms nor nuclei injury related complication had been found.The follow-up interval between 3 months to 28 months,one patient was dead with unexplained,and 1 medulloblastoma patient was relapse.Conclusion Lateral wall type of the transeerebellomedullary fissure approach,under endoscope,combined with the usage of neurophysiological monitoring and intraoperative ultrasound,can degrade the surgical related complications such as facial palsy and amblyacousia.