Background:Apolipoprotein B mRNA editing catalytic polypeptide(APOBEC),an endogenous mutator,induces DNA damage and activates the ataxia telangiectasia and Rad3-related(ATR)-checkpoint kinase 1(Chk1)pathway.Although c...Background:Apolipoprotein B mRNA editing catalytic polypeptide(APOBEC),an endogenous mutator,induces DNA damage and activates the ataxia telangiectasia and Rad3-related(ATR)-checkpoint kinase 1(Chk1)pathway.Although cisplatin-based therapy is the mainstay for muscle-invasive bladder cancer(MIBC),it has a poor survival rate.Therefore,this study aimed to evaluate the efficacy of an ATR inhibitor combined with cisplatin in the treatment of APOBEC catalytic subunit 3B(APOBEC3B)expressing MIBC.Methods:Immunohistochemical staining was performed to analyze an association between APOBEC3B and ATR in patients with MIBC.The APOBEC3B expression in MIBC cell lines was assessed using real-time polymerase chain reaction and western blot analysis.Western blot analysis was performed to confirm differences in phosphorylated Chk1(pChk1)expression according to the APOBEC3B expression.Cell viability and apoptosis analyses were performed to examine the anti-tumor activity of ATR inhibitors combined with cisplatin.Results:There was a significant association between APOBEC3B and ATR expression in the tumor tissues obtained from patients with MIBC.Cells with higher APOBEC3B expression showed higher pChk1 expression than cells expressing low APOBEC3B levels.Combination treatment of ATR inhibitor and cisplatin inhibited cell growth in MIBC cells with a higher APOBEC3B expression.Compared to cisplatin single treatment,combination treatment induced more apoptotic cell death in the cells with higher APOBEC3B expression.Conclusion:Our study shows that APOBEC3B’s higher expression status can enhance the sensitivity of MIBC to cisplatin upon ATR inhibition.This result provides new insight into appropriate patient selection for the effective application of ATR inhibitors in MIBC.展开更多
AIM:To prospectively investigate the association between the XbaⅠpolymorphisms of apolipoprotein B (APOB)gene and gallstone formation following gastrectomy.METHODS:The study was conducted between January 2005 and Dec...AIM:To prospectively investigate the association between the XbaⅠpolymorphisms of apolipoprotein B (APOB)gene and gallstone formation following gastrectomy.METHODS:The study was conducted between January 2005 and December 2006.A total of 186 gastric cancer patients who had undergone radical gastrectomy were grouped according to XbaⅠpolymorphisms of APOB gene(X+X-group,n=24 and X-X-group,n =162)and compared.The XbaⅠpolymorphisms of APOB gene were detected by polymerase chain reaction-restriction fragment length polymorphism(PCRRFLP).RESULTS:The incidence of gallstone was significantly higher in the X + X-group than in the X-X-group[54.2% vs 9.3%,RR=5.85(2.23-15.32),P<0.001].The serum levels of total cholesterol(TC)and low-density lipoprotein(LDL)were higher in the X + X-than in the X-X-group(4.02±1.12 vs 3.48±0.88,P=0.004 before surgery and 3.88±1.09 vs 3.40±0.86,P=0.008 after surgery).LDL was 2.21±0.96 vs 1.89±0.84(P =0.042)before surgery and 2.09±0.95 vs 1.72±0.85 (P=0.029)after surgery in the two groups.No relationship was found between XbaⅠpolymorphisms and gallbladder motility.CONCLUSION:In Chinese patients after radical gastrectomy,X + allele of APOB gene is another risk factor for the development of gallstone besides the gallbladder motility disorder after surgery.展开更多
AIM: To investigate the effect of high homocysteine(Hcy) levels on apolipoprotein E(apoE) expression and the signaling pathways involved in this gene regulation.METHODS: Reverse transcriptase polymerase chain reaction...AIM: To investigate the effect of high homocysteine(Hcy) levels on apolipoprotein E(apoE) expression and the signaling pathways involved in this gene regulation.METHODS: Reverse transcriptase polymerase chain reaction(RT-PCR) and Western blot were used to assess apo E expression in cells treated with various concentrations(50-500 μmol/L) of Hcy. Calcium phosphatetransient transfections were performed in HEK-293 and RAW 264.7 cells to evaluate the effect of Hcy on apoE regulatory elements [promoter and distal multienhancer 2(ME2)]. To this aim, plasmids containing the proximal apoE promoter [(-500/+73)apoE construct] alone or in the presence of ME2 [ME2/(-500/+73)apoE construct] to drive the expression of the reporter luciferase gene were used. Co-transfection experiments were carried out to investigate the downstream effectors of Hcymediated regulation of apoE promoter by using specific inhibitors or a dominant negative form of IKβ. In other co-transfections, the luciferase reporter was under the control of synthetic promoters containing multiple specific binding sites for nuclear factor kappa B(NF-κB), activator protein-1(AP-1) or nuclear factor of activated T cells(NFAT). Chromatin immunoprecipitation(ChI P)assay was accomplished to detect the binding of NF-κB p65 subunit to the apoE promoter in HEK-293 treated with 500 μmol/L Hcy. As control, cells were incubated with similar concentration of cysteine. NF-κB p65 proteins bound to DNA were immunoprecipitated with anti-p65 antibodies and DNA was identified by PCR using primers amplifying the region-100/+4 of the apoE gene. RESULTS: RT-PCR revealed that high levels of Hcy(250-750 μmol/L) induced a 2-3 fold decrease in apoE m RNA levels in HEK-293 cells, while apo E gene expression was not significantly affected by treatment with lower concentrations of Hcy(100 μmol/L). Immunoblotting data provided additional evidence for the negative role of Hcy in apoE expression. Hcy decreased apoE promoter activity, in the presence or absence of ME2, in a dose dependent manner, in both RAW 264.7 and HEK-293 cells, as revealed by transient transfection experiments. The downstream effectors of the signaling pathways of Hcy were also investigated. The inhibitory effect of Hcy on the apo E promoter activity was counteracted by MAPK/ERK kinase 1/2(MEK1/2) inhibitor U0126, suggesting that MEK1/2 is involved in the downregulation of apoE promoter activity by Hcy. Our data demonstrated that Hcy-induced inhibition of apoE took place through activation of NF-κB. Moreover, we demonstrated that Hcy activated a synthetic promoter containing three NF-κB binding sites, but did not affect promoters containing AP-1 or NFAT binding sites. ChI P experiments revealed that NF-κB p65 subunit is recruited to the apoE promoter following Hcy treatment of cells.CONCLUSION: Hcy-induced stress negatively modulates apoE expression via MEK1/2 and NF-κB activation. The decreased apo E expression in peripheral tissues may aggravate atherosclerosis, neurodegenerative diseases and renal dysfunctions.展开更多
Objective We aimed to investigate the cumulative effect of high CRP level and apolipoprotein B-to-apolipoprotein A-1（ApoB/ApoA-1） ratio on the incidence of ischemic stroke（IS） or coronary heart disease（CHD） in a...Objective We aimed to investigate the cumulative effect of high CRP level and apolipoprotein B-to-apolipoprotein A-1（ApoB/ApoA-1） ratio on the incidence of ischemic stroke（IS） or coronary heart disease（CHD） in a Mongolian population in China.Methods From June 2003 to July 2012,2589 Mongolian participants were followed up for IS and CHD events based on baseline investigation.All the participants were divided into four subgroups according to C-reactive protein（CRP） level and ApoB/ApoA-1 ratio.Cox proportional hazard models were used to estimate the hazard ratios（HRs） and 95% confidence intervals（CIs） for the IS and CHD events in all the subgroups.Results The HRs（95% CI） for IS and CHD were 1.33（0.84-2.12）,1.14（0.69-1.88）,and 1.91（1.17-3.11） in the ‘low CRP level with high ApoB/ApoA-1＇,‘high CRP level with low ApoB/ApoA-1＇,and ‘high CRP level with high ApoB/ApoA-1＇ subgroups,respectively,in comparison with the ‘low CRP level with low ApoB/ApoA-1＇ subgroup.The risks of IS and CHD events was highest in the ‘high CRP level with high ApoB/ApoA-1＇ subgroup,with statistical significance.Conclusion High CRP level with high ApoB/ApoA-1 ratio was associated with the highest risks of IS and CHD in the Mongolian population.This study suggests that the combination of high CRP and ApoB/ApoA-1 ratio may improve the assessment of future risk of developing IS and CHD in the general population.展开更多
Apolipoprotein B （apoB） is the main protein component of very low density lipoprotein （VLDL） and is necessary for the assembly and secretion of these triglyceride （TG）-rich particles. Following release from the ...Apolipoprotein B （apoB） is the main protein component of very low density lipoprotein （VLDL） and is necessary for the assembly and secretion of these triglyceride （TG）-rich particles. Following release from the liver, VLDL is converted to low density lipoprotein （LDL） in the plasma and increased production of VLDL can therefore play a detrimental role in cardiovascular disease. Increasing evidence has helped to establish VLDL assembly as a target for the treatment of dyslipidemias. Multiple factors are involved in the folding of the apoB protein and the formation of a secretion-competent VLDL particle. Failed VLDL assembly can initiate quality control mechanisms in the hepatocyte that target apoB for degradation. ApoB is a substrate for endoplasmic reticulum associated degradation （ERAD） by the ubiquitin proteasome system and for autophagy. Efficient targeting and disposal of apoB is a regu- lated process that modulates VLDL secretion and partitioning of TG. Emerging evidence suggests that significant overlap exists between these degradative pathways. For example, the insulin-mediated targeting of apoB to autop- hagy and postprandial activation of the unfolded protein response （UPR） may employ the same cellular machinery and regulatory cues. Changes in the quality control mechanisms for apoB impact hepatic physiology and pathology states, including insulin resistance and fatty liver. Insulin signaling, lipid metabolism and the hepatic UPR may impact VLDL production, particularly during the postprandial state. In this review we summarize our current understanding of VLDL assembly, apoB degradation, quality control mechanisms and the role of these processes in liver physiology and in pathologic states.展开更多
The polymorphisms of variable number of tandem repeats (VNTR) 3’to the apolipoprotein B (apo B) gene were investigated using polymerase chain reaction (PCR) in a sample of 103 patients with documented coronary heart ...The polymorphisms of variable number of tandem repeats (VNTR) 3’to the apolipoprotein B (apo B) gene were investigated using polymerase chain reaction (PCR) in a sample of 103 patients with documented coronary heart disease (CHD) and 100 healthy individuals selected from Chinese Han nationality.Twelve segregating alleles (3’β29 -51) were observed in the pooled total of 203 subjects. The most common allele was 3’β 37. followed by 3’β39 with frequencies of 0. 362 and 0. 296, respectively. This model of allele distribution was coincident with the results form different ethnic groups, but the relative frequencies of alleles were different. In comparison with the allele frequencies between the patients and controls,alleles bigger than 3’β39 (3’VNTR-B) were significantly more common among the patients than among the controls (P<0. 001). Moreover. in the CHD group patients with plasma levels of TC≥3.88 mmol/L,LDL-C≥2. 59 mmol/L and HDL-C<l. 16mmol/L had significantly higher frequencies of 3’ VNTR-B allele (P<0. 01). Therefore,it is suggested that 3’ VNTR-B allele might be involved in the development of coronary atherosclerosis, presumably through their influences on lipid metabolism.This study supported by “8. 5” grant from Ministry of PublicHealth.展开更多
BACKGROUND： Extracts of ginkgo biloba leaves have been reported to improve nerve function and activity in Alzheimer＇s disease, which is associated with reduced secretion of cholinergic neurotransmitter in hippocampa...BACKGROUND： Extracts of ginkgo biloba leaves have been reported to improve nerve function and activity in Alzheimer＇s disease, which is associated with reduced secretion of cholinergic neurotransmitter in hippocampal neurons. OBJECTIVE： To validate the protective effect of bilobalide B against in vitro injury of cholinergic neurons of the hippocampus induced by combined cholesterol and apoE4 DESIGN, TIME AND SETTING： This randomized, controlled animal experiment was performed in the Pathology Laboratory, Tianjin University of Traditional Chinese Medicine from July 2003 to July 2006. MATERIALS： Neonatal Wistar rats, 1-day-old, both male and female, and mean body mass of 5 g were selected for this study. Cholesterol and apolipoprotein E4 （apoE4） were purchased from Sigma Company （USA）, bilobalide B was purchased from Tianjin Zhongyi Pharmaceutical Factory, batch number 20050312. METHODS： Hippocampal neurons were divided into three groups： a normal control group （routinely added media）, a model group （exposed to media containing 40 mg/L cholesterol and 30 mg/L apoE4 for 24 hours） and a bilobalide B group （exposed to media containing 160 mg/L bilobalide B for 16 hours, and then with addition of 40 mg/L cholesterol and 30 mg/L apoE4 for an additional 24 hours）. MAIN OUTCOME MEASURES： Levels of acetylcholine （ACh） and activity of acetylcholinesterase （ACHE） and choline acetyltransferase （CHAT） in hippocampal neurons were determined by microdosage hydroxylamine colorimetry, hydroxylamine colorimetry and radiological chemistry, respectively. RESULTS： The ACh level was significantly lower in the model group than that in the normal control group （P 〈 0.01）, while it was markedly higher in the bilobalide B group than in the model group （P 〈 0.05）. Activity of AChE was significantly decreased in the model group compared with the normal control group （P 〈 0.05）. However, there was no significant difference between the model group and the bilobalide B group （P 〉 0.05）. Activity of ChAT was significantly lower in the model group than in the normal control group （P 〈 0.01）, while the activity was significantly higher in the bilobalide B group than in the model group （P 〈 0.05）. CONCLUSION： Bilobalide B can enhance the ACh level of hippocampal neurons damaged by combined cholesterol and apoE4, by promoting the synthesis, but not the degradation, of ACh.展开更多
基金supported by St.Vincent’s Hospital,the Research Institute of Medical Science(Grant Number:SVHR-2021-03).
文摘Background:Apolipoprotein B mRNA editing catalytic polypeptide(APOBEC),an endogenous mutator,induces DNA damage and activates the ataxia telangiectasia and Rad3-related(ATR)-checkpoint kinase 1(Chk1)pathway.Although cisplatin-based therapy is the mainstay for muscle-invasive bladder cancer(MIBC),it has a poor survival rate.Therefore,this study aimed to evaluate the efficacy of an ATR inhibitor combined with cisplatin in the treatment of APOBEC catalytic subunit 3B(APOBEC3B)expressing MIBC.Methods:Immunohistochemical staining was performed to analyze an association between APOBEC3B and ATR in patients with MIBC.The APOBEC3B expression in MIBC cell lines was assessed using real-time polymerase chain reaction and western blot analysis.Western blot analysis was performed to confirm differences in phosphorylated Chk1(pChk1)expression according to the APOBEC3B expression.Cell viability and apoptosis analyses were performed to examine the anti-tumor activity of ATR inhibitors combined with cisplatin.Results:There was a significant association between APOBEC3B and ATR expression in the tumor tissues obtained from patients with MIBC.Cells with higher APOBEC3B expression showed higher pChk1 expression than cells expressing low APOBEC3B levels.Combination treatment of ATR inhibitor and cisplatin inhibited cell growth in MIBC cells with a higher APOBEC3B expression.Compared to cisplatin single treatment,combination treatment induced more apoptotic cell death in the cells with higher APOBEC3B expression.Conclusion:Our study shows that APOBEC3B’s higher expression status can enhance the sensitivity of MIBC to cisplatin upon ATR inhibition.This result provides new insight into appropriate patient selection for the effective application of ATR inhibitors in MIBC.
基金Supported by Zhongshan Hospital,Fudan University,Shanghai,China
文摘AIM:To prospectively investigate the association between the XbaⅠpolymorphisms of apolipoprotein B (APOB)gene and gallstone formation following gastrectomy.METHODS:The study was conducted between January 2005 and December 2006.A total of 186 gastric cancer patients who had undergone radical gastrectomy were grouped according to XbaⅠpolymorphisms of APOB gene(X+X-group,n=24 and X-X-group,n =162)and compared.The XbaⅠpolymorphisms of APOB gene were detected by polymerase chain reaction-restriction fragment length polymorphism(PCRRFLP).RESULTS:The incidence of gallstone was significantly higher in the X + X-group than in the X-X-group[54.2% vs 9.3%,RR=5.85(2.23-15.32),P<0.001].The serum levels of total cholesterol(TC)and low-density lipoprotein(LDL)were higher in the X + X-than in the X-X-group(4.02±1.12 vs 3.48±0.88,P=0.004 before surgery and 3.88±1.09 vs 3.40±0.86,P=0.008 after surgery).LDL was 2.21±0.96 vs 1.89±0.84(P =0.042)before surgery and 2.09±0.95 vs 1.72±0.85 (P=0.029)after surgery in the two groups.No relationship was found between XbaⅠpolymorphisms and gallbladder motility.CONCLUSION:In Chinese patients after radical gastrectomy,X + allele of APOB gene is another risk factor for the development of gallstone besides the gallbladder motility disorder after surgery.
基金Supported by The grant of the Romanian National Authority for Scientific Research,National Research Council-Executive Agency for Higher Education,Research,Development and Innovation Funding,No.PN-II-ID-PCE-2011-3-0591(grant awarded to Gafencu AV)the Romanian Academy,and the strategic grant financed by the European Social Found within the Sectorial Operational Program Human Resources Development 2007-2013,No.POSDRU/159/1.5/S/133391(Fenyo IM and Trusca VG)
文摘AIM: To investigate the effect of high homocysteine(Hcy) levels on apolipoprotein E(apoE) expression and the signaling pathways involved in this gene regulation.METHODS: Reverse transcriptase polymerase chain reaction(RT-PCR) and Western blot were used to assess apo E expression in cells treated with various concentrations(50-500 μmol/L) of Hcy. Calcium phosphatetransient transfections were performed in HEK-293 and RAW 264.7 cells to evaluate the effect of Hcy on apoE regulatory elements [promoter and distal multienhancer 2(ME2)]. To this aim, plasmids containing the proximal apoE promoter [(-500/+73)apoE construct] alone or in the presence of ME2 [ME2/(-500/+73)apoE construct] to drive the expression of the reporter luciferase gene were used. Co-transfection experiments were carried out to investigate the downstream effectors of Hcymediated regulation of apoE promoter by using specific inhibitors or a dominant negative form of IKβ. In other co-transfections, the luciferase reporter was under the control of synthetic promoters containing multiple specific binding sites for nuclear factor kappa B(NF-κB), activator protein-1(AP-1) or nuclear factor of activated T cells(NFAT). Chromatin immunoprecipitation(ChI P)assay was accomplished to detect the binding of NF-κB p65 subunit to the apoE promoter in HEK-293 treated with 500 μmol/L Hcy. As control, cells were incubated with similar concentration of cysteine. NF-κB p65 proteins bound to DNA were immunoprecipitated with anti-p65 antibodies and DNA was identified by PCR using primers amplifying the region-100/+4 of the apoE gene. RESULTS: RT-PCR revealed that high levels of Hcy(250-750 μmol/L) induced a 2-3 fold decrease in apoE m RNA levels in HEK-293 cells, while apo E gene expression was not significantly affected by treatment with lower concentrations of Hcy(100 μmol/L). Immunoblotting data provided additional evidence for the negative role of Hcy in apoE expression. Hcy decreased apoE promoter activity, in the presence or absence of ME2, in a dose dependent manner, in both RAW 264.7 and HEK-293 cells, as revealed by transient transfection experiments. The downstream effectors of the signaling pathways of Hcy were also investigated. The inhibitory effect of Hcy on the apo E promoter activity was counteracted by MAPK/ERK kinase 1/2(MEK1/2) inhibitor U0126, suggesting that MEK1/2 is involved in the downregulation of apoE promoter activity by Hcy. Our data demonstrated that Hcy-induced inhibition of apoE took place through activation of NF-κB. Moreover, we demonstrated that Hcy activated a synthetic promoter containing three NF-κB binding sites, but did not affect promoters containing AP-1 or NFAT binding sites. ChI P experiments revealed that NF-κB p65 subunit is recruited to the apoE promoter following Hcy treatment of cells.CONCLUSION: Hcy-induced stress negatively modulates apoE expression via MEK1/2 and NF-κB activation. The decreased apo E expression in peripheral tissues may aggravate atherosclerosis, neurodegenerative diseases and renal dysfunctions.
基金supported by the National Natural Science Foundation of China(grant Nos.30972531 and 81320108026)a project of the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘Objective We aimed to investigate the cumulative effect of high CRP level and apolipoprotein B-to-apolipoprotein A-1（ApoB/ApoA-1） ratio on the incidence of ischemic stroke（IS） or coronary heart disease（CHD） in a Mongolian population in China.Methods From June 2003 to July 2012,2589 Mongolian participants were followed up for IS and CHD events based on baseline investigation.All the participants were divided into four subgroups according to C-reactive protein（CRP） level and ApoB/ApoA-1 ratio.Cox proportional hazard models were used to estimate the hazard ratios（HRs） and 95% confidence intervals（CIs） for the IS and CHD events in all the subgroups.Results The HRs（95% CI） for IS and CHD were 1.33（0.84-2.12）,1.14（0.69-1.88）,and 1.91（1.17-3.11） in the ‘low CRP level with high ApoB/ApoA-1＇,‘high CRP level with low ApoB/ApoA-1＇,and ‘high CRP level with high ApoB/ApoA-1＇ subgroups,respectively,in comparison with the ‘low CRP level with low ApoB/ApoA-1＇ subgroup.The risks of IS and CHD events was highest in the ‘high CRP level with high ApoB/ApoA-1＇ subgroup,with statistical significance.Conclusion High CRP level with high ApoB/ApoA-1 ratio was associated with the highest risks of IS and CHD in the Mongolian population.This study suggests that the combination of high CRP and ApoB/ApoA-1 ratio may improve the assessment of future risk of developing IS and CHD in the general population.
文摘Apolipoprotein B （apoB） is the main protein component of very low density lipoprotein （VLDL） and is necessary for the assembly and secretion of these triglyceride （TG）-rich particles. Following release from the liver, VLDL is converted to low density lipoprotein （LDL） in the plasma and increased production of VLDL can therefore play a detrimental role in cardiovascular disease. Increasing evidence has helped to establish VLDL assembly as a target for the treatment of dyslipidemias. Multiple factors are involved in the folding of the apoB protein and the formation of a secretion-competent VLDL particle. Failed VLDL assembly can initiate quality control mechanisms in the hepatocyte that target apoB for degradation. ApoB is a substrate for endoplasmic reticulum associated degradation （ERAD） by the ubiquitin proteasome system and for autophagy. Efficient targeting and disposal of apoB is a regu- lated process that modulates VLDL secretion and partitioning of TG. Emerging evidence suggests that significant overlap exists between these degradative pathways. For example, the insulin-mediated targeting of apoB to autop- hagy and postprandial activation of the unfolded protein response （UPR） may employ the same cellular machinery and regulatory cues. Changes in the quality control mechanisms for apoB impact hepatic physiology and pathology states, including insulin resistance and fatty liver. Insulin signaling, lipid metabolism and the hepatic UPR may impact VLDL production, particularly during the postprandial state. In this review we summarize our current understanding of VLDL assembly, apoB degradation, quality control mechanisms and the role of these processes in liver physiology and in pathologic states.
文摘The polymorphisms of variable number of tandem repeats (VNTR) 3’to the apolipoprotein B (apo B) gene were investigated using polymerase chain reaction (PCR) in a sample of 103 patients with documented coronary heart disease (CHD) and 100 healthy individuals selected from Chinese Han nationality.Twelve segregating alleles (3’β29 -51) were observed in the pooled total of 203 subjects. The most common allele was 3’β 37. followed by 3’β39 with frequencies of 0. 362 and 0. 296, respectively. This model of allele distribution was coincident with the results form different ethnic groups, but the relative frequencies of alleles were different. In comparison with the allele frequencies between the patients and controls,alleles bigger than 3’β39 (3’VNTR-B) were significantly more common among the patients than among the controls (P<0. 001). Moreover. in the CHD group patients with plasma levels of TC≥3.88 mmol/L,LDL-C≥2. 59 mmol/L and HDL-C<l. 16mmol/L had significantly higher frequencies of 3’ VNTR-B allele (P<0. 01). Therefore,it is suggested that 3’ VNTR-B allele might be involved in the development of coronary atherosclerosis, presumably through their influences on lipid metabolism.This study supported by “8. 5” grant from Ministry of PublicHealth.
基金the Natural Science Foundation of Tianjin Educational Bureau, No.20030117
文摘BACKGROUND： Extracts of ginkgo biloba leaves have been reported to improve nerve function and activity in Alzheimer＇s disease, which is associated with reduced secretion of cholinergic neurotransmitter in hippocampal neurons. OBJECTIVE： To validate the protective effect of bilobalide B against in vitro injury of cholinergic neurons of the hippocampus induced by combined cholesterol and apoE4 DESIGN, TIME AND SETTING： This randomized, controlled animal experiment was performed in the Pathology Laboratory, Tianjin University of Traditional Chinese Medicine from July 2003 to July 2006. MATERIALS： Neonatal Wistar rats, 1-day-old, both male and female, and mean body mass of 5 g were selected for this study. Cholesterol and apolipoprotein E4 （apoE4） were purchased from Sigma Company （USA）, bilobalide B was purchased from Tianjin Zhongyi Pharmaceutical Factory, batch number 20050312. METHODS： Hippocampal neurons were divided into three groups： a normal control group （routinely added media）, a model group （exposed to media containing 40 mg/L cholesterol and 30 mg/L apoE4 for 24 hours） and a bilobalide B group （exposed to media containing 160 mg/L bilobalide B for 16 hours, and then with addition of 40 mg/L cholesterol and 30 mg/L apoE4 for an additional 24 hours）. MAIN OUTCOME MEASURES： Levels of acetylcholine （ACh） and activity of acetylcholinesterase （ACHE） and choline acetyltransferase （CHAT） in hippocampal neurons were determined by microdosage hydroxylamine colorimetry, hydroxylamine colorimetry and radiological chemistry, respectively. RESULTS： The ACh level was significantly lower in the model group than that in the normal control group （P 〈 0.01）, while it was markedly higher in the bilobalide B group than in the model group （P 〈 0.05）. Activity of AChE was significantly decreased in the model group compared with the normal control group （P 〈 0.05）. However, there was no significant difference between the model group and the bilobalide B group （P 〉 0.05）. Activity of ChAT was significantly lower in the model group than in the normal control group （P 〈 0.01）, while the activity was significantly higher in the bilobalide B group than in the model group （P 〈 0.05）. CONCLUSION： Bilobalide B can enhance the ACh level of hippocampal neurons damaged by combined cholesterol and apoE4, by promoting the synthesis, but not the degradation, of ACh.
