Impact of apolipoprotein E isoforms on sporadic Alzheimer's disease:beyond the role of amyloid beta

The impact of apolipoprotein E(ApoE)isoforms on sporadic Alzheimer's disease has long been studied;however,the influences of apolipoprotein E gene(APOE)on healthy and pathological human brains are not fully understood.ApoE exists as three common isoforms(ApoE2,ApoE3,and ApoE4),which differ in two amino acid residues.Traditionally,ApoE binds cholesterol and phospholipids and ApoE isoforms display diffe rent affinities for their receptors,lipids transport and distribution in the brain and periphery.The role of ApoE in the human depends on ApoE isoforms,brain regions,aging,and neural injury.APOE E4 is the strongest genetic risk factor for sporadic Alzheimer's disease,considering its role in influencing amyloid-beta metabolism.The exact mechanisms by which APOE gene variants may increase or decrease Alzheimer's disease risk are not fully understood,but APOE was also known to affect directly and indirectly tau-mediated neurodegeneration,lipids metabolism,neurovascular unit,and microglial function.Consistent with the biological function of ApoE,ApoE4 isoform significantly alte red signaling pathways associated with cholesterol homeostasis,transport,and myelination.Also,the rare protective APOE variants confirm that ApoE plays an important role in Alzheimer's disease pathogenesis.The objectives of the present mini-review were to describe classical and new roles of various ApoE isoforms in Alzheimer's disease pathophysiology beyond the deposition of amyloid-beta and to establish a functional link between APOE,brain function,and memory,from a molecular to a clinical level.APOE genotype also exerted a heterogeneous effect on clinical Alzheimer's disease phenotype and its outcomes.Not only in learning and memory but also in neuro psychiatric symptoms that occur in a premorbid condition.Cla rifying the relationships between Alzheimer's disease-related pathology with neuropsychiatric symptoms,particularly suicidal ideation in Alzheimer's disease patients,may be useful for elucidating also the underlying pathophysiological process and its prognosis.Also,the effects of anti-amyloid-beta drugs,recently approved for the treatment of Alzheimer's disease,could be influenced by the APOE genotype.

New insights into ATR inhibition in muscle invasive bladder cancer:The role of apolipoprotein B mRNA editing catalytic subunit 3B

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.

Hepatocyte growth factor enhances the ability of dental pulp stem cells to ameliorate atherosclerosis in apolipoprotein E-knockout mice

BACKGROUND Atherosclerosis(AS),a chronic inflammatory disease of blood vessels,is a major contributor to cardiovascular disease.Dental pulp stem cells(DPSCs)are capable of exerting immunomodulatory and anti-inflammatory effects by secreting cytokines and exosomes and are widely used to treat autoimmune and inflam-mation-related diseases.Hepatocyte growth factor(HGF)is a pleiotropic cytokine that plays a key role in many inflammatory and autoimmune diseases.AIM To modify DPSCs with HGF(DPSC-HGF)and evaluate the therapeutic effect of DPSC-HGF on AS using an apolipoprotein E-knockout(ApoE-/-)mouse model and an in vitro cellular model.METHODS ApoE-/-mice were fed with a high-fat diet(HFD)for 12 wk and injected with DPSC-HGF or Ad-Null modified DPSCs(DPSC-Null)through tail vein at weeks 4,7,and 11,respectively,and the therapeutic efficacy and mechanisms were analyzed by histopathology,flow cytometry,lipid and glucose measurements,real-time reverse transcription polymerase chain reaction(RT-PCR),and enzyme-linked immunosorbent assay at the different time points of the experiment.An in vitro inflammatory cell model was established by using RAW264.7 cells and human aortic endothelial cells(HAOECs),and indirect co-cultured with supernatant of DPSC-Null(DPSC-Null-CM)or DPSC-HGF-CM,and the effect and mechanisms were analyzed by flow cytometry,RT-PCR and western blot.Nuclear factor-κB(NF-κB)activators and inhibitors were also used to validate the related signaling pathways.RESULTS DPSC-Null and DPSC-HGF treatments decreased the area of atherosclerotic plaques and reduced the expression of inflammatory factors,and the percentage of macrophages in the aorta,and DPSC-HGF treatment had more pronounced effects.DPSCs treatment had no effect on serum lipoprotein levels.The FACS results showed that DPSCs treatment reduced the percentages of monocytes,neutrophils,and M1 macrophages in the peripheral blood and spleen.DPSC-Null-CM and DPSC-HGF-CM reduced adhesion molecule expression in tumor necrosis factor-αstimulated HAOECs and regulated M1 polarization and inflammatory factor expression in lipopolysaccharide-induced RAW264.7 cells by inhibiting the NF-κB signaling pathway.CONCLUSION This study suggested that DPSC-HGF could more effectively ameliorate AS in ApoE-/-mice on a HFD,and could be of greater value in stem cell-based treatments for AS.

C-reactive Protein Level,Apolipoprotein B-to-apolipoprotein A-1 Ratio,and Risks of Ischemic Stroke and Coronary Heart Disease among Inner Mongolians in China

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.

XbaⅠpolymorphisms of apolipoprotein B gene:Another risk factor of gallstone formation after radical gastrectomy

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.

Apolipoprotein C3(-455T>C) polymorphism confers susceptibility to nonalcoholic fatty liver disease in the Southern Han Chinese population

AIM:To investigate the relationship between Apolipoprotein C3(APOC3)(-455T>C) polymorphism and nonalcoholic fatty liver disease(NAFLD) in the Southern Chinese han population.METHODS:In this prospective case-control study,we recruited 300 NAFLD patients and 300 healthy controls to a cohort representing Southern Chinese han population at The First Affiliated Hospital,Sun Yat-sen University,from January to December 2012. Polymerase chain reaction-restriction fragment length polymorphism and DNA sequencing were used to genotype the APOC3(-455T>C) variants.RESULTS:After adjusting for age,gender,and bodymass index,TC and CC genotypes were found to increase the susceptibility to NAFLD compared to the TT genotype,with adjusted odds ratios(ORs) of 1.77(95%CI:1.16-2.72) and 2.80(95%CI:1.64-4.79),respectively. Further stratification analysis indicated that carriers of the CC genotype was more susceptible to insulin resistance(IR) than those of the TT genotype,with an OR of 3.24(95%CI:1.52-6.92). The CC genotype also was associated with a significantly higher risk of hypertension,hypertriglyceridemia,and low levels of high-density lipoprotein cholesterol(hDL)(P < 0.05). No association was found between the APOC3(-455T>C) polymorphism and obesity,impaired glucose tolerance,hyperuricemia,hypercholesterolemia,or high levels of low-density lipoprotein cholesterol(LDL)(P > 0.05).CONCLUSION:APOC3(-455T>C) genetic variation is involved in the susceptibility to developing NAFLD,IR,hypertension,hypertriglyceridemia,and low hDL in the Southern Chinese han population.

Autoantibodies to apolipoprotein A-1 as a biomarker of cardiovascular autoimmunity

Immune-driven inflammation plays an important part inatherogenesis and is therefore believed to be key to thedevelopment of cardiovascular disease(CVD), whichis currently the leading cause of death in the Westernworld. By fulfilling some of the Koch postulates, athero-genesis has even been proposed to be considered as anautoimmune disease, raising the hope that CVD couldbe prevented by immunomodulation. Nevertheless,the role of the immune system and autoimmune reac-tions in atherosclerosis appear to be a double edged-sword, with both pro-atherogenic and anti-atherogenicattributes. Hence, if immunomodulation is to becomea therapeutic option for atherosclerosis and CVD, it willbe crucial to correctly identify patients who might ben-efit from targeted suppression of deleterious autoim-mune responses. This could be achieved, for example, by the detection of disease-associated autoantibodies. In this work, we will review the currently available clini-cal, in vitro, and animal studies dedicated to autoan-tibodies against apolipoprotein A-1(anti-apoA-1 IgG), the major proteic fraction of high density lipoprotein. Current clinical studies indicate that high levels of anti-apoA-1 IgG are associated with a worse cardiovascular prognosis. In addition, in vitro and animal studies indi-cate a pro-inflammatory and pro-atherogenic role, sup-porting the hypothesis that these autoantibodies may play a direct causal role in CVD, and furthermore that they could potentially represent a therapeutic target for CVD in the future.

High levels of homocysteine downregulate apolipoprotein E expression via nuclear factor kappa B

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.

Genetic association of apolipoprotein E polymorphisms with inflammatory bowel disease

AIM:To study the association of apolipoprotein E(APOE) polymorphisms with the susceptibility ofinflammatory bowel disease(IBD) in Saudi patients.METHODS:APOE genotyping was performed to evaluate the allele and genotype frequencies in 378 Saudi subjects including IBD patients with ulcerative colitis(n = 84) or Crohn's disease(n = 94) and matched controls(n = 200) using polymerase chain reaction and reverse-hybridization techniques.RESULTS:The frequencies of the APOE ε2 allele and ε2/ε3 and ε2/ε4 genotypes were significantly higher in IBD patients than in controls(P < 0.05),suggesting that the ε2 allele and its heterozygous genotypes may increase the susceptibility to IBD.On the contrary,the frequencies of the ε3 allele and ε3/ε3 genotype were lower in IBD patients as compared to controls,suggesting a protective effect of APOE ε3 for IBD.The prevalence of the ε4 allele was also higher in the patient group compared to controls,suggesting that the ε4 allele may also increase the risk of IBD.Our results also indicated that the APOE ε4 allele was associated with an early age of IBD onset.No effect of gender or type of IBD(familial or sporadic) on the frequency distribution of APOE alleles and genotypes was noticed in this study.CONCLUSION:APOE polymorphism is associated with risk of developing IBD and early age of onset in Saudi patients,though further studies with a large-size population are warranted.

Apolipoprotein E Gene Polymorphisms Are Risk Factors for Spontaneous Intracerebral Hemorrhage:A Systematic Review and Meta-analysis

Intracerebral hemorrhage(ICH)is a serious clinical disease with high morbidity,whose pathogenesis might be related to apolipoprotein E(APOE)gene polymorphisms.To comprehensively evaluate the risk factors for ICH occurrence,we performed a meta-analysis.We searched online databases to identify eligible studies based on the relationship between APOE genetic polymorphisms and ICH occurrence risk.Specific and pooled odds ratios(ORs)were calculated and by assessing small study bias,we drew the relationship between APOE polymorphisms and ICH risk.We included 15 eligible studies in our study containing a total of 1642 ICH samples and 5545 normal controls.The comparison of e4 andε3 APOE genotypes revealed that specific and pooled ORs showed a significantly increased odds ratio in ICH patients with theε4 genotype,indicating thatε4 gene is a risk factor for ICH occurrence,and the heterogeneity is acceptable.Similarly,it was found that theε2 genotype also contributed to the incidence rate of ICH.However,after the subgroup analysis by ethnicity,this APOE genetic polymorphism acted as a harmful factor only in white populations,but did not show an effect in Asian populations.It was suggested that both 82 andε4 APOE alleles were risk factors for ICH in general.They were risk factors in white populations only,neither had a detectable effect in Asian populations after subgroup analysing by ethnicity.

Lack of association between apolipoprotein C3 gene polymorphisms and risk of nonalcoholic fatty liver disease in a Chinese Han population

AIM: To investigate the association between two polymorphisms of apolipoprotein C3 (APOC3) and risk of nonalcoholic fatty liver disease (NAFLD) in a Chinese Han population.

Apolipoprotein B100 quality control and the regulation of hepatic very low density lipoprotein secretion

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.

THE ASSOCIATION OF POLYMORPHISMS AT A VNTR LOCUS 3’TO THE APOLIPOPROTEIN B GENE WITH CORONARY HEART DISEASE IN CHINESE POPULATION

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.

Polymorphism of Apolipoprotein A5 is a Risk Factor for Cerebral Infarction in Type 2 Diabetes

This study investigated the association of apolipoprotein A5 （apoA5） gene polymorphism at position -1131T〉C with cerebral infarction in patients with type 2 diabetes. A total of 256 type 2 diabetic patients without cerebral infarction （T2DM）, 220 type 2 diabetic patients with cerebral infarction （T2DMCI） and 340 healthy subjects were recruited from the same region （Hubei province, China）. The genotype of apoA5 -1131T〉C was analyzed by polymerase chain reaction, followed by restriction fragment length polymorphism （PCR-RFLP）. Total cholesterol, HDL cholesterol, LDL-cholesterol and triglycerides were quantitatively detected by using standard enzymatic tech- niques. The results showed that the prevalence of the apoA5 -1131C allele was significantly higher in T2DMCI group than that in control group （42.7% versus 31.2%, P〈0.01）. The carriers of rare C allele had higher TG levels as compared with carriers of common allele in the three groups （P〈0.01）. Logistic regression models, which were adjusted for age, gender, blood pressure, BMI, FBS, smoking, LDL-C and HDL-C, revealed that patients carrying the apoA5 -1131C allele and CC homozygotes were at high risk for T2DMCI. It was concluded that the apoA5 -1131C allele variant is an independent genetic risk factor for T2DMCI.

27-Hydroxycholesterol/liver X receptor/apolipoprotein E mediates zearalenone-induced intestinal immunosuppression:A key target potentially linking zearalenone and cancer

Zearalenone(ZEN)is a mycotoxin that extensively contaminates food and feed,posing a significant threat to public health.However,the mechanisms behind ZEN-induced intestinal immunotoxicity remain unclear.In this study,Sprague-Dawley(SD)rats were exposed to ZEN at a dosage of 5 mg/kg/day b.w.for a duration of 14 days.The results demonstrated that ZEN exposure led to notable pathological alterations and immunosuppression within the intestine.Furthermore,ZEN exposure caused a significant reduction in the levels of apolipoprotein E(ApoE)and liver X receptor(LXR)(P<0.05).Conversely,it upregulated the levels of myeloid-derived suppressor cells(MDSCs)markers(P<0.05)and decreased the presence of 27-hydroxycholesterol(27-HC)in the intestine(P<0.05).It was observed that ApoE or LXR agonists were able to mitigate the immunosuppressive effects induced by ZEN.Additionally,a bioinformatics analysis highlighted that the downregulation of ApoE might elevate the susceptibility to colorectal,breast,and lung cancers.These findings underscore the crucial role of the 27-HC/LXR/ApoE axis disruption in ZEN-induced MDSCs proliferation and subsequent inhibition of T lymphocyte activation within the rat intestine.Notably,ApoE may emerge as a pivotal target linking ZEN exposure to cancer development.

Apolipoprotein B/Apolipoprotein A1 ratio is associated with sex hormone binding globulin and may be an indicator of metabolic syndrome in PCOS women

Objective To identify significant factors related to the apolipoprotein B/apolipoprotein A1 （apoB/A1） ratio and investigate the association between the apoB/A1 ratio and metabolic syndrome （MS） in polycystic ovary syndrome （PCOS） women. Methods Totally 307 subjects with PCOS were collected and recruited fulfilling the revised 2003 Rotterdam diagnostic criteria. MS was diagnosed by the National Cholesterol Education Program-Adult treatment Panel （NCEP-ATP） III criteria. Results The prevalence of MS in PCOS women was 31.6%, whose average age was 26.2 ___＋ 5.2 years. The apoB/A1 ratio was significantly correlated with age, body mass index （BM1）, waist circumference （WC）, hip circumference, waist-to-hip ratio, blood pressure, metabolic abnormalities, sex hormone binding globulin （SHBG）, and free androgen index. In addition, SHBG had a significant association with all five component risk of MS. The increasing apoB/A1 ratio was associated with the prevalence of MS and was one of the risk factors of MS. Conclusion SHBG was considered as an additional potential factor in predicting the metabolic abnormity in PCOS women. The apoB/A1 ratio is associated with SHBG and might be an indicator of MS in PCOS women.

Effect of bilobalide B on cholinergic hippocampal neurons exposed to cholesterol and apolipoprotein E4

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.

Role of apolipoproteins,ABCA1 and LCAT in the biogenesis of normal and aberrant high density lipoproteins

In this review, we focus on the pathway of biogenesis of HDL, the essential role of apoA-I, ATP binding cassette transporter A1（ABCA1）, and lecithin： cholesterol acyltransferase（LCAT） in the formation of plasma HDL; the generation of aberrant forms of HDL containing mutant apoA-I forms and the role of apoA-IV and apoE in the formation of distinct HDL subpopulations. The biogenesis of HDL requires functional interactions of the ABCA1 with apoA-I（and to a lesser extent with apoE and apoA-IV） and subsequent interactions of the nascent HDL species thus formed with LCAT. Mutations in apoA-I, ABCA1 and LCAT either prevent or impair the formation of HDL and may also affect the functionality of the HDL species formed. Emphasis is placed on three categories of apoA-I mutations. The first category describes a unique bio-engineered apoA-I mutation that disrupts interactions between apoA-I and ABCA1 and generates aberrant prep HDL subpopulations that cannot be converted efficiently to a subpopulations by LCAT. The second category describes natural and bio-engineered apoA-I mutations that generate preβ and small size a4 HDL subpopulations, and are associated with low plasma HDL levels. These phenotypes can be corrected by excess LCAT. The third category describes bio-engineered apoA-I mutations that induce hypertriglyceridemia that can be corrected by excess lipoprotein lipase and also have defective maturation of HDL.The HDL phenotypes described here may serve in the future for diagnosis, prognoses and potential treatment of abnormalities that affect the biogenesis and functionality of HDL.

Pleiotropic effects of apolipoprotein A-Ⅱ on high-density lipoprotein functionality, adipose tissue metabolic activity and plasma glucose homeostasis

Apolipoprotein A-Ⅱ(APOA-Ⅱ) is the second most abundant apolipoprotein of high-density lipoprotein(HDL)synthesized mainly by the liver and to a much lesser extent by the intestine. Transgenic mice overexpressing human APOA-Ⅱ present abnormal lipoprotein composition and are prone to atherosclerosis, though in humans the role for APOA-Ⅱ in coronary heart disease remains controversial. Here, we investigated the effects of overexpressed APOA-Ⅱ on HDL structure and function, adipose tissue metabolic activity, glucose tolerance and insulin sensitivity. C57BL/6 mice were infected with an adenovirus expressing human APOA-Ⅱ or a control adenovirus Ad GFP, and five days post-infection blood and tissue samples were isolated. APOA-Ⅱ expression resulted in distinct changes in HDL apoproteome that correlated with increased antioxidant and anti-inflammatory activities. No effects on cholesterol efflux from RAW 264.7 macrophages were observed. Molecular analyses in white adipose tissue(WAT) indicated a stimulation of oxidative phosphorylation coupled with respiration for ATP production in mice overexpressing APOA-Ⅱ. Finally, overexpressed APOA-Ⅱ improved glucose tolerance of mice but had no effect on the response to exogenously administered insulin. In summary, expression of APOA-Ⅱ in C57BL/6 mice results in pleiotropic effects with respect to HDL functionality, adipose tissue metabolism and glucose utilization, many of which are beneficial to health.

Apolipoprotein E gene polymorphism in cerebrovascular diseases of the Chinese Naxi populations from Yunnan province

Currently it is not well known whether apolipoprotein E （ApoE） is a genetic susceptibility factor for cerebrovascular diseases in the Chinese Naxi population. The present study detected and sequenced ApoE polymorphisms of 90 patients with cerebrovascular diseases （58 cases of cerebral infarction and 32 cases of intracerebral hemorrhage）, and 50 normal people of Naxi nationality from Yunnan province, China. The populations were used to analyze the relationship of ApoE polymorphisms with cerebral infarction and intracerebral hemorrhage. Results showed an association between ApoE gene polymorphism and the onset of cerebral infarction, and a possibility that the ε4 allele is a susceptibility locus for the risk of cerebral infarction. However, there was no evidence of a relationship between the ApoE gene polymorphism and cerebral hemorrhage.