Plasma metabolite profiles of Alzheimer's disease and mild cognitive impairment.

Previous studies have demonstrated altered metabolites in samples of Alzheimer's disease (AD) patients. However, the sample size from many of them is relatively small and the metabolites are relatively limited. Here we applied a comprehensive platform using ultraperformance liquid chromatography-time-of-flight mass spectrometry and gas chromatography-time-of-flight mass spectrometry to analyze plasma samples from AD patients, amnestic mild cognitive impairment (aMCI) patients, and normal controls. A biomarker panel consisting of six plasma metabolites (arachidonic acid, N,N-dimethylglycine, thymine, glutamine, glutamic acid, and cytidine) was identified to discriminate AD patients from normal control. Another panel of five plasma metabolites (thymine, arachidonic acid, 2-aminoadipic acid, N,N-dimethylglycine, and 5,8-tetradecadienoic acid) was able to differentiate aMCI patients from control subjects. Both biomarker panels had good agreements with clinical diagnosis. The 2 panels of metabolite markers were all involved in fatty acid metabolism, one-carbon metabolism, amino acid metabolism, and nucleic acid metabolism. Additionally, no altered metabolites were found among the patients at different stages, as well as among those on anticholinesterase medication and those without anticholinesterase medication. These findings provide a comprehensive global plasma metabolite profiling and may contribute to making early diagnosis as well as understanding the pathogenic mechanism of AD and aMCI.

Validation of the Chinese version of Addenbrooke's cognitive examination-revised for screening mild Alzheimer's disease and mild cognitive impairment.

BACKGROUND/AIMS: As a suitable test to screen for Alzheimer's disease (AD) or mild cognitive impairment (MCI), studies to validate the Chinese version of Addenbrooke's Cognitive Examination-Revised (ACE-R) are rare. METHODS: A total of 151 subjects were recruited and the neuropsychological assessments were employed. One-way analysis of variance and Bonferroni correction were used to compare scores of different psychometric scales. Intraclass correlation coefficient (ICC) and Cronbach's coefficient α were used to evaluate the reliability of psychometric scales. The validity of ACE-R to screen for mild AD and amnestic subtype of MCI (a-MCI) was assessed by receiver operating characteristic (ROC) curves. RESULTS: The Chinese ACE-R had good reliability (inter-rater ICC = 0.994; test-retest ICC = 0.967) as well as reliable internal consistency (Cronbach's coefficient α = 0.859). With its cutoff of 67/68, the sensitivity (0.920) and specificity (0.857) were lower than for the Mini-Mental State Examination (MMSE) cutoff (sensitivity 1.000 and specificity 0.937) to screen for mild AD. However, the sensitivity of ACE-R to screen for a-MCI was superior to the MMSE with a cutoff of 85/86. The specificity of ACE-R was lower than that of the MMSE to screen for a-MCI. The area under the ROC curve of ACE-R was much larger than that of the MMSE (0.836 and 0.751) for detecting a-MCI rather than mild AD. CONCLUSION: The Chinese ACE-R is a reliable assessment tool for cognitive impairment. It is more sensitive and accurate in screening for a-MCI rather than for AD compared to the MMSE.

A complex association of ABCA7 genotypes with sporadic Alzheimer disease in Chinese Han population.

PURPOSE: Recently, a large genome-wide association study has revealed that polymorphism of alleles and genotypes in rs3,764,650 within ABCA7 gene is associated with Alzheimer disease in whites. We conducted a case-control study to investigate whether these susceptible genetic variants are risk factors for sporadic Alzheimer disease (SAD) in Chinese Han population. DESIGN AND METHODS: A total of 633 participants consisting of 350 SAD and 283 nondemented elderly controls matched for sex and age were recruited and genetic variants in ABCA7 (rs3,764,650) were genotyped using DNA sequencing. RESULTS: On the basis of allele and genotype frequencies in both groups, we found a significant association (P=0.004) between ABCA7 genotypes and SAD in Chinese Han population, and the results were influenced by age and ApoEε4 status. ApoEε4-carrier and aging are linked to enhancing ABCA7 risk-associated SAD. However, the prevalence of the minor allele G in rs3,764,650 within ABCA7 showed no significant difference between the 2 groups in this study. CONCLUSIONS: ABCA7 (rs3,764,650) was associated with SAD in the Chinese population, with both ApoEε4-carrier and aging being factors enhancing its risk.

Altered immune pathways in patients of temporal lobe epilepsy with and without hippocampal sclerosis.

Over the past decades, the immune responses have been suspected of participating in the mechanisms for epilepsy. To assess the immune related pathway in temporal lobe epilepsy (TLE), we explored the altered immune pathways in TLE patients with and without hippocampal sclerosis (HS). We analyzed RNA-seq data from 3 TLE-HS and 3 TLE-nonHS patients, including identification of differentially expressed RNA, function pathway enrichment, the protein-protein interaction network and construction of ceRNA regulatory network. We illustrated the immune related landscape of molecules and pathways on human TLE-HS. Also, we identified several differential immune related genes like HSP90AA1 and SOD1 in TLE-HS patients. Further ceRNA regulatory network analysis found SOX2-OT connected to miR-671-5p and upregulated the target gene SPP1 in TLE-HS patients. Also, we identified both SOX2-OT and SPP1 were significantly upregulated in five different databases including TLE-HS patients and animal models. Our findings established the first immune related genes and possible regulatory pathways in TLE-HS patients and animal models, which provided a novel insight into disease pathogenesis in both patients and animal models. The immune related SOX2-OT/miR-671-5p/SPP1 axis may be the potential therapeutic target for TLE-HS.

Combined exposure to multiple air pollutants and incident ischemic heart disease in individuals with and without type 2 diabetes: A cohort study from the UK Biobank.

BACKGROUND: Air pollution and type 2 diabetes (T2D) are both associated with an increased risk of ischemic heart disease (IHD). Little is known about the combined effects of multiple air pollutants on IHD risk, especially among individuals with T2D. We sought to assess the association of combined exposure to multiple air pollutants with incident IHD and examine the modification effect of T2D. METHODS: This study included 388780 individuals (20036 individuals with T2D) free of cardiovascular disease and cancer from the UK Biobank. The combined exposure to multiple air pollutants, including particulate matter (PM) with diameters ≤ 2.5 µm (PM2.5), PM with diameters between 2.5 and 10 µm (PMcoarse), PM with diameters ≤ 10 µm (PM10), nitrogen dioxide (NO2), and nitrogen dioxides (NOx), was assessed by creating a weighted air pollution score (APS), with a higher APS representing a higher level of air pollution exposure. Hazard ratios (HR) and 95 % confidence intervals (CI) for incident IHD were assessed by multivariable-adjusted Cox proportional hazard models. RESULTS: During a median of 12.9 years of follow-up, 27333 incident IHD cases were observed. Compared with the lowest tertile of the APS, the multivariable-adjusted HR (95 % CI) of IHD risk for the highest tertile was 1.13 (1.03-1.23) among individuals with T2D, while the HR was 1.06 (1.03-1.10) among individuals without T2D. Additionally, the associations between APS and IHD incidence showed a linear relationship among individuals with T2D (nonlinearity: P = 0.37), whereas a non-linear relationship was observed among individuals without T2D (nonlinearity: P = 0.02). For the joint analysis, individuals in the highest tertile of APS and with T2D had a 54 % higher risk of IHD compared to individuals in the lowest tertile of APS and without T2D, with a significant additive interaction (Pinteraction < 0.01). The proportion of relative excess risk was 17 % due to the interaction in categorical analyses. CONCLUSIONS: The combined exposure to multiple air pollutants has been associated with an elevated risk of incident IHD, and the association is more pronounced among individuals with T2D.

The prevalence of CD33 and MS4A6A variant in Chinese Han population with Alzheimer's disease.

CD33 and MS4A6A genes play potential key roles in the pathogenesis of Alzheimer's disease (AD). One recent genome-wide association study has revealed that the rs3865444 polymorphism in the CD33 gene and rs610932 polymorphism in the MS4A6A gene are associated with susceptibility to AD in Caucasians. To evaluate the relationship between the polymorphism of the CD33, MS4A6A gene and AD in the ethnic Chinese Han, we conducted a case-control study (n = 383, age > 54) to determine the prevalence of single-nucleotide polymorphism of two genes in patients with AD in Chinese population of Mainland, and clarified whether these polymorphisms are risk factors for AD. The prevalence of the allele (T) in the rs3865444 polymorphism of the CD33 gene and allele (C) in rs610932 polymorphism of the MS4A6A gene was significantly different in AD patients and control subjects (P < 0.001, respectively), and the results were not influenced by age, gender, or APOE status. Our data revealed the allele (T) of the rs3865444 polymorphism of the CD33 gene and the allele (C) of the rs610932 polymorphism of the MS4A6A gene may contribute to AD risk in the Chinese Han population.

Association study of the GAB2 gene with the risk of Alzheimer disease in the chinese population.

PURPOSE: To assess genetic variations of GAB2 as a risk factor for developing Alzheimer disease (AD). DESIGN AND METHODS: A case-control study (n=310; age>50 y) was conducted to determine the prevalence of 5 single nucleotide polymorphisms (SNPs) of GAB2 (rs2373115, rs1385600, rs4945261, rs7101429, and rs7115850) in patients with AD in Chinese population of mainland China, and was investigated whether these polymorphisms are risk factors for AD. RESULTS: Our results supported a possible implication of 3 tested SNPs of GAB2 (rs4945261, rs7101429, and rs7115850) in AD in the ethnic Chinese Han, of which the maximal significance of association was at SNP rs7101429 C allele (P=4.0×10; odds ratio=2.0; 95% confidence interval, 1.4-2.8), and this observed association was not affected by APOEε4 genotype. In the haplotypes analysis, the minor alleles of the 3 tested SNPs were composed of a TCG haplotype, which had a significant difference in haplotype distribution between the 2 groups (P=3.4×10; odds ratio=8.32; 95% confidence interval, 4.57-15.14). CONCLUSIONS: Our findings implicate an association between genetic variations of GAB2 and AD in Han Chinese, and the minor alleles of the 3 tested SNPs (rs4945261, rs7101429, and rs7115850) might increase the risk of AD.

Transthyretin-related hereditary amyloidosis in a Chinese family with TTR Y114C mutation.

BACKGROUND: Transthyretin-related hereditary amyloidosis is an autosomal dominant inherited disease caused by mutations in the transthyretin (TTR) gene. Corresponding to the various transthyretin gene mutations and a wide range of geographical distribution, transthyretin-related hereditary amyloidosis presents diverse characteristics in genotype-phenotype correlation. OBJECTIVE/METHOD: Here, we identify the clinical characteristics of a Chinese family affected by transthyretin-related hereditary amyloidosis with TTR Tyr114Cys mutation. RESULTS/CONCLUSION: The pathogenic mechanism studies showed that the protein encoded by TTR Tyr114Cys is more easily depolymerized to form amyloid fibrils. Moreover, the cytotoxicity of the TTR Tyr114Cys may be attributed to its ability to persistently activate the extracellular-signal-regulated kinase 1/2 pathway.

Economic impact of dementia in developing countries: an evaluation of Alzheimer-type dementia in Shanghai, China.

The main objective of this study was to assess the economic cost of Alzheimer's disease (AD) in Shanghai, China, as a pilot study for future evaluations. Sixty-seven patients with AD were interviewed, and the information of the AD-related cost and resources used was collected from October 2005 to September 2006. By retrospective analysis, annual costs were calculated and expressed in Chinese renminbi (RMB). Direct cost per patient per year averaged approximately 8,432 RMB (1,058 USD), indirect cost per patient per year was 10,568 RMB (1,326 USD), and annual costs were 19,001 RMB (2,384 USD) per patient per year in this investigation. Total cost was significantly associated with the degree of severity including cognitive function (MMSE) and activity of daily living (ADL). With the increase in the number of persons at risk for developing AD, the economic burden of AD patients in China is significantly heavy.

The metric properties of Zarit caregiver burden scale: validation study of a Chinese version.

PURPOSE: To evaluate the Chinese version of the Zarit Burden Interview (ZBI) as an instrument for measuring strain in Chinese caregivers of elderly people with dementia. DESIGN AND METHODS: The objective of the present study was to carry out a metric analysis of a Chinese version of ZBI using a cross-sectional study. Patients and their caregivers completed a variety of questionnaires, including the Mini-Mental State Examination (MMSE), the Neuropsychiatric Inventory (NPI), the Geriatric Depression Scale (GDS), and the Hamilton Anxiety Scale (HAMA). Cronbach alpha coefficient was used to assess inter-item consistency, and a split half correlation coefficient was used to determine the internal consistency of the ZBI. Correlations between the ZBI and GDS, and the ZBI and HAMA were assessed for convergent validity. Correlations of the ZBI and MMSE, the ZBI and NPI were also calculated to evaluate the possible correlation of caregiver burden with the severity of cognitive impairment and neuropsychiatric symptoms. RESULTS: There were 42 patients with dementia in the study. The intraclass correlation coefficient was 0.89 and the split half correlation coefficient was 0.87. The mean ZBI score was 24.40+/-14.68. Item-total (corrected) correlation showed significant coefficients (rs>0.33, P<0.05) for most items. There was a significant correlation between the ZBI and GDS (rs=0.57, P<0.001), and between the ZBI and HAMA (rs=0.44, P=0.003). Furthermore, there was a significant positive correlation between the ZBI and NPI, the ZBI and the agitation score, the ZBI and the apathy score, and the ZBI and MMSE. CONCLUSIONS: The Chinese version of ZBI meets some of the basic reliability and validity standards required for health status measures. Further studies could lead to a better understanding of the difficulties experienced by caregivers of patients suffering from dementia in China.

Verapamil suppresses cardiac alternans and ventricular arrhythmias in acute myocardial ischemia via ryanodine receptor inhibition.

T-wave alternans (TWA) is a potent arrhythmia substrate under the conditions of acute myocardial ischemia. Abnormal intracellular calcium cycling contributes to the genesis of cardiac alternans. Ryanodine receptor (RyR) is a pivotal Ca2+ cycling protein central to Ca2+ signaling in the heart. Here, we investigated the potential role of RyR in cardiac alternans and ventricular arrhythmias in acute myocardial ischemia. Transmembrane action potentials were simultaneously recorded from epicardium and endocardium together with a transmural ECG and isometric contraction force in the arterially perfused left ventricular wedge preparations. Calcium alternans were induced by incremental frequency of field stimulation in rat ventricular myocytes. TWA, mechanical alternans and ventricular arrhythmias were reproducibly induced by rapid pacing in the acute ischemic wedge preparations. Compared with control group, calcium alternans ratio and spontaneous calcium release were increased in acute ischemic myocytes. Verapamil, a phenylalkylamine calcium channel blocker, can successfully abolish spontaneous calcium release, TWA, and ventricular arrhythmias. The inhibition effect of verapamil could be diminished by low concentration of ryanodine (10 nmol/L). However, nifedipine, a dihydropyridine calcium channel blocker, could not block TWA or arrhythmias. Moreover, verapamil, but not nifedipine, significantly decreased ROS production in ischemic myocytes. Collectively, our results indicate that verapamil can significantly inhibit the development of cardiac alternans and ventricular arrhythmias in acute myocardial ischemia, and the mechanism was related to the inhibition of RyR and the protective function to oxidative stress.

Interictal epileptiform discharges were associated with poorer cognitive performance in adult epileptic patients.

OBJECTIVE: Cognitive impairment is one of the major consequences of epilepsy and has been shown to reduce quality of life. Interictal epileptiform discharges (IEDs) were associated with poorer cognitive performance in children, and the aim of this study was to determine whether there was a similar association in adults. METHODS: A prospective cohort of 167 seizure-free adult patients underwent EEG recording and extensive cognitive evaluations. Global cognition was evaluated using Addenbrooke's Cognitive Examination-Revised (ACE-R), while sub-dimensions of cognition were evaluated using the Auditory Verbal Learning Test (AVLT), Trial Making Test (TMT)-A and -B, and the 5 constitutive subscales of ACE-R. RESULTS: Performance in ACER, but not AVLT or TMT, was significantly lower in patients with general IEDs. Furthermore, the five subscale scores of ACE-R were significantly lower in patients with general IEDs, and verbal fluency and language scores contributed in a major way to the low scores. Stratified analysis showed that sleep-phase IEDs were also associated with lower performance in ACE-R and its subscales. Finally, non-rapid eye movement (NREM)-IEDs were found to be associated with visuospatial and memory impairment, and IEDs while awake, with poorer performance in TMT-B. SIGNIFICANCE: The results of this study demonstrate that cognitive performance is associated with IEDs in adult epilepsy patients, and could serve as a springboard for further research into reducing IEDs to bring about better cognitive performance.

The association between two single nucleotide polymorphisms within the insulin-degrading enzyme gene and Alzheimer's disease in a Chinese Han population.

Several previous studies on the relationship between the insulin-degrading enzyme (IDE) gene and Alzheimer's disease (AD) have connected certain genetic variants to late-onset AD, in the absence of the apolipoprotein E (APOE)ε4 allele. However, the conclusions of these studies remain controversial. We investigated the association between two polymorphisms of IDE with AD in the Chinese population and found that the T/A genotype of rs4646958 had an important role in AD (adjusted p=0.007, odds ratio [OR]=2.796, 95% confidence interval [CI]=1.330-5.878), under the co-dominant genetic model. The T/C genotype of rs1887922 was also significantly associated with AD compared to the T/T genotype (adjusted p=0.003, OR=2.644, 95% CI=1.407-4.970). The C allele of rs1887922 conferred a higher risk of AD under the dominant genetics model (adjusted p=0.001, OR=2.719, 95% CI=1.472-5.022). Compared with the two other variant genotypes, the T/T genotype showed a protective effect in both polymorphisms (adjusted p=0.007, OR=0. 358, 95% CI=0.170-0.752 for rs4646958; adjusted p=0.001, OR=0. 368, 95% CI=0.199-0.679 in rs1887922). In the context of APOEε4-negative status, both variants were significantly associated with AD in some genetic models.

A single nucleotide polymorphism in LRP2 is associated with susceptibility to Alzheimer's disease in the Chinese population.

BACKGROUND: LRP2 (also called megalin) plays a potential key role in the pathogenesis of Alzheimer's disease (AD). Recently, one genome-wide association study has revealed that the rs3755166 (G/A) polymorphism located in the LRP2 promoter is associated with development of AD in Caucasians, while there are no studies on the association LRP2 of with AD risk in Asians. METHODS: To evaluate the relationship between the rs3755166 polymorphism of the LRP2 gene and AD in the ethnic Chinese Han, we conducted a case-control study (n=361, age>50) to determine the prevalence of one common single-nucleotide polymorphism (SNP) of LRP2 (rs3755166) in patients with AD in Chinese population of Mainland China, and clarified whether this polymorphism is a risk factor for AD. RESULTS: The prevalence of the minor allele (A) in the rs3755166 polymorphism was significantly different in AD patients and control subjects (P<0.05). The rs3755166 polymorphism was associated with AD in the ethnic Chinese Han (OR=1.378, 95% CI: 1.017-1.867, P=0.039), and the results were not influenced by age, gender, or APOE status (P=0.441, P=0.94, P=0.432, respectively). CONCLUSION: Our data revealed the allele (A) of the rs3755166 polymorphism within LRP2 gene may contribute to AD risk in the Chinese Han Population.

The MTHFD1L gene rs11754661 marker is associated with susceptibility to Alzheimer's disease in the Chinese Han population.

Our objective is to evaluate the relationship between the rs11754661 polymorphism of the MTHFD1L gene and Alzheimer's disease (AD) in the ethnic Chinese Han. We conducted a case-control study (n=380, age>50) to determine the prevalence of one common single-nucleotide polymorphism (SNP) of MTHFD1L (rs11754661) in patients with AD in Chinese population of Mainland China, and clarified whether this polymorphism is a risk factor for AD. The prevalence of the minor allele (A) in the rs11754661 polymorphism was significantly different in AD patients and control subjects (P<0.01). The rs11754661 polymorphism was associated with AD in the ethnic Chinese Han (OR=1.829, 95% CI: 1.277-2.619, P=0.001), and the results were influenced by APOE status. Our data revealed that the allele (A) of the rs11754661 polymorphism within MTHFD1L gene may contribute to AD risk in the Chinese Han population.

Genetic polymorphisms in sigma-1 receptor and apolipoprotein E interact to influence the severity of Alzheimer's disease.

Apolipoprotein E (APOE) ε4 allele and sigma-1 receptor (SIGMAR1) c.5C (Q2P) polymorphisms have been acknowledged as risk factors for developing Alzheimer's disease (AD). However, whether these polymorphisms influence the disease process is unclear. Therefore, two cohorts with a clinical diagnosis of AD were recruited, a postmortem confirmed Australian cohort (82 cases) from the Australian Brain Bank Network, and a Chinese cohort with detailed clinical assessments recruited through an epidemiology study in Shanghai and through the neurology department outpatients clinic of Shanghai Ruijin Hospital (330 cases). SIGMAR1 Q2P and APOE genotyping was performed on all cases. Dementia severity in the Chinese cohort was assessed using MMSE scores, and the stages of senile plaques and neurofibrillary tangles (NFT) assessed in the Australian cohort. Associations between SIGMAR1 Q2P and APOE genotypes and disease severity were assessed using SPSS. Results confirmed that APOE 4 allele associated with increased NFT stages and cognitive decline, with carriers with one APOE ε2 or ε3 allele often having better clinical outcomes compared to carriers with none or two ε2 or ε3 alleles respectively. SIGMAR1 c.5C polymorphism alone did not associate with MMSE score variability in Chinese or with pathological stages in Caucasians. However, the association studies revealed a significant genetic interaction between the APOE ε4 allele and SIGMAR1 2P carriers in both populations, i.e., in APOE non ε4 allele carriers, SIGMAR1 2P variant had increased cognitive dysfunction and more advanced stages of NFT. Our data demonstrate that SIGMAR1 and APOE interact to influence AD severity across ethnic populations.

Association study of clusterin polymorphism rs11136000 with late onset Alzheimer's disease in Chinese Han population.

OBJECTIVE: We conducted a case-control study to investigate whether clusterin polymorphism (rs11136000) was associated with late-onset Alzheimer's disease in Chinese Han population. METHODS: Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay was performed on genotype rs11136000 and APOEε4 in 127 patients with late-onset Alzheimer's disease and 143 control individuals. Previous published data from other Chinese samples was also included for further meta-analysis. RESULTS: APOEε4 was demonstrated to increase the risk of Alzheimer's disease in Chinese population (odds ratio = 2.35, 95% confidence interval: 1.40-3.96). There is no significant association between clusterin rs11136000 with late-onset sporadic AD in our small cohort. However, meta-analysis revealed significant allele and genotype differences between Alzheimer's disease and controls following a recessive model. CONCLUSION: Clusterin (rs11136000) was associated with Alzheimer's disease in Chinese Han population.

CALHM1 P86L polymorphism is a risk factor for Alzheimer's disease in the Chinese population.

We conducted a case-control study to determine the prevalence of the CALHM1 P86L polymorphism (rs2986017) in patients with Alzheimer's disease (AD) in the Chinese population of mainland China, and also to clarify whether this polymorphism is a risk factor for AD. Fourteen heterozygous P86L carriers were identified among 198 AD patients. One control subject was also found to be a P86L heterozygous carrier. The allelic frequencies of the AD patients and control subjects were found to be significantly different. Our study indicates that the CALHM1-P86L polymorphism is associated with AD in the ethnic Chinese Han.