Association Between Carotid Plaque and Alzheimer's Disease Cerebrospinal Fluid Biomarkers and Cognitive Function in Cognitively Intact Adults: The CABLE Study.

Background: The association between carotid plaque and cognitive decline has recently been reported. However, the current research evidence is insufficient, and the possible causes of cognitive changes are unknown. Objective: This study aims to explore the relationships between carotid plaque and cognition functions, cerebrospinal fluid (CSF) Alzheimer's disease (AD) biomarkers in cognitively intact adults, and try to study the underlying mechanisms. Methods: We enrolled 165 cognitively normal participants from the Chinese Alzheimer's Biomarker and LifestylE (CABLE) study, who had CSF AD biomarker measurements and carotid ultrasound. Linear modeling was used to assess the association of carotid plaque with CSF biomarkers and cognition. Additionally, mediation analysis was conducted through 10,000 bootstrapped iterations to explore potential links between carotid plaque, AD pathology, and cognition. Results: We found that carotid plaque exhibited significant correlations with Aß42 (ß = -1.173, p = 0.022), Aß42/Aß40 (ß = -0.092, p < 0.001), P-tau/Aß42 (ß = 0.110, p = 0.045), and T-tau/Aß42 (ß = 0.451, p = 0.010). A significant correlation between carotid plaque and cognition decline was also found in men (ß = -0.129, p = 0.021), and mediation analyses revealed that the effect of carotid plaque on cognitive function could be mediated by Aß42/Aß40 (proportion of mediation = 55.8%), P-tau/Aß42 (proportion of mediation = 51.6%, p = 0.015) and T-tau/Aß42 (proportion of mediation = 43.8%, p = 0.015) mediated. Conclusions: This study demonstrated the link between carotid plaque and CSF AD biomarkers in cognitively intact adults, and the important role that AD pathology may play in the correlation between carotid plaque and cognitive changes.

Amyloid Pathology Modulates the Associations of Neuropsychiatric Symptoms with Cognitive Impairments and Neurodegeneration in Non-Demented Elderly.

BACKGROUND: The associations between neuropsychiatric symptoms (NPSs) and Alzheimer's disease (AD) have been well-studied, yet gaps remain. OBJECTIVE: We aimed to examine the associations of four subsyndromes (hyperactivity, psychosis, affective symptoms, and apathy) of NPSs with cognition, neurodegeneration, and AD pathologies. METHODS: Totally 1,040 non-demented elderly (48.07% males) from the Alzheimer's Disease Neuroimaging Initiative (ADNI) were included. We assessed the relationships between NPSs and AD neuropathologies, cognition, neurodegeneration, and clinical correlates in cross-sectional and longitudinal via multiple linear regression, linear mixed effects, and Cox proportional hazard models. Causal mediation analyses were conducted to explore the mediation effects of AD pathologies on cognition and neurodegeneration. RESULTS: We found that individuals with hyperactivity, psychosis, affective symptoms, or apathy displayed a poorer cognitive status, a lower CSF amyloid-ß (Aß) level and a higher risk of clinical conversion (p < 0.05). Hyperactivity and affective symptoms were associated with increasing cerebral Aß deposition (p < 0.05). Except psychosis, the other three subsyndromes accompanied with faster atrophy of hippocampal volume (p < 0.05). Specific NPSs were predominantly associated with different cognitive domains decline through an 8-year follow-up (p < 0.05). Moreover, the relationships between NPSs and cognitive decline, neurodegeneration might be associated with Aß, the mediation percentage varied from 6.05% to 17.51% (p < 0.05). CONCLUSIONS: NPSs could be strongly associated with AD. The influences of NPSs on cognitive impairments, neurodegeneration might be partially associated with Aß.

Chaperone-mediated autophagy in neurodegenerative diseases: mechanisms and therapy.

Chaperone-mediated autophagy (CMA) is the selective degradation process of intracellular components by lysosomes, which is required for the degradation of aggregate-prone proteins and contributes to proteostasis maintenance. Proteostasis is essential for normal cell function and survival, and it is determined by the balance of protein synthesis and degradation. Because postmitotic neurons are highly susceptible to proteostasis disruption, CMA is vital for the nervous system. Since Parkinson's disease (PD) was first linked to CMA dysfunction, an increasing number of studies have shown that CMA loss, as seen during aging, occurs in the pathogenetic process of neurodegenerative diseases. Here, we review the molecular mechanisms of CMA, as well as the physiological function and regulation of this autophagy pathway. Following, we highlight its potential role in neurodegenerative diseases, and the latest advances and challenges in targeting CMA in therapy of neurodegenerative diseases.

Microglia PTK2B/Pyk2 in the Pathogenesis of Alzheimer's Disease.

Alzheimer's disease (AD) is a highly hereditary disease with complex genetic susceptibility factors. Extensive genome-wide association studies have established a distinct susceptibility link between the protein tyrosine kinase 2ß (PTK2B) gene and late-onset Alzheimer's disease (LOAD), but the specific pathogenic mechanisms remain incompletely understood. PTK2B is known to be expressed in neurons, and recent research has revealed its more important significance in microglia. Elucidating the role of PTK2B high expression in microglia in AD's progression is crucial for uncovering novel pathogenic mechanisms of the disease. Our review of existing studies suggests a close relationship between PTK2B/proline-rich tyrosine kinase 2 (Pyk2) and tau pathology, and this process might be ß-amyloid (Aß) dependence. Pyk2 is hypothesized as a pivotal target linking Aß and tau pathologies. Concurrently, Aß-activated Pyk2 participates in the regulation of microglial activation and its proinflammatory functions. Consequently, it is reasonable to presume that Pyk2 in microglia contributes to amyloid-induced tau pathology in AD via a neuroinflammatory pathway. Furthermore, many things remain unclear, such as identifying the specific pathways that lead to the release of downstream inflammatory factors due to Pyk2 phosphorylation and whether all types of inflammatory factors can activate neuronal kinase pathways. Additionally, further in vivo experiments are essential to validate this hypothesized pathway. Considering PTK2B/Pyk2's potential role in AD pathogenesis, targeting this pathway may offer innovative and promising therapeutic approaches for AD.

Dynamic changes of CSF clusterin levels across the Alzheimer's disease continuum.

BACKGROUND: Clusterin is a multifunctional protein, which is associated with the pathogenesis and the development of Alzheimer's disease (AD). Compared with normal controls, inconsistent results have yielded in previous studies for concentration of cerebrospinal fluid (CSF) clusterin in AD patients. We explored CSF clusterin levels in different pathological processes of AD. METHODS: Following the National Institute on Aging-Alzheimer's Association (NIA-AA) criteria, we employed on the levels of CSF Aß42(A), phosphorylated-Tau (T), and total-tau (N). Based on previously published cutoffs and the close correlation between CSF p-tau and t-tau, 276 participants from the publicly available ADNI database with CSF biomarkers were divided into four groups: A-(TN)- (normal Aß42 and normal p-tau and t-tau; n = 50), A+(TN)- (abnormal Aß42 and normal p-tau and t-tau; n = 39), A+(TN) + (abnormal Aß42 and abnormal p-tau or t-tau; n = 147), A-(TN) + (normal Aß42 and abnormal p-tau or t-tau; n = 40). To assess CSF clusterin levels in AD continuum, intergroup differences in four groups were compared. Pairwise comparisons were conducted as appropriate followed by Bonferroni post hoc analyses. To further study the relationships between CSF clusterin levels and AD core pathological biomarkers, we employed multiple linear regression method in subgroups. RESULTS: Compared with the A-(TN)- group, CSF clusterin levels were decreased in A+ (TN)- group (P = 0.002 after Bonferroni correction), but increased in the A+(TN) + group and the A-(TN) + group (both P <  0.001 after Bonferroni correction). Moreover, we found CSF clusterin levels are positively associated with CSF Aß42 (ß = 0.040, P <  0. 001), CSF p-tau (ß = 0.325, P <  0.001) and CSF t-tau (ß = 0.346, P <  0.001). CONCLUSIONS: Our results indicated that there are differences levels of CSF clusterin in different stages of AD pathology. The CSF clusterin level decreased at the early stage are related to abnormal Aß pathology; and the increased levels are associated with tau pathology and neurodegeneration.

Inhibition of caspase-1 ameliorates tauopathy and rescues cognitive impairment in SAMP8 mice.

The inflammasome assembles leading to increased cleavage and activity of caspase-1 and downstream IL-1ß release, which plays a significant role in the pathogenesis of Alzheimer's disease (AD). Previous studies have shown that caspase-1-mediated neuroinflammation occurs early in AD process. However, the detailed role of caspase-1 in aging-related AD-like neuropathology is still unclear so far. In this study, by using SAMP8 mice, an animal model of accelerated aging, we detected the levels of caspase-1 in brains of 3-, 7-, and 11-month-old mice and observed that caspase-1 was activated during aging process. More importantly, we provided the evidence that VX-765, a selective inhibitor of caspase-1, significantly rescued spatial learning and memory impairments and reduced tau hyperphosphorylation in brains of SAMP8 mice at early stages of the disease. This amelioration might be attributed to IL-1ß-induced hypoactivation of tau kinases. Our results imply that caspase-1 may represent as a potential therapeutic target for neurodegenerative tauopathies.

Caspase-1 variant influencing CSF tau and FDG PET levels in non-demented elders from the ADNI cohort.

BACKGROUND: Genetic variations in the inflammatory Caspase-1 gene have been shown associated with cognitive function in elderly individuals and in predisposition to Alzheimer's disease (AD), but its detailed mechanism before the typical AD onset was still unclear. Our current study evaluated the impact of Caspase-1 common variant rs554344 on the pathological processes of brain amyloidosis, tauopathy, and neurodegeneration. METHODS: Data used in our study were obtained from the Alzheimer's Disease Neuroimaging Initiative (ADNI) cohort. We examined the relationship between Caspase-1 rs554344 allele carrier status with AD-related cerebrospinal fluid (CSF), PET, and MRI measures at baseline by using a multiple linear regression model. We also analyzed the longitudinal effects of this variant on the change rates of CSF biomarkers and imaging data using a mixed effect model. RESULTS: We found that Caspase-1 variant was significantly associated with FDG PET levels and CSF t-tau levels at baseline in total non-demented elderly group, and especially in mild cognitive impairment (MCI) subgroup. In addition, this variant was also detected associated with CSF p-tau levels in MCI subgroup. The mediation analysis showed that CSF p-tau partially mediated the association between Caspase-1 variant and CSF t-tau levels, accounting for 80% of the total effect. CONCLUSIONS: Our study indicated a potential role of Caspase-1 variant in influencing cognitive function might through changing tau related-neurodegeneration process.

Associations of Alzheimer's disease risk variants with gene expression, amyloidosis, tauopathy, and neurodegeneration.

BACKGROUND: Genome-wide association studies have identified more than 30 Alzheimer's disease (AD) risk genes, although the detailed mechanism through which all these genes are associated with AD pathogenesis remains unknown. We comprehensively evaluate the roles of the variants in top 30 non-APOE AD risk genes, based on whether these variants were associated with altered mRNA transcript levels, as well as brain amyloidosis, tauopathy, and neurodegeneration. METHODS: Human brain gene expression data were obtained from the UK Brain Expression Consortium (UKBEC), while other data used in our study were obtained from the Alzheimer's Disease Neuroimaging Initiative (ADNI) cohort. We examined the association of AD risk allele carrier status with the levels of gene expression in blood and brain regions and tested the association with brain amyloidosis, tauopathy, and neurodegeneration at baseline, using a multivariable linear regression model. Next, we analyzed the longitudinal effects of these variants on the change rates of pathology using a mixed effect model. RESULTS: Altogether, 27 variants were detected to be associated with the altered expression of 21 nearby genes in blood and brain regions. Eleven variants (especially novel variants in ADAM10, IGHV1-68, and SLC24A4/RIN3) were associated with brain amyloidosis, 7 variants (especially in INPP5D, PTK2B) with brain tauopathy, and 8 variants (especially in ECHDC3, HS3ST1) with brain neurodegeneration. Variants in ADAMTS1, BZRAP1-AS1, CELF1, CD2AP, and SLC24A4/RIN3 participated in more than one cerebral pathological process. CONCLUSIONS: Genetic variants might play functional roles and suggest potential mechanisms in AD pathogenesis, which opens doors to uncover novel targets for AD treatment.

PET Amyloid and Tau Status Are Differently Affected by Patient Features.

BACKGROUND: Amyloid-ß (Aß) plaques and tau neurofibrillary tangles are two neuropathological hallmarks of Alzheimer's disease (AD), which both can be visualized in vivo using PET radiotracers, opening new opportunities to study disease mechanisms. OBJECTIVE: Our study investigated 11 non-PET factors in 5 categories (including demographic, clinical, genetic, MRI, and cerebrospinal fluid (CSF) features) possibly affecting PET amyloid and tau status to explore the relationships between amyloid and tau pathology, and whether these features had a different association with amyloid and tau status. METHODS: We included 372 nondemented elderly from the Alzheimer's Disease Neuroimaging Initiative cohort. All underwent PET amyloid and tau analysis simultaneously, and were grouped into amyloid/tau quadrants based on previously established abnormality cut points. We examined the associations of above selected features with PET amyloid and tau status using a multivariable logistic regression model, then explored whether there was an obvious correlation between the significant features and PET amyloid or tau levels. RESULTS: Our results demonstrated that PET amyloid and tau status were differently affected by patient features, and CSF biomarker features provided most significant values associating PET findings. CSF Aß42/40 was the most important factor affecting amyloid PET status, and negatively correlated with amyloid PET levels. CSF pTau could significantly influence both amyloid and tau PET status. Besides CSF pTau and Aß42, APOEɛ4 allele status and Mini-Mental State Examination scores also could influence tau PET status, and significantly correlated with tau PET levels. CONCLUSION: Our results support that tau pathology possibly affected by Aß-independent factors, implicating the importance of tau pathology in AD pathogenesis.

Evidence-based prevention of Alzheimer's disease: systematic review and meta-analysis of 243 observational prospective studies and 153 randomised controlled trials.

BACKGROUND: Evidence on preventing Alzheimer's disease (AD) is challenging to interpret due to varying study designs with heterogeneous endpoints and credibility. We completed a systematic review and meta-analysis of current evidence with prospective designs to propose evidence-based suggestions on AD prevention. METHODS: Electronic databases and relevant websites were searched from inception to 1 March 2019. Both observational prospective studies (OPSs) and randomised controlled trials (RCTs) were included. The multivariable-adjusted effect estimates were pooled by random-effects models, with credibility assessment according to its risk of bias, inconsistency and imprecision. Levels of evidence and classes of suggestions were summarised. RESULTS: A total of 44 676 reports were identified, and 243 OPSs and 153 RCTs were eligible for analysis after exclusion based on pre-decided criteria, from which 104 modifiable factors and 11 interventions were included in the meta-analyses. Twenty-one suggestions are proposed based on the consolidated evidence, with Class I suggestions targeting 19 factors: 10 with Level A strong evidence (education, cognitive activity, high body mass index in latelife, hyperhomocysteinaemia, depression, stress, diabetes, head trauma, hypertension in midlife and orthostatic hypotension) and 9 with Level B weaker evidence (obesity in midlife, weight loss in late life, physical exercise, smoking, sleep, cerebrovascular disease, frailty, atrial fibrillation and vitamin C). In contrast, two interventions are not recommended: oestrogen replacement therapy (Level A2) and acetylcholinesterase inhibitors (Level B). INTERPRETATION: Evidence-based suggestions are proposed, offering clinicians and stakeholders current guidance for the prevention of AD.

Longitudinal trajectories of Alzheimer's ATN biomarkers in elderly persons without dementia.

BACKGROUND: Models of Alzheimer's disease (AD) pathophysiology posit that amyloidosis [A] precedes and accelerates tau pathology [T] that leads to neurodegeneration [N]. Besides this A-T-N sequence, other biomarker sequences are possible. This current work investigates and compares the longitudinal trajectories of Alzheimer's ATN biomarker profiles in non-demented elderly adults from the Alzheimer's Disease Neuroimaging Initiative (ADNI) cohort. METHODS: Based on the ATN classification system, 262 individuals were identified before dementia diagnosis and accompanied by baseline and follow-up data of ATN biomarkers (CSF Aß42, p-tau, and FDG-PET). We recorded the conversion processes in ATN biomarkers during follow-up, then analyzed the possible longitudinal trajectories and estimated the conversion rate and temporal evolution of biomarker changes. To evaluate how biomarkers changed over time, we used linear mixed-effects models. RESULTS: During a 6-120-month follow-up period, there were four patterns of longitudinal changes in Alzheimer's ATN biomarker profiles, from all negative to positive through the course of the disease. The most common pattern is that A pathology biomarker first emerges. As well as the classical A-T-N sequence, other "A-first," "T-first," and "N-first" biomarker pathways were found. The N-A-T sequence had the fastest rate of pathological progression (mean 65.00 months), followed by A-T-N (mean 67.07 months), T-A-N (mean 68.85 months), and A-N-T sequences (mean 98.14 months). CONCLUSIONS: Our current work presents a comprehensive analysis of longitudinal trajectories of Alzheimer's ATN biomarkers in non-demented elderly adults. Stratifying disease into subtypes depending on the temporal evolution of biomarkers will benefit the early recognition and treatment.

Diabetes mellitus and risks of cognitive impairment and dementia: A systematic review and meta-analysis of 144 prospective studies.

BACKGROUND: Uncertainties persist about the associations of diabetes with risk of cognitive impairment and dementia. We aimed to illuminate these associations from various aspects. METHODS: We identified relevant prospective studies by searching PubMed up to Jun 2019. Summary relative risks (RR) were estimated using random-effects models. Credibility of each meta-analysis was assessed. Meta-regression and subgroup analyses were conducted. RESULTS: Of 28,082 identified literatures, 144 were eligible for inclusion in the systematic review, among which 122 were included in the meta-analysis. Diabetes conferred a 1.25- to 1.91-fold excess risk for cognitive disorders (cognitive impairment and dementia). Subjects with prediabetes also had higher risk for dementia. As for diabetes-related biochemical indicators, fasting plasma glucose (FPG) was non-linearly related to cognitive disorders; the elevated levels of 2 -h postload glucose (2h-PG), glycosylated hemoglobin (HbA1c), low and high levels of fasting plasma insulin (FPI) were associated with an increased risk of dementia. Encouragingly, the use of pioglitazone exhibited a 47% reduced risk of dementia in diabetic population. CONCLUSIONS: Diabetes, even prediabetes and changes of diabetes-related biochemical indicators, predicted increased incidence of cognitive impairment and dementia. The protective effects of pioglitazone warrant further investigation in randomized trials.

TREML2 Mutation Mediate Alzheimer's Disease Risk by Altering Neuronal Degeneration.

A coding missense mutation (rs3747742) in triggering receptor expressed on myeloid cell-like 2 (TREML2) has been recently proposed as an important protective factor against Alzheimer's disease (AD). However, the link between TREML2 and AD pathology remains unclear. Therefore, we explored the association of TREML2 rs3747742 with cognitive function, neuroimaging biomarkers and cerebrospinal fluid (CSF) biomarkers related to AD, including CSF total-tau (T-tau), phosphor-tau (P-tau), and amyloid-ß (Aß1-42). As for cognitive function, related cognitive scores of Clinical Dementia Rating Sum of Boxes (CDRSB), Alzheimer's Disease Assessment Scale-cognitive section 11 (ADAS-cog 11), Mini-Mental State Examination (MMSE), and Rey Auditory-Verbal Learning Test (RAVLT) were extracted. We used a multiple linear regression model to examine the association of TREML2 rs3747742 with the baseline variables. Furthermore, we also calculated the change rate of above variables influenced by TREML2 rs3747742 via applying a mixed-effects model over a 4-year follow-up. In this analysis, a total of 1,306 individuals from the Alzheimer's Disease Neuroimaging Initiative (ADNI) database were included. Finally, we observed that only in AD patients, but not in normal controls or mild cognitive impairment (MCI) individuals, TREML2 rs3747742 exhibited a strong association with CSF total-tau levels at baseline (ß = -22.1210, p = 0.0166) and 4-year follow-up (ß = -0.3961, p = 0.0115). Furthermore, no associations were found with CSF Aß1-42 levels, P-tau levels, neuroimaging biomarkers and cognitive function neither for baseline variables nor for longitudinal data. Thus, this study indicated that TREML2 mediated the risk of AD through influencing AD-related neurodegeneration (abnormal T-tau levels) but not P-tau levels and Aß pathology.

Genome-wide association study identifies Alzheimer's risk variant in MS4A6A influencing cerebrospinal fluid sTREM2 levels.

The triggering receptor expressed on myeloid cells 2 (TREM2) gene has been reported to increase the risk of Alzheimer's disease (AD). The soluble TREM2 protein (sTREM2) in cerebrospinal fluid (CSF) was also associated with AD. However, the role of sTREM2 in AD and its genetic modifiers remain unclear. We carried out a genome-wide association study for CSF sTREM2 levels using participants from the Alzheimer's Disease Neuroimaging Initiative and validated the significant association in an independent cohort from Chinese Alzheimer's Biomarker and LifestylE study. rs7232 in membrane spanning 4-domains A6A (MS4A6A) gene was associated with CSF sTREM2 levels at genome-wide significance (p = 1.42 × 10-15). The locus influences CSF sTREM2 levels especially in nondemented individuals. And the association was replicable in the validation cohort from Chinese Alzheimer's Biomarker and LifestylE study (p = 0.0106). Besides, the expressions of MS4A6A and TREM2 were correlated in brain regions (p < 2 × 10-16). The findings of our study suggest that the AD risk variant in the MS4A6A gene participates in the regulation of sTREM2.

Soluble TREM1 concentrations are increased and positively correlated with total tau levels in the plasma of patients with Alzheimer's disease.

BACKGROUND/AIMS: Recently, we showed that triggering receptor expressed on myeloid cells 1 (TREM1) was involved in the pathogenesis of Alzheimer's disease (AD) since it modulated microglial phagocytic functions and thus affected amyloid-ß clearance in the brain. Interestingly, a soluble form of TREM1 (sTREM1) can be detected in the plasma of human. To date, whether sTREM1 concentrations were altered in the plasma under AD context remained unclear. METHODS: In this study, we compared the plasma concentrations of sTREM1 between 110 AD patients and 128 age- and gender-matched controls. Meanwhile, the relationship of sTREM1 concentrations with total tau levels in the plasma of AD patients was also assessed. RESULTS: We revealed that the concentrations of sTREM1 were significantly increased in AD patients. Meanwhile, the sTREM1 concentrations were gradually increased during disease progression. More importantly, we showed that the sTREM1 concentrations were positively correlated with the levels of total tau in the plasma of AD patients (r = 0.61, P < 0.001). The subsequent subgroup analysis indicated that this correlation was more pronounced in patients with severe dementia (Mini-Mental State Exam score < 10, r = 0.81, P < 0.01). CONCLUSION: These findings indicate a potential association between sTREM1 and tau pathology, and further confirm an involvement of this immune receptor in AD pathogenesis.

Comparative safety and effectiveness of cholinesterase inhibitors and memantine for Alzheimer's disease: a network meta-analysis of 41 randomized controlled trials.

BACKGROUND: Cholinesterase inhibitors and memantine have been approved for management of Alzheimer's disease (AD), but there has been no consensus about the choice of various types and doses of drugs at different stages. Hence, we compared and ranked the efficacy and tolerability of these available drugs. METHODS: We searched PubMed, the Cochrane Central Register of Controlled Trials, and Embase for randomized controlled trials (RCTs) published from database inception to July 21, 2017. The primary outcomes were the mean overall changes in cognitive function and responders who had any adverse events. We conducted a random-effects network meta-analysis. RESULTS: Forty-one RCTs were included in this study. Compared with placebo, galantamine 32 mg daily (standardized mean difference - 0.51, 95% credible interval - 0.67 to - 0.35), galantamine 24 mg daily (- 0.50, - 0.61 to - 0.40), and donepezil 10 mg daily (- 0.40, - 0.51 to - 0.29) were probably the most effective agents on cognition for mild to moderate AD, and memantine 20 mg combined with donepezil 10 mg (0.76, 0.39 to 1.11) was recommended for moderate to severe patients. Memantine showed the best profile of acceptability. Rivastigmine transdermal 15-cm2 patch was the best optional treatment both in function and global changes. None of the medicines was likely to improve neuropsychiatric symptoms through this analysis. CONCLUSIONS: Pharmacological interventions have beneficial effects on cognition, function, and global changes, but not on neuropsychiatric symptoms, through current network meta-analysis. The choice of drugs may mainly depend on the disease severity and clinical symptoms.

Common Variant in PLD3 Influencing Cerebrospinal Fluid Total Tau Levels and Hippocampal Volumes in Mild Cognitive Impairment Patients from the ADNI Cohort.

Recent studies found the variants in Alzheimer's disease (AD) risk gene PLD3 were associated with cognitive function, but its detailed mechanism before typical AD onset was unknown. Our current study examined the impact of PLD3 common variant rs11667768 on cerebrospinal fluid (CSF) total-tau and phosphorylated-tau levels and structural MRI from the ADNI database. We found rs11667768 was significantly associated with CSF total-tau levels and hippocampal volumes at baseline and six-year follow-up in the total non-demented elderly group and the mild cognitive impairment subgroup, indicating a potential role of PLD3 common variants in influencing cognitive function through changing CSF total-tau levels and hippocampal volumes.

Association of lectin-like oxidized low density lipoprotein receptor 1 (OLR1) polymorphisms with late-onset Alzheimer disease in Han Chinese.

BACKGROUND: Lectin-like oxidized low density lipoprotein receptor 1 (OLR1) locates within the area of chromosome 12p, which has been identified as the AD-susceptible region, and plays a role in lipid metabolism. Therefore, it has been suggested to be a good candidate gene for Alzheimer's disease (AD). Several SNPs within OLR1 have been reported to have association with AD among Caucasians. METHODS: We selected and genotyped three SNPs (rs1050283, rs1050286, rs17808009) in OLR1 to investigate its possible relationship with the onset of late-onset Alzheimer disease(LOAD) in 984 LOAD cases and 1,354 healthy controls among northern Han Chinese. RESULTS: No significant association was found between the OLR1 (rs1050283, rs1050286, rs17808009) polymorphisms and LOAD, even after adjustment for gender and age and stratification for apolipoprotein E (APOE) status. CONCLUSIONS: Our study showed that the SNPs (rs1050283, rs1050286, rs17808009) located in the 3'UTR of OLR1 may not involve in the mechanism of LOAD in Han Chinese population.

Rare Variants in PLD3 Increase Risk for Alzheimer's Disease in Han Chinese.

Next-generation sequencing studies had reported that a rare coding variant p.V232M in PLD3 was associated with Alzheimer's disease (AD) and a two-fold increased AD risk in European cohorts. To test whether coding region variants of PLD3 were associated with AD in a large Han Chinese cohort, we performed sequencing to analyze all exons of PLD3, and demonstrated that rare variants p.I163M and c.1020-8G>A conferred considerable risk of late-onset AD (LOAD) in our cohort. Meanwhile, the previously reported p.V232M variant was identified in our AD group. These findings indicate that rare variants of PLD3 may play an important role in LOAD in northern Han Chinese.