Thalamic cholinergic innervation is spared in Alzheimer disease compared to parkinsonian disorders

There are two major sources of cholinergic projections in the brain. The nucleus basalis of Meynert provides the principal cholinergic input of the cortical mantle and the pedunculopontine nucleus–laterodorsal tegmental complex (PPN–LDTC; hereafter referred to as PPN) provides the major cholinergic input to the thalamus. Cortical cholinergic denervation has previously been shown to be part of Alzheimer and parkinsonian dementia but there is less information about subcortical thalamic cholinergic denervation. We investigated thalamic cholinergic afferent integrity by measuring PPN–Thalamic (PPN–Thal) acetylcholinesterase (AChE) activity via PET imaging in Alzheimer (AD), Parkinson disease without dementia (PD), Parkinson disease with dementia (PDD) and dementia with Lewy bodies (DLB). AD (n = 13; mean age 75.4 ± 5.5), PD (n = 11; age 71.4 ± 6.4), PDD (n = 6; age 70.8 ± 4.7), DLB (n = 6; age 68.0 ± 8.6) and normal controls (NC; n = 14; age 69.0 ± 7.5) subjects underwent AChE [¹¹C]-methyl-4-piperidinyl propionate (PMP) PET imaging. PPN–Thal PET data were analyzed using the Nagatsuka method. There were no significant differences in mean age between the groups (F = 1.86, p = 0.134). Kruskal–Wallis testing demonstrated a significant group effect for PPN–Thal AChE hydrolysis rates (F = 9.62, p < 0.0001). Compared to NC, reduced thalamic k3 hydrolysis rate was noted in subjects with PDD (−19.8%; AChE k3 hydrolysis rates 0.1072 ± 0.0143 min⁻¹), DLB (−17.4%; 0.1103 ± 0.0112 min⁻¹) and PD (−12.8%; 0.1165 ± 0.0114 min⁻¹). Each of these 3 subgroups was statistically different from AD subjects (−0.7%; 0.1326 ± 0.0095 min⁻¹) who showed relatively spared thalamic k3 hydrolysis rates which were comparable to NC (0.1336 ± 0.0142 min⁻¹). Thalamic cholinergic denervation is present in PD, PDD, and DLB but not in AD. Neurodegenerative involvement of thalamic cholinergic afferent projections may contribute to disease-specific motor and cognitive abnormalities.     

HLA rs3129882 variant in Chinese Han patients with late-onset sporadic Parkinson disease

Recently, the rs3129882 variant in intron 1 of HLA-DRA was found to be associated with late-onset sporadic Parkinson disease (PD) in Americans of European ancestry. To evaluate whether the same variant is related to PD in Chinese population, we investigated late-onset sporadic PD patients of Chinese Han ethanicity in Mainland China. We found significant difference in genotypic and allele distribution between patients and control subjects (χ² = 6.446, p = 0.040 for genotypic distribution; χ² = 5.762, p = 0.016 for allele distribution), suggesting this variant is associated with late-onset sporadic PD in Chinese Han population.     

Complete screening for glucocerebrosidase mutations in Parkinson disease patients from Greece

Mutations in β-glucocerebrosidase gene (GBA) have been implicated in Parkinson disease (PD). A Greek cohort of 172 PD patients and 132 control individuals were screened for GBA mutations by complete sequencing of the gene's exons. Four mutations previously associated with Gaucher disease and/or Parkinson's disease (L445P, D409H, E326K, H255Q) were detected, as well as five newly identified variants (R329H, L268L, S271G, T428K, V460L), providing for the first time data regarding the frequency of GBA mutations among PD patients and controls, in the Greek population. H255Q was the most common GBA mutation among Greek PD patients (4/172). V460L was only found in control individuals (2/132). Overall, GBA mutations were significantly overrepresented in a subgroup of early onset PD patients, compared to controls (P = 0.019, OR = 4.2; 95%CI = 1.28–13.82), suggesting that GBA mutations may modify age of onset for PD.     

Association of intron 1 variants of the dopamine transporter gene with schizophrenia

The dopamine transporter (DAT1) gene has been implicated in the pathogenesis of many neuropsychiatric disorders, including schizophrenia. The present study aimed to investigate association of the DAT1 gene polymorphisms with schizophrenia in a Han Chinese population. Two single nucleotide polymorphisms (SNPs) in the DAT1 gene (rs2975223 and rs2455391) were tested in 368 patients with schizophrenia and 420 healthy controls, of whom 293 patients underwent an assessment of psychotic symptoms through the positive and negative syndrome scale (PANSS). The chi-square test (χ²) showed disease association for rs2455391 (corrected p = 0.023 for allelic association and p = 0.034 for genotypic association, respectively). The rs2975223(G)–rs2455391(C) haplotype was associated with increased risk of the illness (p = 0.0012, OR = 2.09, 95% CI = 1.28–3.42). Quantitative trait analysis showed that rs2455391 was associated with positive symptoms, general symptoms and global symptoms but not with negative symptoms. The present results suggest that the DAT1 gene may be mainly involved in the development of the positive symptoms in the Chinese population.     

Cortical acetylcholine esterase activity and ApoE4-genotype in Alzheimer disease

Positron emission tomography (PET) studies have demonstrated reduced acetylcholine esterase (AChE) activity as an indicator of cholinergic impairment, which is a main pathogenic process in Alzheimer's disease (AD). The E4 allele of apolipoprotein ? (ApoE4) is a major risk factor for AD. We examined the relation between ApoE-genotype and cortical AChE activity. In 19 patients (mean age 64) with mild to moderate AD (mean MMSE 22) PET with C-11-labeled N-methyl-4-piperidyl-acetate (MP4A) was performed and the ApoE4-genotype was determined. Parametric images of AChE hydrolysis were generated using a non-invasive technique and analysed globally and regionally. A neuropsychological battery testing memory, attention, executive functions, visuoconstruction, and language was administered. The mean cortical AChE activity was reduced significantly in both groups compared to reference values. The ApoE4 positive subjects (two homozygotes, nine heterozygotes) had significantly higher (p < 0.05) AChE levels (MP4A hydrolysis rate 0.0753 ± 0.0088 min⁻¹) than the ApoE4 negative subjects (n = 8, 0.0654 ± 0.0090 min⁻¹). Both groups were comparable with regard to age (63 versus 65) and dementia severity (MMSE 20 versus MMSE 22). AChE-impairment correlated significantly with the word fluency task (r = 0.041, p < 0.05) in the ApoE4 negative group only. These results indicate that cortical AChE activity is relatively well preserved in ApoE4 carriers, either by preservation of its cellular expression or as AChE activity in amyloid plaques.     

Inter-relation of Th1, Th2, Th17 and Treg cytokines in oral cancer patients and their clinical significance

Background

Altered cytokine production can lead to immune dysfunction in cancer patients. Hence, we investigated the cytokine balance in oral squamous cell carcinoma (OSCC) patients and their significance in providing new therapeutic insights.

Methods

We quantified Th17 (IL17A), Treg (TGFβ1), Th1 (IL2, IFNγ) and Th2 (IL4, IL10) like cytokines in the sera of 78 cases and 39 controls by ELISA. The intracellular expression of these cytokines was analyzed in 10 subjects from each group by flow cytometry.

Results

Serum levels of IL17A, TGFβ1, IL4 and IL10 were significantly higher while IL2 and IFNγ were relatively lower in patients as compared to controls. TGFβ1 (r = 0.55), IL4 (r = 0.75) and IL10 (r = 0.80) significantly (P < 0.0001) correlated with disease progression and their elevated levels showed increased odd ratios of approximately 18, 14 and 37, respectively. IL17A appeared as a risk factor (OR = 2.21, 95% CI = 0.89–5.42) although statistically insignificant. The levels neither correlated with disease progression nor with TGFβ1, IL4 and IL10 but showed positive association with IL2 (r = 0.51, P < 0.0001) and IFNγ (r = 0.24). Flow cytometry data also showed similar trend.

Conclusions

We reported a distinct TGFβ1 and Th2 (IL4, IL10) polarization with a borderline elevation of IL17A while, a suppression of Th1 (IL2, IFNγ) cytokines in OSCC patients.     

Clinical correlates of pathology in the claustrum in Parkinson's disease and dementia with Lewy bodies

Dementia and visual hallucinations are common complications of Parkinson's disease (PD), yet their patho-anatomical bases are poorly defined. We studied α-synuclein (αSyn), tau and amyloid-β (Aβ) pathology in the claustrum of 20 PD cases without dementia, 12 PD cases with dementia (PDD) and 7 cases with dementia with Lewy bodies (DLB). αSyn positivity was observed in 75% of PD cases without dementia and in 100% of PDD and DLB cases. Aβ was observed in the claustrum in 25% of PD, 58% of PDD and 100% of DLB cases. Tau was negligible in all cases restricting further analysis. Compared to PD cases without dementia, PDD cases demonstrated a significantly greater αSyn burden in the claustrum (p = 0.0003). In addition, DLB cases showed a significantly increased αSyn deposition when compared to PDD (p = 0.02) and PD without dementia (p = 0.0002). A similar hierarchy, PD < PDD < DLB was seen in terms of Aβ burden in the claustrum. Comparison of αSyn and Aβ burden in those cases with and without visual hallucinations did not reveal any significant associations (p = 0.13 and 0.1, respectively). We demonstrate that pathology in the claustrum, a region of largely obscure physiological function, strongly relates to the presence of dementia in Parkinson's disease and DLB.     

Quantitative plasma DNA analysis in Parkinson's disease

Parkinson disease (PD) is a neurodegenerative disease resulting from the loss of the dopaminergic neurons from the substantia nigra pars compacta (SNpc). It is characterized by bradykinesia, rigidity, resting tremor and/or postural instability. The diagnosis of PD is essentially clinical and there is no reliable biological marker to assess its progression. Recently, investigations have been performed on the potential use of circulating cell-free deoxyribonucleic acid (DNA) in the plasma for clinical diagnosis, prognosis and monitoring of human diseases. The aim of this work was to assess the role of free DNA as a biological marker of PD. Forty-two patients with PD (19 men, 23 women) and 20 healthy (7 men, 13 women) subjects were enrolled in this study. Mean ± SD plasma DNA concentration in PD patients and control subjects were, respectively, 16,487 ± 16,378 (range: 100–62,034) kilogenomes-equivalents/L and 37,975 ± 17,832 (range: 15,143–78,783) kilogenomes-equivalents/L. There was a significant difference between control and PD groups (p < 0.001). There was no correlation between plasma DNA levels and demographic or clinical parameters in PD patients. Free DNA does not seem to be a reliable marker of PD progression. Further research is warranted to confirm the present results to have some value as biomarkers in other neurodegenerative diseases.     

Telomere length, oxidative stress, and antioxidant status in elderly men in Zutphen and Crete

The incidence of chronic diseases such as cardiovascular diseases is lower in Mediterranean Southern Europe than Northern Europe. This may be due to a lower level of oxidative stress and a higher antioxidant status in people living around the Mediterranean Sea. Oxidative stress may influence the rate of shortening of telomeres, the nucleoprotein structures at the ends of chromosomes. We compared leukocyte telomere length (LTL) in elderly men from Northern and Southern Europe and investigated the possible relationship between LTL and indicators of oxidative stress and antioxidant status. We examined 143 elderly Dutch men (mean age 83.9 years) and 109 Greek elderly men (mean age 84.6 years) and found that the Greek men had significantly longer telomeres (geometric mean 4.95 kbp, 95% confidence interval (CI): 4.71-5.23 kbp) compared to the men from the Netherlands (4.76 kbp, 95% CI: 4.55-4.98 kbp; P = 0.001). Age was inversely associated with LTL (β = −0.10, P = 0.31 in Cretan men and β = −0.19, P = 0.02 in Dutch men). In all men LTL was not related to indicators of oxidative stress and plasma antioxidants. However, the endogenous antioxidants serum albumin (β = 0.18, P = 0.007) and uric acid (β = 0.13, P = 0.045) were positively associated with LTL. The age-adjusted difference between Crete and Zutphen was reduced by 25% after adjustment for serum albumin and uric acid. We conclude that Greek elderly men have significantly longer LTL compared to Dutch counterparts. The endogenous antioxidants albumin and uric acid were positively associated with longer telomeres.     

Microtubule-associated protein tau (MAPT) influences the risk of Parkinson's disease among Indians

Parkinson's disease (PD) is a neurodegenerative disease of the central nervous system and its prevalence increases with age. Microtubule-associated protein tau (MAPT), a neuronal protein is involved in the pathogenesis of several neurodegenerative diseases including PD. To determine the broader significance of this association with PD, replicative studies in distinct ethnic populations are required. In this study, we investigated MAPT for its potential association with PD using five haplotype-tagging SNPs and the del-In9 polymorphism of MAPT in 301 PD patients and 243 healthy controls from eastern India. Our case–control analysis did not show a significant association with any of the markers and PD. However, a risk haplotype [GAC + G] for PD was identified (OR = 1.563; 95% CI = 1.045–2.337; p = 0.03). In addition, haplotype AAC + A (OR = 2.787; 95% CI = 1.372–5.655; p = 0.004) was strongly associated with early onset PD (age at onset ≤40 years) and AAC + G haplotype showed a weak association (OR = 2.233; 95% CI = 1.018–4.895; p = 0.045) with late onset PD (age at onset >40 years). This observation highlights the significance of rs7521 in modifying the age at onset of PD under a common haplotype background. We also identified AGC + A as a risk haplotype for sporadic cases (OR = 2.773, 95% CI = 1.198–6.407, p = 0.016). This is the first association study from India conducted on MAPT among PD patients and provides valuable information for comparison with other ethnic groups.     

Childhood adversity and pubertal timing: Understanding the origins of adulthood cardiovascular risk

Objective

To determine whether greater childhood adversity relates to younger menarcheal age; whether younger menarcheal age relates to increased CVD risk; and whether greater childhood adversity relates to increased CVD risk, directly or indirectly (mediated by menarcheal age).

Methods

Among 650 pre-menopausal women (ages 25–45; M = 34.9[5.6]), SEM was performed to estimate relations between childhood adversity, menarcheal age, and CVD risk.

Results

Results supported a covariate-adjusted model (RMSEA = 0.035; CFI = 0.983) in which greater childhood adversity was related to younger menarcheal age (β = −.13, p < .01) and younger menarcheal age was related to greater CVD risk (β = −.18, p < .05). Direct and indirect effects of childhood adversity on CVD risk were non-significant. Re-evaluation of the same model with additional covariate-adjustment for adulthood body composition showed the relation between menarcheal age and CVD risk attenuated (β = −.03, p = .376).

Conclusions

Cross-sectional evidence suggests family-related adversity experiences in childhood confer risk for earlier menarche which, in turn, relates to increased CVD risk in adulthood, possibly via post-pubertal body size.     

Grooved pegboard test as a biomarker of nigrostriatal denervation in Parkinson's disease

Recent pharmacotherapy trials in Parkinson's disease (PD) using dopaminergic neuroimaging as outcome parameter failed to show significant relationships between imaging and clinical results. One possible explanation is that there is a non-linear relationship between striatal denervation and motor performance reflecting a statistical "floor" effect in the imaging data with advanced disease. Both the motor manifestations and the striatal dopamine denervation of idiopathic PD, however, are typically asymmetric and more meaningful associations may be found by comparing data from the least denervated striatum with motor performance in the corresponding body side. PD patients (n=28) underwent [11C]beta-CFT dopamine transporter (DAT) positron emission tomography (PET) and grooved pegboard testing. Voxel-based analysis of DAT PET and bimanual pegboard scores demonstrated significant correlation clusters within the bilateral striata (P<0.001). However, findings were most prominent in the least denervated striatum. There was a significant inverse correlation between pegboard scores of the least affected arm and DAT binding of the least denervated striatum (Rs=-0.69, P<0.0001) but no significant correlation between pegboard scores of the clinically most affected arm and DAT binding of the most denervated striatum (Rs=-0.15, ns). These data indicate that the robustness of the grooved pegboard test as a biomarker for nigrostriatal denervation in PD mainly reflects the relationship between test performance of the clinically least affected limb and the least denervated striatum. These findings indicate that there is both a statistical "floor" and "ceiling" effect for the most affected striatal and body sides that must be considered when employing imaging as an outcome measure in clinical trials in PD.     

An ambulatory persistence power curve: Motor planning affects ambulatory persistence in Parkinson's disease

Background/objectives: When performing activity associated with walking, the amount of walking a person does often will depend on their plans. This study was designed to evaluate the relationship between motor planning and ambulatory persistence in participants with Parkinson's disease (PD) and to see if ambulatory persistence was related to the ability to perform activities of daily living (ADL). Methods: 20 individuals with idiopathic PD were recruited to perform the Trail making Test (a test of motor planning) and to wear a step activity monitor for 48 h. The measurement of persistence of an ambulatory event consisted of the number of steps taken during an event and an ambulatory event was defined as continuous ambulation (taking step) without pausing for 3 or more seconds. The resumption of taking step (ambulation) after 3 or more seconds counted as a new ambulatory event. UPDRS-motor and ADL scale were also obtained. Analysis and results: The cumulative percentage of the total ambulatory events at each number of steps was plotted for each subject which when plotted could be described as a sigmoid curve. We found that this sigmoidal curve defined by the equation y = xⁿ/(kⁿ + xⁿ), fit the data well, where k represents a constant specific to each subject, x represents the number of steps during each ambulatory event, and y represents the projected percentage of movement events containing x number of steps or less. (Root Mean Square Error (RMSE) = 0.02, R² = 0.98). Trail making test part A was highly associated with the constant k (R = −0.74, p < 0.001). The constant k was also highly associated with the UPDRS ADL subscale (R = −0.81, p = 0.0001). A forward bivariate regression model including Part A of the Trail making test, and the UPDRS-ADL subscale predicted 66% of the variability of the constant k. The overall number of steps taken per day, and the UPDRS motor subscale did not contribute to the model. Conclusions: Defective motor planning in Parkinson's disease as measured by poor performance on a Trail making test is associated with a measurable alteration in ambulatory persistence, and altered ambulatory persistence, quantified by our proposed model parameter, correlates highly with the UPDRS ADL score. Thus, cognitive-motor planning defects might be a major source of disability in PD. We suggest that in future clinical practice gait tests can be used in order to quantify short-term planning ability in neurodegenerative diseases.     

Decline in genomic DNA methylation through aging in a cohort of elderly subjects

Loss of genomic DNA methylation has been found in a variety of common human age-related diseases. Whether DNA methylation decreases over time as individuals age is unresolved. We measured DNA methylation in 1097 blood DNA samples from 718 elderly subjects between 55 and 92 years of age (1-3 samples/subjects), who have been repeatedly evaluated over an 8-year time span in the Boston area Normative Aging Study. DNA methylation was measured using quantitative PCR-Pyrosequencing analysis in Alu and LINE-1 repetitive elements, heavily methylated sequences with high representation throughout the human genome.Age at the visit was negatively associated with Alu element methylation (β = −0.12 %5 mC/year, p = 0.0005). A weaker association was observed with LINE-1 elements (β = −0.06 %5 mC/year, p = 0.049). We observed a significant decrease in average Alu methylation over time, with a −0.2 %5 mC change (p = 0.012) compared to blood samples collected up to 8 years earlier. The longitudinal decline in Alu methylation was linear and highly correlated with time since the first measurement (β = −0.089 %5 mC/year, p < 0.0001). In contrast, average LINE-1 methylation did not vary over time [p = 0.51]. Our results demonstrate a progressive loss of DNA methylation in repetitive elements dispersed throughout the genome.     

Age-related loss of olfactory sensitivity: Association to dopamine transporter binding in putamen

The relationship between age-related reductions in the binding potential for the striatal dopamine transporter (DAT) and age-related deficits in olfactory sensitivity was examined in 12 subjects ranging from 36 to 82 years of age. Positron emission tomography (PET) and the radioligand [¹¹C]β-CIT-FE were used to determine DAT binding in two striatal regions, the caudate and the putamen. The results showed age-related losses of DAT binding from early to late adulthood of similar size for caudate and putamen, and there was a pronounced age deterioration in olfactory sensitivity. Importantly, the age-related olfactory deficit was associated with reductions in DAT binding in putamen, but not caudate. Also, DAT binding in putamen added systematic variance in odor threshold after controlling for age. The findings indicate that DAT binding in putamen is related to age-related olfactory deficits, as well as to odor sensitivity independently of age.     

Leukocyte telomere length is independently associated with gait speed in elderly women

Objectives

Declining gait speed is common in the elderly population and is associated with age-related conditions. Because telomere length is a reflection of aging and known to affect degenerative changes in organ systems, gait speed may be associated with telomere length. We therefore investigated the relationship between gait speed and leukocyte telomere length in elderly Korean women.

Study design

Cross-sectional study.

Main outcome measures

A total of 117 Korean elderly women participated. Metabolic variables were assessed along with gait speed calculated as walking distance (6 m) divided by time. Leukocyte telomere length was measured by real-time quantitative polymerase chain reaction.

Results

Gait speed correlated with telomere length (r = 0.38, p < 0.01), fasting insulin (r = −0.19, p = 0.04), homeostasis model assessment of insulin resistance index (HOMA-IR; r = −0.22, p = 0.02), triglyceride (r = −0.20, p = 0.03), and Korean Mini-Mental State Examination (K-MMSE; r = 0.20, p = 0.03) after adjusting for age. On step-wise multiple regression analysis, telomere length (β = 0.35, p < 0.01), K-MMSE (β = 0.16, p = 0.02), age (β = −0.23, p = 0.01), and HOMA-IR (β = −0.19, p = 0.03) were identified as independent variables associated with gait speed.

Conclusions

This study suggested that telomere length may have a role in maintaining overall health status as well as preserving gait speed in the elderly population. Further studies are required to better understand the significance of our findings.     

Association study between two novel single nucleotide polymorphisms and sporadic Parkinson's disease in Chinese Han population

Two novel single nucleotide polymorphisms (SNPs) (rs6812193 and rs11868035) were recently identified to be associated with Parkinson's disease (PD) in a Web Based Genome-Wide Association Study. Herein, we conducted a case–control study to evaluate the possible associations between these two SNPs and PD in Chinese Han population. All subjects (501 sporadic PD patients and 502 normal controls) were genotyped using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis with these two SNPs. Chi-square test revealed no significant difference in either genotype frequencies or allele frequencies, even after being stratified by age. But we found that the genotype and allele frequency of rs6812193 shows difference between male patients and male controls (p = 0.031, OR = 0.584; p = 0.037, OR = 0.606) but none in the female. Our findings suggest that rs11868035 may have no association with PD in Chinese population and rs6812193 may have marginal association with PD in male Chinese population. However, due to the limited data in the present study, replication studies in larger sample and other populations are required.     

Association between human leukocyte antigen class I and II alleles and hepatitis C virus infection in high-risk hemodialysis patients awaiting kidney transplantation

Recent evidences have shown that several host genetic factors influence susceptibility or protection to hepatitis C virus (HCV) infection. There are controversial data regarding the associations of human leukocyte antigens (HLA) and the clearance or progression of HCV. The aim of this study was to investigate whether particular HLA molecules were associated with HCV infection in recipients awaiting kidney transplantation considered at high-risk to infection due to protracted hemodialysis treatment. To this purpose, 301 kidney recipients with HCV infection and 1103 uninfected recipients were examined for HLA class I and II molecules. In our case-control study, HLA-A^*26 is positively associated with HCV infection while HLA-A^*29, -B^*40 and -DRB1^*01 are negatively associated with HCV infection. Multiple logistic regression analysis demonstrated that age (OR = 1.02; 95% CI = 1.01–1.04; p < 0.00), HLA-A^*26, -A^*29, -B^*40 and -DRB1^*01 [(OR = 1.54; 95% CI = 1.03–2.30; p = 0.03); (OR = 0.50; 95% CI = 0.26–0.99; p = 0.05); (OR = 0.42; 95% CI = 0.23-0, 7; p = 0.01); (OR = 0.62; 95% CI = 0.41-0, 94; p = 0.03); respectively] are independent predictors of HCV infection. Our results suggest that particular HLA molecules, as host genetic factors, may have a relationship with susceptibility or protection to HCV infection also in recipients awaiting kidney transplantation.