Acetyl Cholinesterase Inhibitors and Cell-Derived Peripheral Inflammatory Cytokines in Early Stages of Alzheimer's Disease.

BACKGROUND: Clinical and preclinical studies firmly support the involvement of the inflammation in the pathogenesis of Alzheimer's disease (AD). Despite acetylcholinesterase inhibitors (AChEI) being widely used in AD patients, there is no conclusive evidence about their impact on the inflammatory response. METHODS: This study investigates peripheral proinflammatory cytokines (interferon gamma [IFN-γ], tumor necrosis factor alpha [TNF-α], and interleukins 1ß [IL-1ß] and 6 [IL-6]) by firstly comparing peripheral blood mononuclear cell (PBMC)-derived secretion in drug-naïve and AChEI-treated AD patients versus healthy controls. A subset of those drug-naïve AD patients, who were prescribed the AChEI donepezil, was followed-up for 6 months to investigate if donepezil suppresses proinflammatory cell-derived cytokine secretion. RESULTS: Patients with AD showed higher levels of PBMC-derived proinflammatory cytokines (IFN-γ, TNF-α, IL-1ß, and IL-6) in comparison with healthy controls. On reexamination, previously drug-naïve AD patients who received donepezil treatment for 6 months displayed a decrease in cell-derived IFN-γ, TNF-α, IL-1ß, and IL-6. CONCLUSIONS: Proinflammatory PBMC-derived cytokines were increased in patients with AD in comparison with healthy controls and donepezil-reduced proinflammatory cytokines when examining drug-naïve AD patients before and after AChEI treatment.

Association between Sirtuin 2 gene rs10410544 polymorphism and depression in Alzheimer's disease in two independent European samples.

Among the several genes associated with late-onset Alzheimer's disease (LOAD), recently, Sirtuin genes have roused a growing interest because of their involvement in metabolic homeostasis and in brain aging. Particularly SIRT2 gene has been associated with Alzheimer's disease (AD) as well as with mood disorders. The aim of this study is to investigate the possible associations between Sirtuin 2 gene (SIRT2) rs10410544 polymorphism and AD as well as depression in AD. In addition, we performed some exploratory analyses to investigate possible associations between the rs10410544 genotype and clinical features. We investigated these associations in two independent samples: the first one was composed of 275 Greek inhabitants and 117 patients; the second sample counted 181 Italian people and 43 patients. All patients were affected by LOAD. We failed to find any association between rs10410544 genotype and AD in the two samples. On the other hand, we found an association between the single nucleotide polymorphism (SNP) and depressive symptomatology (in the total sample p = 0.002), which was modulated by the tumor necrosis factor (TNF) values. Particularly, TT genotype seems to be protective versus depression. Finally, in the exploratory analyses, we found that the TT genotype was associated with earlier AD onset and a longer duration of the illness. In conclusion, we confirmed the association between SIRT2 gene and mood disturbances, although in AD patients. Further, we provided evidence that the TT genotype may be protective versus depressive symptoms, allowing an easier and thus earlier diagnosis of AD. This awareness may lead to a more detailed approach to these patients concerning diagnosis and therapy.

COVID-19 Crisis Effects on Caregiver Distress in Neurocognitive Disorder.

BACKGROUND: The outbreak of the COVID-19 pandemic seems to have mental health implications for both people with neurocognitive disorder and their caregivers. OBJECTIVE: The study aimed to shed light on relations between caregiver mental reaction to the pandemic and caregiver distress related to neuropsychiatric symptoms, memory impairment progression, and functional impairment of people with neurocognitive disorder during the period of confinement in Greece. METHODS: The study included caregivers of patients with mild (N = 13) and major (N = 54) neurocognitive disorder. The caregiver-based telephone interview was based on items of the neuropsychiatric inventory questionnaire, the AD8 Dementia Screening Instrument, and the Bristol Activities of Daily Living Scale. Regarding the mental impact of the COVID-19 crisis on caregivers, four single questions referring to their worries in the last seven days were posed, in addition to the scales Generalized Anxiety Disorder 7-Item (GAD-7) and the 22-item Impact of Event Scale-revised (IES-R). A stepwise linear regression model was employed for studying the relationship between caregiver distress and demographic and clinical data and caregiver mental reaction to COVID-19 pandemic outbreak. RESULTS: Caregiver distress severity during the confinement period was influenced not only by memory deficits (p = 0.009) and neuropsychiatric symptoms (p < 0.001) of patients, but also by caregiver hyperarousal (p = 0.003) and avoidance symptoms (p = 0.033) and worries directly linked to the COVID-19 crisis (p = 0.022). CONCLUSION: These observations provide further evidence for the urgent need for support of caregivers of patients with neurocognitive disorder during the COVID-19 pandemic.

APOE epsilon-4 allele and cytokine production in Alzheimer's disease.

OBJECTIVE: The APOE epsilon-4 allele has consistently emerged as a susceptibility factor for Alzheimer's disease (AD). Pro-inflammatory cytokines are detectable at abnormal levels in AD, and are thought to play a pathophysiological role. Animal studies have shown dose-dependent correlations between the number of APOE epsilon-4 alleles and the levels of pro-inflammatory cytokines. The aims of this study were to investigate the influence of APOE genotypes on TNF-alpha, IL-6, and IL-1beta secreted by peripheral blood mononuclear cells (PBMC) from human patients with AD and to analyze the correlation between cytokine production and AD clinical features. METHODS: Outpatients with AD (n = 40) were clinically evaluated for cognitive decline (MMSE) and psychiatric symptoms (Cornell Scale for Depression in Dementia; Neuropsychiatric Inventory) and genotyped for APOE variants. PBMCs were isolated from the donors and used to assess spontaneous and PMA-stimulated secretion of TNF-alpha, IL-6, and IL-1beta. Cytokine production was determined by immuno-enzymatic assays (ELISA). RESULTS: In comparison with their counterparts without APOE4, patients with at least one copy of the APOE epsilon-4 allele showed higher spontaneous (p = 0.037) and PMA-induced (p = 0.039) production of IL-1beta after controlling for clinical variables. Significant correlations were reported between NPI scores (psychotic symptoms) and IL-6 production. CONCLUSION: These preliminary findings suggest the involvement of inflammatory response in the pathogenic effect of the APOE epsilon-4 allele in AD, although their replication in larger samples is mandatory. The modest correlations between pro-inflammatory cytokines released at peripheral level and AD features emphasizes the need for further research to elucidate the role of neuroinflammation in pathophysiology of AD.

Lack of association between interleukin-1 alpha rs1800587 polymorphism and Alzheimer's disease in two Independent European samples.

Interleukin-1 (IL1) can contribute to pathophysiology of Alzheimer's disease (AD) by promoting deposition of amyloid-beta in the brain. The gene encoding IL1 alpha (IL1A) has a common polymorphism in its 5' regulatory region (rs1800587) with possible functional effects. IL1A T/T genotype has been associated with AD but the overall effect is modest and negative studies have been published. The aim of this study was to investigate the association of the IL1A rs1800587 polymorphism with AD in two independent case-control groups from Greece (Athens) and Italy (Faenza and Granarolo). Preliminary results from the ongoing sample (110 patients with sporadic AD and 130 nonpsychiatric controls) showed no association between IL1A variants and AD, however C/T heterozygotes had more severe depression in AD (Cornell Scale for Depression in Dementia) compared to other genotypes (F = 4.56, d.f = 1, p = 0.037) after controlling for age, illness duration and cognitive impairment (MMSE). Despite the small sample size and the possibility of a false negative finding, our preliminary data support the hypothesis the IL1A rs1800587 variants are not associated with AD. The effect of the IL1A on depressive symptomatology warrants further investigations, however the lack of a gene-dose relationship would suggest a false positive.

Differential Expression of Apoptotic and Low-Grade Inflammatory Markers in Alzheimer Disease Compared to Diabetes Mellitus Type 1 and 2.

BACKGROUND: Neuroinflammation, impaired brain insulin signaling, and neuronal apoptosis may be interrelated in the pathophysiology of people with Alzheimer disease (AD) and diabetes, either type 1 or 2 diabetes (T1D or T2D, respectively). METHODS: We studied 116 patients: 41 with AD, 20 with T1D, 21 with T2D, and 34 healthy controls. The number (n) of cytokine-secreting peripheral blood mononuclear cells (PBMCs) before and after mitogenic stimulation was determined for interleukin 1ß (IL1ß), interleukin 6 (IL6), tumor necrosis factor (TNF) by the enzyme-linked-immuno-spot assay. Serum concentrations of C-reactive protein (CRP) and Fas ligand (FASLG) were determined by ELISA. RESULTS: The studied subgroups did not differ in sex but differed in age. Higher CRP concentrations were detected in the AD group than in the T1D group (P = 0.02) and lower in controls (P < 0.001). The nPBMCs was higher in AD patients after stimulation than in basal conditions: after stimulation in nTNF (P < 0.001 vs T2D; P < 0.001 vs T1D; P = 0.001 vs control), nIL6 (P = 0.039 vs T2D; P < 0.001 vs T1D; P = 0.007 vs control), and nIL1ß (P = 0.03 vs control). The nPBMCs increased after stimulation with ΡΜA in all the subgroups (P < 0.001). FASLG in the AD group displayed statistically higher concentrations than in all other subgroups (P < 0.001 vs T2D; P < 0.001 vs T1D; P = 0.012 vs control). The nPBMCs was positively correlated with plasma concentrations of FASLG in the AD subgroup. CONCLUSIONS: Patients with AD display a low-grade systemic inflammation compared to people with diabetes. The FAS-FASLG pathway has a potential role because FASLG concentrations are positively correlated with the inflammatory response in AD. However, this positive correlation cannot be seen in people with diabetes, at least not with the apoptotic markers used in the present study.

Effects of SORL1 gene on Alzheimer's disease. Focus on gender, neuropsychiatric symptoms and pro-inflammatory cytokines.

It was suggested that the gene encoding for sorLa, (SORL1) may affect Alzheimer's disease (LOAD) through a female-specific mechanism. The aims of this study were to confirm the role of gender in modulating the association between SORL1 and LOAD and to ascertain the influence of SORL1 on cognitive impairment, neuropsychiatric symptoms (BPSD) and secretion of pro-inflammatory cytokines. Ninety six outpatients with LOAD and 120 unrelated controls were genotyped for APOE and three SNPs at the 5' end of SORL1(intron 6): SNP 8 (rs668387); SNP 9 (rs68902); SNP 10 (rs641120). Clinical evaluation was made with the MMSE, Neuropsychiatric Inventory (NPI) and Cornell Scale for Depression in Dementia (CDDS). ELISPOT assays were used to measure pro-inflammatory cytokine (TNF-alpha; IL-6; IL-1beta; IFN-gamma) production in peripheral blood mononuclear cell (PBMC) supernatant from AD patients. SORL1 SNPs were not associated with LOAD in overall sample. Instead the G-alleles at SNPs 9 (p=0.015) and 10 (p=0.015) and the CGG haplotype (p=0.02) were associated with LOAD in the women subgroup. The TAA haplotype was marginally protective in AD patients being associated with lower BPSD scores (p=0.01). The same haplotype was also associated with higher IL-1beta (p=0.01) production. These genetic effects were not modified by APOE4 allele and controlled for illness duration and treatment. In conclusion, SORL1 does not appear to be a major risk factor for LOAD. Its contribution could be underestimated in our small sample. Sex-specific factors could modulate the association between SORL1 and AD. The influence of SORL1 variants on production of inflammatory cytokines warrants further investigation.

Association of SORL1 alleles with late-onset Alzheimer's disease. findings from the GIGAS_LOAD study and mega-analysis.

The pathophysiology of Alzheimer's disease (AD) is influenced by sorting-protein related receptor (sorLa) that is less expressed in AD patients. The gene encoding sorLa (SORL1) has been investigated as a susceptibility factor for late-onset AD (LOAD) with conflicting results. Our objectives were to confirm the association between SORL1 SNPs and LOAD in two independent South-European centers and to perform a mega-analysis of published samples. We analyzed three SORL1 SNPs (intron 6: rs668387; rs689021; rs641120) from the Greece-Italy Genetic Association Study on lateonset AD (GIGAS_LOAD). Greek sample included 96 patients with LOAD (DSM-IV) and 120 unrelated controls. In Italy, a community-based sample is ongoing. 47 LOAD patients and 165 controls were recruited until study endpoint. These samples and previously published ones (Alzgene) were pooled as in a single study. A test for trend was used to analyze genotype association. In the GIGAS_LOAD sample no association was detected between SORL1 genotypes and LOAD. Conversely all SNPs were associated with LOAD in mega-analysis based on ordinal classification of genotypes (Armitage's test: p < 0.001). Although our analysis of pooled samples has positive results for the association between SORL1 and AD, there is substantial heterogeneity across studies. Thus further examination into SORL1 SNPs and the population is necessary to determine the role of SORL1 in LOAD.

Vitamin B12 levels in Alzheimer's disease: association with clinical features and cytokine production.

Alzheimer's disease (AD) has been associated with up-regulation of pro-inflammatory cytokines (e.g., specific gene variants for TNF-alpha; IL-6; IFN-gamma) and low plasma levels of cyanocobalamin (vitamin B12). Our goal was to relate B12 levels to AD symptoms and to expression of pro-inflammatory cytokines. Clinical manifestations were investigated for a case series of fifty-five outpatients using the MMSE, Neuropsychiatric Inventory (NPI) and Cornell Scale for Depression in Dementia (CDDS). Plasma B12 levels were measured by radioligand binding assay. Basal and PMA-stimulated levels of IFN-gamma, TNF-alpha, and IL-6 were measured by ELISPOT (PBMC culture supernatant). 47 patients were genotyped for APOE. Ten patients (18%) had their B12 levels below < 250 pg/ml. They did not statistically differ from those 45 who had normal levels in most demographic and clinical features; their MMSE scores were lower (14.7 vs 19.6 p=0.03) but not after adjustment for disease duration. A greater basal production of IL-6 was reported in patients who had low B12 levels compared to normal B12 subjects (1333 pg/ml vs 976 p< 0.01); this association was confirmed after controlling for age of onset and APOE genotype. In conclusion, low B12 level is associated with greater production of IL-6 in peripheral blood mononuclear cells. Further research is warranted to elucidate whether this neuroinflammatory effect of cobalamin is implicated in the pathophysiology of AD.