APOE genetic variants and apoE, miR-107 and miR-650 levels in Alzheimer's disease.

Alzheimer's disease (AD) is a progressive neurodegenerative dementia in adults. Pathogenesis of AD depends on various factors, including APOE genetic variants, apolipoprotein E (apoE) phenotype and oxidative stress, which may promote both DNA and RNA damage, including non-coding RNA (ncRNA). Among ncRNAs, microRNA (miRNA) is known to contribute to pathologic processes in AD. The aim of the study was to analyse the plasma concentration of apoE by ELISA as well as the plasma levels of miR-107 and miR-650 by qPCR in relation to APOE genetic variants and clinical features including the age of onset and dementia severity in 64 AD patients and 132 controls. Our data showed that a low apoE plasma concentration was a risk factor for developing AD (OR = 5.18, p = 6.58E-06) and was particularly pronounced in severe dementia (p < 0.001) and correlated with cognitive functions (R = 0.295, p = 0.020), similarly as the level of miR-650 (R = 0.385, p = 0.033). The presence of APOE E4 allele in both AD patients and controls led to a reduction in apoE, while APOE E3/E3 genotype was associated with an increased apoE concentration and level of miR-107 in AD (p < 0.05) which was inversely correlated with the number of APOE E4 alleles (R = -0.448, p = 0.009). Additionally, patients with the onset at 60-69 years of age showed a reduced level of miR-107 (p < 0.05, as compared to AD above 80 years of age). Changed levels of plasma apoE, miR-107 and miR-650 may be a marker of the neurodegenerative process in the course of AD, associated with amyloid ß metabolism and inordinate cell cycle.

Biothiols and oxidative stress markers and polymorphisms of TOMM40 and APOC1 genes in Alzheimer's disease patients.

Alzheimer's disease (AD) is a progressive disease, with frequently observed improper biothiols turnover, homocysteine (Hcy) and glutathione (GSH). GSH protects cells from oxidative stress and may be determined by 8-oxo-2'-deoxyguanosine (8-oxo2dG) level and its repair enzyme 8-oxoguanine DNA glycosylase (OGG1). The presence of unfavorable alleles, e.g., in APOE cluster, TOMM40 or APOC1 is known to facilitate the dementia onset under oxidative stress. The aim of the study was to analyze rs1052452, rs2075650 TOMM40 polymorphisms, rs4420638 APOC1, and their correlation with Hcy, GSH, 8-oxo2dG, OGG1 levels in plasma of AD patients and controls. We recruited 230 individuals: 88 AD, 80 controls without (UC), 62 controls with (RC) positive family history of AD. The TOMM40 genotype was determined by HRM and capillary electrophoresis, while APOC1 by HRM. The concentrations of OGG1, 8-oxo2dG were determined by ELISA, whereas Hcy, GSH by HPLC/EC. We showed that over 60% of AD patients had increased Hcy levels (p<0.01 vs. UC, p<0.001 vs. RC), while GSH (p<0.01 vs. UC), 8-oxo2dG (p<0.01 vs. UC, p<0.001 vs. RC) were reduced. Minor variants: rs10524523-L, rs4420638-G, rs2075650-G were significantly overrepresented in AD. For rs4420638-G, rs2075650-G variants, the association remained significant in APOE E4 non-carriers. The misbalance of analyzed biothiols, and 8-oxo2dG, OGG1 were more pronounced in carriers of major variants: rs10524523-S/VL, rs4420638-A, rs2075650-A. We showed, for the first time, that APOC1 and TOMM40 rs2075650 polymorphisms may be independent risk factors of developing AD, whose major variants are accompanied by disruption of biothiols metabolism and inefficient removal of DNA oxidation.

Hypermethylation of TRIM59 and KLF14 Influences Cell Death Signaling in Familial Alzheimer's Disease.

Epigenetic mechanisms play an important role in the development and progression of various neurodegenerative diseases. Abnormal methylation of numerous genes responsible for regulation of transcription, DNA replication, and apoptosis has been linked to Alzheimer's disease (AD) pathology. We have recently performed whole transcriptome profiling of familial early-onset Alzheimer's disease (fEOAD) patient-derived fibroblasts. On this basis, we demonstrated a strong dysregulation of cell cycle checkpoints and DNA damage response (DDR) in both fibroblasts and reprogrammed neurons. Here, we show that the aging-correlated hypermethylation of KLF14 and TRIM59 genes associates with abnormalities in DNA repair and cell cycle control in fEOAD. Based on the resulting transcriptome networks, we found that the hypermethylation of KLF14 might be associated with epigenetic regulation of the chromatin organization and mRNA processing followed by hypermethylation of TRIM59 likely associated with the G2/M cell cycle phase and p53 role in DNA repair with BRCA1 protein as the key player. We propose that the hypermethylation of KLF14 could constitute a superior epigenetic mechanism for TRIM59 hypermethylation. The methylation status of both genes affects genome stability and might contribute to proapoptotic signaling in AD. Since this study combines data obtained from various tissues from AD patients, it reinforces the view that the genetic methylation status in the blood may be a valuable predictor of molecular processes occurring in affected tissues. Further research is necessary to define a detailed role of TRIM59 and KLF4 in neurodegeneration of neurons.

Overactive BRCA1 Affects Presenilin 1 in Induced Pluripotent Stem Cell-Derived Neurons in Alzheimer's Disease.

The BRCA1 protein, one of the major players responsible for DNA damage response has recently been linked to Alzheimer's disease (AD). Using primary fibroblasts and neurons reprogrammed from induced pluripotent stem cells (iPSC) derived from familial AD (FAD) patients, we studied the role of the BRCA1 protein underlying molecular neurodegeneration. By whole-transcriptome approach, we have found wide range of disturbances in cell cycle and DNA damage response in FAD fibroblasts. This was manifested by significantly increased content of BRCA1 phosphorylated on Ser1524 and abnormal ubiquitination and subcellular distribution of presenilin 1 (PS1). Accordingly, the iPSC-derived FAD neurons showed increased content of BRCA1(Ser1524) colocalized with degraded PS1, accompanied by an enhanced immunostaining pattern of amyloid-ß. Finally, overactivation of BRCA1 was followed by an increased content of Cdc25C phosphorylated on Ser216, likely triggering cell cycle re-entry in FAD neurons. This study suggests that overactivated BRCA1 could both influence PS1 turnover leading to amyloid-ß pathology and promote cell cycle re-entry-driven cell death of postmitotic neurons in AD.

Efficacy and safety of abobotulinumtoxinA in spastic lower limb: Randomized trial and extension.

OBJECTIVE: To demonstrate single abobotulinumtoxinA injection efficacy in lower limb vs placebo for adults with chronic hemiparesis and assess long-term safety and efficacy of repeated injections. METHODS: In a multicenter, double-blind, randomized, placebo-controlled, single-cycle study followed by a 1-year open-label, multiple-cycle extension, adults ≥6 months after stroke/brain injury received one lower limb injection (abobotulinumtoxinA 1,000 U, abobotulinumtoxinA 1,500 U, placebo) followed by ≤4 open-label cycles (1,000, 1,500 U) at ≥12-week intervals. Efficacy measures included Modified Ashworth Scale (MAS) in gastrocnemius-soleus complex (GSC; double-blind primary endpoint), physician global assessment (PGA), and comfortable barefoot walking speed. Safety was the open-label primary endpoint. RESULTS: After a single injection, mean (95% confidence interval) MAS GSC changes from baseline at week 4 (double-blind, n = 381) were as follows: -0.5 (-0.7 to -0.4) (placebo, n = 128), -0.6 (-0.8 to -0.5) (abobotulinumtoxinA 1,000 U, n = 125; p = 0.28 vs placebo), and -0.8 (-0.9 to -0.7) (abobotulinumtoxinA 1,500 U, n = 128; p = 0.009 vs placebo). Mean week 4 PGA scores were as follows: 0.7 (0.5, 0.9) (placebo), 0.9 (0.7, 1.1) (1,000 U; p = 0.067 vs placebo), and 0.9 (0.7, 1.1) (1,500 U; p = 0.067); walking speed was not significantly improved vs placebo. At cycle 4, week 4 (open-label), mean MAS GSC change reached -1.0. Incremental improvements in PGA and walking speed occurred across open-label cycles; by cycle 4, week 4, mean PGA was 1.9, and walking speed increased +25.3% (17.5, 33.2), with 16% of participants walking >0.8 m/s (associated with community mobility; 0% at baseline). Tolerability was good and consistent with the known abobotulinumtoxinA safety profile. CONCLUSIONS: In chronic hemiparesis, single abobotulinumtoxinA (Dysport Ipsen) administration reduced muscle tone. Repeated administration over a year was well-tolerated and improved walking speed and likelihood of achieving community ambulation. CLINICALTRIALGOV IDENTIFIERS: NCT01249404, NCT01251367. CLASSIFICATION OF EVIDENCE: The double-blind phase of this study provides Class I evidence that for adults with chronic spastic hemiparesis, a single abobotulinumtoxinA injection reduces lower extremity muscle tone.

Serial measurements of levels of the chemokines CCL2, CCL3 and CCL5 in serum of patients with acute ischaemic stroke.

Inflammation, involving cytokine/chemokine expression, occurs after stroke and deteriorates its course with leukocyte-mediated brain infarct progression. Chemokines are cytokines attracting selective leukocyte subsets and subgrouping into the four major subfamilies, CC, CXC, C, and CX3C. The CC subfamily preferentially acts on mononuclears. The study aimed to define serum CCL2, CCL3 and CCL5 levels in stroke patients and their relationship to the extent of disease severity and outcome. 27 ischaemic stroke patients and 20 controls were studied. Blood sampling for the determination of chemokines was performed at days 1, 2 and 3 of stroke, while neurological and functional deficits were estimated, respectively, with the Scandinavian Stroke Scale (SSS) and Barthel Index (BI) at the same time points and at days 14 and 28. Serum CCL3 levels at days 1, 2 and 3 of stroke were significantly higher than in controls. Serum CCL2 and CCL5 levels in stroke patients did not differ from those in controls at any of the time points examined. Serum chemokine levels in stroke studied separately did not differ between each other at any time point studied and demonstrated considerable variability. No correlation between serum chemokine levels and SSS scores was observed. Serum CCL2 and CCL3 levels at days 1, 2 and 3 of stroke correlated with BI scores at day 28. Serum CCL2 levels at days 2 and 3 of stroke also correlated with BI scores at day 14. Serum CCL5 levels at day 2 of stroke correlated with BI scores at day 28. The early and sustained increase in serum CCL3 levels in stroke patients along with correlation between them and short-term poststroke functional disability could indicate that the chemokine response may predispose to poor stroke outcome. The relationship between non-increased serum CCL2 and CCL5 levels and worse stroke outcome seems to be coincidental. Overall, as a result of large interindividual variability, CCL2, CCL3 and CCL5 are not reliable candidates for surrogate markers in stroke.

Mutations in presenilin 1, presenilin 2 and amyloid precursor protein genes in patients with early-onset Alzheimer's disease in Poland.

Mutations in three causative genes have been identified in patients with an autosomal-dominant form of early-onset Alzheimer's disease (EOAD). To determine the spectrum of mutations in a group consisting of 40 Polish patients with clinically diagnosed familial EOAD and 1 patient with mild cognitive impairment (MCI) and family history of AD, we performed a screening for mutations in the presenilin 1 (PSEN1), presenilin 2 (PSEN2) and amyloid precursor protein (APP) genes. Four previously recognized pathogenic mutations in PSEN1 gene (H163R, M139V) and APP gene (T714A, V715A), and three novel putative mutations in PSEN1 gene (P117R and I213F) and PSEN2 gene (Q228L) were identified. The 34 patients with no mutations detected were older than the patients with mutations. A frequency of APOE4 allele was higher in this group. Frequency of mutations is relatively low (17%), possibly due to used operational definition of a patient with familial EOAD (a patient having at least one relative with early-onset dementia). It could be concluded that screening for mutations in the three genes could be included in a diagnostic program directed at patients with a positive family history or age of onset before 55 years.