Genetic Association between Akt1 Polymorphisms and Alzheimer's Disease in a Japanese Population

A recent paper reported that Aβ oligomer causes neuronal cell death through the phosphatidylinositol-3-OH kinase (PI3K)-Akt-mTOR signaling pathway. Intraneuronal Aβ, a main pathological finding of Alzheimer's disease (AD), is also known as inhibiting activation of Akt. This study aims to investigate whether single nucleotide polymorphisms (SNPs) of the Akt1 gene are associated with AD. SNPs genotyped using TaqMan technology was analyzed using a case-control study design. Our case-control dataset consisted of 180 AD patients and 130 age-matched controls. Although two SNPs showed superficial positive, Hardy-Weinberg equilibrium (HWE) tests, and linkage disequilibrium (LD) analyses suggested that genetic regions of the gene are highly polymorphic. We failed to detect any synergetic association among Akt1 polymorphisms, Apolipoprotein E (APO E), and AD. Further genetic studies are needed to clarify the relationship between the Akt1 and AD

Emerging roles of ARHGAP33 in intracellular trafficking of TrkB and pathophysiology of neuropsychiatric disorders

Intracellular trafficking of receptor proteins is essential for neurons to detect various extracellular factors during the formation and refinement of neural circuits. However, the precise mechanisms underlying the trafficking of neurotrophin receptors to synapses remain elusive. Here, we demonstrate that a brain-enriched sorting nexin, ARHGAP33, is a new type of regulator for the intracellular trafficking of TrkB, a high-affinity receptor for brain-derived neurotrophic factor. ARHGAP33 knockout (KO) mice exhibit reduced expression of synaptic TrkB, impaired spine development and neuropsychiatric disorder-related behavioural abnormalities. These deficits are rescued by specific pharmacological enhancement of TrkB signalling in ARHGAP33 KO mice. Mechanistically, ARHGAP33 interacts with SORT1 to cooperatively regulate TrkB trafficking. Human ARHGAP33 is associated with brain phenotypes and reduced SORT1 expression is found in patients with schizophrenia. We propose that ARHGAP33/SORT1-mediated TrkB trafficking is essential for synapse development and that the dysfunction of this mechanism may be a new molecular pathology of neuropsychiatric disorders

An analysis of radioactivity distribution in soil particles using an autoradiogram method

More than 22,000,000 m3 of soil was contaminated with cesium (Cs) radioisotopes following the accident at the Fukushima Daiichi Nuclear Power Plant. For site remediation, it is necessary to reduce this huge volume of contaminated soil. To achieve this, we investigated the distribution of contamination within soil particles. We measured the radioactivity distribution in soil particles using an autoradiogram (ARG) method, with a resolution of 50 × 50 μm, and also determined the elemental distributions with energy-dispersive X-ray spectroscopy. The ARG showed that almost all particles were uniformly contaminated with Cs radioisotopes, while the elemental distributions indicated that the particles were clay aggregates. These results suggest that, by impacting contaminated particles with each other and classifying them, we can reduce the volume of contaminated soil

Assessment of the effect of rainfall erosion on radioactive decontamination by analyzing the sedimentary layer formed by soil transported from mountains

The accident at the Fukushima Daiichi Nuclear Power Plant caused widespread contamination in Fukushima Prefecture. The area was mainly contaminated with radioisotopes of iodine 131, cesium 134, and cesium 137. The surface soil has been removed in an attempt to decontaminate the evacuated area (1,150 km2). Rainfall erosion is believed to decontaminate mountains, so the surface soil has not been removed there. We thus investigated whether the mountains had been decontaminated by analyzing soil from the sedimentary layers found at the mouth of a stream that passes through these mountains. The volumeand radioactivity distributions of the sedimentary layers showed that the heavy rainfall right after the earthquake contained a large amount of radioactive cesium. We confirmed that most small soil particles, those with diameters less than 210 μm, were not deposited at intermediate positions as they were transported downstream. Hence, rainfall erosion is a very effective means of decontaminating the mountains

Carbonyl Stress and Microinflammation-Related Molecules as Potential Biomarkers in Schizophrenia

This literature review primarily aims to summarize our research, comprising both cross-sectional and longitudinal studies, and discuss the possibility of using microinflammation-related biomarkers as peripheral biomarkers in the diagnosis and monitoring of patients with schizophrenia. To date, several studies have been conducted on peripheral biomarkers to recognize the potential markers for the diagnosis of schizophrenia and to determine the state and effects of therapy in patients with schizophrenia. Research has established a correlation between carbonyl stress, an environmental factor, and the pathophysiology of neuropsychiatric diseases, including schizophrenia. In addition, studies on biomarkers related to these stresses have achieved results that are either replicable or exhibit consistent increases or decreases in patients with schizophrenia. For instance, pentosidine, an advanced glycation end product (AGE), is considerably elevated in patients with schizophrenia; however, low levels of vitamin B6 [a detoxifier of reactive carbonyl compounds (RCOs)] have also been reported in some patients with schizophrenia. Another study on peripheral markers of carbonyl stress in patients with schizophrenia revealed a correlation of higher levels of glyceraldehyde-derived AGEs with higher neurotoxicity and lower levels of soluble receptors capable of diminishing the effects of AGEs. Furthermore, studies on evoked microinflammation-related biomarkers (e.g., soluble tumor necrosis factor receptor 1) have reported relatively consistent results, suggesting the involvement of microinflammation in the pathophysiology of schizophrenia. We believe that our cross-sectional and longitudinal studies as well as various previous inflammation marker studies that could be interpreted from several perspectives, such as mild localized encephalitis and microvascular disturbance, highlighted the importance of early intervention as prevention and distinguished the possible exclusion of inflammations in schizophrenia

Age-Related Association between Apolipoprotein E ε4 and Cognitive Function in Japanese Patients with Alzheimer's Disease

Aims: In the present study, we investigated whether apolipoprotein E (APOE) polymorphisms influenced the cognitive function of Japanese patients with Alzheimer's disease (AD) at certain ages. Methods: Among 200 outpatients with dementia and amnestic mild cognitive impairment, 133 Japanese patients with AD were recruited and divided into two genotypic groups: APOE ε4 carriers and noncarriers. Then, we compared several neuropsychological test scores between the two genotypic groups for two different generations: 70s (70-79 years) and 80s (80-89 years). Results: The total Mini-Mental State Examination score (p Conclusion: The present results suggest that APOE may significantly influence comparatively simple memory processing in certain generations of Japanese patients with AD

No Associations Found between PGBD1 and the Age of Onset in Japanese Patients Diagnosed with Sporadic Alzheimer’s Disease

Background/Aims: PiggyBac transposable element derived 1 (PGBD1) encodes a molecule involved in epigenetic mechanisms that have been implicated in Alzheimer’s disease (AD), and recent genome-wide association studies and meta-analyses have indicated that a single nucleotide polymorphism (SNP), rs3800324, in PGBD1 could be associated with AD and the age of onset. However, no Japanese patients were examined in these studies. The aim of the present study was to replicate the previous finding in Japanese AD cases. Methods: We performed a case-control study (211 cases and 156 controls) to investigate the association between PGBD1 and Japanese AD using 4 tag SNPs including rs3800324. Results: Single SNP and haplotype analysis showed no association between AD and age of onset, whereas genotypic and allelic frequencies of the ε4 of apolipoprotein E (APOE) showed an association with AD as expected. Conclusion: In Japanese AD, we observed no influence of PGBD1, as either a risk factor or a modifier, even though APOE was associated with AD in this population

Genetic Association between Neurotrophin-3 Polymorphisms and Alzheimer's Disease in Japanese Patients

Background: Some polymorphisms of the neurotrophin family have previously been investigated as candidate genes for Alzheimer's disease (AD). In the present study, we examined whether neurotrophin-3 (NTF-3) polymorphisms are genetic risk factors in patients with AD. Methods: From a sample of 507 subjects, we recruited 248 age-matched subjects divided into 2 groups: AD patients (n = 143) and normal controls (NCs) (n = 105). We identified 3 representative NTF-3 single nucleotide polymorphisms (SNPs): rs6332, rs6489630, and rs4930767. Next, we statistically compared the allele frequencies of each SNP between the AD and NC groups in the early-onset (Results: We found a significant association between rs6332 and the total group of AD patients (p = 0.013) and significant associations between both rs6332 (p = 0.033) and rs6489630 (p = 0.035) and early-onset AD patients. Conclusion: These results suggest that NTF-3 SNPs may not only be associated with AD itself, but also with early-onset AD in Japanese patients, assuming that the NTF-3 gene may have age-related effects on neurodegenerative diseases