APBB2 genetic polymorphisms are associated with severe cognitive impairment in centenarians

Identification of key candidate genes for wing length-related traits by whole-genome resequencing in 772 geese

1. A total of 772, 420-day-old Xingguo gray geese (XGG) were sequenced using a low-depth (~1×) whole-genome resequencing strategy to reveal the genetic mechanism of wing length-related traits by genome-wide association analysis (GWAS).2. The results showed that 119 SNPs had genome-wide significance for wing length in five regions of chromosome 4, of which the most significant locus (P=7.95E-11) was located upstream of RBM47 and explained 7.3% of phenotypic variation.3. A total of 219 SNPs located on chromosome 4 that were associated with 2-joint-wing length, of which four SNPs reached the genome-wide significant level. However, for the length of 1-joint-wing and primary feather, we did not detect any associated locus.4. Six promising candidate genes, RBM47, SLAIN2, GRXCR1, SLC10A4, APBB2 and NSUN7 on chromosome 4, may play an important role in the growth and development of feathers, muscles and bones.

Physical Activity Rewires the Human Brain against Neurodegeneration

Physical activity may offset cognitive decline and dementia, but the molecular mechanisms by which it promotes neuroprotection remain elusive. In the absence of disease-modifying therapies, understanding the molecular effects of physical activity in the brain may be useful for identifying novel targets for disease management. Here we employed several bioinformatic methods to dissect the molecular underpinnings of physical activity in brain health. Network analysis identified 'switch genes' associated with drastic hippocampal transcriptional changes in aged cognitively intact individuals. Switch genes are key genes associated with dramatic transcriptional changes and thus may play a fundamental role in disease pathogenesis. Switch genes are associated with protein processing pathways and the metabolic control of glucose, lipids, and fatty acids. Correlation analysis showed that transcriptional patterns associated with physical activity significantly overlapped and negatively correlated with those of neurodegenerative diseases. Functional analysis revealed that physical activity might confer neuroprotection in Alzheimer's (AD), Parkinson's (PD), and Huntington's (HD) diseases via the upregulation of synaptic signaling pathways. In contrast, in frontotemporal dementia (FTD) its effects are mediated by restoring mitochondrial function and energy precursors. Additionally, physical activity is associated with the downregulation of genes involved in inflammation in AD, neurogenesis in FTD, regulation of growth and transcriptional repression in PD, and glial cell differentiation in HD. Collectively, these findings suggest that physical activity directs transcriptional changes in the brain through different pathways across the broad spectrum of neurodegenerative diseases. These results provide new evidence on the unique and shared mechanisms between physical activity and neurodegenerative diseases.

Risk and protective factors of neurocognitive disorders in older adults in Central and Eastern Europe: A systematic review of population-based studies

BACKGROUND

A wide range of potentially modifiable risk factors, indicating that the onset of neurocognitive disorders can be delayed or prevented, have been identified. The region of Central and Eastern Europe has cultural, political and economic specifics that may influence the occurrence of risk factors and their link to the cognitive health of the population.

OBJECTIVE

We aimed to systematically review population-based studies from Central and Eastern Europe to gather evidence on risk and protective factors for neurocognitive disorders.

METHODS

We searched the electronic databases PubMed, Cochrane Database of Systematic Reviews, PsycINFO, Web of Science, and Embase. The search was performed on 26th of February 2020 and repeated at the end of the review process on 20th May 2021.

RESULTS

We included 25 papers in a narrative synthesis of the evidence describing cardiovascular risk factors (n = 7), social factors (n = 5), oxidative stress (n = 2), vitamins (n = 2), genetic factors (n = 2) and other areas (n = 7). We found that there was a good body of evidence on the association between neurocognitive disorders and the history of cardiovascular disease while there were gaps in research of genetic and social risk factors.

CONCLUSION

We conclude that the epidemiological evidence from this region is insufficient and population-based prospectively followed cohorts should be established to allow the development of preventive strategies at national levels.

miR‑205‑3p promotes lung cancer progression by targeting APBB2

Non-small cell lung cancer (NSCLC), a leading cause of cancer-associated mortality, has resulted in low survival rates and a high mortality worldwide. Accumulating evidence has suggested that microRNAs (miRs) play critical roles in the regulation of cancer progression and the present study aimed to explore the underlying mechanism of miR-205 in NSCLC. Reverse transcription-quantitative PCR was performed, which determined that miR-205 expression was upregulated in NSCLC, and the present study detected the upregulation of miR-205-3p in a number of NSCLC cell lines and NSCLC tissues. In addition, the mediation of amyloid β precursor protein-binding family B member 2 (APBB2) by miR-205-3p was demonstrated. Moreover, miR-205-3p was predicted to directly target the 3′untranslated region of APBB2, which was confirmed using a dual-luciferase reporter assay. It was found that lentivirus mediated-APBB2 knockdown could promote cellular viability and suppress apoptosis in NSCLC cells, as determined via MTT, TUNEL and flow cytometry assays. Thus, the current findings highlighted the potential promotive impact of miR-205-3p on NSCLC processes and may provide theoretical evidence for miR-205-3p as a potential clinical gene therapy target.

A genome-wide multiphenotypic association analysis identified candidate genes and gene ontology shared by four common risky behaviors

BACKGROUND

Risky behaviors can lead to huge economic and health losses. However, limited efforts are paid to explore the genetic mechanisms of risky behaviors.

RESULT

MASH analysis identified a group of target genes for risky behaviors, such as APBB2, MAPT and DCC. For GO enrichment analysis, FUMA detected multiple risky behaviors related GO terms and brain related diseases, such as regulation of neuron differentiation (adjusted P value = 2.84×10^-5), autism spectrum disorder (adjusted P value =1.81×10^-27) and intelligence (adjusted P value =5.89×10^-15).

CONCLUSION

We reported multiple candidate genes and GO terms shared by the four risky behaviors, providing novel clues for understanding the genetic mechanism of risky behaviors.

METHODS

Multivariate Adaptive Shrinkage (MASH) analysis was first applied to the GWAS data of four specific risky behaviors (automobile speeding, drinks per week, ever-smoker, number of sexual partners) to detect the common genetic variants shared by the four risky behaviors. Utilizing genomic functional annotation data of SNPs, the SNPs detected by MASH were then mapped to target genes. Finally, gene set enrichment analysis of the identified candidate genes were conducted by the FUMA platform to obtain risky behaviors related gene ontology (GO) terms as well as diseases and traits, respectively.

APBB2 is associated with amphetamine use and plasma beta-amyloids in patients receiving methadone maintenance treatment

APBB2, amyloid beta (A4) precursor protein-binding family B member 2, has been reported to be associated with opioid dependence. In this study, we reported the first time that the genetic variants in the APBB2 gene were associated with use of amphetamine in opioid dependent patients undergoing methadone maintenance treatment (MMT). 344 heroin-dependent patients undergoing MMT were recruited and assessed for use of amphetamine and opioids by urine toxicology, withdrawal severity, and side effects. DNAs were genome-widely genotyped for all patients. Single nucleotide polymorphisms (SNPs) in APBB2 were selected for association analyses for methadone treatment responses. Gene expression levels of APBB2 were measured by real-time polymerase chain reaction (PCR) in the EBV-transformed lymphoblastoids from patients. MMT patients who used amphetamine showed a significantly higher percentage of positive results in the urine morphine test (P=0.005), and insomnia (P=0.018). In single locus association analyses, SNPs rs3935357 and rs4861075 located at intron 6 were significantly associated with amphetamine use in both genotype and allele type (general linear model (GLM), P=0.0003, and 0.0002 for genotype, and 0.0003, and 0.002 for allele type, respectively). The major allele type carriers had twice risk of amphetamine use compared to the minor allele type carriers. Subjects with the TT genotype of rs4861075 showed significantly higher levels of APBB2 gene expression in both total (P=0.02) and long-form (P=0.037) than those with CC genotype. Detailed mechanisms underlying the association of APBB2 with amphetamine use and level of plasma amyloid beta in MMT patients require further investigation.

Selection of biomarkers for HIV-1 latency by integrated analysis

A major obstacle in the treatment of human immunodeficiency virus type 1 (HIV-1) is its ability to establish latent infection. To find novel biomarkers associated with the mechanism of HIV-1 latent infection, we identified 70 candidate genes in HIV-1 latently infected cells through the integrated analysis in a previous study. It is important to select more effective biomarkers among 70 candidates and to verify the possibility of selected biomarkers for HIV-1 latency. We identified the 24 and 25 genes from 70 candidate genes in significantly enriched categories selected by Database for Annotation, Visualization and Integrated Discovery (DAVID) software and Gene Set Enrichment Analysis (GSEA) software, respectively. Also, we investigated genes regulated in both HIV-1 latently infected cell lines and PBMCs from HIV-1 infected patients and found the genes with a common pattern of expression levels in both cell lines and PBMCs. Consequently, we identified nine genes, APBB2, GMPR, IGF2BP3, LRP1, MAD2L2, MX1, OXR1, PTK2B, and TNFSF13B, via integrated analysis. Especially, APBB2 and MAD2L2 were identified in both DAVID and GSEA software. Our findings suggest that nine genes were identified via integrated analysis as potential biomarkers and in particular, APBB2 and MAD2L2 may be considered as more significant biomarkers for HIV-1 latency.

Unraveling the genes implicated in Alzheimer's disease

Alzheimer's disease (AD) is a heterogeneous neurodegenerative disorder and it is the most common form of dementia in the elderly. Early onset AD is caused by mutations in three genes: Amyloid-β precursor protein, presenilin 1 (PSEN1) and PSEN2. Late onset AD (LOAD) is complex and apolipoprotein E is the only unanimously accepted genetic risk factor for its development. Various genes implicated in AD have been identified using advanced genetic technologies, however, there are many additional genes that remain unidentified. The present review highlights the genetics of early and LOAD and summarizes the genes involved in different signaling pathways. This may provide insight into neurodegenerative disease research and will facilitate the development of effective strategies to combat AD.

APP Protein Family Signaling at the Synapse: Insights from Intracellular APP-Binding Proteins

Understanding the molecular mechanisms underlying amyloid precursor protein family (APP/APP-like proteins, APLP) function in the nervous system can be achieved by studying the APP/APLP interactome. In this review article, we focused on intracellular APP interacting proteins that bind the YENPTY internalization motif located in the last 15 amino acids of the C-terminal region. These proteins, which include X11/Munc-18-interacting proteins (Mints) and FE65/FE65Ls, represent APP cytosolic binding partners exhibiting different neuronal functions. A comparison of FE65 and APP family member mutant mice revealed a shared function for APP/FE65 protein family members in neurogenesis and neuronal positioning. Accumulating evidence also supports a role for membrane-associated APP/APLP proteins in synapse formation and function. Therefore, it is tempting to speculate that APP/APLP C-terminal interacting proteins transmit APP/APLP-dependent signals at the synapse. Herein, we compare our current knowledge of the synaptic phenotypes of APP/APLP mutant mice with those of mice lacking different APP/APLP interaction partners and discuss the possible downstream effects of APP-dependent FE65/FE65L or X11/Mint signaling on synaptic vesicle release, synaptic morphology and function. Given that the role of X11/Mint proteins at the synapse is well-established, we propose a model highlighting the role of FE65 protein family members for transduction of APP/APLP physiological function at the synapse.

Arginine deprivation and immune suppression in a mouse model of Alzheimer's disease

The pathogenesis of Alzheimer's disease (AD) is a critical unsolved question; and although recent studies have demonstrated a strong association between altered brain immune responses and disease progression, the mechanistic cause of neuronal dysfunction and death is unknown. We have previously described the unique CVN-AD mouse model of AD, in which immune-mediated nitric oxide is lowered to mimic human levels, resulting in a mouse model that demonstrates the cardinal features of AD, including amyloid deposition, hyperphosphorylated and aggregated tau, behavioral changes, and age-dependent hippocampal neuronal loss. Using this mouse model, we studied longitudinal changes in brain immunity in relation to neuronal loss and, contrary to the predominant view that AD pathology is driven by proinflammatory factors, we find that the pathology in CVN-AD mice is driven by local immune suppression. Areas of hippocampal neuronal death are associated with the presence of immunosuppressive CD11c(+) microglia and extracellular arginase, resulting in arginine catabolism and reduced levels of total brain arginine. Pharmacologic disruption of the arginine utilization pathway by an inhibitor of arginase and ornithine decarboxylase protected the mice from AD-like pathology and significantly decreased CD11c expression. Our findings strongly implicate local immune-mediated amino acid catabolism as a novel and potentially critical mechanism mediating the age-dependent and regional loss of neurons in humans with AD.