Association of LRRTM3 polymorphisms with late-onset Alzheimer's disease in Han Chinese

Identification of novel prognostic markers of survival time in high-risk neuroblastoma using gene expression profiles

Neuroblastoma is the most common extracranial solid tumor in childhood. Patients in high-risk group often have poor outcomes with low survival rates despite several treatment options. This study aimed to identify a genetic signature from gene expression profiles that can serve as prognostic indicators of survival time in patients of high-risk neuroblastoma, and that could be potential therapeutic targets. RNA-seq count data was downloaded from UCSC Xena browser and samples grouped into Short Survival (SS) and Long Survival (LS) groups. Differential gene expression (DGE) analysis, enrichment analyses, regulatory network analysis and machine learning (ML) prediction of survival group were performed. Forty differentially expressed genes (DEGs) were identified including genes involved in molecular function activities essential for tumor proliferation. DEGs used as features for prediction of survival groups included EVX2, NHLH2, PRSS12, POU6F2, HOXD10, MAPK15, RTL1, LGR5, CYP17A1, OR10AB1P, MYH14, LRRTM3, GRIN3A, HS3ST5, CRYAB and NXPH3. An accuracy score of 82% was obtained by the ML classification models. SMIM28 was revealed to possibly have a role in tumor proliferation and aggressiveness. Our results indicate that these DEGs can serve as prognostic indicators of survival in high-risk neuroblastoma patients and will assist clinicians in making better therapeutic and patient management decisions.

INPP5D rs35349669 polymorphism with late-onset Alzheimer's disease: A replication study and meta-analysis

Inositol polyphosphate-5-phosphatase (INPP5D) was reported to be associated with Alzheimer's disease (AD) through modulating the inflammatory process and immune response. A recent genome-wide association study discovered a new locus single nucleotide polymorphism (SNP, rs35349669) of INPP5D which was significantly associated with susceptibility to late-onset Alzheimer's disease (LOAD) in Caucasians. In this study, we investigated the relations between the INPP5D polymorphism rs35349669 and LOAD in Han Chinese population comprising 984 LOAD cases and 1352 healthy controls being matched for age and gender. Our results showed no obvious differences in the genotypic or allelic distributions of rs35349669 polymorphism between LOAD cases and healthy controls (genotype: p = 0.167; allele: p = 0.094). Additionally, when these data were stratified by APOEε4 status, there are still no evident differences in the genotypic or allelic distributions in APOEε4 carriers (p > 0.05). Furthermore, meta-analysis of 81964 individuals confirmed that rs35349669 was significantly associated with the risk for LOAD (OR=1.08, 95%CI=1.06-1.11), but the results remained negative in Chinese subgroup (OR=0.77, 95%CI=0.53-1.13). Overall, the current evidence did not indicate that INPP5D rs35349669 polymorphism play a role in the genetic predisposition to LOAD in Chinese population.

ZCWPW1 is associated with late-onset Alzheimer's disease in Han Chinese: a replication study and meta-analyses

Recently, a large genome-wide association study (GWAS) has identified a novel variant (rs1476679) within ZCWPW1 showing strong association with late-onset Alzheimer's disease (LOAD) in Caucasian. However, the effect of rs1476679 on other populations remains unclear. In order to explore whether rs1476679 is also associated with the LOAD risk in other ethnic groups, we recruited 2350 unrelated Northern Han Chinese subjects, which include 992 LOAD patients and 1358 healthy controls. Analysis of data from these subjects suggests that the rs1476679 polymorphism is significantly associated with the LOAD (genotype P = 0.017, allele P = 0.044). The logistic regression reveals the C allele at rs1476679 is a protective factor for LOAD in the dominant model (OR = 0.779, 95%CI = 0.659–0.921, Pc = 0.009) adjusting for gender, age and APOE ε4 status. Furthermore, rs1476679 can decrease the AD risk (Dominant: OR = 0.733, 95%CI = 0.607–0.884, Pc = 0.006; Additive: OR = 0.820, 95%CI = 0.708–0.950, Pc = 0.048) in APOE ε4 non-carriers after stratification. Furthermore, meta-analysis of 82525 individuals confirmed that rs1476679 within ZCWPW1 decreased the risk of LOAD (OR = 0.91, 95%CI = 0.89–0.94). To summarize, the rs1476679 polymorphism in ZCWPW1 is associated with LOAD in Northern Han Chinese population.

FERMT2 rs17125944 polymorphism with Alzheimer's disease risk: a replication and meta-analysis

A recent meta-analysis of genome-wide association studies (GWAS) in population of Caucasian identified a single nucleotide polymorphism (SNP) rs17125944 in the FERMT2 gene as a new susceptibility locus for late-onset Alzheimer's disease (LOAD). In order to validate the association of the rs17125944 polymorphism with LOAD risk in the northern Han Chinese, we recruited a case–control study of 2338 Han Chinese subjects (984 cases and 1354 age- and gender-matched controls). Our results demonstrated that there was no significant association between the rs17125944 polymorphism and LOAD (genotype: P = 0.953; allele: P = 0.975). Furthermore, no significant differences were observed in alleles and genotypes distribution after stratification by apolipoprotein E (APOE) ε4 and multivariate logistic regression analysis. We also performed a meta-analysis in 81908 individuals. The meta-analysis showed that the C allele is the risk factor for LOAD in Caucasian group (OR = 1.15, 95 % CI = 1.10–1.20) and combined population (OR = 1.13, 95 % CI = 1.08–1.19). While in Chinese population, the C allele is not associated with increased risk of LOAD (OR = 1.07, 95 % CI = 0.89–1.28). In conclusion, our study showed that the rs17125944 polymorphism in FERMT2 gene might not be association with LOAD in northern Han Chinese population.

Association study of the PLXNA4 gene with the risk of Alzheimer's disease

BACKGROUND

The Plexin-A 4 (PLXNA4) gene has recently been recognized as a functional candidate gene of late-onset Alzheimer's disease (LOAD). The single nucleotide polymorphism (SNP) rs13232207 of PLXNA4 gene has been reported to be associated with Alzheimer's disease (AD) in Japanese cohorts. We sought to clarify whether this novel locus gains the same effect in northern Han Chinese.

METHODS

To investigate the relationship between SNP rs13232207 and AD sufferers, a case-control study of unrelated individuals was conducted with a total sample size of 2,318 subjects (978 cases and 1,340 age and gender matched healthy controls) in a Northern Han Chinese population. SPSS 22.0 was applied for the statistical process.

RESULTS

No significant difference in polymorphic distribution of rs13232207 was observed on LOAD risk independently under dominant (P=0.057), additive (P=0.233) or recessive model (P=0.392). In terms of interaction with apolipoprotein E (APOE), there is also no positive interaction in dominant (P=0.438), additive (P=0.055) or recessive model (P=0.095).

CONCLUSIONS

Replication of association between the PLXNA4 rs13232207 and AD in a Han ethnic group indicates that this link is not the result of chance.

Association of DISC1 Polymorphisms with Late-Onset Alzheimer's Disease in Northern Han Chinese

The disrupted-in-schizophrenia-1 (DISC1) is a candidate gene for psychiatric diseases and plays various roles in brain development. It has been reported as a candidate gene for Alzheimer's disease (AD) in a recent large genome-wide association study in Caucasians. To explore the associations between DISC1 and AD, we performed a case-control study including 2318 subjects in Northern Han Chinese. We found that one single nucleotide polymorphism (rs6675281) was associated with the risk of late-onset Alzheimer's disease (LOAD) in northern Han Chinese population. As for rs821616 and rs3738401, no association was detected with LOAD. In conclusion, DISC1 increased the risk for LOAD in northern Han Chinese population.

Control of neural circuit formation by leucine-rich repeat proteins

The function of neural circuits depends on the precise connectivity between populations of neurons. Increasing evidence indicates that disruptions in excitatory or inhibitory synapse formation or function lead to excitation/inhibition (E/I) imbalances and contribute to neurodevelopmental and psychiatric disorders. Leucine-rich repeat (LRR)-containing surface proteins have emerged as key organizers of excitatory and inhibitory synapses. Distinct LRR proteins are expressed in different cell types and interact with key pre- and postsynaptic proteins. These protein interaction networks allow LRR proteins to coordinate pre- and postsynaptic elements during synapse formation and differentiation, pathway-specific synapse development, and synaptic plasticity. LRR proteins, therefore, play a critical role in organizing synaptic connections into functional neural circuits, and their dysfunction may contribute to neuropsychiatric disorders.