NEDD9 is genetically associated with Alzheimer's disease in a Han Chinese population

Discrete hippocampal projections are differentially regulated by parvalbumin and somatostatin interneurons

People with schizophrenia show hyperactivity in the ventral hippocampus (vHipp) and we have previously demonstrated distinct behavioral roles for vHipp cell populations. Here, we test the hypothesis that parvalbumin (PV) and somatostatin (SST) interneurons differentially innervate and regulate hippocampal pyramidal neurons based on their projection target. First, we use eGRASP to show that PV-positive interneurons form a similar number of synaptic connections with pyramidal cells regardless of their projection target while SST-positive interneurons preferentially target nucleus accumbens (NAc) projections. To determine if these anatomical differences result in functional changes, we used in vivo opto-electrophysiology to show that SST cells also preferentially regulate the activity of NAc-projecting cells. These results suggest vHipp interneurons differentially regulate that vHipp neurons that project to the medial prefrontal cortex (mPFC) and NAc. Characterization of these cell populations may provide potential molecular targets for the treatment schizophrenia and other psychiatric disorders associated with vHipp dysfunction.

Untangling huge literature to disinter genetic underpinnings of Alzheimer's Disease: A systematic review and meta-analysis

Drug discovery for Alzheimer's Disease (AD) is channeled towards unravelling key disease specific drug targets/genes to predict promising therapeutic candidates. Though enormous literature on AD genetics is available, there exists dearth in data pertinent to drug targets and crucial pathological pathways intertwined in disease progression. Further, the research findings revealing genetic associations failed to demonstrate consistency across different studies. This scenario prompted us to initiate a systematic review and meta-analysis with an aim of unearthing significant genetic hallmarks of AD. Initially, a Boolean search strategy was developed to retrieve case-control studies from PubMed, Cochrane, ProQuest, Europe PMC, grey literature and HuGE navigator. Subsequently, certain inclusion and exclusion criteria were framed to shortlist the relevant studies. These studies were later critically appraised using New Castle Ottawa Scale and Q-Genie followed by data extraction. Later, meta-analysis was performed only for those Single Nucleotide Polymorphisms (SNPs) which were evaluated in at least two different ethnicities from two different reports. Among, 204,351 studies retrieved, 820 met our eligibility criteria and 117 were processed for systematic review after critical appraisal. Ultimately, meta-analysis was performed for 23 SNPs associated with 15 genes which revealed significant associations of rs3865444 (CD33), rs7561528 (BIN1) and rs1801133 (MTHFR) with AD risk.

Identification of the Potential Key Circular RNAs in Elderly Patients With Postoperative Cognitive Dysfunction

Background

Postoperative cognitive dysfunction (POCD) is one of the severe complications after surgery, inducing low life quality and high mortality, especially in elderly patients. However, the underlying molecular mechanism of POCD remains largely unknown, and the ideal biomarker for clinical diagnosis and prognosis is lacking. Circular RNAs (circRNAs), as a unique class of non-coding RNAs, were characterized by its stability and conservativeness, serving as novel biomarkers in various diseases. Nevertheless, the role of circRNAs in the occurrence of POCD remains elusive.

Methods

To investigate the differentially expressed circRNAs in the serum of POCD patients and its potential role in the development of POCD, we performed a circRNA microarray to screen the differentially expressed circRNAs in the serum samples from three patients of the POCD group and three paired patients of the non-POCD group. Subsequently, quantitative real-time polymerase chain reaction analysis (qRT-PCR) was utilized to verify the microarray data with the serum samples from 10 paired patients. Cytoscape software was used to construct the circRNA–miRNA–mRNA network for circRNAs with different expression levels as well as the target genes. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses showed the biological functions of the differentially expressed circRNAs target genes.

Results

In total, we have analyzed 10,198 circRNAs through the microarray. Compared with the non-POCD patient group, there were 210 differentially expressed circRNAs with 133 upregulated and 77 downregulated in the POCD group (≥2-fold differential expression, P ≤ 0.05). The qRT-PCR confirmed 10 circRNAs with different expressed levels, and the results were consistent with the microarray findings. Among them, hsa_circRNA_001145, hsa_circRNA_101138, and hsa_circRNA_061570 had the highest magnitude of change. The GO analysis showed that the differentially expressed circRNAs were associated with the regulation of the developmental process, cell-to-cell adhesion, and nervous system development. The KEGG analysis showed that the target genes of circRNAs were enriched in the MAPK signaling pathway and RAS signaling pathway. According to the targetscan7.1 and mirdbV5 databases, the circRNA–miRNA–mRNA network was constructed, and these results provided a vital landscape of circRNA expression profile in POCD.

Conclusions

Our study provides an essential perspective for the differential expression of circRNAs in POCD patients. Further studies need to be performed to explore their potential therapeutic roles in the development of POCD.

Microarray analysis of an synthetic α-synuclein induced cellular model reveals the expression profile of long non-coding RNA in Parkinson's disease

Long non-coding RNAs (lncRNAs) are a new research focus that are reported to influence the pathogenetic process of neurodegenerative disorders. To uncover new disease-associated genes and their relevant mechanisms, we carried out a gene microarray analysis based on a Parkinson's disease (PD) in vitro model induced by α-synuclein oligomers. This cellular model induced by 25 μmol/L α-synuclein oligomers has been confirmed to show the stable, transmissible neurotoxicity of α-synuclein, a typical PD pathological marker. And several differentially expressed lncRNAs and mRNAs were identified in this model, such as G046036, G030771, AC009365.4, RPS14P3, CTB-11I22.1, and G007549. Subsequent ceRNA analysis determined the potential relationships between these lncRNAs and their associated mRNAs and microRNAs. The results of the present study widen our horizon of PD susceptibility genes and provide new pathways towards efficient diagnostic biomarkers and therapeutic targets for PD.

Mice null for NEDD9 (HEF1α) display extensive hippocampal dendritic spine loss and cognitive impairment

NEDD9 (neural precursor cell expressed, developmentally down-regulated 9) is a member of the CAS (Crk-associated substrate) family of scaffolding proteins that regulate cell adhesion and migration. A Nedd9 knock-out/lacZ knock-in mouse (Nedd9(-/)(-)) was developed in order to study Nedd9 expression and function in the nervous system. Herein we show that NEDD9 is expressed in the adult brain and is prominently expressed in the hippocampus. Behavioral testing uncovered functional deficits in Nedd9(-)(/)(-) mice. In the Morris water maze test, Nedd9(-)(/)(-) mice showed deficits in both the ability to learn the task as well as in their ability to recall the platform location. There was no change in the gross morphology of the hippocampus, and stereological analysis of BrdU-labeled newly formed hippocampal cells suggested that this defect is not secondary to altered neurogenesis. However, analysis of the hippocampus revealed extensive loss of dendritic spine density in both the dentate gyrus (DG) and CA1 regions. Spine loss occurred equally across all branch orders and regions of the dendrite. Analysis of spine density in Nedd9(-)(/)(-) mice at 1.5, 6 and 10 months revealed an age-dependent spine loss. This work shows that NEDD9 is required for the maintenance of dendritic spines in the hippocampus, and suggests it could play a role in learning and memory.

Preclinical and clinical studies of the NEDD9 scaffold protein in cancer and other diseases

Cancer progression requires a significant reprogramming of cellular signaling to support the essential tumor-specific processes that include hyperproliferation, invasion (for solid tumors) and survival of metastatic colonies. NEDD9 (also known as CasL and HEF1) encodes a multi-domain scaffolding protein that assembles signaling complexes regulating multiple cellular processes relevant to cancer. These include responsiveness to signals emanating from the T and B cell receptors, integrins, chemokine receptors, and receptor tyrosine kinases, as well as cytoplasmic oncogenes such as BCR-ABL and FAK- and SRC-family kinases. Downstream, NEDD9 regulation of partners including CRKL, WAVE, PI3K/AKT, ERK, E-cadherin, Aurora-A (AURKA), HDAC6, and others allow NEDD9 to influence functions as pleiotropic as migration, invasion, survival, ciliary resorption, and mitosis. In this review, we summarize a growing body of preclinical and clinical data that indicate that while NEDD9 is itself non-oncogenic, changes in expression of NEDD9 (most commonly elevation of expression) are common features of tumors, and directly impact tumor aggressiveness, metastasis, and response to at least some targeted agents inhibiting NEDD9-interacting proteins. These data strongly support the relevance of further development of NEDD9 as a biomarker for therapeutic resistance. Finally, we briefly discuss emerging evidence supporting involvement of NEDD9 in additional pathological conditions, including stroke and polycystic kidney disease.

Adaptors for disorders of the brain? The cancer signaling proteins NEDD9, CASS4, and PTK2B in Alzheimer's disease

No treatment strategies effectively limit the progression of Alzheimer's disease (AD), a common and debilitating neurodegenerative disorder. The absence of viable treatment options reflects the fact that the pathophysiology and genotypic causes of the disease are not well understood. The advent of genome-wide association studies (GWAS) has made it possible to broadly investigate genotypic alterations driving phenotypic occurrences. Recent studies have associated single nucleotide polymorphisms (SNPs) in two paralogous scaffolding proteins, NEDD9 and CASS4, and the kinase PTK2B, with susceptibility to late-onset AD (LOAD). Intriguingly, NEDD9, CASS4, and PTK2B have been much studied as interacting partners regulating oncogenesis and metastasis, and all three are known to be active in the brain during development and in cancer. However, to date, the majority of studies of these proteins have emphasized their roles in the directly cancer relevant processes of migration and survival signaling. We here discuss evidence for roles of NEDD9, CASS4 and PTK2B in additional processes, including hypoxia, vascular changes, inflammation, microtubule stabilization and calcium signaling, as potentially relevant to the pathogenesis of LOAD. Reciprocally, these functions can better inform our understanding of the action of NEDD9, CASS4 and PTK2B in cancer.

SLC26A4 gene polymorphism and late-onset Alzheimer's disease in a Han Chinese population from Qingdao, China

In a recent genome-wide association study, the SLC26A4 gene rs2072064 polymorphism was found to be associated with late-onset Alzheimer's disease in Caucasians. Here, we investigated this association in a large Northern Han Chinese cohort consisting of 599 sporadic late-onset Alzheimer's disease patients and 598 healthy controls matched for sex and age in a Northern Han Chinese population from Qingdao, China. Genotyping by the polymerase chain reaction-ligase detection reaction revealed that there were significant differences in the genotype (P = 0.017) and allele (P = 0.007) frequencies of the rs2072064 polymorphism between late-onset Alzheimer's disease patients and controls. The A allele of this polymorphism was significantly associated with a reduced risk of late-onset Alzheimer's disease (odds ratio (OR) = 0.792, 95% confidence interval (CI) = 0.670-0.937, P = 0.007). When the data were stratified by the apolipoprotein E ε4 status, there was a significant difference only among apolipoprotein E ε4 non-carriers (genotypic P = 0.001, allelic P = 0.001). Furthermore, the association between rs2072064 and late-onset Alzheimer's disease remained significant by logistic regression analysis after adjustment for age, gender, and the apolipoprotein E ε4 carrier status (dominant model: OR = 0.787, 95% CI = 0.619-1.000, P = 0.050; recessive model: OR = 0.655, 95% CI = 0.448-0.959, P = 0.030; additive model: OR = 0.792, 95% CI = 0.661-0.950, P = 0.012). These findings suggest that SLC26A4 is a susceptibility gene for late-onset Alzheimer's disease in a Northern Han Chinese population from the Qingdao area.

NEDD9 rs760678 polymorphism and the risk of Alzheimer's disease: a meta-analysis

The NEDD9 rs760678 polymorphism has been extensively investigated for association to Alzheimer's disease (AD), however, results of different studies have been inconsistent. The objective of this study is to assess the relationship of NEDD9 rs760678 polymorphism and AD risk by using meta-analysis. Systematic searches of electronic databases Pubmed and Embase, as well as hand searching of the references of identified articles were performed. Statistical analyses were performed using software Revman 4.2 and STATA 11.0. A total of 4436 cases and 4420 controls in 11 case-control studies were included. The results indicated that the homozygote GG had a 13% decreased risk of AD, when compared with the C allele carriers (CC+CG) (OR=0.87, 95%CI=0.77-0.99, P=0.04 for GG vs. CG+CC). In the subgroup analysis by ethnicity, significant decreased risk was associated with homozygote GG or G allele carriers in Caucasians (OR=0.84, 95%CI=0.74-0.96, P=0.008 for GG vs. CG+CC; OR=0.79, 95%CI=0.69-0.91, P=0.001 for GG vs. CC; OR=0.90, 95%CI=0.84-0.96, P=0.002 for G vs. C), but not in Asians. This meta-analysis suggests that the GG genotype of NEDD9 rs760678 polymorphism would be a protective factor for AD in Caucasians but not in Asians. To further evaluate the effect of gene-gene and gene-environmental interactions between NEDD9 rs760678 polymorphism and the risk of AD, more studies with larger number of subjects are required.