ApoE distribution and family history in genetic prion diseases in Germany

Relationship between Apolipoprotein Superfamily and Parkinson's Disease

Objective:

Parkinson's disease (PD) is featured with motor disorder and nonmotor manifestations including psychological symptoms, autonomic nervous system dysfunction, and paresthesia, which results in great inconvenience to the patients’ life. The apolipoprotein (Apo) superfamily, as a group of potentially modifiable biomarkers in clinical practice, is of increasing significance in the diagnosis, evaluation, and prognosis of PD. The present review summarized the current understanding and emerging findings of the relationship between Apo superfamily and PD.

Data Sources:

All literatures were identified by systematically searching PubMed, Embase, and Cochrane electronic databases with terms “Parkinson disease,” “apolipoprotein,” and their synonyms until May 2017.

Study Selection:

We have thoroughly examined titles and abstracts of all the literatures that met our search strategy and the full text if the research is identified or not so definite. Reference lists of retrieved articles were also scrutinized for additional relevant studies.

Results:

The levels of plasma ApoA1 are inversely correlated with the risk of PD and the lower levels of ApoA1 trend toward association with poorer motor performance. Higher ApoD expression in neurons represents more puissant protection against PD, which is critical in delaying the neurodegeneration process of PD. It is suggested that APOE alleles are related to development and progression of cognitive decline and age of PD onset, but conclusions are not completely identical, which may be attributed to different ApoE isoforms. APOJ gene expressions are upregulated in PD patients and it is possible that high ApoJ level is an indicator of PD dementia and correlates with specific phenotypic variations in PD.

Conclusions:

The Apo superfamily has been proved to be closely involved in the initiation, progression, and prognosis of PD. Apos and their genes are of great value in predicting the susceptibility of PD and hopeful to become the target of medical intervention to prevent the onset of PD or slow down the progress. Therefore, further large-scale studies are warranted to elucidate the precise mechanisms of Apos in PD.

APOE gene polymorphisms and susceptibility to Creutzfeldt-Jakob disease

Associations between apolipoprotein E (APOE) gene polymorphisms and Creutzfeldt-Jakob disease (CJD) have been reported, but the results from many of these studies are conflicting. To investigate the association between APOE polymorphisms and CJD risk, we performed a meta-analysis. We used odds ratios (OR) with 95% confidence intervals (CI) to assess the strength of the association. The frequency of putative risk alleles in control subjects was estimated with the Mantel-Haenszel method. Cochran's Q statistic and the inconsistency index (I(2)) were used to test heterogeneity. Egger's test and an inverted funnel plot were used to assess bias. Our study included 11 published case-control studies with APOE genotyping, involving a total of 1001 CJD patients and 1211 controls. Overall, the APOE 34 (OR 1.37, 95% CI: 1.09-1.72), and APOE 44 (OR 3.16, 95% CI: 1.37-7.26) genotypes and the APOE 4 (OR 1.41, 95% CI: 1.08-1.85) allele were associated with an increased risk of CJD, and the APOE 33 (OR 0.81, 95% CI: 0.67-0.97) genotype tended to protect against CJD. However, we did not find significant evidence supporting associations of the APOE 22 (OR 1.15, 95% CI: 0.45-2.93), APOE 23 (OR 0.84, 95% CI: 0.64-1.09), or APOE 24 (OR 1.40, 95% CI: 0.70-2.77) genotypes, nor the APOE 2 (OR 1.02, 95% CI: 0.73-1.42) or APOE 3 (OR 0.82, 95% CI: 0.65-1.02) alleles with CJD using a fixed-effects model. Our results support a genetic association between APOE polymorphisms and CJD.

Tau, prions and Aβ: the triad of neurodegeneration

This article highlights the features that connect prion diseases with other cerebral amyloidoses and how these relate to neurodegeneration, with focus on tau phosphorylation. It also discusses similarities between prion disease and Alzheimer's disease: mechanisms of amyloid formation, neurotoxicity, pathways involved in triggering tau phosphorylation, links to cell cycle pathways and neuronal apoptosis. We review previous evidence of prion diseases triggering hyperphosphorylation of tau, and complement these findings with cases from our collection of genetic, sporadic and transmitted forms of prion diseases. This includes the novel finding that tau phosphorylation consistently occurs in sporadic CJD, in the absence of amyloid plaques.

Beta-amyloid oligomers and cellular prion protein in Alzheimer's disease

Prefibrillar oligomers of the beta-amyloid peptide (A beta) are recognized as potential mediators of Alzheimer's disease (AD) pathophysiology. Deficits in synaptic function, neurotoxicity, and the progression of AD have all been linked to the oligomeric A beta assemblies rather than to A beta monomers or to amyloid plaques. However, the molecular sites of A beta oligomer action have remained largely unknown. Recently, the cellular prion protein (PrP(C)) has been shown to act as a functional receptor for A beta oligomers in brain slices. Because PrP(C) serves as the substrate for Creutzfeldt-Jakob Disease (CJD), these data suggest mechanistic similarities between the two neurodegenerative diseases. Here, we review the importance of A beta oligomers in AD, commonalities between AD and CJD, and the newly emergent role of PrP(C) as a receptor for A beta oligomers.

Molecular pathology of age-related macular degeneration

Age-related macular degeneration (AMD) is a leading cause of irreversible blindness in the world. Although the etiology and pathogenesis of AMD remain largely unclear, a complex interaction of genetic and environmental factors is thought to exist. AMD pathology is characterized by degeneration involving the retinal photoreceptors, retinal pigment epithelium, and Bruch's membrane, as well as, in some cases, alterations in choroidal capillaries. Recent research on the genetic and molecular underpinnings of AMD brings to light several basic molecular pathways and pathophysiological processes that might mediate AMD risk, progression, and/or response to therapy. This review summarizes, in detail, the molecular pathological findings in both humans and animal models, including genetic variations in CFH, CX3CR1, and ARMS2/HtrA1, as well as the role of numerous molecules implicated in inflammation, apoptosis, cholesterol trafficking, angiogenesis, and oxidative stress.