Amyloid plaques, neurofibrillary tangles and neuronal loss in brains of transgenic mice overexpressing a C-terminal fragment of human amyloid precursor protein

Association of interleukin-33 gene polymorphisms with susceptibility to late onset Alzheimer's disease: a meta-analysis

The association between interleukin-33 (IL-33) gene polymorphisms and late onset Alzheimer's disease (LOAD) remains controversial in previous studies. Thus, a meta-analysis was conducted to assess the association between the IL-33 polymorphisms (rs11792633 and rs7044343) and LOAD susceptibility. Crude odds ratio (OR) and 95% confidence interval (CI) were used to investigate the relationship strength. Sensitivity analysis was performed, and publication bias was estimated by the Begg's and Egger's tests. Overall, six independent studies involving 2,589 patients and 8,414 control samples met our inclusion criteria and were included in this meta-analysis. The results showed that IL-33 rs11792633 polymorphism had statistically significant correlation with a decreased risk of LOAD in heterozygous comparison model (OR =0.64, 95% CI =0.48-0.83), homozygote comparison model (OR =0.83, 95% CI =0.74-0.93), dominant model (OR =0.78, 95% CI =0.67-0.91), recessive model (OR =0.70, 95% CI =0.59-0.84), and allelic model (OR =0.79, 95% CI =0.69-0.91), which were also validated by stratified subgroup analysis. Additionally, there was an apparent association between the IL-33 rs7044343 variant and LOAD risk under four genetic models for overall population (heterozygous comparison model: OR =0.75, 95% CI =0.63-0.89; dominant model: OR =0.83, 95% CI =0.70-0.98; recessive model: OR =0.80, 95% CI =0.68-0.94; allelic model: OR =0.86, 95% CI =0.79-0.94) as well as Caucasian subgroup. In summary, our meta-analysis implicated that IL-33 gene polymorphisms rs11792633 and rs7044343 were significantly associated with the susceptibility of LOAD.

Alzheimer's disease: pathological mechanisms and recent insights

Amyloidopathies cause neurodegeneration in a substantial portion of the elderly population. Improvements in long term health care have made elderly individuals a large and growing demographic group, marking these diseases as a major public health concern. Alzheimer's Disease (AD) is the most studied form of neurodegenerative amyloidopathy. Although our understanding of AD is far from complete, several decades of research have advanced our knowledge to the point where it is conceivable that some form of disease modifying therapy may be available in the near future. These advances have been built on a strong mechanistic understanding of the disease from its underlying genetics, molecular biology and clinical pathology. Insights derived from the study of other neurodegenerative diseases, such as some forms of frontotemporal dementia, have been critical to this process. This knowledge has allowed researchers to construct animal models of the disease process that have paved the way towards the development of therapeutics. However, what was once thought to be a straightforward problem has evolved into a series of disappointing outcomes. Examination of pathways common to all neurodegenerative diseases, including the cellular mechanisms that clear misfolded proteins and their regulation, may be the best way to move forward.

GM1 up-regulates Ubiquilin 1 expression in human neuroblastoma cells and rat cortical neurons

GM1 ganglioside was reported to mediate the amyloid beta-protein (Abeta) secretion and accumulation in the pathogenesis of Alzheimer's disease (AD). The objective of this project was to comprehend the underlying molecular changes related to amyloid beta-protein precursor (APP) processing pathway induced by GM1. Using suppression subtractive hybridisation (SSH), we detected one prominent sequence with increased expression in human neuroblastoma cells that stably transfected with human APP695 cDNA treated with GM1. This transcript has high identity to human Ubiquilin 1 gene. Differential expression was initially confirmed by dot blot hybridization. This result was further authenticated with quantitative real-time polymerase chain reaction (RT-PCR) analysis. Furthermore, using Western blots, we discovered that GM1 stimulated the expression of Ubiquilin 1 in human neuroblastoma cells and rat cortical neurons while other gangliosides Asialo-GM1 and GD1b did not. Ubiquilin 1 is one of the candidate genes of AD, which have been shown to modulate the gamma-secretase components in the proteolytic processing of APP, and is therefore a putative candidate for further investigation of GM1 mechanisms in the etiology and pathology of AD.

Potential involvement of the transcription factor NF-kappa B in neurological disorders

Reactive oxygen intermediates (ROIs) are involved in many neurological diseases. Despite the toxic nature of these compounds, low concentrations of ROIs can function as signaling molecules. One target for their signaling function is the inducible transcription factor NF-kappa B. Predominantly in lymphoid cells, induction of NF-kappa B in response to oxidative stress leads to transcriptional activation of many genes which are relevant for pathogen defense. These include the TNF, IL-6, IL-8, GM-CSF, beta-interferon, MHC class I and V-CAM genes. However, NF-kappa B is also abundant in various cell types of the nervous system, including neurons. We propose that NF-kappa B plays a role as a redox-controlled transcriptional activator also in cells of the nervous system and in that property may contribute to neurological disorders. Our finding that some neurons from healthy brain contain constitutively active NF-kappa B suggests a role of NF-kappa B in normal brain function as well.