Alzheimer's Disease Biomarkers: More Than Molecular Diagnostics

Identification of Biomarkers Associated With Alzheimer's Disease by Bioinformatics Analysis

BACKGROUND

This study aimed to explore the biomarkers of Alzheimer's disease (AD).

METHODS

The microarray data of GSE16759 were from the expression profile samples of 4 parietal lobe tissues from patients with AD and 4 ones from age-matched control participants. The differentially expressed micro RNAs (miRNAs) and genes (DEGs) underwent hierarchical clustering and function analysis followed by target genes prediction. Finally, DEGs were mapped to the target genes to construct miRNA-regulated networks.

RESULTS

A total of 427 DEGs were obtained and clustered into 5 functions. After DEGs were mapped to the predicted target genes, 313 regulatory pairs were established. The target genes SEC22 vesicle trafficking protein homolog B (SEC22B) and SEC63 homolog (SEC63) regulated by miRNA-206, RAB10, member RAS oncogene family (RAB10) regulated by miRNA-655, and fms-related tyrosine kinase 1 (FLT1) regulated by miRNA-30e-3p and miRNA-369-3p were involved in the biological processes of protein transport and regulation of cell motion.

CONCLUSION

The target genes SEC22B, RAB10, and FLT1 may be potential biomarkers of AD.

Targeting Cell Membrane Lipid Rafts by Stoichiometric Functionalization of Gold Nanoparticles With a Sphingolipid-Binding Domain Peptide

A non-membrane protein-based nanoparticle agent for the tracking of lipid rafts on live cells is produced by stoichiometric functionalization of gold nanoparticles with a previously characterized sphingolipid- and cell membrane microdomain-binding domain peptide (SBD). The SBD peptide is inserted in a self-assembled monolayer of peptidol and alkane thiol ethylene glycol, on gold nanoparticles surface. The stoichiometric functionalization of nanoparticles with the SBD peptide, essential for single molecule tracking, is achieved by means of non-affinity nanoparticle purification. The SBD-nanoparticles have remarkable long-term resistance to electrolyte-induced aggregation and ligand-exchange and have no detectable non-specific binding to live cells. Binding and diffusion of SBD-nanoparticles bound to the membrane of live cells is measured by real-time photothermal microscopy and shows the dynamics of sphingolipid-enriched microdomains on cells membrane, with evidence for clustering, splitting, and diffusion over time of the SBD-nanoparticle labeled membrane domains. The monofunctionalized SBD-nanoparticle is a promising targeting agent for the tracking of lipid rafts independently of their protein composition and the labelling requires no prior modification of the cells. This approach has potential for further functionalization of the particles to manipulate the organization of, or targeting to microdomains that control signaling events and thereby lead to novel diagnostics and therapeutics.