Alzheimer's disease (AD) is the most common form of dementia and the AD patients gradually lose cognitive function, control over their sense of orientation, their emotions, and other aspects of behaviour. Pathohistologically, AD is characterised by the presence of extracellular deposits of beta amyloid protein (A?) in diffuse and neuritic plaques and intracellular deposition of hyperphosphorylated tau protein in neurofibrillary tangles (1). Accumulation of A?42 is believed to be the earliest pathohistological feature of AD (2). However, the early events in the onset of the pathology remain to be fully elucidated. As such, a greater understanding of the immediate and direct effect of the accumulation of this protein on neuronal cells may shed light on the mechanisms involved in the early, preclinical stage of the disease. To simulate early event in AD a cell model system in which LAN5 neuroblastoma cell were incubated for short time with a recombinant form of A?42 was utilized for a study of the proteome by mass spectrometry. Furthermore, a bioinformatic analysis, by using KEGG tool, indicated that some proteins were up or down regulated and the involvement of four pathway was identified. In particular we found down regulation of the spliceosome pathway. To confirm the existence of a suppressive effect of A?42 on the spliceosomal pathway, SmB/B'/N (a component of the spliceosomal machinery) was quantified. Proteins were extracted from LAN5 cells treated with A?42 at different concentrations and times, and a Western blot was performed. SmB/B'/N levels were found to decrease in a time and dose dependent manner relative to the control suggesting that impaired splicing can occur. However, further studies are necessary to fully elucidate the down-regulation effect of the spliceosome proteins in AD, and how this may contribute to the early event in this disorder.
A BIOINFORMATIC APPROACH TO STUDY EARLY EVENTS IN ALZHEIMER'S DISEASE
Domenico Nuzzo;Luigi Inguglia;Pasquale Picone;Marta Di Carlo
2015
Abstract
Alzheimer's disease (AD) is the most common form of dementia and the AD patients gradually lose cognitive function, control over their sense of orientation, their emotions, and other aspects of behaviour. Pathohistologically, AD is characterised by the presence of extracellular deposits of beta amyloid protein (A?) in diffuse and neuritic plaques and intracellular deposition of hyperphosphorylated tau protein in neurofibrillary tangles (1). Accumulation of A?42 is believed to be the earliest pathohistological feature of AD (2). However, the early events in the onset of the pathology remain to be fully elucidated. As such, a greater understanding of the immediate and direct effect of the accumulation of this protein on neuronal cells may shed light on the mechanisms involved in the early, preclinical stage of the disease. To simulate early event in AD a cell model system in which LAN5 neuroblastoma cell were incubated for short time with a recombinant form of A?42 was utilized for a study of the proteome by mass spectrometry. Furthermore, a bioinformatic analysis, by using KEGG tool, indicated that some proteins were up or down regulated and the involvement of four pathway was identified. In particular we found down regulation of the spliceosome pathway. To confirm the existence of a suppressive effect of A?42 on the spliceosomal pathway, SmB/B'/N (a component of the spliceosomal machinery) was quantified. Proteins were extracted from LAN5 cells treated with A?42 at different concentrations and times, and a Western blot was performed. SmB/B'/N levels were found to decrease in a time and dose dependent manner relative to the control suggesting that impaired splicing can occur. However, further studies are necessary to fully elucidate the down-regulation effect of the spliceosome proteins in AD, and how this may contribute to the early event in this disorder.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
