Long Non-coding RNAs in Peripheral Blood Mononuclear Cells Associated with Alzheimer Disease

Abstract

Noncoding RNAs have been implicated in important roles in cellular processes and in various diseases with the discovery of novel RNAs. Non-coding RNAs are classified as two groups according to their size. Transcripts with a length of 18-25 nucleotides, including microRNAs (miRNAs), which are important classes that can control the expression of many genes are called as short non coding RNAs while RNAs that greater than 200 nucleotides are termed as long non-coding RNAs (lncRNAs). It was found that lncRNAs were able to regulate gene expression at transcriptional, post-transcriptional and epigenetic levels. Recently, many lncRNAs have been shown to regulate amyloid beta (Aβ) production and synaptic loss in neurons in the nervous system in Alzheimer's Disease (AD). AD is a neurodegenerative disease which is most common in elderly, characterized by amyloid beta plaque accumulation outside the cell, neurofibrillary tangles in the cell and neuronal loss in the nervous system. The definitive diagnosis of AD in the clinic can only be made by observing these pathological changes in the brain during postmortem period. Therefore, there is a great need for biomarkers that may allow the disease to be identified especially at an early stage. The lncRNAs, which are thought to contribute to the development of disease, are seen as both targets and tools in new treatment approaches. It is thought that new treatment approaches can be developed by illuminating the functions of all lncRNAs in human genome and it can be used as biomarkers in the early diagnosis of diseases. After the discovery that serum, plasma and mononuclear cells in the blood reflect inflammatory pathogenesis in search for a biomarker to be involved in the diagnosis of AD, studies have focused on peripheral blood. Recent studies have shown that mononuclear cells (PBMC) found in peripheral blood reflect inflammatory and apoptotic mechanisms in AD more in comparison to serum and plasma-based biomarkers.