Circulating miRNAs as Biomarkers for Neurodegenerative Disorders

Abstract

Abstract:Neurodegenerative disorders, such as Alzheimer's disease (AD), Parkinson's disease (PD) and frontotemporal dementias (FTD), are considered distinct entities, however, there is increasing evidence of an overlap from the clinical, pathological and genetic points of view. All neurodegenerative diseases are characterized by neuronal loss and death in specific areas of the brain, for example, hippocampus and cortex for AD, midbrain for PD, frontal and temporal lobes for FTD. Loss of neurons is a relatively late event in the progression of neurodegenerative diseases that is typically preceded by other events such as metabolic changes, synaptic dysfunction and loss, neurite retraction, and the appearance of other abnormalities, such as axonal transport defects. The brain's ability to compensate for these dysfunctions occurs over a long period of time and results in late clinical manifestation of symptoms, when successful pharmacological intervention is no longer feasible. Currently, diagnosis of AD, PD and different forms of dementia is based primarily on analysis of the patient's cognitive function. It is therefore important to find non-invasive diagnostic methods useful to detect neurodegenerative diseases during early, preferably asymptomatic stages, when a pharmacological intervention is still possible. Altered expression of microRNAs (miRNAs) in many disease states, including neurodegeneration, and increasing relevance of miRNAs in biofluids in different pathologies has prompted the study of their possible application as neurodegenerative diseases biomarkers in order to identify new therapeutic targets. Here, we review what is known about the role of miRNAs OPEN ACCESSMolecules 2014, 19 6892 in the pathogenesis of neurodegeneration and the possibilities and challenges of using these small RNA molecules as a signature for neurodegenerative conditions.

miRNAs Differentially Expressed by Next-Generation Sequencing in Cord Blood Buffy Coat Samples of Boys and Girls

“…Epigenetic changes in blood are relevant even if they do not capture all changes observed in organ-specific tissue [100]. An increasing number of studies have demonstrated that levels of circulating miRNAs released by cells into the bloodstream are correlated with tissue miRNA levels [101,102]. Another limitation with use of blood specimens is that cell-type heterogeneity can act as a source of bias if cell-type proportions are associated both with miRNA expression levels and sex.…”

The Entropy of Laughter: Discriminative Power of Laughter’s Entropy in the Diagnosis of Depression

“…A number of new medical methods are being designed for early diagnosis in the most important mental pathologies and neurodegenerative diseases: new biochemical and molecular detectors, EEG, neuroimaging, ocular-macular exploration, pupillometry, exercise and gait analysis, equilibrium platforms, manual exercises, cognitive trials, memory tests, linguistic trials, etc. [27,35,[38][39][40][41]. We think laughter could also be added to that list of biomedical explorations.…”

microRNA‑124‑3p inhibits the progression of congenital hypothyroidism via targeting programmed cell death protein 6

“…miRNAs serve a role in nervous system diseases, including autoim mune neuroinf lam mation (13), Alzheimer's disease (14) and Parkinson's diseases (15). A previous study indicated that the expression of miR-124 was downregulated in newborn rats with thyroid hypofunction (19).…”

“…Binding of miRNA to the 3' untranslated region (UTR) may degrade target mRNA and block translation (12). Previous studies have suggested the role of miRNAs in nervous system diseases, including autoimmune neuroinflammation (13), Alzheimer's disease (14) and Parkinson's disease (15). miR-124-3p may also attenuate matrix metalloproteinase-induced neuronal injury via regulating signal transducer and activator of transcription 3 expression in SH-SY5Y cells (16).…”