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About 20 years have passed since the discovery of the first microRNA (miRNA) and by now microRNAs are implicated in a variety of physiological and pathological processes. Since the discovery of the powerful effect miRNAs have on biological processes, it has been suggested that mutations affecting miRNA function may play a role in the pathogenesis of human diseases. Over the past several years microRNAs have been found to play a major role in various human diseases. In addition, many studies aim to apply miRNAs for diagnostic and therapeutic applications in human diseases. In this chapter, we summarize the role of miRNAs in pathological processes and discuss how miRNAs could be used as disease biomarkers.

Over the last decade, neuroprotective effects of erythropoietin (Epo) and its underlying mechanisms in terms of signal transduction pathways have been defined and there is a growing interest in the potential therapeutic use of Epo for neuroprotection. Several mechanisms by which Epo provides neuroprotection are recognized. In this review, we focused on the neuroprotective mechanisms of Epo and provide a short overview on both experimental and clinical studies, testing Epo as a neuroprotective agent in the neonatal brain injury, and the safety concerns with the clinical use of Epo treatment in neonates., (Copyright © 2010 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.)

Importance of the Field: Erythropoietin (EPO) is a growth hormone and cytokine that plays an important role in erythropoiesis and neuroprotection. However, EPO treatment for neurological diseases requires repeated injections or high-dose systemic administration, which may cause systemic side effects. The lack of any effective treatment of acute and chronic neurodegenerative diseases and the promising outcome by EPO in animal models in vivo demand a critical evaluation of intranasal EPO delivery to the brain as an alternative administration method., Areas Covered in This Review: The current use and intranasal administration of EPO and its derivatives in preclinical studies and recent clinical trials with EPO in neurological diseases., What the Reader Will Gain: This paper gives an overview of the therapeutic considerations of intranasal EPO and EPO derivatives for neuroprotection., Take Home Message: Intranasal delivery (ID) of neuroprotective drugs is an area of great interest. Among the administration strategies used at present, ID of EPO is the most promising. Further preclinical and clinical studies are needed to evaluate the potential significance of this alternative route for increasing EPO bioavailability and decreasing side effects.

MicroRNAs (miRNAs) have recently emerged as a new class of modulators of gene expression. miRNAs control protein synthesis by targeting mRNAs for translational repression or degradation at the posttranscriptional level. These noncoding RNAs are endogenous, single-stranded molecules approximately 22 nucleotides in length and have roles in multiple facets of immunity, from regulation of development of key cellular players to activation and function in immune responses. Recent studies have shown that dysregulation of miRNAs involved in immune responses leads to autoimmunity. Multiple sclerosis (MS) serves as an example of a chronic and organ-specific autoimmune disease in which miRNAs modulate immune responses in the peripheral immune compartment and the neuroinflammatory process in the brain. For MS, miRNAs have the potential to serve as modifying drugs. In this review, we summarize current knowledge of miRNA biogenesis and mode of action and the diverse roles of miRNAs in modulating the immune and inflammatory responses. We also review the role of miRNAs in autoimmunity, focusing on emerging data regarding miRNA expression patterns in MS. Finally, we discuss the potential of miRNAs as a disease marker and a novel therapeutic target in MS. Better understanding of the role of miRNAs in MS will improve our knowledge of the pathogenesis of this disease.