Abstract

Currently the field of epilepsy lacks peripheral blood-based biomarkers that could predict the onset or progression of chronic seizures following an epileptogenic injury. Thiol/disulfide ratios have been shown to provide a sensitive means of assessing the systemic redox potential in tissue and plasma. In this study, we utilized a rapid, simple and reliable method for simultaneous determination of several thiol-containing amino acids in plasma using HPLC with electrochemical detection in kainic acid (KA) and pilocarpine rat models of epilepsy. In contrast to GSH and GSSG levels, the levels of cysteine (Cys) were decreased by 42% and 62% and cystine (Cyss) were increased by 46% and 23% in the plasma of KA- and pilocarpine-injected rats, respectively after 48 h. In chronically epileptic rats, plasma cysteine was decreased by 40.4% and 37.7%, and plasma GSSG increased by 33.8% and 35.0% following KA and pilocarpine, respectively. Treatment of rats with a catalytic antioxidant, 60 min after KA or pilocarpine significant attenuated the decrease of plasma Cys/Cyss ratios at the 48 h time point in both models. These observations suggest that the decreased cysteine and ratio of Cys/Cyss in plasma could potentially serve as redox biomarkers in temporal lobe epilepsy.

Abstract

MicroRNAs (miRNAs) are short, noncoding RNAs that act as key regulators of diverse biological processes by mediating translational repression or mRNA degradation of target genes. Recent studies discovered miRNAs in saliva, and these miRNAs are promising candidates for use as biomarkers of dental diseases. In this review, the results of miRNA studies in the dental field are presented, and a brief overview of the current progress, limitations, and perspectives regarding miRNA biomarkers for dental diseases is given.

Abstract

MicroRNAs (miRNAs) are endogenously initiated, small non-coding RNAs and typically regulate the expression of mRNAs in post transcriptional level either via translational repression or mRNA degradation. Aberrant expression of miRNAs is observed in diverse disease and altered physiological states. Recently, it has been revealed that miRNAs are not only present in cells but also in extracellular milieu especially in different bio-fluids including blood plasma, follicular fluid and even in cell culture media. Such extracellular miRNAs (ECmiRNAs) are remarkably stable in the extracellular harsh environment with the presence of high RNAse activity. Although the precise mechanisms of release of cellular miRNAs to extracellular environment remain largely unknown, recent studies suggest that the expression of these ECmiRNAs can be associated with patho-physiological condition of an organism. Moreover, these ECmiRNAs may deliver to the recipient cells via certain pathways where they can regulate translational activity of target genes. This review will discuss the nature and stability of ECmiRNAs along with their release mechanisms. Furthermore, based on recent evidences, it also summarizes the possible function of these ECmiRNAs in distant cell-to-cell communication and the difficulties we may face during ECmiRNA research.