Identification of exceptionally potent adenosine deaminases RNA editors from high body temperature organisms.

The most abundant form of RNA editing in metazoa is the deamination of adenosines into inosines (A-to-I), catalyzed by ADAR enzymes. Inosines are read as guanosines by the translation machinery, and thus A-to-I may lead to protein recoding. The ability of ADARs to recode at the mRNA level makes them attractive therapeutic tools. Several approaches for Site-Directed RNA Editing (SDRE) are currently under development. A major challenge in this field is achieving high on-target editing efficiency, and thus it is of much interest to identify highly potent ADARs. To address this, we used the baker yeast Saccharomyces cerevisiae as an editing-naïve system. We exogenously expressed a range of heterologous ADARs and identified the hummingbird and primarily mallard-duck ADARs, which evolved at 40-42°C, as two exceptionally potent editors. ADARs bind to double-stranded RNA structures (dsRNAs), which in turn are temperature sensitive. Our results indicate that species evolved to live with higher core body temperatures have developed ADAR enzymes that target weaker dsRNA structures and would therefore be more effective than other ADARs. Further studies may use this approach to isolate additional ADARs with an editing profile of choice to meet specific requirements, thus broadening the applicability of SDRE.

[CONTROLLING THE WAY OF THINKING, THE MENTAL STRESS AND THE ATTENTION ABILITY TO ALLEVIATE THE TINNITUS NUISANCE BY MEANS OF COGNITIVE BEHAVIORAL THERAPY (CBT)].

INTRODUCTION: About 15% of the population suffers from tinnitus but only in 2-3% of cases the tinnitus is severe with great functioning difficulties. The distress caused by tinnitus is mostly caused by the reaction to the tinnitus and not by the tinnitus itself. AIMS: Methods to alleviate the tinnitus distress are presented with emphasis on the importance of the primary detailed explanation to the patient. METHODS: The management of the severe response to tinnitus is based on the ability to control it instead of being controlled by it. This task is accomplished by explaining the essence of the tinnitus and imbuing the patient with control of three things: the way of thinking, the mental stress and attention ability. CONCLUSIONS: The methods to mitigate tinnitus distress are presented. The importance of the primary detailed explanation to the patient is emphasized. The treatment is based on providing methods of mastering the way of thinking, controlling mental stress and managing the attention ability using the CBT technique. DISCUSSION: Ear, nose, and throat (E.N.T) practitioners lack knowledge of treatment of the emotional reaction to tinnitus which results in frustration when dealing with the patient's complaints. In this article the basic tools of Cognitive Behavioral Therapy (CBT) treatment method are presented, along with explanations about the method with regard to coping with the emotional reaction to tinnitus.

A pipeline for identifying guide RNA sequences that promote RNA editing of nonsense mutations that cause inherited retinal diseases.

Adenosine deaminases acting on RNA (ADARs) are endogenous enzymes catalyzing the deamination of adenosines to inosines, which are then read as guanosines during translation. This ability to recode makes ADAR an attractive therapeutic tool to edit genetic mutations and reprogram genetic information at the mRNA level. Using the endogenous ADARs and guiding them to a selected target has promising therapeutic potential. Indeed, different studies have reported several site-directed RNA-editing approaches for making targeted base changes in RNA molecules. The basic strategy has been to use guide RNAs (gRNAs) that hybridize and form a double-stranded RNA (dsRNA) structure with the desired RNA target because of ADAR activity in regions of dsRNA formation. Here we report on a novel pipeline for identifying disease-causing variants as candidates for RNA editing, using a yeast-based screening system to select efficient gRNAs for editing of nonsense mutations, and test them in a human cell line reporter system. We have used this pipeline to modify the sequence of transcripts carrying nonsense mutations that cause inherited retinal diseases in the FAM161A, KIZ, TRPM1, and USH2A genes. Our approach can serve as a basis for gene therapy intervention in knockin mouse models and ultimately in human patients.