An improved SNAP-ADAR tool enables efficient RNA base editing to interfere with post-translational protein modification.

RNA base editing relies on the introduction of adenosine-to-inosine changes into target RNAs in a highly programmable manner in order to repair disease-causing mutations. Here, we propose that RNA base editing could be broadly applied to perturb protein function by removal of regulatory phosphorylation and acetylation sites. We demonstrate the feasibility on more than 70 sites in various signaling proteins and identify key determinants for high editing efficiency and potent down-stream effects. For the JAK/STAT pathway, we demonstrate both, negative and positive regulation. To achieve high editing efficiency over a broad codon scope, we applied an improved version of the SNAP-ADAR tool. The transient nature of RNA base editing enables the comparably fast (hours to days), dose-dependent (thus partial) and reversible manipulation of regulatory sites, which is a key advantage over DNA (base) editing approaches. In summary, PTM interference might become a valuable field of application of RNA base editing.

Is There an Association Between Inflammation and Serum-Vitamin D? - Results of a Retrospective Analysis of Hospitalized Geriatric Patients.

Purpose: Vitamin D deficiency is a common finding in geriatric patients. The ESPEN micronutrient guideline states that vitamin D serum levels significantly decrease in the presence of inflammation and should be interpreted with caution. This is of great interest for hospital care and would imply a significant change to the current approach to hospitalized patients with suspected vitamin D deficiency. Patients and methods: To evaluate the association of vitamin D and inflammation, we reanalyzed the data set of serum 25(OH)D-Levels of 687 consecutive geriatric hospitalized patients of a previously published study. Results: We found that vitamin D deficiency (<20 ng/dl) was prevalent in 78.0% and vitamin D insufficiency (20-30 ng/dl) in 9.9% of patients. Sperman's correlation showed a significant but very weak correlation (R = -0.100, P < 0.01) of serum vitamin D and C-reactive protein. However, linear regression with the inclusion of age and gender revealed no significant association (beta-coefficient -0.070; p=0.067). Conclusion: In this study, we could not confirm a significant and clinically relevant association between serum vitamin D levels and inflammation, contrasting with a previous study. However, longitudinal studies need to be performed to draw a final conclusion.