In situ fluorescence analysis demonstrates active siRNA exclusion from the nucleus by Exportin 5

Two types of short double-stranded RNA molecules, namely microRNAs (miRNAs) and short interfering RNAs (siRNAs), have emerged recently as important regulators of gene expression. Although these molecules show similar sizes and structural features, the mechanisms of action underlying their respective target silencing activities appear to differ: siRNAs act primarily through mRNA degradation, whereas most miRNAs appear to act primarily through translational inhibition. Our understanding of how these overlapping pathways are differentially regulated within the cell remains incomplete. In the present work, quantitative fluorescence microscopy was used to study how siRNAs are processed within human cells. We found that siRNAs are excluded from non-nucleolar areas of the nucleus in an Exportin-5 dependent process that specifically recognizes key structural features shared by these and other small RNAs such as miRNAs. We further established that the Exportin-5-based exclusion of siRNAs from the nucleus can, when Exp5 itself is inhibited, become a rate-limiting step for siRNA-induced silencing activity. Exportin 5 therefore represents a key point of intersection between the siRNA and miRNA pathways, and, as such, is of fundamental importance for the design and interpretation of RNA interference experimentation

Influence of different 3′ and 5′ overhangs on the subcellular localization of short dsRNAs

<p><b>Copyright information:</b></p><p>Taken from " fluorescence analysis demonstrates active siRNA exclusion from the nucleus by Exportin 5"</p><p>Nucleic Acids Research 2006;34(5):1369-1380.</p><p>Published online 6 Mar 2006</p><p>PMCID:PMC1390680.</p><p>© The Author 2006. Published by Oxford University Press. All rights reserved</p> () Sequences and their annealing pattern of the different shifted siGL2 variants were illustrated together with their used abbreviations. For the comparison of the 3′ and the 5′ overhangs two labelled strands were used to keep the dye close to the double-stranded stem. () Quality control of the shifted GL2 short RNAs for non-annealed single strands as described in Materials and Methods with a 4% agarose gel. () Each type of short RNA labelled with Alexa488 was microinjected into HeLa SS6 cells and analysed 10–15 min later with confocal microscopy. The graph shows the ratio of fluorescence intensity nucleus/cytoplasm

Lipid Profiles in Lyme Borreliosis:A Potential Role for Apheresis?

Dyslipidemia and dyslipoproteinemia are common causes of metabolic and cardiovascular diseases. On the other hand, intracellular bacteria, such as Borrelia burgdorferi, utilize host lipids to survive and disseminate within the host. Recent data suggest that elevated lipids are a contributing factor to the maintenance and severity of Lyme disease and its complications. Here we review and discuss the role of lipids in Borreliosis and report on a pilot trial to examine the potential roles of circulating lipids and lipoproteins in patients with Borrelia infection. In this analysis we assessed the clinical and lipid profiles of 519 patients (319 women, 200 men) with a proven history of Lyme disease, before and after an extracorporeal double membrane filtration. Lipid profiles pre- and post-apheresis were analyzed in conjunction with clinical symptoms and parameters of inflammation. Circulating cholesterol, triglycerides, LDL, LP(a), and other inflammatory lipids were significantly reduced after the apheresis, while symptoms of the disorder and bioindexes of inflammation such as CRP improved. Further studies should be initiated to investigate the possibly causal relation between Lyme disease and circulating lipids and to design appropriate therapeutic strategies

Correction: Lipid Profiles in Lyme Borreliosis: A Potential Role for Apheresis?

In the above-mentioned article, the representation of the graphs in Fig. 1, 2 and 3 and the matching captions were incorrect. The correct illustrations with the correct captions are below. (Figure Presented)