Circular RNAs (circRNAs) are emerging as a novel, yet powerful player in many human diseases. They are involved in several cellular processes and are becoming a noteworthy type of biomarkers. Among other functions, circRNAs can serve as RNA sponges or as scaffolds for RNA-binding proteins. Here, we investigated a microarray expression profile of circRNAs in leukocyte samples from ALS patients and age- and sex-matched healthy controls to identify differentially expressed circRNAs. We selected 10 of them for a qPCR validation of expression on a larger set of samples, identification of their associations with clinical parameters, and evaluation of their diagnostic potential. In total, expression of 7/10 circRNAs was significant in a larger cohort of ALS patients, compared with age- and sex-matched healthy controls. Three of them (hsa_circ_0023919, hsa_circ_0063411, and hsa_circ_0088036) showed the same regulation as in microarray results. These three circRNAs also had AUC > 0.95, and sensitivity and specificity for the optimal threshold point > 90%, showing their potential for using them as diagnostic biomarkers.

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Zinc pyrithione ( 1a ), together with its analogues 1b – h and ruthenium pyrithione complex 2a , were synthesised and evaluated for the stability in biologically relevant media and anti-SARS-CoV-2 activity. Zinc pyrithione revealed potent in vitro inhibition of cathepsin L (IC 50 =1.88 ± 0.49 µM) and PL Pro (IC 50 =0.50 ± 0.07 µM), enzymes involved in SARS-CoV-2 entry and replication, respectively, as well as antiviral entry and replication properties in an ex vivo system derived from primary human lung tissue. Zinc complexes 1b – h expressed comparable in vitro inhibition. On the contrary, ruthenium complex 2a and the ligand pyrithione a itself expressed poor inhibition in mentioned assays, indicating the importance of the selection of metal core and structure of metal complex for antiviral activity. Safe, effective, and preferably oral at-home therapeutics for COVID-19 are needed and as such zinc pyrithione, which is also commercially available, could be considered as a potential therapeutic agent against SARS-CoV-2.

Aims IgA vasculitis (IgAV) is a common small‐vessel systemic vasculitisthat is histologically characterised by granulocyte infiltration and IgA deposition in vessel walls. Information on microRNA (miRNA) involvement inIgAVis limited. The aim of this study was to analyse the association between histopathological changes and expression profiles of 14 miRNAs in the affected skin of 70 adult patients with IgAV. Methods and results miRNA expression analysis was performed by quantitative real‐time polymerase chain reaction and evaluation of histopathological changes by light and immunofluorescence microscopy on formalin‐fixed paraffin‐embedded skin excision samples. In IgAV‐affected skin, granulocyte infiltration was significantly associated with vessel fibrinoid necrosis. Of the analysed miRNAs, four showed two‐fold increased expression (let‐7d, let‐7f, miR‐21‐5p, and miR‐203‐3p), five showed five‐fold increased expression (let‐7b, miR‐17‐5p, miR‐155‐5p, miR‐423‐5p, and miR‐451a), and threeshowed 15‐fold increased expression (let‐7a, miR‐21‐3p, miR‐223‐3p), as compared with controls (all P < 0.001). miR‐146a‐5p and miR‐148b‐3p showed three‐fold decreased expression (P = 0.981 and P < 0.001). The expression of miR‐223‐3p also showed a significant positive association with granulocyte infiltration and fibrinoid necrosis. Conclusions Altered miRNA expression, especially of miRNA‐223‐3p, may be associated with the skin inflammatory state in IgAV. The majority of aberrantly expressed miRNAs in IgAV‐affected skin are known to influence the nuclear factor‐κB signalling pathway, which is crucial for activation of key proinflammatory genes, including those encoding tumour necrosis factor‐α, interleukin (IL)‐6, and IL‐8. Furthermore, miR‐146a‐5p and miR‐148b‐3p, which are negative regulators of inflammatory gene expression, showed decreased expression and could contribute to the exaggerated inflammation. Further investigation of miRNA expression in the affected tissues could improve our knowledge of IgAV pathogenesis, and possibly help to identify novel biomarkers in body fluids.

Background: Different cytology preparations can be used for molecular diagnostics, however the influence of pre-analytical and analytical steps on the results are not yet well defined. We aimed to determine optimal steps for efficient extraction of DNA and RNA from fresh cells for molecular diagnostics.Methods: MCF7 and FaDu human cell lines, were used as a model to determine fresh cells storage conditions (temperature: 25°C, 4°C, −20°C, −80°C; duration: 0 h, 4 h, 12 h, 24 h, 48 h) and optimal nucleic acids extraction method. Besides, the minimal number of total cells and minimal percentage of mutated cells needed for successful extraction of nucleic acids and subsequent determination of present mutation were evaluated.Results: Extraction of nucleic acids using spin columns yielded the highest quantity and quality of nucleic acids. Isolation of nucleic acids was feasible in all storage conditions, however higher temperature and longer duration of fresh cells storage were associated with lower quality of isolated nucleic acids and similar quantification cycle of housekeeping genes. Successful molecular testing was feasible with least 10 4 cells, while specific mutation was detected in as low as 5% of mutated cells. Conclusions:Our cell line model, mimicking fresh cytology samples, showed that quantity of extracted either DNA or RNA declined with higher temperatures and longer duration of storage but regardless of the storage conditions, we successfully detected both housekeeping genes and mutated gene using qPCR.