Raymond Ruimy

RNY-derived small RNAs as a signature of coronary artery disease

BackgroundData from next generation sequencing technologies uncovered the existence of many classes of small RNAs. Recent studies reported that small RNAs are released by cells and can be detected in the blood. In this report, we aimed to discover the occurrence of novel circulating small RNAs in coronary artery disease (CAD).MethodsWe used high-throughput sequencing of small RNAs from human and mouse apoptotic primary macrophages, and analyzed the data by empirical Bayes moderated t-statistics to assess differential expression and the Benjamini and Hochberg method to control the false discovery rate. Results were then confirmed by Northern blot and RT-qPCR in foam cells and in two animal models for atherosclerosis, namely ApoE−/− and Ldlr−/− mouse lines. Quantitative RT-PCR to detect identified small RNAs, the RNY-derived small RNAs, was performed using sera of 263 patients with CAD compared to 514 matched healthy controls; the Student t-test was applied to statistically assess differences. Associations of small RNAs with clinical characteristics and biological markers were tested using Spearman’s rank correlations, while multivariate logistic regressions were performed to test the statistical association of small RNA levels with CAD.ResultsHere, we report that, in macrophages stimulated with pro-apoptotic or pro-atherogenic stimuli, the Ro-associated non-coding RNAs, called RNYs or Y-RNAs, are processed into small RNAs (~24–34 nt) referred to as small-RNYs (s-RNYs), including s-RNY1-5p processed from RNY1. A significant upregulation of s-RNY expression was found in aortic arches and blood plasma from ApoE−/− and Ldlr−/− mice and in serum from CAD patients (P <0.001). Biostatistical analysis revealed a positive association of s-RNY1-5p with hs-CRP and ApoB levels; however, no statistical interaction was found between either of these two markers and s-RNY1-5p in relation to the CAD status. Levels of s-RNY1-5p were also independent from statin and fibrate therapies.ConclusionOur results position the s-RNY1-5p as a relevant novel independent diagnostic biomarker for atherosclerosis-related diseases. Measurement of circulating s-RNY expression would be a valuable companion diagnostic to monitor foam cell apoptosis during atherosclerosis pathogenesis and to evaluate patient’s responsiveness to future therapeutic strategies aiming to attenuate apoptosis in foam cells in advanced atherosclerotic lesions.

Impact of the 13-valent pneumococcal conjugate vaccine on nasopharyngeal carriage of Streptococcus pneumoniae among children attending group daycare in southeastern France.

Regular surveys of pneumococcal nasopharyngeal carriage have been conducted among children attending daycare centers in Southeastern France from 1999 to 2012. We compared carriage rate, susceptibility patterns and serotype distribution in 2012, following implementation of the 13-valent pneumococcal conjugate vaccine, with findings from 5 previous surveys. Carriage rate was stable, antibiotic susceptibility improved and only serotype 19A persisted among vaccine-types.

A rare case of histopathological bladder necrosis associated with Actinobaculum schaalii: The incremental value of an accurate microbiological diagnosis using 16S rDNA sequencing

We describe here a rare case of bladder wall necrosis associated with Actinobaculum schaalii in a 72-year-old patient with non-muscle-invasive bladder cancer (NMIBC). A. schaalii microbiological diagnosis requires high index of suspicion and accurate identification methods such as 16S rDNA sequencing or MALDI-TOF Mass spectrometry.

Identification of cancer-associated missense mutations in hace1 that impair cell growth control and Rac1 ubiquitylation

The E3 ubiquitin ligase HACE1 is a potent tumor suppressor that controls cell proliferation and ubiquitylates the small GTPase Rac1 to target it to proteasomal degradation. Whether and how the activity of HACE1 is regulated by the N-terminal ankyrin (ANK) and the middle (MID) domains is ill defined. Here, we identified in the version 64 of the Catalogue of Somatic Mutations in Cancer (COSMIC) 13 missense mutations of hace1 located outside the HECT domain, and found that all lead to defective control of cell proliferation. In addition, several mutations located in the ankyrin domain displayed a dramatic reduction in Rac1 ubiquitylation associated with a decrease of colony formation in soft agar. 3D structure modelling of the 7 ankyrin-repeats coupled to functional analysis identified a surface epitope centered on one of the mutated residue, Gly-175, which is critical for controlling Rac1 binding and ubiquitylation. We also identified a role for the MID domain in conferring the specificity of association of HACE1 to the active form of Rac1. Our study of the functional interplay between HACE1 and Rac1 in cancer thus sheds a new light on the molecular mechanism of Rac1 ubiquitylation by HACE1 and the impact of its cancer-associated mutations in cell proliferation.

Lumbar Discitis Caused by Clostridium perfringens

ABSTRACT We report here a rare case of chronic lumbar discitis caused by Clostridium perfringens in an elderly patient that was treated with a combination of β-lactams and clindamycin. Molecular analysis performed on the strain revealed an unusual toxin gene pattern.