A long and abundant non-coding RNA in Lactobacillus salivarius

Lactobacillus salivarius, found in the intestinal microbiota of humans and animals, is studied as an example of the sub-dominant intestinal commensals that may impart benefits upon their host. Strains typically harbour at least one megaplasmid that encodes functions contributing to contingency metabolism and environmental adaptation. RNA sequencing (RNA-seq) transcriptomic analysis of L. salivarius strain UCC118 identified the presence of a novel unusually abundant long non-coding RNA (lncRNA) encoded by the megaplasmid, and which represented more than 75 % of the total RNA-seq reads after depletion of rRNA species. The expression level of this 520 nt lncRNA in L. salivarius UCC118 exceeded that of the 16S rRNA, it accumulated during growth, was very stable over time and was also expressed during intestinal transit in a mouse. This lncRNA sequence is specific to the L. salivarius species; however, among 45 L. salivarius genomes analysed, not all (only 34) harboured the sequence for the lncRNA. This lncRNA was produced in 27 tested L. salivarius strains, but at strain-specific expression levels. High-level lncRNA expression correlated with high megaplasmid copy number. Transcriptome analysis of a deletion mutant lacking this lncRNA identified altered expression levels of genes in a number of pathways, but a definitive function of this new lncRNA was not identified. This lncRNA presents distinctive and unique properties, and suggests potential basic and applied scientific developments of this phenomenon

Trends in self-rated health in European and North-American adolescents from 2002 to 2010 in 32 countries

Publisher Copyright: © 2015 The Author. Published by Oxford University Press on behalf of the European Public Health Association. All rights reserved.Background: Self-rated health (SRH) in adolescence is known to be associated with health outcomes in later life. We carried out a trend analysis on data coming from three waves of data collected in 32 countries (mostly European) from 2002 to 2010 coming from the Health Behaviour in School-Aged Children surveys. Methods: SRH in adolescents was assessed using a Likert scale (excellent, good, fair and poor). Responses were dichotomized into 'excellent' vs. 'rest'. Country, age and gender groups were compared based on the odds ratio of declaring excellent SRH in 2010 with respect to 2002 and 2006. Results: The trend for European adolescents indicates an improvement over the last decade, although, in the majority of countries, a higher proportion of adolescents rate their health as excellent during the period 2002-06 with respect to the second half of the decade (2006-10).Girls were found to constantly rate their health as poorer, compared to their male peers, in all countries. Age has also a very stable trend towards a decreasing rating of health with increasing age. Conclusion: Decreased rating of health in the period 2006-10 may be a signal of the socio-economic difficulties of Europe in the last part of this decade.publishersversionPeer reviewe

Trends in life satisfaction in European and North-American adolescents from 2002 to 2010 in over 30 countries

Publisher Copyright: © 2015 The Author. Published by Oxford University Press on behalf of the European Public Health Association. All rights reserved.Background: Life satisfaction (LS) is an indicator which is widely used for assessing the perception of a child's feeling about his life. Methods: LS is assessed in Health Behaviour in School-aged Children via the Cantril ladder with 10 steps indicating the worst and best possible life. This range of values (0-10) was dichotomized into 'low' (0-5) vs. 'high' (6-10). Countries, age groups and genders were compared based on the odds ratio (OR) of declaring a higher LS in 2010 with respect to 2002. Results: Analyzing the difference between 2002 and 2010, six countries from Western Europe show decreasing LS: Austria, Canada, Switzerland, Denmark, Finland and Greenland. In contrast, a group of Eastern European Countries, that is, Estonia, Croatia, Lithuania, Latvia, Russia and Ukraine, show a significant increase in LS. Data on gender and age differences confirm the lower rating of LS in girls and a decreasing rating with age. Conclusion: The LS scale appears to be a tool capable of discriminating the level of wellbeing of adolescent population among countries.publishersversionPeer reviewe

Five types of blow-up in a semilinear fourth-order reaction-diffusion equation: an analytic-numerical approach

Five types of blow-up patterns that can occur for the 4th-order semilinear parabolic equation of reaction-diffusion type u_t= -\Delta^2 u + |u|^{p-1} u \quad {in} \quad \ren \times (0,T), p>1, \quad \lim_{t \to T^-}\sup_{x \in \ren} |u(x,t)|= +\iy, are discussed. For the semilinear heat equation $u_t= \Delta u+ u^p$, various blow-up patterns were under scrutiny since 1980s, while the case of higher-order diffusion was studied much less, regardless a wide range of its application.Comment: 41 pages, 27 figure

Microbiota Modulate Host Gene Expression via MicroRNAs

Microbiota are known to modulate host gene expression, yet the underlying molecular mechanisms remain elusive. MicroRNAs (miRNAs) are importantly implicated in many cellular functions by post-transcriptionally regulating gene expression via binding to the 3′-untranslated regions (3′-UTRs) of the target mRNAs. However, a role for miRNAs in microbiota-host interactions remains unknown. Here we investigated if miRNAs are involved in microbiota-mediated regulation of host gene expression. Germ-free mice were colonized with the microbiota from pathogen-free mice. Comparative profiling of miRNA expression using miRNA arrays revealed one and eight miRNAs that were differently expressed in the ileum and the colon, respectively, of colonized mice relative to germ-free mice. A computational approach was then employed to predict genes that were potentially targeted by the dysregulated miRNAs during colonization. Overlapping the miRNA potential targets with the microbiota-induced dysregulated genes detected by a DNA microarray performed in parallel revealed several host genes that were regulated by miRNAs in response to colonization. Among them, Abcc3 was identified as a highly potential miRNA target during colonization. Using the murine macrophage RAW 264.7 cell line, we demonstrated that mmu-miR-665, which was dysregulated during colonization, down-regulated Abcc3 expression by directly targeting the Abcc3 3′-UTR. In conclusion, our study demonstrates that microbiota modulate host microRNA expression, which could in turn regulate host gene expression