Statistical strategies for relating metabolomics and proteomics data: a real case study in nutrition research area

International audienceThe current investigations were carried out in the context of a nutritional case study aiming at assessing the postnatal impact of maternal dietary protein restriction during pregnancy and lactation on rat offspring plasma metabolome and hypothalamic proteome. Although data generated by different "Omics" technologies are usually considered and analyzed separately, their interrelation may offer a valuable opportunity for assessing the emerging 'integrated biology' concept. The overall strategy of analysis first investigated data pretreatment and variable selection for each dataset. Then, three multivariate analyses were applied to investigate the links between the abundance of metabolites and the expression of proteins collected on the same samples. Unfold principal component analysis and regularized canonical correlation analysis did not take into account the presence of groups of individuals related to the intervention study. On the contrary, the predictive MultiBlock Partial Least Squares method used this information. Regularized canonical correlation analysis appeared as a relevant approach to investigate of the relationships between the two datasets. However, in order to highlight the molecular compounds, proteins and metabolites, associated in interacting or common metabolic pathways for the experimental groups, MultiBlock partial least squares was the most appropriate method in the present nutritional case study

Hybrid plasmonic nanosystem with controlled position of nanoemitters

International audienceQuantum dots optically excited in close proximity to a silver nanowire can launch surface plasmons. The challenge related to this promising hybrid system is to control the position of nanoemitters on the nanowire. We report on the use of a two-photon photopolymerization process to strategically position quantum dots on nanowires at controlled sites. A parametric study of the distance between the quantum dots and the nanowire extremity shows that precise control of the position of the launching sites enables command of light intensity at the wire end through surface plasmon propagation