Showing papers by "Dominique Melck published in 2016"
TL;DR: It is found that taproots, as a consequence of the stress, try to restore homeostasis and normal metabolic fluxes thorough the synthesis and/or accumulation of specific compounds related to mechanical forces distribution along the bent taproot.
Abstract: Molecular factors are differentially observed in various bent sectors of poplar (Populus nigra) woody taproots. Responses to stress are modulated by a complex interplay among different hormones and signal transduction pathways. In recent years, metabolomics has been recognized as a powerful tool to characterize metabolic network regulation, and it has been widely applied to investigate plant responses to biotic and abiotic stresses. In this paper we used metabolomics to understand if long term-bending stress induces a “spatial” and a “temporal” metabolic reprogramming in woody poplar roots. By NMR spectroscopy and statistical analysis we investigated the unstressed and three portions of stressed root (above-bent, bent, and below-bent) sectors collected at 12 (T0), 13 (T1) and 14 (T2) months after stress induction. The data indicate a clear between-class separation of control and stressed regions, based on the metabolites regulation, during both spatial and temporal changes. We found that taproots, as a consequence of the stress, try to restore homeostasis and normal metabolic fluxes thorough the synthesis and/or accumulation of specific compounds related to mechanical forces distribution along the bent taproot. The data demonstrate that the impact of mechanical stress on plant biology can efficiently be studied by NMR-based metabolomics.
11 citations
TL;DR: It is found that AuNPs-mmi triggers a subtle and complex cellular response, which is initially characterized by cellular stress and toxicological reaction, and the detected metabolites suggest a protective cellular response to the amounts of endogenous reactive oxygen species.
Abstract: Among various nanoparticles the gold derivatives (AuNPs) possess many features such as ease of synthesis at a tunable size, chemical stability and flexibility to undergo surface modifications, thus making them good candidates as bio-carrier across central nervous system and target diseased cells. However, a significant gap remains in data regarding their biosafety. We previously showed epigenetic modifications by short-term exposures of neuroblastoma SH-SY5Y cells to AuNPs conjugated with 2-mercapto-1-methylimidazole (AuNPs-mmi). Here, we investigated the effects of AuNPs-mmi on SH-SY5Y neuroblastoma cells through nuclear magnetic resonance-based metabolomics, to uncover the occurrence of perturbed pathways and deciphering possible phenotypic alterations. We found that AuNPs-mmi triggers a subtle and complex cellular response, which is initially characterized by cellular stress and toxicological reaction. In particular, we observed changes in catabolism of glucose, acetate and alanine, probably related to the energy-requiring endocytic process and oxidative stress. In addition, following nanoparticles' removal, alteration of acetate, choline, glutamine, glycine, tyrosine and leucine indicates a cellular reaction to stress and immune response. This effect was further confirmed by the production of metabolic endproducts such as glutamate, glycine and alanine. Moreover, the detected metabolites suggest a protective cellular response to the amounts of endogenous reactive oxygen species.
4 citations