Metabolomic and transcriptomic stress response of Escherichia coli

GC-MS-based analysis of the metabolic response of Escherichia coli exposed to four different stress conditions reveals reduction of energy expensive pathways.Time-resolved response of E. coli to changing environmental conditions is more specific on the metabolite as compared with the transcript level.Cease of growth during stress response as compared with stationary phase response invokes similar transcript but dissimilar metabolite responses.Condition-dependent associations between metabolites and transcripts are revealed applying co-clustering and canonical correlation analysis

Identification of functional lipid metabolism biomarkers of brown adipose tissue aging

Objective: Aging is accompanied by loss of brown adipocytes and a decline in their thermogenic potential, which may exacerbate the development of adiposity and other metabolic disorders. Presently, only limited evidence exists describing the molecular alterations leading to impaired brown adipogenesis with aging and the contribution of these processes to changes of systemic energy metabolism. Methods: Samples of young and aged murine brown and white adipose tissue were used to compare age-related changes of brown adipogenic gene expression and thermogenesis-related lipid mobilization. To identify potential markers of brown adipose tissue aging, non-targeted proteomic and metabolomic as well as targeted lipid analyses were conducted on young and aged tissue samples. Subsequently, the effects of several candidate lipid classes on brown adipocyte function were examined. Results: Corroborating previous reports of reduced expression of uncoupling protein-1, we observe impaired signaling required for lipid mobilization in aged brown fat after adrenergic stimulation. Omics analyses additionally confirm the age-related impairment of lipid homeostasis and reveal the accumulation of specific lipid classes, including certain sphingolipids, ceramides, and dolichols in aged brown fat. While ceramides as well as enzymes of dolichol metabolism inhibit brown adipogenesis, inhibition of sphingosine 1-phosphate receptor 2 induces brown adipocyte differentiation. Conclusions: Our functional analyses show that changes in specific lipid species, as observed during aging, may contribute to reduced thermogenic potential. They thus uncover potential biomarkers of aging as well as molecular mechanisms that could contribute to the degradation of brown adipocytes, thereby providing potential treatment strategies of age-related metabolic conditions. Keywords: Brown adipose tissue, Aging, Ceramides, Sphingolipids, Dolichol lipid

Cytochrome respiration pathway and sulphur metabolism sustain stress tolerance to low temperature in the Antarctic species Colobanthus quitensis

Understandingthe strategies employed by plant species that live in extreme environments offersthe possibility to discover stress tolerance mechanisms. We studied thephysiological, antioxidant and metabolic responses to three temperatureconditions (4, 15, and 23°C) of Colobanthusquitensis (CQ), one of the only two native vascular species in Antarctica.We also employed Dianthus chinensis(DC), to assess the effects of the treatments in a non-Antarctic species fromthe same family.-Usingfused LASSO modelling, we associated physiological and biochemical antioxidant responseswith primary metabolism. This approach allowed us to highlight the metabolicpathways driving the response specific to CQ.-Lowtemperature imposed dramatic reductions in photosynthesis (up to 88%) but notin respiration (sustaining rates of 3.0?4.2 µmol CO2 m-2s‑1) in CQ, and no change in the physiological stress parameters wasfound. Its notable antioxidant capacity and mitochondrial cytochromerespiratory activity (20 and two times higher than DC, respectively), whichensure ATP production even at low temperature, was significantly associatedwith sulphur-containing metabolites and polyamines.-Ourfindings potentially open new biotechnological opportunities regarding the roleofantioxidant compounds and respiratory mechanisms associated with sulphurmetabolism instress tolerance strategies to low temperature.Fil: Clemente-Moreno, María J.. Departamento de Biología; EspañaFil: Omranian, Nooshin. Max Planck Institute Of Molecular Plant Physiology; AlemaniaFil: Sáez, Patricia. Universidad de Concepción; ChileFil: Figueroa, Carlos Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Agrobiotecnología del Litoral. Universidad Nacional del Litoral. Instituto de Agrobiotecnología del Litoral; ArgentinaFil: Del-Saz, Néstor. Universidad de Concepción; ChileFil: Elso, Mhartyn. Universidad de Concepción; ChileFil: Poblete, Leticia. Universidad de Concepción; ChileFil: Orf, Isabel. Ben Gurion University of the Negev; IsraelFil: Cuadros-Inostroza, Alvaro. Metasysx Gmbh; AlemaniaFil: Cavieres, Lohengrin. Universidad de Concepción; ChileFil: Bravo, León. Universidad de La Frontera; ChileFil: Fernie, Alisdair. Max Planck Institute Of Molecular Plant Physiology; AlemaniaFil: Ribas-Carbó, Miquel. Departamento de Biología; EspañaFil: Flexas, Jaume. Departamento de Biología; EspañaFil: Nikoloski, Zoran. Max Planck Institute Of Molecular Plant Physiology; AlemaniaFil: Brotman, Yariv. Ben Gurion University of the Negev; IsraelFil: Gago, Jorge. Departamento de Biología; Españ

Low-temperature tolerance of the Antarctic species Deschampsia antarctica: A complex metabolic response associated with nutrient remobilization

The species Deschampsia antarctica (DA) is one of the only two native vascular species that live in Antarctica. We performed ecophysiological, biochemical, and metabolomic studies to investigate the responses of DA to low temperature. In parallel, we assessed the responses in a non-Antarctic reference species (Triticum aestivum [TA]) from the same family (Poaceae). At low temperature (4°C), both species showed lower photosynthetic rates (reductions were 70% and 80% for DA and TA, respectively) and symptoms of oxidative stress but opposite responses of antioxidant enzymes (peroxidases and catalase). We employed fused least absolute shrinkage and selection operator statistical modelling to associate the species-dependent physiological and antioxidant responses to primary metabolism. Model results for DA indicated associations with osmoprotection, cell wall remodelling, membrane stabilization, and antioxidant secondary metabolism (synthesis of flavonols and phenylpropanoids), coordinated with nutrient mobilization from source to sink tissues (confirmed by elemental analysis), which were not observed in TA. The metabolic behaviour of DA, with significant changes in particular metabolites, was compared with a newly compiled multispecies dataset showing a general accumulation of metabolites in response to low temperatures. Altogether, the responses displayed by DA suggest a compromise between catabolism and maintenance of leaf functionality.Fil: Clemente Moreno, María José. Instituto de Agroecología y Economía del Agua; EspañaFil: Omranian, Nooshin. Max Planck Institute Of Molecular Plant Physiology; AlemaniaFil: Sáez, Patricia L.. Universidad de Concepción; ChileFil: Figueroa, Carlos Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Agrobiotecnología del Litoral. Universidad Nacional del Litoral. Instituto de Agrobiotecnología del Litoral; ArgentinaFil: Del Saz, Néstor. Universidad de Concepción; ChileFil: Elso, Mhartyn. Universidad de Concepción; ChileFil: Poblete, Leticia. Universidad de Concepción; ChileFil: Orf, Isabel. Ben Gurion University of the Negev; IsraelFil: Cuadros Inostroza, Alvaro. No especifíca;Fil: Cavieres, Lohengrin A.. Universidad de Concepción; ChileFil: Bravo, León. Universidad de Concepción; ChileFil: Fernie, Alisdair R.. Max Planck Institute Of Molecular Plant Physiology; AlemaniaFil: Ribas Carbó, Miquel. Instituto de Agroecología y Economía del Agua; EspañaFil: Flexas, Jaume. Instituto de Agroecología y Economía del Agua; EspañaFil: Nikoloski, Zoran. Max Planck Institute Of Molecular Plant Physiology; AlemaniaFil: Brotman, Yariv. Ben Gurion University of the Negev; IsraelFil: Gago, Jorge. Instituto de Agroecología y Economía del Agua; Españ