Balanced bacterial metabolism is essential for cell homeostasis and growth and can be impacted by various stress factors. In particular, bacteria exposed to metals, including the nanoparticle form, can significantly alter their metabolic processes. It is known that the extensive and intensive use of food and feed supplements, including zinc, in human and animal nutrition alters the intestinal microbiota and this may negatively impact the health of the host. This study examines the effects of zinc (zinc oxide and zinc oxide nanoparticles) on key metabolic pathways of Escherichia coli. Transcriptomic and proteomic analyses along with quantification of intermediates of tricarboxylic acid (TCA) were employed to monitor and study the bacterial responses. Multi-omics analysis revealed that extended zinc exposure induced mainly oxidative stress and elevated expression/production of enzymes of carbohydrate metabolism, especially enzymes for synthesis of trehalose. After the zinc withdrawal, E. coli metabolism returned to a baseline state. These findings shed light on the alteration of TCA and on importance of trehalose synthesis in metal-induced stress and its broader implications for bacterial metabolism and defense and consequently for the balance and health of the human and animal microbiome.

• Klíčová slova
• Carbohydrate metabolism, Nanoparticles, Proteome, Transcriptome, Trehalose synthesis, Tricarboxylic acid cycle, Virulence, Zinc, Zinc oxide,
• MeSH
• citrátový cyklus * účinky léků   MeSH
• Escherichia coli * metabolismus   genetika   účinky léků   MeSH
• fyziologická adaptace MeSH
• metabolické sítě a dráhy účinky léků   MeSH
• oxid zinečnatý metabolismus   farmakologie   MeSH
• oxidační stres MeSH
• proteiny z Escherichia coli metabolismus   genetika   MeSH
• proteomika MeSH
• regulace genové exprese u bakterií účinky léků   MeSH
• stanovení celkové genové exprese MeSH
• transkriptom MeSH
• trehalosa * metabolismus   MeSH
• zinek * metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• oxid zinečnatý MeSH
• proteiny z Escherichia coli MeSH
• trehalosa * MeSH
• zinek * MeSH

With the advent of human civilization and anthropogenic activities in the shade of urbanization and global climate change, plants are exposed to a complex set of abiotic stresses. These stresses affect plants' growth, development, and yield and cause enormous crop losses worldwide. In this alarming scenario of global climate conditions, plants respond to such stresses through a highly balanced and finely tuned interaction between signaling molecules. The abiotic stresses initiate the quick release of reactive oxygen species (ROS) as toxic by-products of altered aerobic metabolism during different stress conditions at the cellular level. ROS includes both free oxygen radicals {superoxide (O2•-) and hydroxyl (OH-)} as well as non-radicals [hydrogen peroxide (H2O2) and singlet oxygen (1O2)]. ROS can be generated and scavenged in different cell organelles and cytoplasm depending on the type of stimulus. At high concentrations, ROS cause lipid peroxidation, DNA damage, protein oxidation, and necrosis, but at low to moderate concentrations, they play a crucial role as secondary messengers in intracellular signaling cascades. Because of their concentration-dependent dual role, a huge number of molecules tightly control the level of ROS in cells. The plants have evolved antioxidants and scavenging machinery equipped with different enzymes to maintain the equilibrium between the production and detoxification of ROS generated during stress. In this present article, we have focused on current insights on generation and scavenging of ROS during abiotic stresses. Moreover, the article will act as a knowledge base for new and pivotal studies on ROS generation and scavenging.

• Klíčová slova
• ROS, ROS scavenging, abiotic stress, antioxidants, global climate change, signal transduction,
• MeSH
• fyziologický stres fyziologie   MeSH
• klimatické změny MeSH
• lidé MeSH
• peroxidace lipidů fyziologie   MeSH
• poškození DNA fyziologie   MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• rostliny metabolismus   MeSH
• signální transdukce fyziologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• reaktivní formy kyslíku MeSH

The complex development undergone by Streptomyces encompasses transitions from vegetative mycelial forms to reproductive aerial hyphae that differentiate into chains of single-celled spores. Whereas their mycelial life - connected with spore formation and antibiotic production - is deeply investigated, spore germination as the counterpoint in their life cycle has received much less attention. Still, germination represents a system of transformation from metabolic zero point to a new living lap. There are several aspects of germination that may attract our attention: (1) Dormant spores are strikingly well-prepared for the future metabolic restart; they possess stable transcriptome, hydrolytic enzymes, chaperones, and other required macromolecules stabilized in a trehalose milieu; (2) Germination itself is a specific sequence of events leading to a complete morphological remodeling that include spore swelling, cell wall reconstruction, and eventually germ tube emergences; (3) Still not fully unveiled are the strategies that enable the process, including a single cell's signal transduction and gene expression control, as well as intercellular communication and the probability of germination across the whole population. This review summarizes our current knowledge about the germination process in Streptomyces, while focusing on the aforementioned points.

• Klíčová slova
• Streptomyces, cell wall, dormancy, gene expression, germination, metabolism, signaling, spore,
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

BACKGROUND: Drosophila melanogaster is a chill-susceptible insect. Previous studies on this fly focused on acute direct chilling injury during cold shock and showed that lower lethal temperature (LLT, approximately -5°C) exhibits relatively low plasticity and that acclimations, both rapid cold hardening (RCH) and long-term cold acclimation, shift the LLT by only a few degrees at the maximum. PRINCIPAL FINDINGS: We found that long-term cold acclimation considerably improved cold tolerance in fully grown third-instar larvae of D. melanogaster. A comparison of the larvae acclimated at constant 25°C with those acclimated at constant 15°C followed by constant 6°C for 2 d (15°C→6°C) showed that long-term cold acclimation extended the lethal time for 50% of the population (Lt(50)) during exposure to constant 0°C as much as 630-fold (from 0.137 h to 86.658 h). Such marked physiological plasticity in Lt(50) (in contrast to LLT) suggested that chronic indirect chilling injury at 0°C differs from that caused by cold shock. Long-term cold acclimation modified the metabolomic profiles of the larvae. Accumulations of proline (up to 17.7 mM) and trehalose (up to 36.5 mM) were the two most prominent responses. In addition, restructuring of the glycerophospholipid composition of biological membranes was observed. The relative proportion of glycerophosphoethanolamines (especially those with linoleic acid at the sn-2 position) increased at the expense of glycerophosphocholines. CONCLUSION: Third-instar larvae of D. melanogaster improved their cold tolerance in response to long-term cold acclimation and showed metabolic potential for the accumulation of proline and trehalose and for membrane restructuring.

• MeSH
• aklimatizace * MeSH
• aminokyseliny metabolismus   MeSH
• analýza přežití MeSH
• časové faktory MeSH
• Drosophila melanogaster metabolismus   fyziologie   MeSH
• larva metabolismus   fyziologie   MeSH
• mastné kyseliny metabolismus   MeSH
• metabolismus sacharidů MeSH
• metabolom * MeSH
• nízká teplota * škodlivé účinky   MeSH
• polymery metabolismus   MeSH
• zmrazování škodlivé účinky   MeSH
• zvířata MeSH
• Check Tag
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• aminokyseliny MeSH
• mastné kyseliny MeSH
• polymery MeSH
• polyol MeSH Prohlížeč

BACKGROUND: Trehalose, a nonreducing disaccharide of glucose, is synthesized as a stress response factor when cells are exposed to stressful conditions. In the cornea, oxidative stress plays the key role in the development of acute corneal inflammatory response to UVB rays, photokeratitis. We found previously that trehalose reduced UVB-induced oxidative effects on the formation of cytotoxic peroxynitrite, apoptotic corneal epithelial cell death and changes in corneal optics. The aim of the present study was to examine whether trehalose might inhibit UVB-mediated proinflammatory cytokine and matrix metalloproteinase induction and the development of an antioxidant/pro-oxidant imbalance in the corneal epithelium, changes found previously to be strongly involved in the acute corneal UVB-induced inflammation. The expression of heat shock protein 70 as a potential biomarker for corneal UVB-induced damage was also examined. METHODS: The corneas of New Zealand white rabbits were irradiated with UVB rays, 312 nm, daily dose of 0.5 J/cm(2) for 4 days. During the irradiation, trehalose drops were applied on the right eye and buffered saline on the left eye. One day after the end of irradiations, the animals were killed and the corneas examined immunohistochemically for the expression of antioxidant enzymes (catalase, superoxide dismutase, glutathione peroxidase), pro-oxidant xanthine oxidoreductase/xanthine oxidase, proinflammatory cytokines (interleukin-6, interleukin-8), matrix metalloproteinase-9 and heat shock protein 70. RESULTS: After buffered saline treatment during UVB irradiation, an antioxidant/pro-oxidant imbalance appeared in the corneal epithelium: The expression of antioxidant enzymes was highly reduced, whereas the expression of pro-oxidant xanthine oxidase was increased. The pronounced expression of pro-inflammatory cytokines, matrix metalloproteinase and heat shock protein 70 was found in the UVB-irradiated corneal epithelium. Trehalose application significantly suppressed all the above-mentioned UVB-induced corneal disturbances. CONCLUSIONS: Trehalose favorably influenced the oxidative damage of the cornea caused by UVB rays. Trehalose suppressed proinflammatory cytokine induction. It is suggested that suppression of proinflammatory cytokines contributed strongly to reduced matrix metalloproteinase and xanthine oxidase expression in the UVB-irradiated corneal epithelium and to the decreased development of an antioxidant/pro-oxidant imbalance. The overexpression of heat shock protein 70 found in UVB-irradiated cornea after buffered saline treatment was reduced after trehalose application.

• MeSH
• antioxidancia MeSH
• biologické markery metabolismus   MeSH
• cytokiny metabolismus   MeSH
• experimentální radiační poranění farmakoterapie   enzymologie   MeSH
• imunoenzymatické techniky MeSH
• králíci MeSH
• matrixová metaloproteinasa 9 metabolismus   MeSH
• oxidační stres účinky léků   MeSH
• oxidancia MeSH
• oxidoreduktasy metabolismus   MeSH
• počítačové zpracování obrazu MeSH
• proteiny tepelného šoku HSP70 metabolismus   MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• rohovkový epitel enzymologie   účinky záření   MeSH
• trehalosa farmakologie   MeSH
• ultrafialové záření škodlivé účinky   MeSH
• zvířata MeSH
• Check Tag
• králíci MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• antioxidancia MeSH
• biologické markery MeSH
• cytokiny MeSH
• matrixová metaloproteinasa 9 MeSH
• oxidancia MeSH
• oxidoreduktasy MeSH
• proteiny tepelného šoku HSP70 MeSH
• reaktivní formy kyslíku MeSH
• trehalosa MeSH