Sulfidated nanoscale zerovalent iron (S-nZVI) materials show enhanced reactivity and selectivity towards chlorinated solvents compared to non-sulfidated nZVI, thus they have a high potential for subsurface chlorinated solvent remediation. However, little is known about the possible toxic effects of S-nZVI towards microbial communities, which is of particular concern with regard to combined abiotic–biotic chlorinated solvent treatment scenarios. In this study, the toxicity of two different S-nZVI materials towards Shewanella oneidensis MR-1 (S. MR-1) was examined under anaerobic and aerobic conditions using colony forming units (CFU) and adenosine triphosphate (ATP) measurements, and the results were then compared to identical exposures performed with non-sulfidated nZVI. In a second step, the toxicity of S-nZVI and nZVI materials was tested on the commercial bioremediation culture KB-1® and on an in-house trichloroethylene enrichment culture. Under aerobic conditions, S. MR-1 viability was less affected by S-nZVI materials compared to non-sulfidated nZVI materials (up to three times higher viability) and it was generally lower compared to anaerobic conditions where little difference in S. MR-1 viability was observed between the tested materials. In terms of the two dechlorinating cultures, they exhibited significantly higher ATP viability during anaerobic exposures to S-nZVI and nZVI materials. Particularly for KB-1®, which retained comparable ATP-viability after ~60 hours exposure as S. MR-1 after two hours. Moreover, the ATP viability of the mixed cultures was generally higher in S-nZVI exposures compared to nZVI exposures (up to three times higher viability). The observed viability patterns are explained by differences in the shell structure, chemistry and stability of the tested S-nZVI and nZVI materials towards corrosion, while the substantially enhanced resilience of KB-1® is argued to stem from its year-long cultivation in the presence of reduced FeS particulates.

Efficient photosynthesis requires a balance of ATP and NADPH production/consumption in chloroplasts, and the exportation of reducing equivalents from chloroplasts is important for balancing stromal ATP/NADPH ratio. Here, we showed that the overexpression of purple acid phosphatase 2 on the outer membranes of chloroplasts and mitochondria can streamline the production and consumption of reducing equivalents in these two organelles, respectively. A higher capacity of consumption of reducing equivalents in mitochondria can indirectly help chloroplasts to balance the ATP/NADPH ratio in stroma and recycle NADP+, the electron acceptors of the linear electron flow (LEF). A higher rate of ATP and NADPH production from the LEF, a higher capacity of carbon fixation by the Calvin–Benson–Bassham (CBB) cycle and a greater consumption of NADH in mitochondria enhance photosynthesis in the chloroplasts, ATP production in the mitochondria and sucrose synthesis in the cytosol and eventually boost plant growth and seed yields in the overexpression lines.

Heat-shock proteins of 70 kDa (Hsp70s) are ubiquitous molecular chaperones that function in protein folding as well as other vital cellular processes. They bind and hydrolyze ATP in a nucleotide-binding domain (NBD) to control the binding and release of client polypeptides in a substrate-binding domain (SBD). However, the molecular mechanism for this allosteric action has remained unclear. Here, we develop and experimentally quantify a theoretical model for Hsp70 allostery based on equilibria among Hsp70 conformational states. We postulate that, when bound to ATP, Hsp70 is in equilibrium between a restraining state (R) that restricts ATP hydrolysis and binds peptides poorly, if at all, and a stimulating state (S) that hydrolyzes ATP relatively rapidly and has high intrinsic substrate affinity but rapid binding kinetics; after the hydrolysis to ADP, NBD and SBD disengage into an uncoupled state (U) that binds peptide substrates tightly, but now with slow kinetics of exchange.

The effects of haloxyfop {2-[4-[[3-chloro-5(trifluoromethyl)-2-pyridinyl] oxy] phenoxy] propanoic acid} and haloxyfop-methyl on elongation and respiration of primary roots of corn [Zea mays L. ‘B37 X Oh43’] and soybean [Glycine max (L.) Merr. ‘Hodgson 78’] were examined. Intact roots of etiolated seedlings were exposed to both forms of the herbicide. At a concentration of 10-6 M, neither form of the herbicide had an effect on elongation or respiration of soybean roots. In contrast, elongation of corn roots was completely inhibited within 24 h of exposure to 10-6 M haloxyfop. This treatment reduced the respiration rate of corn root apices by 30% but had little effect on ATP content. After 72 h of exposure to haloxyfop [10-6 M], both ATP content and respiration rate of corn root apices had declined 35%. Haloxyfop-methyl produced equivalent effects on elongation and respiration of corn roots. Studies with isolated corn root mitochondria indicated that haloxyfop inhibits electron transport at relatively high concentrations (I50 = approximately 2 mM for various substrates). Because significant reductions in ATP content and respiration rate of corn root apices were not detected during the period when elongation was inhibited (initial 24 h of exposure), it is concluded that impairment of respiration is a secondary response to the herbicide.

The present study aimed to investigate the effects of maternal dietary butyrate supplementation on energy metabolism and mitochondrial biogenesis in offspring skeletal muscle and the possible mediating mechanisms. Virgin female rats were randomly assigned to either control or butyrate diets (1 % butyrate sodium) throughout gestation and lactation. At the end of lactation (21 d), the offspring were killed by exsanguination from the abdominal aorta under anaesthesia. The results showed that maternal butyrate supplementation throughout gestation and lactation did not affect offspring body weight. However, the protein expressions of G-protein-coupled receptors (GPR) 43 and 41 were significantly enhanced in offspring skeletal muscle of the maternal butyrate-supplemented group. The ATP content, most of mitochondrial DNA-encoded gene expressions, the cytochrome c oxidase subunit 1 and 4 protein contents and the mitochondrial DNA copy number were significantly higher in the butyrate group than in the control group. Meanwhile, the protein expressions of type 1 myosin heavy chain, mitochondrial transcription factor A, PPAR-coactivator-1α (PGC-1α) and uncoupling protein 3 were significantly increased in the gastrocnemius muscle of the treatment group compared with the control group. These results indicate for the first time that maternal butyrate supplementation during the gestation and lactation periods influenced energy metabolism and mitochondrial biogenesis through the GPR and PGC-1α pathways in offspring skeletal muscle at weaning.

The main aim of the present study was to examine the hypothesis that an increase in the number of granulosa cells surrounding developing bovine oocytes results in both high ATP levels and an increase in the acetylation level of H4K12 in oocytes grown in vitro. Oocyte–granulosa cell complexes (OGCs) were collected from early antral follicles (EAFs, 0.4–0.7 mm in diameter), and individually cultured on 96-well plates with or without additional granulosa cell mass that had been prepared from other OGCs. After 16 days of culture, we examined: (i) the rate of antrum formation of the OGCs; (ii) the diameter, maturation, and fertilization rate of the oocytes; and (iii) the ATP content and acetylation level of H4K12 in the oocytes grown in vitro. Granulosa cell mass added to the culture medium contributed to the development of OGCs with a higher rate of antrum formation and oocyte growth. Furthermore, the addition of granulosa cells increased the ATP content and acetylation level of H4K12 in oocytes grown in vitro compared with those developed without addition of granulosa cells. In addition, there was a positive correlation between the ATP content in oocytes grown in vitro and the number of granulosa cells in the corresponding OGCs. The results suggest that granulosa cells play a role not only in the development of OGCs and the growth of oocytes, but also in the determination of ATP content and the acetylation of H4K12 in the oocytes developed in vitro.

The enzymatic activities of NTPDase and 5′nucleotidase are important to regulate the concentration of adenine nucleotides, known molecules involved in many physiological functions. Therefore, the objective of this study was to evaluate the activity of NTPDase and 5′nucleotidase in serum and liver tissue of rats infected by Fasciola hepatica. Rats were divided into two groups: uninfected control and infected. NTPDase activity for adenosine triphosphate (ATP) and ADP substrates in the liver was higher compared with the control group at 15 days post-infection (PI), while seric activity was lower. In addition, seric and hepatic samples did not show changes for 5′nucleotidase activity at this time. On the other hand, either NTPDase or 5′nucleotidase activities in liver homogenate and serum were higher at 87 days PI. Early in the infection, low NTPDase activity maintains an increase of ATP in the bloodstream in order to activate host immune response, while in hepatic tissue it decreases extracellular ATP to maintain a low inflammatory response in the tissue. As stated, higher NTPDase and 5′nucleotidase activities 87 days after infection in serum and tissue, probably results on an increased concentration of adenosine molecule which stimulates a Th2 immune response. Thus, it is possible to conclude that F. hepatica infections lead to different levels of nucleotide degradation when considering the two stages of infection studied, which influences the inflammatory and pathological processes developed by the purinergic system.

Type 2 diabetes and non-alcoholic fatty liver disease (NAFLD) are associated with elevated hepatic glucose production and fatty acid synthesis (de novo lipogenesis (DNL)). High carbohydrate diets also increase hepatic glucose production and lipogenesis. The carbohydrate-response element-binding protein (ChREBP, encoded by MLXIPL) is a transcription factor with a major role in the hepatic response to excess dietary carbohydrate. Because its target genes include pyruvate kinase (PKLR) and enzymes of lipogenesis, it is regarded as a key regulator for conversion of dietary carbohydrate to lipid for energy storage. An alternative hypothesis for ChREBP function is to maintain hepatic ATP homeostasis by restraining the elevation of phosphate ester intermediates in response to elevated glucose. This is supported by the following evidence: (i) A key stimulus for ChREBP activation and induction of its target genes is elevation of phosphate esters; (ii) target genes of ChREBP include key negative regulators of the hexose phosphate ester pool (GCKR, G6PC, SLC37A4) and triose phosphate pool (PKLR); (iii) ChREBP knock-down models have elevated hepatic hexose phosphates and triose phosphates and compromised ATP phosphorylation potential; (iv) gene defects in G6PC and SLC37A4 and common variants of MLXIPL, GCKR and PKLR in man are associated with elevated hepatic uric acid production (a marker of ATP depletion) or raised plasma uric acid levels. It is proposed that compromised hepatic phosphate homeostasis is a contributing factor to the elevated hepatic glucose production and lipogenesis that associate with type 2 diabetes, NAFLD and excess carbohydrate in the diet.

The aim of this study was to evaluate the purine levels of lambs experimentally infected with Haemonchus contortus. A total of 12 healthy lambs were divided into two groups, composed of 6 animals each: Group A represented the healthy animals (uninfected), while in Group B the animals were infected with 15 000 larvae of H. contortus. Blood was drawn on days 15, 45 and 75 post-infection (PI) in order to perform the purine analysis (ATP, ADP, AMP, adenosine, inosine, hypoxanthine, xanthine and uric acid) by high pressure liquid chromatography (HPLC) in serum. On day 15 PI a significant (P<0·05) increase in the levels of ATP and inosine was observed in the infected animals, unlike the levels of ADP, adenosine, xanthine and uric acid which were reduced. On day 45 PI a significant (P<0·05) increase in the ATP and xanthine levels in infected animals was observed, contrasting with reduced levels of ADP and uric acid. Finally, on day 75 PI an increase occurred in the levels of ATP, adenosine and hypoxanthine in infected lambs, concomitant with a reduction in the levels of ADP and uric acid (P<0·05). These changes in purine levels may influence the inflammatory process and the pathological events.

Adenosine triphosphate (ATP) is a well-known energy source for muscle contraction. In this study, to visualize localization of ATP, a luciferin-luciferase reaction (LLR) was performed in mouse skeletal muscle with an “in vivo cryotechnique” (IVCT). First, to confirm if ATP molecules could be trapped and detected after glutaraldehyde (GA) treatment, ATP was directly attached to glass slides with GA, and LLR was performed. The LLR was clearly detected as an intentional design of the ATP attachment. The intensity of the light unit by LLR was correlated with the concentration of the GA-treated ATP in vitro. Next, LLR was evaluated in mouse skeletal muscles with IVCT followed by freeze-substitution fixation (FS) in acetone-containing GA. In such tissue sections the histological structure was well maintained, and the intensity of LLR in areas between muscle fibers and connective tissues was different. Moreover, differences in LLR among muscle fibers were also detected. For the IVCT-FS tissue sections, diaminobenzidine (DAB) reactions were clearly detected in type I muscle fibers and erythrocytes in capillaries, which demonstrated flow shape. Thus, it became possible to perform microscopic evaluation of the numbers of ATP molecules in the mouse skeletal muscles with IVCT, which mostly reflect living states.

Trypanosoma evansi is the aetiological agent of trypanosomosis in domestic animals. In this pathology, an inflammatory response can be observed and, as a consequence, the increase of extracellular adenine nucleotides such as ATP. These nucleotide concentrations are regulated by ectoenzymes such as NTPDase (EC 3.6.1.5, CD39), which catalyses the hydrolysis of ATP and ADP into AMP. In this study, the activity of NTPDase in lymphocytes of rats experimentally infected with T. evansi was evaluated. The animals were inoculated with the parasite and monitored by blood smear on a daily basis. The animals were then were divided into 4 groups according to the degree of parasitaemia and period of infection. The blood collections for enzyme analysis and lymphocyte count were performed on the 3rd (beginning of infection), 5th (acute infection) and 15th (chronic infection) days post-infection (p.i.). The control group was composed of non-infected animals. In the infected group a decrease in ATP hydrolysis (36%) was observed on the 3rd day p.i. and a decrease in ADP hydrolysis (62%) was observed on the 5th day p.i. when compared to the control. On the 15th day p.i., an increase in ATP (94%) and ADP (50%) hydrolysis was observed in the infected group. Considering these data it is suggested that NTPDase activity is altered on the surface of lymphocytes of rats infected with T. evansi at different time-points of infection.

Memory consolidation in a discriminative bead pecking task is modulated by endogenous adenosine triphosphate (ATP) acting at purinergic receptors in the hippocampus. Consolidation, from short- to intermediate- to long-term memory during two distinct periods following training, was blocked by the non-selective P2 purinergic receptor antagonist PPADS (pyridoxal phosphate-6-azo(benzene-2,4-disulphonic acid) tetrasodium salt hydrate and the specific P2Y1 receptor antagonist MRS2179. Direct injections of the ATP agonists (ATPγS and ADPβS) potentiated memory consolidation and the effect of ADPβS was blocked by MRS2179, suggesting an important role of ATP on memory consolidation via the P2Y1 receptor in the chick hippocampus. Incubation of astrocytes with ATPγS and ADPβS resulted in the increase of intracellular calcium ([Ca2+]i), the latter being blocked by MRS2179 suggesting a specific role for P2Y1 receptors in the calcium response. This response was prevented by blocking astrocytic oxidative metabolism with fluoroacetate. We argue that the source of the ATP acting on neuronal P2Y1 receptors is most likely to be astrocytes. Thrombin selectively increases [Ca2+]i in astrocytes but not in neurones. The main findings of the present study are: (a) astrocytic [Ca2+]i plays an important role in the consolidation of short-term to long-term memory; and (b) ATP released from chick astrocytes during learning modulates neuronal activity through astrocytic P2Y1 receptors.

Recent studies have indicated that constitutive functions of microglia in the healthy adult central nervous system (CNS) involve immune surveillance, synapse maintenance and trophic support. These functions have been related to the ramified structure of ‘resting’ microglia and the prominent motility in their processes that provide extensive coverage of the entire extracellular milleu. In this review, we examine how external signals, and in particular, ionotropic neurotransmission, regulate features of microglial morphology and process motility. Current findings indicate that microglial physiology in the healthy CNS is constitutively and reciprocally regulated by endogenous ionotropic glutamatergic and GABAergic neurotransmission. These influences do not act directly on microglial cells but indirectly via the activity-dependent release of ATP, likely through a mechanism involving pannexin channels. Microglia in the ‘resting’ state are not only dynamically active, but also constantly engaged in ongoing communication with neuronal and macroglial components of the CNS in a functionally relevant way.

Effects of ATP on the activity of cGMP-gated channels from carp cone photoreceptors were studied. In 29% of the patches examined (N = 45), ATP (1 mM) enhanced a current evoked by cGMP (20 μM, up to about 100%), in 33%, ATP suppressed it by up to about 90%, and in the remaining 38%, ATP had no effect. ATP showed similar effects on a current evoked by 8-bromoguanosine 3′,5′-cyclic monophosphate (2 μM, enhancing in 42% of the patches, suppressing in 25%, no effect in 33%, N = 12), suggesting that the effects were not through modulation of the phosphodiesterase. Both of the effects, enhancement and suppression, were produced by a change in apparent affinity for cGMP, since (1) the maximum current evoked by cGMP of the saturating concentration (≥1 mM) was not affected, and (2) the A1/2 value decreased by approximately 45% (N = 2) or increased by approximately 25% (N = 2). A lower pH (approximately 6) facilitated the enhancing effect. ATP-γ-S (1 mM) showed a suppressing effect in 80% of the patches and no effect in 20% of the patches (N = 10). However, ATP-γ-S did not show an enhancing effect. Thus, ATP had two opposite effects through different mechanisms on the apparent sensitivity of the channel to cGMP; increasing and decreasing.

Somatic cell count (SCC) in milk is considered to be a valuable indicator of cow mastitis. For assessment of SCC in milk, the bioluminescent assay based on determination of ATP from somatic cells ([ATPsom]) in milk was proposed earlier. However, this assay is still not widely used in practice owing to lower reliability compared with conventional methods such as direct microscopy and flow cytometry. We revised the bioluminescent SCC assay and developed a simple protocol based on determination of the total non-bacterial ATP concentration in milk. It was shown that the novel ATP-releasing agent Neonol-10 (oxy-ethylated iso-nonyl phenol) has superior performance providing 100% lysis of somatic cells while not disrupting bacterial cells of milk at a concentration of 1·5% w/w. There was high correlation (R2=0·99) between measured bioluminescence and SCC as measured by direct microscopy. The observed detection limit of the bioluminescent milk SCC assay was as low as 900 cell/ml, time of analysis was 2–3 min per sample. The proposed method has high potential for on-site mastitis diagnostics.

Panspermia, the dissemination of life through space, would require resistance to the conditions found in space, including UV light. All known life forms depend on DNA to store information. In an effort to understand the liabilities of DNA to UV light and modes of DNA protection in terrestrial life forms, we established UV–VUV (125–340 nm) absorption spectra for dry DNA and its polymerized components and mononucleotides, as well as for a selection of potential UV screens ubiquitous in all organisms, including proteins, selected amino acids and amines (polyamines and tyramine). Montmorillonite clay was included as a potential abiotic UV screen. Among the potential screens tested, adenosine triphosphate (ATP) appeared to be particularly attractive, because its UV absorption spectrum was similar to that of DNA. We suggest that the use of ATP in UV protection could have pre-dated its current role in energy transfer. Spectroscopy also showed that UV absorption varied according to nucleotide content, suggesting that base pair usage could be a factor in adaptation to given UV environments and the availability of UV screens.

The distribution of ATP in tomato seeds was visualized by monitoring the luminescence of frozen sections on top of a gel containing all the components of the luciferase reaction, but excluding ATP. ATP was imaged in germinating tomato seeds at intervals of 3, 6, 17, 24 and 48 h and in seeds with primary or secondary dormancy. ATP was present mainly in the embryo and concentrated in the radicle tip towards the completion of germination. In contrast to germinating seeds, ATP was distributed more evenly in dormant seeds. For germination, the ratio of ATP concentration in the radicle tip versus cotyledons was decisive, rather than the absolute concentration.