Higher Adenosine Triphosphate Content Research Articles

Effects of ATP on the Physicochemical Properties and Cytocompatibility of Calcium Sulfate/Calcium Citrate Composite Cement.

Adenosine triphosphate (ATP), acting as a source of energy, has effects on cellular activities, such as adhesion, proliferation, and differentiation. In this study, ATP-loaded calcium sulfate hemihydrate/calcium citrate tetrahydrate cement (ATP/CSH/CCT) was successfully prepared for the first time. The effect of different contents of ATP on the structure and physicochemical properties of ATP/CSH/CCT was also studied in detail. The results indicated that incorporating ATP into the cement did not significantly alter their structures. However, the addition ratio of ATP directly impacted the mechanical properties and in vitro degradation properties of the composite bone cement. The compressive strength of ATP/CSH/CCT gradually decreased with an increasing ATP content. The degradation rate of ATP/CSH/CCT did not significantly change at low concentrations of ATP, but it increased with a higher ATP content. The composite cement induced the deposition of a Ca-P layer in a phosphate buffer solution (PBS, pH = 7.4). Additionally, the release of ATP from the composite cement was controlled. The ATP was controlled releasing at the 0.5% and 1% ATP in cement by the diffusion of ATP and the degradation of the cement, whereas it was controlled by the diffusion process merely at the 0.1% ATP in cement. Furthermore, ATP/CSH/CCT demonstrated good cytoactivity with the addition of ATP and is expected to be used for the repair and regeneration of bone tissue.

Improvement of Left Ventricular Graft Function Using an Iron-Chelator-Supplemented Bretschneider Solution in a Canine Model of Orthotopic Heart Transplantation.

Demand for organs is increasing while the number of donors remains constant. Nevertheless, not all organs are utilized due to the limited time window for heart transplantation (HTX). Therefore, we aimed to evaluate whether an iron-chelator-supplemented Bretschneider solution could protect the graft in a clinically relevant canine model of HTX with prolonged ischemic storage. HTX was performed in foxhounds. The ischemic time was standardized to 4 h, 8 h, 12 h or 16 h, depending on the experimental group. Left ventricular (LV) and vascular function were measured. Additionally, the myocardial high energy phosphate and iron content and the in-vitro myocyte force were evaluated. Iron chelator supplementation proved superior at a routine preservation time of 4 h, as well as for prolonged times of 8 h and longer. The supplementation groups recovered quickly compared to their controls. The LV function was preserved and coronary blood flow increased. This was also confirmed by in vitro myocyte force and vasorelaxation experiments. Additionally, the biochemical results showed significantly higher adenosine triphosphate content in the supplementation groups. The iron chelator LK614 played an important role in this mechanism by reducing the chelatable iron content. This study shows that an iron-chelator-supplemented Bretschneider solution effectively prevents myocardial/endothelial damage during short- as well as long-term conservation.

Effect of energy metabolism and proteolysis on the toughness of intermediate ultimate pH beef

The objective of this study was to identify the tenderness and energy metabolism attributes in normal ultimate pH (pHu, 5.4–5.8, NpHu), intermediate pHu (5.8–6.2, IpHu) and high pHu (> 6.2, HpHu) Longissimus lumborum from beef. During 21 days of aging, the IpHu group exhibited a higher Warner-Bratzler shear force, lower activity of μ-calpain, and a higher content of heat shock protein 27 and greater protein oxidation. Metabolomics analysis revealed that 24 differential metabolites were detected during the first 24 h postmortem between pH groups, and these were mainly the products of glycolysis, the tricarboxylic acid (TCA) cycle and oxidative phosphorylation. The relatively higher adenosine triphosphate content in the IpHu group could delay tenderization by being used as key substrate for protein phosphorylation. In addition, the relationship between guanosine triphosphate, diphosphate and monophosphate, and beef tenderness was worthy to be verified in the future study.

Genome reduction boosts heterologous gene expression in Pseudomonas putida.

BackgroundThe implementation of novel platform organisms to be used as microbial cell factories in industrial applications is currently the subject of intense research. Ongoing efforts include the adoption of Pseudomonas putida KT2440 variants with a reduced genome as the functional chassis for biotechnological purposes. In these strains, dispensable functions removed include flagellar motility (1.1% of the genome) and a number of open reading frames expected to improve genotypic and phenotypic stability of the cells upon deletion (3.2% of the genome).ResultsIn this study, two previously constructed multiple-deletion P. putida strains were systematically evaluated as microbial cell factories for heterologous protein production and compared to the parental bacterium (strain KT2440) with regards to several industrially-relevant physiological traits. Energetic parameters were quantified at different controlled growth rates in continuous cultivations and both strains had a higher adenosine triphosphate content, increased adenylate energy charges, and diminished maintenance demands than the wild-type strain. Under all the conditions tested the mutants also grew faster, had enhanced biomass yields and showed higher viability, and displayed increased plasmid stability than the parental strain. In addition to small-scale shaken-flask cultivations, the performance of the genome-streamlined strains was evaluated in larger scale bioreactor batch cultivations taking a step towards industrial growth conditions. When the production of the green fluorescent protein (used as a model heterologous protein) was assessed in these cultures, the mutants reached a recombinant protein yield with respect to biomass up to 40% higher than that of P. putida KT2440.ConclusionsThe two streamlined-genome derivatives of P. putida KT2440 outcompeted the parental strain in every industrially-relevant trait assessed, particularly under the working conditions of a bioreactor. Our results demonstrate that these genome-streamlined bacteria are not only robust microbial cell factories on their own, but also a promising foundation for further biotechnological applications.Electronic supplementary materialThe online version of this article (doi:10.1186/s12934-015-0207-7) contains supplementary material, which is available to authorized users.

Pharmacologic Prophylactic Treatment for Perioperative Protection of Skeletal Muscle from Ischemia-Reperfusion Injury in Reconstructive Surgery

In autogenous muscle transplantation, unpredictable complications can cause prolonged ischemia, resulting in ischemia-reperfusion injury. The authors investigated the efficacy and mechanism of nicorandil, a nitrovasodilator and adenosine triphosphate-sensitive potassium channel opener, in inducing perioperative protection of muscle flaps from ischemia-reperfusion injury. Pigs (18.2 ± 2.4 kg) were assigned to one control and eight treatment groups. Bilateral latissimus dorsi muscle flaps were raised after saline administration (control) and 0, 4, 8, 12, 24, 48, 72, and 96 hours after nicorandil administration. Subsequently, flaps were subjected to 4 hours of ischemia and 48 hours of reperfusion. Viability was assessed, and biochemical probes were used to study nicorandil-induced infarct protection. Protection by nicorandil was biphasic. Infarction reduced from 40.2 ± 1.9 percent (control) to 27.3 ± 1.7 percent and 24.0 ± 2.3 percent (p < 0.05) 0 and 4 hours after nicorandil administration, respectively (early phase protection). No difference was seen between control and treatment groups between 8 and 12 hours after nicorandil administration compared with the control. Infarct protection increased again (p < 0.05) at 24 (22.4 ± 2.0 percent), 48 (25.1 ± 2.1 percent), and 72 hours (28.5 ± 2.1 percent) but not at 96 hours (43.9 ± 4.6 percent) compared with control (late phase protection). The sarcolemmal and mitochondrial channels played a central role in the trigger and mediator mechanisms, respectively. Late protection was associated with lower myeloperoxidase activity and mitochondrial calcium overload and higher adenosine triphosphate content (p < 0.05). Nicorandil induced 48-hour uninterrupted muscle infarct protection, starting 24 hours after intravenous administration. This category of clinical drug is a potential prophylactic treatment against skeletal muscle ischemia-reperfusion injury in reconstructive surgery.

Intact cumulus cells have beneficial effects to oocytes undergoing vitrification cryopreservation

Our purpose is to determine whether cumulus cells enclosed around the oocyte during vitrification process have any beneficial effects on oocyte metabolism and developmental competencies. Basic animal study to evaluate developmental competencies of MII oocyte after cryopreservation with or without cumulus cells. We superovulated the mice with PMSG and HCG, then collected MII oocytes 14 hours after HCG injection. The collected oocytes were divided into vitrification-denuded oocyte (V-DO) group, vitrification-cumulus oocyte complex (V-COC) group, and control group. Each group included 50 oocytes for study. We used 15% dimethyl sulfoxmide plus 15% ethylene glycol as cryoprotectant and followed the standard vitrification procedures. The vitrified oocytes were stored in liquid nitrogen for at least 24 hours before warming, then cultured in 37OC, 5% CO2 incubator for 2 hours for recovering. We compared oocyte survival rates, Adenosine Triphosphate (ATP) contents, piezo-intracyplasmic sperm injection (piezo-ICSI) fertilization rates, and blastocyst formation rates among all three groups. Our results showed that both V-DO and V-COC groups have comparable oocyte survival rates after cryopreservation. Piezo-ICSI fertilization rates had no significant differences among V-DO and V-COC group, however, fertilization rates in both vitrification groups were lower than the rate in control group. COC group had higher ATP content and blastocyst formation rate as compared to the results from DO group.Table 1Comparison.GroupMIISurvivalATP Content (pmole/oocyte)FertilizationBlastocystV-DO5046 (92.0%)0.082 +/- 0.01*42 (91.3%)26 (61.9%)∗A significant difference: P less than 0.05.V-COC5047 (94.0%)0.110 +/- 0.0143 (91.5%)32 (74.4%)Control500.158 +/- 0.0147 (94.0%)39 (83.0%)* A significant difference: P less than 0.05. Open table in a new tab We conclude that oocytes with intact cumulus cells have better intracellular energy profiles and developmental competencies when undergoes vitritrification/warming procedures as compared with denuded oocytes.

Difference in Energy Metabolism of Annulus Fibrosus and Nucleus Pulposus Cells of the Intervertebral Disc

Low back pain is associated with intervertebral disc degeneration. One of the main signs of degeneration is the inability to maintain extracellular matrix integrity. Extracellular matrix synthesis is closely related to production of adenosine triphosphate (i.e. energy) of the cells. The intervertebral disc is composed of two major anatomical regions: annulus fibrosus and nucleus pulposus, which are structurally and compositionally different, indicating that their cellular metabolisms may also be distinct. The objective of this study was to investigate energy metabolism of annulus fibrosus and nucleus pulposus cells with and without dynamic compression, and examine differences between the two cell types. Porcine annulus and nucleus tissues were harvested and enzymatically digested. Cells were isolated and embedded into agarose constructs. Dynamically loaded samples were subjected to a sinusoidal displacement at 2 Hz and 15% strain for 4 h. Energy metabolism of cells was analyzed by measuring adenosine triphosphate content and release, glucose consumption, and lactate/nitric oxide production. A comparison of those measurements between annulus and nucleus cells was conducted. Annulus and nucleus cells exhibited different metabolic pathways. Nucleus cells had higher adenosine triphosphate content with and without dynamic loading, while annulus cells had higher lactate production and glucose consumption. Compression increased adenosine triphosphate release from both cell types and increased energy production of annulus cells. Dynamic loading affected energy metabolism of intervertebral disc cells, with the effect being greater in annulus cells.

Detection of High-Energy Phosphates in Cortical Bone as an Indicator of Bone Healing and Remodelling: Use of a Rabbit Model

PURPOSE; To study high-energy phosphates in cortical bone through experiments on inbred white New Zealand rabbits. Tibial fractures were induced in 80 rabbits and then stabilised by screw osteosynthesis. After 3 (group A; n=40) or 7 days (groups B; n=40), the defective tissue was covered by local muscle flaps. At increasing intervals (from 1 to 16 weeks), the screws were removed and the animals were euthanised (n=8 per group). The bone was removed and analysed histomorphologically; adenosine triphosphate (ATP) levels were determined by high-performance liquid chromatography. The mean ATP concentration in healthy cortical bone at 16 weeks was 0.092 (standard error, 0.009) nmol/mg dry mass, which was significantly higher than that in the group with delayed healing: 0.081 (0.011) nmol/mg in group A and 0.005 (0.001) nmol/mg in group B (paired t test, p<0.05). Earlier healing led to lower rates of necrosis (0 vs 38; groups A vs B) and osteomyelitis. Early muscle-flap coverage can revascularise the cortical bone, which is reflected in the higher ATP content in the cortical bone measured by high-performance liquid chromatography. Measuring changes of ATP levels can help investigate the metabolism of the pathological bone.

Protection of ischaemic myocardium with coenzyme Q10.

Protection of the ischaemic myocardium with Coenzyme Q10 (COQ10) following constriction of left anterior descending coronary artery was studied in 38 open-chest mongrel dogs. Left anterior descending coronary artery blood flow was independently reduced by tightening a constrictor around the vessel. Aortic pressure and left ventricular pressure were measured, and the Tension Time Index (TTI) was calculated. Myocardial segment shortening in the ischaemic area was measured with an ultrasonic dimension gauge. After obtaining haemodynamic data, the ischaemic myocardium was biopsied and the tissue sample was frozen in liquid nitrogen for adenosine triphosphate (ATP) analysis. Animals premedicated with COQ10 (20 mg . kg-1 iv) had a significantly higher ATP content in ischaemic myocardium (3.25 +/- 0.35 mumol . g-1 wet weight) compared with that in ischaemic myocardium of control animals (2.96 +/- 0.19) (P less than 0.05), when coronary blood flow was reduced by 50 to 74%. There were failure of ATP preservation by COQ10 with a further reduction in coronary blood flow. Changes in the pattern of myocardial segment shortening in the ischemic area induced by a 50 to 74% coronary blood flow reduction were less in COQ10 treated animals than in control animals. Since there were no haemodynamic differences between control and COQ10 treated animals, these effects were considered not to be due to a decrease in myocardial oxygen consumption secondary to haemodynamic changes.