Adenosine Triphosphatase Activity Research Articles

Mechanism of polyadenylation-independent RNA polymerase II termination.

The mechanisms underlying the initiation and elongation of RNA polymerase II (Pol II) transcription are well-studied, whereas termination remains poorly understood. Here we analyze the mechanism of polyadenylation-independent Pol II termination mediated by the yeast Sen1 helicase. Cryo-electron microscopy structures of two pretermination intermediates show that Sen1 binds to Pol II and uses its adenosine triphosphatase activity to pull on exiting RNA in the 5' direction. This is predicted to push Pol II forward, induce an unstable hypertranslocated state and destabilize the transcription bubble, thereby facilitating termination. This mechanism of transcription termination may be widely used because it is conceptually conserved in the bacterial transcription system.

Effects of PEF on Cell and Transcriptomic of Escherichia coli.

Pulsed electric field (PEF) is an up-to-date non-thermal processing technology with a wide range of applications in the food industry. The inactivation effect of PEF on Escherichia coli was different under different conditions. The E. coli inactivated number was 1.13 ± 0.01 lg CFU/mL when PEF was treated for 60 min and treated with 0.24 kV/cm. The treatment times were found to be positively correlated with the inactivation effect of PEF, and the number of E. coli was reduced by 3.09 ± 0.01 lg CFU/mL after 100 min of treatment. The inactivation assays showed that E. coli was inactivated at electrical intensity (0.24 kV/cm) within 100 min, providing an effective inactivating outcome for Gram-negative bacteria. The purpose of this work was to investigate the cellular level (morphological destruction, intracellular macromolecule damage, intracellular enzyme inactivation) as well as the molecular level via transcriptome analysis. Field Emission Scanning Electron Microscopy (TFESEM) and Transmission Electron Microscope (TEM) results demonstrated that cell permeability was disrupted after PEF treatment. Entocytes, including proteins and DNA, were markedly reduced after PEF treatment. In addition, the activities of Pyruvate Kinase (PK), Succinate Dehydrogenase (SDH), and Adenosine Triphosphatase (ATPase) were inhibited remarkably for PEF-treated samples. Transcriptome sequencing results showed that differentially expressed genes (DEGs) related to the biosynthesis of the cell membrane, DNA replication and repair, energy metabolism, and mobility were significantly affected. In conclusion, membrane damage, energy metabolism disruption, and other pathways are important mechanisms of PEF's inhibitory effect on E. coli.

Bacteriostatic Activity of Janthinobacterium lividum and Purified Violacein Fraction against Clavibacter michiganensis

Clavibacter michiganensis causes plant diseases and is included in the list of microorganisms subject to export control. Janthinobacterium lividum is capable of synthesizing a pigment with antagonistic potential. The purpose of the study was to evaluate the activity of J. lividum VKM B-3705D and the pigment fraction against C. michiganensis VKM Ac-1402. The results of spectrophotometric and nuclear magnetic resonance analysis showed that the pigment synthesized by the J. lividum VKM B-3705D corresponds to violacein. The J. lividum strain demonstrated potential bacteriostatic activity against C. michiganensis VKM Ac-1402 when both strains were co-cultured. Compared to the control (DMSO), the violacein solution suppressed the specific growth of Clavibacter by 57.7%. The mechanism of suppression of the growth of Clavibacter is discussed. One of the ways to suppress the growth of C. michiganensis may be the inhibition of key enzymes. Violacein inhibited the activity of adenosine triphosphatase (ATPase, EC 3.6.1.3) compared to the control (DMSO) by 23.2%. Thus, the current study of the bacteriostatic effect may be a decisive step towards the development of a plant protection product.

Ginseng total saponin improves red blood cell oxidative stress injury by regulating tyrosine phosphorylation and glycolysis in red blood cells

BackgroundOxidative stress is the main cause of many diseases, but because of its complex pathogenic factors, there is no clear method for treating it. Ginseng total saponin (GTS) an important active ingredients in Panax ginseng C.A. Mey (PG) and has potential therapeutic ability for oxidative stress due to various causes. However, the molecular mechanism of GTS in the treating oxidative stress damage in red blood cells (RBCs) is still unclear. PurposeThis study aimed to examine the protective effect of GTS on RBCs under oxidative stress damage and to determine its potential mechanism. MethodsThe oxidative stress models of rat RBCs induced by hydrogen peroxide (H2O2) and exhaustive swimming in vivo and in vitro was used. We determined the cell morphology, oxygen carrying capacity, apoptosis, antioxidant capacity, and energy metabolism of RBCs. The effect of tyrosine phosphorylation (pTyr) of Band 3 protein on RBCs glycolysis was also examined. ResultsGTS reduced the hemolysis of RBCs induced by H2O2 at the lowest concentration. Moreover, GTS effectively improved the morphology, enhanced the oxygen carrying capacity, and increased antioxidant enzyme activity, adenosine triphosphate (ATP) levels, and adenosine triphosphatase (ATPase) activity in RBCs. GTS also promoted the expression of membrane proteins in RBCs, inhibited pTyr of Band 3 protein, and further improved glycolysis, restoring the morphological structure and physiological function of RBCs. ConclusionsThis study shows, that GTS can protect RBCs from oxidative stress damage by improving RBCs morphology and physiological function. Changes in pTyr expression and its related pTyr regulatory enzymes before and after GTS treatment suggest that Band 3 protein is the main target of GTS in the treating endogenous and exogenous oxidative stress. Moreover, GTS can enhance the glycolytic ability of RBCs by inhibiting pTyr of Band 3 protein, thereby restoring the function of RBCs.

A four-in-one multifunctional self-assembly hydrogel composed of natural drugs for repairing myocardial infarction

To meet the multiple demands of myocardial repair, it would be a novel strategy for myocardial repair if multiple drugs could be constructed into an integrated multifunctional drug formulation. In this study, four drugs with different functions (thioctic acid with antioxidant effects, quercetin with anti-inflammatory and antioxidant effects, arginine with pro-angiogenic effects, and Mn2+ with imaging functions) were selected to construct a four-in-one injectable hydrogel (thioctic acid-arginine-quercetin-Mn2+) through chemical bonding and supramolecular interactions. First, thioctic acid polymerized to a redox-sensitive degradable polymer—poly(thioctic acid) containing disulfide bonds in the main chains through ring-opening polymerization. Quercetin was conjugated to the main chain of the poly(thioctic acid) molecules via thiyl radical-polyphenol Michael addition. Arginine cross-linked the carboxyl groups side chains of the poly(thioctic acid) molecules through hydrogen bonding. Mn2+ further cross-linked the carboxyl groups' side chains of the poly(thioctic acid) molecules through ionic bonding. The hydrogel has antioxidant properties, promotes neovascularization, inhibits inflammatory, improves intracellular Ca2+ overload and mitochondrial dysfunction, protects adenosine triphosphatase (ATPase) activity, and maintains intracellular energy supply, which can reduce the size of myocardial infarcts, and improves cardiac function. This construction method of preparing integrated multifunctional hydrogels from natural drugs will provide a new therapeutic strategy for myocardial repair.

Acidification of α-granules in megakaryocytes by vacuolar-type adenosine triphosphatase is essential for organelle biogenesis

BackgroundPlatelets coordinate blood coagulation at sites of vascular injury and play fundamental roles in a wide variety of (patho)physiological processes. Key to many platelet functions is the transport and secretion of proteins packaged within α-granules, organelles produced by platelet precursor megakaryocytes. Prominent among α-granule cargo are fibrinogen endocytosed from plasma and endogenously synthesized von Willebrand factor. These and other proteins are known to require acidic pH for stable packaging. Luminal acidity has been confirmed for mature α-granules isolated from platelets, but direct measurement of megakaryocyte granule acidity has not been reported. ObjectivesTo determine the luminal pH of α-granules and their precursors in megakaryocytes and assess the requirement of vacuolar-type adenosine triphosphatase (V-ATPase) activity to establish and maintain the luminal acidity and integrity of these organelles. MethodsCresyl violet staining was used to detect acidic granules in megakaryocytes. Endocytosis of fibrinogen tagged with the pH-sensitive fluorescent dye fluorescein isothiocyanate was used to load a subset of these organelles. Ratiometric fluorescence analysis was used to determine their luminal pH. ResultsWe show that most of the acidic granules detected in megakaryocytes appear to be α-granules/precursors, for which we established a median luminal pH of 5.2 (IQR, 5.0-5.5). Inhibition of megakaryocyte V-ATPase activity led to enlargement of cargo-containing compartments detected by fluorescence microscopy and electron microscopy. ConclusionThese observations reveal that V-ATPase activity is required to establish and maintain a luminal acidic pH in megakaryocyte α-granules/precursors, confirming its importance for stable packaging of cargo proteins such as von Willebrand factor.

Research Progress on the NSP10 Protein of Porcine Reproductive and Respiratory Syndrome Virus.

Porcine reproductive and respiratory syndrome (PRRS) is a highly contagious and pathogenic infectious disease caused by the porcine reproductive and respiratory syndrome virus (PRRSV). It manifests as reproductive disorders in sows and respiratory disorders in piglets. PRRSV infects swine herds with symptoms such as abortions, stillbirths, and mummified fetuses in gestating sows. Piglets mainly experience abdominal respiration and respiratory symptoms. To date, the prevention of PRRS relies primarily on vaccination and the implementation of various preventive and control measures. Swine deaths caused by PRRS have resulted in significant economic losses to the pig industry worldwide. Non-structural protein 10 (NSP10) has helicase and adenosine triphosphatase (ATPase) activities that unwind DNA and RNA and play important roles in viral replication and transcription. Hence, it can be potentially used to develop novel reagents for the detection of PPRSV. This article reviews genetic variations, interaction with viral and host proteins, effects on PRRSV replication, immunomodulation, apoptosis, and viral virulence of NSP10, with the aim of providing a theoretical basis for the prevention and control of PRRS and drug development in the future.

Protective effects of myricetin and morin on neurological damage in Aβ1–42/Al3+ -induced Alzheimer’s disease model of rats

Alzheimer's disease (AD) is a degenerative neurological disorder with unclear pathogenesis. Single-target drugs have very limited efficacy in treating AD, but synthetic multi-target drugs have poor efficacy and safety. Therefore, finding suitable natural multi-target drugs against AD is of great interest for research studies. We chose two flavonols, myricetin and morin, for the relevant study. In this study, we used microinjection of Aβ1–42 oligomers into the CA1 region of rat hippocampus, combined with gavage of Aluminum chloride hexahydrate (AlCl3·6H2O) solution to establish AD rat models, and myricetin and morin were selected as intervening drugs to explore the protective effects against neurological impairment. Experimental results showed that myricetin or morin could reduce the production of Aβ, Tubulin-associated unit (Tau), and Phosphorylated tubulin-associated unit (p-Tau), down-regulate the expression of relevant inflammatory factors, reduce hippocampal cell apoptosis in rats. There was a significant increase in the activity of adenosine triphosphatase, catalase, total superoxide dismutase, and the content of glutathione in the brain tissue. However, the content of malondialdehyde, inducible nitric oxide synthase, and the activity of acetylcholinesterase were decreased in the brain tissue. These two flavonols can regulate the imbalance of monoamine and amino acid neurotransmitter levels. In conclusion, Myricetin or morin can effectively improve learning and memory dysfunction in AD rats induced by Aβ1–42/Al3+ through anti-oxidative stress and anti-apoptotic features.

Astaxanthin activates the Nrf2/Keap1/HO-1 pathway to inhibit oxidative stress and ferroptosis, reducing triphenyl phosphate (TPhP)-induced neurodevelopmental toxicity

Triphenyl phosphate (TPhP) serves as a major organophosphorus flame retardant, and its induced neurodevelopmental toxicity has attracted widespread attention, but the mechanism remains unclear. In this study, we involved zebrafish to explore the new mechanism of TPhP inducing oxidative stress and ferroptosis to promote neurodevelopmental toxicity. The results suggested that TPhP affected the embryonic development, reduced the number of new neurons, and led to abnormal neural behavior in zebrafish larvae. TPhP also induced ROS accumulation, activated the antioxidant defense signal Nrf2 and Keap1, and significantly changed the activities of Acetylcholinesterase (AChE), Adenosine triphosphatase (ATPase) and glutathione S-transferase (GST). In addition, TPhP induced ferroptosis in zebrafish, which was reflected in the increase of Fe2+ content, the abnormal expression of GPX4 protein and genes related to iron metabolism (gpx4a, slc7a11, acsl4b, tfa, slc40a1, fth1b, tfr2, tfr1a, tfr1b and ncoa4). Astaxanthin intervention specifically inhibited ROS levels, and reversed SLC7A11 and GPX4 expression levels and Fe2+ metabolism thus alleviating ferroptosis induced by TPhP. Astaxanthin also partially reversed the activity of AChE, GST and the expression of neurodevelopmental-related genes (gap43, gfap, neurog1 and syn2a), so as to partially rescue the embryonic developmental abnormalities and motor behavior disorders induced by TPhP. More interestingly, the expression of mitochondrial apoptosis-related protein BAX, anti-apoptotic protein BCL-2, Caspase3 and Caspase9 was significantly altered in the TPhP exposed group, which could be also reversed by Astaxanthin intervention. In summary, our results suggested that TPhP exposure can induce oxidative stress and ferroptosis, thereby causing neurodevelopment toxicity to zebrafish, while Astaxanthin can partially reverse oxidative stress and reduce the neurodevelopmental toxicity of zebrafish larvae by activating Nrf2/Keap1/HO-1 signaling pathway.

The inflammatory injury of porcine small intestinal epithelial cells induced by deoxynivalenol is related to the decrease in glucose transport.

The present study aimed to investigate the effects of deoxynivalenol (DON) stimulation on inflammatory injury and the expression of the glucose transporters sodium-dependent glucose transporter 1 (SGLT1) and glucose transporter protein 2 (GLU2) in porcine small intestinal epithelial cells (IPEC-J2). Additionally, the study aimed to provide initial insights into the connection between the expression of glucose transporters and the inflammatory injury of IPEC-J2 cells. DON concentration and DON treatment time were determined using the CCK‑8 assay. Accordingly, 1.0 µg/mL DON and treatment for 24h were chosen for subsequent experiments. Then IPEC-J2 cells were treated without DON (CON, N = 6) or with 1 μg/mL DON (DON, N = 6). Lactate dehydrogenase (LDH) content, apoptosis rate, and proinflammatory cytokines including interleukin (IL)-1β, Il-6, and tumor necrosis factor α (TNF-α) were measured. Additionally, the expression of AMP-activated protein kinase α1 (AMPK-α1), the content of glucose, intestinal alkaline phosphatase (AKP), and sodium/potassium-transporting adenosine triphosphatase (Na+/K+-ATPase) activity, and the expression of SGLT1 and GLU2 of IPEC-J2 cells were also analyzed. The results showed that DON exposure significantly increased LDH release and apoptosis rate of IPEC-J2 cells. Stimulation with DON resulted in significant cellular inflammatory damage, as evidenced by a significant increase in proinflammatory cytokines (IL-1β, IL-6, and TNF-α). Additionally, DON caused damage to the glucose absorption capacity of IPEC-J2 cells, indicated by decreased levels of glucose content, AKP activity, Na+/K+-ATPase activity, AMPK-α1 protein expression, and SGLT1 expression. Correlation analysis revealed that glucose absorption capacity was negatively correlated with cell inflammatory cytokines. Based on the findings of this study, it can be preliminarily concluded that the cell inflammatory damage caused by DON may be associated with decreased glucose absorption.

Uncovering the Multifaceted Roles of DDX21: Bridging Biological Insights and Medical Applications

DDX21 belongs to the DEAD-box (DDX) family of helicases but deviates from the characteristic sequence Asp–Glu–Ala–Asp (DEAD) to Asp–Glu–Val–Asp. In addition to the typical helicase activity associated with the DEAD-box family, DDX21 also possesses foldase and adenosine triphosphatase activities. It plays crucial roles in various molecular processes, including the regulation of transcription, ribosomal RNA processing, modification, and unwinding of RNA spatial structures. DDX21 is subject to intricate regulation by multiple upstream factors, including expression control and posttranslational modification. In numerous cancer types, abnormal expression of DDX21 has been observed to influence cancer cell behaviors, such as the cell cycle, proliferation, invasion, migration, and apoptosis. In addition, DDX21 modulates innate immunity following viral infection and plays a dual role in the viral infection process. This review comprehensively explores the protein structure, molecular regulatory mechanisms, and pathophysiological functions of DDX21. Consequently, this study not only offers potential avenues for future research but also sparks novel ideas for targeted treatments for both cancer and viral infections.

Structure-function relationship of KaiC around dawn.

KaiC is a multifunctional enzyme functioning as the core of the circadian clock system in cyanobacteria: its N-terminal domain has adenosine triphosphatase (ATPase) activity, and its C-terminal domain has autokinase and autophosphatase activities targeting own S431 and T432. The coordination of these multiple biochemical activities is the molecular basis for robust circadian rhythmicity. Therefore, much effort has been devoted to elucidating the cooperative relationship between the two domains. However, structural and functional relationships between the two domains remain unclear especially with respect to the dawn phase, at which KaiC relieves its nocturnal history through autodephosphorylation. In this study, we attempted to design a double mutation of S431 and T432 that can capture KaiC as a fully dephosphorylated form with minimal impacts on its structure and function, and investigated the cooperative relationship between the two domains in the night to morning phases from many perspectives. The results revealed that both domains cooperate at the dawn phase through salt bridges formed between the domains, thereby non-locally co-activating two events, ATPase de-inhibition and S431 dephosphorylation. Our further analysis using existing crystal structures of KaiC suggests that the states of both domains are not always in one-to-one correspondence at every phase of the circadian cycle, and their coupling is affected by the interactions with KaiA or adjacent subunits within a KaiC hexamer.

Antibacterial Activity and Mechanism of Polygonatum sibiricum Extract Against Bacillus cereus and Its Application in Pasteurized Milk.

The purpose of this study was to reveal the antibacterial activity and mechanism of Polygonatum sibiricum extract (PSE) against Bacillus cereus and further analyze the application of PSE in pasteurized milk (PM). The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values and growth curve analysis were used to evaluate the antibacterial activity of PSE against B. cereus. The changes in contents of intracellular adenosine 5'-triphosphate (ATP) and reactive oxygen species (ROS), activities of β-galactosidase, adenosine triphosphatase (ATPase) and alkaline phosphatase (AKP), cell membrane potential, protein and nucleic acid leakage, and cell morphology were used to reveal the antibacterial mechanism. The effects of PSE on viable count and sensory evaluation of PM during storage were analyzed. The results showed that the MIC and MBC values of PSE against B. cereus were 2 and 4 mg/mL, respectively. Growth curve analysis showed that PSE with a concentration of 2 MIC could completely inhibit the growth of B. cereus. After treatments with PSE, the levels of intracellular ATP and ROS, and activities of β-galactosidase, ATPase and AKP of B. cereus were significantly reduced (p < 0.05). Cell membrane was depolarized, amounts of protein and nucleic acid leakage were significantly increased (p < 0.05), and cell morphology was destroyed. Furthermore, PSE significantly reduced the viable count of B. cereus in PM and improved the sensory quality of PM during storage (p < 0.05). Together, our findings suggested that PSE had the desired effect as a natural preservative applied in PM.

Structures of the P. aeruginosa FleQ-FleN master regulators reveal large-scale conformational switching in motility and biofilm control.

Pseudomonas aeruginosa can cause a wide array of chronic and acute infections associated with its ability to rapidly switch between planktonic, biofilm, and dispersed lifestyles, each with a specific arsenal for bacterial survival and virulence. At the cellular level, many of the physiological transitions are orchestrated by the intracellular second messenger c-di-GMP and its receptor-effector FleQ. A bacterial enhancer binding protein, FleQ acts as a master regulator of both flagellar motility and adherence factor secretion and uses remarkably different transcription activation mechanisms depending on its dinucleotide loading state, adenosine triphosphatase (ATPase) activity, interactions with polymerase sigma (σ) factors, and complexation with a second ATPase, FleN. How the FleQ-FleN tandem can exert diverse effects through recognition of a conserved FleQ binding consensus has remained enigmatic. Here, we provide cryogenic electron microscopy (cryo-EM) structures of both c-di-GMP-bound and c-di-GMP-free FleQ-FleN complexes which deepen our understanding of the proteins' (di)nucleotide-dependent conformational switching and fine-tuned roles in gene expression regulation.

Effect of Sublethal Concentrations of Nuvan on Enzymatic Profile of &lt;I&gt;Labeo rohita &lt;/I&gt;(ham.)

Toxic effects of sublethal concentrations of nuvan on acid phosphatase (ACP), alkaline phosphatase (ALP), adenosine triphosphatase (ATPase), succinic dehydrogenase (SDH), lactic dehydrogenase (LDH) and acetyl cholinestrase (AChE) activities were studied in fingerlings of Labeo rohita. Two sublethal concentrations i.e. 10.3 mg/I and 2.06 mg/l were selected basing on the LCso value of nuvan in rohu for this experiment continuing for a period of 45 days. Sublethal exposures at two concentrations reduced the brain AChE, and brain, liver and kidney LDH and ATPase (P &lt; 0.05) over a period of 45 days. The reduction of SDH was detected in all the organs examined except brain on 30 day at 2.06 mg/I. While ALP and AChE activities of brain were decreased, the ACP activity was increased.

Exogenous methyl jasmonate combined with Ca2+ promote resveratrol biosynthesis and stabilize sprout growth for the production of resveratrol-rich peanut sprouts

Promoting resveratrol accumulation in plants and utilizing resveratrol-rich plants as raw materials for the development of functional foods is a promising development direction. The effects of methyl jasmonate (MeJA), in combination with CaCl2 and Ca2+ inhibitors, on physiological metabolism and resveratrol enrichment of peanut sprouts were investigated. MeJA combined with CaCl2 increased Ca2+ content, calmodulin content, and Ca2+- adenosine triphosphatase activity, as well as upregulated calcium-binding proteinase expression levels. Treatment with MeJA plus CaCl2 significantly increased peroxidase and superoxide dismutase activities and antioxidant capacities, significantly decreased the content of malondialdehyde and hydrogen peroxide, which resulted in a significantly increased in sprout length and fresh weight, and alleviated the inhibition of sprout growth. MeJA plus CaCl2 significantly increased the activities of phenylalanine ammonia-lyase and 4-coumarate coenzyme A ligase and upregulated the expression levels of phenylalanine ammonia-lyase, cinnamic acid 4-hydroxylase, and resveratrol synthase, thus significantly increasing resveratrol content. However, MeJA combined with Ca2+ antagonists reversed these effects. These results indicate that MeJA interacts with Ca2+ to promote resveratrol synthesis in peanut sprouts and to improve sprout stress tolerances.

Alternative relay regulates the adenosine triphosphatase activity of Locusta migratoria striated muscle myosin.

Locust (Locusta migratoria) has a single striated muscle myosin heavy chain (Mhc) gene, which contains 5 clusters of alternative exclusive exons and 1 differently included penultimate exon. The alternative exons of Mhc gene encode 4 distinct regions in the myosin motor domain, that is, the N-terminal SH3-like domain, one lip of the nucleotide-binding pocket, the relay, and the converter. Here, we investigated the role of the alternative regions on the motor function of locust muscle myosin. Using Sf9-baculovirus protein expression system, we expressed and purified 5 isoforms of the locust muscle myosin heavy meromyosin (HMM), including the major isoform in the thorax dorsal longitudinal flight muscle (FL1) and 4 isoforms expressed in the abdominal intersegmental muscle (AB1 to AB4). Among these 5 HMMs, FL1-HMM displayed the highest level of actin-activated adenosine triphosphatase (ATPase) activity (hereafter referred as ATPase activity). To identify the alternative region(s) responsible for the elevated ATPase activity of FL1-HMM, we produced a number of chimeras of FL1-HMM and AB4-HMM. Substitution with the relay of AB4-HMM (encoded by exon-14c) substantially decreased the ATPase activity of FL1-HMM, and conversely, the relay of FL1-HMM (encoded by exon-14a) enhanced the ATPase activity of AB4-HMM. Mutagenesis showed that the exon-14a-encoded residues Gly474 and Asn509 are responsible for the elevated ATPase activity of FL1-HMM. Those results indicate that the alternative relay encoded by exon-14a/c play a key role in regulating the ATPase activity of FL1-HMM and AB4-HMM.

Stress of cupric ion and oxytetracycline in Chlorella vulgaris cultured in swine wastewater

Chlorella culturing has the advantages in treatment of wastewater including swine wastewater from anaerobic digesters due to the product of biolipids and the uptake of carbon dioxide. However, there often exist high concentrations of antibiotics and heavy metals in swine wastewater which could be toxic to chlorella and harmful to the biological systems. This study examined the stress of cupric ion and oxytetracycline (OTC) at various concentrations on the nutrient removal and biomass growth in Chlorella vulgaris culturing in swine wastewater from anaerobic digesters, and its biochemical responses were also studied. Results showed that dynamic hormesis of either OTC concentration or cupric ion one on Chlorella vulgaris were confirmed separately, and the presence of OTC not only did not limit biomass growth and lipids content of Chlorella vulgaris but also could mitigate the toxicity of cupric ion on Chlorella vulgaris in combined stress of Cu2+ and OTC. Extracellular polymeric substances (EPS) of Chlorella vulgaris were used to explain the mechanisms of stress for the first time. The content of proteins and carbohydrates in EPS increased, and the fluorescence spectrum intensity of tightly-bound EPS (TB-EPS) of Chlorella vulgaris decreased with increasing concentration of stress because Cu2+ and OTC may be chelated with proteins of TB-EPS to form non-fluorescent characteristic chelates. The low concentration of Cu2+ (≤1.0 mg/L) could enhance the protein content and promote the activity of superoxide dismutase (SOD) while these parameters were decreased drastically under 2.0 mg/L of Cu2+. The activity of adenosine triphosphatase (ATPase) and glutathione (GSH) enhanced with the increase of OTC concentration under combined stress. This study helps to comprehend the impact mechanisms of stress on Chlorella vulgaris and provides a novel strategy to improve the stability of microalgae systems for wastewater treatment.

Cognitive effects of thalamostriatal degeneration are ameliorated by normalizing striatal cholinergic activity.

The loss of neurons in parafascicular thalamus (Pf) and their inputs to dorsomedial striatum (DMS) in Lewy body disease (LBD) and Parkinson's disease dementia (PDD) have been linked to the effects of neuroinflammation. We found that, in rats, these inputs were necessary for both the function of striatal cholinergic interneurons (CINs) and the flexible encoding of the action-outcome (AO) associations necessary for goal-directed action, producing a burst-pause pattern of CIN firing but only during the remapping elicited by a shift in AO contingency. Neuroinflammation in the Pf abolished these changes in CIN activity and goal-directed control after the shift in contingency. However, both effects were rescued by either the peripheral or the intra-DMS administration of selegiline, a monoamine oxidase B inhibitor that we found also enhances adenosine triphosphatase activity in CINs. These findings suggest a potential treatment for the cognitive deficits associated with neuroinflammation affecting the function of the Pf and related structures.

Antibacterial characteristics of allyl methyl disulfide and dimethyl trisulfide of Allium tenuissimum flower essential oil against Escherichia coli O157:H7

The aim of this study was to compare the antibacterial properties of allyl methyl disulfide and dimethyl trisulfide with the chemical compositions of Allium tenuissimum flower essential oil against Escherichia coli O157:H7. Allium tenuissimum flower essential oil was extracted from fresh Allium tenuissimum flower by hydro-distillation method. Its antibacterial activities against Escherichia coli O157:H7, Staphylococcus aureus and Listeria monocytogenes were determined by diameters of the inhibition zone. Escherichia coli O157:H7 treated with the essential oil had the largest diameter of the inhibition zone (15.2 mm) among the three strains. Allyl methyl disulfide and dimethyl trisulfide were two main compounds of the essential oil, as analyzed by gas chromatography-mass spectrometry. The antibacterial characteristics of these two compounds against Escherichia coli O157:H7 were evaluated by minimum inhibitory and bactericidal concentrations, morphologies, cytomembrane destructions, biomacromolecule contents, and metabolic enzyme activities. Minimum inhibitory concentrations of allyl methyl disulfide and dimethyl trisulfide were both 0.7 mg/mL, and minimum bactericidal concentrations of these two compounds were both 1.4 mg/mL. The images of atomic force microscopy exhibited that the surface structures and cytomembranes of Escherichia coli O157:H7 cells were rigorously damaged by 1.4 mg/mL of allyl methyl disulfide and dimethyl trisulfide, leading to the change of β-galactosidases and the leakage of cellular nucleic acids from the bacterial cells. Moreover, the intensities of deoxyribonucleic acid and protein bands of the bacterial cells were significantly decreased after treated with these two compounds at 1.4 mg/mL. Adenosine triphosphatase activities (3.75 and 1.97 U/mg prot) of the bacterial cells treated with allyl methyl disulfide (1.4 mg/mL) and dimethyl trisulfide (1.4 mg/mL) were distinctly lower than the activity of the control (6.05 U/mg prot). Allyl methyl disulfide (1.4 mg/mL) and dimethyl trisulfide (1.4 mg/mL) inactivated 84.20 % and 90.76 % respiratory-chain dehydrogenase of the bacterial cells, respectively. These results demonstrated that allyl methyl disulfide and dimethyl trisulfide exhibited efficient antibacterial characteristics against Escherichia coli O157:H7 and could be used as natural antibacterial agents in the prevention of Escherichia coli O157:H7 infection.