Activity Of Na Research Articles

Rotenone-induced necrosis in insect cells via the cytoplasmic membrane damage and mitochondrial dysfunction

Rotenone, a selective inhibitor of mitochondrial complex I, has been extensively studied on kinds of neuron and neuroblast in Parkinson's disease. However, little is known about the potential mechanism of this promising botanical insecticide upon insect cells. In the article, cell proliferation of two Lepidoptera cell lines, Spodoptera litura SL-1 cells and Spodoptera frugiperda Sf9 cells, were all inhibited by rotenone in a time- and dose-dependent manner. Typical necrotic characteristics of cell morphology and ultrastructure, such as plasma membrane collapses and organelle lyses, were all observed by transmission electron microscope and scanning electron microscope. Moreover, irregular DNA degradation was also detected by DNA gel electrophoresis and Hoechst 33258 staining, while the typical apoptotic feature, DNA ladder, hadn't been observed. Flow cytometric analysis showed that rotenone-induced cell death of Sf9 and SL-1 cells accompanied with the plasma membrane potential depolarization and mitochondrial membrane potential reduction. Furthermore, the activity of Na+-K+-ATPase was detected in our study. In conclusion, rotenone could cause necrosis but not apoptosis in insect cells through a mitochondrial- and plasmic membrane-dependent pattern, which shed a light on the rotenone-induced cytotoxicity on insects

Live visualisation of electrolytes during mouse embryonic development using electrolyte indicators.

Studies have shown that some electrolytes, including Na+ and K+, play important roles in embryonic development. However, these studies evaluated these electrolytes by using inhibitors or knockout mice, with no mention on the changes in the intracellular electrolyte concentrations during embryogenesis. In this study, we used the electrolyte indicators CoroNa Green AM and ION Potassium Green-2 AM to directly visualise intracellular concentrations of Na+ and K+, respectively, at each embryonic developmental stage in mouse embryos. We directly observed intracellular electrolyte concentrations at the morula, blastocyst, and hatching stages. Our results revealed dynamic changes in intracellular electrolyte concentrations; we found that the intracellular Na+ concentration decreased, while K+ concentration increased during blastocoel formation. The degree of change in intensity in response to ouabain, an inhibitor of Na+/K+ ATPase, was considered to correspond to the degree of Na+/K+ ATPase activity at each developmental stage. Additionally, after the blastocyst stage, trophectoderm cells in direct contact with the blastocoel showed higher K+ concentrations than in direct contact with inner cell mass, indicating that Na+/K+ ATPase activity differs depending on the location in the trophectoderm. This is the first study to use CoroNa Green AM and ION Potassium Green-2 AM in mouse embryos and visualise electrolytes during embryonic development. The changes in electrolyte concentration observed in this study were consistent with the activity of Na+/K+ ATPase reported previously, and it was possible to image more detailed electrolyte behaviour in embryo cells. This method can be used to improve the understanding of cell physiology and is useful for future embryonic development studies.

Evolution of Plant Na+-P-Type ATPases: From Saline Environments to Land Colonization.

Soil salinity is one of the major factors obstructing the growth and development of agricultural crops. Eukaryotes have two main transport systems involved in active Na+ removal: cation/H+ antiporters and Na+-P-type ATPases. Key transport proteins, Na+/K+-P-ATPases, are widely distributed among the different taxa families of pumps which are responsible for keeping cytosolic Na+ concentrations below toxic levels. Na+/K+-P-ATPases are considered to be absent in flowering plants. The data presented here are a complete inventory of P-type Na+/K+-P-ATPases in the major branches of the plant kingdom. We also attempt to elucidate the evolution of these important membrane pumps in plants in comparison with other organisms. We were able to observe the gradual replacement of the Na+-binding site to the Ca2+-binding site, starting with cyanobacteria and moving to modern land plants. Our results show that the α-subunit likely evolved from one common ancestor to bacteria, fungi, plants, and mammals, whereas the β-subunit did not evolve in green algae. In conclusion, our results strongly suggest the significant differences in the domain architecture and subunit composition of plant Na+/K+-P-ATPases depending on plant taxa and the salinity of the environment. The obtained data clarified and broadened the current views on the evolution of Na+/K+-P-ATPases. The results of this work would be helpful for further research on P-type ATPase functionality and physiological roles.

Tridax procumbens leaf extract elicits relaxation of rat mesenteric artery by activation of Na+ -K+ ATPase / Na+ - Ca2+ exchanger

Background: Tridax procumbens leaf extract has been reported to show antihypertensive actions through its vasodilatory effects. Although several mechanisms of action have been reported, the sub-cellular mechanism of action of the extract is yet to be fully elucidated. Aim and Objectives: In this study, we investigate the involvement of Na+ - K+ -pump and Na+- Ca2+ exchanger in the vasorelaxant activities of T. procumbens extract (TPE) in isolated rat superior mesenteric arteries. Materials and Methods: Superior mesenteric artery isolated from healthy, young adult Wistar rats (250–300 g) and pre-contracted with phenylephrine (PE) (10-7M) were treated with various concentrations of aqueous extract of TPE (0.5–9 mg/mL). The changes in arterial tension were recorded and interaction between TPE with the selective blocker of Na+ - K+ ATPase (ouabain) and putative Na+-Ca2+ exchanger inhibitor (NiCl2) was evaluated. Results: The result indicated that TPE significantly inhibit the cumulative concentration response curves to PE (10-9 - 10-5 M) in a concentration-dependent manner. Pre-treatment with both ouabain and nickel chloride (NiCl2), abolished the vasorelaxant responses of TPE. Furthermore, TPE reduced the relaxant effect with decreased extracellular Na+ concentration. TPE-induced vasorelaxation was completely abolished in a Na+ -free solution, a condition that eliminates the influence of the forward mode of the exchanger. Conclusion: The results provide direct hypothetical evidence that the activation of Na+ - K+ ATPase and stimulation of the forward mode of the Na+-Ca2+ exchanger contribute to the vasorelaxation induced by TPE in mesenteric artery.

AQP2 as a target of lycopene protects against atrazine-induced renal ionic homeostasis disturbance.

Atrazine (ATR), a ubiquitous environmental contaminant in water and soil, causes environmental nephrosis. To reveal the toxic effect of ATR on the kidney and the potential chemical nephroprotective effect of lycopene (LYC), Kun-Ming mice of specific pathogen-free (SPF) grade were treated with LYC (5 mg kg-1) and/or ATR (50 mg kg-1 or 200 mg kg-1) for 21 days. The degree of renal injury was evaluated by measuring the ion concentration, ATPase activities and the mRNA expressions/levels of associated ATPase subunits. In addition, the expression of renal aquaporins (AQPs) was analyzed. The results showed that the renal tubular epithelial cells of ATR-exposed mice were swollen, the glomeruli were significantly atrophied, and the ion concentrations were obviously changed. The activity of Na+-K+-ATPase and the transcription of its subunits were downregulated. The activity of Ca2+-Mg2+-ATPase and the transcription of its subunits were upregulated. The expression of AQPs, especially the critical AQP2, was affected. Notably, ATR-induced nephrotoxicity was significantly improved by LYC supplementation. Therefore, LYC could protect the kidney against ATR-induced nephrotoxicity via maintaining ionic homeostasis, reversing the changes in ATPase activity and controlling the expression of AQPs on the cell membrane. These results suggested that AQP2 was a target of LYC and protected against ATR-induced renal ionic homeostasis disturbance.

Evolutionary Role of Epigenetics in Ischemic Stroke: A Review

Stroke is a Central Nervous System (CNS) disorder which occurs due to the obstruction in the brain blood flow. Stroke is mainly of two types, such as ischemic and hemorrhagic stroke. Ischemic stroke (80%) caused due to obstruction of blood flow through Middle Cerebral Artery (MCA) and characterized by a decreased supply of oxygen and glucose to CNS. In comparison, Hemorrhagic stroke (20%) mainly occurs due to the rupturing of blood vessels. Epidemiologically, it is the common reason of death after cancer and affecting millions of global population. There are many risk factors such as hypertension; hypercholesterolemia etc. which can exaggerate the condition of stroke. Various conventional therapies like Antiplatelets, Thrombolytic are available, but, there is a need to obtain a therapeutic approach that can provide prevention as well as a cure for the stroke. So the present review is primarily focused on epigenetic approach for ischemic stroke by Endogenous Transplantation of Neural Stem/Progenitor Cells (NSPCs). This, in turn, will decrease the level of REST protein at the genetic level and enhance the activity of Na+-Ca+ exchanger activity and lowers the excitotoxicity.

Cell Volume Changes and Membrane Ruptures Induced by Hypotonic Electrolyte and Sugar Solutions

The cell volume changes induced by hypotonic electrolyte and sucrose solutions were studied in Chinese-hamster-ovary epithelial cells. The effects in the solutions with osmolarities between 32 and 315 mosM/L and distilled water were analyzed using bright-field and fluorescence confocal microscopy. The changes of the cell volume, accompanied by the detachment of cells, the formation of blebs, and the occurrence of almost spherical vesicle-like cells (“cell-vesicles”), showed significant differences in the long-time responses of the cells in the electrolyte solutions compared with the sucrose-containing solutions. A theoretical model based on different permeabilities of ions and sucrose molecules and on the action of Na+/K+-ATPase pumps is applied. It is consistent with the observed temporal behavior of the cells’ volume and the occurrence of tension-induced membrane ruptures and explains lower long-time responses of the cells in the sucrose solutions.

Salinity Gradient Energy Conversion Using Permselective Organic Liquid Membranes

The increases of worldwide energy consumption and the concern about the environment have made us pay attention to eco-friendly and renewable energy, such as solar power, wind power, water power, geothermal power, biofuel energy, etc. [P. A. Owusu and S. Asumadu-Sarkodie, Cogent Eng., 3, 1167990 (2016)]. The salinity gradient between seawater and river water must be one of such energy sources. Reverse electrodialysis (RED) is a power generation system which translates salinity gradient energy to electricity by the use of ion-exchange membranes [Y. Mei and C. Y. Tang, Desalination, 425, 156 (2018)]. Since the waters are sufficient on Earth and RED using them does not generate harmful waste, RED can supply electricity in a sustainable and eco-friendly manner. However, the drop in the power capacity owing to the large resistance of the river water, the high cost of ion-exchange membranes, deterioration and clogging of ion-exchange membranes, etc. are serious problems to be solved.We used organic liquid membranes instead of ion-exchange membranes as the permselective membranes for a RED system. Liquid membranes are often employed in the field of ion sensors in order to give electrodes the selectivity on the objective ions. The permselectivity of the liquid membranes is attributed to both the difference in the transfer energies of coexisting ions and the concentration ratio of them. The characteristics of the liquid-membrane type electric cell were studied.A Na+-permselective liquid membrane (Na+-LM) was prepared in the following manner. First, a 0.2-mm-thick polytetrafluoroethylene (PTFE) sheet opening a hole of 1.0 cm diameter was put on a flat glass plate and was fixed with clips. 74 mg of Sodium tetrakis[3,5-bis(trifluoromethyl)phenyl]borate (NaTFPB), 100 mg of polyvinyl chloride (PVC), and 0.8 mL (L = dm3) of 2-nitrophenyl octyl ether (NPOE) were dissolved in 4 mL of tetrahydrofuran (THF). Then, 0.1 mL of the THF solution was poured into the hole, and the solvent was dried for a day. Finally, a Na+-LM was formed within the hole on the glass plate. The membrane was peeled off from the glass plate and was used along with the PTFE sheet. Similarly, a Cl−-permselective liquid membrane (Cl−-LM) was prepared by the use of a THF solution containing 42 mg of tetraoctylammonium chloride (TOcACl), 100 mg of PVC, and 0.8 mL of NPOE in 4 mL of THF. The thickness of the membranes (Na+-LM and Cl−-LM) was 13 μm.The cell is mainly composed of three aqueous phases (W1, W2, and W3), two permselective liquid membranes (Na+-LM and Cl−-LM), and two Ag|AgCl electrodes (RE1 and RE2). The composition of the cell is as follows: RE1|W1|Na+-LM|W2|Cl−-LM|W3|RE2. W1 and W3 contained 1.0 mol L−1 NaCl aqueous solutions, which corresponded to seawater. A 50 mmol L−1 NaCl aqueous solution simulating river water was used as W2. The thickness of W1 and W3 and that of W2 are 2.3 cm and 2.8 cm, respectively.The power density of the cell was evaluated by normal pulse voltammetry. The potential of the cell, E, was taken as the potential of RE2 against RE1. In each step, E was maintained at the electromotive force E emf (or the open circuit potential) for 370 s, and then the rectangular pulse voltage was applied for 50 s. The current due to the Na+ flow from W1 to W3 was taken to be positive. The measurement was conducted at 298 ± 1 K.The result is shown in the attached figure. The time-course of the current density j and that of E were expressed as a solid line and a broken line, respectively. The measured value of E emf was 138 mV under the conditions. The calculated value of E emf by the Nernst equation using the activities of Na+ and Cl− is 140 mV, and the agreement between the two E emf values demonstrates that Na+-LM and Cl−-LM played as ideal permselective membranes. In order to evaluate the power density of the cell, the values of j at the last 2 s of each pulse were averaged and were related to the E values. The maximum power density was 14 μW cm−2 at 69 mV.In the present study, the liquid membranes were used instead of ion-exchange membranes for the RED system. The NPOE solution of NaTFPB and that of TOcACl showed the good permselectivity in the NaCl aqueous solution. The liquid membranes are able to replace the ion-exchange membranes used in RED systems. Figure 1

Histone Deacetylase Activity and the Renin-Angiotensin-Aldosterone System: Key Elements in Cardiorenal Alterations Provoked by Chronic Malnutrition in Male Adult Rats.

Chronic malnutrition (M) affects >1 billion people worldwide. Epidemiological data point to long-term renal and cardiovascular outcomes (e.g. arterial hypertension, cardiorenal syndromes). The renin-angiotensin-aldosterone system (RAAS) has been implicated in the physiopathology of these disturbances, but M-induced alterations in RAAS-modulated renal Na+ handling and their cardiovascular repercussions are not known. Moreover, altered tissue-specific histone deacetylases (HDAC) results in arterial hypertension and the use of sodium Valproate (Val; a HDAC inhibitor) reduces blood pressure. However, there are no reports regarding the renal and cardiovascular effects of HDAC inhibition in M, or on the signaling pathways involved. The central aim of our study has been to investigate whether alterations in the HDAC/RAAS axis underpin alterations in active Na+ transport in the kidney and heart, and affects blood pressure. Male rats aged 28 days were given either a control (C) or a multideficient diet (Regional Basic Diet, RBD), which mimics alimentary habits from developing countries. Subgroups received Losartan (Los), a blocker of type 1 Angiotensin II receptors. When the rats reached 70 days, new subgroups received Val until they were 90 days of age. Homogenates and enriched plasma membrane fractions from renal cortex corticis and cardiomyocytes were obtained by differential centrifugation of the tissues. The activity of renal and cardiac deacetylases was assayed by measuring - after incubation with the membranes - the amount of deacetylated lysines in a substrate containing an acetylated lysine side chain. Protein kinases activities were measured following the incorporation of the γ-phosphoryl group of [γ-32P]ATP into Ser/Thr residues of histone type III-S. The activity of Na+-transporting ATPases (kidney and heart) was quantified by measuring the release of Pi from ATP that was sensitive to ouabain ((Na++K+)ATPase), or sensitive to furosemide (Na+-ATPase). Tail-cuff plethysmography was used to measure systolic blood pressure and heart rate. M provoked HDAC downregulation, which was reversed by Los and Val, either alone or in combination, with selective upregulation of protein kinases C and A (PKC, PKA) in renal cortex corticis, but not in left ventricle cardiomyocytes. The 2 kinases were strongly inhibited by Los and Val in both organs. Malnourished rats developed elevated systolic arterial pressure (SAP) and heart rate (HR) at 70 days of age; Los and Val restored the control SAP, but not HR. Functional and the above biochemical alterations were associated with the deregulation of renal and cardiac Na+-transporting ATPases. (Na++K+)ATPase activities were downregulated in M rats in both organs, and were further inhibited by the pharmacological treatments in the renal cortex corticis (C and M groups) and the left ventricle (only in C rats). No additional effect was found in cardiac (Na++K+)ATPase from M rats. Ouabain-resistant Na+-ATPase was upregulated in renal cortex corticis and downregulated in cardiomyocytes, returning to C values after administration of Los and Val. The HDAC/RAAS axis appears to be a key regulator of Na+-transporting ATPases in renal cortex corticis and cardiomyocytes via an appropriate balance of PKC and PKA activities. Modifications within the HDAC/RAAS axis provoked by chronic M - with repercussions in renal and cardiac Na+ transport - underpin alterations in bodily Na+ homeostasis that culminate with the onset of arterial hypertension and potential cardiorenal syndrome.

Taurine supplementation restores antioxidant status and hepatic membrane-bound enzymes in streptozotocin-induced diabetic rats

Introduction and Aim: Chronic hyperglycemia in diabetes causes cellular damage through increased lipid peroxidation and reduced levels of antioxidants. The activities of membrane-bound enzymes are affected by oxidative stress. Taurine, a sulfur containing amino acid is shown to have hypoglycemic activity, antioxidant property and membrane stabilization. The aim of the study is to check the effect of supplementation of taurine on lipid peroxidation, antioxidant status and hepatic membrane-bound enzymes in streptozotocin- induced diabetic rats.
 Materials and Methods: Thirty-two Wistar male albino rats of 19±1 weeks of age weighing 200-220 grams were randomly divided into four groups and each group consisted of eight animals. Group I (control) standard chow diet; Group II (chow diet with taurine); Group III (diabetes induced) and Group IV (diabetic receiving taurine). At the end of 45th day, all animals were sacrificed by cervical decapitation after overnight fasting. Blood and liver tissue samples were collected. The levels of glucose in plasma and lipid peroxidation, antioxidants and the activities of Na+/ K+, Ca2+ and Mg2+-ATPases in liver homogenate were analyzed.
 Results: Altered levels of antioxidants and activities of Na+/ K+, Ca2+ and Mg2+-ATPases were restored to normal by taurine supplementation in diabetic rats.
 Conclusion: The present study indicates that supplementation of taurine could protect liver plasma membrane against oxidative damage by acting as antioxidant and restoring the normal activities of Na+/ K+, Ca2+ and Mg2+-ATPases.

Oxidative stress biomarkers, biochemical responses and Na+ -K+ -ATPase activities in Nile tilapia, Oreochromis niloticus exposed to diclofenac

The residues and metabolites from pharmaceuticals have been noted to cause adverse effects to both target and non-target aquatic organisms. The sublethal effects of diclofenac at 0.17, 0.34 and 0.68 mg L−1 on oxidative stress biomarkers, biochemical responses and Na+ -K+ -ATPase activities in the gill tissue of Nile tilapia, Oreochromis niloticus were investigated for 60 days. Elevated levels of some serum biochemical parameters including protein, glutamic oxalacetic transaminase, glucose, glutamic pyruvic transaminase, lactate dehydrogenase, alkaline phosphatase and also some catalysts of gluconeogenic enzymes such as glucose-6-phosphatase, fructose 1, 6 bisphosphatase in the fish liver, increase as the concentration of the diclofenac increased. The reactions of glutathione-S-transferase, catalase, lipid peroxidation, superoxide dismutase, glutathione peroxidase, carbonyl protein and reduced glutathione were elevated (p < 0.05) while the activities of Na+ -K+ -ATPase was significantly reduced (p < 0.05) in fish gill, indicating an adaptive response strategies to mitigate the impact of the drug on the exposed fish. Chronic exposure to sublethal diclofenac can induce oxidative stress and modulates serum biochemical indexes of O. niloticus, suggesting the need for close monitoring of the drug and their metabolites in aquatic environment considering the possible potential adverse effects it may cause even to non-target organisms.

Small molecule inhibitors provide insights into the relevance of LAT1 and LAT2 in materno‐foetal amino acid transport

The placenta supplies the foetus with critical nutrients such as essential amino acids (AA, eg leucine) for development and growth. It also represents a cellular barrier which is formed by a polarized, differentiated syncytiotrophoblast (STB) monolayer. Active Na+‐independent leucine transport across the placenta is mainly attributed to the System L transporters LAT1/SLC7A5 and LAT2/SLC7A8. This study explored the influence of trophoblast differentiation on the activity of LAT1/LAT2 and the relevance of LAT1/LAT2 in leucine uptake and transfer in trophoblasts by applying specific small molecule inhibitors (JPH203/JG336/JX009). L‐leucine uptake (total dose = 167 μmol/L) was sensitive to LAT1‐specific inhibition by JPH203 (EC50 = 2.55 µmol/L). The inhibition efficiency of JPH203 was increased by an additional methoxy group in the JPH203‐derivate JG336 (EC50 = 1.99 µmol/L). Interestingly, JX009 showed efficient System L inhibition (EC50 = 2.35 µmol/L) and was the most potent inhibitor of leucine uptake in trophoblasts. The application of JPH203 and JX009 in Transwell®‐based leucine transfer revealed LAT1 as the major accumulative transporter at the apical membrane, but other System L transporters such as LAT2 as rate‐limiting for leucine efflux across the basal membrane. Therefore, differential specificity of the applied inhibitors allowed for estimation of the contribution of LAT1 and LAT2 in materno‐foetal AA transfer and their potential impact in pregnancy diseases associated with impaired foetal growth.

Morphological changes and variations in Na+/K+-ATPase activity in the gills of juvenile large yellow croaker (Larimichthys crocea) at low salinity

Gill morphological changes and physiological responses in juvenile large yellow croaker (Larimichthys crocea) were examined upon exposure to low salinity after indoor culture of the fish at salinities of 2, 4, 6, 8, and 24‰ (control group). The thickness of the lamellae was significantly higher in the low-salinity groups than in the control group; in contrast, the interlamellar space was significantly lower in the low-salinity groups than in the control group. Additionally, a significant negative correlation was found between the thickness of lamellae and interlamellar spaces (P < 0.01). Mitochondria-rich cells (MRCs) were mainly found in the filament at 24‰ salinity and proliferated in the lamellae at lower salinities, suggesting that filament and lamellar MRCs are responsible for ion secretion and absorption, respectively. Meanwhile, the activity of Na+/K+-ATPase (NKA) was significantly elevated with the decrease in salinity from 24‰ to 4‰ (P < 0.05), which was consistent with MRCs proliferation. Finally, the activity of NKA declined at 2‰ salinity (P < 0.05), indicating the limit of osmoregulation, which was consistent with the degeneration and necrosis of the lamellae. Additionally, different levels of gill histopathological lesions, including pavement cell (PVC) exfoliation, lamellar epithelial lifting, edema, fusion, aneurism, and necrosis, were observed from salinities of 24 to 4‰, likely reducing the respiratory efficiency and compromising the health of juvenile fish. In conclusion, large yellow croaker juveniles could improve the osmoregulatory capacity by increasing lamellar MRCs and NKA activity with the decrease in salinity from 24 to 4‰. However, the associated histopathological lesions are likely to negatively influence the fish by affecting respiration and osmoregulation, especially when the salinity is below 4‰.

Effects on learning and memory and mitochondrial energy metabolism in hippocampus of mice by subacute exposure to n-hexane

Objective: To study the effects on learning and memory, mitochondrial energy metabolism and ATPase activity of hippocampus in mice with subacute exposure to n-hexane. Methods: The SPF 40 Kunming mice were randomly divided into low, middle and high dose groups and control groups according to different dosages. Each group consisted of 10 mice. The mice were given n-hexane by gavage, the mice in the low, middle and high dose groups were given 0.2 ml/d of n-hexane at concentrations of 500, 1000 and 2000 mg/kg respectively, while the mice in the control group were given 0.2 ml/d of cooking oil once a day for 28 days. The y-type maze test, the activity of ATP Enzyme, mitochondrial respiratory chain enzyme complex Ⅰ-IV, the mrna of mitochondrial fusion gene (MFn1, Mfn2) and fission gene (FIs1) in brain tissues were performed. Results: Except for the wrong reaction times of low-dose exposure group in the first test, there existed significantly different in the first and second Y-maze tests in exposure groups and control group (P<0.05) ; in low, middle and high-dose group, the Na(+)-K(+)-ATPase activities were (8.27±2.65) , (5.38±1.55) , (3.55±1.69) μmol/gprot/h, and Ca(2+)-Mg(2+)-ATPase activities were (10.32±2.96) , (7.19±1.94) and (4.49±1.33) μmol/gprot/h, respectively. Compared with those in control group, the activities of Na(+)-K(+)-ATPase and Ca(2+)-Mg(2+)-ATPase decreased significantly in middle-dose group and high-dose group (P<0.05) . Compared with those in control group, the activities of mitochondrial respiratory chain enzyme complex I-IV in each dose group were significantly decreased (P<0.05) . The expressions of Mfn1mRNA and Mfn2mRNA in each dose group was significantly lower than those in control group (P<0.05) . Conclusion: Subacute exposure to n-hexane can result in the decrease of activities of mitochondrial respiratory chain enzyme complex in hippocampus of mice, which may lead to the disorder of mitochondrial energy metabolism by the decrease of ATPase activity and the imbalance of mitochondrial fusion-division, which must be one of the mechanisms of impairment of learning and memory of mice induced by n-hexane.

Advances on GABAergic interneurons in autism spectrum disorders

More and more evidences support that the abnormality of GABAergic interneurons is associated with autism spectrum disorders (ASD), epilepsy, schizophrenia and other neurodevelopmental disorders. In recent years, numerous drugs have been developed to regulate ion channels and receptors in GABAergic interneurons, including sodium channels and N-methyl-D-aspartate (NMDA) receptors. The activators of Na+ channel can enhance the action potential of GABAergic interneurons by reducing the inactivation of Na+ channel. NMDA receptor, as a potential therapeutic target of ASD, can restore the NMDA function of GABAergic interneurons, which would be used to treat behavioral defects. In addition, there are many ion channels and receptors on GABAergic interneurons related to ASD. This article reviews GABAergic interneurons in the pathogenesis of ASD and the related interventions.

Abatement of neurobehavioral and neurochemical dysfunctions in cerebral ischemia/reperfusion injury by Tetrapleura tetraptera fruit extract

Ethnopharmacological relevanceTetrapleura tetraptera Taub. (family Fabaceae), is generally found in the lowland forest of tropical Africa. Its leaves and fruits are traditionally used in West Africa for the management of brain disorders. Aim of the studyThis study evaluated the effect of Tetrapleura tetraptera methanol fruit extract (TT) on bilateral common carotid artery occlusion-induced cerebral ischemia/reperfusion (I/R) injury in male Wistar rats. Materials and methodsRats pretreated with TT for 7 days before a 30 min bilateral common carotid artery occlusion and reperfusion for 24 h were assessed for neurobehavioural deficits. Cortical, striatal and hippocampal oxidative stress, pro-inflammatory events, electrolyte imbalance and neurochemical dysfunctions, as well as hippocampal histopathological alterations, were also evaluated. HPLC-DAD analysis was performed to identify likely compounds contributing to the bioactivity of the extract. ResultsTT reduced I/R-induced behavioral deficits and ameliorated I/R-induced oxidative stress by restoring reduced glutathione level, increasing catalase and superoxide dismutase activities, and also reducing both lipid peroxidation and xanthine oxidase activity in the brain. TT attenuated I/R-increased myeloperoxidase and lactate dehydrogenase activities as well as disturbances in Na+ and K+ levels. Alterations elicited by I/R in the activities of Na+/K+ ATPase, complex I, glutamine synthetase, acetylcholinesterase, and dopamine metabolism were abated by TT pretreatment. TT prevented I/R-induced histological changes in the hippocampus. HPLC-DAD analysis revealed the presence of aridanin, a marker compound for Tetrapleura tetraptera, and other phytochemicals. ConclusionsThese findings indicate that Tetrapleura tetraptera fruit has a protective potential against stroke through modulation of redox and electrolyte imbalances, and attenuation of neurotransmitter dysregulation and other neurochemical dysfunctions. Tetrapleura tetraptera fruit could be a promising source for the discovery of bioactives for stroke therapy.

Pharmacological profiling of JME-173, a novel mexiletine derivative combining dual anti-inflammatory/anti-spasmodic functions and limited action in Na+ channels

Existing evidence suggests that the local anaesthetic mexiletine can be beneficial for patients with asthma. However, caution is required since anaesthesia of the airways inhibits protective bronchodilator neuronal reflexes, limiting applications in conditions of hyperirritable airways. Here, we describe the synthesis of a new series of mexiletine analogues, which were screened for reduced activity in Na+ channels and improved smooth muscle relaxant effects, that were evaluated using the patch-clamp technique and an isolated tracheal organ bath, respectively. JME-173 (1-(4-bromo-3,5-dimethylphenoxy)propan-2-amine) was the most effective among the four mexiletine analogues investigated. JME-173 was then studied in vivo using a murine model of lung inflammation induced by cigarette smoke (CS) and in vitro using neutrophil chemotaxis and mast cell degranulation assays. Finally, the JME-173 pharmacokinetic profile was assessed using HPLC-MS/MS bioanalytical method. JME-173 directly inhibited IL-8 (CXCL8)- and FMLP-induced human neutrophil chemotaxis and allergen-induced mast cell degranulation. After oral administration 1 h before CS exposure, JME-173 (50 mg/kg) strongly reduced the increased number of macrophages and neutrophils recovered in the bronchoalveolar effluent without altering lymphocyte counts. Pharmacokinetic experiments of JME-173 (10 mg/kg, orally) showed values of maximum concentration (Cmax), maximum time (Tmax), area under the blood concentration-time curve (AUC0-t) and area under the blood concentration-time curve from 0–Inf (AUC0-inf) of 163.3 ± 38.3 ng/mL, 1.2 ± 0.3 h, 729.4 ± 118.3 ng*h/ml and 868.9 ± 117.1 ng*h/ml (means ± S.E.M.), respectively. Collectively, these findings suggest that JME-173 has the potential to be an effective oral treatment for diseases associated with bronchoconstriction and inflammation.

Effects of light intensity on cleaning away heat property of Viola yedoensis

The current study was conducted to explore the effects of light intensity in cultivating environment on the cleaning away heat property of Viola yedoensis. In the present study, we established the acute inflammation model of ICR mice by injecting carrageenan. We compared the effects of V. yedoensis grown under different light intensities(100%, 80%, 50%, 35% and 5% of full sunlight) on mice body temperature, thermal radiation and the swelling degree of foot tissue before and after modeling observing by thermal infrared imaging technique and weighing method. The changes of energy metabolism related enzymes in liver were detected by enzyme-linked immunosorbent assay(ELISA). In addition, the effects of V. yedoensis grown under different light intensities on human lung cancer cell A549 proliferation were explored with MTT method. The results showed that the body temperature of all groups of mice in V. yedoensis group were significantly lower than that of the blank group, except 5% full sunlight group, and the body temperature declined in positive proportion to light intensity. V. yedoensis group could alleviate foot swelling, reduce SDH activity in liver tissue(especially 100% full sunlight group and 80% full sunlight group were significantly lower than model group), and the degree of alleviating and reducing was positively correlated with light intensity. There was no significant difference in the activity of Na~+-K~+-ATPase and Ca~(2+)-Mg~(2+)-ATPase in liver tissue among treatments. The contents of IL-1β, IL-6, TNF-α, PGE_2 in foot tissue of mice in V. yedoensis groups were significantly lower than those in model group. Among them, the lowest levels of IL-1β, IL-6, TNF-α, PGE_2 were found in 80% full sunlight group, and there was no significant difference in TNF-α among different groups. The effects of V. yedoensis aqueous extract on A549 cell line proliferation inhibition rate increased with the light intensities of V. yedoensis cultivating environment. And the effects of V. yedoensis grown under 100% of full sunlight showed significantly higher A549 cell line proliferation inhibition rate compared with other groups(P&lt;0.05). In summary, the light intensity of V. yedoensis cultivating environment is positively correlated with the cleaning away heat property of V. yedoensis, which conforms to the &quot;light-cold and heat property&quot; hypothesis,The V. yedoensis should be planted under full light according.

Enhanced protection against lipopolysaccharide-induced acute lung injury by autologous transplantation of adipose-derived stromal cells combined with low tidal volume ventilation in rats.

Adipose-derived stromal cells (ADSCs) showed excellent capacity in regeneration and tissue protection. Low tidal volume ventilation (LVT) strategy demonstrates a therapeutic benefit on the treatment of acute lung injury/acute respiratory distress syndrome (ALI/ARDS). This study, therefore, aimed to undertaken determine whether the combined LVT and ADSCs treatment exerts additional protection against lipopolysaccharide (LPS)-induced ALI in rats. The animals were randomized into seven groups: Group I (control), Group II (instillation of LPS at 10 mg/kg intratracheally), Group III (LPS+LVT 6 ml/kg), Group IV (LPS+intravenous autologous 5 × 106 ADSCs which were pretreated with a scrambled small interfering RNA [siRNA] of keratinocyte growth factor [KGF] negative control), Group V (LPS+ADSCs which were pretreated with a scrambled siRNA of KGF, Group VI (LPS+LVT and ADSCs as in the Group IV), and Group VII (LPS+LVT and ADSCs as in the Group V). We found that levels of tumor necrosis factor-α, transforming growth factor-β1, and interleukin (IL)-1β and IL-6, the proinflammatory cytokines, were remarkably increased in LPS rats. Moreover, the expressions of ENaC, activity of Na, K-ATPase, and alveolar fluid clearance (AFC) were obviously reduced by LPS-induced ALI. The rats treated by ADSCs showed improved effects in all these changes of ALI and further enhanced by ADSCs combined with LVT treatment. Importantly, the treatment of ADSCs with siRNA-mediated knockdown of KGF partially eliminated the therapeutic effects. In conclusion, combined treatment with ADSCs and LVT not only is superior to either ADSCs or LVT therapy alone in the prevention of ALI. Evidence of the beneficial effect may be partly due to improving AFC by paracrine or systemic production of KGF and anti-inflammatory properties.

The effects of a short-term exposure to propiconazole in zebrafish (Danio rerio) embryos.

Propiconazole (PCZ) is a widely used fungicide around the world and was frequently detected in surface waters, which would pose risk to aquatic organisms. Previous studies indicated that PCZ has high toxicity to different kinds of fish. However, most of the studies focus on the toxicity and mechanisms of PCZ to adult fish, the potential toxicity mechanism of PCZ to fish embryos is still poorly understood. The present study investigated the effects of PCZ on content of reactive oxygen species (ROS) and malondialdehyde (MDA); activities of superoxide dismutase (SOD), catalase (CAT), and Na+-K+-ATPase; and expression level of genes related to oxidative stress, cell apoptosis, and innate immune system in zebrafish embryos after 96-h exposure. The results showed that 5.0mg/L PCZ induced oxidative damage in zebrafish embryos, as indicated by increased ROS and MDA content and alteration of antioxidative enzyme activity. The activity of Na+-K+-ATPase in zebrafish embryos was significantly inhibited after exposure to 0.5mg/L PCZ. The expression levels of bax, p53, casp-3, casp-9, and apaf-1 were significantly increased, indicating that cell apoptosis was caused in embryos by 5.0mg/L PCZ. The expression level of interleukin-1b (IL-1b) and IL-8 increased after exposure to 0.5mg/L PCZ, but that of IL-1b, IL-8, and cxcl-c1c (chemokine (C-X-C motif) ligand 18b) decreased in 5.0-mg/L PCZ treatment group, indicating an immunotoxicity effect. Our results suggest that oxidative damage, cell apoptosis, and immunotoxicity would be induced in zebrafish embryos after short-term exposure to PCZ.