Activity Of Na Research Articles

Dynamic self-recovery of injured Escherichia coli O157:H7 induced by high pressure processing

This study was aimed to investigate the dynamic recovery process of high pressure processing (HPP)-injured Escherichia coli O157:H7. E. coli O157:H7 was treated with 100–500 MPa for 5 min, and the pressure with highest injury rate was selected to determine the optimal temperature and duration for repairing HPP-injured cells in PBS. The morphological and physiological changes during the repair process under the above optimal conditions were further investigated. The results showed a stronger inhibition effect with increased pressure, while the lethal effect was not consistent with the injury, since the highest injury rate was observed at 400 MPa for 5 min. Next, HPP-treated cells (400 MPa, 5 min) were repaired in PBS at different temperatures (20, 25, 30, 37 °C) for 108 h, and the optimal recovery condition of the injured cells was found to be 25 °C for 24 h. During the repair process, SEM and TEM morphology, leakage of ions, activities of Na+K+-ATPase and Ca2+Mg2+-ATPase, and the membrane fatty acid composition of HPP-treated cells gradually return to normal levels found in non-HPP cells, which confirmed the dynamic recovery process of HPP-injured E. coli O157:H7, as well as that HPP-injured E. coli O157:H7 could be repaired under appropriate conditions.

Effect of adrenalectomy on pulmonary edema resolution.

The capacity of the lung to clear edema fluid has been shown to be one of the factors that can influence the prognosis of cardiogenic and noncardiogenic pulmonary edema. Active Na+ transport across the alveolar epithelium is the main driving force involved in this physiological process. Since endogenous catecholamines are known to activate the sodium-dependent mechanism of alveolar edema clearance, the objective of the present study was to explore if adrenalectomy, which prevents the release of endogenous catecholamines and other hormones, such as corticosterone, into circulation, would affect edema resolution in a model of lung injury induced by thiourea. A high-permeability pulmonary edema was induced in adult male Sprague-Dawley rats using a thiourea-induced pulmonary edema model. To determine if the release of adrenalin and corticosterone is essential for resolution of the thiourea-induced edema, we measured 1) the release of adrenalin and corticosterone in urine and 2) edema resolution in control animals and adrenalectomized animals. The administration of thiourea significantly increased the wet-to-dry ratio after four and eight hours. After 12 and 24 hours, the wet-to-dry ratio gradually returned to baseline. Although thiourea-induced pulmonary edema was associated with a significant increase in urine adrenalin and corticosterone, the absence of adrenalin and corticosterone response in adrenalectomized animals did not prevent the resolution of the edema. These experiments demonstrated that resolution of thioureainduced pulmonary edema can occur in the absence of hormonal secretion by the adrenal glands.

Glucose Metabolism in Cardiac Hypertrophy and Heart Failure.

Glucose Metabolism in Cardiac Hypertrophy and Heart Failure.

Calcineurin B-Like Proteins CBL4 and CBL10 Mediate Two Independent Salt Tolerance Pathways in Arabidopsis.

In Arabidopsis, the salt overly sensitive (SOS) pathway, consisting of calcineurin B-like protein 4 (CBL4/SOS3), CBL-interacting protein kinase 24 (CIPK24/SOS2) and SOS1, has been well defined as a crucial mechanism to control cellular ion homoeostasis by extruding Na+ to the extracellular space, thus conferring salt tolerance in plants. CBL10 also plays a critical role in salt tolerance possibly by the activation of Na+ compartmentation into the vacuole. However, the functional relationship of the SOS and CBL10-regulated processes remains unclear. Here, we analyzed the genetic interaction between CBL4 and CBL10 and found that the cbl4 cbl10 double mutant was dramatically more sensitive to salt as compared to the cbl4 and cbl10 single mutants, suggesting that CBL4 and CBL10 each directs a different salt-tolerance pathway. Furthermore, the cbl4 cbl10 and cipk24 cbl10 double mutants were more sensitive than the cipk24 single mutant, suggesting that CBL10 directs a process involving CIPK24 and other partners different from the SOS pathway. Although the cbl4 cbl10, cipk24 cbl10, and sos1 cbl10 double mutants showed comparable salt-sensitive phenotype to sos1 at the whole plant level, they all accumulated much lower Na+ as compared to sos1 under high salt conditions, suggesting that CBL10 regulates additional unknown transport processes that play distinct roles from the SOS1 in Na+ homeostasis.

Distribution and functions of \u03b3\u03b4 T cells infiltrated in the ovarian cancer microenvironment

BackgroundThe role of γδ T cells, innate-like lymphocytes with unrestrained MHC, in various malignancies has recently been extensively studied. However, there is limited research regarding γδ T cells in ovarian cancer (OC) patients.MethodsHere, we investigated the distribution patterns of γδ T cells and their main subsets in peripheral blood and tumor tissues among OC patients, benign ovarian tumor (BOT) patients, and age-matched healthy controls (HC) by flow cytometry, as well as the expression levels of IFN-γ and IL-17A secreted from γδ T cells. Immunohistochemical staining was utilized to detect the numbers of γδ T cells and their main subsets in different types of ovarian tumor tissues. Additionally, we also investigated chemotaxis effects on γδ T cells, as well as their cytotoxic activity and proliferation.ResultsWe found that the percentages of γδ T cells and Vδ1 T cells were significantly higher in OC tissues than BOT tissues and normal (N) ovarian tissues, while there were no obvious differences in peripheral blood. Meanwhile, higher numbers of γδ T cells and Vδ1 T cells were observed in OC tissues, and were positively related to advanced clinicopathological features of OC patients. Further, the levels of IFN-γ secreted by γδ T cells were relatively lower, while IL-17A was expressed at a high level in both the peripheral blood and tissues of OC patients. Chemotaxis assay revealed that supernatants derived from OC tissues possessed a stronger capacity to attract and recruit γδ T cells. However, γδ T cells sorted from OC tissues showed weakened cytotoxic activity against ovarian cancer cells, and γδ T cells cocultured with OC tissue supernatants could effectively inhibit the proliferative activity of naïve CD4+ T cells.ConclusionsThese data suggested that γδ T cells might have critical roles in OC progression and potential utilization in treatment approaches or prognosis prediction.

Strongly proton exchanged montmorillonite K10 (H+-Mont) as a solid acid catalyst for highly efficient and environmental benign synthesis of biscoumarins via tandem Knoevenagel–Michael reaction

In this study, synthesis of micro/meso porous acid-activated montmorillonite K10 (H+-Mont) was carried out by the activation of Na+-montmorillonite with HCl (4 M) at the controlled conditions. The prepared H+-Mont clay was then characterized using FT-IR, SEM, EDX, XRD and BET analyses. SEM and BET surface analyses represented that by the acid-activation, adjacent layers of montmorillonite K10 (Mont K10) were exfoliated to tiny segments leading to raise of surface area and total pore volume in H+-Mont system rather than the alone Mont K10. Catalytic activity of the prepared H+-Mont clay was further studied as a potent solid acid catalyst for synthesis of biscoumarin materials via tandem Knoevenagel–Michael reaction of 4-hydroxycoumarin with aromatic aldehydes. All reactions were carried out in a mixture of H2O-EtOH (1:1) at room temperature to afford the products in high to excellent yields within 25–50 min.

Activity of All-Russian Research Institute of Physical-Technical and Radio-Technical Measurements (VNIIFTRI) in the sphere of physicochemical measurements

This article presents the description, metrological characteristics and application of State primary standards developed at the All-Russian Research Institute of Physicol-Technical and Radio-Technical Measurements (VNIIFTRI). These include the state primary standards for pH and pX in aqueous solutions, units of the dispersed parameters of aerosols, suspensions and powdery materials, units of the mass fraction and mass (molar) concentration of inorganic components in aqueous solutions based on gravimetric and spectral methods of analysis. In addition, the article discusses R&D projects that are currently being realized at VNIIFTRI, including the production of standard-titres and buffer solutions for pH-metry, as well as working standards for assessing the activity of Na+, K+, F-, Cl-, Br-, I-, NO3-(pX) ions in aqueous media.

A CASPR1–ATP1B3 protein interaction modulates plasma membrane localization of Na+/K+-ATPase in brain microvascular endothelial cells

Contactin-associated protein 1 (CASPR1 or CNTNAP1) was recently reported to be expressed in brain microvascular endothelial cells (BMECs), the major component of the blood-brain barrier. To investigate CASPR1's physiological role in BMECs, here we used CASPR1 as a bait in a yeast two-hybrid screen to identify CASPR1-interacting proteins and identified the β3 subunit of Na+/K+-ATPase (ATP1B3) as a CASPR1-binding protein. Using recombinant and purified CASPR1, RNAi, GST-pulldown, immunofluorescence, immunoprecipitation, and Na+/K+-ATPase activity assays, we found that ATP1B3's core proteins, but not its glycosylated forms, interact with CASPR1, which was primarily located in the endoplasmic reticulum of BMECs. CASPR1 knockdown reduced ATP1B3 glycosylation and prevented its plasma membrane localization, phenotypes that were reversed by expression of full-length CASPR1. We also found that the CASPR1 knockdown reduces the plasma membrane distribution of the α1 subunit of Na+/K+-ATPase, which is the major component assembled with ATP1B3 in the complete Na+/K+-ATPase complex. The binding of CASPR1 with ATP1B3, but not the α1 subunit, indicated that CASPR1 binds with ATP1B3 to facilitate the assembly of Na+/K+-ATPase. Furthermore, the activity of Na+/K+-ATPase was reduced in CASPR1-silenced BMECs. Interestingly, shRNA-mediated CASPR1 silencing reduced glutamate efflux through the BMECs. These results demonstrate that CASPR1 binds with ATP1B3 and thereby contributes to the regulation of Na+/K+-ATPase maturation and trafficking to the plasma membrane in BMECs. We conclude that CASPR1-mediated regulation of Na+/K+-ATPase activity is important for glutamate transport across the blood-brain barrier.

Exposure to low-level metalaxyl impacts the cardiac development and function of zebrafish embryos

Metalaxyl is an anilide pesticide that is widely used to control plant diseases caused by Peronosporales species. In order to study the toxic effects, zebrafish embryos were exposed to metalaxyl at nominal concentrations of 5, 50 and 500 ng/L for 72 hr, and the cardiac development and functioning of larvae were observed. The results showed that metalaxyl exposure resulted in increased rates of pericardial edema, heart hemorrhage and cardiac malformation. The distance between the sinus venosus and bulbus arteriosus, stroke volume, cardiac output and heart rate were significantly increased in larvae exposed to 50 and 500 ng/L metalaxyl compared to solvent control larvae. Significant upregulation in the transcription of tbx5, gata4 and myh6 was observed in the 50 and 500 ng/L treatments, and that of nkx2.5 and myl7 was observed in the 5, 50 and 500 ng/L groups. These disturbances may be related to cardiac developmental and functional defects in the larvae. The activity of Na+/K+-ATPase and Ca2+-ATPase was significantly increased in zebrafish embryos exposed to 500 ng/L metalaxyl, and the mRNA levels of genes related to ATPase (atp2a11, atp1b2b, and atp1a3b) (in the 50 and 500 ng/L groups) and calcium channels (cacna1ab) (in the 500 ng/L group) were significantly downregulated; these changes might be associated with heart arrhythmia and functional failure.

Activity of Na+/K+-ATPase in model lipid membrane at air-water interface

The Na+/K+-ATPase pump was reconstituted in proteoliposomes composed of DPPC:DPPE, which were then spread at the air-water interface using Langmuir technique. In the presence of the enzyme in the liposomes the resulting lipidic layer at the air-water interface became more liquid. The effect of Na+/K+-ATPase on the morphology of Langmuir lipidic layers was monitored by Brewster angle microscopy, which showed the formation of lattice-like structure in between round-shaped lipid domains. The presence of protein stabilized the DPPC:DPPE mixed monolayer at the air-water interface, which was revealed by surface pressure measurements in time and ascribed to hydrogen bond network formation between the protein and the lipids. The activity of the protein embedded in the lipidic Langmuir layer was measured using spectroscopy and voltammetry. Free phosphate released from ATP reacted with ammonium molybdate and the blue α-Keggin anion formed was detected spectrophotometrically at a wavelength of 710 nm. The results based on spectroscopic assay were complemented with electrochemical methods. The activity of the enzyme could by switched off using the inhibitor – ouabain. The Na+/K+-ATPase activity (2.62 nmol mg−1 min−1) was similar to the activity of the protein solubilized using detergents (3.21 nmol mg−1 min−1). The slightly lower activity was ascribed to the defined orientation of the embedded protein molecules with respect to the air-water interface needed for its activity at the air–water interface.

Synergistic oxidative impact of aluminum chloride and sodium fluoride exposure during early stages of brain development in the rat.

Aluminum is widely used in industry and in cooking utensils, especially in countries with low economic and social standards. Fluoride is also used in industry, a major component of toothpaste and is added to the drinking water in many countries to fight teeth decay and cavities. Consequently, the coexistence of aluminum and fluoride is highly probable. Growing evidence indicates that environmental pollutants during the early stages of embryonic development may reprogram the offspring's brain capabilities to encounter oxidative stress during the rest of their postnatal life. This study investigated the impact of sodium fluoride (NaF, 0.15g/L) and aluminum chloride (AlCl3, 500mg/L) added, individually or in combination, to the deionized drinking water starting from day 6 of gestation until just after weaning, or until the age of 70days postnatal life. A significant decline was observed in tissue contents of vitamin C, reduced glutathione, GSH/GSSH ratio, and the total protein, as well as in the activities of Na+/K+-ATPase and superoxide dismutase (SOD) in almost all cases. On the contrary, lipid peroxidation and NO, as total nitrate, exhibited a significant increase in comparison with the corresponding control. Based on the present results, administration of Al and NaF, alone or in combination abated the quenching effects of the antioxidant system and induced oxidative stress in most brain regions under investigation. In conclusion, aluminum and fluoride are very noxious environmental pollutants that interfere with the proper functions of the brain neurons and their combination together aggravates their hazard.

Crustacean hyperglycemic hormone of Portunus trituberculatus: evidence of alternative splicing and potential roles in osmoregulation.

The crustacean hyperglycemic hormone (CHH) gene of Portunus trituberculatus (Pt-CHH) consists of four exons and three introns spanning 3849bp in size and generating two mature mRNA, Pt-CHH1, and Pt-CHH2. The primary gene transcript produces a cDNA encoding for the putative Pt-CHH2 from exons 1, 2, 3, and 4 and an alternative transcript encodes for a putative Pt-CHH1 peptide from exons 1, 2, and 4. A promoter fragment of about 3kb was obtained by genomic walking. The tissue-specific expression pattern is examined by reverse transcriptase chain reaction, and the results show that Pt-CHH1 is detected in the eyestalk, brain, muscle, and blood. However, Pt-CHH2 is detected in the ganglia thoracalis and gill. The results indicate that the expression of Pt-CHH2 in the gill might suggest a potential role in osmoregulation. The Pt-CHH transcript level in the gill increases when the crab is exposed to low salinity. The injection of dsRNA for Pt-CHH causes a significant reduction in Pt-CHH2 transcript level and the activity of Na+/K+-ATPase, and carbonic anhydrase (CA) show a serious decrease. In conclusion, this study provides molecular evidence to support the osmoregulatory function of Pt-CHH2.

Altering membrane potential for cancer

Cancer Polymorphisms in the G protein–coupled receptor GPR35 are associated with increased risk for certain inflammatory diseases that can progress to cancer. Schneditz et al. found that GPR35 promoted the activity of Na+- and K+-dependent adenosine triphosphatase (Na+,K+-dependent ATPase), a transmembrane pump that sets the membrane potential in cells. This effect was enhanced by a disease-associated GPR35 variant. Stimulation of Na+,K+-ATPase activity by GPR35 increased glycolysis and proliferation in intestinal epithelial cells. Na+,K+-ATPase deficiency or treatment with a pepducin targeting GPR35 decreased tumor burden in mouse models of intestinal cancer. Sci. Signal. 12 , eaau9048 (2019).

Aging Leads to Over-Expression of Na<sup>+</sup>/K<sup>+</sup> Pump Units in Liver and Na<sup>+</sup>/Ca<sup>2+</sup> Exchangers in Brain Cortex

The metabolic controlling of tissue hydration is the fundamental parameter determining cell functional activity and its dysfunction is the common consequence of any cell pathology, including aging. The aim of the present study is to reveal the differences of age-dependent metabolic controlling of cell hydration of excitable tissue such as brain cortex and non-excitable tissues such as liver and spleen. For this purpose, the age-dependent sensitivity of cell hydration in excitable and non-excitablet issues is studied through depressing metabolic activity by cooling and its activation by supplying animals with distilled water, by inactivation of Na+/K+ pump and activation of Na+/Ca2+ exchange in the reverse mode. The obtained data bring us to the conclusion that the metabolic regulation of cell hydration in excitable tissue is realized by the activation of electrogenic Na+/K+ pump and Na+/Ca2+ exchange in the cell membrane and the formation of endogen water by mitochondrial activity, while the regulation of cell hydration in non-excitable tissue is carried out only by the activity of mitochondrial function. Aging leads to an over-expression of Na+/K+ pump units in liver and Na+/Ca2+ exchanger in brain cortex of rats.

Sodium and chloride requirements of yellow-feathered chickens between 22 and 42 days of age

Sodium and chloride are the key factors maintaining normal osmotic pressure (OSM) and volume of the extracellular fluid, and influencing the acid–base balance of body fluids. The experiment was conducted to investigate the effects of dietary Na+ and Cl− level on growth performance, excreta moisture, blood biochemical parameters, intestinal Na+–glucose transporter 1 (SGLT1) messenger RNA (mRNA), and Na+–H+ exchanger 2 (NHE2) mRNA, and to estimate the optimal dietary sodium and chlorine level for yellow-feathered chickens from 22 to 42days. A total of 900 22-day-old Lingnan yellow-feathered male chickens were randomly allotted to five treatments, each of which included six replicates of 30 chickens per floor pen. The basal control diet was based on corn and soybean meal (without added NaCl and NaHCO3). Treatments 2 to 5 consisted of the basal diet supplemented with equal weights of Na+ and Cl−, constituting 0.1%, 0.2%, 0.3% and 0.4% of the diets. Supplemental dietary Na+ and Cl− improved the growth performance (P<0.05). Average daily gain (ADG) showed a quadratic broken-line regression to increasing dietary Na+ and Cl− (R2=0.979, P<0.001), and reached a plateau at 0.1%. Supplemental Na+ and Cl− increased (P<0.05) serum Na+ and OSM in serum and showed a quadratic broken-line regression (R2=0.997, P=0.004) at 0.11%. However, supplemental Na+ and Cl− decreased (P<0.05) serum levels of K+, glucose (GLU) and triglyceride. Higher levels of Na+and Cl− decreased duodenal NHE2 transcripts (P<0.05), but had no effect on ileal SGLT1 transcripts. The activity of Na+ /K+-ATPase in the duodenum decreased (P<0.05) with higher levels of dietary Na+ and Cl−. In conclusion, the optimal dietary Na+ and Cl− requirements for yellow-feathered chickens in the grower phase, from 22 to 42 days of age, to optimize ADG, serum Na+, OSM, K+ and GLU were 0.10%, 0.11%, 0.11%,0.17% and 0.16%, respectively, by regression analysis.

Effect of supplementation of nicotinamide and sodium butyrate on the growth performance, liver mitochondrial function and gut microbiota of broilers at high stocking density.

This study was conducted to investigate the effects of stocking density and dietary nicotinamide (NAM) and butyrate sodium (BA) supplementation on the growth performance, liver mitochondrial function and gut microbiota of broilers at high stocking density. A total of 342, 26-d-old Cobb500 broilers were divided into 5 groups with 6 replicates. Treatments were as follows: (a) Low stocking density (L, 9 birds per cage); (b) High stocking density (H, 12 birds per cage); (c) H + 50 ppm NAM; (d) H + 500 ppm BA; (e) H + 50 ppm NAM + 500 ppm BA (COMB). The results showed that high stocking density significantly reduced the feed intake and body weight gain of broilers, while COMB improved the growth performance at high stocking density. High stocking density significantly reduced the liver metallothionein content, liver mitochondrial membrane potential and the activities of Na+K+-ATPase and Ca2+Mg2+-ATPase. In contrast, the liver metallothionein contents in the NAM, BA and COMB fed group were higher than those in the H group. COMB increased the activity of ATPase as well, but it failed to enhance the mitochondrial membrane potential. Stocking density also affected gut microbiota of broilers. The high-density group increased the relative abundance of Blautia. Supplementation of BA and NAM increased the abundance of Lactobacillus and Bifidobacteria, respectively. In conclusion, a combination of NAM and BA can improve the performance, antioxidant capacity, mitochondrial function and intestinal microbiota of broilers at high stocking density.

Serum Potassium, Sodium, and Chloride Levels in Sickle Cell Disease Patients and Healthy Controls: A Case-Control Study at Korle-Bu Teaching Hospital, Accra.

The activity of Na+-K+ ATPase is altered in sickle cell disease (SCD), which affects serum electrolyte levels. This alteration is associated with several complications in sickle cell patients. This study evaluated the serum levels of sodium, potassium, and chloride in patients with SCD. The study was a case-control cross-sectional study involving 120 SCD patients in the steady state and 48 ‘healthy’ controls. The SCD patients were made up of 69 HbSS patients and 41 HbSC patients. Serum electrolyte levels (Na+, K+, and Cl−) were measured using a Flame Atomic Absorption Spectrometer (Variant 240FS; Varian Australia Pty Ltd). Serum sodium levels were significantly lower in the sickle cell patients, compared with their ‘healthy’ counterparts (P = .0001). Although the study found significantly higher serum levels of potassium in the SCD patients (P = .0001), there was no significant difference in serum chloride levels between patients with SCD and the controls (P = .098). Serum sodium and chloride levels were not significantly different in both HbSS and HbSC patients (P = .197 and P = .553, respectively). The level of serum potassium in the HbSS patients was, however, significantly higher compared with those with the HbSC genotype (P = .0001). There is higher efflux of K+ from the intracellular into the extracellular space in HbSS patients, which may lead to red cell membrane dysfunction and associated complications.

Age-Dependent Impairment of Heart Muscle Contractility as a Primary Mechanism for Overexpression of Na&amp;lt;sup&amp;gt;+&amp;lt;/sup&amp;gt;/Ca&amp;lt;sup&amp;gt;2+&amp;lt;/sup&amp;gt; Exchanger in Brain Cortex Tissues

The cognitive function of brain and contractility of heart muscle are accompanied with age-dependent dehydration of tissues of these two organs. The aim of the present study is to reveal which of the abovementioned two organs primarily fail as a result of dysfunction of age-sensitive metabolic mechanism. For this purpose, the age-dependent sensitivity of cell hydration in brain cortex and heart muscle tissues are studied through depressing metabolic activity by cooling and its activation by supplying animals with distilled water, by inactivation of Na+/K+ pump and activation of Na+/Ca2+ exchange in the reverse mode. The obtained data bring us to the conclusion that the metabolic regulation of brain cortex and heart muscle tissues has different nature. The age-dependent dysfunction of Na+/K+ pump–induced activation of RNa+/Ca2+ exchange leads to dysfunction of heart muscle contractility because of activation of Ca-calmoduline-NO-cGMP production, which brings to FNa+/Ca2+ exchange induced muscle relaxation and it could serve as a primary mechanism for dysfunction of brain tissues’ metabolic control of cell hydration, which leads to overexpression of Na+/Ca2+ exchanger in the membrane.

Association between a novel G94A single nucleotide polymorphism in ATP1A1 gene and type 2 diabetes mellitus among Egyptian patients.

Background:Na+/K+ ATPase enzyme is essential for nerve cell membrane integrity, and reduction in its activity, probably due to ATP1A1 gene polymorphisms, is related to diabetic neuropathy progression. Therefore, the goal of the existent study is to evaluate the Na+/K+ ATPase activity in type 2 diabetes mellitus (T2DM) Egyptian patients with or without neuropathy, search for polymorphism(s) in the highly polymorphic region of ATP1A1 gene, exon 2, and study its (their) associations with T2DM with and without neuropathy.Materials and Methods:A total number of 150 individuals were subclassified into healthy controls (n = 30), T2DM without complications (n = 60), and T2DM with neuropathy (n = 60).Results:The biochemical results exhibited a significant reduction in fasting C-Peptide and activity of Na+/K+ ATPase in T2DM patients with neuropathy followed by T2DM without complication in comparison with healthy controls. ATP1A1 exon2 was amplified by polymerase chain reaction (PCR) then digested by the PstI restriction enzyme, and the obtained data from restriction fragment length polymorphism-PCR and sequencing revealed the existence of a novel synonymous G94A single nucleotide polymorphism (SNP) at nucleotide 27 in exon 2 of ATP1A1 gene (rs1060366). Diabetic groups had only allele A, while the control group had G allele. Interestingly, individuals carrying AA genotype had a significantly lower Na+/K+ ATPase, C-peptide, and higher glycosylated hemoglobin (HBA1c %) than those having GG genotype, suggesting a possible association for this SNP, and this developed phenomenon of not only T2DM but also diabetic neuropathy.Conclusion:Thus, allele A of G94A SNP (rs1060366) could be a risk allele for diabetes susceptibility among Egyptian patients.

The effect of modulation of Na+/К+-АТPase activity on viability of cerebellar granule cells exposed to oxidative stress in vitro

Introduction. Oxidative stress is an important pathogenic factor in cerebral ischemia, which occupies one of the leading places among various forms of cerebral pathology in mortality and disability of the working-age population and is recognized as an actual problem of experimental and clinical neurology. Naturally, modeling of neurodestructive processes and their correction under the action of oxidative stress in vitro contributes to the study of protective mechanisms that counteract ischemic damage of neurons. Objective. To reveal the influence of chemical preconditioning induced by transient inhibition of Na + /K + -ATPase activity on tolerance of cultured cerebellar granule neurons to oxidative stress at different stages of their differentiation in vitro. Materials and methods. The activity of Na + /K + -ATPase was inhibited with ouabain, which was added at 3–4 and 7–8 days in vitro to cerebellar cell cultures of 7-day rats at a concentration of 0.1 mM for 24 hours before induction of oxidative stress by hydrogen peroxide (0.05 and 0.075 mM, 4 hours) or paraquat (0.15 and 0.2 mM, 24 hours). Results. Oxidative stress induced by paraquat causes the most pronounced death of cultured granular neurons in immature (3–4 days) cultures, in which survival was 44±2,5% of neurons, compared to mature (7–8 days) cultures, in which survival was 61±5,4%. Pretreatment of cultures with ouabain has a protective effect, the most significant in mature cultures. The exposure of mature cultures with hydrogen peroxide kills more than 90% of neurons, whereas pretreatment with ouabain increases the survival rate by 44%. At the same time in the immature cultures the damaging effects of H 2 O 2 and the protective effect of ouabain is less pronounced. Conclusion. The increased tolerance of cultured cerebellar granule cells to oxidative stress after transient inhibition of Na + /K + -ATPase activity by ouabain is shown. The direct dependence of the efficiency of the ouabain protection on the degree of neuronal morphochemical differentiation in vitro is revealed.