Lactic Acid Dehydrogenase Activity Research Articles

Early immune response of neuronal cells (U87) to heavy metal Cd or Pb exposure.

Heavy metals such as lead (Pb) and cadmium (Cd) exist as particulate matter (PM) in the air and can cause biological damage to cells, animals, and humans. However, the mechanism underlying the toxic effects of heavy metals on nerve cells has not yet been completely identified. Glioma is the most common and fatal tumor in the central nervous system; the U87 human glioblastoma cell line is commonly used when researching brain cancer, including aggressive malignant gliomas. Therefore, in this study, cell viability, cytotoxicity, and interleukin-6 (IL-6) levels were analyzed to confirm the effect of Cd and Pb exposure on U87 cells. On confirming the absence of significant effects on cell viability at low concentrations of heavy metals, Cd and Pb exposure had no effect on lactic acid dehydrogenase (LDH) activity at the concentrations (1 μg/L, 30 μg/L, and 1 mg/L) used in this study, and there was a remarkable effect of Cd and Pb exposure on the inflammatory response of these cells. Our findings provide a basis for future research elucidating the effects of heavy metal exposure on cellular pathology. Systematic studies with higher heavy metal concentrations and precision are warranted to deepen our understanding of the relationship between heavy metal exposure and neuronal responses.

Toxicological Studies on the Sinai Plant Urginea maritima (Scilla) in Wistar Albino Rats

The varied toxicity of Urginea maritima (a plant that grows in north Sinai) on Wistar albino rats was investigated. Twenty-four rats weighing 100±20 gm. were divided into 4 groups, the first group, which included six male rats, and the second group, which included six female rats, were given di-methyl sulfoxide orally for 45 consecutive days and were regarded as the control groups. The third group included six male rats who received 36 mg/kg B.W (1/20 LD50 from the alcoholic extract of Urginea maritima) for 45 days in succession. The fourth group was made up of six female rats who received a daily dose of 26 mg/kg B.W (1/20 LD50 of the alcoholic Urginea maritima extract) for 45 successive days. Serum samples were taken for biochemical study after the end of the experiment, and sciatic nerve, heart, and brain tissues were also taken for histopathological analysis. The findings demonstrated significant changes in the exposed animals' serum levels of calcium (Ca++), sodium (Na+), and potassium (K+) ions. While serum K+ levels dramatically increased, serum Ca++ and Na+ levels significantly dropped. Lactic acid dehydrogenase (LDH) and serum creatine kinase (CK-MB) activities also significantly increased. In addition, pathological alterations in the heart, brain, and sciatic nerve were discovered when compared to control groups.

The significance of thymoquinone administration on liver toxicity of diazinon and cholinesterase activity; a recommendation for prophylaxis among individuals at risk

BackgroundDiazinon (DZN), a widely used chemical herbicide for controlling agricultural pests, is an important organophosphorus pesticide and an environmental pollutant which induces toxic effects on living organisms during long-term exposure. Thymoquinone (TQ) is a phytochemical bioactive compound with antioxidant and anti-inflammatory properties. We aimed to evaluate the protective effects of TQ against DZN-induced hepatotoxicity through alleviating oxidative stress and enhancing cholinesterase (ChE) enzyme activity.MethodsRats were randomly divided into six groups (n = 8); a negative control group receiving corn oil; a group only receiving DZN (20 mg/kg/day); a group treated with TQ (10 mg/kg/day), and three treatment groups as TQ + DZN, receiving different doses of TQ (2.5, 5, and 10 mg/kg/day). All experimental animals were orally treated for 28 consecutive days. The levels of superoxide dismutase (SOD), glutathione (GSH), malondialdehyde (MDA), alanine transaminase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), and lactic acid dehydrogenase (LDH) were determined. In addition, ChE activity and histopathological changes were evaluated.ResultsThe results showed that DZN decreased GSH level (p < 0.01) and SOD activity (p < 0.01) in parallel to an increase in MDA level (p < 0.01) and increased the activity of AST, ALT, ALP, and LDH (p < 0.01) in comparison to the negative control group. Our findings demonstrated that TQ administration could diminish hepatotoxicity and reduce oxidative damage in DZN-treated rats, which could be linked to its antioxidant and free radical scavenging properties. It was also observed that TQ 10 mg/kg remarkably increased the activity of acetylcholinesterase, butyrylcholinesterase, and SOD enzymes, elevated GSH, decreased MDA, and reduced pathological alternations of the liver induced by DZN.ConclusionThymoquinone 10 mg/kg increased the activity of plasma and blood cholinesterases and reduced DZN-induced alternations of the liver. Improvement of butyryl- and acetylcholinesterase activity suggests that maybe TQ supplement could be beneficial as pre-exposure prophylaxis among farm workers spraying pesticides.

Protective Effects and Mechanisms of Melatonin on Stress Myocardial Injury in Rats.

Prolonged and intense stress can exceed the body's normal self-regulation and limited compensatory and repair capacity, resulting in pathological damage to the body. In this study, we established a rat stress myocardial injury (SMI) model to explore the protective effect of melatonin (MLT) on SMI and its possible mechanisms of action. Adult female Sprague Dawley (SD) rats were randomly divided into 5 groups: blank control group (NC), SMI group, MLT low-dose group, MLT medium-dose group, and MLT high-dose group, and 10 rats in each group were used to establish a SMI model by the water immersion restraint method. We observed the changes in body weight and tail vein glucose of each group. Serum levels of corticosterone (Cort), creatine kinase isoenzyme (CK-MB), and Troponin Ⅰ (Tn-Ⅰ) and activity of lactic acid dehydrogenase were measured by ELISA. Transcriptome sequencing was used to find differentially expressed genes in the control and model groups, and the results were verified by real-time fluorescence quantitative polymerase chain reaction (RT-qPCR). HE staining was used to visualize the pathological changes in the heart tissue of each group, and Western blot was used to study the differences in protein expression in the cardiomyocytes of each group to further corroborate the results. The body weight growth rate of rats in the SMI group was significantly lower than that of the NC group ( P < 0.01), and the body weight growth rate of rats in the MLT high-dose group was significantly higher than that of the SMI group ( P < 0.05) with no significant difference compared with the NC group rats. The mean blood glucose of rats in the SMI group was significantly higher compared with the NC group ( P < 0.001), while the mean blood glucose of rats in the MLT administration groups was dose-dependently reduced compared with the SMI group. By RNA-seq and bioinformatics tools such as KEGG and Gene ontology, we found that the circadian clock-related genes Ciart , Arnt1 , Per1 , and Dbp were significantly downregulated in the SMI group during water immersion stress, and differentially expressed genes were enriched in the p38MAPK signaling pathway and p53 signaling pathway. Moreover, genes related to inflammation and apoptosis were differentially expressed. ELISA results showed that Cort, CK-MB, and Tn-Ⅰ levels were significantly higher in the SMI group compared with the NC group ( P < 0.01) and melatonin reduced the levels of Cort, CK-MB, and Tn-Ⅰ and decreased lactic acid dehydrogenase activity in rat serum. HE staining results showed that melatonin could attenuate stress-generated myocardial injury. Western blot showed that melatonin reduced the expression of p38MAPK, p53, Bax, and caspase-3 and increased the expression of Bcl-2 protein in rat heart. Melatonin can inhibit myocardial injury caused by water immersion, and its mechanism of action may be related to the regulation of the expression of circadian clock genes such as Ciart , Arnt1 , Per1 , and Dbp ; the inhibition of the expression of proapoptotic proteins such as p38MAPK, p53, Bax, and caspase-3; and the increase of the expression of Bcl-2 antiapoptotic protein.

Protective effects of active compounds from on heart and brain of mice at simulated high altitude.

To investigate the active compounds from on the heart and brain of mice at simulated high altitude.Fifty healthy male adult BALB/c mice were randomly divided into normal control group, hypoxic model group, acetazolamide group, petroleum ether extract of (PESI) group and octacosan group with 10 mice in each group. Acetazolamide group, PESI group and octacosan group were treated with acetazolamide PESI (200 mg/kg) or octacosan by single tail vein injection, respectively. Except normal control group, the mice were exposed to a simulated high altitude of for in an animal decompression chamber. After the mice were sacrificed by cervical dislocation, the heart and brain were histologically observed by HE staining; superoxide dismutase (SOD) activity, total anti-oxidant capacity (T-AOC) and the content of malondialdehyde (MDA) in plasma, heart and brain tissues were detected by WST-1 method, ABTS method and TBA method, respectively; lactic acid and lactate dehydrogenase (LDH) activity in plasma, heart and brain tissues were detected by colorimetric method and microwell plate method, respectively; ATP content and ATPase activity in heart and brain tissues were detected by colorimetric method. PESI and octacosane significantly attenuated the pathological damages of heart and brain tissue at simulated high altitude; increased SOD activity, T-AOC and LDH activity, and decreased the contents of MDA and lactic acid in plasma, heart and brain tissues; increased the content of ATP in heart and brain tissues; increased the activities of Na-K ATPase, Mg ATPase, Ca ATPase and Ca-Mg ATPase in myocardial tissue; and increased the activities of Mg ATPase, Ca-Mg ATPase in brain tissue. PESI and octacosan exert anti-hypoxic activity by improving the antioxidant capacity, reducing the free radical levels, promoting the anaerobic fermentation, and alleviating the energy deficiency and metabolic disorders caused by hypoxia in mice.

A Study of Arginase Expression in Chronic Non-healing Wounds.

Arginase expression has been recently shown to increase in numerous disease states like neurodegeneration, inflammation, and malignancies. Although it has been found to be functionally important in various disease pathologies, little is known about its role in wound healing. Here, we look at the expression of arginase and its isoforms in chronic non-healing wounds and also study the expression of nitric oxide synthase (NOS) and oxidative stress enzymes in them. Wound tissues and blood samples were collected at the time of index presentation and follow-up from 61 chronic non-healing wound cases. The expression patterns of arginase isoenzymes, NOS, superoxide dismutases (SOD), lactic acid dehydrogenase (LDH), and catalase were examined by using enzyme-linked immunosorbent assay, immunohistochemistry, and western blot analysis at the transcript and protein level. We reported a significant decrease of serum arginase levels in chronic nonhealing wounds in the progress of wound healing. Interestingly, tissue arginase levels were found to be increased with improved wound condition at follow-up. Tissue NOS, LDH, and catalase activity were also found to be increased with the progress of healing, whereas SOD levels were downregulated. Our findings reported increased expression at the transcript level of arginase-I and arginase-II in chronic non-healing wounds for the first time. In conclusion, we observed decreased serum arginase levels in completely healed patients as compared to non-healed cases. Our study findings support the hypothesis that inhibition of the activity of arginase delays wound healing. Arginase and iNOS may also find their place in the future as possible biomarkers for wound healing.

Remifentanil protects against myocardial ischemia/reperfusion injury via miR-205-mediated regulation of PINK1.

Myocardial ischemia/reperfusion (I/R) injury could lead to severe cardiovascular ischemic disease, including myocardial infarction and contractile dysfunction. Remifentanil demonstrated protective effect on myocardial I/R injury. The underlying pathophysiological mechanism was then investigated in this study. In the current study, primary cardiomyocytes were isolated from rats, and then preconditioned with remifentanil. Rats, tail vein injected with miR-205 antagomir, were subjected to infusion of remifentanil, and then subjected to regional ischemia followed by reperfusion. The results demonstrated that cell viability of hypoxia/reoxygenation-induced cardiomyocytes was increased post remifentanil, while the apoptosis was decreased accompanied with reduced cleaved caspase-3 expression. Hypoxia/reoxygenation treatment increased miR-205 and decreased PINK1 (PTEN induced putative kinase 1) expression. However, preconditioning with remifentanil reduced miR-205 and enhanced PINK1. Moreover, over-expression of miR-205 decreased PINK1 expression and counteracted the effects of remifentanil-induced increase of cell viability and decrease of cell apoptosis in hypoxia/reoxygenation-induced cardiomyocytes. Injection with miR-205 antagomir improved remifentanil-induced decrease of infarct size and LDH (lactic acid dehydrogenase) activity in rat model with I/R injury. In conclusion, miR-205 might participate in the protective effect of remifentanil in rat myocardial I/R injury via regulation of PINK1, providing a potential target for amelioration of cardiovascular ischemic disease.

Systematic Analysis of tRNA-Derived Small RNAs Discloses New Therapeutic Targets of Caloric Restriction in Myocardial Ischemic Rats.

Caloric restriction (CR) is a novel dietary therapy that has a protective effect on myocardial ischemia. However, the mechanisms underlying the therapeutic effect of CR remain unclear. Transfer RNA–derived small RNAs (tsRNAs) are a novel type of short non-coding RNAs that have potential regulatory functions in various physiological and pathological processes. In this study, we explored new therapeutic targets of CR through tsRNA sequencing. Rats were randomly divided into three groups: a normal control group (norm group), isoproterenol (ISO)–induced myocardial ischemic group (MI group), and CR pretreatment plus ISO-induced myocardial ischemic group (CR + MI group). Triphenyl tetrazolium chloride staining, terminal deoxynucleotidyl transferase dUTP nick-end labeling staining, serum creatine kinase (CK) and lactic acid dehydrogenase activity detection kits, and creatine kinase isoenzyme 1 levels were used to measure the degree of myocardial ischemic injury. These indicators of myocardial ischemia were significantly improved in the CR + MI group compared with those in the MI group. In the ischemic myocardial tissue of the MI group, a total of 708 precisely matched tsRNAs were identified, and 302 tsRNAs (fold change >1.5, P < 0.05) were significantly changed when compared with those in the norm group. Furthermore, 55 tsRNAs were significantly regulated by CR pretreatment, among which five tsRNAs (tiRNA-His-GTG-004, tRF-Gly-TCC-018, tRF-Cys-GCA-022, tRF-Lys-CTT-026, tRF-Met-CAT-008) were randomly selected and verified by quantitative real-time polymerase chain reaction. In addition, predictions of target genes and bioinformatics analysis indicated that these tsRNAs may play a therapeutic role through the regulation of macromolecular metabolism. In conclusion, our findings reveal that tsRNAs are potential therapeutic targets for CR pre-pretreatment to improve myocardial ischemic injury. This study provides new ideas for future research on elucidating the mechanisms of CR pretreatment in ameliorating myocardial ischemic injury.

MiR-8-3p regulates hyperthermia-induced lactate secretion by targeting PPP2R5B in boar Sertoli cells.

Lactate produced by glycolysis in Sertoli cells (SCs) is the main energy substrate for developing germ cells and plays a vital role in spermatogenesis. MicroRNAs (miRNAs) function as posttranscriptional regulators of gene expression in biological processes. We have previously shown that hyperthermia (43°C, 30 min) promotes lactate secretion by inhibiting phosphorylation of adenosine monophosphate-activated protein kinase (AMPK) in cultured immature boar SCs. However, it is unclear whether miRNAs are involved in AMPK-modulated glycolysis in SCs. In the present study, we identified 349 miRNAs (227 upregulated and 122 downregulated) in hyperthermia-treated boar SCs by next-generation high-throughput RNA sequencing. MiR-8-3p, which was found to be a novel upregulated miRNA in hyperthermia-treated SCs, suppressed the expression of AMPK upstream genes (protein phosphatase 2 subunit B, PPP2R5B), and further downregulated the expression of p-AMPK. The miR-8-3p mimic upregulated expression of glucose transporter 3, lactate dehydrogenase A and monocarboxylate transporter 1, and increased lactic acid dehydrogenase activity, lactate secretion, and ATP depletion in SCs; the miR-8-3p inhibitor had the opposite effects on these parameters. Our findings indicate that miR-8-3p acts as a novel regulator of AMPK-modulated lactate secretion by targeting PPP2R5B in hyperthermic boar SCs.

Calpain silencing alleviates myocardial ischemia-reperfusion injury through the NLRP3/ASC/Caspase-1 axis in mice

AimsPrior to reperfusion, Calpains remain inactive due to the acidic pH and elevated ionic strength in the ischemic myocardium; but Calpain is activated during myocardial reperfusion. The underlying mechanism of Calpain activation in the ischemia-reperfusion (I/R) is yet to be determined. Therefore, the present study aims to investigate the mechanism of Calpain in I/R-induced mice. Main methodsIn order to detect the function of Calpain and the NLRP3/ASC/Caspase-1 axis in cardiomyocyte pyroptosis, endoplasmic reticulum (ER) stress and myocardial function, the cardiomyocytes were treated with hypoxia-reoxygenation (H/R), and NLRP3 were silenced, Calpain was overexpressed and Caspase-1 inhibitors were used to determine cardiomyocyte pyroptosis. The results obtained from the cell experiments were then verified with an animal experiment in I/R mice. Key findingsThere was an overexpression in Calpain, ASC, NLRP3, GRP78 and C/EBP homologous protein (CHOP) in cardiomyocytes following H/R. A significant increase was witnessed in lactic acid dehydrogenase (LDH) activity, cardiomyocyte pyroptosis rate, Calpain activity, reactive oxygen species (ROS) concentration, as well as activation of ER stress in cardiomyocytes after H/R. However, opposing results were observed in H/R cardiomyocytes that received siRNA Calpain, siRNA NLRP3 or Caspase-1 inhibitor treatment. Overall, the results obtained from the animal experiment were consistent with the results from the cell experiment. SignificanceThe silencing of Calpain suppresses the activation of the NLRP3/ASC/Caspase-1 axis, thus inhibiting ER stress in mice and improving myocardial dysfunction induced by I/R, providing a novel therapeutic pathway for I/R.

PB1702 EXPRESSION OF ANGIOTENSIN‐CONVERTING ENZYME IN PATIENTS WITH ACUTE LEUKEMIAS

Background:Blast cells are characterized by aberrant expression normal markers of early hematopoietic progenitor cells (HPC). Angiotensin‐converting enzyme (ACE/CD143), a key regulator of renin‐angiotensin system, was shown to be expressed in blood‐forming tissues of the human embryo and primitive human HPC. Recent studies indicated that CD143 is over‐expressed in leukemic myeloid blast cells.Aims:To evaluate the surface expression of CD143 in blast cells in patients with newly diagnosed acute leukemia (AL).Methods:The expression of CD143 was estimated in patients with newly diagnosed untreated acute leukemia, using eight‐color flow cytometry. The blast gate was defined on the basis of CD45dim expression and side‐scatter characteristics. Anti‐CD143 monoclonal antibody (clone BB9, BD) conjugated with phycoerythrin was used for analysis of CD143 expression. The percentage of positive cells (PPC) and the mean fluorescence intensity (MFI) was applied to describe expression. The expression of CD143 was devided into three groups according range of PPC ≤1%, 1 – 20 %, and ≥20 %.Results:A total of untreated 68 patients with newly diagnosed acute leukemia were included in the study group. They were diagnosed with non‐promyelocytic acute myeloid leukemia (non‐APL AML) – 35 (51.5 %), of them 3 (8.5 %) patients were related to favorable genetic group, 9 (25.7 %) – intermediate, 23 (65.8 %) – adverse; promyelocytic leukemia (APL) – 10 (14.7 %); B acute lymphoblastic leukemia/lymphoma (B‐ALL) – 13 (19.1 %), including 2 patients with Ph‐positive B‐ALL; T acute lymphoblastic leukemia/lymphoma (T‐ALL) – 10 (14.7 %), including 2 cases of early T‐precursor ALL (ETP). Median age of patients was 35.5 years, 29 male, 39 female.In total group with CD143 expression with PPC≥20% was observed in 7% (5/68) of all cases AL. CD143 expression in non‐APL AML with a range of PPC 1 – 20 % was detected in 12/35 cases (34.2 %), PPC ≥20 % was observed in 2/35 cases with complex karyotype (5.7 %). In group with APL 2/10 (20 %) patients had 1 – 20%, and 2/10 (20 %) patients had &gt;20 %. Among T‐ALL only 1/10 (10 %) had a CD143 expression. ACE expression in B‐ALL was absent (defined as ≤1 %). Median MFI of ACE expression was higher in patients with APL – 477 (range 159 – 4796) than in non‐APL AML ‐ 175 (range 43 – 3253). CD143 expression with PPC≥1% was significantly higher in patients with AML (non‐APL AML and APL), than in ALL (B‐ and T‐ALL), 40 % (18/45) vs. 4.3 % (1/23) (p = 0.0016).Summary/Conclusion:Thus, CD143 expression with PPC≥20% was observed only in 7% (5/68) of all cases AL, 2 was observed in AML with PML‐RARA, 2 ‐ AML with complex karyotype and 1 in ETP‐ALL. No expression of CD143 was detected in B‐ALL. CD143 expression was significantly higher in myeloid blast cells than lymphoid. No correlation was found between the expression of ACE and age, sex, neuroleukemia, leucocytes count, bone marrow blasts, lactic acid dehydrogenase activity and cytogenetic abnormalities in different subgroups. The significance of CD143 expression in AL is not completely clear and has to be studied.

PB2156 RISK FACTORS ASSOCIATED WITH EARLY MORTALITY IN PATIENTS WITH MULTIPLE MYELOMA

Background:Early mortality (EM) in multiple myeloma (MM) ranges from 4% to 25% mostly depending on the patients included and on treatment options. EM tends to be lower in clinical trials including younger, transplant‐eligible patients or in bortezomib‐ and lenalidomide‐based regimens in comparison with elderly patients and conventional chemotherapy treatment.Aims:To estimate risk factors associated with EM in patients with newly diagnosed MM.MethodsPatients with newly diagnosed MM were included into the study (from Jan 2013 to Feb 2019). EM was defined if it occurred within 1 year of entry into the study. Adverse cytogenetic abnormalities were specified as gain(1q), t(4;14), t(14;16), t(14;20) or del(17p).Results:A total of 174 patients with newly diagnosed MM (82 male, 92 female; median age 61 years) were involved in the study. Follow‐up period was 1‐71.4 months (median 8 months). The majority of patients developed an advanced stage of disease (Duriе‐Salmon stage 3–141 (81.1%), ISS stage 3–99 (56.9%)). All patients received chemotherapy regimens containing proteasome inhibitors as first‐line therapy and immunomodulatory drugs, intensive and conventional chemotherapy regimens as second‐ or next‐line therapy. During follow‐up period fatal outcome was observed in 45 (25.9%) of 174 patients, of them 16 (9.2%) patients with EM. Median early mortality was 4.7 months. The age of patients with EM and patients survived &gt; 1 year was comparable (median age 64.5 vs. 61, respectively). A larger proportion of patients with EM had Durie‐Salmon stage 3 (93.8% vs 79.7%), ISS stage 3 (75.0% vs 55.1%). Fish in situ hybridization analysis was conducted in 126 (72.4%) patients, adverse cytogenetic abnormalities were present in 4/8 (50.0%) patients with EM and 33/118 (27.9%) patients survived &gt;1 year. Risk factors assotiated with EM were ECOG performance status ≥ 3 score (87.5% vs 40.5%, p = 0.0003), C‐reactive protein level &gt; 10 mg/L (62.5% vs 26.6%, p = 0.007), high lactic acid dehydrogenase activity (81.3% vs 46.2%, p = 0.008), platelet count &lt; 150 × 109/L (43.8% vs 18.9%, p = 0.047) (tab.). For the 16 patients with EM, 11 (68.8%) of deaths were related to MM progression, 4 (25.0%) were due to infections and 1 (6.2%) ‐ heart failure.Summary/Conclusion:EM in patients with newly diagnosed MM was 9.2%. Risk factors associated with EM were poor performance status, elevated serum LDH activity, low platelet count, high serum C‐reactive protein.image

Response of AMP-activated protein kinase and lactate metabolism of largemouth bass (Micropterus salmoides) under acute hypoxic stress

To study adaptation of largemouth bass (Micropterus salmoides) to hypoxic stress, we investigated physiological responses and lactate metabolism of the fish under acute hypoxia. The objectives of this study were to (a) observe changes in glucose, glycogen, and lactate content; (b) detect the activity of lactate dehydrogenase (LDH) in serum, brain, heart, and liver tissues; and (c) quantify the dynamic gene expression of AMP activated protein kinase alpha (AMPKα), hypoxia-inducible factor-1 alpha (HIF-1α), monocarboxylate transporter 1 (MCT1), monocarboxylate transporter 4 (MCT4), and lactate dehydrogenase-a (LDHa) following exposure to hypoxia. The fish were subjected to two hypoxia stresses (dissolved oxygen [DO] 1.20 ± 0.2 mg/L and 3.50 ± 0.3 mg/L, respectively) for 24 h. Our results showed that hypoxic stress significantly increased the decomposition of liver glycogen and significantly increased the concentration of blood glucose; however, the muscle glycogen content was not significantly decreased, which indicates that liver glycogen was the main energy source under acute hypoxia. Moreover, hypoxia led to accumulation of a large amount of lactic acid in tissues, possibly due to the activity of lactic acid dehydrogenase, but this process was delayed in the heart and brain relative to the liver. Additionally, hypoxia induced the expression of AMPKα, HIF-1α, MCT1, MCT4, and LDHa, suggesting that glycometabolism had switched from aerobic to anaerobic. Our results contribute to a better understanding of the molecular mechanisms of the response to hypoxia in largemouth bass.

Relationship between various maternal conditions and lactic acid dehydrogenase activity in umbilical cord blood at birth.

Lactic acid dehydrogenase (LDH) is a valuable marker for some of the most important diseases in newborns and the plasma LDH activity in newborns correlates well with conditions such as asphyxia. If LDH should be considered as a useful tool also in obstetric care, key factors associated with maternal health before and during pregnancy which could affect umbilical cord LDH activity need to be known. The aims of this study were to explore relationships between selected maternal conditions and arterial lactic acid dehydrogenase activity (aLDH) in umbilical cord blood at delivery. A prospective observational study was conducted at Sodersjukhuset, Stockholm, Sweden. Included in the study were 1247 deliveries, and cord blood samples from each were analyzed for aLDH. Background, delivery and neonatal data were collected from the medical records. Higher median values of aLDH were found (P=0.001) among women with chronic disorders not related to pregnancy but there was no increased frequency of high aLDH levels (>612 μ/L, P=0.30). No difference in aLDH was identified between infants born to women with pregnancy-related disorders compared with healthy women, neither in median values, nor in high values (>612 μ/L, P=0.95). Newborn infants born to women with non-pregnancy-related chronic disorders had a somewhat higher median value of aLDH in cord blood at delivery. The influence of common maternal conditions and diseases on umbilical cord arterial LDH levels is small compared to the increase reported in fetal distress and several other critical conditions in the newborn.

Effects of heat stress on the liver of the Chinese giant salamander Andrias davidianus: Histopathological changes and expression characterization of Nrf2-mediated antioxidant pathway genes

Nuclear factor E2-related factor 2 (Nrf2) is a crucial transcription factor that regulates the basal and inducible expression of many antioxidant-relevant genes, and the Nrf2-mediated antioxidant pathway has been regarded as a critical switch in the initiation of cellular defence systems against oxidative damages. In this study, Nrf2 was first identified and characterized in the Chinese giant salamander (Andrias davidianus). A. davidianus was exposed to a high ambient temperature of 30 °C for various periods of time (0, 3, 6, 12, 24, 48 and 72 h). We investigated the effects of heat stress on alterations of the hepatic malondialdehyde (MDA) concentration, the activities of lactic acid dehydrogenase (LDH), catalase (CAT), glutathione peroxidase (GPx) and superoxide dismutase (SOD), the histology of the liver, and the mRNA expression patterns of 11 genes involved in the Nrf2-mediated antioxidant pathway in A. davidianus. The results showed that both the hepatic LDH activity and MDA content significantly increased after heat exposure, indicating that heat stress could induce cell injury and oxidative damage. Histological analysis of the liver showed that heat stress caused hepatocyte abnormalities, fat accumulation and ultrastructural alterations of the hepatocytes, endoplasmic reticulum and nuclei. The expression patterns of genes involved in the Nrf2-mediated antioxidant pathway in the liver were distinct when A. davidianus was exposed to heat stress. To the best of our knowledge, this study is the first on the characterization of Nrf2 in A. davidianus and even in amphibians. The results indicated that heat stress could induce oxidative damage, and the Nrf2 antioxidant pathway might play a critical role in the resistance against heat stress in A. davidianus. These findings will deepen and enrich the current knowledge on the evolutionary conserved antioxidant roles and mechanisms of Nrf2 in A. davidianus, or even in amphibians, in the antioxidant defence against heat stress.

Disruption of redox homeostasis in liver function and activation of apoptosis on consumption of aspartame in folate deficient rat model

This study assesses the effect of long-term intake of aspartame on liver function and apoptosis signaling pathway in the Wistar albino rats. Several reports have suggested that methanol is one of the major metabolites of Aspartame. Non-primate animals are usually resistant to methanol-induced metabolic acidosis due to high levels of hepatic folate content; hence a folate deficiency model was induced by treating animals with methotrexate (MTX) prior to aspartame exposure. The aspartame treated MTX animals exhibited a marked significant increase in hepatic alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP) and lactic acid dehydrogenase (LDH) activity compared to controls. Aspartame treated MTX animals additionally exhibited down-regulation of genes namely B-cell lymphoma 2 (Bcl2) expression and up-regulation of Bcl-2-associated X protein (Bax), Fas-associated protein with death domain (FADD) and Caspase 3, 9 genes and apoptotic protein expression, indicating the augmentation of hepatic apoptosis. Nuclear condensation, micro vacuole formation in the cytoplasm and necrosis were observed in the liver of the aspartame treated animals on histopathology evaluation. Additionally, Immunohistochemical analysis revealed a significant increase in positive cells expressing Fas, FADD, Bax and Caspase 9 protein, indicating an increase in apoptotic protein expression in the liver. Thus, Aspartame may act as a chemical stressor which alters the functional status of liver, leading to hepatotoxicity.

Energy metabolism and metabolomics response of Pacific white shrimp Litopenaeus vannamei to sulfide toxicity

The toxicity and poisoning mechanisms of sulfide were studied in Litopenaeus vannamei from the perspective of energy metabolism and metabolomics. The lethal concentrations of sulfide in L. vannamei (LC50) at 24h, 48h, 72h, and 96h were determined. Sulfide at a concentration of 0, 1/10 (425.5μg/L), and 1/5 (851μg/L) of the LC50 at 96h was used to test the metabolic responses of L. vannamei for 21days. The chronic exposure of shrimp to a higher sulfide concentration of 851μg/L decreased shrimp survival but did not affect weight gain or the hepatopancreas index. The glycogen content in the hepatopancreas and muscle and the activity of hepatopancreas cytochrome C oxidase of the shrimp exposed to all sulfide concentrations were significantly lower, and the serum glucose and lactic acid levels and lactic acid dehydrogenase activity were significantly lower than those in the control. Metabolomics assays showed that shrimp exposed to sulfide had lower amounts of serum pyruvic acid, succinic acid, glycine, alanine, and proline in the 425.5μg/L group and phosphate, succinic acid, beta-alanine, serine, and l-histidine in the 851μg/L group than in the control. Chronic sulfide exposure could disturb protein synthesis in shrimp but enhance gluconeogenesis and substrate absorption for ATP synthesis and tricarboxylic acid cycles to provide extra energy to cope with sulfide stress. Chronic sulfide exposure could adversely affect the health status of L. vannamei, as indicated by the high amounts of serum n-ethylmaleamic acid, pyroglutamic acid, aspartic acid and phenylalanine relative to the control. This study indicates that chronic exposure of shrimp to sulfide can decrease health and lower survival through functional changes in gluconeogenesis, protein synthesis and energy metabolism.

Evaluation of Thr6-bradykinin purified from Polybia occidentalis wasp venom in the choline uptake of mammal cortices

Context: Thr6-bradykinin is a peptide found in the venom of social and solitary wasps. This kinin, along with other bradykinin-like peptides, is known to cause irreversible paralysis in insects by presynaptic blockade of cholinergic transmission. However, this activity has never been tested in mammals.Objective: As such, the objective of this study was to evaluate the effect of Thr6-bradykinin on the cholinergic system of rats.Materials and methods: The peptide was isolated from the venom of the Neotropical social wasp Polybia occidentalis Olivier (Vespidae). After correct identification and quantification by ESI-MS and MS/MS, the peptide was tested in [14C]-choline uptake using rat cortical synaptosomes. Each uptake assay was accompanied by lactic acid dehydrogenase (LDH) activity measurement to evaluate synaptosome integrity in the presence of six increasing concentrations of BK or Thr6-BK (0.039, 0.156, 0.625, 2.500, 10.000 and 40.000 μM).Results: Data revealed that neither BK nor Thr6-BK at any of the six concentrations tested (from 0.039 to 40.000 μM) affected [14C]-choline uptake in synaptosomes. Moreover, there was no increase in LDH in the supernatants, indicating that BK and Thr6-BK did not disrupt the synaptosomes.Discussion and conclusion: In contrast to previous reports for the insect central nervous system (CNS), Thr6-BK had no effect on mammalian cholinergic transmission. Nevertheless, this selectivity for the insect CNS, combined with its irreversible mode of action may be relevant to the discovery of new sources of insecticides and could contribute to understanding the role of kinins in the mammalian CNS.

The prognostic significance of surface dipeptidylpeptidase IV (CD26) expression in B-cell chronic lymphocytic leukemia

A number of factors related to B-cell chronic lymphocytic leukemia (B-CLL) patients' prognosis have been identified. However, still some factors better reflecting disease activity in individual cases are explored. The study aimed to evaluate prognostic significance of dipeptidylpeptidase IV/CD26 expression on B-CLL cells and its relationship with other well established prognostic factors. The study included 94 patients with newly diagnosed B-CLL and involved analysis of clinical, laboratory, flow-cytometry and cytogenetic data. Detailed analysis showed that CD26 expression on B-CLL cells correlates with Rai’s clinical stage of the disease at diagnosis (p=0.034), β2-microglobulin concentration (p=0.012), lactic acid dehydrogenase activity (p=0.045) and absolute lymphocytes’ count (p=0.027) in the blood. The multivariate analysis revealed that time to treatment (TTT) was significantly influenced by Rai clinical stage, LDH activity in blood and CD26 expression on B-CLL cell’s. Moreover, in the multivariate analysis restricted to the group of patients with documented cytogenetic risk (n=36) CD26 expression, Rai clinical stage and cytogenetic profile remained their independent impact on TTT. The results of our study indicate that the CD26 expression should be incorporated in B-CLL patients risk assessment along with well known prognostic factors, since it seems to have a relationship with the tumor mass and influences TTT.

Effects of glutamate on growth, antioxidant capacity, and antioxidant-related signaling molecule expression in primary cultures of fish enterocytes.

The present study explored the effects of glutamate (Glu) on the growth, antioxidant capacity, and gene expression of NF-E2-related nuclear factor 2 (Nrf2) signaling molecule in enterocytes of Jian carp (Cyprinus carpio var. Jian). The enterocytes were incubated in media containing 0, 2, 4, 6, 8, and 10mM/L Glu for 96h. The results showed that Glu could promote fish enterocytes proliferation and differentiation. Additionally, activities of alkaline phosphatase, Na(+), K(+)-ATPase, γ-glutamyl transpeptidase, and creatine kinase were significantly improved with the increase in Glu level up to 6mM/L. Lactic acid dehydrogenase activity and malondialdehyde content in the medium and cellular protein carbonyls were depressed by Glu. Moreover, optimum Glu significantly enhanced glutathione content and the activities and gene expression of catalase, glutathione reductase, and glutathione peroxidase in enterocytes. Finally, the expression level of Nrf2 in enterocytes was significantly elevated by appropriate Glu content in the medium. Furthermore, optimum Glu significantly decreased Kelch-like ECH-associated protein 1 mRNA level in enterocytes. In conclusion, Glu improved the proliferation, function, and antioxidant capacity and regulated antioxidant-related signaling molecule expression of fish enterocytes.