Differential Protein Expressions in Virus-Infected and Uninfected Trichomonas vaginalis

Protozoan viruses may influence the function and pathogenicity of the protozoa. Trichomonas vaginalis is a parasitic protozoan that could contain a double stranded RNA (dsRNA) virus, T. vaginalis virus (TVV). However, there are few reports on the properties of the virus. To further determine variations in protein expression of T. vaginalis, we detected 2 strains of T. vaginalis; the virus-infected (V⁺) and uninfected (V⁻) isolates to examine differentially expressed proteins upon TVV infection. Using a stable isotope N-terminal labeling strategy (iTRAQ) on soluble fractions to analyze proteomes, we identified 293 proteins, of which 50 were altered in V⁺ compared with V⁻ isolates. The results showed that the expression of 29 proteins was increased, and 21 proteins decreased in V⁺ isolates. These differentially expressed proteins can be classified into 4 categories: ribosomal proteins, metabolic enzymes, heat shock proteins, and putative uncharacterized proteins. Quantitative PCR was used to detect 4 metabolic processes proteins: glycogen phosphorylase, malate dehydrogenase, triosephosphate isomerase, and glucose-6-phosphate isomerase, which were differentially expressed in V⁺ and V⁻ isolates. Our findings suggest that mRNA levels of these genes were consistent with protein expression levels. This study was the first which analyzed protein expression variations upon TVV infection. These observations will provide a basis for future studies concerning the possible roles of these proteins in host-parasite interactions.

Maslinic acid modulates glycogen metabolism by enhancing the insulin signaling pathway and inhibiting glycogen phosphorylase / 中国天然药物

AIM@#To investigate the molecular signaling mechanism by which the plant-derived, pentacyclic triterpene maslinic acid (MA) exerts anti-diabetic effects.@*METHOD@#HepG2 cells were stimulated with various concentrations of MA. The effects of MA on glycogen phosphorylase a (GPa) activity and the cellular glycogen content were measured. Western blot analyses were performed with anti-insulin receptor β (IRβ), protein kinase B (also known as Akt), and glycogen synthase kinase-3β (GSK3β) antibodies. Activation status of the insulin pathway was investigated using phospho-IRβ, as well as phospho-Akt, and phospho-GSK3β antibodies. The specific PI3-kinase inhibitor wortmannin was added to the cells to analyze the Akt expression. Enzyme-linked immunosorbent assay (ELISA) was used to measure the effect of MA on IRβ auto-phosphorylation. Furthermore, the effect of MA on glycogen metabolism was investigated in C57BL/6J mice fed with a high-fat diet (HFD).@*RESULTS@#The results showed that MA exerts anti-diabetic effects by increasing glycogen content and inhibiting glycogen phosphorylase activity in HepG2 cells. Furthermore, MA was shown to induce the phosphorylation level of IRβ-subunit, Akt, and GSK3β. The MA-induced activation of Akt appeared to be specific, since it could be blocked by wortmannin. Finally, MA treatment of mice fed with a high-fat diet reduced the model-associated adiposity and insulin resistance, and increased the accumulated hepatic glycogen content.@*CONCLUSION@#The results suggested that maslinic acid modulates glycogen metabolism by enhancing the insulin signaling pathway and inhibiting glycogen phosphorylase.

Short-Cut Pathway to Synthesize Cellulose of Encysting Acanthamoeba

The mature cyst of Acanthamoeba is highly resistant to various antibiotics and therapeutic agents. Cyst wall of Acanthamoeba are composed of cellulose, acid-resistant proteins, lipids, and unidentified materials. Because cellulose is one of the primary components of the inner cyst wall, cellulose synthesis is essential to the process of cyst formation in Acanthamoeba. In this study, we hypothesized the key and short-step process in synthesis of cellulose from glycogen in encysting Acanthamoeba castellanii, and confirmed it by comparing the expression pattern of enzymes involving glycogenolysis and cellulose synthesis. The genes of 3 enzymes, glycogen phosphorylase, UDP-glucose pyrophosphorylase, and cellulose synthase, which are involved in the cellulose synthesis, were expressed high at the 1st and 2nd day of encystation. However, the phosphoglucomutase that facilitates the interconversion of glucose 1-phosphate and glucose 6-phosphate expressed low during encystation. This report identified the short-cut pathway of cellulose synthesis required for construction of the cyst wall during the encystation process in Acanthamoeba. This study provides important information to understand cyst wall formation in encysting Acanthamoeba.

Plasma levels of N-terminal pro-brain natriuretic peptide and glycogen phosphorylase isoenzyme BB in neonates with asphyxia complicated by myocardial injury / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To investigate the changes and the clinical significance of N-terminal pro-brain natriuretic peptide (NT-proBNP) and glycogen phosphorylase isoenzyme BB (GPBB) levels in neonates with asphyxia complicated by myocardial injury.</p><p><b>METHODS</b>Sixty-four neonates with asphyxia (39 mild, 25 severe) were enrolled. Of the 64 neonates, 30 had myocardial injury and 34 did not develop myocardial injury. Twenty-five healthy neonates served as a control group. Plasma levels of NT-proBNP and GPBB were measured using ELISA. Myocardial enzymes and cardiac troponin I were stimultaneously measured, and electrocardiography and chest radiographs were obtained.</p><p><b>RESULTS</b>The plasma levels of NT-proBNP and GPBB in neonates with myocardial injury were significantly higher than those in neonates without myocardial injury and in the control group (P<0.01). The neonates with severe asphyxia had significantly increased plasma NT-proBNP and GPBB concentrations compared to those with mild asphyxia and the control group (P<0.01). Spearman rank correlation analysis showed that plasma NT-proBNP level was positively correlated with plasma GPBB level in neonates with asphyxia. Plasma levels of NT-proBNP and GPBB were also positively correlated with plasma levels of CK-MB, CK and LDH (P<0.01).</p><p><b>CONCLUSIONS</b>Both NT-proBNP and GPBB can be used as biomarkers of myocardial injury in neonates with asphyxia. The measurement of plasma NT-proBNP and GPBB levels was useful in early identification of myocardial injury and severity evaluation in neonates with asphyxia.</p>

Impact of copper on the oxidative metabolism of the fry of common carp, Cyprinus carpio (Linn.) at different pH.

In order to evaluate the impact of copper on the energetics of a fish, the levels of glucose, glycogen, pyruvate and lactate, the rate of tissue oxygen consumption and the activities of glycogen phosphorylase, isocitrate dehydrogenase (ICDH), succinate dehydrogenase (SDH) and lactate dehydrogenase (LDH) were estimated in the whole body of the fry of Cyprinus carpio immediately after 1, 7, 15 and 30 days on exposure to a sublethal concentration of copper 0.08 mgl(-1) at pH 7.5 (normal), 6.0 (weak acidic) and 9.0 (weak alkaline). Aprogressive increase in glucose level and glycogen phosphorylase activity with the corresponding decrease in glycogen level over the time of exposure at pH 7.5 indicated glycogenolysis. Increase in the rate of oxygen consumption, pyruvate level and ICDH and SDH activities at days 1 and 7 (day 1 > 7) followed by their decrease at days 15 and 30 (day 15 < 30) at pH 7.5 indicated an initial elevation in the energetics of the fish fry with a gradual suppression of it on prolonged exposure. During this period the animal might have relied more on energetically less efficient glycolysis as evident by the progressive increase in the level of lactate and LDH activity. The degree of glycogenolysis was relatively more at pH 6.5 than at pH 7.5. At that pH, a progressive decrease in glucose level with an increase in the pyruvate and lactate levels and in LDH activity and a decrease in the rate of oxygen consumption and ICDH and SDH activities revealed greater reliance of the fish on anaerobic glycolysis than on oxidative metabolism. At pH 9.0 also the fish fry initially exhibited glycogenolysis, but gradually it came to normal on day 30 (day 1 > 7 > 15 > 30). Decrease in the glucose level, increase in pyruvate level, rate of oxygen consumption, and ICDH and SDH activities at all the days of exposure suggested an elevation in oxidative metabolism, but it also came to normal on prolonged exposure. Even the lactate level and LDH activity initially increased but gradually reached to normal on day 30. These results indicated that copper suppresses the energetics of the fish fry at pH 6.0, elevates at pH 9.0 relative to the changes at pH 7.5 suggesting that the toxicity of copper is dependent on pH of the water.

Role of pectin from cucumber (Cucumis sativus) in modulation of protein kinase C activity and regulation of glycogen metabolism in rats.

The regulatory role of protein kinase C (PKC) in glycogen metabolism in pectin fed rats was investigated. Administration of pectin (5 g/kg body wt/day) from cucumber (Cucumis sativius L.) led to inhibitory effects on PKC activity in the liver of rats. In the brain and pancreas, PKC activity was significantly higher in pectin-treated rats as compared to the control group. Level of blood glucose was significantly lowered and the level of glycogen in the liver was significantly increased in pectin-administered rats. Glycogen synthase activity was enhanced, while glycogen phosphorylase enzyme showed inhibition in pectin-treated rats. Results indicated that pectin administration might have caused an increase in the secretion of the insulin, which, in turn, had a stimulatory effect on the PKC activity in the pancreas. The decreased PKC activity in the liver and increased PKC activity in the brain and pancreas on pectin administration indicated enhanced glycogenesis and reduced glycogenolysis.

Glicogênio-fosforilase: marcador promissor de infarto do miocárdio? / Glycogen phosphorylase: promising marker of acute myocardial infarction?

A glicogênio-fosforilase (GP) é uma enzima que participa do processo de glicogenólise, fundamental em casos de isquemia e hipoxia tissular. Possui três isoenzimas, sendo que a GPBB tem despertado muito interesse dos pesquisadores por estar presente de forma representativa no miocárdio, podendo tornar-se um futuro marcador de infarto. Seus níveis séricos elevam-se nas primeiras horas do início dos sintomas e retornam aos valores normais em 24 a 48 horas, demonstrando-se muito sensível. A especificidade da GPBB só não é confiável quando o paciente apresenta danos cerebrais concomitantes, isso porque a predominância da GPBB no organismo humano é no cérebro. Vários autores têm realizado extensa revisão do tema, abordando os principais aspectos desse possível novo marcador.

Infarto agudo do miocárdio no pós-operatório imediato / Perioperative myocardial infarction post cardiac surgery

A cirurgia de revascularização miocárdica tem avançado em tecnologia, anestesia, novas filosofias de tratamento intensivo, melhora do manuseio médico e proteção miocárdica, o que permitiu sua aplicação a pacientes mais idosos e de mais alto risco. Entretanto, esse procedimento não ocorre sem complicações e o infarto perioperatório é uma delas. Seu diagnóstico, porém, é difícil, pois o fato de os sintomas de dor torácica e dispnéia serem comuns nessa população limita a avaliação clínica. O eletrocardiograma possui papel diagnóstico importante quando apresenta novas ondas Q patológicas, mas as alterações do segmento ST e da onda T são inespecíficas. Os marcadores bioquímicos de lesão miocárdica elevam-se na maioria dos pacientes submetidos a cirurgia cardíaca secundária ao próprio manuseio do coração. Desse modo, os níveis de referência para o diagnóstico de infarto do miocárdio perioperatório deverão ser mais elevados que para os níveis de infarto espontâneo e definidos conforme o marcador utilizado em uma população específica. O estudo ecocardiográfico que demonstre nova área de acinesia comparativamente a estudos pré-cirúrgicos é um método sensível para o diagnóstico de isquemia perioperatória e infarto. A cintilografia miocárdica com pirofosfato de tecnécio é mais sensível, principalmente para o diagnóstico de pequenas áreas de necrose. Estudos têm demonstrado que o infarto perioperatório é um preditor de pior evolução a longo prazo após a revascularização miocárdica.

Tests for Acute Coronary Syndrome / 영남의대학술지

The enzyme activities of creatine kinase(CK), its isoenzyme MB(CK-MB) and of lactate dehydrogenase isoenzyme 1(LD-1) have been used for years in diagnosing patients with chest pain in order to differentiate patients with acute myocardial infarction(AMI) from non-AMI patients. These methods are easy to perform as automated analyses, but they are not specific for cardiac muscle damage. During the early 90's the situation changed. First, creatine kinase MB mass(CK-MB mass) replaced the measurement of CK-MB activity. Subsequently cardiac-specific proteins, troponin T(cTnT) and troponin I(cTnI) appeared and displacing LS-1 analysis. However troponin concentration in blood increase only from four to six hours after onset of chest pain. Therefore a rapid marker such as myoglobin, fatty acid binding protein or glycogen phosphorylase BB could be used in early diagnosis of AMI. On the other hand, CK-MB isoforms alone may also be useful in rapid diagnosis of cardiac muscle damage. Myoglobin, CK-MB mass, cTnT and cTnI are nowadays wisely used in diagnosing patients with acute chest pain. Myoglobin is not cardiac-specific and therefore requires supplementation with some other analysis such as troponins to support the myoglobin value. Troponins are very highly cardiac-specific. Only the sera of some patients with severe renal failure, which requires hemodialysis, have elevated cTnT and/or cTnI without there being any evidence of cardiac damage. The latest studies have shown that elevated troponin levels in sera of hemodialysis patients point to an increased risk of future cardiac events in a similar manner to the elevated troponin values in sera of patiets with unstable angina pectoris. In addition, the bedside tests for cTnT and cTnI alone or together with myoglobin and CK-MB mass can be used instead of quantitative analyses in the diagnosis of patients with chest pain. These rapid tests are easy to perform and they do not require expensive instrumentation. For the diagnosis patients with chest pain, routinely myoglobin and CK-MB mass measurements should be performed whenever they are requested (24 h/day) and cTnT and cTnI on admission to the hospital and then 4-6 and 12 hours later and maintained less than 10% imprecision.

Determinação da atividade da fosforilase do glicogênio para o diagnóstico de doenças de estocagem do glicogênio / Determination of the glycogen phosphorylase activity for the glycogen storage diseases diagnostic

A enzima fosforilase do glicogênio (E.C.2.4.1.1.) catalisa a quebra fosforilítica das ligações a(1,4) do glicogênio, produzindo glicose 1 –fosfato e uma dextrina limite. Esta enzima existe sob a forma inativa (b), desfosforilada, e a forma (a), ativa e fosforilada. O déficit em fosforilase é transmitido pelo modo autossômico recessivo e é denominado de doença de Hers, quando o órgão atingido é o fígado e doença de Mc Ardie, quando a musculatura esquelética é afetada. Neste trabalho é desenvolvido um método para a determinação da atividade da fosforilase do glicogênio possibilitando, assim, o diagnóstico laboratorial das doenças de estocagem de glicogênio produzidas pela deficiência desta enzima.