Purification and characterization of phosphoenolpyruvate carboxykinase from<i>Raillietina echinobothrida</i>, a cestode parasite of the domestic fowl

Das, Bidyadhar; Tandon, Veena; Saxena, Jitendra Kumar; Joshi, Sumit; Singh, Alok R.

doi:10.1017/s0031182012001254

Cited by 12 publications

(12 citation statements)

References 47 publications

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“…In this line of evidence, we showed that Met induces a decrease in glycogen levels, the major energy reserve in parasite tissue, and an increase in Eg-α-amylase and Eg-LDH activities, indicating an increase in these catabolic processes in Echinococcus larval stages (Fig 2A and 2B ). On the other hand, our results also showed a decreased expression of Eg- pepck , which encodes a CO 2 -fixing enzyme that participates in the glycolytic pathway of parasitic helminthes [ 30 , 60 , 61 ], and Eg-MDHc, a critical enzyme in the malate—aspartate conversion, both key enzymes in the intermediary metabolism of cestodes [ 30 , 62 ]. This could be affecting the generation of cytosolic and mitochondrial NADH/NAD + , further compromising the ATP pools in Echinococcus Met-treated cells and causing metabolic exhaustion in the parasite.…”

Section: Discussionmentioning

confidence: 92%

In Vitro Anti-Echinococcal and Metabolic Effects of Metformin Involve Activation of AMP-Activated Protein Kinase in Larval Stages of Echinococcus granulosus

Loos

Cumino

2015

PLoS ONE

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Metformin (Met) is a biguanide anti-hyperglycemic agent, which also exerts antiproliferative effects on cancer cells. This drug inhibits the complex I of the mitochondrial electron transport chain inducing a fall in the cell energy charge and leading 5'-AMP-activated protein kinase (AMPK) activation. AMPK is a highly conserved heterotrimeric complex that coordinates metabolic and growth pathways in order to maintain energy homeostasis and cell survival, mainly under nutritional stress conditions, in a Liver Kinase B1 (LKB1)-dependent manner. This work describes for the first time, the in vitro anti-echinococcal effect of Met on Echinococcus granulosus larval stages, as well as the molecular characterization of AMPK (Eg-AMPK) in this parasite of clinical importance. The drug exerted a dose-dependent effect on the viability of both larval stages. Based on this, we proceeded with the identification of the genes encoding for the different subunits of Eg-AMPK. We cloned one gene coding for the catalytic subunit (Eg-ampkɑ) and two genes coding for the regulatory subunits (Eg-ampkβ and Eg-ampkγ), all of them constitutively transcribed in E. granulosus protoscoleces and metacestodes. Their deduced amino acid sequences show all the conserved functional domains, including key amino acids involved in catalytic activity and protein-protein interactions. In protoscoleces, the drug induced the activation of AMPK (Eg-AMPKɑ-P176), possibly as a consequence of cellular energy charge depletion evidenced by assays with the fluorescent indicator JC-1. Met also led to carbohydrate starvation, it increased glucogenolysis and homolactic fermentation, and decreased transcription of intermediary metabolism genes. By in toto immunolocalization assays, we detected Eg-AMPKɑ-P176 expression, both in the nucleus and the cytoplasm of cells as in the larval tegument, the posterior bladder and the calcareous corpuscles of control and Met-treated protoscoleces. Interestingly, expression of Eg-AMPKɑ was observed in the developmental structures during the de-differentiation process from protoscoleces to microcysts. Therefore, the Eg-AMPK expression during the asexual development of E. granulosus, as well as the in vitro synergic therapeutic effects observed in presence of Met plus albendazole sulfoxide (ABZSO), suggest the importance of carrying out chemoprophylactic and clinical efficacy studies combining Met with conventional anti-echinococcal agents to test the potential use of this drug in hydatidosis therapy.

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Section: Discussionmentioning

confidence: 92%

In Vitro Anti-Echinococcal and Metabolic Effects of Metformin Involve Activation of AMP-Activated Protein Kinase in Larval Stages of Echinococcus granulosus

Loos

Cumino

2015

PLoS ONE

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“…This research suggested that tetrahydropalmatine (1) disturbs the downstream signalling pathway of NO, as shown by the change in cGMP concentration in the tissues of R. echinobothrida (Das et al 2009). A further study by the same group (Das et al 2013) found that 1 together with other alkaloids inhibits the activity of phosphoenolpyruvate carboxykinase, an important regulatory enzyme of glycolysis in R. echinobothrida in contrast to its role in gluconeogenesis in their host, domestic fowl. An aqueous extract from the rhizomes of S. glabra and its equimolar mixture with root extract of T. multiloba Miq.…”

Section: Anthelmintic Activitymentioning

confidence: 96%

Efficacy and safety ofStephania glabra: an alkaloid-rich traditional medicinal plant

Semwal

2014

Natural Product Research

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Stephania glabra (Roxb.) Miers (Menispermaceae) has long been used for the treatment of asthma, tuberculosis, dysentery, hyperglycaemia, cancer, fever, intestinal complaints, sleep disturbances and inflammation in many Asian countries. It mainly contains alkaloids and, until now, over 30 alkaloids such as bisbenzylisoquinolines, hasubanalactams, berberines and aporphines have been isolated from its tuber. Most of its traditional medicinal activities are scientifically approved by various in vitro and in vivo studies. It shows remarkable anti-psychotic, anti-diabetic, antipyretic, analgesic, antimicrobial and anti-hypertensive activities. This work includes comprehensive information on the ethnobotany, chemistry and pharmacology of S. glabra. This review also focuses on the future perspectives with main emphasis on the establishment of therapeutic index and safety index of the plant. This review concludes that S. glabra has a great potential to treat various diseases, and could be used as a source for novel healthcare products in the near future, which needs further studies.

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“…The enzyme from the cestode Raillietina echinobothrida is activated by a variety of plant extracts [200].…”

Section: Other Metabolic Pathwaysmentioning

confidence: 99%

Metabolic enzymes of helminth parasites: potential as drug targets

Timson¹

2015

CPPS

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Metabolic pathways which extract energy from carbon compounds are essential for an organism's survival. Therefore, inhibition of enzymes in these pathways represents a potential therapeutic strategy to combat parasitic infections. However, the high degree of similarity between host and parasite enzymes makes this strategy potentially difficult. Nevertheless, several existing drugs to treat infections by parasitic helminths (worms) target metabolic enzymes. These include the trivalent antimonials which target phosphofructokinase and Clorsulon which targets phosphoglycerate mutase and phosphoglycerate kinase. Glycolytic enzymes from a variety of helminths have been characterised biochemically, and some inhibitors identified. To date none of these inhibitors have been developed into therapies. Many of these enzymes are externalised from the parasite and so are also of interest in the development of potential vaccines. Less work has been done on tricarboxylic acid cycle enzymes and oxidative phosphorylation complexes. Again, while some inhibitors have been identified none have been developed into drug-like molecules. Barriers to the development of novel drugs targeting metabolic enzymes include the lack of experimentally determined structures of helminth enzymes, lack of direct proof that the enzymes are vital in the parasites and lack of cell culture systems for many helminth species. Nevertheless, the success of Clorsulon (which discriminates between highly similar host and parasite enzymes) should inspire us to consider making serious efforts to discover novel anthelminthics which target metabolic enzymes.

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Purification and characterization of phosphoenolpyruvate carboxykinase fromRaillietina echinobothrida, a cestode parasite of the domestic fowl

Cited by 12 publications

References 47 publications

In Vitro Anti-Echinococcal and Metabolic Effects of Metformin Involve Activation of AMP-Activated Protein Kinase in Larval Stages of Echinococcus granulosus

In Vitro Anti-Echinococcal and Metabolic Effects of Metformin Involve Activation of AMP-Activated Protein Kinase in Larval Stages of Echinococcus granulosus

Efficacy and safety ofStephania glabra: an alkaloid-rich traditional medicinal plant

Metabolic enzymes of helminth parasites: potential as drug targets

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