A versatile Plasmodium falciparum reporter line expressing NanoLuc enables highly sensitive multi-stage drug assays

Presentation of a versatile Plasmodium falciparum dual reporter line, expressing both a fluorescent protein and NanoLuc under a constitutive promoter, that can be used to screen for novel anti-malarial drugs effective against multiple stages of the parasite.Transgenic luciferase-expressing Plasmodium falciparum parasites have been widely used for the evaluation of anti-malarial compounds. Here, to screen for anti-malarial drugs effective against multiple stages of the parasite, we generate a P. falciparum reporter parasite that constitutively expresses NanoLuciferase (NanoLuc) throughout its whole life cycle. The NanoLuc-expressing P. falciparum reporter parasite shows a quantitative NanoLuc signal in the asexual blood, gametocyte, mosquito, and liver stages. We also establish assay systems to evaluate the anti-malarial activity of compounds at the asexual blood, gametocyte, and liver stages, and then determine the 50% inhibitory concentration (IC50) value of several anti-malarial compounds. Through the development of this robust high-throughput screening system, we identify an anti-malarial compound that kills the asexual blood stage parasites. Our study highlights the utility of the NanoLuc reporter line, which may advance anti-malarial drug development through the improved screening of compounds targeting the human malarial parasite at multiple stages.Host-parasite interactio

Salinomycin and other ionophores as a new class of antimalarial drugs with transmission-blocking activity

The drug target profile proposed by the Medicines for Malaria Venture for a malaria elimination/eradication policy focuses on molecules active on both asexual and sexual stages of Plasmodium, thus with both curative and transmission-blocking activities. The aim of the present work was to investigate whether the class of monovalent ionophores, which includes drugs used in veterinary medicine and that were recently proposed as human anticancer agents, meets these requirements. The activity of salinomycin, monensin, and nigericin on Plasmodium falciparum asexual and sexual erythrocytic stages and on the development of the Plasmodium berghei and P. falciparum mosquito stages is reported here. Gametocytogenesis of the P. falciparum strain 3D7 was induced in vitro, and gametocytes at stage II and III or stage IV and V of development were treated for different lengths of time with the ionophores and their viability measured with the parasite lactate dehydrogenase (pLDH) assay. The monovalent ionophores efficiently killed both asexual parasites and gametocytes with a nanomolar 50% inhibitory concentration (IC50). Salinomycin showed a fast speed of kill compared to that of standard drugs, and the potency was higher on stage IV and V than on stage II and III gametocytes. The ionophores inhibited ookinete development and subsequent oocyst formation in the mosquito midgut, confirming their transmission-blocking activity. Potential toxicity due to hemolysis was excluded, since only infected and not normal erythrocytes were damaged by ionophores. Our data strongly support the downstream exploration of monovalent ionophores for repositioning as new antimalarial and transmission-blocking leads

Gene regulation during sexual development of the human malaria parasite Plasmodium falciparum

Contains fulltext : 146638.pdf (Publisher’s version ) (Open Access)139 p

Isolation and functional characterization of two distinct sexual stage-specific promoters of the human malaria parasite Plasmodium falciparum

Contains fulltext : 112878.pdf (publisher's version ) (Open Access)11 p

Ca2+ and Mg2+ transport in gills and gut of tilapia, Oreochromis mossambicus : a review

Contains fulltext : 10870.pdf (publisher's version ) (Open Access

Psychosocial interventions for women enrolled in alcohol treatment during pregnancy.

Objective: To evaluate the effectiveness of psychosocial interventions in pregnant women enrolled in alcohol treatment programs for improving birth and neonatal outcomes, maternal abstinence and treatment retention

Identification of Novel Bacterial M.SssI DNA Methyltransferase Inhibitors

Contains fulltext : 111520.pdf (publisher's version ) (Closed access

A semi-automated luminescence based standard membrane feeding assay identifies novel small molecules that inhibit transmission of malaria parasites by mosquitoes.

Contains fulltext : 152284.pdf (publisher's version ) (Open Access

Least Absolute Regression Network Analysis of the murine osteoblast differentiation network

Item does not contain fulltextMOTIVATION: We propose a reverse engineering scheme to discover genetic regulation from genome-wide transcription data that monitors the dynamic transcriptional response after a change in cellular environment. The interaction network is estimated by solving a linear model using simultaneous shrinking of the least absolute weights and the prediction error. RESULTS: The proposed scheme has been applied to the murine C2C12 cell-line stimulated to undergo osteoblast differentiation. Results show that our method discovers genetic interactions that display significant enrichment of co-citation in literature. More detailed study showed that the inferred network exhibits properties and hypotheses that are consistent with current biological knowledge. AVAILABILITY: Software is freely available for academic use as a Matlab package, called GENLAB: http://genlab.tudelft.nl/genlab.html. SUPPLEMENTARY INFORMATION: Additional data, results and figures can be found at http://genlab.tudelft.nl/larna.html