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Arimondo, P.

Publications and source records attributed to Arimondo, P..

2 recordsLinked to original sources

An epigenetic molluscicide

Biomphalaria glabrata is a fresh-water mollusk that serves as obligatory intermediate host to Schistosoma mansoni, agent of the neglected tropical disease schistosomiasis that affects roughly 250 Mio people. One of the ways to control the pathogenic agent is to interrupt the life cycle by eliminating the intermediate snail host though foal treatment of water bodies with molluscicides. Currently recommended molluscicides were developed in the 1950ths and lack sufficient specificity, e.g., they are toxic to fish. To provide new lead compounds for the development of a new type of molluscicides we used a rational approach based on the hypotheses that interfering with an important epigenetic mark, DNA methylation, would impede development of the snail host. We present here the compound 29, analogues-based compound that mimic substrates of DNA methyltransferases. We show that compound 29 has (i) low cytotoxicity for human cells, (ii) it inhibits DNA methylation, and (iii) it decreases fecundity in B.glabrata. It is therefore conceivable to produce compounds that act as specific epigenetic molluscicides.

molecular biology↗

Variable oxygen environments and DNMT2 determine the DNA cytosine epigenetic landscape of Plasmodium falciparum

DNA cytosine methylation and its oxidized products are important epigenetic modifications in mammalian cells. Although 5-methylcytosine (5mC) was detected in the human malaria parasite Plasmodium falciparum, the presence of oxidized 5mC forms remain to be characterized. Here we establish a protocol to optimize nuclease-based DNA digestion for the extremely AT-rich genome of P. falciparum (>80% A+T) for quantitative LC-MS/MS analysis of 5-hydroxymethylcytosine (5hmC), 5-formylcytosine (5fC) and 5-carboxylcytosine (5caC). We demonstrate the presence of 5hmC, 5fC and 5caC cytosine modifications in a DNMT2-only organism and observe striking ratio changes between 5mC and 5hmC during the 48-hour blood stage parasite development. Parasite-infected red blood cells cultured in different physiological oxygen concentrations revealed a shift in the cytosine modifications distribution towards the oxidized 5hmC and 5caC forms. In the absence of the canonical C5-DNA methyltransferase (DNMT1 and DNMT3A/B) in P. falciparum, we show that all cytosine modifications depend on the presence of DNMT2. We conclude that DNMT2 and oxygen levels are critical determinants that shape the dynamic cytosine epigenetic landscape in this human pathogen.

molecular biology↗