A PHP Error was encountered

Severity: Warning

Message: Creating default object from empty value

Filename: models/publicacao_item.php

Line Number: 20

In vitro and in vivo silencing of plasmodial dhs and eIF-5A genes in... » Isaúde
  Pesquisar Publicações Científicas  
  Especialidade: carregando especialidades...  Carregando...
Nome da revista:   Volume:   Número:
BMC microbiology [electronic resource]
2012-06-14 03:38:41

In vitro and in vivo silencing of plasmodial dhs and eIF-5A genes in a putative, non-canonical RNAi-related pathway

Descrição: Background:Deoxyhypusine synthase (DHS) catalyzes the first step in hypusine biosynthesis of eukaryotic initiation factor 5A (eIF-5A) in Plasmodium falciparum. Target evaluation of parasitic DHS has recently been performed with CNI-1493, a novel selective pro-inflammatory cytokine inhibitor used in clinical phase II for the treatment of Crohn\'s disease. CNI-1493 prevented infected mice from experimental cerebral malaria by a decrease in eIF-5A and serum TNF-levels, implicating a link between cytokine signaling and the hypusine pathway. Therefore we addressed the question whether either DHS itself or eIF-5A is required for the outcome of severe malaria. In a first set of experiments we performed an in vitro knockdown of the eIF-5A and DHS proteins by RNA interference (RNAi) in 293T cells. Secondly, transfection of siRNA constructs into murine Plasmodium schizonts was performed which, in turn, were used for infection.Results:293T cells treated with DHS- and eIF-5A specific siRNAs or control siRNAs were analyzed by RT-PCR to determine endogenous dhs -and eIF-5A mRNA levels. The expressed DHS-shRNA and EIF-5A-shRNA clearly downregulated the corresponding transcript in these cells. Interestingly, mice infected with transgenic schizonts expressing either the eIF-5A or dhs shRNA showed an elevated parasitemia within the first two days post infection which then decreased intermittently. These results were obtained without drug selection. Blood samples, which were taken from the infected mice at day 5 post infection with either the expressed EIF-5A-shRNA or the DHS-shRNA were analyzed by RT-PCR and Western blot techniques, demonstrating the absence of either the hypusinated form of eIF-5A or DHS.Conclusion:Infection of NMRI mice with schizonts from the lethal P. berghei ANKA wildtype strain transgenic for eIF-5A-specific-shRNA or DHS-specific shRNA resulted in low parasitemia 2-9 days post infection before animals succumbed to hyperparasitemia similar to infections with the related but non-lethal phenotype P. berghei strain NK65. RT-PCR and Western blot experiments performed with blood from the transfected erythrocytic stages demonstrated that both genes are important for the proliferation of the parasite. Moreover, these experiments clearly demonstrate that the hypusine pathway in Plasmodium is linked to human iNos induction.

Identificador: doi:10.1186/1471-2180-12-107
Volume: 0
Página: 1 a


Mais informações

  • Twitter iSaúde
publicidade
Jornal Informe Saúde

Indique o portal
Fechar [X]
  • Você está indicando a notícia: http://www.isaude.net
  • Para que seu amigo(a) receba esta indicação preencha os dados abaixo:

RSS notícias do portal  iSaúde.net
Receba o newsletter do portal  iSaúde.net
Indique o portal iSaúde.net
Notícias do  iSaúde.net em seu blog ou site.
Receba notícias com assunto de seu interesse.
© 2000-2011 www.isaude.net Todos os direitos reservados.