No abstract

Trichomonas vaginalis, a human urogenital tract parasite, is capable of surviving in the male microenvironment, despite of the presence of Zn 2؉ . Concentrations > 1.6 mM of Zn 2؉ have a trichomonacidal effect; however, in the presence of <1.6 mM Zn 2؉ , several trichomonad proteins are up-or down-regulated. Herein, we analyzed the proteome of a T. vaginalis male isolate (HGMN01) grown in the presence of Zn 2؉ and found 32 protein spots that were immunorecognized by male trichomoniasis patient serum. Using mass spectrometry (MS), the proteins were identified and compared with 23 spots that were immunorecognized in the proteome of a female isolate using the same serum. Interestingly, we found a 50-kDa metallopeptidase (TvMP50). Unexpectedly, this proteinase was immunodetected by the serum of male trichomoniasis patients but not by the female patient serum or sera from healthy men and women. We analyzed the T. vaginalis genome and localized the mp50 gene in locus TVAG_403460. Using an RT-PCR assay, we amplified a 1320-bp mp50 mRNA transcript that was expressed in the presence of Zn 2؉ in the HGMN01 and CNCD147 T. vaginalis isolates. According to a Western blot assay, native TvMP50 was differentially expressed in the presence of Zn 2؉ . The TvMP50 proteolytic activity increased in the presence of Zn 2؉ in both isolates and was inhibited by EDTA but not by ptosyl-L-lysine chloromethyl ketone (TLCK), E64, leupeptin, or phenylmethane sulfonyl fluoride. Furthermore, the recombinant TvMP50 had proteolytic activity that was inhibited by EDTA. These data suggested that TvMP50 is immunogenic during male trichomoniasis, and Zn 2؉ induces its expression. Molecular & Cellular

Polyamines are involved in the regulation of some Trichomonas vaginalis virulence factors such as the transcript, proteolytic activity, and cytotoxicity of TvCP65, a cysteine proteinase (CP) involved in the trichomonal cytotoxicity. In this work, we reported the putrescine effect on TvCP39, other CP that also participate in the trichomonal cytotoxicity. Parasites treated with 1,4-diamino-2-butanone (DAB) (an inhibitor of putrescine biosynthesis), diminished the amount and proteolytic activity of TvCP39 as compared with untreated parasites. Inhibition of putrescine biosynthesis also reduced ∼80% the tvcp39 mRNA levels according to RT-PCR and qRT-PCR assays. Additionally, actinomycin D-treatment showed that the tvcp39 mRNA half-life decreased in the absence of putrescine. However, this reduction was restored by exogenous putrescine addition, suggesting that putrescine is necessary for tvcp39 mRNA stability. TvCP39 was localized in the cytoplasm but, in DAB treated parasites transferred into exogenous putrescine culture media, TvCP39 was re-localized to the nucleus and nuclear periphery of trichomonads. Interestingly, the amount and proteolytic activity of TvCP39 was recovered as well as the tvcp39 mRNA levels were restored when putrescine exogenous was added to the DAB-treated parasites. In conclusion, our data show that putrescine regulate the TvCP39 expression, protein amount, proteolytic activity, and cellular localization.

No abstract

Trichomoniasis, caused by the protozoan parasite Trichomonas vaginalis, is the most common nonviral sexually transmitted infection worldwide. Although drug treatment is available, unpleasant side effects and increased resistance to the nitroimidazole family have been documented. Hence, there is a need for the identification of new and safe therapeutic agents against T. vaginalis. Antimicrobial activity of anthraquinone compounds has been reported by a number of authors. The genus Morinda is well known for the diversity of anthraquinones with numerous biological activities. A new anthraquinone, lucidin‐ω‐isopropyl ether, was isolated from the roots of Morinda panamensis Seem. The structure of the compound was determined by 1H and 13C Nuclear Magnetic Resonance (NMR) analyses, in addition to comparison with literature reports. Using in vitro susceptibility assay, the half inhibitory concentration (IC50) of lucidin‐ω‐isopropyl ether for T. vaginalis (1.32 μg/mL) was found similar to that of metronidazole concentration tested (6 μM = 1.03 μg/mL). In addition, this anthraquinone was capable of inhibiting the parasite's ability to kill HeLa cells and decreased proteolytic activity of the proteinase TvMP50 from T. vaginalis. This was associated with the decreased expression of the mp50 gene. These results demonstrate the trichomonicidal potential by lucidin‐ω‐isopropyl ether. Further action‐mode studies are necessary to elucidate the antiparasitic mechanism of this new anthraquinone to develop a more potent antitrichomonal agent.