Trichomonas vaginalis metalloproteinase induces mTOR cleavage of SiHa cells

VPS32, a member of the ESCRT complex, modulates adherence to host cells in the parasite Trichomonas vaginalis by affecting biogenesis and cargo sorting of released extracellular vesicles

Trichomonas vaginalis is a common sexually transmitted extracellular parasite that adheres to epithelial cells in the human urogenital tract. Extracellular vesicles (EVs) have been described as important players in the pathogenesis of this parasite as they deliver proteins and RNA into host cells and modulate parasite adherence. EVs are heterogeneous membrane vesicles released from virtually all cell types that collectively represent a new dimension of intercellular communication. The Endosomal Sorting Complex Required for Transport (ESCRT) machinery contributes to several key mechanisms in which it reshapes membranes. Based on this, some components of the ESCRT have been implicated in EVs biogenesis in other cells. Here, we demonstrated that VPS32, a member of ESCRTIII complex, contribute to the biogenesis and cargo sorting of extracellular vesicles in the parasite T. vaginalis. Moreover, we observe that parasites overexpressing VPS32 have a striking increase in adherence to host cells compared to control parasites; demonstrating a key role for this protein in mediating host: parasite interactions. These results provide valuable information on the molecular mechanisms involved in extracellular vesicles biogenesis, cargo-sorting, and parasite pathogenesis.

Regulation of exosomes released from normal ovarian epithelial cells and ovarian cancer cells

As important cell to cell communicator, exosomes carry a range of bioactive molecules which can significantly influence phenotype of recipient cells. Inhibiting or removing cancer cell-derived exosomes are of therapeutic interest. However, regulation of secretion and release mechanism of exosomes is still unclear. To explore the regulation of exosomes released from normal ovarian epithelial cells and ovarian cancer cells, a normal ovarian epithelial cell line and three ovarian epithelial cancer cell lines were utilized to investigate their exosomes' release and regulation. A cervical cancer cell SiHa was used for identifying tissue specificity. NanoSight NS500 was used to quantify exosome numbers. Exosomes were labeled and observed by confocal microscopy to investigate their interaction with different ovarian cell lines. Exosomes released from normal or ovarian cancer cells were regulated by the extracellular exosomes. Exosome release was inhibited with the extracellular exosome concentration increase. Exosomes from normal ovarian cell and cervical cancer cell also inhibited ovarian cancer cell-derived exosome release, and there was no tissue specificity. PKH26-labeled exosomes from normal ovarian cell and cervical cancer cell were uptaken by ovarian cancer cells. Release of exosomes from ovarian cancer cell is regulated by a feedback mechanism without tissue specificity. This may provide a therapeutic approach to control the release of exosomes from ovarian cancer cells.

Involvement of PI3K/AKT and MAPK Pathways for TNF-α Production in SiHa Cervical Mucosal Epithelial Cells Infected with Trichomonas vaginalis

Trichomonas vaginalis; induces proinflammation in cervicovaginal mucosal epithelium. To investigate the signaling pathways in TNF-α production in cervical mucosal epithelium after T. vaginalis infection, the phosphorylation of PI3K/AKT and MAPK pathways were evaluated in T. vaginalis-infected SiHa cells in the presence and absence of specific inhibitors. T. vaginalis increased TNF-α production in SiHa cells, in a parasite burden-dependent and incubation time-dependent manner. In T. vaginalis-infected SiHa cells, AKT, ERK1/2, p38 MAPK, and JNK were phosphorylated from 1 hr after infection; however, the phosphorylation patterns were different from each other. After pretreatment with inhibitors of the PI3K/AKT and MAPK pathways, TNF-α production was significantly decreased compared to the control; however, TNF-α reduction patterns were different depending on the type of PI3K/MAPK inhibitors. TNF-α production was reduced in a dose-dependent manner by treatment with wortmannin and PD98059, whereas it was increased by SP600125. These data suggested that PI3K/AKT and MAPK signaling pathways are important in regulation of TNF-α production in cervical mucosal epithelial SiHa cells. However, activation patterns of each pathway were different from the types of PI3K/MAPK pathways.