Cellular apoptosis of HFF cells by inorganic nanoparticles not susceptible to modulation by Toxoplasma gondii infection in vitro

Abstract

The interaction of nanoparticles with living cells is becoming one of the urgent areas of collaborative research in materials science and biology. Previously, we showed that nanoparticles have promising anti-Toxoplasma gondii properties. Meanwhile, Toxoplasma gondii has been shown to avert apoptosis in host cells whereas nanoparticles have been implicated for apoptotic tendency. Therefore, in the present study, we assessed the in vitro apoptotic properties of inorganic nanoparticles in the absence or presence of Toxoplasma infection and/or small molecules used as metabolic modulators. Results showed that inorganic nanoparticles dose-dependently caused cellular apoptosis. However, in the presence of infection by Toxoplasma gondii, nanoparticles-induced cellular apoptosis was not mitigated. Likewise, use of several small molecules (anti-metabolites) as metabolic modulators either mildly or nearly failed to abate cellular apoptosis by nanoparticles. Taken together, our findings do not only confirm the apoptotic potential of inorganic nanoparticles but show evidence that cellular apoptosis by inorganic nanoparticles of gold and silver might not be susceptible to modulation by Toxoplasma gondii infection. The findings are new and contribute to deepen our understanding of the cellular interaction of nanoparticles.

<p>Silver Nanoparticle-Induced Apoptosis in ARPE-19 Cells Is Inhibited by <em>Toxoplasma gondii</em> Pre-Infection Through Suppression of NOX4-Dependent ROS Generation</p>

“…Our present results indicated that T. gondii controls the NOX4-dependent ROS production in ARPE-19 cells to maintain a strong anti-oxidative environment, and then prolongs its parasitism in the cells. However, Adeyemi et al 40 have recently reported that T. gondii do not modify cellular apoptosis by inorganic NPs in human fibroblast foreskin cells. The biggest differences between these two studies are the infection time of T. gondii into the host cells and the viability of parasites.…”

“…[17][18][19][20][21][22][23]41,42 These facts were supported by many other studies mentioning that the inhibitory activity by T. gondii requires live intracellular parasites and ongoing protein synthesis. [19][20][21][22] However, Adeyemi et al 40 treated T. gondii with various NPs to infect human foreskin fibroblasts and then evaluated apoptosis; thus T. gondii may contact NPs immediately and directly and cause damage to invade the host cells. 33,43 Therefore, it would not establish a favorable environment for resisting apoptosis by T. gondii.…”

“…About this one, inorganic NPs kill T. gondii by altering the redox status and MMP, 33 and AgNPs induce anti-Toxoplasma potentials by modulating host HIF-1α activity and the tryptophan pathway. 43 In addition, we used a MOI of 5 to infect T. gondii into host cells, whereas an MOI of 0.5 was used by Adeyemi et al, 40 which may have affected the amount of ESP produced by the parasites to change the host cell environment. Other differences including the type of host cell and experimental conditions resulted in different results between the two studies.…”