Biological systems interact with Engineered NanoMaterials (ENMs): Possible environmental risks

There is a growing and controversial public debate on the potential risk of NanoMaterials (NMs) to living organisms, including humans. In particular, the processes of dispersion and bioaccumulation of Engineered NanoMaterials (ENMs) into the environment are poorly investigated. Biological systems interact with ENMs in a very complex dynamic way whose comprehension is still at its infancy. Thus the evaluation of the environmental impact of ENMs may be useful to minimize or eliminate ENMs toxicity and/or ecotoxicity, and to help authorities to draw directives and regulations for a safe production and use of ENMs. Here we briefly review biotoxicity and environmental risks of ENMs (like carbon- and metalnanoparticles) reporting also our experience in the cytotoxicity of carbon (C) and silver (Ag) NanoParticles (NPs) on HeLa cells and nanoecotoxicity on Paracentrotus lividus

Static magnetic field interferes with macrophage phagocytosis

Increasing evidences suggest that static magnetic fields (SMFs) are capable to affect a number of biological functions, including monocyte/macrophage differentiation. Indeed, we found that the presence of 6mT SMF interferes with monocyte/macrophage TPA-induced differentiation of promonocytes U937 and monocytes THP-1 cells, respectively of a 20% increment and a 15% decrement. During the monocyte/macrophage differentiation cells progressively acquire the ability to internalize and finally become active phagocytes. Fluid phase endocytosis and phagocytosis of latex particles and apoptotic cells in TPA-induced U937 and THP1 cells were studied in the presence of 6 mT SMF. Phagocytosis but not fluid phase endocytosis was affected by 6mT SMF exposure. Exposure of cells to SMF during 4h incubation with particles, increased, within the first two hours, the number of bound particles to the plasma membrane and decreased those internalized. At 4 hours of incubation with particles under SMF the number of particles bound to the plasma membrane decreased and increased the number of engulfed ones; the amount, surprisingly, being higher than in non exposed cells. The effects, due to the presence of SMF during the internalization of latex particles or apoptotic cells, were higher at the early stages of the induction to differentiation and in any case they increased the rate of internalization, specific for each cell type (THP1 > U937 cells)

Static magnetic field selects undifferentiated myelomonocytes from low-glutamine concentration stimulated U937 cells

An increasing number of evidence indicates that static magnetic fields (SMF) are capable of altering apoptosis, mainly through modulation of Ca2+ influx. Here we present data that suggest apoptotic-related gene expression as an alternative pathway, through which exposure to 6 milliTesla (mT) SMF can interfere with apoptosis. Exposure to 6 mT SMF affects the apoptotic rate (spontaneous and drug-induced) and [Ca2+]i in isolated human lymphocytes; the aged cells are more susceptible to exposure than fresh ones. The exposure to 6 mT exerted a protective effect on chemical or physical-induced apoptosis, irrespective of the age of the cells. The investigation of the gene expression of bcl-2, bax, p53 and hsp70 in freshly isolated and in culture aged human lymphocytes indicates that these genes are modulated by SMF exposure in the experimental conditions used, in a gene-, age- and time- dependent manner. The exposure of isolated lymphocytes to SMF for up 24 h modulated increased bax and p53 and decreased hsp70, and bcl-2. The amount of increment and/or decrement of the proteins varied for each gene examined and was independent of the apoptotic inducers. Finally, the same stress applied to freshly isolated or aged lymphocytes resulted in different modulation of bcl-2, bax and hsp70

Effect of 6mT static magnetic field on the bcl-2, bax, p53 and hsp70 expression in freshly isolated and in vitro aged human lymphocytes

An increasing number of evidence indicates that static magnetic fields (SMFs) are capable of altering apoptosis, mainly through modulation of Ca2+ influx. Herewe present data that suggest apoptotic-related gene expression as an alternative pathway, through which exposure to 6 milliTesla (mT) SMF can interfere with apoptosis. Exposure to 6mT SMF affects the apoptotic rate (spontaneous and drug-induced) and [Ca2+]i in isolated human lymphocytes; the aged cells are more susceptible to exposure than fresh ones. The exposure to 6mT exerted a protective effect on chemical or physical-induced apoptosis, irrespective of the age of the cells. The investigation of the gene expression of bcl-2, bax, p53 and hsp70 in freshly isolated and in cultureaged human lymphocytes indicates that these genes are modulated by SMF exposure in the experimental conditions used, in a gene-, age- and time-dependent manner. The exposure of isolated lymphocytes to SMF for up to 24 h modulated increased bax and p53 and decreased hsp70, and bcl-2. The amount of increment and/or decrement of the proteins varied for each gene examined and was independent of the apoptotic inducers. Finally, the same stress applied to freshly isolated or aged lymphocytes resulted in different modulation of bcl-2, bax and hsp70

Static magnetic field interferes with macrophage phagocytosis

Increasing evidences suggest that static magnetic fields (SMFs) are capable to affect a number of biological functions, including monocyte/macrophage differentiation. Indeed, we found that the presence of 6mT SMF interferes with monocyte/macrophage TPA-induced differentiation of promonocytes U937 and monocytes THP-1 cells, respectively of a 20% increment and a 15% decrement. During the monocyte/macrophage differentiation cells progressively acquire the ability to internalize and finally become active phagocytes. Fluid phase endocytosis and phagocytosis of latex particles and apoptotic cells in TPA-induced U937 and THP1 cells were studied in the presence of 6 mT SMF. Phagocytosis but not fluid phase endocytosis was affected by 6mT SMF exposure. Exposure of cells to SMF during 4h incubation with particles, increased, within the first two hours, the number of bound particles to the plasma membrane and decreased those internalized. At 4 hours of incubation with particles under SMF the number of particles bound to the plasma membrane decreased and increased the number of engulfed ones; the amount, surprisingly, being higher than in non exposed cells. The effects, due to the presence of SMF during the internalization of latex particles or apoptotic cells, were higher at the early stages of the induction to differentiation and in any case they increased the rate of internalization, specific for each cell type (THP1 > U937 cells)

Rose bengal acetate photodynamic therapy-induced autophagy

Cell deaths in Photodynamic therapy, that is an anticancer therapy requiring exposure of cells or tissue to photosensitizing drug followed by irradiation with visible light of the appropriate wavelength, occur by the efficient induction of apoptotic as well as non-apoptotic cell deaths, like necrosis and autophagy, or by a combination of the three mechanisms. However, the exact role of autophagy in Photodynamic therapy is still a matter of debate. To this purpose, we investigated the induction of autophagy in HeLa cells photosensitized with Rose Bengal Acetate (RBAc). After incubation with Rose Bengal Acetate (10-5 M), HeLa cells were irradiated for 90 seconds (green LED DPL 305, emitting at 530 ± 15 nm in order to obtain 1.6 J/cm2 as total light dose) and allowed to recover for 72 h. Induction of autophagy and apoptosis was observed with peaks at 8 h and 12 h after irradiation respectively for autophagy and apoptosis. Autophagy was detected by biochemical (Western Blot of LC3B protein) and morphological criteria (TEM, cytochemistry). In addition, the pan-caspases inhibitor z-VAD was not able to completely prevent cell deaths. The simultaneous onset of apoptosis and autophagy following Rose Bengal Acetate Photodynamic therapy is of remarkable interest in consideration of the findings that autophagy can result in class II presentation of antigens and thus explain why low dose Photodynamic therapy can yield anti-tumour vaccines

Static magnetic field selects undifferentiated myelomonocytes from low-glutamine concentration stimulated U937 cells.

An increasing number of evidence indicates that static magnetic fields (SMF) are capable of altering apoptosis, mainly through modulation of Ca2+ influx. Here we present data that suggest apoptotic-related gene expression as an alternative pathway, through which exposure to 6 milliTesla (mT) SMF can interfere with apoptosis. Exposure to 6 mT SMF affects the apoptotic rate (spontaneous and drug-induced) and [Ca2+]i in isolated human lymphocytes; the aged cells are more susceptible to exposure than fresh ones. The exposure to 6 mT exerted a protective effect on chemical or physical-induced apoptosis, irrespective of the age of the cells. The investigation of the gene expression of bcl-2, bax, p53 and hsp70 in freshly isolated and in culture aged human lymphocytes indicates that these genes are modulated by SMF exposure in the experimental conditions used, in a gene-, age- and time- dependent manner. The exposure of isolated lymphocytes to SMF for up 24 h modulated increased bax and p53 and decreased hsp70, and bcl-2. The amount of increment and/or decrement of the proteins varied for each gene examined and was independent of the apoptotic inducers. Finally, the same stress applied to freshly isolated or aged lymphocytes resulted in different modulation of bcl-2, bax and hsp70

Morphology and cytochemistry of dissociated cells of Petrosia ficiformis (Porifera)

In the present paper we report the results of our study aimed to the morphological and cytochemical identification of dissociated Petrosia ficiformis cells, a sponge species common on the rocky shores of the Mediterranean Sea. Indeed, in most species classification of sponge cells is difficult for their high plasticity and totipotency, beside the absence of organs and tissues. In a 30-year-old classification, four main classes of sponge cells were identified: covering cells, scleroblast-like cells, i.e. cells secreting the skeleton, contractile cells and archeocytes. After mechanical dissociation of the specimens collected in the Adriatic Sea, we identified three main cell types, with a diameter ranging from 2 mu m to 20 mu m: (i) choanocytes, very small cells (5 mu m in diameter), (ii) archeocytes, intermediate size cells (from 5 to 10 gm in diameter), (iii) spherulous cells, very heterogeneous elements (8-20 mu m in diameter). Indeed, the cytoplasm of these latter cells is filled by a variable number of granules, which confer peculiar cytochemical staining patterns. In addition, we also identified the relevant presence of symbiotic microorganisms, namely cyanobateria, preferentially distributed inside the ectosome

Rose bengal acetate photodynamic therapy-induced autophagy

Cell deaths in Photodynamic therapy, that is an anticancer therapy requiring exposure of cells or tissue to photosensitizing drug followed by irradiation with visible light of the appropriate wavelength, occur by the efficient induction of apoptotic as well as non-apoptotic cell deaths, like necrosis and autophagy, or by a combination of the three mechanisms. However, the exact role of autophagy in Photodynamic therapy is still a matter of debate. To this purpose, we investigated the induction of autophagy in HeLa cells photosensitized with Rose Bengal Acetate (RBAc). After incubation with Rose Bengal Acetate (10-5 M), HeLa cells were irradiated for 90 seconds (green LED DPL 305, emitting at 530 ± 15 nm in order to obtain 1.6 J/cm2 as total light dose) and allowed to recover for 72 h. Induction of autophagy and apoptosis was observed with peaks at 8 h and 12 h after irradiation respectively for autophagy and apoptosis. Autophagy was detected by biochemical (Western Blot of LC3B protein) and morphological criteria (TEM, cytochemistry). In addition, the pan-caspases inhibitor z-VAD was not able to completely prevent cell deaths. The simultaneous onset of apoptosis and autophagy following Rose Bengal Acetate Photodynamic therapy is of remarkable interest in consideration of the findings that autophagy can result in class II presentation of antigens and thus explain why low dose Photodynamic therapy can yield anti-tumour vaccines

ULTRASTRUCTURAL MODIFICATIONS OF NORMAL AND APOPTOTIC U937 CELLS EXPOSED TO SMFS

Exposition to 60 hertz (MFs) magnetic fields may be risk factor for human cancer. A cocarcinogenic and comutagenetic effect of MFs has been hypothesized. One mechanism through which MFs could influence neoplastic development is by interfering with the apoptotic program