Lithium toxicity and expression of stress-related genes or proteins in A549 cells.

To unveil some molecular mechanisms underlying lithium toxicity, expression changes of stress-related genes or proteins were analysed in A549 cells, cultured for 3 days in presence of lithium. A dose-dependent cell-growth inhibition was found for concentrations ranging from 2 (toxicity threshold) to 12 mM (lethality threshold). cDNA arrays technology was used to analyse effects of 5 and 10 mM lithium.

Effect of selected insecticides on growth rate and stress protein expression in cultured human A549 and SH-SY5Y cells.

Two organochlorines (dienochlor, endosulfan) and one neonicotinoid (imidacloprid) insecticides were investigated as putative cellular aggressors, both as pure chemicals and as commercial formulations, in order to evaluate the additional toxicity due to additives present in the commercial formulations. Toxicity was evaluated on human cells in vitro, by culturing neuronal SH-SY5Y and pulmonary A549 cell lines for 3 days in the presence of increasing concentrations of the selected pesticides. LOEC (lowest observed effect concentration), IC50 (concentration leading to a 50% decrease of cell growth) and expression changes of molecular chaperones involved in cellular protein quality control were determined.

Stress proteins (Hsp72/73, Grp94) expression pattern in rat organs following metavanadate administration. Effect of green tea drinking.

Expression pattern of heat shock proteins (Hsp) 72/73 and glucose regulated protein (Grp) 94 was studied in liver, kidney and testis of rats injected with sublethal doses of ammonium metavanadate (5 mg/kg/day). In addition, some batches of animals were given green tea decoction, known to be rich in anti-oxidative compounds, as sole beverage in order to evaluate its protective properties. In control animals, the stress proteins expression was found to be organ-dependent: anti-Grp94 antibody revealed two bands at 96 and 98 kDa in kidney and liver whereas the 98 kDa band only was found in testis; anti-Hsp72/73 antibody revealed that the constitutive Hsp73 was present in all organs whereas the inducible Hsp72 was only present in kidney and testis.

Relationship between toxicity of selected insecticides and expression of stress proteins (HSP, GRP) in cultured human cells: effects of commercial formulations versus pure active molecules.

Three carbamate (formetanate, methomyl, pyrimicarb) and one pyrethroid (bifenthrin) insecticides were investigated both as pure chemicals and as commercial formulations in order to unveil possible toxic effects of additives and solvents present in the commercial formulations and to evaluate the cellular stress response as a defense mechanism. Toxic effects were evaluated on A549 cells, derived from a human lung carcinoma, by measuring (1) threshold concentrations leading to a decrease of the growth rate (LOEC), (2) sublethal concentrations (SC) which arrested growth without killing the cells, and (3) expression levels of several stress proteins, i.e.

Effects of nickel poisoning on expression pattern of the 72/73 and 94 kDa stress proteins in rat organs and in the COS-7, HepG2, and A549 cell lines.

The present study deals with the effects of Ni on the expression level of three stress proteins, namely, the cytosolic HSP72 and HSP73, and the reticulum-associated GRP94. Experiments were carried out on "Wistar'' female rats daily injected with 4 mg NiCl2 per kg body weight for 1, 3, 5, and 10 days. Another set of experiments were carried out using cell lines, derived from the monkey kidney (COS-7), and from human tumors of the lung (A549) and liver (HepG2).

Volatile organic compounds cytotoxicity and expression of HSP72, HSP90 and GRP78 stress proteins in cultured human cells.

The aim of this study was to determine whether overexpression of stress proteins (SPs) could be a sensitive biomarker for cell injury due to exposure to low doses of volatile organic compounds (VOCs) such as benzene, ethylbenzene, toluene, xylene, and chlorinated derivatives (ClB). Sublethal and cytotoxic threshold concentrations of the VOCs were determined by studying the growth rate of normal (fibroblasts) or tumor-derived human cell lines (A549, HepG2) exposed for 4 days to VOCs. Changes in SP expression as a function of concentrations were investigated by Western blotting.

Implication of free radicals and glutathione in the mechanism of cadmium-induced expression of stress proteins in the A549 human lung cell-line.

Cellular mechanisms underlying the expression of stress proteins (HSP) were studied in the human cell-line A549 submitted to a pollutant, cadmium, in the presence of several agents which modulate the glutathione level and, supposedly, the effects of this metal in the cell. It was observed that HSP 90, HSP 72 and HSP 27 are significantly over-expressed after exposure to cadmium chloride for 24 h. Low cadmium concentrations (i.

Pattern of stress protein expression in human lung cell-line A549 after short- or long-term exposure to cadmium.

Exposure to cadmium is associated with the development of pulmonary damage such as emphysema and lung cancer. This metal is also a powerful inducer of stress proteins in many biologic models. The present study was undertaken to evaluate whether an overexpression of the heat shock protein (hsp)72 stress protein, which indicates repair of damaged proteins, could be a sensitive and early biomarker of environmental pollution by Cd.

Hsp72 mRNA production in cultured human cells submitted to nonlethal aggression by heat, ethanol, or propanol. Application to the detection of low concentrations of chromium(VI) (potassium dichromate).

The HT29 and HepG2 human cell lines have been shown to express stress proteins (heat shock proteins, HSP) when submitted to a variety of sublethal environmental aggressions. In the present study, these cells were submitted to standardized mild aggression by heat, ethanol, or propan-1-ol in vitro. Subsequent formation of the hsp72 mRNA was measured by a very specific RNase protection method using a radiolabeled antisense RNA probe.

Modulation by hypergravity of extracellular matrix macromolecules in in vitro human dermal fibroblasts.

In vitro human dermal fibroblasts were submitted to normal gravity (1 g) or to chronic hypergravity (20 g) over a period of 8 days. Changes in organization of extracellular matrix molecules were seen by indirect immunofluorescence. In the fibronectin layer, bundles of fibrils were gathered together leading to a disorganisation of the normal parallel pattern of fibers seen in control cultures.

Effects of hypergravity on the cell shape and on the organization of cytoskeleton and extracelluar matrix molecules of in vitro human dermal fibroblasts.

In vitro human dermal fibroblasts were submitted to normal gravity (1 g) or to chronic hypergravity ranging from 2 to 20 g for 8 days. Changes only appeared above 15 g. The majority of 20 g-subjected cells showed fine filipods in the shape of a star whereas most control cells had rounded shapes and spread by forming lamellipodia.

Influence of a long duration exposure, 69 months, to the space flight factors in Artemia cysts, tobacco and rice seeds.

Three french laboratories have participated in the Free Flyer Biostack experiment. Artemia cysts, tobacco seeds and rice caryopsis and embryos were used. Biological objects in monolayers were dead.

Effects of hypergravity on adherent human cells.

In recent years, accumulating evidence has shown that microgravity or hypergravity may affect cell growth and differentiation. Since it is not easy to carry out researches in space or to simulate weightlessness on earth, we conducted experiments on simulated hypergravity (2 to 15 g) by using a centrifuge (radius: 80 cm; speed motor: 180 rpm). We looked for the effects of chronic hypergravity (7 to 10 days) on cultures of three human cell lines: lung or dermic fibroblasts and lung adenocarcinoma A 549 cells.

Effects of hypergravity on lung carcinoma cells maintained in continuous organotypic culture.

The effects of hypergravity levels ranging from 1 to 15 g were studied on A549 lung adenocarcinoma cell line, cultivated as nodules. This organotypic culture model preserves as closely as possible the cellular structures and differentiation functions of the in vivo situation. Nodules submitted to hypergravity conditions for 27 d did not show any change of cell growth, protein and DNA contents, compared with controls.

Investigations of the effects of cosmic rays on Artemia cysts and tobacco seeds; results of Exobloc II experiment, flown aboard Biocosmos 1887.

Artemia (Brine shrimp) cysts and tobacco seeds, dormant biological material devoid of metabolic activity, were flown aboard the Soviet Biocosmos 1887 in order to investigate the effects of cosmic rays. Artemia cysts and tobacco seeds were used in bulk or in monolayers sandwiched with track detectors. Biological and physical units were located outside and inside the spacecraft.

Space environmental factors affecting responses to radiation at the cellular level.

Previous space experiments suggest a high value for the RBE of cosmic radiation. A possible explanation could be a change in cell radiosensitivity due to a combined effect of radiation and other factors related to the space environment and to the space flight. Results of the EXOBLOC II experiment support this assumption.

Influence on cell proliferation of background radiation or exposure to very low, chronic gamma radiation.

Investigations carried out on the protozoan Paramecium tetraurelia and the cyanobacteria Synechococcus lividus, which were shielded against background radiation or exposed to very low doses of gamma radiation, demonstrated that radiation can stimulate the proliferation of these two single-cell organisms. Radiation hormesis depends on internal factors (age of starting cells) and external factors (lighting conditions). The stimulatory effect occurred only in a limited range of doses and disappeared for dose rates higher than 50 mGy/y.

Stimulating effect of space flight factors on Artemia cysts: comparison with irradiation by gamma rays.

The Artemia cyst, a gastrula in dormant state, is a very suitable material to investigate the individual effects of HZE cosmic particles. Monolayers of Artemia cysts, sandwiched with nuclear emulsions, flew aboard the Soviet biosatellite Cosmos 1129. The space flight stimulated the developmental capacity expressed by higher percentages of emergence, hatching, and alive nauplii at day 4-5.

Radiation-induced changes in late effects and in developmental capacities of exposed artemia cysts.

Artemia dry cysts from a Californian bisexual strain used in several space experiments were irradiated with 60Co gamma rays. The three cyst populations experimented could be differentiated according to their development and survival rates. The variations observed for both of these criteria were related to the age of the cysts and the selection technique.

Changes in developmental capacity of artemia cyst and chromosomal aberrations in lettuce seeds flown aboard Salyut-7 (Biobloc III experiment).

This paper gives the results of investigations performed on the first container (A) of the Biobloc III experiment, flown aboard the orbital station Salyut 7 for 40 days. The space flight resulted in a decreased developmental capacity of Arterlia cysts, hit or not hit by the HZE particles. No effect was observed in cysts in bulk.

[Ultrastructural aspects of the dormant Artemia embryo].

The ultrastructure of the Artemia cyst and larval organism was investigated. The morphology of the blastomere and of the cell organelles was described. Investigations showed the presence of two mitochondria populations: one located in the cytoplasm, the other one embedded inside the yolk platelets.

Results on Artemia cysts, lettuce and tobacco seeds in the Biobloc 4 experiment flown aboard the Soviet Biosatellite Cosmos 1129.

Artemia cysts, lettuce and tobacco seeds were flown aboard the Cosmos 1129 for 19 days. A correlative method was used in order to determine the passage of cosmic heavy ions (HZE particles) through the biological test objects. This space flight resulted in a decrease on hatchability, nucleic acid and protein synthesis in hydrated Artemia cysts.

Effects of 645 MeV and 9.2 GeV protons on Artemia eggs.

Developmental capacities of Artemia eggs have been studied after exposure to 645 MeV or 9.2 GeV protons. Effects of proton irradiation were studied in comparison with 60Co gamma ray irradiation, endpoints being emergence, hatching and 4-5 day old live nauplii percentages.

Development capacity of artemia cysts and lettuce seeds flown in Cosmos 936 and directly exposed to cosmic rays.

Developmental capacity of Artemia cysts and chromosomal aberration frequency in lettuce seeds, flown aboard Cosmos 936 have been investigated. Biological objects were located inside or outside the spacecraft. Lettuce seeds were stuck on plastic plates and sandwiched in cellulose sheets in order to discriminate the objects hit by the cosmic heavy ions from the ones not hit.