Cultured Chinese Hamster Lung Research Articles

Genotoxicity and subchronic general toxicity assessments of Lactobacillus curvatus WiKim 38 using Sprague-Dawley rats

Lactobacillus curvatus WiKim 38 (LCW), isolated from kimchi, has shown novel immunomodulatory and anti-inflammatory properties. In the present study, to obtain data on the safety of LCW, we performed three genotoxicity (bacterial reverse mutation, chromosome aberration, and micronucleus) and two general toxicity (single-dosing and 13-week repeated-dosing) studies. In the genotoxicity assessment, LCW showed no increased reverse mutation for 4 strains of Salmonella typhimurium and a strain of Escherichia coli. In addition, LCW did not induce chromosome aberrations at concentrations up to 5000 μg/mL in cultured Chinese hamster lung (CHL) cells and did not induce an increased frequency of micronuclei in the bone marrow cells of rats at concentrations up to 2000 mg/kg. In the acute toxicity study using Sprague-Dawley (SD) rats, the approximate lethal dose of LCW was determined to be over 5000 mg/kg body weight (b.w.) in both sexes. Finally, in the subchronic toxicity study, no LCW-related adverse effects were observed at concentrations up to 5000 mg/kg b.w./day. Consequently, LCW is considered not to have mutagenic effects, and its no-observed-adverse-effect-level (NOAEL) is 5000 mg/kg b.w., equivalent to approximately 4.71 × 109 CFU/kg b.w., suggesting the LCW could be a potential probiotic for humans based on its safety profile.

Evaluation of Genotoxicity of CSE1034 by Ames and <i>In vitro</i> Chromosomal Aberration Tests

Purpose: To evaluate the genotoxicity of CSE1034, a novel antibiotic adjuvant entity, using bacterial reverse mutation assay (Ames test) and in vitro chromosomal aberration test.Methods: Reverse mutation test was carried out using four strains of Salmonella typhimurium (TA 98, TA100, TA1535 and TA1537) and one strain of E. coli [WP2 (uvrA)], while chromosomal aberration test was done with cultured Chinese hamster lung (CHL) cells. Reverse mutation test was carried out in a dose range of 0.0015 to 0.16 ìg/plate in triplicate with and without S9 activation.Results: No significant increases in the number of revertants were observed at the dose levels where antibacterial effects were not noted. CSE1034 caused no increase in the number of chromosomal aberrants at dose levels of 0.34, 0.69, 1.37, 2.75 and 5.50 mg/ml in the absence and presence ofmetabolic activation.Conclusion: Based on the above observations, it can be concluded that CSE1034 has no mutagenic activity.Keywords: CSE1034, reverse mutation, antibiotic adjuvant entity, Chromosomal aberration, Mutagenic

A Chromosome Aberration Test of HMC05 on Cultured Chinese Hamster Lung Cells

Objectives : We investigated genetic toxicity of HMCO5 in relation to chromosome aberration test on Cultured Chinese Hamster Lung (CHL) in the presence and absence of S-9 mix. Methods : Experimental groups were divided into two groups: with S-9mix (+S) or without S-9 mix (-S). -S group was also divided 2 series by treatment hours (6 hr: 6-S; or 24 hr; 24-S). Each group treated with vehicle only (complete culture medium), HMCO5 (1,250, 2,500, ), and cyclophosphamide monohydrate (CPA) and ethylmethanesulfonate (EMS), respectively. Results : HMC05 did not show any aberrant metaphase. However, there were significant (p

INHIBITORY EFFECTS OF XANTHONE ON PARAQUAT- AND NaNO2-INDUCED GENOTOXICITY IN CULTURED CELLS

The inhibitory effects of xanthone on genotoxicity induced by paraquat and NaNO(2) in cultured Chinese hamster lung (CHL) cells were examined. Xanthone forms the central core of xanthones. Xanthones are present in mangosteen, which is widely used as health food because of its many pharmacological properties. Paraquat (PQ, a superoxide anion generator) and NaNO(2) induce genotoxic effects, including sister chromatid exchange (SCE) and decreased cell cycle rate, in CHL cells. Xanthone inhibited the genotoxic effects of PQ and NaNO(2) at concentrations of more than 5 microM. The present results suggested the potent antigenotoxic effects of xanthones in mangosteens.

Studies of the Toxicological Potential of Tripeptides (L-Valyl-L-prolyl-L-proline and L-lsoleucyl-L-prolyl-L-proline): VIII. Assessment of Cytotoxicity and Clastogenicity of Tripeptides-Containing Casein Hydrolysate and Lactobacillus helveticus-fermented Milk Powders in Chinese Hamster Lung Cells

The objective of this chromosomal aberration test was to assess the mutagenic potential of tripeptides by determining their ability to induce chromosomal aberrations in cultured Chinese hamster lung (CHL) cells. The test agents used in these experiments were (1) powdered casein hydrolysate (CH) and (2) powdered Lactobacillus helveticus-fermented milk (FM). Both test agents contain two tripeptides, L-valyl-L-prolyl-L-proline (VPP) and L-isoleucyl-L-prolyl-L-proline (IPP). CHL cells were cultured and exposed in the presence or absence of a rat hepatic metabolizing system (S9); CH or FM (1250, 2500, 5000 microg/ml of incubation medium); or positive-control agents, mitomycin C (0.1 or 0.05 microg/ml) or benzo(a)pyrene (20 microg/ml). In experiments with CH, cells were incubated for 6 h (either in the presence or absence of S9) or for 24 h (without S9). In experiments with FM, the cells were incubated for 6 h (either in the presence or absence of S9) or for 24 or 48 h (without S9). Neither short-term nor continuous exposure to either CH or FM caused the induction of significant changes in cell growth indices, incidences of chromosomal aberrations or the incidence of polyploids. Exposures of cells to mitomycin C and benzo(a)pyrene consistently resulted in the induction of the anticipated aberrant cells after either short-term or continuous exposures. The results of these assays support the conclusions that, under the conditions of these experiments, neither CH nor FM possesses demonstrable potential for the induction of cytotoxicity or clastogenesis.

Salsolinol, a naturally occurring tetrahydroisoquinoline alkaloid, induces DNA damage and chromosomal aberrations in cultured Chinese hamster lung fibroblast cells

Salsolinol (SAL) is a tetrahydroisoquinoline neurotoxin that has been speculated to contribute to pathophysiology of Parkinson’s disease and chronic alcoholism. The compound is also found in certain beverages and food stuffs, including soy sauce, beer and bananas. Despite potential human exposure to SAL and its endogenous formation, little is known about the genotoxic or carcinogenic potential of this substance. In the present investigation, SAL induced DNA damage in cultured Chinese hamster lung (CHL) fibroblasts as assessed by single cell gel electrophoresis (Comet). CHL cells treated with SAL also exhibited higher frequencies of chromosomal aberrations than did vehicle-treated controls. Our recent study has revealed that SAL in combination with Cu(II) causes the strand scission in øX174 supercoiled DNA [Neurosci. Lett. 238 (1997) 95]. In line with this notion, addition of cupric ion potentiated the DNA damaging and clastogenic activity of SAL. Antioxidant vitamins, such as Vitamin C and Vitamin E, and reduced glutathione inhibited clastogenicity of SAL, suggesting the involvement of reactive oxygen species (ROS) in SAL-induced DNA damage and genotoxicity in CHL cells.

The Effect of Oligomycin on the Adhesion Strength of Cultured Chinese Hamster Lung (CHL) Cells

The Effect of Oligomycin on the Adhesion Strength of Cultured Chinese Hamster Lung (CHL) Cells

The Role of Divalent Cations on the Adhesion Strength of Cultured Chinese Hamster Lung (CHL) Cells

The role of metal ions on the adhesion strength of Chinese Hamster Lung (CHL) cells was determined. With the help of the Microflow chamber, the requirement of Ca+2 cations for adhesion of CHL onto tissue culture grade polystyrene dishes was shown by the finding that the chelation of this metal cation with 4mM EGTA caused 55 % reduction in cell adhesion strength. However, it was found that Ca2+ can be replaced with some other metal ions such as Mg2+, Mn2+ and Co2+ and the most effective studied cation was Mg2+. Absolute necessity of divalent cations for cell adhesion was determined by the fact that in the presence of 4mM EDTA, CHL cell's attachment was totally inhibited. Furthermore, cells need these cations to maintain their adhesives.

Genotoxicity of blue rayon extracts from river waters using sister chromatid exchange in cultured mammalian cells.

Using cultured Chinese hamster lung (CHL) cells, sister chromatid exchange (SCE) assays were carried out with blue rayon extracts recovered at seven sampling locations from the Katsura, Nishitakase and Kamo Rivers, tributaries of the Yodo River, in Kyoto City, Japan. The downstream extracts of wastewater treatment plants showed higher SCE frequencies than the upstream extracts both with and without metabolic activation, suggesting that the effluents from wastewater treatment plants were the possible pollution sources of genotoxic chemicals in the rivers. The results show the possible use of SCE in CHL cells for the monitoring of genotoxicity of blue rayon extracts from river waters. In addition, simultaneous treatment with sodium thiosulfate significantly reduced the frequencies of SCE induced by blue rayon extracts.

Deletion of the pro-alpha 1(I) N-propeptide affects secretion of type I collagen in Chinese hamster lung cells but not in Mov-13 mouse cells.

We have introduced two mutations into a full-length human pro-alpha 1(I) cDNA that delete 114 amino acids or the entire 139 amino acids of the N-propeptide domain. Wild-type and mutated versions of the cDNA were introduced into cultured Chinese hamster lung (CHL) cells, which do not produce endogenous type I collagen, and into Mov-13 mouse cells, which produce endogenous pro-alpha 2(I) chains but not pro-alpha 1(I) chains. As judged by resistance to proteases, neither mutation impaired intracellular triple helical assembly of human alpha 1(I) homotrimers in CHL cells, or of chimeric type I collagen comprised of human alpha 1(I) and mouse alpha 2(I) chains in Mov-13 cells. Thus, the N-propeptide is not necessary for intracellular assembly of the main helical collagen domain of type I collagen. In CHL cells the rate of secretion of the mutant homotrimers was greatly reduced as compared to wild type homotrimers, and by immunofluorescence and immunoelectron microscopy, the mutant chains were shown to be accumulated in large vesicular expansions of the rough endoplasmic reticulum. When such cells were retransfected with cDNA encoding wild-type human alpha 2(I) chains, mutant alpha 1(I) chains were not rescued and heterotrimers containing the mutant chains were also retained in the intracellular vesicles. By contrast, deletion of the N-propeptide did not affect secretion of heterotrimers containing mutant chains from Mov-13 cells. Thus, an intact N-propeptide appears necessary for efficient secretion of type I collagen from some but not all cell types.

MUTAGENICITY TEST OF CEFODIZIME SODIUM

The mutagenicity of cefodizime sodium (THR-221) was investigated by the reverse mutation test using seven bacterial strains (Salmonella typhimurium strains TA100, TA98, TA1535, TA1537 and TA1538, and Escherichia coli strains WP2 and WP2uvrA) and the chromosomal aberration test with cultured Chinese hamster lung (CHL) cells. The reverse mutation test was carried out in dose range from 0.0025 to 5.0 micrograms/plate in the absence and presence of mammalian metabolic activation system. Antibacterial effects were observed at concentrations more than 0.25 microgram/plate, and no significant increases in the number of revertants were observed at the dose levels where antibacterial effects were not detected. THR-221 caused no increases in the number of chromosomal aberrants at dose levels of 0.75, 1.5, 3.0 and 6.0 mg/ml in the absence and presence of the metabolic activation. These results indicate that THR-221 has no mutagenic activity.

Mutagenicity of instant coffee on cultured Chinese hamster lung cells

Coffee showed mutagenic activity in cultured Chinese hamster lung (CHL) cells as assessed by using diphtheria toxin resistance as a selective marker. Most of the mutagenicity was suppressed in the presence of sodium bisulfite. The contribution of methylglyoxal to the total mutagenicity of coffee was less than 3%.

Evidence that the collagen in the culture medium of Chinese hamster lung cells contains components related at the primary structural level to the α1(V) collagen chain

The collagenous protein synthesized by cultured Chinese hamster lung (CHL) cells and present in the culture medium has been isolated after limited pepsin digestion and differential salt precipitation. Molecular size analysis of this material indicates that the CHL cell medium collagen contains chains which exhibit an apparent molecular mass of approximately 85,000 Da. When chromatographed on CM-cellulose under denaturing conditions, the reduced and alkylated CHL cell medium collagen chains elute slightly after the human α1(I) chain but well before the pepsin-derived α1(V) chain, which is the constituent chain present in the CHL cell cellular matrix collagen. Analysis of the peptides derived by CNBr cleavage of the CHL medium collagen chains by chromatography on CM-cellulose reveals, however, that these chains contain peptides which correspond both in size and in chemical properties to those derived from the α1(V) collagen chain, but clearly lack two peptides (α1(V)-CB4 and α1(V)-CB5) which are normally present in pepsin-derived α1(V) chains. Furthermore, analysis of the CHL cell culture medium collagenous material obtained without pepsin digestion indicates the presence of collagenous chains that exhibit after reduction a molecular mass of approximately 160,000 Da, which is smaller than the proposed size of the pro α1(V) collagen chain. These results demonstrate that the collagenous protein present in the culture medium of CHL cells is directly related at the primary structural level to the α1(V) collagen chain, and it is postulated that this material represents the large fragment derived from a collagenase cleavage of the [pro α1(V)] 3 molecules present in the cell layer. Furthermore, these results and previous reports indicate that the only identifiable genetic type of procollagen chain synthesized by this cloned cell line in culture corresponds to the pro α1(V) chain.

Cell-free Synthesis of Putative Type V Procollagen Chains Programmed by Chinese Hamster Lung Cell mRNA

A messenger RNA fraction isolated from cultured Chinese hamster lung (CHL) cells programs in a cell-free system prepared from wheat germ the efficient incorporation of [14C] proline into newly synthesized protein with a significant fraction of the incorporated substrate being digestible with bacterial collagenase. This reaction requires both subcellular fractions, an energy source, and is inhibited by the antibiotic puromycin. The relative amount of collagenase-digestible to non-digestible cell-free product depends upon the ratio of CHL mRNA to wheat germ lysate, is not affected by either the Mg2+ or K+ concentrations employed, and under optimal condition, approximately 38% of the total incorporated substrate is collagenase-sensitive. Electrophoresis on SDS-polyacrylamide gels of the products programmed by CHL mRNA indicates that the collagenase-digestible material corresponds in size to a procollagen chain with an apparent molecular mass of approximately 170,000 daltons. These studies suggest that the collagen α1 (V) chain is initially synthesized as a precursor procollagen chain and demonstrate that a significant amount of the mRNA in Chinese hamster lung cells codes for this protein.

Chinese hamster lung cells synthesize and confine to the cellular domain a collagen composed solely of B chains.

The acid-soluble collagen extracted from cultured Chinese hamster lung (CHL) cell layers has been isolated after limited pepsin digestion and differential salt fractionation. Polyacrylamide gel electrophoresis of this material under denaturing conditions showed the presence of collagen chains with an apparent molecular mass of 120,000 daltons both before and after reduction, indicating the absence of interchain disulfide bonds in the native molecule. When chromatographed on CM-cellulose under denaturing conditions, the majority (> 90%) of the CHL cell layer collagen chains eluted as relatively basic components slightly before the human alpha 2(I) chain and coincident with the human B chain. In addition, the CM-cellulose elution profiles of the cyanogen bromide peptides derived from the human B chain and from the CHL cell layer chain were essentially identical. Examination of CHL cells in culture by using affinity-purified antibody to human B chain revealed this collagen to be localized in an extracellular matrix surrounding the cells. Furthermore, analysis of the culture medium indicated the absence of any comparable collagen chain. These data provide additional evidence for the existence of a molecular form of collagen composed solely of B chains and suggest that this molecular form of collagen has an unusual affinity for the cell layer in this system.