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- Vicente Carrillo, Alejandro, et al.
(författare)
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Boar spermatozoa successfully predict mitochondrial modes of toxicity: Implications for drug toxicity testing and the 3R principles
- 2015
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Ingår i: Toxicology in Vitro. - : Elsevier. - 0887-2333 .- 1879-3177. ; 29:3, s. 582-591
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Tidskriftsartikel (refereegranskat)abstract
- Replacement of animal testing by in vitro methods (3-R principles) requires validation of suitable cell models, preferably obtained non-invasively, defying traditional use of explants. Ejaculated spermatozoa are highly dependent on mitochondrial production and consumption of ATP for their metabolism, including motility display, thus becoming a suitable model for capturing multiple modes of action of drugs and other chemicals acting via mitochondrial disturbance. In this study, a hypothesis was tested that the boar spermatozoon is a suitable cell type for toxicity assessment, providing a protocol for 3R-replacement of animals for research and drug-testing. Boar sperm kinetics was challenged with a wide variety of known frank mito-toxic chemicals with previously shown mitochondrial effects, using a semi-automated motility analyser allied with real-time fluorescent probing of mitochondrial potential (MitoTracker and JC-1). Output of this sperm assay (obtained after 30 min) was compared to cell viability (ATP-content, data obtained after 24-48 h) of a hepatome-cell line (HepG2). Results of compound effects significantly correlated (P less than 0.01) for all sperm variables and for most variables in (HepG2). Dose-dependent decreases of relative ATP content in HepG2 cells correlated to sperm speed (r= 0.559) and proportions of motile (r = 0.55) or progressively motile (r = 0.53) spermatozoa. The significance of the study relies on the objectivity of computerized testing of sperm motility inhibition which is comparable albeit of faster output than somatic cell culture models. Sperm suspensions, easily and painlessly obtained from breeding boars, are confirmed as suitable biosensors for preclinical toxicology screening and ranking of lead compounds in the drug development processes.
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- Boerma, M, et al.
(författare)
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A genetic polymorphism in connexin 37 as a prognostic marker for atherosclerotic plaque development
- 1999
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Ingår i: Journal of Internal Medicine. - : Wiley. - 1365-2796 .- 0954-6820. ; 246:2, s. 211-218
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND AND OBJECTIVES: Atherosclerosis is a multifactorial disease, in part characterized by chronic inflammatory changes in the vessel wall and loss of normal physical and biochemical interactions between endothelial cells and smooth muscle cells. Previous studies [Hu J., Cotgreave IA. J Clin Invest; 99: 1-5] have provided molecular links between inflammation and myoendothelial communication via gap junctions, suggesting that these structures may be important in the development of the atherosclerotic vessel phenotype. In order to strengthen this premise, the aim of the present work was to probe for structural polymorphisms in connexin 37, a gap junctional protein uniquely expressed in endothelial cells, and to assess for potential genotypic segregation in individuals displaying atherosclerotic plaque. METHODS AND RESULTS: Computer-based comparisons of Expressed Sequence Tags (ESTs) predicted a polymorphism in the human gap junctional protein connexin 37 (cx37). The C1019-T mutation results in a proline to serine shift at codon 319 (cx37*1-cx37*2). A Restriction Fragment Length Polymorphism (RFLP) assay, involving the insertion of a novel Drd I cleavage site in the proline variant revealed a statistically significant over-representation of the cx37*1 allele in association with atherosclerotic plaque-bearing individuals (Odds-ratio for the homozygote = 2.38, Chi2 = 7.693, P = 0.006), in comparison to individuals lacking plaque, irrespective of a history of hypertension. CONCLUSIONS: These data suggest that the C1019-T polymorphism in cx37 may provide 'single gene marker', which could be useful in assessing atherosclerotic plaque development, particularly in cardiovascular risk groups such as those with borderline hypertension.
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- Burgess, D H, et al.
(författare)
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Human skeletal muscle cytosols are refractory to cytochrome c-dependent activation of type-II caspases and lack APAF-1.
- 1999
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Ingår i: Cell Death and Differentiation. - : Springer Science and Business Media LLC. - 1350-9047 .- 1476-5403. ; 6:3, s. 256-61
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Tidskriftsartikel (refereegranskat)abstract
- Apoptotic regulatory mechanisms in skeletal muscle have not been revealed. This is despite indications that remnant apoptotic events are detected following exercise, muscle injury and the progression of dystrophinopathies. The recent elicitation of a cytochrome c-mediated induction of caspases has led to speculation regarding a cytochrome c mechanism in muscle. We demonstrate that cytosols from skeletal muscle biopsies from healthy human volunteers lack the ability to activate type-II caspases by a cytochrome c-mediated pathway despite the confirmed presence of both procaspase-3 and -9. This was not due to the presence of an endogenous inhibitor, as the muscle cytosols enhanced caspase activity when added to a control cytosol, subsequently activated by cytochrome c and dATP. In addition, we demonstrate that muscle cytosols lack the apoptosis protease activator protein-1 (APAF-1), both at the protein and mRNA levels. These data indicate that human skeletal muscle cells will be refractory to mitochondrial-mediated events leading to apoptosis and thus can escape a major pro-apoptotic regulatory mechanism. This may reflect an evolutionary adaptation of cell survival in the presence of the profusion of mitochondria required for energy generation in motility.
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