Thimerosal induces neuronal cell apoptosis by causing cytochrome c and apoptosis-inducing factor release from mitochondria
Yel L et al.
Int J Mol Med. 2005 Dec;16(6):971-7.
There is a worldwide increasing concern over the neurological risks of thimerosal (ethylmercury thiosalicylate) which is an organic mercury compound that is commonly used as an antimicrobial preservative. In this study, we show that thimerosal, at nanomolar concentrations, induces neuronal cell death through the mitochondrial pathway. Thimerosal, in a concentration- and time-dependent manner, decreased cell viability as assessed by calcein-ethidium staining and caused apoptosis detected by Hoechst 33258 dye. Thimerosal-induced apoptosis was associated with depolarization of mitochondrial membrane, generation of reactive oxygen species, and release of cytochrome c and apoptosis-inducing factor (AIF) from mitochondria to cytosol. Although thimerosal did not affect cellular expression of Bax at the protein level, we observed translocation of Bax from cytosol to mitochondria. Finally, caspase-9 and caspase-3 were activated in the absence of caspase-8 activation. Our data suggest that thimerosal causes apoptosis in neuroblastoma cells by changing the mitochondrial microenvironment.
PMID: 16273274
Mitochondrial mediated thimerosal-induced apoptosis in a human neuroblastoma cell line (SK-N-SH)
Humphrey ML et al.
Neurotoxicology. 2005 Jun;26(3):407-16.
Environmental exposure to mercurials continues to be a public health issue due to their deleterious effects on immune, renal and neurological function. Recently the safety of thimerosal, an ethyl mercury-containing preservative used in vaccines, has been questioned due to exposure of infants during immunization. Mercurials have been reported to cause apoptosis in cultured neurons; however, the signaling pathways resulting in cell death have not been well characterized. Therefore, the objective of this study was to identify the mode of cell death in an in vitro model of thimerosal-induced neurotoxicity, and more specifically, to elucidate signaling pathways which might serve as pharmacological targets. Within 2 h of thimerosal exposure (5 microM) to the human neuroblastoma cell line, SK-N-SH, morphological changes, including membrane alterations and cell shrinkage, were observed. Cell viability, assessed by measurement of lactate dehydrogenase (LDH) activity in the medium, as well as the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay, showed a time- and concentration-dependent decrease in cell survival upon thimerosal exposure. In cells treated for 24 h with thimerosal, fluorescence microscopy indicated cells undergoing both apoptosis and oncosis/necrosis. To identify the apoptotic pathway associated with thimerosal-mediated cell death, we first evaluated the mitochondrial cascade, as both inorganic and organic mercurials have been reported to accumulate in the organelle. Cytochrome c was shown to leak from the mitochondria, followed by caspase 9 cleavage within 8 h of treatment. In addition, poly(ADP-ribose) polymerase (PARP) was cleaved to form a 85 kDa fragment following maximal caspase 3 activation at 24 h. Taken together these findings suggest deleterious effects on the cytoarchitecture by thimerosal and initiation of mitochondrial-mediated apoptosis.
PMID: 15869795
Biochemical and molecular basis of thimerosal-induced apoptosis in T cells: a major role of mitochondrial pathway
Makani S et al.
Genes Immun. 2002 Aug;3(5):270-8.
http://www.nature.com/gene/journal/v3/n5/pdf/6363854a.pdf
The major source of thimerosal (ethyl mercury thiosalicylate) exposure is childhood vaccines. It is believed that the children are exposed to significant accumulative dosage of thimerosal during the first 2 years of life via immunization. Because of health-related concerns for exposure to mercury, we examined the effects of thimerosal on the biochemical and molecular steps of mitochondrial pathway of apoptosis in Jurkat T cells. Thimerosal and not thiosalcylic acid (non-mercury component of thimerosal), in a concentration-dependent manner, induced apoptosis in T cells as determined by TUNEL and propidium iodide assays, suggesting a role of mercury in T cell apoptosis. Apoptosis was associated with depolarization of mitochondrial membrane, release of cytochrome c and apoptosis inducing factor (AIF) from the mitochondria, and activation of caspase-9 and caspase-3, but not of caspase-8. In addition, thimerosal in a concentration-dependent manner inhibited the expression of XIAP, cIAP-1 but did not influence cIAP-2 expression. Furthermore, thimerosal enhanced intracellular reactive oxygen species and reduced intracellular glutathione (GSH). Finally, exogenous glutathione protected T cells from thimerosal-induced apoptosis by upregulation of XIAP and cIAP1 and by inhibiting activation of both caspase-9 and caspase-3. These data suggest that thimerosal induces apoptosis in T cells via mitochondrial pathway by inducing oxidative stress and depletion of GSH.
PMID: 12140745
Friday, 25 April 2008
Thursday, 17 April 2008
Citations re heavy metal damage.
How obvious does the damage and the proof have to be?
How many more decades of lies against the children?
http://www.talkaboutcuringautism.org/vaccines/autism-studies-april-2008.pdf
How many more decades of lies against the children?
http://www.talkaboutcuringautism.org/vaccines/autism-studies-april-2008.pdf
Tuesday, 1 April 2008
New York Times publishes LIES about details of Poling case
Shocking misrepresentation by Paul Offit, made public by the New York Times. David Kirby sets out the lies.
This calls for a public explanation as to 1) Why Paul Offit lied in this manner 2) Why the New York Times published.
Paul Offit's conflicts of interest in the vaccine business are well known. Why are respectable newspapers still allowing free reign of warped opinion from conflicted individuals to take precedence over anyone who dares raise concerns?
http://www.huffingtonpost.com/david-kirby/lies-my-new-york-time_b_94286.html
This calls for a public explanation as to 1) Why Paul Offit lied in this manner 2) Why the New York Times published.
Paul Offit's conflicts of interest in the vaccine business are well known. Why are respectable newspapers still allowing free reign of warped opinion from conflicted individuals to take precedence over anyone who dares raise concerns?
http://www.huffingtonpost.com/david-kirby/lies-my-new-york-time_b_94286.html
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