Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.22.62 (caspase-9)
 7,507 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Photodynamic therapy (PDT) using the silicon phthalocyanine photosensitizer Pc 4 [HOSiPcOSi(CH3)2(CH2)3N-(CH3)2] is an oxidative stress associated with induction of apoptosis in various cell types. We assessed the effectiveness of Pc 4-PDT on SW480 colon cancer xenografts grown in athymic nude mice. Animals bearing xenografts were treated with 1 mg/kg body weight Pc 4 and 48 h later were irradiated with 150 J/cm2 672-nm light from a diode laser delivered at 150 mW/cm2. Biochemical studies were performed in xenografts resected at various time points up to 26 h after Pc 4-PDT treatment, whereas tumor size was evaluated over a 4-week period in parallel experiments. In the tumors resected for biochemical studies, apoptosis was visualized by activation of caspase-9 and caspase-3 and a gradual increase in the cleavage of the nuclear enzyme poly(ADP-ribose) polymerase (PARP) to a maximum of approximately 60% of the total PARP present at approximately 26 h. At that time all Pc 4-PDT-treated tumors had regressed significantly. Two signaling responses that have previously been shown to be associated with Pc 4-PDT-induced apoptosis in cultured cells, p38 mitogen-activated protein kinase and p21/WAF1/Cip1, were examined. A marked increase in phosphorylation of p38 was observed within 1 h after Pc 4-PDT without changes in levels of the p38 protein. Levels of p21 were not altered in the xenografts in correspondence with the presence of mutant p53 in SW480 cells. Evaluation of tumor size showed that tumor growth resumed after a delay of 9-15 days. Our results suggest that: (a) Pc 4-PDT is effective in the treatment of SW480 human colon cancer xenografts independent of p53 status; (b) PARP cleavage may be mediated by caspase-9 and caspase-3 activation in the Pc 4-PDT-treated tumors; and (c) p38 phosphorylation may be a trigger of apoptosis in response to PDT in vivo in this tumor model.
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PMID:Photodynamic therapy with the phthalocyanine photosensitizer Pc 4 of SW480 human colon cancer xenografts in athymic mice. 1081 28

Acute exposure to trimethyltin (TMT) causes neuronal degeneration in the hippocampus, amygdala, pyriform cortex, and neocortex [Am. J. Pathol. 97 (1979) 59]. Despite extensive efforts elucidating neuropathological changes and behavioral deficits following TMT exposure, only a limited amount of work has examined the molecular signaling mechanisms that lead to these changes. The present paper demonstrates that TMT impairs neurite outgrowth and cell viability in an in vitro model of neuronal development. The decrease in cell viability is paralleled by a decrease in cell body size, an increase in DNA fragmentation, activation of caspase-9, and cleavage of the caspase substrate poly-ADP ribose polymerase (PARP). These results suggest that TMT induces apoptosis. Pharmacological inhibition of caspase activity, p38 stress-responsive protein kinase activity, or oxidative stress prevented TMT-induced cell death. This work provides the first evidence for a TMT-initiated apoptotic pathway requiring oxidative stress, caspase activation, and p38 protein kinase activity.
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PMID:The neurotoxicant trimethyltin induces apoptosis via caspase activation, p38 protein kinase, and oxidative stress in PC12 cells. 1470 May 29

The surrounding medium of periodontal pathogen Porphyromonas gingivalis (P. gingivalis) increased cardiomyocyte hypertrophy and apoptosis whereas Actinobaeillus actinomycetemcomitans and Prevotella intermedia had no effects. The purpose of this study is to clarify the role of p38 pathway in P. gingivalis conditioned medium-induced H9c2 myocardial cell hypertrophy and apoptosis. DNA fragmentation, cellular morphology, nuclear condensation, p38 protein products, and mitochondrial-dependent apoptotic related proteins in cultured H9c2 myocardial cell were measured by agarose gel electrophoresis, immunofluorescence, DAPI, and western blotting following P. gingivalis conditioned medium and/or pre-administration of SB203580 (p38 inhibitor). The p38 protein products and associated activities in H9c2 cells were both upregulated by P. gingivalis conditioned medium. P. gingivalis conditioned medium increased cellular sizes, DNA fragmentation, nuclear condensation, mitochondrial Bcl2-associated death promoter (Bad), cytosolic cytochrome c (cyt c), and the activated form of caspase-9 proteins in H9c2 cells. The increased cellular sizes, DNA fragmentation, nuclear condensation, Bad, cyt c, and caspase-9 activities of H9c2 cells treated with P. gingivalis conditioned medium were all significantly reduced after pre-administration of SB203580. Our findings suggest that the activity of p38 signal pathway may be initiated by P. gingivalis conditioned medium and further activate mitochondrial-dependent apoptotic pathways leading to cell death in cultured H9c2 myocardial cells.
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PMID:P38 mitogen-activated protein kinase pathways are involved in the hypertrophy and apoptosis of cardiomyocytes induced by Porphyromonas gingivalis conditioned medium. 1789 23

Pyrrolidine dithiocarbamate (PDTC) is widely used in pesticides, fungicides, insecticides, and herbicides. Copper (Cu) is a toxic heavy metal in the environment, and an essential trace metal element in the body, which is involved in many biological processes as a catalytic cofactor. The present study is designed to investigate the cellular toxicity of PDTC, CuCl(2), and PDTC/Cu complex exposure in lung alveolar epithelial cells that serve primary structural and functional roles in the lungs. The results showed that PDTC or CuCl(2) alone did not affect cell viability, but PDTC/Cu complex significantly decreased lung alveolar epithelial cell viability. PDTC/Cu complex also significantly increased intracellular copper concentration, but PDTC or CuCl(2) alone had low levels of copper. PDTC/Cu complex dramatically enhanced the JNK protein phosphorylation and ERK protein phosphorylation proteins. PDTC/Cu complex did not affect the p38 protein phosphorylation. PDTC/Cu complex was capable of activating the apoptosis-related caspases including caspase-9, caspase-7, and caspase-3, which could be reversed by the addition of JNK inhibitor SP600125 or transfection of MAPK8 short hairpin RNA. PDTC/Cu complex also increased cytosolic cytochrome c and decreased mitochondrial transmembrane potential. The Bcl-2 mRNA and protein expressions were decreased in lung epithelial cells treated with PDTC/Cu complex, which could be reversed by SP600125. Furthermore, PDTC/Cu complex could trigger the expressions of ER stress-associated signaling molecules including Grp78, Grp94, caspase-12, ATF4, and CHOP, which could be reversed by SP600125. Taken together, these results indicate that exposure to PDTC/Cu complex induces cytotoxicity and apoptosis in alveolar epithelial cells via the mitochondria- and ER-stress-related signaling pathways.
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PMID:Pyrrolidine dithiocarbamate (PDTC)/Cu complex induces lung epithelial cell apoptosis through mitochondria and ER-stress pathways. 2092 May 58