Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.22.56 (caspase-3)
 35,750 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Thrombospondin-1 (TSP1) is an endogenous inhibitor of angiogenesis, which limits blood vessel density in normal tissues and curtails tumor growth. Previous studies of the molecular and cellular effects of TSP1 in angiogenesis have been contradictory. Here, we show that retinal endothelial cells (REC) prepared from TSP1-deficient (TSP1-/-) mice are more proliferative and migratory compared to the wild type REC. We observed up-regulation of the cell cycle regulators, including cyclin A, D1, and Cdk2, as well as the enhanced sequential activities of Src, PI3-kinase, Akt/PKB, Rac1/Cdc42 GTPases, and p38 MAP kinase in TSP1-/- REC. The increased levels of fibronectin and active Akt/PKB were also observed in retinal vasculature of TSP1-/- mice in vivo. Inhibition of Src/PI3-kinase/P38 MAP kinase activities in TSP1-/- REC resulted in decreased migration. Furthermore, TSP1-/- REC showed decreased intracellular levels of active Fyn and JNK2 without affecting caspase-3 activity. Thus, our results demonstrate that in the absence of TSP1, the proangiogenic signaling is enhanced, possibly through up-regulation of fibronectin expression. The enhanced signaling further promotes EC proliferation, migration, and survival. These novel observations support the TSP1's role as an endogenous inhibitor of angiogenesis whose endothelium expression promotes a quiescent, differentiated phenotype.
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PMID:Enhanced proangiogenic signaling in thrombospondin-1-deficient retinal endothelial cells. 1662 39

Iron is essential for neoplastic cell growth, and iron chelators have been tested for potential anti-proliferative and anti-cancer effects, but the effects of iron chelators on oral cancer have not been clearly elucidated. To determine the mechanism of cell death induced by iron chelators, we explored the pathways of the three structurally related mitogen-activated protein (MAP) kinase subfamilies during iron chelator-induced apoptosis and differentiation of immortalized human oral keratinocytes (IHOK) and oral cancer cells (HN4). The iron chelator deferoxamine (DFO) exerted potent time- and dose-dependent inhibitory effects on the growth and apoptosis of IHOK and HN4 cells. DFO strongly activates p38 MAP kinase and extracellular signal-regulated kinase (ERK), but does not activate c-Jun N-terminal kinase/stress-activated protein kinase. Of the three MAP kinase blockers used, the selective p38 MAP kinase inhibitor SB203580 and ERK inhibitor PD98059 protected IHOK and HN4 cells against iron chelator-induced cell death, which indicates that the p38 and ERK MAP kinase is a major mediator of apoptosis induced by this iron chelator. Interestingly, treatment of IHOK and HN4 cells with SB203580 and PD98059 abolished cytochrome c release, as well as the activation of caspase-3 and caspase-8. DFO suppressed the expression of epithelial differentiation markers such as involucrin, CK6, and CK19, and this suppression was blocked by p38 and ERK MAP kinase inhibitors. Collectively, these data suggested that p38 and ERK MAP kinase plays an important role in iron chelator-mediated cell death and in the suppression of differentiation of oral immortalized and malignant keratinocytes, by activating a downstream apoptotic cascade that executes the cell death pathway.
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PMID:p38 and ERK MAP kinase mediates iron chelator-induced apoptosis and -suppressed differentiation of immortalized and malignant human oral keratinocytes. 1669 18

Nitric oxide (NO) and 17beta-estradiol (E2) are both important in gastrointestinal health and disease. NO contributes to gastrointestinal motility as well as to inflammation and carcinogenic processes. By contrast, E2 reduces the incidence of colon adenoma and carcinoma by about 30%. We report the genomic and non-genomic E2-estrogen receptor (ER) beta-induced effects in human colon adenocarcinoma. The effect of NO on ERbeta activities was also assessed. The E2-ERbeta-dependent gene transcription was inhibited by exogenous NO, whereas some non-genomic E2-dependent effects (e.g. p38/MAP kinase), important for the activation of the apoptotic cascade, were unaffected by NO. However, NO impaired the E2-induced pro-apoptotic cascade in human colon adenocarcinoma cells by inhibiting caspase-3. The effects of NO may reflect chemical modification(s) of Cys residues present in the DNA recognition domain of ERbeta as well as in the caspase-3 active site. On the whole, high NO concentrations suppressed the E2 protective effects in the gastrointestinal tract, suggesting that the caspase-dependent apoptotic cascade may become critical under conditions of high redox stress such as occur under specific activation of the immune system by chronic infections or pathogen challenge.
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PMID:Nitric oxide impairs the 17beta-estradiol-induced apoptosis in human colon adenocarcinoma cells. 1672 82

Cartilage loss in osteoarthritis is characterized by cartilage degradation and chondrocyte death. Cartilage degradation is induced by activation of matrix-metalloproteinases (MMPs) activity and degradation of glycosaminoglycan (GAG) and collagen. Also, chondrocyte death is induced by the apoptosis through the activation of MAP kinase and caspases activities. On the basis of this background, our study was designed to examine the cartilage protective and anti-apoptotic effect of Aralia cordata. Cartilage explants and Chondrocytes were cultured from rabbit knee joint cartilage and treated by 5 ng/ml IL-1alpha. Cartilage and chondroprotective effects of Aralia cordata were determined by measuring (1) GAG and collagen expression, (2) GAG and collagen degradation, (3) TIMP and MMPs expression, and (4) TIMP and MMPs activity. Anti-apoptotic effects of Aralia cordata were determined by measuring (1) JNK and p38 MAP kinase expression, (2) apoptotic cells by flow cytometry, and (3) caspase-3 activity. In cartilage explants and chondroctyes treated by IL-1alpha, Aralia cordata showed the decrease of GAG and collagen degradation, decrease of MMPs (MMP-1, -3, -13) activity, and increase of TIMP-1 activity in a dose-dependent manner. Aralia cordata also showed anti-apoptotic effect by inhibition of early and late apoptotic cells, sub-G1 phase cells, and caspase-3 activity through the downregulation of JNK and p38 MAP kinase signaling pathway. Aralia cordata inhibited the cartilage and chondrocyte destruction through the downregulation of MMPs activities and the inhibition of proteoglycan and collagen degradation. Also, Aralia cordata inhibited the chondrocyte apoptosis through the downregulation of JNK and p38 MAP kinase signal, and the inhibition of caspase-3 activity.
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PMID:Effect of Aralia cordata extracts on cartilage protection and apoptosis inhibition. 1681 82

Advanced glycation end products (AGEs) are elevated in aged and diabetic individuals and are associated with pathological changes associated with both. Previously we demonstrated that the AGE N(epsilon)-(carboxymethyl)lysine (CML)-collagen induced fibroblast apoptosis through the cytoplasmic and mitochondrial pathways and the global induction of proapoptotic genes. In the present study we investigated upstream mechanisms of CML-collagen-induced apoptosis. CML-collagen induced activation of the proapoptotic transcription factor FOXO1 compared with unmodified collagen. When FOXO1 was silenced, CML-collagen-stimulated apoptosis was reduced by approximately 75% compared with fibroblasts incubated with nonsilencing small interfering RNA, demonstrating the functional significance of FOXO1 activation (P < 0.05). CML-collagen but not control collagen also induced a 3.3-fold increase in p38 and a 5.6-fold increase in JNK(1/2) activity (P < 0.05). With the use of specific inhibitors, activation of p38 and JNK was shown to play an important role in CML-collagen-induced activation of FOXO1 and caspase-3. Moreover, inhibition of p38 and JNK reduced CML-collagen-stimulated apoptosis by 48 and 57%, respectively, and by 89% when used together (P < 0.05). In contrast, inhibition of the phosphatidylinositol 3-kinase/Akt pathway enhanced FOXO1 activation. p38 and JNK stimulation by CML-collagen was almost entirely blocked when formation of ROS was inhibited and was partially reduced by NO and ceramide inhibitors. These inhibitors also reduced apoptosis to a similar extent. Together these data support a model in which AGE-induced apoptosis involves the formation of ROS, NO, and ceramide and leads to p38 and JNK MAP kinase activation, which in turn induces FOXO1 and caspase-3.
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PMID:Advanced glycation end products induce apoptosis in fibroblasts through activation of ROS, MAP kinases, and the FOXO1 transcription factor. 1700 4

Visceral leishmaniasis (VL) produced in BALB/c mice through intracardial administration of Leishmania donovani amastigotes was accompanied by hepatosplenomegaly with high organ parasite load and lymphadenopathy when followed up to 4-months or so. To elucidate the mechanism of immunosuppression associated with VL, we report here progressive impairment of the proliferative response of lymph node cells (lymphocytes) from infected animals (I-LNC) to in vitro stimulation with the combination of phorbol 12-myristate 13-acetate (PMA) and ionomycin (Io) that could be related to the downregulation of PKC and MAP kinase (ERK 1/2) activation process. Further, pretreatment of I-LNC with the protein phosphatase inhibitor okadaic acid (OA), but not with calyculin A or sodium orthovanadate, significantly restored their proliferative response as well as PMA-induced activation of PKC. A population of LNC (primarily T-lymphocytes) from chronically infected animals was shown to undergo apoptosis, the number of which increased considerably following PMA+ Io stimulation. The apoptotic pathway, which was followed through binding of cells to Annexin V, activation of caspase-3 and fragmentation of DNA, involved destabilization of mitochondria, probably as a result of downregulation of PKC and Bcl-2. Interestingly, prior incubation of I-LNC with OA reversed the state of cell cycle arrest (anergy) and apoptosis through progression of cells from G0/G1 to S and G2/M phases with transcriptional activation of IL-2 and IL-2R genes. Our results suggest that the cellular (immune) dysfunction in VL could be attributed to dephosphorylation of key molecules in the T-lymphocyte signaling pathway by Ser/Thr phosphatase leading to their inactivation.
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PMID:Lymph node cells from BALB/c mice with chronic visceral leishmaniasis exhibiting cellular anergy and apoptosis: involvement of Ser/Thr phosphatase. 1701 55

4-Hydroxynonenal (HNE) is one of the most abundant aldehyde components of ox-LDL and it exerts various effects on intracellular and extracellular signaling cascades. In this mini-review, a brief synopsis of HNE-modulated signaling pathways will be presented mainly focused on cell death, including recent studies from our laboratory. The results of a number of studies demonstrate the ability of HNE to induce apoptosis and ROS formation in a dose-dependent manner. Several signaling pathways have been shown to be modulated by HNE, including MAP kinases, PKC isoforms, cell-cycle regulators, receptor tyrosine kinases and caspases. In order to get insight into the mechanisms of apoptotic response by HNE, MAP kinase and caspase activation pathways have been studied in 3T3 fibroblasts; HNE induced early activation of JNK and p38 proteins but down-regulated the basal activity of ERK-1/2. We have shown that HNE-induced release of cytochrome c from mitochondria, caspase-9 and caspase-3 activation. Activation of AP-1 along with increased c-Jun and phospho-c-Jun levels could be inhibited by pretreatment of cells with certain molecules such as resveratrol. Additionally, overexpression of dominant negative c-Jun and JNK1 in 3T3 fibroblasts prevented HNE-induced apoptosis, which indicated a role for JNK-c-Jun/AP-1 pathway. JNK-dependent induction of c-Jun/AP-1 activation data in the literature indicates a critical potential role for JNK in the cellular response against toxic products of lipid peroxidation.
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PMID:Apoptosis signalling by 4-hydroxynonenal: a role for JNK-c-Jun/AP-1 pathway. 1726 5

Besides its matrix metalloproteinases inhibitory activity, TIMP-1 exhibits other biological activities such as cell survival and proliferation. The intracellular signalling pathway elicited by TIMP-1 begins to be elucidated. We have shown previously that the caspase-3 and the p38alpha MAP kinase were activated during TIMP-1-induced UT-7 cells erythroid differentiation. In this study, we demonstrated that TIMP-1 differentiating effect can be extended to the IL-3-dependent myeloid murine 32D cell line and human erythroid progenitors derived from cord blood CD34(+) cells. By performing small interfering RNA transfection and using chemical inhibitors, we evidenced that caspase-3 was involved in TIMP-1 differentiating effect. We then identified the MEKK1 kinase as a caspase-3 substrate and demonstrated that the MEKK1/MEK6/p38alpha pathway was activated downstream the caspase-3 in TIMP-1-induced hematopoietic differentiation.
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PMID:Tissue inhibitor of metalloproteinase-1 promotes hematopoietic differentiation via caspase-3 upstream the MEKK1/MEK6/p38alpha pathway. 1730 22

This study investigates cell death and survival pathways in experimental glaucoma using the translimbal photocoagulation laser model. Glaucoma was induced unilaterally in 79 Wistar rats and all eyes developed elevated intraocular pressure. The involvement of caspase-3, p-AKT and members of the MAP kinase pathway was evaluated by immunohistochemistry and Western blotting. We found that protein levels of caspase-3 were elevated from day 15 to day 30 (p<0.05). All investigated members of the MAP kinase pathway were significantly activated. P-SAPK/JNK activation began on day 2, reaching a 6-fold elevation by day 30 (p<0.05). The p-P38 level was elevated on days 2 and 8 (p<0.05), followed by a decrease to baseline on day 15. The level of p-ATF-2, the substrate of P38, was significantly elevated at all time points tested, up to day 30 (p<0.05). P-ERK was detected early (p<0.05) on day 1, returning to normal on day 15. The pro-survival protein p-Akt, a member of the PI3-kinase survival pathway, was also detected early on day 1 (p<0.05) returning to baseline on day 8 and remaining unchanged up to 64days. We conclude that retinal ganglion cell death in glaucoma involves activation, at different time points, of multiple pro-apoptotic pathways (the MAP kinase pathway and the caspase family) and pro-survival (PI-3 Kinase/ Akt and p-ERK).
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PMID:Regulation of cell death and survival pathways in experimental glaucoma. 1758 94

Among the group of bioactive sphingolipids, sphingosylphosphorylcholine (SPC) has been known to induce both antiproliferative and proliferative effects depending on cell type. In the present investigation we show that SPC (1-10 microM) reduced the proliferation of FRO cells (an anaplastic thyroid carcinoma cell line) in a concentration dependent manner. The effect was pertussis toxin insensitive, and independent of phospholipase C, protein kinase C, p38 kinase, or jun kinase. In addition to inhibiting the migration of FRO cells, application of SPC induced a rapid (<10 min) rounding of the cells, which was dependent on extracellular sodium. However, DAPI staining and caspase-3 analysis could not reveal any apoptotic effects of SPC. Furthermore, when cells treated with SPC for 24h were washed and replated, they continued to grow, albeit somewhat slower than control cells. Flow cytometry analysis revealed a significant increase in the population of cells in the G2-M phase, and a reduction in S phase. SPC reduced the phosphorylation of Akt with about 50% and evoked a substantial decrease in the amount of phosphorylated mitogen-activated protein (MAP) kinase. In cells treated with the PI3 kinase inhibitor wortmannin, both migration and proliferation were inhibited, as well as the amount of phosphorylated MAP kinase. Treatment of the cells with either SPC or wortmannin increased the levels of p21, but decreased that of cyclin B1 and Cdc2. Taken together, SPC is an effective suppressor of thyroid cancer cell proliferation and migration, and this effect is, in part, mediated by inhibition of both the PI3K-Akt and the MAP kinase signalling pathways.
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PMID:Antiproliferative effect of sphingosylphosphorylcholine in thyroid FRO cancer cells mediated by cell cycle arrest in the G2/M phase. 1760 21


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