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Query: UNIPROT:P42574 (
caspase-3
)
45,978
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Phenylketonuria (PKU) is caused by deficiency of phenylalanine hydroxylase, resulting in an accumulation of phenylalanine in brain tissue and cerebrospinal fluid of phenylketonuria patients. Phenylketonuria is neuropathologically characterized by neuronal cell loss, white matter abnormalities, dendritic simplification, and synaptic density reduction. The neuropathological effect may be due to the "toxicity" of the high concentration of phenylalanine, while the underlying mechanism remains unclear. In this study, we found that cultured cerebral cortical neurons underwent mitochondria-mediated apoptosis when exposed to phenylalanine. We further demonstrated that phenylalanine induced RhoA activation. Phenylalanine also promoted myosin light chain (MLC) phosphorylation, which might be the result of the activation of
Rho
-associated kinase (ROCK). The RhoA antagonist, C3 transferase (C3),
Rho
-associated kinase specific inhibitor, Y-27632, and the overexpression of either dominant negative RhoA or dominant negative
Rho
-associated kinase inhibited phenylalanine-induced
caspase-3
activation and rescued neurons from apoptosis, indicating that the RhoA/
Rho
-associated kinase signalling pathway plays an important role in phenylalanine-induced neuronal apoptosis.
...
PMID:Phenylalanine activates the mitochondria-mediated apoptosis through the RhoA/Rho-associated kinase pathway in cortical neurons. 1742 60
Clostridium difficile toxin A (TcdA) is one of two homologous glucosyltransferases that mono-glucosylate
Rho
GTPases. HT29 cells were challenged with wild-type and mutant TcdA to investigate the mechanism by which apoptosis is induced. The TcdA-induced re-organization of the actin cytoskeleton led to an increased number of cells within the G2/M phase. Depolymerization of the actin filaments with subsequent G2/M arrest, however, was not causative for apoptosis, as shown in a comparative study using latrunculin B. The activation of
caspase-3
, -8, and -9 strictly depended on the glucosylation of
Rho
GTPases. Apoptosis measured by flow cytometry was completely abolished by a pan-caspase inhibitor (z-VAD-fmk). Interestingly, cleavage of procaspase-3 and Bid was not inhibited by z-VAD-fmk, but was inhibited by the calpain/cathepsin inhibitor ALLM. Cleavage of procaspase-8 was susceptible to inhibition by z-VAD-fmk and to the
caspase-3
inhibitor Ac-DMQD-CHO, indicating a contribution to the activation of
caspase-3
in an amplifying manner. Although TcdA induced mitochondrial damage and cytochrome c release, p53 was not activated or up-regulated. A p53-independent apoptotic effect was also checked by treatment of HCT 116 p53(-/-) cells. In summary, TcdA-induced apoptosis in HT29 cells depends on glucosylation of
Rho
GTPases leading to activation of cathepsins and
caspase-3
.
...
PMID:Clostridium difficile toxin A-induced apoptosis is p53-independent but depends on glucosylation of Rho GTPases. 1743 85
Bisphosphonates and chemotherapy have increasingly gained favour in the treatment of metastatic hormone resistant prostate cancer. We investigated whether zoledronic acid, at a concentration found at the bone, would enhance the anti-tumour activity of docetaxel in the hormone resistant prostate cancer cell line PC-3. Cells were exposed to zoledronic acid (1 mM) in combination or in sequence with docetaxel (3 nM). Cell viability, apoptosis and markers for inhibition of the mevalonate pathway were analyzed 48 or 72 hours after drug treatment. Reduction in cell viability and increased apoptosis levels were most pronounced with single agent zoledronic acid. Western blot analysis showed an overall reduction in the proliferation marker Mini chromosome maintenance protein 2 (MCM2) and reduction in
caspase-3
precursor for all drug treatments and a marked reduction in
Rho
A levels with single agent zoledronic acid and zoledronic acid-docetaxel sequence. This study highlights the potency of zoledronic acid, when used at concentrations similar to those found at the bone, in reducing cell viability and causing apoptosis. Clinically, these findings suggest that in patients with bone metastases due to hormone resistance prostate cancer, who are not fit enough for systemic chemotherapy, single agent zoledronic acid may have a direct effect on viability of prostate cancer epithelial cells.
...
PMID:The in vitro anti-tumour activity of zoledronic acid and docetaxel at clinically achievable concentrations in prostate cancer. 1756 44
RhoGDI2, a cytosolic regulator of
Rho
GTPase, is cleaved during apoptosis in a
caspase-3
dependent fashion. By using 2D-gel electrophoresis, mass spectrometry and Western blotting we investigate in this paper the functional consequences of RhoGDI2 processing. We can show that loss of the N-terminal 19 amino acids results in a shift of the isoelectric point of the truncated RhoGDI2 (NDelta19) to a more basic value due to the removal of 9 acidic amino acids from the N-terminus, which may be responsible for enhanced retention of the N-terminally truncated protein within the nuclear compartment. Fusion of the p53 nuclear export signaling sequence MFRELNEALELK to NDelta19 (NDelta19NES) abolished its apoptosis promoting properties, while overexpression of NDelta19 significantly increased the susceptibility to apoptosis induction by the proteasome inhibitor PSI and by staurosporine. These results suggest that cleavage of RhoGDI2 by
caspase-3
is not a functionally irrelevant bystander effect of caspase activation during apoptosis, but rather expedites progression of the apoptotic process.
...
PMID:Functional implications of caspase-mediated RhoGDI2 processing during apoptosis of HL60 and K562 leukemia cells. 1772 46
A protective effect of
Rho
-kinase inhibitor on various organ injuries is gaining attention. Regarding liver injury,
Rho
-kinase inhibitor is reported to prevent carbon tetrachloride (CCl4)- or dimethylnitrosamine-induced liver fibrosis and hepatic ischemia-reperfusion injury in rats. Because
Rho
-kinase inhibitor not only improved liver fibrosis but also reduced serum alanine aminotransferase (ALT) level in CCl4-induced liver fibrosis, we wondered whether
Rho
-kinase inhibitor might exert a direct hepatocyte-protective effect. We examined this possibility in acute CCl4 intoxication in rats.
Rho
-kinase inhibitor, HA-1077, reduced serum alanine ALT level in rats with acute liver injury induced by CCl4 with the improvement of histological damage and the reduction of the number of apoptotic cells. In cultured rat hepatocytes in serum-free condition, HA-1077 reduced apoptosis evaluated by quantitative determination of cytoplasmic histone-associated DNA oligonucleosome fragments with the reduction of
caspase-3
activity and the enhancement of Bcl-2 expression. HA-1077 stimulated phosphorylation of Akt, and wortmannin, an inhibitor of phosphatidylinositol 3-kinase (PI3-kinase)/Akt pathway, abrogated the reduction of hepatocyte apoptosis by HA-1077 in vitro. Furthermore, wortmannin abrogated the reduction of serum ALT level by HA-1077 in rats with acute liver injury induced by CCl4, suggesting that the activation of PI3-kinase/Akt pathway may be involved in the hepatocyte-protective effect by
Rho
-kinase inhibitor in vivo. In conclusion,
Rho
-kinase inhibitor prevented hepatocyte damage in acute liver injury induced by CCl4 in rats and merits consideration as a hepatocyte-protective agent in liver injury, considering its direct antiapoptotic effect on hepatocytes in vitro.
...
PMID:Rho-kinase inhibitor prevents hepatocyte damage in acute liver injury induced by carbon tetrachloride in rats. 1776 35
Rho
-GTPase has been implicated in the apoptosis of many cell types, including neurons, but the mechanism by which it acts is not fully understood. Here, we investigate the roles of
Rho
and ROCK in apoptosis during transplantation of embryonic stem cell-derived neural precursor cells. We find that dissociation of neural precursors activates
Rho
and induces apoptosis. Treatment with the
Rho
inhibitor C3 exoenzyme and/or the ROCK inhibitor Y-27632 decreases the amount of dissociation-induced apoptosis (anoikis) by 20-30%. Membrane blebbing, which is an early morphological sign of apoptosis; cleavage of
caspase-3
; and release of cytochrome c from the mitochondria are also reduced by ROCK inhibition. These results suggest that dissociation of neural precursor cells elicits an intrinsic pathway of cell death that is at least partially mediated through the
Rho
/ROCK pathway. Moreover, in an animal transplantation model, inhibition of
Rho
and/or ROCK suppresses acute apoptosis of grafted cells. After transplantation, tumor necrosis factor-alpha and pro-nerve growth factor are strongly expressed around the graft. ROCK inhibition also suppresses apoptosis enhanced by these inflammatory cytokines. Taken together, these results indicate that inhibition of
Rho
/ROCK signaling may improve survival of grafted cells in cell replacement therapy.
...
PMID:Inhibition of the Rho/ROCK pathway reduces apoptosis during transplantation of embryonic stem cell-derived neural precursors. 1782 70
Gastrins, including amidated gastrin (Gamide) and glycine-extended gastrin (Ggly), are known to accelerate the growth of gastric and colorectal cancer cells by stimulation of proliferation and inhibition of apoptosis. Gamide controls apoptosis by regulation of proteins of the Bcl-2 family and by regulation of the activation of caspases. However the interactions between Ggly and proteins of the Bcl-2 family and caspases are not known. Since in other systems G proteins of the
Rho
family inhibit apoptosis via interaction with proteins of the Bcl-2 family, leading to changes in caspase activities, we have compared the role of
Rho
family G proteins in regulation of Bcl-2-like (Bad/Bax/Bcl-xl) protein expression and
caspase 3
activation by Ggly and Gamide. The effects of the specific inhibitors C3 (for
Rho
) and Y-27632 (for ROCK), and of dominant negative mutants of Rac, Cdc42 and PAK, were investigated in the gastric epithelial cell line IMGE-5. Apoptosis was induced by serum starvation and confirmed by annexin V staining and
caspase 3
activation. Ggly inhibits
caspase 3
activation via a Bcl-2-like protein-mediated pathway which requires activation of both
Rho
/ROCK and Rac/Cdc42/PAK. Gamide inhibits
caspase 3
activation via redundant Bcl-2-like protein-mediated pathways which involve alternative activation of Rac/Cdc42/PAK and
Rho
/ROCK. Gamide and Ggly differentially activate members of
Rho
family G proteins which in turn regulate different proteins of the Bcl-2 family leading to changes in
caspase 3
activity. The findings offer potential targets for blocking the growth-stimulating effects of these gastrins.
...
PMID:Involvement of G proteins of the Rho family in the regulation of Bcl-2-like protein expression and caspase 3 activation by Gastrins. 1793 84
Oncolytic measles virus strains have activity against multiple tumor types and are currently in phase I clinical testing. Induction of the heat shock protein 70 (HSP70) constitutes one of the earliest changes in cellular gene expression following infection with RNA viruses including measles virus, and HSP70 upregulation induced by heat shock has been shown to result in increased measles virus cytotoxicity. HSP90 inhibitors such as geldanamycin (GA) or 17-allylaminogeldanamycin result in pharmacologic upregulation of HSP70 and they are currently in clinical testing as cancer therapeutics. We therefore investigated the hypothesis that heat shock protein inhibitors could augment the measles virus-induced cytopathic effect. We tested the combination of a measles virus derivative expressing soluble human carcinoembryonic antigen (MV-CEA) and GA in MDA-MB-231 (breast), SKOV3.IP (ovarian) and TE671 (rhabdomyosarcoma) cancer cell lines. Optimal synergy was accomplished when GA treatment was initiated 6-24 h following MV infection. Western immunoblotting confirmed HSP70 upregulation in combination-treated cells. Combination treatment resulted in statistically significant increase in syncytia formation as compared to MV-CEA infection alone. Clonogenic assays demonstrated significant decrease in tumor colony formation in MV-CEA/GA combination-treated cells. In addition there was increase in apoptosis by 4,6-diamidino-2-phenylindole staining. Western immunoblotting for caspase-9, caspase-8,
caspase-3
and poly(ADP-ribose) polymerase (PARP) demonstrated increase in cleaved caspase-8 and PARP. The pan-caspase inhibitor Z-VAD-FMK and caspase-8 inhibitor Z-IETD-FMK, but not the caspase-9 inhibitor Z-IEHD-FMK, protected tumor cells from MV-CEA/GA-induced PARP activation, indicating that apoptosis in combination-treated cells occurs mainly via the extrinsic caspase pathway. Treatment of normal cells, such as normal human fibroblasts, however, with the MV-CEA/GA combination, did not result in cytopathic effect, indicating that GA did not alter the MV-CEA specificity for tumor cells. One-step viral growth curves, western immunoblotting for MV-N protein expression, QRT-PCR quantitation of MV-genome copy number and CEA levels showed comparable proliferation of MV-CEA in GA-treated vs -untreated tumor cells.
Rho
activation assays and western blot for total RhoA, a GTPase associated with the actin cytoskeleton, demonstrated decrease in RhoA activation in combination-treated cells, a change previously shown to be associated with increase in paramyxovirus-induced cell-cell fusion. The enhanced cytopathic effect resulting from measles virus/GA combination supports the translational potential of this approach in the treatment of cancer.
...
PMID:Heat shock protein inhibitors increase the efficacy of measles virotherapy. 1835 18
Apoptosis is a genetically programmed and physiological mode of cell death that leads to the removal of unwanted or abnormal cells. Cysteine-proteases called caspases are responsible for the apoptotic execution phase which is characterized by specific biochemical events as well as morphological changes. These changes, which lead to the orderly dismantling of the apoptotic cell, include cell contraction, dynamic membrane blebbing, chromatin condensation, nuclear disintegration, cell fragmentation followed by phagocytosis of the dying cell. They involve major modifications of the cytoskeleton which are largely mediated by cleavage of several of its components by caspases. For example, dynamic membrane blebbing is due to the increased contractility of the acto-myosin system following myosin light chain (MLC) phosphorylation. MLC phosphorylation is a consequence of the cleavage of a
Rho
GTPase effector, the kinase ROCK I, by
caspase-3
. This cleavage induces a constitutive kinase activity by removal of an inhibitory domain. Chromatin condensation is facilitated by the processing of lamins by caspases. Collapse of the cytokeratin network is mediated by cleavage of keratin 18. On another hand, the actin cytoskeleton rearrangement needed in the phagocyte for engulfment of the dying cell is due to the activation of the small GTPase Rac, a GTPase of the
Rho
family that induces actin polymerisation and formation of lamellipodia. In addition to mediating the morphological modifications of the apoptotic cell, several proteins of the cytoskeleton such as actin and keratins are also involved in the regulation of apoptotic signaling.
...
PMID:Cytoskeleton and apoptosis. 1846 7
The intestinal epithelial cell line HT-29 was used to study the apoptotic effect of Clostridium difficile toxin A (TcdA). TcdA is a 300 kDa single-chain protein, which glucosylates and thereby inactivates small GTPases of the
Rho
family (
Rho
, Rac and Cdc42). The effect of TcdA-catalysed glucosylation of the
Rho
GTPases is well known: reorganization of the actin cytoskeleton with accompanying morphological changes in cells, leading to complete rounding of cells and destruction of the intestinal barrier function. Less is known about the mechanism by which apoptosis is induced in TcdA-treated cells. In this study, TcdA induced the activation of
caspase-3
, -8 and -9. Apoptosis, as estimated by the DNA content of cells, started as early as 24 h after the addition of TcdA. The impact of
Rho
glucosylation was obvious when mutant TcdA with reduced or deficient glucosyltransferase activity was applied. TcdA mutant W101A, with 50-fold reduced glucosyltransferase activity, induced apoptosis only at an equipotent concentration compared with wild-type TcdA at a 50% effective concentration of 0.2 nM. The enzyme-deficient mutant TcdA D285/287N was not able to induce apoptosis. Apoptosis induced by TcdA strictly depended on the activation of caspases, and was completely blocked by the pan-caspase inhibitor z-VAD-fmk. Destruction of the actin cytoskeleton by latrunculin B was not sufficient to induce apoptosis, indicating that apoptosis induced by TcdA must be due to another mechanism. In summary, TcdA-induced apoptosis (cytotoxic effect) depends on the glucosylation of
Rho
GTPases, but is not triggered by destruction of the actin cytoskeleton (cytopathic effect).
...
PMID:Glucosylation of Rho GTPases by Clostridium difficile toxin A triggers apoptosis in intestinal epithelial cells. 1848 Mar 35
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