Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P42574 (caspase-3)
 45,978 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cancer confers a prothrombotic state and statins are associated with a lowered risk for prostate cancer in vivo by unknown mechanisms. Prostate cancer cells release tissue factor (TF)-bearing, cholesterol-rich prostasomes which are pro-coagulant in vitro and a possible source for the blood-borne TF found in prostate cancer patients. We investigated the effect of cholesterol depletion on the production of prostasomes and on the TF activity in the conditioned medium of simvastatin-treated PC3 cells. Human PC3 prostate cancer cells were treated with high and low concentrations of simvastatin for different time periods. Caspase-3 was detected with the Array Scan microscope, whereas TF mRNA and protein were analyzed by TaqMan and flow cytometry. TF activity was assessed by measuring the cleavage of a chromogenic thrombin substrate. Prostasomes were isolated by repeated centrifugations and detected and quantified by flow cytometry. A micromolar dose of simvastatin caused reduction of TF expression and induction of apoptosis in the PC3 cells. The levels of TF on the prostasomes were also decreased but the TF activity in the conditioned medium of the simvastatin-treated PC3 cells was increased due to apoptosis-dependent release of prostasomes. Treatment with a nanomolar dose of simvastatin did not induce apoptosis or alter the expression of TF but instead decreased the production and release of the prostasomes. The TF activity was reduced in parity with the decline in prostasome release. In conclusion, in prostate cancer, a nanomolar dose of simvastatin may have an anti-thrombotic effect due to decreased levels of circulating TF-bearing prostasomes.
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PMID:Simvastatin reduces the production of prothrombotic prostasomes in human prostate cancer cells. 1884 Dec 89

Platelets are anucleated cells that upon activation by agonists or during storage may develop apoptotic events. The role of peroxynitrite and its reactive intermediates in apoptotic process in blood platelets is unknown. In order to study the appearance of biomarkers of apoptosis in platelets after treatment with peroxynitrite and with thrombin different markers were chosen: annexin V binding (phosphatidylserine exposure), platelet microparticle formation, mitochondrial membrane depolarization, caspase-3 activation and P-selectin expression. In gel-filtrated platelets treated with different concentrations of peroxynitrite (0.01, 0.1, 1.0 mM, 10 minute, 37 degrees C) a significant increase of phosphatidylserine exposure (about 36% at the highest concentration, p < 0.01) and the platelet microparticle formation were observed. Peroxynitrite caused a dose-dependent caspase-3 activation and depolarization of mitochondrial potential. The same apoptotic markers were appeared in thrombin-activated platelets. Dose-dependent tyrosine nitration in platelet proteins caused by peroxynitrite was reduced in the presence of (-)-epicatechin. Moreover, (-)-epicatechin distinctly reduced the level of apoptotic markers. The obtained results indicate that peroxynitrite responsible for oxidative/nitrative stress and changes in platelet function may promote in vitro apoptotic events in human gel-filtrated platelets via intrinsic pathway. Nitration of tyrosine seems to be partly associated with the appearance of apoptotic markers in platelets.
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PMID:Apoptotic markers in human blood platelets treated with peroxynitrite. 1901 80

Bioluminescence resonance energy transfer (BRET) is a powerful tool for the study of protein-protein interactions and conformational changes within proteins. Two common implementations of BRET are BRET(1) with Renilla luciferase (RLuc) and coelenterazine h (CLZ, lambda(em) approximately 475 nm) and BRET(2) with the substrate coelenterazine 400a (CLZ400A substrate, lambda(em)=395 nm) as the respective donors. For BRET(1) the acceptor is yellow fluorescent protein (YFP) (lambda(em) approximately 535 nm), a mutant of green fluorescent protein (GFP), and for BRET(2) it is GFP(2) (lambda(em) approximately 515 nm). It is not clear from previous studies which of these systems has superior signal-to-background characteristics. Here we directly compared BRET(1) and BRET(2) by placing two different protease-specific cleavage sequences between the donor and acceptor domains. The intact proteins simulate protein-protein association. Proteolytic cleavage of the peptide linker simulates protein dissociation and can be detected as a change in the BRET ratios. Complete cleavage of its target sequence by thrombin changed the BRET(2) ratio by a factor of 28.9+/-0.2 (relative standard deviation [RSD], n=3) and changed the BRET(1) ratio by a factor of 3.05+/-0.07. Complete cleavage of a caspase-3 target sequence resulted in the BRET ratio changes by factors of 15.45+/-0.08 for BRET(2) and 2.00+/-0.04 for BRET(1). The BRET(2) assay for thrombin was 2.9 times more sensitive compared with the BRET(1) version. Calculated detection limits (blank signal+3sigma(b), where sigma(b)=standard deviation [SD] of blank signal) were 53 pM (0.002 U) thrombin with BRET(1) and 15 pM (0.0005 U) thrombin with BRET(2). The results presented here suggest that BRET(2) is a more suitable system than BRET(1) for studying protein-protein interactions and as a potential sensor for monitoring protease activity.
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PMID:Direct comparison of bioluminescence-based resonance energy transfer methods for monitoring of proteolytic cleavage. 1902 7

Trivalent methylated metabolites of arsenic, monomethylarsonous acid (MMA(III)) and dimethylarsinous acid (DMA(III)), have been found highly reactive and toxic in various cells and in vivo animal models, suggesting their roles in the arsenic-associated toxicity. However, their effects on cardiovascular system including blood cells, one of the most important targets for arsenic toxicity, remain poorly understood. Here we found that MMA(III) and DMA(III) could induce procoagulant activity and apoptosis in platelets, which play key roles in the development of various cardiovascular diseases (CVDs) through excessive thrombus formation. In freshly isolated human platelets, treatment of MMA(III) resulted in phosphatidylserine (PS) exposure, a hallmark of procoagulant activation, accompanied by distinctive apoptotic features including mitochondrial membrane potential disruption, cytochrome c release, and caspase-3 activation. These procoagulant activation and apoptotic features were found to be mediated by the depletion of protein thiol and intracellular ATP, and flippase inhibition by MMA(III), while the intracellular calcium increase or reactive oxygen species generation was not involved. Importantly, increased platelet procoagulant activity by MMA(III) resulted in enhanced blood coagulation and excessive thrombus formation in a rat in vivo venous thrombosis model. DMA(III) also induced PS-exposure with apoptotic features mediated by protein thiol depletion, which resulted in enhanced thrombin generation. In summary, we believe that this study provides an important evidence for the role of trivalent methylated arsenic metabolites in arsenic-associated CVDs, giving a novel insight into the role of platelet apoptosis in toxicant-induced cardiovascular toxicity.
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PMID:Trivalent methylated arsenical-induced phosphatidylserine exposure and apoptosis in platelets may lead to increased thrombus formation. 1916 14

Myocardial ischemia-reperfusion (IR) injury occurs frequently in the setting of hypercholesterolemia. We investigated the potential efficacy of a novel thrombin fragment (TP508) on IR injury in a hypercholesterolemic porcine model. Twenty-one hypercholesterolemic male Yucatan pigs underwent 60 min of mid-left anterior descending coronary artery occlusion followed by 120 min of reperfusion. Pigs received either placebo (control, n = 7) or TP508 in two doses (TP508 low dose, n = 7, as bolus of 0.5 mg/kg 50 min into ischemia and an infusion of 1.25 mg.kg(-1).h(-1) during reperfusion period or TP508 high dose, n = 7, a double dose of TP508 low-dose group). Myocardial function was monitored throughout the experiment. The area at risk and myocardial necrosis were determined by Monastryl blue/triphenyl tetrazolium chloride staining. Apoptosis in the ischemic territory was assessed. Coronary microvascular reactivity to endothelium-dependent and -independent factors was measured. Myocardial necrosis was lower in both TP508-treated groups vs. control (P < 0.05). Regional left ventricular function was improved only in the TP508 high-dose group (P < 0.05). Endothelium-dependent coronary microvascular reactivity was greater in both TP508-treated groups (P < 0.05) vs. control. The expression of proteins favoring cell survival, 90-kDa heat shock protein and phospho-Bad (Ser112) was higher in the TP508 high-dose group (P < 0.05). The expression of the cell death signaling proteins, cleaved caspase-3 (P < 0.05), apoptosis-inducing factor (P < 0.05), and poly-ADP ribose polymerase (P = 0.07) was lower in the TP508 low-dose group vs. TP508 high-dose and control. The terminal deoxynucleotidyl transferase dUTP-mediated nick-end labeling positive cell count was lower in both TP508 groups compared with the control (P < 0.05). This study demonstrates that, in hypercholesterolemic pigs, TP508 decreases myocardial necrosis and apoptosis after IR. Thus TP508 may offer a novel approach in protecting the myocardium from IR injury.
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PMID:Effect of thrombin fragment (TP508) on myocardial ischemia-reperfusion injury in hypercholesterolemic pigs. 1937 4

The germinal matrix of human brain gives rise to oligodendrocytes and astrocytes after mid-gestation. Hemorrhage in the germinal matrix of premature infants is associated with suppressed cell proliferation. We hypothesize that soluble blood constituents have an adverse effect on the proliferation of cultured rat subventricular zone (SVZ) cells and the proliferation, migration, and differentiation of oligodendrocyte progenitor cells (OPC). Using caspase 3 activation and lactate dehydrogenase release assays, rat plasma, serum, thrombin, and kallikrein killed SVZ cells when grown in the presence (but not absence) of platelet derived growth factor. Plasma and serum killed OPC at 1:1 to 1:100 dilutions. Using a bromodeoxyuridine incorporation assay OPC proliferation was reduced by plasma, serum, thrombin and plasmin. Blood proteins also suppressed OPC migration in a concentration dependent manner. However, differentiation of OPC into myelin basic protein expressing cells was suppressed only by thrombin. We conclude that soluble blood components, particularly thrombin, have an adverse effect on maturing SVZ cells and OPC derived from newborn rat brain.
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PMID:Toxic effect of blood components on perinatal rat subventricular zone cells and oligodendrocyte precursor cell proliferation, differentiation and migration in culture. 1947 44

NF-kappaB signaling is known to induce the expression of antiapoptotic and proinflammatory genes in endothelial cells (ECs). We have shown recently that Ca(2+) influx through canonical transient receptor potential (TRPC) channels activates NF-kappaB in ECs. Here we show that Ca(2+) influx signal prevents thrombin-induced apoptosis by inducing NF-kappaB-dependent A20 expression in ECs. Knockdown of TRPC1 expressed in human umbilical vein ECs with small interfering RNA (siRNA) suppressed thrombin-induced Ca(2+) influx and NF-kappaB activation in ECs. Interestingly, we observed that thrombin induced >25% of cell death (apoptosis) in TRPC1-knockdown ECs whereas thrombin had no effect on control or control siRNA-transfected ECs. To understand the basis of EC survival, we performed gene microarray analysis using ECs. Thrombin stimulation increased only a set of NF-kappaB-regulated genes 3- to 14-fold over basal levels in ECs. Expression of the antiapoptotic gene A20 was the highest among these upregulated genes. Like TRPC1 knockdown, thrombin induced apoptosis in A20-knockdown ECs. To address the importance of Ca(2+) influx signal, we measured thrombin-induced A20 expression in control and TRPC1-knockdown ECs. Thrombin-induced p65/RelA binding to A20 promoter-specific NF-kappaB sequence and A20 protein expression were suppressed in TRPC1-knockdown ECs compared with control ECs. Furthermore, in TRPC1-knockdown ECs, thrombin induced the expression of proapoptotic proteins caspase-3 and BAX. Importantly, thrombin-induced apoptosis in TRPC1-knockdown ECs was prevented by adenovirus-mediated expression of A20. These results suggest that Ca(2+) influx via TRPC channels plays a critical role in the mechanism of cell survival signaling through A20 expression in ECs.
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PMID:Ca2+ influx via TRPC channels induces NF-kappaB-dependent A20 expression to prevent thrombin-induced apoptosis in endothelial cells. 2003 10

Hemorrhage is a significant pathological feature of some fever or hyperthermia-related diseases, such as dengue fever and heatstroke. Although the mechanisms of hemorrhage in these diseases are thought to be complex, whether there is an association between hemorrhage and hyperthermia or fever remains unclear. Platelets play a central role in maintaining integrity of endothelium and biological hemostasis. To explore the effect of hyperthermia on platelet physiology, platelet-rich plasma or washed platelets were incubated at hypothermia (22 degrees C), normothermia (37 degrees C) or hyperthermia (40 and 42 degrees C) for 1 or 2 hours. ADP and alpha-thrombin induced platelet aggregations were obviously reduced in platelets incubated at hyperthermia. Hyperthermia induced apoptotic events in platelets, including depolarization of mitochondrial inner transmembrane potential, caspase-3 dependent gelsolin cleavage and phosphatidylserine exposure. Furthermore, hyperthermia incurred platelet glycoprotein Ibalpha ectodomain shedding. Thus, these data suggest that hyperthermia induces platelet apoptosis and dysfunction. These findings have important implications for the pathogenesis of hemorrhage in fever or hyperthermia-related diseases, and also suggest that attention should be paid to platelet apoptosis under relatively high temperature conditions.
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PMID:Hyperthermia induces platelet apoptosis and glycoprotein Ibalpha ectodomain shedding. 2015 80

Calmodulin (CaM) antagonists induce apoptosis in various tumor models and inhibit tumor cell invasion and metastasis, thus some of which have been extensively used as anti-cancer agents. In platelets, CaM has been found to bind directly to the cytoplasmic domains of several platelet receptors. Incubation of platelets with CaM antagonists impairs the receptors-related platelet functions. However, it is still unknown whether CaM antagonists induce platelet apoptosis. Here we show that CaM antagonists N-(6-aminohexyl)-5-chloro-1-naphthalene sulfonamide (W7), tamoxifen (TMX), and trifluoperazine (TFP) induce apoptotic events in human platelets, including depolarization of mitochondrial inner transmembrane potential, caspase-3 activation, and phosphatidylserine exposure. CaM antagonists did not incur platelet activation as detected by P-selectin surface expression and PAC-1 binding. However, ADP-, botrocetin-, and alpha-thrombin-induced platelet aggregation, platelet adhesion and spreading on von Willebrand factor surface were significantly reduced in platelets pre-treated with CaM antagonists. Furthermore, cytosolic Ca(2+) levels were obviously elevated by both W7 and TMX, and membrane-permeable Ca(2+) chelator BAPTA-AM significantly reduced apoptotic events in platelets induced by W7. Therefore, these findings indicate that CaM antagonists induce platelet apoptosis. The elevation of the cytosolic Ca(2+) levels may be involved in the regulation of CaM antagonists-induced platelet apoptosis.
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PMID:Calmodulin antagonists induce platelet apoptosis. 2017 94

Intracerebral hemorrhage-associated tissue damage is triggered by blood-derived serine proteases such as thrombin. In addition, our previous studies have suggested that mitogen-activated protein (MAP) kinases contribute to intracerebral hemorrhage- and thrombin-induced striatal tissue damage in vivo. Here we addressed the mechanisms of MAP kinase involvement in thrombin cytotoxicity in rat corticostriatal slice culture, focusing on striatal tissue damage. Thrombin induced apoptotic nuclear condensation and fragmentation in striatal cells, which was suppressed by DEVD-CHO, a caspase-3 inhibitor. DEVD-CHO also prevented shrinkage of the striatal tissue induced by thrombin. Phagocytotic activity may be involved in tissue deterioration, because a phagocytosis inhibitor (cytochalasin D) and an inhibitor of phagocytosis of apoptotic cells (O-phospho-L-serine) suppressed shrinkage of the striatal tissue. OX42 immunostaining revealed that apoptosis-like microglial cell death was induced only when thrombin treatment was combined with application of inhibitors of MAP kinase/extracellular signal-regulated kinase kinase (PD98059), p38 MAP kinase (SB203580), or c-Jun N-terminal kinase (SP600125). Thrombin-induced increase in the number of microglia was also prevented by these inhibitors of MAP kinase pathways. We also found that thrombin-induced production of tumor necrosis factor (TNF)-alpha was inhibited by PD98059, SB203580, and SP600125. Finally, thrombin-induced neuronal apoptosis and shrinkage of the striatal tissue were significantly inhibited by anti-TNF-alpha neutralizing antibody. These results suggest that MAP kinases contribute to thrombin-induced striatal damage by supporting survival of activated microglia, which induce neuron death by producing TNF-alpha and cause tissue shrinkage by phagocytosing apoptotic cells.
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PMID:Mitogen-activated protein kinases support survival of activated microglia that mediate thrombin-induced striatal injury in organotypic slice culture. 2017 9


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