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

Auto-antibodies against the beta(1)-adrenoceptors are present in 30-40% of patients with dilated cardiomyopathy. Recently, a synthetic peptide corresponding to a sequence of the second extracellular loop of the human beta(1)-adrenoceptor (beta(1)-EC(II)) has been shown to produce endoplasmic reticulum (ER) stress, myocyte apoptosis and cardiomyopathy in immunized rabbits. To study the direct cardiac effects of anti-beta(1)-EC(II) antibody in intact animals and if they are mediated via beta(1)-adrenoceptor stimulation, we administered IgG purified from beta(1)-EC(II)-immunized rabbits to recombination activating gene 2 knock-out (Rag2(-/-)) mice every 2 weeks with and without metoprolol treatment. Serial echocardiography and cardiac catheterization showed that beta(1)-EC(II) IgG reduced cardiac systolic function after 3 months. This was associated with increase in heart weight, myocyte apoptosis, activation of caspase-3, -9 and -12, and increased ER stress as evidenced by upregulation of GRP78 and CHOP and cleavage of ATF6. The Rag2(-/-) mice also exhibited increased phosphorylation of CaMKII and p38 MAPK. Metoprolol administration, which attenuated the phosphorylation of CaMKII and p38 MAPK, reduced the ER stress, caspase activation and cell death. Finally, we employed the small-interfering RNA technology to reduce caspase-12 in cultured rat cardiomyocytes. This reduced not only the increase of cleaved caspase-12 but also of the number of myocyte apoptosis produced by beta(1)-EC(II) IgG. Thus, we conclude that ER stress plays an important role in cell death and cardiac dysfunction in beta(1)-EC(II) IgG cardiomyopathy, and the effects of beta(1)-EC(II) IgG are mediated via the beta(1)-adrenergic receptor.
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PMID:Adoptive passive transfer of rabbit beta1-adrenoceptor peptide immune cardiomyopathy into the Rag2-/- mouse: participation of the ER stress. 1815 31

The endoplasmic reticulum (ER) plays a critical role in the maintenance of intracellular homeostasis and its dysfunction is thought to lead to neuronal death, which results in neurodegenerative disorders. Since phospholipase C (PLC) isozymes are involved in maintenance of the intracellular Ca2+ concentration by regulating Ca2+ release from the ER, their expression might be affected by ER stress. Of these isozymes, PLC-beta 1 and -gamma 1, in particular, are known to protect cells from oxidative stress and thus alteration of their expression profile under ER stress-loaded conditions is interesting. Using primary cultured rat cortical neurons, we here examined whether expression of PLC-beta 1 and -gamma 1 was altered in ER stress-loaded neurons induced by tunicamycin (Tm). In ER stress-loaded neurons treated with Tm in the range of 0.03-3 microg/ml for 20 h, the viability of the neurons was decreased dose-dependently, the decrease being significant with 0.3 or more microg/ml, and expression of the representative ER stress markers, GRP78/BiP, and cleaved caspase-3 and -12, was increased after 24 h postincubation, confirming the induction of ER stress in the neurons. In the ER stress-loaded neurons obtained on Tm treatment, the expression level of PLC-beta 1 decreased dose-dependently. On the other hand, there was no difference in the PLC-gamma 1 protein expression level between control and ER stress-loaded neurons. Overall, we demonstrated that ER stress decreases the expression of PLC-beta 1, but not -gamma 1, in neurons.
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PMID:Decreased expression of phospholipase C-beta 1 protein in endoplasmic reticulum stress-loaded neurons. 1837 69

In this report, we investigated a role of endoplasmic reticulum (ER) stress in cigarette smoke (CS)-induced apoptosis of human bronchial epithelial cells (hBEC). Exposure of hBEC to CS or CS extract (CSE) caused expression of endogenous ER stress markers GRP78 and CHOP and induction of apoptosis evidenced by nuclear condensation, membrane blebbing, and activation of caspase-3 and caspase-4. In vivo exposure of mice to CS also caused induction of GRP78 and CHOP in the lung. Attenuation of ER stress by overexpression of ER chaperone GRP78 or ORP150 significantly attenuated CSE-triggered apoptosis. Exposure of hBEC to CSE caused generation of reactive oxygen species, and treatment with antioxidants inhibited CSE-induced apoptosis. Interestingly, antioxidants including a scavenger of O(2)(*-) blunted induction of CHOP by CSE without affecting the level of GRP78, and dominant-negative inhibition of CHOP abolished CSE-induced apoptosis. Furthermore, a generator of O(2)(*-) selectively induced CHOP and apoptosis in hBEC. Our results revealed that: (1) CS induces ER stress in vitro and in vivo, (2) ER stress mediates CS-triggered apoptosis downstream of oxidative stress, (3) CS-initiated apoptosis is caused through oxidative stress-dependent induction of CHOP, (4) O(2)(*-) may play a dominant role in this process, and (5) oxidative stress-independent induction of GRP78 counterbalances the proapoptotic action of CHOP.
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PMID:Induction of apoptosis by cigarette smoke via ROS-dependent endoplasmic reticulum stress and CCAAT/enhancer-binding protein-homologous protein (CHOP). 1839 32

The 78-kDa glucose-regulated protein (GRP78) is an important molecular chaperone in the endoplasmic reticulum (ER) induced by various stresses. This study showed that stimulation with anti-CD3 mAb, PMA plus ionomycin, or an antigen increased the levels of GRP78 mRNA in primary T cells, which was inhibited by Ca(2+) chelators EGTA and BAPTA-AM and by an inhibitor of calcineurin FK506. In addition, the specific knockdown of GRP78 protein expression induced apoptosis in mouse EL-4 T cell line associated with CHOP induction and caspase-3 activation. Furthermore, overexpression of GRP78 inhibited PMA/ionomycin-induced cell death in EL-4 cells. Collectively, GRP78 expression is induced by TCR activation via a Ca(2+)-dependent pathway and may play a critical role in maintaining T cell viability in the steady and TCR-activated states. These results suggest a novel regulatory mechanism and an essential function of GRP78 in T cells.
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PMID:T cell receptor-mediated signaling induces GRP78 expression in T cells: the implications in maintaining T cell viability. 1845 57

Dilated human cardiomyopathy is associated with suppression of the prosurvival phosphatidylinositol-3-kinase (PI3K)/Akt and STAT3 pathways. The present study was carried out to determine if restoration of the PI3K/Akt and STAT3 activity by darbepoetin alfa improved cardiac function or reduced cardiomyocyte apoptosis in rabbit autoimmune cardiomyopathy induced by a peptide corresponding to the second extracellular loop of the ss(1)-adrenergic receptor (ss(1)-EC(II)). We found that ss(1)-EC(II) immunization produced progressive LV dilation, systolic dysfunction and myocyte apoptosis as measured by TUNEL, single-stranded DNA antibody, and active caspase-3. These changes were associated with activation of p38 mitogen-activated protein kinase (MAPK), endoplasmic reticulum stress markers (GRP78 and CHOP), and increased cleavage of procaspase-12, as well as decreased phosphorylation of Akt and STAT3, and decreased Bcl2/Bax ratio. As expected, darbepoetin alfa treatment increased phosphorylation of Akt and STAT3. It also increased the myocardial expression of erythropoietin receptor which was reduced in the failing myocardium, and improved cardiac function in the ss(1)-EC(II)-immunized animals. The latter was associated with reductions of myocyte apoptosis and cleaved caspase-3, as well as reversal of increased phosphorylation of p38-MAPK, increased ER stress, and decline in Bcl2/Bax ratio. The anti-apoptotic effects of darbepoetin alfa via Akt and STAT activation were also demonstrated in cultured cardiomyocytes treated with the anti-ss(1)-EC(II) antibody. These effects of darbepoetin alfa in vitro were prevented by LY294002 and STAT3 peptide inhibitor. Thus, we conclude that darbepoetin alfa improves cardiac function and prevents progression of dilated cardiomyopathy probably by activating the PI3K/Akt and STAT3 pathways and reducing ER stress.
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PMID:Darbepoetin alfa exerts a cardioprotective effect in autoimmune cardiomyopathy via reduction of ER stress and activation of the PI3K/Akt and STAT3 pathways. 1858 65

Polyphyllin D (PD) is a potent cytotoxic saponin found in Paris polyphylla. In the present study, bioinformatic, proteomic and transcriptomic analyses were performed to study the mechanisms of action of PD on human nonsmall cell lung cancer (NSCLC) cell line (NCI-H460). Using a gene expression-based bioinformatic tool (connectivity map), PD was identified as a potential ER stress inducer. Our proteomic and transcriptomic analyses revealed that PD treatment led to upregulation of typical ER stress-related proteins/genes including glucose-regulated protein 78 (BiP/GRP78) and protein disulfide isomerase (PDI). In particular, elevated expression of C/EBP homologous transcription factor (chop) and activation of caspase-4 occurred at early time point (8 h) of PD treatment, signifying an initial ER stress-mediated apoptosis. Induction of tumor suppressor p53, disruption of mitochondrial membrane, activation of caspase-9 and caspase-3 were detected upon prolonged PD treatment. Collectively, these data revealed that PD induced the cytotoxic effect through a mechanism initiated by ER stress followed by mitochondrial apoptotic pathway. The ability of activating two major pathways of apoptosis makes PD an attractive drug lead for anticancer therapeutics.
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PMID:Proteomic and transcriptomic study on the action of a cytotoxic saponin (Polyphyllin D): induction of endoplasmic reticulum stress and mitochondria-mediated apoptotic pathways. 1861 25

Baicalein was investigated for tumor cell-specific cytotoxicity, apoptosis-inducing activity and signal pathway against the MDA-MB-231 human breast cancer cell line. After the MDA-MB-231 cells had been treated with baicalein, trypan blue exclusion, propidium iodide (PI) assay and 4',6-diamidino-2-phenylindole (DAPI) were used to stain the dead cells and detect apoptosis, respectively. The effects of baicalein on the levels of reactive oxygen species (ROS), Ca2+ and mitochondrial membrane potential (deltapsim) on MDA-MB-231 cells were examined by flow cytometric assays. The ROS caused endoplasmic reticulum (ER) stress, confirmed by the increase of GADD153 and GRP78 in the examined cells. GADD153 and GRP78 increases were also confirmed by confocal laser microscopy examination and indicated that both proteins translocated to the nucleus. The effects of baicalein on the expression of apoptotic-regulated genes, such as Bcl-2 family and caspase, were detected by Western blotting. To further investigate the apoptotic pathway and the role of Ca2+ induced by baicalein, a caspase-3 inhibitor and Ca2+ chelator were used to block caspase-3 activity and Ca2+ in MDA-MB-231 cells. Baicalein induced apoptosis in a time-dependent effect through the inhibition of Bcl-2 expression, increased the levels of Bax, reduced the level of deltapsim, and promoted the cytochrome c release and caspase-3 activation. MDA-MB-231 cells were pretreated with BAPTA which reduced the levels of Ca2+, deltapsim and apoptosis. In conclusion, baicalein induced apoptosis via Ca2+ production, mitochondria-dependent and caspase-3 activation in MDA-MB-231 cells.
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PMID:The role of Ca2+ in baicalein-induced apoptosis in human breast MDA-MB-231 cancer cells through mitochondria- and caspase-3-dependent pathway. 1863 May 29

Curcumin, a major component of the Curcuma species, is known to have antioxidant, anti-inflammatory properties and induce apoptosis of cancer cells, however, the precise molecular mechanisms of apoptosis in vitro are unclear. In this study, we showed that curcumin, a plant product containing the phenolic phytochemical, caused DNA damage and endoplasmic reticulum (ER) stress and mitochondrial-dependent-induced apoptosis through the activation of caspase-3 at a treatment concentration of 30 microM in human lung cancer A-549 cells. In contrast, treatment with 5-10 microM of curcumin did not induce significant apoptosis, but rather induced G2/M-phase arrest in A-549 cells. Flow cytometric analysis indicated that curcumin directly increased intracellular oxidative stress based on the cell permeable dye, 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA) acting as an indicator of reactive oxygen species (ROS) generation. GADD153 and GRP78 were increased by curcumin which was indicative of ER stress. Curcumin increased Ca(2+) levels and the mitochondrial membrane potential (DeltaPsi(m)), was decreased in A-549 cells. Overall, our results demonstrated that curcumin treatment causes cell death by activating pathways inducing G2/M-phase arrest and apoptosis.
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PMID:DNA damage and endoplasmic reticulum stress mediated curcumin-induced cell cycle arrest and apoptosis in human lung carcinoma A-549 cells through the activation caspases cascade- and mitochondrial-dependent pathway. 1870 Dec 10

Endoplasmic reticulum stress (ER-stress) is associated with ataxia telangiectasia mutated (ATM) gene. We present here conclusive data showing that ATM blocks ER-stress induced by tunicamycin or ionizing radiation (IR). X-box protein-1 (XBP-1) splicing, GRP78 expression and caspase-12 activation were increased by tunicamycin or IR in Atm-deficient AT5BIVA fibroblasts. Activation of caspase-12 and caspase-3 by tunicamycin was significantly reduced in cells transfected with wild-type Atm (AT5BIVA/wtATM). Atm knockdown by siRNA, however, noticeably elevated ER-stress and chemosensitivity to tunicamycin. In summary, we present substantial data demonstrating that ATM blocks the ER stress signaling associated with cancer cell proliferation.
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PMID:ATM blocks tunicamycin-induced endoplasmic reticulum stress. 1930 90

Capsaicin, a pungent ingredient of red pepper, has been reported to possess antitumor activities. In this study, the effects of capsaicin on human HepG2 cells were investigated. Capsaicin reduced viability by PI incorporation in HepG2 cells in a dose and time dependent manner. Capsaicin promoted intracellular Ca2+ production and reactive oxygen species (ROS). The alpha psi(m) significantly decreased after capsaicin treatment for 24 h. Co-treatment of HepG2 cells with capsaicin and BAPTA (an intracellular Ca2+ chelator) significantly reduced intracellular Ca2+ levels, prevented alpha psi(m) disruption and inhibited apoptosis induction. The protein levels of Bcl-2 decreased and Bax increased in the mitochondrial fraction while the Bax protein decreased, and p53 and cytochrome c protein levels increased in the cytosolic fraction in HepG2 cells after capsaicin treatment for 24 h by Western blot. Immunostaining and confocal microscopic analysis also showed that capsaicin promoted cytoplasmic GADD153 expression and GRP78 nuclear translocation. The caspase-3 activity significantly increased after capsaicin treatment for 24 h. Our results indicated that the capsaicin-induced apoptosis in HepG2 cells may result from the elevation of intracellular Ca2+ production, ROS, disruption of alpha psi(m), regulation of Bcl-2 family protein expression and caspase-3 activity.
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PMID:Capsaicin-induced apoptosis in human hepatoma HepG2 cells. 1933 Nov 47


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