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)

Rifampicin modulates immune response; however, mechanisms by which it exerts these effects are incompletely understood. Recently, rifampicin has been shown to bind to and activate glucocorticoid receptors. Because of the evidence for a role of glucocorticoids in lymphocyte apoptosis, we hypothesized that rifampicin may exert its influence on the immune system by regulating apoptosis. Therefore, we examined the effect of rifampicin on signaling pathway of anti-CD95-induced apoptosis in peripheral blood lymphocytes. Rifampicin, in a concentration-dependent manner, inhibited anti-CD95-induced apoptosis in both CD4+ and CD8+ T cells, which was associated with the inhibition of activation of both caspase-3 and caspase-8. In addition, rifampicin down-regulated the expression of CD95L and Bax. The inhibitory effects of rifampicin on apoptosis and caspase activation as well as its effect on the expression of CD95L and FLIPs were reversed by RU486, an antagonist of glucocorticoid receptor. These data suggest that rifampicin inhibits anti-CD95-mediated apoptosis in lymphocytes by modulating the expression of certain proteins that regulate apoptosis, at least in part, via glucocorticoid receptors.
 ...
PMID:Molecular basis of rifampicin-induced inhibition of anti-CD95-induced apoptosis of peripheral blood T lymphocytes: the role of CD95 ligand and FLIPs. 1264 56

In multiple sclerosis (MS), an impaired apoptotic deletion of activated CNS-specific immune cells, leading to their pathogenic persistence, has been suggested to maintain chronic brain inflammation. We here investigated whether interferon-beta (IFN-beta) therapy induces apoptosis of peripheral immune cells. Serial blood samples from 127 relapsing-remitting MS patients were analyzed prior to the initiation of a weekly IFN-beta 1a therapy and 4, 26, and 52 weeks thereafter. Peripheral immune cells were investigated for apoptosis and for the expression of apoptosis-regulatory genes CD95, CD95 ligand, FLIP, Bcl-2, Bcl-X(L), Bag-1, and caspase 3 by quantitative real-time PCR. Biological efficacy of IFN-beta treatment was checked by quantification of Mx expression (ELISA and real-time PCR). We found a significant increase in the apoptosis rate of immune cells in response to IFN-beta treatment, compared to baseline levels. While Bcl-2 levels were permanently and Bag-1 levels transiently elevated upon therapy, other apoptosis-regulatory genes revealed no alterations. Upregulation of Mx expression confirmed the activity of IFN-beta in vivo. These findings indicate that immunomodulatory IFN-beta therapy involves the induction of apoptotic cell death with the observed RNA upregulation of Bcl-2 family members rather reflecting a possible compensatory mechanism. The increased apoptosis susceptibility of peripheral immune cells may contribute to the known reduction of brain inflammatory lesions during IFN-beta treatment.
 ...
PMID:Systemic IFN-beta treatment induces apoptosis of peripheral immune cells in MS patients. 1266 63

Natural Killer (NK) cells can induce apoptosis in target cells in at least four ways: by secretion of granzyme B/perforin (GrB/P) and via the CD95L, TRAIL and TNF-alpha pathways. In this study we examined the pathways used by interleukin-2 activated rat NK (A-NK) cells to induce apoptosis in the rat colon carcinoma cell line CC531s. Co-incubation of A-NK cells with CC531s cells for three hours resulted in 70% apoptosis in the latter. Addition of the GrB/P pathway-inhibitor concanamycin A reduced the number of apoptotic cells to 54%. Blockade of the CD95L, TRAIL and TNF-alpha pathways by specific antibodies hardly had an additional effect. However, co-incubation with transfected MEC cells that expressed CD95L or 2PK3-cells that expressed TRAIL did induce apoptosis in CC531s cells. Furthermore the A-NK cells contained CD95L and TRAIL. However, comparison of non- and permeabilized cells revealed that the majority of TRAIL was present in the cytosol of A-NK cells and was not available for induction of apoptosis. The presence of elevated levels of bcl-2 in CC531 cells reduced the sensitivity towards induction of apoptosis both by A-NK cells as well as the CD95L and TRAIL expressing cell lines. Using the caspase-inhibitors ac-IEPD-CHO, ac-DEVD-CHO and zVAD-fmk, it was shown that inhibition of the effector caspase-3 prevented A-NK cell induced apoptosis in CC531-bcl-2 cells, but not in CC531s cells. In conclusion, A-NK cells kill by secretion of GrB/P and not by the CD95L, TRAIL or TNF pathways albeit both CD95L and TRAIL are produced by the A-NK cells.
 ...
PMID:Interleukin-2 activated NK cells do not use the CD95L- and TRAIL-pathways in the rapid induction of apoptosis of rat colon carcinoma CC531s cells. 1267 69

Aplidine is a promising antitumor agent derived from the Mediterranean tunicate Aplidium albicans. We have found that Aplidine at nM concentrations (10-100 nM) induced apoptosis in human leukemic cell lines and primary leukemic cell cultures from leukemic patients. Inhibition of the Fas (CD95)/Fas ligand (CD95L) signaling pathway with an antagonistic anti-Fas antibody partially inhibited Aplidine-induced apoptosis. L929 cells were resistant to Aplidine action but underwent apoptosis after transfection with human Fas cDNA. Aplidine induced a rapid and sustained c-Jun NH(2)-terminal kinase activation, and pretreatment with curcumin or SP600125 inhibited Aplidine-induced c-Jun NH(2)-terminal kinase activation and apoptosis. However, inhibition of extracellular signal-regulated kinase and p38 kinase signaling pathways did not affect Aplidine-induced apoptosis. Aplidine induced caspase-3 activation, and caspase inhibition prevented Aplidine-induced apoptosis. Aplidine failed to induce apoptosis in MCF-7 breast cancer cells, defective in caspase-3, additionally implicating caspase-3 in its proapoptotic action. Aplidine also triggered an early release of cytochrome c from mitochondria, and overexpression of bcl-2 by gene transfer abrogated mitochondrial cytochrome c release and apoptosis. Aplidine rapidly induced cleavage of Bid, a mediator that connects the Fas/CD95 cell death receptor to the mitochondrial apoptosis pathway. Primary cultures of normal human cells, including hepatocytes and resting peripheral blood lymphocytes, were spared or weakly affected after Aplidine treatment. Nevertheless, mitogen (phytohemagglutinin/interleukin-2)-activated T lymphocytes resulted sensitively to the apoptotic action of Aplidine. Thus, Aplidine is an extremely potent and rapid apoptotic inducer on leukemic cells that triggers Fas/CD95- and mitochondrial-mediated apoptotic signaling routes, and shows a rather selective apoptotic action on cancer cells and activated T cells.
 ...
PMID:Rapid and selective apoptosis in human leukemic cells induced by Aplidine through a Fas/CD95- and mitochondrial-mediated mechanism. 1268 30

The immune status and the PBL apoptosis were studied in the healthy donors and the opioid addicts. Leukocytosis and the increased percentage of the CD3(+) T cells, CD8(+) T cells, CD19(+) B cells, activated CD25(+) and HLA DR(+) lymphocytes were observed in the addicted patients. The number of the CD95 and CD95L bearing cells also was increased however the percentage of the bcl-2(+) lymphocytes was the same as for the donors. The activated PBL subset "pattern" was accompanied by increased IgM level, decreased IgG and IgA levels and elevated serum IL-1beta and TNFalpha. PBL mitogenic response and LPS-induced IL-1beta, TNFalpha and IFNalpha production were suppressed in the opioid addicts. These changes were associated with the increased level of the spontaneous PBL apoptosis, which was documented by morphological method and caspase 3 activity evaluation. The anti-CD3mAbs-induced T-cell apoptosis in the 72-h cultures also was increased however the activated T cells from the addicted patients were resistant to the dexamethasone-induced apoptosis. The immune abnormalities were more prominent in patients with the clinically manifested infectious immunopathological syndrome. Thus, the activation-induced lymphocyte apoptosis may be the factor of importance in the mechanisms of the immunodeficiency in the opioid addicts.
 ...
PMID:The Immune Status and Lymphocyte Apoptosis in the Opioid Addicts. 1268 28

The molecular mechanisms underlying the clinical effects of alpha interferon (IFN) and ribavirin are not understood. Elimination of infected cells occurs in part by cytotoxic T lymphocytes (CTLs) expressing CD95 ligand and thereby attacking target cells which are positive for the death receptor CD95. Since many viruses have evolved mechanisms to inhibit apoptosis, the opposite, namely, promotion of apoptosis, could be a strategy to strengthen the host antiviral response. In the present study, we have asked whether the antiviral substances IFN and ribavirin could support CD95-mediated apoptosis by interfering with the activation of caspases, a family of proteases known for their essential role in apoptosis. HepG2 cells, stimulated with the agonistic anti-CD95 antibody, served as a minimal model to mimic the CD95 stimulation occurring during a CTL attack of target cells in vivo. Apoptosis was quantitated by flow cytometric detection of hypodiploid nuclei. Caspase activity was measured by cytofluorometry, immunocytochemistry, and immunoblot analysis. IFN and ribavirin sensitized HepG2 cells for CD95-mediated apoptosis. This effect was correlated with an increase in CD95-mediated caspase activation and enhanced cleavage of the caspase substrate poly(ADP-ribose) polymerase. Furthermore, the positive effect on CD95-mediated caspase activation by IFN and ribavirin was confirmed by immunocytochemistry for activated caspase-3 and by immunoblot detection of activated caspase-3, caspase-7, and caspase-8. Our data demonstrate that the antiviral substances IFN and ribavirin are able to sensitize for CD95-mediated apoptosis. IFN and ribavirin also enhance CD95-mediated caspase activation, which might in part be responsible for the apoptosis-promoting effect of these antiviral compounds.
 ...
PMID:Ribavirin and alpha interferon enhance death receptor-mediated apoptosis and caspase activation in human hepatoma cells. 1276 Aug 67

Activation-induced cell death (AICD) is a mechanism of homeostasis that limits the clonal expansion of autoreactive T cells and regulates central and peripheral tolerance. In nonobese diabetic (NOD) mice, defects in central and peripheral tolerance are associated with a proliferative hyporesponsiveness of thymocytes and peripheral T cells elicited upon TCR activation. We investigated whether these defects in tolerance induction and hyporesponsiveness of NOD T cells manifest in an altered susceptibility to TCR-induced AICD. TCR-activated NOD splenic CD4+ and CD8+ T cells are more resistant to AICD than control strain C57BL/6, BALB/c, and NOR T cells. NOR CD4+ but not CD8+ T cells are resistant to TCR-induced AICD. Whereas c-FLIP expression is reduced in activated T cells from control strains, it persists in activated NOD CD8+ T cells and is accompanied by diminished activity of caspase-3 and -8. IL-4 reduces this c-FLIP expression and increases caspase-3 and -8 activity in activated NOD CD8+ T cells. Moreover, IL-4 and CD28 costimulation restores the susceptibility of NOD CD8+ T cells to AICD, and this is associated with increased expression of CD25, CD95, CD95L, and TNFR2. Thus, deficient activation of CD8+ T cells and their greater resistance to TCR-induced AICD may mediate defective peripheral tolerance and the development of T1D in NOD mice.
 ...
PMID:Deficient activation and resistance to activation-induced apoptosis of CD8+ T cells is associated with defective peripheral tolerance in nonobese diabetic mice. 1276 79

Immunophilin ligands such as FK506 and Cyclosporin A, used in immunosuppression, are well-characterized drugs. In the past, they had been the center of attention as a putative therapeutic strategy for neuroregeneration and neuroprotection. In contrast to Cyclosporin A, FK506 readily crosses the brain-blood-barrier and, thus together with its derivatives, may represent a novel approach to the treatment of neurological disorders. FK506 exerts profound neuroprotective and neuroregenerative effects in vivo and in vitro. The mechanism underlying neuroregeneration is fairly well understood. It is independent of the inhibition of calcineurin, which is responsible for the immunosuppression, but operates via the binding of FKBP52 and the heat shock protein (Hsp) 90. In contrast, the underlying pathways of neuroprotection are far less understood. Protection is apparently independent of calcineurin, as shown by non-calcineurin inhibiting derivatives, such as V-10,367 and GPI-1046, but the intracellular actions remain to be defined. FK506 has been shown to interfere with the apoptotic pathway of neuronal cells, including inhibiting JNK activity, cytochrome c release, caspase 3 activation, and CD95 ligand expression. These effects are in part mediated by the inhibition of calcineurin and may not contribute to protection. Our recent studies suggest that the protective properties of FK506 and its non-calcineurin inhibiting derivatives are realized by a fast induction of heat shock proteins. The induction of the heat shock response by immunophilin ligands might prove to be an interesting target for neuroregeneration and neuroprotection.
 ...
PMID:FK506 and its analogs - therapeutic potential for neurological disorders. 1276 96

Antithymocyte globulins (ATGs), the immunoglobulin G (IgG) fraction of sera from rabbits or horses immunized with human thymocytes or T-cell lines, are used in conditioning regimens for bone marrow transplantation, in the treatment of acute graft-versus-host disease, in the prevention or treatment of acute rejection in organ transplantation, and in severe bone marrow aplasia. In nonhuman primates, ATGs induce rapid, dose-dependent, T-cell depletion in peripheral lymphoid tissues, where apoptotic cells can be demonstrated in T-cell zones. We show here that increasing ATG concentrations in vitro resulted in reduced lymphocyte proliferative responses, associated with a rapid increase in the percentage of apoptotic cells. Apoptosis did not require prior exposure to interleukin-2, nor did it result in CD178/CD95 or tumor necrosis factor/tumor necrosis factor receptor (TNF/TNF-R) interactions; it was therefore clearly different from activation-induced cell death. Cytochrome c release, caspase-9, and caspase-3 activation were not implicated, excluding a direct involvement of the intrinsic mitochondrial pathway. The cysteine protease inhibitor E64d and cathepsin-B-specific inhibitors conferred significant protection, whereas apoptosis was associated with the release of active cathepsin B into the cytosol. These data demonstrate a role for cathepsin B in T-cell apoptosis induced by ATGs at concentrations achieved during clinical use.
 ...
PMID:Cathepsin-B-dependent apoptosis triggered by antithymocyte globulins: a novel mechanism of T-cell depletion. 1289 46

The mechanisms of As(2)O(3)-induced apoptosis are very complex. In the present study, we investigated the molecular mechanism of As(2)O(3) in vitro at low concentration (0.25-2.0 micro M) on three human leukemia/lymphoma cell lines: HL-60, RL and K562. As(2)O(3) inhibited the growth of these cell lines significantly. During As(2)O(3) treatment, two forms of cell death, apoptosis in HL-60 and RL and oncosis in K562, were found by morphological study. In HL-60 and RL, cell cycle analysis showed, at a distinct SubG1 region, that CD95 and CD95 ligand (CD95L) expression was upregulated, caspase 8 and caspase 3 were activated, and Bcl-2 protein expression was downregulated. On the other hand, in K562, the cell cycle was arrested at the G2+M phase, CD95/CD95L expression was upregulated, caspase 8 and caspase 3 were activated, but Bcl-2 expression was not changed as compared with untreated cells. These findings suggest that the CD95/CD95L pathway is involved in cell killing by As(2)O(3). Using anti-CD95 IgG monoclonal antibody (anti-CD95 MoAb) or specific caspase inhibitor ZVAD-fmk to block the CD95 pathway, the cell death induced by As(2)O(3) was partially blocked in each cell line. These results suggest that As(2)O(3) inhibits the growth of these leukemia/lymphoma cell lines by inducing apoptosis or oncosis that is partially mediated by the CD95/CD95L pathway.
 ...
PMID:The molecular mechanism of arsenic trioxide-induced apoptosis and oncosis in leukemia/lymphoma cell lines. 1297 49


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>