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)

This study aims to investigate the role of granzyme B in the apoptosis of nasal-type NK/T-cell lymphoma. Twenty-four nasal-type NK/T-cell lymphomas were examined by TdT-mediated deoxyuridine triphosphate (dUTP)-biotin nick-end labeling (TUNEL) assay and immunohistochemical staining for active caspase 3, poly(ADP-ribose) polymerase (PARP-1/p85)/p85, and Bcl-2. In addition, HANK-1 and NKL cell lines were analyzed using Western blot analysis. Immunoprecipitation was performed to identify the binding of granzyme B and intrinsic serpin proteinase inhibitor 9 (PI-9). To localize granzyme B, immunogold labeling and immunofluorescence staining were performed. The expression level of granzyme B in tumor tissue was correlated with the apoptosis rate (P=0.015), degree of necrosis (P=0.002), and the levels of active caspase 3 (P=0.036) and poly ADP-ribose polymerase (PARP)-1/p85 (P=0.040). The granzyme B-positive HANK-1 cell line showed increased spontaneous cell death compared to the granzyme B-negative NKL cell line. The untreated HANK-1 cells released cytochrome c into the cytosol with cleavage of caspase 3 and PARP-1. Treatment with granzyme B inhibitor and caspase inhibitor decreased the cleavage of PARP-1. By performing immunogold labeling, granzyme B was identified within the cytolytic granules as well as in the cytosol. Confocal microscopy and immunoprecipitation assays confirmed the colocalization of PI-9 and granzyme B, which formed an SDS-resistant complex. These results suggested that granzyme B leakage induces cell death in NK/T-cell lymphomas via both caspase-dependent and -independent mechanisms, and this leads to the extensive necrosis that is commonly seen in NK/T-cell lymphoma.
 ...
PMID:Granzyme B leakage-induced apoptosis is a crucial mechanism of cell death in nasal-type NK/T-cell lymphoma. 1726 2

Cytotoxic T cells and natural killer cells play key roles in cell-mediated cytotoxicity and can induce apoptosis in virus-infected and malignant cells by releasing cytotoxic granules. In the current study, apoptosis was induced in Jurkat cells, a human T cell line, by delivering granzyme B into the cells using BioPORTER, a cationic lipid formulation. During granzyme B-induced apoptosis, there was an increase in the cell surface expression of Lewis X and Y antigens. To clarify the roles of initiator and executioner caspases in the expression of Lewis X and Y antigens, we treated Jurkat cells with granzyme B in the presence of caspase 3, 8, and 9 inhibitors. The results indicated that delivery of granzyme B into Jurkat cells induces apoptosis by activating caspase 3 and that caspase 3 but not caspase 8 and 9 plays a key role in enhancing the expression of Lewis X and Y antigens. Real-time PCR revealed that expression of the mRNAs for alpha1,3-fucosyltransferases FUT4 was increased at 3 h during granzyme B-induced apoptosis, while FUT9 mRNA expression gradually increased after 12 h. This increased expression of FUT4 mRNA occurred downstream of caspase 3 activation and resulted in the increased cell surface expression of Lewis X and Y antigens.
 ...
PMID:Increased expression of Lewis X and Y antigens on the cell surface and FUT 4 mRNA during granzyme B-induced Jurkat cell apoptosis. 1740 97

Caspases are proteolytic enzymes that are essential for apoptosis. Understanding the many discrete and interacting signaling pathways mediated by caspases requires the identification of the natural substrate repertoire for each caspase of interest. Using an amplification-based protein selection technique called mRNA display, we developed a high-throughput screen platform for caspase family member specific substrates on a proteome-wide scale. A large number of both known and previously uncharacterized caspase-3 substrates were identified from the human proteome. The proteolytic features of these selected substrates, including their cleavage sites and specificities, were characterized. Substrates that were cleaved only by caspase-8 or granzyme B but not by caspase-3, were readily selected. The method can be widely applied for efficient and systematic identification of the family member specific natural substrate repertoire of any caspase in an organism of interest, in addition to that of numerous other proteases with high specificity.
 ...
PMID:Proteome-wide identification of family member-specific natural substrate repertoire of caspases. 1772 5

Lymphocyte-mediated cytotoxicity via granule exocytosis operates by the perforin-mediated transfer of granzymes from CTLs and NK cells into target cells where caspase activation and other death pathways are triggered. Granzyme B (GzB) is a major cytotoxic effector in this pathway, and its fate in target cells has been studied by several groups using immunodetection. In this study, we have used a newly developed cell-permeable fluorogenic GzB substrate to measure this protease activity in three different living targets following contact with cytotoxic effectors. Although no GzB activity is measurable in CTL or NK92 effector cells, this activity rapidly becomes detectable throughout the target cytoplasm after effector-target engagement. We have combined the GzB substrate with a second fluorogenic substrate selective for caspase 3 to allow both flow cytometry and fluorescence confocal microscopy studies of cytotoxicity. With both effectors, caspase 3 activity appears subsequent to that of GzB inside all three targets. Overexpression of Bcl-2 in target cells has minimal effects on lysis, NK- or CTL-delivered GzB activity, or activation of target caspase 3. Detection of target GzB activity followed by caspase 3 activation provides a unique readout of a potentially lethal injury delivered by cytotoxic lymphocytes.
 ...
PMID:Granzyme B activity in target cells detects attack by cytotoxic lymphocytes. 1778 18

Cyclopentenyl cytosine (CPEC) has been shown to induce apoptosis in human T lymphoblastic cell lines and T cells from leukaemia patients. In this study we have addressed the question of whether CPEC is able to decrease proliferation and effector functions of human alloresponsive T lymphocytes and induce T cell anergy. The proliferative capacity of human peripheral blood mononuclear cells in response to allogeneic stimulation was measured by 5,6-carboxy-succinimidyl-diacetate-fluorescein-ester staining. Flow cytometric analysis was performed using surface CD4, CD8, CD25, CD103 and intracellular perforin, granzyme A, granzyme B, caspase-3 and forkhead box P3 (FoxP3) markers. The in vivo immunosuppressive capacity was tested in a murine skin graft model. Addition of CPEC at a concentration of 20 nM strongly decreased the expansion and cytotoxicity of alloreactive T cells. Specific restimulation in the absence of CPEC showed that the cells became anergic. The drug induced caspase-dependent apoptosis of alloreactive T lymphocytes. Finally, CPEC increased the percentage of CD25(high) FoxP3+ CD4+ and CD103+ CD8+ T cells, and potentiated the effect of rapamycin in increasing the numbers of alloreactive regulatory T cells. Treatment with CPEC of CBA/CA mice transplanted with B10/Br skin grafts significantly prolonged graft survival. We conclude that CPEC inhibits proliferation and cytotoxicity of human alloreactive T cells and induces alloantigen non-responsiveness in vitro.
 ...
PMID:The pyrimidin analogue cyclopentenyl cytosine induces alloantigen-specific non-responsiveness of human T lymphocytes. 1806 97

Granzyme B (gzmB) of cytotoxic T lymphocytes (CTL) is essential for recovery from intracellular pathogens, but the molecular basis of its action is still unresolved. Here, we analyzed gzmB-mediated death pathways under physiological conditions using ex vivo virus-immune CTLs that express perf and gzmB, but not gzmA (gzmB(+)CTL). We show that gzmB(+)CTL abrogate target cell proliferation most likely by inducing cell death, independent of caspases and mitochondrial signaling. In addition, the data reveal that gzmB(+)CTL independently induce pro-apoptotic processes either via caspase-3/-7, leading to plasma membrane perturbance and ROS production or via Bid/Bak/Bax, resulting in cytochrome c release and that both pathways elicit loss of DeltaPsi(m). Our data provide evidence for a pleiotropic pro-apoptotic function of gzmB presumably to counteract evasion strategies of pathogens and to control tumors.
 ...
PMID:Granzyme B-induced cell death exerted by ex vivo CTL: discriminating requirements for cell death and some of its signs. 1806 39

Acute myeloid leukemia (AML) cells of subtypes M4 and M5 show enhanced expression of CD64 (FcgammaRI), the high-affinity receptor for IgG, which is normally expressed at high levels only on activated cells of the myeloid lineage. CD64 is therefore a prime target for the specific delivery of cytotoxic agents. A promising toxin candidate is granzyme B, a human serine protease originating from cytotoxic granules of CD8+ T lymphocytes and natural killer cells. After evaluating the sensitivity of the AML-related cell line U937 toward cytosolic granzyme B, we genetically fused granzyme B to H22, a humanized single-chain antibody fragment (scFv) specific for CD64, to obtain Gb-H22(scFv), a fusion protein lacking the immunogenic properties of nonhuman immunofusions. Gb-H22(scFv) was successfully expressed in human 293T cells, secreted, and purified from cell culture supernatants. The purified protein bound specifically to CD64+ U937 cells. Despite linkage to the binding domain, the proteolytic activity of functional Gb-H22(scFv) was identical to that of free granzyme B. Target cell-specific cytotoxicity was observed with a half-maximal inhibitory concentration (IC50) between 1.7 and 17 nmol/L. In addition, the induction of apoptosis in U937 cells was confirmed by Annexin A5 staining and the detection of activated caspase-3 in the cytosol. Finally, apoptosis was observed in primary CD64+ AML cells, whereas CD64(-) AML cells were unaffected. This is the first report of a completely human granzyme B-based immunotoxin directed against CD64, with activity against an AML-related cell line and primary AML cells.
 ...
PMID:Granzyme B-H22(scFv), a human immunotoxin targeting CD64 in acute myeloid leukemia of monocytic subtypes. 1879 Jul 73

The polycation poly(ethylenimine) (PEI) was used to deliver the plasmids coding for various combinations of caspases to Cox-2 overexpressing cancer cell lines. It was found that the expression of the delivered genes, controlled by the Cox-2 promoter, correlated with the expression of the endogenous Cox-2 gene in each cell line in a relatively linear manner. Among the various caspase combination regimens, the combination of caspase 3 plus caspase 9 proved to be the most effective because of an apparent synergy between the two gene products, and produced phosphatidylserine flipping in addition to fragmentation of genomic DNA. Caspase 1 appeared to work independently of either caspases 3 or 9, as no synergistic effect was observed. Transfections with genes coding for granzyme B and caspase 8 yielded a lesser amount of cell death. The delivery of a combination of caspase genes could be readily moved to in vivo research of bladder and colon cancer treatments, and holds great applicability to a wide array of additional tumor types.
 ...
PMID:Comparison of caspase genes for the induction of apoptosis following gene delivery. 1906 54

The aim of the present study was to identify the mechanism of hepatocellular apoptosis induced by EBV-infected cytotoxic T/natural killer (NK) cells in chronic active EBV infection (CAEBV). Eight patients with CAEBV were studied, and infected T-cell expansion and NK-cell expansion were detected in four patients each. Biopsy or necropsy was performed on lymph node, liver, or spleen, and each specimen was subjected to immunohistochemical double staining of CD3 plus caspase-3 with the addition of cytotoxic markers of T-cell restricted intracellular antigen-1 (TIA-1), perforin, and granzyme B, as well as EBV in situ hybridization (EBV-ISH). In the liver, some of the infiltrating CD3-positive lymphocytes stained positively for EBV-ISH and cytotoxic markers. Double staining of CD3 plus caspase-3 indicated caspase-3 positive hepatocytes with apoptotic features, accompanied by extensive infiltration of CD3-positive cells, which were directly attached to the apoptotic caspase-3 positive hepatocytes. In contrast, far fewer cells stained positive for caspase-3 in lymph node and spleen than in liver. The present findings suggest that in patients with CAEBV, cytotoxic T/NK cells may directly induce hepatocytes to undergo apoptosis more frequently than they do cells in other organs of the reticulo-endothelial system.
 ...
PMID:Hepatocellular apoptosis associated with cytotoxic T/natural killer-cell infiltration in chronic active EBV infection. 1956 6

Cisplatin is a first-line chemotherapeutic agent and a powerful component of standard treatment regimens for several human malignancies including bladder cancer. DNA-Pt adducts produced by cisplatin are mainly responsible for cellular toxicity and induction of apoptosis. Identification of the mechanisms that control sensitivity to cisplatin is central to improving its therapeutic index and to successfully encountering the acquired resistance frequently emerging during therapy. In the present study, using MTT-based assays, Western blotting and semi-quantitative RT-PCR, we examined the apoptosis-related cellular responses to cisplatin exposure in two human urinary bladder cancer cell lines characterized by different malignancy grade and p53 genetic status. Both RT4 (grade I; wild-type p53) and T24 (grade III; mutant p53) cell types proved to be vulnerable to cisplatin apoptotic activity, albeit in a grade-dependent and drug dose-specific manner, as demonstrated by the proteolytic processing profiles of Caspase-8, Caspase-9, Caspase-3, and the Caspase repertoire characteristic substrates PARP and Lamin A/C, as well. The differential resistance of RT4 and T24 cells to cisplatin-induced apoptosis was associated with an RT4-specific phosphorylation (Ser15; Ser392) pattern of p53, together with structural amputations of the Akt and XIAP anti-apoptotic regulators. Furthermore, cisplatin administration resulted in a Granzyme B-mediated proteolytic cleavage of Hsp90 molecular chaperone, exclusively occurring in RT4 cells. To generate functional networks, expression analysis of a number of genes, including Bik, Bim, Bcl-2, FAP-1, Fas, FasL, TRAIL, Puma, Caspase-10, ATP7A, ATP7B and MRP1, was performed, strongly supporting the role of p53-dependent and p53-independent transcriptional responses in cisplatin-induced apoptosis of bladder cancer cells.
 ...
PMID:Human bladder cancer cells undergo cisplatin-induced apoptosis that is associated with p53-dependent and p53-independent responses. 1957 56


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