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

The present study was conducted to determine whether T(3) receptor exists in early placental extravillous trophoblasts (EVTs) and evaluate the influence of T(3) on Fas/Fas ligand expression, caspase-3, and poly (ADP-ribose) polymerase (PARP) cleavage and apoptosis in cultured early placental EVTs. EVTs with invasive phenotype, isolated from normal placental explants from early pregnancy through preincubation on human fibronectin-coated dishes and exhibited cytokeratin 7 and human placental lactogen immunopositive staining, were cultured in the absence or presence of T(3) (10(-7) to 10(-9) m). The presence of T(3) receptor in cultured EVTs was examined by immunocytochemistry, RT-PCR, and Southern blot analysis. Fas sensitivity was determined by treating the cells with an agonistic Fas antibody. Apoptosis was assessed by terminal deoxynucleotidyl transferase deoxyuridine triphosphate nick end labeling, flow cytometry, and Hoechst nuclear staining. Fas and Fas ligand expression and caspase-3 and PARP cleavage were evaluated by immunocytochemistry. Early placental EVTs expressed a 212-bp c-erb Abeta1 transcript and the T(3) receptor protein and exhibited significant levels of apoptosis in culture. Treatment with T(3) reduced the expression of Fas and Fas ligand as well as cleavage of caspase-3 and PARP and suppressed apoptosis in cultured EVTs. Although addition of agonistic Fas antibody increased apoptosis in these cells, this response was markedly attenuated by the presence of T(3). These results demonstrate that T(3) receptor is present in early placental EVTs and that T(3) suppresses apoptosis by down-regulating the expression of Fas and Fas ligand. These findings are consistent with the hypothesis that T(3) promotes EVT invasion to the decidua by suppressing apoptosis in early pregnancy.
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PMID:3,5,3'-Triiodothyronine down-regulates Fas and Fas ligand expression and suppresses caspase-3 and poly (adenosine 5'-diphosphate-ribose) polymerase cleavage and apoptosis in early placental extravillous trophoblasts in vitro. 1529 50

Neutrophils are an important component of airway inflammation and may interact with human airway smooth muscle cells (HASMC). We investigated the effect of neutrophils and of neutrophil-derived proteases on HASMC survival. When co-incubated with neutrophils (0.1-1 x 10(6) cells/ml), attachment of human ASMC was reduced to 12.3 +/- 4.3% compared with untreated controls after 72 h. HASMC showed nuclear condensation and fragmentation (41.6 +/- 8.1% compared with baseline of 3.1 +/- 0.4%), and the biochemical markers of apoptosis, annexin V binding (9.7 +/- 0.7%; baseline 1.1 +/- 0.3%) and cleaved caspase-3 expression, were observed. The proteolytic activity released by neutrophils was essential for the proapoptotic effect because inhibition of elastase activity by alpha(1)-antitrypsin and MeOSuc-Ala-Ala-Pro-Ala-CMK (MSACK) reduced HASMC apoptosis. Human neutrophil elastase (0.1-3 microg/ml) induced apoptosis of HASMC, as well as other neutrophil serine proteases, cathepsin G, and proteinase 3. Fibronectin degradation products were present in HASMC supernatants exposed to neutrophil-conditioned media and to neutrophil elastase. The local release of proteases from neutrophils present in airway smooth muscle cells may lead to HASMC apoptosis as a result of matrix degradation and loss of cell attachment. This may limit pathologic changes such as ASMC hyperplasia and extracellular matrix deposition seen in airway remodeling.
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PMID:Induction of human airway smooth muscle apoptosis by neutrophils and neutrophil elastase. 1565 31

Extracellular matrix (ECM) expansion and mesangial cell (MC) proliferation are prominent features of most types of glomerulosclerosis. A delicate balance between the ECM and MC regulates cell survival. Increasing evidence shows that a loss of ECM components can cause mitochondrial dysfunction and induce cell apoptosis. It is proposed that directly blocking the synthesis of ECM components could lighten ECM accumulation and suppress cell overproliferation status. Fibronectin, one of the predominant adhesive glycoproteins of the mesangial ECM, provides the survival signal for cells. Its accumulation can be observed in most types of glomerulosclerosis. In this study, angiotensin II-induced fibronectin was suppressed by an RNA interference technique. It is interesting that MC slowly underwent apoptosis after infection with a retrovirus that continuously suppressed fibronectin synthesis. It was found that MC apoptosis occurred in a mitochondria-dependent manner mainly as a result of cytochrome c release and downstream caspase-3 and -9 activation. Furthermore, it was demonstrated that fibronectin knockdown affected mitochondrial handling of Ca(2+) release from the endoplasmic reticulum. Importantly, blocking the inositol 1,4,5-triphosphate receptor with, 3,4,5-trimethoxybenzoate or decreasing Ca(2+) in the ECM with EGTA partially saved the cells from apoptosis. These studies, which explored a new method for simultaneously inhibiting MC proliferation and ECM accumulation, may represent a novel therapeutic approach to glomerulosclerosis.
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PMID:Knockdown of fibronectin induces mitochondria-dependent apoptosis in rat mesangial cells. 1567 10

Cardiac myocyte loss, regardless of insult, can trigger compensatory myocardial remodeling leading to heart failure. Identifying mediators of cardiac myocyte survival may advance clinical efforts toward myocardial preservation. Angiopoietin-1 limits ischemia-induced cardiac injury. This benefit is ascribed to angiogenesis because the receptor, tie2, is largely endothelial-specific. We propose that direct, non-tie2 interactions of angiopoietin-1 on cardiac myocytes contribute to this cardioprotection. We found that mouse C2C12 skeletal myocytes lack tie2, yet dose-dependently adhered to angiopoietin-1 and angiopoietin-2 similarly to laminin, fibronectin, vitronectin, and more than to collagen-I, -III, and -IV. Adhesion was divalent cation-mediated (Mn2+, Ca2+, not Mg2+), blocked with EDTA/EGTA, RGD-based peptides, and select integrin subunit antibodies. Similar findings were obtained with human skeletal myocytes (HSMs) and freshly isolated rat neonatal cardiac myocytes (NCMs). Furthermore, angiopoietin-1 conferred significant survival advantage exceeding that of most cell matrices, which was not fully explained by differences in cell adhesion. Angiopoietin-1 promoted survival of serum-starved C2C12, HSM, and NCM (MTT, trypan blue) and prevented taxol-induced apoptosis (caspase-3). Immobilized and soluble angiopoietin-1 phosphorylated Akt(S473) and MAPK(p42/44), (not FAK(Y397)) in C2C12 more than in endothelial cells and more than did angiopoietin-2 or cell matrices. EDTA, RGD-based peptides, and some integrin antibodies blocked these responses. Angiopoietin-1 activated HSM and NCM Akt(S473) and MAPK(p42/44) survival pathways. We propose that this novel function contributes to developmental and cardioprotective actions of angiopoietin-1 presently attributed to vascular effects alone. Angiopoietin-1 may prove therapeutically valuable in cardiac remodeling by supporting myocyte viability and preserving pump function. The full text of this article is available online at http://circres.ahajournals.org.
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PMID:Angiopoietin-1 promotes cardiac and skeletal myocyte survival through integrins. 1569 86

Fibroblast growth factor receptor signaling is an important mechanism regulating osteoblast function. To gain an insight into the regulatory role of FGF receptor-2 (FGFR2) signaling in osteoblasts, we investigated integrin-mediated attachment and cell survival in human calvarial osteoblasts expressing activated FGFR2. FGFR2 activation reduced osteoblast attachment on fibronectin. This was associated with reduced expression of the alpha5 integrin subunit normally expressed in human calvarial osteoblasts in vivo. Treatment with lactacystin, a potent inhibitor of proteasome, restored alpha5 integrin levels in FGFR2 mutant osteoblasts. Immunoprecipitation analysis showed that alpha5 integrin interacts with both the E3 ubiquitin ligase Cbl and ubiquitin. Immunocytochemistry revealed that alpha5 integrin colocalizes with FGFR2 and Cbl at the leading edge in membrane ruffle regions. Transfection with the 70Z-Cbl mutant lacking the RING domain required for Cbl-ubiquitin interaction, or with the G306E Cbl mutant that abolishes the binding ability of Cbl phosphotyrosine-binding domain restored alpha5 integrin levels. This suggests that Cbl-mediated ubiquitination plays an essential role in alpha5 integrin proteasome degradation induced by FGFR2 activation. Reduced alpha5 integrin expression was associated with an increased Bax/Bcl-2 ratio and increased caspase-9 and -3 activities in FGFR2 mutant osteoblasts. Forced expression of alpha5 integrin rescued cell attachment and corrected both the Bax/Bcl-2 ratio and caspase-3 and caspase-9 activities in FGFR2 mutant osteoblasts. We show that Cbl recruitment induced by FGFR2 activation triggers alpha5 integrin degradation by the proteasome, which results in reduced osteoblast attachment on fibronectin and caspase-dependent apoptosis. This identifies a functional role of the alpha5 integrin subunit in the induction of apoptosis triggered by FGFR2 activation in osteoblasts, and reveals that a Cbl-dependent mechanism is involved in the coordinated regulation of cell apoptosis induced by alpha5 integrin degradation.
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PMID:Cbl-mediated ubiquitination of alpha5 integrin subunit mediates fibronectin-dependent osteoblast detachment and apoptosis induced by FGFR2 activation. 1572 56

Maspin is a mammary serine protease inhibitor or serpin with tumor suppressive and antiangiogenic activity that inhibits tumor motility, invasion and metastasis, at least by its actions on cell membrane and extracellular matrix (ECM) proteins. Previous studies documented that the quinazoline-derived alpha1-adrenoceptor antagonist doxazosin affects the attachment and migration of prostate cancer cells. In this study, we investigated the effect of maspin overexpression on the apoptotic/antiadhesion response of prostate cancer cells to doxazosin. The response of maspin-overexpressing clones of human prostate cancer cells DU-145 to doxazosin was evaluated by determining cell viability, apoptosis and cell proliferation on the basis of the trypan blue exclusion assay/methylthiazolyldiphenyl-tetrazolium bromide (MTT) assay, Hoechst staining and caspase-3 activation, and [(3)H]thymidine incorporation assay. Vascular endothelial growth factor (VEGF), transforming growth factor betaRII (TGFbetaRII), Smad4 (a TGFbeta intracellular effector) and bax expression was evaluated at the mRNA and protein level using reverse transcriptase-polymerase chain reaction and Western blotting, respectively. The effect of doxazosin on cell attachment of maspin-expressing prostate cancer cells was evaluated on collagen- and fibronectin-coated plates. Cell migration was assessed using the wounding assay. In response to tumor necrosis factor-related apoptosis-inducing ligand, DU-145-maspin expressing cells undergo apoptosis, via poly(ADP-ribose) polymerasecleavage and caspase-3 activation. DU-145-maspin cells exhibited higher sensitivity to doxazosin and an earlier temporal activation of caspase-3. The number of apoptotic cells detected in response to doxazosin was significantly higher compared to the neo control (P<0.0001). Doxazosin resulted in dramatic downregulation of the 189 isoform of VEGF in maspin transfectants, while a fivefold induction of Smad4 mRNA expression was detected in those cells after 24 h of treatment. Maspin overexpression in prostate cancer cells resulted in an increased ability to attach to ECM-coated plates, and doxazosin treatment considerably antagonized this effect by decreasing the attachment potential to collagen and fibronectin. The present study supports the ability of maspin to enhance the apoptotic threshold of prostate cancer cells to the quinazoline-based alpha1-adrenoceptor antagonist doxazosin. These findings may have therapeutic significance in the development of antiangiogenic targeting by doxazosin and derivative agents for advanced prostate cancer.
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PMID:Maspin sensitizes prostate cancer cells to doxazosin-induced apoptosis. 1600 19

The transforming growth factor-beta (TGF-beta) 1 is a mediator of extracellular matrix (ECM) gene expression in mesangial cells and the development of diabetic glomerulopathy. Here, we investigate the effects of TGF-beta1 on laminin gamma1 and fibronectin polypeptide expression and cell survival in mouse mesangial cells (MES-13). TGF-beta1 (10 ng/ml) stimulates laminin-gamma1 and fibronectin expression approximately two-fold in a time-dependent manner (0-48 h). TGF-beta1 treatment also retards laminin-gamma1 mobility on SDS-gels, and tunicamycin, an inhibitor of the N-linked glycosylation, blocks the mobility shift. TGF-beta1 increases the binding of laminin gamma1 to WGA-agarose and the binding is abolished by tunicamycin suggesting that laminin gamma1 is modified by N-linked glycosylation. TGF-beta1 also elevates fibronectin glycosylation but its mobility is not altered. The degradation of laminin gamma1 and fibronectin proteins is reduced by their glycosylation. In addition, TGF-beta1 enhances mesangial cell viability and metabolic activities initially (0-24 h); however, eventually leads to cell death (24-48 h). TGF-beta1 elevates pro-apoptotic caspase-3 activity and decrease cell cycle progression factor cyclin D1 expression, which parallels cell death. These results indicate that TGF-beta1 plays an important role in ECM expression, protein glycosylation and demise of mesangial cells in the diabetic glomerular mesangium.
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PMID:Transforming growth factor-beta1 regulation of laminin gamma1 and fibronectin expression and survival of mouse mesangial cells. 1618 Jan 2

Overexpression of extracellular matrix metalloproteinase inducer (EMMPRIN or CD147), a member of the immunoglobulin family and a glycoprotein enriched on the surface of tumor cells, promotes invasion, metastasis, and growth and survival of malignant cells and confers resistance to some chemotherapeutic drugs. However, the molecular mechanisms underlying the actions of EMMPRIN are not fully understood. In this study we sought to determine whether EMMPRIN contributes to the malignant phenotype of breast cancer by inhibiting anoikis, a form of apoptosis induced by loss or alteration of cell-cell or cell-matrix anchorage, and to explore the signaling pathways involved. We found that in the absence of attachment, human breast carcinoma cells expressing high levels of EMMPRIN formed less compact aggregates with larger surface area and less fibronectin matrix assembly, had higher viability, and were resistant to anoikis. Knockdown of EMMPRIN expression by RNA interference (small interfering RNA or short hairpin RNA) sensitized cancer cells to anoikis, as demonstrated by activation of caspase-3, increased DNA fragmentation, and decreased cellular viability. Furthermore, we observed that the accumulation of Bim, a proapoptotic BH3-only protein, was reduced in EMMPRIN-expressing cells and that silencing of EMMPRIN expression elevated Bim protein levels and enhanced cellular sensitivity to anoikis. Treatment of cells with a MEK inhibitor (U0126) or proteasome inhibitor (epoxomicin) also up-regulated Bim accumulation and rendered cells more sensitive to anoikis. These results indicated that expression of EMMPRIN protects cancer cells from anoikis and that this effect is mediated at least in part by a MAP kinase-dependent reduction of Bim. Because anoikis deficiency is a key feature of neoplastic transformation and invasive growth of epithelial cancer cells, our study on the role of EMMPRIN in anoikis resistance and the mechanism involved underscores the potential of EMMPRIN expression as a prognostic marker and novel target for cancer therapy.
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PMID:Extracellular matrix metalloproteinase inducer (CD147) confers resistance of breast cancer cells to Anoikis through inhibition of Bim. 1644 28

Cultivation of phenotypically stable auricular chondrocytes will have applications in autologous chondrocyte transplantation and reconstructive surgery of cartilage. Chondrocytes grown in monolayer culture rapidly dedifferentiate assuming a fibroblast-like morphology and lose their cartilage-specific pattern of gene expression. Three-dimensional high-density culture models mimic more closely the in vivo conditions of cartilage. Therefore, this study was undertaken to test whether the high-density cultures might serve as a suitable model system to acquire phenotypically and functionally differentiated auricular chondrocytes from porcine cartilage. Freshly isolated porcine auricular chondrocytes were cultured for 7 passages in monolayer culture. From each passage (passage 0 and 1-7) cells were introduced to high-density cultures and examined by transmission electron microscopy. Western blotting was used to analyse the expression of cartilage-specific markers, such as collagen type II and cartilage specific proteoglycan, fibronectin, cell adhesion and signal transduction receptor beta1-integrin, matrix metalloproteinases (MMP-9, MMP-13), cyclo-oxygenase (COX)-2 and the apoptosis commitment marker, activated caspase-3. When dedifferentiated auricular chondrocytes from monolayer passages 0-4 were cultured in high-density culture, they recovered their chondrocytic phenotype and formed cartilage nodules surrounded by fibroblast-like cells and synthesised collagen type II, proteoglycans, fibronectin and beta1-integrins. However, chondrocytes from monolayer passages 5-7 did not redifferentiate to chondrocytes even when transferred to high-density culture, and did not synthesize a chondrocyte-specific extracellular matrix. Instead, they produced increasing amounts of MMP-9, MMP-13, COX-2, activated caspase-3 and underwent apoptosis. Three-dimensional high-density cultures may therefore be used to obtain sufficient quantities of fully differentiated auricular chondrocytes for autologous chondrocyte transplantation and reconstructive plastic surgery.
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PMID:Development and phenotypic characterization of a high density in vitro model of auricular chondrocytes with applications in reconstructive plastic surgery. 1649 77

Synthetic peptides with sequences present in extracellular matrix protein fibronectin have been described to stimulate human monocytes. We describe now that one of these peptides, FN6, induces apoptotic effects on monocytes and we investigate the molecular mechanisms involved in the regulation of this response. Incubation of monocytes with FN6 induces the activation of the small GTPase Rac. In turn, Rac mediates the increase of both JNK and p38 activities in a sustained fashion, as well as the phosphorylation levels of their respective substrates c-Jun and ATF-2. FN6 also stimulates caspases -9 and -3 and the delayed proteolysis of its substrates PARP and D4-GDI. In addition, initiator caspases-1 and -5 were activated by FN6 treatment of monocytes but, in contrast to that observed for caspases-9 and -3, this effect was not dependent on JNK or p38 activities. These kinases also mediated the increase of Bax levels, but only in some conditions Bcl-2 depletion caused by the peptide. Moreover, whereas initially only caspase-1 is involved in caspase-3 activation, later on caspase-9 seems also to participate. Therefore, we demonstrate that FN6 stimulation allows multiple, JNK and p38-dependent and -independent interacting signals to regulate the apoptotic response in human monocytes.
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PMID:Regulation of apoptosis by peptides of fibronectin in human monocytes. 1650 59


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