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Query: UNIPROT:P42574 (
caspase-3
)
45,978
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
We previously reported that the enterocytic differentiation of human colonic Caco-2 cells correlated with alterations in integrin signaling. We now investigated whether differentiation and apoptosis of Caco-2 cells induced by the short-chain fatty acid butyrate (NaBT) was associated with alterations in the integrin-mediated signaling pathway with special interest in the expression and activity of
focal adhesion kinase
(
FAK
), of the downstream phosphatidylinositol 3'-kinase (PI 3-kinase)-Akt pathway and in the role of the nuclear factor kappaB (NF-kappaB). NaBT increased the level of sucrase. It induced apoptosis as shown by: (1) decreased Bcl-2 and Bcl-X(L) proteins and increased Bax protein; (2) activation of
caspase-3
; and (3) increased shedding of apoptotic cells in the medium. This effect was associated with defective integrin-mediated signaling as shown by: (1) down-regulation of beta1 integrin expression; 2) decreased
FAK
expression and tyrosine phosphorylation; (3) concerted alterations in cytoskeletal and structural focal adhesions proteins (talin, ezrin); and (4) decreased
FAK
ability to associate with PI 3-kinase. However, in Caco-2 cells, beta1-mediated signaling failed to be activated downstream of
FAK
and PI 3-kinase at the level of Akt. Transfection studies show that NaBT treatment of Caco-2 cells promoted a significant activation of the NF-kappaB which was probably involved in the NaBT-induced apoptosis. Our results indicate that the prodifferentiating agent NaBT induced apoptosis of Caco-2 cells probably through NF-kappaB activation together with a defective beta1 integrin-
FAK
-PI 3-kinase pathways signaling.
...
PMID:Butyrate-treated colonic Caco-2 cells exhibit defective integrin-mediated signaling together with increased apoptosis and differentiation. 1456 63
Platelets are cleared from circulation after a life span of 8-10 days. The molecular mechanisms underlying platelet senescence remain poorly characterized. Here we report that, progressive functional impairment in the platelets incubated in vitro in a plasma-free isotonic medium for up to 24 h at 37 degrees C is associated with release of cytochrome c from platelet mitochondria and cleavage of procaspase-9, but without evidence of
caspase-3
activation. Concomitantly, there was proteolysis of survival proteins like
focal adhesion kinase
, Src, gelsolin, and specific cytoskeleton-associated peptides, in a manner regulated by extracellular calcium and calpain activity. Cytoskeleton played a critical role as evidenced from the association of these proteins and their degradation products, as well as procaspase-3 and the actin regulatory small GTPase, CDC42Hs, with the cytoskeleton of the stored platelets. The cytoskeletal enrichment with specific proteins was not associated with increase in the content of F-actin and was cytochalasin-resistant, thus signifying a novel mechanism of interaction of the translocating proteins with the pre-existing cytoskeleton. There was progressive exposure of phosphatidylserine on the outer leaflet of platelet membrane and specific electron microscopic changes suggestive of apoptotic lesions. Based on these observations we discuss the caspase-independent but calpain-mediated signaling events in the stored platelets resembling the features of apoptosis in the nucleated cells.
...
PMID:Platelet storage under in vitro condition is associated with calcium-dependent apoptosis-like lesions and novel reorganization in platelet cytoskeleton. 1475 6
The mechanisms regulating involution of mammary glands after weaning are not clear, but engorgement with milk is a key trigger. Many cell types require to be anchored to an extracellular matrix (ECM) as a prerequisite for survival and this is achieved via intregrins binding to specific motifs and signalling their attachment, intracellularly, via
focal adhesion kinase
(
FAK
). We sought to determine firstly, if expression of beta1-integrin and
FAK
is reduced during the first stage of involution. Expression of beta1-integrin and
FAK
was significantly reduced at 6 h after sealing teats and this was accompanied with a decreased abundance of cytochrome C in mitochondria. Secondly, we sought to determine if expression of beta1-integrin and
FAK
was restored during the first, partially reversible stage of involution (at 24 h), but not during the second irreversible stage, which occurs after 72 h. Re-suckling restored full expression of the 80 kDa fragment of
FAK
, but not of the 125 kDa protein or beta1-integrin at 24 h after weaning. Re-suckling did not restore expression of either peptide after 72 h. Changes in expression of cytochrome C and pro-
caspase-3
(apoptotic markers) were similar to that of the 80 kDa fragment of
FAK
. These data suggest that epithelial cells can restore partial contact with their basement membrane during the first, reversible stage, but not during the second irreversible stage of involution. We speculate that decreased contact between epithelial cells and their basement membrane initiates apoptosis in mammary glands at weaning. This process begins within 6 h of pup withdrawal.
...
PMID:Decreased expression of beta1-integrin and focal adhesion kinase in epithelial cells may initiate involution of mammary glands. 1517 2
The quinazoline family of alpha1-blockers (prazosin, doxazosin, and terazosin) induce apoptosis of prostate cells through an alpha1-adrenoceptor-independent mechanism. The objective of this study was to gain insight into the non-adrenergic, apoptotic mechanism of action of doxazosin in the prostate and the induction of anoikis by doxazosin. Primary cultures of benign prostate stromal and epithelial cells and the LNCaP (androgen sensitive) and PC-3 (androgen insensitive) prostate carcinoma cell lines were treated with doxazosin (0-50 microM). The effects of doxazosin on cell morphology,
caspase-3
activity, and the expression levels of
focal adhesion kinase
(
FAK
) and integrin-linked kinase (ILK) were examined. Doxazosin induced changes in morphology consistent with anoikis in both benign and cancerous prostatic cells and increased
caspase-3
activity. The effects were similar comparing benign cells (which express alpha1-adrenoceptors) and cancer cells (which do not express alpha1-adrenoceptors), but were more robust in benign cells. Norepinephrine had no effect on doxazosin-induced cell morphology or
caspase-3
activity. Treatment of PC-3 cells with doxazosin significantly reduced the protein levels of
FAK
but did not significantly affect the levels of ILK. These findings suggest that doxazosin induces apoptosis and anoikis of prostate cancer cells by a mechanism of action that is alpha1-adrenoceptor independent. The apoptosis of cancer cells induced by doxazosin counteracts cell proliferation and may have the potential of retarding or reversing prostate cancer cell growth.
...
PMID:Induction of anoikis by doxazosin in prostate cancer cells is associated with activation of caspase-3 and a reduction of focal adhesion kinase. 1522 Dec 43
Inadequate or inappropriate adhesion of epithelial cells to extracellular matrix leads to a form of apoptosis known as anoikis. During various tissue remodelling events, such as wound healing or carcinoma invasion, changes in the physical properties, and/or composition of the extracellular matrix, can lead to anoikis of epithelial cells that lack appropriate receptor-matrix interactions. Laminin-5 is the major ligand for keratinocyte adhesion in the epidermis, and it also promotes keratinocyte survival in vivo and in vitro. Integrins alpha 3 beta 1 and alpha 6 beta 4 are the major receptors for laminin-5; however, specific roles for these integrins in keratinocyte survival have not been determined. In the current study, we exploited keratinocyte cell lines derived from wild-type or alpha 3 integrin knockout mice to reveal a critical role for alpha 3 beta 1 in protecting keratinocytes from apoptosis upon serum withdrawal. We show that alpha 3 beta 1-mediated adhesion to laminin-5 extracellular matrix inhibits proteolytic activation of
caspase-3
and TUNEL-staining, both hallmarks of apoptosis. We also show that alpha 3 beta1-mediated adhesion activates
focal adhesion kinase
(
FAK
) and extracellular signal-regulated kinase (ERK), and that inhibition of either
FAK
or ERK signaling leads to apoptosis of keratinocytes attached to laminin-5. alpha 6 beta 4-mediated adhesion to laminin-5 only partially protects cells from apoptosis in the absence of alpha 3 beta 1, and alpha 6 beta 4 is not necessary for cell survival in the presence of alpha 3 beta 1. These results suggest that alpha 3 beta 1 is necessary and sufficient for maximal keratinocyte survival on laminin-5. We propose a model to address the potential importance of alpha 3 beta 1-mediated survival for migrating keratinocytes at the leading edge of a cutaneous wound.
...
PMID:Alpha 3 beta 1 integrin promotes keratinocyte cell survival through activation of a MEK/ERK signaling pathway. 1528 Apr 29
We have previously reported that interferon-alpha (IFNalpha) induces apoptosis and EGF can antagonize this effect in human epidermoid cancer KB cells. Since apoptosis occurs together with cytoskeleton reorganization we have evaluated if IFNalpha and EGF could modulate cell remodeling in our experimental conditions. We have found that 48 h 1,000 IU/ml IFNalpha induced structural reorganization of stress fibers and membrane delocalization and partial capping of the actin severing protein gelsolin. The transfection of KB cells with both a wild type (WT) or a C-terminal truncated form of gelsolin caused overexpression of the protein and an increase of both the spontaneous and IFNalpha-induced apoptosis and cell cytoskeletal modifications. In fact, after 48 h of treatment IFNalpha induced 45% of apoptotic cell death in parental cells while an approximately 80% of cell population was apoptotic in transfected cells. These effects occurred together with an increase of the expression and consequent degradation of gelsolin. Again the addition of EGF to IFNalpha-treated transfected cells caused a recovery of the apoptosis. Notably, IFNalpha and EGF did not modify the expression of other molecules associated to cytoskeleton such as
focal adhesion kinase
and vinculin. In the same experimental conditions IFNalpha induced also gelsolin cleavage that occurred together with
caspase-3
activation and release of cytochrome c. All these effects were antagonized by the exposure of IFNalpha-treated KB to 10 nM EGF for the last 12 h. Moreover, the specific inhibition of
caspase-3
with 20 microM DEVD completely abrogated apoptosis and gelsolin cleavage induced by IFNalpha. In conclusion, our data are the first demonstration that IFNalpha can induce morphological cell changes that are peculiar of apoptosis onset through the
caspase-3
-mediated cleavage of gelsolin. Furthermore, we have demonstrated that EGF is able to antagonize these effects through the inhibition of
caspase-3
activation.
...
PMID:Apoptosis induced by interferon-alpha and antagonized by EGF is regulated by caspase-3-mediated cleavage of gelsolin in human epidermoid cancer cells. 1528 Oct 90
Altered cellular adhesion and apoptotic signaling in cardiac remodeling requires coordinated regulation of multiple constituent proteins that comprise cytoskeletal focal adhesions. One such protein activated by cardiac remodeling is related adhesion focal tyrosine kinase (RAFTK, also known as pyk2). Adenoviral-mediated expression of RAFTK in neonatal rat cardiomyocytes involves concurrent increases in phosphorylation of Src, c-Jun N-terminal kinase, and p38 leading to characteristic apoptotic changes including cleavage of poly(ADP-ribose) polymerase,
caspase-3
activation, and increased DNA laddering. DNA laddering was decreased by mutation of the Tyr(402) Src-binding site in RAFTK, suggesting a central role for Src activity in apoptotic cell death that was confirmed by adenoviral-mediated Src expression. Multiple apoptotic signaling cascades are recruited by RAFTK as demonstrated by prevention of apoptosis using
caspase-3
inhibitor IV (
caspase-3
specific inhibitor), PP2 (Src-specific kinase inhibitor), or Csk (cellular negative regulator for Src), as well as dominant negative constructs for p38beta or MKP-1. These RAFTK-mediated phenotypic characteristics are prevented by concurrent expression of wild-type or a phosphorylation-deficient paxillin mutated at Tyr(31) and Tyr(118). Wild-type or mutant paxillin protein accumulation in the cytoplasm has no overt effect upon cell structure, but paxillin accumulation prevents losses of myofibril organization as well as
focal adhesion kinase
, vinculin, and paxillin protein levels mediated by RAFTK. Apoptotic signaling cascade inhibition by paxillin indicates interruption of signaling proximal to but downstream of RAFTK activity. Chronic RAFTK activation in cardiac remodeling may represent a maladaptive reactive response that can be modulated by paxillin, opening up novel possibilities for inhibition of cardiomyocyte apoptosis and structural degeneration in heart failure.
...
PMID:Cardiomyocyte apoptosis triggered by RAFTK/pyk2 via Src kinase is antagonized by paxillin. 1532 13
Geldanamycin (GA) binds to heat shock protein 90 (Hsp90) and interferes with its function which is to protect various cellular proteins involved in signaling, growth control, and survival from ubiquitination and subsequent degradation by the proteasome. Recently, we demonstrated that GA inhibited migration of glioma cells in vitro associated with downregulation of hypoxia-inducible factor (HIF-1 alpha) and phosphorylation of
focal adhesion kinase
(
FAK
) (Zagzag et al., 2003, J Cell Physiol 196:394-402). Here, we have investigated the mechanisms through which GA treatment of the T98G glioma cell line induces apoptosis. We found that GA treatment induced cell death in a caspase-dependent manner through activation of
caspase-3
and PARP cleavage together with release of cytochrome c and apoptosis inducing factor (AIF) from the mitochondria. Use of synchronized T98G cells showed that GA treatment of glioma cells during S-phase enhanced cytotoxicity followed by M-phase arrest, resulting in mitotic catastrophe. In addition, apoptosis was associated with the downregulation of the survival protein, phosphorylated Akt (pAkt), an important signaling protein in the PI3K pathway, that is overexpressed in many cancers including gliomas. Given that many glioma tumors show deregulation of the PI3K signaling pathway, either through loss of the tumor suppressor protein PTEN or overexpression of the growth factor EGFR, the ability to identify different subsets of patients using simple immunohistochemistry for the presence of absence of pAkt could enable selection of the appropriate kinase inhibitor, such as GA, for drug therapy. Based on our data presented here, GA or its analogs may have potential in the treatment of glioma.
...
PMID:Geldanamycin induces mitotic catastrophe and subsequent apoptosis in human glioma cells. 1538 45
To examine the role of
focal adhesion kinase
in human glioma cells, we studied its effects on proliferation and apoptosis using FAK antisense oligonucleotide. U251 MG cells were transfected with ODNs, sense FAK, mismatch FAK and antisense-FAK, respectively. Expression of FAK proteins were detected by Western blots and Immnofluoressence. Cell apoptosis and mitochondrial membrane potential were analyzed by flow cytometry.
Caspase-3
activity was measured by spectrofluorometer. MTT assay was used to examine changes in cell proliferation. The protein expression of FAK in U251 MG cells decreased in antisense-FAK ODNs group significantly.
Caspase-3
activity increased in cells treated with antisense-FAK and down-regulated when treated with
caspase-3
inhibitor. The level of cell apoptosis and loss of mitochondrial membrane potential in antisense-FAK group was higher than in the mismatch sense group. Cells proliferation was inhibited by antisense-FAK, and the effects were clearly additive when antisense oligonuceotides were added to cells treated with the anticancer agents. The results suggest that antisense-FAK ODNs inhibit U251 MG cells proliferation and induce their apoptosis. It is possible that FAK via mitochondrial and
caspase-3
inhibits U251 MG cells apoptosis. And antisense oligonucleotide treatment enhances U251 MG cells sensitivity to chemotherapy.
...
PMID:Antisense oligonucleodes targeting the focal adhesion kinase inhibit proliferation, induce apoptosis and cooperate with cytotoxic drugs in human glioma cells. 1631 54
We have previously shown that lovastatin induces apoptosis in spontaneously immortalized rat brain neuroblasts. Focal adhesion proteins and protein kinase Cdelta (PKCdelta) have been implicated in the regulation of apoptosis. We found that lovastatin exposure induced
focal adhesion kinase
, Crk-associated substrate (p130(Cas)), PKCdelta cleavage and
caspase-3
activation in a concentration-dependent manner. Lovastatin effects were fully prevented by mevalonate. The cleavage of p130(Cas) was almost completely inhibited by z-DEVD-fmk, a specific
caspase-3
inhibitor, and z-VAD-fmk, a broad spectrum caspase inhibitor, indicating that cleavage is mediated by
caspase-3
. In contrast, the lovastatin-induced cleavage of PKCdelta was only blocked by z-VAD-fmk suggesting that PKCdelta cleavage is caspase-dependent but
caspase-3
-independent. Additionally, z-VAD-fmk partially prevented lovastatin-induced neuroblast apoptosis. The present data show that lovastatin may induce neuroblast apoptosis by both caspase-dependent and independent pathways. These findings may suggest that the caspase-dependent component leading to the neuroblast cell death is likely to involve the cleavage of focal adhesion proteins and PKCdelta, which may be partially responsible for some biochemical features of neuroblast apoptosis induced by lovastatin.
...
PMID:Cleavage of focal adhesion proteins and PKCdelta during lovastatin-induced apoptosis in spontaneously immortalized rat brain neuroblasts. 1636 43
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