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)

CCR2 is a chemokine receptor widely expressed by lymphomyeloid cells involved in maladaptive autoimmune ailments. Therefore CCR2 is of great interest as a biological target for immune suppression due to its direct implication in autoimmune diseases such as rheumatoid arthritis. We have generated a novel fusion protein using GM-CSF and an N-terminal truncated version of MCP-1/CCL2 (6-76, GMME1) and investigated its utility as a CCR2-specific immune suppressor. Using BRET studies, we found that distinct to CCL2, GMME1 binding to CCR2 led to altered conformational changes in the CCR2 homodimer and did not induce the recruitment of beta-arrestin 2 to the receptor. However, CCR2-dependent calcium mobilization, BAX induction and caspase-3 activation followed by cell death was observed. Using Th17 cells harvested from DBA/1 mice ill with bovine collagen-induced arthritis, we demonstrate that GMME1 is capable of blocking their production of IL-17 in vitro. Upon its delivery to mice symptomatic with inflammatory arthritis, a robust clinical recovery occurred with decreased paw thickness to normal levels and a significant reduction in anti-collagen Ab titer and rheumatoid factor titer, as well as reduction of proinflammatory cytokines levels both intraarticular and systemic. Our data demonstrate that GMME1 is a powerful synthetic suppressor cytokine that coopts CCR2-dependent cellular signaling and blunts the effects of CCR2-expressing lymphomyeloid cells causative of autoimmune arthritis.
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PMID:An engineered GM-CSF-CCL2 fusokine is a potent inhibitor of CCR2-driven inflammation as demonstrated in a murine model of inflammatory arthritis. 1959 43

The p38 mitogen-activated protein kinase (MAPK) is activated during heart diseases that might be associated with myocardial damage and cardiac remodeling process. Diabetic cardiomyopathy is associated with increased oxidative stress and inflammation. The purpose of this study was to investigate the role of p38alpha MAPK after experimental diabetes by using transgenic (TG) mice with cardiac-specific expression of a dominant-negative mutant form of p38alpha MAPK. The elevation of blood glucose was comparable between the nontransgenic (NTG) and TG mice. The expression of phospho-p38 MAPK and phospho-MAPK-activated protein kinase 2 levels were significantly suppressed in TG mice heart than in NTG mice after diabetes induction. Left ventricular (LV) dimension in systole was smaller, and the percent fractional shortening was higher in diabetic TG mice compared with diabetic NTG mice. In addition, diabetic TG mice had reduced cardiac myocyte diameter, content of cardiac fibrosis, LV tissue expressions of atrial natriuretic peptide, transforming growth factor beta1, and collagen III compared with diabetic NTG mice. Moreover, LV expression of NADPH oxidase subunits, p22(phox), p67(phox), gp91(phox), and Nox4, reactive oxygen species and lipid peroxidation levels were significantly increased in diabetic NTG mice, but not in diabetic TG mice. Furthermore, myocardial apoptosis, the number of caspase-3-positive cells, and the downregulation of antiapoptotic protein Bcl-X(L) were less in diabetic TG mice compared with diabetic NTG mice. In conclusion, our data establish that p38alpha MAPK activity is required for cardiac remodeling after diabetes induction and suggest that p38alpha MAPK may promote cardiomyocyte apoptosis by downregulation of Bcl-X(L).
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PMID:Dominant-negative p38alpha mitogen-activated protein kinase prevents cardiac apoptosis and remodeling after streptozotocin-induced diabetes mellitus. 1961 8

Delayed Fas-mediated apoptosis in T cells is associated with inflammatory diseases including rheumatoid arthritis (RA). CD3(+) T cells in RA synovia expressed high amounts of phospho-p38 MAPK. Exposure to RA synovial fluid or soluble collagen, a degradation product of extracellular matrix abundant in RA synovium, induced the phosphorylation of p38 MAPK in Jurkat T cells accompanied by resistance against Fas-mediated apoptosis. Blocking beta1 integrin by antibody diminished this effect. In addition, ectopic expression of auto-activated beta1 integrin variant in T cells profoundly induced the phosphorylation of p38 MAPK. Suppression of p38 MAPK sensitized T cells to Fas-mediated apoptosis and increased caspase-8 and caspase-3 cleavage. A physical interaction of p38 MAPK and caspase-8 was demonstrated by using confocal microscopic imaging and co-immunoprecipitation assay. RA synovial fluid markedly increased the formation of phospho-p38 MAPK/caspase-8 complex in Jurkat T cells. In conclusion, abnormal activation of p38 MAPK to prevent Fas-mediated apoptosis may represent a common survival mechanism of RA synovial T cells contributing to the persistent inflammation of affected synovium.
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PMID:Aberrant integrin activation induces p38 MAPK phosphorylation resulting in suppressed Fas-mediated apoptosis in T cells: implications for rheumatoid arthritis. 1969 94

Hyaluronan is a biological polysaccharide that may exist in different degrees of polymerization. Several investigations reported that low molecular mass hyaluronan may have pro-inflammatory activity, while high molecular mass hyaluronan can exert beneficial effects. Starting from these data, the aim of this study was to investigate the effect of hyaluronan of different molecular mass in mouse articular chondrocyte cultures stimulated with lipopolysaccharide (LPS). Inflammation was induced in chondrocytes by acute treatment with 2.0 microg/ml LPS. High levels of tumour necrosis factor (TNF)-alpha, interleukin (IL)-1beta, IL-6, interferon (IFN)-gamma and iNOS gene expression and their related proteins were found in chondrocytes 24 h after treatment with LPS. High concentrations of NO, NF-kappaB activation, IkappaBalpha phosphorylation and apoptosis, evaluated by the increase in caspase-3 expression and its related protein amount were also produced by LPS stimulation. In contrast, LPS reduced aggrecan and collagen type II (Col2A) expression and their protein production. The treatment of chondrocytes with hyaluronan of different molecular mass produced the following effects: (i) low molecular mass hyaluronan exerted a slight inflammatory effect in untreated chondrocytes, while in LPS-treated chondrocytes it enhanced cytokine production and decreased aggrecan and Col2A compared with cells treated with LPS alone; (ii) no effect was exerted on LPS-induced apoptosis and NO production; (iii) medium molecular mass hyaluronan did not exert any inflammatory/anti-inflammatory activity in LPS-untreated/treated cells and failed to reduce apoptosis; and (iv) high molecular mass hyaluronan had no inflammatory effect in LPS-untreated cells while it was able to reduce all the detrimental effects stimulated by LPS treatment. These data confirm the multifactorial role played by hyaluronan and suggest, in particular, that hyaluronan may modulate inflammation during pathologies by its different degrees of polymerization.
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PMID:Differential effect of molecular mass hyaluronan on lipopolysaccharide-induced damage in chondrocytes. 1971 88

Apoptosis of endothelial cells (ECs) is an early pathogenic event in various fibrotic diseases. In this study, we evaluated whether paracrine mediators produced by apoptotic ECs play direct roles in fibrogenesis. C3H mice injected subcutaneously with serum-free medium conditioned by apoptotic ECs (SSC) showed increased skin thickness and heightened protein levels of alpha-smooth-muscle actin (alphaSMA), vimentin and collagen I as compared with mice injected with medium conditioned by non-apoptotic ECs. Fibroblasts exposed to SSC in vitro showed cardinal features of myofibroblast differentiation with increased stress fiber formation and expression of alphaSMA. Caspase-3 silencing in ECs prevented the release of mediators favoring myofibroblast differentiation. To identify the fibrogenic factor(s) released by ECs, the protein contents of media conditioned by either apoptotic or non-apoptotic ECs were compared using SDS-PAGE-liquid chromatography (LC)-tandem mass spectrometry (MS/MS) and two-dimensional LC-MS/MS. Connective tissue growth factor (CTGF) was the only fibrogenic protein found increased in SSC. Pan-caspase inhibition with ZVAD-FMK or caspase-3 silencing in ECs confirmed that CTGF was released downstream of caspase-3 activation. The fibrogenic signaling signatures of SSC and CTGF on fibroblasts in vitro were similarly Pyk2-, Src-family kinases- and PI3K dependent, but TGF-beta-independent. CTGF-immunodepleted SSC failed to induce myofibroblast differentiation in vitro and skin fibrosis in vivo. These results identify caspase-3 activation in ECs as a novel inducer of CTGF release and fibrogenesis.
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PMID:Caspase-3-mediated secretion of connective tissue growth factor by apoptotic endothelial cells promotes fibrosis. 1973 Apr 42

Morphological and immunophenotypic characterization of cells grown on poly(l-lactic acid) (PLLA) electrospun scaffolds is usually performed using immunofluorescence and cryosections. However, these methods present practical limits; histological processing, on the other hand, is believed to lead to artifactual changes in the scaffold structure. Here the formalin-fixed paraffin-embedding (FFPE) procedure was tailored to process PLLA electrospun scaffolds grown with human umbilical vein endothelial cells. After 1 to 7 days of culture, the scaffolds were processed with the FFPE procedure. Using this protocol, not only cross sections but also "en face" sections were obtained. This made possible to perform the effective light microscopy analysis of cell morphology and to assess cell adhesion and penetration without considerable scaffold damage. The method was also suitable for immunohistochemical assays, such as proliferation (Ki67), extracellular matrix production (type IV collagen), survival (cleaved caspase-3), and immunophenotyping (KDR, CD44, vimentin, CD45); results were compared with those obtained using complementary techniques (scanning electron microscopy, Alamar Blue assay, and cryosections). The FFPE protocol can be safely applied to PLLA scaffolds and provides information that are essential to study the mechanisms of interaction between cells and PLLA fibers before their potential implantation in vivo.
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PMID:Paraffin embedding allows effective analysis of proliferation, survival, and immunophenotyping of cells cultured on poly(l-lactic acid) electrospun nanofiber scaffolds. 1982 1

Quinolones and glucocorticoids are frequently used drugs that may cause tendinopathy as a rare adverse effect. We exposed human tenocyte cultures to the steroid dexamethasone alone or in combination with either ciprofloxacin or levofloxacin at concentrations of 3mg/L and 10mg/L. At concentrations corresponding to peak levels in plasma and tissues during therapy (ca. 3-10mg/L), ciprofloxacin caused a significant decrease in collagen type I and the beta(1)-integrin receptor. In contrast, no corresponding effect was induced by 3mg/L levofloxacin. With both quinolones at 3mg/L and 10mg/L, the amount of matrix metalloproteinase-1 (MMP-1) and MMP-13 was increased. In addition, 3mg/L ciprofloxacin and 10mg/L levofloxacin activated caspase-3. Apoptotic changes were confirmed by electron microscopy. Incubation of human tenocytes with dexamethasone decreased the main matrix protein collagen type I, the transmembrane beta(1)-integrin receptor and the cytoskeleton protein vinculin, but only at the high concentrations tested (0.1 microM or 10 microM). Concentrations of 0.1 microM and 10 microM dexamethasone increased the amount of MMPs and activated caspase-3 as an indicator of apoptosis. Combined exposure to quinolones and dexamethasone led to more pronounced effects in tenocyte cultures at most of the analysed endpoints. The clinical observations of an increased risk of quinolone-induced tendinopathy by glucocorticoids are supported by these in vitro data.
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PMID:Synergistic effects of dexamethasone and quinolones on human-derived tendon cells. 2003 66

Previous work suggests that vagus nerve disruption reduces hepatocyte and oval cell expansion after liver injury. The role of postneuronal receptor activation in response to liver injury has not been ascertained. We investigated the actions of scopolamine, a nonselective muscarinic receptor antagonist, and specific genetic ablation of a key cholinergic receptor, muscarinic subtype-3 (Chrm3), on azoxymethane (AOM)-induced liver injury in mice. Animal weights and survival were measured as was liver injury using both gross and microscopic examination. To assess hepatocyte proliferation and apoptosis, ductular hyperplasia, and oval cell expansion, we used morphometric analysis of 5-bromo-2'-deoxyuridine-, activated caspase-3-, hematoxylin and eosin-, cytokeratin-19-, and epithelial cell adhesion molecule-stained liver sections. Sirius red staining was used as a measure of collagen deposition and its association with oval cell reaction. In AOM-treated mice, both muscarinic receptor blockade with scopolamine and Chrm3 ablation attenuated hepatocyte proliferation and augmented gross liver nodularity, apoptosis, and fibrosis. Compared with control, scopolamine-treated and Chrm3(-/-) AOM-treated mice had augmented oval cell reaction with increased ductular hyperplasia and oval cell expansion. Oval cell reaction correlated robustly with liver fibrosis. No liver injury was observed in scopolamine-treated and Chrm3(-/-) mice that were not treated with AOM. Only AOM-treated Chrm3(-/-) mice developed ascites and had reduced survival compared with AOM-treated wild-type controls. In AOM-induced liver injury, inhibiting postneuronal cholinergic muscarinic receptor activation with either scopolamine treatment or Chrm3 gene ablation results in prominent oval cell reaction. We conclude that Chrm3 plays a critical role in the liver injury response by modulating hepatocyte proliferation and apoptosis.
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PMID:Scopolamine treatment and muscarinic receptor subtype-3 gene ablation augment azoxymethane-induced murine liver injury. 2019 74

When cells attach to the extracellular matrix (ECM) a proliferation permissive signal is engaged. The mechanism involves activation of the integrin/PI3K/Akt signal pathway. FoxO3a is a transcriptional activator and inhibits cell proliferation via up-regulating the expression of the cell cycle inhibitor p27. Furthermore, it is known that activated Akt can suppress FoxO3a function. However, it is not known whether integrin interaction with the ECM regulates FoxO3a function. We examined whether the beta1-integrin-mediated signaling pathway promotes fibroblast proliferation via FoxO3a suppression. We found that when fibroblasts are attached to collagen, PTEN protein expression and activity are inhibited due to promotion of PTEN degradation. This decrease in PTEN function permits FoxO3a suppression via the PI3K/Akt pathway. In contrast, the inhibition of PI3K/Akt or reconstitution of PTEN restores FoxO3a expression on collagen. Furthermore, we found that the serine/threonine phosphatase PP2A also regulates FoxO3a. PP2A expression/activity is low when fibroblasts are attached to collagen, and PP2A overexpression augments FoxO3a levels. Thus the mechanism involves a coordinated decrease in PTEN and PP2A phosphatase activity and increase in PI3K/Akt activity. We show that beta1-integrin-ECM interaction decreases FoxO3a protein levels via caspase-3-mediated cleavage. Our novel finding indicates that during fibroblast interaction with ECM, activation of beta1-integrin/PI3K/Akt by inhibiting PTEN in combination with low PP2A phosphatase activity synergistically inhibits FoxO3a, promoting fibroblast proliferation.
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PMID:beta1-Integrin-collagen interaction suppresses FoxO3a by the coordination of Akt and PP2A. 2022 31

Osteosarcoma (OS) is the most common primary malignant bone tumour, mainly afflicting the young. While there has been substantial improvement in treatment of OS with surgery and chemotherapy in the past two decades, this disease remains a significant health problem, warranting efforts to find better therapeutic options. In this study, we examined the RANK/RANKL axis in OS cells, using a RANK-Fc protein to perturb this coupling in an effort to reduce OS cell growth. RANK-Fc suppressed OS cell migration (P < 0.005), invasion ability (P < 0.05), and anchorage-independent ability in collagen-1 gel (P < 0.005) following induction of anoikis and activation of caspase-3. OS cell proliferation was not perturbed by RANK-Fc. The anti-invasion and anti-metastasis capability of RANK-Fc is attributed to reduced extracellular signal-regulated protein kinase (ERK) signaling via RANK-Fc, though activation of NFkappaB, and altered expression of Akt, p38, JNK, and matrix metalloproteinase (MMP)-2 and -9 were ruled out. In vivo, activity of the RANK-Fc against OS cell migration and invasion was confirmed in a model strictly monitoring metastasis. Thus, RANK-Fc, given its ability to directly reduce OS aggression, is a potential drug candidate.
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PMID:RANK-Fc inhibits malignancy via inhibiting ERK activation and evoking caspase-3-mediated anoikis in human osteosarcoma cells. 2038 67


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