Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P42574 (caspase-3)
 45,978 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Diabetic nephropathy is the leading cause of end-stage renal disease in the Western world. Poor glycemic control contributes to the development of diabetic nephropathy, but the mechanisms underlying high glucose-induced tissue injury are not fully understood. In the present study, the effect of high glucose on a proximal tubular epithelial cell (PTEC) line was investigated. Reactive oxygen species (ROS) were detected using the fluorescent probes dichlorofluorescein diacetate, dihydrorhodamine 123, and 2,3-diaminonapthalene. Peroxynitrite (ONOO-) generation and nitrite concentrations were increased after 24 h of high glucose treatment (P<0.05). LLC-PK1 cells exposed to high D-glucose (25 mM) for up to 48 h had increased DNA fragmentation (P<0.01), caspase-3 activity (P<0.001), and annexin-V staining (P<0.05) as well as decreased expression of XIAP when compared with controls (5 mM D-glucose). The ONOO- scavenger ebselen reduced DNA fragmentation and caspase-3 activity as well as the high glucose-induced nitrite production and DCF fluorescence. High glucose-induced DNA fragmentation was completely prevented by an inhibitor of caspase-3 (P<0.01) and a pan-caspase inhibitor (P<0.001). Caspase inhibition did not affect ROS generation. This study, in a PTEC line, demonstrates that high glucose causes the generation of ONOO-, leading to caspase-mediated apoptosis. Ebselen and a caspase-3 inhibitor provided significant protection against high glucose-mediated apoptosis, implicating ONOO- as a proapoptotic ROS in early diabetic nephropathy.
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PMID:High glucose-induced oxidative stress causes apoptosis in proximal tubular epithelial cells and is mediated by multiple caspases. 1267 Aug 85

Fumonisin B1 (FB1), the most potent of the fumonisin mycotoxins, is a carcinogen and causes a wide range of species-specific toxicoses. FB1 modulates the activity of protein kinase C (PKC), a family of phospholipid-dependent serine/threonine kinases that play important role in modulating a variety of biologic responses ranging from regulation of cell growth to cell death. Although it has been demonstrated that FB1 induces apoptosis in many cell lines, the precise mechanism of apoptosis is not fully understood. In this study, we investigated the membrane localization of various PKC isoforms, PKC enzyme activity, and its downstream targets, namely nuclear factor-kappa B (NF-kappaB), tumor necrosis factor alpha (TNFalpha), and caspase 3, in porcine renal epithelial (LLC-PK1) cells. FB1 repressed cytosol to membrane translocation of PKC-alpha, -delta, -epsilon, and -zeta isoforms over 24-72 h. The FB1-induced membrane PKC repression was corroborated by a concentration-dependent decrease in total PKC activity. Exposure of cells to phorbol 12-myristate 13-acetate (PMA) for this duration also resulted in repressed PKC membrane localization and activity comparable to FB1. Exposure of cells to FB1 (10 microM) was associated with inhibition of cytosol to nuclear translocation of NF-kappaB and NF-kappaB-DNA binding at 72 h. The expression of TNFalpha was significantly inhibited at 24 and 48 h in response to 1 and 10 microM FB1. Increased caspase 3 activity was observed in LLC-PK1 cells exposed to > or =1 microM FB1 at 48 h. PMA also increased the caspase 3 activity at 24 and 48 h. Results suggest that FB1-induced apoptosis involves the activation of caspase 3, which is associated with the repression of PKC and possibly its down-stream effectors, NF-kappaB and TNFalpha.
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PMID:Fumonisin B1-induced apoptosis is associated with delayed inhibition of protein kinase C, nuclear factor-kappaB and tumor necrosis factor alpha in LLC-PK1 cells. 1459 27

Cisplatin is a commonly used antitumor agent in the treatment of various human cancers, with nephrotoxicity as a major side effect. Cisplatin causes the loss of cell-cell contacts of renal proximal tubular epithelial cells prior to the onset of apoptosis. We studied the involvement of protein kinase C in these events in the renal epithelial cell line LLC-PK1. Cisplatin caused apoptosis in LLC-PK1 cells, which was directly related to the activation of caspase-3 and DNA fragmentation. Apoptosis was almost completely inhibited by the protein kinase C inhibitors bisindolylmaleimide (Bis) I and Go6983 [2-[1-(3-dimethylaminopropyl)-5-methoxyindol-3-yl]-3-(1H-indol-3-yl) maleimide], but not by Go6976 [12-(2-cyanoethyl)-6,7,12,13-tetrahydro-13-methyl-5-oxo-5H-indolo(2,3-a)pyrrolo(3,4-c)-carbazole]. Also, in primary cultured rat renal proximal tubular cells, inhibition of protein kinase C (PKC) inhibited apoptosis. Cisplatin also caused the early loss of cell-cell adhesions, which was associated with the altered localization of the adherens junction-associated protein beta-catenin in association with PKC-mediated phosphorylation of the actincapping protein adducin. These events preceded and were independent of caspase activation. beta-Catenin did not dissociate from E-cadherin. Cisplatin-induced loss of cell-cell contacts was associated with the increased formation of F-actin stress fibers, which was inhibited by Bis I and Go6983 as well as dominant-negative PKC-epsilon. Also, the loss of cell-cell adhesions by cisplatin was prevented by Bis I and Go6983. Activation of protein kinase C with phorbol esters promoted cisplatin-induced loss of cell-cell adhesions as well as apoptosis. In conclusion, the combined data fit a model whereby protein kinase C mediates the cisplatin-induced loss of cellular interactions. Such a loss of these interactions has a role in the onset of apoptosis.
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PMID:Protein kinase C mediates cisplatin-induced loss of adherens junctions followed by apoptosis of renal proximal tubular epithelial cells. 1538 33

Fumonisin B1 (FB1) is a toxic mycotoxin produced by Fusarium verticillioides, predominantly present in corn. The principal biochemical responses of FB1 involve disruption of sphingolipid metabolism from the inhibition of ceramide synthesis leading to accumulation of free sphingoid bases, particularly sphinganine. The ability of FB1 to modulate signal transduction pathways plays a role in its toxicity. We recently reported that FB1 selectively and transiently activates protein kinase Calpha (PKCalpha) in porcine renal epithelial cells (LLC-PK1). The aim of current study was to investigate the effect of PKCalpha activation by FB1 on NF-kappaB activation and subsequently on TNFalpha gene expression and caspase 3 induction in LLC-PK1 cells. FB1 (1 micromol/L for 5 min) transiently activated PKCalpha and increased nuclear translocation of NF-kappaB, followed by their down-regulation at later time points. Preincubating the cells with the PKC inhibitor, calphostin C, prevented the activation of NF-kappaB by FB1. TNFalpha mRNA expression was increased after 15 min exposure to FB1 or the PKC activator, phorbol 12-myristate 13-acetate. In addition, an increase in caspase 3 activity was observed after addition of FB1 for 1 h. Calphostin C prevented both the FB1-induced increase in TNFalpha expression and caspase 3 activation. In summary, we hereby demonstrate that the FB1 activation of NF-kappaB and sequential induction of TNFalpha expression resulting in the subsequent increase in caspase 3 activity are all dependent on PKCalpha stimulation in LLC-PK1 cells.
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PMID:The mycotoxin fumonisin B1 transiently activates nuclear factor-kappaB, tumor necrosis factor alpha and caspase 3 via protein kinase Calpha-dependent pathway in porcine renal epithelial cells. 1549 68

The addition of tumor necrosis factor (TNF)-alpha into the cultured porcine kidney LLC-PK1 cells caused apoptosis concomitantly with caspase-3 activation and the inductions of an endogenous Bcl-2 protein. An SDS-polyacrylamide electrophoretic analysis revealed that a 37-kDa protein in a nuclear fraction was increased during TNF-alpha-induced apoptosis. Partial amino acid sequence of the protein was A-L-T-G-H-L-E-E-V, perfectly matching that of annexin I. Immunocytochemistry revealed that annexin I migrated to the nucleus and/or peri-nucleus region upon exposure to TNF-alpha. Overexpression of Bcl-2 proteins inhibited the nuclear localization of annexin I during TNF-alpha-induced apoptosis. Antisense oligodeoxynucleotides complementary to annexin I-inhibited TUNEL (terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end-labelling) staining in TNF-alpha-treated cells, suggesting that annexin I expression is a possible prerequisite for the induction of apoptosis by the cytokine. Thus, it is first time to show that annexin I is regulated by an anti-apoptotic Bcl-2 protein in TNF-alpha-induced renal apoptotic events.
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PMID:Overexpression of Bcl-2 inhibits nuclear localization of annexin I during tumor necrosis factor-alpha-mediated apoptosis in porcine renal LLC-PK1 cells. 1554 40

The Ets family of transcription factors is defined by a conserved DNA-binding Ets domain that forms a winged helix-turn-helix structure motif. The Ets family is involved in a diverse array of biologic functions, including cellular growth, migration, and differentiation. The hypothesis in this study was that Ets-1 is re-expressed during regeneration after acute renal failure (ARF) and plays a key role in the transcriptional regulation of cyclin D1 and the cell cycle progression in renal tubular cells. For clarifying the significance of Ets-1 in ARF, a rat ARF model in vivo and LLC-PK1 cells as an in vitro model were used. After the left rat renal artery was clamped for 1 h, the whole kidney homogenate was examined and total RNA was extracted at 6, 12, 24, 48, and 72 h after reperfusion by Western blot analysis and real-time reverse transcription-PCR. Ets-1 mRNA and protein expression were strongly increased at 6 to 24 h after the ischemia, respectively. The expression of hypoxia-inducible factor-1alpha was increased dramatically as early as 6 h after ischemia-reperfusion and decreased at 48 and 72 h after ischemia-reperfusion. In the immunohistologic examination, Ets-1 was expressed in the proximal tubules and coexpressed with proliferating cell nuclear antigen (PCNA). Furthermore, overexpression of Ets-1 promoted the cell cycle and increased the promoter activity and protein expression of cyclin D1 in LLC-PK1 cells. Ets-1 promoter activity increased between 3 and 6 h in hypoxia, and hypoxia also induced changes in the Ets-1 protein level in LLC-PK1 cells. The Ets-1 induction by hypoxia was abolished by the transfection of dominant-negative hypoxia-inducible factor-1alpha. A gel shift assay demonstrated that Ets-1 binds to the ets-1 binding site of the cyclin D1 promoter in the ischemia-reperfusion condition. Overexpression of Ets-1 did not significantly change the caspase 3 activity or the value of cell death ELISA in LLC-PK1 cells. Taken together, these data suggest that Ets-1 plays a key role in the cell-cycle progression of renal tubules in ARF. The Ets-1 pathway may regulate the transcription of cyclin D1 and control the regeneration of renal tubules in ARF.
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PMID:Expression and function of Ets-1 during experimental acute renal failure in rats. 1557 11

We reported previously that radiocontrast medium induces caspase-dependent apoptosis and that cAMP analogs inhibit cell injury in cultured renal tubular cells. In the present study, cellular mechanisms underlying the protective effects of cAMP were determined. Ioversol, a radiocontrast medium, caused cell injury accompanied by decreases in Bcl-2, increases in Bax, and caspase activation in LLC-PK1 cells. Both cell injury and cellular events induced by ioversol were inhibited by dibutyryl cAMP and the prostacyclin analog beraprost. Dibutyryl cAMP increased phosphorylation of Akt and CREB, both of which were reversed by H89, wortmannin and the Akt inhibitor SH-6. The protective effect of dibutyryl cAMP was also reversed by these kinase inhibitors. In dominant-negative CREB-transfected cells, dibutyryl cAMP no longer prevented cell injury or inhibited changes in mRNA expression of Bcl-2 and Bax. In mice with unilateral renal occlusion, ioversol increased urinary excretion of N-acetyl-beta-d-glucosaminidase with concomitant decreases in Bcl-2 mRNA, increases in Bax mRNA, activation of caspase-3, and induction of apoptosis in tubular and interstitial cells. Beraprost completely reversed these in vivo effects of ioversol. These findings suggest that elevation of endogenous cAMP effectively prevents radiocontrast nephropathy through activation of A kinase/PI 3-kinase/Akt followed by CREB phosphorylation and enhanced expression of Bcl-2.
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PMID:A prostacyclin analog prevents radiocontrast nephropathy via phosphorylation of cyclic AMP response element binding protein. 1585 35

Reactive oxygen metabolites are important mediators in cisplatin-induced apoptosis in renal tubular epithelial cells (LLC-PK1). Mitochondria have been implicated to play a principal role in cisplatin-induced apoptosis. Caspase 12, an endoplasmic reticulum (ER)-specific caspase, participates in apoptosis under ER stress. Cytochrome P450 system is crucial to the generation of reactive oxygen metabolites and is present at high concentration in the ER. The direct role of caspase 12 in any model of renal injury has not previously been described. In this study, cleavage of procaspase 12 preceded that of caspases 3 and 9 after cisplatin treatment of LLC-PK1 cells. The active form of caspase 8 was not detected throughout the course of study. Preincubation of the LLC-PK1 cells with the caspase 9 inhibitor did not attenuate caspase 3 activation and provided no significant protection. Caspase 3 inhibitor provided only modest protection against cisplatin-induced apoptosis. LLC-PK1 cells that were transfected with anti-caspase 12 antibody significantly attenuated cisplatin-induced apoptosis. Taken together, these data indicate that caspase 12 plays a pivotal role in cisplatin-induced apoptosis. It is proposed that the oxidative stress that results from the interaction of cisplatin with the ER cytochrome P450 leads to activation of procaspase 12, resulting in apoptosis.
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PMID:Endoplasmic reticulum stress-associated caspase 12 mediates cisplatin-induced LLC-PK1 cell apoptosis. 1590 68

Gentamicin accumulates in lysosomes and induces apoptosis in kidney proximal tubules and renal cell lines. Using LLC-PK1 cells, we have examined the concentration- and time-dependency of the effects exerted by gentamicin (1-3 mM; 0-3 days) on (i) lysosomal stability; (ii) activation of mitochondrial pathway; (iii) occurrence of apoptosis (concentrations larger than 3 mM caused extensive necrosis as assessed by the measurement of lactate dehydrogenase release). Within 2 h, gentamicin induced a partial relocalization [from lysosomes to cytosol] of the weak organic base acridine orange. We thereafter observed (a) a loss of mitochondrial membrane potential (as from 10 h, based on spectrophotometric and confocal microscopy using JC1 probe) and (b) the release of cytochrome c from granules to cytosol, and the activation of caspase-9 (as from 12 h; evidenced by Western blot analysis). Increase in caspase-3 activity (assayed with Ac-DEVD-AFC in the presence of z-VAD-fmk]) and appearance of fragmented nuclei (DAPI staining) was then detected as from 16 to 24 h together with nuclear fragmentation. Gentamicin produces a fast (within 4 h) release of calcein from negatively-charged liposomes at pH 5.4, which was slowed down by raising the pH to 7.4, or when phosphatidylinositol was replaced by cardiolipin (to mimic the inner mitochondrial membrane). The present data provide temporal evidence that gentamicin causes apoptosis in LLC-PK1 with successive alteration of the permeability of lysosomes, triggering of the mitochondrial pathway, and activation of caspase-3.
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PMID:Gentamicin-induced apoptosis in LLC-PK1 cells: involvement of lysosomes and mitochondria. 1603 43

The nephrotoxicity induced by the immunosuppressive drug FK506 (tacrolimus or fujimycin), limits its usefulness in widespread application, and the underlying mechanism has not been completely understood. The primary targets of FK506 in the kidney are the proximal tubular epithelial cells. In this study, the protection of green tea extract against FK506-induced cell death of LLC-PK1 cells was investigated. FK506 caused a significant decrease in survival of the cells, but the addition of green tea extract reduced this effect in a dose-dependent manner. Treatment of the cells with 50 microM (41.1 microg/ml) FK506 induced a significant increase in annexin V-positive/propidium iodide-negative cells from 2.68 to 14.5%, whereas the addition of 6.25, 12.5, and 25 microg/ml of green tea extract caused a significant protective effect in apoptotic cells from 14.5 to 6.51, 3.20 and 3.02%, respectively. The effect of five different constituent tea polyphenols was also examined. Epigallocatechin-gallate and epigallocatechin significantly reduced FK506-induced cytotoxicity but epicatechin and catechin had no effect on cell viability. Furthermore, changes in cytochrome c release and caspase activation, which characterize apoptosis, were studied. Epigallocatechin-gallate and epigallocatechin suppressed a significant release of cytochrome c and activation of caspase-3 in FK506-treated LLC-PK1 cells.
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PMID:Protective effect of green tea extract and tea polyphenols against FK506-induced cytotoxicity in renal cells. 1644 94


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