Animals ; Mice ; Myocardium/metabolism* ; Oxidative Stress ; Physical Conditioning, Animal ; Protein Kinase C-delta/metabolism* ; Src Homology 2 Domain-Containing, Transforming Protein 1/metabolism* ; Swimming

OBJECTIVETo investigate the expression of ASK1 and PRKCD in the process of monocyte differentiation, and explore their role in functional changes of hypersplenism spleen macrophages (Mφ) in portal hypertension (PH).

METHODSU937 cells were stimulated to differentiate into monocyte/macrophage-like cells by cultivation in PMA and the mRNA expressions of ASK1 and PRKCD were detected by q-PCR and the changes of protein expression were identified by western blot analysis. The secretion of phagocytose related cytokines such as IL-10 and TNF-α were tested by ELISA, and the function of the macrophage-like cells were studied by chicken red blood cell phagocytose test.

RESULTSThe expressions of PRKCD and ASK1 mRNA were gradually decreased along with the cell differentiation, while the secretion of TNF-α was increased, IL-10 secretion reached a maximum at 24 h after PAM stimulation, and then gradually fell. The expression of ASK1 and p-ASK1 were rapidly increased compared with the non-stimulated U937 cells, while the expression of PRKCD and p-PRKCD were sightly declined. The phagocytose test show that U937 cells induced with PMA were able to swallow the chicken red blood cell.

CONCLUSIONUp-regulated protein expression of ASK1 and p-ASK1 and down-regulated protein expression of PRKCD and p-PRKCD in the process of PMA induced monocyte differentiation, are consist with the expression changes of splenic macrophage phagocytosis in hypersplenism, which leads to increased activity of Mφ.

Cell Differentiation ; Down-Regulation ; Humans ; Hypersplenism ; Hypertension, Portal ; Interleukin-10 ; secretion ; MAP Kinase Kinase Kinase 5 ; physiology ; Macrophages ; cytology ; Phagocytosis ; Protein Kinase C-delta ; physiology ; RNA, Messenger ; Tumor Necrosis Factor-alpha ; secretion ; U937 Cells

Pulmonary edema is a major cause of mortality due to acute lung injury (ALI). The involvement of protein kinase C-delta (PKC-delta) in ALI has been a controversial topic. Here we investigated PKC-delta function in ALI using PKC-delta knockout (KO) mice and PKC inhibitors. Our results indicated that although the ability to produce proinflammatory mediators in response to LPS injury in PKC-delta KO mice was similar to that of control mice, they showed enhanced recruitment of neutrophils to the lung and more severe pulmonary edema. PKC-delta inhibition promoted barrier dysfunction in an endothelial cell layer in vitro, and administration of a PKC-delta-specific inhibitor significantly increased steady state vascular permeability. A neutrophil transmigration assay indicated that the PKC-delta inhibition increased neutrophil transmigration through an endothelial monolayer. This suggests that PKC-delta inhibition induces structural changes in endothelial cells, allowing extravasation of proteins and neutrophils.
Acute Lung Injury* ; Animals ; Capillary Permeability* ; Endothelial Cells ; Lung ; Mice ; Mortality ; Neutrophils ; Protein Kinase C-delta* ; Protein Kinases* ; Pulmonary Edema

OBJECTIVETo investigate the effects of mRNA transcriptional and protein expressions of protein kinase Cδ (PKCδ) on the development of arsenic liver injury caused by coal-burning.

METHODSPopulation study:133 arsenic exposures were selected as arsenic exposure groups including the ward non-patient group (25 cases) , no obvious hepatopathy group (38 cases) , mild (43 cases) and moderate to severe hepatopathy group (27 cases) from the area with endemic arsenism in Guizhou province. Another 34 healthy residents were selected as the control group in non-arsenic pollution village. The urine and peripheral blood were collected from the subjects. The arsenic contents in urine and mRNA expressions of PKCδ in peripheral blood were detected. Animal experiment study:thirty wistar rats were randomly by random number table divided into control group, drinking water arsenic poisoning group and coal-burning arsenic poisoning group (i.e., low, medium and high arsenic contaminated grain group) by random number table method, including 6 rats in each group. The control group was fed normally for 3 months, drinking water arsenic poisoning group and coal-burning arsenic poisoning groups were fed respectively with 10 mg/kg As2O3 solution and different concentrations (25, 50 and 100 mg/kg) of arsenic-containing feed which was persisted 3 months. The arsenic contents in urine, mRNA expression levels of PKCδ in peripheral blood and liver tissue and the protein expression levels of phosphorylated protein kinase Cδ(pPKCδ) in liver tissue were detected.

RESULTSThe median(quartile) of arsenic contents in urine were 25.58 (18.62-40.73), 56.66 (38.93-76.77), 64.90 (39.55- 98.37) and 75.47 (41.30-109.70) µg/g Cr respectively for the non-patient group, no obvious hepatopathy group, mild and moderate to severe hepatopathy group. The levels were higher than that in the control group (23.34 (17.84-37.45) µg/g Cr) (P < 0.05), except for the ward non-patient group. The arsenic contents in rat urine were 2223.61 (472.98-3976.73), 701.16 (194.01-1300.27), 1060.94 (246.33-2585.47) and 3101.11 (1919.97-5407.07) µg/g Cr, respectively for the drinking water arsenic poisoning group, the low, medium and high dosage arsenic grain contamination groups, all higher than that in the control group (94.32 (22.65-195.25) µg/g Cr) (P < 0.05) . The protein expressions of pPKC&delta; in liver tissue were 324.83 ± 25.06, 278.50 ± 30.57, 308.83 ± 34.67 and 326.33 ± 35.09, which were significantly higher than that in the control group (240.17 ± 28.07) (P < 0.05) . The protein expression levels of pPKC&delta; in liver cell membrane were 0.49 ± 0.06,0.33 ± 0.05,0.37 ± 0.06 and 0.50 ± 0.08, which were significantly higher than that in the control group (0.28 ± 0.04) (P < 0.05) . The protein expression levels of pPKC&delta; in liver cell cytoplasm were 0.38 ± 0.06,0.31 ± 0.05, 0.35 ± 0.05 and 0.36 ± 0.05, which were significantly higher than that in the control group (0.24 ± 0.05) (P < 0.05).

CONCLUSIONThe arsenic may regulate protein expressions of pPKC&delta; and induce its membrane translocation, and cause the development of arsenic liver injury caused by coal-burning.

Animals ; Arsenic ; urine ; Arsenic Poisoning ; epidemiology ; metabolism ; Case-Control Studies ; China ; epidemiology ; Coal ; Environmental Exposure ; Female ; Humans ; Liver ; enzymology ; pathology ; Liver Diseases ; enzymology ; etiology ; Male ; Protein Kinase C-delta ; metabolism ; Rats ; Rats, Wistar

Store-operated Ca(2+) channels (SOCs) are plasma membrane Ca(2+) permeable channels activated by depletion of intracellular Ca(2+) store. Ca(2+) entry through SOCs is known as store-operated Ca(2+) entry (SOCE), which plays an important role in the functional regulation of airway smooth muscle cells (ASMCs). Protein kinase C (PKC) has been shown to have an activating or inhibiting effect on SOCE, depending on cell types and PKC isoforms that are involved. In ASMCs, the effect of PKC on SOCE has not been elucidated so far. In this study, the role of PKC in the activation of SOCE in rat ASMCs was examined by using Ca(2+) fluorescence imaging technique. The results showed that acute application of PKC activators PMA and PDBu did not affect SOCE induced by the sarcoplasmic reticulum Ca(2+)-ATPase (SERCA) inhibitor thapsigargin. The non-selective PKC inhibitor chelerythrine significantly inhibited thapsigargin- and bradykinin-induced SOCE. RT-PCR assay identified PKCα, &delta; and ɛ isoforms in rat ASMCs. PKCα-selective inhibitor Gö6976 and PKCɛ-inhibiting peptide Epsilon-V1-2 had no effect on SOCE; by contrast, PKC&delta;-selective inhibitor rottlerin attenuated SOCE dramatically, suggesting that PKC&delta; was the major PKC isoform involved in the activation of SOCE in ASMCs. Moreover, PKC down-regulation by extended exposure to high doses of PMA or PDBu also reduced SOCE, confirming the essential role of PKC in the activation of SOCE in ASMCs. In addition, PKC down-regulation did not influence the expression of stromal interaction molecule 1 (STIM1) and Orai1, two elementary molecules in the regulation and activation of SOCs. These results identified PKC&delta; as an essential PKC isoform involved in the activation of SOCE, and confirmed that PKC regulates the function of ASMCs in a SOCE-dependent manner.
Animals ; Bronchi ; metabolism ; Calcium ; metabolism ; Calcium Channels ; Calcium Signaling ; physiology ; Cells, Cultured ; Male ; Membrane Glycoproteins ; metabolism ; Myocytes, Smooth Muscle ; metabolism ; ORAI1 Protein ; Protein Kinase C-delta ; metabolism ; Rats ; Rats, Sprague-Dawley ; Stromal Interaction Molecule 1

OBJECTIVETo investigate the effect of DADLE, a &delta;-opioid receptor agonist, on the proliferation of human liver cancer HepG2 cells and explore the mechanism involving PKC pathway.

METHODSHepG2 cells were treated with DADLE at different doses (0.01, 0.1, 1.0 and 10 µmol/L). Cell viability was determined using methyl thiazolyl terazolium (MTT) assay. The expression of PKC mRNA and p-PKC protein were examined by RT-PCR and Western blot assay. After treated separately with DADLE plusing NAL or PMA, the cell cycle of HepG2 cells was analyzed by flow cytometer. MTT was used to detect their proliferation capacity and Western blot was used to examine the p-PKC expression. The growth inhibitory rate of HepG2 cells treated with DADLE and cis-diammine dichloridoplatinum (CDDP) was analyzed.

RESULTSDADLE at different concentrations showed an inhibitory effect on the proliferation of HepG2 cells though inhibiting the expression of PKC mRNA and p-PKC protein. The results of flow cytometry showed that compared with the control group, the percentage of S + G(2)/M cells in DADLE-treated group was lowered by 3.94% (P < 0.01). Meanwhile, after treated with NAL and PMA, the percentage was elevated by 3.22% and 3.63%, respectively (P < 0.01). The MTT and Western blot assays showed that compared with the control group, the values of A570 and p-PKC protein levels in the HepG2 cells of DADLE-treated group were significantly decreased (P < 0.01). After treatment with NAL and PMA, the values of A570 and p-PKC protein levels were elevated significantly (P < 0.01). The growth inhibitory rate of DADLE + CDDP group was 79.9%, significantly lower than 25.2% and 43.2% of the DADLE and CDDP groups, respectively.

CONCLUSIONSActivation of &delta;-opioid receptor by DADLE inhibits the apoptosis of human liver cancer HepG2 cells. The underlying mechanism may be correlated with PKC pathway. DADLE can enhance the chemosensitivity of HepG2 cells to CDDP.

Antineoplastic Agents ; pharmacology ; Cell Cycle ; drug effects ; Cell Proliferation ; drug effects ; Cisplatin ; pharmacology ; Dose-Response Relationship, Drug ; Drug Resistance, Neoplasm ; Enkephalin, Leucine-2-Alanine ; administration & dosage ; pharmacology ; Hep G2 Cells ; Humans ; Naltrexone ; analogs & derivatives ; pharmacology ; Phosphorylation ; Protein Kinase C ; genetics ; metabolism ; RNA, Messenger ; metabolism ; Receptors, Opioid, delta ; agonists ; Signal Transduction ; Tetradecanoylphorbol Acetate ; analogs & derivatives ; pharmacology

PURPOSE: This study demonstrated that apoptosis induced by mycophenolic acid (MPA) is mediated by mitochondrial membrane potential transition (MPT) changes in Jurkat cells. METHODS: Cell viability and MPT changes were measured by flow cytometry. Western blotting was performed to evaluate the expression of Bcl-2 family proteins, Bid, truncated Bid (tBid), cytochrome c, voltage dependent anion channel (VDAC), poly ADP-ribose polymerase (PARP), and protein kinase C-delta (PKC-delta). The catalytic activity of caspase-9 and -3 was also measured. RESULTS: Cell viability was decreased in time- and dose-dependent manners. Bcl-2 protein expression was decreased, but Bax protein expression was identified. A decreased Bcl-XL /Bcl-XS ratio was also noted. The expression of tBid protein also increased in a time-dependent manner in Jurkat cells treated with MPA. While normal MPT appeared as orange fluorescence, abnormal MPT corresponded to green fluorescence. Green fluorescence increased as orange decreased in the MPA-treated cells. Significantly increased concentrations of MPA induced the release of cytosolic cytochrome c. MPA also augmented the catalytic activity of caspase-9 and caspase-3 in Jurkat cells. Our findings demonstrated that MPA-induced apoptosis is mediated by MPT changes accompanied by decreased Bcl-XL expression and the appearance of tBid protein. The release of cytosolic cytochrome c from mitochondria and increased catalytic activity of caspase-9 and caspase-3 were observed in MPA-treated Jurkat cells. CONCLUSION: These results suggest that mitochondrial dysfunction caused by MPA induces human T lymphocyte apoptosis.
Adenosine Diphosphate Ribose ; Apoptosis ; bcl-2-Associated X Protein ; BH3 Interacting Domain Death Agonist Protein ; Blotting, Western ; Caspase 3 ; Caspase 9 ; Cell Survival ; Citrus sinensis ; Cytochromes c ; Cytosol ; Flow Cytometry ; Fluorescence ; Humans ; Jurkat Cells ; Lymphocytes ; Membrane Potential, Mitochondrial ; Mitochondria ; Mitochondrial Membranes ; Mycophenolic Acid ; Protein Kinase C-delta ; Proteins

Cyclooxygenase-2 (COX-2) is an important enzyme in inflammation. In this study, we investigated the underlying molecular mechanism of the synergistic effect of rottlerin on interleukin1beta (IL-1beta)-induced COX-2 expression in MDA-MB-231 human breast cancer cell line. Treatment with rottlerin enhanced IL-1beta-induced COX-2 expression at both the protein and mRNA levels. Combined treatment with rottlerin and IL-1beta significantly induced COX-2 expression, at least in part, through the enhancement of COX-2 mRNA stability. In addition, rottlerin and IL-1beta treatment drove sustained activation of p38 Mitogen-activated protein kinase (MAPK), which is involved in induced COX-2 expression. Also, a pharmacological inhibitor of p38 MAPK (SB 203580) and transient transfection with inactive p38 MAPK inhibited rottlerin and IL-1beta-induced COX-2 upregulation. However, suppression of protein kinase C delta (PKC delta) expression by siRNA or overexpression of dominant-negative PKC delta (DN-PKC-delta) did not abrogate the rottlerin plus IL-1beta-induced COX-2 expression. Furthermore, rottlerin also enhanced tumor necrosis factor-alpha (TNF-alpha), phorbol myristate acetate (PMA), and lipopolysaccharide (LPS)-induced COX-2 expression. Taken together, our results suggest that rottlerin causes IL-1beta-induced COX-2 upregulation through sustained p38 MAPK activation in MDA-MB-231 human breast cancer cells.
Acetophenones/*pharmacology ; Benzopyrans/*pharmacology ; Breast Neoplasms/drug therapy/*genetics/immunology ; Cell Line, Tumor ; Cyclooxygenase 2/*genetics ; Enzyme Activation/drug effects ; Enzyme Inhibitors/*pharmacology ; Female ; Gene Expression Regulation, Neoplastic/*drug effects ; Humans ; Interleukin-1beta/*immunology ; MAP Kinase Signaling System/drug effects ; Mallotus Plant/chemistry ; NF-kappa B/immunology ; Protein Kinase C-delta/antagonists & inhibitors ; Reactive Oxygen Species/immunology ; p38 Mitogen-Activated Protein Kinases/*immunology

PURPOSE: Protein kinase C (PKC) has been implicated in a wide variety of cellular processes. Although PKC-delta is implicated in cell growth inhibition, as well as in cell differentiation, apoptosis, and tumor suppression, its role in atherosclerosis remains unclear. This study aimed to identify the mechanism of PKC-delta in the development of atherosclerosis. METHODS: To induce atherosclerosis, we performed allograft transplantations on aortas in mice. At 2, 4, and 6 weeks after transplantation, grafted aortas were obtained to compare the degree of atherosclerosis between wild type and PKC-delta (-/-) aorta. Alloantibody levels in the recipient mice's blood were measured. Reverse transcriptase-polymerase chain reaction (RT-PCR) was performed to quantitatively measure chemokine and cytokine mRNA expression of the inflammation from the harvested aorta. RESULTS: Atherosclerosis was more severe in the PKC-delta (-/-) aorta than in the wild type aorta. Alloantibody levels were higher in the mice grafted with aorta from the PKC-delta (-/-) mice than in the mice grafted with aorta from the wild type mice. RT-PCR revealed higher expressions of MRP-2, MCP-1, MIP-1alpha, and IL-2 in the mice grafted with aorta from the PKC-delta (-/-) mice than the wild type mice. CONCLUSION: Aorta allograft transplantation is a useful modality for inducing atherosclerosis. PKC-delta may be a negative regulator of atherosclerosis.
Animals ; Aorta ; Apoptosis ; Atherosclerosis ; Cell Differentiation ; Chemokine CCL3 ; Inflammation ; Interleukin-2 ; Mice ; Protein Kinase C ; Protein Kinase C-delta ; Protein Kinases ; RNA, Messenger ; Transplantation, Homologous ; Transplants

OBJECTIVETo study the role of protein kinase C-delta (PKC-delta) in hyperthermia-induced apoptosis in human tongue squamous cell carcinoma Tca8113 cells.

METHODSTca8113 cells were treated at 43 degrees C in a heating water bath for 0, 40, 80, 120 min after pretreatment with Rottlerin, a specific inhibitor of PKC-delta, and equal volume dimethyl sulfoxide (DMSO) for 30 min, respectively. The cells were stained by propidium iodide (PI) and Rhodamine 123 to analysis apoptotic rate and the changes of mitochondrial transmembrane potential by flow cytometry (FCM). The total proteins were extracted for Western blotting analysis of activation and proteolysis of PKC-delta, and for colorimetric assay of relative activity of Caspase-3.

RESULTSHyperthermia could induce proteolysis and activation of PKC-delta, and this was attenuated by Rottlerin. Apoptotic rate, decreasing of mitochondrial transmembrane potential and activity of Caspase-3 which being induced by hyperthermia in Tca8113 cells were inhibited by PKC-delta specific inhibitor Rottlerin. There were significantly statistical differences in apoptosis rates, mitochondrial transmembrane potential and activity of Caspase-3 between Rottlerin- and non-Rottlerin-pretreated cells after hyperthermia for 40, 80, 120 min (P < 0.01).

CONCLUSIONActivated PKC-delta may facilitate hyperthermia-induced apoptosis in Tca8113 cells, and may be one of the mechanisms of apoptosis induced by hyperthermia.

Acetophenones ; Apoptosis ; Benzopyrans ; Carcinoma, Squamous Cell ; Humans ; Protein Kinase C ; Protein Kinase C-delta