Protein kinase C (PKC) is a critical molecule in cellular signal transduction in mammals. It is involved in many biological processes in embryonic development, including nuclear remodeling, cell cycle adjustment and cellular polarity regulation. The present study aimed to observe the location of PKCα, an important isozyme of PKC, in fertilized, parthenogenetic and tetraploid preimplantation embryos, and compare the expression of PKCα during embryonic compaction in Kunming mice. The location of PKCα was detected by immunochemistry and laser confocal microscopy. Western blot was performed to quantify PKCα expression during embryonic compaction in the three kinds of embryos. In the experiment, fertilized embryos were flushed from oviduct or uterus at 45, 52, 69, 76 and 93 h after injection of human chorionic gonadotrophin (hCG); parthenogenetic embryos were collected by SrCl2 activation of oocytes for 6 h; and tetraploid embryos were produced by electrofusion of 2-cell embryos. Embryos were fixed at different developmental stages for immunofluorescent staining. 8-cell/4-cell embryos and morula were lysed for Western blot. The results showed that PKCα had similar location pattern in different embryos. It was distributed mainly in the nuclear aggregating around chromatin at different developmental stages. However, PKCα expressed strongly in the interphase than in mitotic blastomere. Before embryonic compaction, PKCα was localized at the blastomere boundary. At late blastocyst stage of fertilized embryos, PKCα was localized only in the polar trophoblast, but not in other trophoblast. At late stage of pathenogenetic blastocyst, there was no clear PKCα signal in the polar trophoblast. Tetraploid embryos had larger blastomere than other embryos and compacted after 4-cell stage, but not after 8-cell stage. Meanwhile, there was PKCα signal at the blastomere boundary at 4-cell stage. Our results showed that the expression of PKCα lasted through all the preimplantation stage. Although there were different expression levels among different stages, the expression increased around embryonic compaction. Quantification of expression of PKCα by Western blot demonstrated that the expression increased after compaction, indicating that the compaction was possibly dependent on the relocation of PKCα. Moreover, it was shown that the second relocation of PKCα occurred during the blastocyst formation. PKCα had different expression patterns in the three kinds of preimplantation embryos. However, the effects of PKCα on embryonic development started in early stage. There must be a necessary connection between PKCα relocation and cell adhesion starting at embryonic compaction.
Animals ; Embryonic Development ; Female ; Mice ; Parthenogenesis ; Pregnancy ; Protein Kinase C-alpha ; metabolism ; Tetraploidy ; Trophoblasts ; enzymology

Consumption of herbal tea [flower buds of Cleistocalyx operculatus (Roxb.) Merr. et Perry (Myrtaceae)] is associated with health beneficial effects against multiple diseases including diabetes, asthma, and inflammatory bowel disease. Emerging evidences have reported that High mobility group box 1 (HMGB1) is considered as a key "late" proinflammatory factor by its unique secretion pattern in aforementioned diseases. Dimethyl cardamonin (2',4'-dihydroxy-6'-methoxy-3',5'-dimethylchalcone, DMC) is a major ingredient of C. operculatus flower buds. In this study, the anti-inflammatory effects of DMC and its underlying molecular mechanisms were investigated on lipopolysaccharide (LPS)-induced macrophages. DMC notably suppressed the mRNA expressions of TNF-alpha, IL-1beta, IL-6, and HMGB1, and also markedly decreased their productions in a time- and dose-dependent manner. Intriguingly, DMC could notably reduce LPS-stimulated HMGB1 secretion and its nucleo-cytoplasmic translocation. Furthermore, DMC dose-dependently inhibited the activation of phosphatidylinositol 3-kinase (PI3K), phosphoinositide-dependent kinase 1 (PDK1), and protein kinase C alpha (PKCalpha). All these data demonstrated that DMC had anti-inflammatory effects through reducing both early (TNF-alpha, IL-1beta, and IL-6) and late (HMGB1) cytokines expressions via interfering with the PI3K-PDK1-PKCalpha signaling pathway.
Asthma ; Teas, Herbal ; Cytokines ; Flowers ; HMGB1 Protein ; Inflammatory Bowel Diseases ; Interleukin-6 ; Macrophages ; Phosphatidylinositol 3-Kinase ; Phosphotransferases ; Protein Kinase C-alpha ; RNA, Messenger ; Tumor Necrosis Factor-alpha

BACKGROUNDAirway smooth muscle proliferation plays an important role in airway remodeling in asthma. But little is known about the intracellular signal pathway in the airway smooth muscle cell proliferation in asthma. The objective of this paper is to investigate the contribution of protein kinase C (PKC) and its alpha isoform to passively sensitized human airway smooth muscle cells (HASMCs) proliferation.

METHODSHASMCs in culture were passively sensitized with 10% serum from asthmatic patients, with non-asthmatic human serum treated HASMCs used as the control. The proliferation of HASMCs was examined by cell cycle analysis, 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyltetrazoliumbromide (MTT) colorimetric assay and proliferating cell nuclear antigen (PCNA) immunofluorescence staining. The effect of PKC agonist phorbol 12-myristate 13-acetate (PMA) and PKC inhibitor Ro-31-8220 on the proliferation of HASMCs exposed to human asthmatic serum and non-asthmatic control serum was also examined by the same methods. The protein and mRNA expression of PKC-alpha in passively sensitized HASMCs were detected by immunofluorescence staining and reverse transcription-polymerase chain reaction.

RESULTSThe percentage of S phase, absorbance (value A) and the positive percentage of PCNA protein expression in HASMCs passively sensitized with asthmatic serum were (16.30 +/- 2.68)%, 0.430 +/- 0.060 and (63.4 +/- 7.4)% respectively, which were significantly increased compared with HASMCs treated with control serum [(10.01 +/- 1.38)%, 0.328 +/- 0.034 and (37.2 +/- 4.8)%, respectively] (P < 0.05). After HASMCs were passively sensitized with asthmatic serum, they were treated with PMA, the percentage of S phase, value A and the positive percentage of PCNA protein expression were (20.33 +/- 3.39)%, 0.542 +/- 0.065 and (76.0 +/- 8.7)% respectively, which were significantly increased compared with asthmatic serum sensitized HASMCs without PMA(P < 0.05). After HASMCs passively sensitized with asthmatic serum were treated with Ro-31-8220, the percentage of S phase, value A and the positive percentage of PCNA protein expression were (11.21 +/- 1.56)%, 0.331 +/- 0.047 and (38.8 +/- 6.0)% respectively, which were significantly decreased compared with asthmatic serum sensitized HASMCs without Ro-31-8220 (P < 0.05). The relative ratio of value A of PKC-alpha mRNA and the positive percentage of PKC-alpha protein expression in passively sensitized HASMCs were 1.23 +/- 0.10 and (61.1 +/- 9.4)% respectively, which were significantly increased compared with HASMCs treated with control serum [1.05 +/- 0.09 and (34.9 +/- 6.7)%, respectively] (P < 0.05).

CONCLUSIONSThe proliferation of HASMCs passively sensitized with human asthmatic serum is increased. PKC and its alpha isoform may contribute to this proliferation.

Asthma ; immunology ; pathology ; Cell Division ; physiology ; Cells, Cultured ; Humans ; Immunization, Passive ; Myocytes, Smooth Muscle ; pathology ; physiology ; Protein Kinase C ; physiology ; Protein Kinase C-alpha ; Signal Transduction ; physiology

OBJECTIVETo observe the role of PKC-potentiated inhibitory protein for protein phosphatase 1 of 17 x 10(3) (CPI-17) in vascular calcium sensitivity regulated by protein kinase Calpha (PKCalpha) and Cepsilon (PKCepsilon) in rats with hemorrhagic shock (HS).

METHODSEight Wistar rats were used to reproduce 2 h HS model. Superior mesenteric artery (SMA) rings from HS rats were randomly divided into 2 h shock group (without treatment), PKCalpha agonist group (with addition of thymelea toxin into the nutrient solution), CPI-17 antibody + PKCalpha agonist group [incubation with thymelea toxin and CPI-17 antibody (1:800)], PKCepsilon agonist group (with addition of carbachol into the nutrient solution), and CPI-17 antibody + PKCepsilon agonist group [incubation with carbachol and CPI-17 antibody (1:800)]. SMA rings from another eight normal rats were used as normal control group. Calcium sensitivity indices (Emax, pD2) of SMA rings were measured by isolated organ perfusion system. Hypoxic VSMCs in primary culture were randomly divided into 2 h hypoxia group, PKCalpha agonist group (with above-mentioned treatment), PKCepsilon agonist group (with above-mentioned treatment), normal VSMCs were used as normal control group. Protein expression and phosphorylation of CPI-17 were measured via Western blot.

RESULTSEmax and pD2 in all the experimental groups were lower than those in normal control group (P < 0.01). Emax in PKCalpha agonist group and PKCepsilon agonist group was increased (5.8 +/- 0.8, 5.8 +/- 0.9 mN, respectively) as compared with that of 2 h shock group (4.1 +/- 0.6 mN, P < 0.01). Protein expression and phosphorylation of CPI-17 in VSMC were significantly decreased in 2 h hypoxia group, compared with those in normal control group (P < 0.05), and those in PKCalpha agonist and PKC agonist groups (P < 0.05 or P < 0.01).

CONCLUSIONSPKCalpha and PKCepsilon may regulate vascular calcium sensitivity through change in protein expression and activity of CPI-17 in HS rats.

Animals ; Calcium ; blood ; pharmacology ; Female ; Male ; Muscle Proteins ; metabolism ; Phosphoproteins ; metabolism ; Phosphorylation ; Protein Kinase C-alpha ; metabolism ; Protein Kinase C-epsilon ; metabolism ; Rats ; Rats, Wistar ; Shock, Hemorrhagic ; metabolism

OBJECTIVETo investigate the expressions of protein kinase C (PKC) isoforms in X-ray-exposed HepG2 cells and identify the PKC isoforms that induce radioresistance in HepG2 cells.

METHODSCultured HepG2 cells were divided into control group and 6 Gy radiation group for corresponding treatments. The fluorescence intensity (FI) and the percentage of positive cells were determined using flow cytometry.

RESULTSThe FI of PKCalpha and PKCdelta were 2.28 and 5.05 in the radiation group, respectively, significantly higher than those in the control group (P<0.05). The percentages of PKCalpha- and PKCdelta -positive cells were significantly higher in the radiation group than in the control group (P<0.05). The FI and the percentages of PKC zeta, gamma, epsilon, zeta positive cells were rather low and showed no significant differences between the two groups (P>0.05); PKCbeta expression was not detected in the two groups of cells. The apoptosis rates of the control and radiation groups were 1.73% and 20.90%, respectively.

CONCLUSIONPKCalpha and PKCdelta may be involved in protecting HepG2 cells from radiation-induced apoptosis.

Apoptosis ; physiology ; radiation effects ; Hep G2 Cells ; Humans ; Isoenzymes ; classification ; metabolism ; Protein Kinase C-alpha ; metabolism ; Protein Kinase C-delta ; metabolism ; Radiation Tolerance ; Signal Transduction ; drug effects ; physiology

AIMTo investigate the effects of sulfated polymannuroguluronate (SPMG), a novel candidate anti-AIDS drug in Phase II clinical trial, on Tat-induced release of proinflammatory cytokines (i.e., TNFalpha, IL-1beta and IL-6) and its related mechanism.

METHODSThe effects of SPMG on Tat induced TNFalpha (4 h), IL-1beta and IL-6 (6 h) secretion in THP-1 cells were measured by ELISA. Western blotting analysis was used to study the effects of SPMG on Tat induced PKCzeta, PKCtheta and PKCsigma phosphorylation.

RESULTSSPMG (50 to 100 microg x mL(-1)) markedly suppressed TNFalpha, IL-1beta and IL-6 secretion in Tat activated THP-1 cells. In THP-1 cells the phosphorylation levels of PKCzeta, PKCtheta and PKCsigma significantly increased following Tat stimulation, and only PKCsigma phosphorylation levels was inhibited by SPMG (50 to 100 microg x mL(-1)).

CONCLUSIONSPMG suppresses the secretion of proinflammatory cytokines in THP-1 cells may be by inhibiting PKCsigma activation.

Cell Line, Tumor ; Gene Products, tat ; pharmacology ; Humans ; Interleukin-1beta ; secretion ; Interleukin-6 ; secretion ; Isoenzymes ; metabolism ; Phosphorylation ; Polysaccharides ; pharmacology ; Protein Kinase C ; metabolism ; Protein Kinase C-delta ; metabolism ; Protein Kinase C-theta ; Tumor Necrosis Factor-alpha ; secretion

OBJECTIVE: To predict the targets and pathways in the therapeutic mechanism of Guizhi Gancao Decoction (GZGCD) against heart failure (HF) based on network pharmacology. METHODS: The chemical components of GZGCD were analyzed using the databases including TCMSP, TCMID and TCM@Taiwan, and the potential targets of GZGCD were predicted using the SwissTargetPrediction database. The targets of HF were obtained using the databases including DisGeNET, Drugbank and TTD. The intersection targets of GZGCD and HF were identified using VENNY. Uniport database was used to convert the information, and the components-targets-disease network was constructed using Cytoscape software. The Bisogene plug-in, Merge plug-in, and CytoNCA plug-in in Cytoscape software were used for protein-protein interaction (PPI) analysis to acquire the core targets. Metascape database was used for GO and KEGG analysis. The results of network pharmacology analysis were verified with Western blot analysis. Three factors (PKCα, ERK1/2 and BCL2) were screened according to the degree value of network pharmacology results and the degree of correlation with heart failure process. The pentobarbtal sodium was dissolvein H9C2 cells treated with serum-free high glucose medium to simulate the ischemic anoxic environment of heart failure. The total proteins of myocardial cells were extracted. The protein contents of PKCα, ERK1/2 and BCL2 were determined. RESULTS: We identified a total of 190 intersection targets between GZGCD and HF using Venny database, involving mainly the circulatory system process, cellular response to nitrogen compounds, cation homeostasis, and regulation of the MAPK cascade. These potential targets were also involved in 38 pathways, including the regulatory pathways in cancer, calcium signal pathway, cGMP-PKG signal pathway, and cAMP signal pathway. Western blot analysis showed that in an in vitro H9C2 cell model of HF, treatment with GZGCD downregulated PKCα and ERK1/2 expressions and upregulated BCL2 expression. CONCLUSION The therapeutic mechanism of GZGCD for HF involves multiple targets including PRKCA, PRKCB, MAPK1, MAPK3, and MAPK8 and multiple pathways including the regulatory pathway in cancer and the calcium signaling pathway.
Humans ; Protein Kinase C-alpha ; Network Pharmacology ; Heart Failure/drug therapy* ; Proto-Oncogene Proteins c-bcl-2

Endothelial dysfunction is implicated in a variety of cardiovascular diseases although the detailed mechanisms are not yet completely understood. A relationship has been suggested to exist between inflammation and endothelial dysfunction. TNF-&alpha; serves as one of the most important pro-inflammatory cytokines. The main objectives of the present study were to explore the effect of PKC-ζ on TNF-&alpha;-impaired endothelial function as well as the underlying mechanisms. Acetylcholine-induced endothelium-dependent vasodilation of mouse thoracic aorta stimulated by TNF-&alpha; was initially determined. PKC-ζ deficient mice and the specific inhibitor of NADPH oxidase were respectively applied to elucidate their roles in TNF-&alpha;-induced endothelial dysfunction. In vitro superoxide generation in HAECs was detected by DHE staining after administration of TNF-&alpha;. Meanwhile, the regulatory p47(phox) subunit of NADPH oxidase was evaluated by Western blotting and RT-PCR. The results showed that TNF-&alpha; conspicuously impaired endothelium-dependent vasodilation and the impairment was attenuated by either depleting PKC-ζ or inhibiting NADPH oxidase. In vitro TNF-&alpha; increased superoxide production and p47(phox) expression in HAECs, and such increases could be ameliorated by the specific PKC-ζ inhibitor. Our findings suggest that superoxide over-production triggered by PKC-ζ-dependent NADPH oxidase activation contributes to TNF-&alpha;-induced endothelial dysfunction.
Animals ; Endothelium, Vascular ; metabolism ; Male ; Mice ; NADPH Oxidases ; metabolism ; Protein Kinase C ; metabolism ; Tumor Necrosis Factor-alpha ; metabolism

OBJECTIVETo study the expression of protein kinase C (PKC) alpha subtype in Chinese hamster ovary (CHO) cells.

METHODSThe PKC alpha primer pairs were designed based on the GenBank sequence of PKC alpha of a species with the highest homology to Chinese hamster identified using EMBL Data Library Clustalw tool. The sequence coding for PKC alpha, amplified from the CHO cells using RT-PCR, was ligated to the pGEM-T plasmid vector, and the recombinant vector was transformed into E.coli DH5alpha with the positive colones selected by blue/white screening. Restriction enzyme digestion, gel electrophoresis analysis, followed by sequencing of the digestion products were performed for identification of the recombinant. Western blotting was used to analyze the PKC alpha expression in the CHO cells.

RESULTSThe presence of PKC alpha mRNA was detected in the CHO cells by RT-PCR. Western blotting also identified PKC alpha expression in the cells.

CONCLUSIONSPKC alpha expression has been identified in the CHO cells, which may facilitate further structural and functional study of PKC alpha and investigation of its role in the intracellular signal transduction pathways.

Animals ; Blotting, Western ; CHO Cells ; Cloning, Molecular ; Cricetinae ; Cricetulus ; Female ; Protein Kinase C-alpha ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction

BACKGROUND: Endotoxin, the component of outermembrane of gram negative organism, plays an important role in the initiation and amplification of inflammatory reaction by its effects on inflammatory cells. Until recently, there have been continuing efforts to delinate the mechanisms of the signal trasduction pathway of endotoxin stimuli on inflammatory cells. By uncovering the mechanisms of signal transduction pathway of endotoxin stimuli, we can expect to have tools to control the excessive inflammatory responses which sometimes may be fatal to the involved host. It was generally accepted that endotoxin exerts its inflammatory effects through inflammatory cytokines that are produced by endotoxin-stimulated inflammatory cells and there were some reports on the importance of protein kinase C and protein tyrosine kinase activation in the production of inflammatory cytokines by endotoxin. So we evaluated the effect of pretreatment of protein kinase C inhibitors (H7, Staurosporin) and protein tyrosine kinase inhibitors(Herbimycin, Genistein) on the endotoxin-stimulated cytokines(IL-8 & TNF-alpha) mRNA expression. METHOD: Peripheral blood monocytes were isolated from healthy volunteers by Ficoll-Hypaque density gradient method and purified by adhesion to 60mm Petri dishes. Endotoxin(LPS 100ng/ml) was added to each dishes except one control dish, and each endotoxin-stimulated dishes was preincubated with H7, Staurosporin(protein kinase C inhibitor), Herbimycin or Genistein(protein tyrosine kinase inhibitor) respectively except one dish. Four hours later the endotoxin stimulation, total RNA was extracted and Northern blot analysis for IL-8 mRNA and TNF-alpha mRNA was done. RESULT: Endotoxin stimulation increased the expression of IL-8 mRNA and TNF-alpha mRNA expression in human peripheral blood monocyte as expected and the stimulatory effect of endotoxin on TNF-alpha mRNA expression was inhibited by protein kinase C inhibitors(H7, Staurosporin) and protein tyrosine kinase inhibitors (Herbimycin, Genistein). The inhibitory effect of each drugs was increased with increasing concentration. The stimulatory effect of endotoxin on IL-8 mRNA was also inhibited by H7 and protein tyrosine kinase inhibitors (Herbimycin, Genistein) dose-dependently but not by Staurosporin. CONCLUSION: Protein kinase C and protein tyrosine kinase are involved in the endotoxin induced signal transduction pathway in human peripheral blood monocyte.
Blotting, Northern ; Cytokines ; Healthy Volunteers ; Humans ; Interleukin-8 ; Monocytes* ; Phosphotransferases ; Protein Kinase C* ; Protein Kinases* ; Protein-Tyrosine Kinases* ; RNA ; RNA, Messenger ; Signal Transduction* ; Tumor Necrosis Factor-alpha