共查询到20条相似文献,搜索用时 46 毫秒
1.
Chao-Wei Chiang Yi Huang Ka-Wai Leong Lih-Chyang Chen Hua-Chien Chen Shu-Jen Chen Chen-Kung Chou 《Journal of biomedical science》2010,17(1):35
Background
Protein Kinase C (PKC) is a serine/threonine kinase that involved in controlling of many cellular processes such as cell proliferation and differentiation. We have observed previously that TPA (12-O-tetradecanoylphorbol 13-acetate) induces cell cycle arrest in G0/G1 phase in human hepatoma HepG2 cells. However, is there any miRNA involved in PKCα mediated cell growth arrest is still unknown. 相似文献2.
Jean-Hugues?Parmentier Gautam?K?Gandhi Monique?T?Wiggins Abdelwahab?E?Saeed Sylvain?G?Bourgoin Kafait?U?Malik
Background
Phenylephrine (PHE), an α1 adrenergic receptor agonist, increases phospholipase D (PLD) activity, independent of classical and novel protein kinase C (PKC) isoforms, in rat-1 fibroblasts expressing α1A adrenergic receptors. The aim of this study was to determine the contribution of atypical PKCζ to PLD activation in response to PHE in these cells. 相似文献3.
Background
Prostaglandin (PG) F2α is a key regulator of endometrial function and exerts its biological action after coupling with its heptahelical G protein-coupled receptor (FP receptor). In endometrial adenocarcinoma the FP receptor expression is elevated. We have shown previously that PGF2α-FP receptor signalling in endometrial adenocarcinoma cells can upregulate several angiogenic factors including fibroblast growth factor-2 (FGF2). In the present study, we investigated the paracrine effect of conditioned medium produced via PGF2α-FP receptor signalling in endometrial adenocarcinoma cells stably expressing the FP receptor (Ishikawa FPS cells), on endothelial cell function. 相似文献4.
Kellie J. Hall Matthew T. Harper Karen Gilio Judith M. Cosemans Johan W. M. Heemskerk Alastair W. Poole 《PloS one》2008,3(9)
Background
PKCθ is a novel protein kinase C isozyme, predominately expressed in T cells and platelets. PKCθ−/− T cells exhibit reduced activation and PKCθ−/− mice are resistant to autoimmune disease, making PKCθ an attractive therapeutic target for immune modulation. Collagen is a major agonist for platelets, operating through an immunoreceptor-like signalling pathway from its receptor GPVI. Although it has recently been shown that PKCθ positively regulates outside-in signalling through integrin αIIbβ3 in platelets, the role of PKCθ in GPVI-dependent signalling and functional activation of platelets has not been assessed.Methodology/Principal Findings
In the present study we assessed static adhesion, cell spreading, granule secretion, integrin αIIbβ3 activation and platelet aggregation in washed mouse platelets lacking PKCθ. Thrombus formation on a collagen-coated surface was assessed in vitro under flow. PKCθ−/− platelets exhibited reduced static adhesion and filopodia generation on fibrinogen, suggesting that PKCθ positively regulates outside-in signalling, in agreement with a previous report. In contrast, PKCθ−/− platelets also exhibited markedly enhanced GPVI-dependent α-granule secretion, although dense granule secretion was unaffected, suggesting that PKCθ differentially regulates these two granules. Inside-out regulation of αIIbβ3 activation was also enhanced downstream of GPVI stimulation. Although this did not result in increased aggregation, importantly thrombus formation on collagen under high shear (1000 s−1) was enhanced.Conclusions/Significance
These data suggest that PKCθ is an important negative regulator of thrombus formation on collagen, potentially mediated by α-granule secretion and αIIbβ3 activation. PKCθ therefore may act to restrict thrombus growth, a finding that has important implications for the development and safe clinical use of PKCθ inhibitors. 相似文献5.
Adaptive response is differently induced depending on the sensitivity to radiation-induced cell death in mouse epidermal cells 总被引:2,自引:0,他引:2
We investigated the relationship between induction of radio-adaptive response and cell death in mouse normal and neoplastic
epidermal cells. Mouse normal primary keratinocytes (PK), cancer-prone cells [v-ras
Ha-transfected mouse keratinocytes (ras-PK), and line 308 cells (mouse skin papilloma cells which have activatedras
Ha gene with A-to-T transversion at codon 61) were primed with a low dose of γ-rays (0.01 Gy), and were challenged with a high
dose (4 Gy) after a 4 or 7 h interval. The induction of cell death in PK was 2–10 times higher and was also more rapid in
PK than in ras-PK or 308 cells. Low-dose pretreatment with a 4 h interval decreased cell death, and this adaptive response
was prominent in PK, whereas it was less obvious in the cases of ras-PK and 308 cells. The response of each protein kinase
C (PKC) isozymes to high-dose radiation, especially PKCα, PKCδ, PKCε, and PKCη, were different between the normal andras oncogene-activated neoplastic keratinocytes; translocation of these isozymes to membrane occurred more rapidly in normal
than in neoplastic cells. Furthermore, low-dose pretreatment did not induce the translocation of PKCδ in PK significantly
more than in ras-PK and 308. Thus, the difference in the induction of radio-adaptive responses between mouse normal and neoplastic
epidermal cells reflects difference in the rapidity of cell death, and responsiveness of PKC may affect this adaptive response.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
6.
Background
The intravenous anaesthetic propofol retracts neurites and reverses the transport of vesicles in rat cortical neurons. Orexin A (OA) is an endogenous neuropeptide regulating wakefulness and may counterbalance anaesthesia. We aim to investigate if OA interacts with anaesthetics by inhibition of the propofol-induced neurite retraction.Methods
In primary cortical cell cultures from newborn rats’ brains, live cell light microscopy was used to measure neurite retraction after propofol (2 µM) treatment with or without OA (10 nM) application. The intracellular signalling involved was tested using a protein kinase C (PKC) activator [phorbol 12-myristate 13-acetate (PMA)] and inhibitors of Rho-kinase (HA-1077), phospholipase D (PLD) [5-fluoro-2-indolyl des-chlorohalopemide (FIPI)], PKC (staurosporine), and a PKCε translocation inhibitor peptide. Changes in PKCε Ser729 phosphorylation were detected with Western blot.Results
The neurite retraction induced by propofol is blocked by Rho-kinase and PMA. OA blocks neurite retraction induced by propofol, and this inhibitory effect could be prevented by FIPI, staurosporine and PKCε translocation inhibitor peptide. OA increases via PLD and propofol decreases PKCε Ser729 phosphorylation, a crucial step in the activation of PKCε.Conclusions
Rho-kinase is essential for propofol-induced neurite retraction in cortical neuronal cells. Activation of PKC inhibits neurite retraction caused by propofol. OA blocks propofol-induced neurite retraction by a PLD/PKCε-mediated pathway, and PKCε maybe the key enzyme where the wakefulness and anaesthesia signal pathways converge. 相似文献7.
In previous studies, we showed that lacrimal gland acini express three isoforms of protein kinase C (PKC): PKCα,-δ, and -ε.
In the present study, we report the identification of two other PKC isoforms, namely PKCμ and -ι/λ. Using immunofluorescence
techniques, we showed that these isoforms are differentially located. PKCα and -μ showed the most prominent membrane localization,
whereas PKCδ, -ε and -ι/λ were mainly cytosolic. Using cell fractionation and western blotting techniques, we showed that
the phorbol ester, phorbol 12, 13-dibutyrate (PdBu, 10−6
m), translocated all PKC isoforms, except PKCι/λ, from the soluble fraction into the particulate fraction. The effect was maximum
at 5 min and persisted at 10 min. PKCε was the most responsive to PdBu reaching almost maximal translocation at a PdBu concentration
as low as 10−9
m. The cholinergic agonist, carbachol (10−5 and 10−3
m), induced translocation which was transient for PKCδ, and -μ, but persisted for 10 min for PKCε. Carbachol did not translocate
PKCα and, like PdBu, did not translocate PKCι/λ. We concluded that lacrimal gland PKC isoforms are differentially localized
and that they translocate differentially in response to phorbol esters and cholinergic agonists.
Received: 25 June 1996/Revised: 24 December 1996 相似文献
8.
Background
Intracellular trafficking of mycobacteria is comprehensively dependent on the unusual regulation of host proteins. Recently, we have reported that infection of macrophages by Mycobacterium tuberculosis H37Rv (Rv) selectively downregulates the expression of PKCα while infection by Mycobacterium smegmatis (MS) does not. 相似文献9.
10.
Maria Grazia Di Certo Enrico M Batassa Ida Casella Annalucia Serafino Aristide Floridi Claudio Passananti Paola Molinari Elisabetta Mattei 《BMC cell biology》2008,9(1):56
Background
Chimeric proteins obtained by the fusion of a G protein-coupled receptor (GPCR) sequence to the N-terminus of the G protein α-subunit have been extensively used to investigate several aspects of GPCR signalling. Although both the receptor and the G protein generally maintain a fully functional state in such polypeptides, original observations made using a chimera between the β2-adrenergic receptor (β2AR) and Gαs indicated that the fusion to the α-subunit resulted in a marked reduction of receptor desensitization and down-regulation. To further investigate this phenomenon, we have compared the rates of internalization and recycling between wild-type and Gαs-fused β2AR. 相似文献11.
Mhaidat NM Thorne R Zhang XD Hersey P 《Apoptosis : an international journal on programmed cell death》2008,13(12):1505-1512
Our previous studies revealed that Docetaxel-induced apoptosis of melanoma cells is entirely dependent on activation of the
JNK signalling pathway. Here, we show that Docetaxel-induced apoptosis is mediated by induction of ER stress. This was shown
by Docetaxel-induced activation of proteins involved in ER stress signalling namely GRP78, ATF6, IRE1α, and PERK/eIF2α. Knockdown
of IRE1α by siRNA markedly inhibited Docetaxel-induced JNK activation and downstream targets of JNK indicating that activation
of IRE1α was upstream of activation of the JNK. Co-immunoprecipitation experiments showed that activation of JNK is due to
activation of ASK1 through formation of an IRE1α-TRAF2-ASK1 complex. ER stress mediated activation of the JNK pathway is downstream
of activation of PKCδ in that downregulation of PKCδ expression using specific PKCδ siRNA significantly inhibited Docetaxel-induced
activation of IRE1α and the JNK pathway. These findings provide new insights to understand the mode of action of taxanes in
treatment of human melanoma. 相似文献
12.
Kristina L Bailey Tricia D LeVan Daniel A Yanov Jaqueline A Pavlik Jane M DeVasure Joseph H Sisson Todd A Wyatt 《Respiratory research》2012,13(1):49
Background
Haemophilus influenzae infection of the nasal epithelium has long been associated with observations of decreased nasal ciliary beat frequency (CBF) and injury to the ciliated epithelium. Previously, we have reported that several agents that slow CBF also have the effect of activating protein kinase C epsilon (PKCϵ) activity in bronchial epithelial cells. The subsequent auto-downregulation of PKCϵ or the direct inhibition of PKCϵ leads to the specific detachment of the ciliated cells. METHODS: Primary cultures of ciliated bovine bronchial epithelial cells were exposed to filtered conditioned media supernatants from non-typeable H. influenzae (NTHi) cultures. CBF and motile points were measured and PKCϵ activity assayed.Results
NTHi supernatant exposure significantly and rapidly decreased CBF in a dose-dependent manner within 10 minutes of exposure. After 3 hours of exposure, the number of motile ciliated cells significantly decreased. Direct measurement of PKCϵ activity revealed a dose-dependent activation of PKCϵ in response to NTHi supernatant exposure. Both CBF and PKCϵ activity changes were only observed in fresh NTHi culture supernatant and not observed in exposures to heat-inactivated or frozen supernatants.Conclusions
Our results suggest that CBF slowing observed in response to NTHi is consistent with the stimulated activation of PKCϵ. Ciliated cell detachment is associated with PKCϵ autodownregulation. 相似文献13.
Background
Norepinephrine (NE), a classic neurotransmitter in the sympathetic nervous system, induces vasoconstriction of canine isolated mesenteric vein that is accompanied by a sustained membrane depolarization. The mechanisms underlying the NE-elicited membrane depolarization remain undefined. In the present study we hypothesized that phosphatidylinositol 3-kinase (PI3K) and protein kinase C (PKC) are involved in the electrical field stimulation (EFS)-induced slow membrane depolarization (SMD) in canine isolated mesenteric vein. EFS (0.1–2 Hz, 0.1 ms, 15V, 10 s)-induced changes in the membrane potential were recorded with a conventional intracellular microelectrode technique and evaluated in the absence and presence of inhibitors of neuronal activity, α-adrenoceptors, membrane ion channels, PI3K, inositol 1,4,5-triphosphate (InsP3) receptors, and PKC. Activation of PI3Kγ and PKCζ in response to exogenous NE and clonidine in the absence and presence of receptor and kinase inhibitors were also determined. 相似文献14.
Introduction
During wound healing, fibroblasts initially migrate into the wound bed and later contract the matrix. Relevant mediators of transcellular contractility revealed by systems analyses are protein kinase c delta/myosin light chain-2 (PKCδ/MLC-2). PKCδ is activated by growth factor-driven PLCγ1 hydrolysis of phosphoinositide bisphosphate (PIP2) hydrolysis when it becomes tranlocated to the membrane. This leads to MLC-2 phosphorylation that regulates myosin for contractility. Furthermore, PKCδ n-terminus mediates PKCδ localization to the membrane in relative proximity to PLCγ1 activity. However, the role this localization and the relationship to its activation and signaling of force is not well understood. Therefore, we investigated whether the membrane localization of PKCδ mediates the transcellular contractility of fibroblasts.Methods
To determine PKCδ activation in targeted membrane locations in mouse fibroblast cells (NR6-WT), two PKCδ constructs were generated; PKCδ-CaaX with farnesylation moiety targeting PKCδ to the membrane and PKCδ-SaaX a non-targeting control.Results
Increased mean cell force was observed before and during EGF stimulation in fibroblasts expressing membrane-targeted PKCδ (PKCδ-CaaX) when analyzed with 2D cell traction force and 3D compaction of collagen matrix. This effect was reduced in cells deficient in EGFR/PLCy1 signaling. In cells expressing non-membrane targeted PKCδ (PKCδ-SaaX), the cell force exerted outside the ECM (extracellular matrix) was less, but cell motility/speed/persistence was increased after EGF stimulation. Change in cell motility and increased force exertion was also preceded by change in cell morphology. Organization of actin stress fibers was also decreased as a result of increasing membrane targeting of PKCδ.Conclusion
From these results membrane tethering of PKCδ leads to increased force exertion on ECM. Furthermore, our data show PLCγ1 regulation of PKCδ, at least in part, drives transcellular contractility in fibroblasts. 相似文献15.
16.
Hamplova B Novakova O Tvrzicka E Kolar F Novak F 《Cell biochemistry and biophysics》2005,43(1):105-117
Total protein kinase C (PKC) activity, its isoform expression, and concentration and fatty acid (FA) composition of diacylglycerol
(DAG) were determined in the left ventricular myocardium of the rat during early postnatal development (d 2, 3, 5, 7, and
10). PKC activity measured by the incorporation of 32P into histone IIIS decreased between d 2 and 10 in the homogenate as well as in cytosolic, membrane (100,000g), and nuclear-cytoskeletal-myofilament
fractions (1000g). Likewise, the expression of PKC isoforms (α, δ, and ε) determined by immunoblotting generally declined
during the period analyzed, although with a variable pattern. In the membrane and nuclear cytoskeletal myofilament fractions,
PKCδ and PKCε expression decreased markedly by d 3, returning to or close to the d 2 level immediately on d 5. PKCα expression
in the membrane fraction remained almost unchanged by d 7, declining thereafter. PKCδ and PKCε were associated predominantly
with particulate fractions, whereas PKCα was more abundant in the cytosolic fraction. DAG concentration exhibited a significant
decline by d 5, consistent with the decrease in maximal PKC activity. The unsaturation index of FA in DAG tended to decrease
on d 3 owing to the lowered proportion of all polyunsaturated FA of n−6 and n−3 series. These results demonstrate that the
developmental decrease in PKC activity and expression in the rat myocardium is not linear and that subcellular localization
of the enzyme exhibits isoform-specific day-by-day changes during the early postnatal period. These changes are compatible
with the view that PKC signaling may be involved in the control of a rapid switch of myocardial growth pattern during the
first week of life. 相似文献
17.
Background
Fibroblasts, as connective tissue cells, are able to transform into another cell type including smooth muscle cells. α1A-adrenergic receptor (α1A-AR) stimulation in rat-1 fibroblasts is coupled to cAMP production. However, the significance of an increase in cAMP produced by α1A-AR stimulation on proliferation, hypertrophy and differentiation in these cells is not known. 相似文献18.
Jean-Luc Davignon Jean-Frédéric Boyer Bénédicte Jamard Delphine Nigon Arnaud Constantin Alain Cantagrel 《Arthritis research & therapy》2010,12(4):R142-8
Introduction
Anti-tumor necrosis factor (TNF)-α biotherapies have considerably changed the treatment of rheumatoid arthritis (RA). However, serious infections are a major concern in patients with rheumatic diseases treated with anti-TNF-α. Little is known about viral, especially latent, infections in anti-TNF-α treatments. Infections by cytomegalovirus (CMV), a β-herpes virus, are frequent and induce a strong CD4pos T-cell immunity, which participates in the control of infection. We thus have chosen to analyze the CD4pos T-cell response to CMV antigens as a model of antiviral response in RA patients treated with anti-TNF-α. CD28 expression was evaluated. 相似文献19.
Yeong-Shiau Pu Chao-Yuan Huang Jyue-Yu Chen Wang-Yi Kang Ying-Chu Lin Yu-Shiang Shiu Shu-Ju Chuang Hong-Jeng Yu Ming-Kuen Lai Yu-Chieh Tsai Wen-Jeng Wu Tzyh-Chyuan Hour 《Journal of biomedical science》2012,19(1):39
Background
Metastatic renal cell carcinoma (RCC) is highly resistant to systemic chemotherapy. Unfortunately, nearly all patients die of the metastatic and chemoresistant RCC. Recent studies have shown the atypical PKCζ is an important regulator of tumorigenesis. However, the correlation between PKCζ expression and the clinical outcome in RCC patients is unclear. We examined the level of PKCζ expression in human RCC.Methods
PKCζ mRNA and protein expressions were examined by real-time polymerase chain reaction (PCR) and immunohistochemistry (IHC) respectively in RCC tissues of 144 patients. Cellular cytotoxicity and proliferation were assessed by MTT.Results
PKCζ expression was significantly higher in normal than in cancerous tissues (P < 0.0001) by real-time PCR and IHC. Similarly, PKCζ expression was down-regulated in four renal cancer cell lines compared to immortalized benign renal tubular cells. Interestingly, an increase of PKCζ expression was associated with the elevated tumor grade (P = 0.04), but no such association was found in TNM stage (P = 0.13). Tumors with higher PKCζ expression were associated with tumor size (P = 0.048). Expression of higher PKCζ found a poor survival in patients with high tumor grade. Down-regulation of PKCζ showed the significant chemoresistance in RCC cell lines. Inactivation of PKCζ expression enhanced cellular resistance to cisplatin and paclitaxel, and proliferation in HK-2 cells by specific PKCζ siRNA and inhibitor.Conclusions
PKCζ expression was associated with tumorigenesis and chemoresistance in RCC. 相似文献20.
Regulation of cyclin-dependent kinase inhibitor p21<Superscript>WAF1/CIP1</Superscript> by protein kinase Cδ-mediated phosphorylation 总被引:1,自引:0,他引:1
Oh YT Chun KH Park BD Choi JS Lee SK 《Apoptosis : an international journal on programmed cell death》2007,12(7):1339-1347
Cyclin-dependent kinase (CDK) inhibitor p21WAF1/CIP1(-/-)-null mice have an increased incidence of tumor formation. Here, we demonstrate that p21WAF1/CIP1 is unstable in HeLa cells treated with siRNA duplexes that target PKCδ. PKCδ phosphorylates p21WAF1/CIP1 at a serine residue (146Ser) located in its C-terminal domain. In cells treated with 12-O-tetradecanoylphorbol 13-acetate, the levels of both p21WAF1/CIP1 and its 146Ser-phosphorylated form increased significantly. We also show that a substitution, resulting from a single nucleotide polymorphism
(SNP) at 149Asp found in certain cancer patients, strongly compromises PKCδ-mediated phosphorylation at 146Ser and results in cells that are relatively resistant to TNFα-induced apoptosis. Thus, post-translational phosphorylation
of p21WAF1/CIP1 is important from an apoptotic cell death, and may also have patho-physiological relevance for the development of human cancer. 相似文献