The major pathological changes in Alzheimer's disease are beta amyloid deposits and cognitive impairment. Calycosin is a typical phytoestrogen derived from radix astragali that binds to estrogen receptors to produ...The major pathological changes in Alzheimer's disease are beta amyloid deposits and cognitive impairment. Calycosin is a typical phytoestrogen derived from radix astragali that binds to estrogen receptors to produce estrogen-like effects. Radix astragali Calycosin has been shown to relieve cognitive impairment induced by diabetes mellitus, suggesting calycosin may improve the cognitive function of Alzheimer's disease patients. The protein kinase C pathway is upstream of the mitogen-activated protein kinase pathway and exerts a neuroprotective effect by regulating Alzheimer's disease-related beta amyloid degradation. We hypothesized that calycosin improves the cognitive function of a transgenic mouse model of Alzheimer's disease by activating the protein kinase C pathway. Various doses of calycosin(10, 20 and 40 mg/kg) were intraperitoneally injected into APP/PS1 transgenic mice that model Alzheimer's disease. Calycosin diminished hippocampal beta amyloid, Tau protein, interleukin-1 beta, tumor necrosis factor-alpha, acetylcholinesterase and malondialdehyde levels in a dose-dependent manner, and increased acetylcholine and glutathione activities. The administration of a protein kinase C inhibitor, calphostin C, abolished the neuroprotective effects of calycosin including improving cognitive ability, and anti-oxidative and anti-inflammatory effects. Our data demonstrated that calycosin mitigated oxidative stress and inflammatory responses in the hippocampus of Alzheimer's disease model mice by activating the protein kinase C pathway, and thereby improving cognitive function.展开更多
Protein kinase Cδ(PKCδ)is a member of the PKC family,and its implications have been reported in various biological and cancerous processes,including cell proliferation,cell death,tumor suppression,and tumor progress...Protein kinase Cδ(PKCδ)is a member of the PKC family,and its implications have been reported in various biological and cancerous processes,including cell proliferation,cell death,tumor suppression,and tumor progression.In liver cancer cells,accumulating reports show the bi-functional regulation of PKCδin cell death and survival.PKCδfunction is defined by various factors,such as phosphorylation,catalytic domain cleavage,and subcellular localization.PKCδhas multiple intracellular distribution patterns,ranging from the cytosol to the nucleus.We recently found a unique extracellular localization of PKCδin liver cancer and its growth factor-like function in liver cancer cells.In this review,we first discuss the structural features of PKCδand then focus on the functional diversity of PKCδbased on its subcellular localization,such as the nucleus,cell surface,and extracellular space.These findings improve our knowledge of PKCδinvolvement in the progression of liver cancer.展开更多
To explore the regulatory role of protein kinase C (PKC) in the expression of Th 2 cytokines, interleukin 4 (IL 4) and interleukin 5 (IL 5) by T lymphocytes in asthma. T lymphocytes were isolated and purified from blo...To explore the regulatory role of protein kinase C (PKC) in the expression of Th 2 cytokines, interleukin 4 (IL 4) and interleukin 5 (IL 5) by T lymphocytes in asthma. T lymphocytes were isolated and purified from blood and bronchial alveolus lavage fluid (BALF) of each guinea pig of normal control group and asthmatic group and from peripheral blood of the asthmatic patients and normal controls, and were stimulated with PKC accelerant phorbol 12 myristate 13 acetate (PMA) and inhibitor Ro31 8220. The expression of IL 4 and IL 5 mRNA and protein was detected by using in situ hybridization staining and ELISA respectively. The expression of IL 4 and IL 5 mRNA and protein of asthmatic T lymphocytes stimulated with PMA was significantly higher than that of asthmatic T lymphocytes stimulated without PMA respectively ( P <0.01) and that of normal T lymphocytes stimulated with PMA respectively ( P <0.01). The expression of IL 4 and IL 5 mRNA and protein of asthmatic T lymphocytes stimulated with PMA and Ro31 8220 was significantly lower than that of asthmatic T lymphocytes stimulated only with PMA respectively ( P <0.01). It was concluded that PKC might participate in regulating the expression of IL 4 and IL 5 in asthmatic T lymphocytes, and the activation of PKC in T lymphocytes might play an important role in the pathogenesis of asthma.展开更多
Objective To investigate the interaction between fragile histamine triad (FHIT) and protein kinase C alpha (PKCα) in human non-small cell lung cancer tissues. Methods FHIT and PKCα double positive samples were scree...Objective To investigate the interaction between fragile histamine triad (FHIT) and protein kinase C alpha (PKCα) in human non-small cell lung cancer tissues. Methods FHIT and PKCα double positive samples were screened by immunohistochemical staining from 13 human non-small cell lung cancer tissues. Co-immunoprecipitation was performed by using anti-FHIT and anti-PKCα. The immune precipitate was analyzed by SDS-PAGE and Western blot. Results Immune precipitate staining detection showed that 3 samples out of the 13 cases were double positive for FHIT and PKCα. FHIT protein was present in the immune precipitate of anti-PKCα while there was PKCα in the immune precipitate of anti-FHITmAb. Conclusion FHIT and PKCα exist as a complex in human non-small cell lung cancer tissues, which will provide a new route for studying the pathogenesis and immunotherapy of human non-small cell lung cancer.展开更多
The roles of protein kinase C signal pathway in the pathogenesis of obstructive jaundice were studied. PKC from cytosolic and membrane fractions of peripheral blood lymphocytes in 51 patients with obstructive jaundice...The roles of protein kinase C signal pathway in the pathogenesis of obstructive jaundice were studied. PKC from cytosolic and membrane fractions of peripheral blood lymphocytes in 51 patients with obstructive jaundice and 16 cases of normal controls was isolated and purified. The activities of PKC were determined by radioactive isotope γ 32 P ATP catalyzing assay. The results showed that the total PKC activities in PBL in the patients with obstructive jaundice were significantly increased as compared with those in the normal controls . Moreover, the membrane PKC activities and their percentages of the total PKC activities were higher in obstructive jaundice group than in those in the normal controls . The total PKC activities in PBL in the patients with obstructive jaundice were significantly positively correlated with the levels of soluble IL 2 receptor and the degree of jaundice in serum. It was concluded that the activities of PKC signal pathway was related with the degree of T BIL. PKC signal pathway might took part in the activation of T lymphocytes in the patients with obstructive jaundice and play an important role in the immune regulation and the assessment of pathosis in the patients with obstructive jaundice.展开更多
Objective To explore the expression of novel protein kinase C ε ( PKCε) in normal prostate ( NP) tissue, benign prostate hyperplasia ( BPH) ,pericancerous ( PC) tissue and prostate cancer ( Pca) ,and study its corre...Objective To explore the expression of novel protein kinase C ε ( PKCε) in normal prostate ( NP) tissue, benign prostate hyperplasia ( BPH) ,pericancerous ( PC) tissue and prostate cancer ( Pca) ,and study its correlation with the grade and stage of Pca. Methods Ten NP slides,ten BPH slides,ten PC slides and 43 Pca展开更多
The endoplasmic reticulum is the central organelle within a eukaryotic cell where newly synthesized proteins are processed and properly folded. An excess of unfolded or mis-folded proteins induces ER stress signalling...The endoplasmic reticulum is the central organelle within a eukaryotic cell where newly synthesized proteins are processed and properly folded. An excess of unfolded or mis-folded proteins induces ER stress signalling pathways. Usually this means a pro-survival strategy for the cell, whereas under extended stress conditions the ER stress signalling pathways have a pro-apoptotic function. CK2 plays a key role in the regulation of the pro-survival as well as the proapoptotic ER stress signalling by directly modulating the activities of members of the ER stress signalling pathways by phosphorylation, regulating the expression of the key factors of the signalling pathways or binding to regulator proteins. The present review will summarize the state of the art in this new emerging field.展开更多
INTRODUCTIONGastrin is atrophic gastrointestinal hormone whichis secreted by G cell.Gastrin has long beenconsidered a growth stimulatory hormone formucosa of the gastrointestinal tract.The growthresponses of certain c...INTRODUCTIONGastrin is atrophic gastrointestinal hormone whichis secreted by G cell.Gastrin has long beenconsidered a growth stimulatory hormone formucosa of the gastrointestinal tract.The growthresponses of certain colorectal cancer cells,andxenografts,can be stimulated by endogenousgastrin.Protein kinase C (PKC) is a family ofisozymes that plays a crucial role in transducingsignals of many hormones,growth peptides,展开更多
The potential role of the protein kinase C (PKC) transduction systemin controlling proliferation of human pituitary somatotrophinomas was investigat-ed. Twenty somatotrophinomas were studied using PCR and diract seque...The potential role of the protein kinase C (PKC) transduction systemin controlling proliferation of human pituitary somatotrophinomas was investigat-ed. Twenty somatotrophinomas were studied using PCR and diract sequencing methods. No point mutation within the QPKC gene, previously thought to be as-sociated with invasive pituitary tumors, was found in any of the 20 somatotrophi-nomas. It is concluded that PKC trareduction system may play an important rolein controlling pituitary somatotrophinoma proliferation, but there is no correlation between invasiveness and the previously reported QPKC gene mutation.展开更多
BACKGROUND: The molecular mechanism of hepaticmetastasis of colorectal cancer is not well understood. Theaim of this study was to assess the relations between phos-pholipid contents of cellular membrane and isoenzyme ...BACKGROUND: The molecular mechanism of hepaticmetastasis of colorectal cancer is not well understood. Theaim of this study was to assess the relations between phos-pholipid contents of cellular membrane and isoenzyme ex-pression of protein kinase C (PKC) and their effects on he-patic metastasis of colorectal cancer.METHODS: High performance liquid chromatography wasused to detect contents of cell membrane phospholipids:phosphatidylinosital (PI), phosphatidylserine (PS), phos-phatidylethanolamine (PE) and phosphatidylcholine (PC)in primary foci, paratumor mucosa and hepatic metastaticfoci in patients with colorectal carcinoma. The mRNA ex-pression levels of PKC-α, -δ, -ε, -λ, -ξ isoenzymeswere detected with the QRT-PCR technique.RESULTS: The levels of PI, PC and PE in primary foci andhepatic metastatic foci were higher than those in paratumormucosa. The level of PE in hepatic metastatic foci wasmuch higher than that in primary foci (t =98.88, P <0.01);but the levels of PI and PC were not significantly differentbetween primary foci and hepatic metastatic foci (t =1.73 ,1.36, P>0.05). The expression levels of -δ, -ε,-λ, -ξ were enhanced in primary foci and hepatic metasta-tic foci, but the level of PKC-α in primary foci was de-creased as compared with that in paratumor mucosa. Thelevels of PKC-δ, -ε, -λ, -ξ in hepatic metastatic foci werehigher than those in primary foci. A positive correlationwas observed between the expression levels of PI, PC andand also between those of PE and PKC-δ, -ε, -λ,-ξ. However, there was a close negative correlation be-tween PE and PKC-α.CONCLUSION: Increased levels of PI and PC and de-creased ratio of PKC-α to are related to colorectalcancer genesis. Increased levels of PE, increased expressionof PKC-δ, -ε, -λ, -ξ isoenzymes and decreased level ofPKC-α are related to hepatic metastasis in colorectal carci-noma.展开更多
The effects of ATP-sensitive mitochondrial K + channel(mitoK ATP) on mitochondrial membrane potential(Δψm),cell proliferation and protein kinase C alpha(PKCα) expression in airway smooth muscle cells(ASMCs) were in...The effects of ATP-sensitive mitochondrial K + channel(mitoK ATP) on mitochondrial membrane potential(Δψm),cell proliferation and protein kinase C alpha(PKCα) expression in airway smooth muscle cells(ASMCs) were investigated.Thirty-six Sprague-Dawley(SD) rats were immunized with saline(controls) or ovalbumin(OVA) with alum(asthma models).ASMCs were cultured from the lung of control and asthma rats.ASMCs were treated with diazoxide(the potent activator of mitoK ATP) or 5-hydroxydencanote(5-HD,the inhibitor of mitoK ATP).Rhodamine-123(R-123) was used to detect Δψm.The expression of PKCα protein was examined by using Western blotting,while PKCα mRNA expression was detected by using real-time PCR.The proliferation of ASMCs was measured by MTT assay and cell cycle analysis.In diazoxide-treated normal ASMCs,the R-123 fluorescence intensity,protein and mRNA levels of PKCα,MTT A values and percentage of cells in S phase were markedly increased as compared with untreated controls.The ratio of G 0 /G 1 cells was decreased(P<0.05) in diazoxide-treated ASMCs from normal rats.However,there were no significant differences between the ASMCs from healthy rats treated with 5-HD and the normal control group.In untreated and diazoxide-treated ASMCs of asthmatic rats,the R-123 fluorescence intensity,protein and mRNA levels of PKCα,MTT A values and the percentage of cells in S phase were increased in comparison to the normal control group.Furthermore,in comparison to ASMCs from asthmatic rats,these values were considerably increased in asthmatic group treated with diazoxide(P<0.05).After exposure to 5-HD for 24 h,these values were decreased as compared with asthma control group(P<0.05).In ASMCs of asthma,the signal transduction pathway of PKCα may be involved in cell proliferation,which is induced by the opening of mitoK ATP and the depolarization of Δψm.展开更多
AIM: To identify whether Aspergillus fumigatus(A.fumigatus) hyphae antigens induced the release of interleukin-8(IL-8) in anti-fungal innate immunity of cultured human corneal epithelial cells(HCECs) and determine the...AIM: To identify whether Aspergillus fumigatus(A.fumigatus) hyphae antigens induced the release of interleukin-8(IL-8) in anti-fungal innate immunity of cultured human corneal epithelial cells(HCECs) and determine the involvement of intracellular signalling pathways. METHODS: HCECs were treated with A. fumigatus hyphae antigens with different concentrations and time.The cytoplasmic calcium of HCECs were assessed by fluorescence imaging. Western blot was used to detect the expression of Ca2 +-dependent protein kinase C(PKC). The IL-8 levels were determined by specific human IL-8 enzyme-linked immunosorbent assay(ELISA) and reverse transcriptase polymerase chain reaction(RT-PCR). Using a series of pharmacological inhibitors, we examined the upstream signalling pathway responsible for IL-8 expression in response to A.fumigatus hyphae antigens. RESULTS: Cells exposed to A. fumigatus hyphae antigens showed higher level of IL-8 m RNA expression and protein production. We demonstrated here that stimulation of HCECs with A. fumigatus hyphae triggers an intracellular Ca2 +flux and results in the activation of Ca2 +-dependent PKC(α, βⅠ and βⅡ) which can be attenuated by pre-treatment of cells with laminarin,suggesting that Dectin-1 signals pathway induced cytoplasmic calcium and influence the activation of PKC in HCECs. Inhibitors of Ca2 +-dependent PKC(Ro-31-8220 and Go6976) significantly abolished hyphae-induced expression of IL-8.CONCLUSION: Our findings suggest that A. fumigatushyphae-induced IL-8 expression was regulated by the activation of Dectin-1-mediated Ca2 +-dependent PKC in HCECs.展开更多
BACKGROUND: Fructose is cytoprotective during bile salt-induced apoptosis of hepatocytes by regulating protein kinase C (PKC). This study was undertaken to explore the regulating mechanism of hepatic injury in rats wi...BACKGROUND: Fructose is cytoprotective during bile salt-induced apoptosis of hepatocytes by regulating protein kinase C (PKC). This study was undertaken to explore the regulating mechanism of hepatic injury in rats with obstructive jaundice, and to detect the PKC signal pathway. METHODS: Rat hepatocytes were isolated by in situ colla-genase perfusion and primary culture, and pretreated with various concentrations of PKC agonist phorbol myristate acetale (PMA) and inhibitor chelerythrine for 20 minutes. After pretreatment, 50 μmol/L glycochenodeoxycholate (GCDC) was added for additional 24 hours. Subsequently, the cells were detected by FCM and TUNEL. After adding with different concentrations of fructose and 100 μmol GCDC , the hepatocytes were evaluated by FCM and TUNEL. Experimental obstructive jaundice was induced with fructose and without fructose via double ligation of the bile duct for 3, 7, 14, and 21 days. Apoptotic status in the liver of all rats was detected with TUNEL, and PKC protein in the liver of obstructive jaundice ( OJ) with the immunohisto-chemistry method. RESULTS: PMA increased GCDC-induced apoptosis and chelerythrine decreased GCDC-induced apoptosis in a concentration-dependent manner. Adding with different concentration of fructose and 100 μmol GCDC, the decreased apoptotic rate was related to the concentration of fructose. The apoptotic rate of the liver was related to times of OJ. PKC and apoptosis index (AI) were the highest after a 14-day ligation of the bile duct without use of fructose. AI and PKC were decreasing from a 14-day ligation of the bile duct with fructose. CONCLUSIONS: PKC takes part in the regulation, occurrence , and progression of hepatic injury in OJ. Fructose is cytoprotective during bile salt-induced apoptosis of hepato-cytes by regulating PKC.展开更多
Protein kinase C (PKC) has a crucial role in signal transduction for a variety of biologically active substances which activate cellular functions and proliferation. We previously isolated the full-length PKC gene fro...Protein kinase C (PKC) has a crucial role in signal transduction for a variety of biologically active substances which activate cellular functions and proliferation. We previously isolated the full-length PKC gene from Dunaliella salina (DsPKC) using rapid amplification of cDNA ends (RACE) and RT-PCR methods. And we submitted the mRNA sequence of DsPKC gene to NCBI (Genbank No. JN625213). In the present paper, the DsPKC gene open reading frame obtained by PCR was cloned into pGS-21a vector and transformed into Escherichia coli to generate the fusion protein. Bioinformatics analysis revealed that DsPKC gene was a member of serine/threonine kinase with two conserved domains and highly conserved motifs. The DsPKC was highly expressed upon induction with isopropyl-β-d-thiogalactoside (IPTG) at a final concentration of 0.2 mmol L 1 at 37℃. Under salt stress, the fu- sion protein Green Fluorescent Protein (GFP)-DsPKC was transferred from the cytoplasm to the cell membrane. The expression pat- tern of DsPKC gene was analyzed using real-time quantitative PCR, and indicated that DsPKC gene was up-regulated by 3.0 mol L 1 NaCl at 12 h, which was significantly higher than in control values (P < 0.05). These results suggest that the DsPKC gene plays an important role in response to salt stress in D. salina.展开更多
AIM: To investigate the role of protein kinase C(PKC)-δ activation in the pathogenesis of acute liver failure(ALF) in a well-characterized mouse model of D-galactosamine(D-Gal N)/lipopolysaccharide(LPS)-induced ALF.M...AIM: To investigate the role of protein kinase C(PKC)-δ activation in the pathogenesis of acute liver failure(ALF) in a well-characterized mouse model of D-galactosamine(D-Gal N)/lipopolysaccharide(LPS)-induced ALF.METHODS: BALB/c mice were randomly assigned to five groups, and ALF was induced in mice by intraperitoneal injection of D-Ga IN(600 mg/kg) and LPS(10 μg/kg). Kaplan-Meier method was used for survival analysis. Serum alanine aminotransferase(ALT) and aspartate aminotransferase(AST) levels at different time points within one week were determined using a multiparameteric analyzer. Serum levels of high-mobility group box 1(HMGB1), tumor necrosis factor(TNF)-α, interleukin(IL)-1β, IL-6, and IL-10 as well as nuclear factor(NF)-κB activity were determined by enzyme-linked immunosorbent assay. Hepatic morphological changes at 36 h after ALF induction were assessed by hematoxylin and eosin staining. Expression of PKC-δ in liver tissue and peripheral blood mononuclear cells(PBMCs) was analyzed by Western blot.RESULTS: The expression and activation of PKC-δ were up-regulated in liver tissue and PBMCs of mice with D-Gal N/LPS-induced ALF. Inhibition of PKC-δ activation with rottlerin significantly increased the survival rates and decreased serum ALT/AST levels at 6, 12 and 24 h compared with the control group(P < 0.001). Rottlerin treatment also significantly decreased serum levels of HMGB1 at 6, 12, and 24 h, TNF-α, IL-6 and IL-1 β at 12 h compared with the control group(P < 0.01). The inflammatory cell infiltration and necrosis in liver tissue were also decreased in the rottlerin treatment group. Furthermore, sphingosine kinase 1(Sph K1) dependent PKC-δ activation played an important role in promoting NF-κB activation and inflammatory cytokine production in ALF.CONCLUSION: Sph K1 dependent PKC-δ activation plays an important role in promoting NF-κB activation and inflammatory response in ALF, and inhibition of PKC-δ activation might be a potential therapeutic strategy for this disease.展开更多
This study examined the effect of GHRP-6,a known GHSs receptor agonist,on the phosphorylation of cAMP-responsive element-binding protein(CREB) and the underly mechanism.GH3 cells were cultured and subjected to differe...This study examined the effect of GHRP-6,a known GHSs receptor agonist,on the phosphorylation of cAMP-responsive element-binding protein(CREB) and the underly mechanism.GH3 cells were cultured and subjected to different treatments as follows:GHRP-6,GHRP-6 plus GHRH,phorbol ester(PMA),an activator of PKC,alone or in combination with GHRP-6,G?6983,a general inhibitor of PKCs,in the presence or absence of GHRP-6,rottlerin,an inhibitor of PKCs,alone or plus GHRP-6.The cells were transiently transfected with PKCσ-specific siRNA and then treated with GHRP-6.GH level was measured by enzyme-linked immunosorbent assay(ELISA).The expression of phosphor-CREB,PKCσ,PKCθ and phosphor-PKCσ was determined by Western blotting.The results showed that GHRP-6 stimulated GH secretion in both time-and dose-dependent manners and enhanced the effect of GHRH on GH secretion.GHRP-6 was also found to induce CREB phosphorylation.Moreover,GH secretion was enhanced by the PKC activator PMA and reduced by the PKC inhibitors(G?6983,rottlerin) and knockdown of PKCσ.PKCσ could be activated by GHRP-6.It is concluded that PKC,especially PKCσ,mediates CREB phosphorylation and GHRP-6-induced GH secretion.展开更多
Trail, a tumor necrosis factor-related apoptosis-inducing ligand, is a novel potent endogenous activator of the cell death pathway through the activation of cell surface death receptors Trail-R1 and Trail-R2. Its role...Trail, a tumor necrosis factor-related apoptosis-inducing ligand, is a novel potent endogenous activator of the cell death pathway through the activation of cell surface death receptors Trail-R1 and Trail-R2. Its role, like FasL in activation-induced cell death (AICD), has been demonstrated in immune system. However the mechanism of Trail induced apoptosis remains nuclear. In this report, the recombinant Trail protein was expressed and purified. The apoptosis-inducing activity and the regulation mechanism of recombinant Trail on Jurkat T cells were explored in vitro. Trypan blue exclusion assay demonstrated that the recombinant Trail protein actively killed Jurkat T cells in a dose-dependent manner. Trail-induced apoptosis in Jurkat T cells were remarkably reduced by Bcl-2 over expression in BcL-2 gene transfected cells. Treatment with PMA (phorbol 12-myristate 13-acetate), a PKC activator, suppressed nail-induced apoptosis in Jurkat T cells. The inhibition of apoptosis by PMA was abolished by pretreatment with Bis, a PKC inhibitor. Taken together, it was suggested that Bcl-2 over-expression and PMA activated PKC actively down-regulated the Trail-mediated apoptosis in Jurkat T cell.展开更多
Background and Objectives: Protein kinase C (PKC) activation plays an important role in activation of T-lymphocytes in asthma. Airway hypersensitivity is one of the main characteristic features of asthma, the mechanis...Background and Objectives: Protein kinase C (PKC) activation plays an important role in activation of T-lymphocytes in asthma. Airway hypersensitivity is one of the main characteristic features of asthma, the mechanism of onset of which is not clearly understood. Therefore, the objective was to elucidate the role of PKC in etiopathogenesis of airway hypersensitivity in asthma. Methods: Male guinea pigs (n = 30) were sensitized with ovalbumin and day of initial allergen-specific immune response determined by intradermal test, airway hypersensitivity, BALF cytology and lung histopathology. Total PKC activity, PKC isoenzymes and phosphoinositides were assessed in airway smooth muscles (ASM) and peripheral blood lymphocytes. Results: Intradermal test revealed that day 9 was the earliest time of allergen-specific response and onset of airway hypersensitivity to ovalbumin. It was associated with significant increase in total and differential (lymphocytes and eosinophils) BALF counts and grade I peribronchiolar chronic lymphocytic inflammation in lung. On day 14, grade II infiltration of lymphocytes and eosinophils with onset ofstructural remodelingofproximal and distal airways was seen. Total PKC activity, expression of PKCα, PKCε and phosphoinositides increased significantly in ASM and lymphocytes on day 9 and were maximum on day 14. There was no change in PKC-τ expression. Conclusions: Activation of PKC, particularly PKCα and PKCε, mediated signal transduction pathway plays a critical role in lymphocyte infiltration and onset of airway hypersensitivity, airway remodeling and asthma pathophysiology. The present study is the first one on the mechanism of the etiopathogenesis of the disease, which shows a direct evidence of the role of PKC mediated pathway in the initiation and onset of airway hypersensitivity in ovalbumin sensitized guinea pig model.展开更多
基金supported by the a grant from China Postdoctoral Science Project,No.801161020425the Natural Science Foundation of China,No.8160010172
文摘The major pathological changes in Alzheimer's disease are beta amyloid deposits and cognitive impairment. Calycosin is a typical phytoestrogen derived from radix astragali that binds to estrogen receptors to produce estrogen-like effects. Radix astragali Calycosin has been shown to relieve cognitive impairment induced by diabetes mellitus, suggesting calycosin may improve the cognitive function of Alzheimer's disease patients. The protein kinase C pathway is upstream of the mitogen-activated protein kinase pathway and exerts a neuroprotective effect by regulating Alzheimer's disease-related beta amyloid degradation. We hypothesized that calycosin improves the cognitive function of a transgenic mouse model of Alzheimer's disease by activating the protein kinase C pathway. Various doses of calycosin(10, 20 and 40 mg/kg) were intraperitoneally injected into APP/PS1 transgenic mice that model Alzheimer's disease. Calycosin diminished hippocampal beta amyloid, Tau protein, interleukin-1 beta, tumor necrosis factor-alpha, acetylcholinesterase and malondialdehyde levels in a dose-dependent manner, and increased acetylcholine and glutathione activities. The administration of a protein kinase C inhibitor, calphostin C, abolished the neuroprotective effects of calycosin including improving cognitive ability, and anti-oxidative and anti-inflammatory effects. Our data demonstrated that calycosin mitigated oxidative stress and inflammatory responses in the hippocampus of Alzheimer's disease model mice by activating the protein kinase C pathway, and thereby improving cognitive function.
基金Supported by the Japan Society for the Promotion of Science,KAKENHI Grant,No.19H03519,16K18434,and 18K15253 to Yamada K,No.17H03584,18K19484,and 20H03519 to Yoshida KAMED under Grant No.A326TS to Yamada K+1 种基金The Jikei University Graduate Research Fund to Yamada Kand the Science Research Promotion Fund to Yoshida K.
文摘Protein kinase Cδ(PKCδ)is a member of the PKC family,and its implications have been reported in various biological and cancerous processes,including cell proliferation,cell death,tumor suppression,and tumor progression.In liver cancer cells,accumulating reports show the bi-functional regulation of PKCδin cell death and survival.PKCδfunction is defined by various factors,such as phosphorylation,catalytic domain cleavage,and subcellular localization.PKCδhas multiple intracellular distribution patterns,ranging from the cytosol to the nucleus.We recently found a unique extracellular localization of PKCδin liver cancer and its growth factor-like function in liver cancer cells.In this review,we first discuss the structural features of PKCδand then focus on the functional diversity of PKCδbased on its subcellular localization,such as the nucleus,cell surface,and extracellular space.These findings improve our knowledge of PKCδinvolvement in the progression of liver cancer.
基金This project was supported by a grant from NationalNatural Sciences foundation (No.30 0 70 332 ) and EducationMinistry college cadreman teachers imbursement plan (2 0 0 0year)
文摘To explore the regulatory role of protein kinase C (PKC) in the expression of Th 2 cytokines, interleukin 4 (IL 4) and interleukin 5 (IL 5) by T lymphocytes in asthma. T lymphocytes were isolated and purified from blood and bronchial alveolus lavage fluid (BALF) of each guinea pig of normal control group and asthmatic group and from peripheral blood of the asthmatic patients and normal controls, and were stimulated with PKC accelerant phorbol 12 myristate 13 acetate (PMA) and inhibitor Ro31 8220. The expression of IL 4 and IL 5 mRNA and protein was detected by using in situ hybridization staining and ELISA respectively. The expression of IL 4 and IL 5 mRNA and protein of asthmatic T lymphocytes stimulated with PMA was significantly higher than that of asthmatic T lymphocytes stimulated without PMA respectively ( P <0.01) and that of normal T lymphocytes stimulated with PMA respectively ( P <0.01). The expression of IL 4 and IL 5 mRNA and protein of asthmatic T lymphocytes stimulated with PMA and Ro31 8220 was significantly lower than that of asthmatic T lymphocytes stimulated only with PMA respectively ( P <0.01). It was concluded that PKC might participate in regulating the expression of IL 4 and IL 5 in asthmatic T lymphocytes, and the activation of PKC in T lymphocytes might play an important role in the pathogenesis of asthma.
基金supported by the Scientific and Technological Development Research Project of Shaanxi Province (No.2005k09-G1)
文摘Objective To investigate the interaction between fragile histamine triad (FHIT) and protein kinase C alpha (PKCα) in human non-small cell lung cancer tissues. Methods FHIT and PKCα double positive samples were screened by immunohistochemical staining from 13 human non-small cell lung cancer tissues. Co-immunoprecipitation was performed by using anti-FHIT and anti-PKCα. The immune precipitate was analyzed by SDS-PAGE and Western blot. Results Immune precipitate staining detection showed that 3 samples out of the 13 cases were double positive for FHIT and PKCα. FHIT protein was present in the immune precipitate of anti-PKCα while there was PKCα in the immune precipitate of anti-FHITmAb. Conclusion FHIT and PKCα exist as a complex in human non-small cell lung cancer tissues, which will provide a new route for studying the pathogenesis and immunotherapy of human non-small cell lung cancer.
文摘The roles of protein kinase C signal pathway in the pathogenesis of obstructive jaundice were studied. PKC from cytosolic and membrane fractions of peripheral blood lymphocytes in 51 patients with obstructive jaundice and 16 cases of normal controls was isolated and purified. The activities of PKC were determined by radioactive isotope γ 32 P ATP catalyzing assay. The results showed that the total PKC activities in PBL in the patients with obstructive jaundice were significantly increased as compared with those in the normal controls . Moreover, the membrane PKC activities and their percentages of the total PKC activities were higher in obstructive jaundice group than in those in the normal controls . The total PKC activities in PBL in the patients with obstructive jaundice were significantly positively correlated with the levels of soluble IL 2 receptor and the degree of jaundice in serum. It was concluded that the activities of PKC signal pathway was related with the degree of T BIL. PKC signal pathway might took part in the activation of T lymphocytes in the patients with obstructive jaundice and play an important role in the immune regulation and the assessment of pathosis in the patients with obstructive jaundice.
文摘Objective To explore the expression of novel protein kinase C ε ( PKCε) in normal prostate ( NP) tissue, benign prostate hyperplasia ( BPH) ,pericancerous ( PC) tissue and prostate cancer ( Pca) ,and study its correlation with the grade and stage of Pca. Methods Ten NP slides,ten BPH slides,ten PC slides and 43 Pca
文摘The endoplasmic reticulum is the central organelle within a eukaryotic cell where newly synthesized proteins are processed and properly folded. An excess of unfolded or mis-folded proteins induces ER stress signalling pathways. Usually this means a pro-survival strategy for the cell, whereas under extended stress conditions the ER stress signalling pathways have a pro-apoptotic function. CK2 plays a key role in the regulation of the pro-survival as well as the proapoptotic ER stress signalling by directly modulating the activities of members of the ER stress signalling pathways by phosphorylation, regulating the expression of the key factors of the signalling pathways or binding to regulator proteins. The present review will summarize the state of the art in this new emerging field.
文摘INTRODUCTIONGastrin is atrophic gastrointestinal hormone whichis secreted by G cell.Gastrin has long beenconsidered a growth stimulatory hormone formucosa of the gastrointestinal tract.The growthresponses of certain colorectal cancer cells,andxenografts,can be stimulated by endogenousgastrin.Protein kinase C (PKC) is a family ofisozymes that plays a crucial role in transducingsignals of many hormones,growth peptides,
文摘The potential role of the protein kinase C (PKC) transduction systemin controlling proliferation of human pituitary somatotrophinomas was investigat-ed. Twenty somatotrophinomas were studied using PCR and diract sequencing methods. No point mutation within the QPKC gene, previously thought to be as-sociated with invasive pituitary tumors, was found in any of the 20 somatotrophi-nomas. It is concluded that PKC trareduction system may play an important rolein controlling pituitary somatotrophinoma proliferation, but there is no correlation between invasiveness and the previously reported QPKC gene mutation.
基金This study was supported by a grant from the National Nature Science Foun-dation of China (No. 30070747)
文摘BACKGROUND: The molecular mechanism of hepaticmetastasis of colorectal cancer is not well understood. Theaim of this study was to assess the relations between phos-pholipid contents of cellular membrane and isoenzyme ex-pression of protein kinase C (PKC) and their effects on he-patic metastasis of colorectal cancer.METHODS: High performance liquid chromatography wasused to detect contents of cell membrane phospholipids:phosphatidylinosital (PI), phosphatidylserine (PS), phos-phatidylethanolamine (PE) and phosphatidylcholine (PC)in primary foci, paratumor mucosa and hepatic metastaticfoci in patients with colorectal carcinoma. The mRNA ex-pression levels of PKC-α, -δ, -ε, -λ, -ξ isoenzymeswere detected with the QRT-PCR technique.RESULTS: The levels of PI, PC and PE in primary foci andhepatic metastatic foci were higher than those in paratumormucosa. The level of PE in hepatic metastatic foci wasmuch higher than that in primary foci (t =98.88, P <0.01);but the levels of PI and PC were not significantly differentbetween primary foci and hepatic metastatic foci (t =1.73 ,1.36, P>0.05). The expression levels of -δ, -ε,-λ, -ξ were enhanced in primary foci and hepatic metasta-tic foci, but the level of PKC-α in primary foci was de-creased as compared with that in paratumor mucosa. Thelevels of PKC-δ, -ε, -λ, -ξ in hepatic metastatic foci werehigher than those in primary foci. A positive correlationwas observed between the expression levels of PI, PC andand also between those of PE and PKC-δ, -ε, -λ,-ξ. However, there was a close negative correlation be-tween PE and PKC-α.CONCLUSION: Increased levels of PI and PC and de-creased ratio of PKC-α to are related to colorectalcancer genesis. Increased levels of PE, increased expressionof PKC-δ, -ε, -λ, -ξ isoenzymes and decreased level ofPKC-α are related to hepatic metastasis in colorectal carci-noma.
基金supported by grants from Natural Science Foundation of Hubei Province,China (No. 2010CDB096)the National Key Technology R&D Program of the 12th National Five-year Development Plan of China (No. 2012BAI05B01)
文摘The effects of ATP-sensitive mitochondrial K + channel(mitoK ATP) on mitochondrial membrane potential(Δψm),cell proliferation and protein kinase C alpha(PKCα) expression in airway smooth muscle cells(ASMCs) were investigated.Thirty-six Sprague-Dawley(SD) rats were immunized with saline(controls) or ovalbumin(OVA) with alum(asthma models).ASMCs were cultured from the lung of control and asthma rats.ASMCs were treated with diazoxide(the potent activator of mitoK ATP) or 5-hydroxydencanote(5-HD,the inhibitor of mitoK ATP).Rhodamine-123(R-123) was used to detect Δψm.The expression of PKCα protein was examined by using Western blotting,while PKCα mRNA expression was detected by using real-time PCR.The proliferation of ASMCs was measured by MTT assay and cell cycle analysis.In diazoxide-treated normal ASMCs,the R-123 fluorescence intensity,protein and mRNA levels of PKCα,MTT A values and percentage of cells in S phase were markedly increased as compared with untreated controls.The ratio of G 0 /G 1 cells was decreased(P<0.05) in diazoxide-treated ASMCs from normal rats.However,there were no significant differences between the ASMCs from healthy rats treated with 5-HD and the normal control group.In untreated and diazoxide-treated ASMCs of asthmatic rats,the R-123 fluorescence intensity,protein and mRNA levels of PKCα,MTT A values and the percentage of cells in S phase were increased in comparison to the normal control group.Furthermore,in comparison to ASMCs from asthmatic rats,these values were considerably increased in asthmatic group treated with diazoxide(P<0.05).After exposure to 5-HD for 24 h,these values were decreased as compared with asthma control group(P<0.05).In ASMCs of asthma,the signal transduction pathway of PKCα may be involved in cell proliferation,which is induced by the opening of mitoK ATP and the depolarization of Δψm.
基金Supported by National Natural Science Foundation of China (No. 81470609 No. 81170825)+2 种基金the Specialized Research Fund for the Doctoral Program of Higher Education (No. 20123706110003)the Key Project of Natural Science Foundation of Shandong Province (No. ZR2012FZ001) the Youth Project of Natural Science Foundation of Shandong Province (No. ZR2013HQ007)
文摘AIM: To identify whether Aspergillus fumigatus(A.fumigatus) hyphae antigens induced the release of interleukin-8(IL-8) in anti-fungal innate immunity of cultured human corneal epithelial cells(HCECs) and determine the involvement of intracellular signalling pathways. METHODS: HCECs were treated with A. fumigatus hyphae antigens with different concentrations and time.The cytoplasmic calcium of HCECs were assessed by fluorescence imaging. Western blot was used to detect the expression of Ca2 +-dependent protein kinase C(PKC). The IL-8 levels were determined by specific human IL-8 enzyme-linked immunosorbent assay(ELISA) and reverse transcriptase polymerase chain reaction(RT-PCR). Using a series of pharmacological inhibitors, we examined the upstream signalling pathway responsible for IL-8 expression in response to A.fumigatus hyphae antigens. RESULTS: Cells exposed to A. fumigatus hyphae antigens showed higher level of IL-8 m RNA expression and protein production. We demonstrated here that stimulation of HCECs with A. fumigatus hyphae triggers an intracellular Ca2 +flux and results in the activation of Ca2 +-dependent PKC(α, βⅠ and βⅡ) which can be attenuated by pre-treatment of cells with laminarin,suggesting that Dectin-1 signals pathway induced cytoplasmic calcium and influence the activation of PKC in HCECs. Inhibitors of Ca2 +-dependent PKC(Ro-31-8220 and Go6976) significantly abolished hyphae-induced expression of IL-8.CONCLUSION: Our findings suggest that A. fumigatushyphae-induced IL-8 expression was regulated by the activation of Dectin-1-mediated Ca2 +-dependent PKC in HCECs.
文摘BACKGROUND: Fructose is cytoprotective during bile salt-induced apoptosis of hepatocytes by regulating protein kinase C (PKC). This study was undertaken to explore the regulating mechanism of hepatic injury in rats with obstructive jaundice, and to detect the PKC signal pathway. METHODS: Rat hepatocytes were isolated by in situ colla-genase perfusion and primary culture, and pretreated with various concentrations of PKC agonist phorbol myristate acetale (PMA) and inhibitor chelerythrine for 20 minutes. After pretreatment, 50 μmol/L glycochenodeoxycholate (GCDC) was added for additional 24 hours. Subsequently, the cells were detected by FCM and TUNEL. After adding with different concentrations of fructose and 100 μmol GCDC , the hepatocytes were evaluated by FCM and TUNEL. Experimental obstructive jaundice was induced with fructose and without fructose via double ligation of the bile duct for 3, 7, 14, and 21 days. Apoptotic status in the liver of all rats was detected with TUNEL, and PKC protein in the liver of obstructive jaundice ( OJ) with the immunohisto-chemistry method. RESULTS: PMA increased GCDC-induced apoptosis and chelerythrine decreased GCDC-induced apoptosis in a concentration-dependent manner. Adding with different concentration of fructose and 100 μmol GCDC, the decreased apoptotic rate was related to the concentration of fructose. The apoptotic rate of the liver was related to times of OJ. PKC and apoptosis index (AI) were the highest after a 14-day ligation of the bile duct without use of fructose. AI and PKC were decreasing from a 14-day ligation of the bile duct with fructose. CONCLUSIONS: PKC takes part in the regulation, occurrence , and progression of hepatic injury in OJ. Fructose is cytoprotective during bile salt-induced apoptosis of hepato-cytes by regulating PKC.
基金the functional analysis of PKC signaling pathway involved in response to salt stress of Dunaliella salinathe National Natural Science Foundation of China (No. 31472260)
文摘Protein kinase C (PKC) has a crucial role in signal transduction for a variety of biologically active substances which activate cellular functions and proliferation. We previously isolated the full-length PKC gene from Dunaliella salina (DsPKC) using rapid amplification of cDNA ends (RACE) and RT-PCR methods. And we submitted the mRNA sequence of DsPKC gene to NCBI (Genbank No. JN625213). In the present paper, the DsPKC gene open reading frame obtained by PCR was cloned into pGS-21a vector and transformed into Escherichia coli to generate the fusion protein. Bioinformatics analysis revealed that DsPKC gene was a member of serine/threonine kinase with two conserved domains and highly conserved motifs. The DsPKC was highly expressed upon induction with isopropyl-β-d-thiogalactoside (IPTG) at a final concentration of 0.2 mmol L 1 at 37℃. Under salt stress, the fu- sion protein Green Fluorescent Protein (GFP)-DsPKC was transferred from the cytoplasm to the cell membrane. The expression pat- tern of DsPKC gene was analyzed using real-time quantitative PCR, and indicated that DsPKC gene was up-regulated by 3.0 mol L 1 NaCl at 12 h, which was significantly higher than in control values (P < 0.05). These results suggest that the DsPKC gene plays an important role in response to salt stress in D. salina.
基金Supported by The National Natural Science Foundation of ChinaNo.81160065
文摘AIM: To investigate the role of protein kinase C(PKC)-δ activation in the pathogenesis of acute liver failure(ALF) in a well-characterized mouse model of D-galactosamine(D-Gal N)/lipopolysaccharide(LPS)-induced ALF.METHODS: BALB/c mice were randomly assigned to five groups, and ALF was induced in mice by intraperitoneal injection of D-Ga IN(600 mg/kg) and LPS(10 μg/kg). Kaplan-Meier method was used for survival analysis. Serum alanine aminotransferase(ALT) and aspartate aminotransferase(AST) levels at different time points within one week were determined using a multiparameteric analyzer. Serum levels of high-mobility group box 1(HMGB1), tumor necrosis factor(TNF)-α, interleukin(IL)-1β, IL-6, and IL-10 as well as nuclear factor(NF)-κB activity were determined by enzyme-linked immunosorbent assay. Hepatic morphological changes at 36 h after ALF induction were assessed by hematoxylin and eosin staining. Expression of PKC-δ in liver tissue and peripheral blood mononuclear cells(PBMCs) was analyzed by Western blot.RESULTS: The expression and activation of PKC-δ were up-regulated in liver tissue and PBMCs of mice with D-Gal N/LPS-induced ALF. Inhibition of PKC-δ activation with rottlerin significantly increased the survival rates and decreased serum ALT/AST levels at 6, 12 and 24 h compared with the control group(P < 0.001). Rottlerin treatment also significantly decreased serum levels of HMGB1 at 6, 12, and 24 h, TNF-α, IL-6 and IL-1 β at 12 h compared with the control group(P < 0.01). The inflammatory cell infiltration and necrosis in liver tissue were also decreased in the rottlerin treatment group. Furthermore, sphingosine kinase 1(Sph K1) dependent PKC-δ activation played an important role in promoting NF-κB activation and inflammatory cytokine production in ALF.CONCLUSION: Sph K1 dependent PKC-δ activation plays an important role in promoting NF-κB activation and inflammatory response in ALF, and inhibition of PKC-δ activation might be a potential therapeutic strategy for this disease.
基金supported by a grant from the National Natural Sciences Foundation of China (No. 30672161)
文摘This study examined the effect of GHRP-6,a known GHSs receptor agonist,on the phosphorylation of cAMP-responsive element-binding protein(CREB) and the underly mechanism.GH3 cells were cultured and subjected to different treatments as follows:GHRP-6,GHRP-6 plus GHRH,phorbol ester(PMA),an activator of PKC,alone or in combination with GHRP-6,G?6983,a general inhibitor of PKCs,in the presence or absence of GHRP-6,rottlerin,an inhibitor of PKCs,alone or plus GHRP-6.The cells were transiently transfected with PKCσ-specific siRNA and then treated with GHRP-6.GH level was measured by enzyme-linked immunosorbent assay(ELISA).The expression of phosphor-CREB,PKCσ,PKCθ and phosphor-PKCσ was determined by Western blotting.The results showed that GHRP-6 stimulated GH secretion in both time-and dose-dependent manners and enhanced the effect of GHRH on GH secretion.GHRP-6 was also found to induce CREB phosphorylation.Moreover,GH secretion was enhanced by the PKC activator PMA and reduced by the PKC inhibitors(G?6983,rottlerin) and knockdown of PKCσ.PKCσ could be activated by GHRP-6.It is concluded that PKC,especially PKCσ,mediates CREB phosphorylation and GHRP-6-induced GH secretion.
基金Major State BasicResearch (973) Program of China, (G1999053905).
文摘Trail, a tumor necrosis factor-related apoptosis-inducing ligand, is a novel potent endogenous activator of the cell death pathway through the activation of cell surface death receptors Trail-R1 and Trail-R2. Its role, like FasL in activation-induced cell death (AICD), has been demonstrated in immune system. However the mechanism of Trail induced apoptosis remains nuclear. In this report, the recombinant Trail protein was expressed and purified. The apoptosis-inducing activity and the regulation mechanism of recombinant Trail on Jurkat T cells were explored in vitro. Trypan blue exclusion assay demonstrated that the recombinant Trail protein actively killed Jurkat T cells in a dose-dependent manner. Trail-induced apoptosis in Jurkat T cells were remarkably reduced by Bcl-2 over expression in BcL-2 gene transfected cells. Treatment with PMA (phorbol 12-myristate 13-acetate), a PKC activator, suppressed nail-induced apoptosis in Jurkat T cells. The inhibition of apoptosis by PMA was abolished by pretreatment with Bis, a PKC inhibitor. Taken together, it was suggested that Bcl-2 over-expression and PMA activated PKC actively down-regulated the Trail-mediated apoptosis in Jurkat T cell.
文摘Background and Objectives: Protein kinase C (PKC) activation plays an important role in activation of T-lymphocytes in asthma. Airway hypersensitivity is one of the main characteristic features of asthma, the mechanism of onset of which is not clearly understood. Therefore, the objective was to elucidate the role of PKC in etiopathogenesis of airway hypersensitivity in asthma. Methods: Male guinea pigs (n = 30) were sensitized with ovalbumin and day of initial allergen-specific immune response determined by intradermal test, airway hypersensitivity, BALF cytology and lung histopathology. Total PKC activity, PKC isoenzymes and phosphoinositides were assessed in airway smooth muscles (ASM) and peripheral blood lymphocytes. Results: Intradermal test revealed that day 9 was the earliest time of allergen-specific response and onset of airway hypersensitivity to ovalbumin. It was associated with significant increase in total and differential (lymphocytes and eosinophils) BALF counts and grade I peribronchiolar chronic lymphocytic inflammation in lung. On day 14, grade II infiltration of lymphocytes and eosinophils with onset ofstructural remodelingofproximal and distal airways was seen. Total PKC activity, expression of PKCα, PKCε and phosphoinositides increased significantly in ASM and lymphocytes on day 9 and were maximum on day 14. There was no change in PKC-τ expression. Conclusions: Activation of PKC, particularly PKCα and PKCε, mediated signal transduction pathway plays a critical role in lymphocyte infiltration and onset of airway hypersensitivity, airway remodeling and asthma pathophysiology. The present study is the first one on the mechanism of the etiopathogenesis of the disease, which shows a direct evidence of the role of PKC mediated pathway in the initiation and onset of airway hypersensitivity in ovalbumin sensitized guinea pig model.
