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Calphostin C (calphostin + c)
Selected AbstractsEffects of PKC , on early genome transcription activation in mouse 1-cell stage fertilized eggsCELL BIOCHEMISTRY AND FUNCTION, Issue 6 2007Bing-zhi Yu Abstract Effects of PKC , on the activation of embryonic transcription in 1-cell stage fertilized mouse eggs were explored. The effects of PKC antagonist calphostin C and PKC , specific inhibitor on the activation of embryonic early transcription were observed by Western blotting and cell immunofluorescence. PKC activity increased gradually from G1 phase to late G2 phase in mouse 1-cell stage fertilized eggs, and reached a maximum in G2 stage. Calphostin C inhibited PKC activity by about 47% in 1-cell stage fertilized eggs. Calphostin C inhibited early transcription in 1-cell stage fertilized eggs (p,<,0.01). PKC ,-Thr410 in G2 were about 27% and 110% higher than those in G1 phase of 1-cell stage fertilized eggs and MII oocytes, respectively. PKC , specific inhibitor can also inhibit early transcription in 1-cell stage fertilized eggs (p,<,0.05). The results suggest that PKC , participates in early transcription activation in mouse 1-cell stage fertilized eggs. Copyright © 2006 John Wiley & Sons, Ltd. [source] Atrazine increases the sodium absorption in frog (Rana esculenta) skinENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 2 2006Giuseppe Cassano Abstract The presence of atrazine in agricultural sites has been linked to the decline in amphibian populations. The efforts of the scientific community generally are directed toward investigating the long-term effect of atrazine on complex functions (reproduction or respiration), but in the present study, we investigated the short-term effect on the short-circuit current (ISC), a quantitative measure of the ion transport operated by frog (Rana esculenta) skin. Treatment with 5 ,M atrazine (1.08 mg/L) does not affect the transepithelial outfluxes of [14C]mannitol or [14C]urea; therefore, atrazine does not damage the barrier properties of frog skin. Atrazine causes a dose-dependent increase in the short-circuit current, with a minimum of 4.64 ± 0.76 ,A/cm2 (11.05% ± 1.22%) and a maximum of 12.7 ± 0.7 ,A/cm2 (35% ± 2.4%) measured at 10 nM and 5 ,M, respectively. An increase in ISC also is caused by 5 ,M ametryne, prometryn, simazine, terbuthylazine, or terbutryn (other atrazine derivatives). In particular, atrazine increases the transepithelial 22Na+ influx without affecting the outflux. Finally, stimulation of ISC by atrazine is suppressed by SQ 22536, H89, U73122, 2-aminoethoxydiphenyl borate, and W7 (blockers of adenylate cyclase, protein kinase A, phospholipase C, intracellular Ca2+ increase, and calmodulin, respectively), whereas indomethacin and calphostin C (inhibitors of cyclooxygenase and protein kinase C, respectively) have no effect. [source] Analysis of the signal transduction pathway of nickel-induced matrix metalloproteinase-2 expression in the human keratinocytes in vitro: preliminary findingsJOURNAL OF CUTANEOUS PATHOLOGY, Issue 6 2007Brunella Perfetto Background:, Nickel can induce cellular and nuclear damages responsible for chronic diseases, like allergic contact dermatitis (ACD). We previously showed that matrix metalloproteinase-2 (MMP-2) gene expression was induced by nickel in nontumorigenic human keratinocytes cell line (HaCat). Objective:, To investigate the signal transduction pathways involved in gelatinolytic activity induced in HaCat under nickel stimulation. Methods:, We analyzed the involvement of protein kinase A (PKA), protein kinase C (PKC), tyrosine kinase (PTK), nuclear factor-kB (NF-kB) and activator protein-1 (AP-1) using specific inhibitors (H89, calphostin C, genistein, carpain and curcumin) by electrophoretic mobility shift assay, reverse transcription-polymerase chain reaction and gelatin zymography. Results:, Our results indicate that nickel-induced MMP-2 production was inhibited with PTK, PKC and AP-1 specific inhibitors. Moreover, both PKA and NF-kB were not involved in nickel pathway. Conclusions:, Using HaCat, we showed that curcumin and genistein can revert nickel-induced MMP-2 upregulation. Whether the use of PTK and AP-1 inhibitors has therapeutic ramifications in the management of ACD remains to be investigated. [source] Prostaglandin F2, upregulates interleukin-6 production in human gingival fibroblastsJOURNAL OF PERIODONTAL RESEARCH, Issue 2 2001Kazuyuki Noguchi Prostaglandin F2,(PGF2,) is a bioactive lipid mediator which has been suggested to be involved in the pathogenesis of periodontal disease. However, the roles of PGF2, in periodontal lesions are poorly understood. In the present study, we investigated the effect of PGF2, on interleukin (IL)-6 production in human gingival fibroblasts (HGF). PGF2,stimulated IL-6 production in a time- and concentration-dependent fashion. IL-1, and tumor necrosis factor ,(TNF,), proinflammatory cytokines, induced IL-6 production in a time-dependent manner, and PGF2,synergistically enhanced IL-6 production induced by IL-1, and TNF,. IL-6 mRNA was expressed in PGF2, -stimulated HGF, and PGF2, increased IL-6 mRNA levels induced by IL-1, and TNF,. Fluprostenol, a selective FP receptor agonist, could mimic PGF2, -induced IL-6 production. Since FP receptors are coupled to elevation of intracellular calcium and activation of protein kinase C (PKC), the mechanism of IL-6 production by PGF2, was investigated using TMB-8, an inhibitor of Ca2+ mobilization from intracellular stores, and calphostin C, an inhibitor of PKC. TMB-8 significantly suppressed PGF2, -induced IL-6 production, whereas calphostin C showed a stimulatory effect on PGF2, -induced IL-6 production. From these data, we suggest that PGF2, upregulates IL-6 production through FP receptors in HGF, that PGF2, synergistically enhances IL-6 production in IL-1,- and TNF,-stimulated HGF, and that PGF2, -induced IL-6 production may be dependent on intracellular Ca2+ mobilization and be downregulated by PKC activation. PGF2, may be involved in the pathogenesis of periodontal disease by enhancing IL-6 levels in periodontal lesions. [source] Antiproliferative effect of Scutellaria barbata D. Don. on cultured human uterine leiomyoma cells by down-regulation of the expression of Bcl-2 proteinPHYTOTHERAPY RESEARCH, Issue 5 2008Kyung-Woon Kim Abstract Scutellaria barbata D. Don (Lamiaceae; SB) inhibited the growth of leiomyomal cells (LM). A time-dependent antiproliferative effect was noted when 10,5m buserelin, gonadotrophin-releasing hormone (GnRH) agonist or 20,40 µg/mL SB was added. The inhibition of cell growth decreased with the addition of the PKC activator (12-O-tetradecanoylphorbor-13-acetate; TPA) much as it did with the addition of SB, and the decreases in the viable cells caused by the addition of SB were reversed completely by pretreatment with a protein kinase C (PKC) inhibitor (calphostin C). The findings suggest that SB inhibits cell proliferation in cultured human uterine leiomyoma cells accompanied by PKC activation. Next, the study investigated the effect of SB on fetal development for toxicity. Pregnant Sprague-Dawley rats, from gestation day 6,15, were administered 20 g/L or 50 g/L SB in the drinking water and then killed on day 20. No maternal toxicity was observed, however, embryonic loss in the treatment groups was double that of the controls (p < 0.05). No gross morphologic malformations were seen in the treated fetuses. Fetuses exposed to SB were found to be significantly heavier than the controls, an effect that was greater in female fetuses and was not correlated with increased placental size. The results suggest that the SB had no toxicity and that in utero exposure to SB resulted in increased early embryo loss with increased growth in surviving fetuses. On the other hand, Western blot analyses revealed that Bcl-2 protein of a 26 kDa was abundant in leiomyomal cells, but not in normal myometrial cells. The addition of progesterone (100 ng/mL) resulted in a striking increase in Bcl-2 protein expression in the cultured leiomyoma cells. However, the addition of SB (20 µg/mL) resulted in a significant reduction in Bcl-2 protein expression in the cells. The results indicated that human uterine leiomyomal cells express Bcl-2 protein and progesterone enhances its expression, however, SB reduces the expression of Bcl-2 protein in human uterine leiomyoma cells. Copyright © 2008 John Wiley & Sons, Ltd. [source] Effects of PKC , on early genome transcription activation in mouse 1-cell stage fertilized eggsCELL BIOCHEMISTRY AND FUNCTION, Issue 6 2007Bing-zhi Yu Abstract Effects of PKC , on the activation of embryonic transcription in 1-cell stage fertilized mouse eggs were explored. The effects of PKC antagonist calphostin C and PKC , specific inhibitor on the activation of embryonic early transcription were observed by Western blotting and cell immunofluorescence. PKC activity increased gradually from G1 phase to late G2 phase in mouse 1-cell stage fertilized eggs, and reached a maximum in G2 stage. Calphostin C inhibited PKC activity by about 47% in 1-cell stage fertilized eggs. Calphostin C inhibited early transcription in 1-cell stage fertilized eggs (p,<,0.01). PKC ,-Thr410 in G2 were about 27% and 110% higher than those in G1 phase of 1-cell stage fertilized eggs and MII oocytes, respectively. PKC , specific inhibitor can also inhibit early transcription in 1-cell stage fertilized eggs (p,<,0.05). The results suggest that PKC , participates in early transcription activation in mouse 1-cell stage fertilized eggs. Copyright © 2006 John Wiley & Sons, Ltd. [source] Sensitivity of human glioma U-373MG cells to radiation and the protein kinase C inhibitor, calphostin CCELL PROLIFERATION, Issue 1 2001M. Acevedo-Duncan We assessed the radiosensitivity of the grade III human glioma cell line U-373MG by investigating the effects of radiation and the specific protein kinase C inhibitor, calphostin C on the cell cycle and cell proliferation. Irradiated glioma U-373MG cells progressed through G1 -S and underwent an arrest in G2 -M phase. The radiosensitivity of U-373MG cells to graded doses of either photons or electrons was determine by microculture tetrazolium assay. The data was fitted to the linear-quadratic model. The proliferation curves demonstrated that U-373MG cells appear to be highly radiation resistant since 8 Gy was required to achieve 50% cell mortality. Compared to radiation alone, exposure to calphostin C (250 n m) 1 h prior to radiation decreased the proliferation of U-373MG by 76% and calphostin C provoked a weakly synergistic effect in concert with radiation. Depending on the time of application following radiation, calphostin C produced an additive or less than additive effect on cell proliferation. We postulate that the enhanced radiosensitivity observed when cells are exposed to calphostin C prior to radiation may be due to direct or indirect inhibition of protein kinase C isozymes required for cell cycle progression. [source] Role Of Protein Kinase C In Myogenic Calcium, Contraction Coupling Of Rat Cannulated Mesenteric Small ArteriesCLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 10 2001Jos Pm Wesselman SUMMARY 1. The present study was designed to determine the role of protein kinase C (PKC) in the myogenic response of small arteries. In particular, we tested whether inhibition of PKC reverses the previously found pressure-induced elevation of contractile element calcium sensitivity. 2. Rat mesenteric small arteries were cannulated and pressurized. The internal diameter was continuously monitored with a video camera and intracellular calcium levels were measured by means of fura-2. Myogenic responses were observed when the pressure was raised stepwise from 20 to 60 and then to 100 mmHg in physiological saline solution and during application of phenylephrine (0.1 or 1 ,mol/L) or potassium (36 mmol/L). 3. The PKC inhibitors H-7 (20 ,mol/L), staurosporine (100 nmol/L) and calphostin C (10 nmol/L) all completely abolished the myogenic response. Whereas staurosporine caused an ongoing reduction in intracellular calcium, pressure-induced calcium transients were not affected by either H-7 or calphostin C. In particular, the slope of the wall tension,calcium relationship remained similar in the presence of both H-7 and calphostin C, despite an upward shift of this relationship to higher calcium levels in the case of calphostin C. 4. These results show that activity of PKC isoform(s) is essential for myogenic calcium,contraction coupling. [source] Protein kinase C activity in mouse eggs regulates gamete membrane interaction,MOLECULAR REPRODUCTION & DEVELOPMENT, Issue 11 2007Hiroto Akabane Abstract Gamete membrane interaction is critical to initiate the development of a new organism. The signaling pathways governing this event, however, are poorly understood. In this report, we provide the first evidence that protein kinase C activity in mouse eggs plays a crucial role in the regulation of this process. Stimulating PKC activity in mouse eggs by phorbol 12-myristate 13-acetate (PMA) drastically inhibited the egg's membrane ability to bind and fuse with sperm. Surprisingly, this significant reduction of gamete membrane interaction was also observed in eggs treated with the PKC inhibitors staurosporine and calphostin c. In further analysis, we found that while no change of egg actin cytoskeleton was detected after either PMA or calphostin c treatment, the structural morphology of egg surface microvilli was severely altered in the PMA-treated eggs, but not in the calphostin c-treated eggs. Moreover, sperm, which bound but did not fuse with the eggs treated with the anti-CD9 antibody KMC8, were liberated from the egg membrane after PMA, but not calphostin c, treatment. Taken together, these results suggest that egg PKC may be precisely balanced to regulate gamete membrane interaction in a biphasic mode, and this biphasic regulation is executed through two different mechanisms. Mol. Reprod. Dev. 74: 1465,1472, 2007. © 2007 Wiley-Liss, Inc. [source] | |||||||||||||