The aim of the study was to evaluate the expression of phosphorylated p38 mitogen-activated protein kinase (p38 MAPK) and MAPK-activated transcription factors elk-1, c-jun and c-myc in rat cerebellar Purkinje cells after soman poisoning to investigate the pathogenetic mechanism of non-specific long-term adverse effects of nerve agents. Male Wistar rats were poisoned by intramuscular administration of soman at a dose 60 microg kg(-1) (80% LD(50)), while control animals were administered physiological saline. Samples were taken 1, 7 and 14 days after poisoning, immunohistochemically stained and p-p38MAPK, p-c-jun, p-c-myc, and p-elk-1 expressions were measured using computer image analysis. An increased expression of phosphorylated p38 MAPK and c-myc 14 days after soman poisoning was found, while both activated elk-1 and c-jun expression remained unchanged 1, 7 and 14 days after intoxication. Late activation of p38 MAPK and their targets might be the underlying mechanism of chronic neurophysiological adverse effects.

• MeSH
• cholinesterasové inhibitory otrava   MeSH
• fosforylace MeSH
• imunohistochemie MeSH
• krysa rodu rattus MeSH
• mitogenem aktivované proteinkinasy p38 biosyntéza   fyziologie   genetika   MeSH
• mozeček cytologie   patologie   účinky léků   MeSH
• počítačové zpracování obrazu MeSH
• potkani Wistar MeSH
• proteiny nervové tkáně biosyntéza   MeSH
• Purkyňovy buňky patologie   účinky léků   MeSH
• signální transdukce účinky léků   MeSH
• soman otrava   MeSH
• transkripční faktory genetika   účinky léků   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• práce podpořená grantem MeSH

In malignant melanoma complex reprogramming of cell death and survival pathways leads to increased chemoresistance and poor longer-term survival. Sulforaphane (SF) is a promising isothiocyanate compound occurring in cruciferous plants with reported antiproliferative and proapoptotic activity in several tumor cell lines including melanoma. In this work we investigated the effects of SF in several melanoma cell lines and fresh melanoma cultivates. We found that SF is cytotoxic and induces mitochondrial, caspase-dependent apoptosis in our study model, however with lower efficiency in fresh melanoma cultivates. Moreover, our results indicate that in melanoma cell lines and fresh melanoma cultivates SF induces multiple signaling including oxidative stress-mediated activation of DNA-damage response pathway, changes in p38 kinase activity and enhanced expression of Bax and Puma proapoptotic proteins. In addition, in SF-exposed p53-mutant melanoma cells Puma expression seem to be under p38 control and acts as a compensatory proapoptotic mechanism. Conversely, decreased apoptosis in SF-exposed melanoma cultivates might be attributed to Akt-mediated suppression of p38 as well as p53 activity. Together, our results suggest that SF inhibits growth and proliferation and induces mitochondrial apoptosis both in melanoma cell lines as well as in fresh melanoma cultivates. This proapoptotic effect might be enhanced in combination with Akt inhibitors, in particular in melanoma samples. SF is thus commendable for further preclinical testing, both as a single agent as well as in combination regimens.

• MeSH
• antikarcinogenní látky farmakologie   MeSH
• apoptóza účinky léků   MeSH
• isothiokyanatany farmakologie   MeSH
• kaspasy metabolismus   MeSH
• lidé MeSH
• melanom patologie   MeSH
• mitochondrie metabolismus   MeSH
• mitogenem aktivované proteinkinasy p38 metabolismus   MeSH
• nádorové buněčné linie účinky léků   MeSH
• nádorový supresorový protein p53 metabolismus   MeSH
• nádory kůže patologie   MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• signální transdukce MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The treatment of human promyelocytic leukemia cell lines HL-60, and to some extent NB-4, with 1alpha,25-dihydroxyvitamin D(3) (VD3) induces differentiation toward the monocytic/macrophage lineage, demonstrated by the increased expression of CD11b and CD14, and the production of opsonized zymosan particles (OZP)-stimulated reactive oxygen species (ROS). Moreover, in more sensitive HL-60 cells, increased expression of 5-lipoxygenase (5-LPO), Mcl-1, IkappaB, and c-Jun, accompanied by the activation of p38 MAPK, was detected. These VD3 effects on HL-60 cell differentiation were significantly potentiated by 5-LPO inhibitors MK-886 and AA-861 and were inverted by SB202190 (SB), a p38 MAPK inhibitor. The inhibition of differentiation by SB was demonstrated by a reduction of CD14 expression and by a decrease in OZP-activated ROS production. These results indicated that p38 MAPK pathway is involved in 5-LPO inhibitors-dependent potentiation of VD3-induced monocytic differentiation.

• MeSH
• arachidonát-5-lipoxygenasa genetika   MeSH
• benzochinony farmakologie   MeSH
• buněčná diferenciace účinky léků   MeSH
• HL-60 buňky MeSH
• indoly farmakologie   MeSH
• inhibitory lipoxygenas farmakologie   MeSH
• lidé MeSH
• mitogenem aktivované proteinkinasy p38 metabolismus   MeSH
• monocyty cytologie   MeSH
• vitamin D analogy a deriváty   farmakologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• práce podpořená grantem MeSH

In this study, we provide evidence that photostimulation of various cancer cells preloaded with a new photosensitizing compound, tetrakis-meso-(4-ethyleneglycol-2,3,5,6-tetrafluorophenyl) porphyrin (PORF-TEG), results in rapid activation of the cell death machinery. PORF-TEG, although primarily localized in lysosomes, induces mitochondria-driven apoptosis. The induction of apoptosis is accompanied by immediate and sustained activation of p38 mitogen-activated protein kinase (MAPK) and transient activation of c-Jun N-terminal kinase (JNK). Conversely, the inhibition of p38 by PD 169316 or SB202190 and by the p38alpha dominant-negative mutant as well as the deletion of the p38alpha gene (MEFs-KO) protected cells from apoptosis, whereas inhibition of JNK did not. Activation of the p38 signaling pathway occurs upstream of caspase activation. In addition, preincubation of cells with scavengers of reactive oxygen species attenuated p38 and caspase activation and increased cell survival, thus connecting reactive oxygen species formation with the activation of the p38 pathway. Later events included degradation of Bcl-2, activation of tBid, and cleavage of Bad and Mcl-1. The data suggest a key role for p38 MAPK in PORF-TEG-photoinduced apoptosis.

• MeSH
• apoptóza fyziologie   MeSH
• buněčné linie MeSH
• cytochromy c metabolismus   MeSH
• ethylenglykol farmakologie   chemie   MeSH
• financování organizované MeSH
• kaspasy metabolismus   MeSH
• lidé MeSH
• mitochondrie enzymologie   MeSH
• mitogenem aktivované proteinkinasy p38 fyziologie   metabolismus   MeSH
• nádorové buněčné linie MeSH
• porfyriny chemie   MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• světlo MeSH
• Check Tag
• lidé MeSH

PURPOSE: To examine the p38 mitogen-activated protein kinase (p38) phosphorylation and transforming growth factor beta 1 (TGF-β1) expression in rat colon enterocytes after irradiation and their contribution to pathology of intestinal radiation disease. MATERIALS AND METHODS: Male Wistar rats were irradiated with whole body γ-radiation of 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10 Gy ((60)Co, 1.44 Gy.min(-1)). Samples were taken 4 and 24 h after irradiation, immunohistochemically stained, then p38 phosphorylation and TGF-β1 expression were measured in apical and cryptal enterocytes using computer image analysis. In selected groups, morphometric parameters, mitosis and apoptosis were evaluated. RESULTS: P38 phosphorylation integrated optical density (IOD)-based levels increased 2.4-fold (p ≤ 0.01) and 3.6 to 22.8-fold (p ≤ 0.001) in apical enterocytes 4 h after 0.5 Gy and 24 h after 3-10 Gy, respectively. TGF-β1 IOD-based expression increased 3.3- to 6.9-fold (p ≤ 0.001) and 1.6- to 4.9-fold (p ≤ 0.001) in apical cells 4 h after 0.5-2, 4, 5 Gy and 24 h after 6-10 Gy, respectively. No changes were observed in crypts. CONCLUSIONS: We found a chronological and dose-dependent order of p38 activation and TGF-β1 expression in apical enterocytes. Transient up-regulation of p38 and TGF-β1 signalling observed 4 h after low-dose irradiation may participate in molecular mechanisms creating cellular over-expression in apical compartment, while persistent patterns measured 24 h after high-dose irradiation might provide protection of remaining cells in order to maintain tissue integrity.

• MeSH
• aktivace enzymů účinky záření   MeSH
• apoptóza účinky záření   MeSH
• časové faktory MeSH
• celotělové ozáření škodlivé účinky   MeSH
• enterocyty cytologie   enzymologie   metabolismus   účinky záření   MeSH
• fosforylace účinky záření   MeSH
• kolon cytologie   účinky záření   MeSH
• krysa rodu rattus MeSH
• mitogenem aktivované proteinkinasy p38 metabolismus   MeSH
• mitóza účinky záření   MeSH
• polarita buněk účinky záření   MeSH
• potkani Wistar MeSH
• regulace genové exprese účinky záření   MeSH
• záření gama škodlivé účinky   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The role of p38 in irinotecan (CPT-11)-induced damage and cell death in colon cancer cell line SW620 was investigated. We demonstrate that CPT-11 treatment activates p38 in exposed cells, however with concentration dependent dynamics and differing consequences. Higher CPT-11 concentrations induce a massive early but relatively short-lasting p38 activity leading to apoptosis mediated by mitochondria and caspases. Pharmacological or siRNA inhibition of p38 then significantly prevents CPT-11-dependent cell death. Conversely, lower CPT-11 concentrations activate p38 in a delayed, however sustained manner, with apoptosis occurring only in a fraction of cells and in the absence of significant autophagy. Blocking p38 in thus treated cells increases their sensitivity toward CPT-11 and increases cell death. In summary, our results confirm the involvement of p38 in colon cancer cells response to CPT-11 while indicating a varying role of p38 in the final biological response.

• MeSH
• apoptóza účinky léků   MeSH
• autofagie účinky léků   MeSH
• časosběrné zobrazování MeSH
• cytochromy c metabolismus   MeSH
• fytogenní protinádorové látky farmakologie   MeSH
• kamptothecin analogy a deriváty   farmakologie   MeSH
• kaspasy metabolismus   MeSH
• kvantitativní polymerázová řetězová reakce MeSH
• lidé MeSH
• membránový potenciál mitochondrií účinky léků   MeSH
• messenger RNA genetika   MeSH
• mitochondrie účinky léků   metabolismus   MeSH
• mitogenem aktivované proteinkinasy p38 genetika   metabolismus   MeSH
• nádorové buňky kultivované MeSH
• nádory tračníku farmakoterapie   genetika   patologie   MeSH
• polymerázová řetězová reakce s reverzní transkripcí MeSH
• poškození DNA účinky léků   MeSH
• western blotting MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The purpose of our study was to examine an early activation of JNK and p38 mitogen activated protein kinases (MAPK) and their substrate c-Myc after soman poisoning in order to enlighten the pathogenetic mechanism of nerve agent-induced non-specific effects. Male Wistar rats were intramuscularly poisoned by soman (60 μg.kg-1 - 70% LD50). Samples were taken 4, 24, and 72 hours after poisoning, immunohistochemically stained and phospho-JNKThr-183/Tyr-185, phospho-p38Thr180/Tyr182, and phospho-c- MycThr58/Ser62 expressions were measured using a computer Image analysis in apical and cryptal enterocytes of the colon transversum. We observed decreased phospho-JNK in apical enterocytes 4 and 24 h after poisoning and increased phospho-JNK in cryptal and apical enterocytes 72 h after intoxication. Phosphop38 dropped significantly in the apical compartment 72 h after soman poisoning. An activation of c-Myc decreased in both apical and cryptal compartment 4 and 24 h after soman intoxication, while increased in both compartments 72 h after poisoning. Soman poisoning seems to temporarily suppress promitotic pathways of proliferating cryptal cells and causes delayed activation of JNK stress signaling pathway.

• MeSH
• časové faktory MeSH
• colon transversum chemie   MeSH
• enterocyty chemie   MeSH
• experimenty na zvířatech MeSH
• financování organizované MeSH
• JNK mitogenem aktivované proteinkinasy chemie   MeSH
• kontrolní skupiny MeSH
• MAP kinasový signální systém fyziologie   MeSH
• mitogenem aktivované proteinkinasy p38 chemie   MeSH
• potkani Wistar MeSH
• protoonkogenní proteiny c-myc chemie   MeSH
• soman otrava   toxicita   MeSH
• výzkumný projekt MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• zvířata MeSH

Saturated stearic acid (SA) induces apoptosis in the human pancreatic β-cells NES2Y. However, the molecular mechanisms involved are unclear. We showed that apoptosis-inducing concentrations of SA activate the p38 MAPK signaling pathway in these cells. Therefore, we tested the role of p38 MAPK signaling pathway activation in apoptosis induction by SA in NES2Y cells. Crosstalk between p38 MAPK pathway activation and accompanying ERK pathway inhibition after SA application was also tested. The inhibition of p38 MAPK expression by siRNA silencing resulted in a decrease in MAPKAPK-2 activation after SA application, but it had no significant effect on cell viability or the level of phosphorylated ERK pathway members. The inhibition of p38 MAPK activity by the specific inhibitor SB202190 resulted in inhibition of MAPKAPK-2 activation and noticeable activation of ERK pathway members after SA treatment but in no significant effect on cell viability. p38 MAPK overexpression by plasmid transfection produced an increase in MAPKAPK-2 activation after SA exposure but no significant influence on cell viability or ERK pathway activation. The activation of p38 MAPK by the specific activator anisomycin resulted in significant activation of MAPKAPK-2. Concerning the effect on cell viability, application of the activator led to apoptosis induction similar to application of SA (PARP cleavage and caspase-7, -8, and -9 activation) and in inhibition of ERK pathway members. We demonstrated that apoptosis-inducing concentrations of SA activate the p38 MAPK signaling pathway and that this activation could be involved in apoptosis induction by SA in the human pancreatic β-cells NES2Y. However, this involvement does not seem to play a key role. Crosstalk between p38 MAPK pathway activation and ERK pathway inhibition in NES2Y cells seems likely. Thus, the ERK pathway inhibition by p38 MAPK activation does not also seem to be essential for SA-induced apoptosis.

• MeSH
• aktivace enzymů MeSH
• apoptóza * účinky léků   MeSH
• beta-buňky účinky léků   metabolismus   MeSH
• buněčné linie MeSH
• exprese genu MeSH
• inhibitory proteinkinas farmakologie   MeSH
• kyseliny stearové farmakologie   MeSH
• lidé MeSH
• MAP kinasový signální systém účinky léků   MeSH
• mastné kyseliny metabolismus   farmakologie   MeSH
• mitogenem aktivované proteinkinasy p38 antagonisté a inhibitory   metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Cytochrome P450 1B1 (CYP1B1) is an enzyme that has a unique tumor-specific pattern of expression and is capable of bioactivating a wide range of carcinogenic compounds. We have reported previously that coordinated upregulation of CYP1B1 by inflammatory cytokines, such as tumor necrosis factor-α (TNF-α) and the aryl hydrocarbon receptor ligands, may increase bioactivation of promutagens, such as benzo[a]pyrene (BaP) in epithelial cells. Here, we extend those studies by describing a novel mechanism participating in the regulation of CYP1B1 expression, which involves activation of the p38 mitogen-activated protein kinase (p38) and mitogen- and stress-activated protein kinase 1 (MSK1). Using inhibitors of p38 and MSKs, as well as mouse embryonic cells derived from p38α-deficient and MSK1/2 double knockout mice, we show here that TNF-α potentiates CYP1B1 upregulation via the p38/MSK1 kinase cascade. Effects of this inflammatory cytokine on CYP1B1 expression further involve the positive transcription elongation factor b (P-TEFb). The inhibition of the P-TEFb subunit, cyclin-dependent kinase 9 (CDK9), which phosphorylates RNA polymerase II (RNAPII), prevented the enhanced CYP1B1 induction by a combination of BaP and inflammatory cytokine. Furthermore, using chromatin immunoprecipitation assays, we found that cotreatment of epithelial cells with TNF-α and BaP resulted in enhanced recruitment of both CDK9 and RNAPII to the Cyp1b1 gene promoter. Overall, these results have implications concerning the contribution of inflammatory factors to carcinogenesis, since enhanced CYP1B1 induction during inflammation may alter metabolism of exogenous carcinogens, as well as endogenous CYP1B1 substrates playing role in tumor development.

• MeSH
• cyklin-dependentní kinasa 9 genetika   MeSH
• cytochrom P450 CYP1B1 biosyntéza   genetika   MeSH
• cytokiny metabolismus   MeSH
• karcinogeneze účinky léků   genetika   MeSH
• karcinogeny toxicita   MeSH
• lidé MeSH
• mitogenem aktivované proteinkinasy p38 antagonisté a inhibitory   genetika   metabolismus   MeSH
• myši MeSH
• nádory chemicky indukované   genetika   patologie   MeSH
• pozitivní transkripční elongační faktor b genetika   MeSH
• regulace genové exprese u nádorů účinky léků   MeSH
• RNA-polymerasa II genetika   MeSH
• signální transdukce účinky léků   MeSH
• TNF-alfa metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The c-Myb transcription factor is important for maintenance of immature cells of many tissues including colon epithelium. Overexpression of c-Myb occurring in colorectal carcinomas (CRC) as well as in other cancers often marks poor prognosis. However, the molecular mechanism explaining how c-Myb contributes to progression of CRC has not been fully elucidated. To address this point, we investigated the way how c-Myb affects sensitivity of CRC cells to anticancer drugs. Using CRC cell lines expressing exogenous c-myb we show that c-Myb protects CRC cells from the cisplatin-, oxaliplatin-, and doxorubicin-induced apoptosis, elevates reactive oxygen species via up-regulation of NOX1, and sustains the pro-survival p38 MAPK pathway. Using pharmacological inhibitors and gene silencing of p38 and NOX1 we found that these proteins are essential for the protective effect of c-Myb and that NOX1 acts upstream of p38 activation. In addition, our result suggests that transcription of NOX1 is directly controlled by c-Myb and these genes are strongly co-expressed in human tumor tissue of CRC patients. The novel c-Myb/NOX1/p38 signaling axis that protects CRC cells from chemotherapy described in this study could provide a new base for design of future therapies of CRC.

• MeSH
• aktivace enzymů účinky léků   MeSH
• apoptóza účinky léků   MeSH
• cisplatina farmakologie   MeSH
• doxorubicin farmakologie   MeSH
• kolorektální nádory genetika   patologie   MeSH
• lidé MeSH
• messenger RNA genetika   metabolismus   MeSH
• mitogenem aktivované proteinkinasy p38 genetika   metabolismus   MeSH
• myši MeSH
• NADH, NADPH oxidoreduktasy genetika   metabolismus   MeSH
• nádorové buněčné linie MeSH
• NADPH-oxidasy genetika   metabolismus   MeSH
• organoplatinové sloučeniny farmakologie   MeSH
• oxidační stres účinky léků   MeSH
• promotorové oblasti (genetika) genetika   MeSH
• protoonkogenní proteiny c-myb metabolismus   MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• regulace genové exprese u nádorů * účinky léků   MeSH
• sekvence nukleotidů MeSH
• upregulace účinky léků   MeSH
• vazebná místa MeSH
• viabilita buněk MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH