Identification of a protein kinase activity that phosphorylates connexin43 in a pH-dependent manner

The carboxyl-terminal (CT) domain of connexin43 (Cx43) has been implicated in both hormonal and pH-dependent gating of the gap junction channel. An in vitro assay was utilized to determine whether the acidification of cell extracts results in the activation of a protein kinase that can phosphorylate the CT domain. A glutathione S-transferase (GST)-fusion protein was bound to Sephadex beads and used as a target for protein kinase phosphorylation. A protein extract produced from sheep heart was allowed to bind to the fusion protein-coated beads. The bound proteins were washed and then incubated with 32P-ATP. Phosphorylation was assessed after the proteins were resolved by SDS-PAGE. Incubation at pH 7.5 resulted in a minimal amount of phosphorylation while incubation at pH 6.5 resulted in significant phosphorylation reaction. Maximal activity was achieved when both the binding and kinase reactions were performed at pH 6.5. The protein kinase activity was stronger when the incubations were performed with manganese rather than magnesium. Mutants of Cx43 which lack the serines between amino acids 364-374 could not be phosphorylated in the in vitro kinase reaction, indicating that this is a likely target of this reaction. These results indicate that there is a protein kinase activity in cells that becomes more active at lower pH and can phosphorylate Cx43.

TIMP-1 mediates the inhibitory effect of interleukin-6 on the proliferation of a hepatocarcinoma cell line in a STAT3-dependent manner

The tissue inhibitor of metalloproteinases (TIMP)-1 is a multifunctional protein which is not only an inhibitor of matrix metalloproteinases (MMPs) but also to have a possible "cytokine-like" action. Here, we first compared mRNA expression of TIMP-1 and MMP-9 in BEL-7402 (a hepatocellular carcinoma cell line), L-02 (a normal liver cell line) and QSG-7701 (a cell line derived from peripheral tissue of liver carcinoma) using real-time quantitative RT-PCR. By evaluating the variation of the MMP-9/TIMP-1 ratio as an index of reciprocal changes of the expression of the two genes, we observed that the MMP-9/TIMP-1 ratio was about 13- and 5-fold higher in BEL-7402 than in L-02 and QSG-7701, respectively. Significantly, overexpression of TIMP-1 decreased the MMP-9/TIMP-1 ratio in BEL-7402 and then inhibited the cell growth to 60% and reduced the migration to about 30%. Meanwhile, our data showed that interleukin-6 (IL-6) (100 ng/mL) could also inhibited the cell growth of BEL-7402. Further studies indicated that TIMP-1 mediated the inhibitory effect of IL-6 on BEL-7402 cell proliferation in a STAT3-dependent manner, which could further accelerate the expression of the cyclin-dependent kinase inhibitor p21. A dominant negative STAT3 mutant totally abolished IL-6-induced TIMP-1 expression and its biological functions. The present results demonstrate that TIMP-1 may be one of the mediators that regulate the inhibitory effect of IL-6 on BEL-7402 proliferation in which STAT3 signal transduction and p21 up-regulation also play important roles.

Theses, quas, cons. max. vener. facult. theol. in exercitationem stipendiariorum ad Academiam Imperialem Aboënsem, exhibet Henricus Snellman, theol. doct. [et] professor, Imper. Ord. de S. Wolod. in IV cl. eques, stipendiariorum h. a. inspector, respondente Claudio Alb. Tulindberg, stipend. publ. Ostrob. In auditorio philosophico die XII Junii MDCCCXXII. horis a. m. solitis

Painovuosi nimekkeestä.

Angiotensin II induces NF-κB, JNK and p38 MAPK activation in monocytic cells and increases matrix metalloproteinase-9 expression in a PKC- andRho kinase-dependent manner

Angiotensin II (ANG II), the main effector of the renin-angiotensin system, is implicated in endothelial permeability, recruitment and activation of the immune cells, and also vascular remodeling through induction of inflammatory genes. Matrix metalloproteinases (MMPs) are considered to be important inflammatory factors. Elucidation of ANG II signaling pathways and of possible cross-talks between their components is essential for the development of efficient inhibitory medications. The current study investigates the inflammatory signaling pathways activated by ANG II in cultures of human monocytic U-937 cells, and the effects of specific pharmacological inhibitors of signaling intermediates on MMP-9 gene (MMP-9) expression and activity. MMP-9 expression was determined by real-time PCR and supernatants were analyzed for MMP-9 activity by ELISA and zymography methods. A multi-target ELISA kit was employed to evaluate IκB, NF-κB, JNK, p38, and STAT3 activation following treatments. Stimulation with ANG II (100 nM) significantly increased MMP-9 expression and activity, and also activated NF-κB, JNK, and p38 by 3.8-, 2.8- and 2.2-fold, respectively (P < 0.01). ANG II-induced MMP-9 expression was significantly reduced by 75 and 67%, respectively, by co-incubation of the cells with a selective inhibitor of protein kinase C (GF109203X, 5 µM) or of rho kinase (Y-27632, 15 µM), but not with inhibitors of phosphoinositide 3-kinase (wortmannin, 200 nM), tyrosine kinases (genistein, 100 µM) or of reactive oxygen species (α-tocopherol, 100 µM). Thus, protein kinase C and Rho kinase are important components of the inflammatory signaling pathways activated by ANG II to increase MMP-9 expression in monocytic cells. Both signaling molecules may constitute potential targets for effective management of inflammation.

Finska adelns och riddarhusets historia med den philosophiska facultetens i Åbo bifall, under inseende af Joh. Fredr. Wallenius, canzli-råd, f. d. eloquentiae professor, riddare af Kejserl. St. Wladimirs Ordens tredje och St. Anna Ordens andra class, utgifven, och, för lagerkransens vinnande, till allmän ompröfning framställd af Gustaf Aminoff, grefve, Nyländska Nationens medlem, i den juridiska lärosalen den 23 Junii 1827, på vanlig tid förmiddagen

Painovuosi nimekkeestä.

Em memória: professor José Silvério Santos Diniz (1935-2011)

Em 23 de maio de 2011, faleceu o Professor José Silvério Santos Diniz, um dos expoentes da Nefrologia Pediátrica brasileira. Este editorial descreve de forma sumária a trajetória desse grande professor, médico e pesquisador de nosso País.

Förteckning öfver framlidne professor emeritus, collegii-rådet Nils Abraham af Ursins efterlemnade boksamling, som kommer att å offentlig auktion i Helsingfors försäljas under loppet af våren år 1852

Imprimatur: H. Molander.

O ensino da filosofia e o papel do professor-filósofo em Hegel

Este artigo tem por objetivo trazer à luz os meandros e as particularidades do pensamento de Hegel sobre o ensino da filosofia. Embora esta não seja uma questão central em seu pensamento, é possível notar sua preocupação acerca do tema, especificamente nos textos que escreveu durante o período no qual exerceu a função de professor e diretor do ginásio em Nürember. A apresentação que aqui se faz do pensamento de Hegel sobre o ensino da filosofia divide-se em três momentos: no primeiro, são pontuados os conteúdos que ele julga necessários para a formação do pensamento filosófico; no segundo, é apresentada a questão do método e a sua relação com os conteúdos no ensino da filosofia; e finalmente, no terceiro, procura-se entender o papel que o professor exerce nesse ensino.