AVE0991, a Nonpeptide Compound, Attenuates Angiotensin II-Induced Vascular Smooth Muscle Cell Proliferation via Induction of Heme Oxygenase-1 and Downregulation of p-38 MAPK Phosphorylation

The nonpeptide AVE0991 is an agonist of the angiotensin-(1–7) (Ang-(1–7)) Mas receptor and is expected to be a putative new drug for treatment of cardiovascular disease. However, the mechanisms involved in the antiproliferative effects of AVE0991 are not fully understood. We saw that the compound attenuated proliferation in an angiotensin II-induced rat vascular smooth muscle cells (VSMC) proliferation model. Moreover, treatment with AVE0991 (10−5 mol/L or 10−7 mol/L) significantly attenuated reactive oxygen species (ROS) production, phosphorylation of p38 MAPK, and dose-dependently (10−8 to 10−5 mol/L) inhibited Ang II-induced VSMC proliferation. Meanwhile, heme oxygenase-1 (HO-1) expression increased in the AVE0991 + Ang II group (10−5 mol/L or 10−6 mol/L). However, the beneficial effects of AVE0991 were completely abolished when the VSMC were pretreated with A-779 (10−6 mol/L). Furthermore, treatment with the HO-1 inhibitor ZnPPIX attenuated the inhibitory effect of AVE0991 on Ang II-induced p38MAPK phosphorylation. These results suggest that AVE0991 attenuates Ang II-induced VSMC proliferation in a dose-dependent fashion and that this effect is associated with the Mas/HO-1/p38 MAPK signaling pathway

Immunolocalization of dually phosphorylated MAPKs in dividing root meristem cells of Vicia faba, Pisum sativum, Lupinus luteus and Lycopersicon esculentum

Key message In plants, phosphorylated MAPKs display constitutive nuclear localization; however, not all studied plant species show co-localization of activated MAPKs to mitotic microtubules. Abstract The mitogen-activated protein kinase (MAPK) signaling pathway is involved not only in the cellular response to biotic and abiotic stress but also in the regulation of cell cycle and plant development. The role of MAPKs in the formation of a mitotic spindle has been widely studied and the MAPK signaling pathway was found to be indispensable for the unperturbed course of cell division. Here we show cellular localization of activated MAPKs (dually phosphorylated at their TXY motifs) in both interphase and mitotic root meristem cells of Lupinus luteus, Pisum sativum, Vicia faba (Fabaceae) and Lycopersicon esculentum (Solanaceae). Nuclear localization of activated MAPKs has been found in all species. Colocalization of these kinases to mitotic microtubules was most evident in L. esculentum, while only about 50 % of mitotic cells in the root meristems of P. sativum and V. faba displayed activated MAPKs localized to microtubules during mitosis. Unexpectedly, no evident immunofluorescence signals at spindle microtubules and phragmoplast were noted in L. luteus. Considering immunocytochemical analyses and studies on the impact of FR180204 (an inhibitor of animal ERK1/2) on mitotic cells, we hypothesize that MAPKs may not play prominent role in the regulation of microtubule dynamics in all plant species

International Journal of Pharma and Bio Sciences REVIEW ARTICLE BIOCHEMISTRY P38

Ischaemic heart disease remains, and is likely to continue to be, the leading life threatening disease around the world. Signaling pathways have become more interesting as novel therapeutic targets in ischaemic heart disease. However, one needs to be very careful in picking the therapeutic target as one signaling molecule can activate and also cross-talk with other kinases. The activation of the p38-MAPK during myocardial ischaemia aggravates lethal injury. Recent evidences suggested the mechanism of p38-MAPK activation may differ by circumstances. Determining the precise mechanisms is crucial since it may allow prevention of the detrimental, but not the beneficial, and lead to the identification of the relevant downstream signals. Therefore, p38 MAPK may be a viable clinical target and form the basis of future studies designed to further dissect the signaling pathways and discover the downstream substrates will become hopes as a new frontier of therapeutic approach in ischaemic heart diseases. This article can be downloaded from www.ijpbs.ne