Structure-Based Design of GNE-495, a Potent and Selective MAP4K4 Inhibitor with Efficacy in Retinal Angiogenesis

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S100A12 promotes inflammation and apoptosis in ischemia/reperfusion injury via ERK signaling in vitro study using PC12 cells

S100A12 is a member of S100 calcium‐binding proteins with effect to promote inflammation in brain damage and stroke. However, the role of S100A12 in ischemia/reperfusion (I/R) remains to be clarified. This study aimed to explore the effect of S100A12 on I/R and discover the possible mechanism. Oxygen‐glucose deprivation and reperfusion (OGD/R) was used to induce I/R injury model in vitro. Knockdown or overexpression of S100A12 was utilized to explore the role of S100A12 in I/R‐induced inflammation and apoptosis. Results indicated that S100A12 expression was dramatically upregulated after OGD/R. Knockdown of S100A12 inhibited, while overexpression of S100A12 enhanced, the activation of ERK1/2 protein. OGD/R also triggered the occurrence of inflammation and oxidative stress, while these effects were blunted by S100A12 silencing and aggravated by S100A12 overexpression, and the presence of MAP kinase signaling system (ERK) inhibitor MK‐8353 counteracted the effect of S100A12 overexpression. Besides, S100A12 silencing abolished, while its overexpression restored, the OGD/R‐induced increased apoptosis rate and pro‐apoptotic proteins expression. Similarly, ERK inhibitor MK‐8353 reversed the effects of S100A12 overexpression. In conclusion, S100A12 promoted OGD/R‐induced inflammation, oxidative stress and apoptosis via activation of ERK signaling in vitro.     

Organization of pyramidal neurons in area 17 of monkey visual cortex.

In sections of area 17 of monkey visual cortex treated with an antibody to MAP2 the disposition of the cell bodies and dendrites of the neurons is readily visible. In such preparations it is evident that the apical dendrites of the pyramidal cells of layer VI form fascicles that pass into layer IV, where most of them gradually taper and form their terminal tufts. In contrast, the apical dendrites of the smaller layer V pyramidal cells come together in a more regular fashion. They form clusters that pass through layer IV and into layer II/III where the apical dendrites of many of the pyramidal cells in that layer add to the clusters. In horizontal sections taken through the middle of layer IV, these clusters of apical dendrites are found to have an average center-to-center spacing of about 30 microns, and it is proposed that each cluster of apical dendrites represents the axis of a module of pyramidal cells that has a diameter of about 30 microns and contains about 142 neurons. The MAP2 antibody reaction also reveals that some pyramidal cells in layers IVA and IVB have their cell bodies arranged into cones. There are about 118 such cones beneath 1 mm2 of cortical surface and the apical dendrites of the pyramidal cells within them bundle together at the apex of each cone to pass into layer III. Surrounding the cones of neurons there are horizontally aligned, thin dendrites. The location of these dendrites coincides with the dark walls of the honeycomb pattern seen in layer IVA after cytochrome oxidase reactions, or after the parvocellular input from the lateral geniculate nucleus has been labeled. Thus the cones of pyramidal cells within upper layer IV fit into the pockets of the honeycomb pattern. Below the cones of pyramidal cells are the outer Meynert cells within layer IVB, and the cell bodies of these large neurons are disposed so that they preferentially lie beneath the neuropil between the cones of pyramids. It is suggested that pyramidal cell modules are a basic feature of the cerebral cortex, and that these are combined together by afferent inputs to the cortex to generate the systems of functional columns.     

Anillin localization defect in cardiomyocyte binucleation

Heart growth is augmented during early development by cardiomyocyte proliferation. In contrast, heart growth during postnatal life occurs by increasing cell size. Postnatal cardiomyocytes can undergo DNA synthesis, mitosis and binucleation. However, they lose the ability to complete cytokinesis. The underlying mechanism is poorly understood. It has been suggested that incomplete disassembly of contractile elements prohibits cytokinesis. Here, we show that serum-induced binucleation results in the normal disassembly of the contractile apparatus. In contrast, analysis of Aurora B and Anillin localization demonstrates that binucleation is characterized by asymmetric constriction, delay of furrow constriction and defective mid-body formation. Anillin fails to focus at the cortex in anaphase and shows an expanded localization around the mid-body during cytokinesis. p38 inhibition rescues the mid-body formation defect. We show that p38 accumulates during cytokinesis at the mid-body and suggest that p38 activity has a regulatory role in cytokinesis. Microarray analysis reveals that p38 inhibition upregulates core components of the central spindle. Taken together, our results demonstrate that postnatal cardiomyocytes form a cleavage furrow and that binucleation is associated with an Anillin localization defect.