Correlation between receptor-interacting protein 140 expression and directed differentiation of human embryonic stem cells into neural stem cells

Overexpression of receptor-interacting protein 140（RIP140） promotes neuronal differentiation of N2 a cells via extracellular regulated kinase 1/2（ERK1/2） signaling.However,involvement of RIP140 in human neural differentiation remains unclear.We found both RIP140 and ERK1/2 expression increased during neural differentiation of H1 human embryonic stem cells.Moreover,RIP140 negatively correlated with stem cell markers Oct4 and Sox2 during early stages of neural differentiation,and positively correlated with the neural stem cell marker Nestin during later stages.Thus,ERK1/2 signaling may provide the molecular mechanism by which RIP140 takes part in neural differentiation to eventually affect the number of neurons produced.

Insulin-like signaling pathway regulates integration and learning in C. elegans

Animals can sense many environment stimuli simultaneously and integrate these signals within the nervous system. However, the neural system and molecular

Activation of glycine site and GluN2B subunit of NMDA receptors is necessary for ERK/CREB signaling cascade in rostral anterior cingulate cortex in rats:Implications for affective pain

Objective The rostral anterior cingulate cortex （rACC） is implicated in processing the emotional component of pain. N-methyl-D-aspartate receptors （NMDARs） are highly expressed in the rACC and mediate painrelated affect by activating a signaling pathway that involves cyclic adenosine monophosphate （cAMP）/protein ki- nase A （PKA） and/or extracellular regulated kinase （ERK）/cAMP-response element-binding protein （CREB）. The present study investigated the contributions of the NMDAR glycine site and GluN2B subunit to the activation of ERK and CREB both in vitro and in vivo in rat rACC. Methods Immunohistochemistry and Western blot analy- sis were used to separately assess the expression of phospho-ERK （pERK） and phospho-CREB （pCREB） in vitro and in vivo. Double immunostaining was also used to determine the colocalization of pERK and pCREB. Results Both bath application of NMDA in brain slices in vitro and intraplantar injection of formalin into the rat hindpaw in vivo induced significant up-regulation of pERK and pCREB in the rACC, which was inhibited by the NMDAR antago- nist DL-2-amino-5-phospho-novaleric acid. Selective blockade of the NMDAR GluN2B subunit and the glycine- binding site, or degradation of endogenous D-serine, a co-agonist for the glycine site, significantly decreased the up- regulation of pERK and pCREB expression in the rACC. Further, the activated ERK predominantly colocalized with CREB. Conclusion Either the glycine site or the GluN2B subunit of NMDARs participates in the phosphorylation of ERK and CREB induced by bath application of NMDA in brain slices or hindpaw injection of 5% formalin in rats, and these might be fundamental molecular mechanisms underlying pain affect.

Inhibition Mechanism of Qingluo Tongbi Granule(清络通痹颗粒)on Osteoclast Differentiation Induced by Synovial Fibroblast and Monocytes Co-Culture in Adjuvant-Induced Arthritic Rats

Objective： To study the mechanism underlying the inhibitory effect of Qingluo Tongbi Granule （清络通痹颗粒, QTG） on osteoclast differentiation in rheumatoid arthritis in rats. Methods： Fibroblast and monocyte co-culture were used to induce osteoclast differentiation in adjuvant-induced arthritic （AIA） rats. Serum containing QTG was prepared and added to the osteoclasts, and activation of the tumor necrosis factor receptorassociated factor 6/mitogen-activated protein kinase/nuclear factor of activated T cells, cytoplasmic1 （TRAF6/ MAPK/NFATcl） pathways was examined. Results： The induced osteoclasts were multinucleated and stained positive for tartrate-resistant acid phosphatase （TRAP） staining. Serum containing QTG at 14.4, 7.2 or 3.6 g/kg inhibited the activation of TRAF6, extracellular regulated protein kinase （ERK）1/2, c-Jun N-terminal kinase （JNK） and p38 and decreased the percentage of cells with nuclear NFATcl in a dose-dependent manner, the high and middle doses exhibited clear inhibitory activity （P〈0.01 and P〈0.05, respectively）. After the addition of MAPK inhibitors, the NFATcl expression showed no significant difference compared with the control group （P〉0.05）. Conclusions： Serum containing QTG could generally inhibit the TRAF6/MAPK pathways and possibly inhibit the NFATcl pathway. In addition, QTG may regulate other signaling pathways that are related to osteoclast differentiation and maturation.