1992, 1994). Similar to PDGF, bFGF is another key mitogen for OPCs. Importantly, bFGF synergizes with PDGF to promote OPC proliferation and survival (Grinspan 2002). Therefore, it is likely that higher levels of PDGF and bFGF in ACDM were responsible for its potent survival and mitotic http://www.selleckchem.com/products/Gemcitabine-Hydrochloride(Gemzar).html effects on OPCs. The selective effects of ACDM and MCDM on OL developmental phenotypes are in general accordance with cytokine array data which showed distinct cytokine patterns in

ACDM and MCDM. Most factors detected at higher levels in ACDM are known to play mitotic and/or survival roles Inhibitors,research,lifescience,medical in OL development. It is worth noting that PDGF can work together with bFGF to promote OPC proliferation and survival, and such ability Inhibitors,research,lifescience,medical is inversely linked to their strong inhibition for OL differentiation (Tang et al. 2000). Interestingly, TIMP-1, which was also detected at higher levels in ACDM, has recently been shown to regulate

the number of NG2+ OPCs in the developing mice brain (Moore et al. 2011). One exception is CNTF. Although CNTF is a potent trophic factor for OPCs, it also strongly promotes OL differentiation (Louis et al. Inhibitors,research,lifescience,medical 1993; Mayer et al. 1994). The fact that CNTF levels are at high levels raises the question as why only a weak effect of ACDM on OL differentiation was observed? One of the possible explanations is that CNTF-activated signaling pathway(s) pertinent to OL differentiation was Inhibitors,research,lifescience,medical masked by proliferating/survival pathways activated by other cytokines (such as PDGF and bFGF), for example, due to cross talks between these intracellular signaling pathways. In fact, multiple signaling pathways including Akt, Erk, STAT3, and CREB were activated in OLs following ACDM exposure, while these pathways are frequently linked to cell survival and proliferation. As for Inhibitors,research,lifescience,medical those factors at higher levels

in MCDM, IGF-1 is one of the best characterized trophic factors for OL development and myelination, both in vivo and in vitro. For example, mice with IGF-1 overexpression exhibit increased number of OLs and enhanced myelination in the brain (D’Ercole et al. 2002). In vitro, IGF-1 not only provides strong trophic support (Cui et al. 2005) but also facilitates OPC differentiation (Pang et al. 2007). Less known is the effect of VEGF GSK-3 on OLs and/or myelination, but several studies suggest that VEGF is involved in OPC migration but not proliferation (Hayakawa et al. 2011, 2012). Finally, other factors, including E-selectin, CX3CL1, IL-2, IL-5, are sellekchem either cytokines or chemokines. While effects of these individual cytokine/chemokines on OL development are less clear, recent studies suggest that many cytokines and chemokines play roles in early neural/glia development. For example, it has been suggested that CX3CL1 may mediate microglia–neuron communication and synaptogenesis (Hoshiko et al.