Toll-like receptor 4 inhibitor protects against retinal ganglion cell damage induced by optic nerve crush in mice

Autor: Yukimichi Nakano, Masamitsu Shimazawa, Kazuki Ojino, Hiroshi Izawa, Hiroto Takeuchi, Yuki Inoue, Kazuhiro Tsuruma, Hideaki Hara
Jazyk: angličtina
Rok vydání: 2017
Předmět:
Zdroj: Journal of Pharmacological Sciences, Vol 133, Iss 3, Pp 176-183 (2017)
Druh dokumentu: article
ISSN: 1347-8613
DOI: 10.1016/j.jphs.2017.02.012
Popis: Toll-like receptor 4 (TLR4) plays key roles in innate immune responses and inflammatory reactions. TAK-242 (resatorvid) is a small-molecule cyclohexene derivative that selectively inhibits TLR4 signaling pathways and suppresses inflammatory reactions. Here we investigated the protective effects of TAK-242 against optic nerve crush (ONC) which induces axonal injury like glaucoma in mice. TAK-242 was injected intravitreally immediately after ONC. The effect of TAK-242 was evaluated by measuring the number of fluorogold-labeled retinal ganglion cells (RGCs) at 10 days after ONC. Furthermore, the expression levels of phosphorylated-nuclear factor-kappa B (p-NF-κB) and phosphorylated-p38 (p-p38) were measured by Western blotting. In addition, we examined activated astrocytes by immunostaining. TAK-242 significantly abrogated the loss of RGCs associated with ONC. Moreover, the expression levels of p-NF-κB and p-p38 were significantly reduced by TAK-242 treatment. Furthermore, TAK-242 and C34, a TLR4 inhibitor, significantly reduced astrocyte activation in the ganglion cell and inner plexiform layers, compared with vehicle treatment. These findings indicate that TAK-242 inhibits not only the TLR4 signaling pathway but also astrocyte activation downstream of this pathway, suggesting that the inhibition of TLR4 signaling is a promising candidate for the treatment of glaucoma.
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