AIM: To investigate the expression changes of Toll like recepter 9(TLR-9)and myeloid differentiation factor 88(MyD88)in retina of mice following optic nerve injury(ONI).

METHODS: There were 36 male 8-week-old C57BL/6J mice randomly divided into 6 groups: blank control(no treatment), ONI 1d group(materials were taken at 1d after optic nerve injury), ONI 3d group(materials were taken at 3d after optic nerve injury), ONI 5d group(materials were taken at 5d after optic nerve injury), ONI 7d group(materials were taken at 7d after optic nerve injury), ONI 14d group(materials were taken at 14d after optic nerve injury). The mice optic nerve model was made by optic nerve gripping, and the mRNA and protein levels of Toll like recepter 9 and myeloid differentiation factor 88 in each retinal were measured by RT-qPCR and Western-blot.

RESULTS: The mRNA and protein levels of Toll like recepter 9 and myeloid differentiation factor 88 in the retina of ONI 1d group were not significantly different from those of the blank control group(P>0.05), the mRNA and protein levels of TLR-9 and MyD88 in the retina of ONI 3d group, ONI 5d group, ONI 7d group and ONI 14d group were significantly increased compared with the blank control group, and the differences were statistically significant(P<0.01). Compared with the blank control group, the mRNA and protein levels of TLR-9 and MyD88 in the retina of mice began to increase at ONI 3d(P<0.01), peaked at ONI 5d(P<0.001), and gradually decreased at ONI 7d(P<0.01).

CONCLUSION: Optic nerve injury can activate the expression of TLR-9 and MyD88 in mice retina. TLR-9 and MyD88 may play an essential role in the process of optic nerve injury.