AIM: To investigate the effect of electroacupuncture on the expression of matrix metalloproteinase-3(MMP-3), tissue inhibitor of metalloproteinase-3(TIMP-3)and collagen type III alpha 1(Col3α1)in the retina of guinea pigs with lens-induced myopia.

METHODS:A total of 80 guinea pigs were randomly divided into the normal control(NC)group, negative lens-induced myopia(LIM)group, electro-acupuncture(EA)group, and sham group, with 20 guinea pigs in each group. The NC group did not receive any intervention, the LIM, EA and the sham groups were all wearing -6.0 D lens in the right eye and no lens in the left eye. The EA group was given electroacupuncture stimulation at Hegu Point and temple, and guinea pigs in the sham group were given intervention at false points. The refraction was measured by optometry, the axial length was measured by A-ultrasound, and the changes in retinal tissue structure were observed by HE staining. Quantitative polymerase chain reaction(Q-PCR)and western blot(WB)were used to detect the expression of MMP-3, TIMP-3, and Col3α1 at mRNA and protein levels before modeling and at 2 and 4 wk after modeling.

RESULTS:The axial length of the negative LIM group was significantly increased compared with the NC group at 2 and 4 wk after modeling(all P<0.05), and the diopter was significantly decreased(all P<0.05); the axial length of the eye in the EA group was decreased compared with the negative LIM group(all P<0.05), and the diopter was increased(all P<0.05). HE staining showed that the boundaries of retinal tissue in the NC group were obvious and arranged regularly. The retinal thickness, the thickness of the inner and outer nuclear layers, and the number of cells were reduced and irregularly arranged in the negative LIM group. The overall structure of the retina in the group EA was relatively perfect, the arrangement was more regular, and the morphological structure of each layer of the tissue did not appear obvious abnormalities. Q-PCR and WB detection results showed that the mRNA and protein relative expression levels of MMP-3, TIMP-3, and Col3α1 in the negative LIM group were significantly higher than those in the NC group(all P<0.05); the expression levels of the EA group was significantly decreased after intervention compared with the negative LIM group(all P<0.05).

CONCLUSION: Electroacupuncture can delay axial growth in negative LIM guinea pigs, and downregulate negative LIM induced expression of MMP-3, TIMP-3, and Col3α1 in the retina.