Acupuncture blocks the STAT3-MMP-2 pathway in a guinea pig model of lens-induced myopia

Objective: To investigate the effects of manual acupuncture (MA) on the signal transduction and activator of transcription (STAT)3 – matrix metalloproteinase (MMP)-2 pathway in a guinea pig model of lens-induced myopia (LIM). Methods: A total of 36 male pigmented guinea pigs (aged 2 weeks) were randomly assigned to the normal control (NC) (n = 12), LIM (n = 12) and LIM + MA (n = 12) groups. The NC group received no intervention. To create myopia, the right eyes of the LIM and LIM + MA groups were covered with −6.00 D lenses. The LIM + MA group received 30 min of acupuncture stimulation daily at Taiyang and LI4. The effect of LIM modelling and MA on ocular measurements, expression of STAT3, phosphorylated (p)-STAT3, MMP-2 and tissue inhibitor of MMP-2 (TIMP)-2 expression (as well as histopathology, morphology and immunohistochemistry of the guinea pigs’ eyes) were evaluated. Results: Compared with the NC group, the LIM group showed increased expression of STAT3, p-STAT3 and MMP-2, and decreased expression of TIMP-2, as well as an increase in ocular measurements. The eye tissue morphology was disrupted and fibres became thinner in the LIM group. Compared to the LIM group, the LIM + MA group exhibited a noteworthy decline in the expression of STAT3, p-STAT3 and MMP-2, a significant increase in TIMP-2, and a decrease in ocular measurements and tissue morphology, which were similar to that of the NC group. Conclusion: Acupuncture has the potential to decrease STAT3 activation and block the STAT3-MMP-2 pathway in the ocular tissue of guinea pigs with experimental LIM, thereby delaying the development of myopia.