Abstract
Purpose :
To explore whether neurotrophins is altered in extraocular muscles of AACE and the correlation with innervation of extraocular muscles.
Methods :
From January 2022 to December 2022, 18 patients with AACE who meet the surgical conditions were prepared and relatively weak extraocular muscle (lateral rectus muscles) were amputated in compliance with medical ethics during the surgery, and 21 controls were collected from eye bank specimens. The qPCR and WB were respectively used to verify whether there were abnormal gene level and protein level content of neurotrophins (GDNF and IGF-1) in the lateral rectus muscle of AACE. Meanwhile, the number of nerve fibers （neurofilament，proteintech）and the density of neuromuscular junction （synaptophysin，proteintech）of the lateral rectus muscle of AACE were verified by immunofluorescence. SPSS 26.0 statistical software was used for data processing, and P < 0.05 was considered statistically different.
Results :
Compared with the control group, the expressions of GDNF were significantly increased in gene level p=0.02), and in protein level (p<0.0001) from the lateral rectus of AACE patients. IGF-1 was also significantly increased in gene level p=0.002) as well as in the protein level (p<0.0001). Mann Whitney test analysis showed that compared with the control group, the ratio of neurofilament/synaptophysin in AACE patients was significantly higher than that in the control group (p=0.008), and synaptophysin was significantly lower than that in the control group (p=0.03), However, there was no significant difference in neurofilament (p=0.559) between two groups. In the regression analysis, there was significant correlation between the ratio of neurofilament/synaptophysin and IGF-1 at gene level (p=0.015), and regression equation was obtained as Y=0.82+0.38X.
Conclusions :
GDNF and IGF-1 were increased in the relatively weak extraocular muscle (lateral rectus muscles) in the gene and protein levels, which may be a compensatory increase to keep the balance of horizontal extraocular muscle in AACE. The synaptophysin of lateral rectus decreased significantly, but no significant change for the nerve fibers. The ratio of neurofilament/synaptophysin was associated with IGF-1 at gene level, highlighting the correlation of altered neurotrophins and innervation in the relatively weak extraocular muscle of AACE patients.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.