AUTHOR=Yang Qin , Tan Qing Qing , Lan Chang Jun , Lv Bo Zhen , Zhou Gui Mei , Zhong Wei Qi , Gu Zhi Ming , Mao Yu Mei , Liao Xuan 

TITLE=The Changes of KCNQ5 Expression and Potassium Microenvironment in the Retina of Myopic Guinea Pigs

JOURNAL=Frontiers in Physiology

VOLUME=Volume 12 - 2021

YEAR=2021

URL=https://www.frontiersin.org/journals/physiology/articles/10.3389/fphys.2021.790580

DOI=10.3389/fphys.2021.790580

ISSN=1664-042X

ABSTRACT=KCNQ5 is suggestively associated with myopia, but its specific role in the myopic process has not been studied further. In order to investigate the expression of potassium channel gene KCNQ5 and the changes of K+ microenvironment within the retina of form deprivation myopia (FDM) guinea pigs. A total of 60 guinea pigs were randomly divided into the normal control (NC) group, the self-control (SC) group and the form-deprivation (FD) group. Molecular assays and immunohistochemistry (IHC) were conducted to measure the expression and distribution of KCNQ5-related gene and protein in the retina. We determined the K+ concentration in the retina. In addition, the possible effects of form deprivation on potassium ionic currents and the pharmacological sensitivity of KCNQ5 activator Retigabine and inhibitor XE991 to the M-current in RPE cells were investigated using the patch-clamp technique. As a result, FD eyes exhibited more myopic refraction and longer AL. The mRNA and protein levels of KCNQ5 significantly decreased in the FD eyes, but the K+ concentration increased. In addition, the M-type K+ current (IK(M)) density decreased in FD RPE cells, and were activated or inhibited in a concentration-dependent manner due to the addition of Retigabine or XE991. Overall, KCNQ5 was significantly downregulated in the retina of FD guinea pigs, which may be associated with the increasing K+ concentration, decreasing IK(M) density and elongating ocular axis. KCNQ5 may play an important role in the process of myopia. Its channel inhibitors or activators may be beneficial to myopia prevention and control.