マウスにおけるMHC-II陽性ミクログリアの調節を介した網膜アミロイド除去の促進
Wang Sheng1,2,3,4,5, Qichang Wang1,2, Yinhua Huang1,3
1Aier Academy of Ophthalmology, Central South University, Changsha, Hunan, China.
Purpose:
This study aimed to investigate whether 40-Hz light flicker could modulate the expression of major histocompatibility complex class II (MHC-II) and enhance the clearance of amyloid-β (Aβ) deposition.
Methods:
We examined retinal MHC-II expression via RNA sequencing, immunofluorescence, and western blotting in mice 8 weeks, 9 months, and 18 to 20 months old. Retinal metabolic waste accumulation was induced by intravitreal and subretinal injections of Aβ oligomers. The impact of 40-Hz flicker on MHC-II expression, microglial activation, and retinal function was evaluated using immunofluorescence, western blotting, dot immunobinding assay, electroretinography, and optokinetic reflex (OKR) testing. Minocycline was used to inhibit microglial activity.
Results:
The 40-Hz light flicker upregulated MHC-II expression in the retinas of aged mice. MHC-II⁺ microglia accumulated along retinal veins and exhibited increased numbers and enlarged morphology in the subretinal space. Following intravitreal or subretinal Aβ injection, 40-Hz flicker enhanced microglial activation, further upregulated MHC-II expression, promoted Aβ clearance, and improved electroretinogram responses and OKR performance. These effects were abolished by minocycline treatment.
Conclusions:
We observed that 40-Hz light flicker enhances retinal microglial clearance of Aβ oligomers by upregulating MHC-II expression. These findings support 40-Hz light flicker as a non-invasive therapeutic strategy for age-related retinal disorders by promoting metabolic waste clearance.
