Hop flower extracts mitigate retinal ganglion cell degeneration in a glaucoma mouse model

Tomoko Hasegawa,Hanako O Ikeda,Norio Sasaoka,Akitaka Tsujikawa,Sachiko Iwai,Akira Kakizuka

doi:10.1038/s41598-020-78731-2

Abstract

In glaucoma, retinal ganglion cells degenerate progressively, leading to visual field loss and blindness. Presently, the only treatment strategy for glaucoma is lowering the intraocular pressure. However, there are cases in which patients develop progressive visual field loss even though their intraocular pressures are within normal ranges. Therefore, the development of novel therapeutic strategies is an urgent endeavor. Besides high intraocular pressure, several other factors have been proposed to be associated with glaucoma progression, e.g., myopia, blood flow impairment, and amyloid β accumulation. We have previously reported that hop flower extracts possess γ-secretase inhibitory activities and reduce amyloid β deposition in the brains of Alzheimer’s disease model mice. In the current study, we showed that administration of hop flower extracts to glutamate-aspartate transporter (GLAST) knockout mice, the glaucoma model mice, attenuated glaucomatous retinal ganglion cell degeneration. Preservation of retinal ganglion cells in hop flower extract-administered mice was confirmed using optical coherence tomography, confocal scanning laser ophthalmoscopy, and retinal flatmount and histological evaluations. Hop flower extracts are, therefore, deemed a possible candidate as a novel therapeutic agent to treat glaucoma.

Highlights

In glaucoma, retinal ganglion cells degenerate progressively, leading to visual field loss and blindness
We have previously shown that hop flower extracts exhibit γ-secretase inhibitory activities and inhibit amyloid β (Aβ) production in cultured cells and in Alzheimer’s disease model mice with mutated amyloid precursor protein (APP), in which the C-terminal portion of human APP with the Indiana mutation (V717F) was expressed in neuronal cells driven by the neuron-specific enolase (NSE) p romoter[12]
We examined if administration of hop flower extracts attenuates retinal ganglion cell degeneration in glutamate-aspartate transporter (GLAST) knockout mice

Summary

Introduction

Retinal ganglion cells degenerate progressively, leading to visual field loss and blindness. We have previously reported that hop flower extracts possess γ-secretase inhibitory activities and reduce amyloid β deposition in the brains of Alzheimer’s disease model mice. We showed that administration of hop flower extracts to glutamate-aspartate transporter (GLAST) knockout mice, the glaucoma model mice, attenuated glaucomatous retinal ganglion cell degeneration. Glutamate-aspartate transporter (GLAST) knockout mice have been widely used as a model for normal tension glaucoma, which is characterized by chronic retinal ganglion cell death and optic nerve degeneration without elevated intraocular pressure[13]. We examined if administration of hop flower extracts attenuates retinal ganglion cell degeneration in GLAST knockout mice

Methods

Results

Conclusion