Endogenous Apelin Is Protective Against Age-Associated Loss of Retinal Ganglion Cells in Mice

Yuki Ishimaru; Akihide Sumino; Fumiya Shibagaki; Akiko Yamamuro; Yasuhiro Yoshioka; Sadaaki Maeda

doi:10.3389/fnagi.2020.00058

Endogenous Apelin Is Protective Against Age-Associated Loss of Retinal Ganglion Cells in Mice

Front Aging Neurosci. 2020 Mar 20:12:58. doi: 10.3389/fnagi.2020.00058. eCollection 2020.

Authors

Yuki Ishimaru¹, Akihide Sumino^{1

2}, Fumiya Shibagaki¹, Akiko Yamamuro¹, Yasuhiro Yoshioka¹, Sadaaki Maeda¹

Affiliations

¹ Laboratory of Pharmacotherapeutics, Faculty of Pharmaceutical Sciences, Setsunan University, Hirakata, Japan.
² Laboratory of Food Chemistry, Yokohama University of Pharmacy, Yokohama, Japan.

Abstract

Age-associated loss of retinal ganglion cells (RGCs) causes visual deficits, but there is not yet any therapeutic agent to prevent the loss of these cells. Herein, we report that apelin, an endogenous peptide ligand of APJ receptor, is protective against the age-related loss of RGCs in mice. The mRNA expression of apelin was reduced in the retina of old mice compared with that in young mice, whereas retinal APJ expression increased with age. Immunofluorescence staining showed that APJ was present in RGCs and their surrounding cells expressed apelin. In addition, both functional and histological analyses demonstrated that apelin deficiency accelerated the loss of RGCs associated with age in mice. These results suggest that endogenous apelin plays a protective role against the degeneration of RGCs and that the apelinergic axis may be a new target for preventing age-related visual impairment.

Keywords: aging; apelin; apelin receptor (APJ); cell loss; knock-out; retinal ganglion cell (RGC).