TY - JOUR
T1 - Implication of n-methyl-D-aspartate receptor in homocysteine-induced age-related macular degeneration
AU - Samra, Yara A.
AU - Kira, Dina
AU - Rajpurohit, Pragya
AU - Mohamed, Riyaz
AU - Owen, Leah A.
AU - Shakoor, Akbar
AU - Kim, Ivana K.
AU - Deangelis, Margaret M.
AU - Sheibani, Nader
AU - Al-Shabrawey, Mohamed
AU - Tawfik, Amany Mohamed
N1 - Funding Information:
Funding: This research was funded by NEI grant award R01 EY029751-01–NEI00072 and NEI grant award R01 EY030054.
Publisher Copyright:
© 2020 by the authors. Licensee MDPI, Basel, Switzerland.
PY - 2021/9/1
Y1 - 2021/9/1
N2 - Age-related macular degeneration (AMD) is a leading cause of vision loss. Elevated ho-mocysteine (Hcy) (Hyperhomocysteinemia) (HHcy) has been reported in AMD. We previously reported that HHcy induces AMD-like features. This study suggests that N-Methyl-D-aspartate receptor (NMDAR) activation in the retinal pigment epithelium (RPE) is a mechanism for HHcy-induced AMD. Serum Hcy and cystathionine-β-synthase (CBS) were assessed by ELISA. The involvement of NMDAR in Hcy-induced AMD features was evaluated (1) in vitro using ARPE-19 cells, primary RPE isolated from HHcy mice (CBS), and mouse choroidal endothelial cells (MCEC); (2) in vivo using wild-type mice and mice deficient in RPE NMDAR (NMDARR-/-) with/without Hcy injection. Isolectin-B4, Ki67, HIF-1α, VEGF, NMDAR1, and albumin were assessed by immunofluorescence (IF), Western blot (WB), Optical coherence tomography (OCT), and fluorescein angiography (FA) to evaluate retinal structure, fluorescein leakage, and choroidal neovascularization (CNV). A neo-vascular AMD patient’s serum showed a significant increase in Hcy and a decrease in CBS. Hcy significantly increased HIF-1α, VEGF, and NMDAR in RPE cells, and Ki67 in MCEC. Hcy-injected WT mice showed disrupted retina and CNV. Knocking down RPE NMDAR improved retinal structure and CNV. Our findings underscore the role of RPE NMDAR in Hcy-induced AMD features; thus, NMDAR inhibition could serve as a promising therapeutic target for AMD.
AB - Age-related macular degeneration (AMD) is a leading cause of vision loss. Elevated ho-mocysteine (Hcy) (Hyperhomocysteinemia) (HHcy) has been reported in AMD. We previously reported that HHcy induces AMD-like features. This study suggests that N-Methyl-D-aspartate receptor (NMDAR) activation in the retinal pigment epithelium (RPE) is a mechanism for HHcy-induced AMD. Serum Hcy and cystathionine-β-synthase (CBS) were assessed by ELISA. The involvement of NMDAR in Hcy-induced AMD features was evaluated (1) in vitro using ARPE-19 cells, primary RPE isolated from HHcy mice (CBS), and mouse choroidal endothelial cells (MCEC); (2) in vivo using wild-type mice and mice deficient in RPE NMDAR (NMDARR-/-) with/without Hcy injection. Isolectin-B4, Ki67, HIF-1α, VEGF, NMDAR1, and albumin were assessed by immunofluorescence (IF), Western blot (WB), Optical coherence tomography (OCT), and fluorescein angiography (FA) to evaluate retinal structure, fluorescein leakage, and choroidal neovascularization (CNV). A neo-vascular AMD patient’s serum showed a significant increase in Hcy and a decrease in CBS. Hcy significantly increased HIF-1α, VEGF, and NMDAR in RPE cells, and Ki67 in MCEC. Hcy-injected WT mice showed disrupted retina and CNV. Knocking down RPE NMDAR improved retinal structure and CNV. Our findings underscore the role of RPE NMDAR in Hcy-induced AMD features; thus, NMDAR inhibition could serve as a promising therapeutic target for AMD.
KW - Age-related macular degeneration
KW - Blood retinal barrier
KW - Cystathionine-β-synthase
KW - Homocysteine
KW - Mouse
KW - N-methyl-D-aspartate receptor
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U2 - 10.3390/ijms22179356
DO - 10.3390/ijms22179356
M3 - Article
C2 - 34502266
AN - SCOPUS:85113800402
SN - 1661-6596
VL - 22
JO - International journal of molecular sciences
JF - International journal of molecular sciences
IS - 17
M1 - 9356
ER -