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Updated: Jun 23, 2026
Examination of Anatomical Features of Retinal Ganglion Cells Under N-methyl-D-aspartic Acid (NMDA)-induced Excitotoxicity
Published on: September 19, 2025
NR_045396/MicroRNA761/FADD axis regulates necroptosis and survival of retinal ganglion cells
Ke Tian1, Xiangwei Duan1, Biyue Chen1
1Department of Ophthalmology, The Second Xiangya Hospital, Central South University, Changsha, People's Republic of China; Hunan Clinical Research Center of Ophthalmic Disease, Changsha, People's Republic of China.
Abstract:
The involvement of necroptosis and the underlying mechanism in retinal ganglion cell (RGC) death is not fully understood. We aim to determine whether the NR_045396/miRNA761/Fas-associated protein with death domain (FADD) axis participates in the regulation of necroptosis in RGCs. A mouse model of optic nerve crush was employed for in vivo experiments. Apoptosis and necrosis were assessed by TUNEL and Propidium iodide (PI) exclusion. We found that the necrotic rate increased in a time-dependent manner in RGCs following optic nerve injury, whereas apoptosis peaked at 7 days following nerve damage. Immunohistochemistry revealed that the expression levels of key markers of necroptosis, pRIP3 and pMLKL, were upregulated, whereas FADD expression was reduced in RGCs at 14 days after optic nerve injury. Enforced expression of FADD in RGCs by an AAV vector attenuated necrotic response and promoted RGC survival. A dual-luciferase reporter gene assay showed that miR761 directly regulated FADD expression. Intraocular application of AAV2 expressing sequences complementary to miR761 binding site (AAV2-miR761 sponge) enhanced FADD expression and regulated RGC necrosis and survival. Moreover, the long non-coding RNA (lncRNA) NR_045396 binds directly to miR761 and modulates the necrotic program of RGCs. Thus, we demonstrate the anti-necroptosis and neuroprotective effects of the NR_045396/miR761/FADD axis.
Insights
This study reveals the NR_045396/miRNA761/FADD pathway protects retinal ganglion cells (RGCs) from necroptosis after injury. This axis demonstrates significant anti-necroptosis and neuroprotective effects in RGCs.
Area of Science:
- Ophthalmology
- Neuroscience
- Molecular Biology
Background:
- Necroptosis mechanisms in retinal ganglion cell (RGC) death remain unclear.
- Understanding RGC death pathways is crucial for treating optic nerve injuries.
Purpose of the Study:
- To investigate the role of the NR_045396/miRNA761/FADD axis in RGC necroptosis.
- To determine the neuroprotective potential of this pathway in RGCs.
Main Methods:
- Optic nerve crush mouse model for in vivo studies.
- Assessment of apoptosis and necrosis using TUNEL and Propidium iodide (PI) exclusion assays.
- Immunohistochemistry for necroptosis markers (pRIP3, pMLKL) and FADD expression.
- Dual-luciferase reporter gene assay to confirm miR761-FADD interaction.
- Adeno-associated virus (AAV) vectors for gene/sponge expression in RGCs.
Main Results:
- Optic nerve injury induced time-dependent RGC necrosis and increased necroptosis markers (pRIP3, pMLKL).
- FADD expression was reduced post-injury, while enforced FADD expression attenuated necrosis and improved RGC survival.
- miR761 directly targets FADD, and inhibiting miR761 via a sponge enhanced FADD levels, RGC necrosis regulation, and survival.
- The long non-coding RNA (lncRNA) NR_045396 directly binds miR761, modulating RGC necroptosis.
Conclusions:
- The NR_045396/miR761/FADD axis plays a critical role in regulating necroptosis in RGCs.
- This pathway exhibits significant anti-necroptotic and neuroprotective effects, offering potential therapeutic targets for optic nerve damage.
