Related Experiment Video
Updated: Jun 17, 2026
An Optic Nerve Crush Injury Murine Model to Study Retinal Ganglion Cell Survival
Published on: April 25, 2011
Transcriptomic Analysis Reveals That Granulocyte Colony-Stimulating Factor Trigger a Novel Signaling Pathway
Rong-Kung Tsai1,2,3, Keh-Liang Lin4, Chin-Te Huang1,2,5
1Institute of Eye Research, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Hualien 970473, Taiwan.
Abstract:
Optic nerve head (ONH) infarct can result in progressive retinal ganglion cell (RGC) death. The granulocyte colony-stimulating factor (GCSF) protects the RGC after ON infarct. However, protective mechanisms of the GCSF after ONH infarct are complex and remain unclear. To investigate the complex mechanisms involved, the transcriptome profiles of the GCSF-treated retinas were examined using microarray technology. The retinal mRNA samples on days 3 and 7 post rat anterior ischemic optic neuropathy (rAION) were analyzed by microarray and bioinformatics analyses. GCSF treatment influenced 3101 genes and 3332 genes on days 3 and 7 post rAION, respectively. ONH infarct led to changes in 702 and 179 genes on days 3 and 7 post rAION, respectively. After cluster analysis, the levels of TATA box-binding protein (TBP)-associated factor were significantly reduced after ONH infarct, but these significantly increased after GCSF treatment. The network analysis revealed that TBP associated factor 9 (TAF9) can bind to P53 to induce TP53-regulated inhibitor of apoptosis 1 (TRIAP1) expression. To evaluate the function of TAF9 in RGC apoptosis, GCSF plus TAF9 siRNA-treated rats were evaluated using retrograde labeling with FluoroGold assay, TUNEL assay, and Western blotting in an rAION model. The RGC densities in the GCSF plus TAF9 siRNA-treated rAION group were 1.95-fold (central retina) and 1.75-fold (midperipheral retina) lower than that in the GCSF-treated rAION group (p < 0.05). The number of apoptotic RGC in the GCSF plus TAF9 siRNA-treated group was threefold higher than that in the GCSF-treated group (p < 0.05). Treatment with TAF9 siRNA significantly reduced GCSF-induced TP53 and TRIAP1 expression by 2.4-fold and 4.7-fold, respectively, in the rAION model. Overexpression of TAF9 significantly reduced apoptotic RGC and CASP3 levels, and induced TP53 and TRIAP1 expression in the rAION model. Therefore, we have demonstrated that GCSF modulated a new pathway, TAF9-P53-TRIAP1-CASP3, to control RGC death and survival after ON infarct.
Insights
Granulocyte colony-stimulating factor (GCSF) protects retinal ganglion cells after optic nerve head infarct. GCSF utilizes the TAF9-P53-TRIAP1-CASP3 pathway to control cell death and survival.
Area of Science:
- Neuroscience
- Ophthalmology
- Molecular Biology
Background:
- Optic nerve head (ONH) infarct causes retinal ganglion cell (RGC) death.
- Granulocyte colony-stimulating factor (GCSF) shows protective effects on RGCs post-ONH infarct, but its mechanisms are complex and not fully understood.
Purpose of the Study:
- To elucidate the protective mechanisms of GCSF in RGCs following ONH infarct.
- To investigate the role of TATA box-binding protein (TBP)-associated factor 9 (TAF9) in GCSF-mediated RGC protection.
Main Methods:
- Microarray analysis of transcriptome profiles in GCSF-treated rat retinas post-anterior ischemic optic neuropathy (rAION).
- Bioinformatics and network analyses to identify key molecular pathways.
- Experimental validation using TAF9 siRNA, retrograde labeling, TUNEL assay, and Western blotting in an rAION model.
Main Results:
- GCSF significantly altered gene expression, including TBP-associated factors.
- TAF9 was identified as a key mediator, binding P53 to induce TRIAP1 expression.
- Silencing TAF9 abolished GCSF's protective effects, increasing RGC apoptosis and reducing TP53 and TRIAP1 levels.
Conclusions:
- GCSF protects RGCs from death after ONH infarct through a novel pathway involving TAF9, P53, TRIAP1, and CASP3.
- TAF9 acts as a crucial downstream effector of GCSF, modulating RGC survival and apoptosis.
