📋 Browse Articles

Experimental autoimmune uveoretinitis (EAU) shows degeneration of retinal neurons, including retinal ganglion cells (RGCs), already in its early phase. Based on our previous study demonstrating the attenuation of EAU by brain-derived neurotrophic factor (BDNF), whose retinal levels were increased by visual stimulation (VS), this study evaluated the effect of VS on BDNF protein expression in brain visual centers, its retrograde transport to the retina, and RGC survival in healthy and EAU mice. 14-day VS increased BDNF expression in the superior colliculus (SC) but not in the lateral geniculate nucleus and primary visual cortex in healthy and EAU mice compared to their unstimulated groups. Furthermore, VS increased numbers of BDNF-positive neurons and astrocytes in the retinorecipient superficial SC (sSC) in healthy and EAU mice, although stimulated EAU mice showed a modest reduction in BDNF-positive neurons compared to stimulated healthy mice. In contrast, unstimulated EAU mice exhibited a marked loss of sSC BDNF-positive neurons and astrocytes compared to unstimulated healthy mice. Additionally, VS promoted retrograde axonal transport of fluorescently labeled BDNF from the sSC to the retina, where it was detected in RGCs, inner retinal neurons, and Müller cells (MCs). These results suggest that VS-induced increases in BDNF expression in the sSC and its retrograde transport to the retina may directly affect multiple types of retinal neurons and MCs, on which BDNF can exert neurotrophic and protective effects. The overall attenuation of EAU histopathology and retinal inflammation, along with improved survival of RGCs in VS-treated EAU mice, is consistent with this suggestion. Show less

This pilot study investigated the protective effect of transfecting brain-derived neurotrophic factor (BDNF) and B-cell lymphoma 2 (bcl-2) genes in retinal ganglion cells (RGCs) using in vivo electroporation in an adult rat optic nerve transection model. Sprague-Dawley rats were randomly divided into five groups: BDNF(+)/bcl-2(+), BDNF(+), bcl-2(+), empty plasmid (EP), and no surgery (NS). The plasmids were intravitreally injected and electroporated into the left eye. Seven days later, optic nerve transection was performed in all groups except the NS group. Protein expression was examined using Western blotting, RGC survival was quantified using 1,1'-dioctadecyl-3,3,3',3'-tetramethyl-indocarbocyanine perchlorate (DiI) retrograde labeling, and apoptosis was assessed using terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) at multiple time points (7, 14, and 28 d after transfection). A significantly higher number of DiI (+) RGCs and lower number of apoptotic cells were observed in the BDNF(+)/bcl-2(+), BDNF(+), and bcl-2(+) groups compared to those in the EP group at all time points. The number of DiI (+) RGCs in the three treatment groups was significantly lower than that in the NS group. However, there were no significant differences among the three treatment groups. The protective effects of gene transfection tended to be strongest in the BDNF(+)/bcl-2(+) group, followed by the BDNF(+) group and then the bcl-2(+) group. Thus, all gene transfection treatments had a protective effect against the loss of DiI(+) RGCs induced by optic nerve transection but did not result in full recovery. This study also confirmed the value of in vivo electroporation. The findings of this pilot study provide a working base for the development of gene therapy for blinding optic nerve disorders. Show less