Brain-derived neurotrophic factor and retinal ganglion cells in the retina of diabetic rat after intravitreal injection of human umbilical cord mesenchymal stem cells-induced neural stem cells

Abstract

Objective To investigate the effect of intravitreal injection of neural stem cells (NSC) derived from human umbilical cord mesenchymal stem cells (hUCMSC) on the expression of brain-derived neurotrophic factor (BDNF) and the number of retinal ganglion cells (RGC). Methods Fifty-two adult male Sprague-Dawley rats were randomly divided into normal group (group A) and diabetes mellitus group which received intraperitoneal injection of streptozocin to make diabetic rat models. One month after the diabetic rat models were confirmed successfully, diabetic rats were randomly divided into diabetic group (group B), hUCMSC group (group C) and hUCMSC-induced NSC group (group D). And thirteen diabetic rats were included in each group. Immuno-cytochemistry was applied to observe BDNF and thymosin-1(Thy-1) staining in the retina. Then mean integrated absorbance of the staining region on the retina slices were analyzed by Image-Pro Plus 6.0. The number of Thy-1 labeled RGC was record. Results BDNF and Thy-1 were positive on the retina slices from group A. The staining intensity from group B became weak and the expression of BDNF and Thy-1 gradually decrease with time (P 0.05) at 2 weeks after injection, but were significant different for other time points (P<0.05). Significant positive correlation between the expression of BDNF and the number of RGC were found by the Pearson correlation analysis (r=0.964, P<0.05). Conclusion Intravitreal injection of hUCMSC-derived NSC to diabetic rat may protect the retina by promoting the expression of BDNF and increasing the number of RGC. Key words: Diabetic retinopathy/therapy; Neural stem cells/transplantation; Brain-derived neurotrophic factor; Retinal ganglion cells; Animal experimentation