A comparative study on the transplantation of different concentrations of human umbilical mesenchymal cells into diabetic rats.
OBJECTIVE
To observe the effects of intravitreal injections of different concentrations of human umbilical mesenchymal stem cells on retinopathy in rats with diabetes mellitus.


METHODS
Healthy and adult male Sprague-Dawley (SD) rats were randomly assigned to a normal control group (group A), a diabetic retinopathy (DR) blank control group (group B), a high-concentration transplantation group (group C), a low-concentration transplantation group (group D) and a placebo transplantation group (group E). The expression of nerve growth factor (NGF) protein in the retinal layers was detected by immunohistochemical staining at 2, 4, 6 and 8wk.


RESULTS
The expression of NGF was positive in group A and most positive in the retinal ganglion cell layer. In groups B and E, the expression of NGF was positive 2wk after transplantation and showed an increase in all layers. However, the level of expression had decreased in all layers at 4wk and was significantly reduced at 8wk. In groups C and D, the expression of NGF had increased at 2wk and continued to increase up to 8wk. The level of expression in group C was much higher than that in group D.


CONCLUSIONS
DR can be improved by intravitreal injection of human umbilical mesenchymal stem cells. High concentrations of human umbilical mesenchymal stem cells confer a better protective effect on DR than low concentrations.
Clinical College of Ophthalmology, Tianjin Medical University, Tianjin Eye Hospital, Tianjin Institute of Ophthalmology, Tianjin Key Laboratory of Ophthalmology and Visual Sciences, Tianjin 300020, China.
Jia-Hui
JH
Kong
Clinical College of Ophthalmology, Tianjin Medical University, Tianjin Eye Hospital, Tianjin Institute of Ophthalmology, Tianjin Key Laboratory of Ophthalmology and Visual Sciences, Tianjin 300020, China.
Dan
D
Zheng
Clinical College of Ophthalmology, Tianjin Medical University, Tianjin Eye Hospital, Tianjin Institute of Ophthalmology, Tianjin Key Laboratory of Ophthalmology and Visual Sciences, Tianjin 300020, China.
Song
S
Chen
Clinical College of Ophthalmology, Tianjin Medical University, Tianjin Eye Hospital, Tianjin Institute of Ophthalmology, Tianjin Key Laboratory of Ophthalmology and Visual Sciences, Tianjin 300020, China.
Hong-Tao
HT
Duan
Clinical College of Ophthalmology, Tianjin Medical University, Tianjin Eye Hospital, Tianjin Institute of Ophthalmology, Tianjin Key Laboratory of Ophthalmology and Visual Sciences, Tianjin 300020, China.
Yue-Xin
YX
Wang
Clinical College of Ophthalmology, Tianjin Medical University, Tianjin Eye Hospital, Tianjin Institute of Ophthalmology, Tianjin Key Laboratory of Ophthalmology and Visual Sciences, Tianjin 300020, China.
Meng
M
Dong
Clinical College of Ophthalmology, Tianjin Medical University, Tianjin Eye Hospital, Tianjin Institute of Ophthalmology, Tianjin Key Laboratory of Ophthalmology and Visual Sciences, Tianjin 300020, China.
Jian
J
Song
diabetic retinopathy; human umbilical mesenchymal stem cells; nerve growth factor; stem cell therapy