The Effects Of IGF-1 On Human Retinal Vascular Endothelial Cells

Background and ObjectiveRetinal neovascularization caused by retinal dysfunction is different from physiological vessel in structure, position and function. Under pathological condition retinal neovascular have higher permeability, so they cannot provide oxygen to surrounding tissue effectively, hence visual function can be damaged due to it. In current research, many efforts have been made to explore the possible mechanism and to find effective intervention onto retinal neovascularization.Insulin-like growth factor-1 is one kind of active protein peptides, which plays an important role in promotingmitosis and differentiation of cells and wound healing. Previous studies have showed that IGF-1 could affect the growth of tumor and the process of disease by promoting the proliferation and suppressing the apoptosis of endothelial cells. The effect of IGF-1 in the process of retinal neovascularization is still unknown.To address the effect of IGF-1 on the process ofretinal neovascularization, human retinal vascular endothelial cells(HRECs) was cultured in vitro stimulated with different concentration of IGF-1, the influence and mechanism of IGF-1 on the migration, apoptosis and cell capillary tube formation of HRECs was analyzed. It may provide some beneficial theoretical basis for understanding the pathogenesis of retinal neovascularization and facilitate to explore new therapeutic targets in clinical setting.Materials and Method1. HRECs was cultured in vitro, and cell in exponential phase was used for this experiment. IGF-1 receptor(IGF-1R) m RNAexpression in human retinal vascular endothelial cells(HRECs) were quantified by reverse transcription polymerase chain reaction(RT-PCR).2. HRECs cell migration, cultured with theconcentrations of 0, 10 and 200 ng of IGF-1, was detected using wound scratch assay.3. Flow cytometry was used to test the effect of500 and 1000 ng/ml IGF-1 onapoptosis of HRECs.4. After intervention with IGF-1at theconcentrations of 10, 100 and 200 ng/ml, cell capillary tube formation of HRECs was examined using three-dimensional matrigel assay.5. After intervention of IGF-1at theconcentrations of500 and 1000 ng/ml, the effects of IGF-1 on HRECs expression of PDGF-BBand Caspase-3 were quantified by Realtime-PCR.Results1. IGF-1receptor(IGF-1R) in HRECs was quantified by RT-PCR.2. Wound scratch assay results showed a significant increase in the migrated distance of HRECs with IGF-1 stimulation under the concentration of 200 ng/ml after intervention of 24 hours, the differences were statistically significant(F=0.023, P=0.021).3. Flow cytometry results showed that, compared with the control group, the intervention of 1000 ng/ml IGF-1 can effectively inhibit the apoptosis of HRECs.(F=4.243, P=0.046).4. Three-dimensional matrigel assayshowed that IGF-1 can increase the number of intact capillary tube formation at the concentration of 200 ng/ml after IGF-1 intervention after 12 hours,the differences were statistically significant(F=0.26, P=0.048).5. Realtime-PCR results showed that IGF-1 at theconcentrations of1000 ng/ml can promote the m RNA expression of PDGF-BB(F=5.457, t=-3.489, P=0.025)but inhibit the expression of Caspase-3(F=1.093, t=7.287, P=0.002),the differences were statistically significant.Conclusion1. IGF-1 promotemigration, capillary tubeformation and suppress apoptosis of HRECs.2. The mechanism of pro-angiogenesis may via regulating the expression of PDGF-BB and Caspase-3.