Objective To observe the inhibition of LipofectamineTM2000 (LF2000)mediated pSUPER recombinant plasmid expressing small interference RNA targeting hypoxia-induced factor (HIF)-1alpha;(pSUPERsiHIF-1alpha;) on retinal neovascularization in mice. Methods pSUPERsiHIF-1alpha; recombinant plasmid was created. Forty-eight (seven-day-old) C57BL/6J mice were randomly divided into a normal group, the control group, empty vector group and gene therapy group with 12 mice in each group. Mice in the normal group were kept in normal room air, while the other three groups retinal neovascularization was induced by hypoxia. The mice in control group were not treated. The mice in the vector group received intravitreous injection of pSUPER and LF2000 (1 mu;l), and the gene therapy group received pSUPERsiHIF-1alpha; and LF2000 (1 mu;l)one day before being returned to normal room air．Fluorescent angiography was used to assess the vascular pattern. The proliferative neovascular response was quantified by counting the nuclei of new vessels extending from the retina into the vitreous in cross-sections．HIF-lalpha;and vascular endothelial growth factor (VEGF) levels in retinas were measured by immune histochemical staining method and reverse transeriptase-polymerase chain reaction (RT-PCR). Results Fluorescent angiography showed radial branching pattern vessels in the normal group and distorted large vessels, obstructed capillaries, many neovascular tuffs, fluorescence leakage in the peripheral retina in the control group and vector group. The gene therapy group demonstrated a significant reduction in neovascular tufts and fluorescence leakage compared with the control group and the vector group. The number of vascular cell nuclei extending breaking through the internal limiting membrane(ILM) of control group and vector group increased significantly compared with normal group (F=5850.016,P＜0.05), while obviously decreasing in the gene therapy group compared with control group (F=3012.469,P＜0.05). Immunohistochemical staining showed the expression of HIF-1alpha; protein in nucleus and VEGF protein in cytoplasm. The expression of HIF-1alpha; protein in retina was negative, while VEGF protein was weakly positive in normal group. The expression of HIF-1alpha; and VEGF protein were both positive in control group and vector group, while weakly positive in gene therapy group. The Results of RT-PCR showed that the expression of HIF-1alpha; mRNA in retina was increased significantly in control group and vector group as compared with normal group (F=3102.326,P＜0.05), while decreasing significantly in gene therapy group as compared with control group (F=3336.425,P＜0.05). Conclusion Retinal neovascularization in the mice is significantly inhibited by intravitreal injection of LF2000-mediated recombinant plasmid pSUPERsiHIF-1alpha;.
Objective To compare the transfection effects on soluble fms-like tyrosine kinase receptor-1 (sFlt-1) gene (2-4 transcellular region) mediated by carboxymethylated dextran coated nanoparticle and lipofectamineTM2000.Methods The plasmid pcDNA3.1-EGFP/sFlt-1(2-4) was constructed and assessed by enzyme cut, electrophoresis, and genetic sequencing. Three groups were divided: nanoparticle group, lipofectamine group, and non-transfected group. Twenty-four and 48 hours after the transfection, the distribution of cellular green fluorescence was oberved under the inverted phase contrast fluorescence microscope; the expression rate of green fluorescence was measured by flow cytometry; the expression of sFlt-1(2-4)mRNA and the protein was detected by reverse transcriptionpolymerase chain reaction (RT-PCR) and Western blot; the growth of the cells was observed by methyl thiazolyl tetrazolium (MTT) colorimetry and the relative growth rate (RGR) of the cells in each group was calculated; the cellular apoptosis in each group was detected by Hoechst staining.Results The sequence of sFlt-1(2-4) gene was equal to 915 base pair (bp).The transfection rate was 45% in nanoparticle group and 21% in lipofectamine group; the difference between the two groups was significant (t=2.541，Plt;0.05). Forty-eight hours after the transfection, the expression of sFlt-1（2-4）mRNA and protein was obviously higher in nanoparticle group than that in lipofectamine group (t=2.454，2.398；Plt;0.05) . Twenty-four and 48 hours after the transfection,the difference of RGR of the cells between nanoparticle and non-transfected group was not significant（t=1.436，Pgt;0.05）; the RGR in lipofectamine group differed much from that in non-transfected and nanoparticle group (t=2.412，2.545; Plt;0.05) ; the difference of cellular apoptosis was not significant between nanoparticle and nontransfected group (t=1.436，Pgt;0.05), but significant between nanoparticle and lipofectamine group (t=2.236，Plt;0.05). Conclusion The transfection rate of sFlt-1(2-4) mediated by carboxymethylated dextran coated nanoparticle was higher than that mediated by lipofectamineTM2000.
Microvesicles (MVs) is small membrane vesicles released from different cell types under different conditions. Studies have shown that MVs may mediate vascular inflammation, angiogenesis, and other pathological processes. MVs may play an important role in the pathogenesis of diabetic retinopathy (DR) by mediating endothelial cell injury, thrombosis and neovascularization. The plasma MV level may be an effective parameter to monitor the development of DR. This article will summarize the research progress of the relationship between MVs and DR in recent years.