Experimental Study Of The Protective Effect Of MicroRNA24to Retinal Damage Caused By Sodium Iodate

Background: The retinal disease is a type of serious diseases affecting human visionand quality of lives. So far,there has not found a reliable and effective treatment method inclinical to the retinal damage especially the damage of the epithelium. With thedevelopment of medicine,although we can control the disease by using of drugs, surgery,and laser, not to treat the defects of gene fundamentally. Gene therapy has attracted moreattention. With the deepening of the microRNAs family,the function of microRNA24genehas caused research boom. Currently, the research of the mechanism about microRNA24todisease of eyes especially the retinal damages are still rare in the domestic.Objective: Using the packaged lentivirus vectors to the cell and animal experiments,to detect if the expression of microRNA24has a protective effect to ARPE-19with thestimulation of sodium iodide in vitro and in vivo.Methods:(1)Constructing lentiviral vector in accordance with the desired gene, andthen proceed to lentiviral packaging, harvested and concentrated, and tested the titer.(2)Cell experiment:Using0.3mg/ml,0.6mg/ml,1.2mg/ml,2.4mg/ml,4.8mg/ml,9.6mg/mlconcentration of sodium iodide to stimulate the different retina cells (ARPE-19, Muller,RGC-5), comparing the sensitivity of different retina cells to sodium iodide, to provide abasis for the establishment of an animal model. Adding5μl,10μl,15μl of the packagedvirus to infect ARPE-19cells, to detect if there is a change about the sensitivity to sodiumiodide by comparing ARPE-19cells which are infected with different doses of virus withARPE-19cells.(3) The animal experiment: Take about160g of SD rats20, divided intotwo groups, slit lamp ophthalmoscopy exclude corneal disease, cataracts and retinaldisease, ERG examination to exclude a difference of a and b-wave amplitude of the leftand right eyes. The first group initially using50mg/kg dose of sodium iodide by tail veininjection, then2days conduct the subretinal space virus injection, uniform provisions theright eye to inject virus5μl, sterilization of the left-eye to inject with an equal volume ofPBS. The second group firstly injecting virus one week in advance, after one week toinject sodium iodide according to the injection of the first set of standards and way.Conducting the ERG to detect a and b-wave amplitude after one week, two weeks,four weeks, six weeks injection,to see whether there is a statistical difference.Results:(1) successfully constructed a lentiviral vector and test virus titer is2E+7TU/μl.(2) Cell experiments: using different concentrations of sodium iodate after48h,three cells (ARPE-19, Muller, of RGC-5) IC50, respectively is(2.26±0.12),(2.34±0.76),(2.13±0.69) mg/ml. Three cell sensitivity to sodium iodate order is RGC-5> ARPE>Muller. For each cell, the survival rate is increasing with the high concentration of sodiumiodate. Collected24h,48h,72h ARPE-19cells which are infected by virus, the cells(ARPE-19+5μl, ARPE-19+10μl, ARPE+15μl) infected by different doses of virus ofthe IC50are (2.49±0.32),(3.62±0.42),(4.83±0.51) mg/ml. ARPE-19infected bydifferent doses of virus, its50%inhibition of sodium iodate concentration wassignificantly higher than those ARPE-19cells (P <0.05, a=0.05), and (ARPE+15μl) thegroup relatively in ARPE-19group increased more significantly (P <0.05, a=0.05). Itmeans in the stimulation of the same concentration of sodium iodide,(ARPE+15μl) grouphas more cell survival. This preliminary description microRNA24ARPE-19cells have aprotective effect. And this protective effect was more pronounced effect in the high dosegroup of viruses.(3) Animal experiments: after1w,2w,4w weeks two groups doing theERG check, a and b-wave of two groups under five intensity in contrast no significantdifference (P>0.05). After six weeks to do ERG check, the two group both have a andb-wave, but the two groups were compared in the five intensity of a spread in a and b-waveamplitude,there is no significant difference (P>0.05).Conclusion: By tail vein injection of sodium iodate can elective destruction of retinalpigment epithelial cells in the rat, successfully established animal model of retinal damage;ARPE-19cells infected by virus is resistant to stimulation of sodium iodide, increased cellviability, indicating microRNA24has a protective effect to retinal damage caused bysodium iodine, and a positive correlation with the virus dose; in the sixth week of retinalafter inferior vena injection virus, ERG check found that a and b-wave amplitude verifythe same protective effect of microRNA24to retinal damage, but if there is pre-protectiveeffecthas not been verified in this experiment.