| Retinal degeneration is difficult to cure. Age related degeneration (AMD) and retinitispigmentosa (RP) are common to us. It do great harm to millions of people in the worldwho are blind permanently because of suffering from the problem. Due to retina belongs toterminal nerve which is difficult to regenerate, these disease are troublesome.Bone mesenchymal stem cells(BMSCs) are adult stem cells which have proficiency todifferentiate into many kinds of cells. It may differentiate into retinal neuron and glial cell.It may inhibit neuron apoptosis and secrete various cytokine which has trophic function.However, the vast majority of BMSCs remain in the subretinal space after subretinalinjection. It is difficult for BMSCs to migrate and integrate into retina. This preventBMSCs to repair degenerative retina.It was shown that glial cell and chondroitin sulfate proteoglycans are obstacle forMüller stem cells to migrate into retina of RCS rat. However，grafted Müller stem cells haddramatic improvement in migration into retina after chondroitin sulfate proteoglycans(CSPGs)degradation with chondroitinaseABC(ChABC). Thus, the difficulty for BMSCsto migrate may have association with CSPGs in degenerative retina. Our study will graftBMSCs treated with ChABC into subretinal space of RP rat,and then observe BMSCsmigration in retina and photoreceptor apoptosis after CSPGs degradation with ChABC.The purpose is to find methods which may promote the efficiency of BMSCs therapy forRP.Purpose:Establish retinitis pigmentosa model induced by intraperiboneal injection of sodiumiodate. Establish methods to isolate,culture,test and label BMSCs. Inject BMSCs treatedwith ChABC into subretinal space of RP rat. Explore the effect of CSPGs degradation inBMSCs therapy for RP.Method:1.NaIO3(3%，100mg/kg)was intraperitoneal injected to SD rats (postnatal day28)to establish retinal degeneration models. HE assay of retina were performed at14d、28d、90d and180d after NaIO3injection. Isolate BMSCs of SD rats in vitro and culture BMSCsby density gradient centrifugation technique. Test BMSCs by flow cytometryits. Evaluatethe plasticity of adipogenic and osteogenic differentiation. Label BMSCs with BrdU. 2.Establish retinitis pigmentosa model induced by intraperiboneal injection of sodiumiodate. Rats were devided into4groups. A group were not injected, B group were injectedwith BMSCs,C group were injected with BMSCs and ChABC, D group were injected withPBS.After28d, subretinal injection were applied with BMSCs and ChABC. Tunel,immunofluorescence and immunohistochemistry assay were performed14d after subretinalinjection.Result:1. RPE cells transformed and shrinked after NaIO3injection. The structure of DZ andONL became disordered. The number of photoreceptor cell decreased gradually. BMSCsexpanded rapidly in vitro. Flow cytometry analysis showed that over95%BMSCs of3passage were positive for CD44,CD90and negative for CD34,CD45. BMSCs had theplasticity of adipogenic and osteogenic differentiation. Over90%BMSCs were positive forBrdU label.2.(1) The vast majority of BMSCs stayed in subretinal space in B group. Themigration rate was(7.2±3.71)%. However, a great number of BMSCs migrated into retinain C group. The migration rate was (68.6±6.09)%. There was obvious statisticaldifference between B and C groups(P<0.01).(2) The apoptosis rates of photoreceptor cellswere(41.7±2.75)%of A group,(34.4±3.44)%of B group,(32.2±3.08)%of C groupand (40.9±2.96)%of D group. There were statistical difference between B,C groups andA,D groups(P <0.05).(3) The grafted BMSCs expressed GFAP.Conclusion:1. Intraperiboneal injection of sodium iodate may establish retinitis pigmentosa model.Density gradient centrifugation technique has high efficiency for BMSCs culture. BMSCsmay be labeled with BrdU appropriatly.2. CSPGs degradation can promote migration of BMSCs in degenerative retina.BMSCs may protect retinal photoreceptor cells through alleviating apoptosis. |
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