人牙周膜干细胞向光感受器前体细胞分化及移植治疗视网膜变性疾病的实验研究

Retinal neuron regeneration and retinal function reconstruction have been the difficulties and hotspots for treatment of retinal degenerative diseases, but so far there is no effective treatment available. Exciting advances in the field of stem cell-based replacement therapy provide new hope for patients suffering from retinal degeneration. However, there are many restrictions surrounding the use of current sources of stem cells. Thus, identifying an ideal candidate for retinal repair and regeneration is imperative. In our previous investigation, we found that neural crest derived-human PDLSCs can be directed to retinal progenitor identity with a tendency to preferentially differentiate toward a photoreceptor-like fate. Accordingly, further studies are needed to elucidate the functional properties of the differentiated cells. Our project will initially focuse on the isolation, purification and identification of human PDLSCs, hence laying the technology foundation for their experimental manipulation. Furthermore, we will induce human PDLSCs to differentiate towards retinal progenitor-like cells and photoreceptor precursor-like cells in vitro. To identify the generated cells, a combination of morphological, phenotypic characterization and functional analyses will be applied. Finally, we will adopt a mouse model of retinal degeneration to assess the therapeutic potential of human PDLSCs on retinal degenerative diseases. Cell survival, integration and differentiation in host retina, as well as improvement in visual function by transplantation of human PDLSCs are to be investigated. The safety of grafted human PDLSCs will also be evaluated. Our study may hold promise for providing a new avenue on the development of future therapeutic strategies for retinal degenerative diseases.

视网膜神经元再生和视功能重建是视网膜变性疾病治疗的热点和难点，迄今仍无有效治疗。干细胞替代治疗研究的不断深入为视网膜变性患者带来了曙光。然而，目前研究的种子细胞都有一定局限性，因此，寻求视网膜组织修复的理想种子细胞来源迫在眉睫。申请者在前期研究中发现, 神经嵴来源的人牙周膜干细胞（PDLSCs）可以在体外诱导分化为视网膜前体样细胞并具有优先向光感受器细胞表型分化的倾向。因此，非常有必要进一步开展其功能性的实验研究。本项目首先拟分离、纯化及鉴定人PDLSCs，为其应用奠定技术基础。然后，在体外诱导人PDLSCs向视网膜前体样细胞和光感受器前体样细胞定向分化，并进行细胞形态学、功能学及表型特征鉴定。最后，以视网膜变性小鼠为模型开展人PDLSCs移植的实验性治疗研究，观察移植细胞的存活、分化和对视功能的改善情况，并评价其安全性。本研究有望为未来视网膜变性疾病的治疗策略开辟新途径。

年龄相关性黄斑变性（AMD）、视网膜色素变性(RP)、Stargardt病等视网膜变性疾病常常引起进行性视网膜神经细胞的损伤和死亡，从而导致不可逆的视功能丧失。这类视网膜病变目前尚缺乏有效的治疗方法。干细胞治疗研究的不断深入为视网膜变性患者带来了曙光。我们在前期研究工作中发现人牙周膜干细胞(hPDLSCs)经条件培养基诱导可以表达视网膜前体样细胞和光感受器细胞特异性标志。本项目研究利用RCS大鼠为视网膜变性的模式大鼠开展视网膜下腔移植hPDLSCs干预治疗研究，发现hPDLSCs移植对大鼠视网膜结构有明显的保护作用，并且对视功能有一定的改善作用。本项目研究发现hPDLSCs移植可能为视网膜变性疾病提供视网膜神经保护作用。本课题组率先在国内外开展hPDLSCs修复视网膜变性的体内动物实验，首次提出hPDLSCs未来可能成为视网膜干细胞移植治疗的一种重要细胞来源，为视网膜变性疾病防治提供了新的思路。