脂肪间充质干细胞干预视网膜变性的临床转化研究

Retinal degeneration (RD) is one of the leading causes of blindness worldwide, which is characterized by age-related macular degeneration and retinitis pigmentosa. The etiology of RD involves the progressive and eventual death of photoreceptors and retinal pigment epithelial (RPE) cells. To date, there is no efficient approach to treat this disease on clinic. Mesenchymal stem cells possess great plasticity and are able to differentiate into a variety of cell types, as well as produce many kinds of growth factors and cytokines, which result in their powerful therapeutic potential for treatment of RD. Adipose-derived stem cells (ADSCs) have higher proliferation rate and self-renewal capacity in comparison to other mesenchymal stem cells, and show lower immunorejection after transplantation. Our preliminary study showed that subretinal graft of ADSCs was able to reduce photoreceptor apoptosis and delay retina degeneration in SD rats pretreated with sodium iodate to induce RD development. Prompted by these results, we try to establish primate RD model in Macaca fascicularis, and clarify ADSC therapeutic functions in primate RD model, thus evaluate the efficiency and safety of ADSCs, as well as confirm the cell dosage and treatment window for RD disease. Furthermore, we will carry out clinical trials and establish the technical standard and scientific procedure for treatment of RD disease.

视网膜变性疾病（Retinal degeneration disease, RD）包括视网膜色素变性、年龄相关性黄斑变性等疾病，是眼科主要的致盲性疾病。发病原因是视网膜感光细胞和视网膜色素上皮细胞功能减低或丧失引起视功能损害，目前临床上缺乏有效的治疗手段。多向分化和旁分泌特性赋予间充质干细胞治疗RD的潜能。而在各种间充质干细胞中，脂肪组织来源的干细胞(Adipose-derived stem cells, ADSCs)取材方便、患者顺应性好、自体移植无免疫排斥等因素赋予其独特的优势。我们前期研究已经证实在大鼠RD模型中，视网膜下腔移植ADSCs能够延缓感光细胞凋亡，对视网膜具有保护作用。本课题拟建立食蟹猴RD模型，评价ADSCs治疗大动物RD的疗效和安全性，确定细胞剂量及治疗窗口，并阐述其治疗机制。在此基础上，开展ADSCs治疗RD的临床试验研究，建立干细胞治疗RD的技术标准与规范。

与多能干细胞相比，成体干细胞来源较丰富，取材相对容易，其中，科学家们对MSCs的研究最为广泛。在各种MSCs中，最容易被接受作为供体细胞的是脂肪干细胞(ADSCs)。取材方便、患者顺应性好、自体移植无免疫排斥等因素都赋予其独特的优势。视网膜变性疾病至今无法治愈，ADSCs有望成为理想的供体细胞。本研究主要在以下方面取得进展：（一）本研究多种造模方法，发现视网膜下腔注射anti-mir24的方法构建食蟹猴视网膜变性疾病模型较好，在大鼠及食蟹猴视网膜下腔注射anti-mir24，引起了RPE层损伤，视网膜发生变性，有望用于视网膜变性模型的构建。（二）将hADSCs移植到RCS大鼠视网膜下腔，hADSCs具有明显的视网膜保护作用。（三）来源于1.5月龄大鼠的ADSC比来源于年老大鼠的ADSC具有更强的视网膜细胞保护作用。（四）阐述移植位点对ADSCs治疗RD疾病的治疗效果影响。前膜样结构的形成及引起的视网膜折叠可能是导致玻璃体腔移植ASC后光反应熄灭的主要原因，因而临床实验的最有移植方式是视网下腔移植治疗RD疾病。（五）颈动脉注射碘酸钠20mg/kg，3天后移植细胞ADSCs细胞，视网膜下腔注射各种间充质干细胞。治疗效果不太明显，主要是出现免疫排斥反应。（六）初步建立遗传资源库，为数十名遗传性眼底变性病人及其家属进行详细遗传咨询和免费遗传诊断，并收集遗传性眼底变性疾病。本项目的实施，为采用干细胞治疗老年黄斑变性及视网膜色素变性提供有一种具有很好发展潜力的临床选择，为促进临床转化医学的发展奠定基础，并创造可观的经济价值。