背景:视网膜变性(RD)是一组不可逆性视力丧失的疾病。在RD治疗的临床试验中使用多种类型的干细胞。然而,尚不清楚哪种干细胞对治疗最有效。因此,我们研究了几种类型干细胞的视网膜下移植,人脂肪干细胞(hADSC),羊水干细胞(hAFSCs),骨髓干细胞(hBMSCs),牙髓干细胞(hDPSC),诱导多能干细胞(hiPSC),和hiPSC来源的视网膜色素上皮(RPE)细胞的保护作用,RD疾病模型大鼠的旁分泌作用和治疗效率。
方法:在移植前进行这些干细胞和hiPSC衍生的RPE细胞的产生和表征。将用CellTrackerGreen标记以检测移植细胞的干细胞或hiPSC衍生的RPE细胞悬浮液递送到3周龄RCS大鼠的视网膜下间隙中。对照组接受视网膜下PBS注射或不注射。包括眼底摄影在内的一系列检测,视运动反应(OMR)评估,明暗盒子测试,视网膜电图(ERG),视网膜下注射细胞后,进行视网膜切片的苏木精和伊红(HE)染色。
结果:每个干细胞,将hiPSC来源的RPE细胞或PBS(空白实验)成功地移植到至少6只RCS大鼠的视网膜下。与对照组大鼠相比,接受除hiPSC外的任何干细胞的视网膜下移植的RCS大鼠显示出较高的ERG波(p<0.05)和定量OMR(qOMR)指数值(hADSC:1.166,hAFSC:1.249,hBMSCs:1.098,hDPSC:1.238,hiPSC:1.208,hiPSC-RPE细胞:1.294,非注射:1.03,PBS:这表明更好的视觉功能,在注射后4周。然而,仅接受hiPSC来源的RPE细胞的大鼠在注射后8周保持其视觉功能(p<0.05)。HE染色后在组织学切片中观察到的外核层厚度显示出与ERG和qOMR结果相同的模式。
结论:与hiPSC来源的RPE细胞相比,成人和胎儿干细胞在注射后长达4周的时间内改善了视觉功能;这一结果主要基于干细胞分泌的几种生长因子的旁分泌效应.RD患者将受益于干细胞疗法。
Retinal degeneration (RD) is a group of disorders on irreversible vision loss. Multiple types of stem cells were used in clinical trials for RD treatment. However, it remains unknown what kinds of stem cells are most effective for the treatment. Therefore, we investigated the subretinal transplantation of several types of stem cells, human adipose-derived stem cells (hADSCs), amniotic fluid stem cells (hAFSCs), bone marrow stem cells (hBMSCs), dental pulp stem cells (hDPSCs), induced pluripotent stem cell (hiPSC), and hiPSC-derived retinal pigment epithelium (RPE) cells for protection effects, paracrine effects and treatment efficiency in an RD disease model rats.
The generation and characterization of these stem cells and hiPSC-derived RPE cells were performed before transplantation. The stem cells or hiPSC-derived RPE cell suspension labelled with CellTracker Green to detect transplanted cells were delivered into the subretinal space of 3-week-old RCS rats. The control group received subretinal PBS injection or non-injection. A series of detections including fundus photography, optomotor response (OMR) evaluations, light-dark box testing, electroretinography (ERG), and hematoxylin and eosin (HE) staining of retinal sections were conducted after subretinal injection of the cells.
Each stem cell, hiPSC-derived RPE cell or PBS (blank experiment) was successfully transplanted into at least six RCS rats subretinally. Compared with the control rats, RCS rats subjected to subretinal transplantation of any stem cells except hiPSCs showed higher ERG waves (p < 0.05) and quantitative OMR (qOMR) index values (hADSCs: 1.166, hAFSCs: 1.249, hBMSCs: 1.098, hDPSCs: 1.238, hiPSCs: 1.208, hiPSC-RPE cells: 1.294, non-injection: 1.03, PBS: 1.06), which indicated better visual function, at 4 weeks post-injection. However, only rats that received hiPSC-derived RPE cells maintained their visual function at 8 weeks post-injection (p < 0.05). The outer nuclear layer thickness observed in histological sections after HE staining showed the same pattern as the ERG and qOMR results.
Compared to hiPSC-derived RPE cells, adult and fetal stem cells yielded improvements in visual function for up to 4 weeks post-injection; this outcome was mainly based on the paracrine effects of several types of growth factors secreted by the stem cells. Patients with RD will benefit from the stem cell therapy.