图 1 人诱导多能干细胞(hiPSCs)培养及其标记物的表达
纸质出版日期:2023-01-20,
收稿日期:2022-10-26
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利用人诱导多能干细胞(hiPSCs)定向分化为γ-氨基丁酸能(GABA)神经前体细胞后种植到脱细胞视神经(DON)材料内,以构建出具有突触形成潜能的hiPSC源性抑制性神经网络组织。为研究与治疗修复中枢神经系统损伤提供一种新的组织工程产品。
采用分步定向诱导和组织工程构建技术相结合的方法。将hiPSCs体外定向诱导为GABA能神经前体细胞(hNPCs)后,种植于DON材料上三维培养,在特定神经元诱导环境下,将其进一步分化为GABA能神经元。应用透射电镜和全细胞膜片钳技术分别检测hiPSCs分化的神经元之间能否形成类突触结构,以及这些神经元是否具有自发性抑制性突触后电流。从结构与功能角度证实这些hiPSCs分化的神经元可形成具有突触传递潜能的抑制性神经网络组织。
在体外将hiPSCs成功诱导出GABA能表型的抑制性神经元,且其培养28 d仍保持良好活力。透射电镜下,观察到三维材料上hiPSC源性神经细胞突起之间形成许多的细胞连接,其中一些为类突触样结构,表现为:一侧细胞突起的细胞膜稍增厚并且其内侧面胞质含有少量囊泡,形成类突触前成分的结构;其对侧为另一个细胞突起的细胞膜局部增厚,形成类突触后膜的结构。全细胞膜片钳检测可记录到已分化的hiPSC源性神经细胞具有产生动作电位和自发性抑制性突触后电流的能力。
本研究结果表明,在体外诱导hiPSCs定向分化为GABA能神经前体细胞后种植到DON材料内三维培养,可成功构建成具有突触传递潜能的hiPSC源性抑制性神经网络组织,这将为后期研究与治疗中枢神经系统损伤提供一种新型干细胞组织工程来源的神经组织。
Directed differentiation of human induced pluripotent stem cells (hiPSCs) into spinal cord γ-aminobutyric acid (GABA)-ergic progenitor cells were implanted into an decellularized optical nerve (DON) bioscaffold to construct a hiPSC-derived inhibitory neural network tissue with synaptic activities. This study aimed to provide a novel stem cell-based tissue engineering product for the study and the repair of central nervous system injury.
The combination of stepwise directional induction and tissue engineering technology was applied in this study. After hiPSCs were directionally induced into human neural progenitor cells (hNPCs) in vitro, they were seeded into a DON for three-dimensional culture, allowing further differentiation into inhibitory GABAergic neurons under the specific neuronal induction environment. Transmission electron microscopy and whole cell patch clamp technique were used to detect whether the hiPSCs differentiated neurons could form synapse-like structures and whether these neurons had spontaneous inhibitory postsynaptic currents, respectively, in order to validate that the hiPSC-derived neurons would form neural networks with synaptic transmission potentials from a structural and functional perspective.
The inhibitory neurons of GABAergic phenotype were successfully induced from hiPSCs in vitro, and maintained good viability after 28 days of culture. With the transmission electron microscopy, it was observed that many cell junctions were formed between hiPSC-derived neural cells in the three-dimensional materials, some of which presented a synapse- like structure, manifested as the slight thickness of cell membrane and a small number of vesicles within one side of the cell junctions, the typical structure of a presynatic component, and focal thickness of the membrane of the other side of the cell junctions, a typical structure of a postsynaptic component. According to whole-cell patch-clamp recording, the hiPSC-derived neurons had the capability to generate action potentials and spontaneous inhibitory postsynaptic currents were recorded in this biotissue.
The results of this study indicated that hiPSCs can be induced to differentiate into GABAergic progenitor cells in vitro and can successfully construct iPSC-derived inhibitory neural network tissue with synaptic transmission after implanted into a DON for three-dimensional culture. This study would provide a novel neural network tissue for future research and treatment of central nervous system injury by stem cell tissue engineering technology.
2006年日本京都大学Yamanaka团队首次用Oct3/4、Sox2、c-Myc和 Klf4四种基因转录因子将小鼠成纤维细胞逆转去分化,重回一种与胚胎干细胞(embryonic stem cells, ESCs)性质相似的干细胞,并命名为诱导多能干细胞(induced pluripotent stem cells, iPSCs)[
1.1.1 细胞来源与生物工程材料
人诱导多能干细胞由中山大学干细胞与再生医学教育部重点实验室提供。视神经取自2岁成年猪(50% 杜洛克血统,由西北农林科技大学动物科技学院提供)。实验动物许可证号为【SCXK(浙)2019-0001】。实验过程中对动物的处置符合《实验动物福利伦理审查指南(GB/T35892-2018)》以及中山大学动物实验中心伦理委员会的要求。
1.1.2 试剂与耗材 GelMA水凝胶(江阴司特易生物技术有限公司)、mTeSRTM1 medium(Stemcell,85850)、Matrigel® Matrix(Corning,354277)、Y-27632 dihydrochloride(Tocris,1254/1)、Mouse-anti-GABA antibody(Sigma,A0310)、Mouse-anti-Nestin antibody(abcam,ab6142)、Mouse-anti-Oct4 antibody(abcam,ab184665)、Chicken-anti-GFAP antibody(abcam,ab4674)、Rabbit-anti-Nanog antibody(abcam,ab21624)、Mouse-anti- PAX6 antibody(Sigma,AMAB91372)、Mouse-anti-PTF1A antibody(Santa Cruz Biotechnology,SC-393011)、Mouse-anti-VGLUT2 antibody(Millipore,MAB5504)、Rabbit-anti-CHAT antibody(Proteintech,20747-1-AP)、Mouse-anti-SOX1 antibody(R&D,AF3369)、Chicken-anti-MAP2 antibody(abcam,ab5392)、羊抗小鼠Alexa Fluor488(abcam,ab150113)、羊抗鸡Alexa Fluor647(abcam,ab150171)、羊抗兔Alexa Fluor647(abcam,ab150079)
1.1.3 主要仪器
切片机(Thermofisher NX50,美国),全自动倒置荧光显微镜(Leica,DM6B,德国),激光共聚焦显微镜(Zeiss,LSM800,德国),透射电子显微镜(FEI ,Tecnai Spirit Twin G2,捷克),集成钳制放大器(Sutter, IPA,美国)。
1.2.1 脱细胞视神经三维支架材料制备
参照前期技术方案[
1.2.2 人诱导多能干细胞(hiPSCs)复苏及培养
细胞复苏前使用Matrigel® Matrix进行铺板,在细胞培养箱中孵育2 h。从液氮罐中取出hiPSCs细胞,置于37 ℃水浴锅中至完全融化,缓慢加入至含有4 mL mTeSRTM1 培养基的15 mL的无菌离心管中,335.4×g离心5 min,去掉上清液,加入含有10 μg/mL Y-27632 dihydrochloride的mTeSRTM1 培养基1 mL,重悬细胞,将其种植入Matrigel® Matrix包被的孔板中,置于细胞培养箱中培养,每天更换培养液。倒置光学显微镜下观察细胞状态,当细胞生长达到80%融合时,使用 0.05% EDTA 以 1:6比例进行传代或进行后续分化实验。
1.2.3 人诱导多能干细胞(hiPSC)源性抑制性神经前体细胞(hNPCs)的构建
脊髓抑制神经元起源于发育中脊髓背侧的dI4结构域,基于Gong等[
1.2.4 构建iPSC源性抑制性神经网络组织
在无菌条件下,将7.5 %(W/V)的GelMA胶和蓝光引发剂(LAP)以3:2的比例配制GelMA水凝胶。使用GelMA水凝胶将诱导的抑制性hNPCs(1×106/10 μL)重悬,种植入脱细胞视神经三维支架材料内,蓝光照射5 s固化。加入神经元诱导培养基(含有0.5 % N2 + 1 % B27 + 20 μg/L BDNF + 20 μg/L GDNF + 1 μmol/L db-cAMP + 0.1 μmol/L RA + 200 μmol/L AA的Neuronbasal A)继续诱导培养14 d,将祖细胞进一步诱导分化为GABA能神经元且细胞之间相互连接形成抑制性神经网络组织。诱导培养14 d后,取出三维材料置于40 g/L多聚甲醛中固定30 min后,进行横切或矢状面冷冻切片,片厚为25 μm。置于烘箱中烤干后,0.01 mol/L PBS漂洗3次后备用。
1.2.5 免疫荧光组织化学法染色
将培养的hiPSCs、hNPCs和hiPSC源性神经网络组织用40 g/L多聚甲醛(PFA)室温固定30 min后,用0.01 mol/L PBS漂洗3次。加入10%的山羊血清,37 ℃封闭30 min。去掉血清,分别加入一抗:anti-Oct4(1:200)、anti-Nanog(1:500)、anti-SOX1(1:500)、anti- PAX6(1:200)、anti-Nestin(1:500)、anti-PTF1A(1:200)、anti-GFAP antibody(1:400)、anti-MAP2(1:500)、anti-GABA(1:200)、anti-VGLUT2(1:500)或Anti-CHAT(1:1 000)。4 ℃封闭过夜。第2天复温30 min后,弃掉一抗,加入0.01 mol/L PBS漂洗3次,加入相对应的荧光二抗,37 ℃孵育2 h,弃掉二抗,加入0.01 mol/L PBS漂洗3次,加入Hoechst33342,37 ℃染色15 min,常规漂洗,封片,于激光共聚焦显微镜下观察并拍照。
1.2.6 膜片钳检测hiPSC源性抑制性神经网络组织内神经元的电生理特性
为了明确hiPSC源性神经网络的功能,我们用全细胞膜片钳方法记录培养28 d的hiPSC源性神经网络组织中分化成神经细胞膜上的钠电流,神经细胞动作电位以及微小抑制性突触后电流(miniature inhibitory postsynaptic current, mIPSC)。膜片钳放大器为Integrated Patch-Clamp Amplifier, IPA,并用Igor8软件进行信号采集且过滤频率为1 kHz,采样频率为50 kHz。电流钳模式下记录动作电位,电极内液成分为(mM):130 K-gluconate、10 KCl、10 HEPES、4 Mg2ATP、0.5 Na3GTP和10 Na-phosphocreatine;aCSF存在10 mmol/L TEA-Cl,电压钳模式下记录钠电流(内液140 mmol/L CsCl,2 mmol/L MgCl2·6H2O,0.1 mmol/L CaCl2·2H2O,1.1 mmol/L EGTA,10 mmol/L HEPES)。aCSF存在1 μmol/L TTX, 20 μmol/L CNQX与100 μmol/L D, L-APV,电压钳模式下记录抑制性突触后电流(内液140 mmol/L CsCl、0.2 mmol/L CaCl2·2H2O、8 mmol/L NaCl、2 mmol/L EGTA、5 mmol/L QX-314、10 mmol/L HEPES、4 mmol/L Mg2ATP和0.5 mmol/L Na3GTP)。
1.2.7 透射电镜下观察人诱导多能干细胞源性神经元之间突触形成
将培养28 d的hiPSC源性神经网络组织支架材料用40 g/L戊二醛固定30 min;1%锇酸锇化1 h后,PB清洗2次,每次5 min;梯度酒精处理,依次为50%酒精 1×15 min、70%酒精 1×15 min、95%酒精 2×15 min、100%酒精 2×15 min和100%丙酮 2×15 min;然后50% Epon812包埋剂浸透2 h,100% Epon812 包埋剂浸透过夜;最后100% Epon812包埋剂包埋组织块,60 ℃烤箱聚合48 h。将hiPSC源性神经网络组织包埋块进行半薄切片,甲苯胺蓝染色,定位后再进行超薄切片,经醋酸铀和柠檬酸双重染色,电镜下观察。重点观察支架材料内细胞之间的连接,分析突触连接形态。
在鉴定hiPSCs及其分化表型的每种标记物的细胞免疫荧光组化染色的细胞爬片中,任意选取 3个不重复的高倍视野,计算视野中的标记物阳性的细胞百分率,每个独立实验重复 5 次。数据以均数 ± 标准差(ˉx±s)表示,应用 SPSS 20.0 软件进行统计学处理。
人诱导多能干细胞(hiPSCs)的形态及各标记物的表达情况如
图 1 人诱导多能干细胞(hiPSCs)培养及其标记物的表达
Fig. 1 Culture of human induced pluripotent stem cells (hiPSCs) and expression of the representative markers
A. Cell morphology under inverted phase contrast microscope. B. hiPSCs expressing Nanog (green). C. hiPSCs expressing Oct4 (green). D. A bar chart showing the percentage of cells expressing Nanog or Oct4 in hiPSCs, respectively. Scale bars in A-C = 50 μm.
人诱导多能干细胞(hiPSCs)在体外诱导14 d后,分化为神经上皮细胞,继而分化为dI4区的人抑制性神经前体细胞(hNPCs)。应用细胞免疫荧光化学染色鉴定神经祖细胞标记物Pax6、Sox1、Nestin、PTF1A的表达,其中PTF1A是脊髓背侧祖细胞的标记物。结果显示,Sox1(
图2 hiPSCs 源性 hNPCs细胞形态及其标记物的表达
Fig. 2 Cell morphology and expression of markers of hiPSCs derived hNPCs
The representative figures of the immunostaining positive cells for Sox1 (A), Pax6 (B), Nestin (C), and PTF1A (D). E: cell morphology of hNPCs under phase contrast microscope. F: MAP2 expression of hNPCs. G-H: GFAP and Oct4 were not detected in hNPCs. I: A bar chart showing the percentage of immnuopositive cells with different markers. Scale bars in A-H = 50 μm.
hiPSC源性hNPCs体外向抑制性神经元诱导分化14d后,利用细胞免疫荧光化学染色检测hiPSC源性神经元γ-氨基丁酸(GABA)、胆碱乙酰基转移酶(ChAT)、及谷氨酸转运蛋白2(vGLUT2)的表达情况。染色结果表明,hiPSC源性神经元多表达GABA(
图3 人诱导多能干细胞源性神经元表达的神经递质类型
Fig. 3 Types of neurotransmitters expressed by hiPSC-derived neurons
A-C: The co-labeling immunostaining of GABA (green) and MAP2 (red) showed that most hiPSC-derived MAP2+ neurons were GABAergic (GABA) neurons. D-F: The co-labeling immunostaining of vGLUT2 (red) and MAP2 (green) showed that only a small portion of hiPSC-derived MAP2+ neurons were vGLUT2+ glutamatergic neurons. G-I: hiPSC derived MAP2+ neurons were not ChAT+ cholinergic neurons. Scale bars in A-I = 50 μm.
为验证在体外所构建的hiPSC源性抑制性神经网络组织中的神经元之间是否存在信息传递,具有形成突触的潜能。三维材料(
图 4 hiPSC源性抑制性神经网络组织类突触形成检测
Fig. 4 hiPSC derived inhibitory neural network tissue synaptic formation detection
A: The expression of presynaptic marker 1 (Syn1, red) and MAP2 (green, neuronal marker) after the hiPSC-derived neural network tissue was constructed in vitro for 14 days. B: A high magnification of the boxed area in Fig 4A showed the co-labeling staining with Syn1 (red) and MAP2 (green). C: hiPSC-derived neurons were cultured under two-dimensional conditions as control. After 14 days of induction, the expression of Syn1 (red) was co-localized with MAP2 (green). D: iPSC-derived inhibitory neural network tissue was semi-thin sectioned and stained with toluidine blue. E: Transmission electron microscopy showed that the synaptic structures (green arrows) such as axons and synaptic vesicles (red arrows) between cells. F: A higher magnification of the boxed area in Fig 4E showed synaptic vesicles (red arrows) and synaptic structures (green arrows) between neurons. Scale bars in A, D = 50 μm, B = 10 μm, C = 20 μm, E = 0.5 μm and F = 200 nm
hiPSC源性hNPCs在体外向抑制性神经元诱导培养28 d后,hiPSC源性神经元可诱导出钠电流(
图5 hiPSC源性hNPCs分化为抑制性神经元的电生理特征
Fig. 5 Electrophysiological features of hiPSC-derived hNPCs differentiating into inhibitory neurons
A: Sodium currents could be recorded in hiPSC derived neurons. B: Action potentials were recorded in whole cell mode at 28 days after hiPSC derived hNPCs were induced in the bio-tissue. C: mIPSCs were recorded at 28 days in the bio-tissue. D: PTX (GABA receptor antagonist) completely blocked mIPSC.
γ-氨基丁酸能神经元(GABAergic neuron)是以GABA为递质的神经元。GABA能神经传递的失调与多种神经退行性疾病和病理生理障碍有关。例如,慢性神经性疼痛的病理生理学与癫痫类似,是由于GABA能神经元的功能丧失,导致抑制性 GABA信号传导功能失调[
生物支架材料在组织工程学研究中发挥着重要的作用,合适的生物支架材料可以为组织工程的移植细胞提供一个三维的生长、营养空间,同时对损伤部位空洞进行填充和替代,进而引导轴突再生与神经环路的重建。本课题组前期实验研究集中在体外利用三维明胶海绵支架材料及大鼠或比格犬的BMSCs/NSCs构建外源性神经网络组织且获得自主知识产权[
本课题组自主研发的脱细胞的猪视神经作为支架材料,它不仅去除了抑制神经纤维生长的髓鞘成分和硫酸软骨素成分,而且还保留了有利于细胞和神经纤维生长的细胞外基质、多孔隙形态特征和适宜的机械性能[
Takahashi K, Yamanaka S. Induction of pluripotent stem cells from mouse embryonic and adult fibroblast cultures by defined factors[J]. Cell, 2006, 126(4): 663-676. [百度学术]
Petit I, Kesner NS, Karry R, et al. Induced pluripotent stem cells from hair follicles as a cellular model for neurodevelopmental disorders[J]. Stem Cell Res, 2012, 8(1): 134-140. [百度学术]
Yamanaka S. Pluripotent stem cell-based cell therapy- promise and challenges[J]. Cell Stem Cell, 2020, 27(4): 523-531. [百度学术]
Zeng X, Qiu XC, Ma YH, et al. Integration of donor mesenchymal stem cell-derived neuron-like cells into host neural network after rat spinal cord transection[J]. Biomaterials, 2015, 53: 184-201. [百度学术]
Sun J-H, Li G, Wu T-T, et al. Decellularization optimizes the inhibitory microenvironment of the optic nerve to support neurite growth[J]. Biomaterials, 2020, 258: 120289. [百度学术]
Zhu H, Sun T, Wang Y, et al. Directed differentiation of porcine induced pluripotent stem cells into forebrain GABAergic neuron progenitors[J]. J South Med Univ, 2021, 41(6): 820-827. [百度学术]
Gong C, Zheng X, Guo F, et al. Human spinal GABA neurons alleviate spasticity and improve locomotion in rats with spinal cord injury[J]. Cell Rep, 2021, 34(12): 108889. [百度学术]
Treiman DM. GABAergic mechanisms in epilepsy[J]. Epilepsia, 2001, 42 Suppl 3: 8-12. [百度学术]
Basbaum AI, Braz JM. Cell transplants to treat the "disease" of neuropathic pain and itch[J]. Pain, 2016, 157(2): S42-S47. [百度学术]
Hwang I, Hahm SC, Choi KA, et al. Intrathecal transplantation of embryonic stem cell-derived spinal GABAergic neural precursor cells attenuates neuropathic pain in a spinal cord injury rat model[J]. Cell Transplant, 2016, 25(3): 593-607. [百度学术]
Braz JM, Juarez-Salinas D, Ross SE, et al. Transplant restoration of spinal cord inhibitory controls ameliorates neuropathic itch[J]. J Clin Invest, 2014, 124(8): 3612-3616. [百度学术]
Jacobson LH, Vlachou S, Slattery DA, et al. The Gamma-Aminobutyric Acid B Receptor in Depression and Reward[J]. Biol Psychiatry, 2018, 83(11): 963-976. [百度学术]
陈舒婷, 任力, 闵苏. 氨基丁酸能神经元在丙泊酚缓解抑郁模型大鼠电休克后脑损伤中的作用[J]. 中国神经精神疾病杂志, 2020, 46(3): 159-165. [百度学术]
Chen ST, Ren L, Min S. The role of GABAergic neurons in propofol-mediated alleviation of electroconvulsive shock-induced learning and memory impairment in rats with depression after electroshock[J]. Chin J Nerv Ment Dis, 2020, 46(3): 159-165. [百度学术]
Sun ZQ, Sun L, Tu LX. GABA(B) receptor-mediated PI3K/Akt signaling pathway alleviates oxidative stress and neuronal cell injury in a rat model of Alzheimer's disease[J]. J Alzheimers Dis, 2020, 76(4): 1513-1526. [百度学术]
钟斯然, 邝琦,覃宁, 等. ATRNL1在阿尔茨海默病中的基因功能分析及ceRNA网络预测[J]. 重庆医科大学学报, 2022, 47(7): 871-876. [百度学术]
Zhong SR,Kuang Q,Qin N,et al. Gene function analysis of ATRNL1 and ceRNA network construction in Alzheimer’s disease[J]. J Chongqing Med Univ, 2022, 47(7): 871-876. [百度学术]
Tyagi RK, Bisht R, Pant J, et al. Possible role of GABA-B receptor modulation in MPTP induced Parkinson's disease in rats[J]. Exp Toxicol Pathol, 2015, 67(2): 211-217. [百度学术]
Maccioni P, Colombo G. Potential of GABA(B) receptor positive allosteric modulators in the treatment of alcohol use disorder[J]. CNS Drugs, 2019, 33(2): 107-123. [百度学术]
Kalinichev M, Girard F, Haddouk H, et al. The drug candidate, ADX71441, is a novel, potent and selective positive allosteric modulator of the GABA(B) receptor with a potential for treatment of anxiety, pain and spasticity[J]. Neuropharmacology, 2017, 114: 34-47. [百度学术]
Glausier JR, Lewis DA. GABA and schizophrenia: Where we stand and where we need to go[J]. Schizophr Res, 2017, 181: 2-3. [百度学术]
Lehmann A, Jensen JM, Boeckxstaens GE. GABA(B) receptor agonism as a novel therapeutic modality in the treatment of gastroesophageal reflux disease[M]//Blackburn TP. GABAb Receptor Pharmacology: A Tribute to Norman Bowery. Elsevier Academic Press Inc, 525 B Street, Suite 1900, San Diego, Ca 92101-4495 USA. 2010: 287-313. [百度学术]
Li G, Zhang B, Sun JH, et al. An NT-3-releasing bioscaffold supports the formation of TrkC-modified neural stem cell-derived neural network tissue with efficacy in repairing spinal cord injury[J]. Bioact Mater, 2021, 6(11): 3766-3781. [百度学术]
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