Micro RNA-9 promotes the neuronal differentiation of rat bone marrow mesenchymal stem cells by activating autophagy

Micro RNA-9(mi R-9) has been shown to promote the differentiation of bone marrow mesenchymal stem cells into neuronal cells, but the precise mechanism is unclear. Our previous study confirmed that increased autophagic activity improved the efficiency of neuronal differentiation in bone marrow mesenchymal stem cells. Accumulating evidence reveals that mi RNAs adjust the autophagic pathways. This study used mi R-9-1 lentiviral vector and mi R-9-1 inhibitor to modulate the expression level of mi R-9. Autophagic activity and neuronal differentiation were measured by the number of light chain-3(LC3)-positive dots, the ratio of LC3-II/LC3, and the expression levels of the neuronal markers enolase and microtubule-associated protein 2. Results showed that LC3-positive dots, the ratio of LC3-II/LC3, and expression of neuron specific enolase and microtubule-associated protein 2 increased in the mi R-9+ group. The above results suggest that autophagic activity increased and bone marrow mesenchymal stem cells were prone to differentiate into neuronal cells when mi R-9 was overexpressed, demonstrating that mi R-9 can promote neuronal differentiation by increasing autophagic activity.     

Chitosan-collagen porous scaffold and bone marrow mesenchymal stem cell transplantation for ischemic stroke

In this study, we successfully constructed a composite of bone marrow mesenchymal stem cells and a chitosan-collagen scaffold in vitro, transplanted either the composite or bone marrow mesenchymal stem cells alone into the ischemic area in animal models, and compared their effects. At 14 days after co-transplantation of bone marrow mesenchymal stem cells and the hitosan-collagen scaffold, neurological function recovered noticeably. Vascular endothelial growth factor expression and nestin-labeled neural precursor cells were detected in the ischemic area, surrounding tissue, hippocampal dentate gyrus and subventricular zone. Simultaneously, a high level of expression of glial fibrillary acidic protein and a low level of expression of neuron-specific enolase were visible in Brd U-labeled bone marrow mesenchymal stem cells. These findings suggest that transplantation of a composite of bone marrow mesenchymal stem cells and a chitosan-collagen scaffold has a neuroprotective effect following ischemic stroke.     

Human umbilical cord mesenchymal stem cells promote peripheral nerve repair via paracrine mechanisms

Human umbilical cord-derived mesenchymal stem cells(h UCMSCs) represent a promising young-state stem cell source for cell-based therapy. h UCMSC transplantation into the transected sciatic nerve promotes axonal regeneration and functional recovery. To further clarify the paracrine effects of h UCMSCs on nerve regeneration, we performed human cytokine antibody array analysis, which revealed that h UCMSCs express 14 important neurotrophic factors. Enzyme-linked immunosorbent assay and immunohistochemistry showed that brain-derived neurotrophic factor, glial-derived neurotrophic factor, hepatocyte growth factor, neurotrophin-3, basic fibroblast growth factor, type I collagen, fibronectin and laminin were highly expressed. Treatment with h UCMSC-conditioned medium enhanced Schwann cell viability and proliferation, increased nerve growth factor and brain-derived neurotrophic factor expression in Schwann cells, and enhanced neurite growth from dorsal root ganglion explants. These findings suggest that paracrine action may be a key mechanism underlying the effects of h UCMSCs in peripheral nerve repair.     

Differentiation of Wharton's jelly mesenchymal stem cells into neurons in alginate scaffold

Alginate scaffold has been considered as an appropriate biomaterial for promoting the differentiation of embryonic stem cells toward neuronal cell lineage. We hypothesized that alginate scaffold is suitable for culturing Wharton's jelly mesenchymal stem cells(WJMSCs) and can promote the differentiation of WJMSCs into neuron-like cells. In this study, we cultured WJMSCs in a three-dimensional scaffold fabricated by 0.25% alginate and 50 m M Ca Cl2 in the presence of neurogenic medium containing 10 μM retinoic acid and 20 ng/m L basic fibroblast growth factor. These cells were also cultured in conventional two-dimensional culture condition in the presence of neurogenic medium as controls. After 10 days, immunofluorescence staining was performed for detecting β-tubulin(marker for WJMSCs-differentiated neuron) and CD271(motor neuron marker). β-Tubulin and CD271 expression levels were significantly greater in the WJMSCs cultured in the three-dimensional alginate scaffold than in the conventional two-dimensional culture condition. These findings suggest that three-dimensional alginate scaffold cell culture system can induce neuronal differentiation of WJMSCs effectively.     

Propofol promotes spinal cord injury repair by bone marrow mesenchymal stem cell transplantation

Propofol is a neuroprotective anesthetic. Whether propofol can promote spinal cord injury repair by bone marrow mesenchymal stem cells remains poorly understood. We used rats to investigate spinal cord injury repair using bone marrow mesenchymal stem cell transplantation combined with propofol administration via the tail vein. Rat spinal cord injury was clearly alleviated; a large number of newborn non-myelinated and myelinated nerve fibers appeared in the spinal cord, the numbers of CM-Dil-labeled bone marrow mesenchymal stem cells and fluorogold-labeled nerve fibers were increased and hindlimb motor function of spinal cord-injured rats was markedly improved. These improvements were more prominent in rats subjected to bone marrow mesenchymal cell transplantation combined with propofol administration than in rats receiving monotherapy. These results indicate that propofol can enhance the therapeutic effects of bone marrow mesenchymal stem cell transplantation on spinal cord injury in rats.     

Biodegradable chitin conduit tubulation combined with bone marrow mesenchymal stem cell transplantation for treatment of spinal cord injury by reducing glial scar and cavity formation

We examined the restorative effect of modified biodegradable chitin conduits in combination with bone marrow mesenchymal stem cell transplantation after right spinal cord hemisection injury. Immunohistochemical staining revealed that biological conduit sleeve bridging reduced glial scar formation and spinal muscular atrophy after spinal cord hemisection. Bone marrow mesenchymal stem cells survived and proliferated after transplantation in vivo, and differentiated into cells double-positive for S100(Schwann cell marker) and glial fibrillary acidic protein(glial cell marker) at 8 weeks. Retrograde tracing showed that more nerve fibers had grown through the injured spinal cord at 14 weeks after combination therapy than either treatment alone. Our findings indicate that a biological conduit combined with bone marrow mesenchymal stem cell transplantation effectively prevented scar formation and provided a favorable local microenvironment for the proliferation, migration and differentiation of bone marrow mesenchymal stem cells in the spinal cord, thus promoting restoration following spinal cord hemisection injury.     

Repair of peripheral nerve defects with chemically extracted acellular nerve allografts loaded with neurotrophic factors-transfected bone marrow mesenchymal stem cells

Chemically extracted acellular nerve allografts loaded with brain-derived neurotrophic factor-transfected or ciliary neurotrophic factor-transfected bone marrow mesenchymal stem cells have been shown to repair sciatic nerve injury better than chemically extracted acellular nerve allografts alone, or chemically extracted acellular nerve allografts loaded with bone marrow mesenchymal stem cells. We hypothesized that these allografts compounded with both brain-derived neurotrophic factor- and ciliary neurotrophic factor-transfected bone marrow mesenchymal stem cells may demonstrate even better effects in the repair of peripheral nerve injury. We cultured bone marrow mesenchymal stem cells expressing brain-derived neurotrophic factor and/or ciliary neurotrophic factor and used them to treat sciatic nerve injury in rats. We observed an increase in sciatic functional index, triceps wet weight recovery rate, myelin thickness, number of myelinated nerve fibers, amplitude of motor-evoked potentials and nerve conduction velocity, and a shortened latency of motor-evoked potentials when allografts loaded with both neurotrophic factors were used, compared with allografts loaded with just one factor. Thus, the combination of both brain-derived neurotrophic factor and ciliary neurotrophic factor-transfected bone marrow mesenchymal stem cells can greatly improve nerve injury.     

visual bone marrow mesenchymal stem cell transplantation in the repair of spinal cord injury

An important factor in improving functional recovery from spinal cord injury using stem cells is maximizing the number of transplanted cells at the lesion site. Here, we established a contusion model of spinal cord injury by dropping a weight onto the spinal cord at T7–8. Superparamagnetic iron oxide-labeled bone marrow mesenchymal stem cells were transplanted into the injured spinal cord via the subarachnoid space. An outer magnetic field was used to successfully guide the labeled cells to the lesion site. Prussian blue staining showed that more bone marrow mesenchymal stem cells reached the lesion site in these rats than in those without magnetic guidance or superparamagnetic iron oxide labeling, and immunofluorescence revealed a greater number of complete axons at the lesion site. Moreover, the Basso, Beattie and Bresnahan(BBB) locomotor rating scale scores were the highest in rats with superparamagnetic labeling and magnetic guidance. Our data confirm that superparamagnetic iron oxide nanoparticles effectively label bone marrow mesenchymal stem cells and impart sufficient magnetism to respond to the external magnetic field guides. More importantly, superparamagnetic iron oxide-labeled bone marrow mesenchymal stem cells can be dynamically and non-invasively tracked in vivo using magnetic resonance imaging. Superparamagnetic iron oxide labeling of bone marrow mesenchymal stem cells coupled with magnetic guidance offers a promising avenue for the clinical treatment of spinal cord injury.     

Elastic modulus affects the growth and differentiation of neural stem cells

It remains poorly understood if carrier hardness, elastic modulus, and contact area affect neural stem cell growth and differentiation. Tensile tests show that the elastic moduli of Tiansu and SMI silicone membranes are lower than that of an ordinary dish, while the elastic modulus of SMI silicone membrane is lower than that of Tiansu silicone membrane. Neural stem cells from the cerebral cortex of embryonic day 16 Sprague-Dawley rats were seeded onto ordinary dishes as well as Tiansu silicone membrane and SMI silicone membrane. Light microscopy showed that neural stem cells on all three carriers show improved adherence. After 7 days of differentiation, neuron specific enolase, glial fibrillary acidic protein, and myelin basic protein expression was detected by immunofluorescence. Moreover, flow cytometry revealed a higher rate of neural stem cell differentiation into astrocytes on Tiansu and SMI silicone membranes than on the ordinary dish, which was also higher on the SMI than the Tiansu silicone membrane. These findings confirm that all three cell carrier types have good biocompatibility, while SMI and Tiansu silicone membranes exhibit good mechanical homogenization. Thus, elastic modulus affects neural stem cell differentiation into various nerve cells. Within a certain range, a smaller elastic modulus results in a more obvious trend of cell differentiation into astrocytes.     

Propofol injection combined with bone marrow mesenchymal stem cell transplantation better improves electrophysiological function in the hindlimb of rats with spinal cord injury than monotherapy

The repair effects of bone marrow mesenchymal stem cell transplantation on nervous system damage are not satisfactory. Propofol has been shown to protect against spinal cord injury. Therefore, this study sought to explore the therapeutic effects of their combination on spinal cord injury. Rat models of spinal cord injury were established using the weight drop method. Rats were subjected to bone marrow mesenchymal stem cell transplantation via tail vein injection and/or propofol injection via tail vein using an infusion pump. Four weeks after cell transplantation and/or propofol treatment, the cavity within the spinal cord was reduced. The numbers of PKH-26-positive cells and horseradish peroxidase-positive nerve fibers apparently increased in the spinal cord. Latencies of somatosensory evoked potentials and motor evoked potentials in the hindlimb were noticeably shortened, amplitude was increased and hindlimb motor function was obviously improved. Moreover, the combined effects were better than cell transplantation or propofol injection alone. The above data suggest that the combination of propofol injection and bone marrow mesenchymal stem cell transplantation can effectively improve hindlimb electrophysiological function, promote the recovery of motor funtion, and play a neuroprotective role in spinal cord injury in rats.     

Citalopram increases the differentiation efifcacy of bone marrow mesenchymal stem cells into neuronal-like cells

Several studies have demonstrated that selective serotonin reuptake inhibitor antidepressants can promote neuronal cell proliferation and enhance neuroplasticity both in vitro and in vivo. It is hypothesized that citalopram, a selective serotonin reuptake inhibitor, can promote the neuronal differentiation of adult bone marrow mesenchymal stem cells. Citalopram strongly enhanced neuronal characteristics of the cells derived from bone marrow mesenchymal stem cells. The rate of cell death was decreased in citalopram-treated bone marrow mesenchymal stem cells than in control cells in neurobasal medium. In addition, the cumulative population doubling level of the citalopram-treated cells was signiifcantly increased compared to that of control cells. Also BrdU incorporation was elevated in citalopram-treated cells. These ifndings suggest that citalopram can improve the neuronal-like cell differentiation of bone marrow mesenchymal stem cells by increasing cell proliferation and survival while maintaining their neuronal characteristics.     

Bone marrow mesenchymal stem cells transplantation promotes the release of endogenous erythropoietin after ischemic stroke

This study investigated whether bone marrow mesenchymal stem cell(BMSC) transplantation protected ischemic cerebral injury by stimulating endogenous erythropoietin. The model of ischemic stroke was established in rats through transient middle cerebral artery occlusion. Twenty-four hours later, 1 × 106 human BMSCs(h BMSCs) were injected into the tail vein. Fourteen days later, we found that h BMSCs promoted the release of endogenous erythropoietin in the ischemic region of rats. Simultaneously, 3 μg/d soluble erythropoietin receptor(s EPOR) was injected into the lateral ventricle, and on the next 13 consecutive days. s EPOR blocked the release of endogenous erythropoietin. The neurogenesis in the subventricular zone was less in the h BMSCs + s EPOR group than in the h BMSCs + heat-denatured s EPOR group. The adhesive-removal test result and the modified Neurological Severity Scores(m NSS) were lower in the h BMSCs + s EPOR group than in the heat-denatured s EPOR group. The adhesive-removal test result and m NSS were similar between the h BMSCs + heat-denatured s EPOR group and the h BMSCs + s EPOR group. These findings confirm that BMSCs contribute to neurogenesis and improve neurological function by promoting the release of endogenous erythropoietin following ischemic stroke.     

12 hours after cerebral ischemia is the optimal time for bone marrow mesenchymal stem cell transplantation

Cell therapy using stem cell transplantation against cerebral ischemia has been reported. However, it remains controversial regarding the optimal time for cell transplantation and the transplantation route. Rat models of cerebral ischemia were established by occlusion of the middle cerebral artery. At 1, 12 hours, 1, 3, 5 and 7 days after cerebral ischemia, bone marrow mesenchymal stem cells were injected via the tail vein. At 28 days after cerebral ischemia, rat neurological function was evaluated using a 6-point grading scale and the pathological change of ischemic cerebral tissue was observed by hematoxylin-eosin staining. Under the fluorescence microscope, the migration of bone marrow mesenchymal stem cells was examined by PKH labeling. Caspase-3 activity was measured using spectrophotometry. The optimal neurological function recovery, lowest degree of ischemic cerebral damage, greatest number of bone marrow mesenchymal stem cells migrating to peri-ischemic area, and lowest caspase-3 activity in the ischemic cerebral tissue were observed in rats that underwent bone marrow mesenchymal stem cell transplantation at 12 hours after cerebral ischemia. These findings suggest that 12 hours after cerebral ischemia is the optimal time for tail vein injection of bone marrow mesenchymal stem cell transplantation against cerebral ischemia, and the strongest neuroprotective effect of this cell therapy appears at this time.     

成人骨髓间充质干细胞培养条件优化及多向分化的能力

背景：成人骨髓中间充质干细胞数量少,要使其能够更好地应用于组织工程和细胞治疗,就必须建立成熟、简便、有效的分离培养扩增体系。 目的：建立成人骨髓间充质干细胞最佳培养方法,并观察诱导其向成脂肪、成骨及软骨细胞分化结果。 方法：分别采用密度梯度离心法和全骨髓培养法,分离培养成人骨髓间充质干细胞,通过光镜观察细胞形态,绘制生长曲线比较不同培养方法对骨髓间充质干细胞的影响;免疫荧光法鉴定表面抗原CD34、CD44和CD105的表达。不同诱导培养基诱导成人骨髓间充质干细胞,采用油红O、茜素红染色以及阿利新蓝染色检测成脂、成骨和成软骨诱导情况。 结果与结论：全骨髓培获得的骨髓间充质干细胞,其增殖能力和生长特性明显优于密度梯度离心法;细胞表面抗原CD44、CD105强阳性,CD34阴性;经过诱导培养,油红O、茜素红染色以及阿利新蓝染色均为阳性,证明全骨髓培养法获得细胞具有更强的生长增殖能力,并具有向脂肪,骨和软骨等组织多向分化的潜能。     

骨髓间充质干细胞定向分化为心脏瓣膜构成细胞及鉴定

背景：心脏瓣膜的组成成分中不是只有内皮细胞发挥作用,成纤维细胞、平滑肌细胞等均参与心脏瓣膜基质成分构建。 目的：建立可以在体外获得大量内皮细胞、平滑肌细胞、成纤维细胞的简便方法,并对获得细胞进行形态观察及表面标志鉴定。 方法：全髓贴壁法获取大鼠原代骨髓间充质干细胞,体外培养、扩增,第3代细胞在特定条件下分别向内皮细胞、血管平滑肌细胞、成纤维细胞方向诱导分化,每日于倒置显微镜下观察细胞生长情况,并对诱导分化的细胞行免疫细胞化学检测。 结果与结论：骨髓间充质干细胞在特定条件下诱导培养后,诱导后的细胞分别具有内皮细胞、平滑肌细胞和成纤维细胞的特点。提示骨髓间充质干细胞在体外可以定向分化为内皮细胞、平滑肌细胞、成纤维细胞。     

Electroacupuncture in the repair of spinal cord injury:inhibiting the Notch signaling pathway and promoting neural stem cell proliferation

Electroacupuncture for the treatment of spinal cord injury has a good clinical curative effect, but the underlying mechanism is unclear. In our experiments, the spinal cord of adult Sprague-Dawley rats was clamped for 60 seconds. Dazhui(GV14) and Mingmen(GV4) acupoints of rats were subjected to electroacupuncture. Enzyme-linked immunosorbent assay revealed that the expression of serum inflammatory factors was apparently downregulated in rat models of spinal cord injury after electroacupuncture. Hematoxylin-eosin staining and immunohistochemistry results demonstrated that electroacupuncture contributed to the proliferation of neural stem cells in rat injured spinal cord, and suppressed their differentiation into astrocytes. Real-time quantitative PCR and western blot assays showed that electroacupuncture inhibited activation of the Notch signaling pathway induced by spinal cord injury. These findings indicate that electroacupuncture repaired the injured spinal cord by suppressing the Notch signaling pathway and promoting the proliferation of endogenous neural stem cells.     

Neural cell co-culture induced differentiation of bone marrow mesenchymal stem cells into neuronal-like cells★

BACKGROUND: It has been previously demonstrated that the neural cell microenvironment has the ability to induce differentiation of bone marrow mesenchymal stem cells (BMSCs) into the neural cells. OBJECTIVE: To establish a co-culture system of human BMSCs and neural cells, and to observe effects of this co-culture system on differentiation of human BMSCs into neural cells. DESIGN, TIME AND SETTING: A comparative observation experiment, performed at the Center Labora-tory of the Affiliated Hospital of Medical College Qingdao University from October 2006 to December 2007. MATERIALS: Neural cells were obtained from human fetal brain tissue. BMSCs were harvested from fe-male patients that underwent autonomous stem cell transplantation. METHODS: BMSCs in the co-culture group consisted of BMSCs and third passage neural cells. BMSCs in the control group were solely cultured in vitro. MAIN OUTCOME MEASURES: Morphological changes of BMSCs were observed, and expression of the neuronal specific marker, neuron-specific enolase (NSE), was analyzed by immunofluorescence staining after 4–5-day co-culture. RESULTS: The number of neural cells in the co-culture group increased and the cells spread on the culture bottle surface. Radial dendrite formed and connected with each other. NSE-immunoreactive cells were also detected. The positive ratio of NSE-positive cells reached (32.7±11.5)%, with morphological characteristics similar to neuronal cells. Human BMSCs did not express NSE in the control group. CONCLUSION: The microenvironment provided by neurons induced differentiation of BMSCs into neu-ronal-like cells. Key Words: bone marrow mesenchymal stem cells; stem cell transplantation; cell differentiation; neurons     

骨髓间充质干细胞诱导分化及在视网膜疾病中的应用

背景：近年来诸多研究已经报道了骨髓间充质干细胞分化为神经元样细胞并能与原视网膜结构发生融合,且可治疗部分视网膜变性。 目的：分析总结骨髓间充质干细胞的生物学特性及其在视网膜疾病中的研究与应用。 方法：应用计算机检索CNKI和PubMed数据库中1995-01/2010-05关于“骨髓间充质干细胞在视网膜疾病中的研究与应用”的文章,以“骨髓间充质干细胞,视网膜”或“视网膜疾病” 为检索词进行检索。选择文章内容与骨髓间充质干细胞治疗视网膜疾病相关,同一领域文献则选择近期发表或发表在权威杂志文章。初检得到中英文共286篇文献,根据纳入标准选择29篇文章进行综述。 结果与结论：骨髓间充质干细胞有向视网膜样细胞分化的能力,具有分化为视网膜神经细胞以修补受损视网膜的可能性,骨髓间充质干细胞可以分化为视网膜神经细胞,并能够帮助损伤的视网膜重新修复,骨髓间充质干细胞视网膜下移植可用于一些视网膜变性的治疗。然而,目前骨髓间充质干细胞移植后分化为视网膜细胞还不理想,诱导分化的机制还不清楚,故视网膜下移植的途径及移植后的效果还需要进一步的研究。     

电针诱导人骨髓间充质干细胞向成骨细胞分化

背景：目前经报道的成骨诱导方法很多,为骨髓间充质干细胞的成骨诱导提出很多新的思路及方法。但是电针是否能诱导骨髓间充质干细胞向成骨细胞分化尚不清楚。 目的：尝试应用电针治疗仪诱导人骨髓间充质干细胞向成骨细胞分化,评价其作为骨组织工程种子细胞的可行性。 方法：从患者髂后上棘抽取骨髓,分离培养鉴定为骨髓间充质干细胞后,取第3代细胞进行培养。当细胞铺满培养瓶底90%以上时进行胰酶消化,分别以3.0×103/cm2的浓度接种于6孔培养板中。实验随机分为3组：空白对照组：加入2 mL体积分数为10%胎牛血清的L-DMEM/F12培养液;化学诱导组：每孔内加2 mL含10%胎牛血清的L-DMEM培养液,当细胞贴壁生长达到60%~70%汇合时,加入骨诱导剂;电针刺激组：加入2 mL体积分数为10%胎牛血清的L-DMEM/F12培养液,电针刺激,采取连续波输出,基波脉冲频率为50 Hz,基波脉冲宽度0.5 ms,持续作用30 min,共电针刺激28 d。相差倒置显微镜观察细胞形态变化;茜素红染色结果;细胞诱导14,28 d后碱性磷酸酶活性;RT-PCR测定细胞中骨钙素mRNA的表达;Western Blot测定细胞中骨钙素蛋白表达。 结果与结论：①在28 d的诱导过程中,化学诱导组5~7 d细胞汇合成单层,细胞突起互相连接,并可重叠生长而不发生细胞间的接触抑制现象;电针刺激组9 d或10 d发现细胞体积大,呈三角形、多角形或鳞形;空白对照组细胞形态仍然是纺锤状。②化学诱导组和电针刺激组28 d在倒置相差显微镜下均观察到有矿化结节出现,进行茜素红均呈阳性反应,而空白对照组呈阴性反应。③骨髓间充质干细胞在体外进行诱导时化学诱导组和电针刺激组碱性磷酸酶水平在14,28 d高于空白对照组(P < 0.05);且化学诱导组碱性磷酸酶14 d时高于电针刺激组(P < 0.05),但28 d时差异无显著性意义(P > 0.05)。④空白对照组骨钙素mRNA及蛋白含量均低于化学诱导组和电针刺激组(P < 0.05)。提示电针可定向诱导人骨髓间充质干细胞向成骨细胞分化。     

Biological conduits combining bone marrow mesenchymal stem cells and extracellular matrix to treat long-segment sciatic nerve defects

The transplantation of polylactic glycolic acid conduits combining bone marrow mesenchymal stem cells and extracellular matrix gel for the repair of sciatic nerve injury is effective in some respects, but few data comparing the biomechanical factors related to the sciatic nerve are available. In the present study, rabbit models of 10-mm sciatic nerve defects were prepared. The rabbit models were repaired with autologous nerve, a polylactic glycolic acid conduit + bone marrow mesenchymal stem cells, or a polylactic glycolic acid conduit + bone marrow mesenchymal stem cells + extracellular matrix gel. After 24 weeks, mechanical testing was performed to determine the stress relaxation and creep parameters. Following sciatic nerve injury, the magnitudes of the stress decrease and strain increase at 7,200 seconds were largest in the polylactic glycolic acid conduit + bone marrow mesenchymal stem cells + extracellular matrix gel group, followed by the polylactic glycolic acid conduit + bone marrow mesenchymal stem cells group, and then the autologous nerve group. Hematoxylin-eosin staining demonstrated that compared with the polylactic glycolic acid conduit + bone marrow mesenchymal stem cells group and the autologous nerve group, a more complete sciatic nerve regeneration was found, including good myelination, regularly arranged nerve fibers, and a completely degraded and resorbed conduit, in the polylactic glycolic acid conduit + bone marrow mesenchymal stem cells + extracellular matrix gel group. These results indicate that bridging 10-mm sciatic nerve defects with a polylactic glycolic acid conduit + bone marrow mesenchymal stem cells + extracellular matrix gel construct increases the stress relaxation under a constant strain, reducing anastomotic tension. Large elongations under a constant physiological load can limit the anastomotic opening and shift, which is beneficial for the regeneration and functional reconstruction of sciatic nerve. Better regeneration was found with the polylactic glycolic acid conduit + bone marrow mesenchymal stem cells + extracellular matrix gel grafts than with the polylactic glycolic acid conduit + bone marrow mesenchymal stem cells grafts and the autologous nerve grafts.