Stem cells for treatment of cerebral ischemia

Three articles regarding the effects of gene-modified stem cell transplantation and the reinfocing effects of dl-3-butylphthalide on hematopoietic stem cell transplantation and endogenous stem cell mobilization in the treatment of cerebral ischemia were published in Neural Regeneration Research. We hope that our readers find these papers useful to their research.     

Neuronal differentiation of adipose-derived stem cells and their transplantation for cerebral ischemia

OBJECTIVE:To review published data on the biological characteristics,differentiation and applications of adipose-derived stem cells in ischemic diseases.DATA RETRIEVAL:A computer-based online search of reports published from January 2005 to June 2012 related to the development of adipose-derived stem cells and their transplantation for treatment of cerebral ischemia was performed in Web of Science using the key words "adipose-derived stem cells","neural-like cells","transplantation","stroke",and "cerebral ischemia".SELECTION CRITERIA:The documents associated with the development of adipose-derived stem cells and their transplantation for treatment of cerebral ischemia were selected,and those published in the last 3-5 years or in authoritative journals were preferred in the same field.Totally 89 articles were obtained in the initial retrieval,of which 53 were chosen based on the inclusion criteria.MAIN OUTCOME MEASURES:Biological characteristics and induced differentiation of adipose-derived stem cells and cell transplantation for disease treatment as well as the underlying mechanism of clinical application.RESULTS:The advantages of adipose-derived stem cells include their ease of procurement,wide availability,rapid expansion,low tumorigenesis,low immunogenicity,and absence of ethical constraints.Preclinical experiments have demonstrated that transplanted adipose-derived stem cells can improve neurological functions,reduce small regions of cerebral infarction,promote angiogenesis,and express neuron-specific markers.The improvement of neurological functions was demonstrated in experiments using different methods and time courses of adipose-derived stem cell transplantation,but the mechanisms remain unclear.CONCLUSION:Further research into the treatment of ischemic disease by adipose-derived stem cell transplantation is needed to determine their mechanism of action.     

Human neural stem cells promote proliferation of endogenous neural stem cells and enhance angiogenesis in ischemic rat brain

Transplantation of human neural stem cells into the dentate gyrus or ventricle of rodents has been reportedly to enhance neurogenesis. In this study, we examined endogenous stem cell proliferation and angiogenesis in the ischemic rat brain after the transplantation of human neural stem cells. Focal cerebral ischemia in the rat brain was induced by middle cerebral artery occlusion. Human neural stem cells were transplanted into the subventricular zone. The behavioral performance of human neural stem cells-treated ischemic rats was significantly improved and cerebral infarct volumes were reduced compared to those in untreated animals. Numerous transplanted human neural stem cells were alive and preferentially localized to the ipsilateral ischemic hemisphere. Furthermore, 5-bromo-2′-deoxyuridine-labeled endogenous neural stem cells were observed in the subventricular zone and hippocampus, where they differentiated into cells immunoreactive for the neural markers doublecortin, neuronal nuclear antigen Neu N, and astrocyte marker glial fibrillary acidic protein in human neural stem cells-treated rats, but not in the untreated ischemic animals. The number of 5-bromo-2′-deoxyuridine-positive ? anti-von Willebrand factor-positive proliferating endothelial cells was higher in the ischemic boundary zone of human neural stem cells-treated rats than in controls. Finally, transplantation of human neural stem cells in the brains of rats with focal cerebral ischemia promoted the proliferation of endogenous neural stem cells and their differentiation into mature neural-like cells, and enhanced angiogenesis. This study provides valuable insights into the effect of human neural stem cell transplantation on focal cerebral ischemia, which can be applied to the development of an effective therapy for stroke.     

Ipsilateral versus bilateral limb-training in promoting the proliferation and differentiation of endogenous neural stem cells following cerebral infarction in rats

We investigated the effects of ipsilateral versus bilateral limb-training on promotion of endogenous neural stem cells in the peripheral infarct zone and the corresponding cerebral region in the unaffected hemisphere of rats with cerebral infarction. Middle cerebral artery occlusion was induced in Wistar rats. The rat forelimb on the unaffected side was either wrapped up with tape to force the use of the paretic forelimb in rats or not braked to allow bilateral forelimbs to participate in training. Daily training consisted of mesh drum training, balance beam training, and stick rolling training for a total of 40 minutes, once per day. Control rats received no training. At 14 days after functional training, rats receiving bilateral limb-training exhibited milder neurological impairment than that in the ipsilateral limb-training group or the control group. The number of nestin/glial fibrillary acidic protein-positive and nestin/microtubule-associated protein 2-positive cells in the peripheral infarct zone and in the corresponding cerebral region in the unaffected hemisphere was significantly higher in rats receiving bilateral limb-training than in rats receiving ipsilateral limb-training. These data suggest that bilateral limb-training can promote the proliferation and differentiation of endogenous neural stem cells in the bilateral hemispheres after cerebral infarction and accelerate the recovery of neurologic function. In addition, bilateral limb-training produces better therapeutic effects than ipsilateral limb-training.     

Effects of leukemia inhibitory factor and basic fibroblast growth factor on free radicals and endogenous stem cell proliferation in a mouse model of cerebral infarction

The present study established a mouse model of cerebral infarction by middle cerebral artery occlusion,and monitored the effect of 25 μg/kg leukemia inhibitory factor and(or) basic fibroblast growth factor administration 2 hours after model establishment.Results showed that following administration,the number of endogenous neural stem cells in the infarct area significantly increased,malondialdehyde content in brain tissue homogenates significantly decreased,nitric oxide content,glutathione peroxidase and superoxide dismutase activity significantly elevated,and mouse motor function significantly improved as confirmed by the rotarod and bar grab tests.In particular,the effect of leukemia inhibitory factor in combination with basic fibroblast growth factor was the most significant.Results indicate that leukemia inhibitory factor and basic fibroblast growth factor can improve the microenvironment after cerebral infarction by altering free radical levels,improving the quantity of endogenous neural stem cells,and promoting neurological function of mice with cerebral infarction.     

Effects of leukemia inhibitory factor on endogenous neural stem cell proliferation and glycoprotein-130 expression in a mouse model of cerebral infarction

Leukemia inhibitory factor (LIF) has been shown to promote proliferation of endogenous neural stem cells. In this study, we treated mice with cerebral infarction using LIF to investigate whether the LIF receptor subunit glycoprotein (gp)130 is involved in neuroprotection. After LIF treatment, the motor function of model mice was significantly improved. Immunofluorescence histochemistry showed increased numbers of endogenous neural stem cells surrounding the infarct foci. Western blot analysis revealed that gp130 expression was significantly decreased surrounding the infarcted foci. Results demonstrated that LIF promoted the proliferation of endogenous neural stem cells by inhibiting gp130 protein expression.     

Application of magnetic resonance imaging for monitoring stem cell transplantation for the treatment of cerebral ischemia

OBJECTIVE:To identify global research trends in the application of MRI for monitoring stem cell transplantation using a bibliometric analysis of Web of Science.DATA RETRIEVAL:We performed a bibliometric analysis of studies relating to the application of MRI for detecting stem cell transplantation for the treatment of cerebral ischemia using papers in Web of Science published from 2002 to 2011.SELECTION CRITERIA:The inclusion criteria were:(a) peer-reviewed articles on the application of MRI for detecting transplanted stem cells published and indexed in Web of Science;(b) year of publication between 2002 and 2011.Exclusion criteria were:(a) articles that required manual searching or telephone access;(b) some corrected papers.MAIN OUTCOME MEASURES:(1) Annual publication output;(2) distribution according to journals;(3) distribution according to institution;(4) distribution according to country;(5) top cited authors over the last 10 years.RESULTS:A total of 1 498 studies related to the application of MRI for monitoring stem cell transplantation appeared in Web of Science from 2002 to 2011,almost half of which were derived from American authors and institutes.The number of studies on the application of MRI for detecting stem cell transplantation has gradually increased over the past 10 years.Most papers on this topic appeared in Magnetic Resonance in Medicine.CONCLUSION:This analysis suggests that few experimental studies have been investigated the use of MRI for tracking SPIO-labeled human umbilical cord blood-derived mesenchymal stem cells during the treatment of cerebral ischemia.     

Human umbilical cord Wharton’s jelly-derived oligodendrocyte precursor-like cells for axon and myelin sheath regeneration

Human umbilical mesenchymal stem cells from Wharton’s jelly of the umbilical cord were induced to differentiate into oligodendrocyte precursor-like cells in vitro. Oligodendrocyte precursor cells were transplanted into contused rat spinal cords. Immunofluorescence double staining indicated that transplanted cells survived in injured spinal cord, and differentiated into mature and immature oligodendrocyte precursor cells. Biotinylated dextran amine tracing results showed that cell transplantation promoted a higher density of the corticospinal tract in the central and caudal parts of the injured spinal cord. Luxol fast blue and toluidine blue staining showed that the volume of residual myelin was significantly increased at 1 and 2 mm rostral and caudal to the lesion epicenter after cell transplantation. Furthermore, immunofluorescence staining verified that the newly regenerated myelin sheath was derived from the central nervous system. Basso, Beattie and Bresnahan testing showed an evident behavioral recovery. These results suggest that human umbilical mesenchymal stem cell-derived oligodendrocyte precursor cells promote the regeneration of spinal axons and myelin sheaths.     

Stem cell transplantation for treating spinal cord injury A literature comparison between studies of stem cells obtained from various sources

OBJECTIVE:To identify global research trends of stem cell transplantation for treating spinal cord injury using a bibliometric analysis of the Web of Science.DATA RETRIEVAL:We performed a bibliometric analysis of data retrievals for stem cell transplantation for treating spinal cord injury from 2002 to 2011 using the Web of Science.SELECTION CRITERIA:Inclusion criteria:(a) peer-reviewed articles on stem cell transplantation for treating spinal cord injury that were published and indexed in the Web of Science;(b) type of articles:original research articles,reviews,meeting abstracts,proceedings papers,book chapters,editorial material,and news items;and(c) year of publication:2002-2011.Exclusion criteria:(a) articles that required manual searching or telephone access;(b) documents that were not published in the public domain;and(c) a number of corrected papers from the total number of articles.MAIN OUTCOME MEASURES:(1) Annual publication output;(2) distribution according to country;(3) distribution according to institution;(4) distribution according to journals;(5) distribution according to funding agencies;and(6) top cited articles over the last 10 years.RESULTS:Bone marrow mesenchymal stem cells and embryonic stem cells have been widely used for treating spinal cord injury.In total,191 studies of bone marrow mesenchymal stem cell transplantation and 236 studies of embryonic stem cell transplantation for treating spinal cord injury appeared in the Web of Science from 2002 to 2011,and almost half of which were derived from American or Japanese authors and institutes.The number of studies of stem cell transplantation for treating spinal cord injury has gradually increased over the past 10 years.Most papers on stem cell transplantation for treating spinal cord injury appeared in journals with a particular focus on stem cell research,such as Stem Cells and Cell Transplantation.Although umbilical cord blood stem cells and adipose-derived stem cells have been studied for treating spinal cord injury,the number of published papers was much smaller,with only 21 and 17 records,respectively,in the Web of Science.CONCLUSION:Based on our analysis of the literature and research trends,we found that stem cells transplantation obtained from various sources have been studied for treating spinal cord injury;however,it is difficult for researchers to reach a consensus on this theme.     

Adult stem cell therapy in stroke

PURPOSE OF REVIEW: Acute cerebral infarction causes irreversible locally restricted loss of the neuronal circuitry and supporting glial cells with consecutive functional deficits and disabilities. The currently available and effective therapy targets fast vessel recanalization accompanied by symptomatic measures. Research activities focusing on stem cells, which represent a promising source for organotypic cell replacement and functional recovery after stroke, have gained momentum in recent years, making regenerative cell-based therapies a much more feasible realistic approach. This review provides an update about preclinical and clinical cell-based studies in stroke focusing on stem cells derived from the adult central nervous and hematopoetic systems. RECENT FINDINGS: Endogenous neural stem cells, which have been shown to reside throughout life in the central nervous system, have the capacity to replace lost neurons in models for numerous disorders, including cerebral ischemia. Considering adult neural stem cell transplantation as a regenerative strategy after stroke, progress has been made in isolating human adult neural stem cells and demonstrating the feasibility of autologous neural stem cell transplantation. An increasing number of studies provide evidence that hematopoietic stem cells, either after stimulation of endogenous stem cell pools or after exogenous hematopoietic stem cell application (transplantation), improve functional outcome after ischemic brain lesions. Various underlying mechanisms such as transdifferentiation into neural lineages, neuroprotection through trophic support, and cell fusion have been deciphered. SUMMARY: Many preclinical studies employing adult stem cell-based strategies hold great promise. For endogenous approaches the correlate of cell replacement underlying functional improvement needs to be demonstrated. Transplantation approaches on the experimental level need further development before clinical application can be considered.     

Human embryonic neural stem cell transplantation increases subventricular zone cell proliferation and promotes peri‐infarct angiogenesis after focal cerebral ischemia

Neurogenesis and angiogenesis are two important processes that may contribute to the repair of brain injury after stroke. This study was designed to investigate whether transplantation of human embryonic neural stem cells (NSCs) into cortical peri‐infarction 24 h after ischemia effects cell proliferation in the subventricular zone (SVZ) and angiogenesis in the peri‐infarct zone. NSCs were prepared from embryonic human brains at 8 weeks gestation. Focal cerebral ischemia was induced by permanent occlusion of the middle cerebral artery of adult rats. Animals were randomly divided into two groups (n = 30, each) at 24 h after ischemia: NSC‐grafted and medium‐grafted groups. Toluidine blue staining and 5′‐bromo‐2′‐deoxyuridine (BrdU) or von Willebrand factor (vWF) immunohistochemistry were performed at 7, 14 and 28 days after transplantation. NSC transplantation increased the number of BrdU‐positive cells in the ischemic ipsilateral SVZ compared with the medium control at 7 days (P < 0.01). This difference in SVZ cell proliferation persisted at 14 days (P < 0.01), but was not significant at 28 days (P > 0.05). In addition, angiogenesis, as indicated by BrdU and vWF staining in cortical peri‐infarct regions, was augmented by 46% and 65% in NSC‐grafted rats versus medium‐grafted rats at 7 and 14 days, respectively (P < 0.05). However, this increase became non‐significant at 28 days (P > 0.05). Our results indicate that NSC transplantation enhances endogenous cell proliferation in the SVZ and promotes angiogenesis in the peri‐infarct zone, even if it is performed in the acute phase of ischemic injury.     

腰椎穿刺移植自体骨髓间充质干细胞治疗脑梗死后遗症6例

背景：骨髓间充质干细胞具有多向分化潜能,而且取材方便,扩增迅速,免疫原性低,在移植过程避免了免疫排斥等反应,是治疗脑梗死等神经系统疾病的理想种子细胞。 目的：探讨自体骨髓间充质干细胞培养后经腰穿治疗脑梗死后遗症的安全性、可行性及疗效。 方法：6例脑梗死后遗症患者进行自体骨髓间充质干细胞移植,骨穿采集自体骨髓单个核细胞,体外分离培养骨髓间充质干细胞4 d后经腰椎穿刺移植蛛网膜下腔,移植后观察疗效及并发症。 结果与结论：培养后骨髓间充质干细胞数量明显增多,患者手术前后肌力和NIHSS评分通过统计分析有显著性差异(P < 0.05),总体症状改善较术前有明显改善;移植后无严重不良事件发生。结果提示,自体骨髓间充质干细胞培养后移植治疗可使脑梗死后遗症患者症状明显改善,治疗安全有效且不良反应小。     

Transplanted human embryonic neural stem cells survive,migrate, differentiate and increase endogenous nestin expression in adult rat cortical peri‐infarction zone

Transplantation of stem cells is a potential therapeutic strategy for stroke damage. The survival, migration, and differentiation of transplanted human embryonic neural stem cells in the acute post‐ischemic environment were characterized and endogenous nestin expression after transplantation was investigated. Human embryonic neural stem cells obtained from the temporal lobe cortex were cultured and labeled with fluorescent 1,1′‐dioctadecy‐6,6′‐di (4‐sulfopheyl)‐3,3,3′,3′‐tetramethylindocarbocyanin (DiI) in vitro. Labeled cells were transplanted into cortical peri‐infarction zones of adult rats 24 h after permanent middle cerebral artery occlusion. Survival, migration, and differentiation of grafted cells were quantified in immunofluorescence‐stained sections from rats sacrificed at 7, 14, and 28 days after transplantation. Endogenous nestin‐positive cells in the cortical peri‐infarction zone were counted at serial time points. The cells transplanted into the cortical peri‐infarction zone displayed the morphology of living cells and became widely located around the ischemic area. Moreover, some of the transplanted cells expressed nestin, GFAP, or NeuN in the peri‐infarction zone. Furthermore, compared with the control group, endogenous nestin‐positive cells in the peri‐infarction zone had increased significantly 7 days after cell transplantation. These results confirm the survival, migration, and differentiation of transplanted cells in the acute post‐ischemic environment and enhanced endogenous nestin expression within a brief time window. These findings indicate that transplantation of neural stem cells into the peri‐infarction zone may be performed as early as 24 h after ischemia.     

Human bone marrow mesenchymal stem cell transplantation attenuates axonal injury in stroke rats

Previous studies have shown that transplantation of human bone marrow mesenchymal stem cells promotes neural functional recovery after stroke, but the neurorestorative mechanisms remain largely unknown. We hypothesized that functional recovery of myelinated axons may be one of underlying mechanisms. In this study, an ischemia/reperfusion rat model was established using the middle cerebral artery occlusion method. Rats were used to test the hypothesis that intravenous transplantation of human bone marrow mesenchyrnal stem cells through the femoral vein could exert neuroprotective effects against cerebral ischemia via a mechanism associated with the ability to attenuate axonal injury. The results of behavioral tests, infarction volume analysis and immunohistochemistry showed that cerebral ischemia caused severe damage to the myelin sheath and axons. After rats were intravenously transplanted with human bone marrow mesenchymal stem cells, the levels of axon and myelin sheath-related proteins, including microtubule-associated protein 2, myelin basic protein, and growth-associated protein 43, were elevated, infarct volume was decreased and neural function was improved in cerebral ischemic rats. These findings suggest that intravenously transplanted human bone marrow mesenchymal stem cells promote neural function. Possible mechanisms underlying these beneficial effects include resistance to demyelination after cerebral ischemia, prevention of axonal degeneration, and promotion of axonal regeneration.     

恩必普软胶囊治疗急性脑梗死疗效观察

目的评价恩必普软胶囊治疗急性脑梗死的疗效。方法入选106例病人,随机分为治疗组60例和对照组46例,2组病人治疗前的一般情况、神经功能缺损积分具有可比性。对照组给予脉络宁注射液20ml静滴,1次/d,疗程2周;治疗组在对照组基础上给予恩必普软胶囊0.2g,3次/d,口服,疗程2周。治疗结束时统计神经功能缺损积分。结果治疗组用药后神经功能缺损积分较用药前显著减少(P<0.05),差异有统计学意义。结论恩必普软胶囊治疗急性脑梗死疗效满意,有应用价值。