改良的酶消化后植块法体外培养雪旺细胞

目的 观察改良的酶(浓度为2g/L的胶原酶)消化后植块法体外培养雪旺细胞(SCs)效果,探讨高效获取高纯度、高活性SCs的培养纯化方法.方法 取新生SD大鼠坐骨神经,剥离神经外膜,剪块,分别采用单酶消化后植块法与双酶消化法进行培养.以活细胞计数和S-100单抗标记相结合判断SCs增殖和纯化程度,比较2种方法的优劣.结果 改良的单酶消化后植块法可获取3.5x106个SCs,成活率为96%,纯度达94%以上:双酶消化法约获取3.0×106个SCs,成活率为92%,纯度达90%.结论 采用改良的酶消化后植块法培养SCs,可较快得到数量多、纯度高的SCs,符合实验要求,值得推广应用.

Abstract：

Objective To introduce an efficient method for culturing and purifying Schwann cells (SCs) in vitro. Methods Sciatic nerves were harvested from neonatal SD rats and the epineuria were removed. Single enzyme digestion combined with explans and double enzyme digestion were employed, respectively, to digest the nerve tissues following trituration. The proliferation of SCs and degree of purification were evaluated by viable count method and the combination of S-100 labeled monoclonal antibody and SCs. Results Proximally 3.5 × 106 cells were harvested with 96% survival rate and a purity of Schwann cells over 94% by single enzyme digestion combined with explans, however only 3.0×106 cells were gained with the purity being 90% and survival rate being 92% by double enzyme digestion. Conclusion This method yields large amount of viable Schwann cells with high purity and survival rate.     

HLA class Ⅱ alleles and risk for peripheral neuropathy in type 2 diabetes patients

The potential impact of human leukocyte antigen (HLA) genotype variations on development of diabetic peripheral neuropathy (DPN) is not well determined. hTis study aimed to identify the association of HLA class II alleles with DPN in type 2 diabetes (T2D) patients. Totally 106 T2D patients, 49 with DPN and 57 without DPN, and 100 ethnic-matched healthy controls were analyzed. Both groups of the patients were matched based on sex, age, body mass index (BMI) and duration of T2D. Polyneuropathy was diagnosed using electrodiagnostic methods. HLA-DRB1 and DQB1 genotyping was performed in all subjects by the polymerase chain reaction with sequence-specific primers (PCR-SSP) method. T2D patients with DPN showed higher frequencies of HLA-DRB1*10 and DRB1*12 alleles compared to control group (P = 0.04). HLA-DQB1*02 allele and HLA-DRB1*07-DQB1*02 haplotype were associated with a decreased risk for developing DPN in T2D patients (P = 0.02 andP = 0.05 respectively). Also, patients with severe neurop-athy showed higher frequencies of DRB1*07 (P = 0.003) and DQB1*02 (P = 0.02) alleles than those with mild-to-moderate form of neuropathy. The distribution of DRB1 and DQB1 alleles and haplotypes were not statistically different between all patients and healthy controls. Our ifndings implicate a possible protective role of HLA-DQB1*02 allele and HLA-DRB1*07-DQB1*02 haplotype against development of peripheral neuropathy in T2D patients. Therefore, variations in HLA genotypes might be used as genetic markers for prediction and potentially management of neuropathy in T2D patients.     

靶向纳米铁磁共振造影剂特异性标记阿尔茨海默病鼠脑内老年斑

目的 开发具有高度特异性的靶向磁共振对比剂,验证其特异性显示阿尔茨海默病(AD)脑内老年斑的可能性及有效性.方法 利用热分解法获得水相的磁性纳米四氧化三铁颗粒(MNPs),经过表面官能化学修饰,完成MNPs与β淀粉样蛋白肽段1-40(Aβ40)及蛋白质转导结合域(protein transduction domain,Tat-PTD)的连接后,制备出特异性与老年斑相结合的靶向纳米铁造影剂Aβ40-MNPs-Tat PTD,通过尾静脉注射人20只AD鼠和20只阴性对照C57小鼠(4、6、9、12月龄各5只)体内,不同的时间点采用7.0 T动物磁共振检测获得磁共振图像,观察靶向纳米造影剂对脑实质内老年斑信号的强化效果,继之处死小鼠后灌流取脑做连续冰冻切片,进行铁染色和Thioflavine S染色组织学验证.结果 所获得的靶向纳米颗粒Aβ40-MNPs-Tat PTD能够在体外进入细胞内进而改变细胞磁共振T2信号强度.尾静脉注射入AD鼠体内后能特异性负性强化AD鼠脑内老年斑病变,经组织学验证,能够与老年斑染色及铁染色相对应.结论 特异靶向性的磁性纳米铁造影剂Aβ40-MNPs-Tat PTD能特异性地针对小鼠脑内的老年斑病变进行负性强化和标记.

Abstract：

Objective To develop specific targeted magnetic biomarkers which can selectively mark the senile plaques in Alzheimer' s disease (AD) and verify its feasibility and validity.Methods Aβ1-40 peptide and Tat-PTD ( Tat-protein transduction domain) was binded with dextran-coated ultrasmall superparamagnetic iron oxide ( USPIO) particles.Visualization of plaques in vivo in Alzheimer transgenic mice was investigated at 7.0 Tesla using T2 sequences after intravenous administration of the targeted nanoiron contrast agent and verified by histological staining.Results The targeted nano-iron contrast agent could enter the cultured neural stem cells,and was able to accelerate T2 relaxation rates of water protons in the cells and negatively reinforce the T2 signal intensity in the labeled cells.Plaques were specifically detected in vivo by magnetic resonance imaging ( MRI) and correlated well with histological staining after injection of nano-iron contrast agent into the APP/PS1 mice.Conclusion The targeted nano-iron contrast agent has the ability of selectively labeling the senile plaques in AD brain tissues in vivo,which might enable the early detection of plaques by MRI and can be further applied in the studies of early diagnosis of AD.     

Protective effect of thodioloside and bone marrow mesenchymal stem cells infected with HIF-1-expressing adenovirus on acute spinal cord injury

Rhodioloside has been shown to protect cells from hypoxia injury,and bone marrow mesenchymal stem cells have a good efrect on tissue repair.To study the effects of rhodioloside and bone marrow mesenchymal stem cells on spinal cord injury,a rat model of spinal cord injury was established using the Infinite Horizons method.After establishing the model,the rats were randomly divided into five groups.Rats in the control group were intragastrically injected with phosphate buffered saline(PBS)(5μL).PBS was injected at 6 equidistant points around5 mm from the injury site and at a depth of 5 mm.Rats in the rhodioloside group were intragastrically injected with rhodioloside(5 g/kg)and intramuscularly injected with PBS.Rats in the mesenchymal stem cell(MSC)group were intramuscularly injected with PBS and intramuscularly with MSCs(8×10~6/mL in a 50-μL. cell suspension).Rats in the Ad-HIF-MSC group were intragastrically injected with PBS and intramuscularly injected with HIF-1 adenovirus-infected MSCs.Rats in the rhodioloside+Ad-HIF-MSC group were intramuscularly injected with MSCs infected with the HIF-1 adenovirus and intragastrically injected with rhodioloside.One week after treatment,exercise recovery was evaluated with a modified combined behavioral score scale.Hematoxylin-eosin staining and Pischingert's methylene blue staining were used to detect any histological or pathological changes in spinal cord tissue.Levels of adenovirus IX and Sry mRNA were detected by real-time quantitative polymerase chain reaction and used to determine the number of adenovirus and mesenchymal stem cells that were transfected into the spinal cord.Immunohistochemical staining was applied to detect HIF-1 protein levels in the spinal cord.The results showed that:(1)compared with the other groups,the rhodioloside+Ad-HIF-MSC group exhibited the highest combined behavioral score(P0.05),the most recovered tissue,and the greatest number of neurons,as indicated by Pischingert's methylene blue staining.(2)Compared with the PBS group,HIF-1 protein expression was greater in the rhodioloside group(P0.05).(3)Compared with the Ad-HIF-MSC group,Sry mRNA levels were higher in the rhodioloside+Ad-HIF-MSC group(P0.05).These results confirm that rhodioloside combined with bone marrow mesenchymal stem cells can promote the recovery of spinal cord injury and activate the HIF-1 pathway to promote the survival of bone marrow mesenchymal stem cells and repair damaged neurons within spinal cord tissue.This experiment was approved by the Animal Ethics Committee of Gansu University of Traditional Chinese Medicine,China(approval No.2015KYLL029)in June 2015.     

Electroacupuncture promotes the proliferation of endogenous neural stem cells and oligodendrocytes in the injured spinal cord of adult rats

A contusive model of spinal cord injury at spinal segment T8-9 was established in rats. Huantiao (GB30) and Huatuojiaji (Ex-B05) were punctured with needles, and endogenous neural stem cells were labeled with 5-bromo-2’-deoxyuridine (BrdU) and NG2. Double immunofluorescence staining showed that electroacupuncture markedly increased the numbers of BrdU+/NG2+ cells at spinal cord tissue 15 mm away from the injury center in the rostral and caudal directions. The results suggest that electroacupuncture promotes the proliferation of endogenous neural stem cells and oligodendrocytes in rats with spinal cord injury.     

Brain-derived neurotrophic factor mediates macrophage migration inhibitory factor to protect neurons against oxygen-glucose deprivation

Macrophage migration inhibitory factor(MIF)is a chemokine that plays an essential role in immune system function.Previous studies suggested that MIF protects neurons in ischemic conditions.However,few studies are reported on the role of MIF in neurological recovery after ischemic stroke.The purpose of this study is to identify the molecular mechanism of neuroprotection mediated by MIF.Human neuroblastoma cells were incubated in Dulbecco’s modified Eagle’s medium under oxygen-glucose deprivation(OGD)for 4 hours and then returned to normal aerobic environment for reperfusion(OGD/R).30 ng/mL MIF recombinant(30 ng/mL)or ISO-1(MIF antagonist;50μM)was administered to human neuroblastoma cells.Then cell cultures were assigned to one of four groups:control,OGD/R,OGD/R with MIF,OGD/R with ISO-1.Cell viability was analyzed using WST-1 assay.Expression levels of brain-derived neurotrophic factor(BDNF),microtubule-associated protein 2(MAP2),Caspase-3,Bcl2,and Bax were detected by western blot assay and immunocytochemistry in each group to measure apoptotic activity.WST-1 assay results revealed that compared to the OGD/R group,cell survival rate was significantly higher in the OGD/R with MIF group and lower in the OGD/R with ISO-1 group.Western blot assay and immunocytochemistry results revealed that expression levels of BDNF,Bcl2,and MAP2 were significantly higher,and expression levels of Caspase-3 and Bax were significantly lower in the MIF group than in the OGD/R group.Expression levels of BDNF,Bcl2,and MAP2 were significantly lower,and expression levels of Caspase-3 and Bax were significantly higher in the ISO-1 group than in the OGD/R group.MIF administration promoted neuronal cell survival and induced high expression levels of BDNF,MAP2,and Bcl2(anti-apoptosis)and low expression levels of Caspase-3 and Bax(pro-apoptosis)in an OGD/R model.These results suggest that MIF administration is effective for inducing expression of BDNF and leads to neuroprotection of neuronal cells against hypoxic injury.     

HER-2/neu siRNA对人胶质瘤细胞增殖及相关基因表达的影响

目的 探讨HER-2/neu特异性小干扰核糖核酸(siRNA)对高表达HER-2/neu的人胶质瘤细胞系U251MG和T98G增殖的影响及其可能机制.方法 脂质体介导HER-2/neu siRNA转染体外常规培养的U251MG和T98G细胞,同时设脂质体为对照组.转染后3 d实时定量PCR和免疫印迹实验检测HER-2/neu mRNA和蛋白的表达;四甲基偶氮唑盐(MTT)比色法检测转染后3、4d细胞增殖率的变化;免疫印迹实验检测转染后3 d细胞蛋白激酶B(AKT)、磷酸化AKT、磷酸化叉头转录因子(FOXO1)、p27、Cyclin D1蛋白的表达.结果 与脂质体组比较,HER-2/neu siRNA组U251MG、T98G细胞转染后3 d HER-2/neu mRNA和蛋白的表达均下降,转染后3、4 d细胞增殖率均下降,转染后3 d细胞磷酸化AKT和磷酸化FOXO1水平降低、p27蛋白表达增多、Cyclin D1蛋白表达减少,差异均有统计学意义(P＜0.05).结论 HER-2/neu siRNA转染人胶质瘤细胞系U251MG和T98G后明显抑制细胞增殖,可能与抑制AKT/FOXO1信号通路,调控下游基因p27、Cyclin D1蛋白的表达有关.

Abstract：

Objective To investigate the effect of HER-2/neu siRNA on proliferation of human glioma cell lines U251MG and T98G which over-express HER-2/neu, and explore its mechanism.Methods Liposome-mediated HER-2/neu siRNA was transfected into human glioma cell lines U251MG and T98G;lipofectin group was established as controls. The mRNA and protein levels of HER-2/neu were detected by real-time PCR and Western blotting 3 d after the transfection. The proliferation of glioma cells was investigated using methyl thiazolyl tetrazolium (MTT) assay 3 and 4 d after the transfection. The effects of HER-2/neu siRNA on AKT/FOXO1 pathway and protein expression of p27 and Cyclin D1 were studied using Western blotting. Results HER-2/neu mRNA and protein expressions in the transfected U251MG cells were decreased to (28.833±4.174)% and (22.167±1.955)% while those in cells of the lipofectin group were (92.067±5.698)% and (96.100±1.682)%, respectively,with significant differences (P=0.000, 0.001). HER-2/neu mRNA and protein expressions of the transfected T98G cells were decreased to (28.067 ±6.165)% and (12.433 ±8.864)% while those in the untransfected cells were (96.000 ±5.110)% and (94.333 ±3.215)%, respectively, with significant differences (P=0.001, 0.008). Three d after the transfection, the rates of proliferation in the transfected T98G and U251MG cells were (58.467±5.561)% and (63.933±5.363)%, respectively;4 d after the transfection, the rates of proliferation in the transfected T98G and U251MG cells were (57.500±4.770)% and (60.167±3.253)%, respectively;an obvious decrease was noted as compared them with cells of the lipofectin group (P=0.020, 0.023, 0.021, 0.008). Cyclin Dl expression was decreased, while p27 protein expression was up-regulated in the transfected cells as compared with those in cells of the lipofectin group (P<0.05). Moreover, the levels of phosphorylated AKT and phosphorylated FOXO1 were decreased in the transfected cells as compared with those in cells of the lipofectin group (P<0.05).Conclusion The specific siRNA targeting HER-2/neu in human glioma cell lines U251MG and T98G could inhibit the cell proliferation, which might relate to the suppression of AKT/FOXO1 pathway and the regulation of expresion of thier downstream molecules such as p27 and Cyclin D1.     

Effects of increased human tumor necrosis factor-like molecule 1A expression in peripheral blood of children with acute Guillain-Barre syndrome on interferon-gamma secretion

BACKGROUND： Human tumor necrosis factor-like molecule 1A （hTL1A） is a strong T helper cell type 1 （Thl） co-stimulator. Guillain-Barre syndrome （GBS） is an autoimmune disorder of the nervous system, which is mediated by Thl cells. OBJECTIVE： To determine hTL1A expression in peripheral blood T lymphocytes of acute GBS children and the effects of hTL1A on secretion of interferon-γ. DESIGN, TIME AND SETTING： A randomized, controlled, neuroimmunological in vitro study was performed at the Central Laboratory of First Hospital of Jilin University, China from November 2005 to November 2007. MATERIALS： Venous blood samples were obtained from 6 healthy donors, aged 6-12 years （all routine blood examination items were normal）, and 6 additional children with acute GBS, aged 6-12 years. The GBS children fell ill within 1 week and were not treated with hormones or immunoglobulin Purified recombinant human soluble tumor necrosis factor-like molecule 1A （rhsTL1A, 1 mg/mL, relative molecular mass 22 000, 6× His tag, soluble form） was supplied by the Central Laboratory of First Hospital of Jilin University, China. METHODS： Peripheral blood mononuclear cells were isolated from healthy donors using the standard Ficoll gradient centrifugation and were incubated in 96-well culture plates. The cells were assigned to the following groups： control （2 μg/mL phytohemagglutinin）, 2μg/mL phytohemagglutinin ＋ 25, 100 and 400 ng/mL rhsTL1A. T cell proliferation was quantified using the tritiated thymidine （3H-TdR） method. Serum interferon-γ levels in acute GBS children were detected by enzyme-linked immunosorbent assay （ELISA）. The ratio of hTL1A-positive T cells to CD3-positive T cells in peripheral blood of acute GBS children was determined using flow cytometry. Following in vitro pre-activation of peripheral blood mononuclear cells by 2 μg/mL phytohemagglutinin, the peripheral blood mononuclear cells were treated with 400 ng/mL exogenous rhsTLIA. Finally, peripheral blood mononuclear cell-secreted interferon-γlevels were measured by ELISA. MAIN OUTCOME MEASURES： The following parameters were measured： rhsTLIA stimulation index to stimulate proliferation of T cells; the serum interferon-γ levels in acute GBS children; the ratio of hTL1A-positive cells to CD3-positive cells; the levels of interferon-γ secreted by peripheral blood mononuclear cells in acute GBS children, as well as rhsTL1A-stimulated interferon-γ levels. RESULTS： T cell proliferation assay revealed that the stimulation index in each rhsTL1A group was greater than the control group. The stimulation index of the 400 ng/mL rhsTL1A group was the greatest. Serum interferon-γ levels in acute GBS children were significantly greater than the control group （P 〈 0.05）. The ratio of hTLIA＋ CD3＋ T cells to CD3＋ T cells in acute GBS children was significantly greater than the control group （P 〈 0.01 ）. Phytohemagglutinin stimulated peripheral blood mononuclear cells to a greater extent than 400 ng/mL rhsTL1A in the acute GBS group, and the secreted interferon-γ levels were significantly increased （P 〈 0.05）. CONCLUSION： In T cells pre-activated with 2 μg/mL phytohemagglutinin, proliferation was effectively increased with 400 ng/mL rhsTL1A treatment. Expression of hTLIA was increased in activated T cells from peripheral blood of acute GBS children, followed by increased interferon-γ secretion. These mechanisms are considered to be part of the pathological process that induces the secretion of inflammatory cytokines in GBS syndrome.     

NG2 expression in rats with acute T10 spinal cord injury

Rat models of T10 spinal cord injury were established with a clamp method.NG2 expression was detected with immunohistochemical staining and western blot.Ten days after spinal cord injury,the number of NG2-positive cells in the damaged areas and NG2 absorbance were both significantly increased.The findings indicate that acute T10 spinal cord injury in rats can lead to upregulation of NG2 protein expression in damaged areas.     

肿瘤干细胞致敏的树突状细胞对脑胶质瘤细胞免疫的影响

目的 研究肿瘤干细胞(BTSCs)致敏的树突状细胞(DCs)疫苗对颅内荷瘤小鼠的治疗作用.方法 无血清培养基中加入表皮生长因子和碱性成纤维细胞生长因子,将C6胶质瘤细胞诱导成胶质瘤干细胞,以此致敏大鼠骨髓来源的树突状细胞制备疫苗;立体定向建立大鼠颅内C6胶质瘤模型,分为A、B、C、D四组.每组分别经尾静脉注射1×107BTSCs致敏的DCs(DCs-BTSCs)、1×107 C6胶质瘤细胞致敏的DCs(DCs-C6)、1×107DCs及PBS,Kaplan-Meier法对大鼠生存情况进行分析,大鼠脑组织标本行HE染色及免疫组化分析.结果 胶质瘤干细胞CD133+及nestin染色阳性;DCs具有典型的树突状结构,特异性标志OX62+表达阳性;生存时间A组较其他组明显延长,Log-rank检验差异有统计学意义(P＜0.05);A组HE染色炎性细胞浸润最多,免疫组化可见较多的CD8+T淋巴细胞.结论 肿瘤干细胞致敏的树突状细胞疫苗能明显提高机体对胶质瘤的免疫力,其作用优于胶质瘤细胞致敏的树突状细胞疫苗,为树突状细胞疫苗的临床应用提供了新的依据.

Abstract：

Objective To investigate the effect of dendritic cells pulsed with brain tumor stem cells which are used to treat on intracranial glioma.MethodWe obtained murine brain tumor stem cells by growing C6 cells in epidermal growth factor/basic fibroblast growth factor without serum.Dendritic cells isolated from rat bone marrow were pulsed with BTSCs.Rat brain glioma models were established by stereotactic technique.107 DCs pulsed with BTSCs and C6 were injected through tail vein in group A and group B respectively.The same number of DCs and the same volume PBS were applied to group C and group D.The survival time of rats was analyzed by Log- rank survival analysis.Tumor samples were examinedwithHE staining and immunohistochemistry.Methods BTSCs expressedCD133 + and nestin.DCs appeared typical long dentrite in morphology and expressed OX62+ markers.The survival analysis showed group A was statistically significant in constrast to the other goups (P<0.05).The tumors in group A have the most inflammation and CD8 + T lymphocytes.Concluion DCs loading with BTSCs lysates can provide a higher level of immunity protect against gliomas than those loading with C6 cells,which provide a new method in the immuntherapy of brain glioma.     

不同种类超顺磁性氧化铁标记猪骨髓间充质干细胞的体外MR成像

背景：干细胞磁性标记是新近开展的一项干细胞体外标记技术,结合MR成像设备可以活体监控移植入体内的干细胞。 目的：明确超顺磁性氧化铁粒子体外标记猪骨髓间充质干细胞的方法、不同种类超顺磁性氧化铁标记细胞经MR成像的特征及可成像的最低标记细胞量。 设计、时间及地点：对比观察,于2006-09/ 2007-03在苏州大学医学部心血管外科实验室及苏州大学附属第一医院影像中心完成。 材料：猪髂骨骨髓由太湖梅山猪新鲜采集;超顺磁性氧化铁纳米颗粒为德国Schering公司产品;超微型超顺磁性氧化铁纳米颗粒由苏州大学化学与化工学院提供：铁颗粒晶核表面包被葡聚糖,3种超微型超顺磁性氧化铁包被葡聚糖后根据颗粒大小(12,15,20 nm)分别依次简称为1#,2#,3#。 方法：分离、纯化、培养猪骨髓间充质干细胞,体外进行不同种类超顺磁性氧化铁标记,染色及荧光显微镜观察;测量并绘制未标记细胞和标记细胞的MTT生长曲线;选取不同的细胞量组(Feridex标记细胞分别选取1×106、5×105及1×105 L-1量组,未标记细胞选取5×105 L-1量组,1#、2#及3#超微型超顺磁性氧化铁标记细胞均选取 5×105 L-1量组)进行标记后MR成像,测量不同扫描序列标记细胞管的信号强度改变,并进行统计学分析。 主要观察指标：超顺磁性氧化铁标记干细胞的普鲁士蓝染色检测标记率;标记干细胞的MTT生长曲线;双染色法检测细胞凋亡;不同Ependoff管内细胞团T1WI、T2WI和FFE图像的信号强度。 结果：应用多聚赖氨酸介导干细胞磁标记方法标记骨髓间充质干细胞有效率为100%,普鲁士蓝染色见细胞浆内有多少不等的蓝染铁颗粒;超顺磁性氧化铁标记的间充质干细胞在T2WI尤其是FFE(T2*WI)序列信号明显降低;在25 mg/L Fe培养液标记浓度下,MR成像的最低细胞量为1×105;在不同种类超顺磁性氧化铁标记下,2#、3#USPIO与Feridex在T2WI及T2*WI上有显著性差异 (P < 0.01);而1#USPIO与Feridex在T2WI及T2*WI上差异无显著性意义(P > 0.05);Feridex标记间充质干细胞在T2WI及T2*WI上与T1WI相比,差异均有显著性意义(P < 0.01)。 结论：超顺磁性氧化铁可以简便标记间充质干细胞并且在适当浓度下对间充质干细胞的生物学活性没有影响,MR T2WI和T2*WI序列可敏感显像磁性标记的干细胞。     

MRI of monocyte infiltration in an animal model of neuroinflammation using SPIO-labeled monocytes or free USPIO.

Magnetic resonance imaging (MRI) has been applied to visualize monocyte infiltration with the use of intravenously injected ultrasmall superparamagnetic iron oxide (USPIO). However, USPIO uptake in vivo remains elusive, and the heterogeneous enhancement patterns observed by MRI point to multiple pathophysiological events. This study focused on specific imaging of monocyte infiltration into the brain by transfusion of superparamagnetic iron oxide (SPIO)-labeled monocytes in a rat model of neuroinflammation, experimentally induced photothrombosis (PT). At day 5 after lesion induction, animals were transfused with SPIO-labeled monocytes (5 x 10(6) cells) or free USPIO (17 mg Fe/kg). MRI was performed 24, 72 and, 120 h later. To investigate temporal changes directly after intravenous USPIO administration, MRI was performed repeatedly up to 8 h. Relaxation measurements showed that rat monocytes were efficiently labeled in vitro using SPIO (R2=12+/-0.9 s(-1)). After transfusion of SPIO-labeled monocytes, a significant increase in contrast enhanced area (340%+/-106%) in the PT lesion was observed not before 72 h. Contrast enhancement after USPIO injection increased up to 407%+/-39% at a much earlier point of time (24 h) and diminished thereafter. Repetitive MRI directly after USPIO injection showed significant contrast enhancement in the lesion within 2 h. Our study shows that MRI enables in vivo tracking of SPIO-labeled monocytes longitudinally. Moreover, our data suggest that contrast enhancement after injection of free USPIO does not primarily represent signals from peripherally labeled monocytes that migrated toward the inflammatory lesion. The use of SPIO-labeled monocytes provides a better tool to specifically assess the time window of monocyte infiltration.     

USPIO标记大鼠骨髓源性神经干细胞移植脑皮层影像及形态学初步研究

目的将超小超顺磁性氧化铁（USPIO）Sinerem标记的大鼠骨髓源性神经干细胞移植鼠脑后，初步观察其在大脑中的活性、迁移和整合情况，确定MRI成像示踪Sinerem标记神经干细胞的可行性。方法分离SD大鼠骨髓基质细胞，体外培养诱导成骨髓源性神经干细胞。将Sinerem氧化铁和神经干细胞共孵育培养过夜。采用普鲁士蓝染色和透射电镜确定细胞内铁的摄取、定位情况。将标记细胞立体定向移植微注射到大鼠脑皮层。在不同时间点以SE序列T2WI行4．7T磁共振干细胞成像示踪，然后用组织学方法观察标记细胞在脑内的转归情况。结果Sinerem标记神经干细胞效率为98％～100％，普鲁士蓝染色显示铁颗粒存在胞质中，电镜显示铁颗粒集中于内涵体／溶酶体中；移植细胞体内的T2WI信号强度明显降低．可在4周时检测到细胞沿胼胝体迁移；组织学检测结果表明标记后的细胞可在脑内存活，并能沿神经纤维迁移。结论USPIO能有效地标记骨髓源性神经干细胞，利用磁共振成像可进行大脑中活体示踪监测。     

SPIO标记猪脂肪干细胞的生物学特性与多向分化潜能及体外3.0T MR成像****

背景：不同种类细胞的最佳化标记方案需要大量实验证明,而每种细胞对应标记策略的安全性检测至关重要。 目的：应用超顺磁性氧化铁联合多聚左旋赖氨酸标记猪脂肪干细胞,探讨磁标记对细胞生物学特性和多向分化潜能的影响以及标记细胞体外3.0T MR成像特性。 方法：五指山小型猪皮下脂肪分离培养脂肪干细胞;超顺磁性氧化铁-多聚左旋赖氨酸复合物标记液标记脂肪干细胞;应用3.0T MR对不同浓度标记细胞进行T1WI、T2WI及T2*WI序列体外成像。 结果与结论：普鲁士蓝染色显示标记细胞胞质内含有多少不等的蓝染铁颗粒,细胞标记率近100%;标记细胞向心肌、骨、脂肪方向诱导分化成功;不同浓度标记细胞MR扫描显示,随细胞浓度升高,3种序列信号变化率均增加;相同浓度细胞T2*WI信号变化率最大,T1WI最小,同一浓度3种MR序列间信号变化率差异均有显著性意义(P < 0.01);3.0T MR成像能检测到至少1×106 L-1标记细胞。结果显示应用超顺磁性氧化铁联合多聚左旋赖氨酸标记方案可有效标记脂肪干细胞,不影响细胞活力、增殖及多向分化能力;T2*WI序列检测标记细胞最敏感。     

不同MR扫描序列对脑内移植SPIO标记神经干细胞大鼠的成像对比研究

目的比较3种不同MR扫描序列对脑内移植的超顺磁性氧化铁(SPIO)示踪标记神经干细胞显示作用的优劣,找出最佳扫描方案.方法将SPIO标记的神经干细胞移植到大鼠脑内,制备动物移植模型.行MR扫描,扫描序列包括SE T2WI(TR 6 000 ms,TE 100ms)、FSE T2WI(TR 2 200ms,TE 90 ms)和GRE T2*WI(TR 500ms,TE 30 ms),分析3种扫描序列在SPIO标记神经干细胞移植大鼠脑的显像特征,并进行病理学检查对照分析.结果3种扫描序列均示靶点(标)信号强度较靶点(未)有不同程度的下降,而且靶点(标)的信号强度衰减率(PSIL)在GRE T2*WI明显高于其他序列,SE T2WI、FSE T2WI中靶点(标)之间PSIL没有显著性差异;3种扫描序列中靶点(未)的信号与正常脑组织信号没有显著性差别.结论SPIO标记的神经干细胞移植到大鼠脑内后,3种MRI扫描序列显像中以GRET2*WI最为敏感.     

脂联素转染的内皮祖细胞对糖尿病大鼠脑缺血再灌注损伤的保护作用

目的 探讨脂联素(adiponectin, APN)基因转染的内皮祖细胞(endothelial progenitor cells, EPCs)移植对2型糖尿病大鼠(type 2 diabetes mellitus, T2DM)脑缺血再灌注损伤(ischemic-reperfusion injury,I/R)的保护作用及其可能的作用机制。方法 4周龄SD雄性大鼠骨髓分离培养EPCs,随机分组并干预:未干预组(EPCs组)、转染APN基因的EPCs(LV-APN-EPCs组)和空白病毒EPCs(LV-EPCs组); 5周龄SD雄性大鼠70只,随机分为假手术组(sham组)、对照组(PBS组)、LV-APN-EPCs治疗组、LV-EPCs治疗组和EPCs治疗组,高脂结合链脲佐菌素诱导T2DM模型,线栓法造I/R模型,I/R损伤后1 h分别静脉注射1 mL PBS、PBS、 LV-APN-EPCs、LV-EPCs和EPCs,I/R前和I/R后的第1、7、14 d,各组进行mNss评分; 细胞治疗后第14 d,各组行脑组织HE染色、CD31+免疫荧光染色,ELISA法检测炎症因子IL-β和TNF-α的水平。结果 I/R后第7、14 d LV-APN-EPCs组的mNss评分明显小于LV-EPCs组、EPCs组和PBS组(P<0.05); 细胞治疗后第14 d,LV-APN-EPCs组神经元破坏较LV-EPCs组、EPCs组和PBS组明显减轻; CD31+免疫荧光染色显示LV-APN-EPCs治疗显著增加了I/R损伤区皮质的血管密度(P<0.05); ELISA显示LV-APN-EPCs组脑组织的炎症因子IL-β和TNF-α的水平明显较LV-EPCs组、EPCs组和PBS组低(P<0.05)。结论 LV-APN-EPCs治疗对T2DM大鼠脑I/R损伤发挥保护作用,其可能的作用机制是促进脑I/R损伤区血管再生和抑制炎症因子的表达。     

纳米氧化铁颗粒表征分析及其对体外标记肿瘤细胞磁信号变化的影响

背景：超顺磁性纳米氧化铁颗粒的粒径小,且具有良好的水溶性、组织相容性、超顺磁性及表面积效应,使其应用于磁共振成像和作为生物大分子等药物载体成为可能。 目的：构建葡聚糖包被的超顺磁性四氧化三铁纳米颗粒(dextran coated iron oxide nanoparticles, DCIONP),分析其主要物理性质和磁学特性,并探讨其标记肿瘤细胞后对肿瘤细胞磁学特性的影响。 方法：通过化学共沉淀法制备葡聚糖包被的DCIONP。透射电镜和X射线粉末衍射法分析DCIONP的粒径和晶体结构,磁共振仪测定其弛豫率等主要物理和磁学参数。体外DCIONP分别标记人骨肉瘤MG63细胞、人肝癌HGP2细胞和鼠骨髓间充质干细胞后,用普鲁士蓝铁显色法和透射电镜观察DCIONP粒子在细胞内的分布,1.5T磁共振仪测量DCIONP体外标记肿瘤细胞后对肿瘤细胞磁信号的影响。 结果与结论：X射线衍射分析确定所制备的葡聚糖包被的磁性纳米粒子主要为Fe3O4晶体,氧化铁核心约为10 nm,具有超顺磁性,其弛豫率达3.936×106 mol/s。体外标记3种细胞后,见DCIONP主要分布在细胞核中,细胞浆中所占比率相对较小。体外磁标记后,肿瘤细胞的T2信号随着细胞数的增加而逐渐缩短,且2×109 L-1和2×1010 L-1磁标记细胞的磁信号呈明显的衰减状态。结果证实所制备的DCIONP粒子物理性能稳定,磁标记肿瘤细胞后在MR上能产生特征性的低信号。 关键词：超顺磁性四氧化三铁纳米颗粒;肿瘤;细胞;磁共振成像;衰减;纳米生物材料 doi:10.3969/j.issn.1673-8225.2010.08.017     

USPIO增强核磁共振活体内监测局部脑缺血再灌注损伤的炎症反应

目的 探讨超微超顺磁性氧化铁粒子(USPIO)增强磁共振(MR)活体监测局部脑缺血再灌注损伤炎症反应的可行性.方法 40只雄性SD大鼠按照随机数字表法分为5组:氯化三苯基四氮唑(TTC)染色组(n=4)、假手术组(n=6)、缺血再灌注24 h组(n=10)、缺血再灌注48 h(n=10)和缺血再灌注72h组(n=10).局部脑缺血再灌注模型制作成功后经大鼠尾静脉注射USPIO,分别于再灌注24 h、48 h、72 h行MR扫描.成像后分别于相应的时间点处死大鼠,取脑组织冰冻切片行HE染色观察细胞死亡.普鲁士蓝染色观察铁粒,CD68免疫组织化学染色和荧光标记观察巨噬细胞(活化的小胶质细胞).结果 成功的模型可以在T2WI上看到高信号的水肿区,USPIO在T1WI上呈正性强化,T2WI上呈负性增强;24hT1WI增强信号缺血侧/对侧比值为1.60±0.28,稍高于48h和72 h,48 h T2WI增强信号缺血侧/对侧比值为0.92±0.17,稍高于24 h和72 h,对照组中信号无类似变化;各时间点T1WI缺血侧增强效应均明显高于T2WI,差异有统计学意义(P<0.05).普鲁士蓝染色证实梗死灶周边及坏死灶内可见铁粒子沉积.CD68免疫组化染色显示小胶质细胞增生活跃.结论 应用USPIO这种相对细胞特异的MR对比剂,可以活体动态观察局部脑缺血再灌注损伤的炎症反应变化.     

自体骨髓内皮祖细胞移植治疗动脉粥样硬化大鼠急性脑缺血的实验研究

目的 探讨自体骨髓内皮祖细胞移植治疗动脉粥样硬化大鼠急性局灶性脑缺血的有效性.方法 高脂膳食制备20只动脉粥样硬化大鼠模型,采集骨髓,分离血管内皮祖细胞(EPCs)并扩增培养,检测其表面标记物的表达;第7天采用线栓法制作急性局灶性脑缺血模型,造模后3 h进行移植,其中实验组经颈静脉自体移植BrdU标记的EPCs,对照组给予等量的PBS.急性脑缺血术后6 h和第1、3、7、10、14天通过神经功能缺损评分(mNSS)量表行行为学评价,免疫组化染色观察BrdU标记的EPCs在缺血脑组织的分布和血管密度.结果体外培养大鼠骨髓来源的EPCs,细胞数目可达到5×106;CD34免疫荧光和FLK-1免疫组化鉴定呈阳性,并能特异性吸附FITC-UEA和内吞DIL-Ac-LDL.第14天实验组mNSS得分为6.13±0.30.对照组为8.50±0.46,比较差异具有统计学意义(P<0.05),实验组神经功能的恢复优于对照组.第28天实验组脑缺血区和血管壁可见BrdU标记的EPCs,而对照组则为阴性.免疫组化染色显示实验组大鼠缺血脑组织血管数为16.87±5.52,对照组大鼠缺血脑组织血管数为12.76±4.94,比较差异具有统计学意义(P<0.05).结论 从活体大鼠骨髓中分离的EPCs通过自体移植后可以进入脑缺血区并长期存活,其能够促进神经功能恢复,这可能与血管再生有关.