Differentiation of Mesenchymal Stem Cells Into Dopaminergic Neuron-like Cells in vitro

To explore the way to induce mesenchymal stem cells (MSCs) to differentiate into dopaminergic neurons in vitro. Methods MSCs were obtained from rat bone marrow, cultured and passaged. MSCs used in this experiment had multipotency, which was indirectly proved by being induced to differentiate into chondrocytes and adipocytes. MSCs were cultured in medium containing 0.5 mmol/L IBMX for 2 days. Then the medium was replaced with induction medium, which contained GDNF, IL-1β, mesencephalic glial-cell-conditioned medium and flash-frozen mesencephalic membrane fragments. The surface markers of the differentiated neurons, such as NSE, nestin, MAP-2a, b and TH were detected by immunocytochemistry and Western blot after MSCs were cultured in induction medium for 7 days and 15 days. Results MSCs differentiated into neural progenitors and expressed nestin after MSCs were incubated with medium containing IBMX for 2 d. After the medium was replaced with induction medium containing many inducing agents, MSCs differentiated into neuron-like cells and dopaminergic neuron-like cells and expressed NSE, MAP-2a, b and TH. The percentage of NSE-positive cells, MAP-2a, b-positive cells and TH-positive cells was 30.032±2.489%, 41.580±5.101% and 34.958±5.534%, respectively after MSCs were induced in medium containing GDNF, IL-1β, mesencephalic glial-cell-conditioned medium and flash-frozen mesencephalic membrane fragments for 15 days. Conclusion MSCs can differentiate into dopaminergic neuron-like cells and are a new cell source for the treatment of neurodegeneration diseases and have a great potential for wide application

Brain-derived neurotrophic factor induces neuron-like cellular differentiation of mesenchymal stem cells derived from human umbilical cord blood cells in vitro

Human umbilical cord blood was collected from full-term deliveries scheduled for cesarean section. Mononuclear cells were isolated, amplified and induced as mesenchymal stem cells. Isolated mesenchymal stem cells tested positive for the marker CD29, CD44 and CD105 and negative for typical hematopoietic and endothelial markers. Following treatment with neural induction medium containing brain-derived neurotrophic factor for 7 days, the adherent cells exhibited neuron-like cellular morphology. Immunohistochemical staining and reverse transcription-PCR revealed that the induced mesenchymal stem cells expressed the markers for neuron-specific enolase and neurofilament. The results demonstrated that human umbilical cord blood-derived mesenchymal stem cells can differentiate into neuron-like cells induced by brain-derived neurotrophic factor in vitro.

Autophagy and apoptosis during adult adipose-derived stromal cells differentiation into neuron-like cells in vitro

β-mercaptoethanol can induce adult adipose-derived stromal cells to rapidly and efficiently differentiate into typical neuron-like cells in vitro. Immunohistochemistry showed that neuron specific enolase and neurofilament-200 expression gradually increased with the extension of induction time, and peaked at 5 hours. By contrast, glial fibrillary acidic protein was negatively expressed at all time points. Induced cells possessed a typical Nissl body, apoptosis showing condensed chromatin in the nucleus, autophagosomes with a bilayered membrane and autolysosomes in the cytoplasm at 5 hours. TUNEL assay and immunohistochemistry and immunofluorescence demonstrated that apoptosis and caspase-3 expression increased and peaked at 8 hours. Immunohistochemistry and immunofluorescence showed that microtubuleassociated protein light chain 3 gradually increased with induction and reached a peak at 5 hours These results indicate that autophagy played an important role in protecting cells during adult adipose-derived stromal cells differentiation into neuron-like cells in vitro.

In vitro induction and differentiation of umbilical cord mesenchymal stem cells into neuron-like cells by alltrans retinoic acid

AIM: To determine the optimal concentration for inducing the differentiation of human umbilical cord-derived mesenchymal stem cells(h UC-MSCs) into neuron-like cells, although it is understood that all-trans retinoic acid(ATRA) regulates cell proliferation in the nervous system by modulating the balance between mitosis and apoptosis.METHODS: The abilities of ATRA to promote apoptosis as well as neural differentiation were assessed in cultured h UC-MSCs by morphological observation, MTT assay, annexin V-FITC/PI flow cytometry and immunocytochemistry.RESULTS: The data showed that low concentrations of ATRA(0.5 μmol, 0.25 μmol) had no effect on the number of cells. However, treatment with 1.0 μmol or 2.0 μmol ATRA induced a 24.16% and 52.67% reduction in cell number, respectively, compared with vehicle-treated cultures. Further, 4.0 μmol ATRA had a potent effect on cell number, with almost no adherent cells recovered after 24 h. We further showed that 0.5 μmol ATRA caused these cells to express characteristic markers of neuronal progenitor cells.CONCLUSION: Taken together, we conclude that ATRA has a dose-dependent influence on the neural differentiation and apoptosis of h UC-MSCs. These findings have implications on the use of ATRA-differentiated h UC-MSCs for the study of neural degeneration diseases.

A Novel Artificial Neuron-Like Gas Sensor Constructed from CuS Quantum Dots/Bi2S3 Nanosheets

Real-time rapid detection of toxic gases at room temperature is particularly important for public health and environmental monitoring.Gas sensors based on conventional bulk materials often suffer from their poor surface-sensitive sites,leading to a very low gas adsorption ability.Moreover,the charge transportation efficiency is usually inhibited by the low defect density of surface-sensitive area than that in the interior.In this work,a gas sensing structure model based on CuS quantum dots/Bi_(2)S_(3) nanosheets(CuS QDs/Bi_(2)S_(3) NSs)inspired by artificial neuron network is constructed.Simulation analysis by density functional calculation revealed that CuS QDs and Bi_(2)S_(3) NSs can be used as the main adsorption sites and charge transport pathways,respectively.Thus,the high-sensitivity sensing of NO_(2) can be realized by designing the artificial neuron-like sensor.The experimental results showed that the CuS QDs with a size of about 8 nm are highly adsorbable,which can enhance the NO_(2) sensitivity due to the rich sensitive sites and quantum size effect.The Bi_(2)S_(3) NSs can be used as a charge transfer network channel to achieve efficient charge collection and transmission.The neuron-like sensor that simulates biological smell shows a significantly enhanced response value(3.4),excellent responsiveness(18 s)and recovery rate(338 s),low theoretical detection limit of 78 ppb,and excellent selectivity for NO_(2).Furthermore,the developed wearable device can also realize the visual detection of NO2 through real-time signal changes.

Differentiation of human adipose-derived stem cells into neuron-like cells by Radix Angelicae Sinensis

Human adipose tissues are an ideal source of stem cells. It is important to find inducers that can safely and effectively differentiate stem cells into functional neurons for clinical use. In this study, we investigate the use of Radix Angelicae Sinensis as an inducer of neuronal differentiation. Primary human adipose-derived stem cells were obtained from adult subcutaneous fatty tissue, then pre-induced with 10% Radix Angelicae Sinensis injection for 24 hours, and incubated in serum-free Dulbecco＇s modified Eagle＇s medium/Nutrient Mixture F-12 containing 40% Radix Angelicae Sinensis to induce its differentiation into neuron-like cells. Butylated hydroxyanisole, a common in- ducer for neuronal differentiation, was used as the control. After human adipose-derived stem cells differentiated into neuron-like cells under the induction of Radix Angelicae Sinensis for 24 hours, the positive expression of neuron-specific enolase was lower than that of the butylated hydroxyani- sole-induced group, and the expression of glial fibrillary acidic protein was negative. Alter they were induced for 48 hours, the positive expression of neuron specific enolase in human adipose-derived stem cells was significantly higher than that of the butylated hydroxyanisole-induced group. Our experimental findings indicate that Radix Angelicae Sinensis can induce human adipose-derived stem cell differentiation into neuron-like cells and produce less cytotoxicity.

Differentiation of fetal pancreatic stem cells into neuron-like and islet-like cells in vitro

Pancreatic stem cells were isolated and cultured from aborted human fetal pancreases of gestational age 14-20 weeks. They were seeded at a density of 1 × 104 in serum-free media for differentiation into neuron-like cells, expressing β-tubulin III and glial fibrillary acidic protein. These neuron-like cells displayed a synapse-like morphology and appeared to form a neuronal network. Pancreatic stem cells were also seeded at a density of 1 × 105 for differentiation into islet-like cells, expressing insulin and glucagon, with an islet-like morphology. These cells had glucose-stimulated secretion of human insulin and C-peptide. Results suggest that pancreatic stem cells can be differentiated into neuron-like and islet-like cells.

Mechanism of in Vitro Differentiation of Bone Marrow Stromal Cells into Neuron-like Cells

Summary: In order to study whether marrow stromal cells (MSCs) can be induced into nerve-like cells in vitro, and the mechanism, the MSCs in Wistar rats were isolated and cultured, and then induced with DMSO and BHA in vitro. The expression of specific marking proteins in neurons, glia and neural stem cells were detected before preinduction, at 24 h of preinduction, at 6 h, 24 h, and 48 h of neuronal induction by using immunohistochemistry and Western blotting. The ultrastructural changes after the inducement were observed. The results showed that after the inducement, many MSCs turned into bipolar, multipolar and taper, and then intersected as network structure. At the same time, some MSCs had the typical neuron-like ultrastructure. Immunohistochemistry revealed that NeuN and Nestin expression was detectable after inducement, but there was no GFAP and CNP expression. Western blotting showed the expression of Nestin was strong at 6 h of neuronal induction, and decreased at 24 h, 48 h of the induction. NeuN was detectable at 6 h of neuronal induction, and increased at 24 h, 48 h of the induction. It was concluded MSCs were induced into neural stem cells, and then differentiated into neuron-like cells in vitro.

Protein hairy enhancer of split-1 expression during differentiation of muscle-derived stem cells into neuron-like cells

Muscle-derived stem cells were isolated from the skeletal muscle of Sprague-Dawley neonatal rats aged 3 days old. Cells at passage 5 were incubated in Dulbecco＇s modified Eagle＇s medium supplemented with 10% （v/v） fetal bovine serum, 20 IJg/L nerve growth factor, 20 pg/L basic fibroblast growth factor and 1% （v/v） penicillin for 6 days. Cells presented with long processes, similar to nerve cells. Connections were formed between cell processes. Immunocytochemical staining with neuron specific enolase verified that cells differentiated into neuron-like cells. Immunofluorescence cytochemistry and western blot results revealed that the expression of protein hairy enhancer of split-1 was significantly reduced. These results indicate that low expression of protein hairy enhancer of split-1 participates in the differentiation of muscle-derived stem cells into neuron-like cells.

Improvement of learning and memory abilities and motor function in rats with cerebral infarction by intracerebral transplantation of neuron-like cells derived from bone marrow stromal cells

BACKGROUND： Transplantation of fetal cell suspension or blocks of fetal tissue can ameliorate the nerve function after the injury or disease in the central nervous system, and it has been used to treat neurodegenerative disorders induced by Parkinson disease. OBJECTIVE： To observe the effects of the transplantation of neuron-like cells derived from bone marrow stromal cells （rMSCs） into the brain in restoring the dysfunctions of muscle strength and balance as well as learning and memory in rat models of cerebral infarction. DESIGN ： A randomized controlled experiment.SETTING ： Department of Pathophysiology, Zhongshan Medical College of Sun Yat-sen University.MATERIALS ： Twenty-four male SD rats （3-4 weeks of age, weighing 200-220 g） were used in this study （Certification number：2001A027）. METHODS： The experiments were carried out in Zhongshan Medical College of Sun Yat-sen University between December 2003 and December 2004. ① Twenty-four male SD rats randomized into three groups with 8 rats in each： experimental group, control group and sham-operated group. Rats in the experiment al group and control group were induced into models of middle cerebral artery occlusion （MCAO）. After in vitro cultured, purified and identified with digestion, the Fischer344 rMSCs were induced to differentiate by tanshinone IIA, which was locally injected into the striate cortex （18 area） of rats in the experimental group, and the rats in the control group were injected by L-DMEM basic culture media （without serum） of the same volume to the corresponding brain area. In the sham-operated group, only muscle and vessel of neck were separated. ② At 2 and 8 weeks after the transplantation, the rats were given the screen test, prehensile-traction test, balance beam test and Morris water-maze test. ③ The survival and distribution of the induced cells in corresponding brain area were observed with Nissl stained with toluidine blue and hematoxylin and eosin （HE） staining in the groups.MAIN OUTCOME MEASURES ： ① Results of the behavioral tests （time of the Morris water-maze test screen test, prehensile-traction test, balance beam test）; ② Survival and distribution of the induced cells.RESULTS： All the 24 rats were involved in the analysis of results. ① Two weeks after transplantation, rats with neuron-like cells grafts in the experimental group had significant improvement on their general muscle strength than those in the control group [screen test： （9.4±1.7）, （4.7±1.0） s, P 〈 0.01]; forelimb muscle strength [prehensile-traction test： （7.6±1.4）, （5.2±1.2） s, P 〈 0.01], ability to keep balance [balance beam test： （7.9±0.74）, （6.1±0.91） s, P 〈 0.01] and abilities of learning and memory [latency to find the platform： （35.8±5.9）, （117.5±11.6） s, P 〈 0.01; distance： （623.1±43.4）, （1 902.3±98.6） cm, P 〈 0.01] as compared with those in the control group. The functional performances in the experimental group at 8 weeks were better than those at two weeks, which were still obviously different from those in the sham-operated group （P 〈 0.05）. ② The HE and Nissl stained brain tissue section showed that there was nerve cell proliferation at the infarcted cortex in the experiment group, the density was higher than that in the control group, plenty of aggregative or scattered cells could be observed at the site where needle was inserted for transplantation, the cells migrated directively towards the area around them, the cerebral vascular walls were wrapped by plenty of cells; In the control group, most of the cortices were destroyed, karyopyknosis and necrosis of neurons were observed, normal nervous tissue structure disappeared induced by edema, only some nerve fibers and glial cells remained.CONCLUSION： The rMSCs transplantation can obviously enhance the motor function and the abilities of learning and memory in rat models of cerebral infarction.

Thrombospondin 1 promotes synaptic formation in bone marrow-derived neuron-like cells

In this study, a combination of growth factors was used to induce bone marrow mesenchymal stem cells differentiation into neuron-like cells, in a broader attempt to observe the role of thrombospondin 1 in synapse formation. Results showed that there was no significant difference in the differentiation rate of neuron-like cells between bone marrow mesenchymal stem cells with thrombospondin induction and those without. However, the cell shape was more complex and the neurites were dendritic, with unipolar, bipolar or multipolar morphologies, after induction with thrombospondin 1. The induced cells were similar in morphology to normal neurites. Immunohistochemical staining showed that the number of positive cells for postsynaptic density protein 95 and synaptophysin 1 protein was significantly increased after induction with thrombospondin 1. These findings indicate that thrombospondin 1 promotes synapse formation in neuron-like cells that are differentiated from bone marrow mesenchymal stem cells.

Neuron-like differentiation of adult rat bone marrow stromal cells induced by transforming growth factor-beta and brain-derived neurotrophic factor

BACKGROUND： It has been demonstrated that transforming growth factor-β （TGF-β） and brain- derived neurotrophic factor （BDNF） can induce stem cell differentiation into neuron-like cells. OBJECTIVE： To investigate the efficacy of TGF-β and BDNF at inducing the differentiation of adult rat bone marrow stromal cells （BMSCs） into neuron-like cells, both in combination or alone. DESIGN, TIME AND SETTING： A comparative observation experiment was performed at the Department of Orthopedics, First Affiliated Hospital of Liaoning Medical University between October 2007 and January 2008. MATERIALS： TGF-~ and BDNF were purchased from Sigma, USA; mouse anti-rat neuron specific enolase, neurofilament and glial fibrillary acidic protein were purchased from Beijing HMHL Biochem Ltd., China. METHODS： BMSCs were isolated from rats aged 4 weeks and incubated with TGF-β（1μ g/L） and/or BDNF （50 μ g/mL）. MAIN OUTCOME MEASURES： Expression of neuron-specific enolase, neurofilament and glial fibrillary acidic protein were determined by immunocytochemistry. RESULTS： BMSCs differentiated into neuron-like cells following induction of TGF-β and BDNF, and expressed both neuron-specific enolase and neurofilament. The percent of positive cells was significantly greater in the combination group than those induced with TGF-β or BDNF alone （P 〈 0.01）. CONCLUSION： Treatment of BMSCs with a combination of TGF-β and BDNF induced differentiation into neuron-like cells, with the induction being significantly greater than with TGF-β or BDNF alone.

In vitro differentiation of human adipose-derived adult stromal cells into neuron-like cells in hippocampal astrocyte conditioned medium

BACKGROUND: At present, researches on differentiating from human adipose-derived adult stromal cells (hADASC) to neuron-like cells are focus on inducing by artificial-synthetic compound solution; however, hippocampal astrocyte conditioned medium (HCAM) can induce in vitro differentiation from hADASC to neuron-like cells is still unclear. OBJECTIVE: To observe whether HCAM can induce in vitro differentiation from hADASC to neuron-like cells. DESIGN: Randomized control study. SETTING: Department of Neurology, Taixing People's Hospital; Central Laboratory, North China Coal Medical College. MATERIALS: Donor of adipose tissue was donated by female volunteers suffering from caesarean section in the department of obstetrics & gynecology in our hospital and aged 20-35 years. Adipose tissue was collected from subcutaneous tissue of abdomen during the operation. In addition, 8 male newborn Wistar rats within 24 hours with average body mass of 20 g were provided by Animal Institute of Chinese Academy of Medical Sciences. Rabbit-anti-human Nestin polyclonal antibody, rabbit-anti-human glial fibriliary acidic protein (GFAP) polyclonal antibody, rabbit-anti-human neuro-specific enolase polyclonal antibody and mouse-anti-human microtubal associated protein 2 (MAP-2) polyclonal antibody were provided by Wuhan Boster Company. METHODS: The experiment was carried out in the Central Laboratory of North China Coal Medical College from October 2004 to June 2005. hADASC was cultured with HCAM and its growth and morphological changes were observed under inverted phase contrast microscope. Immunocytochemistry, immunofluorescence and Western blotting were used to evaluate the expressions of Nestin, which was a specific sign of nerve precursor, neuro-specific enolase and MAP-2, which was a specific sign of nerve cell, and GFAP, which was a specific sign of neuroglial cells. MAIN OUTCOME MEASURES: Nestin, which was a specific sign of nerve precursor, neuro-specific enolase and MAP-2, which was a specific sign of nerve cell, and GFAP, which was a specific sign of neuroglial cells. RESULTS: On the 3rd day of culture, partial hADASC started deformation from slender shuttle-shape cells to neuron-like cells. It suggested that cells stretched out apophysis, which were mainly double-pole or multiple-pole cells. Five days later, immunohistochemical detection suggested that expression of Nestin (10.5±0.037) was found out in cells; meanwhile, expressions of GFAP (38.4±0.052) and neuro-specific enolase (NSE) (15.7±0.023) were also found out in cells; however, expression of MAP-2 was not observed. Western blot indicated that, 5 days after effect of HCAM, Nestin was found out in hADASC; meanwhile, expressions of GFAP and neuro-specific enolase were also found out; however, expression of MAP-2 was not observed. CONCLUSION: HCAM can induce the differentiation from hADASC to neuron-like cells in vitro.

Bone morphogenetic protein-7 induced bone marrow stromal cells differentiate into neuron-like cells

Bone morphogenetic protein-7 is widely accepted as an inducer for bone marrow stem cells differentiating into osteoblasts and chondrocytes. Whether bone marrow stromal cells differentiate into neuron-like cells remains unclear. The current study examined the presence of positive cells for intermediate filament protein and microtubule associated protein-2 in the cytoplasm of bone marrow stromal cells induced by bone morphogenetic protein-7 under an inverted microscope, while no expression of glial fibrillary acidic protein was found. Reverse transcription PCR electrophoresis also revealed a positive target band for intermediate filament protein and microtubule-associated protein 2 mRNA. These results confirmed that bone morphogenetic protein-7 induces rat bone marrow stromal cells differentiating into neuron-like cells.

Targeted Induction of Differentiation of Human Bone Mesenchymal Stem Cells into Neuron-like Cells

A systematic method of isolating and culturing human bone mesenchymal stem cells （hMSCs）, and inducing them to differentiate into neuron-like cells in vitro was established. The hMSCs were isolated from bone marrow with the lymphocyte-separating medium, cultured and expanded in vitro, and induced after addition of compound neuro-revulsants. The morphological changes of hMSCs were observed, and the expression of surface markers in induced hMSCs was immunocytochemically identified during induction period. The hMSCs could be separated, cultured and expanded in vitro. After induction by compound neuro-revulsants for 48 h, the changes of neuron-like cells, such as cellular shrinkage and neurite growth, were observed in some cells. The immunochemical staining revealed nestin （＋） or NF （＋）, and GFAP （-）. It was concluded that hMSCs were successfully cultured and induced to differentiate into neuron-like cells.

Synergistic effects of brain-derived neurotrophic factor and retinoic acid on inducing the differentiation of bone marrow stromal cells into neuron-like cells in adult rats in vitro

BACKGROUND： Under induction of retinoic acid （RA）, bone marrow stromal cells （BMSCs） can differentiate into nerve cells or neuron-like cells, which do not survive for a long time, so those are restricted to an application. Other neurotrophic factors can also differentiate into neuronal cells through inducing BMSCs; especially, brain-derived neurotrophic factor （BDNF） can delay natural death of neurons and play a key role in survival and growth of neurons. The combination of them is beneficial for differentiation of BMSCs. OBJECTIVE： To investigate the effects of BDNF combining with RA on inducing differentiation of BMSCs to nerve cells of adult rats and compare the results between common medium group and single BDNF group. DESIGN： Randomized controlled animal study SETTING： Department of Neurology, Affiliated Hospital of Xuzhou Medical College MATERIALS： The experiment was carried out in the Clinical Neurological Laboratory of Xuzhou Medical College from September 2003 to April 2005. A total of 24 SD rats, of either gender, 2 months old, weighing 130-150 g, were provided by Experimental Animal Center of Xuzhou Medical College [certification： SYXK （su） 2002-0038]. Materials and reagents： low-glucose DMEM medium, bovine serum, BDNF, RA, trypsin, separating medium of lymphocyte, monoclonal antibody of mouse-anti-nestin, neuro-specific enolase, glial fibrillary acidic protein （GFAP） antibody, SABC kit, and diaminobenzidine （DAB） color agent. All these mentioned above were mainly provided by SIGMA Company, GIBCO Company and Boshide Company. METHODS： Bone marrow of SD rats was selected for density gradient centrifugation. BMSCs were undertaken primary culture and subculture; and then, those cells were induced respectively in various mediums in total of 3 groups, including control group （primary culture）, BDNF group （20 μg/L BDNF） and BDNF＋RA group （20 μg/L BDNF plus 20 μg/L RA）. On the 3^rd and the 7^th days after induction, BMSCs were stained immunocytochemically with nestin （sign of nerve stem cells）, neuron-specific enolase （NSE, sign of diagnosing neurons） and GFAP （diagnosing astrocyte）, and evaluated cellular property. MAIN OUTCOME MEASURES ： Induction and differentiation in vitro of BMSCs in 3 groups RESULTS： （1） Induction and differentiation of BMSCs： Seven days after induction, cells having 2 or more apophyses were observed. Soma shaped like angle or erose form, which were similar to neurons and glial cells having strong refraction. （2） Results of immunocytochemical detection： Three days after induction, rate of positive cells in BDNF＋RA group was higher than that in BDNF group and control group [（86.15±4.58）%, （65.43±4.23）%, （4.18±1.09）%, P 〈 0.01]. Seven days after induction, rate of positive cells was lower in BDNF group and BDNF＋RA group than that in both groups at 3 days after induction [（31.12±3.18）%, （29.35±2.69）%, P 〈 0.01]; however, amounts of positive cells of NSE and GFAP were higher than those at 3 days after induction （P 〈 0.01）; meanwhile, the amount in BDNF＋RA group was remarkably higher than that in BDNF group （P 〈 0.01）. CONCLUSION： Combination of BDNF and RA can cooperate differentiation of BMSCs into neurons and astrocyte, and the effect is superior to single usage of BDNF.

Editor's Choice—Differentiation of adipose stromal cells into neuron-like cells

Adult adipose stromal cells are accessible, numerous, show multipotent differentiation potential and low immunogenicity, and are not subjected to ethical issues. Additionally, they can be induced to differentiate into neuron-like cells and astrocytes in vitro through addition of β-mercaptoethanol and 0,5% anhydrous ethanol.

Adult adipose-derived stromal cells differentiating into neurons and neuron-like cells

Totally three articles regarding autophagy and apoptosis during differentiation of adult adipose-derived stromal cells into neurons and neuron-like cells were published in Neural Regeneration Research. We hope that our readers find these papers useful to their research.

Cyclin D1在黄芪甲苷诱导BMSCs向神经元样细胞分化中的表达

目的:研究黄芪甲苷诱导骨髓间充质干细胞(bone marrow mesenchymal stem cells,BMSCs)分化的特点和诱导过程中Cyclin D1的表达特点。方法:采用100 mg·L^(-1)黄芪甲苷诱导BMSCs分化,在1、12、24 h倒置显微镜观察细胞形态变化,免疫细胞化学方法观察巢蛋白(Nestin)、神经元特异性烯醇化酶(neuron specific enolase,NSE)、Cyclin D1的表达,RT-PCR检测Cyclin D1 mRNA的表达。结果:收集获得的骨髓细胞采用原代和传代培养,至第3代BMSCs细胞基本纯化。经100 mg·L^(-1)黄芪甲苷作用后,部分细胞自胞体长出突起,形态似神经元样细胞且表达Nestin和NSE抗体,Nestin的表达时相早于NSE且表达强度高于NSE(P<0.05)。在药物作用1 h后,BMSCs细胞Cyclin D1不论在基因转录水平还是在蛋白表达水平均出现大幅度下调,此时BMSCs开始有Nestin的表达;药物作用12、24 h,BMSCs细胞Cyclin D1表达与药物作用前表达水平无显著性差异(P>0.05)。结论:黄芪甲苷可能首先通过调整细胞周期,延长了G1期向S期转变的时间,从而启动了BMSCs的分化程序,诱导BMSCs向神经干细胞分化。在黄芪甲苷的营养作用下,细胞的突起进一步生长并向神经元分化。

甘草苷通过TLR4/IL-6信号通路改善癫痫幼鼠认知功能及海马神经元损伤

目的探讨甘草苷改善癫痫幼鼠认知功能、海马神经元损伤及对Toll样受体4(TLR4)/白细胞介素-6(IL-6)信号通路的调节作用。方法将60只幼鼠随机分为正常组、模型组、甘草苷组、激动剂组和激动剂+甘草苷组,每组12只。除正常组外,其余组幼鼠腹腔注射氯化锂-匹罗卡品建立癫痫模型。采用水迷宫实验检测幼鼠认知功能,酶联免疫吸附法检测血清IL-1β、肿瘤坏死因子α(TNF-α)和高迁移率族蛋白B1(HMGB1)水平,苏木精-伊红染色法观察海马神经元组织病理形态,末端脱氧核苷酸转移酶介导的dUTP标记测定法检测海马神经元凋亡率,蛋白印迹法检测海马B淋巴细胞瘤-2基因(Bcl-2)、Bcl-2相关X蛋白(Bax)、TLR4、IL-6、IL-1β、TNF-α和HMGB1蛋白表达水平。结果模型组和激动剂组幼鼠海马神经元形态不规则,排列紊乱,细胞核固缩、碎裂,细胞数减少,甘草苷组和激动剂+甘草苷组幼鼠海马神经元损伤程度明显改善。与模型组比较,甘草苷组幼鼠逃避潜伏期缩短,穿越平台次数增加,血清IL-1β、TNF-α和HMGB1表达水平,海马神经元凋亡率以及Bax、TLR4、IL-6、IL-1β、TNF-α和HMGB1蛋白表达水平均降低,Bcl-2蛋白表达水平升高(P<0.05);与激动剂组比较,激动剂+甘草苷组幼鼠逃避潜伏期缩短,穿越平台次数增加,血清IL-1β、TNF-α和HMGB1表达水平,海马神经元凋亡率以及Bax、TLR4、IL-6、IL-1β、TNF-α和HMGB1蛋白表达水平均降低,Bcl-2蛋白表达水平升高(P<0.05)。结论甘草苷可减轻癫痫幼鼠炎症反应,降低神经元损伤程度,改善认知功能和空间记忆能力。甘草苷可能是通过抑制TLR4/IL-6信号通路发挥作用。