Anti-inflammatory Effect of Mesenchymal Stromal Cell Transplantation and Quercetin Treatment in a Rat Model of Experimental Cerebral Ischemia.

Here, we have investigated the synergistic effect of quercetin administration and transplantation of human umbilical cord mesenchymal stromal cells (HUMSCs) following middle cerebral artery occlusion in rat. Combining quercetin treatment with delayed transplantation of HUMSCs after local cerebral ischemia significantly (i) improved neurological functional recovery; (ii) reduced proinflammatory cytokines (interleukin(IL)-1ß and IL-6), increased anti-inflammatory cytokines (IL-4, IL-10, and transforming growth factor-ß1), and reduced ED-1 positive areas; (iii) inhibited cell apoptosis (caspase-3 expression); and (iv) improved the survival rate of HUMSCs in the injury site. Altogether, our results demonstrate that combined HUMSC transplantation and quercetin treatment is a potential strategy for reducing secondary damage and promoting functional recovery following cerebral ischemia.

Comparison of the neural differentiation potential of human mesenchymal stem cells from amniotic fluid and adult bone marrow.

Human mesenchymal stem cells (MSCs) are considered a promising tool for cell-based therapies of nervous system diseases. Bone marrow (BM) has been the traditional source of MSCs (BM-MSCs). However, there are some limitations for their clinical use, such as the decline in cell number and differentiation potential with age. Recently, amniotic fluid (AF)-derived MSCs (AF-MSCs) have been shown to express embryonic and adult stem cell markers, and can differentiate into cells of all three germ layers. In this study, we isolated AF-MSCs from second-trimester AF by limiting dilution and compared their proliferative capacity, multipotency, neural differentiation ability, and secretion of neurotrophins to those of BM-MSCs. AF-MSCs showed a higher proliferative capacity and more rapidly formed and expanded neurospheres compared to those of BM-MSCs. Both immunocytochemical and quantitative real-time PCR analyses demonstrated that AF-MSCs showed higher expression of neural stemness markers than those of BM-MSCs following neural stem cell (NSC) differentiation. Furthermore, the levels of brain-derived growth factor and nerve growth factor secreted by AF-MSCs in the culture medium were higher than those of BM-MSCs. In addition, AF-MSCs maintained a normal karyotype in long-term cultures after NSC differentiation and were not tumorigenic in vivo. Our findings suggest that AF-MSCs are a promising and safe alternative to BM-MSCs for therapy of nervous system diseases.

[Long-term behavioral and ultrastructural alterations following hypoxic-ischemic brain damage in neonatal rats].

OBJECTIVE: To study long-term behavioral and ultrastructural alterations in a hypoxic-ischemic brain damage (HIBD) model of neonatal rats. METHODS: Sixty seven-day-old Sprague-Dawley rats were randomly subjected to unilateral carotid artery ligation followed by hypoxic exposure (HIBD group) or sham operation (n=30 each). A battery of behavioral tests, including Morris water maze test and sensorimotor tests, were performed at a postnatal age of 5 weeks. Nissl staining was used for counting neurons. Transmission electron microscopy was used for observing synapse structures and measuring the thickness of the postsynaptic density area and the length of the postsynaptic active area. The correlations of histological changes with the results of behavioral tests were evaluated. RESULTS: The HIBD group showed a significantly longer escape latency (P<0.05) and a lower frequency of original platform crossing (P<0.05) in the Morris water maze test compared with the sham operation group. The sensorimotor function test showed that the sensorimotor function in the HIBD group was worse than in the sham operation group. Nissl staining showed that the number of neurons in the HIBD group was significantly reduced (P<0.01) compared with the sham operation group. Transmission electron microscopy showed that synapses were significantly reduced in number, and that the thickness of the postsynaptic density area and the length of the postsynaptic active area were reduced in the HIBD group. The thickness of the postsynaptic density area was negatively correlated with escape latency in the Morris water maze test (r=-0.861, P<0.01), and also negatively correlated with the total score of sensorimotor function tests (r=-0.758, P<0.05) in the HIBD group. CONCLUSIONS: Hypoxia ischemia can lead to neuron loss and ultrastructure damage, resulting in long-term deficit of behavioral functions in neonatal rats.

Expression of cytokines in rat brain with focal cerebral ischemia after grafting with bone marrow stromal cells and endothelial progenitor cells.

BACKGROUND AIMS: This study aimed to observe nine factors expressed in rat ischemic brain after transplantation of bone marrow stromal cells (BMSC) and/or endothelial progenitor cells (EPC). These factors were vascular endothelial growth factor (VEGF), stromal cell-derived factor-1 (SDF-1), basic fibroblast growth factor (bFGF), insulin-like growth factor (IGF-l), transforming growth factor-ß (TGF-ß), platelet-derived growth factor-BB (PDGF-BB), brain-derived neurotrophic factor (BDNF), glial cell line-derived neurotrophic factor (GDNF) and nerve growth factor (NGF). METHODS: Adult Wistar rats were divided randomly into four groups: a vehicle group, BMSC group, EPC group and BMSC combined with EPC group. The rats were subjected to middle cerebral artery occlusion (MCAO) then implanted intravenously with 3 × 10(6) BMSC, EPC, BMSC/EPC or phosphate-buffered saline (PBS) 24 h after MCAO. Neurologic functional deficits were measured on days 1, 7, 14, 28 after transplantation. On day 7 after transplantation, quantitative reverse transcription (qRT)-polymerase chain reaction (PCR) and Western blot were employed to detect the expression of VEGF, SDF-1, bFGF, IGF-l, TGF-ß, PDGF-BB, BDNF, GDNF and NGF. RESULTS: The neurologic evaluation found that the neurologic severity scores were no different between the four groups on day 1, and the scores of rats in the BMSC/EPC group were significantly lower than those of rats in the other groups on days 7, 14 and 28 after transplantation. The expressions of bFGF, VEGF and BNDF were significantly higher in the BMSC/EPC group compared with the other groups. CONCLUSIONS: The intravenous transplantation of BMSC combined with EPC could promote the functional rehabilitation of rats with focal cerebral ischemia, and the mechanism may be related to the enhanced expression of factors.

Comparison of transdifferentiated and untransdifferentiated human umbilical mesenchymal stem cells in rats after traumatic brain injury.

Transdifferentiated and untransdifferentiated mesenchymal stem cells (MSCs) have shown therapeutic benefits in central nervous system (CNS) injury. However, it is unclear which would be more appropriate for transplantation. To address this question, we transplanted untransdifferentiated human umbilical mesenchymal stem cells (HUMSCs) and transdifferentiated HUMSCs (HUMSC-derived neurospheres, HUMSC-NSs) into a rat model of traumatic brain injury. Cognitive function, cell survival and differentiation, brain tissue morphology and neurotrophin expression were compared between groups. Significant improvements in cognitive function and brain tissue morphology were seen in the HUMSCs group compared with HUMSC-NSs group, which was accompanied by increased neurotrophin expression. Moreover, only few grafted cells survived in both the HUMSCs and HUMSC-NSs groups, with very few of the cells differentiating into neural-like cells. These findings indicate that HUMSCs are more appropriate for transplantation and their therapeutic benefits may be associated with neuroprotection rather than cell replacement.

Human Wharton's jelly cells can be induced to differentiate into growth factor-secreting oligodendrocyte progenitor-like cells.

Human Wharton's jelly-derived mesenchymal stromal cells (hWJ-MSCs) are capable of differentiating into neural and astroglia-like cell types. However, a reliable means of inducing the selective differentiation of hWJ-MSCs into oligodendrocyte progenitor cells (OPCs) in vitro has not yet been established. In this study, the OPC-like differentiation of hWJ-MSCs was characterized using and immunoblotting. The hWJ-MSC-derived OPC-like cells were able to secrete nerve growth factors and promote neurite outgrowth in vitro. These results show that hWJ-MSCs can be induced to differentiate into cells with the morphologic, phenotypic and functional characteristics of OPC-like cells.

Investigation of a plasmid containing a novel immunotoxin VEGF165-PE38 gene for antiangiogenic therapy in a malignant glioma model.

Inhibition of tumor neovascularization has profound effects on the growth of solid tumors. Our previous studies have shown the effect of VEGF165-PE38 recombinant immunotoxin on proliferation and apoptosis in human umbilical vein endothelial cells in vitro. In this study, we explored the direct inhibition of angiogenesis in chick chorioallantoic membrane and antiangiogenic therapy in a malignant glioma model. HEK293 cells were transfected with the pVEGF165PE38-IRES2-EGFP plasmid. ELISA was used to confirm the expression of VEGF165-PE38 in the transfected cells. These cells released 1396 + or - 131.9 pg VEGF165-PE38/1x10(4) cells/48 h into the culture medium and the supernatant was capable of inhibiting the growth of capillary-like structures in chick chorioallantoic membrane assay. In a murine malignant glioma model, plasmid was directly administered via multiple local intratumoral delivery. After day 16 the tumor volume in mice treated with pVEGF165PE38-IRES2-EGFP was significantly lower than that in mice in the control groups. Immunohistochemistry studies showed that the treated group had decreased expression of CD31. Quantitative analysis of microvessel density in the treated group was 1.99 + or - 0.69/0.74 mm(2), and was significantly lower than that in the control groups (9.33 + or - 1.99/0.74 mm(2), 8.09 + or - 1.39/0.74 mm(2) and 8.49 + or - 1.69/0.74 mm(2)). Immunohistochemistry analysis indicated that immunotoxin VEGF165-PE38 was distributed in the treated group in malignant glioma tissue. Our findings provide evidence that the in vivo production of VEGF165-PE38 through gene therapy using a eukaryotic expression plasmid had potential antiangiogenic activity in malignant glioma in vivo.

Therapeutic DNA vaccination as a repair strategy following spinal cord injury.

Myelin-derived proteins, such as tenascin-R (TN-R), myelin associate glycoprotein (MAG), oligodendrocyte-myelin glycoprotein (OMgp), and Nogo-A, inhibit the central nervous system regeneration. In this study, the DNA vaccine encoding for oligodendrocyte and myelin-related antigens was employed to attenuate the axonal growth inhibitory properties of myelin in the setting of spinal cord injury. Using a rat spinal cord dorsal hemisection model, the vaccine directed against the inhibitory epitopes of Nogo-A, MAG, OMgp, and TN-R was administered intramuscularly once a week following spinal cord injury, supplemented with local application of specific anti-sera against the four antigens. Anterograde labeling of dorsal column fibers showed active axonal regeneration through the lesion site at the eighth week following the treatment in experimental group but not in control groups. Light microscopic and ultrastructural analysis revealed that vaccination with these myelin-related antigens did not lead to demyelinating disease. OMgp and TN-R levels were down-regulated at the lesion site together with a parallel increase in growth-associated protein 43 levels in the treatment groups. This study reveals the effective approach of a DNA vaccine strategy by attaining the special antibody to direct neutralization of the myelin inhibitors during spinal cord injury.

Human umbilical vein-derived dopaminergic-like cell transplantation with nerve growth factor ameliorates motor dysfunction in a rat model of Parkinson's disease.

Mesenchymal stem cells are capable of differentiating into dopaminergic-like cells, but currently no report has been available to describe the induction of human umbilical vein mesenchymal stem cells (HUVMSCs) into dopaminergic-like cells. In this study, we induced HUVMSCs in vitro into neurospheres constituted by neural stem-like cells, and further into cells bearing strong morphological, phenotypic and functional resemblances with dopaminergic-like cells. These HUVMSC-derived dopaminergic-like cells, after grafting into the brain of a rat model of Parkinson's disease (PD), showed a partial therapeutic effect in terms of the behavioral improvement. Nerve growth factor was reported to improve the local microenvironment of the grafted cells, and we therefore further tested the effect of dopaminergic-like cell grafting combined with nerve growth factor (NGF) administration at the site of cell transplantation. The results showed that NGF administration significantly promoted the survival of the grafted cells in the host brain and enhanced the content of dopaminergic in the local brain tissue. Behavioral test demonstrated a significant improvement of the motor function of the PD rats after dopaminergic-like cell grafting with NGF administration as compared with that of rats receiving the cell grafting only. These results suggest that transplantation of the dopaminergic-like cells combined with NGF administration may represent a new strategy of stem cell therapy for PD.

Passive immunization with LINGO-1 polyclonal antiserum afforded neuroprotection and promoted functional recovery in a rat model of spinal cord injury.

LINGO-1 (leucine-rich repeat and Ig domain-containing, Nogo receptor-interacting protein) is an important component of the NgR receptor complex involved in RhoA activation and axon regeneration. The authors report on passive immunization with LINGO-1 polyclonal antiserum, a therapeutic approach to overcome NgR-mediated growth inhibition after spinal cord injury (SCI). The intrathecally administered high-titer rabbit-derived antiserum can be detected around the injury site within a wide time window; it blocks LINGO-1 in vivo with high molecular specificity. In this animal model, passive immunization with LINGO-1 antiserum significantly decreased RhoA activation and increased neuronal survival. Adult rats immunized in this manner show recovery of certain hindlimb motor functions after dorsal hemisection of the spinal cord. Thus, passive immunotherapy with LINGO-1 polyclonal antiserum may represent a promising repair strategy following acute SCI.

Adenoviral-mediated interleukin-18 expression in mesenchymal stem cells effectively suppresses the growth of glioma in rats.

Glioma is the most common primary intracranial malignant tumor. Despite advances in surgical techniques and adjuvant radio- and chemotherapies, the prognosis for patients with glioma remains poor. We have explored the effects of using genetically modified mesenchymal stem cells (MSCs) to treat malignant glioma in rats. Mesenchymal stem cells isolated from Sprague-Dawley rats can directly suppress the growth of C6 cells in vitro. MSCs transplanted intratumorally can also significantly inhibit the growth of glioma and prolong survival in C6 glioma-bearing models. MSCs producing Interleukin-18 infected by adenoviral vector inhibited glioma growth and prolonged the survival of glioma-bearing rats. Transplantation of IL-18 secreting MSCs was associated with enhanced T cell infiltration and long-term anti-tumor immunity. Thus, IL-18 may be an effective adoptive immunotherapy for malignant glioma. When used in conjunction with MSCs as targeting vehicles in vivo, IL-18 may offer a promising new treatment option for malignant glioma.

Human mesenchymal stem cells-like cells as cellular vehicles for delivery of immunotoxin in vitro.

Human mesenchymal stem cells-like cells (hMSCs-like cells) were used as a tumor treatment platform for the systemic delivery of immunotoxin genes. VEGF165-PE38 recombinant immunotoxin served as the model system. hMSCs-like cells were isolated, expanded, and electroporated with the pIRES2-VEGF165PE38-EGFP plasmid. RT-PCR and ELISA were used to confirm the expression of VEGF165-PE38 in the transfected hMSCs-like cells. These cells released 1390 +/- 137 pg VEGF165-PE38/10(4)cells over 48 h into the culture medium and the supernatant was capable of selectively killing human umbilical vein endothelial cells (HUVECs) and increasing apoptosis in these cells. In contrast, RPMI8226 was not inhibited by identical supernatants. Thus, these results lay the foundation for further studies on the potential role of hMSCs-like cells as a targeted therapeutic delivery vehicle for immunotoxins.

[Dynamic atomic force microscopic observation of the three-dimensional conformation of protein A-gold single molecule].

OBJECTIVE: To determine the three-dimensional (3D) conformation of staphylococcal protein A-gold (SPA-G) single molecule using atomic force microscope (AFM) so as to evaluate the feasibility of using this molecule for in situ labeling of the neuronal membrane protein. METHODS: AFM was used to acquire the images of SPA-G binding to the surface of mica under physiological condition for determining the 3D conformation of the molecule. RESULTS: SPA-G single molecule was shown to contain a characteristic structure with a chain in the shape of mirror image of the letter C, which had the dimension of 48.80 nm x 42.13 nm x 20.53 nm. CONCLUSION: AFM provide a new means for morphological investigation of the biomacromolecule at the nanometer scale in physiological conditions, and SPA-G can be utilized for in situ labeling of the neuronal membrane receptors.

[Application of atomic force microscope in life science research].

OBJECTIVE: Atomic force microscope (AFM) is one of the most recent imaging and manipulation techniques in biological science. Among its various merits, AFM typically enables simple sample preparation, acquisition of three-dimensional images to identify single atoms under different conditions, detection of the interactive forces between two single biomolecules and their manipulation. AFM is currently applied in the research of the structure and function, at the nanometric scale, of various tissues, cells, microbes and biomolecules, and studies of the interaction between two biomolecules as well as the manipulation of some biological processes. AFM possesses the potential to become an important instrument in life science research, in spite of its current limits that require improvements such as in carbon nanotube tip, rigidity of soft biological samples and result interpretation.

[Relationship between aquaporin-4 expression in astrocytes and brain edema caused by glioma].

OBJECTIVE: To investigate the relationship between aquaporin-4 (AQP4) water channel expression in astrocytes and brain edema caused by glioma. METHODS: The changes of water transport in in vitro blood-brain barrier models were examined using high-performance liquid chromatography (HPLC), and the expression level of AQP4 was assayed by semiquantitative RT-PCR. RESULTS: The water transport of the in vitro blood-brain barrier model from the luminal side to basolateral side was increased after coculture with glioma cells, which induced significantly decreased expression level of AQP4 in the astrocytes. CONCLUSIONS: Glioma cells can promote water transport in in vitro blood-brain barrier model from the luminal side to abluminal side, and the brain edema induced by the glioma cells may not necessarily be the result of hyperpermeability of the blood-brain barrier to macromolecules in the plasma. The decreased expression level of AQP4 induced by glioma cells may be a molecular mechanism for neoplastic brain edema in patients with glioma.

[Induced differentiation of rabbit bone marrow stromal cells into neuron-like cells].

OBJECTIVE: To study whether the neuron-like cells derived from bone marrow stromal cells (BMSCs) may excrete amino acids with neurobiological activities and possess the biochemical characteristics of neurons. METHOD: Under sterile condition, BMSCs from New Zealand rabbits were purified by gradient density centrifugation, and were induced to differentiate into neural stem cells and neuronal-like cells in the culture medium for neural stem cells containing retinoic acid (RA, 0.5 microg/ml) and glial-derived neurotrophic factor (GDNF, 20 ng/ml). The differentiated cells were then examined with immunocytochemical method and high-performance liquid chromatograpy (HPLC). RESULTS: The round and enlarged BMSCs on day 10 of cell culture were positive for nestin, and on day 20, the cells with RA+GDNF stimulation differentiated into neuron-like cells with long protrusions and presented neuron-specific enolase (NSE) antigen. HPLC identified high levels of amino acids like Asp, Glu, Gly and Ala in the differentiated cells (P<0.01). CONCLUSIONS: Rabbit BMSCs may proliferate in vitro as from nestin-positive cells and differentiate into NSE-positive cells containing high levels of excitatory and inhibitory amino acid neurotransmitters. RA and GDNF are important promoters for in vitro differentiation of the BMSCs toward neural stem cells.

[Effect of hyperthermia on tight junctions between endothelial cells of the blood-brain barrier model in vitro].

OBJECTIVE: To investigate the effect of hyperthermia in vitro on tight junctions between the endothelial cells of the blood-brain barrier. METHODS: An in vitro blood-brain barrier model was established by coculture of ECV304 cells with astrocytes. Transendothelial resistance (TER) of in vitro blood-brain barrier was determined by Millicell-ERS system, and the morphological change of tight junctions examined by silver staining. The expression level of zonula occluden-1(ZO-1) was analyzed by semi-quantitative reverse transcriptase-PCR. RESULTS: The integrity of tight junctions was disrupted and the expression level of ZO-1 decreased after treatment with hyperthermia. CONCLUSIONS: Tight junctions between the endothelial cells of the blood-brain barrier can be destroyed by hyperthermia, and decreased expression level of ZO-1 induced by hyperthermia is one of the most important molecular mechanisms.

[Rapid construction and identification of full-length cDNA library of human glioma tissues].

OBJECTIVE: To explore a method for rapid construction of a full-length cDNA library of human glioma tissues using switching mechanism at 5' end of RNA transcript (SMART). METHODS: The total RNA was extracted from several samples of human glioma tissues and the mRNA was subsequently separated. Multiple mRNA samples were mixed to be used as the template for the first-strand cDNA synthesis. The CDS /3' PCR primer (containing Sfi IB site) was used in the first-strand reaction, and the SMART IV Oligo(dT) (containing Sfi A site) served as the short, extended template at the 5' end of the mRNA. With the above two primers, the primer-extension step generated full-length double-strand cDNA, which was digested by Sfi I restriction enzyme and ligated to the Sfi I A & B -digested lambdaTriplEx2 vector. The ligated vector was then packaged by lambda packaging extract for the final construction of the cDNA library. RESULTS: The unamplified human glioma cDNA library consisted of 2.4x10(6) independent clones with a recombination rate of 100%. The titer of the amplified cDNA library was 4.5x10(9) pfu/ml, and the average exogenous inserts of the recombinants was 1.2 kb in length. CONCLUSION: A high-quality full-length cDNA library of human gliomas was constructed successfully, which may facilitate further study of the screening and cloning of new tumor suppressor genes and tissue-specific genes of human glioma.

Vasculogenic mimicry and its clinical significance in medulloblastoma.

Vasculogenic mimicry (VM), a process involving the formation of a tubular structure by highly invasive and genetically dysregulated tumor cells, can supplement the function of blood vessels to transport nutrients and oxygen to maintain the growth of tumor cells in many malignant tumors. We aimed to explore the existence of VM and its clinical significance in medulloblastoma in this study. VM was identified in 9 out of 41 (22%) medulloblastoma tissues. Immunohistochemical studies revealed that the presence of VM was associated with the expression of MMP-2, MMP-14, EphA2 and laminin 5γ2. Tumor tissues with VM were associated with lower microvessel density (MVD), which was indirect evidence of the blood supply function of VM. Survival analysis and log-rank tests showed that patients with VM had shorter overall survival time than those without VM. Multivariate analysis and the Cox proportional hazards model identified VM as independent prognostic factor for overall survival. Our results confirmed the existence of VM for the first time and revealed that VM is a strong independent prognostic factor for survival in patients with medulloblastoma.

Passive immunization with tenascin-R (TN-R) polyclonal antibody promotes axonal regeneration and functional recovery after spinal cord injury in rats.

Tenascin-R (TN-R) is a neural specific protein and an important molecule involved in inhibition of axonal regeneration after spinal cord injury (SCI). Here we report on rabbit-derived TN-R polyclonal antibody, which acts as a TN-R antagonist with high titer and high specificity, promoted neurite outgrowth and sprouting of rat cortical neurons cultured on the inhibitory TN-R substrate in vitro. When locally administered into the lesion sites of rats received spinal cord dorsal hemisection, these TN-R antibodies could significantly decrease RhoA activation and improve functional recovery from corticospinal tract (CST) transection. Thus, passive immunotherapy with specific TN-R antagonist may represent a promising repair strategy following acute SCI.