Ruxiang Xu

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.

MiRNA-329 targeting E2F1 inhibits cell proliferation in glioma cells

BackgroundMicroRNAs have recently emerged as key regulators of cancers, miR-329 located on 14q32.31 is one of down-regulated miRNAs in glioma, but the function and molecular mechanisms of miR-329 in determining the malignant phenotype of human glioma are elusive. This study therefore was conducted to investigate the role of miR-329 in biological behaviors of human glioma LN18 and T98G cell lines and its molecular mechanisms.MethodsNine patients with GBM were analyzed for the expression of miR-329 by quantitative RT–PCR. MiR-329 overexpression was established by transfecting miR-329 precursor into LN18 and T98G cells, and its effects on cell proliferation were studied using MTT assay, anchorage-independent growth ability assay, colony formation assays, Bromodeoxyuridine labeling and immunofluorescence.The effects of miR-329 on cell cycle were studied by flow cytometry. The target of miR-329 was determined by luciferase assays. The regulation of miR-329 on Akt pathway was determined by western blot.ResultsThe E2F1 was identified as the target of miR-329. Overexpression of miR-329 blocked G1/S transition in LN18 and T98G cell lines, dramatically suppressed cell proliferation and the ability of colony formation. MiR-329 significantly decreased the phosphorylation levels of intracellular kinases Akt and expression of cyclin D1, but the expression of p21 was upregulated, cell growth was suppressed by inhibiting E2F1-mediated Akt pathway.ConclusionsMiR-329 may inhibit cell proliferation in human glioma cells through regulating E2F1-mediated suppression of Akt pathway.

Functional endothelial progenitor cells derived from adipose tissue show beneficial effect on cell therapy of traumatic brain injury

Endothelial progenitor cells (EPCs) are responsible for postnatal vasculogenesis in physiological and pathological neovascularization. Adipose tissue (AT) is an abundant source of mesenchymal stem cells (MSCs), which have multipotent differentiation ability. We successfully derived EPCs from AT, which maintained a strong proliferative capacity and demonstrated the characteristic endothelial function of uptaking of acetylated low-density lipoprotein. They formed tube-like structures in vitro. Endothelial nitric oxide synthase (eNOS) gene expression in EPCs was similar to that in mature endothelial cells. Transplantation of EPCs derived from AT after the acute phase was applied in rats with traumatic brain injury (TBI). Transplanted EPCs participated in the neovascularization of injured brain. Improving functional recovery, reducement of deficiency volume of brain, host astrogliosis and inflammation were found. These results suggest that adult AT derived stem cells can be induced to functional EPCs and have beneficial effect on cell therapy.

Neural differentiation ability of mesenchymal stromal cells from bone marrow and adipose tissue: a comparative study

BACKGROUND AIMSnThe characteristics, such as morphologic and phenotypic characteristics and neural transdifferentiation ability, of mesenchymal stromal cells (MSC) derived from different origins have yet to be reported for cases isolated from the same individual.nnnMETHODSnThe proliferation capacity, secretion ability of neurotrophins (NT) and neural differentiation ability in rat MSC isolated from bone marrow (BMSC) and adipose tissue (ADSC) were compared from the same animal.nnnRESULTSnThe ADSC had a significantly higher proliferation capacity than BMSC according to cell cycle and cumulative population doubling analyses. The proportion of cells expressing neural markers was greater in differentiated ADSC than in differentiated BMSC. Furthermore, the single neurosphere derived from ADSC showed stronger expansion and differentiation abilities than that derived from BMSC. The findings from Western blot lent further support to the immunocytochemical data. The mRNA and protein levels of nerve growth factor (NGF) and brain-derived growth factor (BDNF) expressed in ADSC were significantly higher than those in BMSC at different stages before and following induction.nnnCONCLUSIONSnOur study suggests that the proliferation ability of ADSC is superior to that of BMSC. Furthermore, differentiated ADSC expressed higher percentages of neural markers. As one possible alternative source of BMSC, ADSC may have wide potential for treating central nervous system (CNS) diseases.

Transplantation of autologous bone marrow mesenchymal stem cells in the treatment of complete and chronic cervical spinal cord injury.

Neuronal injuries have been a challenging problem for treatment, especially in the case of complete and chronic cervical spinal cord injury (SCI). Recently, particular attention is paid to the potential of stem cell in treating SCI, but there are only few clinical studies and insufficient data. This study explored the efficacy of autologous bone marrow mesenchymal stem cells (BMMSCs) transplantation in the treatment of SCI. Forty patients with complete and chronic cervical SCI were selected and randomly assigned to one of the two experimental groups, treatment group and control group. The treatment group received BMMSCs transplantation to the area surrounding injury, while the control group was not treated with any cell transplantation. Both the transplant recipients and the control group were followed up to 6 months, postoperatively. Preoperative and postoperative neurological functions were evaluated with AIS grading, ASIA score, residual urine volume and neurophysiological examination. Results showed that in the treatment group 10 patients had a significant clinical improvement in terms of motor, light touch, pin prick sensory and residual urine volume, while nine patients showed changes in AIS grade. Neurophysiological examination was consistent with clinical observations. No sign of tumor was evident until 6 months postoperatively. In the control group, no improvement was observed in any of the neurological functions specified above. BMMSCs transplantation improves neurological function in patients with complete and chronic cervical SCI, providing valuable information on applications of BMMSCs for the treatment of SCI.

Beneficial effect of autologous transplantation of bone marrow stromal cells and endothelial progenitor cells on cerebral ischemia in rabbits

We tested the therapeutic effect of autologous transplanted bone marrow stromal cells (BMSCs) and endothelial progenitor cells (EPCs) on cerebral ischemia in rabbits. Rabbit permanent middle cerebral artery occlusion (MCAO) models were intravenously injected with ex vivo expanded autologous BMSCs (n = 8), EPCs (n = 8), or phosphate-buffered saline (n = 6). 14 days after the transplantation, both infusion groups witnessed a functional improvement, a decrease in the number of apoptotic cells and an increase in the microvessel density in the ischemic boundary area, as compared to vehicle-treated control group. The EPCs treated group also exhibited a diminished infarct area in comparison with the control group. Moreover, immunohistochemistry revealed that few transplanted BMSCs expressed markers for astrocytes (GFAP+) and neurons (NeuN+), and most of EPCs were capable of binding to UEA-1 lectin and were incorporated into capillaries. Our data suggest that both BMSCs and EPCs, despite differences in their action mechanism, can be functional cytoreagents for treatment of cerebral ischemia in rabbits.

Comparison of adult neurospheres derived from different origins for treatment of rat spinal cord injury

This study is designed to evaluate the therapeutic effects of three types of neurospheres (NSs) derived from brain, bone marrow and adipose tissue in a rat model of spinal contusive injury. As shown by BBB locomotor rating scale and grid test, the optimal therapeutic responses generated by subventricular zone-derived NSs (SVZ-NSs), and followed by adipose-derived (AD-NSs) and bone marrow-derived NSs (BM-NSs) after being grafted into the injured spinal cord. In three cell-treated groups, very few (<1%) grafted cells survived and these survived cells mainly differentiated into oligodendrocytes at week 12 after injury. Additionally, all the cell-treated groups, especially in the SVZ-treated group showed an increase in host oligodendrocytes than control group. Moreover, the level of selective neurotrophins (NTs) in the SVZ-NSs group were significantly higher than those in the BM-NSs and AD-NSs groups, and the level of NTs in the saline group was also significantly higher than sham group. Therefore, not cell replacement or infusion but neuroprotective action associated with endogenous oligodendrocytes and NTs that active by the grafted NSs may contribute to the functional recovery.

In vivo magnetic resonance tracking of Feridex-labeled bone marrow-derived neural stem cells after autologous transplantation in rhesus monkey.

Bone marrow stroma cells-derived neural stem cells (BMSCs-D-NSCs) transplantation is a promising strategy for the treatment of nervous system disorders. The development of a non-invasive method to follow the fate of BMSCs-D-NSCs in vivo is very important for the future application of this treatment. In this paper, we show for the first time, that BMSCs-D-NSCs from rhesus monkeys can be labeled in vitro with the superparamagnetic iron oxide (SPIO) contrast agent Feridex and Poly-L-lysine (PLL) without affecting morphology, cell cycle, telomerase activity, proliferation and differentiation ability of the labeled cells. Furthermore, when autografted into the striatum, these cells survived, differentiated and were incorporated into the brain, and could be reliably tracked using MRI, as confirmed by histological examination of the grafting sites with PKH(67) fluorescence. These results suggest that Feridex labeling of BMSCs-D-NSCs is feasible, efficient and safe for MRI tracing following autografting into the rhesus monkey nervous system.

Effects of Differentiated Versus Undifferentiated Adipose Tissue-derived Stromal Cell Grafts on Functional Recovery After Spinal Cord Contusion

Controversies exist concerning the need for mesenchymal stromal cells (MSCs) to be transdifferentiated prior to their transplantation. In the present study, we compared the results of grafting into the rat contused spinal cord undifferentiated, adipose tissue-derived stromal cells (uADSCs) versus ADSCs induced by two different protocols to form differentiated nervous tissue. Using Basso, Beattie, and Bresnahan scores and grid tests, we found that three cell-treated groups, including uADSCs-treated, dADSCs induced by Protocol 1 (dADSC-P1)-treated, and dADSCs induced by Protocol 2 (dADSC-P2)-treated groups, significantly improved locomotor functional recovery in SCI rats, compared with the saline-treated group. Furthermore, functional recovery was better in the uADSC-treated and dADSC-P2-treated groups than in the dADSC-P1-treated group at week 12 postinjury (Pxa0<xa00.05 for dADSC-P1 group vs. uADSCs or dADSC-P2 groups). Although both protocols could induce high percentages of cells expressing neural markers in vitro, few BrdU-labeled cells survived at the injury sites in the three cell-treated groups, and only a small percentage of BrdU-positive cells expressed neural markers. On the other hand, the number of NF200-positive axons in the uADSC-treated and dADSC-P2-treated groups was significantly larger than those in the dADSC-P1-treated and saline-treated control groups. Our results indicate that ADSCs are able to differentiate into neural-like cells in vitro and in vivo. However, neural differentiated ADSCs did not result in better functional recovery than undifferentiated ones, following SCI. In vitro neural transdifferentiation of ADSCs might therefore not be a necessary pretransplantation step. Furthermore, cellular replacement or integration might not contribute to the functional recovery of the injured spinal cord.

Expression profile of cancer-related genes in human adult bone marrow–derived neural stemlike cells highlights the need for tumorigenicity study

Human adult bone marrow–derived neural stemlike cells (MDNSCs) may serve as ideal seed cells for cell replacement therapy for human neurological disorders and injuries. However, the long‐term safety of this cell population after transplantation must be thoroughly explored before clinical application, and tumorigenicity is a major concern. In this study, we generated MDNSCs capable of forming neurospherelike aggregates and with the potency to differentiate into neural lineage cells in vitro and investigated hundreds of cancer‐related genes in MDNSCs in order to determine whether there were any characteristics that could help in the evaluation of their tumorigenic potential. According to the results of testing by PCR and DNA sequencing, there were no mutations at the frequent mutation sites of tumor‐suppressor genes p53, p16, and Rb1. Of the 440 cancer‐related genes covered by Oligo GEArray Human Cancer Microarray OHS‐802, 63 were found to be significantly overexpressed compared with that in fresh normal human adult bone marrow depleted of red blood cells (RBCs). In particular, the overexpressed genes included those promoting cell proliferation and cell invasion and metastasis and members of several oncogenic signaling pathways. The overexpression of MYC, MMP2, Notch2, STC1, ITGA3, STAT5b, RhoC, and Wnt1 was also revealed by quantitative real‐time RT‐PCR. Because it has been shown that activation of some of these genes promote tumorigenesis, our findings highlight the need for further studies of long‐term tumorigenicity in MDNSCs.