Transplantation of adipocyte-derived stem cells in a hydrogel scaffold for the repair of cortical contusion injury in rats.

Adipocyte-derived stem cells have emerged as a novel source of stem cell therapy for their autologous and readily accessible and pluripotent potential to differentiate into different lineages such as neural stem cells (NSCs) and endothelial progenitor cells (EPCs). Transplantation of NSCs and EPCs has been promising for the repair of brain injury. We explored using co-transplanted hydrogel scaffold to improve the survival of the transplanted cells and recovery of neurological function. Adult Wistar rats were transplanted with EPC-hydrogel, NSC-hydrogel, NSC-EPC-hydrogel, EPC only, or NSC only 7 days after cortical contusion injury. Behavioral tests were performed to evaluate neurological function before, and 1, 2, 3, and 4 weeks after transplantation. Size of injury, extent of vascularization, as well as the survival and differentiation of the transplanted EPCs and NSCs, were evaluated at week 5. All transplantation groups displayed significantly better neurological function compared with the control groups. Improved neurological function correlated with significantly smaller injury volumes than that of the saline group. Using immunostaining, we have shown that while transplanted NSCs differentiated into both neurons and astrocytes, the EPCs were incorporated into vessel epithelia. The extent of reactive gliosis (based on glial fibrillary acidic protein immunostaining) was significantly reduced in all treatment groups (NSC-EPC-hydrogel, NSC-hydrogel, and EPC-hydrogel) when compared with the saline group, with the highest reduction in the NSC-EPC-hydrogel transplantation group. Thus, co-transplantation of hydrogel scaffold provides a more conducive environment for the survival and differentiation of NSCs and EPCs at the site of brain injury, leading to improved vascularization and better recovery of neurological function.

Up-regulation of the transient A-type K+ current (IA) in the differentiation of neural stem cells of the early postnatal rat hippocampus.

BACKGROUND: Neural stem cells (NSCs) not only are essential to cell replacement therapy and transplantation in clinical settings, but also provide a unique model for the research into neurogenesis and epigenesis. However, little attention has been paid to the electrophysiological characterization of NSC development. This work aimed to identify whether the morphological neuronal differentiation process in NSCs included changes in the electrophysiological properties of transient A-type K(+) currents (I(A)). METHODS: NSCs were isolated from early postnatal rat hippocampus and were multiplied in basic serum-free medium containing basic fibroblast growth factor. Potassium currents were investigated and compared using whole-cell patch-clamp techniques and one-way analysis of variance (ANOVA), respectively. RESULTS: Compared with NSC-derived neurons, cloned NSCs (cNSCs) had a more positive resting membrane potential, a higher input resistance, and a lower membrane capacitance. Part of cNSCs and NSC-derived neurons possessed both delayed-rectifier K(+) currents (I(DR)) and I(A), steady-state activation of I(A) in cNSCs (half-maximal activation at (21.34 +/- 4.37) mV) occurred at a more positive voltage than in NSC-derived neurons at 1-6 days in vitro (half-maximal activation at (12.85 +/- 4.19) mV). CONCLUSIONS: Our research revealed a developmental up-regulation of the I(A) component during differentiation of postnatal NSCs. Together with the marked developmental up-regulation of I(DR) in vitro neuronal differentiation we have previously found, the voltage-gated potassium channels may participate in neuronal maturation process.

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.

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.

[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.

[Responses of neurons and astrocytes in rat hippocampus to kainic acid-induced seizures].

OBJECTIVE: To investigate the time course of the responses of neurons and astrocytes in rat hippocampus (HI) to kainic acid (KA)-induced seizures in various regions. METHODS: By means immunohistochemical staining for anti-Fos protein and anti-glial fibrillary acidic protein (GFAP), the regional distribution of reactive neurons and astrocytes in the HI was observed at different time points after a unilateral stereotaxic microinjection of KA into the lateral ventricle of rats to cause limbic and generalized convulsive seizures. RESULTS: The injection of KA triggered limbic motor seizures including immobilization, staring, facial and jaw clonus ect. followed by recurrent generalized convulsive seizures. After KA-induced seizures, the GFAP-positive astrocytes and Fos-positive neurons were markedly increased in the HI. The increase of GFAP immunoreactivity was observed 30 min after the seizure onset, reaching the maximum at 1 h; the increase of Fos immunoreactivity was detected at 1 h after the onset, peaking at 2 h. CONCLUSION: The neurons and astrocytes in rat HI are highly active during seizures and the reactive astrocytes might play an important role in epileptogenesis.