Monosialotetrahexosyl ganglioside at an optimal concentration: inducing neuron-like differentiation of human umbilical cord mesenchymal stem cells / 中国组织工程研究

BACKGROUND: Studies have confirmed that monosialotetrahexosyl ganglioside can induce human umbilical cord mesenchymal stem cells to differentiate into neuron-like cells, but little is reported on its optimal concentration. OBJECTIVE: To explore the optimal concentration of monosialotetrahexosyl ganglioside that induces human umbilical cord mesenchymal stem cells to differentiate into neuron-like cells in vitro. METHODS: Human umbilical cord mesenchymal stem cells were isolated by using collagenase digestion method, and after expansion, passage 3 cells were randomly allocated into five groups. When 70%-80% of cells were confluent, 50, 100, 150 and 200 mg/L monosialotetrahexosyl ganglioside induction solutions were added in corresponding experimental groups, while cells in the blank control group were cultured in the same volume of L-DMEM medium. Cell morphology was observed under inverted phase contrast microscope. Expression levels of microtubule-associated protein 2, neurofilament protein and glial fibrillary acidic protein were measured by using immunohistochemistry at 6 hours after induction. RESULTS AND CONCLUSION: Human umbilical cord mesenchymal stem cells were isolated successfully and sub-cultured stably. These cells could express surface markers of mesenchymal stem cells. Monosialotetrahexosyl ganglioside at the optimal concentration of 150 mg/L was confirmed to induce the neuron-like differentiation of human umbilical cord mesenchymal stem cells, and differentiated cells could express microtubule-associated protein 2 and neurofilament protein as neuron-specific markers.

Changes of protein kinase C activity in experimental presyrinx state in rabbits / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the changes of protein kinase C (PKC) activity and its role in the development of presyrinx state in rabbits.</p><p><b>METHODS</b>Presyrinx state was established in 56 rabbits by intra-cisternal injection of kaolin. At 1, 3, 7, 14, and 21 days after the injection, the water content in the upper cervical spinal cord was measured, its pathological changes observed microscopically and the PKC activity determined with substrate phosphorolysis kinase assay.</p><p><b>RESULTS</b>Spinal cord edema occurred in rabbits one day after kaolin injection, with water content of (68.35-/+0.70)%, which increased to (72.70-/+0.88)% on day 3, reaching the peak level of (72.92-/+0.86)% on day 7, followed by gradual decline after 3 weeks [(70.03-/+0.77)%]. The membrane PKC activity increased from 5.67-/+0.26 pmol.mg(-1).min(-1) on day 1 after the injection to reach the peak level on day 7 (13.27-/+3.15 pmol.mg(-1).min(-1)), which was maintained till day 14 with subsequent decrease to 8.85-/+1.56 pmol.mg(-1).min(-1) on day 21. The cytoplasmic PKC activity showed changes of a reverse pattern.</p><p><b>CONCLUSION</b>In rabbits with experimental presyrinx state, PKC translocation and activation is involved in ischemic spinal edema.</p>

Transplantation of human umbilical cord stem cells improves neurological function recovery after spinal cord injury in rats / 中国医学科学院学报

<p><b>OBJECTIVE</b>To study whether intraspinally transplanted human cord blood CD34+ cells can survive, differentiate, and improve neurological functional recovery after spinal cord injury in rats.</p><p><b>METHODS</b>Rats were randomly divided into two groups. One group of rats was subjected to spinal cord left-hemisection and transplanted with human cord blood CD34+ cells labeled by bromodeoxyuridine (BrdU); The other group was carried by left-hemisection with injection of PBS (control group). The neurological function was determined before and 24 h, 1, 2, 3 and 4 weeks after spinal cord injury and cell transplantation using the modified Tarlov score. The distribution and differentiation of transplanted human cord blood cells in vivo in rat spinal cord were evaluated by histological and immnuhistochemical analysis.</p><p><b>RESULTS</b>Functional recovery determined by modified Tarlov score was significantly improved in the group receiving human cord blood CD34+ cells compared with the control group (P < 0.05). Moreover, human cord blood CD34+ cells were found to survive in rat spinal cord microenvironment, with the expression of the neural nuclear specific protein (NeuN) in 2% BrdU-reactive human cells and of the astrocytic specific protein glial fibrillary acidic protein (GFAP) in 7% BrdU-reactive human cells.</p><p><b>CONCLUSIONS</b>Intraspinally administered human cord blood CD34+ cells can survive, differentiate, and improve functional recovery after spinal cord injury in rats. Transplantation of human cord blood cells may provide a novel strategy for the treatment of neural injury.</p>

The preliminary study on in vitro differentiation of human umbilical cord blood cells into neural cells / 中华血液学杂志

<p><b>OBJECTIVE</b>To explore the feasibility of in vitro differentiation of human umbilical cord blood cells (HUCBC) into neural cells induced by receptor activator of NF-KappaB ligand (RANKL) and brain-derived neurotrophic factor (BDNF).</p><p><b>METHODS</b>Normal fresh HUCBC were cultured as the following: (1) Control group cultured by differentiation medium only; (2) BDNF group, cultured by differentiation medium + BDNF; (3) RANKL group, cultured by differentiation medium + human soluble RANKL (sRANKL); (4) BDNF + RANKL group, cultured by differentiation medium + BDNF and sRANKL. Cultured cells were observed with invert microscope. After ten-days culture, the expression of glial fibrillary acidic protein (GFAP) and neuron-specific nuclear protein (NeuN) of the cultured cells were detected by immunocytochemical staining.</p><p><b>RESULTS</b>After 10 day's culture, the NeuN positive cells were (97.0 +/- 13.5), (85.0 +/- 5.6), (167.0 +/- 19.7) in RANKL, BDNF and BDNF + RANKL groups, respectively, with 1.7, 1.5, 3.0 fold in crease than that of control (55.7 +/- 8.5), the GFAP positive cells were (114.7 +/- 18.0), (233.3 +/- 21.7), (289.0 +/- 24.7), respectively, with 1.4, 2.9, 3.6 fold increase compared with the control group. The differentiation ratio of neurons in RANKL group was similar to that of the BDNF group, but the differentiation ratio of glial cells was lower than that in the BDNF group. In the RANKL + BDNF group, the differentiation of HUCBC into neurons and glial cells were enhanced obviously, the differentiated neural cells were typical with longer axons and dendrites.</p><p><b>CONCLUSION</b>RANKL and BDNF could induce HUCBC into neurons and glial cells, and they have synergistic effect on the induced differentiation. It is hopeful that HUCBC might be an source of stem cells for the treatment of central nervous system injury.</p>