ObjectiveTo observe the effects of human umbilical cord mesenchymal stem cells (hUCMSCs) on blood glucose levels and diabetic retinopathy in diabetes mellitus (DM) rats. MethodA total of 45 healthy male Sprague-Dawley rats were randomly divided into normal control group (group A, 10 rats) and DM group (33 rats). Diabetic model was established in DM group by tail vein injection of streptozotocin.The DM group was further randomly divided into 3 groups (11 rats in each group), including group B (no transplantation), group C (hUCMSC was injected through tail vein) and group D (hUCMSC was injected into the vitreous). Blood glucose, retina wholemont staining and expression of brain derived neurotrophic factor (BDNF) in the retina were measured at 2, 4, 6, 8 weeks after hUCMSC injection. The blood glucose was significantly different between A-D groups before injection (t=-64.400, -60.601, -44.065, -43.872; P=0.000) BDNF expression was studied by real time fluorescence quantitative polymerase chain reaction (RT-PCR) and immunohistochemistry staining. ResultsThe blood glucose was significantly different between A-D groups after hUCMSC injection (F=400.017, 404.410, 422.043, 344.109; P=0.000), and between group C and group B/D (t=4.447, 4.990; P < 0.01). Immuno-staining shown that BDNF was positive in ganglion cell layer (RGC) of group A, weak in group B while BDNF expression increased in group C/D. BDNF mRNA expression was significantly different between group B, C and D at 4, 6 and 8 weeks after hUCMSC injection (F=29.372, 188.492, 421.537; P=0.000), and between group B and C/D (t=66.781, 72.401, 63.880, 88.423, 75.120, 83.002; P < 0.01) by RT-PCR analysis. The BDNF mRNA expression was significantly different between C and D groups only at 8 weeks after hUCMSC injection (t=127.321, P=0.005). ConclusionsTail vein injection of hUCMSCs can significantly reduce the blood glucose levels of rats. Intravenous and intravitreal injection of hUCMSCs can increase the expression of BDNF.
Objective To observe the expression of related proteins of retina after subretinal implantation with inactive chips.Methods A total of 27 healthy adult New Zealand white rabbits were randomly divided into three groups: operation group (12 rabbits) in which the rabbits were implanted with inactive chips into the interspace beneath retina;shamoperation group (12 rabbits) in which the rabbits were implanted with inactive chips into the interspace beneath retina which was taken out immediately;the control group (3 rabbits). Animals were sacrified for immunohistological study 7,15,30 and 60 days after surgery.The rabbits in control group group were sacrified for immunohistological study after bred for 30 days.The expressions of glial fibrillary acidic protein (GFAP) and brain derived neurotrophic facor (BDNF) were observed.Results In operation group, the outer nulear layer of retina thinned, and the cells in the inner nulear layer was disorganized 7,15,and 30 days after the surgery;glial cells proliferated 60 days after surgery; the positive expression of BDNF and GFAP was more than that in the shamoperation and control group.In shamoperation group, the positive expression of BDNF and GFAP was more than that in the control group.No obvious difference of expression of BDNF and GFAP between each time point groups was found.Conclusions The expression of neroprotective related proteins increased after subretinal implantation with inactive chips suggests that limited neuroprotective effects might be led by the implantation.
ObjectiveThe aim of this study was to evaluate the repair effect of spontaneous reinnervation in rats underwent recurrent laryngeal nerve (RLN) transection. MethodsThirty male Wistar rats (340-360 g) were divided into experiment group (n=15) and blank control group (n=15), and then 15 rats of these 2 groups were divided into 3 time point groups equally:4 weeks group, 8 weeks group, and 12 weeks group. Fifteen rats of experiment group underwent right RLN transection with excision of a 5 mm segment, and other 15 rats of blank control group exposed RLN only, without transection. Grade of vocalization, maximum angle of arytenoid cartilage, axon number of distal part of RLN, and expression of the brain-derived neurotrophic factor (BDNF) in right thyroarytenoid muscle were evaluated at different time points, including 4, 8, and 12 weeks after operation. ResultsGrade of vocalization, maximum angle of arytenoid cartilage, axon numbers of distal part of RLN, and the expression of BDNF in the right thyroarytenoid muscle of experiment group were all lower than those corresponding index of blank control group (P < 0.05), and these indexes of experiment group were restored gradually with time, but failed to reach normal level during the observed time. ConclusionsEven though spontaneous reinnervation is presented after RLN injury, but the effect is unsatisfactory.
Objective To construct expression plasmid of the fusion protein of brainderived neurotrophic factor (BDNF)green fluorescent protein (GFP), and observe its characteristics.Methods BDNF cDNA segment was inserted into plasmid pcDNA3.1/ NT-GFP-TOPO and in the same reading frame with GFP. After verified by sequencing, the BDNFGFP plasmid was transferred into cultured Schwann cells by electroporation. And the expression of BDNFGFP fusion protein was observed by immunohistochemistry and Western blotting. The neuralprotective function of the fusion protein was evaluated by transferring the plasmid into adult rat retinas with transected optic nerve.Results The sequence of BDNFGFP plasmid was verified correctly by autosequencing. The results of Western blotting showed that the BDNF-GFP fusion protein expressed a brand with the relative molecular mass of 41times;103. Seven days after the optic nerve was transected, the number of survival retinal ganglion cells (RGC) in BDNF-GFP group and GFP group was （1201plusmn;286） and（482plusmn;151）cells/mm2, respectively; and the survival rate was （51.39plusmn;12.24）% and （20.62plusmn;6.46）% , respectively. Twentyeight days after the optic nerve was transected, the number of survival RGC in the two groups was （715plusmn;71） and （112plusmn;24）cells/mm2, respectively; the survival rate was（30.59plusmn;3.04）% and (4.79plusmn;1.03）% respectively. The differences of the survival rate of RGC between the two groups were significant (t=3.144，11.378；Plt;0.01).Conclusion BDNF-GFP fusion plasmid can express a fusion protein which emit green fluorescence and has the biological activity of BDNF.
Objective To investigate the memory amelioration of the Alzheimer disease (AD)model rat after being transplanted the single neural stem cells(NSC) and NSC modified with human brain-derived neurotrophic factor（hBDNF） gene. Methods Forty SD rats were divided evenly into 4 groups randomly. The AD model rats were made by cutting unilaterallythe fibria fornix of male rats. Ten to twelve days after surgery, the genetically modified and unmodified NSC were implanted into the lateral cerebral ventricle of group Ⅲ and group Ⅳ respectively. Two weeks after transplantation, theamelioration of memory impairment of the rats was detected by Morris water maze. Results The average escaping latency of the group Ⅲ and group Ⅳ (41.84±21.76 s,25.23±17.06 s respectively) was shorter than that of the group Ⅱ(70.91±23.67 s) (Plt;0.01). The percentage of swimming distance inthe platform quadrant in group Ⅲ (36.9%) and in group Ⅳ(42.0%) was higherthan that in the group Ⅱ(26.0%) (Plt;0.01). More marginal and random strategies were used in group Ⅱ.The percentage of swimming distance in the platform quadrant in group Ⅳ was also greater than that in group Ⅲ(Plt;0.05). There were no significant differences in the average escaping latency, the percentage of swimming distance in the platform quadrant and the probe strategy between group Ⅳ and group Ⅰ(Pgt;0.05).More lineal and oriented strategies were used in group Ⅳ. Conclusion The behavioral amelioration of AD model rat was obtained by transplanting single NSC and hBDNF-gene-modified NSC. The effect of the NSC group modified with hBDNF gene is better than that of the groupⅢ.
ObjectiveTo investigate the protective effects of carboxymethylated chitosan (CMCS) on oxidative stress induced apoptosis of Schwann cells (SCs), and the expressions of brain derived neurotrophic factor (BDNF) and gl ial cell line derived neurotrophic factor (GDNF) in oxidative stress induced SCs. MethodsTwenty-four 3-5 days old Sprague Dawley rats (weighing 25-30 g, male or female) were involved in this study. The bilateral sciatic nerves of rats were harvested and SCs were isolated and cultured in vitro. The purity of SCs was identified by immunofluorescence staining of S-100. SCs were treated with different concentrations of hydrogen peroxide (H2O2, 0.01, 0.10, and 1.00 mmol/L) for 3, 6, 12, and 24 hours to establ ish the apoptotic model. The cell counting kit 8 (CCK-8) and flow cytometry analysis were used to detect the cell viabil ity and apoptosis induced by H2O2, and the optimal concentration and time for the apoptotic model of SCs were determined. The 2nd passage SCs were divided into 5 groups and were treated with PBS (control), with 1.00 mmol/L H2O2, with 1.00 mmol/L H2O2+50 μg/mL CMCS, with 1.00 mmol/L H2O2+100 μg/mL CMCS, and with 1.00 mmol/L H2O2+200 μg/mL CMCS, respectively. After cultured for 24 hours, the cell viabil ity was assessed by CCK-8, cell apoptosis was detected by flow cytometry analysis, the expressions of mRNA and protein of BDNF and GDNF were detected by real-time quantitative PCR and Western blot. ResultsThe immunofluorescence staining of S-100 indicated the positive rate was more than 95%. CCK-8 and flow cytometry results showed that H2O2 can inhibit the proliferation of SCs and induce the SCs apoptosis with dose dependent manner, the effect was the most significant at 1.00 mmol/L H2O2 for 24 hours; after addition of CMCS, SCs exhibited the increased proliferation and decreased apoptosis in a dose dependent manner. Real-time quantitative PCR and Western blot analysis showed that 1.00 mmol/L H2O2 can significantly inhibit BDNF and GDNF expression in SCs when compared with control group (P<0.05), 50-200 μg/mL CMCS can reverse the oxidative stress-induced BDNF and GDNF expression in SCs in a dose dependent manner, showing significant difference compared with control group and 1.00 mmol/L H2O2 induced group (P<0.05). There were significant differences among different CMCS treated groups (P<0.05). ConclusionCMCS has the protective stress on oxidative stress induced apoptosis of SCs, and may promote the BDNF and GDNF expressions of neurotrophic factors in oxidative stress induced SCs.