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Objective To explore the role of apoptosis signal regulating kinase 1(ASK1) in inflammatory mediated secondary injury after spinal cord injury(SCI) in rats.Methods The rat contusion SCI model was used.Forty-eight rats were randomly divided into the sham operation group(Sham),normal saline(Saline group) and inflammatory factors group (Cytokine group) respectively.The expressions of ASK1 and phosphorylated ASK1(pASK1) were detected by using Western blot.The Basso Beattie Bresnahan (BBB) scores and Grid Walking method were performed to assess the behavior changes of injured rat hindlimbs.Somatosensory evoked potential(SEP) and motor evoked potential(MEP) were used to examine the electrophysiological change.Results The expression levels of ASK1 mRNA and protein had no obvious change at 1 week after SCI;the pASK1 expression level in the Cytokine group was significantly up-regulated compared with the Saline group(P=0.002);the BBB scores at 3 or 4 weeks after SCI in the Cytokine group was significantly decreased compared with the Saline group (P =0.000,P =0.000);the hindlimbs missed step rate at 4 weeks following SCI in the Cytokine group was increased compared with the Saline group (P =0.032);the latent period of SEP and MEP in the Cytokine group was prolonged(P =0.043,P =0.045),while the wave peak value had no obvious changed (P =0.889,P=0.434).Conclusion Inflammatory cytokines may lead the hindlimbs movement dysfunction to be aggravated after SCI in rat,its mechanism may be related with the phosphorylation elevation of ASK1.
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Objective To investigate the mechanism of IL-1β in promoting glial scar formation after spinal cord injury.Methods The experimental model of SCI was created by extradural compression of the spinal cord using an aneurysm clip.Rats were randomly divided into model group, sham operation group, IL-1β inhibitor IL-1RA group, IL-1β group and IL-1β+JAK2-STAT3 inhibitor AG490 group, according to different interventions, then were given normal saline, IL-1RA, IL-1β and IL-1β+AG490 every 10 μL respectively, sham group received only laminectomy.The motion function of the hindlimbs of rats was measured by Basso Beattie Bresnahan(BBB) scores and the expression of GFAP, vimentin and p-STAT3 were detected by Western blot technique, immunofluorescence assay and immunohistochemistry technique at corresponding time points(at the 8th, 12th hour, 1st, 3rd, 7th and 14th day after SCI).Results The expression trend of p-STAT3(at the 8th and 12th hour after SCI),GFAP and vimentin(at the 7th and 14th day after SCI)was: the expressions of p-STAT3, GFAP and vimentin in the model group were significantly higher compared with the sham group(P<0.01), the expression of p-STAT3,GFAP andvimentin in the IL-1RA group were significantly lower compared with the model group(P<0.05) whereas significantly higher compared with the sham group(P<0.05);the expressions of p-STAT3, GFAP and vimentin in the IL-1β+AG490 group were significantly lower compared with the model group(P<0.05)whereas significantly higher compared with the sham group(P<0.05), the expressions of p-STAT3, GFAP and vimentin in the IL-1β group were significantly higher compared with the model group(P<0.05).Conclusions IL-1β can improve glial scar formation via JAK2-STAT3 signal.Inhibition of IL-1β or JAK2-STAT3 can reduce glial scar formation and promote functional recovery of spinal nerve.
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Objective The study was to investigate the value of deduction and application of anterior compression index in evaluation of atlantoaxial dislocation and restoration. Method Twenty-eight cases of the control group and 28 cases of atlantoaxial dislocation treated with posterior restoration and screw-rod internal fixation technique before and af?ter surgery were recruited in this study and their data was retrospectively analyzed. All of the people underwent sagittal computerized tomography scan films. The anterior compression index was measured in all cases. Results The mean value of anterior compression index of the control group was 87.86±24.98. The mean value of anterior compression index of the preoperative patients was 230.44 ± 97.60 and the mean value of the postoperative patients was 106.27 ± 73.53. There was significant difference in those two parameters between the preoperative patients and the controls(t=-7.50,P<0.0001). There was no significant difference between the postoperative patients and the control group (t=-1.26, P=0.2171). Anteri?or compression index were significantly lower after surgical operation (t=10.35, compared with before, P<0.0001). Con?clusion Anterior compression index can be an excellent measurement tool for the assessment of relationship of atlas and axis in atlantoaxial dislocation patients before and after posterior restoration operation.
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Objective To evaluate the value of electrospun polymethyl methacrylate (PMMA) nanofibers with different topological structures as scaffolds for growth of Schwann cells (SCs).Methods Electrospun PMMA nanofibers with random or aligned topological structures were fabricated and measured with biocompatibility.Lentivirus-transfected green fluorescent protein was used as the reporting gene to monitor form and growth manner of SCs on different substrates and dependency of cell body and process with fiber structure,with PMMA thin films served as the control.Results Electrospun PMMA nanofibers revealed good biocompatibility and could exert contact guidance to the growth of SCs.Topological structures of the electrospun nanofibers influenced cell morphology.SCs were aligned with the orientation of substrate fibers and form longer cell process when growing on aligned nanofibers (P ＜0.01).Primary SCs preferred to follow the cue of aligned nanofibers compared to random fibers.Conclusion Aligned electrospun PMMA nanofibers have the potentiality as transplantable scaffolds for loading SCs after neural injury.
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<p><b>OBJECTIVE</b>To evaluate the impact of the topographic features of electrospun polymethylmethacrylate (PMMA) nanofibers on growth pattern of primary rat astrocytes.</p><p><b>METHODS</b>Rat astrocytes were cultured on fabricated random and aligned electrospun nanofibers. Using PMMA film as the control, the cells were transfected with a lentivirus harboring GFP gene to reveal the cell growth pattern on different substrates.</p><p><b>RESULTS</b>oth random and aligned electrospun PMMA nanofibers could support the growth of rat astrocytes, but the topographic features of the fibers significantly affected their growth pattern. On aligned nanofibers, astrocytes extended long cell processes along the direction of the substrate fibers, and on random fibers the astrocytes formed shorter processes. On merged images of GFP expressions and substrate fibers, the cell processes of the astrocytes were shown to adhere to and elongate along the fibers both on random and aligned nanofibers.</p><p><b>CONCLUSION</b>The topographic features of PMMA nanofibers can significantly influence the growth pattern of primary rat astrocytes. Aligned electrospun nanofibers has the potential to serve as scaffold material for reducing glia scar formation after spinal cord injury.</p>
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Animals , Rats , Astrocytes , Cell Biology , Cells, Cultured , Nanofibers , Polymethyl Methacrylate , Tissue Engineering , Tissue ScaffoldsABSTRACT
Objective To discuss the effect of deferoxamine in the treatment of chronic hydrocephalus (CH) after intraventricular hemorrhage (IVH) in rats. Methods A total of 184 female Sprague Dawley rats were randomly divided into normal saline group ( NS group), intracerebroventricular blood infusion group (Group A ) and deferoxamine plus intracerebroventricular blood infusion group ( Group B). The rat CH models were made by infusing autologous whole blood ( 130 μl) into the right lateral cerebral ventricle. The escape latency time was detected by Morris water maze at days 14 and 28.The rats were sacrificed 1,3, 7, 14, 28 days later, the transverse diameter of the lateral ventricle on the coronal slice of rat brain 0.4 mm posterior to the bregma was measured for evaluation of hydrocephalus and the index of ventricle. Pathological changes of the brain were observed. Results No CH was found in the NS group. The incidence of CH in the Group A was 73% (11/15), which was significantly higher than 27% (4/15) in Group B at day 28. The escape latency time in the NS group was (8.21 ± 2.00) s,which was significantly shorter than ( 16.36 ±5.93 ) s of the Group A ( P ＜0.01 ). There was no significant difference in the escape latency time between the NS group and Group B [(11.38 ± 2.57 )s] (P ＞0.05 ). The index of ventricle in the NS group was 1.05 ± 0.41, which was smaller than 4.53 ± 1.70 in Group A and 2.77 ± 1.53 in Group B (P ＜ 0.05 ). There were no obvious pathological changes in the NS group at different time points. There found edema of white matter surrounding the ventricle, twist and engorged callosum, proliferation of rhagiocrine cell as well as hemosiderin deposit in Group A. However, no hemosiderin deposit was found in Group B. Conclusions The content of iron in the cerebrospinal fluid may be correlated with hydrocephalus after IVH. Preventive use of deferoxamine can reduce incidence of hydrocephalus after ICH.
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Objective To establish the rat model of chronic hydrocephalus after intraventricular hemorrhage(IVH).Methods Totally 110 Sprague Dawley female rats were divided into 3 groups:IVH group(n=50),saline control group(n=50)and the normal group(n=10).The rats in IVH group were infused autologous whole blood(130 ?l)into the right lateral cerebral ventricle.All rats except the normal group were sacrificed on day 1,3,7,14,28 after operation,and the transverse diameter of the lateral ventricle was measured to evaluate hydrocephalus and the index of ventricle.The pathological changes of the brain were observed.Results Hydrocephalus occurred in 7 out of 10 rats in IVH group at 28 d.The index of ventricle in IVH group(4.51?1.94)was higher than that of saline control group(1.05?0.41)and the normal group(0.79?0.49)(P
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Objective To investigate the effect of recombinant antisense Vim retrovirus on Vim gene expression of injured astrocytes(AST).Methods The injured AST in vitro was established and divided into two groups: experiment and control.After transfected with retrovirus carrying antisense complementary DNA(cDNA) for vimentin,vimentin gene expression of injured astrocytes was investigated by immunocytofluoresence,RT-PCR and Western blotting.Results The processes of the injured astrocytes transfected by retrovirus became retracted.Transfection of antisense vimentin retrovirus into injured astrocytes also inhibited the growth of astrocytes and decreased the expression of vimentin at both transcription and translation level.Conclusion Retrovirus carrying vimentin antisense cDNA could inhibit effectively the growth and vimentin gene expression of injured astrocytes in vitro.