Objective To investigate the effects of chondroitinase ABC (ChABC) on axonal myelination and glial scar after spinal cord injury (SCI) in rats. Methods Seventy-two adult male Sprague Dawley rats were randomly assigned into ChABC treatment group (group A), saline treatment group (group B), and sham operation group (group C), 24 rats in each group. In groups A and B, the SCI model was established with modified Allen’s method and then the rats of groups A and B were administrated by subarachnoid injection of 6 μL ChABC (1 U/mL) and saline respectively at 1 hour after injury and every day for 1 week; the rats of group C served as control, which canal was opened without damage to spinal cord. At 1, 7, 14, and 28 days after operation, the locomotor functions were evaluated according to the Basso-Beattie-Bresnahan (BBB) score scale; and the spinal cord samples were harvested for HE staining, Nissl staining, and immunohistochemistry analysis to detect the change of myelin basic protein (MBP), growth associated protein 43 (GAP-43), and glial fibrillary acidic protein (GFAP) of the injured spinal cord. Results At different time points, the BBB score of group C was significantly higher than those of groups A and B (P lt; 0.05), and the BBB score of group A was significantly better than that of group B at 14 and 28 days after operation (P lt; 0.05). HE staining and Nissl staining showed that the morphous and the neuron number of the remainant injured spinal cord in group A were better than those in group B. The integral absorbance (IA) values of MBP and GAP-43 and the positive area of GFAP after SCI in groups A and B were significantly higher than those in group C at different time points (P lt; 0.05), and the IA values of MBP and GAP-43 were significantly higher in group A than those in group B at 7, 14, and 28 days after operation (P lt; 0.05), but the positive area of GFAP was significantly smaller in group A than that in group B (P lt; 0.05). Conclusion The ChABC can effectively improve the microenvironment of the injured spinal cord of rats, enhance the expressions of MBP and GAP-43, and inhibit the expression of GFAP, which promotes the axonal regeneration and myelination, attenuate glial scar formation, and promote the recovery of nerve function.
Objective To explore the expression of nestin and glialfibrillary acidic protein (GFAP) at different time and sites after spinal cord injury in adult rats. Methods Seventy-two adult Sprague-Dawley rats, aging 8 weeks and weighing from 180 to 220 g, were randomly divided into 11 experimental groups(66, n=6) and 1 control group(n=6). In the experimental groups, the rat spinal cord injury models were established by aneurysm clip compression, and the expression and proliferation of nestin and GFAP at different time（1 day,3 days, 5 days, 1 week, 2 weeks, 3 weeks, 4 weeks, 5 weeks, 6 weeks,7 weeks and 8 weeks）and at different sites(injured site and adjacent site) were observed with toludine blue staining, immunofluorescent staining and the analytical system of photographs. In control group, the same site of the rat spinal cord was exposed without aneurysm clip compression. The same preparation and examination were done as the experimental groups. Results Toluidine blue staining results showed thatcontour of neurite and pericaryon were distinct and nucleus were deep blue in normal control rats. One day after injury, the number of big and medium-sized neuron decreased obviously; neurite was deep blue with clouding Nissl bodies and ellipse or triangular typed nucleus. In the normal control group, the expression of nestin was hardly seen except ependymal cells of central canal, and the low expression of GFAP was seen. In the experimental groups, the nestin and GFAP expressions increased obviously in the injured sites and adjacent sites 24 hours after injury, reached the peak value after 3-7 days and followed by gradual decrease. There were statistically significant differences in the nestin and GFAP expressions between theexperimental groups and the control group.Conclusion The aboveresults suggestthat spinal cord injury can induce the expression of nestin and GFAP. There is a positive correlation between nestin expression and the proliferation of the reactive astrocytes.
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.
Objective To study the relationship between the expression ratio of induced nitric oxide synthase (iNOS) over glial fibrillary acidic protein (GFAP) and the time of injury after brain concussion in rat, in order to acquire a new visual angle for determining injury time of cerebral concussion. Methods Eighty-five healthy Sprague-Dawley rats were divided into three groups randomly: model group (n=25), experimental group (n=55), and control group (n=5). The rats in the model group were used to confirm the attack hight to make the model of brain concussion; according to the time of execution, rats in the experimental group were then subdivided into 11 groups with 5 rats in each subgroup, and their execution time was respectively hour 0.5, 1, 3, 6, 12, 24, 48, 96, 168, 240, and 336; the rats in the control group were executed after fed for 24 hours. After the model of cerebral concussion was established through freefalling dart method, hematoxylin-eosin staining and immunohistochemistry staining of iNOS and GFAP were conducted for the brain of the rats. All related experimental results were studied by using microscope with image analytical system and homologous statistics. Results The ratio of positive expression of iNOS over that of GFAP increased gradually during hour 0.5- 3 after injury in brain (from 5.03 to 10.47). At the same time, the positive expression of iNOS increased significantly (from 14.61% to 37.45%). However, the increase of the positive expression of GFAP was not obvious. Between hour 3 and 12, the ratio began to decline to 4.98, which was still at a high level, and during the same time period, the positive expressions of iNOS and GFAP also experienced the same change pattern. Later, the ratio began to decline between hour 12 and 336 after injury (from 4.98 to 0.95). All ratios at this time were lower than those between hour 0.5 and 12. The positive expression of iNOS and GFAP both increased to a climax before declining. Conclusions The ratio of positive expression of iNOS over GFAP and the respective change pattern of iNOS and GFAP can be used as the evidence of estimating the injury time of cerebral concussion. We can use the ratio of two or more markers to provide a new visual angle for concluding the concussion injury time.
ObjectiveTo investigate the effect of dexamethasone on mammalian target of rapamycin (mTOR) expression of astrocytes in hippocampus of rats with sepsis associated encephalopathy (SAE). MethodsTotally, 90 cases of 30-day-old male Wistar rats were randomly divided into sham-operation group (n=10) and cecal ligation and puncture (CLP) group (n=80). Models of rats with sepsis were established by CLP. At 12 hours after CLP, if rats appeared lower neurobehavioral scores, abnormal electroencephalogram (EEG) and somatosensory evoked potential (SEP), they were diagnosed with SAE. And then, they were randomly divided into non-treated group and dexamethasone group. Rats in the dexamethasone group were injected with dexamethasone (1 mg/kg) via tail vein every other day for a total of 3 times. The same dose of saline was used in the non-treated group. The neurobehavioral score was measured, SEP and EEG were examined in the age of 40 days, and then the rats were killed and the hippocampus was taken. Expressions of mTOR protein were measured by Western blot. The glial fibrillary acidic protein (GFAP) and mTOR were detected by immunofluorescence assay, and the number of positive cells was calculated by image analysis system software. ResultsSix of 80 CLP rats died in 12 hours after operation, and 28 of 74 rats were diagnosed as SAE because they appeared lower neurobehavioral scores, abnormal EEG and SEP at 12 hours after CLP. The incidence of SAE was 37.84% (28/74). In the age of 40 days, compared with non-treated group, neurobehavioral score of rats in the dexamethasone group was low, the amount of alpha waves in EEG reduced, delta waves increased, the amplitude of P1 waves in SEP was decreased, and the latencies of P1 and N1 waves were prolonged (P＜0.05). GFAP immunofluorescence staining showed astrocytic body and processes were small in the sham operation group. However, astrocytes in the non-treated group had large body and hypertrophic processes, and compared with the sham operation group, the number of these cells increased significantly (P＜0.05). Astrocytic body and processes were small in the dexamethasone group compared with the non-treated group, and the number of cells also decreased (P＜0.05). The mTOR positive astrocytes in the non-treated group were more than those in the sham operation group (P＜0.05). But mTOR positive astrocytes in the dexamethasone group were fewer than those in the non-treated group (P＜0.05). ConclusionsAstrocytes are activated in the hippocampus of rats with SAE. They show features of reactive hyperplasia, and the expression of mTOR is up-regulated, while dexamethasone can inhibit effects on these.
Objectives To detect expressions of heat shock protein 70 (HSP70) and glial fibrillary acidic protein (GFAP) , and to estimate the post-injury interval after concussion of brain via the ratios of percentage of HSP70/GFAP-positive cells. Methods We established a brain concussion model of rat. Tissue levels of HSP70 and GFAP were determined by immunohistochemical staining at different time points after injury. Finally, the relationship between the ratio of percentage of HSP70/GFAP-positive cells and the post-injury interval was measured. Results The ratio of percentage of positive cells (increased from 7.15 to 11.73) and the percentage of HSP70-positive cells (P<0.05, compared with control group) increased, and the percentage of GFAP-positive cells did not change remarkably (P<0.05, compared with control group); the post-injury interval was between 0.5 hour and 3 hours. High ratio (>6.66) and high percentage of HSP70 and GFAP-positive cells (P<0.05, compared with control group) indicated the post-injury interval was between 3 and 12 hours. A low ratio (<6.66) and high percentage of HSP70 and GFAP-positive cells (P<0.05, compared with control group) suggested that the post-injury interval was later than 12 hours. Conclusion By analyzing the variation rule of the ratio of percentage positive cells after brain concussion, the post-injury interval after concussion of brain could be estimated.
ObjectiveTo observe the clinical characteristics of the patients with positive anti-glial fibrillary acidic protein (GFAP) antibody. MethodsA retrospective study. From January 2017 through December 2021, 4 patients with positive anti-GFAP antibodies hospitalized in Departments of Ophthalmology and Neurology of Xijing Hospital, Air Force Medical University were included in this study. There were 3 patients with optic neuritis (ON) and 1 patient with the spinal and cerebral lesions. All patients were female, with an average age of 35 years. Three patients with ON received the examinations of best corrected visual acuity (BCVA), optical coherence tomography, visual evoked potential and magnetic resonance imaging (MRI) for the head and orbital. Another 1 patient with the spinal and cerebral lesions underwent MRI for the head, cervical and thoracic vertebras. All patients were tested for demyelinating ON-related antibodies in the serum, and the patient with the spinal and cerebral lesions for the antibodies in both serum and cerebrospinal fluid. Patients with ON received intravenous infusion of methylprednisolone sodium succinate in the acute stage, while the patients with spinal cord and brain lesions were given glucocorticoid and immunosuppressive therapy. ResultsThe initial symptoms of the patients with ON were sudden blurred vision in the right eye together with a pain when the eye rotated. BCVA were hand moving/in-front, 0.2 and 0.12, respectively. The serum anti-GFAP antibodies were positive. MRI showed a rough and thickened optic nerve in 1 patient. For patients with BCVA of hand moving/in-front, the BCVA was increased to counting fingers/30 cm on discharge; while the other 2 patients had no changes for BCVA. When followed up on phone 2-3 years after discharge, BCVA of the patients with ON increased to higher than 0.6. No ocular symptoms occurred in the patient with spinal and cerebral lesions and his initial symptoms were numbness, weakness and convulsions of limbs, accompanied by slurred speech. His anti-GFAP antibodies in the serum were negative but positive in the cerebrospinal fluid. MRI showed enhanced cerebellum and spinal dura mater. The initial symptoms were relieved on discharge, and vanished when followed up on phone after discharge. ConclusionsThe patients with positive anti-GFAP antibodies are more common in young and middle-aged women. Monocular optic neuritis is more often seen in the form of sudden blurred vision with an eye-rotating pain. Anti-GFAP antibodies in the serum are positive, and a few patient show a rough and thickened optic nerve. They are sensitive to glucocorticoid therapy with a satisfied prognosis.