| Brain traumatic injury (TBI) is recognized as one of the injuries, with high morbidity, high cost, high mortality rate By using different ways of the treatment, there are 75% of survivors to lose their labor ability, and 40% of them with severe disability。The stats bring the heavy burden to both of family and society。There is still no satisfacyory stratergy to treat the TBI until now。In recent years, a series of experimental researches on nerve cells regeneration made the hopeness for TBI treatment。It was well know some of aspects about brain tissue regeneration as below:First, it is difficult for the nerve cells themselves to regenerate follwing the TBI。Secondly, oligodendrocytes can regenerate, but will form some of glial scar to obstruct the axonal regeneration。Thridly, the ability of axonal regeneration following the brain injury is influenced by many factors such as the inhibit factory and glail scar, but the axonal regeneration in CNS is still possible as soon as removing the inhibit factories in the damaged brain。Many new methods such as neural transplantations including peripheral nerve transplantation, NSCs transplantation, olfactory ensheathing cells transplant, gene therapy etc, can make adult animals to show some degree of recovery。 A series of reactions including the glail scar formation will start following the brain damage。The dense scar tissue will separate the normal brain tissue from the damaged area, and obstruct the renewable axons to generation by the glial scar。Meanwhile, the reactive astrocytes will secrete some of proteins polysaccharides during their accumulation, which also will inhibit the nerve regeneration in the injury brain。It was proved that the chondroitin sulfate proteoglycans (CSPGs) possese the strong inhibiting rolo for axonal regeneration。However, the chondroitin sulfateABC (ChABC), as a kind of cleavage enzyme, can effectively reset the glail scar by degradeting the CSPGs.This research will mainly include the contents as below。To establish the brain glial scar animal model after rat TBI, by freefall bump method。In treatment group, the different concentrations of ChABC were infected at the same time with TBI, and then the brain tissue specimens were harvested at the 1st,2nd and 4th week, following the TBI for observating the degree of the astrocytes accumulation, in order to understand the scar tissue growth situation。The positive expressions of CSPGs and glial fibers acidic acid protein (GFAP) were tested in order to estimating the scar healing.Part One Rats glial scar model after TBIObjective:To construct the glial scar model after rat TBI, and to supply the foundation for studing glail scar treatment further。Methods:Thirty eight of wistar rats were divided into 5 groups inclueling: control group (n=9), treatment group 1～3 (n=9, respectively), and normal group (n=2)。Rats TBI model was made by freefall bump method。Hammer weighing 20 g and drop height 30 cm, so the impact was 20×30g·cm。Rat's head was fixed to the stereo-frame。Along The midline of the scalp, to cut skin about 2 cm, then to separate the cut subcutaneous fascia layer by layer, up to the skull, Around anterior fontanelle 2 mm and left 2 mm of sagittal seam on the left side of the brain, a circular with diameter 5mm was opened, but the dura mater remained intact。20g weightfalled on the epidural bone window from 30cm high, and then sutured scalp after hemostasis。Treatment groups (group 1～3) were treated by ChABC with different concentrations。Results:The rat TBI model by freefall bump method provided research receptor for forming glial scar after rat TBI。Conclusion:Using free fallers bump method to establish rat TBI model, the brain damage exactly, have the conditions for glial scar formation。Part two Morphology of glial scar formation after the rat TBIObjective:Observing the astrocytes aggregation and definiting the formation of the glial scar and its scope preliminarily。Methods:Following the TBI by freefall bump method, the model rats were reared for much more than 1 week, in order to form glial scar in the injured brain tissue。The TBI'rats were fixed by perfussion with parafor and then the rats brains were removed respectively at the 1st,2nd and 4th week after TBI。The pathology was tested to determine the abnormal glial scar tissue。Results:In three time points, abnorma astrocytel could be found in each group, with the clear border from the normal brain tissue。The abnormal aggregation of astrocytes showed much more obvious in the model control group at the 2nd week and 4th week after TBI than at the 1st week。However, there was no difference between the 2nd week and 4th week。Compared to the control group, the abnormal astrocytes aggregation in the three of treatment groups showed much less significantly。Conclusion:The glia scar appeared just at the 1st week afer rat TBI。About the abnormal astrocytes aggregation, there was a significant difference between the normal and the injured brain tissue。Part three The effect of ChABC on glial scar in the rat TBI model。Objective:To observate the effect of ChABC on glial scar in the TBI rat。Methods:The specimens in different groups were performed by 4% formaldehyde perfusion or reservation at freezing according to the different requirements of immunohistochemical or protein assay by western blot respectively。The specimens for the immunohistochemistry were detected the expression of CSPGs, GFAP respectively after paraffin embedding, sectioning, dewaxing and immunohistochemical test。On the other hand, The specimen for the western blot were observed the protein expression of CSPGs or GFAP respectively, after protein denaturation, glue production, electrophoresis, turn film, closed, ECL detection, and darkroom exposure, et。Results:The CSPGs-positive expressing glial scar tissue showed the dark yellow in the model control group, but pale yellow in the treated groups。Amoung the three of treatment groups, the (5U/ml)ChABC treatment group showen the most obvious effect。The result of the western blot assay supported the immunohistochemical foundation。Conclusion:ChABC reduced the expression of CSPGs in the treatment groups, compared with control group, especially 5U/ml group as the most obvious effect in this experiment。... |
PDF Full Text Request