Effect of Urinary Kallidinogenase on Transforming Growth Factor-ß1 and High-Sensitivity C-Reactive Protein Expression in Rat Focal Cerebral Ischemic Injury.

BACKGROUND In this study we investigated the effect of urinary kallidinogenase (UK) on transforming growth factor beta 1 (TGF-ß1) expression in brain tissue. We also explored the neuroprotective mechanism of UK against ischemic injury by measuring serum high-sensitivity C-reactive protein (hs-CRP) level changes after rat cerebral ischemic injury. MATERIAL AND METHODS The rat middle cerebral artery ischemia/reperfusion model was established using the suture method. Sprague-Dawley rats were randomly divided into 3 groups: treatment, Gegen control, and blank control. Each group was subsequently divided into 5 subgroups according to time (6, 12, 24, 48, and 72 h). Rats in the treatment group were administered UK as treatment. TGF-ß1 expression was observed at each time point using SABC and immunohistochemical staining methods to estimate cerebral infarct volume percentage. Serum hs-CRP levels were also measured. RESULTS TGF-ß1 protein expression in ischemic brain tissues of the treatment group significantly increased at each time point (P<0.01) compared with both control groups. Treatment group serum hs-CRP levels significantly decreased at each time point (P<0.05) compared with both control groups. CONCLUSIONS UK exerts a neuroprotective effect by upregulating TGF-ß1 expression and inhibiting excessive inflammatory responses.

Effect of ischemic postconditioning on cerebral edema and the AQP4 expression following hypoxic-eschemic brain damage in neonatal rats.

BACKGROUND: A rat model for neonatal hypoxic-ischemic brain damage (HIBD) was established to observe the effect of ischemic postconditioning (IPostC) on cerebral edema and the AQP4 expression following HIBD and to verify the neuroprotection of IPostC and the relationship between changes of AQP4 expression and cerebral edema. METHODS: Water content was measured with dry-wet method, and AQP4 transcription and the protein expression of the lesions were detected with real-time PCR and immunohistochemistry staining, respectively. RESULTS: Within 6-48 hours, the degree of ipsilateral cerebral edema was significantly lower in IPostC-15 s/15 s group than in HIBD group. Similar to the HIBD group, the AQP4 transcription and expression in the IPostC group showed a downward and then upward trend. But the expression was still more evident in the HIBD group than in the IPostC-15 s/15 s group. From 24 to 48 hours, IPostC-15 s/15 s decreased the slowing down expression of AQP4. CONCLUSION: IPostC has neuroprotective effect on neonatal rats with HIBD and it may relieve cerebral edema by regulating the expression of AQP4.

Improvement of the suture-occluded method in rat models of focal cerebral ischemia-reperfusion.

The aim of the present study was to provide a simple method of establishing a rat model for focal cerebral ischemia-reperfusion (FCIR). The suture-occluded method was used to establish FCIR in male Sprague-Dawley rats. An incision was made over the bifurcation of the common carotid artery (CCA), through which a suture was inserted up to the internal carotid artery (ICA). The suture remained in the skin subsequent to model establishment and was withdrawn to the CCA to enable reperfusion. The reliability of the rat model was assessed via analysis of nerve function, tetrazolium (TTC) staining and pathological examination. Following FCIR in rats, the resulting neurological impairments were observed. TTC staining revealed infarcts and pathological examination revealed typical pathological changes. This modified method was simple, reliable and, therefore, may be used to investigate FCIR.

[Organotypic slice culture of neonatal rat cortex and induced neural stem cell differentiation].

OBJECTIVE: To establish a method for organotypic slice culture of neonatal rat cortex in a modified condition and investigate the effect of spatial signals on neural stem cell (NSC) differentiation. METHODS: The brain slices (200 µm in thickness) of neonatal SD rats (3 to 5 days old) were prepared and cultured in modified serum-free DMEM/F12 medium at 37 degrees celsius; with 95% O(2) and 5% CO(2). The organotypic slice cultures were observed regularly. NSCs isolated from the cortex of rat embryos (14-15 embryonic days) were cultured in serum-free DMEM/F12 supplemented with B27 and N2, and the passage 3 NSCs were labeled by CM-DiI before transplanted onto the organotypic slices cultured for 2 weeks. The survival of transplanted NSCs was assessed, and the cell differentiation was identified by immunofluorescence staining. RESULTS: The organotypic slice cultures were well maintained for at least 4 weeks in the modified medium. The thickness of the organotypic slices reduced from 200 µm to 130 µm after 2-week culture in vitro due to the migration of the cells on the edge of the slices. CM-DiI-labeled NSCs survived well and differentiated into GFAP(+) glia and ß-tubullin III(+) neurons. CONCLUSION: Neonatal rat organotypic brain slice can be successfully cultured in a modified condition to serve as a model for studying NSC differentiation induced by spatial signals.

[Culture and identification of neural stem cells from mouse embryos].

OBJECTIVE: The purpose of this study was to culture and identify neural stem cells from mouse embryos in vitro using a modified method and provide a basis for further study of the biology of neural stem cells under hypoxia. METHODS: The cells were isolated mechanically from the front cortex of fetal Institute of Cancer Research (ICR) mice on embryonic day 14. They were passaged by mechanical dissociation and enzymatic digestion. The neurospheres were identified by immunofluorescent staining of nestin. Cell differentiation was induced by 1% fetal bovine serum and then the cells were identified by immunohistochemistry of ß-tubulin III and GFAP. RESULTS: The cells obtained from the front cortex of fetal ICR mice had the capacity of forming neurospheres which showed nestin immunoreactive positivity. After being induced by 1% fetal bovine serum, the cells were differentiated into ß-tubulin III-positive cells and GFAP-positive cells. CONCLUSIONS: Using mechanical dissociation of primary cells and mechanical dissociation with enzymatic digestion of primary cells, the NSCs from the front cortex of mouse embryos can be obtained.