Cerebral expression and junction of 5-lipoxygenase in surgical brain injury model of rats / 第二军医大学学报

ABSTRACT

Abstract Objective To investigate the spatial distribution, cell localization and lime-dependent changes of 5-lipoxygenase (5-LOX) expression in brain tissues of rats with surgical brain injury (SBI) and its role in the pathogenesis of SBI. Methods Seventy-two healthy male SD rats were randomly divided into Sham group, 1-day post surgery (SBI-ld) group, 3-day post surgery (SBI-3d) group and 7-day post surgery (SBl-7d) group, each group with 18 rats. SBI rat model was established by right frontal lobectomy in the SBI-ld, SBI-3d and SBl-7d groups, while rats in the Sham group only with the corresponding skull removed with the dura intact. Brain water content (BWC) of ipsilateral and contralateral brain tissues was measured by wet-dry weight formula. The neurobehavioral functions of all rats were evaluated by modified Garcia score and beam balance test. The spatial distribution and cellular location of 5-LOX were detected by immunofluorescence staining. The expressions of 5-LOX and NF-κB in the damaged brain tissues were detected by Western blotting analysis. The activity of superoxide dismutase (SOD) and the content of malondialdehyde (MDA) around the lesion areas were determined by biochemical method. Results (1) Compared with the Sham group, neurological dysfunction was significant in the SBI-ld and SHI-3d and SHI-7d groups (P<0.01). and the BWC of injured brain tissue of rats was significantly increased in the SHI-1d and SHI-3d groups (P<0.05). The modified Garcia score in the SBI-7d group was significantly higher than that in the SBI-ld and SBI-3d groups (P<0.05). (2) 5-LOX was mainly distributed around the lesion areas, which was mainly localized in the cytoplasm of neurons, followed by glial cells and microglia. (3) The expressions of 5-LOX and NF-κB were significantly increased in the SBI-ld and SBI-3d groups (P<0.05) versus the Sham and SBI-7d groups. (4) Compared with the Sham group, the activity of SOD was significantly decreased in the other three groups (P<0.05); while the content of MDA was significantly increased in the SBI-ld and SBI-3d groups (P<0.05). Conclusion 5-LOX is mainly expressed in the neurons around the lesion areas after SBI. followed by glial cells and microglia, with the highest expression at 1 day after surgery. The mechanism by which 5-LOX aggravates brain injury may be related to increased expression of NF-κB and oxidative stress injury.