| Objectives To evaluate nuclear factor-κappaB（NF-κB）, interleukin-1β（IL-1β）and Toll-like receptor4（TLR4）expression changes and the effects of simvastatin onthe inflame-matory injury after intracerebral hemorrhage（ICH）in experimental rats,and further investigate the possible mechanism of the secondary inflammatory reactioninduced by ICH and the protective effects of simvastatin.Methods The intracerebral hemorrhage models were established by nonthrombogenicautologous blood injection method in rats. Rats were randomly divided into3groups:sham group; ICH group and SIM group. Each group was randomly divided into12hgroup,24h group,48h group,72h group, and7d group prespectively by different time. Aneedle was inserted into right basal ganglia and removed after15minutes. In contrast,50μl autologous artery blood was injected into the ipsilateral basal ganglia at a rate of7~10μl/min in ICH and SIM groups. The SIM groups were injected into simvastatin（3mg kg-1d-1）by intragastric administration. The behavioral changes were detected withneurologic deficit score by Garcia method. By employing Brain edema changes, thewater content of brain was checked up with dry/wet weight method. The histo-pathological changes were measured by Nissl staining and HE staining, the location ofNF-κB, TLR4and IL-1β around the hematoma in cerebral tissues was determined byimmunofluorescence. The number of Positive cells and the level of protein expressionabout NF-κB, TLR4and IL-1β in cerebral tissues were determined byimmunohistochemistry and western blot.Results1Neurological function is normal on six aspects: Spontaneous activity (in cagefor5min)， Symmetry of movements（four limbs）, Symmetry of forelimbs（outstretching while held by tail），Climbing wall of wire cage，Reaction to touch oneither side of trunk，Response to vibrissae touch. Neurological function score wassignificantly decreased in the ICH group but the score was increased in the SIM groupcompared with the ICH group（P<0.05）. The Nissl’s body of neuron cell in ICH groupwere obviously lost，by contrast the numbers of the Nissl’s body were increased in theSIM group compared with the ICH group（P<0.05）.2The water content of brain incerebral tissues in ICH group was obviously increased at ICH12h, and reached the peak at72h, and was higher than those in sham-operated group at each time point（P<0.05）.3The level of the expression about NF-κB and TLR4in the ICH group: the expression ofNF-κB and TLR4in ICH group was significantly increased at ICH12h, reached the peakat72h, and gradually reduced at the following time. There was a correlation between theexpression of NF-κB and TLR4（P<0.05）; NF-κB and BWC（P<0.05）; TLR4andBWC（P<0.05）. The result of double-labeling immunofluorescence assay: the NF-κBand the TLR4, and the NF-κB and the IL-1β are obtained double staining.4The changesof protein expression about NF-κB, TLR4and IL-1β determined by western blot in eachgroup after injection of simvastatin: Compared with the Sham group, the expression ofNF-κB, TLR4and IL-1β following ICH was much higher. The results detected byimmunohistochemistry support it（P<0.05）.Conclusions1NF-κB, TLR4and IL-1β may worsen inflammation and take part in thepathological process of brain edema around the hematoma in the ICH rats.2In the ICHrats, regulate the inflammatory reaction by inhibiting expression of NF-κB, acrossdecreased the TLR4, and process the occurrence of apoptosis around the hematoma.3Our results indicate that injection of SIM at the onset of ICH is associated with activationof TLR4and amelioration of the brain injured; it is thought to reduce behavioral deficitand neuronal damage. |
