Effect Of Activated PPAR? On Phagocytosis Of Microglia Cells And Expression Of CD36 In Rat Brain Tissue Around ICH

Part? Effects of activating PPAR?on the phagocytic ability and CD36 expression in thrombin-activated microglia Objective: To investigate the effects of regulating PPAR ? on phagocytic activity and expression of CD36 in microglial cells activated by the thrombin.Method: Primary microglial cells were obtained from the brain tissue of newborn Sprague–Dawley rats.Following successful culture and separation of the primary microglias,they were randomly divided into four groups: a control(Control)group,a thrombin stimulation group(TH),a PPAR?agonist group(RSG),and a PPAR?antagonist group(GW9662).The microglial cells were labeled OX-42 and identified by the immunofluorescence microscopy.Laser confocal microscopy was used to observe the microglial ability to phagocytose the red fluorescent microspheres.The levels of PPAR?and CD36 were determined by a RT-PCR method and Western-blot.Result: The purification rate of microglia detected by the immunofluorescence microscopy was above 95%,The laser confocal microscopy showed that the microglial cells in each group could phagocytose the red fluorescent microspheres.The PPAR ? agonist group(RSG)showed a significant increase in phagocytic activity compared to the other groups,while the PPAR?antagonist group(GW9662)significantly reduced the microglial phagocytic ability compared to the PPAR ? agonist group(RSG)and the control group(Control).The Western-Blot and RT-PCR showed that the PPAR? and CD36 protein as well as m RNA could be observed in each group.However,the PPAR? and CD36 increased considerably in the RSG group compared with the control and the TH group(P<0.01).On the contrary,the levels of the PPAR ? and CD36 decreasedremarkably in the PPAR?antagonist group(GW9662)compared to the PPAR?agonist group(RSG)(P<0.01).Conclusion: Activation of the PPAR? could increase the phagocytic ability of the microglial cells activited by the thrombin,and could promote the expression of the PPAR? and the CD36.Part? Effects of Activating PPAR?on Perihematomal Distribution of Microglial Cells and the Expression of PPAR?and CD36 in Rat Model of ICHObjective: To observe the effects of activating PPAR? on the perihematomal distribution of microglial cells,the expression of the PPAR? and CD36 in rat model of ICH.Methods: Ninety-two healthy,male rats were randomly divided into four groups:control group(Control group),ICH model control group(ICH group),PPAR?agonist group(RSG group),and PPAR? antagonist group(GW9662 group).In the Control group,the animals only received the process of puncture without injection of blood into the brain.For the other three groups,autologous arterial blood taken from the rats' tail was injected into the basal ganglia to establish the ICH model.The RSG group received infusion of the rosiglitazone into the stomach 3 days prior to model preparation.For the GW9662 group,the GW9662 was intraperitoneally injected after the ICH model was established successfully.The neurological function scores were determined at 6h,24 h,48h,and 72 h in each group before the animals were sacrificed.The brain was taken out after the animals were killed and the brain tissues were fixed with paraformaldehyde for histomorphological observation.A HE staining was used to observe the brain edema in the model control group.Immunohistochemistry was used to observe the perihemoatomal distribution of the microglial cells,the expression of the PPAR ? and the CD36.The levels of the PPAR?and CD36 around the hematoma were determined by the method of Western blot and RT-PCR.Results: The neurological function scores in the RSG group reduced significantly compared with those in the ICH group at each time point(P<0.01).In the GW9662 group,however,the neurological function scores increased significantly compared to those in the RSG group(P<0.01).Histomorphologically,the hematoma was found to be located in the basal ganglia,and squeezed the surrounding brain tissue.The HE staining showed that the brain edema was very remarkable 72 hours after the model was established successfully.Simultaneously,the OX-42-labeled perihematomal microglial cells became strong positive.Immunohistochemistry showed that the expression of PPAR ? and CD36 increased significantly in ICH group and the RSG group compared with the control group,especially in the RSG group.The expression of the PPAR?and the CD36 decreased significantly in the GW9662 group compared with the RSG group.The RT-PCR showed that the PPAR?and the CD36 protein and m RNA were observed in each group.The levels of the PPAR?and the CD36 were the highest in 72 hours compared to other time points after successful preparation of the ICH model.The expression of PPAR?and CD36 increased in the RSG group compared with the ICH group(P<0.01).However,the expression of PPAR?and CD36 decreased in the GW9662 group compared with the ICH group as well as the RSG group(P<0.01).The Western-blot method also obtained similar results.Conclusion: Activation of the PPAR ? could modulate the perihematomal distribution of the microglial cells,increase the expression of PPAR ? and CD36,and improve the neurological functions.