Effects Of Desflurane On Cognitive Function In Mice With Central Inflammation And Its Mechanism

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Effects of desflurane pretreatment on degranulation of mast cells and neuroinflammatory response in miceObjectives: The purpose of this study was to determine whether desflurane prevents mast cells(MCs)from degranulation in the acute inflammation of CNS model induced by lateral ventricular injection with Compound C48/80(C48/80)in C57BL/6 male mice,and to explore the mechanism related of desfluraneMethods: Total 100 C57BL/6 male mice were randomized and allocated into four group:(1)the saline group(Lateral ventricular injection with 0.9% Na Cl 1?L);(2)the C48/80(Lateral ventricular injection with C48/80 1?L(1?g/?L));(3)the CRO+C48/80 group(lateral ventricular pre-injection with Cro1 ?L(15?g/?L),and injection with C48/80 at the same site in half an hour later;(4)the DES+C48/80 group(first inhalation with the mixture gases(100% oxygen+7.5% DES)for 2 h,and then receiving lateral ventricular injection with C48/80 1?L.Brain slices at thalamus were prepared for toluidine blue staining(mast cells)and immunochemistry(fluorescence of Iba1 and GFAP,respectively),and brain tissues were extracted for western blotting to probe IL-6,TNF-?,NF-?B,JNK and p-JNK,p38 and p-p38,TLR4 and NF-?B in comparison the control of GAPDH.Results:1.The results indicated that after the thalamus of mice brain was lateral ventricular injected with the C48/80,the number and degree of MCs granulation were facilitated(P < 0.01).2.The results showed that after the thalamus of mice brain was lateral ventricular injected with the C48/80,the microglia and astrocytes were activated,and the fluorescence intensities of Iba1 and GFAP were both increased respectively under immuno-fluorescence(p < 0.05).3.The expression levels of IL-6,TNF-?,NF-?B,p-JNK,p-p38,and TLR4 were augmented after c48/80 being injected into lateral ventricular under Western blot(P < 0.05).4.Pretreatment of desflurane preserved and prevented MCs from degranulation,decreasing the fluorescent intensities of Iba1 and GFAP,inhibiting activation of hypothalamic microglia and astrocytes.The potency of desflurane was displayed as the same as sodium cromolyn did.5.Pretreatment of desflurane and cromolyn sodium prevented neuroinflammation C48/80-induced in the lateral ventricle,showing that the expression of IL-6,TNF-?,NF-?B,p-JNK,p-p38,and TLR4 were reduced(P < 0.05).6.Compared with cromolyn sodium pretreatment group,there were no statistically significant difference on degranulation of Mcs,the fluorescence intensities of Iba1 and GFAP,and the expression levels of IL-6,TNF-?,NF-?B,p-JNK,p-p38 and TLR4 in desflurane pretreatment group(P > 0.05).Conclusions:1.Degranulation of mast cells and neuroinflammation were induced by lateral ventricular injected with the C48/80 in mice.2.Desflurane and cromolyn sodium had the same effect on inhibiting degranulation of mast cells and neuroinflammation.3.Desflurane can inhibit the acute inflammation degranulation of mast cell induced through p-JNK/p-p38-TLR4-NF-?B pathway,providing a new avenue for the application of desflurane in perioperative inflammatory diseases of the central nervous system.Part ? Effect and mechanism of desflurane on neuroinflammation induced by MPTP in Parkinson's disease miceObjectives: To observe the effects of desflurane on oxidative stress in mice with chronic PD model established by intraperitoneal injection of MPTP,and to explore its related mechanism involving central nervous system.Methods: Model of chronic Parkinson's disease(PD)was developed using one hundred of the 120 healthy adult C57BL/6 with body weight of 26~30 g aged 20~24 weeks by intraperitoneal injection of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP)(4mg/kg)for 20 consecutive days.In addition,the control group(Saline group)mice were established by intraperitoneal injection of 0.9% sodium chloride injection with dose of 2ml/kg.The PD mice were randomly divided into four groups by random number table method after success of PD model tested by pole test: MPTP + DES0 group,MPTP + DES1 group,MPTP + DES2 group,and MPTP + DES4 group.The inhalation time of DESflurane(7.5% desflurane + 100% oxygen)in the four groups of PD mice was 0,1,2,and 4 hours,respectively,and and all the mice were sacrificed for the following tests.Degranulation of mast cells in substantia nigra,striatum,hippocampus and cortex were observed by toluidine blue staining.Immunohistochemical staining was used in substantia nigra and striatum of mice.The expression of ionized calcium binding adaptor molecule-1(Iba1)and glial fibrillary acid protein(GFAP)was detected by immunofluorescence assay.Western blot was applied to detect the protein expression of p38 mitogen-activated protein kinase(p38),phosphorylated p38 mitogen-activated protein kinase(p-p38),toll-like receptor 4(TLR4),interleukin-6(IL-6),and tumor necrosis factor-alpha(TNF-?)in hippocampal and frontal cortex tissues.Results:The PD model was established as follows: four of one hundred mice died during the modeling process.On the 21 st day,the results of the pole test showed that the time of pole test in PD group mice were significantly reduced compared with the saline group(P < 0.01),indicating that the chronic PD model was successfully established.Toluidine blue staining found that,compared with saline group,PD model mice had a higher degranulation and ratio of degranulation cell with intraperitoneal injection of MPTP,in the substantia nigra and striatum,hippocampus,and cortex(? < 0.05).MCs degranulation was characterized by cell enlargement,cell membrane rupture and even disappearance,and the release of intracellular granule.Compared with not inhalation of desflurane,degranulation of MCs were partially restrained with inhalation of desflurane in one hour(P < 0.05),which were still lower than those in control group.There were no statistical significance in ratio of mast cell degranulation in group desflurane inhalation with 2 hours and 4 hours,compared with the group without desflurane inhalation.Immunohistochemistry in substantia nigra of mice showed that,compared with saline group,dopamine positive cells were significantly decrease with intraperitoneal injection of MPTP(P < 0.05),however,the dopamine positive fiber density in striatal had no statistical effect by ntraperitoneal injection of MPTP(P > 0.05).Reduction of positive dopaminergic cells were suppressed by inhalation of 7.5% desflurane with 100% oxygen in one hour,which were not inhibited in two and four hours in inhalation of 7.5% desflurane with 100% oxygen.Immunofluorescence displayed that microglia and astrocytes were actived by intraperitoneal injection of MPTP with expression of Iba1 and GFAP increased in substantia nigra,striatum,hippocampus and cortex of PD model.The expression of Iba1 and GFAP were inhibited by inhalation of 7.5% desflurane with 100% oxygen in PD mice.Compared with the group without desflurane inhalation,there were no statistical significance on expression of Iba1 and GFAP in group desflurane inhalation with 2 hours and 4 hours respectively.Western blots detection revealed that compared with the saline group,the expression of p-p38,TLR4,TNF-?,and IL-6 in hippocampus and frontal cortex were significantly higher than that in PD group(P < 0.05).The expression of p-p38,TLR4,TNF-?,and IL-6 induced by MPTP were inhibited after desflurane treatment in one hour,however,those inflammatory factors related were not influenced by desflurane management both two and four hours.Conclusions:1.Chronic PD model was successfully established by intraperitoneal injection of MPTP(4mg/kg)for 20 consecutive days.2.Degranulation of mast cells and neuroinflammation induced by MPTP were reduced in the substantia nigra,striatum,hippocampus and frontal cortex with inhalation of 7.5% desflurane miture 100% oxygen.3.Neuroinflammation MPTP-induced was prevented with treatmen of 7.5% desflurane combined 100% oxygen,and its mechanism was acheived by inhibiting the p38-TLR4 pathway.Part ? Effect and mechanism of DESflurane on cognitive function in Parkinson's disease mice induced by MPTPObjectives: To observe the effects of desflurane on cognitive function in mice with chronic PD model builded by intraperitoneal injection of MPTP,and to explore its related mechanism involving central nervous system.Methods: Model of chronic Parkinson's disease was established using healthy adult C57BL/6 by intraperitoneal injection of MPTP(4mg/kg)for 20 consecutive days),and the control group(Saline group)mice were intraperitoneal injected with 0.9% sodium chloride injection(2ml/kg).The PD mice were randomly scheduled into four groups after modeling PD: MPTP+DES0 group,MPTP+DES1 group,MPTP+DES2 group,and MPTP+DES4 group.The inhalation time of desflurane(7.5% desflurane +100% oxygen)in the four groups of PD mice was 0,1,2,and 4 hours,respectively.All the mice were detected in motor function by hang test and open field test from 22 nd day to 24 th day after inhalation,conducted in cognitive function using Y maze and fear condition experiment from 25 th day to 26 nd day,and sacrificed on the 27 rd day.Western blot was used to detect Janus kinase 2(JAK2),phosphorylated Janus kinase 2(p-JAK2),signal transducer and activator of transcription 3(STAT3),phosphorylated signal transducer and activator of transcription 3(p-STAT3),Tau protein,phosphorylated Tau protein(p Tau),and postsynaptic density protein 95(PSD-95)expression in the hippocampal and frontal cortex of mice,which were killed at the 33 rd day after inhalation.Results:1.Hang test showed that,compared with the saline group,MPTP-treated mice had significant suspension time loss(P < 0.01).Compared with the MPTP+DES0 group,the MPTP+DES1 group showed a significant increase in suspension time(P < 0.01).There were no statistical significance in suspension time in group desflurane inhala-tion with 2 hours and 4 hours,compared with the group without desflurane inhalation.2.Open field test found that,compared with the control group,MPTP-treated mice had significant decrease in total distance and journey of exploration(? < 0.01).Compared with the MPTP+DES0 group,the MPTP+DES1 group and MPTP+DES2 group indicated a significant increase in total distance and journey of exploration(P < 0.05).There were no statistical significance in total distance and journey of exploration in group desflurane inhalation with 4 hours,compared with the group without desflurane inhalation.3.Y maze revealed that,compared with the saline group,MPTP-treated mice had significant decrease in independent alternating rate(P < 0.05).Compared with the MPTP+DES0 group,the MPTP+DES1 group showed a significant increase in independent alternating rate(P < 0.05).There were no statistical significance in independent alternating rate in group desflurane inhalation with 4 hours,compared with the group without DESflurane inhalation.4.Fear conditioning test displayed that,compared with the saline group,MPTP-treated mice had significant decrease in time of stiffened(P < 0.01).Compared with the MPTP+DES0 group,the MPTP+DES1 group showed a significant increase in time of stiffened(P < 0.05).There were no statistical significance in time of stiffened in group desflurane inhalation with 2 hours and 4 hours,compared with the group without desflurane inhalation.5.Western blots detection revealed that,compared with the saline group,the expression of p-JAK2 and p-STAT3 in hippocampus and frontal cortex were significantly higher than that in PD group(P < 0.05),furthermore,the expression of PSD-95 were lower than that in PD group(P < 0.05).The expression of p-JAK2 and p-STAT3 induced by MPTP were inhibited after desflurane treatment in one hour,however,those protein related cognition were not influenced by desflurane management both in two and four hours.The expression of PSD-95 were promoted in PD mice by desflurane treatment in one hour.The expressions of Tau and p-Tau were not independently affected by MPTP and desflurane(P > 0.05).Conclusions:Impairment of motor and cognitive functions induced by MPTP were restrained with inhalation of 7.5% desflurane miture 100% oxygen for one hour,and its mechanism was acheived by inhibiting phosphorylation pathway of JNK2-STAT3,and promoting expression of PSD.