| Objective:Acute Ischemic Stroke(AIS)is the most common type of stroke,with high morbidity and mortality.The lateral circulation in AIS patients is the critical determinant of the "tissue time window",helping to maintain cerebral perfusion after arterial occlusion and thus improving the survival of brain tissue.Therefore,actively increasing the head blood flow of AIS patients to improve collateral circulation and save the ischemic penumbra(IP)are the difficulties and key points.Head down position(HDP)is a physical intervention method,using gravity to influence the blood flow distribution,easily and quickly increasing the blood flow in the head.Although related research on HDP has become a hot topic in recent years and its neuroprotective role in AIS patients has gradually clarified,the relevant mechanism of neuroprotection is unclear.Moreover,relevant experiments are still scarce in basic research,and there were no clear experimental conditions for HDP intervention.Based on the preliminary basic experiments and clinical trial results of the research group,and by establishing of rat brain ischemia-reperfusion(IR)model,this study gradually defines the optimal conditions for HDP intervention in terms of further exploring the possible mechanisms of its neuroprotective effect.While based on the research of the research group,utilizing the prospective database.xHOPES2(Head dOwn-Position for acutE moderate ischemic Stroke with large artery atherosclerosis)for a secondary analysis,this study is set to explore whether there is an association between HDP and some clinically relevant indicators or past medical history,providing a clinical basis for targeting a more appropriate population for HDP,also trying to use traditional Chinese medicine(TMC)theory to explain its relevance,hoping to provide a theoretical basis for the development of HDP in the field of TCM.Materials and Methods:There are three parts for animal experiment.The experimental animal was Sprague-Dawley(SD)rats.The rat IR model was established by line bolt occlusion of the middle cerebral artery.In experiment 1,all rats used for this study were randomized into sham group,IR group,and HDP group,compared the efficacy of IR model rats,selected appropriate intervention Angle(10°,20°,30°),time(1h,3h),and intervention timing(time 1:ischemia-reperfusion,time 2:3h after ischemia-reperfusion,time 3:6h after ischemia-reperfusion,time 4:12h after ischemia-reperfusion).In experiment 2 and 3,there are three groups,which are head low intervention group(intervention condition was obtained from experiment 1),control group,and sham group.During the experiment,a multi-angle temperature control platform and a rat one-way cage were used to intervene in the head.1 To clarify the optimal conditions for the HDP interventionIn experiment 1,after the low head intervention,rats were scored,weighed,and collected brains 24 hours after the establishment of the IR model.The neurological deficit score scale was used to assess the neurological deficit,all data regarding the volume of weight change,mortality,and cause of death before and after surgery were recorded;2,3,5-triphenyl chloride tetrazolium(TTC)staining to calculate volume of the cerebral infarction;and the water content of brain tissue was calculated by dry and wet method.2 To define the neuroprotective effects of HDPHematoxylin and Eosin(HE)staining to evaluate the pathological changes of the brain tissue;Nith’s staining to evaluate nerve cell apoptosis in brain tissue;Terminal deoxynucleotidyl transferase-mediated dUTP Nick-End Labeling(TUNEL)staining to clarify the apoptosis of the total nerve cells in the brain tissue;Immunofluorescence staining to evaluate the polarization of microglia;Western blot(WB)to detect the protein expression of apoptosis-related protein Bel 2-Associated X protein(Bax),B-cell lymphoma-2(Bel 2),Cleaved-Caspase3,Caspase3,and blood-brain barrier(BBB)related protein Matrix metalloproteinase-9(MMP-9),the tightly linked protein ZO-1,Claudin-5,multidrug resistance-associated protein-1(MRP 1),P-glycoprotein(P-gp)in ischemic penumbra tissue.3 To explore the mechanisms underlying the neuroprotective effects of HDPWB detected the protein expression of phosphoinositide 3 kinase(PI3K),serine-threonine protein kinase(Akt),phosphorylated Akt(p-AKT),mammalian target of rapamycin(mTOR),vascular endothelial growth factor(VEGF),endothelial nitric oxide synthase(eNOS),Nuclear factor kappa-B(NF-κB),phosphorylated NF-κB(p-NF-κB)?inhibitor kappa B-α(I κ B α),phosphorylated-I κ B α(p-I κ Bα)in the ischemic penumbra tissue to clarify the relevant mechanisms of HDP neuroprotection;Luminex technology to detect the inflammatory factors in serum.4 The investigation on interaction of plasma protein-related index and HDP efficacy in both Chinese and Western medicine perspectiveThis study was based on a secondary analysis of the prospective database HOPES2,including 72 patients who had completed the HOPES2 study and had plasma protein-related indicators.Baseline demographic and clinical data were collected from the electronic data acquisition system,including age,gender,current smoker,current drinker,hypertension,coronary heart disease,hyperlipidemia,past stroke,diabetes,baseline National Institute of Health Stroke Scale(NIHSS),baseline systolic blood pressure and diastolic blood pressure,the site and degree of vascular stenosis,and antithrombotic treatment regimen,etc.According to baseline data to group total protein(TP),albumin(ALB),globulin(GLB)by using a median number,patients were divided into low TP and high TP,low ALB and high ALB,low GLB and high GLB groups,respectively.The endpoint event was the 90-day modified RANKKIN scale(mRS)score.5 The investigation on interaction of coronary heart disease history and HDP efficacy in both Chinese and Western medicine perspectiveThis study was based on a secondary analysis of the prospective database HOPES2,including 88 patients who had completed the HOPES2 study and had a clear history of CHD.Baseline demographic and clinical data were collected from the electronic data collection system,including age,gender,current smokers,current smokers,drinkers,hypertension,coronary heart disease,hyperlipidemia,past stroke,diabetes,baseline NIHSS,baseline systolic blood pressure and diastolic blood pressure,vascular stenosis,and antithrombotic treatment,etc.Two group was planned according to subject suffered coronary heart disease or not.The endpoint events are defined as the improvement in NIHSS scores at 12 days and 90 days.Result:1.HDP intervention can reduce the symptoms of neurological deficit,reduce the volume of cerebral infarction,and improve cerebral edema,which is safe and effective;after the screening of intervention angle,duration,and intervention timing,the intervention is the best effect of ischemia-reperfusion.2.HDP intervention can play a neuroprotective role by reducing the damage to the blood-brain barrier,protecting the integrity of the blood and brain barrier,reducing neural tissue edema,and rescuing the IP area by reducing the apoptosis of the IP area and reducing the volume of cerebral infarction.3.HDP intervention can achieve neuroprotective effects from anti-inflammatory,promotion of PI3K/Akt signaling pathway,inhibition of apoptosis,and protection of BBB integrity,including NF-κB,VE GF,eNOS,Bcl 2,Bax and Caspase3.It provides an experimental basis for the exploration of mechanisms related to the neuroprotective effects of HDP.4.The interaction between the neural effect of plasma protein and HDP:for people who has relatively low levels of plasma protein,the neuroprotective effect of HDP is more obvious,while for relatively high levels,the neuroprotective effect of HDP is weakened or even disappeared.In perspective of traditional Chinese medicine,for people with ischemic stroke and relatively low levels of plasma protein,if they were set to head low position to increase cerebral perfusion,by enhancing "filling deficiency",it will withstand the deficiency caused by the low plasma protein levels,while for people with relatively high levels of plasma protein,head low deficiency" is weakened or even disappear.5.The interaction between coronary heart disease history and neuroprotective effect of HDP.For people with a history of coronary heart disease,the neuroprotective effect of HDP is more significant than that in those without a history of coronary heart disease,this may be related to the increase of cardiac output,stroke volume and the decrease of peripheral resistance.In perspective of traditional Chinese medicine,the body position with the head low and the foot high redistributes the blood,the lower coke blood corrects the deficiency of the heart and the qi,the redistribution of blood to the important organs corrects the loss of the viscera and meridians,and the two "treat different diseases" in the way of filling deficiency".Conclusion:1.For IR model rats,the best conditions for HDP intervention were:low 20 head intervention for 1 hour immediately during successful ischemia and reperfusion.2.HDP intervention is safe and effective,which can relief the edema of nerve tissue by reducing the damage on IR model rats.It can also protect nerve cell in two ways,firstly to decrease IP nerve cell apoptosis and inflammatory response to save IP area,meanwhile,to reduce the volume of cerebral infarction.3.The neuroprotective mechanism of HDP is possibly related to the activation of the PI3K/Akt signaling pathway and the intervention of multiple downstream molecules protein expression including NF-κB,VEGF,eNOS,Bcl 2,Bax,and Caspase3,with all aspects on anti-inflammation,promotion of vascular endothelium,inhibition of nerve cell apoptosis,and protection of the integrity of the blood and brain barrier.4.For the secondary molecules of the clinical prospective database,it states that plasma protein and other related indicators have some interaction with the protection between coronary heart disease history and neuroprotective effect of HDP,and the neuroprotective effect of HDP was more obvious in people with relatively low levels plasma protein and related indicators and those with a history of coronary heart disease.5.Low plasma protein,coronary heart disease,and stroke are all interpreted from the perspective of traditional Chinese medicine.The intervention method of HDP may be corrected by "supplementing deficiency". |
PDF Full Text Request