本文選題：去鐵胺　切入點：低氧誘導因子-1α　出處：《山西醫(yī)科大學》2012年碩士論文

【摘要】：目的：新生兒缺氧缺血性腦損傷(hypoxic-ischemic brain damage ,HIBD)是指各種圍生期窒息而導致腦的缺氧缺血性損害，臨床出現(xiàn)一系列腦病的表現(xiàn),是我國傷殘兒童致殘重要的原因之一。本實驗通過建立新生大鼠缺氧缺血性腦損傷(HIBD)模型，觀察缺氧誘導因子1α(hypoxia-inducible factor 1α)表達與去鐵胺（deferoxamine，DFO）可能的保護機制，為其在新生兒缺氧缺血性腦�。╤ypoxic-ischemic encephalopathy, HIE）的臨床應(yīng)用提供理論依據(jù)。 方法：新生7日齡Wistar大鼠120只隨機分為假手術(shù)組（8只）、HIBD模型組及去鐵胺（DFO）組，后兩組再根據(jù)處死時間不同又分為7個亞組：3h組、6h組、12h組、24h組、48h組、3d組及7d組，每亞組各8只。假手術(shù)組給予頸正中切口游離左側(cè)頸總動脈，不進行缺血缺氧。模型采用阻斷左側(cè)頸總動脈后置于含8%O2的低氧環(huán)境中2小時制備而成。去鐵胺組,制成HIBD動物模型前24 h以去鐵胺(200mg/kg,溶于生理鹽水)單次腹腔內(nèi)注射。各組分別于不同時間點處死動物,肉眼觀察腦組織大體形態(tài)變化，，光鏡下觀察各組大鼠左側(cè)腦組織HE染色的病理改變，并采用免疫組織化學方法檢測HIF-1α和Caspase3的表達。 結(jié)果：(1)缺氧缺血后新生大鼠出現(xiàn)不同程度的行為異常。(2)缺氧缺血后各時間點可見腦組織大體有不同程度的異常改變,去鐵胺干預(yù)后上述改變減輕。(3)HE染色：假手術(shù)組腦組織結(jié)構(gòu)及細胞層次清晰，神經(jīng)元排列整齊緊密；HIBD模型組各時間點出現(xiàn)不同程度的神經(jīng)細胞腫脹、變性、壞死，細胞核碎裂、溶解，神經(jīng)元數(shù)目減少，膠質(zhì)細胞增生。去鐵胺組各時間點損傷程度較HIBD組明顯減輕，神經(jīng)細胞存活數(shù)量多，細胞排列尚規(guī)則，僅見少量神經(jīng)細胞變性壞死。(4)免疫組織化學染色：HIF-1α及Caspase-3的陽性表達均呈棕黃色細顆粒沉積，陽性細胞可表達于大腦皮層和海馬，陽性著色主要位于神經(jīng)細胞胞漿及突起。①HIF-1α的表達：假手術(shù)組HIF-1α呈低水平表達，各時間點無明顯變化；HIBD模型組各時間點均可見HIF-1α陽性表達，同一時間點與假手術(shù)組相比，HIF-1α表達明顯增加，差異均有統(tǒng)計學意義（P0.05）。HIF-1α在HIBD后3h即增強，12h達高峰，之后逐漸降低；而DFO組則6h達高峰，12 h和24 h仍在較高水平，各時間點HIF-1α表達水平較HIBD組明顯升高,差異有統(tǒng)計學意義（P0.05）。②Caspase-3的表達：假手術(shù)組Caspase-3呈低水平表達，各時間點無明顯變化；HIBD模型組Caspase-3陽性表達，6h明顯升高, 12h和24h仍在較高水平，7d開始降低仍保持一定的表達水平，且各時間點表達高于假手術(shù)組,兩組差異有統(tǒng)計學( P＜0.05)；DFO組，3h輕微表達，12h明顯升高, 24h和48h仍保持一定的表達水平，7d開始降低,DFO組各時間點Caspase3表達低于HIBD組，兩組差異有統(tǒng)計學意義（P＜0．05）。TUNEL陽性細胞(AI指數(shù))表達主要分布于皮層及海馬區(qū)。假手術(shù)組TUNEL陽性細胞極少，HIBD組TUNEL陽性細胞較對照組增多,且隨著時間延長逐漸增多；兩組比較差異有統(tǒng)計學意義（P0.05）。DFO組TUNEL陽性細胞比HIBD組明顯降低，兩組比較差異有統(tǒng)計學意義（P0.05）。 結(jié)論：（1）新生大鼠給予去鐵胺后HIBD的可減輕腦組織的病理改變，提示去鐵胺對新生大鼠HIBD可能具有神經(jīng)保護作用。（2）去鐵胺可能通過上調(diào)HIF-1α的表達，降低HIBD后Caspase-3的表達，減輕HIBD病理損傷過程，抑制神經(jīng)細胞凋亡，從而對新生大鼠缺氧缺血引起的神經(jīng)細胞損傷起到一定的保護作用，進一步為臨床治療新生兒缺氧缺血性腦損傷提供新的治療思路。
[Abstract]:Objective : To observe the protective mechanism of hypoxia - inducible factor 1偽 ( hypoxia - inducible factor 1偽 ) and deferrioxamine ( DFO ) in neonatal hypoxic - ischemic brain damage ( HIBD ) and to provide a theoretical basis for the clinical application of hypoxic - ischemic encephalopathy ( HIE ) .
Methods : 120 Wistar rats were randomly divided into sham operation group ( 8 rats ) , HIBD model group and deferrioxamine ( DFO ) group . The rats were divided into 7 subgroups : 3h group , 6h group , 12h group , 24h group , 48h group , 3d group and 7d group .
Results : ( 1 ) Different degrees of behavioral abnormalities were observed in neonatal rats after hypoxia ischemia . ( 2 ) There were some abnormal changes in brain tissue at various time points after hypoxia ischemia .
The expression of HIF - 1偽 and Caspase - 3 was significantly lower than HIBD group . The positive staining of HIF - 1偽 and Caspase - 3 was found in the cerebral cortex and hippocampus .
HIF - 1偽 positive expression was found at all time points in HIBD model group , and the expression of HIF - 1偽 was significantly increased in the same time point compared with sham operation group ( P0.05 ) . HIF - 1偽 increased at 3h after HIBD , peaked at 12h , and then decreased gradually ;
Compared with HIBD group , the expression level of HIF - 1偽 in DFO group was significantly higher than that in HIBD group ( P0.05 ) .
Caspase - 3 positive expression in HIBD model group was significantly higher than that in sham operation group at 6 h , 12 h and 24 h , and the expression level was higher than that in sham operation group ( P < 0.05 ) .
The expression levels of Caspase - 3 in DFO group and DFO group were significantly higher than those in HIBD group ( P < 0.05 ) . TUNEL positive cells ( AI index ) were mainly distributed in cortex and hippocampus . TUNEL positive cells in sham operation group were very few , TUNEL positive cells in HIBD group were higher than those of control group , and gradually increased with time .
Compared with HIBD group , TUNEL positive cells in DFO group were significantly lower than those in HIBD group ( P0.05 ) .
Conclusion : ( 1 ) In neonatal rats , HIBD can reduce the pathological changes of HIBD . It is suggested that deferrioxamine may have neuroprotection effect on neonatal rat HIBD . ( 2 ) Deferrioxamine may inhibit the expression of HIF - 1偽 , decrease the expression of Caspase - 3 after HIBD , reduce the apoptosis of HIBD , and provide a new treatment for neonatal hypoxic - ischemic brain injury .

【學位授予單位】：山西醫(yī)科大學
【學位級別】：碩士
【學位授予年份】：2012
【分類號】：R722.1

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