碱性成纤维细胞生长因子在周围神经损伤局部的基因表达与细胞定位

The expression and cellular localization of basic fibroblast growth factor mRNA in peripheral nerve following crushedinjury

目的观察碱性成纤维细胞生长因子(basicfibroblastgrowthfactor ,bFGF)mRNA在周围神经损伤后的局部表达规律及细胞定位。方法60只Wistar大鼠随机分为正常组(4只)、对照组和实验组(各28只)。用改良持针器钳夹大鼠坐骨神经制成神经挤压伤模型 ,分别于术后4h ,1、3、7、14、21、28d处死大鼠 ,切取包括挤压伤及其上下各2mm的神经段 ,应用引物原位标记技术 (primedinsitulabel ing,PRINS) ,结合光镜及计算机图像分析系统检测损伤局部的bFGFmRNA表达变化及细胞定位 ,分别以图像分析结果中灰度值和阳性面积值表示bFGFmRNA的表达强度和阳性细胞数。结果实验组于术后4h ,表达强度开始增加 (176.07±16.64) ,阳性细胞数增多[(725.33±60.45) μm2] ,与正常组及对照组比较差异有显著性意义 (均P<0.05) ;术后7d ,表达强度最高(122.89±10.77) ,阳性细胞数最多[(1876.35±108.40)μm2] ,与对照组比较差异有显著性意义 (均P<0.05) ;术后28d表达强度(189.85±19.51)及阳性细胞数[(605.25±36.40) μm2]均降至正常组及对照组水平 (P>0.05)。

ObjectiveToobservetheexpressionandcellularlocalizationofbasicfibroblastgrowth factor(bFGF)mRNAintheperipheralnervefollowingcrushedinjury.MethodsSixtymaleWistarrats (nineweeksold)wererandomlydividedintonormal(n=4),control(n=28)andexperimentalgroup(n= 28).Inthenormalgroup,allratswerenotoperateduponbeforesacrifice.Inthecontrolgroup,thesciatic nervewasonlyexposedbyoperation,whileintheexperimentalgroup,thesciaticnerveofratswerecrushedby modifiedneedleholderfor5minutesandSunderlandⅡtypeinjurywereproduced.Theratsweresacrificedat 4thhour,1,3,7,14,21,and28thday,andthecrushedregion(includingadjacent2mm)ofnervewerere movedfordectectingbFGFmRNA.Primedinsitulabeling (PRINS)combining withlightelectromicroscopy andcomputerimageanalysissystemwereusedtomonitortheexpressionintensityandnumbersofpositivecells ofbFGFmRNA.Thegraycolourscoresandsizeofarearepresenttheexpressionintensityandnumbersof positivecellsrespectively.ResultsTheexpressionintensity176.07±16.64andnumberofpositiveexpressing cells(725.33±60.45)μm2 begantoincreaseat4thhourinexperimentalgroup.Thedifferenceswereobvious comparingwithnormalandcontrolgroup(P<0.05).TheexpressionofbFGFmRNAreachedhighestlevelat 7thday,intensity122.89±10.77,positivecells(1876.35±108.40) μm2 andreturnedtothecontrollevelsat 28thdayaftercrushinginjury,intensity189.85±19.51,positivecells(605.25±36.40)μm2(P>0.05).bFGF mRNAweremainlyexpressedbySchwanncells,macrophages,fibroblastsandvascularendothelialcells. ConclusionTheincreaseoftheexpressionofendogenousbFGFmRNAmayenhanceregenerationofpe ripheralnerveafterinjury.