IGF-1R抑制剂抑制糖尿病肾病小鼠肾脏纤维化

PossiblemechanismofIGF-1Rinhibitorinhibitingrenalfibrosisinmicewithdiabeticnephropathy

摘要:

目的：探究胰岛素样生长因子1受体（insulin-likegrowthfactor1receptor，IGF-1R）抑制剂抑制糖尿病肾病小鼠的肾脏纤维化。方法：选取90只8周龄C57/BL6雄鼠，依据随机数字表法分为5组，每组18只。依次为A组（糖尿病肾病组）、B组（IGF-1R组）、C组（血管紧张素转换酶抑制剂组）、D组（胰岛素组）和对照组。A组、B组、C组和D组雄鼠腹腔注射100mg/kg链脲霉素，48h随机血糖≥16.7mmol/L，尿糖（+~4+）定性为糖尿病。造模8周后，A组使用生理盐水灌胃，B组48h/次使用30mg/kgIGF-1R抑制剂灌胃，C组48h/次使用30mg/kgIGF-1R抑制剂灌胃，D组皮下注射1~2U/kg胰岛素。常规检测各组尿肌酐、血糖、24h蛋白排泄量。16周龄时对各组小鼠进行麻醉处死，收集其肾组织样本，行常规石蜡包埋后进行组织病理学检测。结果：对照组小鼠血糖正常，A组、B组和C组小鼠血糖均高于16.7mmol/L，D组小鼠血糖低于16.7mmol/L，差异具有统计学意义（P＜0.05）。A组小鼠尿蛋白排泄率高于对照组小鼠，B组和D组小鼠尿蛋白排泄率低于A组，差异具有统计学意义（P＜0.05）。A组小鼠尿蛋白肌酐比高于对照组小鼠，B组小鼠尿蛋白肌酐比低于A组，D组小鼠尿蛋白肌酐比低于A组，差异具有统计学意义（P＜0.05）。组织原位杂交检测，糖尿病肾病时肾组织中Snail1和IGF-1表达上调，A组小鼠IGF-1mRNA表达变化无统计意义（P＞0.05），Snail1mRNA表达明显降低，差异具有统计学意义（P＜0.05）。C组和D组小鼠肾组织中Snail1和IGF-1表达无明显变化（P＞0.05）。免疫组织化学染色，A组小鼠肾组织中Snail1和IGF-1表达高于对照组，差异具有统计学意义（P＜0.05）。B组小鼠IGF-1蛋白表达无明显变化，Snail1蛋白表达降低，差异具有统计学意义（P＜0.05）。C组和D组小鼠较A组小鼠Snail1和IGF-1蛋白表达无明显变化。结论：抑制IGF-1R或沉默IGF-1可抑制肾小管上皮细胞间质转分化，缓解肾纤维化。

Abstract:

Objective：Toinvestigatethepossiblemechanismofinsulin-likegrowthfactor1receptor（IGF-1R）inhibitorinhibitingrenalfibrosisinmicewithdiabeticnephropathy.Methods：Ninety8-week-oldC57/BL6maleratswereequallyandrandomlydividedintofivegroups：groupA（diabeticnephropathygroup），groupB（IGF-1Rgroup），groupC（angiotensin-converting-enzymeinhibitorgroup），groupD（insulingroup），andcontrolgroup.GroupsA-Dwereintraperitoneallyinjectedwith100mg/kgstreptozotocintoestablishadiabetesmodel，whichwasconfirmedwith48hrandombloodglucose（≥16.7mmol/L）andurineglucose（+~4+）.After8weeksofmodeling，groupAwasgivennormalsalinebygavage，groupBwasgiven30mg/kgIGF-1Rinhibitorbygavageonceevery48h，groupCwasgiven30mg/kgangiotensin-converting-enzymeinhibitoronceevery48h，andgroupDwasinjectedsubcutaneouslywith1-2U/kginsulin.Theurinecreatinine，bloodglucose，and24-hourproteinexcretionineachgroupwereroutinelytested.Attheageof16weeks，themiceineachgroupwereanesthetizedandsacrificed.Therenaltissuesampleswerecollectedandroutinelyparaffin-embeddedforhistopathologicalexamination.Results：Thebloodglucoseinthecontrolgroupwasnormal.ThebloodglucoselevelsingroupsA-Cwerehigherthan16.7mmol/L，andthatingroupDwaslowerthan16.7mmol/L.Therewasasignificantdifferenceinbloodglucosebetweenthegroups（P<0.05）.Theurinarypro－teinexcretionrateingroupAwassignificantlyhigherthanthatinthecontrolgroup（P<0.05）；theurinaryproteinexcretionratesingroupBandDweresignificantlylowerthanthatingroupA（P<0.05）.Theurinaryprotein/creatinineratioingroupAwassignificantlyhigherthanthatinthecontrolgroup（P<0.05）；comparedwithgroupA，groupsBandDhadasignificantlylowerurineprotein/creatinineratio（bothP<0.05）.InsituhybridizationassayshowedthattheexpressionofSnail1andIGF-1intherenaltissuewasup-regulatedinmicewithdiabeticnephropathy.Comparedwiththecontrolgroup，groupAhadnosignificantchangeinthemRNAexpressionofIGF-1（P>0.05），buthadsignificantlylowermRNAexpressionofSnail1（P<0.05）；nosignificantchangesinthemRNAexpressionofSnail1andIGF-1intherenaltissuewereobservedingroupsCandD（P>0.05）.Immunohistochemicalstainingresultsshowedthatcomparedwiththecontrolgroup，groupAhadsignifi－cantlyhigherproteinexpressionofSnail1andIGF-1intherenaltissue（P<0.05）；groupBhadnosignificantchangeintheproteinexpressionofIGF-1（P>0.05），buthadsignificantlylowerproteinexpressionofSnail1（P<0.05）.NosignificantchangesintheproteinexpressionofSnail1andIGF-1wereobservedingroupsCandDcomparedwithgroupA（P>0.05）.Conclusion：InhibitingIGF-1RorsilencingIGF-1caninhibitrenaltubularepithelial-mesenchymaltransitionandrelieverenalfibrosis.