人发角蛋白人工腱体内降解的形态学及泛肽、溶酶体酶的活性变化

目的阐明人发角蛋白(HHK)人工腱植入体内后的降解过程。方法选取30只新西兰大白兔,随机分为术后第1、3、6、9、12周实验组和正常对照组。实验组行跟腱切除后植入HHK人工腱,按期进行常规形态学观察和泛肽组化及酸性磷酸酶(AcP)酶细胞化学观察。结果光镜形态学观察显示,人工腱植入后第1周出现人发毛小皮脱落、消失,人发呈均质状,表面附着巨噬细胞和多核巨细胞,到第3~6周可见降解成颗粒的人工腱被巨噬细胞和多核巨细胞吞噬。泛肽酶组化显示第1~3周,人发周围的巨噬细胞、多核巨细胞和成腱细胞内反应呈强阳性,周围组织呈中等阳性,到第9周,大部分人发被降解,泛肽酶反应在基质呈弱阳性,在腱细胞中呈中等阳性。电镜形态学观察显示毛发之间出现成腱细胞,并开始分泌蛋白多糖和前胶原蛋白,第9~12周,人工腱基本被降解,同时完成了新生自体腱的形成。酶细胞化学观察显示被吞噬的颗粒呈AcP酶反应阳性。结论在HHK人工腱的降解过程中,泛肽系统首先在细胞外将大体积的人发降解,降解后期细胞内泛肽系统通路和溶酶体通路分别对吞入的人工腱颗粒进行降解,且具有协同作用。

Morphology of the degradation of human hair keratin artificial tendon in vivo and activities of ubiquitin and lysosomal enzyme in this process

Objective To understandthein vivo degradationprocessof humanhairkeratin(HHK)artificialtendon.Method A totalof30New ZealandWhiteRabbitswererandomlyassignedinto6groupsincluding1controlgroupand5operation groupsin whichspecimenswerecollectedat1,3,6,9,12postoperativeweeks,respectively.HHKartificialtendonswere implantedaftertenonectomyintheoperationgroupswhilethecontrolrabbitsreceivedimplantationwithnormalrabbittendon.The degradationof HHKartificialtendonwas observedmorphologicallyandby histochemistryfor ubiquitindetectionand cytochemistryforacidphosphatase(AcPase).Results Observationunderlightmicroscoperevealedthathumanhaircuticles brokeofffromtheimplantedhumanhairandresolved1weekaftertheimplantation,andmacrophagocytesandmultinuclear giantcells (MnGCs)wereseen attachedto thesurfaceof thehumanhairimplant.HHKartificialtendonwasbrokendown intosmallparticles,phagocytosedby the macrophagocytesand MnGCs3to6weeksafterthe implantation.Enzyme cytochemistryforubiquitindetectionproducedstrongpositivereactioninthemacrophagocytes,MnGCsandtenoblasts1to3weeksfollowingtheoperation,withmoderatepositivereactionintheextracellularmatrixintheninthweekwhenmostof the humanhairhadbeendegraded.Underelectronmicroscope,tenocyteswereseenin thehumanhairandsecretedmatrixto formcollagenfibers.Attheninth week,mostof HHKartificialtendonsweredegradedandautotendonreconstructioninduced by HHKartificialtendonshad completed.Cytochemistryshowedthatthe phagocytosedparticleswereAcPase-positive.Conclusion Largemassesof humanhairare firstdegradedextracellularlyby ubiquitinsystemandtheresultedparticlesare thenphagocytosedandfurtherdegradedby coordinatedactionof lysosomeandubiquitin,to completethedegradationprocess of HHKartificialtendons.