異質(zhì)性細(xì)胞器

異質(zhì)性細(xì)胞器第1頁(yè)，課件共10頁(yè)，創(chuàng)作于2023年2月CharacteristicsofLysosomesLysosomeisaheterogenousorganelle（異質(zhì)性細(xì)胞器）:Primarylysosome（初級(jí)溶酶體）Secondlysosomes（次級(jí)溶酶體）

heterophagic（異噬溶酶體）

autophagic（自噬溶酶體）Residualbody（殘余小體）PrimaryLysSecondLys第2頁(yè)，課件共10頁(yè)，創(chuàng)作于2023年2月TheFunctionsofLysosomesLysosomesareinvolvedinthreemajorcellfunctions:①phagocytosis（吞噬）Asummaryofthephagocyticpathway第3頁(yè)，課件共10頁(yè)，創(chuàng)作于2023年2月②autophagy（自吞）Electronmicrographofamitochondrionandperoxisome(過(guò)氧化物酶體)enclosedinadoublemembranewrapperderivedfromtheER.Thisautophagicvacuolewouldhavefusedwithalysosomeanditscontentsdigested.第4頁(yè)，課件共10頁(yè)，創(chuàng)作于2023年2月③endocytosis（內(nèi)吞作用）第5頁(yè)，課件共10頁(yè)，創(chuàng)作于2023年2月DisordersResultingfromDefectsinlysosomalFunctionI-celldisease:Manycellsinthesepatientscontainlysosomesthatarebloatedwithundergradedmaterials.Whenfibroblastsfromthesepatientswerestudiedinculture,itwasfoundthatlysosomalenzymesaresynthesizedatnormallevelsbutaresecretedintothemediumandnottargetedtolysosomes.

第6頁(yè)，課件共10頁(yè)，創(chuàng)作于2023年2月TheI-celldefectwassoontracedtothedeficiencyofanenzyme(N-acetyglucosaminephosphotransferase)requiredformannosephosphorylation.Thesecretedenzymeslackedthemannosephosphateresiduethatarepresentonthecorrespondingenzymesofcellsfromnormalindividuals.第7頁(yè)，課件共10頁(yè)，創(chuàng)作于2023年2月Pompedisease:afatalinheritedcondition

intheabsenceofα-glucosidase,undigestedglycogenaccumulatedinlysosomes,causingswellingoftheorganellesandirreversibledamagetothecellsandtissuesDiseasesofthistype,characterizedbythedeficiencyofasinglelysosomalenzymeandthecorrespondingaccumulationofundergradedsubstrate,arecalledlysosomalstoragediseases第8頁(yè)，課件共10頁(yè)，創(chuàng)作于2023年2月Otherlysosomalstoragediseases

DiseaseEnzymeDeficiencyPrincipleStoragesubstanceconsequencesGM1Gangliosid-osisGM1β-GalactosidaseGangliosideGM1Mentalretardation,liverenlargement,skeletalinvolvement,deathbyage2Tay-SachsdieaseHexosaminidaseAGangliosideGM2Mentalretardation,blindness,deathbyage3Fabry’sdiseaseα-GalactosidaseATrihexosylceramideSkinrash,kidneyfailure,paininlowerextremitiesSandhoff’sdiseaseHexosaminidaseAandBGangliosideGM2andglobosideSimilartoTay-SachsdieasebutmorerapidlyprogressingGaucher’sdiseaseGlucocerebrosidaseGlucocerebrosideLiverandspleenenlargement,erosionoflongbones,mentalretardationininfantileformonly第9頁(yè)，課件共10頁(yè)，創(chuàng)作于2023年2月Tay-Sachsdisease:thebest–studiedlysosomalstoragediseases

Itresultsfromadeficiencyoftheenzymeβ-N-hexosaminidaseA,anenzymethatdegradesthegangliosideGM2

GM2isamajorcomponentofthemembranesofbraincells,andintheabsenceofthehydrolyticenzyme,thegangliosideaccumulatesinthebloatedlysosomesofbraincells,causingdysfunctionInitssevereform,whichstrikesduringinfancy,