Immunohistochemical Study Of CD24 In Mammary Epithelial Small Light Cells During Different Development Stage

Rodentine mammary epithelium first emerges from mammary gland zone,which can develop into future glandular tube systemic sprout.After 3 weeks,controlled by sex hormone glandular tube system ingresses fat pads and forms terminal end buds (TEBs),which is the genesis of mammary ducts,is one kind of body cell corps surrounded by outer goblet cell.Accompanied by ducts stretching and TEBs developing,the ducts of the mammary gland comprise an outer tube of myoepithelial cells juxtaposing an inner tube of lumenal epithelial cells surrounding a central lumen. During the process of duct lumen development,body cells often apoptosis and goblet cells can enter body cells layer,thereof goblet cells are called the origin of stem cells.The mature mammary can comprise of cells having similar stem cells function. Rodentine mammary cells can quickly proliferate and lead to a great branch and secretory vacuole similar to grape emerge.In secretory vacuole,lumen epithelium produce milk,but myoepithelial epithelium can squeez milk into ducts through contraction.Once weaning,these structure usually disappear because of apoptosis,as don't happen pregnant process,ducts structure in fat pads may become quite thin. Such as circulation would happen many times in life.Only proliferation latent of stem cells can sustain the above process,hint the presence of temporary stem cells, which stand still before sexual stimulus.Furthermore the no complement process exists in estrous cycle.Identical circulation can happen to pregnancy and menstrual cycle of the humen,but the degree of proliferation is different.In addition,mature mammary epithelial stem cells(MaSC) may function specially during the usually mammary cell renew.During lactation,deciduous epithelial cells can be founded in milk.Deciduous cells into duct system must be added,otherwise the quantity of epithelial cells can not retain constantly;the kind of cells which posseses the function may be persistent active stem cells.As for mature mammary epithelium,stem cells at least hold in two manifest distinctly roles, including the transit and the persistent.Although stem cells exist mammary tissue,to present,there is not a specific marker of MaSC,many researcher utilize of a great of way such as mammary sphere cultivation,BrdU labeling,cell surface marker including Sca-1 and CD49f identification,Hoechst staining etc.to identify MASC.Especially,the phenotype analysis of MaSC based on surface antigen becomes the key technique to research the biology trait and select efficiently MaSC to clinical transplantation therapy;the phenotype analysis technique have been operated entensively to isolate subtype cells nowadays,of which Sca-1 molecule is the most common marker.But recently some datas verify the existence of Sca-1^---MaSCs,Stingl sorted out CD49f⁺/Sca-1^hi mammary epithelium cells through Flow Cytometry,the kind of cell can't develop clone during translation experiments,but CD49f/Sca-1^low cell have quite strong restitution ability,and mammary epithelium cells expressing CD49f⁺ phenotype can lastly express Sca-1 through cultivation,which imply on Sca1^---MaSCs is more primitive than Scal⁺--MaSCs.Alvi etc found SP and non-SP have similar clone regeneration ability,although which include 15.8%Sca-1 in SP and 1.8%Sca-1 in non-SP cells respectively,(To isolate haematopoietic stem cell through Hoechst dye and Flow Cytometry,the SP subtype cell is found,which holds in the self-renewal and multi-differentiation ability,and taked as common stem cell phenotype) Thus,it is quite necessary to find new and more particular phenotype of stem cell.The antigen CD24 provokes attention during the researcher.Most recently,Shackleton etc. made mammary tissue into single cell suspension,then sorted out special phenotype cells through Flow Cytometry,and lastly these cells were injected into LacZ transgene mice body,they found all mice inoculated Lin'CD29^hiCD24⁺ cells can develop obviously clone in 10 weeks.Although the correlated research is not profound,the perspective is attractive.There is a kind of special morph epithelium cells distributed along ducts and acinus.Observing above cells through optics microscope,its shape is round,nucleus strong basophilia and located in central,the ratio of nucleus and cytoplasm high, cytoplasm having little cell organelle and transparent.The kind of kind is called as small light small(SLC),and the similar cell can be found in the human mammary tissue.Presently,most researcher insist the SLC represent MaSCs.Modeled by mature mouse and adopt histology,immunohistochemical technique and light microscope detection,we investigate mammary development rule of mature mouse, the genesis and succession of peripheral tissue,and the expression quantity and location of CD24 positive on SLC in mature mouse mammary tissue.One:the morphology of different development stage about mature mouse mammaryObserving the mouse mammary tissue during 3 months in virgin,pregnant 13 days,postnatal 7 and 21 days after HE dye experiments.The result reveal,the mammary mostly consist of connective tissue and adipose tissue during unpregnancy 3 months and postnatal 21 days,ducts and acinus of the epithelium tissue is little, sole or clustering distribute sporadic into connective or adipose tissue.Located in ducts or acinus,the cell body of SLC is small,some SLC appear to be embedded within recesses or indentations in the bodies of luminal cells,which consequently isolated them from basement membrane direct contact or exposure,SLC reside directly above a myoepithelial cell,the mammary epithelium cells extensively proliferate into mammary duct stroma during pregnant 13 days andpostnatal 7,the quantity of acinus increases,the cell body of glandular epithelium cell become big, we can more conveniently find SLC in ducts and acinus,and occasionly see the cluster of cell made of 1-3 SLC near to basement membrane.Two:Immunohistochemical study of CD24 in mammary epithelial small light cells during different developing stage and statistics analysisWe observe the expression of CD24 in mammary epithelial small light cells through enzyme linked immunosorbent assay technique,and statistics the result of CD24 positive cells during enzyme linked immunosorbent assay.Immunohist -ochemical study reveal whether in ducts or acinus epithelium cells,the CD24 positive SLC is observed in all the four stage,the dye degree is more high in ducts than acinus;contrary to quiescence and degeneration,CD24 is more high in gestation and lactation;there is no difference between quiescence and degeneration(P＞0. 05),or gestation and lactation(P＞0.05).we conclude both the quantity and distribution of CD24 positive SLC in different development stage of mammary epithelium is obviously different,the degree of differentiation is more deep,and the more high of the expression is.The CD24 positive SLC can deputy on mammary progenitor cells of relative differentiation status.