-Delile
- Yini ama-erythrocyte?
- Yini ama-erythroblasts?
- Kuyini i-erythropoiesis?
- Ukuhlukaniswa kwe-Erythroblast kuma-erythrocyte
- Ukuhlukaniswa kweseli
- Ama-pathologies ahambisana namaphutha ekuhlukanisweni kwe-erythroblast
- Izinkomba
I- erythroblasts zingamaseli andulela ama-erythrocyte e-vertebrate. Ukwehla kokuhlushwa komoya-mpilo ezicutshini kuzothuthukisa imicimbi yokuhlukanisa amaselula kulawa maseli azokhulisa ama-erythrocyte avuthiwe. Isethi yayo yonke le micimbi yaziwa njenge-erythropoiesis.
Ngesikhathi se-erythropoiesis, i-hemoglobin synthesis iyanda. Amaprotheni amaningi kuma-erythrocyte alamula ukulethwa komoya-mpilo ezicutshini kanye nokukhishwa kobuthi be-carbon dioxide kuzo, umkhiqizo odoti wokuphefumula kwamaselula onobuthi kumaseli.
Ukulahleka okuphelele kwe-nucleus, kanye nama-organelles amaselula, kukhombisa umvuthwandaba wenqubo ye-erythropoiesis kumaseli e-vertebral mammalian. Kuwo wonke ama-vertebrate afana nezilwane ezihuquzelayo, i-nucleus iyaqhubeka lapho inqubo yokuhlukanisa isiqedile.
Amaphutha enqubeni yokuhlukanisa i-erythroblast aletha isethi yezifo zegazi ezibizwa ngokuthi ama-megaloblastic anemias.
Yini ama-erythrocyte?
Ama-erythrocyte, aziwa kakhulu njengamaseli abomvu egazi, angamaseli amaningi kakhulu egazini lomgogodla.
Bane-morphology yesici efana nama-biconcave disc futhi umsebenzi wabo omkhulu ukwenza ukuthuthwa komoya-mpilo (O2) uye ezicutshini ezahlukahlukene zomzimba, ngasikhathi sinye lapho ubakhipha ku-carbon dioxide (CO2) ekhiqizwa ngesikhathi seselula ukuphefumula.
Lokhu kushintshaniswa kwe-CO2 nge-O2 kungenzeka ngoba lawa maseli ahlala amaprotheni abomvu abizwa ngokuthi yi-hemoglobin, akwazi ukusebenzisana nazo zombili izinhlobo zamakhemikhali ngeqembu le-heme elikhona esakhiweni sawo.
Okukhethekile kwalawa maseli ezilwaneni ezincelisayo maqondana nawo wonke amanye ama-vertebrate ukungabikho kwe-nucleus ne-cytoplasmic organelles. Kodwa-ke, phakathi nezigaba zokuqala zokukhiqizwa ezigabeni zokuqala zokukhula kombungu, kuye kwabonwa ukuthi izandulela zamaseli ezivela kuzo ziveza i-nucleus yesikhashana.
Okokugcina akumangazi ngoba izigaba zokuqala zokukhula kombungu zivame ukufana kuwo wonke ama-vertebrate, ziphambukisa kuphela lezo zigaba ezibeka umehluko omkhulu.
Yini ama-erythroblasts?
Ama-erythroblast amaseli azokhuphula ama-erythrocyte avuthiwe ngemuva kokwenza izehlakalo ezilandelanayo zokuhlukaniswa kwamaseli.
Lawa maseli wangaphambi kokuqalwa avela kumuntu ovamile we-myeloid ozalweni lomnkantsha we-vertebrate njengamaseli we-nucleated, anikezwe ama-nuclei nama-cell organelles.
Izinguquko kokuqukethwe yi-cytoplasm yayo nasekuhlelweni kabusha kwe-cytoskeleton zizophelela ekwakhiweni kwama-erythrocyte akulungele ukungena ekusakazeni kwegazi. Lezi zinguquko ziphendula kwisikhuthazo semvelo esibonisa ukwehla komoya-mpilo ezicutshini ngakho-ke isidingo ekukhiqizeni ama-erythrocyte.
Kuyini i-erythropoiesis?
I-Erythropoiesis yigama elisetshenziselwa ukuchaza inqubo okwenziwa ngayo ukukhiqizwa nokwakhiwa kwamaseli abomvu egazi, adingekayo ukugcina ukutholakala komoya-mpilo kuzitho nezicubu ezahlukahlukene kwenzeka.
Le nqubo ilawulwa kahle yisenzo se-erythropoietin (EPO), i-renal synthesis hormone yona elandelwa ukugxila komoya-mpilo okutholakala ezicutshini.
Ukugxila okuphansi kwe-oxygen oxygen kubangela ukuhlanganiswa kwe-EPO yi-hypoxia-inducible transcript factor (HIF-1), evuselela ukwanda kwama-erythrocyte ngokuwabopha kwawo kuma-EpoR receptors, akhona kumaseli wangaphambi kwe-erythrocyte.
Ezincelisayo, i-erythropoiesis yenziwa ngezigaba ezimbili ezibizwa ngokuthi i-erythropoiesis yakudala ne-erythropoiesis eqondile.
Owokuqala wenzeka esikhwameni se-yolk ngesikhathi sokukhula kombungu, okudala ama-erythroblast amakhulu, kuyilapho okwamuva kwenzeka esibindini se-fetal futhi kuqhubeka emnkantsheni emva kwenyanga yesibili yokubeletha, kukhiqiza ama-erythrocyte amancane enuclear.
Amanye amaprotheni afana ne-antipoptotic cytokine Bcl-X, okubhalwa kwayo kulawulwa yi-factor factor GATA-1, nakho kuthonya kahle inqubo ye-erythropoiesis. Ngaphezu kwalokho, ukutholakala kwensimbi, uvithamini B12 ne-folic acid nakho kuyadingeka.
Ukuhlukaniswa kwe-Erythroblast kuma-erythrocyte
Enkambisweni ye-erythropoiesis ecacile, ama-erythrocyte akhiwa emnkantsheni wethambo kusuka kuseli elingenakulinganiswa noma isizukulwane esivamile se-myeloid esikwazi ukuphakamisa amanye amaseli afana nama-granulocyte, ama-monocyte nama-platelets.
Lesi seli kumele sithole amasiginali afanele angaphandle kwamaseli ukuze anciphise ukwahlukana kwawo ohlwini lozalo lwe-erythroid.
Lapho nje lokhu kuzibophezela sekutholakele, kuqala ukulandelana kwemicimbi yokwehlukanisa eqala ngokwakhiwa kwe-pronormoblast, eyaziwa nangokuthi i-proerythroblast. Iseli elikhulu lesandulela le-erythroblast eline-nucleus.
Ngemuva kwalokho, i-proerythroblast izobhekana nokwehla okuqhubekayo komthamo wamaseli enuzi ohambisana nokwanda kwe-hemoglobin synthesis. Zonke lezi zinguquko zenzeka kancane njengoba leli seli lidlula ezigabeni ezahlukahlukene zamaseli: i-basophilic erythroblast noma i-normoblast, i-polychromatic erythroblast ne-orthochromatic erythroblast.
Le nqubo iphetha ngokulahleka okuphelele kwe-nucleus, kanye nama-organelles akhona ku-orthochromatic erythroblast, okwenza i-erythrocyte evuthiwe.
Ukuze ekugcineni kufinyelelwe kulokhu, owokugcina kufanele adlule esigabeni se-reticulocyte, iseli elenziwe ngensimbi elisaqukethe ama-organelles nama-ribosomes ku-cytoplasm yalo. Ukuqedwa ngokuphelele kwe-nucleus ne-organelles kwenziwa nge-exocytosis.
Ama-erythrocyte avuthiwe aphuma emnkantsheni angena egazini lapho ahlala ejikeleza khona cishe izinsuku eziyi-120, ngaphambi kokugwinywa ngama-macrophage. Ngakho-ke, i-erythropoiesis yinqubo eyenzeka ngokuqhubekayo kuyo yonke impilo yomzimba.
Ukuhlukaniswa kweseli
Njengoba ama-erythoblast ethuthukela ekuhlukanisweni okuphelele kwe-erythrocyte evuthiwe, bathola izinguquko eziningi kuma-cytoskeleton abo, kanye nasekubonakalisweni kwamaprotheni wokunamathela kwamaseli.
I-Actin microfilaments depolymerize kanye ne-cytoskeleton entsha esekwe ku-spectrin ihlanganisiwe. I-Spectrin yiprotheni eline-peripheral membrane etholakala ebusweni be-cytoplasmic exhumana ne-ankyrin, iphrotheni elamula ukubopha kwe-cytoskeleton ne-Band 3 transmembrane protein.
Lezi zinguquko ku-cytoskeleton nasekuvezeni ama-Epo receptors, kanye nezinqubo ezizilinganisa, zibaluleke kakhulu ekuvuthweni kwe-erythroid.
Lokhu kungenxa yokuthi balalela ukusungulwa kokusebenzisana phakathi kwama-erythroblast namaseli akhona endaweni encane yomnkantsha wamathambo, okwenza kube lula ukudluliswa kwamasiginali adingekayo ukuqala nokuqeda umehluko.
Lapho umehluko usuphelile, kwenzeka izinguquko ezintsha ezithanda ukulahleka kokunamathela kwamaseli emnkantsheni nokudedelwa kwawo kungene egazini lapho zizofeza khona umsebenzi wazo.
Ama-pathologies ahambisana namaphutha ekuhlukanisweni kwe-erythroblast
Amaphutha ngesikhathi sokuhlukaniswa kwama-erythroblast emnkantsheni wethambo aholela ekubonakaleni kwe-pathologies yegazi, njenge-megaloblastic anemias. Lokhu kusuka ekushodeni kokuphakelwa kukavithamini B12 namafrathi adingekayo ukukhuthaza ukwahlukaniswa kwe-erythroblast.
Igama elithi megaloblastic lisho usayizi omkhulu ama-erythroblasts ngisho nama-erythrocyte afinyelela kuwo njengomkhiqizo we-erythropoiesis engasebenzi ekhonjiswa yi-DNA synthesis.
Izinkomba
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- I-Kingsley PD, i-Malik J, i-Fantauzzo KA, i-Palis J. Yolk etholwe ngama-erythroblasts eyakhiwe nge-sac ngesikhathi se-mammalian embryogenesis. Igazi (2004); 104 (1): 19-25.
- UKonstantinidis DG, Pushkaran S, Johnson JF, Cancelas JA, Manganaris S, Harris CE, Williams AE, Zheng Y, Kalfa TA. Izimpawu zokusayina nezama-cytoskeletal ku-erythroblast enucleation. Igazi. (2012); 119 (25): 6118-6127.
- Migliaccio AR. I-Erythroblast Enucleation. I-Haematologica. 2010; 95: 1985-1988.
- UShivani Soni, uShashi Bala, uBabette Gwynn, uKenneth E, uLuanne L, uManjit Hanspal. Ukungabikho Kwe-Erythroblast Macrophage Protein (Emp) Kuholela Ekuhlulekeni kwe-Erythroblast Nuclear Extrusion. Ijenali yamakhemikhali ezinto eziphilayo. 2006; 281 (29): 20181-20189.
- USkutelsky E, uDanon D.Ucwaningo oluncane lwe-electron lokuqedwa kwenuzi kusuka erythroblast sekwephuzile. J Iseli Biol. 1967; 33 (3): 625-635.
- UTordjman R, Delaire S, Plouet J, Ting S, Gaulard P, Fichelson S, Romeo P, Lemarchandel V. Erythroblasts angumthombo wezici ze-angiogenic. Igazi (2001); I-97 (7): 1968-1974.
