Abathathu abawine Umklomelo KaNobel kuPhysiology noma Medicine ka-2019, uWilliam G. Kaelin, Omncane, u-Gregg L. Semenza kanye no-Sir Peter J. Ratcliffe base bevele bawine uMklomelo we-Lasker ku-Basic Medicine wezi-2016 ngomsebenzi wabo wokuthi amangqamuzana azizwa kanjani futhi azivumelanise nezimo ku-hypoxia, ngakho-ke akumangazi. Bathole futhi bakhombe i-molecule engukhiye ye-hypoxia-inducible factor 1 (HIF-1). Namuhla sifuna ukubuyela emuva emsuka wocwaningo, okuyi-erythropoietin, noma i-EPO, i-molecule eyisimangaliso.
Yisici esibaluleke kakhulu ekukhiqizeni amangqamuzana abomvu egazi
Amangqamuzana egazi abomvu awuhlobo oluningi kakhulu lwamangqamuzana egazi egazini, futhi ayindlela eyinhloko yokuthutha umoya-mpilo nesikhutha ngegazi lezilwane ezinomgogodla. Ama-erythrocyte akhiqizwa emnkantsheni wamathambo: Amangqamuzana e-hematopoietic stem aqala ukwanda futhi ahlukanise abe okhokho bamangqamuzana egazi ahlukahlukene, futhi okhokho be-erythroid bangaqhubeka nokuhlukanisa futhi bavuthwe babe ama-erythrocyte. Ngaphansi kwezimo ezivamile, izinga lokukhiqizwa kwe-erythrocyte yomuntu liphansi kakhulu, kodwa ngaphansi kokucindezeleka okunjengokopha, i-hemolysis, ne-hypoxia, izinga lokukhiqizwa kwe-erythrocyte lingakhuphuka izikhathi ezifika kweziyisishiyagalombili. Kule nqubo, i-erythropoietin EPO ingenye yezinto ezibaluleke kakhulu.
I-EPO iyi-hormone ekhiqizwa ngokuyinhloko ezinso. Imvelo yayo yamakhemikhali iyiprotheni ene-glycosylated. Kungani ezinso? Cishe ilitha legazi ligeleza ezinsweni njalo ngomzuzu, ukuze zikwazi ukubona ngokushesha nangempumelelo izinguquko emazingeni komoyampilo egazini. Lapho amazinga omoya-mpilo egazini ephansi, izinso zisabela ngokushesha futhi zikhiqize inani elikhulu le-EPO. Lesi sakamuva sizungeza egazini siye emnkantsheni wamathambo, lapho sithuthukisa khona ukuguqulwa kwamangqamuzana e-erythroid progenitor abe amangqamuzana abomvu egazi. Amangqamuzana egazi abomvu avuthiwe akhululwa emnkantsheni aye esimisweni sokujikeleza kwegazi ukuze athuthukise ikhono lomzimba lokubopha umoya-mpilo. Lapho izinso zizwa ukwanda komoya-mpilo egazini, zinciphisa ukukhiqizwa kwe-EPO, yona leyo enciphisa inani lamangqamuzana abomvu egazi emnkantsheni.
Lokhu kwenza iluphu yokulungisa ephelele. Kodwa-ke, abantu abahlala endaweni ephakeme kanye nezinye iziguli ezine-anemia zivame ukuhlangana nesimo sokuhlala okuphansi kwezinga le-oksijeni yegazi, elingakwazi ukuqedela ukujikeleza okungenhla futhi kushukumise izinso ukuthi ziqhubeke zikhipha i-EPO, ukuze ukuhlushwa kwe-EPO egazini kuphakeme kunabantu abavamile.
Kwathatha iminyaka ecishe ibe ngu-80 ukuyidalula
Njengezinto eziningi ezitholakele ezinkulu, ukuqonda kososayensi nge-EPO akuhambanga kahle, kunemibuzo nezinselelo endleleni. Kuthathe cishe iminyaka engu-80 kusukela emcabangweni we-EPO kuya ekunqunyweni kokugcina kwe-molecule ethile.
Ngo-1906, ososayensi baseFrance uCarnot noDeflandre bajova onogwaja abavamile nge-serum onogwaja abane-anemic futhi bathola ukuthi inani lamangqamuzana egazi abomvu ku-plasma onogwaja abavamile liyenyuka. Babekholelwa ukuthi izici ezithile ezihlekisayo ku-plasma zingashukumisa futhi zilawule ukukhiqizwa kwamangqamuzana abomvu egazi. Lesi kwakuyisibonelo sokuqala somqondo we-EPO. Ngeshwa, imiphumela ayizange iphindwe emashumini eminyaka alandelayo, ikakhulukazi ngenxa yokuthi isibalo samangqamuzana abomvu egazi amasha sasinganembile.
Ukuhlolwa kwe-parabiosis ka-Reissmann no-Ruhenstroth-Bauer ngo-1950 kwanikeza ubufakazi obuqinile ngempela. Baxhumanisa ngokuhlinza izimiso zokujikeleza kwegazi zamagundane amabili aphilayo, bebeka elilodwa endaweni ene-hypoxic kanti elinye liphefumula umoya ovamile. Ngenxa yalokho, womabili amagundane akhiqiza inani elikhulu lamangqamuzana abomvu egazi. Akungabazeki ukuthi kune-hormone egazini ekhuthaza ukukhiqizwa kwamangqamuzana abomvu egazi, i-EPO eqanjwe ngayo. Ngakolunye uhlangothi, i-EPO izwela kakhulu ku-hypoxia.
Iyini i-molecule ye-EPO? Kuthathe usosayensi waseMelika u-Goldwasser iminyaka engu-30 ukuze ekugcineni acacise inkinga ezingeni le-biochemical. Uma isisebenzi sifuna ukwenza umsebenzi omuhle, kufanele siqale silole amathuluzi aso. Umsebenzi we-EPO uwukuvuselela amangqamuzana egazi abomvu amasha, kodwaisibalo sakamuva asinembile. I-molecule ebaluleke kakhulu esebenza kumangqamuzana abomvu egazi i-hemoglobin ene-heme, equkethe i-ion eyinsimbi phakathi kwayo. Ngakho-ke ithimba lika-Goldwasser lalebula amangqamuzana egazi abomvu asanda kuzalwa ngama-isotopes ensimbi enemisebe futhi lenza indlela ebucayi yokuthola umsebenzi we-EPO. Lokhu kwenza kube nokwenzeka ukuhlukanisa nokuhlanza ukugxila okuphansi kakhulu kwe-EPO (ama-nanogram ngemililitha) kumasampula oketshezi lwezilwane. Kodwa ukuhlukaniswa kwe-EPO kwakunzima kakhulu. Bashintsha kusuka ezinso kuya ku-plasma yezimvu ezine-anemic, baya emchameni weziguli ezinokuntuleka okukhulu kwensimbi ngenxa yokutheleleka nge-hookworm, futhi ekugcineni, ngo-1977, bahlanza amamiligremu angu-8 weprotheyini ye-EPO yomuntu kusuka ku-2,550 wamalitha omchamo weziguli zaseJapane ezine-aplastic anemia.
Ngo-1985, ukulandelana kwamaprotheni kanye nokuhlanganiswa kofuzo kwe-EPO yomuntu kwaqedwa. Isakhi sofuzo se-EPO sifaka i-polypeptide enezinsalela ze-amino ezingu-193, eba iphrotheni evuthiwe ehlanganiswe nezinsalela ze-amino acid ezingu-166 ngemva kokuba i-peptide yesignali inqanyuliwe ngesikhathi sokukhishwa, futhi iqukethe amasayithi angu-4 okuguqulwa kwe-glycosylation. Ngo-1998, kwahlaziywa ukwakheka kwesixazululo se-NMR se-EPO kanye nesakhiwo sekristalu se-EPO kanye ne-receptor complex. Kuleli qophelo, abantu banokuqonda okunembile kwe-EPO.
Kuze kube manje, ukwelashwa kwe-anemia ngokuvamile kwakudinga ukumpontshelwa igazi ukuze kugcwalise ukuntuleka kwamangqamuzana abomvu egazi. Njengoba abantu befunda okwengeziwe nge-EPO, ukuyijova ukuze kushukumise ukukhiqizwa kwamangqamuzana egazi abomvu emnkantsheni wabo kuye kwenza inkinga yaba lula. Kodwa ukuhlanza i-EPO ngokuqondile emanzini omzimba, njengoba kwenza i-Goldwasser, kunzima futhi isivuno siphansi. Ukunqunywa kwephrotheni ye-EPO nokulandelana kofuzo kwenze kwaba nokwenzeka ukukhiqiza kabusha i-EPO yomuntu ngamanani amakhulu.
Kwenziwa inkampani ye-biotechnology ebizwa ngokuthi i-Applied Molecular Genetics (Amgen). I-Amgen yasungulwa ngo-1980 inamalungu ayisikhombisa nje kuphela, ngethemba lokwenza i-biopharmaceuticals ngamasu avela ngaleso sikhathi ebhayoloji yamangqamuzana. I-Interferon, i-hormone yokukhula ekhulula isici, umuthi wokugomela i-hepatitis B, isici sokukhula kwe-epidermal sasiphakathi kwamagama ashisayo ohlwini lwazo okuhloswe ngalo, kodwa ayikho kule mizamo eyaphumelela. Kuze kube ngu-1985, u-Lin Fukun, usosayensi waseShayina waseTaiwan, eChina, wenza isakhi sofuzo se-EPO yomuntu, wabe eseqaphela ukukhiqizwa kwe-EPO yokwenziwa esebenzisa ubuchwepheshe bokuhlanganiswa kabusha kwe-DNA.
I-Recombinant EPO yomuntu inokulandelana okufanayo nephrotheni ye-EPO engapheli, futhi inokuguqulwa okufanayo kwe-glycosylation. Ngokwemvelo, i-EPO yomuntu ehlanganisiwe nayo inomsebenzi we-EPO engapheli. Ngo-June 1989, umkhiqizo wokuqala we-Amgen, i-erythropoietin Epogen yabantu ehlangene, wagunyazwa yi-US FDA yokwelapha i-anemia ebangelwa ukwehluleka okungapheli kwezinso kanye ne-anemia ekwelapheni ukutheleleka nge-HIV. Ukuthengiswa kwe-Epogen kufinyelele ku-$16 million ezinyangeni ezintathu nje kuphela. Eminyakeni engamashumi amabili eyalandela, i-Amgen ibiphethe imakethe ye-EPO yabantu ehlanganiswe kabusha. I-Epogen ilethe i-Amgen $ 2.5 billion emalini engenayo ngo-2010 kuphela. Ngo-2018, inani lemakethe yesitoko se-Amgen lalingama- $ 128.8 billion, okuyenza ibe inkampani yesishiyagalombili ngobukhulu emhlabeni.
Kuyaphawuleka ukuthi u-Amgen ekuqaleni wasebenza no-Goldwasser ukuhlinzeka ngamaprotheni e-EPO abantu ahlanziwe ukuze alandelelane, kodwa u-Goldwasser no-Amgen basheshe bawa ngenxa yokuhlukana kwemibono. UGoldwasser kanye neNyuvesi yakhe yaseChicago, abenza ucwaningo oluyisisekelo, abakaze bacabange ukunikeza ilungelo lobunikazi lehomoni ayitholile, ngakho abakaze bathole ngisho indibilishi yempumelelo enkulu yezohwebo ye-EPO.
I -- iyisikhuthazi kanjani
Lapho siphefumula, umoya-mpilo ungena emitochondria yamaseli ukuze uqhube uchungechunge lokuphefumula futhi ukhiqize amanani amakhulu e-ATP, umthombo oyinhloko wamandla emizimbeni yethu. Abantu abane-anemia abanawo amangqamuzana egazi abomvu anempilo eyanele, futhi umphumela osheshayo ukuthi abawutholi umoya-mpilo owanele, okubenza bazizwe bekhathele, kufana nezinkinga zokuphefumula ngesikhathi eside. Lapho ijovwe nge-EPO yomuntu ephinde yahlanganiswa, imizimba yeziguli ezine-anemia ikhiqiza amangqamuzana egazi abomvu engeziwe,ithwala umoya-mpilo owengeziwe, futhi ikhiqize i-ATP ye-molecule yamandla, edambisa izimpawu.
Kodwa-ke, abanye abasebenzi bezemidlalo nabo baqale ukucabanga nge-EPO yomuntu ehlanganisiwe. Uma i-hormone yokwenziwa kabusha yohlobo lwe-EPO isetshenziselwa ukukhuthaza umzimba wabasubathi ukuthi ukhiqize amangqamuzana egazi abomvu engeziwe, kungenzeka ukuthuthukisa ikhono labasubathi lokuthola umoya-mpilo nokukhiqiza ama-molecule wamandla, okungase futhi kuthuthukise ukusebenza kwabasubathi ekukhuthazeleni. imicimbi efana nokuhamba ngebhayisikili, ukugijima amabanga amade nokushushuluza eqhweni. Iphepha lango-1980 kuyi-Journal of Applied Physiology labonisa ukuthi izinto ezishukumisa igazi (i-erythropoietin, izinto ezithwala umoya-mpilo zokwenziwa nokumpontshelwa igazi) zingandisa ukukhuthazela ngamaphesenti angu-34. Uma abasubathi besebenzisa i-EPO, bangagijima amakhilomitha angu-8 ku-treadmill ngemizuzwana engu-44 isikhathi esingaphansi kunangaphambili. Eqinisweni, ukuhamba ngebhayisikili nama-marathon kube yizigebengu ezimbi kakhulu zezikhuthazi ze-EPO. Ngo-1998 i-Tour de France, udokotela weqembu laseSpain weqembu le-Festina waboshwa emngceleni waseFrance namabhodlela angu-400 e-EPO yokwenziwa kabusha! Umphumela, vele, kwaba ukuthi lonke iqembu laxoshwa ku-Tour futhi lavinjelwa.
I-International Olympic Committee yengeze i-EPO ohlwini lwayo olwaluvinjelwe eMidlalweni ye-Barcelona yango-1992, kodwa ukuhlela kabusha ukuhlolwa kwe-EPO yabantu kwakunzima kangangokuthi ngaphambi kweMidlalo ka-2000 yayingekho indlela yokuthola ngempumelelo ukuthi abasubathi babeyisebenzisa yini. Kunezizathu eziningana: 1) Okuqukethwe kwe-EPO emanzini omzimba kuphansi kakhulu, futhi i-EPO nge-ml yegazi kubantu abavamile imayelana nama-nanogram angu-130-230; 2) Ukwakheka kwe-amino acid ye-EPO yokwenziwa kabusha kwe-EPO kufana ncamashi naleyo yephrotheni ye-EPO yomuntu, kuphela uhlobo lwe-glycosylation oluhluke kakhulu; I-3) I-half-life ye-EPO egazini ingamahora angu-5-6 kuphela, futhi ngokuvamile ayibonakali izinsuku ezingu-4-7 ngemva komjovo wokugcina; 4) Izinga le-EPO ngalinye lihluke kakhulu, ngakho-ke kunzima ukusungula indinganiso yobuningi obuphelele.
Kusukela ngo-2000, i-WADA isebenzise ukuhlola umchamo njengendlela yokuqinisekisa yesayensi kuphela yokuthola ngokuqondile i-EPO ehlangene. Ngenxa yomehluko omncane phakathi kwefomu le-glycoylated le-EPO yokwenziwa kabusha kwe-EPO kanye naleyo ye-EPO yomuntu, izakhiwo ezishajwayo zama-molecule amabili zincane kakhulu futhi zingahlukaniswa ngendlela ye-electrophoresis ebizwa ngokuthi i-isoelectric focusing, okuyisu eliyinhloko ukutholwa okuqondile kwe-EPO yokwenziwa kabusha kwenhlanganisela. Kodwa-ke, enye i-EPO ehlanganisiwe evezwa amaseli atholwe kubantu ayizange ibonise mehluko ku-glycosylation, ngakho-ke abanye ochwepheshe baphakamise ukuthi i-EPO yangaphandle kanye ne-EPO ye-endogenous kufanele ihlukaniswe ngokuqukethwe okuhlukile kwe-carbon isotope.
Eqinisweni, kusenemikhawulo ezindleleni ezihlukene zokuhlola ze-EPO. Isibonelo, u-Lance Armstrong, inganekwane yamabhayisikili waseMelika, uvumile ukuthi wathatha i-EPO nezinye izikhuthazi phakathi nokunqoba kwakhe okuyisikhombisa kwe-Tour de France, kodwa empeleni akuzange kuqinisekiswe ukuthi une-EPO kunoma yikuphi ukuhlolwa kwe-doping ngaleso sikhathi. Kusafanele silinde sibone ukuthi "unyawo olulodwa phezulu" noma "unyawo olulodwa phezulu".
Iwenza kanjani uMklomelo KaNobel
Igama lokugcina mayelana nokuxhumana phakathi kwe-EPO kanye Nomklomelo KaNobel kuPhysiology noma Medicine ka-2019.
I-EPO yisimo esijwayelekile kakhulu sokubona komzimba womuntu kanye nokusabela ku-hypoxia. Ngakho-ke, u-Semenza kanye no-Ratcliffe, abahlomuli bakaNobel ababili, bakhethe i-EPO njengendawo yokuqala yokutadisha indlela yokubona amaseli kanye nokuzivumelanisa ne-hypoxia. Isinyathelo sokuqala kwakuwukuthola izakhi zofuzo ze-EPO ezingasabela ekushintsheni komoyampilo. U-Semenza uhlonze ukhiye wokulandelana okungabhalwanga kwekhodi okungu-256 kwesisekelo esingu-3 'ekugcineni komfula ongezansi kwe-EPO yokufaka ikhodi yofuzo, okuqanjwe isici sokuphendula se-hypoxia. Uma lokhu kulandelana kwe-elementi kuguqulwa noma kususwa, amandla ephrotheni ye-EPO okuphendula ku-hypoxia ancipha kakhulu. Uma lokhu kulandelana kwe-elementi kuhlanganiswe ekugcineni komfula 3 'wezinye izakhi zofuzo ezingahlotshaniswa ne-hypoxia, lezi zakhi zofuzo eziguquliwe ziphinda zibonise ukwenza kusebenze okufana ne-EPO.ngaphansi kwezimo ze-hypoxia.
U-Ratcliffe nethimba lakhe babe sebethola ukuthi le ngxenye yempendulo ye-hypoxic ayikho kuphela ezinso noma kumaseli esibindi abhekele ukukhiqizwa kwe-EPO, kodwa nakwezinye izinhlobo eziningi zamaseli ezingasebenza ngaphansi kwezimo ze-hypoxic. Ngamanye amazwi, le mpendulo ku-hypoxia ingase ingacacisi ku-EPO, kodwa kunalokho into esabalele kakhulu kumaseli. Lawa amanye amaseli, angabophezeleki ekukhiqizweni kwe-EPO, kufanele aqukathe ama-molecule (njengama-transcription factors anesibopho sokuvula isisho sofuzo) azwa izinguquko ekugxilweni komoyampilo futhi abophezele kuzakhi zokusabela ze-hypoxic ukuze avule izakhi zofuzo ezifana ne-EPO.
