Abathathu abaphumelele iBhaso lika-2019 leNobel kwiPhysiology okanye Medicine, uWilliam G. Kaelin, oMnci., uGregg L. Semenza kunye noMhlekazi uPeter J. Ratcliffe babesele bephumelele iBhaso leLasker kuNyango oluSiseko lowama-2016 ngomsebenzi wabo wokuba iiseli ziziva kwaye zilungelelaniswe njani. kwi-hypoxia, ngoko akumangalisi. Bafumene kwaye bachonge i-molecule ephambili ye-hypoxia-inducible factor 1 (HIF-1). Namhlanje sifuna ukubuyela kwimvelaphi yophononongo, eyi-erythropoietin, okanye i-EPO, imolekyuli engummangaliso.
Yeyona nto ibalulekileyo ekuvelisweni kweeseli ezibomvu zegazi
Iiseli ezibomvu zegazi lolona didi luninzi lweeseli zegazi egazini, kwaye zingowona mthombo wokuthutha ioksijini kunye nekharbon diokside ngegazi lezilwanyana ezinethambo lomqolo. I-Erythrocytes iveliswa kumongo wethambo: Iiseli ze-Hematopoietic stem ziqala ukwanda kwaye zihluke kwi-progenitors yeeseli ezahlukeneyo zegazi, kwaye i-erythrocyte progenitors inokwahlula ngakumbi kwaye ikhule ibe yi-erythrocytes. Ngaphantsi kweemeko eziqhelekileyo, izinga lokuvelisa i-erythrocyte yomntu liphantsi kakhulu, kodwa phantsi koxinzelelo olunjengokopha, i-hemolysis, kunye ne-hypoxia, izinga lokuvelisa i-erythrocyte linganyuswa ukuya kuthi ga kwizihlandlo ezisibhozo. Kule nkqubo, i-erythropoietin EPO yenye yezona zinto zibalulekileyo.
I-EPO yincindi yedlala edityaniswe ikakhulu kwizintso. Ubume bayo bekhemikhali yiprotheni ene-glycosylated. Kutheni kwizintso? Ngokumalunga ne-litha yegazi ihamba ngeentso yonke iminithi, ngoko ke banokukhawuleza kwaye babone utshintsho kumanqanaba e-oksijini egazini. Xa amanqanaba e-oxygen egazini ephantsi, izintso ziphendula ngokukhawuleza kwaye zivelise inani elikhulu le-EPO. Le yokugqibela ijikeleza ngegazi ukuya kumongo wethambo, apho ikhuthaza ukuguqulwa kweeseli ze-erythroid progenitor zibe ziiseli ezibomvu zegazi. Iiseli zegazi ezibomvu ezikhulileyo zikhululwa kumongo wethambo zisiwe kwinkqubo yokujikeleza kwegazi ukuze kuphuculwe amandla omzimba okubopha ioksijini. Xa izintso zibona ukwanda kweoksijini egazini, zinciphisa ukuveliswa kweEPO, nto leyo enciphisa umlinganiselo weeseli ezibomvu zegazi kumongo wethambo.
Oku kwenza ulungelelwaniso olugqibeleleyo loop. Nangona kunjalo, abantu abahlala kwindawo ephakamileyo kunye nezigulane ezithile ze-anemia zihlala zidibana nemeko yezinga le-oksijini yegazi ngokuqhubekayo, elingenako ukugqibezela ukujikeleza ngasentla kwaye ivuselele intso ukuba ikhuphe i-EPO ngokuqhubekayo, ukuze i-concentration ye-EPO yegazi iphezulu kunabantu abaqhelekileyo.
Kwathatha phantse iminyaka engama-80 ukuyityhila
Njengezinto ezininzi eziye zafunyaniswa, ukuqonda kwezazinzulu nge-EPO akukhange kuhambe kakuhle, kunemibuzo kunye nemingeni endleleni. Kuthathe phantse iminyaka engama-80 ukusuka kwingqikelelo ye-EPO ukuya ekumiselweni kokugqibela kwemolekyuli ethile.
Ngo-1906, izazinzulu zaseFransi uCarnot noDeflandre batofa imivundla eqhelekileyo ngeserum yemivundla eneanemic baza bafumanisa ukuba inani leeseli ezibomvu zegazi kwiplasma yemivundla eqhelekileyo liye landa. Babekholelwa ukuba ezinye izinto ezihlekisayo kwiplasma zinokuvuselela zize zilawule ukuveliswa kweeseli ezibomvu zegazi. Le yayiyiprototype yokuqala yeengcinga zeEPO. Ngelishwa, iziphumo azizange ziphindwe kumashumi eminyaka alandelayo, ngakumbi ngenxa yokuba ubalo lweeseli ezibomvu zegazi ezintsha aluchanekanga.
Ulingo lukaReissmann noRuhenstroth-Bauer lweparabiosis ngowe-1950 lwanikela ubungqina obunamandla ngokwenene. Badibanisa ngotyando iinkqubo zokujikeleza kwegazi ezimbini zeempuku eziphilayo, bebeka enye kwindawo ene-hypoxic kwaye enye iphefumla umoya oqhelekileyo. Ngenxa yoko, zombini iimpuku zavelisa izixa ezikhulu zeeseli ezibomvu zegazi. Alithandabuzeki elokuba kukho incindi egazini ebangela ukuveliswa kweeseli ezibomvu zegazi, ethiywa kuyo igama elithi EPO. Kwelinye icala, i-EPO inovelwano kakhulu kwi-hypoxia.
Yeyiphi imolekyuli yi-EPO? Kwathatha inzululwazi yaseMelika i-Goldwasser iminyaka engama-30 ekugqibeleni icacisa ingxaki kwinqanaba le-biochemical. Ukuba umsebénzi ufuna ukwenza umsebenzi omhle, kufuneka aqale azilole izixhobo zakhe. Umsebenzi we-EPO kukuvuselela iiseli ezibomvu zegazi ezintsha, kodwaubalo lwamva aluchanekanga. Eyona molekyuli ibalulekileyo esebenzayo kwiiseli ezibomvu zegazi yi
hemoglobin equlethe i
heme, equlethe i-ion yeferrous embindini wayo. Ke iqela likaGoldwasser libhale iiseli ezibomvu zegazi ezisandula ukuzalwa ezine-isotopi zentsimbi ezisebenza ngeradioactive kwaye zaphuhlisa indlela enovakalelo yokubona umsebenzi we-EPO. Oku kwenza kube lula ukwahlula kunye nokucoca ukugxilwa okuphantsi kakhulu kwe-EPO (i-nanograms nge-milliliter) kwiisampuli zolwelo lwezilwanyana. Kodwa ukuba yedwa kwe-EPO kwakunzima kakhulu. Batshintshela kwizintso ukuya kwiplasma yeegusha ezine-anemic, ukuya kumchamo wezigulane ezinentsimbi enzima ngenxa yosulelo lwe-hookworm, kwaye ekugqibeleni, ngo-1977, bahlambulula i-8 milligrams yeprotein ye-EPO yomntu ukusuka kwiilitha ezingama-2,550 zomchamo kwizigulane zaseJapan ezine-anemia ye-aplastic.
Ngo-1985, ulandelelwano lweprotheyini kunye nokuveliswa kwemfuza kwe-EPO yabantu kwagqitywa. I-EPO gene ifaka i-polypeptide kunye neentsalela ze-amino ze-193, eziba yiprotheni evuthiweyo ehlanganiswe neentsalela ze-amino acid ze-166 emva kokuba i-peptide yomqondiso inqunyulwe ngexesha lokukhupha, kwaye iqulethe iisayithi ze-4 zokuguqulwa kwe-glycosylation. Kwi-1998, isakhiwo sesisombululo se-NMR se-EPO kunye ne-crystal structure ye-EPO kunye ne-receptor complex yayo yahlaziywa. Ngeli xesha, abantu banokuqonda okubonakalayo kwe-EPO.
Ukuza kuthi ga ngoku, unyango lwe-anemia ludla ngokufuna utofelo-gazi ukuze luzalise ukusilela kweeseli ezibomvu zegazi. Njengoko abantu befunda ngakumbi nge-EPO, ukuyitofela ukuze kukhuthazwe ukuveliswa kweeseli ezibomvu zegazi kumongo wabo kuye kwayenza yaba lula le ngxaki. Kodwa ukuhlambulula i-EPO ngokuthe ngqo kumanzi omzimba, njengoko i-Goldwasser yenza, kunzima kwaye isivuno siphantsi. Ukuzimisela kweprotheyini ye-EPO kunye nolandelelwano lwemfuza lwenza ukuba kube lula ukuvelisa i-EPO yabantu ephinda iphinda iphinde isetyenziswe ngobuninzi.
Yenziwa yinkampani yebiotechnology ebizwa ngokuba yiApplied Molecular Genetics (Amgen). I-Amgen yasekwa ngo-1980 inamalungu asixhenxe kuphela, ngethemba lokwenza i-biopharmaceuticals ngeendlela ezavelayo zebhayoloji yemolekyuli. I-Interferon, i-hormone yokukhula ekhupha into, isitofu sokugonya i-hepatitis B, i-epidermal growth factor yayiphakathi kwamagama ashushu kuluhlu lwabo ekujoliswe kulo, kodwa akukho nanye kwezi nzame eziphumelele. Kwade kwangowe-1985, u-Lin Fukun, isazinzulu saseTshayina saseTaiwan, eTshayina, wabumba ijini ye-EPO yabantu, emva koko waqonda ukuveliswa kwe-EPO yokwenziwa esebenzisa itekhnoloji yokudibanisa kwakhona iDNA.
I-Recombinant ye-EPO yomntu inolandelelwano olufanayo njengeprotein ye-EPO engapheliyo, kwaye inokuguqulwa okufanayo kwe-glycosylation. Ngokwendalo, i-EPO yabantu ephinda idibene nayo inomsebenzi we-EPO engapheliyo. NgoJuni 1989, imveliso yokuqala ye-Amgen, i-recombinant erythropoietin Epogen yabantu, yamkelwa yi-US FDA yonyango lwe-anemia ebangelwa ukungaphumeleli kwe-renal engapheliyo kunye ne-anemia kunyango lwe-HIV. Ukuthengiswa kwe-Epogen kuphezulu kwi-16 yezigidi zeedola kwiinyanga nje ezintathu. Kule minyaka ingamashumi amabini ilandelayo, i-Amgen ibilawula intengiso ye-EPO yabantu ephinde yadityaniswa. I-Epogen yazisa i-Amgen i-2.5 yeebhiliyoni zeedola kwingeniso kwi-2010 kuphela. Ngo-2018, ixabiso lemakethi ye-Amgen yayiyi-128.8 yeebhiliyoni zeedola, nto leyo eyenza ukuba ibe yinkampani yesibhozo ngobukhulu emhlabeni.
Kuyafaneleka ukuba uqaphele ukuba u-Amgen ekuqaleni wasebenza kunye ne-Goldwasser ukubonelela ngeeprotheni ze-EPO ezihlambulukileyo zokulandelelanisa, kodwa u-Goldwasser kunye no-Amgen bakhawuleza bawa ngenxa yokungafani kweengcamango. I-Goldwasser kunye neYunivesithi yaseChicago, eyenze uphando olusisiseko, ayizange icinge ukuba i-patent ye-hormone ayifumene, kwaye ke ayizange ifumane ipeni kwimpumelelo enkulu yorhwebo ye-EPO.
Yona -- injani isivuseleli
Xa siphefumla, ioksijini ingena kwimitochondria yeeseli ukuze iqhube ikhonkco lokuphefumla kwaye ivelise izixa ezikhulu ze-ATP, owona mthombo wamandla emizimbeni yethu. Abantu abane-anemia abanazo iiseli zegazi ezibomvu ezaneleyo ezisempilweni, kwaye eyona mpembelelo ikhawulezileyo kukuba abayifaki ioksijini eyaneleyo, nto leyo ebenza bazive bediniwe, kufana neengxaki zokuphefumla ngexesha elide. Xa itofwe nge-EPO yabantu ephindayo, imizimba yezigulane ezine-anemia ivelisa iiseli ezibomvu zegazi ezininzi.baphathe ioksijini eninzi, kwaye bavelise ngakumbi i-ATP ye-molecule yamandla, ngokufanelekileyo ukukhulula iimpawu.
Nangona kunjalo, abanye abasebenzi bezemidlalo baye baqala ukucinga nge-EPO yabantu abahlaziyiweyo. Ukuba i-hormone yokwenziwa kwakhona yohlobo lwe-EPO isetyenziselwa ukukhuthaza umzimba wabadlali ukuba bavelise iiseli ezibomvu zegazi, kunokwenzeka ukuphucula amandla eembaleki zokufumana ioksijini kunye nokuvelisa iimolekyuli zamandla, ezinokuthi ziphucule ukusebenza kwabadlali ekunyamezeleni. iminyhadala efana nokukhwela ibhayisekile, ukubaleka umgama omde kunye nokutyibiliza ekhephini. Iphepha lowe-1980 elikwi
Journal of Applied Physiology labonisa ukuba izinto ezivuselela igazi (ierythropoietin, izinto ezithwala ioksijini eyenziweyo kunye notofelo-gazi) zinokwandisa unyamezelo ngama-34 ekhulwini. Ukuba iimbaleki zisebenzisa i-EPO, zinokubaleka iikhilomitha ezisi-8 kwi-treadmill ngemizuzwana engama-44 ixesha elingaphantsi kunangaphambili. Enyanisweni, ukukhwela ibhayisekile kunye neembaleki zibe zezona zenzo zonileyo kwi-EPO stimulants. Ngexesha le-Tour de France ye-1998, ugqirha weqela laseSpain kwiqela le-Festina wabanjwa kumda waseFransi kunye neebhotile ze-400 ze-EPO eyenziwe ngokutsha! Isiphumo, ngokuqinisekileyo, yayikukuba iqela lonke lakhutshelwa ngaphandle koKhenketho kwaye kwavalwa.
IKomiti ye-Olimpiki yamazwe ngamazwe yongeze i-EPO kuluhlu lwayo oluvaliweyo kwiMidlalo ye-Barcelona ye-1992, kodwa ukulungelelanisa kwakhona uvavanyo lwe-EPO yabantu kwakunzima kangangokuba ngaphambi kweMidlalo ye-2000 kwakungekho ndlela yokufumanisa ngokufanelekileyo ukuba abadlali bayayisebenzisa. Kukho izizathu ezininzi: 1) Umxholo we-EPO kumanzi omzimba uphantsi kakhulu, kwaye i-EPO nge-ml yegazi kubantu abaqhelekileyo malunga ne-130-230 nanograms; 2) Ukwakhiwa kwe-amino acid ye-EPO yokwenziwa kwakhona kwe-EPO ifana ngqo naleyo yeprotheni ye-EPO yabantu, kuphela uhlobo lwe-glycosylation luhluke kancinane kakhulu; I-3) Ubomi besiqingatha se-EPO egazini ziiyure ezingama-5-6 kuphela, kwaye ngokuqhelekileyo ayibonakali iintsuku ezi-4-7 emva kwesitofu sokugqibela; I-4) Inqanaba le-EPO lomntu lihluke kakhulu, ngoko kunzima ukuseka umgangatho wobungakanani obupheleleyo.
Ukusukela ngo-2000, i-WADA isebenzise uvavanyo lomchamo njengeyona ndlela yokuqinisekisa yenzululwazi yokufumanisa ngokuthe ngqo i-EPO. Ngenxa yomahluko omncinci phakathi kwefom ye-glycoylated ye-EPO eyenziwe ngokutsha kunye ne-EPO yomntu, iipropati ezihlawulisiweyo ze-molecule ezimbini zincinci kakhulu kwaye ziyakwazi ukwahlulwa ngendlela ye-electrophoresis ebizwa ngokuba yi-isoelectric focusing, eyona ndlela iphambili ye ukufunyanwa ngokuthe ngqo kwe-EPO yokwenziwa kwakhona. Nangona kunjalo, enye i-EPO edibeneyo echazwe ziiseli ezithathwe ngabantu ayizange ibonise mahluko kwi-glycosylation, ngoko ke ezinye iingcali zacebisa ukuba i-EPO yangaphandle kunye ne-EPO engapheliyo kufuneka yahlulwe ngomxholo we-carbon isotope.
Enyanisweni, kusekho imida kwiindlela ezahlukeneyo zokuvavanya i-EPO. Umzekelo, uLance Armstrong, intsomi yebhayisikile yaseMelika, wavuma ukuba uthathe i-EPO kunye nezinye izivuseleli ngexesha loloyiso lwakhe olusixhenxe lweTour de France, kodwa akazange aqinisekise ukuba une-EPO kulo naluphi na uvavanyo lwedoping ngelo xesha. Kusafuneka silinde kwaye sibone ukuba "inyawo enye phezulu" okanye "inyawo enye ngaphezulu".
Uyenza njani iBhaso leNobel
