Okuthi Izingxenye Zemizimba Yakho Zembulani Ngezinga Lakho Lokuguga
Kungenzeka yini ukuthi izinso zakho, inhliziyo noma amabele akho asebekhulile kunomzimba wakho wonke? Olunye ucwaningo lubonisa ukuthi akuzona zonke izingxenye zomzimba womzimba ngesilinganiso esifanayo . Ukutholakala - uma kuqhubeka ukuhlinzeka ngesilinganiso somgomo wokuthi izicubu ezisheshayo ziguga kanjani - ekugcineni zingasiza ososayensi bahlehlise noma baphinde baphenduke inqubo yokuguga.
Umgcini Wezinsuku Emangceleni
I-athikili eshicilelwe ngo-2013 ka-Genome Biology ichaza ukuthi inqubo yamakhemikhali yemvelo eyenzeka ngaphakathi kweseli ingasetshenziswa kanjani njengomhlobo wesikhathi sokugcina noma ukukala ukuthi leso seli selikhuphuka kangakanani.
Le nqubo, ebizwa ngokuthi i-methylation, iguqula i-DNA - izakhi zofuzo zezakhi - ngephethini ehambisana nokukhula.
Ucwaningo olwaluvele eNyuvesi yaseCalifornia eLos Angeles (UCLA) lusebentisa amasampuli ematheni avela kuma-pair amabili amawele afanayo ukuze abonise ukuthi yiziphi izingosi ze-DNA ezixhunyaniswe ne-methylation ngokwethembeka eminyakeni yezifundo. Ososayensi base behlolisisa ama-methylation rates kubantu abaningi futhi bakwazi ukukhomba iminyaka yobudala bomuntu ngamunye eminyakeni emihlanu, besebenzisa kuphela umquba womuntu.
USteve Horvath, uprofesa we-UCLA womuntu kanye noprofesa we-biostatistics, wathatha lolu cwaningo ngokuqhubekayo futhi wahlola izicubu ezingaphezu kuka-8 000 nezicubu zeseli ezazinikelwa abanye ososayensi. Amasampula omuntu athathwa ngaphambi kokuzalwa afike eminyakeni eyi-101, ezingaphezu kwezingu-50 izinhlobo ezahlukene zamathiskhi namaseli ezivela ezingxenyeni ezahlukene zomzimba, kuhlanganise nesibindi, izinso, ubuchopho, amaphaphu nenhliziyo. I-DNA methylation rates yenza i-gauge engaguquki yokuthi izicubu ezihlukahlukene ziguga kanjani ngokushesha.
UHorvath nozakwabo basebenzise i-gauge ukuhlola izinga lokuguga emasampheni ahlukene omdlavuza angu-6 000, emele izinhlobo ezingu-20 zesifo.
Izingxenye Ezihlukene Zomzimba Womzimba Emalini Ahlukene
Ithimba likaHorvath lathola ukuthi ama-tissue amaningi asezingeni elihle kakhulu ngendlela efanayo; empeleni, iminyaka yabo yobudala , okusho ukuthi isebenza kahle kangakanani, ihambisana nesikhathi sabo sokulandelana kwesikhathi , okungukuthi inani leminyaka elimelelwe ekhalendeni.
Nokho, izicubu zesisu zazingavamile. Izicubu zebele ezempilo zikhula ngokushesha futhi ziseminyakeni emibili kuya kwemibili emdala kunomzimba womzimba wesifazane. Lokhu kungase kuchaze ukuthi kungani umdlavuza webele isindlela esivamile kakhulu yomdlavuza kwabesifazane kusukela eminyakeni yobudala kuyinto engozini futhi izicubu ezisheshayo ngokushesha zingase zithinteke kakhulu umdlavuza.
Kulabo besifazane abanesifo somdlavuza webele, ukuguga okusheshayo kukhulunywa nakakhulu. Izicubu zokuhlola eziseduze nezicubu zomdlavuza webele, abacwaningi bathola ukuthi cishe kuneminyaka engama-12 ubudala kunomzimba wonke.
Ingabe Amaseli Aguga Ngokushesha Ayenziwe Kakhulu Kwegciwane?
Izicubu zomdlavuza zitholakale zidala kakhulu kunezicubu ezinempilo ezitholakala kwenye indawo emzimbeni. Ithimba lezocwaningo lihlola izinhlobo ezingaphezu kuka-20 zomdlavuza futhi zathola izimpawu eziqhubekayo zokuguga ngokushesha ezinkampeni ezigulayo. Eqinisweni, izicubu zomdlavuza zaziphakathi kweminyaka engama-36 ubudala kunomzimba wonke.
Lokhu kubangela umbuzo obalulekile: Ingabe amangqamuzana asebekhulile asheshe akhathele umdlavuza noma enza amangqamuzana agezavuza umdlavuza ngokushesha? UHorvath uchaza ukuthi kokubili lezi zinto kungenzeka zibe yiqiniso. Isibonelo, emacaleni amaningi omdlavuza, izicubu eziseduze zibukeka zincane, noma okungenani ubudala besikhathi sabantu amasampula aphuma kuwo, okuphakamisa umdlavuza ngokwawo ngamaseli.
Ukuthi ngisho nezicubu zesifuba ezinempilo zibonakala zikhulile ngokwezinga le-methylation uma kuqhathaniswa nomunye umzimba wesifazane kuphakamisa ukuthi izicubu ezisheshayo ngokushesha zingaba nomdlavuza.
"Ucwaningo olwengeziwe luzodingeka ukuze kuvivinywe lesi sizathu," kusho uHorvath. "Sifuna ngempela ukulinganisa iminyaka yobucubu besifazane enempilo, engenayo umdlavuza." Ngaphezu kwalokho, sifuna ukuhlola ukuthi ukunyuka kweminyaka emathunzini asebele kusho ukuthini ukuthuthukiswa komdlavuza esikhathini esizayo. "
Ukuhlolwa okuningi kwezicubu zesifuba enempilo ngezigaba ezihlukahlukene empilweni yowesifazane - ukukhulelwa, emva kokukhulelwa, ngemuva kokukhulelwa nangemva kokuya esikhathini sokuya esikhathini - kuzosiza ukucacisa ukuthi ngabe izicubu zesifuba eziguga ngokushesha kangakanani, empeleni, amathuba okuba nomdlavuza.
Uma kunjalo, ukuhlola izinga le-methylation ngaphakathi kwamabele kungenza ngelinye ilanga lishaye ithuba lomfazi lokuthola lesi sifo esongela ukuphila.
I-Telomeres
I-Telomeres inikeza enye indlela yokukala izinga lokuguga. I-Telomeres yizinhlaka ezincane ezithinta izinto eziphathelene nama-gene ngaphakathi kweseli njengoba iseli lilungele ukwahlukanisa. Ngesikhathi ngasinye ukuhlukaniswa kweseli kwenzeka, ama-telomere anciphisa kancane; uma esincane kakhulu, iseli alinakukwazi ukwahlukana, okuholela ekufeni kweseli.
Kukhona ucwaningo oluqhubekayo lokukala ubude be-telomere njengenhlobo yokwenza umgomo wokuqondisa ukuthi amangqamuzana okusheshayo emzimbeni wakho asekhulile. Ngaphezu kwalokho, ososayensi baphenya ukuthi ukugcina i-telomeres isikhathi eside kungavumela amangqamuzana amancane ahlukanise kahle.
Imithombo:
I-Methylation. I-US National Cancer Institute Dictionary ye-Cancer Imigomo. Ifinyelele ngo-Okthoba 25, 2013.
http://www.cancer.gov/dictionary?cdrid=655031
USteve Horvath. "I-DNA i-methylation yobudala bezicubu zomuntu namaseli." I-Genome Biology 2013, 14: R115.
http://genomebiology.com/2013/14/10/R115
USven Bocklandt, Wen Lin, uMary E. Sehl, uFrancisco J. Sánchez, uJanet S. Sinsheimer, uSteve Horvath no-Eric Vilain. "I-Epigenetic Predictor Age." PLoS ONE 6 (6): e14821.
http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0014821