First study to show development of interspecies chimera as a new source of organs for transplants
Katika utafiti uliochapishwa katika Kiini1, chimera - jina lake baada ya monster ya hadithi ya simba-mbuzi-nyoka - hufanywa kwa mara ya kwanza kwa kuchanganya nyenzo kutoka kwa binadamu na wanyama. The seli za binadamu inaweza kuonekana kwa mafanikio ikikua ndani ya nguruwe baada ya seli shina za binadamu (ambazo zina uwezo wa kukua na kuwa tishu yoyote) kudungwa kwenye kiinitete cha nguruwe kwa teknolojia ya kisasa ya seli shina.
Utafiti huu ulioongozwa na Profesa Juan Carlos Izpisua Belmonte katika Taasisi ya Salk ya Mafunzo ya Biolojia huko California ni mafanikio makubwa na kazi ya upainia katika kuelewa na kutambua uwezo wa chimera za spishi na hutoa uwezo usio na kifani wa kusoma ukuaji wa kiinitete mapema na chombo malezi.
Je, kengele ya binadamu na nguruwe inakuzwaje?
However, the authors describe this process as fairly inefficient with low success rate of only ~9 percent but they also observed that human cells were seen successfully functioning when part of a human-pig chimera. Thelow success rate is mainly attributed to the evolutionary gaps between human and pig and also there was no evidence that human cells were integrating into the premature form of brain tissue. The low success rate not with standing, the observations show that billions of cells in the chimera embryo would still have millions of human cells. The testing of these cells alone (even 0.1% to 1%) would certainly be meaningful in a larger context to achieve long term understanding of interspecies chimera.
Utafiti unaohusiana wa chimera pia ulichapishwa karibu wakati huo huo katika Nature iliyoongozwa na Hiromitsu Nakauchi katika Taasisi ya Stanford ya Biolojia ya seli ya shina na Tiba ya Kurejesha ambayo inaripoti visiwa vinavyofanya kazi katika chimera za panya.2.
Majadiliano ya kimaadili kuhusu chimera, tunaweza kufikia umbali gani?
Hata hivyo, tafiti zinazohusiana na ukuzaji wa chimera za spishi tofauti pia zinaweza kujadiliwa kimaadili na huzua wasiwasi kuhusu ni kwa kiwango gani tafiti kama hizo zinaweza kufanywa na zinakubalika kisheria na kijamii. Hii inahusisha uwajibikaji wa kimaadili na vyombo vya kufanya maamuzi vya kisheria na pia huzua maswali kadhaa.
If we take into account all ethical considerations, it is uncertain if a binadamu-animal chimera can be ever born. Will it be ethical if its born but not allowed breed by making it sterile? Also, how much percentage of human brain cells can be part of chimera is also questionable. Could the chimera potentially fall into some uncomfortable gray area as a subject in between of animal and human research. Scientists don’t know much about their own species because of the many barriers to research on humans. These barriers include no support for embryo research, prohibition of any clinical trials related to germline (cells that become sperm or eggs) genetic modification and limitations on the human developmental biology research.
Bila shaka, wanasayansi watalazimika kujibu maswali haya kwa wakati unaofaa badala ya kuyaepuka. Juhudi kama hizo zitatoa msingi na kuendeleza njia ya utafiti zaidi ambao ni sahihi kimaadili na kutoa maarifa ya kina kuhusu "kuwa binadamu".
Waandishi wanasema kinamna kwamba lengo lao ni kuelewa kimsingi jinsi seli za spishi mbili tofauti (nguruwe na mwanadamu hapa) huchanganyika, kutofautisha na kuunganishwa na kwamba wamechanganua chimera ya binadamu na nguruwe katika hatua ya mapema sana ya ukuzaji.
Changamoto nyingi lakini tumaini kubwa kwa siku zijazo
Utafiti huu ni wa kusisimua licha ya kuwa na changamoto za kimaadili na unaashiria hatua ya kwanza kuelekea kuzalisha viungo vya binadamu vinavyoweza kupandikizwa kwa kutumia wanyama wakubwa (nguruwe, ng'ombe n.k.) ambao chombo size and physiology is very close and similar to humans. However, if we look at the current study, the levels of immune rejection are very high as we speak. The pig contributions (cells from pig) into every organ that grows in the chimera is an extremely big challenge for any thoughts about successful organ transplantation into humans.
Hata hivyo, tumaini la kweli la wakati ujao hapa ni kuweza kuwa na a chanzo kipya cha viungo vya upandikizaji kwa binadamu kwa kutumia teknolojia ya seli-shina na uhariri wa jeni. Hili ni muhimu na hitaji la wakati huu, ikizingatiwa hitaji kubwa la upandikizaji kati ya wagonjwa, ambao wengi wao hufa kwenye orodha ya kungojea (haswa kwa mahitaji ya figo na ini) na pia ukosefu mkubwa wa wafadhili wa kutosha.
Authors assert that this study shall impact other related areas of research as well. The continued development of chimeras with relatively more human tissue has implications and usefulness in studying onset of diseases in humans and for screening drugs before trials on human participants apart from understanding the differences between the species. In this study, the technology was not used for human chimeras, but theoretically speaking a complementary methodology could be devised in the future in trying to use chimeras to make human organs for transplantation. More work in this area shall throw insights on the possible success and limitations of these technologies when used to develop chimera.
Huu ni utafiti wa kwanza na muhimu juu ya ukuzaji wa chimera za binadamu na wanyama na unafungua njia ya kuendeleza uelewa wa jumuiya ya kisayansi kuhusu uundaji na maendeleo ya seli katika mazingira ya wanyama.
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Chanzo (s)
1. Wu J et al. 2018. Interspecies Chimerism with Mamalia Pluripotent Stem Cells. Kiini. 168 (3). https://doi.org/10.1016/j.cell.2016.12.036
2. Yamaguchi T et al. 2018. Interspecies organogenesis inazalisha islets kazi autologous. Asili. 542. https://doi.org/10.1038/nature21070
