Scientists have developed the first patient-derived stem cell mfano of albinism. The model will help studying eye conditions related to oculocutaneous albinism (OCA).
Sseli za tem hawana utaalam. Haziwezi kufanya kazi yoyote maalum katika mwili lakini zinaweza kujigawanya na kujifanya upya kwa muda mrefu na kuwa na uwezo wa kuwa maalum na kukua katika aina mbalimbali za mwili kama vile seli za misuli, seli za damu, seli za ubongo nk.
Stem cells are present in our bodies at all stages of life, from kiinitete to adulthood. Embryonic stem cells (ESCs) or fetal seli shina huonekana katika hatua ya awali huku seli shina za watu wazima ambazo hutumika kama mfumo wa kurekebisha mwili huonekana katika utu uzima.
Stem cells can be grouped into four: embryonic stem cells (ESCs), adult stem cells, kansa stem cells (CSCs) and induced pluripotent stem cells (iPSCs). Embryonic stem cells (ESCs) are derived from inner mass cells of the blastocyst-stage of mammalian embryo that are three to five days old. They can self-renew indefinitely and differentiate into cell types of all three germ layers. On the other hand, adult stem cells serve as a repair system to maintain cell homeostasis in tissues. They can replace dead or injured cells but have limited proliferation and differentiation potential in comparison with ESCs. Cancer stem cells (CSCs) arise from normal stem cells that undergo gene mutations. They initiate tumours forming a large colony or clones. Cancer stem cells play important roles in malignant tumours hence targeting them could provide a way to treat cancers.
Seli shina za pluripotent (iPSCs) zinazotokana na seli za watu wazima. Pluripotency yao imechochewa kimaabara katika maabara kwa kupanga upya seli za somatic kupitia jeni na mambo mengine. iPSC ni kama seli shina za kiinitete katika kuenea na kutofautisha. IPSC ya kwanza ilitengenezwa kutoka kwa murine fibroblasts na Yamanaka katika 2006. Tangu wakati huo, iPSC kadhaa za binadamu zimetengenezwa kutoka kwa sampuli maalum za wagonjwa. Kwa kuwa jenetiki ya mgonjwa inaonekana katika jenetiki ya iPSCs, seli hizi za somatic zilizopangwa upya hutumiwa kuiga magonjwa ya kijeni na zimeleta mapinduzi makubwa katika utafiti wa matatizo ya jeni ya binadamu.
Mfano ni mnyama au seli zinazoonyesha michakato yote au baadhi ya michakato ya patholojia inayozingatiwa katika ugonjwa halisi. Upatikanaji wa modeli ya majaribio ni muhimu kwa kuelewa maendeleo ya ugonjwa katika viwango vya seli na molekuli ambayo husaidia katika kukuza matibabu ya kutibu. Mfano husaidia kuelewa jinsi ugonjwa hukua na katika kujaribu mbinu zinazowezekana za matibabu. Kwa mfano, mtu anaweza kutambua malengo madhubuti ya dawa kwa usaidizi wa modeli au skrini ya molekuli ndogo ambazo zinaweza kupunguza ukali na kusimamisha kuendelea kwa ugonjwa. Mifano ya wanyama imetumika kwa muda mrefu lakini ina hasara kadhaa. Zaidi ya hayo, mifano ya wanyama haifai kwa matatizo ya maumbile kutokana na kutofautiana kwa maumbile. Sasa, seli shina za binadamu (embryonic na induced pluripotent) zinazidi kutumika kuiga magonjwa ya binadamu.
Uundaji wa magonjwa kwa kutumia iPSC za kibinadamu umefanywa kwa mafanikio kwa kadhaa hali kama vile ugonjwa wa uti wa mgongo, matatizo ya damu, kisukari, ugonjwa wa Huntington, kudhoofika kwa misuli ya uti wa mgongo n.k. Kuna idadi nzuri ya mifano ya binadamu ya iPSC of human neural diseases, congenital heart diseases and other genetic machafukos.
Hata hivyo, mfano wa iPSC wa binadamu wa ualbino haukupatikana hadi tarehe 11 Januari 2022 wakati wanasayansi katika Taasisi ya Kitaifa ya Macho (NEI) ambayo ni sehemu ya Taasisi za Kitaifa za Afya (NIH) waliripoti maendeleo ya modeli ya binadamu ya iPSC-msingi katika vitro kwa. ualbino wa oculocutaneous (OCA)
Oculocutaneous albinism (OCA) is a shida ya maumbile affecting pigmentation in the eye, skin, and hair. The patients suffer eye problems like reduced best-corrected visual acuity, reduced ocular pigmentation, abnormalities in fovea development, and/or abnormal crossing of optic nerve fibres. It is thought that improving eye pigmentation could prevent or rescue some of the vision defects.
The researchers developed an in-vitro model for studying pigmentation defects in human retinal pigment epithelium (RPE) and showed that the retina pigment epithelium tissue derived in vitro from patients recapitulates the pigmentation defects seen in albinism. This is very interesting in view of the fact that animal models of albinism are unsuitable and there is limited human cell lines to study melanogenesis and pigmentation defects. The patient-derived OCA1A- and OCA2-iPSCs developed in this study can be a renewable and reproducible source of cells for the production of target cell and/or tissue types. In vitro derived OCA tissues and OCA-iRPE will allow deeper understanding of how melanin formation takes place and identify molecules involved in pigmentation defects, and further probe for molecular and/or physiologic differences.
Hii ni hatua muhimu sana kuelekea lengo la matibabu ya ualbino wa oculocutaneous (OCA).
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Marejeo:
- Avior, Y., Sagi, I. & Benvenisty, N. Pluripotent seli shina katika muundo wa magonjwa na ugunduzi wa dawa. Nat Rev Mol Cell Biol 17, 170–182 (2016). https://doi.org/10.1038/nrm.2015.27
- Chamberlain S., 2016. Uundaji wa magonjwa kwa kutumia iPSC za binadamu. Jenetiki za Molekuli ya Binadamu, Juzuu 25, Toleo la R2, 1 Oktoba 2016, Kurasa R173–R181, https://doi.org/10.1093/hmg/ddw209
- Bai X., 2020. Uundaji wa Ugonjwa wa Msingi wa Shina na Tiba ya Kiini. Visanduku 2020, 9(10), 2193; https://doi.org/10.3390/cells9102193
- George A., et al 2022. In Vitro Disease Modeling of Oculocutaneous Albinism Type I and II Kwa kutumia Human Induced Pluripotent Stem Cell-Derived Retinal Pigment Epithelium (2022). Ripoti za Seli Shina. Juzuu 17, Toleo la 1, P173-186, Januari 11, 2022 DOI: https://doi.org/10.1016/j.stemcr.2021.11.016
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