一個國際研究小組日前發(fā)現(xiàn),，一旦胰腺中生成胰島素的胰島β細(xì)胞全被破壞，那么胰腺中就會有其他細(xì)胞出來“救急”,，“變身”為胰島β細(xì)胞,。這一發(fā)現(xiàn)表明，胰島β細(xì)胞可以“再生”,，這也許有助于醫(yī)學(xué)專家重新設(shè)計對糖尿病的療法,。
一般而言，胰腺中的胰島α細(xì)胞負(fù)責(zé)制造胰高血糖素,，胰島β細(xì)胞負(fù)責(zé)制造胰島素,。但日本奈良尖端科學(xué)技術(shù)大學(xué)院大學(xué)和瑞士日內(nèi)瓦大學(xué)研究人員通過小鼠實驗表明，這種分工并不是不可改變的,。
研究人員給小鼠使用了一種名為白喉的毒素,，將小鼠體內(nèi)的胰島β細(xì)胞全部破壞，結(jié)果小鼠出現(xiàn)糖尿病癥狀,。為了維持小鼠的生命,，研究人員給它們注射胰島素。兩到四周后,，他們驚訝地發(fā)現(xiàn),，小鼠體內(nèi)的胰島α細(xì)胞出現(xiàn)變化，原本只負(fù)責(zé)制造胰高血糖素的胰島α細(xì)胞現(xiàn)在開始制造新的胰島β細(xì)胞,。
在接受實驗的8只小鼠中，有一半在10個月以后胰島β細(xì)胞增殖到原有數(shù)量的20％左右,，擺脫了糖尿病癥狀,。
此前，研究人員從未發(fā)現(xiàn)胰島α細(xì)胞能夠成為胰島β細(xì)胞的來源,。他們指出,，如果人體內(nèi)胰島α細(xì)胞能夠代替數(shù)目減少或者功能減弱的胰島β細(xì)胞，將會為糖尿病治療帶來希望,。這一研究成果刊登在最新一期英國《自然》雜志網(wǎng)絡(luò)版上,。(生物谷Bioon.com)
生物谷推薦原文出處：
Nature doi:10.1038/nature08894
Conversion of adult pancreatic α-cells to β-cells after extreme β-cell loss
Fabrizio Thorel1,3, Virginie Népote1,3, Isabelle Avril1,3, Kenji Kohno2, Renaud Desgraz1, Simona Chera1 & Pedro L. Herrera1
Department of Cell Physiology & Metabolism, University of Geneva Faculty of Medicine, 1 rue Michel-Servet, CH-1211 Geneva 4, Switzerland
Graduate School of Biological Sciences, Nara Institute of Science and Technology (NAIST), 8916-5 Takayama, Ikoma, Nara 630-0192, Japan
These authors contributed equally to this work.
Pancreatic insulin-producing β-cells have a long lifespan, such that in healthy conditions they replicate little during a lifetime. Nevertheless, they show increased self-duplication after increased metabolic demand or after injury (that is, β-cell loss). It is not known whether adult mammals can differentiate (regenerate) new β-cells after extreme, total β-cell loss, as in diabetes. This would indicate differentiation from precursors or another heterologous (non-β-cell) source. Here we show β-cell regeneration in a transgenic model of diphtheria-toxin-induced acute selective near-total β-cell ablation. If given insulin, the mice survived and showed β-cell mass augmentation with time. Lineage-tracing to label the glucagon-producing α-cells before β-cell ablation tracked large fractions of regenerated β-cells as deriving from α-cells, revealing a previously disregarded degree of pancreatic cell plasticity. Such inter-endocrine spontaneous adult cell conversion could be harnessed towards methods of producing β-cells for diabetes therapies, either in differentiation settings in vitro or in induced regeneration.
