Contra o marasmo #7

O Prémio Nobel de Fisiologia ou Medicina de 2012 reconheceu o trabalho de dois investigadores, o britânico John Gurdon e o japonês Shinya Yamanaka, iniciado em 1962 pelo primeiro e complementado em 2006 pelo segundo, e que, muito sucintamente, esclarece que é possível reprogramar células maturas - já diferenciadas - em células estaminais, ou seja, pluripotentes, uma noção que sempre criou cépticos na comunidade científica. O que é que isto traz de relevante para a ciência? Muito claramente: o entendimento da diferenciação celular, o estudo do mecanismo de várias doenças e a expansão da medicina regenerativa, entre muitas outras áreas. Ler a notícia no Público aqui. O Scientific Background, fornecido na atribuição do prémio pode ser consultado aqui. E começa assim: 

 «The 2012 Nobel Prize in Physiology or Medicine is awarded to Dr. John B. Gurdon and Dr. Shinya Yamanaka for their discovery that mature, differentiated cells can be reprogrammed to a pluripotent stem cell state. This represents a paradigm shift in our understanding of cellular differentiation and of the plasticity of the differentiated state. Cellular differentiation appears as a unidirectional process, where undifferentiated cells mature to various specialised cell fates, such as neurons, muscle and skin cells. The prevalent view during the first half of the 20 th century was that the mature cells were permanently locked into the differentiated state, and unable to return to a fully immature, pluripotent stem cell state. In 1962, John B. Gurdon radically changed this view by demonstrating that the nucleus from a differentiated frog intestinal epithelial cell was capable of generating a fully functional tadpole upon transplantation to an enucleated egg. This discovery shattered the dogma that cellular differentiation could only be a unidirectional process. Gurdon’s discovery was the starting point for cloning endeavours in various organisms. However, the question remained whether an intact differentiated cell could be fully reprogrammed to become pluripotent. In 2006, by an astonishingly simple procedure, Shinya Yamanaka proved that introduction of a small set of transcription factors into a differentiated cell was sufficient to revert the cell to a pluripotent state. The resulting cells were called induced pluripotent stem (iPS) cells. Together, Gurdon and Yamanaka have transformed our understanding of cellular differentiation. They have demonstrated that the usually very stable differentiated state can be unlocked because it harbours a potential for reversion to pluripotency. This discovery has introduced fundamentally new research areas, and offers exciting new opportunities to study disease mechanisms.»

Hermenegildo Espinoza