美國俄亥俄州的兒童醫院(Cincinnati Children hospital)日前利用誘導式多功能幹細胞(iPSC),取代胚胎細胞,第一次成功的分化成小腸細胞.這項研究已在12日發表在自然(nature)期刊中.
iPSC如同胚胎細胞,就有高度分化能力,可分化身體三個胚層的組織.科學家利用化學和蛋白質的生長因子,促使iPSC只分化出內胚層組織.內胚層組織包含體內的器官組織,像是食道、胃、小腸、胰臟、肺臟和肝臟.
將細胞培養在富含腸道營養環境的培養基中,iPSC會誘導分化為尾腸前趨細胞(hindgut progenitors).28天後利用螢光立體顯微鏡觀察,可看到新的細胞與正常的小腸上皮細胞極為相似,具有腸細胞(enterocyte)、杯狀細胞(goblet cell)、絨毛膜細胞(Paneth cell)和腸道內分泌細胞(enteroendocrine cells),並具有吸收和分泌的功能.
科學家在實驗室分化出小腸細胞,其最終目的是希望可以培養出完整小腸組織,以利移植的臨床治療,應用在壞死性腸炎(necrotizing enterocolitis)、炎症性腸病(inflammatory bowel disease)和短長症(short bowel syndromes).
詳細影片請看 http://www.gizmag.com/intestinal-tissue-created-from-stem-cells/17258/
Functional intestinal tissue created from stem cells
Both human embryonic stem cells (hESCs) and induced pluripotent stem cells (iPSCs) were used in the research. hESCs have the natural ability to become any type of cell found in the human body, while the iPSCs were created by reprogramming biopsied human skin cells into stem cells. The two types were used so that the researchers could compare the transformative capabilities of the relatively-new iPSC technology with the more established hESC methodology.
It is now hoped that such lab-grown tissue could be used to research treatments for gastro-intestinal diseases, or for transplantation.
The team, led by Cincinnati Children’s Dr. James Wells, used chemical and protein growth factors to manipulate the pluripotent stem cells. They were first coaxed into becoming definitive endoderm embryonic cells – these are the cells that have the potential to become the lining of the esophagus, stomach and intestines, or the lungs, pancreas and liver. Using a pro-intestinal cell culture, the cells were then swayed to further develop into embryonic intestinal cells known as hindgut progenitors.
After 28 days, these progenitors had formed into three-dimensional tissue that closely resembled human intestinal tissue, complete with the usual enterocytes, goblet, Paneth and enteroendocrine cells. It also contained intestine-specific stem cells, and had the ability to absorb and secrete, just like natural intestinal tissue.
“This is the first study to demonstrate that human pluripotent stem cells in a petri dish can be instructed to efficiently form human tissue with three-dimensional architecture and cellular composition remarkably similar to intestinal tissue,” said Dr. Wells. “The hope is that our ability to turn stem cells into intestinal tissue will eventually be therapeutically beneficial for people with diseases such as necrotizing enterocolitis, inflammatory bowel disease and short bowel syndromes.”
The team is also looking into using the tissue for testing how different drugs are absorbed by the digestive system.
The research was published this Sunday in the journal Nature.
