现代医学：研究生 干细胞 课件.pptx

干细胞研究获得 2012年 诺贝尔生理和医学奖 ;;e;什么是“干” 细胞;细胞分化的地形图模型;;;Types of stem cell: Embryonic stem cells Tissue stem cells 3) Induced pluripotent (iPS) stem cells ;Embryonic stem (ES) cells: Where we find them;Embryonic stem (ES) cells: What they can do;Tissue stem cells: Where we find them;Tissue stem cells: What they can do;Induced pluripotent stem cells (iPS cells);Induced pluripotent stem cells (iPS cells);Stem cell jargon;1981?年英国科学家?Evans?和?Martin?等人用延缓着床的胚泡首次成功地分离出小鼠胚胎干细胞，并成功地用于体外培养，从而在全球掀起了有关干细胞的研究热潮。;美国科学家Jumes?Thomson首次取得了“人”体胚胎干细胞在体外的非分化增殖，他们从体外受精的人体胚胎内细胞团分离胚胎干细胞，进行体外培养，并获得了成功，证明了人体胚胎干细胞与啮齿类动物有极为相似的特点，从而使胚胎干细胞可能被用来取代病人体内的病损组织细胞，达到医学的目的。;;20世纪50年代，?英国剑桥大学的约翰·格登等人的实验就已经得知卵细胞质能重编程体细胞核。这些实验是为了解决分化细胞的基因组是否经历了不可逆转的变化，以及是否不再支持早期发育这些问题而进行的。格登的实验表明并非如此，蝌蚪的分化细胞的细胞核在移植进入卵母细胞质中后，能指导卵细胞发育为性成熟成体青蛙。 1962年，格登宣布他用非洲爪蟾的体细胞成功克隆出了蝌蚪。;这一实验具有划时代的意义，他首次证实了已分化细胞的基因组的可通核移植技术将其重新转化为具有多能性的细胞。这将为人体受损的或者病变的细胞提供无限的与之匹配的干细胞的供给，也将为帕金森综合症和其他硬化症患者带来福音。;;In 2006, Shinya Yamanaka found that exposing adult mouse skin cells to four specific genes could reprogram the cells to a more primitive form, much like embryonic stem cells.;;;A scheme of the generation of induced pluripotent stem (IPS) cells.?(1)Isolate and culture donor cells. (2)Transfect stem cell-associated genes into the cells by viral vectors. Red cells indicate the cells expressing the exogenous genes. (3)Harvest and culture the cells according to ES cell culture, using mitotically inactivated?feeder cells?(lightgray). (4)A small subset of the transfected cells become iPS cells and generate ES-like colonies.;Generation of iPS Cells from MEF Cultures via 24 Factors;Narrowing down the Candidate Factors;;Oct-3/4?(Pou5f1) Oct-3/4 is one of the family of?octamer (Oct) transcription factors, and plays a crucial role in maintaining pluripotency. The absence of Oct-3/4 in Oct-3/4+?cells, such as?blastomeres?and?embryonic stem cells, leads to spontaneous?trophoblast?differentiation, and presence of Oct-3/4 thus gives rise to the pluripotency and