哺乳动物成体干细胞的研究进展

Mammalian Adult Stem Cell Research Progress

干细胞具有自我更新能力,能够产生高度分化的功能细胞。干细胞按照发育阶段分为胚胎干细胞和成体干细胞。根据干细胞的发育潜能分为三类:全能干细胞、多能干细胞和单能干细胞。胚胎干细胞的发育等级较高,是全能干细胞,而成体干细胞的发育等级较低,是多能或单能干细胞。一般认为成年组织或器官内的干细胞具有组织特异性,只能分化成特定的细胞或组织,然而,研究结果表明,组织特异性干细胞同样具有分化成其他细胞或组织的潜能,这为干细胞的应用开创了更广泛的空间。作者主要综述了干细胞的研究进展及几种成体干细胞的诱导分化。

Stem cells are primal cells existing in multi-cellular organisms and have held limelight in biomedical research in that they are characterized by the ability to renew themselves through mitotic cell division and to differentiate into diverse range of specialized cells. Stem cell therapy has the potential to change radically the treatment of diseases, and therefore, has been proposed or used to treat Parkinsion＇s disease, diabetes, spinal cord injury. Stem cells can be classified into embryo stem （ES） cells and adult stem cells or somatic stem cells. The latter, including several subclasses, are undifferentiated cells found in a- dult bodies and act as a repair system for the body, replenishing specialized cells. ES cells, so called pluripotent cells, are cells derived from the undifferentiated inner cell mass of embryos, and considered the best stem cells because they have ability to de velop into all derivatives of the three germ layers, i.e. ectoderm, endoderm, and mesoderm. Stem cells can also be classified into several subclasses according to their potency： Totipotent; pluripotent （i. e. ES cells）;multipotent （hematopoietcin stem cells） ; and oligopotent （still have the property of self-renewal）. However, recent studies have demonstrated that pluripotent stem cells can be induced from somatic cells, opening a new era for obtaining stem cells. This review summarizes the progress and the discoveries in stem cell research and induced pluripotent stem （iPS） cells.