Du Dongshu, Lou Xiangxin
Department of Bioengineering, College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620, People׳s Republic of China; Laboratory of Neuropharmacology and Neurotoxicology, Shanghai University, Shanghai 200444, People׳s Republic of China.
Department of Bioengineering, College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620, People׳s Republic of China.
Differentiation. 2014 Mar-Apr;87(3-4):127-33. doi: 10.1016/j.diff.2014.02.004. Epub 2014 Feb 28.
The sensory epithelium (SE) within the mammalian cochleae has a limited capacity for regeneration, and the loss of mammalian cochlear hair cells always lead to permanent hearing loss. Previous reports show that early postnatal cochlea harbors stem/progenitor-like cells nominated otospheres which have a limited regenerative/repair capacity, while these cell populations are progressively lost during the postnatal development. Induced pluripotent stem cells (iPS cells) directly reprogrammed from non-embryonic cells have captured great attentions in the scientific community. In the present study, we determine whether Yamanaka׳s factors can induce the reprogramming of cochlear cells into iPS cells. We introduce defined factors Oct3/4, Sox2 and Klf4 into otospheres derived from postnatal day-1 (P1) mouse SE, and analyze characteristics alterations in cochlear cells. After transduction, otospheres generated colonies exhibiting a normal karyotype and morphology similar to that of mouse embryonic stem cells (ESCs). Moreover, these cochlear iPS cells also express ESC-like markers. Importantly, the cochlear iPS cells show pluripotency in vitro and in vivo, as evidenced by differentiation into three germ layers by embryoid body formation, as well as high efficient formation of teratomas containing three germ layers in immunodeficient mice. Thus, pluripotent cochlear iPS cells can be generated from cochlear cells by using three Yamanaka׳s transcription factors. These attempts represent the first step toward generating fully pluripotent iPS cells from mammalian cochleae with defined exogenous genes.
哺乳动物耳蜗内的感觉上皮（SE）再生能力有限，哺乳动物耳蜗毛细胞的丧失总会导致永久性听力损失。先前的报道表明，出生后早期的耳蜗含有被称为耳球的干/祖细胞样细胞，其再生/修复能力有限，而这些细胞群体在出生后发育过程中会逐渐丧失。从非胚胎细胞直接重编程得到的诱导多能干细胞（iPS细胞）在科学界引起了极大关注。在本研究中，我们确定山中因子是否能诱导耳蜗细胞重编程为iPS细胞。我们将确定的因子Oct3/4、Sox2和Klf4导入出生后第1天（P1）小鼠SE来源的耳球，并分析耳蜗细胞的特征变化。转导后，耳球形成了具有正常核型且形态与小鼠胚胎干细胞（ESC）相似的集落。此外，这些耳蜗iPS细胞也表达类似ESC的标志物。重要的是，耳蜗iPS细胞在体外和体内均表现出多能性，通过胚状体形成分化为三个胚层以及在免疫缺陷小鼠中高效形成包含三个胚层的畸胎瘤可证明这一点。因此，利用三种山中转录因子可从耳蜗细胞生成多能性耳蜗iPS细胞。这些尝试代表了利用特定外源基因从哺乳动物耳蜗生成完全多能性iPS细胞的第一步。
