Laminin isoforms in human embryonic stem cells: synthesis, receptor usage and growth support
Laminin isoforms in human embryonic stem cells: synthesis, receptor usage and growth support
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DOI：
10.1111/j.1582-4934.2008.00643.x
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发表时间：
2009-08-01
影响因子：
5.3
通讯作者：
Otonkoski, Timo
中科院分区：
文献类型：
--
作者：
Vuoristo, Sanna;Virtanen, Ismo;Otonkoski, Timo
为了揭示人胚胎干细胞（hESC）的功能固有生态位，我们在无饲料的细胞培养条件下检测了基底膜（BM）蛋白的产生及其受体的存在。此外，我们研究了hESCs与纯化的人骨髓蛋白的结合，并鉴定了介导这种接触的受体。此外，我们还测试了纯化的人层粘连蛋白（Lm）异构体是否在短期培养的hESC自我更新和生长中起作用。结果表明，hESCs合成了Lm α(1)和Lm α(5)链以及Lm β(1)和γ(1)链，表明在培养基中产生了Lm -111和-511并沉积在细胞上。hESCs含有功能重要的整合素（Int）亚基，Int β (1), α (3), α (6), α (5), β(5)和α (V)，以及Lm α(5)受体，Lutheran （Lu）糖蛋白及其截断形式，基底细胞粘附分子（B-CAM）。在细胞粘附实验中，Int β(1)对于粘附大多数纯化的人BM蛋白至关重要。Lu/B-CAM与Int α (3) β(1)一起介导了对Lm-511的粘附，并且对于hESCs与胚胎饲养细胞的粘附至关重要。对Lm-411的粘附是由α (6) β(1)介导的。Lm-511与Matrigel一样支持hESC在特定培养基中的生长。这些结果为骨髓在hESCs中的生物学作用提供了重要的信息，为进一步研究人类多能干细胞的骨髓生物学提供了依据。
To reveal the functional intrinsic niche of human embryonic stem cells (hESC) we examined the production of basement membrane (BM) proteins and the presence of their receptors in feeder-free cell culture conditions. In addition, we investigated binding of hESCs to purified human BM proteins and identified the receptors mediating these contacts. Also, we tested whether purified human laminin (Lm) isoforms have a role in hESC self-renewal and growth in short-term cultures. The results show that hESCs synthesize Lm alpha(1) and Lm alpha(5) chains together with Lm beta(1) and gamma(1) chains suggesting the production of Lms-111 and -511 into the culture medium and deposits on cells. hESCs contain functionally important integrin (Int) subunits, Int beta(1), alpha(3), alpha(6), alpha(5), beta(5) and alpha(V), as well as the Lm alpha(5) receptor, Lutheran (Lu) glycoprotein and its truncated form, basal cell adhesion molecule (B-CAM). In cell adhesion experiments, Int beta(1) was crucial for adhesion to most of the purified human BM proteins. Lu/B-CAM mediated adhesion to Lm-511 together with Int alpha(3)beta(1), and was essential for the adhesion of hESCs to embryonic feeder cells. Adhesion to Lm-411 was mediated by Int alpha(6)beta(1). Lm-511 supported hESC growth in defined medium equally well as Matrigel. These results provide consequential information of the biological role of BM in hESCs, warranting further investigation of BM biology of human pluripotent stem cells.