Syangtan Deepsing, Al Mahbuba Deena, Masuko Sayaka, Li Qiao, Elton Andrew C, Zaltsman Yefim, Wrighton Paul J, Xia Ke, Han Xiaorui, Ouyang Yilan, Zhang Fuming, Linhardt Robert J, Kiessling Laura L
Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA.
School of Pharmacy, University of Wisconsin-Madison, 777 Highland Avenue, Madison, WI 53705, USA.
Stem Cell Reports. 2025 Jan 14;20(1):102384. doi: 10.1016/j.stemcr.2024.11.014. Epub 2024 Dec 26.
Heparan sulfate (HS) is an anionic polysaccharide generated by all animal cells, but our understanding of its roles in human pluripotent stem cell (hPSC) self-renewal and differentiation is limited. We derived HS-deficient hPSCs by disrupting the EXT1 glycosyltransferase. These EXT1 hPSCs maintain self-renewal and pluripotency under standard culture conditions that contain high levels of basic fibroblast growth factor(bFGF), a requirement for sufficient bFGF signaling in the engineered cells. Intriguingly, Activin/Nodal signaling is also compromised in EXT1 hPSCs, highlighting HS's previously unexplored involvement in this pathway. As a result, EXT1 hPSCs fail to differentiate into mesoderm or endoderm lineages. Unexpectedly, HS is dispensable for early ectodermal differentiation of hPSCs but still critical in generating motor neurons. Those derived from HS-deficient hPSCs lack proper neuronal projections and show alterations in axonogenesis gene expression. Thus, our study uncovers expected and unexpected mechanistic roles of HS in hPSC fate decisions.
硫酸乙酰肝素（HS）是一种由所有动物细胞产生的阴离子多糖，但我们对其在人类多能干细胞（hPSC）自我更新和分化中的作用了解有限。我们通过破坏EXT1糖基转移酶获得了缺乏HS的hPSC。这些EXT1 hPSC在含有高水平碱性成纤维细胞生长因子（bFGF）的标准培养条件下维持自我更新和多能性，这是工程细胞中充分的bFGF信号传导所必需的。有趣的是，Activin/Nodal信号传导在EXT1 hPSC中也受到损害，这突出了HS以前未被探索的在该途径中的参与。因此，EXT1 hPSC无法分化为中胚层或内胚层谱系。出乎意料的是，HS对于hPSC的早期外胚层分化是可有可无的，但在生成运动神经元方面仍然至关重要。那些源自缺乏HS的hPSC的运动神经元缺乏适当的神经投射，并在轴突发生基因表达上表现出改变。因此，我们的研究揭示了HS在hPSC命运决定中预期和意外的机制作用。
