Wnt5a Supports Osteogenic Lineage Decisions in Embryonic Stem Cells
Wnt5a Supports Osteogenic Lineage Decisions in Embryonic Stem Cells
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DOI：
10.1089/scd.2015.0367
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发表时间：
2016-07-01
影响因子：
4
通讯作者：
Nieden, Nicole I. Zur
中科院分区：
文献类型：
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作者：
Keller, Kevin C.;Ding, Huawen;Nieden, Nicole I. Zur
多能干细胞向成骨细胞分化的过程已经在许多研究中进行了探索。然而，目前的文献尚未充分阐明Wnt糖蛋白在多能干细胞沿着成骨谱系分化中的作用。在小鼠胚胎干细胞（ESC）体外成骨过程中，非经典WNT 5a在早期就表达，无论是通过WNT 5a阳性表达分选的细胞，还是在2天的时间窗内添加重组WNT 5a（rWNT 5a）的细胞，其成骨产量均显著增加。在机制上，rWNT 5a补充上调蛋白激酶C（PKC）、钙/钙调蛋白依赖性激酶II（CamKII）和c-Jun N-末端激酶（JNK）活性，同时拮抗经典Wnt信号传导的关键效应子：β-连环蛋白。相反，当在同一时间窗期间使用重组WNT 3a（rWNT 3a）或β-连环蛋白的其他正调节剂时，成骨标志物表达降低。然而，如果在rWNT 5a处理后的时间窗内补充rWNT 3a，则在鼠和人ESC中的成骨分化均增强。阐明这些WNT配体在指导成骨早期阶段的作用有可能大大改善组织工程方案和再生医学的应用。
The specification of pluripotent stem cells into the bone-forming osteoblasts has been explored in a number of studies. However, the current body of literature has yet to adequately address the role of Wnt glycoproteins in the differentiation of pluripotent stem cells along the osteogenic lineage. During mouse embryonic stem cell (ESC) in vitro osteogenesis, the noncanonical WNT5a is expressed early on. Cells either sorted by their positive WNT5a expression or when supplemented with recombinant WNT5a (rWNT5a) during a 2-day window showed significantly enhanced osteogenic yield. Mechanistically, rWNT5a supplementation upregulated protein kinase C (PKC), calcium/calmodulin-dependent kinase II (CamKII) and c-Jun N-terminal kinase (JNK) activity while antagonizing the key effector of canonical Wnt signaling: beta-catenin. Conversely, when recombinant WNT3a (rWNT3a) or other positive regulators of beta-catenin were employed during this same time window there was a decrease in osteogenic marker expression. However, if rWNT3a was supplemented during a time window following rWNT5a treatment, osteogenic differentiation was enhanced both in murine and human ESCs. Elucidating the role of these WNT ligands in directing the early stages of osteogenesis has the potential to considerably improve tissue engineering protocols and applications for regenerative medicine.