Lee Chun-Ting, Bendriem Raphael M, Kindberg Abigail A, Worden Lila T, Williams Melanie P, Drgon Tomas, Mallon Barbara S, Harvey Brandon K, Richie Christopher T, Hamilton Rebecca S, Chen Jia, Errico Stacie L, Tsai Shang-Yi A, Uhl George R, Freed William J
Intramural Research Program, National Institute on Drug Abuse, Department of Health and Human Services, NIH, Baltimore, MD 21224, USA.
Intramural Research Program, National Institute on Drug Abuse, Department of Health and Human Services, NIH, Baltimore, MD 21224, USA.
Cell Rep. 2015 Feb 3;10(4):616-32. doi: 10.1016/j.celrep.2014.12.050. Epub 2015 Jan 29.
Human pluripotent stem cell (hPSC) lines exhibit repeated patterns of genetic variation, which can alter in vitro properties as well as suitability for clinical use. We examined associations between copy-number variations (CNVs) on chromosome 17 and hPSC mesodiencephalic dopaminergic (mDA) differentiation. Among 24 hPSC lines, two karyotypically normal lines, BG03 and CT3, and BG01V2, with trisomy 17, exhibited amplification of the WNT3/WNT9B region and rapid mDA differentiation. In hPSC lines with amplified WNT3/WNT9B, basic fibroblast growth factor (bFGF) signaling through mitogen-activated protein kinase (MAPK)/ERK amplifies canonical WNT signaling by phosphorylating LRP6, resulting in enhanced undifferentiated proliferation. When bFGF is absent, noncanonical WNT signaling becomes dominant due to upregulation of SIAH2, enhancing JNK signaling and promoting loss of pluripotency. When bFGF is present during mDA differentiation, stabilization of canonical WNT signaling causes upregulation of LMX1A and mDA induction. Therefore, CNVs in 17q21.31, a "hot spot" for genetic variation, have multiple and complex effects on hPSC cellular phenotype.
人多能干细胞（hPSC）系表现出重复的遗传变异模式，这可能会改变其体外特性以及临床应用的适用性。我们研究了17号染色体上的拷贝数变异（CNV）与hPSC中脑多巴胺能（mDA）分化之间的关联。在24个人多能干细胞系中，两个核型正常的细胞系BG03和CT3，以及具有17号染色体三体的BG01V2，表现出WNT3/WNT9B区域的扩增和快速的mDA分化。在WNT3/WNT9B扩增的hPSC系中，碱性成纤维细胞生长因子（bFGF）通过丝裂原活化蛋白激酶（MAPK）/ERK信号通路，通过磷酸化低密度脂蛋白受体相关蛋白6（LRP6）来放大经典WNT信号通路，从而导致未分化增殖增强。当不存在bFGF时，由于SIAH2的上调，非经典WNT信号通路占主导地位，增强JNK信号通路并促进多能性丧失。当在mDA分化过程中存在bFGF时，经典WNT信号通路的稳定会导致LMX1A上调和mDA诱导。因此，17q21.31（遗传变异的“热点”）中的CNV对hPSC细胞表型具有多重且复杂的影响。
