Samuel Ryan M, Navickas Albertas, Maynard Ashley, Gaylord Eliza A, Garcia Kristle, Bhat Samyukta, Majd Homa, Richter Mikayla N, Elder Nicholas, Le Daniel, Nguyen Phi, Shibata Bradley, Llabata Marta Losa, Selleri Licia, Laird Diana J, Darmanis Spyros, Goodarzi Hani, Fattahi Faranak
Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, CA 94158, USA.
Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA, 94143, USA.
bioRxiv. 2023 Mar 7:2023.03.06.531220. doi: 10.1101/2023.03.06.531220.
The neural crest (NC) is highly multipotent and generates diverse lineages in the developing embryo. However, spatiotemporally distinct NC populations display differences in fate potential, such as increased gliogenic and parasympathetic potential from later migrating, nerve-associated Schwann cell precursors (SCPs). Interestingly, while melanogenic potential is shared by both early migrating NC and SCPs, differences in melanocyte identity resulting from differentiation through these temporally distinct progenitors have not been determined. Here, we leverage a human pluripotent stem cell (hPSC) model of NC temporal patterning to comprehensively characterize human NC heterogeneity, fate bias, and lineage development. We captured the transition of NC differentiation between temporally and transcriptionally distinct melanogenic progenitors and identified modules of candidate transcription factor and signaling activity associated with this transition. For the first time, we established a protocol for the directed differentiation of melanocytes from hPSCs through a SCP intermediate, termed trajectory 2 (T2) melanocytes. Leveraging an existing protocol for differentiating early NC-derived melanocytes, termed trajectory 1 (T1), we performed the first comprehensive comparison of transcriptional and functional differences between these distinct melanocyte populations, revealing differences in pigmentation and unique expression of transcription factors, ligands, receptors and surface markers. We found a significant link between the T2 melanocyte transcriptional signature and decreased survival in melanoma patients in the cancer genome atlas (TCGA). We performed an CRISPRi screen of T1 and T2 melanocyte signature genes in a human melanoma cell line and discovered several T2-specific markers that promote lung metastasis in mice. We further demonstrated that one of these factors, SNRPB, regulates the splicing of transcripts involved in metastasis relevant functions such as migration, cell adhesion and proliferation. Overall, this study identifies distinct developmental trajectories as a source of diversity in melanocytes and implicates the unique molecular signature of SCP-derived melanocytes in metastatic melanoma.
神经嵴（NC）具有高度多能性，在发育中的胚胎中产生多种细胞谱系。然而，时空上不同的神经嵴群体在命运潜能上存在差异，例如，后期迁移的、与神经相关的雪旺细胞前体（SCPs）具有增强的生成神经胶质细胞和副交感神经的潜能。有趣的是，虽然早期迁移的神经嵴和雪旺细胞前体都具有黑色素生成潜能，但尚未确定通过这些时间上不同的祖细胞分化产生的黑素细胞身份差异。在这里，我们利用神经嵴时间模式的人类多能干细胞（hPSC）模型，全面表征人类神经嵴的异质性、命运偏向和谱系发育。我们捕捉到了在时间和转录上不同的黑色素生成祖细胞之间神经嵴分化的转变，并确定了与这种转变相关的候选转录因子和信号活性模块。我们首次建立了一种通过SCP中间体从hPSC定向分化黑素细胞的方案，称为轨迹2（T2）黑素细胞。利用现有的用于分化早期神经嵴来源黑素细胞的方案，称为轨迹1（T1），我们首次对这些不同黑素细胞群体之间的转录和功能差异进行了全面比较，揭示了色素沉着差异以及转录因子、配体、受体和表面标志物的独特表达。我们发现T2黑素细胞转录特征与癌症基因组图谱（TCGA）中黑色素瘤患者生存率降低之间存在显著联系。我们在人黑色素瘤细胞系中对T1和T2黑素细胞特征基因进行了CRISPRi筛选，发现了几个促进小鼠肺转移的T2特异性标志物。我们进一步证明，这些因子之一，SNRPB，调节参与转移相关功能（如迁移、细胞粘附和增殖）的转录本的剪接。总体而言，这项研究确定了不同的发育轨迹是黑素细胞多样性的一个来源，并暗示了SCP来源黑素细胞的独特分子特征与转移性黑色素瘤有关。
