Supplementary Material for: Regulator of G Protein Signaling Transcript Expression in Human Neural Progenitor Differentiation: R7 Subfamily Regulation by DNA Methylation

G protein-coupled receptors (GPCRs) and their ligands are critical regulators of neural progenitor differentiation, and GPCR signaling pathways are regulated by regulator of G protein signaling (RGS) proteins. RGS protein expression is dynamically regulated, and we have recently described the epigenetic regulation of RGS transcript expression. Given the potential of RGS proteins to regulate GPCR signaling and the established role of epigenetic regulation in progenitor differentiation, we explored the impact of epigenetic regulation of RGS transcripts during in vitro differentiation of human neural progenitors. Here, we demonstrate robust upregulation of the RGS transcripts RGS4, RGS5, RGS6, RGS7, and RGS11 during neuronal differentiation, while DNA methyltransferase (DNMT) and histone deacetylase enzyme expression is suppressed during differentiation. Transcripts encoding R7 subfamily RGS proteins and the R7-binding partners R7BP and R9AP showed the greatest upregulation. Further, we showed that direct pharmacological inhibition of DNMT activity enhances expression of RGS2, RGS4, RGS5, RGS6, RGS7, RGS8, RGS9L, RGS10, and RGS14 as well as R7BP and R9AP transcripts in progenitors, consistent with regulation by DNMTs. Our results reveal marked upregulation of RGS expression during neuronal differentiation and suggest that decreased expression of DNMT enzymes during differentiation contributes to upregulation. © 2014 S. Karger AG, Basel

G蛋白偶联受体（G protein-coupled receptors, GPCRs）及其配体是调控神经祖细胞分化的关键因子，而GPCR信号通路受G蛋白信号调节蛋白（regulator of G protein signaling, RGS）的调控。RGS蛋白的表达具有动态调控特性，我们团队近期阐明了RGS转录本表达的表观遗传调控机制。鉴于RGS蛋白调控GPCR信号通路的潜在作用，以及表观遗传调控在祖细胞分化中的既定功能，我们探究了表观遗传调控RGS转录本在人类神经祖细胞体外分化过程中的影响。本研究证实，在神经元分化期间，RGS4、RGS5、RGS6、RGS7及RGS11的转录本出现显著上调；而分化过程中DNA甲基转移酶（DNA methyltransferase, DNMT）与组蛋白去乙酰化酶的表达则受到抑制。编码R7亚家族RGS蛋白以及R7结合蛋白R7BP和R9AP的转录本上调幅度最为显著。此外，我们发现直接通过药物抑制DNMT活性可增强祖细胞中RGS2、RGS4、RGS5、RGS6、RGS7、RGS8、RGS9L、RGS10、RGS14以及R7BP和R9AP转录本的表达，这与DNMT介导的调控作用相符。本研究结果揭示了神经元分化过程中RGS表达的显著上调现象，并提示分化期间DNMT酶表达下调是导致该上调现象的原因之一。© 2014 S. Karger AG, 巴塞尔