Juntendo Itch Research Center (JIRC), Institute for Environmental and Gender Specific Medicine, Juntendo University Graduate School of Medicine, 2-1-1 Tomioka, Urayasu, Chiba, 279-0021, Japan.
Atopy (Allergy) Research Center, Juntendo University Graduate School of Medicine, 2-1-1 Hongo, Bunkyo-ku, Tokyo, 113-8421, Japan.
Sci Rep. 2020 Mar 9;10(1):4360. doi: 10.1038/s41598-020-60036-z.
Because intractable itch reduces quality of life, understanding the fundamental mechanisms of itch is required to develop antipruritic treatments. Itch is mediated by peripheral sensory neurons, which originate from the neural crest (NC) during development. Itch-associated signaling molecules have been detected in genetically engineered animals and in cultures of peripheral neurons from dorsal root ganglia (DRG). Ethical difficulties collecting peripheral neurons from human DRG have limited analysis of itch in humans. This study describes a method of differentiating peripheral neurons from human induced pluripotent stem cells (hiPSCs) for physiological study of itch. This method resulted in the robust induction of p75 and HNK1 double-positive NC cells from hiPSCs. The expression of NC markers TFAP2A, SOX10 and SNAI1 increased during NC induction. The induction efficiency was nearly 90%, and human peripheral neurons expressing peripherin were efficiently differentiated from hiPSC-derived NC cells. Moreover, induced peripheral neurons expressed the sensory neuronal marker BRN3A and the itch-related receptors HRH1, MRGPRX1, IL31R and IL-4R. Calcium imaging analyses indicated that these peripheral neurons included sensory neurons responsive to itch-related stimuli such as histamine, BAM8-22, IL-31 and IL-4. These findings may enable detailed analyses of human DRG neurons and may result in new therapies for intractable itch.
由于顽固性瘙痒会降低生活质量，因此需要了解瘙痒的基本机制，以便开发止痒治疗方法。瘙痒是由外周感觉神经元介导的，这些神经元在发育过程中起源于神经嵴（NC）。在基因工程动物和背根神经节（DRG）的外周神经元培养物中已经检测到与瘙痒相关的信号分子。从人 DRG 中收集外周神经元存在伦理难题，这限制了对人类瘙痒的分析。本研究描述了一种从人诱导多能干细胞（hiPSC）中分化外周神经元的方法，用于瘙痒的生理研究。该方法能够从 hiPSC 中强力诱导出 p75 和 HNK1 双阳性 NC 细胞。在 NC 诱导过程中，NC 标志物 TFAP2A、SOX10 和 SNAI1 的表达增加。诱导效率接近 90%，并且能够从 hiPSC 衍生的 NC 细胞中高效分化出表达 peripherin 的人外周神经元。此外，诱导的外周神经元表达感觉神经元标志物 BRN3A 以及与瘙痒相关的受体 HRH1、MRGPRX1、IL31R 和 IL-4R。钙成像分析表明，这些外周神经元包括对组胺、BAM8-22、IL-31 和 IL-4 等瘙痒相关刺激有反应的感觉神经元。这些发现可能使对人 DRG 神经元进行详细分析成为可能，并可能为顽固性瘙痒提供新的治疗方法。
