Department of Avian and Animal Sciences, University of Maryland, College Park, College Park, United States.
Department of Microbiology and Cell Biology, Montana State University, Bozeman, United States.
Elife. 2022 Jun 17;11:e71455. doi: 10.7554/eLife.71455.
Familial dysautonomia (FD) is a sensory and autonomic neuropathy caused by mutations in elongator complex protein 1 (). FD patients have small trigeminal nerves and impaired facial pain and temperature perception. These signals are relayed by nociceptive neurons in the trigeminal ganglion, a structure that is composed of both neural crest- and placode-derived cells. Mice lacking in neural crest derivatives (' CKO') are born with small trigeminal ganglia, suggesting Elp1 is important for trigeminal ganglion development, yet the function of Elp1 in this context is unknown. We demonstrate that Elp1, expressed in both neural crest- and placode-derived neurons, is not required for initial trigeminal ganglion formation. However, CKO trigeminal neurons exhibit abnormal axon outgrowth and deficient target innervation. Developing nociceptors expressing the receptor TrkA undergo early apoptosis in CKO, while TrkB- and TrkC-expressing neurons are spared, indicating Elp1 supports the target innervation and survival of trigeminal nociceptors. Furthermore, we demonstrate that specific TrkA deficits in the CKO trigeminal ganglion reflect the neural crest lineage of most TrkA neurons versus the placodal lineage of most TrkB and TrkC neurons. Altogether, these findings explain defects in cranial gangliogenesis that may lead to loss of facial pain and temperature sensation in FD.
家族性自主神经异常(FD)是一种感觉和自主神经病变,由延伸复合物蛋白 1 ()突变引起。FD 患者的三叉神经较小,面部疼痛和温度感知受损。这些信号由三叉神经节中的伤害感受神经元传递,三叉神经节由神经嵴和基板衍生细胞组成。缺乏神经嵴衍生细胞中的(' CKO')的小鼠出生时三叉神经节较小,表明 Elp1 对三叉神经节发育很重要,但 Elp1 在这种情况下的功能尚不清楚。我们证明,在神经嵴和基板衍生神经元中表达的 Elp1 对于初始三叉神经节形成不是必需的。然而, CKO 三叉神经神经元表现出异常的轴突生长和缺陷的靶神经支配。表达受体 TrkA 的发育中的伤害感受器在 CKO 中发生早期细胞凋亡,而 TrkB 和 TrkC 表达神经元则幸免,表明 Elp1 支持三叉神经伤害感受器的靶神经支配和存活。此外,我们证明 CKO 三叉神经节中特定的 TrkA 缺陷反映了大多数 TrkA 神经元的神经嵴谱系,而大多数 TrkB 和 TrkC 神经元的基板谱系。总之,这些发现解释了颅神经节生成缺陷,这可能导致 FD 中面部疼痛和温度感觉丧失。