感觉神经元Dock4缺失上调Piezo1表达调控机械瘙痒

Loss of Dock4 in sensory neurons increases Piezo1 to regulate mechanical itch.

摘要:

目的：探究胞质分裂作用因子4(Dedicator of cytokinesis 4,Dock4)在瘙痒中的作用及其潜在的调控机制。方法：通过鞘内注射AAV-Cre病毒实现条件性敲除背根神经节(Dorsal Root Ganglion,DRG)神经元中的Dock4。利用行为学观察敲除Dock4后对小鼠机械性瘙痒、痒觉异化、组胺能化学性瘙痒和非组胺能化学性瘙痒的影响。通过蛋白免疫印迹(Western Blotting,WB)检测Dock4敲除后Piezo1蛋白在DRG中的表达变化。免疫荧光(Immunofluorescence,IF)检测Dock4与Piezo1的共定位以及Dock4敲除后对Piezo1表达的影响。结果：我们发现,敲除 DRG 神经元中的 Dock4 会显著增强小鼠的机械性瘙痒行为,并对氯喹(Chloroquine,CQ)引起的非组胺能化学性瘙痒具有一定的抑制作用。同时,敲除 DRG 的 Dock4 不会影响组胺(Histamine,His)引起的组胺能化学性瘙痒及白介素-31(Interleukin 31,IL-31)引起的非组胺能化学性瘙痒。此外,Dock4 的敲除能显著上调 DRG 神经元中 Piezo1 的表达。结论：缺失Dock4显著上调DRG神经元中Piezo1的表达,增强小鼠的机械性瘙痒。

Abstract:

Objective: This study aims to elucidate the role of dedicator of cytokinesis 4 (Dock4) in the modulation of itch and its underlying regulatory mechanisms. Methods: Conditional knockout of Dock4 in dorsal root ganglion (DRG) neurons was achieved via intrathecal injection of AAV-Cre virus. Behavioral assessments were conducted to evaluate the impact of Dock4 deletion on mechanical itch responses, alloknesis, histaminergic chemical itch, and non-histaminergic chemical itch in mice. Western blotting analysis was utilized to assess the alterations in Piezo1 expression in DRG following Dock4 knockout. Additionally, immunofluorescence was performed to examine the co-localization of Dock4 and Piezo1, as well as the effects of Dock4 deficiency on Piezo1 expression levels. Results: Our findings reveal that the knockout of Dock4 in DRG neurons significantly amplifies mechanical itch behavior in mice and partially mitigates non-histaminergic chemical itch induced by chloroquine (CQ). Moreover, Dock4 knockout did not influence histaminergic chemical itch triggered by histamine (His) or non-histaminergic chemical itch induced by interleukin-31 (IL-31). Additionally, Dock4 deficiency led to a pronounced upregulation of Piezo1 expression in DRG neurons. Conclusion: The absence of Dock4 significantly enhances Piezo1 expression in DRG neurons and exacerbates mechanical itch in mice, indicating a crucial role for Dock4 in the regulation of itch sensitivity.