PDF(Pubmed)
Abstract：
Itch sensitization has been reported in patients with chronic allergic skin diseases and observed in a mouse model of allergic contact dermatitis (ACD). There is evidence suggesting that neuroimmune interactions may contribute to itch sensitization, as an increase in dendritic cells (DCs) within ganglia has been observed during allergic conditions. However, how DCs interact with sensory neurons in ganglia during allergic conditions is still not known. This study aims to investigate the role of DCs in dorsal root ganglion (DRG) under ACD conditions, specifically focusing on itch sensitization within the DRG. The tolylene-2,4-diisocyanate (TDI) mouse model for ACD and the co-culture model of DCs and DRG neurons was employed in this study.
We successfully induced ACD by TDI, as evidenced by the development of edema, elevated total serum IgE levels, and an observed itch reaction in TDI-sensitized mice. Calcium imaging and RT-qPCR analysis revealed that TDI-sensitized mice exhibited signs of peripheral sensitization, including a higher percentage of neurons responding to pruritogens and increased activation and expression of itch receptors in excised DRG of TDI-sensitized mice. Immunofluorescence and flow cytometric analysis displayed an increase of MHCII+ cells, which serves as a marker for DCs, within DRG during ACD. The co-culture study revealed that when DRG neurons were cultured with DCs, there was an increase in the number of neurons responsive to pruritogens and activation of itch receptors such as TRPA1, TRPV1, H1R, and TRPV4. In addition, the immunofluorescence and RT-qPCR study confirmed an upregulation of TRPV4.
Our findings indicate that there is an increase of MHCII+ cells and itch peripheral sensitization in DRG under TDI-induced ACD condition. It has been found that MHCII+ cells in DRG might contribute to the itch peripheral sensitization by activating itch receptors, as shown through co-culture studies between DRG neurons and DCs. Further studies are required to identify the specific mediator(s) responsible for peripheral sensitization induced by activated DCs.
We successfully induced ACD by TDI, as evidenced by the development of edema, elevated total serum IgE levels, and an observed itch reaction in TDI-sensitized mice. Calcium imaging and RT-qPCR analysis revealed that TDI-sensitized mice exhibited signs of peripheral sensitization, including a higher percentage of neurons responding to pruritogens and increased activation and expression of itch receptors in excised DRG of TDI-sensitized mice. Immunofluorescence and flow cytometric analysis displayed an increase of MHCII+ cells, which serves as a marker for DCs, within DRG during ACD. The co-culture study revealed that when DRG neurons were cultured with DCs, there was an increase in the number of neurons responsive to pruritogens and activation of itch receptors such as TRPA1, TRPV1, H1R, and TRPV4. In addition, the immunofluorescence and RT-qPCR study confirmed an upregulation of TRPV4.
Our findings indicate that there is an increase of MHCII+ cells and itch peripheral sensitization in DRG under TDI-induced ACD condition. It has been found that MHCII+ cells in DRG might contribute to the itch peripheral sensitization by activating itch receptors, as shown through co-culture studies between DRG neurons and DCs. Further studies are required to identify the specific mediator(s) responsible for peripheral sensitization induced by activated DCs.
摘要：
背景：已经报道了慢性过敏性皮肤病患者的瘙痒致敏作用，并在过敏性接触性皮炎（ACD）的小鼠模型中观察到了瘙痒致敏作用。有证据表明，神经免疫相互作用可能有助于瘙痒致敏，在过敏性疾病期间，已经观察到神经节内树突状细胞（DC）的增加。然而,在过敏性疾病期间，DC如何与神经节中的感觉神经元相互作用尚不清楚。本研究旨在探讨DCs在ACD条件下在背根神经节(DRG)中的作用。特别关注DRG内的瘙痒敏化。本研究采用了用于ACD的甲苯-2,4-二异氰酸酯（TDI）小鼠模型以及DC和DRG神经元的共培养模型。
结果：我们成功通过TDI诱导ACD，水肿的发展证明了这一点，血清总IgE水平升高，和在TDI致敏小鼠中观察到的瘙痒反应。钙成像和RT-qPCR分析显示，TDI致敏小鼠表现出外周致敏的迹象，包括TDI致敏小鼠切除的DRG中更高百分比的神经元对瘙痒原的反应以及瘙痒受体的激活和表达增加。免疫荧光和流式细胞术分析显示MHCII+细胞增加，作为DC的标记，在ACD期间在DRG内。共培养研究表明，当DRG神经元与DCs一起培养时，有一个增加的神经元的数量反应的瘙痒原和激活的受体，如TRPA1，TRPV1，H1R，TRPV4此外,免疫荧光和RT-qPCR研究证实了TRPV4的上调。
结论：我们的发现表明，在TDI诱导的ACD条件下，DRG中MHCII细胞和瘙痒外周敏化增加。已经发现DRG中的MHCII+细胞可能通过激活瘙痒受体促进瘙痒外周敏化,如通过DRG神经元和DC之间的共培养研究所示。需要进一步的研究来鉴定负责由活化DC诱导的外周致敏的特异性介质。
结果：我们成功通过TDI诱导ACD，水肿的发展证明了这一点，血清总IgE水平升高，和在TDI致敏小鼠中观察到的瘙痒反应。钙成像和RT-qPCR分析显示，TDI致敏小鼠表现出外周致敏的迹象，包括TDI致敏小鼠切除的DRG中更高百分比的神经元对瘙痒原的反应以及瘙痒受体的激活和表达增加。免疫荧光和流式细胞术分析显示MHCII+细胞增加，作为DC的标记，在ACD期间在DRG内。共培养研究表明，当DRG神经元与DCs一起培养时，有一个增加的神经元的数量反应的瘙痒原和激活的受体，如TRPA1，TRPV1，H1R，TRPV4此外,免疫荧光和RT-qPCR研究证实了TRPV4的上调。
结论：我们的发现表明，在TDI诱导的ACD条件下，DRG中MHCII细胞和瘙痒外周敏化增加。已经发现DRG中的MHCII+细胞可能通过激活瘙痒受体促进瘙痒外周敏化,如通过DRG神经元和DC之间的共培养研究所示。需要进一步的研究来鉴定负责由活化DC诱导的外周致敏的特异性介质。
