Shimizu Nobutaka, Wada Naoki, Shimizu Takahiro, Suzuki Takahisa, Takaoka Ei-Ichiro, Kanai Anthony J, de Groat William C, Hirayama Akihide, Hashimoto Mamoru, Uemura Hirotsugu, Yoshimura Naoki
Department of Urology, University of Pittsburgh, Pittsburgh, PA, 15213, United States; Department of Urology, Faculty of Medicine, Kindai University, Osaka-Sayama, Japan.
Department of Urology, University of Pittsburgh, Pittsburgh, PA, 15213, United States.
Neurosci Lett. 2018 Sep 14;683:100-103. doi: 10.1016/j.neulet.2018.06.049. Epub 2018 Jun 28.
Nerve growth factor (NGF) is reportedly involved in the changes in C-fiber bladder afferent pathways that induce detrusor overactivity (DO) following spinal cord injury (SCI). This study examined the roles of NGF in TRP channel expression in bladder afferent neurons in mice with SCI using laser-capture microdissection (LCM) methods. Spinal intact (SI) and SCI mice were divided into 3 groups: (1) SI with vehicle treatment; (2) SCI with vehicle treatment; and (3) SCI with anti-NGF antibody. Two weeks after SCI, an osmotic pump was placed subcutaneously into the back of the mice and vehicle or anti-NGF antibody was administered at a rate of 10 μg/kg per hour for two weeks. Four weeks after SCI, the L6 dorsal root ganglia (DRG) were removed. Expression of the TRPV1, TRPC1, TRPC3, and TRPC6 genes was analyzed using real-time polymerase chain reaction (PCR) following LCM of the bladder afferent neurons, which were labeled by Fast Blue injected into the bladder wall 1 week prior to tissue removal. The mRNA expression of TRPV1 was found to be higher in vehicle-treated SCI mice than in SI mice. The expression level of TRPC3 and TRPC6 in vehicle-treated SCI mice was lower than in SI mice. However, in SCI mice treated with anti-NGF antibody, the mRNA expression of TRPV1 was lower, and the mRNA levels of TRPC3 and TRPC6 were higher than in vehicle-SCI mice. These results suggest that the NGF-dependent changes in specific TRP channel genes, such as TRPV1, TRPC3, and TRPC6, could be involved in SCI-induced afferent hyperexcitability and DO.
据报道，神经生长因子（NGF）参与了脊髓损伤（SCI）后诱导逼尿肌过度活动（DO）的C纤维膀胱传入通路的变化。本研究使用激光捕获显微切割（LCM）方法，研究了NGF在SCI小鼠膀胱传入神经元中TRP通道表达中的作用。将脊髓完整（SI）和SCI小鼠分为3组：（1）接受载体处理的SI组；（2）接受载体处理的SCI组；（3）接受抗NGF抗体的SCI组。SCI后两周，将渗透泵皮下植入小鼠背部，并以每小时10μg/kg的速率给予载体或抗NGF抗体，持续两周。SCI后四周，取出L6背根神经节（DRG）。在对膀胱传入神经元进行LCM后，使用实时聚合酶链反应（PCR）分析TRPV1、TRPC1、TRPC3和TRPC6基因的表达，这些神经元在组织切除前1周通过注入膀胱壁的快蓝进行标记。发现载体处理的SCI小鼠中TRPV1的mRNA表达高于SI小鼠。载体处理的SCI小鼠中TRPC3和TRPC6的表达水平低于SI小鼠。然而，在用抗NGF抗体处理的SCI小鼠中，TRPV1的mRNA表达较低，而TRPC3和TRPC6的mRNA水平高于载体处理的SCI小鼠。这些结果表明，特定TRP通道基因（如TRPV1、TRPC3和TRPC6）中依赖NGF的变化可能与SCI诱导的传入性兴奋性过高和DO有关。
