Cox Christopher D, West Eric J, Liu Ming Cheng, Wang Kevin K W, Hayes Ronald L, Lyeth Bruce G
Department of Neurological Surgery, University of California at Davis, Davis, California 95616-8797, USA.
J Neurotrauma. 2008 Nov;25(11):1355-65. doi: 10.1089/neu.2008.0671.
Recent studies indicate that alphaII-spectrin breakdown products (SBDPs) have utility as biological markers of traumatic brain injury (TBI). However, the utility of SBDP biomarkers for detecting effects of therapeutic interventions has not been explored. Acetylcholine plays a role in pathological neuronal excitation and TBI-induced muscarinic cholinergic receptor activation may contribute to excitotoxic processes. In experiment I, regional and temporal changes in calpain-mediated alpha-spectrin degradation were evaluated at 3, 12, 24, and 48 h using immunostaining for 145-kDa SBDP. Immunostaining of SBDP-145 was only evident in the hemisphere ipsilateral to TBI and was generally limited to the cortex except at 24 h when immunostaining was also prominent in the dentate gyrus and striatum. In Experiment II, cerebral spinal fluid (CSF) samples were analyzed for various SBDPs 24 h after moderate lateral fluid percussion TBI. Rats were administered either dicyclomine (5 mg/kg i.p.) or saline vehicle (n = 8 per group) 5 min prior to injury. Injury produced significant increases (p < 0.001) of 300%, 230%, and >1000% in SBDP-150, -145, and -120, respectively in vehicle-treated rats compared to sham. Dicyclomine treatment produced decreases of 38% (p = 0.077), 37% (p = 0.028), and 63% (p = 0.051) in SBDP-150, -145, and -120, respectively, compared to vehicle-treated injury. Following CSF extraction, coronal brain sections were processed for detecting degenerating neurons using Fluoro-Jade histofluorescence. Stereological techniques were used to quantify neuronal degeneration in the dorsal hippocampus CA2/3 region and in the parietal cortex. No significant differences were detected in numbers of degenerating neurons in the dorsal CA2/3 hippocampus or the parietal cortex between saline and dicyclomine treatment groups. The percent weight loss following TBI was significantly reduced by dicyclomine treatment. These data provide additional evidence that, as TBI biomarkers, SBDPs are able to detect a therapeutic intervention even in the absence of changes in neuronal cell degeneration measured by Fluoro-jade.
近期研究表明，αII-血影蛋白降解产物（SBDPs）可作为创伤性脑损伤（TBI）的生物标志物。然而，尚未探讨SBDP生物标志物在检测治疗干预效果方面的实用性。乙酰胆碱在病理性神经元兴奋中起作用，TBI诱导的毒蕈碱胆碱能受体激活可能导致兴奋性毒性过程。在实验I中，使用针对145-kDa SBDP的免疫染色，在3、12、24和48小时评估钙蛋白酶介导的α-血影蛋白降解的区域和时间变化。SBDP-145的免疫染色仅在TBI同侧半球明显，并且一般限于皮质，除了在24小时时，此时齿状回和纹状体中免疫染色也很突出。在实验II中，在中度侧方液体冲击性TBI后24小时，分析脑脊液（CSF）样本中的各种SBDP。在损伤前5分钟，给大鼠腹腔注射双环维林（5mg/kg）或生理盐水载体（每组n = 8）。与假手术组相比，损伤使载体处理的大鼠中SBDP-150、-145和-120分别显著增加（p <0.001）300％、230％和> 1000％。与载体处理的损伤相比，双环维林处理使SBDP-150、-145和-120分别降低38％（p = 0.077）、37％（p = 0.028）和63％（p = 0.051）。脑脊液提取后，对冠状脑切片进行处理，使用Fluoro-Jade组织荧光检测变性神经元。使用体视学技术量化背侧海马CA2/3区域和顶叶皮质中的神经元变性。在生理盐水和双环维林治疗组之间，背侧CA2/3海马或顶叶皮质中变性神经元的数量未检测到显著差异。双环维林治疗显著降低了TBI后的体重减轻百分比。这些数据提供了额外的证据，即作为TBI生物标志物，即使在通过Fluoro-jade测量的神经元细胞变性没有变化的情况下，SBDPs也能够检测到治疗干预。
