Inhibitory effect of N-acetylcysteine on cell apoptosis after acute spinal cord injury
Jiang Jipeng
Cheng Yuanchi
Liu Baohu
Zhu Xu
Pang Aibo
Wang Sijun
Chen Xuyi
Zhang Sai
Abstract：Objective To explore the mechanism of inhibitory effect of N-acetylcysteine (NAC) on cell apoptosis after acute spinal cord injury (SCI).Methods Fifty-four clean and healthy adult male Sprague Dawley rats were randomly divided into simple laminectomy group(Sham group),acute SCI control group(SCI group) and NAC group,with 18 rats in each group.Rats in Sham group had Tg-10 laminectomy;rats in SCI group and NAC group were made acute SCI models,after which the NAC group was intraperitoneally injected 150 mg/kg NAC,2 times/d(at 30 min,12 h after modeling on the 1st day),lasting for 7 d.Twelve rats in each group were sacrificed 24 h after modeling;6 rats were used to observe apoptotic cells by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) technique;6 rats were used to test expressions of anti-apoptotic B-cell lymphoma/leukemia-2 (Bcl-2) and pro-apoptotic Bcl-2-related protein Bax by western blot assay.Six rats were fed for 8 weeks in each group;neurologic function was evaluated by the Basso-Beattie-Bresnahan locomotor rating scale(BBB) for rat spinal cord injury and the slope experiment at 1,2,4,6,8 weeks after modeling.Results The number of positive cells of TUNEL staining in SCI group and NAC group was significantly more than that in Sham group[(95.0 ± 3.0),(72.0 ± 2.6) vs (0.0 ± 0.0)] (F =2 763.375,P ＜ 0.01).Western blot showed positive expressions of Bcl-2 and Bax in 3 groups.The relative expression quantity of Bcl-2 in SCI group and NAC group was significantly lower than that in Sham group[(0.225 ±0.025),(0.798 ±0.042) vs (1.000 ±0.071)] and there was a significant difference between NAC group and SCI group(P ＜0.01).The relative expression quantity of Bax in SCI group and NAC group was significantly higher than that in Sham group [(4.59 ±0.34),(3.22 ± 0.23) vs (1.00 ± 0.16)] and there was also a significant difference between NAC group and SCI group(P ＜0.01).The 1,2,4,6,8-week BBB scores in SCI group and NAC group were significantly lower than those in Sham group [0 (0,0),1 (0,1) scores vs 21 (21,21) scores;(1.3 ± 0.5),(2.7 ± 0.8) scores vs (21.0 ±0.0)scores;(3.5±1.1),(7.0 ±l.4)scores vs (21.0 ±0.0)scores;(5.3 ±1.8),(9.3 ±2.1)scores vs (21.0 ± 0.0) scores;(7.8 ± 1.5),(12.5 ± 1.4) scores vs (21.0 ± 0.0) scores] (P ＜ 0.05);the scores in NAC group were significantly higher than those in SCI group (P ＜ 0.05).Slope angles at 1,2,4,6,8 weeks after modeling in SCI group and NAC group were significantly smaller than those in Sham group [(16.0 ± 2.6) °,(18.3 ±2.6)° vs (78.3 ±3.4)°;(18.7 ±2.6)°,(21.3 ±3.2)° vs (78.0±3.6)°;(22.3 ±3.3)°,(30.0 ±4.1)° vs (77.7±3.3)°;(27.8 ±2.9)°,(38.8 ±2.8)° vs (78.8±2.6)°;(30.5 ±2.9)°,(44.8 ±3.4)°vs (78.5 ± 3.3) °] (P ＜ 0.05);slope angles at 4,6,8 weeks after modeling in NAC group were significantly larger than those in SCI group(P ＜ 0.05).Conclusion NAC may have neuroprotective effect through lowering expression of pro-apoptotic gene Bax and enhancing expression of anti-apoptotic gene Bcl-2 in spinal injury tissue in rats.
Keywords：Acute spinal cord injuryAcetylcysteineApoptosis
Publication Date：2017-01-01
Online Publishing Date：2026-09-14(First online date of this platform, not the publication date of the document)
Pages：5( 1644-1648 )