姜黄素对大鼠脊髓损伤后微生物多样性及脊髓转录组学的影响

Effects of curcumin on microbial diversity and transcriptomics in rats with spinal cord injury

摘要:

【背景】脊髓损伤是一种中枢神经系统的严重创伤，除了导致运动、感觉、自主神经功能障碍外，还会引起胃肠道功能障碍，不利于后续功能恢复。先前的研究表明，姜黄素对脊髓损伤具有一定的治疗作用，但姜黄素对脊髓损伤后肠道菌群是否具有调节作用及治疗相关通路鲜有报道。【目的】观察姜黄素对脊髓损伤大鼠行为学和组织形态学的影响，并利用高通量测序技术探讨姜黄素对盲肠组织微生物及其代谢产物的影响，探究姜黄素对脊髓损伤大鼠微生物多样性及脊髓转录组学的影响。【方法】将50只6−8周、220−240 g左右雌性SD大鼠随机分为假手术组、脊髓损伤模型组、脊髓损伤后姜黄素低、中、高剂量给药组。假手术组无脊髓损伤，模型组和姜黄素组建立脊髓损伤模型，在脊髓损伤模型建立30 min后分别腹腔注射姜黄素50、100和200 mg/kg，每天1次，连续治疗1周。术后采用大鼠脊髓损伤评分(basso, beattie & bresnahan locomotor rating scale, BBB scale)量表评定运动功能；苏木精-伊红染色观察大鼠脊髓组织形态学变化；通过对16S rRNA基因的V3+V4可变区进行高通量测序，分析α及β多样性、菌群的相对丰度以及短链脂肪酸含量，评估治疗前后对肠道菌群的影响。【结果】中等剂量姜黄素100 mg/kg可使脊髓损伤后肢体运动功能明显改善，对受损脊髓有一定的保护和修复作用；姜黄素给药可改善脊髓损伤后微生物群多样性，提高短链脂肪酸水平；脊髓损伤后大鼠肠道菌群信号转导通路发生变化，在应用姜黄素后部分信号通路恢复表达。【结论】姜黄素可以影响脊髓损伤大鼠肠道微生物多样性并提高短链脂肪酸水平，对脊髓损伤大鼠具有治疗作用。

Abstract:

[Background] Spinal cord injury, a severe trauma of the central nervous system, causes not only motor, sensory, and autonomic nerve dysfunction but also gastrointestinal dysfunction, being not conducive to subsequent functional recovery. Studies have shown that curcumin has a therapeutic effect on spinal cord injury, while little is known about whether curcumin can regulate intestinal microbiota after spinal cord injury or not and the treatment-related pathways. [Objective] To observe the effects of curcumin on the behaviors, the spinal cord histomorphology, the diversity and metabolites of cecal microbiota, and the spinal cord transcriptomics in the rats with spinal cord injury. [Methods] A total of 50 female SD rats of 6−8 weeks and 220−240 g were randomized into a sham operation group, a model (spinal cord injury) group, and low-, medium-, and high-dose (50, 100, and 200 mg/kg, respectively) curcumin+spinal cord injury groups. Curcumin 50 mg/kg, 100 mg/kg, and 200 mg/kg was intraperitoneally injected 30 min after the establishment of the rat model of spinal cord injury, once a day for a week. The Basso, Beattie & Bresnahan (BBB) locomotor rating scale was used for scoring of the motor function. Hematoxylin-eosin staining was used to observe the histomorphological changes in the spinal cord of rats. High-throughput sequencing of the V3+V4 variable region of 16S rRNA gene was carried out to analyze the α diversity, β diversity, and relative abundance of microflora, and the levels of short-chain fatty acids were measured, on the basis of which the changes of intestinal microbiota before and after treatment were evaluated. [Results] The medium dose (100 mg/kg) of curcumin significantly improved the limb motor function after spinal cord injury, demonstrating protective and repair effects on the damaged spinal cord. Curcumin administration in the rat model of spinal cord injury improved the diversity of microbiota and elevated the levels of short-chain fatty acids. The spinal cord injury altered the signaling pathways of intestinal microbiota, which was restored after the administration of curcumin. [Conclusion] Curcumin can affect intestinal microbial diversity and increase the levels of short-chain fatty acids in the rat model of spinal cord injury, and had a therapeutic effect on rats with spinal cord injury.