葡萄籽原花青素通过恢复线粒体功能改善早产儿脑白质损伤模型小鼠低髓鞘化的研究

Grape Seed Proanthocyanidin Extracts Improve Hypomyelination by Restoring Mitochondrial Function in a Mouse Model of Premature White Matter Injury

摘要: 目的：本研究旨在探究葡萄籽原花青素(GSPE)对早产儿白质脑损伤(PWMI)模型小鼠的保护作用，并阐明其潜在机制。材料与方法：手术结扎P9日龄c57小鼠右侧颈动脉，于8%低氧环境中并腹腔注射细菌脂多糖(LPS)，构建PWMI模型。在PWMI造模后立即口服GSPE (20 mg/Kg)连续5天，至P14日龄。取材观察小鼠脑损伤情况，统计并计算小鼠存活率。通过透射电镜(TEM)、Western blot及qPCR评价髓鞘损伤情况。对三组(假手术组、PWMI组、PWMI + GSPE组)小鼠右侧脑皮质进行RNA测序，通过KEGG富集分析差异表达基因(DEGs)。采用qPCR对差异表达基因进行验证。结果：PWMI模型小鼠出现显著脑损伤且存活率较低。GSPE干预显著提高PWMI模型小鼠存活率并减轻髓鞘损伤。RNA测序分析显示各组间存在显著差异基因表达：PWMI组和sham组相比，差异基因富集于炎症、缺血–缺氧信号通路、鞘脂信号通路、线粒体功能相关信号通路；GSPE干预组与PWMI组相比，上调基因与鞘脂合成和线粒体稳态相关，下调基因与凋亡和炎症相关。结论：GSPE通过改善线粒体功能从而改善缺氧缺血合并炎症所致的早产儿白质脑损伤。这些发现证实了GSPE在髓鞘保护中的潜在作用，并提示GSPE可能成为PWMI的潜在治疗策略。

Abstract: Objective: To investigate the protective effect of grape seed proanthocyanidin extract (GSPE) on white matter brain injury (PWMI) in preterm mice and the underlying mechanism. Materials and methods: PWMI model was established by surgical ligation of the right carotid artery in P9-day-old c57 mice, which were subsequently exposed to 8% hypoxia and intraperitoneally injected with bacterial lipopolysaccharide (LPS). GSPE (20 mg/Kg) was administered orally for 5 consecutive days immediately after modeling until P14 days of age. The brain injury of mice was observed, and the survival rate of mice was counted and calculated. Transmission electron microscopy (TEM), Western blot and qPCR were used to evaluate myelin sheath injury. RNA sequencing was performed on the right cerebral cortex of the three groups of mice (sham operation group, PWMI group, PWMI + GSPE group), and the differentially expressed genes (DEGs) were analyzed by KEGG enrichment. qPCR was used to verify the differentially expressed genes. Results: PWMI mice showed significant brain damage and poor survival rate. GSPE intervention significantly improved the survival rate of PWMI mice and alleviated myelin sheath injury. RNA sequencing analysis showed that there were significant differentially expressed genes among all groups. Compared with the sham group, the differentially expressed genes in the PWMI group were enriched in inflammation, ischemia-hypoxia signaling pathway, sphingolipid signaling pathway, and mitochondrial function-related signaling pathway. The up-regulated genes were related to sphingolipid synthesis and mitochondrial homeostasis and the down-regulated genes were related to apoptosis and inflammation in the GSPE intervention group compared with the PWMI group. Conclusions: GSPE can improve mitochondrial function in preterm infants with white matter brain damage caused by hypoxic-ischemia and inflammation. These findings confirm the potential role of GSPE in myelin protection and suggest that GSPE may be a potential therapeutic strategy for PWMI.