Department of Oral and Maxillofacial Surgery, Affiliated Stomatology Hospital of Kunming Medical University, 1088 HaiYuan middle road, Kunming, 650106, Yunnan, China.
Stomatology Centre, The First People's Hospital of Yunnan Province, Kunming, 650032, Yunnan, China.
J Mol Histol. 2024 Oct;55(5):741-752. doi: 10.1007/s10735-024-10227-z. Epub 2024 Jul 28.
Facial nerve is an integral part of peripheral nerve. Schwann cells are important microglia involved in the repair and regulation of facial nerve injury. LncRNA growth arrest‑specific transcript 5 (GAS5) is involved in the behavioral regulation of Schwann cell and the regeneration of peripheral nervous system. However, there is little research about the effect of GAS5 on the repair of facial nerve injury (FNI) by regulating Schwann cells. This study aimed to investigate the role of GAS5 in Schwann cell function and FNI repair, focusing on the miR-138-5p/CXCL12 axis. Hematoxylin and eosin staining, Luxol fast blue staining, transmission electron microscope, and immunofluorescence (IF) experiments were used to verify the effect of GAS5 on FNI rats. Reverse transcription real-time polymerase chain reaction was performed to detect GAS5, miR-138-5p, and C-X-C motif chemokine ligand 12 (CXCL12) mRNA expression. IF staining was used to detect the inflorescence of S100 calcium binding protein B (S100β), SRY-box transcription factor 10 (SOX10), and tubulin beta 3 class III (β-Tubulin III). Glial fibrillary acidic protein (GFAP), nerve growth factor receptor (NGFR), S100β, brain derived neurotrophic factor (BDNF), ciliary neurotrophic factor (CNTF), and CXCL12 proteins were detected using western blot. The 5-bromo-2'-deoxyuridine staining, Transwell, and flow cytometry assays were conducted to detect Schwann cell function. Dual-luciferase, RNA immunoprecipitation, and RNA pulldown assay were used to identify the interaction among GAS5, miR-138-5p, and CXCL12. Results found that GAS5 was downregulated in facial nerve tissues of FNI rats. Overexpressed GAS5 decreased facial grading, inhibited demyelination, and promoted proliferation, migration, and suppressed apoptosis of Schwann cells. Mechanistically, GAS5 was a sponge of miR-138-5p and positively regulated CXCL12 expression. GAS5 inhibition repressed CXCL12 expression and decreased cell proliferation and migration, increased apoptosis rate of Schwann cells by sponging miR-138-5p. In conclusion, overexpression of GAS5 accelerates facial nerve repair in FNI rats by regulating miR-138-5p/CXCL12 axis.
面神经是周围神经的重要组成部分。许旺细胞是参与面神经损伤修复和调节的重要小胶质细胞。长链非编码 RNA 生长停滞特异性转录物 5（GAS5）参与许旺细胞的行为调节和周围神经系统的再生。然而，关于 GAS5 通过调节许旺细胞对面神经损伤（FNI）修复的影响的研究甚少。本研究旨在探讨 GAS5 在外周神经损伤修复中的作用及其对 FNI 修复的影响，重点关注 miR-138-5p/CXCL12 轴。苏木精-伊红染色、卢索快速蓝染色、透射电子显微镜和免疫荧光（IF）实验用于验证 GAS5 对 FNI 大鼠的影响。逆转录实时聚合酶链反应检测 GAS5、miR-138-5p 和 C-X-C 基序趋化因子配体 12（CXCL12）mRNA 表达。IF 染色检测 S100 钙结合蛋白 B（S100β）、SRY 盒转录因子 10（SOX10）和微管蛋白β 3 类 III（β-Tubulin III）的花序。使用免疫印迹检测神经生长因子受体（NGFR）、S100β、脑源性神经营养因子（BDNF）、睫状神经营养因子（CNTF）和 CXCL12 蛋白。5-溴-2'-脱氧尿苷染色、Transwell 和流式细胞术检测许旺细胞功能。双荧光素酶报告基因、RNA 免疫沉淀和 RNA 下拉实验用于鉴定 GAS5、miR-138-5p 和 CXCL12 之间的相互作用。结果发现，GAS5 在 FNI 大鼠面神经组织中表达下调。过表达 GAS5 降低面神经分级，抑制脱髓鞘，并促进许旺细胞增殖、迁移和抑制凋亡。机制上，GAS5 是 miR-138-5p 的海绵体，正向调节 CXCL12 的表达。GAS5 抑制通过海绵 miR-138-5p 抑制 CXCL12 表达和减少许旺细胞增殖和迁移，增加许旺细胞的凋亡率。综上所述，过表达 GAS5 通过调节 miR-138-5p/CXCL12 轴加速 FNI 大鼠面神经修复。
