Department of Ophthalmology, Fujian Medical University Union Hospital, Fu Zhou, China.
Invest Ophthalmol Vis Sci. 2019 Jan 2;60(1):16-25. doi: 10.1167/iovs.18-24968.
To investigate the contribution and mechanism of miRNAs and autophagy in diabetic peripheral neuropathy.
In this study, we used streptozotocin (STZ)-induced type I diabetes C57 mice as animal models, and we detected the expression of miR-34c and autophagic intensity in trigeminal ganglion (TG) tissue. The bioinformatics software was used to predict and analyze the potential targets of miR-34c. Primary trigeminal ganglion neurons were cultured in vitro to investigate the effect of miR-34c on axon growth and survival of TG cells. A corneal epithelial damage-healing model was established on the diabetic mice, then miR-34c antagomir was injected subconjunctivally. The condition of corneal epithelial healing was observed through sodium fluorescein staining, and the peripheral nerve degeneration of the cornea was evaluated by β-tublin corneal nerve staining.
The expression of miR-34c was significantly increased in TG tissue of type I diabetic mice by real-time PCR. Western blot showed that autophagy-related proteins Atg4B and LC3-II were significantly down-regulated in diabetes TG compared with normal control. Trigeminal neuron immunofluorescence showed that the length of the trigeminal ganglion cell synapses was significantly increased after miR-34c antagomir treatment compared with normal cultures. Subconjunctival injection of miR-34c antagomir can significantly promote corneal epithelium healing of diabetic mice and appreciably promote the regeneration of corneal nerve. At the same time, it can significantly increase the expression of autophagy in TG tissue of type I diabetic mice.
In this study , miR-34c was found to affect the growth of trigeminal sensory neurons and the repair of diabetic corneal nerve endings by acting directly on Atg4B.
研究 miRNA 和自噬在糖尿病周围神经病变中的作用及机制。
本研究采用链脲佐菌素（STZ）诱导的 I 型糖尿病 C57 小鼠作为动物模型，检测三叉神经节（TG）组织中 miR-34c 的表达和自噬强度。利用生物信息学软件预测和分析 miR-34c 的潜在靶标。体外培养原代三叉神经节神经元，观察 miR-34c 对 TG 细胞轴突生长和存活的影响。在糖尿病小鼠上建立角膜上皮损伤愈合模型，然后经结膜下注射 miR-34c 拮抗剂。通过荧光素钠染色观察角膜上皮愈合情况，β-微管蛋白角膜神经染色评估角膜周围神经变性。
实时 PCR 显示 I 型糖尿病小鼠 TG 组织中 miR-34c 的表达明显增加。Western blot 显示与正常对照组相比，糖尿病 TG 中自噬相关蛋白 Atg4B 和 LC3-II 明显下调。三叉神经神经元免疫荧光显示，与正常培养相比，miR-34c 拮抗剂处理后，三叉神经节细胞突触的长度明显增加。结膜下注射 miR-34c 拮抗剂可显著促进糖尿病小鼠角膜上皮愈合，明显促进角膜神经再生，同时可显著增加 I 型糖尿病小鼠 TG 组织中自噬的表达。
本研究发现，miR-34c 通过直接作用于 Atg4B 影响三叉神经感觉神经元的生长和糖尿病角膜神经末梢的修复。
