Department of Orthopedics, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China.
J Cell Biochem. 2018 Dec;119(12):9675-9684. doi: 10.1002/jcb.27280. Epub 2018 Aug 26.
This study aimed to investigate the effects and possible mechanisms of long noncoding RNA (lncRNA) Sox2 overlapping transcript (Sox2ot) on hydrogen peroxide (H O )-induced injury in pheochromocytoma (PC-12) cells. PC-12 cells were treated with H O to cell injury. The cells were transfected with short-hairpin RNA directed against Sox2ot (sh-Sox2ot), small interfering RNA directed against myeloid cell leukemia-1 (MCL-1) isoform2 (si-MCL-1), a miR-211 mimic, a miR-211 inhibitor, and their negative controls. Under different transfected treatments, cell viability, migration, invasion, and apoptosis as well as the expressions of apoptosis- and autophagy-related proteins were investigated. Besides, the regulatory relationships between Sox2ot and miR-211, miR-211 and MCL-1, as well as between MCL-1 and the protein kinase B (Akt)/mammalian target of the rapamycin (mTOR)/p70 ribosomal S6 protein kinase (p70S6K) signaling pathway were explored. Suppression of Sox2ot inhibited H O -induced PC-12 cell injury by increasing cell viability, migration, invasion, and decreasing apoptosis and autophagy. Moreover, suppression of Sox2ot increased miR-211 expression and alleviated H O -induced injury in PC-12 cells possibly via upregulation of miR-211. Furthermore, MCL-1 isoform2 was identified as a direct target of miR-211 and could be negatively regulated by miR-211. Suppression of miR-211 aggravated H O -induced cell injury by regulation of MCL-1 isoform2. Besides, inhibition of miR-211 suppressed the activation of the Akt/mTOR/p70S6K signaling pathway in H O -treated PC-12 cells, which was reversed after knockdown of MCL-1 isoform2 at the same time. Our findings indicate that downregulation of Sox2ot may protect PC-12 cells from H O -induced injury in SCI via targeting the miR-211/MCL-1 isoform2 axis. MCL-1 isoform2 may further regulate the activation of the Akt/mTOR/p70S6K pathway to mediate H O -induced injury. The Sox2ot-miR-211-MCL-1 isoform2 axis may be a promising therapeutic strategy for SCI.
本研究旨在探讨长链非编码 RNA（lncRNA）Sox2 重叠转录物（Sox2ot）对过氧化氢（H₂O₂）诱导的嗜铬细胞瘤（PC-12）细胞损伤的作用及其可能机制。用 H₂O₂处理 PC-12 细胞以诱导细胞损伤。用短发夹 RNA（sh-Sox2ot）、针对髓样细胞白血病-1（MCL-1）亚型 2（si-MCL-1）的小干扰 RNA、miR-211 模拟物、miR-211 抑制剂及其阴性对照转染细胞。在不同的转染处理下，研究细胞活力、迁移、侵袭和凋亡以及凋亡和自噬相关蛋白的表达。此外，还探讨了 Sox2ot 与 miR-211、miR-211 与 MCL-1 以及 MCL-1 与蛋白激酶 B（Akt）/哺乳动物雷帕霉素靶蛋白（mTOR）/p70 核糖体 S6 蛋白激酶（p70S6K）信号通路之间的调控关系。抑制 Sox2ot 可通过增加细胞活力、迁移、侵袭和减少凋亡和自噬来抑制 H₂O₂诱导的 PC-12 细胞损伤。此外，抑制 Sox2ot 可增加 miR-211 的表达，并通过上调 miR-211 来减轻 H₂O₂诱导的 PC-12 细胞损伤。此外，MCL-1 亚型 2 被鉴定为 miR-211 的直接靶标，并可被 miR-211 负调控。抑制 miR-211 通过调节 MCL-1 亚型 2 加重 H₂O₂诱导的细胞损伤。此外，抑制 miR-211 可抑制 H₂O₂处理的 PC-12 细胞中 Akt/mTOR/p70S6K 信号通路的激活，同时敲低 MCL-1 亚型 2 可逆转该激活。我们的研究结果表明，下调 Sox2ot 可能通过靶向 miR-211/MCL-1 亚型 2 轴来保护 SCI 中的 PC-12 细胞免受 H₂O₂诱导的损伤。MCL-1 亚型 2 可能进一步调节 Akt/mTOR/p70S6K 通路的激活，从而介导 H₂O₂诱导的损伤。Sox2ot-miR-211-MCL-1 亚型 2 轴可能是 SCI 的一种有前途的治疗策略。
