Mettl14-mediated m6A modification modulates neuron apoptosis during the repair of spinal cord injury by regulating the transformation from pri‐mir‐375 to miR-375

Abstract

Background Spinal cord injury (SCI) is a disabling disorder, resulting in neurological impairments. This study investigated the mechanism of methyltransferase-like 14 (Mettl14) on apoptosis of spinal cord neurons during SCI repair by mediating pri-microRNA (miR) dependent N6-methyladenosine (m6A) methylation. Methods The m6A content in total RNA and Mettl14 levels in spinal cord tissues of SCI rats were detected. Mettl14 expression was intervened in SCI rats to examine motor function, neuron apoptosis, and recovery of neurites. The cell model of SCI was established and intervened with Mettl14. miR-375, related to SCI and positively related to Mettl14, was screened out. The expression of miR-375 and pri-miR-375 after Mettl14 intervention was detected. The expression of pri-miR-375 combined with DiGeorge critical region 8 (DGCR8) and that modified by m6A was detected. Furthermore, the possible downstream gene and pathway of miR-375 were analysed. SCI cell model with Mettl14 intervention was combined with Ras-related dexamethasone-induced 1 (RASD1)/miR-375 intervention to observe the apoptosis. Results Mettl14 level and m6A content in spinal cord tissue were significantly increased. After Mettl14 knockdown, the injured motor function was restored and neuron apoptosis was reduced. In vitro, Mettl14 silencing reduced the apoptosis of SCI cells; miR-375 was reduced and pri-miR-375 was increased; miR-375 targeted RASD1. Silencing Mettl14 inactivated the mTOR pathway. The apoptosis in cells treated with silencing Mettl14 + RASD1/miR-375 was inhibited. Conclusions Mettl14-mediated m6A modification inhibited RASD1 and induced the apoptosis of spinal cord neurons in SCI by promoting the transformation of pri-miR-375 to mature miR-375.

METTL14 promotes apoptosis of spinal cord neurons by inducing EEF1A2 m6A methylation in spinal cord injury

“…m6A2Target database predicted that METTL14 might work on EEF1A2 and regulate its downstream methylation (Table 1 ). METTL14 and m6A were elevated in spinal cord tissues in SCI, and impaired motor function was restored and neuronal apoptosis was decreased after silencing METTL14 [ 22 ]. SRAMP database predicted that EEF1A2 might be modified by m6A methylation (Fig.…”

“…Laminectomy (3 mm) was performed from the caudal end of the T10 vertebra to the caudal end of the T11 vertebra under a dissection stereomicroscope. Infinite Horizons impactor (Infinite Horizons, L.L.C., Lexington, KY, USA) was utilized to induce contusion SCI at the force of 60 kdyn/cm [ 2 , 22 ]. The incision was sutured, followed by intramuscular injection of 20000 units of penicillin once a day for three days.…”

The role, mechanism, and application of RNA methyltransferase METTL14 in gastrointestinal cancer

“…Recent researches have demonstrated that dysregulation of METTL14 is tightly relative to the phenotypes involved in the malignant development of various cancer, including proliferation [88][89][90], metastasis [91][92][93][94][95][96], apoptosis [97][98][99][100][101], drug resistance [102][103][104][105], cancer stem cell like characteristic [106,107], immunotherapy [21,108,109], chronic inflammation [110] and glycolipid metabolism (Fig. 2) [95].…”

Mechanism of Ferroptosis and Its Role in Spinal Cord Injury

“…Therefore, the study of ferroptosis-related genes and proteins will be an important strategy to attenuate neuronal and oligodendrocyte injury and promote the recovery of neurological function after SCI. Our previous work showed that Mettl14-mediated m6A modification inhibited RASD1 and induced the apoptosis of spinal cord neurons in SCI by promoting the transformation of pri-miR-375 to mature miR-375 ( 123 ). However, it is still unclear of the iconic molecules of ferroptosis yet, the study of ferroptosis mechanism is still not deep enough, and the role of ferroptosis in SCI is still in the mist, the studies with patient and clinical proximity are relatively rare, which are the urgent issues in this field.…”