MiR-34a Inhibits Spinal Cord Injury and Blocks Spinal Cord Neuron Apoptosis by Activating Phatidylinositol 3-kinase (PI3K)/AKT Pathway Through Targeting CD47.

Dysregulation of miR-34a has been reported for its implication in neuronal development. This study aims to explore the effect and possible mechanism of miR-34a on neuron apoptosis induced by Spinal Cord Injury (SCI). SCI model was established using Allen's weight-drop method and rats in the sham group were performed with laminectomy without weight-drop injury. Basso Bcattie Bresnahan (BBB) rating scale was applied to evaluate the locomotor function of rats. Pathological changes of spinal cord tissues in SCI rats were observed after hematoxylin and eosin (HE) staining. Rats were separately injected with miR-34a agomir, miR-34a agomir NC, si-CD47 and si- CD47 NC before their spinal cord tissues were collected for terminal-deoxynucleoitidyl Transferase Mediated nick end labeling (TUNEL) staining. Expressions of miR-34a, si-CD47, apoptosis related proteins and AKT pathway related proteins were measured by quantitative reverse transcription- polymerase chain reaction (qRT-PCR) and western blot. SCI rat models were successfully established evidenced by decreased BBB scores and HE staining. Injection of miR-34a agomir and/or si-CD47 could suppress neuron cell apoptosis, with deceased apoptotic index (AI) and pro-apoptotic protein (cleaved caspase-3 and Bax) levels, and increased expressions of anti-apoptotic proteins (Bcl-2 and Mcl-1). Phosphorylated levels of phatidylinositol 3-kinase (PI3K) and AKT were further increased in rats injected with miR-34a agomir and si-CD47, compared with miR-34a agomir or si-CD47 injection alone. MiR-34a can downregulate CD47 expression to activate PI3K/AKT signal pathway, and thus inhibit SCI induced spinal neuron apoptosis.

Qi L ，Jiang-Hua M ，Ge-Liang H ，Qing C ，Ya-Ming L ... -  《-》

MiR-21-5p reduces apoptosis and inflammation in rats with spinal cord injury through PI3K/AKT pathway.

Lv X ，Liang J ，Wang Z 《-》

MiR-212-3p improves rat functional recovery and inhibits neurocyte apoptosis in spinal cord injury models via PTEN downregulation-mediated activation of AKT/mTOR pathway.

Multiple cellular and molecular changes are involved in the etiology of spinal cord injury (SCI) and the recovery from SCI. Accumulating studies showed aberrant expression of microRNAs (miRNAs) after SCI. Here, we established in vivo and in vitro models to analyze the role of miR-212-3p in SCI. An in vivo model of SCI was established in Sprague-Dawley rats. SCI-induced histopathological changes of the spinal cord were observed by hematoxylin-eosin staining. Functional recovery of rats with SCI was evaluated using the Basso-Beattie-and-Bresnahan scale. PC12 cells were stimulated by lipopolysaccharide (LPS) to establish SCI model of neuronal apoptosis in vitro. Dual-luciferase reporter assay was performed to validate the potential target of miR-212-3p predicted by TargetScan 7.2. MTT assay and flow cytometry were carried out to measure the viability and apoptosis of PC12 cell, respectively. The expressions of miR-212-3p, PTEN, phosphorylated (p)-AKT, AKT, p-mTOR, mTOR, Cleaved caspase-3 and BCl-2 in spinal cord tissues and PC12 cells were analyzed by qRT-PCR or Western blot. In the spinal cord of rats with SCI, the expressions of miR-212-3p, p-AKT, p-mTOR and BCl-2 were downregulated, whereas those of PTEN and Cleaved caspase-3 were upregulated. BBB scores were low, and there were histopathological changes, which were all reversed after the injection of agomiR-212-3p. MiR-212-3p directly targeted PTEN. Upregulated miR-212-3p in LPS-injured PC12 cells suppressed apoptosis, downregulated the expressions of PTEN and Cleaved caspase-3, promoted viability and upregulated the expressions of p-AKT, p-mTOR and BCl-2, which were all reversed by overexpressed PTEN. MiR-212-3p improved functional recovery of SCI rats and inhibited LPS-induced neurocyte apoptosis by targeting PTEN to activate AKT/mTOR pathway.

Guan C ，Luan L ，Li J ，Yang L ... -  《-》

Enhancement of miR-16-5p on spinal cord injury-induced neuron apoptosis and inflammatory response through inactivating ERK1/2 pathway.

Zhao QC ，Xu ZW ，Peng QM ，Zhou JH ，Li ZY ... -  《-》

Local Delivery of β-Elemene Improves Locomotor Functional Recovery by Alleviating Endoplasmic Reticulum Stress and Reducing Neuronal Apoptosis in Rats with Spinal Cord Injury.

Spinal cord injury (SCI) is a serious global problem that leads to permanent motor and sensory deficits. This study explores the anti-apoptotic and neuroprotective effects of the natural extract β-elemene in vitro and in a rat model of SCI. CCK-8 assay was used to evaluate cell viability and lactate dehydrogenase assay was used to evaluate cytotoxicity. A model of cell injury was established using cobalt chloride. Apoptosis was evaluated using a fluorescence-activated cell sorting assay of annexin V-FITC and propidium iodide staining. A rat SCI model was created via the modified Allen's method and Basso, Beattie, and Bresnahan (BBB) scores were used to assess locomotor function. Inflammatory responses were assessed via enzyme-linked immunosorbent assay (ELISA). Apoptotic and surviving neurons in the ventral horn were respectively observed via terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining and Nissl staining. Western blotting was used to measure protein expression. β-elemene (20 μg/ml) promoted cell viability by activating phosphorylation of the PI3K-AKT-mTOR pathway. β-elemene reduced CoCl2-induced cellular death and apoptosis by suppressing the expression levels of CHOP, cleaved-caspase 12, 78-kilodalton glucose-regulated protein, cleaved-caspase 3, and the Bax/Bcl-2 ratio. In the rat model of SCI, Nissl and TUNEL staining showed that β-elemene promoted motor neuron survival and reduced neuronal apoptosis in the spinal cord ventral horn. BBB scores showed that β-elemene significantly promoted locomotor behavioral recovery after SCI. In addition, β-elemene reduced the ELISA-detected secretion of interleukin (IL)-6 and IL-1β. β-elemene reduces neuronal apoptosis by alleviating endoplasmic reticulum stress in vitro and in vivo. In addition, β-elemene promotes locomotor function recovery and tissue repair in SCI rats. Thus, our study provides a novel encouraging strategy for the potential treatment of β-elemene in SCI patients.

Wang J ，Li H ，Ren Y ，Yao Y ，Hu J ，Zheng M ，Ding Y ，Chen YY ，Shen Y ，Wang LL ，Zhu Y ... -  《-》