Protective role of microRNA-219-5p inhibitor against spinal cord injury via liver receptor homolog-1/Wnt/β-catenin signaling pathway regulation

miR-153 attenuates the inflammatory response and oxidative stress induced by spinal cord injury by targeting of NEUROD2

OBJECTIVE

Spinal cord injury (SCI) is a common spine surgical injury that leads to loss of activities of daily living. NEUROD2, a member of the neuroD family, is newly known to play a crucial role in SCI progression. We aimed to investigate the underlying mechanism wherein miR-153 and NEUROD2 modulate the process of SCI.

METHODS

Expression of miR-153 and NEUROD2 in spinal cord in mice of SCI were analyzed employing western blot and qRT-PCR assays. Microglial cells were transfected with mimic of miR-153 or siRNA targeting NEUROD2 to determine the impact of miR-153 and NEUROD2 on SCI induced inflammatory reaction and oxidative stress. A luciferase reporter assay was conducted to verify the regulation of miR-153 on NERUOD2.

RESULTS

MiR-153 expression was decreased in injured spinal cord, while NERUOD2 was increased in a time-dependent manner. Addition of miR-153 mimic or silencing NERUOD2 might significantly inhibit the production of inflammation cytokines and attenuated oxidative stress in microglia cells of SCI. Luciferase reporter assay suggested that NERUOD2 was a direct target of miR-153.

CONCLUSION

We proved that miR-153 attenuated inflammatory response and oxidative stress induced by SCI by targeting of NEUROD2, indicating a protective role in SCI progression.

MicroRNA-219-5p participates in cyanotic congenital heart disease progression by regulating cardiomyocyte apoptosis

MicroRNAs (miRs) play important roles in the protection against and development of congenital heart disease (CHD). However, the role and potential mechanisms of miR-219-5p in cyanotic CHD remains unclear. Reverse transcription-quantitative PCR (RT-qPCR) was used to measure miR-219-5p levels in cyanotic CHD and hypoxia-induced H9C2 cells. Dual luciferase reporter gene assay was used to confirm whether liver receptor homolog-1 (LRH-1) was a direct target of miR-219-5p. miR-219-5p inhibitor and LRH-1-small interfering RNA were transfected into H9C2 cells under hypoxic conditions to investigate the role of miR-219-5p in hypoxia-induced H9C2 cells. Subsequently, cell viability was detected using an MTT assay and cell apoptosis was detected using flow cytometry. In addition, RT-qPCR and western blotting assays were performed to detect the mRNA and protein expression of LRH-1, cyclin D1 and β-catenin, respectively. The data showed that miR-219-5p expression was higher in patients with cyanotic CHD compared with patients with acyanotic CHD gradually increased in H9C2 cells with prolonged hypoxia time. Dual luciferase reporter assay results showed that LRH-1 was a direct target gene of miR-219-5p. Inhibition of miR-219-5p reversed hypoxia-induced cell viability reduction and attenuated hypoxia-induced cell apoptosis. In addition, hypoxia induction inhibited the expression of LRH-1, cyclin D1 and β-catenin, which was reversed by miR-219-5p inhibitor. However, LRH-1 downregulation reversed the miR-219-5p inhibitor enhanced cell viability, decreased cell apoptosis and increased expression of LRH-1, cyclin D1 and β-catenin in hypoxia-treated cardiomyocytes. The present results demonstrated that downregulation of miR-219-5p promoted the expression of the LRH-1/Wnt/β-catenin signaling pathway-associated components, reduced cardiomyocyte apoptosis and increased cell growth under hypoxic conditions. miR-219-5p may be a potential therapeutic target for cyanotic CHD therapy.

Comprehensive analysis of the differential expression profile of microRNAs in rats with spinal cord injury treated by electroacupuncture

Abnormal microRNA (miRNA) expression has been implicated in spinal cord injury (SCI), but the underlying mechanisms are poorly understood. To observe the effect of electroacupuncture (EA) on miRNA expression profiles in SCI rats and investigate the potential mechanisms involved in this process, Sprague-Dawley rats were divided into sham, SCI and SCI+EA groups (n=6 each). Basso, Beattie and Bresnahan (BBB) scoring and hematoxylin-eosin staining of cortical tissues were used to evaluate spinal cord recovery with EA treatment 21 days post-surgery across the three groups. To investigate miRNA expression profiles, 6 Sprague-Dawley rats were randomly divided into SCI and SCI+EA groups (n=3 in each group) and examined using next-generation sequencing. Integrated miRNA-mRNA-pathway network analysis was performed to elucidate the interaction network of the candidate miRNAs, their target genes and the involved pathways. Behavioral scores suggested that hindlimb motor functions improved with EA treatments. Apoptotic indices were lower in the SCI+EA group compared with the SCI group. It was also observed that 168 miRNAs were differentially expressed between the SCI and SCI+EA groups, with 29 upregulated and 139 downregulated miRNAs in the SCI+EA group. Changes in miRNA expression are involved in SCI physiopathology, including inflammation and apoptosis. Reverse transcription-quantitative PCR measurement of the five candidate miRNAs, namely rno-miR-219a-5p, rno-miR-486, rno-miR-136-5p, rno-miR-128-3p, and rno-miR-7b, was consistent with RNA sequencing data. Integrated miRNA-mRNA-pathway analysis suggested that the MAPK, Wnt and NF-κB signaling pathways were involved in EA-mediated recovery from SCI. The present study evaluated the miRNA expression profiles involved in EA-treated SCI rats and demonstrated the potential mechanism and functional role of miRNAs in SCI in rats.

Application of stem cells and chitosan in the repair of spinal cord injury

Cytology and histology obstacles have been the main barriers to multiple tissues injury repair. In search of the most promising treatment strategies for spinal cord injury (SCI), stem cell-based transplantation coupled with various materials/technologies have been explored extensively to enhance SCI repair. Chitosan (CS) has demonstrated immense potential for widespread application in the form of scaffolds and micro-particles for SCI repair. The current review summarizes the evidences for stem cell-based transplantation and CS in SCI repair. Stem cells transplantation, which plays a key role in the repair of SCI, mainly results from its neural differentiation potential and neurotrophic effects. Application of CS enhances the survival of grafted stem cells, upregulates the expression level of neurotrophic factors and heightens the neural differentiation of stem cells as well as the functional recovery of spinal cord. Meanwhile, CS can also be exploited as growth factors/RNA carriers to control the release of regenerating molecules which are beneficial to damage spinal cord repair.