MicroRNA-21-5p promotes the inflammatory response after spinal cord injury by targeting PLAG1

K. Han, F.-R. Wang, M.-Q. Yu

Department of Traumatic Orthopaedics, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, China. sdslyygkhk@126.com

---

• Orthopedics

OBJECTIVE: The aim of this study was to investigate the expression level of microRNA-21-5p and its target gene PLAG1 in the serum of patients with spinal cord injury (SCI), as well as the role and mechanism of microRNA-21-5p in lipopolysaccharide-induced primary microglial inflammation.

PATIENTS AND METHODS: The levels of microRNA-21-5p and PLAG1 in the peripheral blood of 24 patients with spinal cord injury and 24 healthy people were examined by quantitative Polymerase Chain Reaction (qPCR) analysis. The expressions of inflammatory factors, including IL-1, IL-6 and TNF-α were measured by enzyme-linked immunosorbent assay (ELISA). After microglial BV2 cells were treated with different concentrations of LPS, microRNA-21-5p, and PLAG1 expressions were examined by qPCR, while IL-1, IL-6, and TNF-α levels in cell supernatant were measured by ELISA. Finally, the binding relationship between microRNA-21-5p and its target gene was analyzed by Luciferase reporter assay.

RESULTS: The data showed that microRNA-21-5p was upregulated in the serum of SCI patients, and also increased in LPS-treated cells, with a certain concentration dependence. On the contrary, PLAG1 was remarkably downregulated, suggesting that the above two genes were negatively correlated in SCI patients. ELISA results indicated that the knockdown of microRNA-21-5p or overexpression of PLAG1 reduced the levels of IL-1, IL-6 and TNF-α in BV2 cells. Meanwhile, microRNA-21-5p might be involved in regulating the inflammatory response of BV2 cells by modulating PLAG1.

CONCLUSIONS: MicroRNA-21-5p promotes the inflammatory response after SCI by targeting PLAG1.

Free PDF Download