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Updated: Nov 19, 2025
Identifying Microglia and Peripheral Infiltrating Macrophages in the Injured Spinal Cords Using Flow Cytometry
Published on: June 24, 2025
MiR-665 inhibits inflammatory response in microglia following spinal cord injury by targeting TREM2
1Department of Orthopaedics, Changhai Hospital, Second Military Medical University, Shanghai, China. zhicaishi@vip.sina.com.
Objective:
The purpose of this study was to uncover the role of microRNA-665 (miR-665) in protecting inflammatory response in microglia following spinal cord injury (SCI) and the underlying mechanism.
Patients And Methods:
The serum levels of miR-665 and TREM2 (triggering receptor expressed on myeloid 2) in SCI patients (n=24) and healthy subjects (n=24) were detected by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). Then, the serum levels of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) were detected by enzyme-linked immunosorbent assay (ELISA). After lipopolysaccharide (LPS) induction in BV2 cells, the relative levels of miR-665 and TREM2 were detected by qRT-PCR, and relative levels of IL-6 and TNF-α in the culture medium were examined by ELISA. Next, TREM2, the target gene of miR-665, was determined by Dual-Luciferase reporter assay, and the relationship between the expression levels of TREM2 and miR-665 in SCI patients and BV2 cells was analyzed. Finally, the regulatory effects of miR-665 and TREM2 on IL-6 and TNF-α levels in the culture medium of LPS-induced BV2 cells were assessed.
Results:
It was found that miR-665 was downregulated in serum of SCI patients and LPS-induced BV2 cells, while TREM2 was upregulated. Silenced miR-665 or overexpressed TREM2 was involved in protecting inflammatory response following SCI. Besides, rescue experiments showed that miR-665 participated in the regulation of inflammatory response following SCI by targeting TREM2.
Conclusions:
MiR-665 inhibits inflammatory response following SCI by targeting TREM2.
Insights
MicroRNA-665 (miR-665) protects against inflammation after spinal cord injury (SCI) by targeting TREM2. This study reveals miR-665
Area of Science:
- Neuroscience
- Molecular Biology
- Immunology
Background:
- Spinal cord injury (SCI) triggers significant inflammatory responses in microglia.
- MicroRNAs play crucial roles in regulating cellular processes, including inflammation.
- Understanding the molecular mechanisms underlying SCI-induced inflammation is vital for developing therapeutic strategies.
Purpose of the Study:
- To investigate the role of microRNA-665 (miR-665) in mitigating microglial inflammatory responses post-SCI.
- To elucidate the underlying molecular mechanism involving miR-665 and its target gene, TREM2.
Main Methods:
- Quantitative Real-Time Polymerase Chain Reaction (qRT-PCR) and Enzyme-Linked Immunosorbent Assay (ELISA) were used to measure miR-665, TREM2, IL-6, and TNF-α levels in patient serum and cell cultures.
- Dual-Luciferase reporter assay was employed to confirm TREM2 as a direct target of miR-665.
- In vitro experiments involved lipopolysaccharide (LPS) induction in BV2 microglial cells to mimic SCI conditions.
Main Results:
- miR-665 levels were found to be downregulated in SCI patients and LPS-induced BV2 cells, while TREM2 expression was upregulated.
- Silencing miR-665 or overexpressing TREM2 exacerbated the inflammatory response.
- Rescue experiments confirmed that miR-665 regulates inflammatory responses in SCI by targeting TREM2.
Conclusions:
- MicroRNA-665 plays a protective role in the inflammatory response following spinal cord injury.
- The mechanism involves miR-665 targeting and downregulating the expression of TREM2.
- Targeting the miR-665/TREM2 axis presents a potential therapeutic avenue for SCI.
