Related Experiment Video
Updated: Aug 11, 2025
Mechanical Conflict-Avoidance Assay to Measure Pain Behavior in Mice
Published on: February 18, 2022
miR-26a-5p alleviates CFA-induced chronic inflammatory hyperalgesia through Wnt5a/CaMKII/NFAT signaling in mice
Yitian Lu1,2, Maozhu Liu3, Xiangna Guo1
1Department of Anesthesiology, Nanfang hospital, Southern Medical University, Guangzhou, China.
Background:
Inflammation often leads to the occurrence of chronic pain, and many miRNAs have been shown to play a key role in the development of inflammatory pain. However, whether miR-26a-5p relieves pain induced by inflammation and its possible mechanism are still unclear.
Methods:
The complete Freund's adjuvant (CFA)-induced inflammatory pain mouse model was employed. Intrathecal or subcutaneous injection of miR-26a-5p agomir was performed after modeling to study its antinociceptive effect and the comparison of different administration methods. Bioinformatics analysis of miRNAs was performed to study the downstream mechanisms of miR-26a-5p. HE staining, RT-qPCR, Western blotting, and immunofluorescence were used for further validation.
Results:
A single intrathecal and subcutaneous injection of miR-26a-5p both reversed mechanical hypersensitivity and thermal latency in the left hind paw of mice with CFA-induced inflammatory pain. HE staining and immunofluorescence studies found that both administrations of miR-26a-5p alleviated inflammation in the periphery and spinal cord. Bioinformatics analysis and dual-luciferase reporter gene analysis identified Wnt5a as a direct downstream target gene of miR-26a-5p. Wnt5a was mainly expressed in neurons and microglia in the spinal cord of mice with inflammatory pain. Intrathecal injection of miR-26a-5p could significantly reduce the expression level of Wnt5a and inhibit the downstream molecules of noncanonical Wnt signaling Camk2/NFAT, inhibiting the release of spinal cord inflammatory factors and alleviating the activation of microglia. In addition, miR-26a-5p could also inhibit lipopolysaccharide (LPS)-stimulated BV2 cell inflammation in vitro through a noncanonical Wnt signaling pathway.
Conclusions:
miR-26a-5p is a promising therapy for CFA-induced inflammatory pain. Both intrathecal and subcutaneous injections provide relief for inflammatory pain. miR-26a-5p regulated noncanonical Wnt signaling to be involved in analgesia partly through antineuroinflammation, suggesting a pain-alleviating effect via noncanonical Wnt signaling pathway in the CFA-induced inflammatory pain model in vivo.
Insights
MicroRNA-26a-5p offers a promising therapy for chronic inflammatory pain by reducing pain sensitivity and inflammation. This microRNA alleviates pain through the noncanonical Wnt signaling pathway, impacting neuroinflammation.
Area of Science:
- Neuroscience
- Molecular Biology
- Pain Research
Background:
- Inflammation is a common cause of chronic pain.
- MicroRNAs (miRNAs) are implicated in inflammatory pain development.
- The role of miR-26a-5p in inflammatory pain and its mechanisms remain largely unknown.
Purpose of the Study:
- To investigate the potential of miR-26a-5p in alleviating inflammation-induced pain.
- To elucidate the underlying molecular mechanisms of miR-26a-5p's analgesic effects.
- To compare the efficacy of different administration routes for miR-26a-5p.
Main Methods:
- Established a Complete Freund's Adjuvant (CFA)-induced inflammatory pain mouse model.
- Administered miR-26a-5p via intrathecal or subcutaneous injection.
- Utilized bioinformatics, HE staining, RT-qPCR, Western blotting, and immunofluorescence for analysis.
- Performed dual-luciferase reporter gene assays to identify targets.
Main Results:
- Both administration routes of miR-26a-5p reversed pain hypersensitivity and reduced inflammation in mice.
- miR-26a-5p directly targets Wnt5a, a key component of noncanonical Wnt signaling.
- miR-26a-5p inhibited Wnt5a expression, downstream signaling (Camk2/NFAT), and microglial activation in the spinal cord.
- miR-26a-5p demonstrated anti-inflammatory effects in vitro on LPS-stimulated BV2 cells.
Conclusions:
- miR-26a-5p is a potential therapeutic agent for CFA-induced inflammatory pain.
- Both intrathecal and subcutaneous delivery of miR-26a-5p provide pain relief.
- miR-26a-5p exerts analgesic effects by modulating noncanonical Wnt signaling and reducing neuroinflammation.
