Silencing of miR-324-5p alleviates rat spinal cord injury by Sirt1
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Updated: Nov 4, 2025
Spinal Cord Neurons Isolation and Culture from Neonatal Mice
Published on: July 11, 2017
Chuanbao Wang1, Xiuli Guo2, Ying Wang3
1Department of Orthopedics, Yantai Mountain Hospital, Yangtai, 264001, Shandong, China.
Abstract:
MicroRNAs (miRNAs) are implicated in the pathogenesis of spinal cord injury (SCI) as primary regulators. Previous studies have reported that miR-324-5p is involved in the modulation of neural injury, while the underlying mechanisms of miR-324-5p in SCI remain unclear. In a SCI rat model, miR-324-5p was significantly upregulated in the spinal cord tissues after SCI. Downregulation of miR-324-5p via injection of adeno-associated viruses (AAV) expressing miR-324-5p inhibitor relieved animal motor deficits and pathological changes in the tissues. Furthermore, downregulation of miR-324-5p significantly altered the expression of genes regulating neural growth, apoptosis, and the inflammatory and antioxidant response, which are implicated in SCI pathogenesis. In a H2O2-induced cell injury model, miR-324-5p silencing rescued the elevated apoptosis of PC12 cells. Finally, miR-324-5p directly targeted the 3'-untranslated region of NAD-dependent protein deacetylase sirtuin-1 (Sirt1) and negatively regulated the levels of Sirt1, an anti-inflammatory protein involved in SCI. Silencing of Sirt1 aggravated SCI and rescued the effects of miR-324-5p downregulation in rats. Overall, our findings indicated that silencing of miR-324-5p alleviates the loss of animal locomotion and concurrently mediates several degenerative processes relevant to the pathogenesis of SCI by Sirt1, which may provide clues for SCI treatment.
Insights
Silencing microRNA-324-5p (miR-324-5p) in spinal cord injury (SCI) models improved motor function and reduced tissue damage. This suggests miR-324-5p inhibition is a potential therapeutic strategy for SCI.
Area of Science:
- Neuroscience
- Molecular Biology
- Regenerative Medicine
Background:
- MicroRNAs (miRNAs) play a key role in spinal cord injury (SCI) pathogenesis.
- The specific role and mechanisms of miR-324-5p in SCI are not fully understood.
- Previous research suggests miR-324-5p involvement in neural injury modulation.
Purpose of the Study:
- To investigate the role and underlying mechanisms of miR-324-5p in SCI.
- To determine if targeting miR-324-5p could be a therapeutic strategy for SCI.
- To elucidate the relationship between miR-324-5p, Sirt1, and SCI pathology.
Main Methods:
- Development of a rat model of spinal cord injury (SCI).
- Utilized adeno-associated viruses (AAV) to deliver miR-324-5p inhibitors in vivo.
- Employed an in vitro cell injury model (H2O2-induced PC12 cell apoptosis).
- Investigated gene expression related to neural growth, apoptosis, inflammation, and antioxidant response.
- Performed target validation by assessing the interaction between miR-324-5p and Sirt1.
Main Results:
- miR-324-5p was significantly upregulated in spinal cord tissues post-SCI.
- Downregulation of miR-324-5p using AAV inhibitors improved motor function and reduced pathological changes in SCI rats.
- miR-324-5p silencing altered gene expression involved in neural growth, apoptosis, inflammation, and antioxidant response.
- In vitro, miR-324-5p inhibition protected PC12 cells from H2O2-induced apoptosis.
- miR-324-5p directly targets Sirt1, negatively regulating its expression; Sirt1 silencing aggravated SCI.
Conclusions:
- Silencing miR-324-5p alleviates motor deficits and pathological processes in SCI.
- The therapeutic effects of miR-324-5p downregulation are mediated through the Sirt1 pathway.
- Targeting miR-324-5p offers a promising therapeutic avenue for spinal cord injury treatment.
