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Published on: May 3, 2024
miR-122-3p Alleviates LPS-Induced Pyroptosis of Macrophages via Targeting NLRP1
Min Li1,2,3, Longhui Hu1,3, Qiao Ke1,2
1Hainan Affiliated Hospital of Hainan Medical University (Hainan General Hospital), Hainan, China.
Objective:
Sepsis, a life-threatening organ dysfunction, is among the leading causes of mortality in intensive care units. Sepsis occurrence is associated with macrophage pyroptosis, and microRNAs (miRNAs) have emerged as key factors in this process. However, the specific role of miR-122-3p in pyroptosis during sepsis progression and its underlying mechanisms remain to be fully elucidated.
Methods:
We established an in vitro sepsis model using lipopolysaccharide (LPS)-activated macrophages, followed by transfection of a miR-122-3p mimic into RAW264.7 macrophages. We subsequently determined the effects of miR-122-3p on cell viability and pyroptosis using cell viability, western blot, and qPCR assays. The binding affinity between miR-122-3p and NLR pyrin domain containing 1 (NLRP1) mRNA was then confirmed using a dual-luciferase reporter assay. Finally, the secretion of pro-inflammatory cytokines (interleukin (IL)-2, IL-6, and tumor necrosis factor-α (TNF-α) was determined using ELISA.
Results:
The results revealed that LPS treatment lead to a significant increase in the production of pro-inflammatory cytokines including IL-2, IL-6, and TNF-α in RAW264.7 cells. We observed that overexpression of miR-122-3p effectively restored cell viability and attenuated the expression of key inflammatory markers promoted by LPS, such as caspase-1, pro-caspase-1, IL-18, IL-1β, NLRP3, apoptosis-associated speck-like protein containing CARD, and cleaved- gasdermin-D. Our data indicate that miR-122-3p is capable of directly bounding to NLRP1 and inhibiting its expression.
Conclusions:
These results confirmed that miR-122-3p plays a crucial role in the inhibition of sepsis by suppressing macrophage pyroptosis in an NLRP1-dependent manner. Therefore, miR-122-3p presents as a promising therapeutic target for sepsis.
Insights
MicroRNA-122-3p inhibits sepsis by suppressing macrophage pyroptosis, a key process in sepsis development. This microRNA targets NLRP1, offering a potential therapeutic strategy for sepsis treatment.
Area of Science:
- Biochemistry
- Immunology
- Molecular Biology
Background:
- Sepsis is a critical condition causing significant mortality in intensive care units.
- Macrophage pyroptosis is closely linked to sepsis development.
- MicroRNAs (miRNAs) are implicated in pyroptosis, but miR-122-3p's role in sepsis remains unclear.
Purpose of the Study:
- To investigate the role of miR-122-3p in macrophage pyroptosis during sepsis.
- To elucidate the underlying molecular mechanisms of miR-122-3p in sepsis.
Main Methods:
- An in vitro sepsis model using lipopolysaccharide (LPS)-activated RAW264.7 macrophages was established.
- miR-122-3p mimic transfection was performed to study its effects on cell viability and pyroptosis.
- Western blot, qPCR, dual-luciferase reporter assay, and ELISA were used to analyze pyroptosis markers, cytokine secretion, and gene expression.
Main Results:
- LPS treatment significantly increased pro-inflammatory cytokines (IL-2, IL-6, TNF-α) and pyroptosis markers.
- Overexpression of miR-122-3p restored cell viability and reduced inflammatory markers.
- miR-122-3p directly binds to and inhibits NLR pyrin domain containing 1 (NLRP1) mRNA expression.
Conclusions:
- miR-122-3p suppresses macrophage pyroptosis in a sepsis model.
- The inhibitory effect is dependent on targeting NLRP1.
- miR-122-3p represents a potential therapeutic target for sepsis.
