Related Experiment Video
Updated: Dec 6, 2025
Bronchoalveolar Lavage Exosomes in Lipopolysaccharide-induced Septic Lung Injury
Published on: May 21, 2018
LncRNA MEG3 expression in sepsis and its effect on LPS-induced macrophage function
1Department of Infectious Disease, Shengzhou People's Hospital(The First Affiliated Hospital of Zhejiang University Shengzhou Branch), Shengzhou, 312400, China.
Abstract:
Sepsis is a dangerous disease that is caused by an overreaction of the body's immune system to infection and gradually spreads throughout the body. This experiment was carried out to explore the expression of LncRNA MEG3 in sepsis and its effect on LPS-induced macrophage function. Methods 60 sepsis patients admitted to our hospital from February 2017 to September 2018 were selected as the sepsis group, and 50 non-septic patients diagnosed and treated in our hospital during the same period were selected as the control group. qRT-PCR was used to detect the expression level of MEG3. ROC curve was used to analyze the diagnostic value of serum MEG3 in sepsis. The human macrophage cell line U937 was cultured in vitro and randomly divided into NC group, LPS group, LPS + pcDNA group, and LPS + pcDNA-MEG3 group. Flow cytometry was applied to detect the apoptosis rate. The levels of IL-1β and TNF-α were detected by ELISA. Western blot was used to detect the expression of Bax, Bcl-2 and NF-κB signaling pathway-related proteins p65 and p-p65. Results: The expression level of serum MEG3 in the sepsis group was significantly lower than that in the control group (P <0.05). ROC curve analysis showed that the AUC area was 0.856, the sensitivity was 0.700, and the specificity was 0.883. Compared with the NC group, the macrophage apoptosis rate in the LPS group was increased (P <0.05), the levels of Bax and p-p65 protein were significantly increased (P <0.05), and the level of Bcl-2 protein was decreased (P <0.05), the levels of IL-1β and TNF-α were increased (P <0.05). Compared with the LPS + pcDNA group, the apoptosis rate of the LPS + pcDNA-MEG3 group was significantly reduced (P <0.05), the levels of Bax and p-p65 protein were reduced (P <0.05), and the level of Bcl-2 protein was significantly increased (P <0.05), the levels of IL-1β and TNF-α were reduced (P <0.05). Conclusion: The low expression of LncRNA MEG3 in the serum of patients with sepsis can predict the occurrence of sepsis. Overexpression of MEG3 can inhibit LPS-induced macrophage apoptosis and secretion of inflammatory factors by inhibiting the activation of the NF-κB signaling pathway.
Insights
Sepsis is linked to low levels of long non-coding RNA MEG3 (lncRNA MEG3), which can be detected in serum. Overexpressing lncRNA MEG3 reduces sepsis-induced macrophage apoptosis and inflammation by inhibiting the NF-κB pathway.
Area of Science:
- Immunology
- Molecular Biology
- Genetics
Background:
- Sepsis results from a dysregulated immune response to infection.
- Long non-coding RNAs (lncRNAs) play crucial roles in various biological processes, including immune responses.
- The role of lncRNA MEG3 in sepsis-induced immune dysregulation requires further investigation.
Purpose of the Study:
- To investigate the expression levels of lncRNA MEG3 in sepsis patients.
- To explore the effect of lncRNA MEG3 on lipopolysaccharide (LPS)-induced macrophage function.
- To analyze the diagnostic value of serum MEG3 in sepsis.
Main Methods:
- Serum samples from 60 sepsis patients and 50 healthy controls were analyzed for MEG3 expression using qRT-PCR.
- The diagnostic accuracy of serum MEG3 was evaluated using ROC curve analysis.
- Human U937 macrophages were treated with LPS and transfected with MEG3 overexpression vectors to assess apoptosis, inflammatory cytokine levels (IL-1β, TNF-α), and NF-κB pathway activation (Bax, Bcl-2, p65/p-p65) via flow cytometry and Western blot.
Main Results:
- Serum MEG3 levels were significantly lower in sepsis patients compared to controls (P <0.05), with an AUC of 0.856, sensitivity of 0.700, and specificity of 0.883.
- LPS treatment increased macrophage apoptosis, inflammatory cytokine levels, and NF-κB pathway activation (increased Bax, p-p65; decreased Bcl-2).
- Overexpression of MEG3 significantly reduced LPS-induced macrophage apoptosis, inflammatory cytokine secretion, and NF-κB pathway activation.
Conclusions:
- Reduced serum lncRNA MEG3 expression is a potential biomarker for sepsis diagnosis.
- lncRNA MEG3 plays a protective role in sepsis by inhibiting LPS-induced macrophage apoptosis and inflammation.
- MEG3 exerts its protective effects by suppressing the activation of the NF-κB signaling pathway.
